Making a Back-Illuminated Imager with Back-Side Contact and Alignment Markers

Science.gov (United States)

Pain, Bedabrata

2008-01-01

A design modification and a fabrication process that implements the modification have been conceived to solve two problems encountered in the development of back-illuminated, back-sidethinned complementary metal oxide/ semiconductor (CMOS) image-detector integrated circuits. The two problems are (1) how to form metal electrical-contact pads on the back side that are electrically connected through the thickness in proper alignment with electrical contact points on the front side and (2) how to provide alignment keys on the back side to ensure proper registration of backside optical components (e.g., microlenses and/or color filters) with the front-side pixel pattern. The essence of the design modification is to add metal plugs that extend from the desired front-side locations through the thickness and protrude from the back side of the substrate. The plugs afford the required front-to-back electrical conduction, and the protrusions of the plugs serve as both the alignment keys and the bases upon which the back-side electrical-contact pads can be formed.

Ultrasmooth metallic films with buried nanostructures for backside reflection-mode plasmonic biosensing

Energy Technology Data Exchange (ETDEWEB)

Lindquist, N.C.; Johnson, T.W.; Jose, J.; Otto, L.M. [Laboratory of Nanostructures and Biosensing, Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455 (United States); Oh, S.H. [Laboratory of Nanostructures and Biosensing, Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455 (United States); Department of Biophysics and Chemical Biology, Seoul National University, Seoul, 151-747 (Korea, Republic of)

2012-11-15

A new plasmonic device architecture based on ultrasmooth metallic surfaces with buried plasmonic nanostructures is presented. Using template-stripping techniques, ultrathin gold films with less than 5 Aa surface roughness are optically coupled to an arbitrary arrangement of buried metallic gratings, rings, and nanodots. As a prototypical example, linear plasmonic gratings buried under an ultrasmooth 20 nm thick gold surface for biosensing are presented. The optical illumination and collection are completely decoupled from the microfluidic delivery of liquid samples due to the backside, reflection-mode geometry. This allows for sensing with opaque or highly scattering liquids. With the buried nanostructure design, high sensitivity and decoupled backside (reflective) optical access are maintained, as with traditional prism-based surface plasmon resonance (SPR) sensors. In addition, the benefits offered by nanoplasmonic sensors such as spectral tunability and high-resolution, wide-field SPR imaging with normal-incidence epi-illumination that is simple to construct and align are gained as well. Beyond sensing, the buried plasmonic nanostructures with ultrasmooth metallic surfaces can benefit nanophotonic waveguides, surface-enhanced spectroscopy, nanolithography, and optical trapping. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

BCB Bonding Technology of Back-Side Illuminated COMS Device

Science.gov (United States)

Wu, Y.; Jiang, G. Q.; Jia, S. X.; Shi, Y. M.

2018-03-01

Back-side illuminated CMOS(BSI) sensor is a key device in spaceborne hyperspectral imaging technology. Compared with traditional devices, the path of incident light is simplified and the spectral response is planarized by BSI sensors, which meets the requirements of quantitative hyperspectral imaging applications. Wafer bonding is the basic technology and key process of the fabrication of BSI sensors. 6 inch bonding of CMOS wafer and glass wafer was fabricated based on the low bonding temperature and high stability of BCB. The influence of different thickness of BCB on bonding strength was studied. Wafer bonding with high strength, high stability and no bubbles was fabricated by changing bonding conditions.

Current Total Knee Designs: Does Baseplate Roughness or Locking Mechanism Design Affect Polyethylene Backside Wear?

Science.gov (United States)

Sisko, Zachary W; Teeter, Matthew G; Lanting, Brent A; Howard, James L; McCalden, Richard W; Naudie, Douglas D; MacDonald, Steven J; Vasarhelyi, Edward M

2017-12-01

Tibial baseplate roughness and polyethylene-insert micromotion resulting from locking-mechanism loosening can lead to polyethylene backside wear in TKAs. However, many retrieval studies examining these variables have evaluated only older TKA implant designs. We used implant-retrieval analysis to examine if there were differences in: (1) backside damage scores, (2) backside damage modes, and (3) backside linear wear rates in five TKA implant designs owing to differing baseplate surface roughness and locking mechanisms. Additionally, we examined if (4) patient demographics influence backside damage and wear. Five TKA implant models (four modern and one historical design) were selected with different tibial baseplate and/or locking mechanism designs. Six tibial inserts retrieved at the time of revision from each TKA model were matched for time in vivo, age of the patient at TKA revision, BMI, sex, revision number, and revision reason. Each insert backside was analyzed for: (1) visual total damage score and (2) individual visual damage modes, both by two observers and with an intraclass correlation coefficient of 0.66 (95% CI, 0.39-0.92), and (3) linear wear rate measured by micro-CT. Median primary outcomes were compared among the five designs. For our given sample size among five groups we could detect with 80% power a 10-point difference in damage score and an 0.11-mm per year difference in wear rate. The polished tibial design with a partial peripheral capture locking mechanism and anterior constraint showed a lower total damage score compared with the nonpolished tibial design with only a complete peripheral-rim locking mechanism (median, 12.5; range, 9.5-18.0; 95% CI, 9.58-16.42 versus median, 22.3; range, 15.5-27.0; 95% CI, 17.5-26.5; p = 0.019). The polished baseplate with a tongue-in-groove locking mechanism showed more abrasions than the nonpolished baseplate with a peripheral-rim capture and antirotational island (median, 7.25; range, 0.5-8.0; 95% CI, 2

Indirect optical crosstalk reduction by highly-doped backside layer in single-photon avalanche diode arrays

NARCIS (Netherlands)

Osrečki, Željko; Knežević, Tihomir; Nanver, Lis K.; Suligoj, Tomislav

2018-01-01

A method of reducing indirect optical crosstalk in single-photon avalanche diode arrays is investigated by TCAD simulations. The reduction is accomplished by taking advantage of an enhanced optical absorption in a highly-doped Si layer on the backside of the wafer. A simulation environment was

[Wet work].

Science.gov (United States)

Kieć-Swierczyńska, Marta; Chomiczewska, Dorota; Krecisz, Beata

2010-01-01

Wet work is one of the most important risk factors of occupational skin diseases. Exposure of hands to the wet environment for more than 2 hours daily, wearing moisture-proof protective gloves for a corresponding period of time or necessity to wash hands frequently lead to the disruption of epidermal stratum corneum, damage to skin barrier function and induction of irritant contact dermatitis. It may also promote penetration of allergens into the skin and increase the risk of sensitization to occupational allergens. Exposure to wet work plays a significant role in occupations, such as hairdressers and barbers, nurses and other health care workers, cleaning staff, food handlers and metalworkers. It is more common among women because many occupations involving wet work are female-dominated. The incidence of wet-work-induced occupational skin diseases can be reduced by taking appropriate preventive measures. These include identification of high-risk groups, education of workers, organization of work enabling to minimize the exposure to wet work, use of personal protective equipment and skin care after work.

CMS RPC detectors assembled in Pakistan installed on the backside of the YE+1 endcap yoke

CERN Multimedia

Walter Van Doninck, VUB-Brussels and CERN

2006-01-01

Resistive Plate Chambers (RPCs) are sensitive to the passage of muons and provide a "trigger" signal for CMS. This image shows RPC detectors, which were assembled in Pakistan, installed on the backside of an endcap yoke disc, known as YE+1.

Photolithographic Pattern Transformation by Backside Exposure in a-Si:H Thin-Film Transistor Liquid Crystal Displays

Science.gov (United States)

Uchikoga, Shuichi; Hiromasu, Yasunobu; Onozuka, Yutaka; Koizumi, Takashi; Akiyama, Masahiko; Ikeda, Mitsushi; Suzuki, Kouji

1995-02-01

Resist pattern transformation by backside exposure, which is a key process for a self-alignment technique is investigated. The light intensity and a-Si:H thickness markedly affect the pattern transformation, while the effect of gate insulator thickness is small. Numerical simulations based on Fresnel diffraction showed fairly good agreement with the experimental results.

Indirect optical crosstalk reduction by highly-doped backside layer in PureB single-photon avalanche diode arrays

NARCIS (Netherlands)

Osrečki, Željko; Knežević, Tihomir; Nanver, Lis K.; Suligoj, Tomislav

2017-01-01

A method of reducing indirect optical crosstalk in a PureB single-photon avalanche diode (SPAD) array is investigated by TCAD simulations. The reduction is accomplished by taking advantage of the enhanced optical absorption of a highly-doped Si layer (p-type, 3×1020 cm-3) on the backside of the

Modeling and simulation of stamp deflections in nanoimprint lithography: Exploiting backside grooves to enhance residual layer thickness uniformity

DEFF Research Database (Denmark)

Taylor, Hayden; Smistrup, Kristian; Boning, Duane

2011-01-01

We describe a model for the compliance of a nanoimprint stamp etched with a grid of backside grooves. We integrate the model with a fast simulation technique that we have previously demonstrated, to show how etched grooves help reduce the systematic residual layer thickness (RLT) variations...

Reactive wetting by liquid sodium on thin Au platin

International Nuclear Information System (INIS)

Kawaguchi, Munemichi; Hamada, Hirotsugu

2014-01-01

For practical use of an under-sodium viewer, the behavior of sodium wetting is investigated by modeling the reactive and non-reactive wetting of metallic-plated steels by liquid sodium to simulate sodium wetting. The non-reactive wetting simulation results showed good agreement with Tanner's law, in which the time dependencies of the droplet radius and contact angle are expressed as R N ∝ t 1/10 and θ∝ t -3/10 , respectively; therefore, the model was considered suitable for the simulation. To simulate reactive wetting, the model of fluid flow induced by the interfacial reaction was incorporated into the simulation of non-reactive wetting. The reactive wetting simulation results, such as the behavior of the precursor liquid film and central droplet, showed good agreement with sodium wetting experiments using thin Au plating at 250°C. An important result of the reactive wetting simulation is that the gradient of the reaction energy at the interface appeared on the new interface around the triple line, and that fluid flow was induced. This interfacial reactivity during sodium wetting of thin Au plating was enhanced by the reaction of sodium and nickel oxide through pinholes in the plating. (author)

Trench process and structure for backside contact solar cells with polysilicon doped regions

Science.gov (United States)

De Ceuster, Denis; Cousins, Peter John; Smith, David D.

2010-12-14

A solar cell includes polysilicon P-type and N-type doped regions on a backside of a substrate, such as a silicon wafer. An interrupted trench structure separates the P-type doped region from the N-type doped region in some locations but allows the P-type doped region and the N-type doped region to touch in other locations. Each of the P-type and N-type doped regions may be formed over a thin dielectric layer. Among other advantages, the resulting solar cell structure allows for increased efficiency while having a relatively low reverse breakdown voltage.

Ultra-short laser processing of transparent material at the interface to liquid

International Nuclear Information System (INIS)

Boehme, R; Pissadakis, S; Ehrhardt, M; Ruthe, D; Zimmer, K

2006-01-01

Similarly to laser-induced backside wet etching (LIBWE) with nanosecond ultraviolet (ns UV) laser pulses, the irradiation of the solid/liquid interface of fused silica with sub-picosecond (sub-ps) UV and femtosecond near infrared (fs NIR) laser pulses results in etching of the fused silica surface and deposition of decomposition products from liquid. Furthermore, the etch threshold is reduced compared with both direct ablation with an fs laser in air and backside etching with UV ns pulses. Using 0.5 M pyrene/toluene as absorbing liquid, the thresholds were determined to be 70 mJ cm -2 (sub-ps UV) and 330 mJ cm -2 (fs NIR). Furthermore, an almost linear increase in the etch rate with increasing laser fluence was found. The roughness of surfaces backside etched with ultra-short pulses is higher in comparison with ns pulses but lower than that obtained using direct fs laser ablation. Hence a combination of processes involved in fs laser ablation and ns backside etching can be expected. The processes at the ultra-short pulse laser irradiated solid/liquid interface are discussed, considering the effects of ultra-fast heating, multi-photon absorption processes, as well as defect generation in the materials

The first back-side illuminated types of Kyoto's X-ray astronomy SOIPIX

Energy Technology Data Exchange (ETDEWEB)

Itou, Makoto, E-mail: itou@cr.scphys.kyoto-u.ac [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Tsuru, Takeshi Go; Tanaka, Takaaki; Takeda, Ayaki; Matsumura, Hideaki; Ohmura, Shunichi; Uchida, Hiroyuki [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Nakashima, Shinya [Institute of Space and Astronautical Science (ISAS)/JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Arai, Yasuo; Kurachi, Ikuo [Institute of Particle and Nuclear Studies, High Energy Accelerator Research Org., KEK, 1-1 Oho, Tsukuba 305-0801 (Japan); Mori, Koji; Takenaka, Ryota; Nishioka, Yusuke [Department of Applied Physics, Faculty of Engineering, University of Miyazaki,1-1 Gakuen Kibana-dai Nishi, Miyazaki 889-2192 (Japan); Kohmura, Takayoshi; Tamasawa, Koki [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Tindall, Craig [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

2016-09-21

We have been developing Kyoto's X-ray astronomy SOI pixel sensors, called “XRPIX”, aiming to extend the frontiers of X-ray astronomy with the wide-band imaging spectroscopy in the 0.5–40 keV band. A dead layer on the X-ray incident surface should ideally be as thin as possible to achieve a high sensitivity below 1 keV, and the depletion layer is required to be thick enough to detect 40 keV X-rays. Thus, we have started developing fully-depleted back-side illuminated (BI) types of XRPIXs. This paper reports on our first two BI devices and their X-ray evaluation (2.6–12 keV). The device named “XRPIX2b-FZ-LA” successfully reaches a full depletion with a thickness of 500 μm. On the other hand, it has a dead layer with a thickness of 1.1–1.5 μm and struggles to achieve the requirement of 1.0 μm. The other device named “XRPIX2b-CZ-PZ”, which is applied with a thin Si sensor-layer and an improved back-side process, is found to satisfy the requirement with its thickness of 0.9–1.0 μm, including Al optical blocking filter of 0.2 μm, although the Si sensor-layer is rather thin with 62 μm. We also describe in this paper the X-ray calibration system that we have built for the X-ray evaluation of XRPIXs.

Three-dimensional block copolymer nanostructures by the solvent-annealing-induced wetting in anodic aluminum oxide templates.

Science.gov (United States)

Chu, Chiang-Jui; Chung, Pei-Yun; Chi, Mu-Huan; Kao, Yi-Huei; Chen, Jiun-Tai

2014-09-01

Block copolymers have been extensively studied over the last few decades because they can self-assemble into well-ordered nanoscale structures. The morphologies of block copolymers in confined geometries, however, are still not fully understood. In this work, the fabrication and morphologies of three-dimensional polystyrene-block-polydimethylsiloxane (PS-b-PDMS) nanostructures confined in the nanopores of anodic aluminum oxide (AAO) templates are studied. It is discovered that the block copolymers can wet the nanopores using a novel solvent-annealing-induced nanowetting in templates (SAINT) method. The unique advantage of this method is that the problem of thermal degradation can be avoided. In addition, the morphologies of PS-b-PDMS nanostructures can be controlled by changing the wetting conditions. Different solvents are used as the annealing solvent, including toluene, hexane, and a co-solvent of toluene and hexane. When the block copolymer wets the nanopores in toluene vapors, a perpendicular morphology is observed. When the block copolymer wets the nanopores in co-solvent vapors (toluene/hexane = 3:2), unusual circular and helical morphologies are obtained. These three-dimensional nanostructures can serve as naontemplates for refilling with other functional materials, such as Au, Ag, ZnO, and TiO2 . © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Visible Wavelength Color Filters Using Dielectric Subwavelength Gratings for Backside-Illuminated CMOS Image Sensor Technologies.

Science.gov (United States)

Horie, Yu; Han, Seunghoon; Lee, Jeong-Yub; Kim, Jaekwan; Kim, Yongsung; Arbabi, Amir; Shin, Changgyun; Shi, Lilong; Arbabi, Ehsan; Kamali, Seyedeh Mahsa; Lee, Hong-Seok; Hwang, Sungwoo; Faraon, Andrei

2017-05-10

We report transmissive color filters based on subwavelength dielectric gratings that can replace conventional dye-based color filters used in backside-illuminated CMOS image sensor (BSI CIS) technologies. The filters are patterned in an 80 nm-thick poly silicon film on a 115 nm-thick SiO 2 spacer layer. They are optimized for operating at the primary RGB colors, exhibit peak transmittance of 60-80%, and have an almost insensitive response over a ± 20° angular range. This technology enables shrinking of the pixel sizes down to near a micrometer.

Defined wetting properties of optical surfaces

Science.gov (United States)

Felde, Nadja; Coriand, Luisa; Schröder, Sven; Duparré, Angela; Tünnermann, Andreas

2017-10-01

Optical surfaces equipped with specific functional properties have attracted increasing importance over the last decades. In the light of cost reduction, hydrophobic self-cleaning behavior is aspired. On the other side, hydrophilic properties are interesting due to their anti-fog effect. It has become well known that such wetting states are significantly affected by the surface morphology. For optical surfaces, however, this fact poses a problem, as surface roughness can induce light scattering. The generation of optical surfaces with specific wetting properties, hence, requires a profound understanding of the relation between the wetting and the structural surface properties. Thus, our work concentrates on a reliable acquisition of roughness data over a wide spatial frequency range as well as on the comprehensive description of the wetting states, which is needed for the establishment of such correlations. We will present our advanced wetting analysis for nanorough optical surfaces, extended by a vibration-based procedure, which is mainly for understanding and tailoring the wetting behavior of various solid-liquid systems in research and industry. Utilizing the relationships between surface roughness and wetting, it will be demonstrated how different wetting states for hydrophobicity and hydrophilicity can be realized on optical surfaces with minimized scatter losses.

Investigations of the Local Supercluster velocity field. III. Tracing the backside infall with distance moduli from the direct Tully-Fisher relation

Science.gov (United States)

Ekholm, T.; Lanoix, P.; Teerikorpi, P.; Fouqué, P.; Paturel, G.

2000-03-01

We have extended the discussion of Paper II (Ekholm et al. \\cite{Ekholm99a}) to cover also the backside of the Local Supercluster (LSC) by using 96 galaxies within Theta 2.1 and sigma B_Tuniversal density profile of dark matter clustering in an Einstein-deSitter universe (Tittley & Couchman \\cite{Tittley99}).

The waffle: a new photovoltaic diode geometry having high efficiency and backside contacts

DEFF Research Database (Denmark)

Leistiko, Otto

1994-01-01

By employing anisotropic etching techniques and advanced device processing it is possible to micromachine new types of mechanical, electronic, and optical devices of silicon, which have unique properties. In this paper the characteristics of a new type of photovoltaic diode fabricated employing...... these processing techniques are described. This novel device has not only high efficiency, but also has both contacts placed on the backside of the cell. The first devices which are only 50 mm in diameter are of relatively good quality with low leakage currents (nA), high breakdown voltages (80 V), and low series...... resistance (mohms). The measured efficiencies at AM 1.5 lie between 12 to 15% with short circuit currents of 25-30 mA/cm2, and open circuit voltages of 0.58-0.6 V...

Order of wetting transitions in electrolyte solutions.

Science.gov (United States)

Ibagon, Ingrid; Bier, Markus; Dietrich, S

2014-05-07

For wetting films in dilute electrolyte solutions close to charged walls we present analytic expressions for their effective interface potentials. The analysis of these expressions renders the conditions under which corresponding wetting transitions can be first- or second-order. Within mean field theory we consider two models, one with short- and one with long-ranged solvent-solvent and solvent-wall interactions. The analytic results reveal in a transparent way that wetting transitions in electrolyte solutions, which occur far away from their critical point (i.e., the bulk correlation length is less than half of the Debye length) are always first-order if the solvent-solvent and solvent-wall interactions are short-ranged. In contrast, wetting transitions close to the bulk critical point of the solvent (i.e., the bulk correlation length is larger than the Debye length) exhibit the same wetting behavior as the pure, i.e., salt-free, solvent. If the salt-free solvent is governed by long-ranged solvent-solvent as well as long-ranged solvent-wall interactions and exhibits critical wetting, adding salt can cause the occurrence of an ion-induced first-order thin-thick transition which precedes the subsequent continuous wetting as for the salt-free solvent.

Non-monotonic wetting behavior of chitosan films induced by silver nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Praxedes, A.P.P.; Webler, G.D.; Souza, S.T. [Instituto de Física, Universidade Federal de Alagoas, 57072-970 Maceió, AL (Brazil); Ribeiro, A.S. [Instituto de Química e Biotecnologia, Universidade Federal de Alagoas, 57072-970 Maceió, AL (Brazil); Fonseca, E.J.S. [Instituto de Física, Universidade Federal de Alagoas, 57072-970 Maceió, AL (Brazil); Oliveira, I.N. de, E-mail: italo@fis.ufal.br [Instituto de Física, Universidade Federal de Alagoas, 57072-970 Maceió, AL (Brazil)

2016-05-01

Highlights: • The addition of silver nanoparticles modifies the morphology of chitosan films. • Metallic nanoparticles can be used to control wetting properties of chitosan films. • The contact angle shows a non-monotonic dependence on the silver concentration. - Abstract: The present work is devoted to the study of structural and wetting properties of chitosan-based films containing silver nanoparticles. In particular, the effects of silver concentration on the morphology of chitosan films are characterized by different techniques, such as atomic force microscopy (AFM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). By means of dynamic contact angle measurements, we study the modification on surface properties of chitosan-based films due to the addition of silver nanoparticles. The results are analyzed in the light of molecular-kinetic theory which describes the wetting phenomena in terms of statistical dynamics for the displacement of liquid molecules in a solid substrate. Our results show that the wetting properties of chitosan-based films are high sensitive to the fraction of silver nanoparticles, with the equilibrium contact angle exhibiting a non-monotonic behavior.

Laser ablation of toluene liquid for surface micro-structuring of silica glass

International Nuclear Information System (INIS)

Niino, H.; Kawaguchi, Y.; Sato, T.; Narazaki, A.; Gumpenberger, T.; Kurosaki, R.

2006-01-01

Microstructures with well-defined micropatterns were fabricated on the surfaces of silica glass using a laser-induced backside wet etching (LIBWE) method by diode-pumped solid state (DPSS) UV laser at the repetition rate of 10 kHz. For a demonstration of flexible rapid prototyping as mask-less exposure system, the focused laser beam was directed to the sample by galvanometer-based point scanning system. Additionally, a diagnostics study of plume propagation in the ablated products of toluene solid film was carried out with an intensified CCD (ICCD) camera

MEMS pressure sensor with maximum performances by using novel back-side direct-exposure concept featuring through glass vias

Science.gov (United States)

Mukhopadhyay, B.; Fritz, M.; Mackowiak, P.; Vu, T. C.; Ehrmann, O.; Lang, K.-D.; Ngo, H.-D.

2013-05-01

Design, simulation, fabrication, and characterization of novel MEMS pressure sensors with new back-side-direct-exposure packaging concept are presented. The sensor design is optimized for harsh environments e.g. space, military, offshore and medical applications. Unbreakable connection between the active side of the Si-sensor and the protecting glass capping was realized by anodic bonding using a thin layer of metal. To avoid signal corruption of the measured pressure caused by an encapsulation system, the media has direct contact to the backside of the Si membrane and can deflect it.

High performance GaN-based LEDs on patterned sapphire substrate with patterned composite SiO2/Al2O3 passivation layers and TiO2/Al2O3 DBR backside reflector.

Science.gov (United States)

Guo, Hao; Zhang, Xiong; Chen, Hongjun; Zhang, Peiyuan; Liu, Honggang; Chang, Hudong; Zhao, Wei; Liao, Qinghua; Cui, Yiping

2013-09-09

GaN-based light-emitting diodes (LEDs) on patterned sapphire substrate (PSS) with patterned composite SiO(2)/Al(2)O(3) passivation layers and TiO(2)/Al(2)O(3) distributed Bragg reflector (DBR) backside reflector have been proposed and fabricated. Highly passivated Al(2)O(3) layer deposited on indium tin oxide (ITO) layer with excellent uniformity and quality has been achieved with atomic layer deposition (ALD) technology. With a 60 mA current injection, an enhancement of 21.6%, 59.7%, and 63.4% in the light output power (LOP) at 460 nm wavelength was realized for the LED with the patterned composite SiO(2)/Al(2)O(3) passivation layers, the LED with the patterned composite SiO(2)/Al(2)O(3) passivation layers and Ag mirror + 3-pair TiO(2)/SiO(2) DBR backside reflector, and the LED with the patterned composite SiO(2)/Al(2)O(3) passivation layer and Ag mirror + 3-pair ALD-grown TiO(2)/Al(2)O(3) DBR backside reflector as compared with the conventional LED only with a single SiO(2) passivation layer, respectively.

Sphere impact and penetration into wet sand

KAUST Repository

Marston, J. O.

2012-08-07

We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.

Sphere impact and penetration into wet sand

KAUST Repository

Marston, J. O.; Vakarelski, Ivan Uriev; Thoroddsen, Sigurdur T

2012-01-01

We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.

Automatic Welding System of Aluminum Pipe by Monitoring Backside Image of Molten Pool Using Vision Sensor

Science.gov (United States)

Baskoro, Ario Sunar; Kabutomori, Masashi; Suga, Yasuo

An automatic welding system using Tungsten Inert Gas (TIG) welding with vision sensor for welding of aluminum pipe was constructed. This research studies the intelligent welding process of aluminum alloy pipe 6063S-T5 in fixed position and moving welding torch with the AC welding machine. The monitoring system consists of a vision sensor using a charge-coupled device (CCD) camera to monitor backside image of molten pool. The captured image was processed to recognize the edge of molten pool by image processing algorithm. Neural network model for welding speed control were constructed to perform the process automatically. From the experimental results it shows the effectiveness of the control system confirmed by good detection of molten pool and sound weld of experimental result.

Wetting front instability in an initially wet unsaturated fracture

International Nuclear Information System (INIS)

Nicholl, M.J.; Glass, R.J.; Nguyen, H.A.

1992-01-01

Experimental results exploring gravity-driven wetting front instability in a pre-wetted, rough-walled analog fracture are presented. Initial conditions considered include a uniform moisture field wetted to field capacity of the analog fracture and the structured moisture field created by unstable infiltration into an initially dry fracture. As in previous studies performed under dry initial conditions, instability was found to result both at the cessation of stable infiltration and at flux lower than the fracture capacity under gravitational driving force. Individual fingers were faster, narrower, longer, and more numerous than observed under dry initial conditions. Wetting fronts were found to follow existing wetted structure, providing a mechanism for rapid recharge and transport

Wetting front instability in an initially wet unsaturated fracture

International Nuclear Information System (INIS)

Nicholl, M.J.; Glass, R.J.; Nguyen, H.A.

1993-01-01

Experimental results exploring gravity-driven wetting from instability in a pre-wetted, rough-walled analog fractures such as those at Yucca Mountain are presented. Initial conditions considered include a uniform moisture field wetted to field capacity of the analog fracture and the structured moisture field created by unstable infiltration into an initially dry fracture. As in previous studies performed under dry initial conditions, instability was found to result both at the cessation of stable infiltration and at flux lower than the fracture capacity under gravitational driving force. Individual fingers were faster, narrower, longer, and more numerous than observed under dry initial conditions. Wetting fronts were found to follow existing wetted structure, providing a mechanism for rapid recharge and transport

PREFACE: Dynamics of wetting Dynamics of wetting

Science.gov (United States)

Grest, Gary S.; Oshanin, Gleb; Webb, Edmund B., III

2009-11-01

Capillary phenomena associated with fluids wetting other condensed matter phases have drawn great scientific interest for hundreds of years; consider the recent bicentennial celebration of Thomas Young's paper on equilibrium contact angles, describing the geometric shape assumed near a three phase contact line in terms of the relevant surface energies of the constituent phases [1]. Indeed, nearly a century has passed since the seminal papers of Lucas and Washburn, describing dynamics of capillary imbibition [2, 3]. While it is generally appreciated that dynamics of fluid wetting processes are determined by the degree to which a system is out of capillary equilibrium, myriad complications exist that challenge the fundamental understanding of dynamic capillary phenomena. The topic has gathered much interest from recent Nobel laureate Pierre-Gilles de Gennes, who provided a seminal review of relevant dissipation mechanisms for fluid droplets spreading on solid surfaces [4] Although much about the dynamics of wetting has been revealed, much remains to be learned and intrinsic technological and fundamental interest in the topic drives continuing high levels of research activity. This is enabled partly by improved experimental capabilities for resolving wetting processes at increasingly finer temporal, spatial, and chemical resolution. Additionally, dynamic wetting research advances via higher fidelity computational modeling capabilities, which drive more highly refined theory development. The significance of this topic both fundamentally and technologically has resulted in a number of reviews of research activity in wetting dynamics. One recent example addresses the evaluation of existing wetting dynamics theories from an experimentalist's perspective [5]. A Current Opinion issue was recently dedicated to high temperature capillarity, including dynamics of high temperature spreading [6]. New educational tools have recently emerged for providing instruction in wetting

Prediction of the wetting-induced collapse behaviour using the soil-water characteristic curve

Science.gov (United States)

Xie, Wan-Li; Li, Ping; Vanapalli, Sai K.; Wang, Jia-Ding

2018-01-01

Collapsible soils go through three distinct phases in response to matric suction decrease during wetting: pre-collapse phase, collapse phase and post-collapse phase. It is reasonable and conservative to consider a strain path that includes a pre-collapse phase in which constant volume is maintained and a collapse phase that extends to the final matric suction to be experienced by collapsible soils during wetting. Upon this assumption, a method is proposed for predicting the collapse behaviour due to wetting. To use the proposed method, two parameters, critical suction and collapse rate, are required. The former is the suction value below which significant collapse deformations take place in response to matric suction decease, and the later is the rate at which void ratio reduces with matric suction in the collapse phase. The value of critical suction can be estimated from the water-entry value taking account of both the microstructure characteristics and collapse mechanism of fine-grained collapsible soils; the wetting soil-water characteristic curve thus can be used as a tool. Five sets of data of wetting tests on both compacted and natural collapsible soils reported in the literature were used to validate the proposed method. The critical suction values were estimated from the water-entry value with parameter a that is suggested to vary between 0.10 and 0.25 for compacted soils and to be lower for natural collapsible soils. The results of a field permeation test in collapsible loess soils were also used to validate the proposed method. The relatively good agreement between the measured and estimated collapse deformations suggests that the proposed method can provide reasonable prediction of the collapse behaviour due to wetting.

Wetting of doped carbon nanotubes by water droplets

DEFF Research Database (Denmark)

Kotsalis, E. M.; Demosthenous, E.; Walther, Jens Honore

2005-01-01

We study the wetting of doped single- and multi-walled carbon nanotubes by water droplets using molecular dynamics simulations. Chemisorbed hydrogen is considered as a model of surface impurities. We study systems with varying densities of surface impurities and we observe increased wetting......, as compared to the pristine nanotube case, attributed to the surface dipole moment that changes the orientation of the interfacial water. We demonstrate that the nature of the impurity is important as here hydrogen induces the formation of an extended hydrogen bond network between the water molecules...

Study of polycaprolactone wet electrospinning process

Directory of Open Access Journals (Sweden)

E. Kostakova

2014-08-01

Full Text Available Wet electrospinning is a useful method for 3-dimensional structure control of nanofibrous materials. This innovative technology uses a liquid collector instead of the metal one commonly used for standard electrospinning. The article compares the internal structural features of polycaprolactone (PCL nanofibrous materials prepared by both technologies. We analyze the influence of different water/ethanol compositions used as a liquid collector on the morphology of the resultant polycaprolactone nanofibrous materials. Scanning electron micro-photographs have revealed a bimodal structure in the wet electrospun materials composed of micro and nanofibers uniformly distributed across the sample bulk. We have shown that the full-faced, twofold fiber distribution is due to the solvent composition and is induced and enhanced by increasing the ethanol weight ratio. Moreover, the comparison of fibrous layers morphology obtained by wet and dry spinning have revealed that beads that frequently appeared in dry spun materials are created by Plateau-Rayleigh instability of the fraction of thicker fibers. Theoretical conditions for spontaneous and complete immersion of cylindrical fibers into a liquid collector are also derived here.

Inorganic Surface Coating with Fast Wetting-Dewetting Transitions for Liquid Manipulations.

Science.gov (United States)

Yang, Yajie; Zhang, Liaoliao; Wang, Jue; Wang, Xinwei; Duan, Libing; Wang, Nan; Xiao, Fajun; Xie, Yanbo; Zhao, Jianlin

2018-06-06

Liquid manipulation is a fundamental issue for microfluidics and miniaturized sensors. Fast wetting-state transitions by optical methods have proven being efficient for liquid manipulations by organic surface coatings, however rarely been achieved by using inorganic coatings. Here, we report a fast optical-induced wetting-state transition surface achieved by inorganic coating, enabling tens of second transitions for a wetting-dewetting cycle, shortened from an hour, as typically reported. Here, we demonstrate a gravity-driven microfluidic reactor and switch it to a mixer after a second-step exposure in a minimum of within 80 s of UV exposure. The fast wetting-dewetting transition surfaces enable the fast switchable or erasable smart surfaces for water collection, miniature chemical reaction, or sensing systems by using inorganic surface coatings.

SOLAR ENERGETIC PARTICLE EVENT ONSETS: FAR BACKSIDE SOLAR SOURCES AND THE EAST–WEST HEMISPHERIC ASYMMETRY

Energy Technology Data Exchange (ETDEWEB)

Kahler, S. W., E-mail: stephen.kahler@kirtland.af.mil [Air Force Research Laboratory, Space Vehicles Directorate, 3550 Aberdeen Avenue, Kirtland AFB, NM 87117 (United States)

2016-03-10

Prompt onsets and short rise times to peak intensities Ip have been noted in a few solar energetic (E > 10 MeV) particle (SEP) events from far behind (≥25°) the west limb. We discuss 15 archival and recent examples of these prompt events, giving their source longitudes, onset and rise times, and associated coronal mass ejection (CME) speeds. Their timescales and CME speeds are not exceptional in comparison with a larger set of SEP events from behind the west limb. A further statistical comparison of observed timescales of SEP events from behind the west limb with events similarly poorly magnetically connected to the eastern hemisphere (EH) shows the longer timescales of the latter group. We interpret this result in terms of a difference between SEP production at parallel shocks on the eastern flanks of western backside events and at perpendicular shocks on the western flanks of EH events.

[Effects of drying and wetting cycles induced by tides on net ecosystem exchange of CO2 over a salt marsh in the Yellow River Delta, China.

Science.gov (United States)

He, Wen Jun; Han, Guang Xuan; Xu, Yan Ning; Zhang, Xi Tao; Wang, An Dong; Che, Chun Guang; Sun, Bao Yu; Zhang, Xiao Shuai

2018-01-01

As a unique hydrological characteristic, the tidal action can strongly affect carbon balance in a salt marsh despite their short duration. Using the eddy covariance technique, we measured the net ecosystem CO 2 exchange (NEE) and its environmental factors and tidal change over a salt marsh in the Yellow River Delta. It aimed to investigate the effect of tidal process and drying and wetting cycles induced by tides on NEE. The results showed that the tidal process promoted the daytime CO 2 uptake, but it didn't clearly affect the nighttime CO 2 release. Tidal inundation was a major factor influencing daytime NEE. The diurnal change of NEE showed a distinct U-shaped curve on both drought and wet stages, but not with substantial variation in its amplitude during the drought stage. The drying and wetting cycles enhanced the absorption of daytime CO 2 . Under drought stage, the mean of the maximum photosynthetic rate (A max ), apparent quantum yield (α) and ecosystem respiration (R eco ) were higher than those in wet stage. In addition, the drying and wetting cycles suppressed the nighttime CO 2 release from the salt marsh but increased its temperature sensitivity.

Rapid Deceleration-Driven Wetting Transition during Pendant Drop Deposition on Superhydrophobic Surfaces

Science.gov (United States)

Kwon, Hyuk-Min; Paxson, Adam T.; Varanasi, Kripa K.; Patankar, Neelesh A.

2011-01-01

A hitherto unknown mechanism for wetting transition is reported. When a pendant drop settles upon deposition, there is a virtual “collision” where its center of gravity undergoes rapid deceleration. This induces a high water hammer-type pressure that causes wetting transition. A new phase diagram shows that both large and small droplets can transition to wetted states due to the new deceleration driven and the previously known Laplace mechanisms, respectively. It is explained how the attainment of a nonwetted Cassie-Baxter state is more restrictive than previously known.

Nanosecond laser-induced back side wet etching of fused silica with a copper-based absorber liquid

Science.gov (United States)

Lorenz, Pierre; Zehnder, Sarah; Ehrhardt, Martin; Frost, Frank; Zimmer, Klaus; Schwaller, Patrick

2014-03-01

Cost-efficient machining of dielectric surfaces with high-precision and low-roughness for industrial applications is still challenging if using laser-patterning processes. Laser induced back side wet etching (LIBWE) using UV laser pulses with liquid heavy metals or aromatic hydrocarbons as absorber allows the fabrication of well-defined, nm precise, free-form surfaces with low surface roughness, e.g., needed for optical applications. The copper-sulphatebased absorber CuSO4/K-Na-Tartrate/NaOH/formaldehyde in water is used for laser-induced deposition of copper. If this absorber can also be used as precursor for laser-induced ablation, promising industrial applications combining surface structuring and deposition within the same setup could be possible. The etching results applying a KrF excimer (248 nm, 25 ns) and a Nd:YAG (1064 nm, 20 ns) laser are compared. The topography of the etched surfaces were analyzed by scanning electron microscopy (SEM), white light interferometry (WLI) as well as laser scanning microscopy (LSM). The chemical composition of the irradiated surface was studied by energy-dispersive X-ray spectroscopy (EDX) and Fourier transform infrared spectroscopy (FT-IR). For the discussion of the etching mechanism the laser-induced heating was simulated with finite element method (FEM). The results indicate that the UV and IR radiation allows micro structuring of fused silica with the copper-based absorber where the etching process can be explained by the laser-induced formation of a copper-based absorber layer.

Nanoimprinted backside reflectors for a-Si:H thin-film solar cells: critical role of absorber front textures.

Science.gov (United States)

Tsao, Yao-Chung; Fisker, Christian; Pedersen, Thomas Garm

2014-05-05

The development of optimal backside reflectors (BSRs) is crucial for future low cost and high efficiency silicon (Si) thin-film solar cells. In this work, nanostructured polymer substrates with aluminum coatings intended as BSRs were produced by positive and negative nanoimprint lithography (NIL) techniques, and hydrogenated amorphous silicon (a-Si:H) was deposited hereon as absorbing layers. The relationship between optical properties and geometry of front textures was studied by combining experimental reflectance spectra and theoretical simulations. It was found that a significant height variation on front textures plays a critical role for light-trapping enhancement in solar cell applications. As a part of sample preparation, a transfer NIL process was developed to overcome the problem of low heat deflection temperature of polymer substrates during solar cell fabrication.

Wet Snow Mapping in Southern Ontario with Sentinel-1A Observations

Science.gov (United States)

Chen, H.; Kelly, R. E. J.

2017-12-01

Wet snow is defined as snow with liquid water present in an ice-water mix. It is can be an indicator for the onset of the snowmelt period. Knowledge about the extent of wet snow area can be of great importance for the monitoring of seasonal snowmelt runoff with climate-induced changes in snowmelt duration having implications for operational hydrological and ecological applications. Spaceborne microwave remote sensing has been used to observe seasonal snow under all-weather conditions. Active microwave observations of snow at C-band are sensitive to wet snow due to the high dielectric contrast with non-wet snow surfaces and synthetic aperture radar (SAR) is now openly available to identify and map the wet snow areas globally at relatively fine spatial resolutions ( 100m). In this study, a semi-automated workflow is developed from the change detection method of Nagler et al. (2016) using multi-temporal Sentinel-1A (S1A) dual-polarization observations of Southern Ontario. Weather station data and visible-infrared satellite observations are used to refine the wet snow area estimates. Wet snow information from National Operational Hydrologic Remote Sensing Center (NOHRSC) is used to compare with the S1A estimates. A time series of wet snow maps shows the variations in backscatter from wet snow on a pixel basis. Different land cover types in Southern Ontario are assessed with respect to their impacts on wet snow estimates. While forests and complex land surfaces can impact the ability to map wet snow, the approach taken is robust and illustrates the strong sensitivity of the approach to wet snow backscattering characteristics. The results indicate the feasibility of the change detection method on non-mountainous large areas and address the usefulness of Sentinel-1A data for wet snow mapping.

Backside illuminated CMOS-TDI line scan sensor for space applications

Science.gov (United States)

Cohen, Omer; Ofer, Oren; Abramovich, Gil; Ben-Ari, Nimrod; Gershon, Gal; Brumer, Maya; Shay, Adi; Shamay, Yaron

2018-05-01

A multi-spectral backside illuminated Time Delayed Integration Radiation Hardened line scan sensor utilizing CMOS technology was designed for continuous scanning Low Earth Orbit small satellite applications. The sensor comprises a single silicon chip with 4 independent arrays of pixels where each array is arranged in 2600 columns with 64 TDI levels. A multispectral optical filter whose spectral responses per array are adjustable per system requirement is assembled at the package level. A custom 4T Pixel design provides the required readout speed, low-noise, very low dark current, and high conversion gains. A 2-phase internally controlled exposure mechanism improves the sensor's dynamic MTF. The sensor high level of integration includes on-chip 12 bit per pixel analog to digital converters, on-chip controller, and CMOS compatible voltage levels. Thus, the power consumption and the weight of the supporting electronics are reduced, and a simple electrical interface is provided. An adjustable gain provides a Full Well Capacity ranging from 150,000 electrons up to 500,000 electrons per column and an overall readout noise per column of less than 120 electrons. The imager supports line rates ranging from 50 to 10,000 lines/sec, with power consumption of less than 0.5W per array. Thus, the sensor is characterized by a high pixel rate, a high dynamic range and a very low power. To meet a Latch-up free requirement RadHard architecture and design rules were utilized. In this paper recent electrical and electro-optical measurements of the sensor's Flight Models will be presented for the first time.

Tetra point wetting at the free surface of liquid Ga-Bi

International Nuclear Information System (INIS)

Huber, P.; Shpyrko, O.G.; Pershan, P.S.; Ocko, B.M.; Di Masi, E.; Deutsch, M.

2002-01-01

A continuous surface wetting transition, pinned to a solid-liquid-liquid-vapor tetra coexistence point, is studied by x-ray reflectivity in liquid Ga-Bi binary alloys. The short-range surface potential is determined from the measured temperature evolution of the wetting film. The thermal fluctuations are shown to be insufficient to induce a noticeable breakdown of mean-field behavior, expected in short-range-interacting systems due to their d u =3 upper critical dimensionality

Tropical Drosophila ananassae of wet-dry seasons show cross resistance to heat, drought and starvation

Directory of Open Access Journals (Sweden)

Chanderkala Lambhod

2017-11-01

Full Text Available Plastic responses to multiple environmental stressors in wet or dry seasonal populations of tropical Drosophila species have received less attention. We tested plastic effects of heat hardening, acclimation to drought or starvation, and changes in trehalose, proline and body lipids in Drosophila ananassae flies reared under wet or dry season-specific conditions. Wet season flies revealed significant increase in heat knockdown, starvation resistance and body lipids after heat hardening. However, accumulation of proline was observed only after desiccation acclimation of dry season flies while wet season flies elicited no proline but trehalose only. Therefore, drought-induced proline can be a marker metabolite for dry-season flies. Further, partial utilization of proline and trehalose under heat hardening reflects their possible thermoprotective effects. Heat hardening elicited cross-protection to starvation stress. Stressor-specific accumulation or utilization as well as rates of metabolic change for each energy metabolite were significantly higher in wet-season flies than dry-season flies. Energy metabolite changes due to inter-related stressors (heat versus desiccation or starvation resulted in possible maintenance of energetic homeostasis in wet- or dry-season flies. Thus, low or high humidity-induced plastic changes in energy metabolites can provide cross-protection to seasonally varying climatic stressors.

Particle-assisted wetting

International Nuclear Information System (INIS)

Xu Hui; Yan Feng; Tierno, Pietro; Marczewski, Dawid; Goedel, Werner A

2005-01-01

Wetting of a solid surface by a liquid is dramatically impeded if either the solid or the liquid is decorated by particles. Here it is shown that in the case of contact between two liquids the opposite effect may occur; mixtures of a hydrophobic liquid and suitable particles form wetting layers on a water surface though the liquid alone is non-wetting. In these wetting layers, the particles adsorb to, and partially penetrate through, the liquid/air and/or the liquid/water interface. This formation of wetting layers can be explained by the reduction in total interfacial energy due to the replacement of part of the fluid/fluid interfaces by the particles. It is most prominent if the contact angles at the fluid/fluid/particle contact lines are close to 90 0

Immunotherapy for choroidal neovascularization in a laser-induced mouse model simulating exudative (wet) macular degeneration

Science.gov (United States)

Bora, Puran S.; Hu, Zhiwei; Tezel, Tongalp H.; Sohn, Jeong-Hyeon; Kang, Shin Goo; Cruz, Jose M. C.; Bora, Nalini S.; Garen, Alan; Kaplan, Henry J.

2003-03-01

Age-related macular degeneration (AMD) is the leading cause of blindness after age 55 in the industrialized world. Severe loss of central vision frequently occurs with the exudative (wet) form of AMD, as a result of the formation of a pathological choroidal neovasculature (CNV) that damages the macular region of the retina. We tested the effect of an immunotherapy procedure, which had been shown to destroy the pathological neovasculature in solid tumors, on the formation of laser-induced CNV in a mouse model simulating exudative AMD in humans. The procedure involves administering an Icon molecule that binds with high affinity and specificity to tissue factor (TF), resulting in the activation of a potent cytolytic immune response against cells expressing TF. The Icon binds selectively to TF on the vascular endothelium of a CNV in the mouse and pig models and also on the CNV of patients with exudative AMD. Here we show that the Icon dramatically reduces the frequency of CNV formation in the mouse model. After laser treatment to induce CNV formation, the mice were injected either with an adenoviral vector encoding the Icon, resulting in synthesis of the Icon by vector-infected mouse cells, or with the Icon protein. The route of injection was i.v. or intraocular. The efficacy of the Icon in preventing formation of laser-induced CNV depends on binding selectively to the CNV. Because the Icon binds selectively to the CNV in exudative AMD as well as to laser-induced CNV, the Icon might also be efficacious for treating patients with exudative AMD.

ABB wet flue gas desulfurization

Energy Technology Data Exchange (ETDEWEB)

Niijhawan, P.

1994-12-31

The wet limestone process for flue gas desulfurization (FGD) is outlined. The following topics are discussed: wet flue gas desulfurization, wet FGD characteristics, wet scrubbers, ABB wet FGD experience, wet FGD forced oxidation, advanced limestone FGD systems, key design elements, open spray tower design, spray tower vs. packed tower, important performance parameters, SO{sub 2} removal efficiency, influence by L/G, limestone utilization, wet FGD commercial database, particulate removal efficiencies, materials of construction, nozzle layout, spray nozzles, recycle pumps, mist elimination, horizontal flow demister, mist eliminator washing, reagent preparation system, spray tower FGDS power consumption, flue gas reheat options, byproduct conditioning system, and wet limestone system.

Modelling of chloride penetration in concrete under wet/dry cycle

Directory of Open Access Journals (Sweden)

Hong Sung-In

2017-01-01

Full Text Available This present study concerns modelling of chloride penetration in partially saturated concrete. To mimic the intermittent exposure of sea water to concrete, varying environmental conditions for relative humidity and chloride concentration were considered. As for the moisture distribution in concrete, statistical permeability model based on pore size distribution was used to represent influence of material properties on moisture transport. Then, a combined chloride diffusion and convection was modelled in variation of moisture level in concrete. As a result, smaller relative wet duration induces higher rate of chloride penetration due to enhanced moisture permeability from the surface, and also higher concentration gradient near the surface of concrete due to repeated wet/dry cycle. This implies that only diffusion analysis on chloride induced corrosion in concrete structure may underestimate the serviceability in given material performance.

A Three-Dimensional Pore-Scale Model for Non-Wetting Phase Mobilization with Ferrofluid

Science.gov (United States)

Wang, N.; Prodanovic, M.

2017-12-01

Ferrofluid, a stable dispersion of paramagnetic nanoparticles in water, can generate a distributed pressure difference across the phase interface in an immiscible two-phase flow under an external magnetic field. In water-wet porous media, this non-uniform pressure difference may be used to mobilize the non-wetting phase, e.g. oil, trapped in the pores. Previous numerical work by Soares et al. of two-dimensional single-pore model showed enhanced non-wetting phase recovery with water-based ferrofluid under certain magnetic field directions and decreased recovery under other directions. However, the magnetic field selectively concentrates in the high magnetic permeability ferrofluid which fills the small corners between the non-wetting phase and the solid wall. The magnetic field induced pressure is proportional to the square of local magnetic field strength and its normal component, and makes a significant impact on the non-wetting phase deformation. The two-dimensional model omitted the effect of most of these corners and is not sufficient to compute the magnetic-field-induced pressure difference or to predict the non-wetting blob deformation. Further, it is not clear that 3D effects on magnetic field in an irregular geometry can be approximated in 2D. We present a three-dimensional immiscible two-phase flow model to simulate the deformation of a non-wetting liquid blob in a single pore filled with a ferrofluid under a uniform external magnetic field. The ferrofluid is modeled as a uniform single phase because the nanoparticles are 104 times smaller than the pore. The open source CFD solver library OpenFOAM is used for the simulations based on the volume of fluid method. Simulations are performed in a converging-diverging channel model on different magnetic field direction, different initial oil saturations, and different pore shapes. Results indicate that the external magnetic field always stretches the non-wetting blob away from the solid channel wall. A magnetic

Wet steam wetness measurement in a 10 MW steam turbine

Directory of Open Access Journals (Sweden)

Kolovratník Michal

2014-03-01

Full Text Available The aim of this paper is to introduce a new design of the extinction probes developed for wet steam wetness measurement in steam turbines. This new generation of small sized extinction probes was developed at CTU in Prague. A data processing technique is presented together with yielded examples of the wetness distribution along the last blade of a 10MW steam turbine. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o.

Introduction to wetting phenomena

International Nuclear Information System (INIS)

Indekeu, J.O.

1995-01-01

In these lectures the field of wetting phenomena is introduced from the point of view of statistical physics. The phase transition from partial to complete wetting is discussed and examples of relevant experiments in binary liquid mixtures are given. Cahn's concept of critical-point wetting is examined in detail. Finally, a connection is drawn between wetting near bulk criticality and the universality classes of surface critical phenomena. (author)

Lanthanide-Doped Ceria Nanoparticles as Backside Coaters to Improve Silicon Solar Cell Efficiency.

Science.gov (United States)

Hajjiah, Ali; Samir, Effat; Shehata, Nader; Salah, Mohamed

2018-05-23

This paper introduces lanthanide-doped ceria nanoparticles as silicon solar cell back-side coaters, showing their influence on the solar cell efficiency. Ceria nanoparticles can be synthesized to have formed oxygen vacancies (O-vacancies), which are associated with converting cerium ions from the Ce 4+ state ions to the Ce 3+ ones. These O-vacancies follow the rule of improving silicon solar cell conductivity through a hopping mechanism. Besides, under near-ultra violet (near-UV) excitation, the reduced trivalent cerium Ce 3+ ions are directly responsible for down converting the un-absorbed UV wavelengths to a resultant green photo-luminescence emission at ~520 nm, which is absorbed through the silicon solar cell’s active layer. Adding lanthanide elements such as Neodymium “Nd” as ceria nanoparticle dopants helps in forming extra oxygen vacancies (O-vacancies), followed by an increase in the number of Ce 4+ to Ce 3+ ion reductions, thus enhancing the conductivity and photoluminescence down conversion mechanisms. After introducing lanthanide-doped ceria nanoparticles on a silicon solar cell surface, a promising enhancement in the behavior of the solar cell current-voltage curve is observed, and the efficiency is improved by about 25% of its initial value due to the mutual impact of improving both electric conductivity and optical conversions.

Effects of sulphuric acid, mechanical scarification and wet heat ...

African Journals Online (AJOL)

Effects of different treatment methods on the germination of seeds of Parkia biglobosa (mimosaceae) were carried out. Prior treatment of seeds with sulphuric acid, wet heat and mechanical scarification were found to induce germination of the dormant seeds. These methods could be applied to raise seedlings of the plant for ...

Haptic perception of wetness

NARCIS (Netherlands)

Bergmann Tiest, W.M.; Kosters, N.D.; Kappers, Astrid M.L.; Daanen, H.A.M.

2012-01-01

In daily life, people interact with textiles of different degrees of wetness, but little is known about the mechanics of wetness perception. This paper describes an experiment with six conditions regarding haptic discrimination of the wetness of fabrics. Three materials were used: cotton wool,

Haptic perception of wetness

NARCIS (Netherlands)

Bergmann Tiest, W.M.; Kosters, N.D.; Daanen, H.A.M.; Kappers, A.M.L.

2011-01-01

The sensation of wetness is well-known but barely investigated. There are no specific wetness receptors in the skin, but the sensation is mediated by temperature and pressure perception. In our study, we have measured discrimination thresholds for the haptic perception of wetness of three di erent

Haptic perception of wetness

NARCIS (Netherlands)

Bergmann Tiest, W.M.; Dolfine Kosters, N.; Daanen, h.a.m.; Kappers, A.M.L.

2012-01-01

In daily life, people interact with textiles of different degrees of wetness, but little is known about the me-chanics of wetness perception. This paper describes an experiment with six conditions regarding haptic dis-crimination of the wetness of fabrics. Three materials were used: cotton wool,

Wet-Bulb-Globe Temperature Data Report

Science.gov (United States)

2015-03-01

Hour Min Pressure Dry Nat Wet Globe Dry Nat Wet Globe Dry Nat Wet Globe Wind Cld amt Cld type Obscuration Quest RH Kestrel RH VPSc RH S1 WBGT Q WBGT...Wet Globe Dry Nat Wet Globe Dry Nat Wet Globe Wind Cld amt Cld type Obscuration Quest RH Kestrel RH VPSc RH S1 WBGT Q WBGT K2 WBGT GMT millibars deg F...Dry Nat Wet Globe Dry Nat Wet Globe Wind Cld amt Cld type Obscuration Quest RH Kestrel RH VPSc RH S1 WBGT Q WBGT K2 WBGT GMT millibars deg F deg F deg

Wetting on micro-structured surfaces: modelling and optimization

DEFF Research Database (Denmark)

Cavalli, Andrea

-patterns, and suggests that there is a balance between optimal wetting properties and mechanical robustness of the microposts. We subsequently analyse liquid spreading on surfaces patterned with slanted microposts. Such a geometry induces unidirectional liquid spreading, as observed in several recent experiments. Our...... liquid spreading and spontaneous drop removal on superhydrophobic surfaces. We do this by applying different numerical techniques, suited for the specific topic. We first consider superhydrophobicity, a condition of extreme water repellency associated with very large static contact angles and low roll......The present thesis deals with the wetting of micro-structured surfaces by various fluids, and its goal is to elucidate different aspects of this complex interaction. In this work we address some of the most relevant topics in this field such as superhydrophobicity, oleophobicity, unidirectional...

Deceleration-driven wetting transition of "gently" deposited drops on textured hydrophobic surfaces

Science.gov (United States)

Varanasi, Kripa; Kwon, Hyukmin; Paxson, Adam; Patankar, Neelesh

2010-11-01

Many applications of rough superhydrophobic surfaces rely on the presence of droplets in a Cassie state on the substrates. A well established understanding is that if sessile droplets are smaller than a critical size, then the large Laplace pressure induces wetting transition from a Cassie to a Wenzel state, i.e., the liquid impales the roughness grooves. Thus, larger droplets are expected to remain in the Cassie state. In this work we report a surprising wetting transition where even a "gentle" deposition of droplets on rough substrates lead to the transition of larger droplets to the Wenzel state. A hitherto unknown mechanism based on rapid deceleration is identified. It is found that modest amount of energy, during the deposition process, is channeled through rapid deceleration into high water hammer pressure which induces wetting transition. A new "phase" diagram is reported which shows that both large and small droplets can transition to Wenzel states due to the deceleration and Laplace mechanisms, respectively. This novel insight reveals for the first time that the attainment of a Cassie state is more restrictive than previous criteria based on the Laplace pressure transition mechanism.

Wetting of alkanes on water

Energy Technology Data Exchange (ETDEWEB)

Bertrand, E.; Bonn, D.; Meunier, J.; Shahidzadeh, N. [Ecole Normale Superieure, Laboratoire de Physique Statistique, 24 rue Lhomond, 75231, Cedex 05 Paris (France); Broseta, D.; Ragil, K. [Institut Francais du Petrole, 1-4 avenue de Bois Preau, 92852 Rueil-Malmaison Cedex (France); Dobbs, H.; Indekeu, J.O. [Katholieke Universiteit Leuven, Laboratorium voor Vaste-Stoffysica en Magnetisme, B-3001 Leuven (Belgium)

2002-04-01

The wetting behavior of oil on water (or brine) has important consequences for the transport properties of oil in water-containing porous reservoirs, and consequently for oil recovery. The equilibrium wetting behavior of model oils composed of pure alkanes or alkane mixtures on brine is reviewed in this paper. Intermediate between the partial wetting state, in which oil lenses coexist on water with a thin film of adsorbed alkane molecules, and the complete wetting state, in which a macroscopically thick oil layer covers the water, these systems display a third, novel wetting state, in which oil lenses coexist with a mesoscopic (a few-nanometers-thick) oil film. The nature and location of the transitions between these wetting regimes depend on oil and brine compositions, temperature and pressure.

High quantum efficiency annular backside silicon photodiodes for reflectance pulse oximetry in wearable wireless body sensors

International Nuclear Information System (INIS)

Duun, Sune; Haahr, Rasmus G; Hansen, Ole; Birkelund, Karen; Thomsen, Erik V

2010-01-01

The development of annular photodiodes for use in a reflectance pulse oximetry sensor is presented. Wearable and wireless body sensor systems for long-term monitoring require sensors that minimize power consumption. We have fabricated large area 2D ring-shaped silicon photodiodes optimized for minimizing the optical power needed in reflectance pulse oximetry. To simplify packaging, backside photodiodes are made which are compatible with assembly using surface mounting technology without pre-packaging. Quantum efficiencies up to 95% and area-specific noise equivalent powers down to 30 fW Hz -1/2 cm -1 are achieved. The photodiodes are incorporated into a wireless pulse oximetry sensor system embedded in an adhesive patch presented elsewhere as 'The Electronic Patch'. The annular photodiodes are fabricated using two masked diffusions of first boron and subsequently phosphor. The surface is passivated with a layer of silicon nitride also serving as an optical filter. As the final process, after metallization, a hole in the center of the photodiode is etched using deep reactive ion etch.

THE 2012 JULY 23 BACKSIDE ERUPTION: AN EXTREME ENERGETIC PARTICLE EVENT?

Energy Technology Data Exchange (ETDEWEB)

Gopalswamy, N. [Code 671, Solar Physics Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Yashiro, S.; Thakur, N.; Mäkelä, P.; Xie, H.; Akiyama, S., E-mail: nat.gopalswamy@nasa.gov [Department of Physics, The Catholic University of America, Washington, DC 20064 (United States)

2016-12-20

The backside coronal mass ejection (CME) of 2012 July 23 had a short Sun-to-Earth shock transit time (18.5 hr). The associated solar energetic particle (SEP) event had a >10 MeV proton flux peaking at ∼5000 pfu, and the energetic storm particle event was an order of magnitude larger, making it the most intense event in the space era at these energies. By a detailed analysis of the CME, shock, and SEP characteristics, we find that the July 23 event is consistent with a high-energy SEP event (accelerating particles to gigaelectronvolt energies). The times of maximum and fluence spectra in the range 10–100 MeV were very hard, similar to those of ground-level enhancement (GLE) events. We found a hierarchical relationship between the CME initial speeds and the fluence spectral indices: CMEs with low initial speeds had SEP events with the softest spectra, while those with the highest initial speeds had SEP events with the hardest spectra. CMEs attaining intermediate speeds result in moderately hard spectra. The July 23 event was in the group of hard-spectrum events. During the July 23 event, the shock speed (>2000 km s{sup −1}), the initial acceleration (∼1.70 km s{sup −2}), and the shock-formation height (∼1.5 solar radii) were all typical of GLE events. The associated type II burst had emission components from meter to kilometer wavelengths, suggesting a strong shock. These observations confirm that the 2012 July 23 event is likely to be an extreme event in terms of the energetic particles it accelerated.

Determination of aerodynamic damping of twin cables in wet conditions through passive-dynamic wind tunnel tests

DEFF Research Database (Denmark)

Eriksen, Mads Beedholm; Mattiello, E.; Georgakis, Christos T.

2013-01-01

Moderate amplitude cable vibrations continue to be reported on the cable-stayed Øresund Bridge, despite the presence of helical fillets and dampers. The vibrations are particularly notable in wet conditions, which would suggest a form of rain-wind induced vibrations (RWIV). A statistical...... of the bridge cables. For the wet tests, the twin cable surfaces were treated in order to obtain uniform upper and lower water rivulets. The interaction between water rivulets, surface properties and the flow was found to govern the activation of the RWIV mechanism. The resulting aerodynamic damping from wet...

A study on electric properties for pulse laser annealing of ITO film after wet etching

International Nuclear Information System (INIS)

Lee, C.J.; Lin, H.K.; Li, C.H.; Chen, L.X.; Lee, C.C.; Wu, C.W.; Huang, J.C.

2012-01-01

The electric properties of ITO thin film after UV or IR laser annealing and wet etching was analyzed via grazing incidence in-plane X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectra and residual stress measurement. The laser annealing process readily induced microcracks or quasi-microcracks on the ITO thin film due to the residual tension stress of crystalline phase transformation between irradiated and non-irradiated areas, and these defects then became the preferred sites for a higher etching rate, resulting in discontinuities in the ITO thin film after the wet etching process. The discontinuities in the residual ITO thin film obstruct carrier transmission and further result in electric failure. - Highlights: ► The laser annealing process induces microcracks in InSnO 2 thin films. ► The defects result in higher local etching rate during wet etching. ► These process defects originate from residual tension stress. ► Decreasing the thermal shock is suggested in order to reduce these process defects.

Simple Multi-level Microchannel Fabrication by Pseudo-Grayscale Backside Diffused Light Lithography.

Science.gov (United States)

Lai, David; Labuz, Joseph M; Kim, Jiwon; Luker, Gary D; Shikanov, Ariella; Takayama, Shuichi

2013-11-14

Photolithography of multi-level channel features in microfluidics is laborious and/or costly. Grayscale photolithography is mostly used with positive photoresists and conventional front side exposure, but the grayscale masks needed are generally costly and positive photoresists are not commonly used in microfluidic rapid prototyping. Here we introduce a simple and inexpensive alternative that uses pseudo-grayscale (pGS) photomasks in combination with backside diffused light lithography (BDLL) and the commonly used negative photoresist, SU-8. BDLL can produce smooth multi-level channels of gradually changing heights without use of true grayscale masks because of the use of diffused light. Since the exposure is done through a glass slide, the photoresist is cross-linked from the substrate side up enabling well-defined and stable structures to be fabricated from even unspun photoresist layers. In addition to providing unique structures and capabilities, the method is compatible with the "garage microfluidics" concept of creating useful tools at low cost since pGS BDLL can be performed with the use of only hot plates and a UV transilluminator: equipment commonly found in biology labs. Expensive spin coaters or collimated UV aligners are not needed. To demonstrate the applicability of pGS BDLL, a variety of weir-type cell traps were constructed with a single UV exposure to separate cancer cells (MDA-MB-231, 10-15 μm in size) from red blood cells (RBCs, 2-8 μm in size) as well as follicle clusters (40-50 μm in size) from cancer cells (MDA-MB-231, 10-15 μm in size).

Comparison of annual dry and wet deposition fluxes of selected pesticides in Strasbourg, France

International Nuclear Information System (INIS)

Sauret, Nathalie; Wortham, Henri; Strekowski, Rafal; Herckes, Pierre; Nieto, Laura Ines

2009-01-01

This work summarizes the results of a study of atmospheric wet and dry deposition fluxes of Deisopropyl-atrazine (DEA), Desethyl-atrazine (DET), Atrazine, Terbuthylazine, Alachlor, Metolachlor, Diflufenican, Fenoxaprop-p-ethyl, Iprodione, Isoproturon and Cymoxanil pesticides conducted in Strasbourg, France, from August 2000 through August 2001. The primary objective of this work was to calculate the total atmospheric pesticide deposition fluxes induced by atmospheric particles. To do this, a modified one-dimensional cloud water deposition model was used. All precipitation and deposition samples were collected at an urban forested park environment setting away from any direct point pesticide sources. The obtained deposition fluxes induced by atmospheric particles over a forested area showed that the dry deposition flux strongly contributes to the total deposition flux. The dry particle deposition fluxes are shown to contribute from 4% (DET) to 60% (cymoxanil) to the total deposition flux (wet + dry). - A modified one-dimensional cloud water deposition model is used to estimate the deposition fluxes of pesticides in the particle phase and compare the relative importance of dry and wet depositions

Comparison of annual dry and wet deposition fluxes of selected pesticides in Strasbourg, France

Energy Technology Data Exchange (ETDEWEB)

Sauret, Nathalie [Marseilles University, Laboratoire Chimie Provence - UMR 6264, Campus Saint Charles, Case 29, 3 Place Victor Hugo, 13331 Marseilles Cedex 03 (France); Wortham, Henri [Marseilles University, Laboratoire Chimie Provence - UMR 6264, Campus Saint Charles, Case 29, 3 Place Victor Hugo, 13331 Marseilles Cedex 03 (France)], E-mail: Henri.Wortham@univ-provence.fr; Strekowski, Rafal [Marseilles University, Laboratoire Chimie Provence - UMR 6264, Campus Saint Charles, Case 29, 3 Place Victor Hugo, 13331 Marseilles Cedex 03 (France); Herckes, Pierre [Arizona State University, Department of Chemistry and Biochemistry, Tempe, AZ 85287-1604 (United States); Nieto, Laura Ines [Marseilles University, Laboratoire Chimie Provence - UMR 6264, Campus Saint Charles, Case 29, 3 Place Victor Hugo, 13331 Marseilles Cedex 03 (France)

2009-01-15

This work summarizes the results of a study of atmospheric wet and dry deposition fluxes of Deisopropyl-atrazine (DEA), Desethyl-atrazine (DET), Atrazine, Terbuthylazine, Alachlor, Metolachlor, Diflufenican, Fenoxaprop-p-ethyl, Iprodione, Isoproturon and Cymoxanil pesticides conducted in Strasbourg, France, from August 2000 through August 2001. The primary objective of this work was to calculate the total atmospheric pesticide deposition fluxes induced by atmospheric particles. To do this, a modified one-dimensional cloud water deposition model was used. All precipitation and deposition samples were collected at an urban forested park environment setting away from any direct point pesticide sources. The obtained deposition fluxes induced by atmospheric particles over a forested area showed that the dry deposition flux strongly contributes to the total deposition flux. The dry particle deposition fluxes are shown to contribute from 4% (DET) to 60% (cymoxanil) to the total deposition flux (wet + dry). - A modified one-dimensional cloud water deposition model is used to estimate the deposition fluxes of pesticides in the particle phase and compare the relative importance of dry and wet depositions.

LED based opto-wetting platforms for micromixing

Science.gov (United States)

Thomas, Tony; Narayanan Unni, Harikrishnan

2018-02-01

The digital microfluidics utilizes the gradient in wettability for droplet transportation. This paper reports a novel technique of LED induced wetting ( Opto-wetting) where a single low power LED (Light emitting diode) emitting light of wavelength 395nm peak with luminous intensity of 300mcd (milli candela) is used to move two droplets of 20μL each on a photo responsive substrate of azobenzene (C12H10N2) coated PDMS (Poly Dimethyl Siloxane) substrate. The PDMS substrate of size 5cmx2cmx0.5cm were modified by thin film coating of Azobenzene dissolved in olive oil solution. The LED was aligned vertically on the top of the substrate. The pulsed operation of LED induces a spatial gradient of surface energy due to the reversible process of photo isomerization of Azobenzene molecules coated on the surface. The Photo-isomerization changes the conformation of the molecules thereby changing its surface energy .The change in surface energy of the substrate induces a change in contact angle of the droplet which initiates its movement. Two water droplets each of 20μL were dispensed on the substrate using micro syringe. Two droplets which were initially at a few cm distance apart were gradually moved towards the focus of light and merged together. The urine droplets (20μL) were moved and mixed with the red dye reagent (20μL) by controlling the light intensity of the LED. This concept provides a cost effective technique of droplet manipulation in the Lab on a chip domain where various multiplexed operations on proteins and DNA droplets can be done for point of care diagnostics.

Wet Gas Airfoil Analyses

OpenAIRE

Larsen, Tarjei Thorrud

2011-01-01

Subsea wet gas compression renders new possibilities for cost savings and enhanced gas recovery on existing gas wells. Technology like this opens to make traditional offshore processing plants redundant. With new technology, follows new challenges. Multiphase flows is regarded as a complex field of study, and increased knowledge on the fundamental mechanisms regarding wet gas flow is of paramount importance to the efficiency and stability of the wet gas compressor. The scope of this work was ...

Modeled Wet Nitrate Deposition

Data.gov (United States)

U.S. Environmental Protection Agency — Modeled data on nitrate wet deposition was obtained from Dr. Jeff Grimm at Penn State Univ. Nitrate wet depostion causes acidification and eutrophication of surface...

Wet gas sampling

Energy Technology Data Exchange (ETDEWEB)

Welker, T.F.

1997-07-01

The quality of gas has changed drastically in the past few years. Most gas is wet with hydrocarbons, water, and heavier contaminants that tend to condense if not handled properly. If a gas stream is contaminated with condensables, the sampling of that stream must be done in a manner that will ensure all of the components in the stream are introduced into the sample container as the composite. The sampling and handling of wet gas is extremely difficult under ideal conditions. There are no ideal conditions in the real world. The problems related to offshore operations and other wet gas systems, as well as the transportation of the sample, are additional problems that must be overcome if the analysis is to mean anything to the producer and gatherer. The sampling of wet gas systems is decidedly more difficult than sampling conventional dry gas systems. Wet gas systems were generally going to result in the measurement of one heating value at the inlet of the pipe and a drastic reduction in the heating value of the gas at the outlet end of the system. This is caused by the fallout or accumulation of the heavier products that, at the inlet, may be in the vapor state in the pipeline; hence, the high gravity and high BTU. But, in fact, because of pressure and temperature variances, these liquids condense and form a liquid that is actually running down the pipe as a stream or is accumulated in drips to be blown from the system. (author)

A critical analysis of one standard and five methods to monitor surface wetness and time-of-wetness

Science.gov (United States)

Camuffo, Dario; della Valle, Antonio; Becherini, Francesca

2018-05-01

Surface wetness is a synergistic factor to determine atmospheric corrosion, monument weathering, mould growth, sick buildings, etc. However, its detection and monitoring are neither easy nor homogeneous, for a number of factors that may affect readings. Various types of methods and sensors, either commercial or prototypes built in the lab, have been investigated and compared, i.e. the international standard ISO 9223 to evaluate corrosivity after wetness and time-of-wetness; indirect evaluation of wetness, based on the dew point calculated after the output of temperature and relative humidity sensors and direct measurements by means of capacitive wetness sensors, safety sensors, rain sensors (also known as leaf wetness sensors), infrared reflection sensors and fibre optic sensors. A comparison between the different methods is presented, specifying physical principles, forms of wetting to which they are respondent (i.e. condensation, ice melting, splashing drops, percolation and capillary rise), critical factors, use and cost.

Doubly Reentrant Cavities Prevent Catastrophic Wetting Transitions on Intrinsically Wetting Surfaces

KAUST Repository

Domingues, Eddy

2017-06-05

Omniphobic surfaces, i.e. which repel all known liquids, have proven of value in applications ranging from membrane distillation to underwater drag reduction. A limitation of currently employed omniphobic surfaces is that they rely on perfluorinated coatings, increasing cost and environmental impact, and preventing applications in harsh environments. There is, thus, a keen interest in rendering conventional materials, such as plastics, omniphobic by micro/nano-texturing rather than via chemical make-up, with notable success having been achieved for silica surfaces with doubly reentrant micropillars. However, we found a critical limitation of microtextures comprising of pillars that they undergo catastrophic wetting transitions (apparent contact angles, θr → 0° from θr > 90°) in the presence of localized physical damages/defects or on immersion in wetting liquids. In response, a doubly reentrant cavity microtexture is introduced, which can prevent catastrophic wetting transitions in the presence of localized structural damage/defects or on immersion in wetting liquids. Remarkably, our silica surfaces with doubly reentrant cavities could exhibited apparent contact angles, θr ≈ 135° for mineral oil, where the intrinsic contact angle, θo ≈ 20°. Further, when immersed in mineral oil or water, doubly reentrant microtextures in silica (θo ≈ 40° for water) were not penetrated even after several days of investigation. Thus, microtextures comprising of doubly reentrant cavities might enable applications of conventional materials without chemical modifications, especially in scenarios that are prone to localized damages or immersion in wetting liquids, e.g. hydrodynamic drag reduction and membrane distillation.

Wetting of cholesteric liquid crystals.

Science.gov (United States)

Silvestre, Nuno M; Figueirinhas Pereira, Maria Carolina; Bernardino, Nelson R; Telo da Gama, Margarida M

2016-02-01

We investigate theoretically the wetting properties of cholesteric liquid crystals at a planar substrate. If the properties of substrate and of the interface are such that the cholesteric layers are not distorted, the wetting properties are similar to those of a nematic liquid crystal. If, on the other hand, the anchoring conditions force the distortion of the liquid crystal layers the wetting properties are altered, the free cholesteric-isotropic interface is non-planar and there is a layer of topological defects close to the substrate. These deformations can either promote or hinder the wetting of the substrate by a cholesteric, depending on the properties of the cholesteric liquid crystal.

Application of risk curve for statistical analysis of backside corrosion in the bottom floors of oil storage tanks

International Nuclear Information System (INIS)

Kasai, Naoya; Maeda, Takuma; Tamura, Koichi; Kitsukawa, Shigeo; Sekine, Kazuyoshi

2016-01-01

Overall thickness profile data for backside corrosion of the bottom floors of 17 oil storage tanks were collected, and a risk curve from the overall thickness profile and discrete thickness data was derived to evaluate the corrosion risk of the bottom floors. The slope of the risk curve in the large corrosion region was found to indicate the local corrosion condition. Parameters for evaluating localized corrosion derived from the corrosion distributions were also investigated to evaluate the corrosion risk of the bottom floors. Compared with the parameters obtained using the overall thickness profile and discrete thickness data, the slope of the risk curve is an excellent evaluation parameter using discrete thickness data. Thus, it is possible to accurately evaluate the corrosion characteristics of the bottom floors of oil storage tanks with the parameters obtained from discrete thickness data. - Highlights: • The risk curves for corrosion show the corrosion characteristic. • The obtained parameters indicate the corrosion characteristic. • The corrosion characteristic can be evaluated with discrete thickness data.

Mercury removal in utility wet scrubber using a chelating agent

Science.gov (United States)

Amrhein, Gerald T.

2001-01-01

A method for capturing and reducing the mercury content of an industrial flue gas such as that produced in the combustion of a fossil fuel or solid waste adds a chelating agent, such as ethylenediaminetetraacetic acid (EDTA) or other similar compounds like HEDTA, DTPA and/or NTA, to the flue gas being scrubbed in a wet scrubber used in the industrial process. The chelating agent prevents the reduction of oxidized mercury to elemental mercury, thereby increasing the mercury removal efficiency of the wet scrubber. Exemplary tests on inlet and outlet mercury concentration in an industrial flue gas were performed without and with EDTA addition. Without EDTA, mercury removal totaled 42%. With EDTA, mercury removal increased to 71%. The invention may be readily adapted to known wet scrubber systems and it specifically provides for the removal of unwanted mercury both by supplying S.sup.2- ions to convert Hg.sup.2+ ions into mercuric sulfide (HgS) and by supplying a chelating agent to sequester other ions, including but not limited to Fe.sup.2+ ions, which could otherwise induce the unwanted reduction of Hg.sup.2+ to the form, Hg.sup.0.

49 CFR 173.159 - Batteries, wet.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Batteries, wet. 173.159 Section 173.159... Batteries, wet. (a) Electric storage batteries, containing electrolyte acid or alkaline corrosive battery fluid (wet batteries), may not be packed with other materials except as provided in paragraphs (g) and...

Enhanced Oil Recovery from Oil-wet Carbonate Rock by Spontaneous Imbibition of Aqueous Surfactant Solutions

Energy Technology Data Exchange (ETDEWEB)

Standnes, Dag Chun

2001-09-01

The main theme of this thesis is an experimental investigation of spontaneous imbibition (SI) of aqueous cationic surfactant solution into oil-wet carbonate (chalk- and dolomite cores). The static imbibition process is believed to represent the matrix flow of oil and water in a fractured reservoir. It was known that aqueous solution of C{sub 12}-N(CH{sub 3}){sub 3}Br (C12TAB) was able to imbibe spontaneously into nearly oil-wet chalk material, but the underlying mechanism was not understood. The present work was therefore initiated, with the following objectives: (1) Put forward a hypothesis for the chemical mechanism underlying the SI of C12TAB solutions into oil-wet chalk material based on experimental data and (2) Perform screening tests of low-cost commercially available surfactants for their ability to displace oil by SI of water into oil-wet carbonate rock material. It is essential for optimal use of the surfactant in field application to have detailed knowledge about the mechanism underlying the SI process. The thesis also discusses some preliminary experimental results and suggests mechanisms for enhanced oil recovery from oil-wet carbonate rock induced by supply of thermal energy.

Adult Bed-Wetting: A Concern?

Science.gov (United States)

Adult bed-wetting: A concern? My 24-year-old husband has started to wet the bed at ... of Privacy Practices Notice of Nondiscrimination Manage Cookies Advertising Mayo Clinic is a not-for-profit organization ...

Early age sealing of buffer-rock gap by artificial wetting to induce bentonite swelling

International Nuclear Information System (INIS)

Holt, Erika; Marjavaara, Pieti

2012-01-01

400% of the buffer. The area near the top of the sample often had a higher water content, attributed to the concentration of material and upward swelling. Two weeks after wetting, the dry density of the gap area with plain water filling or pellets is on the order of 1000 kg/m 3 . The small-scale artificial wetting laboratory test program has provided the basis for some aspects of the First Phase Test of Bentonite Buffer. This test was started in autumn 2011 in Onkalo, Finland at the depth of 140 m below surface. The test is scaled 40% from the current repository hole dimensions, having two separate holes of 800 mm in diameter and three meters depth, both holes have heaters. The 35 mm gap between the rock and bentonite buffer was filled with custom-made roller-compacted MX- 80 pellets. Both the buffer and pellets were made from the same material and had a water content of 17%. In this field demonstration, one hole was artificially wetted and the other was left to dry only exposed to the natural water coming from host rock. The start of the test showed that it was possible to artificially wet the buffer-pellet system as the buffer was confined with a lid. The tests are on-going in ONKALO at the moment and it is planned for them to run for least of two years but it can be continued longer if necessary. The planning of the second phase, full-scale test to be done at the level 420 m below ground in ONKALO has started. Overall, this initial 2009-10 experimental research project showed that it was possible to uniformly wet the buffer to induce a high level of swelling within the first days, which would provide a higher level of safety with respect to thermal, mechanical and chemical stability during the waste deposition construction phase. The uncertainties that remain were the up-scaling of results to full-size deposition scale, especially with respect to the level of buffer uplift

Variability of extreme wet events over Malawi

Directory of Open Access Journals (Sweden)

Libanda Brigadier

2017-01-01

Full Text Available Adverse effects of extreme wet events are well documented by several studies around the world. These effects are exacerbated in developing countries like Malawi that have insufficient risk reduction strategies and capacity to cope with extreme wet weather. Ardent monitoring of the variability of extreme wet events over Malawi is therefore imperative. The use of the Expert Team on Climate Change Detection and Indices (ETCCDI has been recommended by many studies as an effective way of quantifying extreme wet events. In this study, ETCCDI indices were used to examine the number of heavy, very heavy, and extremely heavy rainfall days; daily and five-day maximum rainfall; very wet and extremely wet days; annual wet days and simple daily intensity. The Standard Normal Homogeneity Test (SNHT was employed at 5% significance level before any statistical test was done. Trend analysis was done using the nonparametric Mann-Kendall statistical test. All stations were found to be homogeneous apart from Mimosa. Trend results show high temporal and spatial variability with the only significant results being: increase in daily maximum rainfall (Rx1day over Karonga and Bvumbwe, increase in five-day maximum rainfall (Rx5day over Bvumbwe. Mzimba and Chileka recorded a significant decrease in very wet days (R95p while a significant increase was observed over Thyolo. Chileka was the only station which observed a significant trend (decrease in extremely wet rainfall (R99p. Mzimba was the only station that reported a significant trend (decrease in annual wet-day rainfall total (PRCPTOT and Thyolo was the only station that reported a significant trend (increase in simple daily intensity (SDII. Furthermore, the findings of this study revealed that, during wet years, Malawi is characterised by an anomalous convergence of strong south-easterly and north-easterly winds. This convergence is the main rain bringing mechanism to Malawi.

Mechanisms of dynamic wetting failure in the presence of soluble surfactants

Science.gov (United States)

Kumar, Satish; Liu, Chen-Yu; Carvalho, Marcio S.

2017-11-01

A hydrodynamic model and flow visualization experiments are used to understand the mechanisms through which soluble surfactants can influence the onset of dynamic wetting failure. In the model, a Newtonian liquid displaces air in a rectangular channel in the absence of inertia. A Navier-slip boundary condition and constant contact angle are used to describe the dynamic contact line, and surfactants are allowed to adsorb to the interface and moving channel wall (substrate). The Galerkin finite element method is used to calculate steady states and identify the critical capillary number Cacrit at which wetting failure occurs. It is found that surfactant solubility weakens the influence of Marangoni stresses, which tend to promote the onset of wetting failure. The experiments indicate that Cacrit increases with surfactant concentration. For the more viscous solutions used, this behaviour can largely be explained by accounting for changes to the mean surface tension and static contact angle produced by surfactants. For the lowest-viscosity solution used, comparison between the model predictions and experimental observations suggests that other surfactant-induced phenomena such as Marangoni stresses may play a more important role.

Dynamic wetting and spreading and the role of topography

International Nuclear Information System (INIS)

McHale, Glen; Newton, Michael I; Shirtcliffe, Neil J

2009-01-01

The spreading of a droplet of a liquid on a smooth solid surface is often described by the Hoffman-de Gennes law, which relates the edge speed, v e , to the dynamic and equilibrium contact angles θ and θ e through v e ∝θ(θ 2 -θ e 2 ). When the liquid wets the surface completely and the equilibrium contact angle vanishes, the edge speed is proportional to the cube of the dynamic contact angle. When the droplets are non-volatile this law gives rise to simple power laws with time for the contact angle and other parameters in both the capillary and gravity dominated regimes. On a textured surface, the equilibrium state of a droplet is strongly modified due to the amplification of the surface chemistry induced tendencies by the topography. The most common example is the conversion of hydrophobicity into superhydrophobicity. However, when the surface chemistry favors partial wetting, topography can result in a droplet spreading completely. A further, frequently overlooked consequence of topography is that the rate at which an out-of-equilibrium droplet spreads should also be modified. In this report, we review ideas related to the idea of topography induced wetting and consider how this may relate to dynamic wetting and the rate of droplet spreading. We consider the effect of the Wenzel and Cassie-Baxter equations on the driving forces and discuss how these may modify power laws for spreading. We relate the ideas to both the hydrodynamic viscous dissipation model and the molecular-kinetic theory of spreading. This suggests roughness and solid surface fraction modified Hoffman-de Gennes laws relating the edge speed to the dynamic and equilibrium contact angle. We also consider the spreading of small droplets and stripes of non-volatile liquids in the capillary regime and large droplets in the gravity regime. In the case of small non-volatile droplets spreading completely, a roughness modified Tanner's law giving the dependence of dynamic contact angle on time is

WET SOLIDS FLOW ENHANCEMENT; SEMIANNUAL

International Nuclear Information System (INIS)

Hugo S Caram; Natalie Foster

1998-01-01

The strain-stress behavior of a wet granular media was measured using a split Parfitt tensile tester. In all cases the stress increases linearly with distance until the maximum uniaxial tensile stress is reached. The stress then decreases exponentially with distance after this maximum is reached. The linear region indicates that wet solids behave elastically for stresses below the tensile stresses and can store significant elastic energy. The elastic deformation cannot be explained by analyzing the behavior of individual capillary bridges and may require accounting for the deformation of the solids particles. The elastic modulus of the wet granular material remains unexplained

Wetting of Water on Graphene

KAUST Repository

Bera, Bijoyendra; Shahidzadeh, Noushine; Mishra, Himanshu; Bonn, Daniel

2016-01-01

The wetting properties of graphene have proven controversial and difficult to assess. The presence of a graphene layer on top of a substrate does not significantly change the wetting properties of the solid substrate, suggesting that a single graphene layer does not affect the adhesion between the wetting phase and the substrate. However, wetting experiments of water on graphene show contact angles that imply a large amount of adhesion. Here, we investigate the wetting of graphene by measuring the mass of water vapor adsorbing to graphene flakes of different thickness at different relative humidities. Our experiments unambiguously show that the thinnest of graphene flakes do not adsorb water, from which it follows that the contact angle of water on these flakes is ~180o. Thicker flakes of graphene nanopowder, on the other hand, do adsorb water. A calculation of the van der Waals (vdW) interactions that dominate the adsorption in this system confirms that the adhesive interactions between a single atomic layer of graphene and water are so weak that graphene is superhydrophobic. The observations are confirmed in an independent experiment on graphene-coated water droplets that shows that it is impossible to make liquid 'marbles' with molecularly thin graphene.

Wetting of Water on Graphene

KAUST Repository

Bera, Bijoyendra

2016-11-28

The wetting properties of graphene have proven controversial and difficult to assess. The presence of a graphene layer on top of a substrate does not significantly change the wetting properties of the solid substrate, suggesting that a single graphene layer does not affect the adhesion between the wetting phase and the substrate. However, wetting experiments of water on graphene show contact angles that imply a large amount of adhesion. Here, we investigate the wetting of graphene by measuring the mass of water vapor adsorbing to graphene flakes of different thickness at different relative humidities. Our experiments unambiguously show that the thinnest of graphene flakes do not adsorb water, from which it follows that the contact angle of water on these flakes is ~180o. Thicker flakes of graphene nanopowder, on the other hand, do adsorb water. A calculation of the van der Waals (vdW) interactions that dominate the adsorption in this system confirms that the adhesive interactions between a single atomic layer of graphene and water are so weak that graphene is superhydrophobic. The observations are confirmed in an independent experiment on graphene-coated water droplets that shows that it is impossible to make liquid \\'marbles\\' with molecularly thin graphene.

Wetting-layer formation mechanisms of surface-directed phase separation under different quench depths with off-critical compositions in polymer binary mixture

Science.gov (United States)

Yan, Li-Tang; Xie, Xu-Ming

2007-02-01

Focusing on the off-critical condition, the quench depth dependence of surface-directed phase separation in the polymer binary mixture is numerically investigated by combination of the Cahn-Hilliard-Cook theory and the Flory-Huggins-de Gennes theory. Two distinct situations, i.e., for the wetting, the minority component is preferred by the surface and the majority component is preferred by the surface, are discussed in detail. The simulated results show that the formation mechanism of the wetting layer is affected by both the quench depth and the off-critical extent. Moreover, a diagram, illustrating the formation mechanisms of the wetting layer with various quench depths and compositions, is obtained on the basis of the simulated results. It is found that, when the minority component is preferred by the surface, the growth of the wetting layer can exhibit pure diffusion limited growth law, logarithmic growth law, and Lifshitz-Slyozov growth law. However, when the majority component is preferred by the surface, the wetting layer always grows logarithmically, regardless of the quench depth and the off-critical extent. It is interesting that the surface-induced nucleation can be observed in this case. The simulated results demonstrate that the surface-induced nucleation only occurs below a certain value of the quench depth, and a detailed range about it is calculated and indicated. Furthermore, the formation mechanisms of the wetting layer are theoretically analyzed in depth by the chemical potential gradient.

Adsorption of chlorinated hydrocarbons from aqueous solutions by wetted and non-wetted synthetic sorbents:dynamics

NARCIS (Netherlands)

Rexwinkel, G.; Rexwinkel, Glenn; Berkhout, J.T.A.M.; Heesink, Albertus B.M.

2003-01-01

In the present investigation the dynamics of the adsorption of several chlorinated hydrocarbons onto wetted and non-wetted synthetic sorbents was studied. A single particle model was developed to describe the adsorption behavior. The values of the mass transfer coefficient, needed to describe the

Evaporation from rain-wetted forest in relation to canopy wetness, canopy cover, and net radiation

NARCIS (Netherlands)

Klaassen, W.

2001-01-01

Evaporation from wet canopies is commonly calculated using E-PM, the Penman-Monteith equation with zero surface resistance. However, several observations show a lower evaporation from rain-wetted forest. Possible causes for the difference between E-PM and experiments are evaluated to provide rules

Wet storage integrity update

International Nuclear Information System (INIS)

Bailey, W.J.; Johnson, A.B. Jr.

1983-09-01

This report includes information from various studies performed under the Wet Storage Task of the Spent Fuel Integrity Project of the Commercial Spent Fuel Management (CSFM) Program at Pacific Northwest Laboratory. An overview of recent developments in the technology of wet storage of spent water reactor fuel is presented. Licensee Event Reports pertaining to spent fuel pools and the associated performance of spent fuel and storage components during wet storage are discussed. The current status of fuel that was examined under the CSFM Program is described. Assessments of the effect of boric acid in spent fuel pool water on the corrosion and stress corrosion cracking of stainless steel and the stress corrosion cracking of stainless steel piping containing stagnant water at spent fuel pools are discussed. A list of pertinent publications is included. 84 references, 21 figures, 11 tables

Nanoimprinted polymer chips for light induced local heating of liquids in micro- and nanochannels

DEFF Research Database (Denmark)

Thamdrup, Lasse Højlund; Pedersen, Jonas Nyvold; Flyvbjerg, Henrik

2010-01-01

A nanoimprinted polymer chip with a thin near-infrared absorber layer that enables light-induced local heating (LILH) of liquids inside micro- and nanochannels is presented. An infrared laser spot and corresponding hot-spot could be scanned across the device. Large temperature gradients yield...... a 785 nm laser diode was focused from the backside of the chip to a spot diameter down to 5 ..m in the absorber layer, yielding a localized heating (Gaussian profile) and large temperature gradients in the liquid in the nanochannels. A laser power of 38 mW yielded a temperature of 40°C in the center...

European wet deposition maps based on measurements

NARCIS (Netherlands)

Leeuwen EP van; Erisman JW; Draaijers GPJ; Potma CJM; Pul WAJ van; LLO

1995-01-01

To date, wet deposition maps on a European scale have been based on long-range transport model results. For most components wet deposition maps based on measurements are only available on national scales. Wet deposition maps of acidifying components and base cations based on measurements are needed

Proteomic effects of wet cupping (Al-hijamah).

Science.gov (United States)

Almaiman, Amer A

2018-01-01

Wet cupping (Al-hijamah) is a therapeutic technique practiced worldwide as a part of the Unani system of medicine. It involves bloodletting from acupoints on a patient's skin to produce a therapeutic outcome. A thorough review of research articles on wet cupping with relevance to proteomics field that are indexed by Google Scholar, PubMed, and/or Science Direct databases was performed. Eight original research articles were summarized in this paper. Overall, wet cupping did not have a significant effect on C-reactive protein, Hsp-27, sister chromatid exchanges, and cell replication index. In contrast, wet cupping was found to produce higher oxygen saturation, eliminate lactate from subcutaneous tissues, remove blood containing higher levels of malondialdehyde and nitric oxide, and produce higher activity of myeloperoxidase. The proteomic effects of wet cupping therapy have not been adequately investigated. Thus, future studies on wet cupping that use systemic and sound protocols to avoid bias should be conducted.

Proteomic effects of wet cupping (Al-hijamah

Directory of Open Access Journals (Sweden)

Amer A. Almaiman

2018-01-01

Full Text Available Wet cupping (Al-hijamah is a therapeutic technique practiced worldwide as a part of the Unani system of medicine. It involves bloodletting from acupoints on a patient’s skin to produce a therapeutic outcome. A thorough review of research articles on wet cupping with relevance to proteomics field that are indexed by Google Scholar, PubMed, and/or Science Direct databases was performed. Eight original research articles were summarized in this paper. Overall, wet cupping did not have a significant effect on C-reactive protein, Hsp-27, sister chromatid exchanges, and cell replication index. In contrast, wet cupping was found to produce higher oxygen saturation, eliminate lactate from subcutaneous tissues, remove blood containing higher levels of malondialdehyde and nitric oxide, and produce higher activity of myeloperoxidase. The proteomic effects of wet cupping therapy have not been adequately investigated. Thus, future studies on wet cupping that use systemic and sound protocols to avoid bias should be conducted.

Wetting and evaporation of binary mixture drops.

Science.gov (United States)

Sefiane, Khellil; David, Samuel; Shanahan, Martin E R

2008-09-11

Experimental results on the wetting behavior of water, methanol, and binary mixture sessile drops on a smooth, polymer-coated substrate are reported. The wetting behavior of evaporating water/methanol drops was also studied in a water-saturated environment. Drop parameters (contact angle, shape, and volume) were monitored in time. The effects of the initial relative concentrations on subsequent evaporation and wetting dynamics were investigated. Physical mechanisms responsible for the various types of wetting behavior during different stages are proposed and discussed. Competition between evaporation and hydrodynamic flow are evoked. Using an environment saturated with water vapor allowed further exploration of the controlling mechanisms and underlying processes. Wetting stages attributed to differential evaporation of methanol were identified. Methanol, the more volatile component, evaporates predominantly in the initial stage. The data, however, suggest that a small proportion of methanol remained in the drop after the first stage of evaporation. This residual methanol within the drop seems to influence subsequent wetting behavior strongly.

Quantification of wet-work exposure in nurses using a newly developed wet-work exposure monitor

NARCIS (Netherlands)

Visser, Maaike J.; Behroozy, Ali; Verberk, Maarten M.; Semple, Sean; Kezic, Sanja

2011-01-01

Occupational contact dermatitis (OCD) is an important work-related disease. A major cause of OCD is 'wet work': frequent contact of the skin with water, soap, detergents, or occlusive gloves. The German guidance TRGS 401 recommends that the duration of wet work (including use of occlusive gloves)

Carbon nanotube fiber spun from wetted ribbon

Science.gov (United States)

Zhu, Yuntian T; Arendt, Paul; Zhang, Xiefei; Li, Qingwen; Fu, Lei; Zheng, Lianxi

2014-04-29

A fiber of carbon nanotubes was prepared by a wet-spinning method involving drawing carbon nanotubes away from a substantially aligned, supported array of carbon nanotubes to form a ribbon, wetting the ribbon with a liquid, and spinning a fiber from the wetted ribbon. The liquid can be a polymer solution and after forming the fiber, the polymer can be cured. The resulting fiber has a higher tensile strength and higher conductivity compared to dry-spun fibers and to wet-spun fibers prepared by other methods.

Long term wet spent nuclear fuel storage

International Nuclear Information System (INIS)

1987-04-01

The meeting showed that there is continuing confidence in the use of wet storage for spent nuclear fuel and that long-term wet storage of fuel clad in zirconium alloys can be readily achieved. The importance of maintaining good water chemistry has been identified. The long-term wet storage behaviour of sensitized stainless steel clad fuel involves, as yet, some uncertainties. However, great reliance will be placed on long-term wet storage of spent fuel into the future. The following topics were treated to some extent: Oxidation of the external surface of fuel clad, rod consolidation, radiation protection, optimum methods of treating spent fuel storage water, physical radiation effects, and the behaviour of spent fuel assemblies of long-term wet storage conditions. A number of papers on national experience are included

Analysis on Wetting Deformation Properties of Silty Clay

Directory of Open Access Journals (Sweden)

Xinrong Liu

2014-06-01

Full Text Available Changes in water level that cause deformation and stability problems often occur in foundation pit engineering. Water damage is one of the main problems that will lead to disasters in foundation pit engineering. Research findings with regard to properties of wetting deformation due to water damage can be applied not only in foundation pit engineering, slope engineering, hydraulic engineering, and mining engineering but also in related issues in the field of theoretical research and practice. In this study, the characteristics of silty clay deformation after wetting are examined from the perspective of the effect of wetting on the side wall of foundation pit, and wetting experiments on silty clay of a selected area’s stratum located in Chongqing Municipality are conducted under different confining pressures and stress levels through a multi-function triaxial apparatus. Then, laws of silty clay wetting deformation are obtained, and the relationship between wetting stress level and wetting deformation amount is also figured out. The study reveals that the maximum values of wetting deformation under different confining pressures have appear at a particular stress level; therefore, the related measures should be taken to avoid this deformation in the process of construction.

Transitioning aluminum clad spent fuels from wet to interim dry storage

International Nuclear Information System (INIS)

Louthan, M.R. Jr.; Iyer, N.C.; Sindelar, R.L.; Peacock, H.B. Jr.

1994-01-01

The United States Department of Energy (DOE) currently owns several hundred metric tons of aluminum clad, spent nuclear fuel and target assemblies. The vast majority of these irradiated assemblies are currently stored in water basins that were designed and operated for short term fuel cooling prior to fuel reprocessing. Recent DOE decisions to severely limit the reprocessing option have significantly lengthened the time of storage, thus increasing the tendency for corrosion induced degradation of the fuel cladding and the underlying core material. The portent of continued corrosion, coupled with the age of existing wet storage facilities and the cost of continuing basin operations, including necessary upgrades to meet current facility standards, may force the DOE to transition these wet stored, aluminum clad spent fuels to interim dry storage. The facilities for interim dry storage have not been developed, partially because fuel storage requirements and specifications for acceptable fuel forms are lacking. In spite of the lack of both facilities and specifications, current plans are to dry store fuels for approximately 40 to 60 years or until firm decisions are developed for final fuel disposition. The transition of the aluminum clad fuels from wet to interim dry storage will require a sequence of drying and canning operations which will include selected fuel preparations such as vacuum drying and conditioning of the storage atmosphere. Laboratory experiments and review of the available literature have demonstrated that successful interim dry storage may also require the use of fuel and canister cleaning or rinsing techniques that preclude, or at least minimize, the potential for the accumulation of chloride and other potentially deleterious ions in the dry storage environment. This paper summarizes an evaluation of the impact of fuel transitioning techniques on the potential for corrosion induced degradation of fuel forms during interim dry storage

Wet-cupping removes oxidants and decreases oxidative stress.

Science.gov (United States)

Tagil, Suleyman Murat; Celik, Huseyin Tugrul; Ciftci, Sefa; Kazanci, Fatmanur Hacievliyagil; Arslan, Muzeyyen; Erdamar, Nazan; Kesik, Yunus; Erdamar, Husamettin; Dane, Senol

2014-12-01

Wet-cupping therapy is one of the oldest known medical techniques. Although it is widely used in various conditions such as acute\\chronic inflammation, infectious diseases, and immune system disorders, its mechanism of action is not fully known. In this study, we investigated the oxidative status as the first step to elucidate possible mechanisms of action of wet cupping. Wet cupping therapy is implemented to 31 healthy volunteers. Venous blood samples and Wet cupping blood samples were taken concurrently. Serum nitricoxide, malondialdehyde levels and activity of superoxide dismutase and myeloperoxidase were measured spectrophotometrically. Wet cupping blood had higher activity of myeloperoxidase, lower activity of superoxide dismutase, higher levels of malondialdehyde and nitricoxide compared to the venous blood. Wet cupping removes oxidants and decreases oxidative stress. Copyright © 2014 Elsevier Ltd. All rights reserved.

Surface changes of biopolymers PHB and PLLA induced by Ar+ plasma treatment and wet etching

Science.gov (United States)

Slepičková Kasálková, N.; Slepička, P.; Sajdl, P.; Švorčík, V.

2014-08-01

Polymers, especially group of biopolymers find potential application in a wide range of disciplines due to their biodegradability. In biomedical applications these materials can be used as a scaffold or matrix. In this work, the influence of the Ar+ plasma treatment and subsequent wet etching (acetone/water) on the surface properties of polymers were studied. Two biopolymers - polyhydroxybutyrate with 8% polyhydroxyvalerate (PHB) and poly-L-lactic acid (PLLA) were used in these experiments. Modified surface layers were analyzed by different methods. Surface wettability was characterized by determination of water contact angle. Changes in elemental composition of modified surfaces were performed by X-ray Photoelectron Spectroscopy (XPS). Surface morphology and roughness was examined using Atomic Force Microscopy (AFM). Gravimetry method was used to study the mass loss. It was found that the modification from both with plasma and wet etching leads to dramatic changes of surface properties (surface chemistry, morphology and roughness). Rate of changes of these features strongly depends on the modification parameters.

Contact angle and local wetting at contact line.

Science.gov (United States)

Li, Ri; Shan, Yanguang

2012-11-06

This theoretical study was motivated by recent experiments and theoretical work that had suggested the dependence of the static contact angle on the local wetting at the triple-phase contact line. We revisit this topic because the static contact angle as a local wetting parameter is still not widely understood and clearly known. To further clarify the relationship of the static contact angle with wetting, two approaches are applied to derive a general equation for the static contact angle of a droplet on a composite surface composed of heterogeneous components. A global approach based on the free surface energy of a thermodynamic system containing the droplet and solid surface shows the static contact angle as a function of local surface chemistry and local wetting state at the contact line. A local approach, in which only local forces acting on the contact line are considered, results in the same equation. The fact that the local approach agrees with the global approach further demonstrates the static contact angle as a local wetting parameter. Additionally, the study also suggests that the wetting described by the Wenzel and Cassie equations is also the local wetting of the contact line rather than the global wetting of the droplet.

Allergenic Ingredients in Personal Hygiene Wet Wipes.

Science.gov (United States)

Aschenbeck, Kelly A; Warshaw, Erin M

Wet wipes are a significant allergen source for anogenital allergic contact dermatitis. The aim of the study was to calculate the frequency of potentially allergenic ingredients in personal hygiene wet wipes. Ingredient lists from brand name and generic personal hygiene wet wipes from 4 large retailers were compiled. In the 54 personal hygiene wet wipes evaluated, a total of 132 ingredients were identified (average of 11.9 ingredients per wipe). The most common ingredients were Aloe barbadensis (77.8%), citric acid (77.8%), fragrance (72.2%), sorbic acid derivatives (63.0%), tocopherol derivatives (63.0%), glycerin (59.3%), phenoxyethanol (55.6%), disodium cocoamphodiacetate (53.7%), disodium ethylenediaminetetraacetic acid (EDTA) (42.6%), propylene glycol (42.6%), iodopropynyl butylcarbamate (40.7%), chamomile extracts (38.9%), sodium benzoate (35.2%), bronopol (22.2%), sodium citrate (22.2%), lanolin derivatives (20.4%), parabens (20.4%), polyethylene glycol derivatives (18.5%), disodium phosphate (16.7%), dimethylol dimethyl hydantoin (DMDM) (14.8%), and cocamidopropyl propylene glycol (PG)-dimonium chloride phosphate (11.1%). Of note, methylisothiazolinone (5.6%) was uncommon; methylchloroisothiazolinone was not identified in the personal hygiene wet wipes examined. There are many potential allergens in personal hygiene wet wipes, especially fragrance and preservatives.

Pressure and partial wetting effects on superhydrophobic friction reduction in microchannel flow

Science.gov (United States)

Kim, Tae Jin; Hidrovo, Carlos

2012-11-01

Friction reduction in microchannel flows can help alleviate the inherently taxing pumping power requirements associated with the dimensions involved. One possible way of achieving friction reduction is through the introduction of surface microtexturing that can lead to a superhydrophobic Cassie-Baxter state. The Cassie-Baxter state is characterized by the presence of air pockets within the surface microtexturing believed to act as an effective "shear free" (or at least shear reduced) layer, decreasing the overall friction characteristics of the surface. Most work in this area has concentrated on optimizing the surface microtexturing geometry to maximize the friction reduction effects and overall stability of the Cassie-Baxter state. However, less attention has been paid to the effects of partially wetted conditions induced by pressure and the correlation between the liquid-gas interface location within the surface microtexturing and the microchannel flow characteristics. This is mainly attributed to the difficulty in tracking the interface shape and location within the microtexturing in the typical top-down view arrangements used in most studies. In this paper, a rectangular microchannel with regular microtexturing on the sidewalls is used to visualize and track the location of the air-water interface within the roughness elements. While visually tracking the wetting conditions in the microtextures, pressure drops versus flow rates for each microchannel are measured and analyzed in terms of the non-dimensional friction coefficient. The frictional behavior of the Poiseuille flow suggests that (1) the air-water interface more closely resembles a no-slip boundary rather than a shear-free one, (2) the friction is rather insensitive to the degree of microtexturing wetting, and (3) the fully wetted (Wenzel state) microtexturing provides lower friction than the non-wetted one (Cassie state), in corroboration with observations (1) and (2).

Monitoring of multiple solvent induced form changes during high shear wet granulation and drying processes using online Raman spectroscopy.

Science.gov (United States)

Reddy, Jay Poorna; Jones, John W; Wray, Patrick S; Dennis, Andrew B; Brown, Jonathan; Timmins, Peter

2018-04-25

Form changes during drug product processing can be a risk to the final product quality in terms of chemical stability and bioavailability. In this study, online Raman spectroscopy was used to monitor the form changes in real time during high shear wet granulation of Compound A, a highly soluble drug present at a high drug load in an extended release formulation. The effect of water content, temperature, wet massing time and drying technique on the degree of drug transformation were examined. A designed set of calibration standards were employed to develop quantitative partial least square regression models to predict the concentration of each drug form during both wet granulation and the drying process. Throughout all our experiments we observed complex changes of the drug form during granulation, manifest as conversions between the initial non-solvated form of Compound A, the hemi-hydrate form and the "apparent" amorphous form (dissolved drug). The online Raman data demonstrate that the non-solvated form converts to an "apparent" amorphous form (dissolved drug) due to drug dissolution with no appearance of the hemi-hydrate form during water addition stage. The extent of conversion of the non-solvated form was governed by the amount of water added and the rate of conversion was accelerated at higher temperatures. Interestingly, in the wet massing zone, the formation of the hemi-hydrate form was observed at a rate equivalent to the rate of depletion of the non-solvated form with no change in the level of the "apparent amorphous" form generated. The level of hemi-hydrate increased with an increase in wet massing time. The drying process had a significant effect on the proportion of each form. During tray drying, changes in drug form continued for hours. In contrast fluid bed drying appeared to lock the final proportions of drug form product attained during granulation, with comparatively small changes observed during drying. In conclusion, it was possible to

Technical Efficiency of Wet Season Melon Farming

Directory of Open Access Journals (Sweden)

Ananti Yekti

2017-03-01

Full Text Available Melon is one of high-value horticulture commodity which is cultivated widely in Kulon Progo regency. The nature of agricultural products is heavily dependent on the season, so it causes the prices of agricultural products always fluctuated every time. In wet season the price of agricultural products tends to be more expensive. Melon cultivation in wet season provide an opportunity to earn higher profits than in the dry season. The price of agricultural products tends to be more expensive in wet season, thus melon cultivation in wet season prospectively generate high profits. In order to achieve high profitability, melon farming has to be done efficiently. Objective of this study was to 1 determined the factors that influence melon production in wet season 2 measured technical efficiency of melon farming and 3 identified the factors that influanced technical efficiency. Data collected during April – June 2014. Location determined by multistage cluster sampling. 45 samples of farmers who cultivated melon during wet season obtained based on quota sampling technique. Technical efficiency was measured using Cobb-Douglas Stochastic Frontier. The result reveals that 1 land use, quantity of seed, K fertilizer contributed significantly increasing melon production, while N fertilizer decreased melon production significantly 2 technical efficiency indeces ranged from 0.40 to 0.99, with a mean of  0.77; 3 farmer’s experience gave significant influence to technical efficiency of melon farming in wet season.

Study of the La-related dipole in TiN/LaO{sub x}/HfSiON/SiON/Si gate stacks using hard X-ray photoelectron spectroscopy and backside medium energy ion scattering

Energy Technology Data Exchange (ETDEWEB)

Boujamaa, R. [STMicroelectronics, 850, rue Jean Monnet, 38926 Crolles (France); CEA-LETI, MINATEC Campus, F38054 Grenoble (France); Laboratoire des Matériaux et du Génie Physique, CNRS, Grenoble INP, 3 parvis L. Néel, BP 257, 38016 Grenoble (France); Martinez, E.; Pierre, F.; Renault, O. [CEA-LETI, MINATEC Campus, F38054 Grenoble (France); Detlefs, B.; Zegenhagen, J. [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, F-38000 Grenoble (France); Baudot, S. [STMicroelectronics, 850, rue Jean Monnet, 38926 Crolles (France); Gros-Jean, M., E-mail: Mickael.Gros-Jean@st.com [STMicroelectronics, 850, rue Jean Monnet, 38926 Crolles (France); Bertin, F. [STMicroelectronics, 850, rue Jean Monnet, 38926 Crolles (France); Dubourdieu, C., E-mail: Catherine.Dubourdieu@ec-lyon.fr [Institut des Nanotechnologies de Lyon, CNRS, Ecole Centrale de Lyon, 36 avenue Guy de Collongue, 69134 Ecully (France)

2015-04-30

Highlights: • Precise La depth distribution in gate stacks before and after annealing by MEIS. • Analysis by HAXPES of the buried high K/SiO{sub 2} interface without removing TiN gate. • Formation of La-silicate at the HfSiON/SiON interface. • Internal electrical field induced at the HfSiON/SiON interface by the La diffusion. • Increase of electric field strength with initial LaO{sub x} thickness. - Abstract: In this paper, we report the effect of high temperature annealing on the chemical and electronic structure of technologically relevant TiN/LaO{sub x}/HfSiON/SiON/Si gate stacks. Using medium energy ion scattering from the backside of the samples, a non-destructive compositional depth profile of La has been obtained, revealing the lanthanum diffusion in the SiON interface layer upon annealing. To complement this analysis, hard X-ray photoelectron spectroscopy with synchrotron radiation has been performed to investigate the chemical and electronic structure of the gate stacks. The results show clear changes in the Hf and Ti core level energy positions with respect to Si bulk, with changes in the thickness of the LaO{sub x} capping layer. We infer that La diffusion generates an internal electrical field at the La-silicate interface between HfSiON and SiON, and that its strength increases with the increase of LaO{sub x} thickness. These findings support the band alignment model based on a La-induced interfacial dipole.

Characteristics of wet work in the cleaning industry

NARCIS (Netherlands)

Jungbauer, F H W; Van Der Harst, J J; Schuttelaar, M L; Groothoff, J W; Coenraads, P J

Wet work is the main cause of occupational contact dermatitis in the cleaning industry. Dermatologists and occupational physicians need to base their primary and secondary prevention for workers in the cleaning industry on the characteristics of wet work exposures. We quantified the burden of wet

Electrochemical migration, whisker formation, and corrosion behavior of printed circuit board under wet H2S environment

International Nuclear Information System (INIS)

Zou, Shiwen; Li, Xiaogang; Dong, Chaofang; Ding, Kangkang; Xiao, Kui

2013-01-01

Highlights: •The electrochemical migration, whisker formation, and corrosion behavior of PCB under wet H 2 S environment were observed and studied systematically. •The process of electrochemical migration of solder joints is explained. •The corrosion mechanism of PCB interconnectors induced by micro pores under wet H 2 S environment is discussed, and the corrosion reaction model is proposed. -- Abstract: Electrochemical migration, whisker formation, and corrosion behavior of printed circuit board (PCB) under wet H 2 S environment were analyzed by environment scanning electron microscope (ESEM), Energy dispersive X-ray spectroscopy (EDS) with mapping and element phase cluster (EPC) techniques, Raman Spectrum analysis and electrochemical impedance spectroscopy (EIS) technology. The results showed that nonuniform corrosion behavior occurred on PCB surfaces under 1 ppm wet H 2 S at 40 °C; whiskers formed on the inner sidewall of via-holes with a growth rate of 1.2 Å/s; numerous corrosion products migrated through the pore of plated gold layer, which broke off the protective layer. The corrosion rate was accelerated according to the big-cathode-small-anode model

Leaf Wetness within a Lily Canopy

NARCIS (Netherlands)

Jacobs, A.F.G.; Heusinkveld, B.G.; Klok, E.J.

2005-01-01

A wetness duration experiment was carried out within a lily field situated adjacent to coastal dunes in the Netherlands. A within-canopy model was applied to simulate leaf wetness in three layers, with equal leaf area indices, within the canopy. This simulation model is an extension of an existing

7 CFR 29.2316 - Wet (W).

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.2316 Section 29.2316 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Official Standard Grades for Virginia Fire-Cured Tobacco (u.s. Type 21) § 29.2316 Wet (W...

7 CFR 29.3077 - Wet (W).

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.3077 Section 29.3077 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Wet (W). Any sound tobacco containing excessive moisture to the extent that it is in an unsafe or...

Advanced methods for the treatment of organic aqueous wastes: wet air oxidation and wet peroxide oxidation

Energy Technology Data Exchange (ETDEWEB)

Debellefontaine, Hubert; Chakchouk, Mehrez; Foussard, Jean Noel [Institut National des Sciences Appliquees (INSA), 31 - Toulouse (France). Dept. de Genie des Procedes Industriels; Tissot, Daniel; Striolo, Phillipe [IDE Environnement S.A., Toulouse (France)

1994-12-31

There is a growing concern about the problems of wastes elimination. Various oxidation techniques are suited for elimination of organic aqueous wastes, however, because of the environmental drawbacks of incineration, liquid phase oxidation should be preferred. `Wet Air Oxidation` and `Wet Peroxide Oxidation`are alternative processes which are discussed in this paper. 17 refs., 13 figs., 4 tabs.

Advanced methods for the treatment of organic aqueous wastes: wet air oxidation and wet peroxide oxidation

Energy Technology Data Exchange (ETDEWEB)

Debellefontaine, Hubert; Chakchouk, Mehrez; Foussard, Jean Noel [Institut National des Sciences Appliquees (INSA), 31 - Toulouse (France). Dept. de Genie des Procedes Industriels; Tissot, Daniel; Striolo, Phillipe [IDE Environnement S.A., Toulouse (France)

1993-12-31

There is a growing concern about the problems of wastes elimination. Various oxidation techniques are suited for elimination of organic aqueous wastes, however, because of the environmental drawbacks of incineration, liquid phase oxidation should be preferred. `Wet Air Oxidation` and `Wet Peroxide Oxidation`are alternative processes which are discussed in this paper. 17 refs., 13 figs., 4 tabs.

Advance of Wetting Front in Silt Loam Soil

Directory of Open Access Journals (Sweden)

Mohamed Mahmood

2013-04-01

Full Text Available Under drip irrigation , the plant's root is concentrated inside the wetted bulb (region. Thus, the development of these roots and the plant production are greatly affected by the wetting pattern. Therefore, the wetting pattern of soil under drip irrigation must be taken into consideration in the design of drip irrigation system for both single dripping source or multi-overlapping wetting patterns of dripping water sources.2The aim of this study is to evaluate the effect of initial water content of the soil and spacing between two adjacent dripping sources with different flow rate on the movement of the wetting front.This study included 16 tests for monitoring the advancement of the wetting front with time during and after the water application phase. The water advance and water distribution measurement are carried out for two cases of the soil profile: for the first case with initial volumetric water content of 4.08% and for the second case with initial volumetric water content of 12.24%. Two spacing between the emitter were tested 25cm and 50 cm using application flow rates of 0.606, 1.212, 1.818, and 2.424 cm3 /min/cm to show the combined effect of spacing and flow rate on the performance of two adjacent emitter.The study proposed a method for determining the spacing between the two emitting sources , the water application rate and watering time. The proposed method depends on a wetted zone whose depth is equal to the root zone depth with a values equals to the maximum vertical advance of the wetting front underneath the drip line at time when this depth is equal to the depth of wetting at mid­point between the drip line. the study revealed that both the vertical water advance in soil underneath the emitter and the horizontal advance of the wetting front is larger than those in the case of single emitter.Furthermore, the vertical water advance increases with the decrease spacing between the two drip lines. Also, the horizontal advance of the

Andreas Acrivos Dissertation Award: Onset of Dynamic Wetting Failure - The Mechanics of High-Speed Fluid Displacement

Science.gov (United States)

Vandre, Eric

2014-11-01

Dynamic wetting is crucial to processes where a liquid displaces another fluid along a solid surface, such as the deposition of a coating liquid onto a moving substrate. Dynamic wetting fails when process speed exceeds some critical value, leading to incomplete fluid displacement and transient phenomena that impact a variety of applications, such as microfluidic devices, oil-recovery systems, and splashing droplets. Liquid coating processes are particularly sensitive to wetting failure, which can induce air entrainment and other catastrophic coating defects. Despite the industrial incentives for careful control of wetting behavior, the hydrodynamic factors that influence the transition to wetting failure remain poorly understood from empirical and theoretical perspectives. This work investigates the fundamentals of wetting failure in a variety of systems that are relevant to industrial coating flows. A hydrodynamic model is developed where an advancing fluid displaces a receding fluid along a smooth, moving substrate. Numerical solutions predict the onset of wetting failure at a critical substrate speed, which coincides with a turning point in the steady-state solution path for a given set of system parameters. Flow-field analysis reveals a physical mechanism where wetting failure results when capillary forces can no longer support the pressure gradients necessary to steadily displace the receding fluid. Novel experimental systems are used to measure the substrate speeds and meniscus shapes associated with the onset of air entrainment during wetting failure. Using high-speed visualization techniques, air entrainment is identified by the elongation of triangular air films with system-dependent size. Air films become unstable to thickness perturbations and ultimately rupture, leading to the entrainment of air bubbles. Meniscus confinement in a narrow gap between the substrate and a stationary plate is shown to delay air entrainment to higher speeds for a variety of

7 CFR 29.2570 - Wet (W).

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.2570 Section 29.2570 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2570 Wet (W). Any sound tobacco containing...

7 CFR 29.3567 - Wet (W).

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.3567 Section 29.3567 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 95) § 29.3567 Wet (W). Any sound tobacco containing excessive moisture to the extent that it is in...

7 CFR 29.1083 - Wet (W).

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Wet (W). 29.1083 Section 29.1083 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1083 Wet (W). Any sound tobacco containing excessive moisture to the extent that it is in...

Design considerations for wet flue gas desulfurization systems - wet scrubber hardware issues

Energy Technology Data Exchange (ETDEWEB)

Hurwitz, H.

1994-12-31

About 20 years ago the first wet flue gas desulfurization systems installed on coal fired utility boilers in the United States were experiencing extreme operating problems. In addition to their failure to achieve the necessary SO{sub 2} removal efficiencies, these FGD systems required a major investment in maintenance, both material and labor, just to remain operational. These first generation systems demonstrated that a lack of understanding of the chemistry and operating conditions of wet flue gas desulfurization can lead to diastrous results. As the air pollution control industry developed, both in the United States and in Japan, a second generation of FGD systems was introduced. These designs incorporated major improvements in both system chemistry control and in the equipment utilized in the process. Indeed, the successful introduction of utility gas desulfurization systems in Germany was possible only through the transfer of the technology improvements developed in the US and in Japan. Today, technology has evolved to a third generation of wet flue gas desulfurication systems and these systems are now offered worldwide through a series of international licensing agreements. The rapid economic growth and development in Asia and the Pacific Rim combined with existing problems in ambient air quality in these same geographic areas, has resulted in the use of advanced air pollution control systems; including flue gas desulfurization both for new utility units and for many retrofit projects. To meet the requirements of the utility industry, FGD systems must meet high standards of reliability, operability and performance. Key components in achieving these objectives are: FGD System reliability/operability/performance; FGD system supplier qualifications; process design; equipment selection. This paper will discuss each of the essential factors with a concentration on the equipment selection and wet scrubber hardware issues.

Model determination and validation for reactive wetting processes

Energy Technology Data Exchange (ETDEWEB)

Yost, F.G.; O`Toole, E.J.; Sackinger, P.A. [Sandia National Labs., Albuquerque, NM (United States); Swiler, T.P. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Chemical and Nuclear Engineering

1998-01-01

It is shown that dissolutive wetting initially yields a metastable equilibrium. A compact model for the kinetics of approach to this metastable state is described. The technique for constructing these kinetics stems from the early work of Onsager and begins with a relationship for the entropy production. From this, a coupled set of nonlinear, ordinary differential equations can be written directly. The equations are solved numerically for the wetted area and compared with experimental data. The model captures many of the subtle complexities of dissolutive wetting such as multiple metastable states. Sessile drop experiments involving a variety of Bi-Sn alloys on solid Bi substrates were performed. Substrates prepared from small and large-grained polycrystals and single crystals were used to measure equilibrium and metastable contact angles and estimate the surface tension and equilibrium contact angle of the solid-liquid interface. The substrates were also used to investigate the coupling of the dissolution and wetting processes and to investigate the effect of substrate grain size on wetting. It was determined that the equilibrium wetting geometry is independent of linear scale and that grain size has little influence on wetting or dissolution in the Bi-Sn system. To investigate the atomic behavior of liquids at interfaces during wetting, the authors simulated wetting in the Ag-Cu system using molecular dynamics with atomic potentials and observed both atomic dynamics and structural correlations of the liquid-solid interface. The authors found that spreading is prompted by interactions between the liquid and the substrate surface that cause the liquid layer in contact with the substrate to take on some of the symmetry of the substrate surface and result in the formation of a liquid monolayer that extends beyond the major part of the liquid droplet.

Wet in situ transesterification of spent coffee grounds with supercritical methanol for the production of biodiesel.

Science.gov (United States)

Son, Jeesung; Kim, Bora; Park, Jeongseok; Yang, Jeongwoo; Lee, Jae W

2018-07-01

This work introduces biodiesel production from wet spent coffee grounds (SCGs) with supercritical methanol without any pre-drying process. Supercritical methanol and subcritical water effectively produced biodiesel via in situ transesterification by inducing more porous SCG and enhancing the efficiency of lipid extraction and conversion. It was also found that space loading was one of the critical factors for biodiesel production. An optimal biodiesel yield of 10.17 wt% of dry SCG mass (86.33 w/w% of esterifiable lipids in SCG) was obtained at reaction conditions of 270 °C, 90 bars, methanol to wet SCG ratio 5:1, space loading 58.4 ml/g and reaction time 20 min. Direct use of wet SCG waste as feedstock for supercritical biodiesel production eliminates the conventional dying process and the need of catalyst and also reduces environmental problems caused by landfill accumulation. Copyright © 2018 Elsevier Ltd. All rights reserved.

Mechanisms of wet oxidation by hydrogen peroxide

International Nuclear Information System (INIS)

Baxter, R.A.

1987-08-01

A research programme is currently under way at BNL and MEL to investigate the possible use of Hydrogen Peroxide with metal ion catalysts as a wet oxidation treatment system for CEGB organic radioactive wastes. The published literature relating to the kinetics and mechanism of oxidation and decomposition reactions of hydrogen peroxide is reviewed and the links with practical waste management by wet oxidation are examined. Alternative wet oxidation systems are described and the similarities to the CEGB research effort are noted. (author)

Human skin wetness perception: psychophysical and neurophysiological bases

Science.gov (United States)

Filingeri, Davide; Havenith, George

2015-01-01

The ability to perceive thermal changes in the surrounding environment is critical for survival. However, sensing temperature is not the only factor among the cutaneous sensations to contribute to thermoregulatory responses in humans. Sensing skin wetness (i.e. hygrosensation) is also critical both for behavioral and autonomic adaptations. Although much has been done to define the biophysical role of skin wetness in contributing to thermal homeostasis, little is known on the neurophysiological mechanisms underpinning the ability to sense skin wetness. Humans are not provided with skin humidity receptors (i.e., hygroreceptors) and psychophysical studies have identified potential sensory cues (i.e. thermal and mechanosensory) which could contribute to sensing wetness. Recently, a neurophysiological model of human wetness sensitivity has been developed. In helping clarifying the peripheral and central neural mechanisms involved in sensing skin wetness, this model has provided evidence for the existence of a specific human hygrosensation strategy, which is underpinned by perceptual learning via sensory experience. Remarkably, this strategy seems to be shared by other hygroreceptor-lacking animals. However, questions remain on whether these sensory mechanisms are underpinned by specific neuromolecular pathways in humans. Although the first study on human wetness perception dates back to more than 100 years, it is surprising that the neurophysiological bases of such an important sensory feature have only recently started to be unveiled. Hence, to provide an overview of the current knowledge on human hygrosensation, along with potential directions for future research, this review will examine the psychophysical and neurophysiological bases of human skin wetness perception. PMID:27227008

Wetting transitions: A functional renormalization-group approach

International Nuclear Information System (INIS)

Fisher, D.S.; Huse, D.A.

1985-01-01

A linear functional renormalization group is introduced as a framework in which to treat various wetting transitions of films on substrates. A unified treatment of the wetting transition in three dimensions with short-range interactions is given. The results of Brezin, Halperin, and Leibler in their three different regimes are reproduced along with new results on the multicritical behavior connecting the various regimes. In addition, the critical behavior as the coexistence curve is approached at complete wetting is analyzed. Wetting in the presence of long-range substrate-film interactions that fall off as power laws is also studied. The possible effects of the nonlinear terms in the renormalization group are examined briefly and it appears that they do not alter the critical behavior found using the truncated linear renormalization group

Nonlocality and short-range wetting phenomena.

Science.gov (United States)

Parry, A O; Romero-Enrique, J M; Lazarides, A

2004-08-20

We propose a nonlocal interfacial model for 3D short-range wetting at planar and nonplanar walls. The model is characterized by a binding-potential functional depending only on the bulk Ornstein-Zernike correlation function, which arises from different classes of tubelike fluctuations that connect the interface and the substrate. The theory provides a physical explanation for the origin of the effective position-dependent stiffness and binding potential in approximate local theories and also obeys the necessary classical wedge covariance relationship between wetting and wedge filling. Renormalization group and computer simulation studies reveal the strong nonperturbative influence of nonlocality at critical wetting, throwing light on long-standing theoretical problems regarding the order of the phase transition.

Nonlocality and Short-Range Wetting Phenomena

Science.gov (United States)

Parry, A. O.; Romero-Enrique, J. M.; Lazarides, A.

2004-08-01

We propose a nonlocal interfacial model for 3D short-range wetting at planar and nonplanar walls. The model is characterized by a binding-potential functional depending only on the bulk Ornstein-Zernike correlation function, which arises from different classes of tubelike fluctuations that connect the interface and the substrate. The theory provides a physical explanation for the origin of the effective position-dependent stiffness and binding potential in approximate local theories and also obeys the necessary classical wedge covariance relationship between wetting and wedge filling. Renormalization group and computer simulation studies reveal the strong nonperturbative influence of nonlocality at critical wetting, throwing light on long-standing theoretical problems regarding the order of the phase transition.

Surface changes of biopolymers PHB and PLLA induced by Ar{sup +} plasma treatment and wet etching

Energy Technology Data Exchange (ETDEWEB)

Slepičková Kasálková, N. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Slepička, P., E-mail: petr.slepicka@vscht.cz [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Sajdl, P. [Department of Power Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Švorčík, V. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic)

2014-08-01

Polymers, especially group of biopolymers find potential application in a wide range of disciplines due to their biodegradability. In biomedical applications these materials can be used as a scaffold or matrix. In this work, the influence of the Ar{sup +} plasma treatment and subsequent wet etching (acetone/water) on the surface properties of polymers were studied. Two biopolymers – polyhydroxybutyrate with 8% polyhydroxyvalerate (PHB) and poly-L-lactic acid (PLLA) were used in these experiments. Modified surface layers were analyzed by different methods. Surface wettability was characterized by determination of water contact angle. Changes in elemental composition of modified surfaces were performed by X-ray Photoelectron Spectroscopy (XPS). Surface morphology and roughness was examined using Atomic Force Microscopy (AFM). Gravimetry method was used to study the mass loss. It was found that the modification from both with plasma and wet etching leads to dramatic changes of surface properties (surface chemistry, morphology and roughness). Rate of changes of these features strongly depends on the modification parameters.

Dynamic Wetting Behavior of Vibrated Droplets on a Micropillared Surface

Directory of Open Access Journals (Sweden)

Zhi-hai Jia

2016-01-01

Full Text Available The dynamical wetting behavior has been observed under vertical vibration of a water droplet placed on a micropillared surface. The wetting transition takes place under the different processes. In compression process, the droplet is transited from Cassie state to Wenzel state. The droplet undergoes a Wenzel-Cassie wetting transition in restoring process and the droplet bounces off from the surface in bouncing process. Meanwhile, the wetting and dewetting models during vibration are proposed. The wetting transition is confirmed by the model calculation. This study has potential to be used to control the wetting state.

Solder wetting behavior enhancement via laser-textured surface microcosmic topography

Energy Technology Data Exchange (ETDEWEB)

Chen, Haiyan [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072 (China); Shaanxi Key Laboratory of Friction Welding Technologies, Xi’an 710072 (China); Peng, Jianke [Shaanxi Key Laboratory of Friction Welding Technologies, Xi’an 710072 (China); Fu, Li, E-mail: fuli@nwpu.edu.cn [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072 (China); Shaanxi Key Laboratory of Friction Welding Technologies, Xi’an 710072 (China); Wang, Xincheng [Shaanxi Key Laboratory of Friction Welding Technologies, Xi’an 710072 (China); Xie, Yan [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China)

2016-04-15

Graphical abstract: - Highlights: • The wetting angle of lead free solder on Cu was reduced by surface microstructure. • The wetting form of Sn-Ag-Cu solder on Cu was “non-composite surface”. • The experimental results had a sound fit with the theoretical calculation. - Abstract: In order to reduce or even replace the use of Sn-Pb solder in electronics industry, the laser-textured surface microstructures were used to enhance the wetting behavior of lead free solder during soldering. According to wetting theory and Sn-Ag-Cu lead free solder performance, we calculated and designed four microcosmic structures with the similar shape and different sizes to control the wetting behavior of lead free solder. The micro-structured surfaces with different dimensions were processed on copper plates by fiber femtosecond laser, and the effect of microstructures on wetting behavior was verified experimentally. The results showed that the wetting angle of Sn-Ag-Cu solder on the copper plate with microstructures decreased effectively compared with that on the smooth copper plate. The wetting angles had a sound fit with the theoretical values calculated by wetting model. The novel method provided a feasible route for adjusting the wetting behavior of solders and optimizing solders system.

Solving the Controversy on the Wetting Transparency of Graphene.

Science.gov (United States)

Kim, Donggyu; Pugno, Nicola M; Buehler, Markus J; Ryu, Seunghwa

2015-10-26

Since its discovery, the wetting transparency of graphene, the transmission of the substrate wetting property over graphene coating, has gained significant attention due to its versatility for potential applications. Yet, there have been debates on the interpretation and validity of the wetting transparency. Here, we present a theory taking two previously disregarded factors into account and elucidate the origin of the partial wetting transparency. We show that the liquid bulk modulus is crucial to accurately calculate the van der Waals interactions between the liquid and the surface, and that various wetting states on rough surfaces must be considered to understand a wide range of contact angle measurements that cannot be fitted with a theory considering the flat surface. In addition, we reveal that the wetting characteristic of the substrate almost vanishes when covered by any coating as thick as graphene double layers. Our findings reveal a more complete picture of the wetting transparency of graphene as well as other atomically thin coatings, and can be applied to study various surface engineering problems requiring wettability-tuning.

Wetting properties of liquid lithium on lithium compounds

Energy Technology Data Exchange (ETDEWEB)

Krat, S.A., E-mail: stepan.krat@gmail.com [Center for Plasma Material Interactions, Department of Nuclear, Plasma, and Radiological Engineering, University Illinois at Urbana-Champaign, Urbana (United States); National Research Nuclear University MEPhI, Moscow (Russian Federation); Popkov, A.S. [Center for Plasma Material Interactions, Department of Nuclear, Plasma, and Radiological Engineering, University Illinois at Urbana-Champaign, Urbana (United States); National Research Nuclear University MEPhI, Moscow (Russian Federation); Gasparyan, Yu. M.; Pisarev, A.A. [National Research Nuclear University MEPhI, Moscow (Russian Federation); Fiflis, Peter; Szott, Matthew; Christenson, Michael; Kalathiparambil, Kishor; Ruzic, David N. [Center for Plasma Material Interactions, Department of Nuclear, Plasma, and Radiological Engineering, University Illinois at Urbana-Champaign, Urbana (United States)

2017-04-15

Highlights: • Contact angles of liquid lithium and Li{sub 3}N, Li{sub 2}O, Li{sub 2}CO{sub 3} were measured. • Liquid lithium wets lithium compounds at relatively low temperatures: Li{sub 3}N at 257 °C, Li{sub 2}O at 259 °C, Li{sub 2}CO{sub 3} at 323 °C. • Li wets Li{sub 2}O and Li{sub 3}N better than previously measured fusion-relevant materials (W, Mo, Ta, TZM, stainless steel). • Li wets Li{sub 2}CO{sub 3} better than most previously measured fusion-relevant materials (W, Mo, Ta). - Abstract: Liquid metal plasma facing components (LMPFC) have shown a potential to supplant solid plasma facing components materials in the high heat flux regions of magnetic confinement fusion reactors due to the reduction or elimination of concerns over melting, wall damage, and erosion. To design a workable LMPFC, one must understand how liquid metal interacts with solid underlying structures. Wetting is an important factor in such interaction, several designs of LMPFC require liquid metal to wet the underlying solid structures. The wetting of lithium compounds (lithium nitride, oxide, and carbonate) by 200 °C liquid lithium at various surface temperature from 230 to 330 °C was studied by means of contact angle measurements. Wetting temperatures, defined as the temperature above which the contact angle is less than 90°, were measured. The wetting temperature was 257 °C for nitride, 259 °C for oxide, and 323 °C for carbonate. Surface tensions of solid lithium compounds were calculated from the contact angle measurements.

Wetting-dewetting films: the role of structural forces.

Science.gov (United States)

Nikolov, Alex; Wasan, Darsh

2014-04-01

The liquid wetting and dewetting of solids are ubiquitous phenomena that occur in everyday life. Understanding the nature of these phenomena is beneficial for research and technological applications. However, despite their importance, the phenomena are still not well understood because of the nature of the substrate's surface energy non-ideality and dynamics. This paper illustrates the mechanisms and applications of liquid wetting and dewetting on hydrophilic and hydrophobic substrates. We discuss the classical understanding and application of wetting and film stability criteria based on the Frumkin-Derjaguin disjoining pressure model. The roles of the film critical thickness and capillary pressure on the film instability based on the disjoining pressure isotherm are elucidated, as are the criteria for stable and unstable wet films. We consider the film area in the model for the film stability and the applicable experiments. This paper also addresses the two classic film instability mechanisms for suspended liquid films based on the conditions of the free energy criteria originally proposed by de Vries (nucleation hole formation) and Vrij-Scheludko (capillary waves vs. van der Waals forces) that were later adapted to explain dewetting. We include a discussion of the mechanisms of nanofilm wetting and dewetting on a solid substrate based on nanoparticles' tendency to form a 2D layer and 2D inlayer in the film under the wetting film's surface confinement. We also present our view on the future of wetting-dewetting modeling and its applications in developing emerging technologies. We believe the review and analysis presented here will benefit the current and future understanding of the wetting-dewetting phenomena, as well as aid in the development of novel products and technologies. © 2013.

Wet granular matter a truly complex fluid

CERN Document Server

Herminghaus, Stephan

2013-01-01

This is a monograph written for the young and advanced researcher who is entering the field of wet granular matter and keen to understand the basic physical principles governing this state of soft matter. It treats wet granulates as an instance of a ternary system, consisting of the grains, a primary, and a secondary fluid. After addressing wetting phenomena in general and outlining the basic facts on dry granular systems, a chapter on basic mechanisms and their effects is dedicated to every region of the ternary phase diagram. Effects of grain shape and roughness are considered as well. Rather than addressing engineering aspects such as existing books on this topic do, the book aims to provide a generalized framework suitable for those who want to understand these systems on a more fundamental basis. Readership: For the young and advanced researcher entering the field of wet granular matter.

Verification of wet blasting decontamination technology

International Nuclear Information System (INIS)

Matsubara, Sachito; Murayama, Kazunari; Yoshida, Hirohisa; Igei, Shigemitsu; Izumida, Tatsuo

2013-01-01

Macoho Co., Ltd. participated in the projects of 'Decontamination Verification Test FY 2011 by the Ministry of the Environment' and 'Decontamination Verification Test FY 2011 by the Cabinet Office.' And we tested verification to use a wet blasting technology for decontamination of rubble and roads contaminated by the accident of Fukushima Daiichi Nuclear Power Plant of the Tokyo Electric Power Company. As a results of the verification test, the wet blasting decontamination technology showed that a decontamination rate became 60-80% for concrete paving, interlocking, dense-grated asphalt pavement when applied to the decontamination of the road. When it was applied to rubble decontamination, a decontamination rate was 50-60% for gravel and approximately 90% for concrete and wood. It was thought that Cs-134 and Cs-137 attached to the fine sludge scraped off from a decontamination object and the sludge was found to be separated from abrasives by wet cyclene classification: the activity concentration of the abrasives is 1/30 or less than the sludge. The result shows that the abrasives can be reused without problems when the wet blasting decontamination technology is used. (author)

Leaf wetness distribution within a potato crop

Science.gov (United States)

Heusinkveld, B. G.

2010-07-01

The Netherlands has a mild maritime climate and therefore the major interest in leaf wetness is associated with foliar plant diseases. During moist micrometeorological conditions (i.e. dew, fog, rain), foliar fungal diseases may develop quickly and thereby destroy a crop quickly. Potato crop monocultures covering several hectares are especially vulnerable to such diseases. Therefore understanding and predicting leaf wetness in potato crops is crucial in crop disease control strategies. A field experiment was carried out in a large homogeneous potato crop in the Netherlands during the growing season of 2008. Two innovative sensor networks were installed as a 3 by 3 grid at 3 heights covering an area of about 2 hectares within two larger potato crops. One crop was located on a sandy soil and one crop on a sandy peat soil. In most cases leaf wetting starts in the top layer and then progresses downward. Leaf drying takes place in the same order after sunrise. A canopy dew simulation model was applied to simulate spatial leaf wetness distribution. The dew model is based on an energy balance model. The model can be run using information on the above-canopy wind speed, air temperature, humidity, net radiation and within canopy air temperature, humidity and soil moisture content and temperature conditions. Rainfall was accounted for by applying an interception model. The results of the dew model agreed well with the leaf wetness sensors if all local conditions were considered. The measurements show that the spatial correlation of leaf wetness decreases downward.

Nuclear turbine efficiency improvement by wet steam study

International Nuclear Information System (INIS)

Nishikawa, Tsuyoshi; Morson, A.; Markytan, R.

2000-01-01

Most of the turbine used at the nuclear power plant are operated at environment of wet steam, which composes of a big factor of its inner loss in comparison with those of the thermal power plant. If an analytical method predictable on behavior of the wet steam is established, it could be upgraded efficiency of the turbine and also reliability against corrosion formed by moisture. This study, therefore, aims at understanding of physical property of the wet steam flow scarcely known at present, development of an optimum turbine cascade design tool reflected by the property, development of a turbine cascade design reducible of steam loss due to wet steam by using the tool, and development on a method of removing moisture in the turbine to its outer portion. For the tool, a new three dimensional flow numerical analysis is necessary to be developed, to aim at accurately and numerically understanding of the behavior of wet steam. As this study is in advancing now, by using a turbine cascade optimized on the wet steam flow and a developed moisture removing apparatus, about 0.6 % of upgrading in turbine efficiency can be predicted in comparison with that of the advanced aero-cascade of the GE Corporation. (G.K.)

Development of Wet Noodles Based on Cassava Flour

Directory of Open Access Journals (Sweden)

Akhmad Z. Abidin

2013-04-01

Full Text Available Cassava is one of Indonesia’s original commodities and contains good nutrition and has high productivity and a relatively low price. Cassava flour has a high potential as a substitute for imported wheat flour that is widely used in noodle production. The main purpose of this research was to develop wet noodles from cassava flour that can compete with wet noodles from wheat flour. The research consisted of experiments with several variations of composition and production method for producing cassava flour-based wet noodles. The best result was then examined for its nutritional value, economical value, and market response, and also a comparison was made between the prepared wet noodles and the standard noodles made from wheat flour. The analysis was based on five characteristics: taste, texture, chewiness, aroma, and appearance. Relations between these characteristics with composition, materials used, and methods applied are discussed. The developed cassava flour-based wet noodle meets physical, nutritional, and economical standards. Raw materials of the noodle were cassava flour and a wheat flour composite with a 5:1 ratio, egg, gluten, soda-ash, water, and vegetable oil, while the process was completed in multiple stages. Market response showed that the cassava flour-based wet noodles were 80% similar to wheat-flour noodles.

A new remote optical wetness sensor and its applications

NARCIS (Netherlands)

Heusinkveld, B.G.; Berkowicz, S.M.; Jacobs, A.F.G.; Hillen, W.C.A.M.; Holtslag, A.A.M.

2008-01-01

An optical wetness sensor (OWS) was developed for continuous surface wetness measurements. The sensor is an all-weather instrument that does not interfere with the surface wetting and drying process and is unaffected by solar radiation. It is equipped with its own light source with which it can scan

Wetting Transition and Line Tension of Oil on Water

Science.gov (United States)

Matsubara, H.; Aratono, M.

Wetting has attracted wide attention in the field of applied chemistry because of its crucial importance in industrial operations such as coating, painting, and lubrication. Here, we summarize our fundamental understandings of surfactant-assisted wetting transitions which we have found and studied for the last ten years. The difference between the surfactant-assisted wetting transitions and existing ones is discussed. Moreover, the relation between wetting transitions and the stability of the three-phase contact line is examined in terms of the line tension of oil lenses.

Sn-based Ge/Ge{sub 0.975}Sn{sub 0.025}/Ge p-i-n photodetector operated with back-side illumination

Energy Technology Data Exchange (ETDEWEB)

Chang, C.; Li, H.; Huang, S. H.; Cheng, H. H., E-mail: hhcheng@ntu.edu.tw [Center for Condensed Matter Sciences and Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 106, Taiwan (China); Sun, G.; Soref, R. A. [Department of Engineering, University of Massachusetts Boston, Boston, Massachusetts 02125 (United States)

2016-04-11

We report an investigation of a GeSn-based p-i-n photodetector grown on a Ge wafer that collects light signal from the back of the wafer. Temperature dependent absorption measurements performed over a wide temperature range (300 K down to 25 K) show that (a) absorption starts at the indirect bandgap of the active GeSn layer and continues up to the direct bandgap of the Ge wafer, and (b) the peak responsivity increases rapidly at first with decreasing temperature, then increases more slowly, followed by a decrease at the lower temperatures. The maximum responsivity happens at 125 K, which can easily be achieved with the use of liquid nitrogen. The temperature dependence of the photocurrent is analyzed by taking into consideration of the temperature dependence of the electron and hole mobility in the active layer, and the analysis result is in reasonable agreement with the data in the temperature regime where the rapid increase occurs. This investigation demonstrates the feasibility of a GeSn-based photodiode that can be operated with back-side illumination for applications in image sensing systems.

Using magnetic seeds to improve the aggregation and precipitation of nanoparticles from backside grinding wastewater.

Science.gov (United States)

Wan, Terng-Jou; Shen, Shu-Min; Siao, Sheng-Han; Huang, Chong-Fu; Cheng, Chiung-Yi

2011-12-01

Backside grinding (BG) wastewater treatment typically requires large quantities of chemicals, i.e. polyaluminum chloride (PAC) coagulant and produces considerable amounts of sludge, increasing the loading and cost of subsequent sludge treatment and disposal processes. This study investigated the effects of the addition of magnetic seeds (FeO*Fe(2)O(3)) of selected particle sizes and of optimized combinations of magnetic seeds and PAC on the aggregation of silica nanoparticles from BG wastewater and on the sedimentation time at various pH values. The results show that the turbidity of BG wastewater was significantly reduced by the magnetic aggregation treatment. The dosage of PAC combined with 2.49gL(-1) or 1.24gL(-1) of magnetic seeds was reduced by 83% (from 60 to 10mgL(-1)) compared to the conventional process of using only PAC as a coagulant. The turbidity of the BG wastewater, initially 1900-2500NTU, could also be successfully decreased about to 23NTU by the addition of 3.74gL(-1) magnetite (FeO*Fe(2)O(3)) only at pH 5 with an applied magnetic field of 1000G. Different coagulation conditions using magnetic seeds combined with coagulant resulted in different aggregation performances. The treatment performance was more effective by using two-stage dosing, in which magnetic seeds and PAC were added separately, than that with one-stage dosing, where the magnetic seeds and PAC were added simultaneously during rapid mixing. The two-stage dosing allowed for a reduction in the optimum dosage of magnetic seeds from 3.74gL(-1) to 2.49gL(-1) or 1.24gL(-1) without affecting performance when coupled with 0.01gL(-1) of PAC coagulant. The developed method effectively reduced the production of waste sludge. Copyright © 2011 Elsevier Ltd. All rights reserved.

Wet plume atop of the flattening slab: Insight into intraplate volcanism in East Asia

Science.gov (United States)

He, Lijuan

2017-08-01

Geophysical observations imply the intraplate volcanism in East Asia is related to dehydration of slab stagnating in the transition zone. To better understand the dynamics of such process, a thermochemical mantle convection model is constructed to simulate numerically the thermal evolution of slab and the transportation of water in the process of slab downgoing, flattening and stagnation. Equation of water transfer is included, and water effects on density and viscosity are considered. Model results indicate the warming of slab by surrounding mantle is rather slow. Water could be successfully dragged into the transition zone if the reference viscosity of the hydrous layer (with initial water of 2 wt%) is higher than 1017 Pa s and that of mantle is 1021 Pa s. Wet plumes could then originate in the flat-lying part of the slab, relatively far from the trench. Generally, the viscosity of the hydrous layer governs the initiation of wet plume, whereas the viscosity of the overlying mantle wedge controls the activity of the ascending wet plumes - they are more active in the weaker wedge. The complex fluid flow superposed by corner flow and free thermal convection influences greatly the water transport pattern in the upper mantle. Modeling results together with previous modeling infer three stages of water circulation in the big mantle wedge: 1) water is brought into the mantle transition zone by downward subducting slab under some specific thermo-rheological conditions, otherwise water is released at shallow depth near wedge tip; 2) wet plume generates from surface of the flattening slab warmed by surrounding mantle, and 3) water spreads over the big mantle wedge. Wet plume from the flattening Pacific Plate arrives at the lithospheric base and induces melting, which can explain the intraplate Cenozoic volcanoes in East Asia.

Curvature controlled wetting in two dimensions

DEFF Research Database (Denmark)

Gil, Tamir; Mikheev, Lev V.

1995-01-01

. As the radius of the substrate r0→∞, the leading effect of the curvature is adding the Laplace pressure ΠL∝r0-1 to the pressure balance in the film. At temperatures and pressures under which the wetting is complete in planar geometry, Laplace pressure suppresses divergence of the mean thickness of the wetting...... term reduces the thickness by the amount proportional to r0-1/3...

Wetting characteristics of 3-dimensional nanostructured fractal surfaces

Science.gov (United States)

Davis, Ethan; Liu, Ying; Jiang, Lijia; Lu, Yongfeng; Ndao, Sidy

2017-01-01

This article reports the fabrication and wetting characteristics of 3-dimensional nanostructured fractal surfaces (3DNFS). Three distinct 3DNFS surfaces, namely cubic, Romanesco broccoli, and sphereflake were fabricated using two-photon direct laser writing. Contact angle measurements were performed on the multiscale fractal surfaces to characterize their wetting properties. Average contact angles ranged from 66.8° for the smooth control surface to 0° for one of the fractal surfaces. The change in wetting behavior was attributed to modification of the interfacial surface properties due to the inclusion of 3-dimensional hierarchical fractal nanostructures. However, this behavior does not exactly obey existing surface wetting models in the literature. Potential applications for these types of surfaces in physical and biological sciences are also discussed.

Effect of wetting-drying cycles on soil desiccation cracking behaviour

Directory of Open Access Journals (Sweden)

Tang Chao-Sheng

2016-01-01

Full Text Available Better understanding the desiccation cracking process is essential in analysing drought effects on soil hydraulic and mechanical properties through consideration of the atmosphere-ground interaction. Laboratory tests were conducted to investigate the consequence of wetting-drying cycles on the initiation and propagation characteristics of desiccation cracks on soil surface. Initially saturated slurry specimens were prepared and subjected to five subsequent wetting-drying cycles. Image processing technique was employed to quantitatively analyze the morphology characteristics of crack patterns formed during each drying path. The results show that the desiccation cracking behaviour of soil is significantly affected by the wetting-drying cycles. Before the third wetting-drying cycle is reached, the surface crack ratio and the average crack width increases while the average clod area decreases with increasing the number of wetting-drying cycles. The number of intersections and crack segments per unit area reaches the peak values after the second wetting-drying cycle. After the third wetting-drying cycle is reached, the effect of increasing wetting-drying cycles on crack patterns is insignificant. Moreover, it is observed that the applied wetting-drying cycles are accompanied by a continual reconstruction of soil structure. The initial homogenous slurry structure is completely replaced with aggregated structure after the third cycles, and a significant increase in the inter-aggregate porosity can be observed.

Water wizards : reshaping wet nature and society

NARCIS (Netherlands)

Vleuten, van der E.B.A.; Disco, C.

2004-01-01

The article investigates how humans ‘networked’ wet nature and how this affected the shaping of Dutch society. First, it takes a grand view of Dutch history and describes how wet network building intertwined with the shaping of the Dutch landscape, its economy and its polity. Second, it investigates

Wet water glass production plant

Directory of Open Access Journals (Sweden)

Stanković Mirjana S.

2003-01-01

Full Text Available The IGPC Engineering Department designed basic projects for a wet hydrate dissolution plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects, a production plant of a capacity of 75,000 t/y was manufactured, at "Zeolite Mira", Mira (VE, Italy, in 1997. and 1998, increasing detergent zeolite production, from 50,000 to 100,000 t/y. Several goals were realized by designing a wet hydrate dissolution plant. The main goal was increasing the detergent zeolite production. The technological cycle of NaOH was closed, and no effluents emitted, and there is no pollution (except for the filter cake. The wet water glass production process is fully automatized, and the product has uniform quality. The production process can be controlled manually, which is necessary during start - up, and repairs. By installing additional process equipment (centrifugal pumps and heat exchangers technological bottlenecks were overcome, and by adjusting the operation of autoclaves, and water glass filters and also by optimizing the capacities of process equipment.

Can I Stop Myself From Having a Wet Dream? (For Teens)

Science.gov (United States)

... Can I Stop Myself From Having a Wet Dream? KidsHealth / For Teens / Can I Stop Myself From Having a Wet Dream? Print Can I stop myself from having a wet dream? – Tom* You really can't stop wet dreams, ...

A microstructure-composition map of a ternary liquid/liquid/particle system with partially-wetting particles.

Science.gov (United States)

Yang, Junyi; Roell, David; Echavarria, Martin; Velankar, Sachin S

2017-11-22

We examine the effect of composition on the morphology of a ternary mixture comprising two molten polymeric liquid phases (polyisobutylene and polyethylene oxide) and micron-scale spherical silica particles. The silica particles were treated with silanes to make them partially wetted by both polymers. Particle loadings up to 30 vol% are examined while varying the fluid phase ratios across a wide range. Numerous effects of particle addition are catalogued, stabilization of Pickering emulsions and of interfacially-jammed co-continuous microstructures, meniscus-bridging of particles, particle-induced coalescence of the dispersed phase, and significant shifts in the phase inversion composition. Many of the effects are asymmetric, for example particle-induced coalescence is more severe and drop sizes are larger when polyisobutylene is the continuous phase, and particles promote phase continuity of the polyethylene oxide. These asymmetries are likely attributable to a slight preferential wettability of the particles towards the polyethylene oxide. A state map is constructed which classifies the various microstructures within a triangular composition diagram. Comparisons are made between this diagram vs. a previous one constructed for the case when particles are fully-wetted by polyethylene oxide.

Visual wetness perception based on image color statistics.

Science.gov (United States)

Sawayama, Masataka; Adelson, Edward H; Nishida, Shin'ya

2017-05-01

Color vision provides humans and animals with the abilities to discriminate colors based on the wavelength composition of light and to determine the location and identity of objects of interest in cluttered scenes (e.g., ripe fruit among foliage). However, we argue that color vision can inform us about much more than color alone. Since a trichromatic image carries more information about the optical properties of a scene than a monochromatic image does, color can help us recognize complex material qualities. Here we show that human vision uses color statistics of an image for the perception of an ecologically important surface condition (i.e., wetness). Psychophysical experiments showed that overall enhancement of chromatic saturation, combined with a luminance tone change that increases the darkness and glossiness of the image, tended to make dry scenes look wetter. Theoretical analysis along with image analysis of real objects indicated that our image transformation, which we call the wetness enhancing transformation, is consistent with actual optical changes produced by surface wetting. Furthermore, we found that the wetness enhancing transformation operator was more effective for the images with many colors (large hue entropy) than for those with few colors (small hue entropy). The hue entropy may be used to separate surface wetness from other surface states having similar optical properties. While surface wetness and surface color might seem to be independent, there are higher order color statistics that can influence wetness judgments, in accord with the ecological statistics. The present findings indicate that the visual system uses color image statistics in an elegant way to help estimate the complex physical status of a scene.

Energy and heat balance in wet DCT

Energy Technology Data Exchange (ETDEWEB)

Saxena, Viren; Moser, Alexander; Schaefer, Michael; Ritschel, Michael [BorgWarner Drivetrain Engineering GmbH, Ketsch (Germany)

2012-11-01

Wet clutch systems are well known for their thermal robustness and versatility in a wide range of automotive applications. Conventional automatics have used them for a long time as torque converter lock-up clutches, shift elements and launch clutches. With the development of DCTs, wet clutch technology has evolved in terms of launch and shift performance, controllability, robustness and efficiency. This paper discusses improvements in the wet clutch and their impact on today's vehicle applications in terms of heat and energy management. Thermal robustness is a crucial aspect for an automatic transmission. In addition to the clutch thermal performance, the influence of transmission oil cooler and oil sump warm-up behavior are discussed. Based on our latest development activities, test results and simulations, we shall discuss the latest friction material enhancement and its impact on DCTs in terms of efficiency and performance. Drag loss is a much-discussed topic during the development of wet clutch systems. This paper discusses in detail the cause and break-up of various energy losses in a wet DCT. Efficient energy management strategies for actuation systems, cooling, and lubrication, clutch apply, and pre-selection in modern power trains with engine start / stop are evaluated based on the latest test and simulation results. Finally, the paper summarizes the performance and efficiency optimized moist clutch system. (orig.)

Low-resistivity photon-transparent window attached to photo-sensitive silicon detector

International Nuclear Information System (INIS)

Holland, S.E.

2000-01-01

The invention comprises a combination of a low resistivity, or electrically conducting, silicon layer that is transparent to long or short wavelength photons and is attached to the backside of a photon-sensitive layer of silicon, such as a silicon wafer or chip. The window is applied to photon sensitive silicon devices such as photodiodes, charge-coupled devices, active pixel sensors, low-energy x-ray sensors and other radiation detectors. The silicon window is applied to the back side of a photosensitive silicon wafer or chip so that photons can illuminate the device from the backside without interference from the circuit printed on the frontside. A voltage sufficient to fully deplete the high-resistivity photosensitive silicon volume of charge carriers is applied between the low-resistivity back window and the front, patterned, side of the device. This allows photon-induced charge created at the backside to reach the front side of the device and to be processed by any circuitry attached to the front side. Using the inventive combination, the photon sensitive silicon layer does not need to be thinned beyond standard fabrication methods in order to achieve full charge-depletion in the silicon volume. In one embodiment, the inventive backside window is applied to high resistivity silicon to allow backside illumination while maintaining charge isolation in CCD pixels

Engineering and economic evaluation of wet/dry cooling towers for water conservation

International Nuclear Information System (INIS)

Hu, M.C.

1976-11-01

The results are presented of a design and cost study for wet/dry tower systems used in conjunction with 1000 MWe nuclear power plants to reject waste heat while conserving water. Design and cost information for wet/dry tower systems are presented, and these cooling system alternatives are compared with wet and dry tower systems to determine whether the wet/dry tower concept is an economically viable alternative. The wet/dry cooling tower concept investigated is one which combines physically separated wet towers and dry towers into an operational unit. In designing the wet/dry tower, a dry cooling tower is sized to carry the plant heat load at low ambient temperatures, and a separate wet tower is added to augment the heat rejection of the dry tower at higher ambient temperatures. These wet/dry towers are designed to operate with a conventional low back pressure turbine commercially available today. The component wet and dry towers are state-of-the-art designs. From this study it was concluded that: wet/dry cooling systems can be designed to provide a significant economic advantage over dry cooling yet closely matching the dry tower's ability to conserve water, a wet/dry system which saves as much as 99 percent of the make-up water required by a wet tower can maintain that economic advantage, and therefore, for power plant sites where water is in short supply, wet/dry cooling is the economic choice over dry cooling

WetA bridges cellular and chemical development in Aspergillus flavus.

Directory of Open Access Journals (Sweden)

Ming-Yueh Wu

Full Text Available Bridging cellular reproduction and survival is essential for all life forms. Aspergillus fungi primarily reproduce by forming asexual spores called conidia, whose formation and maturation is governed by the central genetic regulatory circuit BrlA→AbaA→WetA. Here, we report that WetA is a multi-functional regulator that couples spore differentiation and survival, and governs proper chemical development in Aspergillus flavus. The deletion of wetA results in the formation of conidia with defective cell walls and no intra-cellular trehalose, leading to reduced stress tolerance, a rapid loss of viability, and disintegration of spores. WetA is also required for normal vegetative growth, hyphal branching, and production of aflatoxins. Targeted and genome-wide expression analyses reveal that WetA exerts feedback control of brlA and that 5,700 genes show altered mRNA levels in the mutant conidia. Functional category analyses of differentially expressed genes in ΔwetA RNA-seq data indicate that WetA contributes to spore integrity and maturity by properly regulating the metabolic pathways of trehalose, chitin, α-(1,3-glucan, β-(1,3-glucan, melanin, hydrophobins, and secondary metabolism more generally. Moreover, 160 genes predicted to encode transcription factors are differentially expressed by the absence of wetA, suggesting that WetA may play a global regulatory role in conidial development. Collectively, we present a comprehensive model for developmental control that bridges spore differentiation and survival in A. flavus.

Damage Features of Altered Rock Subjected to Drying-Wetting Cycles

Directory of Open Access Journals (Sweden)

Zhe Qin

2018-01-01

Full Text Available An abandoned open pit was used as a tailing pond for a concentrating mill, with the height of the water surface subject to cyclic fluctuation. The effects of drying and wetting cycles on the mechanical parameters of pit rock were tested. Interactions of the hydrochemical environment, due to the dissolution of tailings, and drying and wetting cycles caused degradation of mechanical properties in the rock. It was found that uniaxial compressive strength and elastic modulus decreased as the number of dry/wet cycles increased. The quantitative relationship between the mechanical parameters and the number of dry/wet cycles was indicated by an exponential function. In addition to uniaxial testing, cohesion and the internal friction angle were determined through triaxial testing. The shear strength index deteriorated under the drying and wetting cycles. The hydrochemical environment also negatively affected the mechanical parameters. Potential effects between drying and wetting cycles and slope displacement were analyzed by on-site monitoring. The results show that the displacement increased because of the drying and wetting cycles, which may lead to sudden failure of the slope.

Junction formation of CuInSe2 with CdS: A comparative study of 'dry' and 'wet' interfaces

International Nuclear Information System (INIS)

Hunger, R.; Lebedev, M.V.; Sakurai, K.; Schulmeyer, T.; Mayer, Th.; Klein, A.; Niki, S.; Jaegermann, W.

2007-01-01

The junction formation of polycrystalline CuInSe 2 absorbers (CIS) with thermally evaporated CdS was investigated by high-resolution synchrotron X-ray photoelectron spectroscopy. The chemistry and electronics of the interfaces of Cd partial electrolyte treated CIS ('wet' processed) and clean, decapped CIS ('dry' processed) were compared. A valence band offset of 0.96(10) eV was determined in both cases. The Cd(Se,OH) surface layer induced by the wet Cd partial electrolyte process does not significantly modify the band alignment at the CIS/CdS heterointerface from the 'dry', vacuum-processed CIS/CdS interface. During the stepwise interface formation the energy converting capability of the CIS/CdS heterojunction was assessed by in situ surface photovoltage measurements at room temperature. The evolution of the surface photovoltage significantly differs for the 'wet' and the 'dry' interfaces and is discussed in relation to the function in solar cell devices

Wetting, superhydrophobicity, and icephobicity in biomimetic composite materials

Science.gov (United States)

Hejazi, Vahid

Recent developments in nano- and bio-technology require new materials. Among these new classes of materials which have emerged in the recent years are biomimetic materials, which mimic structure and properties of materials found in living nature. There are a large number of biological objects including bacteria, animals and plants with properties of interest for engineers. Among these properties is the ability of the lotus leaf and other natural materials to repel water, which has inspired researchers to prepare similar surfaces. The Lotus effect involving roughness-induced superhydrophobicity is a way to design nonwetting, self-cleaning, omniphobic, icephobic, and antifouling surfaces. The range of actual and potential applications of superhydrophobic surfaces is diverse including optical, building and architecture, textiles, solar panels, lab-on-a-chip, microfluidic devices, and applications requiring antifouling from biological and organic contaminants. In this thesis, in chapter one, we introduce the general concepts and definitions regarding the wetting properties of the surfaces. In chapter two, we develop novel models and conduct experiments on wetting of composite materials. To design sustainable superhydrophobic metal matrix composite (MMC) surfaces, we suggest using hydrophobic reinforcement in the bulk of the material, rather than only at its surface. We experimentally study the wetting properties of graphite-reinforced Al- and Cu-based composites and conclude that the Cu-based MMCs have the potential to be used in the future for the applications where the wear-resistant superhydrophobicity is required. In chapter three, we introduce hydrophobic coating at the surface of concrete materials making them waterproof to prevent material failure, because concretes and ceramics cannot stop water from seeping through them and forming cracks. We create water-repellant concretes with CA close to 160o using superhydrophobic coating. In chapter four, experimental

Wetting in a Colloidal Liquid-Gas System

Science.gov (United States)

Wijting, W. K.; Besseling, N. A.; Stuart, M. A.

2003-05-01

We present first observations of wetting phenomena in depletion interaction driven, phase separated colloidal dispersions (coated silica cyclohexane-polydimethylsiloxane). The contact angle of the colloidal liquid-gas interface at a solid substrate (coated glass) was determined for a series of compositions. Upon approach to the critical point, a transition occurs from partial to complete wetting.

Wetting in a colloidal liquid-gas system

OpenAIRE

Wijting, W.K.; Besseling, N.A.M.; Cohen Stuart, M.A.

2003-01-01

We present first observations of wetting phenomena in depletion interaction driven, phase separated colloidal dispersions (coated silica-cyclohexane-polydimethylsiloxane). The contact angle of the colloidal liquid-gas interface at a solid substrate (coated glass) was determined for a series of compositions. Upon approach to the critical point, a transition occurs from partial to complete wetting.

Wetting behavior of mixtures of water and nonionic polyoxyethylene alcohol.

Science.gov (United States)

Wu, Chih-Kang; Chen, Li-Jen

2005-07-19

Five binary water + C4Ej mixtures, water + n-C4E0, water + 2-C4E0, water + iso-C4E0, water + n-C4E1, and water + iso-C4E1, were chosen to perform the surface/interfacial tension measurements over the experimental temperature range from 10 to 85 degrees C at the normal pressure by using a homemade pendent drop/bubble tensiometer. The symbol CiEj is the abbreviation of a nonionic polyoxyethylene alcohol CiH(2i+1)(OCH2CH2)jOH. The wetting behavior of the CiEj-rich phase at the interface separating gas and the aqueous phase is systematically examined according to the wetting coefficient resulting from the experimental data of surface/interfacial tensions measurements. For those systems with a lower critical solution temperature, for example, water + n-C6E2, water + n-C4E1, and water + iso-C4E1, a wetting transition from partial wetting to nonwetting is always observed when the system is brought to close to its lower critical solution temperature. On the other hand, to start with a partial wetting CiEj-rich phase, a wetting transition from partial wetting to complete wetting is always observed when the system is driven to approach its upper critical solution temperature. The effect of hydrophobicity of CiEj on the wetting behavior of the CiEj-rich phase at the interface separating gas and the aqueous phase was carefully investigated by using five sets of mixtures: (1) water + n-C4E0, water + n-C5E0, and water + n-C6E0; (2) water + 2-C4E0 and water + 2-C5E0; (3) water + 2-C4E0 and water + n-C4E0; (4) water + n-C4E1, water + n-C5E1, and water + n-C6E1; (5) water + n-C4E0 and water + n-C4E1. The CiEj-rich phase would tend to drive away from complete wetting (or nonwetting) to partial wetting with an increase in the hydrophobicity of CiEj in the binary water + CiEj system. All the wetting behavior observed in the water + CiEj mixtures is consistent with the prediction of the critical point wetting theory of Cahn.

Adsorption effect in non-reaction wetting: In-Ti on CaF2

International Nuclear Information System (INIS)

Glickman, E.; Fuks, D.; Frage, N.; Barzilai, S.; Froumin, N.

2012-01-01

The experiments show that the alloying liquid In with only (0.1-0.5) at% Ti dramatically reduces the equilibrium contact angle Θ ∞ formed by In on the surface of CaF 2 . The aim of this paper is to clarify whether this practically important and conceptually challenging effect can be explained solely by Ti adsorption at the F-terminated solid-liquid interface without resorting to any other Ti-induced effect. The combination of ab initio calculations and regular solution approximation was proposed for finding the binding energy, ΔE Ti of Ti adatom with the interface ''CaF 2 /liquid solutions In-Ti.'' With thus obtained ΔE Ti =1.16 eV, we calculated from the Shishkovsky isotherm the reduction in the solid-liquid interface energy, Δγ SL induced by Ti adsorption from liquid In with various Ti concentration, C. It was found that Δγ SL (C) dependence demonstrated close inverse correspondence with Θ ∞ (C) and that the theory fitted very well all available experimental data on the concentration and temperature dependence of Δγ SL . It was concluded that the Ti adsorption effect is large enough to account for the observed wetting improvement. The proposed multiscale modeling approach to the role of adsorption in wetting can be applied also to other nonreactive systems ''liquid metal-ceramics'' where the substrate determines the surface density of the adsorption sites for the active element. (orig.)

Radiofrequency ablation in the liver using two cooled-wet electrodes in the bipolar mode

International Nuclear Information System (INIS)

Han, Joon Koo; Lee, Jeong Min; Kim, Se Hyung; Lee, Jae Young; Park, Hee Sun; Eo, Hong; Choi, Byung Ihn

2005-01-01

The purpose of this study was to demonstrate the efficacy of bipolar radiofrequency ablation (RFA) using cooled-wet electrodes inducing coagulation in ex vivo bovine livers and in in vivo canine livers. In ex vivo experiments, 20 coagulations were created by monopolar (group A), and bipolar RFA (group B) using a 200 W generator (Valleylab) and one or two cooled-wet electrodes. In in vivo experiments, one coagulation was created by bipolar RFA in each of eight dogs via laparotomy. In ex vivo and in vivo experiments, RF was applied to one or two electrodes at 100 W for 10 min. The dimensions of the coagulations were compared in the two groups. In ex vivo experiments, the mean volumes of the coagulations produced in group B (54.0±16.5 cm 3 ) were greater than those produced in group A (33.9±12.7 cm 3 ) (P=0.007). In in vivo experiments, bipolar RFA produced a coagulation of 39.4±15.6 cm 3 without a major complication. The present study showed that a RF electrode system using two cooled-wet electrodes in the bipolar mode created larger coagulation volumes than the monopolar mode, and this system can be used to create large coagulation without major complications. (orig.)

Wetting induced by near-surface Ti-enrichment in the CaF2/In-Ti and CaF2/Cu-Ti systems

International Nuclear Information System (INIS)

Froumin, N.; Barzilai, S.; Aizenshtein, M.; Lomberg, M.; Frage, N.

2008-01-01

This paper is concerned with the wetting of CaF 2 by liquid Cu and In and with the effect of Ti additions to the melt. According to thermodynamic analysis and to the experimental observations, the significantly decreased contact angle following the addition of Ti to the molten metals is not due to the formation of interfacial fluoride phases, in contrast to previously reported results. Ab initio density functional calculations indicate that preferential Ti adsorption takes place at the near CaF 2 surface. It is suggested that the presence of a Ti-enriched liquid, adjacent to the substrate, gives rise, by means of heterogeneous nucleation, to the formation of a thin intermetallic compound layer that stands behind the experimentally observed enhanced wetting. The suggested wetting mechanism is supported by the notable correlation that has been observed between the temperature dependence of the contact angle and the temperature domains, associated with the presence of intermetallic compounds in both Me-Ti (Me = Cu, In) binary systems

Description and cost analysis of a deluge dry/wet cooling system.

Energy Technology Data Exchange (ETDEWEB)

Wiles, L.E.; Bamberger, J.A.; Braun, D.J.; Braun, D.J.; Faletti, D.W.; Willingham, C.E.

1978-06-01

The use of combined dry/wet cooling systems for large base-load power plants offers the potential for significant water savings as compared to evaporatively cooled power plants and significant cost savings in comparison to dry cooled power plants. The results of a detailed engineering and cost study of one type of dry/wet cooling system are described. In the ''deluge'' dry/wet cooling method, a finned-tube heat exchanger is designed to operate in the dry mode up to a given ambient temperature. To avoid the degradation of performance for higher ambient temperatures, water (the delugeate) is distributed over a portion of the heat exchanger surface to enhance the cooling process by evaporation. The deluge system used in this study is termed the HOETERV system. The HOETERV deluge system uses a horizontal-tube, vertical-plate-finned heat exchanger. The delugeate is distributed at the top of the heat exchanger and is allowed to fall by gravity in a thin film on the face of the plate fin. Ammonia is used as the indirect heat transfer medium between the turbine exhaust steam and the ambient air. Steam is condensed by boiling ammonia in a condenser/reboiler. The ammonia is condensed in the heat exchanger by inducing airflow over the plate fins. Various design parameters of the cooling system have been studied to evaluate their impact on the optimum cooling system design and the power-plant/utility-system interface. Annual water availability was the most significant design parameter. Others included site meteorology, heat exchanger configuration and air flow, number and size of towers, fan system design, and turbine operation. It was concluded from this study that the HOETERV deluge system of dry/wet cooling, using ammonia as an intermediate heat transfer medium, offers the potential for significant cost savings compared with all-dry cooling, while achieving substantially reduced water consumption as compared to an evaporatively cooled power plant. (LCL)

EB curable wetting resins for magnetic media coatings

International Nuclear Information System (INIS)

Laskin, L.; Ansel, R.E.; Murray, K.P.; Schmid, S.R.

1984-01-01

The magnetic media industry is studying means to improve the recording density, durability, product uniformity and production efficiency and to reduce wetting agent migration in the magnetic film. The use of electron beam curable resin binders for magnetic coatings is one of the approaches being studied for this. This paper compares the wetting efficiencies of several electron beam curable systems with a conventional resin and a conventional wetting agent. In this study it has been demonstrated that EB resins can be designed to effect proper magnetic pigment dispersion

Polyimide hollow fiber membranes for CO2 separation from wet gas mixtures

Directory of Open Access Journals (Sweden)

F. Falbo

2014-12-01

Full Text Available Matrimid®5218 hollow fiber membranes were prepared using the dry-wet spinning process. The transport properties were measured with pure gases (H2, CO2, N2, CH4 and O2 and with a mixture (30% CO2 and 70% N2 in dry and wet conditions at 25 ºC, 50 ºC, 60 ºC and 75 ºC and up to 600 kPa. Interesting values of single gas selectivity up to 60 ºC (between 31 and 28 for CO2/N2 and between 33 and 30 for CO2/CH4 in dry condition were obtained. The separation factor measured for the mixture was 20% lower compared to the single gas selectivity, in the whole temperature range analyzed. In saturation conditions the data showed that water influences the performance of the membranes, inducing a reduction of the permeance of all gases. Moreover, the presence of water caused a decrease of single gas selectivity and separation factor, although not so significant, highlighting the very high water resistance of hollow fiber membrane modules.

Performance improvement and better scalability of wet-recessed and wet-oxidized AlGaN/GaN high electron mobility transistors

Science.gov (United States)

Takhar, Kuldeep; Meer, Mudassar; Upadhyay, Bhanu B.; Ganguly, Swaroop; Saha, Dipankar

2017-05-01

We have demonstrated that a thin layer of Al2O3 grown by wet-oxidation of wet-recessed AlGaN barrier layer in an AlGaN/GaN heterostructure can significantly improve the performance of GaN based high electron mobility transistors (HEMTs). The wet-etching leads to a damage free recession of the gate region and compensates for the decreased gate capacitance and increased gate leakage. The performance improvement is manifested as an increase in the saturation drain current, transconductance, and unity current gain frequency (fT). This is further augmented with a large decrease in the subthreshold current. The performance improvement is primarily ascribed to an increase in the effective velocity in two-dimensional electron gas without sacrificing gate capacitance, which make the wet-recessed gate oxide-HEMTs much more scalable in comparison to their conventional counterpart. The improved scalability leads to an increase in the product of unity current gain frequency and gate length (fT × Lg).

Bianchi Type-I Universe with wet dark fluid

Indian Academy of Sciences (India)

Bianchi-type Universe; wet dark fluid; cosmological parameters. Abstract. The Bianchi Type-I Universe filled with dark energy from a wet dark fluid has been considered. A new equation of ... Pramana – Journal of Physics | News. © 2017 Indian ...

Effect of ethanol-wet-bonding technique on resin–enamel bonds

Directory of Open Access Journals (Sweden)

Muhammet Kerim Ayar

2014-03-01

Conclusion: The ethanol-wet-bonding technique may increase the bond strength of commercial adhesives to enamel. The chemical composition of the adhesives can affect the bond strength of adhesives when bonding to acid-etched enamel, using the ethanol-wet-bonding technique. Some adhesive systems used in the present study may simultaneously be applied to enamel and dentin using ethanol-wet-bonding. Furthermore, deploying ethanol-wet-bonding for the tested commercial adhesives to enamel can increase the adhesion abilities of these adhesives to enamel.

Wetting and crystallization at grain boundaries: Origin of aluminum-induced crystallization of amorphous silicon

International Nuclear Information System (INIS)

Wang, J.Y.; He, D.; Zhao, Y.H.; Mittemeijer, E.J.

2006-01-01

It has been shown experimentally that the grain boundaries in aluminium in contact with amorphous silicon are the necessary agents for initiation of the crystallization of silicon upon annealing temperatures as low as 438 K. Thermodynamic analysis has shown (i) that Si can 'wet' the Al grain boundaries due to the favorable Si/Al interface energy as compared to the Al grain-boundary energy and (ii) that Si at the Al grain boundaries can maintain its amorphous state up to a thickness of about 1.0 nm. Beyond that thickness crystalline Si develops at the Al grain boundaries

Modeling of Direct Contact Wet Cooling Tower in ETRR-2

International Nuclear Information System (INIS)

El Khatib, H.H.; Ismail, A.L.; ElRefaie, M.E.

2008-01-01

The Egyptian Testing and Research Reactor no.2 (ETRR-2) was commissioned at 1997 with maximum power 22 MW for research purposes; an induced draft wet cooling tower (counter flow type) was putted in operation in 2003 instead of the first one. Investigations are achieved to evaluate cooling tower performance to guarantee that the cooling tower capable to dissipate heat generated in reactor core. Merkel and Poppe analysis was applied to simulate this cooling tower packing. Merkel analysis was applied to predict water outlet temperature from cooling tower and also to show the effect of ambient conditions on this temperature. Poppe analysis was applied to predict Merkel number which evaluate cooling tower. The Runge-Kutta numerical method was applied to solve the differential equations in this model and an engineering equation solver (EES) is the language used to model the cooling tower. This research illustrates that the cooling tower achieves good performance in various sever ambient condition at maximum operating condition of reactor power. The results show that at severe summer condition of wet bulb temperature equals 24 degree c and tower inlet temperature equals 37 degree c, the outlet water temperature equals 30.4 degree c from cooling tower, while the Merkel number is be found 1.253

Biodiesel production from wet microalgae feedstock using sequential wet extraction/transesterification and direct transesterification processes.

Science.gov (United States)

Chen, Ching-Lung; Huang, Chien-Chang; Ho, Kao-Chia; Hsiao, Ping-Xuan; Wu, Meng-Shan; Chang, Jo-Shu

2015-10-01

Although producing biodiesel from microalgae seems promising, there is still a lack of technology for the quick and cost-effective conversion of biodiesel from wet microalgae. This study was aimed to develop a novel microalgal biodiesel producing method, consisting of an open system of microwave disruption, partial dewatering (via combination of methanol treatment and low-speed centrifugation), oil extraction, and transesterification without the pre-removal of the co-solvent, using Chlamydomonas sp. JSC4 with 68.7 wt% water content as the feedstock. Direct transesterification with the disrupted wet microalgae was also conducted. The biomass content of the wet microalgae increased to 56.6 and 60.5 wt%, respectively, after microwave disruption and partial dewatering. About 96.2% oil recovery was achieved under the conditions of: extraction temperature, 45°C; hexane/methanol ratio, 3:1; extraction time, 80 min. Transesterification of the extracted oil reached 97.2% conversion within 15 min at 45°C and 6:1 solvent/methanol ratio with simultaneous Chlorophyll removal during the process. Nearly 100% biodiesel conversion was also obtained while conducting direct transesterification of the disrupted oil-bearing microalgal biomass. Copyright © 2015 Elsevier Ltd. All rights reserved.

Solvent-annealing-induced nanowetting in templates: towards tailored polymer nanostructures.

Science.gov (United States)

Chen, Jiun-Tai; Lee, Chih-Wei; Chi, Mu-Huan; Yao, I-Chun

2013-02-25

We study the solvent-annealing-induced nanowetting in templates using porous anodic aluminum oxide membranes. The morphology of polystyrene and poly(methyl methacrylate) nanostructures can be controlled, depending on whether the swollen polymers are in the partial or complete wetting regimes, which are characterized by the spreading coefficient. When the swollen polymers are in the partial wetting regime, polymers wet the nanopores by capillary action, resulting in the formation of polymer nanorods. When the swollen polymers are in the complete wetting regime, polymers form wetting layers in the nanopores, resulting in the formation of polymer nanotubes. The solubility parameters of polymers and solvents are also used to predict the wetting behavior of swollen polymers in cylindrical geometry. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

PREFACE: Wetting: introductory note

Science.gov (United States)

Herminghaus, S.

2005-03-01

The discovery of wetting as a topic of physical science dates back two hundred years, to one of the many achievements of the eminent British scholar Thomas Young. He suggested a simple equation relating the contact angle between a liquid surface and a solid substrate to the interfacial tensions involved [1], γlg cos θ = γsg - γsl (1) In modern terms, γ denotes the excess free energy per unit area of the interface indicated by its indices, with l, g and s corresponding to the liquid, gas and solid, respectively [2]. After that, wetting seems to have been largely ignored by physicists for a long time. The discovery by Gabriel Lippmann that θ may be tuned over a wide range by electrochemical means [3], and some important papers about modifications of equation~(1) due to substrate inhomogeneities [4,5] are among the rare exceptions. This changed completely during the seventies, when condensed matter physics had become enthusiastic about critical phenomena, and was vividly inspired by the development of the renormalization group by Kenneth Wilson [6]. This had solved the long standing problem of how to treat fluctuations, and to understand the universal values of bulk critical exponents. By inspection of the critical exponents of the quantities involved in equation~(1), John W Cahn discovered what he called critical point wetting: for any liquid, there should be a well-defined transition to complete wetting (i.e., θ = 0) as the critical point of the liquid is approached along the coexistence curve [7]. His paper inspired an enormous amount of further work, and may be legitimately viewed as the entrance of wetting into the realm of modern physics. Most of the publications directly following Cahn's work were theoretical papers which elaborated on wetting in relation to critical phenomena. A vast amount of interesting, and in part quite unexpected, ramifications were discovered, such as the breakdown of universality in thin film systems [8]. Simultaneously, a number

What's So Bad about Being Wet All Over: Investigating Leaf Surface Wetness.

Science.gov (United States)

Brewer, Carol A.

1996-01-01

Presents investigations of leaf surface wetness that provide ideal opportunities for students to explore the relationships between leaf form and function, to study surface conditions of leaves and plant physiology, and to make predictions about plant adaptation in different environments. Describes simple procedures for exploring questions related…

Surface modification of polyethylene by radiation-induced grafting for adhesive bonding. IV. Improvement in wet peel strength

International Nuclear Information System (INIS)

Yamakawa, S.; Yamamoto, F.

1980-01-01

Adhesive joints of hydrolyzed methyl acrylate grafts, bonded with epoxy adhesives, yield extremely high peel strength (adherend failure) in dry conditions. However, when the joints are exposed to humid environments, the peel strength rapidly decreases with exposure time and then reaches a constant value (wet peel strength). Since the locus of failure changes from the adherend to the homopolymer layer with decreasing peel strength, the decrease is due to a decrease in mechanical strength of the homopolymer layer itself, which results from its swelling by water absorption. Many attempts to reduce the swelling of the homopolymer layer or to strengthen the swollen homopolymer layer were unsuccessful except (1) priming with epoxy solutions consisting of a base epoxy resin and organic solvents which can dissolve not only epoxy resins but also hydrolyzed poly(methyl acrylate) and (2) partial etching of the homopolymer layer by photo-oxidative degradation. All the results on the improvement in wet peel strength can be explained in terms of the penetration of epoxy resins into the homopolymer layer and subsequent curing of the penetrated epoxy resin. 15 figures, 1 table

Wetting characteristics of 3-dimensional nanostructured fractal surfaces

Energy Technology Data Exchange (ETDEWEB)

Davis, Ethan, E-mail: ethan.davis4@huskers.unl.edu [Nano & Microsystems Research Laboratory, Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, W342 Nebraska Hall, Lincoln, NE 68588-0526 (United States); Liu, Ying; Jiang, Lijia; Lu, Yongfeng [Laser Assisted Nano Engineering Lab, Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, 209N Scott Engineering Center, Lincoln, NE 68588-0511 (United States); Ndao, Sidy, E-mail: sndao2@unl.edu [Nano & Microsystems Research Laboratory, Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, W342 Nebraska Hall, Lincoln, NE 68588-0526 (United States)

2017-01-15

Highlights: • Hierarchically structured surfaces were fabricated on the micro/nano-scale. • These structures reduced the contact angle of the inherently hydrophilic material. • Similar surfaces have applications in two-phase heat transfer and microfluidics. - Abstract: This article reports the fabrication and wetting characteristics of 3-dimensional nanostructured fractal surfaces (3DNFS). Three distinct 3DNFS surfaces, namely cubic, Romanesco broccoli, and sphereflake were fabricated using two-photon direct laser writing. Contact angle measurements were performed on the multiscale fractal surfaces to characterize their wetting properties. Average contact angles ranged from 66.8° for the smooth control surface to 0° for one of the fractal surfaces. The change in wetting behavior was attributed to modification of the interfacial surface properties due to the inclusion of 3-dimensional hierarchical fractal nanostructures. However, this behavior does not exactly obey existing surface wetting models in the literature. Potential applications for these types of surfaces in physical and biological sciences are also discussed.

Thermo-fluid dynamic analysis of wet compression process

Energy Technology Data Exchange (ETDEWEB)

Mohan, Abhay; Kim, Heuy Dong [School of Mechanical Engineering, Andong National University, Andong (Korea, Republic of); Chidambaram, Palani Kumar [FMTRC, Daejoo Machinery Co. Ltd., Daegu (Korea, Republic of); Suryan, Abhilash [Dept. of Mechanical Engineering, College of Engineering Trivandrum, Kerala (India)

2016-12-15

Wet compression systems increase the useful power output of a gas turbine by reducing the compressor work through the reduction of air temperature inside the compressor. The actual wet compression process differs from the conventional single phase compression process due to the presence of latent heat component being absorbed by the evaporating water droplets. Thus the wet compression process cannot be assumed isentropic. In the current investigation, the gas-liquid two phase has been modeled as air containing dispersed water droplets inside a simple cylinder-piston system. The piston moves in the axial direction inside the cylinder to achieve wet compression. Effects on the thermodynamic properties such as temperature, pressure and relative humidity are investigated in detail for different parameters such as compression speeds and overspray. An analytical model is derived and the requisite thermodynamic curves are generated. The deviations of generated thermodynamic curves from the dry isentropic curves (PV{sup γ} = constant) are analyzed.

Thermo-fluid dynamic analysis of wet compression process

International Nuclear Information System (INIS)

Mohan, Abhay; Kim, Heuy Dong; Chidambaram, Palani Kumar; Suryan, Abhilash

2016-01-01

Wet compression systems increase the useful power output of a gas turbine by reducing the compressor work through the reduction of air temperature inside the compressor. The actual wet compression process differs from the conventional single phase compression process due to the presence of latent heat component being absorbed by the evaporating water droplets. Thus the wet compression process cannot be assumed isentropic. In the current investigation, the gas-liquid two phase has been modeled as air containing dispersed water droplets inside a simple cylinder-piston system. The piston moves in the axial direction inside the cylinder to achieve wet compression. Effects on the thermodynamic properties such as temperature, pressure and relative humidity are investigated in detail for different parameters such as compression speeds and overspray. An analytical model is derived and the requisite thermodynamic curves are generated. The deviations of generated thermodynamic curves from the dry isentropic curves (PV γ = constant) are analyzed

Wetting characteristics of 3-dimensional nanostructured fractal surfaces

International Nuclear Information System (INIS)

Davis, Ethan; Liu, Ying; Jiang, Lijia; Lu, Yongfeng; Ndao, Sidy

2017-01-01

Highlights: • Hierarchically structured surfaces were fabricated on the micro/nano-scale. • These structures reduced the contact angle of the inherently hydrophilic material. • Similar surfaces have applications in two-phase heat transfer and microfluidics. - Abstract: This article reports the fabrication and wetting characteristics of 3-dimensional nanostructured fractal surfaces (3DNFS). Three distinct 3DNFS surfaces, namely cubic, Romanesco broccoli, and sphereflake were fabricated using two-photon direct laser writing. Contact angle measurements were performed on the multiscale fractal surfaces to characterize their wetting properties. Average contact angles ranged from 66.8° for the smooth control surface to 0° for one of the fractal surfaces. The change in wetting behavior was attributed to modification of the interfacial surface properties due to the inclusion of 3-dimensional hierarchical fractal nanostructures. However, this behavior does not exactly obey existing surface wetting models in the literature. Potential applications for these types of surfaces in physical and biological sciences are also discussed.

Ultrafast switching in wetting properties of TiO2/YSZ/Si(001) epitaxial heterostructures induced by laser irradiation

International Nuclear Information System (INIS)

Bayati, M. R.; Molaei, R.; Narayan, J.; Joshi, S.; Narayan, R. J.

2013-01-01

We have demonstrated dark hydrophilicity of single crystalline rutile TiO 2 (100) thin films, in which rapid switching from a hydrophobic to a hydrophilic surface was achieved using nanosecond excimer laser irradiation. The TiO 2 /YSZ/Si(001) single crystalline heterostructures were grown by pulsed laser deposition and were subsequently irradiated by a single pulse of a KrF excimer laser at several energies. The wettability of water on the surfaces of the samples was evaluated. The samples were hydrophobic prior to laser annealing and turned hydrophilic after laser annealing. Superhydrophilic surfaces were obtained at higher laser energy densities (e.g., 0.32 J.cm −2 ). The stoichiometries of the surface regions of the samples before and after laser annealing were examined using XPS. The results revealed the formation of oxygen vacancies on the surface, which are surmised to be responsible for the observed superhydrophilic behavior. According to the AFM images, surface smoothening was greater in films that were annealed at higher laser energy densities. The samples exhibited hydrophobic behavior after being placed in ambient atmosphere. The origin of laser induced wetting behavior was qualitatively understood to stem from an increase of point defects near the surface, which lowered the film/water interfacial energy. This type of rapid hydrophobic/hydrophilic switching may be used to facilitate fabrication of electronic and photonic devices with novel properties.

Wetting of real surfaces

CERN Document Server

Bormashenko, Edward Yu

2013-01-01

The problem of wetting and drop dynamics on various surfaces is very interesting from both the scientificas well as thepractical viewpoint, and subject of intense research.The results are scattered across papers in journals, sothis workwill meet the need for a unifying, comprehensive work.

Wet-dry cycles impact DOM retention in subsurface soils

Science.gov (United States)

Olshansky, Yaniv; Root, Robert A.; Chorover, Jon

2018-02-01

Transport and reactivity of carbon in the critical zone are highly controlled by reactions of dissolved organic matter (DOM) with subsurface soils, including adsorption, transformation and exchange. These reactions are dependent on frequent wet-dry cycles common to the unsaturated zone, particularly in semi-arid regions. To test for an effect of wet-dry cycles on DOM interaction and stabilization in subsoils, samples were collected from subsurface (Bw) horizons of an Entisol and an Alfisol from the Catalina-Jemez Critical Zone Observatory and sequentially reacted (four batch steps) with DOM extracted from the corresponding soil litter layers. Between each reaction step, soils either were allowed to air dry (wet-dry treatment) before introduction of the following DOM solution or were maintained under constant wetness (continually wet treatment). Microbial degradation was the dominant mechanism of DOM loss from solution for the Entisol subsoil, which had higher initial organic C content, whereas sorptive retention predominated in the lower C Alfisol subsoil. For a given soil, bulk dissolved organic C losses from solution were similar across treatments. However, a combination of Fourier transform infrared (FTIR) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopic analyses revealed that wet-dry treatments enhanced the interactions between carboxyl functional groups and soil particle surfaces. Scanning transmission X-ray microscopy (STXM) data suggested that cation bridging by Ca2+ was the primary mechanism for carboxyl association with soil surfaces. STXM data also showed that spatial fractionation of adsorbed OM on soil organo-mineral surfaces was diminished relative to what might be inferred from previously published observations pertaining to DOM fractionation on reaction with specimen mineral phases. This study provides direct evidence of the role of wet-dry cycles in affecting sorption reactions of DOM to a complex soil matrix. In the soil

Cascading hazards: Understanding triggering relations between wet tropical cyclones, landslides, and earthquakes

Science.gov (United States)

Wdowinski, S.; Peng, Z.; Ferrier, K.; Lin, C. H.; Hsu, Y. J.; Shyu, J. B. H.

2017-12-01

Earthquakes, landslides, and tropical cyclones are extreme hazards that pose significant threats to human life and property. Some of the couplings between these hazards are well known. For example, sudden, widespread landsliding can be triggered by large earthquakes and by extreme rainfall events like tropical cyclones. Recent studies have also shown that earthquakes can be triggered by erosional unloading over 100-year timescales. In a NASA supported project, titled "Cascading hazards: Understanding triggering relations between wet tropical cyclones, landslides, and earthquake", we study triggering relations between these hazard types. The project focuses on such triggering relations in Taiwan, which is subjected to very wet tropical storms, landslides, and earthquakes. One example for such triggering relations is the 2009 Morakot typhoon, which was the wettest recorded typhoon in Taiwan (2850 mm of rain in 100 hours). The typhoon caused widespread flooding and triggered more than 20,000 landslides, including the devastating Hsiaolin landslide. Six months later, the same area was hit by the 2010 M=6.4 Jiashian earthquake near Kaohsiung city, which added to the infrastructure damage induced by the typhoon and the landslides. Preliminary analysis of temporal relations between main-shock earthquakes and the six wettest typhoons in Taiwan's past 50 years reveals similar temporal relations between M≥5 events and wet typhoons. Future work in the project will include remote sensing analysis of landsliding, seismic and geodetic monitoring of landslides, detection of microseismicity and tremor activities, and mechanical modeling of crustal stress changes due to surface unloading.

Formation of Mach angle profiles during wet etching of silica and silicon nitride materials

Energy Technology Data Exchange (ETDEWEB)

Ghulinyan, M., E-mail: ghulinyan@fbk.eu [Centre for Materials and Microsystems, Fondazione Bruno Kessler, I-38123 Povo (Italy); Bernard, M.; Bartali, R. [Centre for Materials and Microsystems, Fondazione Bruno Kessler, I-38123 Povo (Italy); Deptartment of Physics, University of Trento, I-38123 Povo (Italy); Pucker, G. [Centre for Materials and Microsystems, Fondazione Bruno Kessler, I-38123 Povo (Italy)

2015-12-30

Highlights: • Photoresist adhesion induces the formation of complex etch profiles in dielectrics. • Hydrofluoric acid etching of silica glass and silicon nitride materials was studied. • The phenomenon has been modeled in analogy with sonic boom propagation. • The material etch rate and resist adhesion/erosion define the final profile. - Abstract: In integrated circuit technology peeling of masking photoresist films is a major drawback during the long-timed wet etching of materials. It causes an undesired film underetching, which is often accompanied by a formation of complex etch profiles. Here we report on a detailed study of wedge-shaped profile formation in a series of silicon oxide, silicon oxynitride and silicon nitride materials during wet etching in a buffered hydrofluoric acid (BHF) solution. The shape of etched profiles reflects the time-dependent adhesion properties of the photoresist to a particular material and can be perfectly circular, purely linear or a combination of both, separated by a knee feature. Starting from a formal analogy between the sonic boom propagation and the wet underetching process, we model the wedge formation mechanism analytically. This model predicts the final form of the profile as a function of time and fits the experimental data perfectly. We discuss how this knowledge can be extended to the design and the realization of optical components such as highly efficient etch-less vertical tapers for passive silicon photonics.

Selective Oxidation and Reactive Wetting During Hot-Dip Galvanizing of a 1.0 pct Al-0.5 pct Si TRIP-Assisted Steel

Science.gov (United States)

Bellhouse, E. M.; McDermid, J. R.

2012-07-01

Selective oxidation and reactive wetting during continuous galvanizing were studied for a low-alloy transformation induced plasticity (TRIP)-assisted steel with 0.2 pct C, 1.5 pct Mn, 1.0 pct Al and 0.5 pct Si. Three process atmospheres were tested during annealing prior to galvanizing: 220 K (-53 °C) dew point (dp) N2-20 pct H2, 243 K (-30 °C) dp N2-5 pct H2 and 278 K (+5 °C) dp N2-5 pct H2. The process atmosphere oxygen partial pressure affected the oxide chemistry, morphology and thickness. For the 220 K (-53 °C) dp and 243 K (-30 °C) dp process atmospheres, film and nodule-type manganese, silicon and aluminum containing oxides were observed at the surface. For the 278 K (+5 °C) dp atmosphere, MnO was observed at the grain boundaries and as thicker localized surface films. Oxide morphology, thickness and chemistry affected reactive wetting, with complete wetting being observed for the 220 K (-53 °C) dp and 243 K (-30 °C) dp process atmospheres and incomplete reactive wetting being observed for the 278 K (+5 °C) dp atmosphere. Complete reactive wetting for the 220 K (-53 °C) dp and 243 K (-30 °C) dp process atmospheres was attributed to a combination of zinc bridging of oxides, aluminothermic reduction of surface oxides and wetting of the oxides. Incomplete wetting for the 278 K (+5 °C) dp atmosphere was attributed to localized thick MnO films.

Characteristics of wetting temperature during spray cooling

International Nuclear Information System (INIS)

Mitsutake, Yuichi; Monde, Masanori; Hidaka, Shinichirou

2006-01-01

An experimental study has been done to elucidate the effects of mass flux and subcooling of liquid and thermal properties of solid on the wetting temperature during cooling of a hot block with spray. A water spray was impinged at one of the end surfaces of a cylindrical block initially heated at 400 or 500degC. The experimental condition was mass fluxes G=1-9 kg/m 2 s and degrees of subcooling ΔT sub =20, 50, 80 K. Three blocks of copper, brass and carbon steel were prepared. During spray cooling internal block temperature distribution and sputtering sound pressure level were recorded and the surface temperature and heat flux were evaluated with 2D inverse heat conducting analysis. Cooling process on cooling curves is divided into four regimes categorized by change in a flow situation and the sound level. The wetting temperature defined as the wall temperature at a minimum heat flux point was measured over an extensive experimental range. The wetting wall temperature was correlated well with the parameter of GΔT sub . The wetting wall temperature increases as GΔT sub increases and reaches a constant value depending on the material of the surface at higher region of GΔT sub . (author)

A Novel Approach to Estimating Nitrous Oxide Emissions during Wetting Events from Single-Timepoint Flux Measurements.

Science.gov (United States)

Davis, Brian W; Needelman, Brian A; Cavigelli, Michel A; Yarwood, Stephanie A; Maul, Jude E; Bagley, Gwendolyn A; Mirsky, Steven B

2017-03-01

Precipitation and irrigation induce pulses of NO emissions in agricultural soils, but the magnitude, duration, and timing of these pulses remain uncertain. This uncertainty makes it difficult to accurately extrapolate emissions from unmeasured time periods between chamber sampling events. Therefore, we developed a modeling protocol to predict NO emissions from data collected daily for 7 d after wetting events. Within a cover crop-based corn ( L.) production system in Beltsville, MD, we conducted the 7-d time series during four time periods representing a range of corn growth stages in 2013 and 2014. Treatments included mixtures and monocultures of grass and legume cover crops that were fertilized with pelletized poultry litter or urea-ammonium nitrate solution (9-276 kg N ha). Most fluxes did not exhibit the expected exponential decay over time (82%); therefore, cumulative emissions were calculated using trapezoidal integration over 7 d after the wetting event. Cumulative 7-d emissions were well correlated with single point gas fluxes on the second day after a wetting event using a generalized linear mixed model (ln[emissions] = 0.809∙ln[flux] + 2.47). Soil chemical covariates before or after a wetting event were weakly associated with cumulative emissions. The ratio of dissolved organic C to total inorganic N was negatively correlated with cumulative emissions ( = 0.23-0.29), whereas nitrate was positively correlated with cumulative emissions ( = 0.23-0.33). Our model is an innovative approach that is calibrated using site-specific time series data, which may then be used to estimate short-term NO emissions after wetting events using only a single flux measurement. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Phase Change Materials and the perception of wetness.

NARCIS (Netherlands)

Bergmann Tiest, W.M.; Kappers, A.M.L.; Daanen, H.A.M.

2012-01-01

Phase change materials (PCMs) are increasingly incorporated in textiles in order to serve as a thermal buffer when humans change from a hot to a cold environment and the reverse. Due to the absence of wetness sensors in the skin, cooling of the skin may be perceived as a sensation of wetness instead

Phase change materials and the perception of wetness

NARCIS (Netherlands)

Bergmann Tiest, W.M.; Kosters, N.D.; Kappers, A.M.L.; Daanen, H.A.M.

2012-01-01

Phase change materials (PCMs) are increasingly incorporated in textiles in order to serve as a thermal buffer when humans change from a hot to a cold environment and the reverse. Due to the absence of wetness sensors in the skin, cooling of the skin may be perceived as a sensation of wetness instead

Wetting kinetics of nanodroplets on lyophilic nanopillar-arrayed surfaces: A molecular dynamics study

Science.gov (United States)

Zong, Diyuan; Yang, Zhen; Duan, Yuanyuan

2017-10-01

Wetting kinetics of water droplets on substrates with lyophilic nanopillars was investigated using molecular dynamics simulations. Early spreading of the droplet is hindered by the nanopillars because of the penetration of the liquid which induce an extra dissipation in the droplet. Droplet spreading is mainly controlled by liquid viscosity and surface tension and not dependent on solid wettability. Propagation of the fringe film is hindered by the enhanced solid wettability because of the energy barrier introduced by the interaction between water molecules and nanopillars which increase with solid wettability.

Skid resistance determination for pavement management and wet-weather road safety

Directory of Open Access Journals (Sweden)

T.F. Fwa

2017-09-01

Full Text Available Road accidents during wet weather have been a topic of major concern of road engineers in regions of wet-tropical climate and in other parts of the world during the wet season of the year. Road safety studies indicate that approximately 20% of all road accidents occurred during wet weather, and that the skid resistance of wet pavements have a major influence on the occurrences of wet-weather accidents. Monitoring of wet pavement skid resistance has been an integral part of a typical pavement management system. However, because of the lack of prediction capability of pavement skid resistance under various rainfall intensities, the minimum skid resistance threshold for safe wet-weather driving has been specified by highway agencies based on either engineering judgement or past experience. It is shown in this paper that the single-point minimum skid resistance threshold is inadequate to offer a complete description of the skid resistance performance of the pavement sections in question for effective management of a road network. It is unable to assess the risk involved in an actual wet-weather condition where the pavement surface water-film thickness and vehicle speed are different from standard test conditions. This limitation of the current system of specifying a minimum skid resistance threshold can be overcome by adopting a theoretically sound approach to represent pavement skid resistance under different conditions of water-film thickness and vehicle speed. This paper describes the theoretical basis of the approach and the development of a mechanistically derived three-dimensional finite-element skid resistance simulation model to predict skid resistance. The application of the proposed approach and the skid resistance prediction procedure in pavement management system and wet-weather driving safety assessment is presented.

Apparent de-wetting due to superfluid flow

CERN Document Server

Poujade, M; Rolley, E

2002-01-01

We have investigated the wetting behaviour of superfluid helium-4 on silicon. Surprisingly, we observe pseudo-de-wetting: though a thick superfluid film covers the substrate, the meniscus displays a finite contact angle which decreases from about 5 deg C at low temperature down to zero at the superfluid transition. We show that this behaviour can be explained by a pressure decrease due to a superfluid flow, closely related to the Kontorovich effect. (authors)

The Sequence of Wet and Dry Days at Ibadan and Onne (Sub ...

African Journals Online (AJOL)

Twenty-three years daily rainfall data were collected for Ibadan while twenty years data were collected for Onne. These data were analysed and modelled for the dependence of wet days following dry days; dry days following wet days; dry days following dry days and wet days following wet days using the first order Markov ...

The effect of an exceptionally wet summer on methane effluxes from a 15-year re-wetted fen in north-east Germany

Directory of Open Access Journals (Sweden)

V. Huth

2013-10-01

Full Text Available Re-wetting minerotrophic fens has become an important strategy to mitigate climate change in Germany. However, recent studies report raised methane (CH4 effluxes during the first years after flooding. A minerotrophic fen in north-east Germany that was re-wetted 15 years ago was exposed to exceptionally heavy rainfall and freshwater flooding in August 2011. We measured CH4 effluxes from wetland vegetation stands dominated by Phragmites australis (Cav. Trin. ex Steud., Typha latifolia L. and Carex acutiformis Ehrh., using the closed-chamber method, fortnightly from March 2011 to March 2012 with extra sampling during the flooding. The respective annual effluxes of CH4 (mean ± 1 standard error from the three vegetation types were 18.5 ± 1.3, 21.1 ± 1.2 and 47.5 ± 5.0 g m-2 a-1, with the August effluxes contributing 40 %, 50 % and 10 % of the annual effluxes. Despite the freshwater flooding in August, annual CH4 effluxes from the 15-year re-wetted fen are similar to those reported from pristine fens. These results are promising because they indicate that, although CH4 effluxes are elevated after re-wetting, they may return to values typical for pristine fens after 15 years. Hence, re-wetting can achieve the purpose of reducing greenhouse gas effluxes from drained minerotrophic fens.

Run don't walk: locomotor performance of geckos on wet substrates.

Science.gov (United States)

Stark, Alyssa Y; Ohlemacher, Jocelyn; Knight, Ashley; Niewiarowski, Peter H

2015-08-01

The gecko adhesive system has been under particular scrutiny for over a decade, as the field has recently attracted attention for its application to bio-inspired design. However, little is known about how the adhesive system behaves in ecologically relevant conditions. Geckos inhabit a variety of environments, many of which are characterized by high temperature, humidity and rain. The van der Waals-based gecko adhesive system should be particularly challenged by wet substrates because water can disrupt the intimate contact necessary for adhesion. While a few previous studies have focused on the clinging ability of geckos on wet substrates, we tested a dynamic performance characteristic, sprint velocity. To better understand how substrate wettability and running orientation affect locomotor performance of multiple species on wet substrates, we measured average sprint velocity of five species of gecko on substrates that were either hydrophilic or intermediately wetting and oriented either vertically or horizontally. Surprisingly, we found no indication that wet substrates impact average sprint velocity over 1 m, and rather, in some species, sprint velocity was increased on wet substrates rather than reduced. When investigating physical characteristics and behavior that may be associated with running on wet substrates, such as total number of stops, slips and wet toes at the completion of a race, we found that there may be habitat-related differences between some species. Our results show that in general, unlike clinging and walking, geckos running along wet substrates suffer no significant loss in locomotor performance over short distances. © 2015. Published by The Company of Biologists Ltd.

Wetting and Capillary Condensation as Means of Protein Organization in Membranes

DEFF Research Database (Denmark)

Gil, Tamir; Sabra, Mads Christian; Ipsen, John Hjorth

1997-01-01

Wetting and capillary condensation are thermodynamic phenomena in which the special affinity of interfaces to a thermodynamic phase, relative to the stable bulk phase, leads to the stabilization of a wetting phase at the interfaces. Wetting and capillary condensation are here proposed as mechanisms...

Static and dynamic wetting behaviour of ionic liquids.

Science.gov (United States)

Delcheva, Iliana; Ralston, John; Beattie, David A; Krasowska, Marta

2015-08-01

Ionic liquids (ILs) are a unique family of molecular liquids ('molten salts') that consist of a combination of bulky organic cations coupled to inorganic or organic anions. The net result of steric hindrance and strong hydrogen bonding between components results in a material that is liquid at room temperature. One can alter the properties of ionic liquids through chemical modification of anion and cation, thus tailoring the IL for a given application. One such property that can be controlled or selected is the wettability of an IL on a particular solid substrate. However, the study of wetting of ionic liquids is complicated by the care required for accurate and reproducible measurement, due to both the susceptibility of the IL properties to water content, as well as to the sensitivity of wettability measurements to the state of the solid surface. This review deals with wetting studies of ILs to date, including both static and dynamic wetting, as well as issues concerning line tension and the formation of precursor and wetting films. Copyright © 2014 Elsevier B.V. All rights reserved.

Electrostatic cloaking of surface structure for dynamic wetting

Science.gov (United States)

Shiomi, Junichiro; Nita, Satoshi; Do-Quang, Minh; Wang, Jiayu; Chen, Yu-Chung; Suzuki, Yuji; Amberg, Gustav

2017-11-01

Dynamic wetting problems are fundamental to the understanding of the interaction between liquids and solids. Even in a superficially simple experimental situation, such as a droplet spreading over a dry surface, the result may depend not only on the liquid properties but also strongly on the substrate-surface properties; even for macroscopically smooth surfaces, the microscopic geometrical roughness can be important. In addition, as surfaces may often be naturally charged, or electric fields are used to manipulate fluids, electric effects are crucial components that influence wetting phenomena. Here we investigate the interplay between electric forces and surface structures in dynamic wetting. While surface microstructures can significantly hinder the spreading, we find that the electrostatics can ``cloak'' the microstructures, i.e. deactivate the hindering. We identify the physics in terms of reduction in contact-line friction, which makes the dynamic wetting inertial force dominant and insensitive to the substrate properties. This work was financially supported in part by, the Japan Society for the Promotion of Science, Swedish Governmental Agency for Innovation Systems, and the Japan Science and Technology Agency.

Wetting and dewetting of extracellular matrix and glycocalix models

International Nuclear Information System (INIS)

Tanaka, Motomu; Rehfeldt, Florian; Schneider, Matthias F; Mathe, Gerald; Albersdoerfer, Antero; Neumaier, Klaus R; Purrucker, Oliver; Sackmann, Erich

2005-01-01

In this paper, we study wetting and dewetting of hydrated biopolymer layers mediating cell-cell and cell-tissue contacts, called the extracellular matrix and cell surface glycocalix, by the combination of various physical techniques. Here, the sum of the net effects of the various interfacial forces, which is referred to as the disjoining pressure, is used as a semi-quantitative measure to describe the thermodynamics of hydrated interlayers. The disjoining pressure can be measured by applying external forces to maintain the equilibrium distance between two parallel surfaces (in biology, two neighbouring plasma membranes). Using artificial models of the extracellular matrix and glycocalix, we describe stable cell-cell contacts in terms of the wetting (or spreading) of complex fluids on polymer surfaces. In fact, the adjustment of the wetting interaction via thin hydrating layers enables us to transform three-dimensional cell membranes into quasi-two-dimensional films on macroscopically large surfaces. Fine-tuning of local wetting conditions at the interface further allows for the selective wetting of native cell membranes on microstructured polysaccharide films, which has a large potential for individual detection of biological functions in confined geometries

Drying and wetting of building materials and components

CERN Document Server

2014-01-01

This book, Drying and Wetting of Building Materials and Components, provides a collection of recent contributions in the field of drying and wetting in porous building materials. The main benefit of the book is that it discusses some of the most important topics related to the drying and wetting processes, namely, innovations and trends in drying science and technology, drying mechanism and theory, equipment, advanced modelling, complex simulation and experimentation. At the same time, these topics will be going to the encounter of a variety of scientific and engineering disciplines. The book is divided in several chapters that intend to be a resume of the current state of knowledge for benefit of professional colleagues.

Technology of turbine plant operating with wet steam

International Nuclear Information System (INIS)

1989-01-01

The technology of turbine plant operating with wet steam is a subject of continuing interest and importance, notably in view of the widespread use of wet steam cycles in nuclear power plants and the recent developments of advanced low pressure blading for both conventional and wet steam turbines. The nature of water formation in expanding steam has an important influence on the efficiency of turbine blading and on the integrity and safe operating life of blading and associated turbine and plant components. The subjects covered in this book include research, flow analysis and measurement, development and design of turbines and ancillary plant, selection of materials of construction, manufacturing methods and operating experience. (author)

Wet oxidation of quinoline

DEFF Research Database (Denmark)

Thomsen, A.B.; Kilen, H.H.

1998-01-01

The influence of oxygen pressure (0.4 and 2 MPa). reaction time (30 and 60 min) and temperature (260 and 280 degrees C) on the wet oxidation of quinoline has been studied. The dominant parameters for the decomposition of quinoline were oxygen pressure and reaction temperature. whereas the reactio...

Ceramic joining through reactive wetting of alumina with calcium ...

Indian Academy of Sciences (India)

phase analysis of the fractured joint surface clearly indicate reactive wetting of the alumina ceramics. This wetting enhances ... ally considered oxide materials for many applications. .... three cases but is more pronounced in the case of C12A7.

Hydrodynamics of a Multistage Wet Scrubber Incineration Conditions

Science.gov (United States)

Said, M. M.; Manyele, S. V.; Raphael, M. L.

2012-01-01

The objective of the study was to determine the hydrodynamics of the two stage counter-current cascade wet scrubbers used during incineration of medical waste. The dependence of the hydrodynamics on two main variables was studied: Inlet air flow rate and inlet liquid flow rate. This study introduces a new wet scrubber operating features, which are…

Wetting behavior of liquid Fe-C-Ti alloys on sapphire

International Nuclear Information System (INIS)

Gelbstein, M.; Froumin, N.; Frage, N.

2008-01-01

Wetting behavior in the (Fe-C-Ti)/sapphire system was studied at 1823 K. The wetting angle between sapphire and Fe-C alloys is higher than 90 deg. (93 deg. and 105 deg. for the alloys with 1.4 and 3.6 at.% C, respectively). The presence of Ti improves the wetting of the iron-carbon alloys, especially for the alloys with carbon content of 3.6 at.%. The addition of 5 at.% Ti to Fe-3.6 at.% C provides a contact angle of about 30 deg., while the same addition to Fe-1.4 at.% C decreases the wetting angle to 70 deg. only. It was established that the wetting in the systems is controlled by the formation of a titanium oxicarbide layer at the interface, which composition and thickness depend on C and Ti contents in the melt. The experimental observations are well accounted for by a thermodynamic analysis of the Fe-Ti-Al-O-C system

Microbial community composition of transiently wetted Antarctic Dry Valley soils.

Science.gov (United States)

Niederberger, Thomas D; Sohm, Jill A; Gunderson, Troy E; Parker, Alexander E; Tirindelli, Joëlle; Capone, Douglas G; Carpenter, Edward J; Cary, Stephen C

2015-01-01

During the summer months, wet (hyporheic) soils associated with ephemeral streams and lake edges in the Antarctic Dry Valleys (DVs) become hotspots of biological activity and are hypothesized to be an important source of carbon and nitrogen for arid DV soils. Recent research in the DV has focused on the geochemistry and microbial ecology of lakes and arid soils, with substantially less information being available on hyporheic soils. Here, we determined the unique properties of hyporheic microbial communities, resolved their relationship to environmental parameters and compared them to archetypal arid DV soils. Generally, pH increased and chlorophyll a concentrations decreased along transects from wet to arid soils (9.0 to ~7.0 for pH and ~0.8 to ~5 μg/cm(3) for chlorophyll a, respectively). Soil water content decreased to below ~3% in the arid soils. Community fingerprinting-based principle component analyses revealed that bacterial communities formed distinct clusters specific to arid and wet soils; however, eukaryotic communities that clustered together did not have similar soil moisture content nor did they group together based on sampling location. Collectively, rRNA pyrosequencing indicated a considerably higher abundance of Cyanobacteria in wet soils and a higher abundance of Acidobacterial, Actinobacterial, Deinococcus/Thermus, Bacteroidetes, Firmicutes, Gemmatimonadetes, Nitrospira, and Planctomycetes in arid soils. The two most significant differences at the genus level were Gillisia signatures present in arid soils and chloroplast signatures related to Streptophyta that were common in wet soils. Fungal dominance was observed in arid soils and Viridiplantae were more common in wet soils. This research represents an in-depth characterization of microbial communities inhabiting wet DV soils. Results indicate that the repeated wetting of hyporheic zones has a profound impact on the bacterial and eukaryotic communities inhabiting in these areas.

7 CFR 51.897 - Wet.

Science.gov (United States)

2010-01-01

... the grapes are wet from moisture from crushed, leaking, or decayed berries or from rain. Grapes which are moist from dew or other moisture condensation such as that resulting from removing grapes from a...

Tuning and predicting the wetting of nanoengineered material surface

Science.gov (United States)

Ramiasa-MacGregor, M.; Mierczynska, A.; Sedev, R.; Vasilev, K.

2016-02-01

The wetting of a material can be tuned by changing the roughness on its surface. Recent advances in the field of nanotechnology open exciting opportunities to control macroscopic wetting behaviour. Yet, the benchmark theories used to describe the wettability of macroscopically rough surfaces fail to fully describe the wetting behaviour of systems with topographical features at the nanoscale. To shed light on the events occurring at the nanoscale we have utilised model gradient substrata where surface nanotopography was tailored in a controlled and robust manner. The intrinsic wettability of the coatings was varied from hydrophilic to hydrophobic. The measured water contact angle could not be described by the classical theories. We developed an empirical model that effectively captures the experimental data, and further enables us to predict the wetting of surfaces with nanoscale roughness by considering the physical and chemical properties of the material. The fundamental insights presented here are important for the rational design of advanced materials having tailored surface nanotopography with predictable wettability.The wetting of a material can be tuned by changing the roughness on its surface. Recent advances in the field of nanotechnology open exciting opportunities to control macroscopic wetting behaviour. Yet, the benchmark theories used to describe the wettability of macroscopically rough surfaces fail to fully describe the wetting behaviour of systems with topographical features at the nanoscale. To shed light on the events occurring at the nanoscale we have utilised model gradient substrata where surface nanotopography was tailored in a controlled and robust manner. The intrinsic wettability of the coatings was varied from hydrophilic to hydrophobic. The measured water contact angle could not be described by the classical theories. We developed an empirical model that effectively captures the experimental data, and further enables us to predict the

Analysis of corrosion products of carbon steel in wet bentonite

International Nuclear Information System (INIS)

Osada, Kazuo; Nagano, Tetsushi; Nakayama, Shinichi; Muraoka, Susumu

1992-02-01

As a part of evaluation of the long-term durability for the overpack containers for high-level radioactive waste, we have conducted corrosion tests for carbon steel in wet bentonite, a candidate buffer material. The corrosion rates were evaluated by weight difference of carbon steel and corrosion products were analyzed by Fourier transform infrared spectroscopy (FT-IR) and colorimetry. At 40degC, the corrosion rate of carbon steel in wet bentonite was smaller than that in pure water. At 95degC, however, the corrosion rate in wet bentonite was much higher than that in pure water. This high corrosion rate in wet bentonite at 95degC was considered to result from evaporation of moisture in bentonite in contact with the metal. This evaporation led to dryness and then to shrinkage of the bentonite, which generated ununiform contact of the metal with bentonite. Probably, this ununiform contact promoted the local corrosion. The locally corroded parts of specimen in wet bentonite at 95degC were analyzed by Fourier transform infrared microspectroscopy (micro-FT-IR), and lepidocrocite γ-FeO(OH) was found as well as goethite α-FeO(OH). In wet bentonite at 95degC, hematite α-Fe 2 O 3 was identified by means of colorimetry. (author)

Wetting layers effect on InAs/GaAs quantum dots

International Nuclear Information System (INIS)

Sun Chao; Lu Pengfei; Yu Zhongyuan; Cao Huawei; Zhang Lidong

2012-01-01

FEM combining with the K·P theory is adopted to systematically investigate the effect of wetting layers on the strain-stress profiles and electronic structures of self-organized InAs quantum dot. Four different kinds of quantum dots are introduced at the same height and aspect ratio. We found that 0.5 nm wetting layer is an appropriate thickness for InAs/GaAs quantum dots. Strain shift down about 3%∼4.5% for the cases with WL (0.5 nm) and without WL in four shapes of quantum dots. For band edge energy, wetting layers expand the potential energy gap width. When WL thickness is more than 0.8 nm, the band edge energy profiles cannot vary regularly. The electron energy is affected while for heavy hole this impact on the energy is limited. Wetting layers for the influence of the electronic structure is obviously than the heavy hole. Consequently, the electron probability density function spread from buffer to wetting layer while the center of hole's function moves from QDs internal to wetting layer when introduce WLs. When WLs thickness is larger than 0.8 nm, the electronic structures of quantum dots have changed obviously. This will affect the instrument's performance which relies on the quantum dots' optical properties.

Mercury Wet Scavenging and Deposition Differences by Precipitation Type.

Science.gov (United States)

Kaulfus, Aaron S; Nair, Udaysankar; Holmes, Christopher D; Landing, William M

2017-03-07

We analyze the effect of precipitation type on mercury wet deposition using a new database of individual rain events spanning the contiguous United States. Measurements from the Mercury Deposition Network (MDN) containing single rainfall events were identified and classified into six precipitation types. Mercury concentrations in surface precipitation follow a power law of precipitation depth that is modulated by precipitation system morphology. After controlling for precipitation depth, the highest mercury deposition occurs in supercell thunderstorms, with decreasing deposition in disorganized thunderstorms, quasi-linear convective systems (QLCS), extratropical cyclones, light rain, and land-falling tropical cyclones. Convective morphologies (supercells, disorganized, and QLCS) enhance wet deposition by a factor of at least 1.6 relative to nonconvective morphologies. Mercury wet deposition also varies by geographic region and season. After controlling for other factors, we find that mercury wet deposition is greater over high-elevation sites, seasonally during summer, and in convective precipitation.

Retention mechanisms and the flow wetted surface - implications for safety analysis

International Nuclear Information System (INIS)

Elert, M.

1997-02-01

The purpose of this report is to document the state-of-the-art concerning the flow wetted surface, its importance for radionuclide transport in the geosphere and review various suggestions on how to increase the present knowledge. Definitions are made of the various concepts used for the flow wetted surface as well as the various model parameters used. In the report methods proposed to assess the flow wetted surface are reviewed and discussed, tracer tests, tunnel and borehole investigations, geochemical studies, heat transport studies and theoretical modelling. Furthermore, a review is made of how the flow wetted surface has been treated in various safety analyses. Finally, an overall discussion with recommendations is presented, where it is concluded that at present no individual method for estimating the flow wetted surface can be selected that satisfies all requirements concerning giving relevant values, covering relevant distances and being practical to apply. Instead a combination of methods must be used. In the long-term research as well as in the safety assessment modelling focus should be put on assessing the ratio between flow wetted surface and water flux. The long-term research should address both the detailed flow within the fractures and the effective flow wetted surface along the flow paths. 55 refs

Design Aspects of Wet Scrubber System

International Nuclear Information System (INIS)

Lee, Hyun-Chul; Bang, Young-suk; Jung, Woo-Young; Lee, Doo-Yong

2015-01-01

The water pool in the wet scrubber system has advantage to cope with decay heat based on the thermal hydraulic balance such as condensation and evaporation inside it. This study focuses on the design aspects of the wet scrubber system to estimate the required water pool mass during the mission time and size of the scrubbing tank including inner structures. The design of the wet scrubber system include the estimation of the required water mass during the mission time and sizing of the scrubber vessel to contain the water pool. The condensation due to the inlet steam and evaporation due to the steam and non-condensable gas superheat and decay heat from filtered fission products should be considered to estimate the water mass required to maintain its function during the mission time. On the other hand, the level swelling due to the noncondensable gas is another important design aspect on the sizing of the scrubber vessel and determination of the entry elevation of the filtration components such as the droplet separator or filter. The minimum water level based on the minimum collapsed water level should be higher than the exit of scrubber nozzle

Design Aspects of Wet Scrubber System

Energy Technology Data Exchange (ETDEWEB)

Lee, Hyun-Chul; Bang, Young-suk; Jung, Woo-Young; Lee, Doo-Yong [FNC Technology Co. Ltd., Yongin (Korea, Republic of)

2015-10-15

The water pool in the wet scrubber system has advantage to cope with decay heat based on the thermal hydraulic balance such as condensation and evaporation inside it. This study focuses on the design aspects of the wet scrubber system to estimate the required water pool mass during the mission time and size of the scrubbing tank including inner structures. The design of the wet scrubber system include the estimation of the required water mass during the mission time and sizing of the scrubber vessel to contain the water pool. The condensation due to the inlet steam and evaporation due to the steam and non-condensable gas superheat and decay heat from filtered fission products should be considered to estimate the water mass required to maintain its function during the mission time. On the other hand, the level swelling due to the noncondensable gas is another important design aspect on the sizing of the scrubber vessel and determination of the entry elevation of the filtration components such as the droplet separator or filter. The minimum water level based on the minimum collapsed water level should be higher than the exit of scrubber nozzle.

A study of the tyre/road interface under wet conditions

OpenAIRE

Mosley, J. H.

1985-01-01

This work addresses the problem of tyre tread pattern design for optimum wet grip performance. A mathematical model of tyre behaviour on wet roads has been developed. This utilizes the finite element method in the representation of tread pattern geometry. The performance of a particular tread pattern is found in terms of the fluid pressures and film thicknesses existing within the contact patch, under wet conditions. Many modern tread patterns are based on 'blocks', an...

Wet cutting

Energy Technology Data Exchange (ETDEWEB)

Hole, B. [IMC Technical Services (United Kingdom)

1999-08-01

Continuous miners create dust and methane problems in underground coal mining. Control has usually been achieved using ventilation techniques as experiments with water based suppression have led to flooding and electrical problems. Recent experience in the US has led to renewed interest in wet head systems. This paper describes tests of the Hydraphase system by IMC Technologies. Ventilation around the cutting zone, quenching of hot ignition sources, dust suppression, the surface trial gallery tests, the performance of the cutting bed, and flow of air and methane around the cutting head are reviewed. 1 ref., 2 figs., 2 photos.

Quantitative analysis of wet-heat inactivation in bovine spongiform encephalopathy

International Nuclear Information System (INIS)

Matsuura, Yuichi; Ishikawa, Yukiko; Bo, Xiao; Murayama, Yuichi; Yokoyama, Takashi; Somerville, Robert A.; Kitamoto, Tetsuyuki; Mohri, Shirou

2013-01-01

Highlights: ► We quantitatively analyzed wet-heat inactivation of the BSE agent. ► Infectivity of the BSE macerate did not survive 155 °C wet-heat treatment. ► Once the sample was dehydrated, infectivity was observed even at 170 °C. ► A quantitative PMCA assay was used to evaluate the degree of BSE inactivation. - Abstract: The bovine spongiform encephalopathy (BSE) agent is resistant to conventional microbial inactivation procedures and thus threatens the safety of cattle products and by-products. To obtain information necessary to assess BSE inactivation, we performed quantitative analysis of wet-heat inactivation of infectivity in BSE-infected cattle spinal cords. Using a highly sensitive bioassay, we found that infectivity in BSE cattle macerates fell with increase in temperatures from 133 °C to 150 °C and was not detected in the samples subjected to temperatures above 155 °C. In dry cattle tissues, infectivity was detected even at 170 °C. Thus, BSE infectivity reduces with increase in wet-heat temperatures but is less affected when tissues are dehydrated prior to the wet-heat treatment. The results of the quantitative protein misfolding cyclic amplification assay also demonstrated that the level of the protease-resistant prion protein fell below the bioassay detection limit by wet-heat at 155 °C and higher and could help assess BSE inactivation. Our results show that BSE infectivity is strongly resistant to wet-heat inactivation and that it is necessary to pay attention to BSE decontamination in recycled cattle by-products

Quantitative analysis of wet-heat inactivation in bovine spongiform encephalopathy

Energy Technology Data Exchange (ETDEWEB)

Matsuura, Yuichi; Ishikawa, Yukiko; Bo, Xiao; Murayama, Yuichi; Yokoyama, Takashi [Prion Disease Research Center, National Institute of Animal Health, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856 (Japan); Somerville, Robert A. [The Roslin Institute and Royal (Dick) School of Veterinary Studies, Roslin, Midlothian, EH25 9PS (United Kingdom); Kitamoto, Tetsuyuki [Division of CJD Science and Technology, Department of Prion Research, Center for Translational and Advanced Animal Research on Human Diseases, Tohoku University Graduate School of Medicine, 2-1 Seiryo, Aoba, Sendai 980-8575 (Japan); Mohri, Shirou, E-mail: shirou@affrc.go.jp [Prion Disease Research Center, National Institute of Animal Health, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856 (Japan)

2013-03-01

Highlights: ► We quantitatively analyzed wet-heat inactivation of the BSE agent. ► Infectivity of the BSE macerate did not survive 155 °C wet-heat treatment. ► Once the sample was dehydrated, infectivity was observed even at 170 °C. ► A quantitative PMCA assay was used to evaluate the degree of BSE inactivation. - Abstract: The bovine spongiform encephalopathy (BSE) agent is resistant to conventional microbial inactivation procedures and thus threatens the safety of cattle products and by-products. To obtain information necessary to assess BSE inactivation, we performed quantitative analysis of wet-heat inactivation of infectivity in BSE-infected cattle spinal cords. Using a highly sensitive bioassay, we found that infectivity in BSE cattle macerates fell with increase in temperatures from 133 °C to 150 °C and was not detected in the samples subjected to temperatures above 155 °C. In dry cattle tissues, infectivity was detected even at 170 °C. Thus, BSE infectivity reduces with increase in wet-heat temperatures but is less affected when tissues are dehydrated prior to the wet-heat treatment. The results of the quantitative protein misfolding cyclic amplification assay also demonstrated that the level of the protease-resistant prion protein fell below the bioassay detection limit by wet-heat at 155 °C and higher and could help assess BSE inactivation. Our results show that BSE infectivity is strongly resistant to wet-heat inactivation and that it is necessary to pay attention to BSE decontamination in recycled cattle by-products.

Medications to Treat Bed-Wetting

Science.gov (United States)

... suggest that depression plays a role in the cause of bed-wetting. This type of drug is thought to work one of several ways: by changing the child's sleep and wakening pattern by affecting the time ...

Accelerated Drying of Wet Boots

National Research Council Canada - National Science Library

Dyck, Walter

2002-01-01

.... One such material is sodium polyacrylate. Because recent field trials with Canadian Forces soldiers have reconfirmed that donning wet combat boots is very uncomfortable, a study was done to assess the efficacy of using sodium polyacrylate...

Phase change materials and the perception of wetness.

Science.gov (United States)

Tiest, Wouter M Bergmann; Kosters, N Dolfine; Kappers, Astrid M L; Daanen, Hein A M

2012-01-01

Phase change materials (PCMs) are increasingly incorporated in textiles in order to serve as a thermal buffer when humans change from a hot to a cold environment and the reverse. Due to the absence of wetness sensors in the skin, cooling of the skin may be perceived as a sensation of wetness instead of cold. In order to investigate if this phenomenon occurs when manipulating textiles, nine subjects were asked to touch or manipulate PCM-treated and untreated fabrics. In 75% of the cases, the subjects indicated that the treated material felt wetter than the untreated material independent of the way the textiles were manipulated. We conclude that incorporating PCMs in textiles may lead to a feeling of wetness which might be uncomfortable. Therefore, we recommend investigating a change in cooling properties to minimise this feeling. This article describes a psychophysical experiment into the sensation of wetness of textiles treated with phase change materials. It was found that in 75% of the cases, subjects found the treated fabric to feel wetter than the untreated. This may affect the comfort of wearing clothes made of these textiles.

Exposure of the hands to wet work in nurses

NARCIS (Netherlands)

Jungbauer, F.H.W.; Lensen, G.J.; Groothoff, J.W.; Coenraads, P.J.

Prevention of hand dermatitis among nurses can be achieved by reduction of wet-work exposure. A preventive programme should be based on knowledge of exposure levels. An accurate method to assess such exposure levels is needed. Duration and frequency of wet-work activities were assessed by a

Design, development and operating experience with wet steam turbines

International Nuclear Information System (INIS)

Bolter, J.R.

1989-01-01

The paper first describes the special characteristics of wet steam units. It then goes on to discuss the principal features of the units manufactured by the author's company, the considerations on which the designs were based, and the development work carried out to validate them. Some of the design features such as the separator/reheater units and the arrangements for water extraction in the high pressure turbine are unconventional. An important characteristic of all nuclear plant is the combination of high capital cost and low fuel cost, and the consequent emphasis placed on high availability. The paper describes some service problems experienced with wet steam plant and how these were overcome with minimum loss of generation. The paper also describes a number of the developments for future wet steam plant which have evolved from these experiences, and from research and development programmes aimed at increasing the efficiency and reliability of both conventional and wet steam units. Blading, rotor construction and separator/reheater units are considered. (author)

Erosion corrosion in wet steam

International Nuclear Information System (INIS)

Tavast, J.

1988-03-01

The effect of different remedies against erosion corrosion in wet steam has been studied in Barsebaeck 1. Accessible steam systems were inspected in 1984, 1985 and 1986. The effect of hydrogen peroxide injection of the transport of corrosion products in the condensate and feed water systems has also been followed through chemical analyses. The most important results of the project are: - Low alloy chromium steels with a chromium content of 1-2% have shown excellent resistance to erosion corrosion in wet steam. - A thermally sprayed coating has shown good resistance to erosion corrosion in wet steam. In a few areas with restricted accessibility minor attacks have been found. A thermally sprayed aluminium oxide coating has given poor results. - Large areas in the moisture separator/reheater and in steam extraction no. 3 have been passivated by injection of 20 ppb hydrogen peroxide to the high pressure steam. In other inspected systems no significant effect was found. Measurements of the wall thickness in steam extraction no. 3 showed a reduced rate of attack. - The injection of 20 ppb hydrogen peroxide has not resulted in any significant reduction of the iron level result is contrary to that of earlier tests. An increase to 40 ppb resulted in a slight decrease of the iron level. - None of the feared disadvantages with hydrogen peroxide injection has been observed. The chromium and cobalt levels did not increase during the injection. Neither did the lifetime of the precoat condensate filters decrease. (author)

From royal wet nurses to Facebook: The evolution of breastmilk sharing.

Science.gov (United States)

Baumgartel, Kelley L; Sneeringer, Larissa; Cohen, Susan M

2016-11-01

Wet-nursing was an essential practice that allowed for infant survival after many mothers died in childbirth. The story of wet-nursing is complicated by both religious pressures and cultural expectations of women. It is likely that these historical practices have shaped our current social, political and legislative environments regarding breastfeeding. The aim of this article is to provide a historical perspective on the practice of wet-nursing, with a focus on: 1) social views of wet nurses, 2) breastmilk evaluation and 3) the ideal wet nurse. Historical perspectives from Ancient Egypt, Ancient Greece and Rome, 19th and 20th century America and current practices are examined. An appreciation for the evolution of breastmilk sharing provides clinicians and lactation advocates with the historical origins which provided the template for current practice as it relates to donor milk, breastfeeding culture and relevant legislation.

Wetting layers effect on InAs/GaAs quantum dots

Energy Technology Data Exchange (ETDEWEB)

Sun Chao [State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, P.O. Box 49(BUPT), Xitucheng Road No. 10, Beijing 100876 (China); Lu Pengfei, E-mail: photon.bupt@gmail.com [State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, P.O. Box 49(BUPT), Xitucheng Road No. 10, Beijing 100876 (China); Yu Zhongyuan; Cao Huawei; Zhang Lidong [State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, P.O. Box 49(BUPT), Xitucheng Road No. 10, Beijing 100876 (China)

2012-11-15

FEM combining with the K{center_dot}P theory is adopted to systematically investigate the effect of wetting layers on the strain-stress profiles and electronic structures of self-organized InAs quantum dot. Four different kinds of quantum dots are introduced at the same height and aspect ratio. We found that 0.5 nm wetting layer is an appropriate thickness for InAs/GaAs quantum dots. Strain shift down about 3%{approx}4.5% for the cases with WL (0.5 nm) and without WL in four shapes of quantum dots. For band edge energy, wetting layers expand the potential energy gap width. When WL thickness is more than 0.8 nm, the band edge energy profiles cannot vary regularly. The electron energy is affected while for heavy hole this impact on the energy is limited. Wetting layers for the influence of the electronic structure is obviously than the heavy hole. Consequently, the electron probability density function spread from buffer to wetting layer while the center of hole's function moves from QDs internal to wetting layer when introduce WLs. When WLs thickness is larger than 0.8 nm, the electronic structures of quantum dots have changed obviously. This will affect the instrument's performance which relies on the quantum dots' optical properties.

Bio-Inspired Extreme Wetting Surfaces for Biomedical Applications

Science.gov (United States)

Shin, Sera; Seo, Jungmok; Han, Heetak; Kang, Subin; Kim, Hyunchul; Lee, Taeyoon

2016-01-01

Biological creatures with unique surface wettability have long served as a source of inspiration for scientists and engineers. More specifically, materials exhibiting extreme wetting properties, such as superhydrophilic and superhydrophobic surfaces, have attracted considerable attention because of their potential use in various applications, such as self-cleaning fabrics, anti-fog windows, anti-corrosive coatings, drag-reduction systems, and efficient water transportation. In particular, the engineering of surface wettability by manipulating chemical properties and structure opens emerging biomedical applications ranging from high-throughput cell culture platforms to biomedical devices. This review describes design and fabrication methods for artificial extreme wetting surfaces. Next, we introduce some of the newer and emerging biomedical applications using extreme wetting surfaces. Current challenges and future prospects of the surfaces for potential biomedical applications are also addressed. PMID:28787916

Case for a wet, warm climate on early Mars

International Nuclear Information System (INIS)

Pollack, J.B.; Kasting, J.F.; Richardson, S.M.; Poliakoff, K.

1987-01-01

Arguments are presented in support of the idea that Mars possessed a dense CO 2 atmosphere and a wet, warm climate early in its history. The plausibility of a CO 2 greenhouse is tested by formulating a simple model of the CO 2 geochemical cycle on early Mars. By scaling the rate of silicate weathering on Earth, researchers estimated a weathering time constant of the order of several times 10 to the 7th power years for early Mars. Thus, a dense atmosphere could have existed for a geologically significant time period (approx. 10 to the 9th power years) only if atmospheric CO 2 was being continuously resupplied. The most likely mechanism by which this could have been accomplished is the thermal decomposition of carbonate rocks induced directly or indirectly by intense, global scale volcanism

Enhanced mobility of non aqueous phase liquid (NAPL) during drying of wet sand

Science.gov (United States)

Govindarajan, Dhivakar; Deshpande, Abhijit P.; Raghunathan, Ravikrishna

2018-02-01

Enhanced upward mobility of a non aqueous phase liquid (NAPL) present in wet sand during natural drying, and in the absence of any external pressure gradients, is reported for the first time. This mobility was significantly higher than that expected from capillary rise. Experiments were performed in a glass column with a small layer of NAPL-saturated sand trapped between two layers of water-saturated sand. Drying of the wet sand was induced by flow of air across the top surface of the wet sand. The upward movement of the NAPL, in the direction of water transport, commenced when the drying effect reached the location of the NAPL and continued as long as there was significant water evaporation in the vicinity of NAPL, indicating a clear correlation between the NAPL rise and water evaporation. The magnitude and the rate of NAPL rise was measured at different water evaporation rates, different initial locations of the NAPL, different grain size of the sand and the type of NAPL (on the basis of different NAPL-glass contact angle, viscosity and density). A positive correlation was observed between average rate of NAPL rise and the water evaporation while a negative correlation was obtained between the average NAPL rise rate and the NAPL properties of contact angle, viscosity and density. There was no significant correlation of average NAPL rise rate with variation of sand grain size between 0.1 to 0.5 mm. Based on these observations and on previous studies reported in the literature, two possible mechanisms are hypothesized -a) the effect of the spreading coefficient resulting in the wetting of NAPL on the water films created and b) a moving water film due to evaporation that "drags" the NAPL upwards. The NAPL rise reported in this paper has implications in fate and transport of chemicals in NAPL contaminated porous media such as soils and exposed dredged sediment material, which are subjected to varying water saturation levels due to drying and rewetting.

Pore-scale imaging of capillary trapped supercritical CO2 as controlled by water-wet vs. CO2-wet media and grain shapes

Science.gov (United States)

Chaudhary, K.; Cardenas, M.; Wolfe, W. W.; Maisano, J. A.; Ketcham, R. A.; Bennett, P.

2013-12-01

The capillary trapping of supercritical CO2 (s-CO2) is postulated to comprise up to 90% of permanently trapped CO2 injected during geologic sequestration. Successive s-CO2/brine flooding experiments under reservoir conditions showed that water-wet rounded beads trapped 15% of injected s-CO2 both as clusters and as individual ganglia, whereas CO2¬-wet beads trapped only 2% of the injected s-CO2 as minute pockets in pore constrictions. Angular water-wet grains trapped 20% of the CO2 but flow was affected by preferential flow. Thus, capillary trapping is a viable mechanism for the permanent CO2 storage, but its success is constrained by the media wettability.

Characteristics of Wet Deposition in Japan

Science.gov (United States)

Iwasaki, A.; Arakaki, T.

2017-12-01

Acid deposition survey in Japan has started since 1991 by Japan Environmental Laboratories Association (JELA). The JELA has about 60 monitoring sites for wet deposition including remote, rural and urban area. The measured constituents of wet deposition are; precipitation, pH, electric conductivity, major Anions, and major Cations. From those data, we analyze spatial and temporal variations of wet deposition components in Japan. Among the 60 monitoring sites, 39 sampling sites were selected in this study, which have kept sampling continuously between 2003JFY and 2014JFY. All samples were collected by wet-only samplers. To analyze area characteristics, all the areas were divided into 6 regions; Northern part of Japan (NJ), Facing the Japan Sea (JS), Eastern part of Japan (EJ), Central part of Japan (CJ), Western part of Japan (WJ) and Southern West Islands (SW). NO3- and non-sea-salt-SO42- (nss-SO42-) are major components of rain acidification. Especially, between December and February (winter) the air mass from west affected the temporal variations of those acid components and the concentrations were higher in JS and WJ regions than those in other regions. Japanese ministry of the Environment reported that mixing ratio of NO2 in Japan has been less than 0.04ppm since 1976, and that of SO2 has been less than 0.02ppm since 1978. Their concentrations in Japan have remained flat or slowly decreased recently. However the temporal variations of NO3-/nss-SO42- ratio in winter in JS region were significantly increased on average at 2.2% y-1 from 2003JFY to 2014JFY. The results suggest that long-range transboundary air pollutants increased NO3- concentrations and NO3-/nss-SO42- ratio.

Influence of Storage of Wet Arabica Parchment Prior to Wet Hulling on Moulds Development, OchratoxinA Contamination, and Cup Quality of Mandheling Coffee

Directory of Open Access Journals (Sweden)

Cahya Ismayadi

2005-08-01

Full Text Available Mandheling coffee has been a well known specialty coffees for decades and the demand for this coffee is currently increasing. This coffee is characterised by low acidity, heavy-complex body, spicy-little earthy and fruity flavor. Mandheling coffee is produced by smallholder farmers in the highland surrounding Lake TobaNorth Sumatra in an unique way i.e. following de-pulping and 1–2 days sundrying, wet parchment is stored for varying periods up to a few weeks, the parchments are then de-hulled when still wet (40–45% moisture content then the beans sundried. The handling procedure presumably contributes to the unique cup character of Mandheling coffee. On the other hand the storage of wet pachments may cause mould growth and mycotoxin contamination. This trial was designed to study the influence of storage of wet parchments prior to wet hulling on mould development, OTA contamination and cup Mandheling characteristic of the coffee product. The normal wet process, drying of parchment thoroughly to 12% moisture content was used as the control. Parchment coffees (6 lots used for this trial were drawn from farmers and collectors in the region. The wet parchments (41.74–53.96% moisture content were stored for 1 (D1, 7 (D7 and 14 (D14 days in PE sacks in a warehouse in the region. During the storage period, when there was visible mould growth, the parchments were spread on a plastic sheet inside the warehouse, as per common practice to suppress the mould growth. Following storage, the wet parchment was de-hulled and then sun-dried to a moisture content of 12% (MC12% or dried to a moisture content of 17%, and held in storage for 3 weeks prior to final drying to 12% mc. The ‘normal wet process’ i.e. fresh-non stored parchments dried thoroughly to 12%, were used as the control. Parameters measured were visual evaluation, mould infestation, a w, moisture content (MC on the stored parchment; while for dried beans mould infestation, OTA content and

Low pressure-induced secondary structure transitions of regenerated silk fibroin in its wet film studied by time-resolved infrared spectroscopy.

Science.gov (United States)

He, Zhipeng; Liu, Zhao; Zhou, Xiaofeng; Huang, He

2018-06-01

The secondary structure transitions of regenerated silk fibroin (RSF) under different external perturbations have been studied extensively, except for pressure. In this work, time-resolved infrared spectroscopy with the attenuated total reflectance (ATR) accessory was employed to follow the secondary structure transitions of RSF in its wet film under low pressure. It has been found that pressure alone is favorable only to the formation of β-sheet structure. Under constant pressure there is an optimum amount of D 2 O in the wet film (D 2 O : film = 2:1) so as to provide the optimal condition for the reorganization of the secondary structure and to have the largest formation of β-sheet structure. Under constant amount of D 2 O and constant pressure, the secondary structure transitions of RSF in its wet film can be divided into three stages along with time. In the first stage, random coil, α-helix, and β-turn were quickly transformed into β-sheet. In the second stage, random coil and β-turn were relatively slowly transformed into β-sheet and α-helix, and the content of α-helix was recovered to the value prior to the application of pressure. In the third and final stage, no measurable changes can be found for each secondary structure. This study may be helpful to understand the secondary structure changes of silk fibroin in silkworm's glands under hydrostatic pressure. © 2018 Wiley Periodicals, Inc.

Adaptive mechanical-wetting lens actuated by ferrofluids

Science.gov (United States)

Cheng, Hui-Chuan; Xu, Su; Liu, Yifan; Levi, Shoshana; Wu, Shin-Tson

2011-04-01

We report an adaptive mechanical-wetting lens actuated by ferrofluids. The ferrofluids works like a piston to pump liquids in and out from the lens chamber, which in turn reshapes the lens curvature and changes the focal length. Both positive and negative lenses are demonstrated experimentally. The ferrofluid-actuated mechanical-wetting lens exhibits some attractive features, such as high resolution, fast response time, low power consumption, simple structure and electronic control, weak gravity effect, and low cost. Its potential applications in medical imaging, surveillance, and commercial electronics are foreseeable.

Establishment of 3D culture and induction of osteogenic differentiation of pre-osteoblasts using wet-collected aligned scaffolds

Energy Technology Data Exchange (ETDEWEB)

Ding, Huifen [Hubei-MOSTKLOS & KLOBM, School and Hospital of Stomatology, Wuhan University, Wuhan 430079 (China); Chongqing Affiliated Hospital of Stomatology, Chongqing University of Medical Sciences, Chongqing 400015 (China); Zhong, Junwen [Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074 (China); Xu, Fei; Song, Fangfang; Yin, Miao; Wu, Yanru; Hu, Qiyi [Hubei-MOSTKLOS & KLOBM, School and Hospital of Stomatology, Wuhan University, Wuhan 430079 (China); Wang, Jiawei, E-mail: wangjwei@hotmail.com [Hubei-MOSTKLOS & KLOBM, School and Hospital of Stomatology, Wuhan University, Wuhan 430079 (China)

2017-02-01

Aligned fibrous scaffolds have attracted much interest in bone tissue engineering, because they are supposed to induce osteogenic differentiation. For the first time, aligned silk fibroin nanofibres were loosely packed using a novel wet-collection electrospinning method. Moreover, three-dimensional (3D) culture of MC3T3-E1 pre-osteoblasts was established on these fibrous scaffolds. Physicochemical properties of the scaffolds and the behaviour of MC3T3-E1 pre-osteoblasts on the scaffolds were analysed and compared with scaffolds obtained using traditional method. Ethanol bath improved the uniformity and alignment of the fibres and increased the thickness and porosity of the scaffolds. Structures of the fibres were well maintained after immediate crosslinking in ethanol. Cells on the wet-collected scaffolds exhibited more ordered arrangement and elongated morphology as well as faster and deeper infiltration. The ordered infiltration resulted in the establishment of the 3D culture of cells, promoting proliferation and osteogenic differentiation of the pre-osteoblasts. Thus, the wet-collected aligned scaffolds with improved topographical and physicochemical properties presents significant potential application in bone regeneration. - Highlights: • Aligned silk fibroin nanofibres were loosely packed using a novel wet-collection electrospinning method. • Structural properties of the aligned nanofibres were improved. • Three-dimensional culture of MC3T3-E1 pre-osteoblasts was established. • The arrangement, morphology, infiltration, proliferation and osteogenic differentiation of cells were enhanced.

Properties and sinterability of wet and dry attrition-milled OREOXed powder

International Nuclear Information System (INIS)

Lee, J. W.; Kim, J. H.; Kim, W. K.; Park, K. I.; Lee, J. W.

2001-01-01

The powder properties and sinterability were investigated with the powder prepared by wet and dry attrition milling of OREOX-treated powder. The OREOX-treated powder was prepared from the simulated spent fuel. Powder having less than 1 μm of average particle size could be obtained by dry milling, but not be obtained by wet milling. Thus, specific surface area of dry milled powder was higher than that of wet milled powder. With increasing of milling time, dry milled powder formed dense agglomerate while wet milled powder showed loose agglomerate. The pellets with higher than 95% T.D. of sintered density and larger than 7 μm of grain size were made with the milled powder regardless of milling method. The milling time in wet milling has greatly improved the sinterability. The pellets produced with dry milled powder have higher sintered density and larger grain size

Erosion of a wet/dry granular interface

Science.gov (United States)

Jop, Pierre; Lefebvre, Gautier

2013-04-01

To model the dynamic of landslides, the evolution of the interface between the erodible ground and the flowing material is still studied experimentally or numerically (ie. Mangeney et al. 2010, Iverson 2012). In some cases, the basal material is more cohesive than the flowing one. Such situation arises for example due to cementation or humidity. What are the exchange rates between these phases? What is the coupling between the evolution of the interface and the flow? We studied the erosion phenomenon and performed laboratory experiments to focus on the interaction between a cohesive unsaturated granular material and a dry granular flow. Both materials were spherical grains, the cohesion being induced by adding a given mass of liquid to the grains. Two configurations were explored: a circular aggregate submitted to a dry flow in a rotating drum, and a granular flow eroding a wet granular pile. First, we focused on the influence of the cohesion, controlled by the liquid properties, such as the surface tension and the viscosity. Then the flow characteristics were modified by varying the grain size and density. These results allowed us to present a model for the erosion mechanisms, based on the flow and fluid properties. The main results are the need to take into account the whole probability distribution the stress applied on the wet grains and that both the surface tension and the viscosity are important since they play a different roles. The latter is mainly responsible of the time scale of the dynamic of a wet grain, while the former acts as a threshold on the force distribution. In the second configuration, we could also control the inclination of the slope. This system supported the previous model and moreover revealed an interface instability, leading the formation of steep steps, which is a reminiscence of the cyclic-steps observed during river-channel incision (Parker and Izumi 2000). We will present the dynamics of such granular steps. [1] Mangeney, A., O

Control of Alq3 wetting layer thickness via substrate surface functionalization.

Science.gov (United States)

Tsoi, Shufen; Szeto, Bryan; Fleischauer, Michael D; Veinot, Jonathan G C; Brett, Michael J

2007-06-05

The effects of substrate surface energy and vapor deposition rate on the initial growth of porous columnar tris(8-hydroxyquinoline)aluminum (Alq3) nanostructures were investigated. Alq3 nanostructures thermally evaporated onto as-supplied Si substrates bearing an oxide were observed to form a solid wetting layer, likely caused by an interfacial energy mismatch between the substrate and Alq3. Wetting layer thickness control is important for potential optoelectronic applications. A dramatic decrease in wetting layer thickness was achieved by depositing Alq3 onto alkyltrichlorosilane-derivatized Si/oxide substrates. Similar effects were noted with increasing deposition rates. These two effects enable tailoring of the wetting layer thickness.

The wetting of cladding materials and other metals and alloys by sodium

International Nuclear Information System (INIS)

Hodkin, E.N.; Nicholas, M.G.

1976-05-01

The sessile drop technique has been used to investigate the wetting behaviour between sodium and various metals and alloys including FV548, 316L, M316 and PE16. Unoxidised smooth surfaces of these alloys were not wetted by sodium containing 20 ppm of oxygen at temperatures below 300 0 C but were well wetted with advancing contact angles of 20 0 or less at temperatures of 550 0 to 600 0 C. Cold working and surface roughness had little effect on wetting behaviour but other factors exercised significant influences. Chemically or electrolytically polished M316 and PE16 surfaces were less readily wetted than those which had been prepared by mechanical polishing. In general, preoxidation of the alloy surfaces and increased oxygen contamination of the sodium had detrimental effects on wetting behaviour. On the other hand, increasing the chromium content of the alloys, decreasing the oxygen content of the sodium or ion bombarding the alloy sample surfaces had beneficial effects. Auger spectroscopy studies revealed a correlation between the chromium/oxygen ratio of PE16 surfaces and their wettability. The implications of this and other factors on fast reactor coolant/clad wetting behaviour is discussed. (author)

Capillary contact angle in a completely wet groove.

Science.gov (United States)

Parry, A O; Malijevský, A; Rascón, C

2014-10-03

We consider the phase equilibria of a fluid confined in a deep capillary groove of width L with identical side walls and a bottom made of a different material. All walls are completely wet by the liquid. Using density functional theory and interfacial models, we show that the meniscus separating liquid and gas phases at two phase capillary coexistence meets the bottom capped end of the groove at a capillary contact angle θ(cap)(L) which depends on the difference between the Hamaker constants. If the bottom wall has a weaker wall-fluid attraction than the side walls, then θ(cap) > 0 even though all the isolated walls are themselves completely wet. This alters the capillary condensation transition which is now first order; this would be continuous in a capped capillary made wholly of either type of material. We show that the capillary contact angle θ(cap)(L) vanishes in two limits, corresponding to different capillary wetting transitions. These occur as the width (i) becomes macroscopically large, and (ii) is reduced to a microscopic value determined by the difference in Hamaker constants. This second wetting transition is characterized by large scale fluctuations and essential critical singularities arising from marginal interfacial interactions.

Thermodynamic and aerodynamic meanline analysis of wet compression in a centrifugal compressor

International Nuclear Information System (INIS)

Kang, Jeong Seek; Cha, Bong Jun; Yang, Soo Seok

2006-01-01

Wet compression means the injection of water droplets into the compressor of gas turbines. This method decreases the compression work and increases the turbine output by decreasing the compressor exit temperature through the evaporation of water droplets inside the compressor. Researches on wet compression, up to now, have been focused on the thermodynamic analysis of wet compression where the decrease in exit flow temperature and compression work is demonstrated. This paper provides thermodynamic and aerodynamic analysis on wet compression in a centrifugal compressor for a microturbine. The meanline dry compression performance analysis of centrifugal compressor is coupled with the thermodynamic equation of wet compression to get the meanline performance of wet compression. The most influencing parameter in the analysis is the evaporative rate of water droplets. It is found that the impeller exit flow temperature and compression work decreases as the evaporative rate increases. And the exit flow angle decreases as the evaporative rate increases

Does Surface Roughness Amplify Wetting?

Czech Academy of Sciences Publication Activity Database

Malijevský, Alexandr

2014-01-01

Roč. 141, č. 18 (2014), s. 184703 ISSN 0021-9606 R&D Projects: GA ČR GA13-09914S Institutional support: RVO:67985858 Keywords : density functional theory * wetting * roughness Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.952, year: 2014

Bevasiranib for the Treatment of Wet, Age-Related Macular Degeneration

Directory of Open Access Journals (Sweden)

Adinoyi O. Garba

2010-01-01

Full Text Available Age- related Macular Degeneration (AMD is the leading cause of severe visual impairment in people 65 years and older in industrialized nations. Exudative, or “wet”, AMD is a late form of AMD (as distinguished from atrophic, so-called dry, AMD and is responsible for over 60% of all cases of blindness due to AMD. It is widely accepted that vascular endothelial growth factor (VEGF is a key component in the pathogenesis of choroidal neo-vascularization (CNV, which is a precursor to wet AMD. The current gold-standard for treating wet AMD is the monoclonal antibody fragment ranibizumab (trade name Lucentis, which targets VEGF. Other agents used to treat wet AMD include pegaptanib (Macugen, bevacizumab (Avastin; off-label use, and several other experimental agents. The advent of small interfering RNA (siRNA has presented a whole new approach to inhibiting VEGF. This article reviews the status of a novel siRNA-based therapeutic, bevasiranib, for the treatment of wet AMD. Bevasiranib is believed to work by down regulating VEGF production in the retina. Studies in human cell-lines and animal models have shown that VEGF siRNAs are effective in inhibiting VEGF production. Although there is a lack of sufficient published data on human studies supporting the use of bevasiranib for wet AMD, available data indicates that due to its unique mechanism of action, bevasiranib might hold some promise as a primary or adjunct treatment for wet AMD.

Controlling RPV embrittlement through wet annealing in support of life attainment and life extension decisions

International Nuclear Information System (INIS)

Krasikov, E. A.

2012-01-01

As a main barrier against radioactivity outlet reactor pressure vessel (RPV) is a key component in terms of Nuclear Power Plant (NPP) safety. Therefore present-day demands in RPV reliability enhance have to be met by all possible actions for RPV in-service embrittlement mitigation. Annealing treatment is known to be the effective measure to restore the RPV metal properties deteriorated by neutron irradiation. Low temperature 'wet' annealing at a maximum coolant temperature which can be obtained using the reactor core or primary circuit pumps, although it cannot be expected to produce complete recovery, is more attractive from the practical point of view especially in cases when the removal of the internals is impossible. As a rule there is no recovery effect up to annealing and irradiation temperature difference of 70 deg. C. It is known, however, that along with radiation embrittlement neutron irradiation may mitigate the radiation damage in metals. Therefore we have tried to test the possibility to use the effect of radiation-induced ductilization in 'wet' annealing technology by means of nuclear heat utilization as heat and neutron irradiation sources at once. In support of the above-mentioned conception the 3-year duration reactor experiment on 15Cr3NiMoV type steel with preliminary irradiation at operating Pressurized Water Reactor (PWR) at 270 deg. C and following extra irradiation (87 h at 330 deg. C) at IR-8 test reactor was fulfilled. In fact, embrittlement was partly suppressed up to value equivalent to 1,5 fold neutron fluence decrease. The degree of recovery in case of radiation enhanced annealing is equal to 27% whereas furnace annealing results in zero effect under existing conditions. Mechanism of the radiation-induced damage mitigation is proposed. It is hoped that 'wet' annealing technology will help provide a better management of the RPV degradation as a factor affecting the lifetime of nuclear power plants which, together with associated

Controlling RPV embrittlement through wet annealing in support of life attainment and life extension decisions

Energy Technology Data Exchange (ETDEWEB)

Krasikov, E. A. [National Research Centre Kurchatov Inst., 1, Kurchatov Sq., Moscow, 123182 (Russian Federation)

2012-07-01

As a main barrier against radioactivity outlet reactor pressure vessel (RPV) is a key component in terms of Nuclear Power Plant (NPP) safety. Therefore present-day demands in RPV reliability enhance have to be met by all possible actions for RPV in-service embrittlement mitigation. Annealing treatment is known to be the effective measure to restore the RPV metal properties deteriorated by neutron irradiation. Low temperature 'wet' annealing at a maximum coolant temperature which can be obtained using the reactor core or primary circuit pumps, although it cannot be expected to produce complete recovery, is more attractive from the practical point of view especially in cases when the removal of the internals is impossible. As a rule there is no recovery effect up to annealing and irradiation temperature difference of 70 deg. C. It is known, however, that along with radiation embrittlement neutron irradiation may mitigate the radiation damage in metals. Therefore we have tried to test the possibility to use the effect of radiation-induced ductilization in 'wet' annealing technology by means of nuclear heat utilization as heat and neutron irradiation sources at once. In support of the above-mentioned conception the 3-year duration reactor experiment on 15Cr3NiMoV type steel with preliminary irradiation at operating Pressurized Water Reactor (PWR) at 270 deg. C and following extra irradiation (87 h at 330 deg. C) at IR-8 test reactor was fulfilled. In fact, embrittlement was partly suppressed up to value equivalent to 1,5 fold neutron fluence decrease. The degree of recovery in case of radiation enhanced annealing is equal to 27% whereas furnace annealing results in zero effect under existing conditions. Mechanism of the radiation-induced damage mitigation is proposed. It is hoped that 'wet' annealing technology will help provide a better management of the RPV degradation as a factor affecting the lifetime of nuclear power plants which

Influence of chemistry on wetting dynamics of nanotextured hydrophobic surfaces.

Science.gov (United States)

Di Mundo, Rosa; Palumbo, Fabio; d'Agostino, Riccardo

2010-04-06

In this work, the role of a chemical parameter, such as the degree of fluorination, on the wetting behavior of nanotextured hydrophobic surfaces is investigated. Texture and chemistry tuning of the surfaces has been accomplished with single batch radiofrequency low-pressure plasma processes. Polystyrene substrates have been textured by CF(4) plasma etching and subsequently covered by thin films with a tunable F-to-C ratio, obtained in discharges fed with C(4)F(8)-C(2)H(4). Measurements of wetting dynamics reveal a regime transition from adhesive-hydrophobic to slippery-superhydrophobic, i.e., from wet to non wet states, as the F-to-C rises at constant topography. Such achievements are strengthened by calculation of the solid fraction of surface water contact area applying Cassie-Baxter advancing and receding equations to water contact angle data of textured and flat reference surfaces.

Microscopic aspects of wetting using classical density functional theory

Science.gov (United States)

Yatsyshin, P.; Durán-Olivencia, M.-A.; Kalliadasis, S.

2018-07-01

Wetting is a rather efficient mechanism for nucleation of a phase (typically liquid) on the interface between two other phases (typically solid and gas). In many experimentally accessible cases of wetting, the interplay between the substrate structure, and the fluid–fluid and fluid–substrate intermolecular interactions brings about an entire ‘zoo’ of possible fluid configurations, such as liquid films with a thickness of a few nanometers, liquid nanodrops and liquid bridges. These fluid configurations are often associated with phase transitions occurring at the solid–gas interface and at lengths of just several molecular diameters away from the substrate. In this special issue article, we demonstrate how a fully microscopic classical density-functional framework can be applied to the efficient, rational and systematic exploration of the rich phase space of wetting phenomena. We consider a number of model prototype systems such as wetting on a planar wall, a chemically patterned wall and a wedge. Through density-functional computations we demonstrate that for these simply structured substrates the behaviour of the solid–gas interface is already highly complex and non-trivial.

Concept of CFD model of natural draft wet-cooling tower flow

Directory of Open Access Journals (Sweden)

Hyhlík T.

2014-03-01

Full Text Available The article deals with the development of CFD model of natural draft wet-cooling tower flow. The physical phenomena taking place within a natural draft wet cooling tower are described by the system of conservation law equations along with additional equations. The heat and mass transfer in the counterflow wet-cooling tower fill are described by model [1] which is based on the system of ordinary differential equations. Utilization of model [1] of the fill allows us to apply commonly measured fill characteristics as shown by [2].The boundary value problem resulting from the fill model is solved separately. The system of conservation law equations is interlinked with the system of ordinary differential equations describing the phenomena occurring in the counterflow wet-cooling tower fill via heat and mass sources and via boundary conditions. The concept of numerical solution is presented for the quasi one dimensional model of natural draft wet-cooling tower flow. The simulation results are shown.

A model of hemorrhagic cystitis induced with acrolein in mice

Directory of Open Access Journals (Sweden)

C.K.L.P. Batista

2006-11-01

Full Text Available Acrolein is a urinary metabolite of cyclophosphamide and ifosfamide, which has been reported to be the causative agent of hemorrhagic cystitis induced by these compounds. A direct cytotoxic effect of acrolein, however, has not yet been demonstrated. In the present study, the effects of intravesical injection of acrolein and mesna, the classical acrolein chemical inhibitor, were evaluated. Male Swiss mice weighing 25 to 35 g (N = 6 per group received saline or acrolein (25, 75, 225 µg intravesically 3, 6, 12, and 24 h before sacrifice for evaluation of bladder wet weight, macroscopic and histopathological changes by Gray's criteria, and 3 and 24 h for assessment of increase in vascular permeability. In other animals, mesna was administered intravesically (2 mg or systemically (80 mg/kg 1 h before acrolein. Intravesical administration of acrolein induced a dose- and time-dependent increase in vascular permeability and bladder wet weight (within 3 h: 2.2- and 21-fold increases in bladder wet weight and Evans blue dye exuded, respectively, at doses of 75 µg/bladder, as confirmed by Gray's criteria. Pretreatment with mesna (2-mercaptoethanesulfonic acid, which interacts with acrolein resulting in an inactive compound, inhibited all changes induced by acrolein. Our results are the first demonstration that intravesical administration of acrolein induces hemorrhagic cystitis. This model of acrolein-induced hemorrhagic cystitis in mice may be an important tool for the evaluation of the mechanism by which acrolein induces bladder lesion, as well as for investigation of new uroprotective drugs.

Wet precipitators for sulphuric acid plants

International Nuclear Information System (INIS)

Ojanpera, R.O.

1989-01-01

Both the service requirements and design construction details have changed considerably in recent years for wet electrostatic precipitators as used for gas cleaning ahead of metallurgical sulphuric acid plants. Increased concern over acid quality has resulted in more emphasis on dust efficiencies compared to collection of acid mist. Also, higher static operating pressures have caused large structural loads on casing and internal components. In this paper these two issues are addressed in the following ways: Recognition that all dusts do not collect similarly. The mechanism by which various dusts collect affect the design of the entire wet gas cleaning system. Use of both traditional and newer materials of construction to accommodate the higher design pressures while still maintaining corrosion resistance

Development of Wet Noodles Based on Cassava Flour

OpenAIRE

Akhmad Z. Abidin; Cinantya Devi; Adeline

2013-01-01

Cassava is one of Indonesia's original commodities and contains good nutrition and has high productivity and a relatively low price. Cassava flour has a high potential as a substitute for imported wheat flour that is widely used in noodle production. The main purpose of this research was to develop wet noodles from cassava flour that can compete with wet noodles from wheat flour. The research consisted of experiments with several variations of composition and production method for producing c...

Southern African Regional Science Initiative (SAFARI 2000): wet season campaigns

CSIR Research Space (South Africa)

Otter, LB

2002-03-01

Full Text Available The Southern African Regional Science Initiative (SAFARI 2000) involved two wet season and one dry season field campaigns. This paper reports on the wet season campaigns. The first was conducted at five sites along the Kalahari Transect in Zambia...

Phycoremediation of Heavy Metals in Wet Market Wastewater

Science.gov (United States)

Apandi, Najeeha; Saphira Radin Mohamed, Radin Maya; Al-Gheethi, Adel; Latiffi, Atikah; Nor Hidayah Arifin, Siti; Gani, Paran

2018-04-01

The efficiency of phycoremediation using microalgae for removing nutrients and heavy metals from wastewaters has been proved. However, the differences in the composition of wastewaters as well as microalgae species play an important role in the efficient of this process. Therefore, the present study aimed to investigate the effectiveness of Scenedesmus sp. to removal of heavy metals from wet market wastewater. Scenedesmus sp. was inoculated with 106 cells/mL into each wet market wastewater concentration included 10, 25, 50, 75 and 100% and incubated for 18 days. The highest growth rate was recorded in 50% WM with a maximum dry weight of 2006 mg L-1 which subsequently removed 93.06% of Cd, 91.5% of Cr, 92.47% of Fe, 92.40% of Zn. These findings reflected the high potential of Scenedesmus sp. in the treatment of wet market wastewater and production microalgae biomass.

Corrosion behavior of carbon steel in wet Na-bentonite medium

International Nuclear Information System (INIS)

Yeon, Jae-Won; Ha, Young-Kyoung; Choi, In-Kyu; Chun, Kwan-Sik

1996-01-01

Corrosion behaviors of carbon steel in wet Na-bentonite medium were studied. Corrosion rate of carbon steel in wet bentonite was measured to be 20 μm/yr at 25 deg C using the AC impedance technique. This value is agreed with that obtained by weight loss at 40 deg C for 1 year. The effect of bicarbonate ion on the corrosion of carbon steel in wet bentonite was also evaluated. The carbon steels in wet bentonite having 0.001, 0.01, and 0.1 M concentration of bicarbonate ion gave corrosion rates of 20, 8, and 0.2 μm/yr, respectively. Corrosion potentials of specimens were also measured and compared with the AC impedance results. Both results indicated that bicarbonate ion could effectively reduce the corrosion rate of carbon steels in bentonite due to the formation of protective layer on the carbon steel. (author)

Conditioning of Si-interfaces by wet-chemical oxidation: Electronic interface properties study by surface photovoltage measurements

Energy Technology Data Exchange (ETDEWEB)

Angermann, Heike, E-mail: angermann@helmholtz-berlin.de

2014-09-01

Highlights: • Determination of electronic interface properties by contact-less surface photovoltage (SPV) technique. • Systematic correlations of substrate morphology and surface electronic properties. • Optimization of surface pre-treatment for flat, saw damage etched, and textured Si solar cell substrates. • Ultra-thin passivating Si oxide layers with low densities of rechargeable states by wet-chemical oxidation and subsequent annealing. • Environmentally acceptable processes, utilizing hot water, diluted HCl, or ozone low cost alternative to current approaches with concentrated chemicals. • The effect of optimized wet-chemical pre-treatments can be preserved during subsequent layer deposition. - Abstract: The field-modulated surface photovoltage (SPV) method, a very surface sensitive technique, was utilized to determine electronic interface properties on wet-chemically oxidized and etched silicon (Si) interfaces. The influence of preparation-induced surface micro-roughness and un-stoichiometric oxides on the resulting the surface charge, energetic distribution D{sub it}(E), and density D{sub it,min} of rechargeable states was studied by simultaneous, spectroscopic ellipsometry (SE) measurements on polished Si(111) and Si(100) substrates. Based on previous findings and new research, a study of conventional and newly developed wet-chemical oxidation methods was established, correlating the interactions between involved oxidizing and etching solutions and the initial substrate morphology to the final surface conditioning. It is shown, which sequences of wet-chemical oxidation and oxide removal, have to be combined in order to achieve atomically smooth, hydrogen terminated surfaces, as well as ultra-thin oxide layers with low densities of rechargeable states on flat, saw damage etched, and textured Si substrates, as commonly applied in silicon device and solar cell manufacturing. These conventional strategies for wet-chemical pre-treatment are mainly

Conditioning of Si-interfaces by wet-chemical oxidation: Electronic interface properties study by surface photovoltage measurements

International Nuclear Information System (INIS)

Angermann, Heike

2014-01-01

Highlights: • Determination of electronic interface properties by contact-less surface photovoltage (SPV) technique. • Systematic correlations of substrate morphology and surface electronic properties. • Optimization of surface pre-treatment for flat, saw damage etched, and textured Si solar cell substrates. • Ultra-thin passivating Si oxide layers with low densities of rechargeable states by wet-chemical oxidation and subsequent annealing. • Environmentally acceptable processes, utilizing hot water, diluted HCl, or ozone low cost alternative to current approaches with concentrated chemicals. • The effect of optimized wet-chemical pre-treatments can be preserved during subsequent layer deposition. - Abstract: The field-modulated surface photovoltage (SPV) method, a very surface sensitive technique, was utilized to determine electronic interface properties on wet-chemically oxidized and etched silicon (Si) interfaces. The influence of preparation-induced surface micro-roughness and un-stoichiometric oxides on the resulting the surface charge, energetic distribution D it (E), and density D it,min of rechargeable states was studied by simultaneous, spectroscopic ellipsometry (SE) measurements on polished Si(111) and Si(100) substrates. Based on previous findings and new research, a study of conventional and newly developed wet-chemical oxidation methods was established, correlating the interactions between involved oxidizing and etching solutions and the initial substrate morphology to the final surface conditioning. It is shown, which sequences of wet-chemical oxidation and oxide removal, have to be combined in order to achieve atomically smooth, hydrogen terminated surfaces, as well as ultra-thin oxide layers with low densities of rechargeable states on flat, saw damage etched, and textured Si substrates, as commonly applied in silicon device and solar cell manufacturing. These conventional strategies for wet-chemical pre-treatment are mainly based on

"Breath figures" on leaf surfaces-formation and effects of microscopic leaf wetness.

Science.gov (United States)

Burkhardt, Juergen; Hunsche, Mauricio

2013-01-01

"Microscopic leaf wetness" means minute amounts of persistent liquid water on leaf surfaces which are invisible to the naked eye. The water is mainly maintained by transpired water vapor condensing onto the leaf surface and to attached leaf surface particles. With an estimated average thickness of less than 1 μm, microscopic leaf wetness is about two orders of magnitude thinner than morning dewfall. The most important physical processes which reduce the saturation vapor pressure and promote condensation are cuticular absorption and the deliquescence of hygroscopic leaf surface particles. Deliquescent salts form highly concentrated solutions. Depending on the type and concentration of the dissolved ions, the physicochemical properties of microscopic leaf wetness can be considerably different from those of pure water. Microscopic leaf wetness can form continuous thin layers on hydrophobic leaf surfaces and in specific cases can act similar to surfactants, enabling a strong potential influence on the foliar exchange of ions. Microscopic leaf wetness can also enhance the dissolution, the emission, and the reaction of specific atmospheric trace gases e.g., ammonia, SO2, or ozone, leading to a strong potential role for microscopic leaf wetness in plant/atmosphere interaction. Due to its difficult detection, there is little knowledge about the occurrence and the properties of microscopic leaf wetness. However, based on the existing evidence and on physicochemical reasoning it can be hypothesized that microscopic leaf wetness occurs on almost any plant worldwide and often permanently, and that it significantly influences the exchange processes of the leaf surface with its neighboring compartments, i.e., the plant interior and the atmosphere. The omission of microscopic water in general leaf wetness concepts has caused far-reaching, misleading conclusions in the past.

Improved hydrogen sorption kinetics in wet ball milled Mg hydrides

Energy Technology Data Exchange (ETDEWEB)

Meng, Li

2011-05-04

In this work, wet ball milling method is used in order to improve hydrogen sorption behaviour due to its improved microstructure of solid hydrogen materials. Compared to traditional ball milling method, wet ball milling has benefits on improvement of MgH{sub 2} microstructure and further influences on its hydrogen sorption behavior. With the help of solvent tetrahydrofuran (THF), wet ball milled MgH{sub 2} powder has much smaller particle size and its specific surface area is 7 times as large as that of dry ball milled MgH{sub 2} powder. Although after ball milling the grain size is decreased a lot compared to as-received MgH{sub 2} powder, the grain size of wet ball milled MgH{sub 2} powder is larger than that of dry ball milled MgH{sub 2} powder due to the lubricant effect of solvent THF during wet ball milling. The improved particle size and specific surface area of wet ball milled MgH{sub 2} powder is found to be determining its hydrogen sorption kinetics especially at relatively low temperatures. And it also shows good cycling sorption behavior, which decides on its industrial applicability. With three different catalysts MgH{sub 2} powder shows improved hydrogen sorption behavior as well as the cyclic sorption behavior. Among them, the Nb{sub 2}O{sub 5} catalyst is found to be the most effective one in this work. Compared to the wet ball milled MgH{sub 2} powder, the particle size and specific surface area of the MgH{sub 2} powder with catalysts are similar to the previous ones, while the grain size of the MgH{sub 2} with catalysts is much finer. In this case, two reasons for hydrogen sorption improvement are suggested: one is the reduction of the grain size. The other may be as pointed out in some literatures that formation of new oxidation could enhance the hydrogen sorption kinetics, which is also the reason why its hydrogen capacity is decreased compared to without catalysts. After further ball milling, the specific surface area of wet ball milled Mg

Comparison of energy expenditure when moving on wet and dry clothes.

OpenAIRE

Hrubý, Pavel

2013-01-01

Title: Comparison of energy expenditure when moving on wet and dry clothes. Objectives: The aim of this study is to compare energy expenditure based on heart rate when moving in dryand wet clothes in different speeds. Methods: Quantitative research and subsequent intra-individual comparison of pulse frequency and energy expenditure when moving in dry and wet clothes. Movements were conducted on a treadmill and heart rate was measured by using sporttesters. Results: From the results we can ded...

Simulations of tropical rainforest albedo: is canopy wetness important?

Directory of Open Access Journals (Sweden)

Silvia N.M. Yanagi

Full Text Available Accurate information on surface albedo is essential for climate modelling, especially for regions such as Amazonia, where the response of the regional atmospheric circulation to the changes on surface albedo is strong. Previous studies have indicated that models are still unable to correctly reproduce details of the seasonal variation of surface albedo. Therefore, it was investigated the role of canopy wetness on the simulated albedo of a tropical rainforest by modifying the IBIS canopy radiation transfer code to incorporate the effects of canopy wetness on the vegetation reflectance. In this study, simulations were run using three versions of the land surface/ecosystem model IBIS: the standard version, the same version recalibrated to fit the data of albedo on tropical rainforests and a modified version that incorporates the effects of canopy wetness on surface albedo, for three sites in the Amazon forest at hourly and monthly scales. The results demonstrated that, at the hourly time scale, the incorporation of canopy wetness on the calculations of radiative transfer substantially improves the simulations results, whereas at the monthly scale these changes do not substantially modify the simulated albedo.

Wetting of water on graphene nanopowders of different thicknesses

Science.gov (United States)

Bera, Bijoyendra; Shahidzadeh, Noushine; Mishra, Himanshu; Belyaeva, Liubov A.; Schneider, Grégory F.; Bonn, Daniel

2018-04-01

We study the wetting of graphene nanopowders by measuring the water adsorption in nanopowder flakes of different flake thicknesses. Chemical analysis shows that the graphene flakes, especially the thin ones, might exist in the partially oxidized state. We observe that the thinnest graphene nanopowder flakes do not adsorb water at all, independent of the relative humidity. Thicker flakes, on the other hand, do adsorb an increasing amount of water with increasing humidity. This allows us to assess their wetting behavior which is actually the result of the competition between the adhesive interactions of water and graphene and the cohesive interactions of water. Explicit calculation of these contributions from the van der Waals interactions confirms that the adhesive interactions between very thin flakes of graphene oxide and water are extremely weak, which makes the flakes superhydrophobic. "Liquid marble" tests with graphene nanopowder flakes confirm the superhydrophobicity. This shows that the origin of the much debated "wetting transparency" of graphene is due to the fact that a single graphene or graphene oxide layer does not contribute significantly to the adhesion between a wetting phase and the substrate.

Wetting of water on graphene nanopowders of different thicknesses

KAUST Repository

Bera, Bijoyendra; Shahidzadeh, Noushine; Mishra, Himanshu; Belyaeva, Liubov A.; Schneider, Gré gory F.; Bonn, Daniel

2018-01-01

We study the wetting of graphene nanopowders by measuring the water adsorption in nanopowder flakes of different flake thicknesses. Chemical analysis shows that the graphene flakes, especially the thin ones, might exist in the partially oxidized state. We observe that the thinnest graphene nanopowder flakes do not adsorb water at all, independent of the relative humidity. Thicker flakes, on the other hand, do adsorb an increasing amount of water with increasing humidity. This allows us to assess their wetting behavior which is actually the result of the competition between the adhesive interactions of water and graphene and the cohesive interactions of water. Explicit calculation of these contributions from the van der Waals interactions confirms that the adhesive interactions between very thin flakes of graphene oxide and water are extremely weak, which makes the flakes superhydrophobic. “Liquid marble” tests with graphene nanopowder flakes confirm the superhydrophobicity. This shows that the origin of the much debated “wetting transparency” of graphene is due to the fact that a single graphene or graphene oxide layer does not contribute significantly to the adhesion between a wetting phase and the substrate.

Wetting of water on graphene nanopowders of different thicknesses

KAUST Repository

Bera, Bijoyendra

2018-04-12

We study the wetting of graphene nanopowders by measuring the water adsorption in nanopowder flakes of different flake thicknesses. Chemical analysis shows that the graphene flakes, especially the thin ones, might exist in the partially oxidized state. We observe that the thinnest graphene nanopowder flakes do not adsorb water at all, independent of the relative humidity. Thicker flakes, on the other hand, do adsorb an increasing amount of water with increasing humidity. This allows us to assess their wetting behavior which is actually the result of the competition between the adhesive interactions of water and graphene and the cohesive interactions of water. Explicit calculation of these contributions from the van der Waals interactions confirms that the adhesive interactions between very thin flakes of graphene oxide and water are extremely weak, which makes the flakes superhydrophobic. “Liquid marble” tests with graphene nanopowder flakes confirm the superhydrophobicity. This shows that the origin of the much debated “wetting transparency” of graphene is due to the fact that a single graphene or graphene oxide layer does not contribute significantly to the adhesion between a wetting phase and the substrate.

Wetting phase permeability in a partially saturated horizontal fracture

International Nuclear Information System (INIS)

Nicholl, M.J.; Glass, R.J.

1994-01-01

Fractures within geologic media can dominate the hydraulic properties of the system. Therefore, conceptual models used to assess the potential for radio-nuclide migration in unsaturated fractured rock such as that composing Yucca Mountain, Nevada, must be consistent with flow processes in individual fractures. A major obstacle to the understanding and simulation of unsaturated fracture flow is the paucity of physical data on both fracture aperture structure and relative permeability. An experimental procedure is developed for collecting detailed data on aperture and phase structure from a transparent analog fracture. To facilitate understanding of basic processes and provide a basis for development of effective property models, the simplest possible rough-walled fracture is used. Stable phase structures of varying complexity are created within the horizontal analog fracture. Wetting phase permeability is measured under steady-state conditions. A process based model for wetting phase relative permeability is then explored. Contributions of the following processes to reduced wetting phase permeability under unsaturated conditions are considered: reduction in cross-sectional flow area, increased path length, localized flow restriction, and preferential occupation of large apertures by the non-wetting phase

ROE Wet Sulfate Deposition 2009-2011

Data.gov (United States)

U.S. Environmental Protection Agency — The raster data represent the amount of wet sulfate deposition in kilograms per hectare from 2009 to 2011. Summary data in this indicator were provided by EPA’s...

Wet flue gas desulphurization and new fuels

Energy Technology Data Exchange (ETDEWEB)

Kiil, S.; Dam-Johansen, K.; Michelsen, M.L.

1998-04-01

This thesis describes experimental and theoretical investigations of wet flue gas desulphurization (FGD). A review of the current knowledge of the various rate determining steps in wet FDG plants is presented. The mechanism underlying the rate of dissolution of finely grained limestone particles was examined in a laboratory batch apparatus using acid titration. Three Danish limestones of different origin were tested. A transient, mass transport controlled, mathematical model was developed to describe the dissolution process. Model predictions were found to be qualitatively in good agreement with experimental data. Empirical correlations for the dimensionless mass transfer coefficients in a pilot plant (falling-film column) were determined. The presence of inert particles in the liquid phase was found to decrease the rate of gas phase mass transport with up to 15%, though the effect could not be correlated. A detailed model for a wet FGD pilot plant, based on the falling film principle, was developed. All important rate determining steps, absorption of SO{sub 2}, oxidation of HSO{sub 3}{sup -}, dissolution of limestone, and crystallisation of gypsum were included. Model predictions were compared to experimental data such as gas phase concentration profiles of SO{sub 2}, slurry pH-profiles, solids contents of slurry, liquid phase concentrations, and residual limestone in the gypsum. The possibility of co-firing straw and coal was investigated in a full-scale power plant. No effects on the overall performance of the wet FGD plant were observed, though laboratory experiments with fine dust and fly ash from the full-scale experiments showed a decrease in limestone reactivity. (EG) EFP-95. 45 refs.; Also ph.d. thesis of Soeren Kiil

Formation of Pentacene wetting layer on the SiO2 surface and charge trap in the wetting layer

International Nuclear Information System (INIS)

Kim, Chaeho; Jeon, D.

2008-01-01

We studied the early-stage growth of vacuum-evaporated pentacene film on a native SiO 2 surface using atomic force microscopy and in-situ spectroscopic ellipsometry. Pentacene deposition prompted an immediate change in the ellipsometry spectra, but atomic force microscopy images of the early stage films did not show a pentacene-related morphology other than the decrease in the surface roughness. This suggested that a thin pentacene wetting layer was formed by pentacene molecules lying on the surface before the crystalline islands nucleated. Growth simulation based on the in situ spectroscopic ellipsometry spectra supported this conclusion. Scanning capacitance microscopy measurement indicated the existence of trapped charges in the SiO 2 and pentacene wetting layer

Anisotropic wetting characteristics versus roughness on machined surfaces of hydrophilic and hydrophobic materials

International Nuclear Information System (INIS)

Liang, Yande; Shu, Liming; Natsu, Wataru; He, Fuben

2015-01-01

Graphical abstract: - Highlights: • The aim is to investigate the influence of roughness on anisotropic wetting on machined surfaces. • The relationship between roughness and anisotropic wetting is modeled by thermodynamical analysis. • The effect of roughness on anisotropic wetting on hydrophilic materials is stronger than that on hydrophobic materials. • The energy barrier existing in the direction perpendicular to the lay is one of the main reasons for the anisotropic wetting. • The contact angle in the parallel direction is larger than that in the perpendicular direction. - Abstract: Anisotropic wetting of machined surfaces is widely applied in industries which can be greatly affected by roughness and solid's chemical properties. However, there has not been much work on it. A free-energy thermodynamic model is presented by analyzing geometry morphology of machined surfaces (2-D model surfaces), which demonstrates the influence of roughness on anisotropic wetting. It can be concluded that the energy barrier is one of the main reasons for the anisotropic wetting existing in the direction perpendicular to the lay. In addition, experiments in investigating anisotropic wetting, which was characterized by the static contact angle and droplet's distortion, were performed on machined surfaces with different roughness on hydrophilic and hydrophobic materials. The droplet's anisotropy found on machined surfaces increased with mean slope of roughness profile Kr. It indicates that roughness on anisotropic wetting on hydrophilic materials has a stronger effect than that on hydrophobic materials. Furthermore, the contact angles predicted by the model are basically consistent with the experimentally ones

Determination of optimal wet ethanol composition as a fuel in spark ignition engine

International Nuclear Information System (INIS)

Fagundez, J.L.S.; Sari, R.L.; Mayer, F.D.; Martins, M.E.S.; Salau, N.P.G.

2017-01-01

Highlights: • Batch distillation to produce HEF and fuel blends of wet ethanol. • Conversion efficiency of a SI engine operating with HEF and wet ethanol. • NEF as a new metric to calculate the energy efficiency of HEF and wet ethanol. • Optimal wet ethanol composition as a fuel in SI engine based on NEF. - Abstract: Studies are unanimous that the greatest fraction of the energy necessary to produce hydrous ethanol fuel (HEF), i.e. above 95%v/v of ethanol in water, is spent on water removal (distillation). Previous works have assessed the energy efficiency of HEF; but few, if any, have done the same for wet ethanol fuel (sub-azeotropic hydrous ethanol). Hence, a new metric called net energy factor (NEF) is proposed to calculate the energy efficiency of wet ethanol and HEF. NEF calculates the ratio of Lower Heating Value (LHV) derived from ethanol fuel, total energy out, to energy used to obtain ethanol fuel as distillate, total energy in. Distillation tests were performed batchwise to obtain as distillate HEF and four different fuel blends of wet ethanol with a range from 60%v/v to 90%v/v of ethanol and the amount of energy spent to distillate each ethanol fuel calculated. The efficiency parameters of a SI engine operating with the produced ethanol fuels was tested to calculate their respective conversion efficiency. The results of net energy factors show a clear advantage of wet ethanol fuels over HEF; the optimal efficiency was wet ethanol fuel with 70%v/v of ethanol.

Precipitation chemistry and wet deposition in a remote wet savanna site in West Africa: Djougou (Benin)

Science.gov (United States)

Akpo, A. B.; Galy-Lacaux, C.; Laouali, D.; Delon, C.; Liousse, C.; Adon, M.; Gardrat, E.; Mariscal, A.; Darakpa, C.

2015-08-01

In the framework of the IDAF (IGAC/DEBITS/AFrica) international program, this study aims to study the chemical composition of precipitation and associated wet deposition at the rural site of Djougou in Benin, representative of a West and Central African wet savanna. Five hundred and thirty rainfall samples were collected at Djougou, Benin, from July 2005 to December 2009 to provide a unique database. The chemical composition of precipitation was analyzed for inorganic (Ca2+, Mg2+, Na+, NH4+, K+, NO3-, Cl-, SO42-) and organic (HCOO-, CH3COO-, C2H5COO-, C2O42-) ions, using ion chromatography. The 530 collected rain events represent a total of 5706.1 mm of rainfall compared to the measured pluviometry 6138.9 mm, indicating that the collection efficiency is about 93%. The order of total annual loading rates for soluble cations is NH4+ > Ca2+ > Mg2+ > K+. For soluble anions the order of loading is carbonates > HCOO- > NO3- > CH3COO- > SO42- > Cl- > C2O42- > C2H5COO-. In the wet savanna of Djougou, 86% of the measured pH values range between 4.7 and 5.7 with a median pH of 5.19, corresponding to a VWM (Volume Weighed Mean) H+ concentration of 6.46 μeq·L-1. This acidity results from a mixture of mineral and organic acids. The annual sea salt contribution was computed for K+, Mg2+, Ca2+ and SO42- and represents 4.2% of K+, 41% of Mg2+, 1.3% of Ca2+, and 7.4% of SO42-. These results show that K+, Ca2+, SO42-, and Mg2+ were mainly of non-marine origin. The marine contribution is estimated at 9%. The results of the chemical composition of rainwater of Djougou indicates that, except for the carbonates, ammonium has the highest VWM concentration (14.3 μeq·L-1) and nitrate concentration is 8.2 μeq·L-1. The distribution of monthly VWM concentration for all ions is computed and shows the highest values during the dry season, comparing to the wet season. Identified nitrogenous compound sources (NOx and NH3) are domestic animals, natural emissions from savanna soils, biomass

Wet-air oxidation cleans up black wastewater

Energy Technology Data Exchange (ETDEWEB)

1993-09-01

Sterling Organics produces the analgesic paracetamol (acetaminophen) at its Dudley, England, plant. The wastewater from the batch process contains intermediates such as para-aminophenol (PAP) and byproducts such as thiosulfates, sulfites and sulfides. To stay ahead of increasingly strict environmental legislation, Sterling Organics installed a wet-air oxidation system at the Dudley facility in August 1992. The system is made by Zimpro Environmental Inc. (Rothschild, Wis.). Zimpro's wet-air oxidation system finds a way around the limitations of purely chemical or physical processes. In the process, compressed air at elevated temperature and pressure oxidizes the process intermediates and byproducts and removes the color from the wastewater.

Numerical study on over reading coefficient in wet steam flow measurement

International Nuclear Information System (INIS)

Bai Xuesong; Yuan Dewen; Yan Xiao; Peng Xingjian

2013-01-01

This paper investigated the flow process of wet steam in Venturi under interested conditions with CFD simulation software. The effect of pressure, mass flow rate, throat radius on over reading factor was analyzed. This paper aims to improve the wet steam over reading model and the prediction accuracy in wet steam. The results prove that the mass flow has a small effect on over reading coefficient, while the effect that throat radius has on over reading coefficient increases as the pressure rises. (authors)

Organic micropollutants in wet and dry depositions in the Venice Lagoon.

Science.gov (United States)

Gambaro, Andrea; Radaelli, Marta; Piazza, Rossano; Stortini, Angela Maria; Contini, Daniele; Belosi, Franco; Zangrando, Roberta; Cescon, Paolo

2009-08-01

Atmospheric transport is an important route by which pollutants are conveyed from the continents to both coastal and open sea. The role of aerosol deposition in the transport of polycyclic aromatic hydrocarbons (PAHs), polychlorobiphenyls (PCBs) and polybromodiphenyls ethers (PBDEs) to water and soil systems has been evaluated by measuring their concentrations in wet and dry depositions to the Venice Lagoon. The organic micropollutant flux data indicate that they contribute to the total deposition flux in different ways through wet and dry deposition, showing that the prevalent contribution derives from wet deposition. The fluxes calculated for PBDEs, showed the prevalence of 47, 99, 100 and 183 congeners, both in dry and wet fluxes. With regard to PCBs, the flux of summation operatorPCB for wet deposition is in the same order of magnitude of the diffusive flux at the air-water interface. The PAH fluxes obtained in the present study are similar to those obtained in previous studies on the atmospheric bulk deposition to the Venice Lagoon. The ratios between Phe/Ant and Fl/Py indicate that the pollutants sources are pyrolytic, deriving from combustion fuels.

Exposure to wet work in working Australians.

Science.gov (United States)

Keegel, Tessa G; Nixon, Rosemary L; LaMontagne, Anthony D

2012-02-01

The Australian National Hazard Exposure Worker Surveillance (NHEWS) Survey 2008 was a cross-sectional survey undertaken by Safe Work Australia to inform the development of exposure prevention initiatives for occupational disease. This is a descriptive study of workplace exposures. To assess the occupational and demographic characteristics of workers reporting exposure to wet work. Computer-assisted telephone interviews were conducted with 4500 workers. Two wet work exposure outcomes (frequent washing of hands and duration of time spent at work with the hands immersed in liquids) were analysed. The response rate for the study was 42.3%. For hand-washing, 9.8% [95% confidence interval (CI) 8.9-10.7] reported washing their hands more than 20 times per day. For immersion of hands in liquids, 4.5% (95% CI 3.9-5.1) reported immersion for more than 2 hr per day. Females were more likely to report exposure to frequent hand-washing than males [odds ratio (OR) 1.97, 95% CI 1.49-2.61]. Workers in the lowest occupational skill level jobs were more likely to report increased exposure to hands immersed in liquids than those in the highest (OR 6.41, 95% CI 3.78-10.88). Workers reporting skin exposure to chemicals were more likely to report exposure to hand-washing (OR 3.68, 95% CI 2.91-4.66) and immersion of the hands in liquids (OR 4.09, 95% CI 2.92-5.74). Specific groups of workers reported high levels of exposure to wet work. There were differences between the profiles of workers reporting frequent hand-washing and workers reporting increased duration of exposure to hands immersed in liquids. We also found a high correlation between wet work and chemical exposure. © 2011 John Wiley & Sons A/S.

Core-shell polymer nanorods by a two-step template wetting process

International Nuclear Information System (INIS)

Dougherty, S; Liang, J

2009-01-01

One-dimensional core-shell polymer nanowires offer many advantages and great potential for many different applications. In this paper we introduce a highly versatile two-step template wetting process to fabricate two-component core-shell polymer nanowires with controllable shell thickness. PLLA and PMMA were chosen as model polymers to demonstrate the feasibility of this process. Solution wetting with different concentrations of polymer solutions was used to fabricate the shell layer and melt wetting was used to fill the shell with the core polymer. The shell thickness was analyzed as a function of the polymer solution concentration and viscosity, and the core-shell morphology was observed with TEM. This paper demonstrates the feasibility of fabricating polymer core-shell nanostructures using our two-step template wetting process and opens the arena for optimization and future experiments with polymers that are desirable for specific applications.

Critical Casimir forces and anomalous wetting

Indian Academy of Sciences (India)

(3) With Dirichlet boundary conditions, the critical temperature in the film is sig- ... studies: new experiments should identify the origin of the L-dependence, and ... and complete wetting should occur as T approaches Tt. The above argument is ...

Water Productivity of Irrigated Rice under Transplanting, Wet Seeding and Dry Seeding Methods of Cultivation

Directory of Open Access Journals (Sweden)

Murali, NS.

1997-01-01

Full Text Available Water productivity (WP of irrigated lowland rice was determined during the 1994 dry (January to May and wet (August to December seasons on a heavy clay acid sulphate soil. Treatments consisted of three cultivation methods : transplanted rice, pregerminated seeds broadcasted on puddled soil (wet seeding and dry seeds broadcasted on unpuddled soil (dry seeding. In wet and dry seeded plots, continuous standing water condition was initiated 17 days after sowing. Total water requirement for rice production was highest in transplanted plots (755 mm in wet season and 1154 mm in dry season and was lowest in dry seeded plots (505 mm in wet season and 1040 mm in dry season. Dry seeding required no water for land preparation but transplanting and wet seeding methods required 18 - 20 % of total water requirement in dry season and 27 - 29 % in wet season. Total percolation was maximum (99 mm in wet season and 215 mm in dry season in dry seeding method and was minimum (62 mm in wet season and 94 mm in dry season in transplanting method. In dry and wet seeding methods, daily percolation gradually decreased with the age of the crop. Total seepage loss did not show any significant difference between the cultivation methods in the two seasons. Grain yield was not affected by the three cultivation methods in both seasons. Water productivity (the ratio between grain yield and total amount of water used in production was 3.5 - 4.1 kg ha-1 mm-1, 3.8 - 4.4 kg ha-1 mm-1 and 4.1 - 5.5 kg ha-1 mm-1 in transplanted, wet seeded and dry seeded rice, respectively. Labour requirement for land preparation and sowing was maximum in transplanted (219 - 226 man-hours ha-1 followed by wet (104 -112 man-hours ha-1 and dry seeded (94 - 99 man-hours ha-1 methods. However, in wet season extra labour (77 man-hours ha-1 was required for weeding after crop establishment in dry and wet seeding methods. Crop maturity was 20 days earlier in wet and dry seeding methods compared to

Robust non-wetting PTFE surfaces by femtosecond laser machining.

Science.gov (United States)

Liang, Fang; Lehr, Jorge; Danielczak, Lisa; Leask, Richard; Kietzig, Anne-Marie

2014-08-08

Nature shows many examples of surfaces with extraordinary wettability,which can often be associated with particular air-trapping surface patterns. Here,robust non-wetting surfaces have been created by femtosecond laser ablation of polytetrafluoroethylene (PTFE). The laser-created surface structure resembles a forest of entangled fibers, which support structural superhydrophobicity even when the surface chemistry is changed by gold coating. SEM analysis showed that the degree of entanglement of hairs and the depth of the forest pattern correlates positively with accumulated laser fluence and can thus be influenced by altering various laser process parameters. The resulting fibrous surfaces exhibit a tremendous decrease in wettability compared to smooth PTFE surfaces; droplets impacting the virgin or gold coated PTFE forest do not wet the surface but bounce off. Exploratory bioadhesion experiments showed that the surfaces are truly air-trapping and do not support cell adhesion. Therewith, the created surfaces successfully mimic biological surfaces such as insect wings with robust anti-wetting behavior and potential for antiadhesive applications. In addition, the fabrication can be carried out in one process step, and our results clearly show the insensitivity of the resulting non-wetting behavior to variations in the process parameters,both of which make it a strong candidate for industrial applications.

Robust Non-Wetting PTFE Surfaces by Femtosecond Laser Machining

Directory of Open Access Journals (Sweden)

Fang Liang

2014-08-01

Full Text Available Nature shows many examples of surfaces with extraordinary wettability, which can often be associated with particular air-trapping surface patterns. Here, robust non-wetting surfaces have been created by femtosecond laser ablation of polytetrafluoroethylene (PTFE. The laser-created surface structure resembles a forest of entangled fibers, which support structural superhydrophobicity even when the surface chemistry is changed by gold coating. SEM analysis showed that the degree of entanglement of hairs and the depth of the forest pattern correlates positively with accumulated laser fluence and can thus be influenced by altering various laser process parameters. The resulting fibrous surfaces exhibit a tremendous decrease in wettability compared to smooth PTFE surfaces; droplets impacting the virgin or gold coated PTFE forest do not wet the surface but bounce off. Exploratory bioadhesion experiments showed that the surfaces are truly air-trapping and do not support cell adhesion. Therewith, the created surfaces successfully mimic biological surfaces such as insect wings with robust anti-wetting behavior and potential for antiadhesive applications. In addition, the fabrication can be carried out in one process step, and our results clearly show the insensitivity of the resulting non-wetting behavior to variations in the process parameters, both of which make it a strong candidate for industrial applications.

Converting SDAP into gypsum in a wet limestone scrubber

Energy Technology Data Exchange (ETDEWEB)

Fogh, F [Faelleskemikerne, Elsamprojekt A/S, Fredericia (Denmark)

1996-12-01

The ELSAM power pool has an installed electrical capacity of approx. 5 GW{sub e}, mainly firing import coal. The major base load units are equipped with desulphurization units and three different desulphurization technologies are used: the wet limestone gypsum process, the spray dry absorption process and a sulphuric acid process. Gypsum and sulphuric acid are commercialized, whereas it has been difficult to utilize the spray dry absorption product (SDAP). The main constituents of SDAP are calcium sulphide, calcium chloride, hydrated lime and impurities mainly originating from fly ash. Sulphide can be oxidized into sulphate in acidic solution - the reaction is utilized in the wet limestone gypsum process - and the possibility of using any spare capacity in the wet limestone gypsum units to oxidize the sulphide content of SDAP into sulphate and produce usable gypsum has been investigated in the laboratory and in a 400 MW{sub e} equivalent wet limestone unit. The limestone inhibition effect of the addition of SDAP is currently being studied in the laboratory in order to determine the effect of different SDAP types (plant/coal sources) on limestone reactivity before further long-term full-scale tests are performed and permanent use of the process planned. (EG)

A review of monitoring methods for pharmaceutical wet granulation.

Science.gov (United States)

Hansuld, E M; Briens, L

2014-09-10

High-shear wet granulation is commonly used in the pharmaceutical industry to improve powder properties for downstream processes such as tabletting. Granule growth, however, is difficult to predict because the process is sensitive to raw material properties and operating conditions. Development of process analytical technologies is encouraged by regulatory bodies to improve process understanding and monitor quality online. The primary technologies investigated for high-shear wet granulation monitoring include power consumption, near-infrared spectroscopy, Raman spectroscopy, capacitance measurements, microwave measurements, imaging, focused beam reflectance measurements, spatial filter velocimetry, stress and vibration measurements, as well as acoustic emissions. This review summarizes relevant research related to each of these technologies and discusses the challenges associated with each approach as a possible process analytical technology tool for high-shear wet granulation. Copyright © 2014 Elsevier B.V. All rights reserved.

Analysis of corrosion products of carbon steel in wet bentonite

International Nuclear Information System (INIS)

Osada, K.; Nagano, T.; Kozai, N.; Nakashima, S.; Nakayama, S.; Muraoka, S.

1991-01-01

The following conclusions were obtained; (1) At 40degC, the average corrosion rate of SS41 carbon steel in wet bentonite was 0.025 mm/y. This is smaller than the value of 0.042 mm/y obtained in pure water at 40degC. However, at 95degC, the corrosion rate of SS41 carbon steel in wet bentonite was 0.27 mm/y, which is much larger than that in pure water at 95degC. (2) At 95degC, γ-FeO(OH) (lepidocrocite) was formed only in wet bentonite, and it was absent in pure water. Evaporation of moisture resulted in the formation of partial covering of bentonite, which promoted local corrosion. Consequently, γ-FeO(OH) was considered to be formed. (3) In wet bentonite at 95degC, α-Fe 2 O 3 (hematite) can be identified by means of colorimetry. The color of corrosion products is orangish, indicating the contribution of α-Fe 2 O 3 in iron hydroxides. (author)

Fatigue Performance of SFPSC under Hot-Wet Environments and Cyclic Bending Loads

Directory of Open Access Journals (Sweden)

Shanshan Luo

2018-01-01

Full Text Available A new structural material named “steel fiber polymer structural concrete (SFPSC” with features of both high strength and high toughness was developed by this research group and applied to the bridge superstructures in the hot-wet environments. In order to investigate the fatigue performance and durability of SFPSC under hot-wet environments, the environment and fatigue load uncoupling method and the coupling action of environment and fatigue load were used or developed. Three-point bending fatigue experiments with uncoupling action of environments and cyclic loads were carried out for SFPSC specimens which were pretreated under hot-wet environments, and the experiments with the coupling action of environments and cyclic loads for SFPSC specimens were carried out under hot-wet environments. Then, the effects of hot-wet environments and the experimental methods on the fatigue mechanism of SFPSC material were discussed, and the environmental fatigue equations of SFPSC material under coupling and uncoupling action of hot-wet environments and cyclic bending loads were established. The research results show that the fatigue limits of SFPSC under the coupling action of the environments and cyclic loads were lower about 15%. The proposed fatigue equations could be used to estimate the fatigue lives and fatigue limits of SFPSC material.

The wetting behavior of alkanes on water

Energy Technology Data Exchange (ETDEWEB)

Ragil, Karine; Broseta, Daniel; Kalaydjian, Francois [Institut Francais du Petrole, BP 311, 92852 Rueil Malmaison Cedex (France); Bonn, Daniel; Meunier, Jacques [ENS, Laboratoire de Physique Statistique, 24 rue Lhomond, 75231 Paris Cedex 05 (France); Indekeu, Joseph [Katholieke Universiteit Leuven, Laboratorium voor Vaste-Stoffysica en Magnetisme, B-3001 Leuven (Belgium)

1998-06-06

This paper presents recent experimental and theoretical results concerning the wetting behavior of n-alkanes on water as a function of thermodynamic conditions (i.e., temperature, pressure, etc.). The transition from lenses to a macroscopically thick film, that takes place when the temperature is increased, occurs for n-alkanes on water in a manner very different from that encountered in other fluid systems. For n-pentane on water, ellipsometric measurements reveal that the growth of the pentane layer to a macroscopically thick film occurs in a continuous manner, for a temperature ({approx}53C) corresponding to a change in the sign of the Hamaker constant. A theoretical approach based on the Cahn-Landau theory, which takes into account long-range (van der Waals) forces, enables us to explain the mechanism of this continuous wetting transition. This transition is preceded (at a lower temperature) by a discontinuous transition from a thin film (of adsorbed molecules) to a thick (but not macroscopically thick) film. The latter transition was not visible for pentane on water (it should occur below the freezing temperature for water), but we expect to observe it for longer alkanes (e.g., hexane) on water. Work is underway to examine the wetting behavior of oil/brine systems more representative of reservoir conditions

A novel nano-hydroxyapatite — PMMA hybrid scaffolds adopted by conjugated thermal induced phase separation (TIPS) and wet-chemical approach: Analysis of its mechanical and biological properties

Energy Technology Data Exchange (ETDEWEB)

G, Radha [National Centre for Nanoscience and Nanotechnology, University of Madras, Guindy Campus, Chennai 600025 (India); S, Balakumar, E-mail: balasuga@yahoo.com [National Centre for Nanoscience and Nanotechnology, University of Madras, Guindy Campus, Chennai 600025 (India); Venkatesan, Balaji; Vellaichamy, Elangovan [Department of Biochemistry, University of Madras, Guindy Campus, Chennai 600025 (India)

2017-06-01

In this study, we report the preparation of nano-hydroxyapatite (nHAp) incorporated poly(methyl methacrylate) (PMMA) scaffolds by conjugated thermal induced phase separation (TIPS) and wet-chemical approach, which essentially facilitates the enhancement of both mechanical as well as biological properties of the scaffolds. The dissolution of PMMA was accomplished by acetone (Ace scaffold), ethanol-water (E-W scaffold) and isopropanol-water (I-W scaffold) mixtures as solvents. The existence of nHAp in PMMA matrix was investigated systematically. The higher degree of porous architecture was achieved from Ace scaffolds compared to both I-W and E-W scaffolds. On the other hand, the dense porous architecture of the I-W scaffold exhibited superior hardness and compressive strength than that of the Ace and E-W scaffolds. All the fabricated samples demonstrated enhanced in vitro bioactivity with respect to increasing immersion period as a result of flower-like in vitro apatite layer formation. The MTT assay was carried out for 1 day and 3 day culture using Saos-2 osteoblast-like cells, which showed better cell proliferation with increasing culture period owing to the interconnected pore architecture of scaffolds and the rational hemocompatibility as per the ASTM standard F756-00. - Highlights: • Conjugated TIPS – wet chemical derived strategy was adopted for PMMA-nHAp composite scaffolds preparation. • TIPS method was carried out by varying solvents such as acetone, isopropanol-water and ethanol-water mixtures. • The impact of solvents on porosity and mechanical properties has been explored. • The existence of nHAp in PMMA has improved in-vitro bioactivity through apatitic-flowers formation. • Hemocompatibility of the scaffolds are in agreement with ASTM standards.

Wetting kinetics of water nano-droplet containing non-surfactant nanoparticles: A molecular dynamics study

International Nuclear Information System (INIS)

Lu, Gui; Hu, Han; Sun, Ying; Duan, Yuanyuan

2013-01-01

In this Letter, dynamic wetting of water nano-droplets containing non-surfactant gold nanoparticles on a gold substrate is examined via molecular dynamics simulations. The results show that the addition of non-surfactant nanoparticles hinders the nano-second droplet wetting process, attributed to the increases in both surface tension of the nanofluid and friction between nanofluid and substrate. The droplet wetting kinetics decreases with increasing nanoparticle loading and water-particle interaction energy. The observed wetting suppression and the absence of nanoparticle ordering near the contact line of nano-sized droplets differ from the wetting behaviors reported from nanofluid droplets of micron size or larger

What to Do If Your Appliances Are Wet After a Disaster

Centers for Disease Control (CDC) Podcasts

2006-08-10

If your home was flooded, look for signs that your appliances have gotten wet. Throw away wet or flooded appliances to protect from shock and fire.  Created: 8/10/2006 by Emergency Communications System.   Date Released: 7/30/2008.

Control technology for crystalline silica exposures in construction: wet abrasive blasting.

Science.gov (United States)

Golla, Vijay; Heitbrink, William

2004-03-01

This study was designed to document the effect that wet abrasive blasting has on reducing worker exposure to crystalline silica, which has been associated with silicosis and premature death. In this study, worker exposure to respirable crystalline silica was monitored during wet abrasive blasting on the exterior walls of a parking garage to remove surface concrete and expose the underlying aggregate. In this process a wet sand mix comprised of 80% dry sand and 20% water was used. Sampling and analysis revealed that the geometric mean respirable quartz concentration was 0.2 mg/m(3) for workers conducting abrasive blasting and 0.06 mg/m(3) for helpers. When abrasive blasting was conducted in areas that apparently had reduced natural ventilation, dust exposures appeared to increase. When compared with other published data, this case study suggests that wet abrasive blasting causes less exposure to crystalline silica than dry abrasive blasting.

Fate and wetting potential of bio-refractory organics in membrane distillation for coke wastewater treatment.

Science.gov (United States)

Ren, Jing; Li, Jianfeng; Chen, Zuliang; Cheng, Fangqin

2018-06-02

Membrane distillation (MD) has been hindered in industrial applications due to the potential wetting or fouling caused by complicated organic compositions. This study investigated the correlations between the fate and wetting potential of bio-refractory organics in the MD process, where three coke wastewater samples pre-treated with bio-degradation and coagulation served as feed solutions. Results showed that although most of the bio-refractory organics in coke wastewater were rejected by the hydrophobic membrane, some volatile aromatic organics including benzenes, phenols, quinolines and naphthalenes passed through the membrane during the MD process. Interestingly, membrane wetting occurred coincidently with the penetration of phenolic and heterocyclic organics. The wetting rate was obviously correlated with the feed composition and membrane surface properties. Ultimately, novel insights into the anti-wetting strategy of MD with bio-refractory organics was proposed, illustrating that the polyaluminum chloride/polyacrylamide coagulation not only removed contaminants which could accelerate membrane wetting, but also retarded membrane wetting by the complexation with organics. The deposition of these complexes on the membrane surface introduced a secondary hydrophilic layer on the hydrophobic substrate, which established a composite membrane structure with superior wetting resistance. These new findings would be beneficial to wetting control in membrane distillation for wastewater treatment. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Effect of Wetting on The Course of The Drum Granulation

Directory of Open Access Journals (Sweden)

Błaszczyk Michał

2017-06-01

Full Text Available This paper presents the results of experimental drum granulation of silica flour with the use of wetting liquids with different values of surface tension. Additionally, different liquid jet breakup and different residual moisture of the bed were applied in the tests. The process was conducted periodically in two stages: wetting and proper granulation, during which no liquid was supplied to the bed. The condition of the granulated material after the period of wetting (particle size distribution and moisture of separate fractions and a change in the particle size distribution during the further conduct of the process (granulation kinetics were determined.

WASTECOST-Wet - developed for Electric Power Research Institute

International Nuclear Information System (INIS)

Anon.

1996-01-01

WASTECOST-Wet specifically addresses liquid processing systems and their impact on solid waste volumes. The WASTECOST-Wet code models the entire liquid processing activity from media descriptions and volume throughput to solid waste volume generated, processing efficiency and disposal costs. WASTECOST gives a detailed economic and performance view of liquid waste processing activities. The code provides users a standardized methodology for calculating and comparing costs and system performance characteristics. Detailed reports are provided showing major costs centers. Performance and cost factors include gallons processed per cubic foot of waste generated, cost per cubic foot of waste generated and cost per gallon processed

Results on (UNPublished Wet Runs on Pulsating DB White Dwarfs

Directory of Open Access Journals (Sweden)

Handler G.

2003-03-01

Full Text Available I have collected all the WET archival data on the pulsating DB white dwarf stars (DBVs and re-reduced them. In addition, the WET has recently observed three DBVs. Preliminary results on PG 1115+158, PG 1351+489, KUV 05134+2605, PG 1654+160 and PG 1456+103 are presented, and the future use of the data is outlined.

Investigation into the surface of implanted monocrystalline silicon with the aid of wetting angle

International Nuclear Information System (INIS)

Lebedeva, N.N.; Bakovets, V.V.; Sedymova, E.A.; Pridachin, N.B.

1986-01-01

The dependence of silicon wetting margical angle on its irradiation dose by ions of electrically active and neutral materials is studied. It has been found that the system of immiscible liquids - ether and water can be successfully used for studying the silicon ion implantation effect on its water wetting. Changing of implanted silicon wetting is bound up with the increase of the defects presence level of surface layers. The specimens annealing reestablishes silicon wetting up to parameters characteristic of non irradiated specimens. The most effective annealing region is within the 550-700 deg C range. The implanted silicon wetting by melts at increased temperatures can be employed for studying kinetics and defect annealing mechanism

Wet deposition flux of trace elements to the Adirondack region

International Nuclear Information System (INIS)

Huang, X.; Keskin, S.S.; Gullu, G.; Olmez, I.

2001-01-01

Wet deposition samples from two locations in the Adirondack region of New York were analyzed for trace elemental composition by instrumental neutron activation analysis. Annual fluxes of the measured species were determined by precipitation-weighted and linear-regression methods. Despite several episodes of high deposition fluxes, the cumulative areal wet deposition of trace elements increased fairly linearly (r 2 > 0.9) over the two year sampling period at both sites. This implies that short duration sampling programs may be used to estimate long-term fluxes and cumulative wet deposition impacts. Based on the magnitude of their fluxes, the measured species have been divided into four groups: acidic anions, electroneutral balancing cations, and minor and trace elements of anthropogenic origin. (author)

Recent advances in treatment of wet age-related macular degeneration

Directory of Open Access Journals (Sweden)

Ming Li

2015-02-01

Full Text Available Age-related macular degeneration(AMDis one of the important eye diseases of the WHO present three big blindness, is one of the main blinding eye disease in people over the age of 50, people over the age of 65, about 2% of the disease caused by monocular blindness, as the population ages, AMD prevalence is increasing in our country. AMD with respect to its clinical manifestations can be divided into dry AMD and wet AMD, wet AMD is the most harmful for the vision of patients, at present there are many treatments for AMD(mainly for wet age-related macular degeneration, mainly including laser treatment, drug therapy, surgical treatment, gene therapy,etc. The treatments of AMD would be illuminated in this article.

Management of Herbaceous Seeps and Wet Savannas for Threatened and Endangered Species

National Research Council Canada - National Science Library

Harper, Mary

1998-01-01

Wetland communities such as herbaceous seeps and wet savannas occur on military installations throughout the southeastern United States, usually as pockets of wet habitat within a matrix of drier longleaf pine woodlands...

Elimination and accumulation of polycyclic aromatic hydrocarbons (PAHs) in urban stormwater wet detention ponds

DEFF Research Database (Denmark)

Istenič, Daria; Arias, Carlos Alberto; Matamoros, Victor

2011-01-01

The concentrations of polycyclic aromatic hydrocarbons (PAHs) in water and sediments of seven wet detention ponds receiving urban stormwater were investigated. The ponds comprised traditional wet detention ponds with a permanent wet volume and a storage volume as well as ponds that were expanded...

Dynamics of Wetting of Ultra Hydrophobic Surfaces

Science.gov (United States)

Mohammad Karim, Alireza; Kim, Jeong-Hyun; Rothstein, Jonathan; Kavehpour, Pirouz; Mechanical and Industrial Engineering, University of Massachusetts, Amherst Collaboration

2013-11-01

Controlling the surface wettability of hydrophobic and super hydrophobic surfaces has extensive industrial applications ranging from coating, painting and printing technology and waterproof clothing to efficiency increase in power and water plants. This requires enhancing the knowledge about the dynamics of wetting on these hydrophobic surfaces. We have done experimental investigation on the dynamics of wetting on hydrophobic surfaces by looking deeply in to the dependency of the dynamic contact angles both advancing and receding on the velocity of the three-phase boundary (Solid/Liquid/Gas interface) using the Wilhelmy plate method with different ultra-hydrophobic surfaces. Several fluids with different surface tension and viscosity are used to study the effect of physical properties of liquids on the governing laws.

Avoided critical behavior in dynamically forced wetting.

Science.gov (United States)

Snoeijer, Jacco H; Delon, Giles; Fermigier, Marc; Andreotti, Bruno

2006-05-05

A solid object can be coated by a nonwetting liquid since a receding contact line cannot exceed a critical speed. In this Letter we study the dynamical wetting transition at which a liquid film gets deposited by withdrawing a vertical plate out of a liquid reservoir. It has recently been predicted that this wetting transition is critical with diverging time scales and coincides with the disappearance of stationary menisci. We demonstrate experimentally and theoretically that the transition is due to the formation of a solitary wave, well below the critical point. As a consequence, relaxation times remain finite at threshold. The structure of the liquid deposited on the plate involves a capillary ridge that does not trivially match the Landau-Levich film.

Partial to complete wetting transitions in immiscible ternary blends with PLA: the influence of interfacial confinement.

Science.gov (United States)

Zolali, Ali M; Favis, Basil D

2017-04-12

In this study it is shown that the three different intermediate phases in melt blended ternary PLA/PHBV/PBS, PLA/PBAT/PE and PLA/PE/PBAT systems all demonstrate partial wetting, but have very different wetting behaviors as a function of composition and annealing. The interfacial tension of the various components, their spreading coefficients and the contact angles of the confined partially wet droplets at the interface are examined in detail. A wetting transition from partially wet droplets to a complete layer at the interface is observed for both PHBV and PBAT by increasing the concentration and also by annealing. In contrast, in PLA/PE/PBAT, the partially wet droplets of PE at the interface of PLA/PBAT coalesce and grow in size, but remain partially wet even at a high PE concentration of 20% and after 30 min of quiescent annealing. The dewetting speed of the intermediate phase is found to be the principal factor controlling these wetting transitions. This work shows the significant potential for controlled wetting and structuring in ternary polymer systems.

Effects of Wet-Blending on Detection of Melamine in Spray-Dried Lactose.

Science.gov (United States)

Yakes, Betsy Jean; Bergana, Marti M; Scholl, Peter F; Mossoba, Magdi M; Karunathilaka, Sanjeewa R; Ackerman, Luke K; Holton, Jason D; Gao, Boyan; Moore, Jeffrey C

2017-07-19

During the development of rapid screening methods to detect economic adulteration, spray-dried milk powders prepared by dissolving melamine in liquid milk exhibited an unexpected loss of characteristic melamine features in the near-infrared (NIR) and Raman spectra. To further characterize this "wet-blending" phenomenon, spray-dried melamine and lactose samples were produced as a simplified model and investigated by NIR spectroscopy, Raman spectroscopy, proton nuclear magnetic resonance ( 1 H NMR), and direct analysis in real time Fourier transform mass spectrometry (DART-FTMS). In contrast to dry-blended samples, characteristic melamine bands in NIR and Raman spectra disappeared or shifted in wet-blended lactose-melamine samples. Subtle shifts in melamine 1 H NMR spectra between wet- and dry-blended samples indicated differences in melamine hydrogen-bonding status. Qualitative DART-FTMS analysis of powders detected a greater relative abundance of lactose-melamine condensation product ions in the wet-blended samples, which supported a hypothesis that wet-blending facilitates early Maillard reactions in spray-dried samples. Collectively, these data indicated that the formation of weak, H bonded complexes and labile, early Maillard reaction products between lactose and melamine contribute to spectral differences observed between wet- and dry-blended milk powder samples. These results have implications for future evaluations of adulterated powders and emphasize the important role of sample preparation methods on adulterant detection.

The transfer function model for dynamic response of wet cooling coils

International Nuclear Information System (INIS)

Yao Ye; Liu Shiqing

2008-01-01

This paper mainly concerned about the dynamic response model of wet cooling coils that is developed by the Laplace transform method. The theoretic equations are firstly established based on the theory of energy conservation. Then, the transfer functions on the transient responses of wet cooling coils have been deduced using the method of Laplace transform. The transfer functions reveal the dynamic relationships between the inlet variables and the outlet ones of the cooling coils. Partial-fraction method and Newton-Raphson method are both used in the inversion of the transfer functions from the s-domain to τ-domain. To make the dynamic model of wet cooling coils more adaptive, RBFNN method is employed to determine the coefficients of heat and mass transfer. Experiments have been done and manifested that the coefficients of heat and mass transfer by RBFNN will be of great value to the validity of the transient response model of wet cooling coils in this study

Die wet is evangelie: Die Heidelbergse Kategismus steeds aktueel na 450 jaar

Directory of Open Access Journals (Sweden)

Piet Strauss

2013-09-01

Full Text Available In die denke van Martin Luther bestaan daar spanning tussen die wet van God en die evangelie. Vir Luther is liefde die eie werk en die wet die vreemde werk van God. Daarteenoor integreer of versoen Johannes Calvyn God se wet met die evangelie. Hy vertolk die openingswoorde van die wet byvoorbeeld as liefdevol en bevrydend en daarom evangelies. Calvyn beskou die wet as die manier waarop ’n Christen sy liefde vir God uitleef en sy dankaarheid teenoor God vir sy verlossing betoon. Calvyn se siening oor die verhouding tussen die wet en die evangelie het ’n betekenisvolle invloed op die Heidelbergse Kategismus se formulering ten opsigte van hierdie saak. Volgens die Kategismus is die wet evangelie, of die vorm wat die evangelie in die lewe van die mens aanneem. In the thought of Martin Luther tension exists between the law of God and the gospel. Luther regards love as the own work of God and the law as something strange to the Lord. John Calvin, however, integrates Gods law and the gospel to the extent that the opening words of the ten commandments are regarded as words of love and redemption and therefore evangelical. To Calvin the law becomes the way in which a converted Christian lives and shows his gratitude to God for his salvation. Calvin’s view on the relationship between law and gospel had a significant influence on the way in which the Heidelberg Cathecism formulates these two concepts. For the Cathecism the law is gospel or the form in which the gospel takes shape in human life.

Shrinkage stress in concrete under dry-wet cycles: an example with concrete column

Science.gov (United States)

Gao, Yuan; Zhang, Jun; Luosun, Yiming

2014-02-01

This paper focuses on the simulation of shrinkage stress in concrete structures under dry-wet environments. In the modeling, an integrative model for autogenous and drying shrinkage predictions of concrete under dry-wet cycles is introduced first. Second, a model taking both cement hydration and moisture diffusion into account synchronously is used to calculate the distribution of interior humidity in concrete. Using the above two models, the distributions of shrinkage strain and stress in concrete columns made by normal and high strength concrete respectively under dry-wet cycles are calculated. The model results show that shrinkage gradient along the radial direction of the column from the center to outer surface increases with age as the outer circumference suffers to dry. The maximum and minimum shrinkage occur at the outer surface and the center of the column, respectively, under drying condition. As wetting starts, the shrinkage strain decreases with increase of interior humidity. The closer to the wetting face, the higher the humidity and the lower the shrinkage strain, as well as the lower the shrinkage stress. As results of the dry-wet cycles acting on the outer circumference of the column, cyclic stress status is developed within the area close to the outer surface of the column. The depth of the influencing zone of dry-wet cyclic action is influenced by concrete strength and dry-wet regime. For low strength concrete, relatively deeper influencing zone is expected compared with that of high strength concrete. The models are verified by concrete-steel composite ring tests and a good agreement between model and test results is found.

Calculations of the nozzle coefficient of discharge of wet steam turbine stages

International Nuclear Information System (INIS)

Jinling, Z.; Yinian, C.

1989-01-01

A method is presented for calculating the coefficient of discharge of wet steam turbine nozzles. The theoretical formulation of the problem is rigorously in accordance with the theory of two-phase wet steam expansion flow through steam turbine nozzles. The computational values are plotted as sets of curves in accordance with orthogonality test principles. They agree satisfactorily both with historical empirical data and the most recent experimental data obtained in the wet steam two-phase flow laboratory of Xian Jiaotong University. (author)

Wetting of heterogeneous substrates. A classical density-functional-theory approach

Science.gov (United States)

Yatsyshin, Peter; Parry, Andrew O.; Rascón, Carlos; Duran-Olivencia, Miguel A.; Kalliadasis, Serafim

2017-11-01

Wetting is a nucleation of a third phase (liquid) on the interface between two different phases (solid and gas). In many experimentally accessible cases of wetting, the interplay between the substrate structure, and the fluid-fluid and fluid-substrate intermolecular interactions leads to the appearance of a whole ``zoo'' of exciting interface phase transitions, associated with the formation of nano-droplets/bubbles, and thin films. Practical applications of wetting at small scales are numerous and include the design of lab-on-a-chip devices and superhydrophobic surfaces. In this talk, we will use a fully microscopic approach to explore the phase space of a planar wall, decorated with patches of different hydrophobicity, and demonstrate the highly non-trivial behaviour of the liquid-gas interface near the substrate. We will present fluid density profiles, adsorption isotherms and wetting phase diagrams. Our analysis is based on a formulation of statistical mechanics, commonly known as classical density-functional theory. It provides a computationally-friendly and rigorous framework, suitable for probing small-scale physics of classical fluids and other soft-matter systems. EPSRC Grants No. EP/L027186,EP/K503733;ERC Advanced Grant No. 247031.

Wetting Behavior in Colloid-Polymer Mixtures at Different Substrates.

Science.gov (United States)

Wijting, Willem K; Besseling, Nicolaas A M; Cohen Stuart, Martien A

2003-09-25

We present experimental observations on wetting phenomena in depletion interaction driven, phase separated colloidal dispersions. The contact angle of the colloidal liquid-gas interface at a solid substrate was determined for a series of compositions. Upon approach to the critical point, a transition occurs from partial to complete wetting. The interaction with the substrate was manipulated by modifying the substrate with a polymer. In that case, a transition from partial to complete drying is observed upon approach to the critical point.

Wet steam turbines for CANDU-Reactors

International Nuclear Information System (INIS)

Westmacott, C.H.L.

1977-01-01

The technical characteristics of 4 wet steam turbine aggregates used in the Pickering nuclear power station are reported on along with operational experience. So far, the general experience was positive. Furthermore, plans are mentioned to use this type of turbines in other CANDU reactors. (UA) [de

Effects of zerumbone on cisplatin-induced clastogenesis in Sprague ...

African Journals Online (AJOL)

Administrator

2011-06-20

Jun 20, 2011 ... bol ester-induced papilloma formation in mouse skin which is another indication of its ... zerumbet plant. The rhizomes were obtained from the wet market in ... erythrocyte micronucleus test), guideline No. 474 (OECD 1997).

Performance of a UASB reactor treating coffee wet wastewater

International Nuclear Information System (INIS)

Guardia Puebla, Yans; Rodríguez Pérez, Suyén; Janet Jiménez Hernández; Sánchez Girón, Víctor

2014-01-01

The present work shows the results obtained in the anaerobic digestion process of coffee wet wastewater processing. An UASB anaerobic reactor was operated in single-stage in mesophilic temperature controlled conditions (37±1ºC). The effect of both organic loading rate (OLR) and hydraulic retention time (HRT) in the anaerobic digestion of coffee wet wastewater was investigated. The OLR values considered in the single-stage UASB reactor varied in a range of 3,6-4,1 kgCOD m-3 d-1 and the HRT stayed in a range of 21,5-15,5 hours. The evaluation results show that the best performance of UASB reactor in single-stage was obtained at OLR of 3,6 kg COD m-3 d-1 with an average value of total and soluble COD removal of 77,2% and 83,4%, respectively, and average methane concentration in biogas of 61%. The present study suggests that the anaerobic digestion is suitable to treating coffee wet wastewater. (author)

Wet milling versus co-precipitation in magnetite ferrofluid preparation

Directory of Open Access Journals (Sweden)

Almásy László

2015-01-01

Full Text Available Various uses of ferrofluids for technical applications continuously raise the interest in improvement and optimization of preparation methods. This paper deals with preparation of finely granulated magnetite particles coated with oleic acid in hydrocarbon suspensions following either chemical co-precipitation from iron salt precursors or wet milling of micron size magnetite powder with the goal to compare the benefits and disadvantages of each method. Microstructural measurements showed that both methods gave similar magnetite particle size of 10-15 nm. Higher saturation magnetization was achieved for the wet-milled magnetite suspension compared to relatively rapid co-precipitation synthesis. Different efficacies of ferrophase incorporation into kerosene could be related to the different mechanisms of oleic acid bonding to nanoparticle surface. The comparative data show that wet milling represents a practicable alternative to the traditional co-precipitation since despite of longer processing time, chemicals impact on environment can be avoided as well as the remnant water in the final product.

Critical wetting of n-alkanes on water; Mouillage critique des alcanes sur l`eau

Energy Technology Data Exchange (ETDEWEB)

Ragil, K

1996-10-18

This study concerns the wetting properties of n-alkanes on water under thermodynamic equilibrium conditions, a problem that is interesting for the petroleum industry as well as for the fundamental understanding of wetting phenomena. An experimental study using ellipsometry reveals that pentane on water undergoes a continuous or critical wetting transition at a temperature equal to 53.1 deg. C. This is the first experimental observation of such a transition, confirming theoretical predictions made on this subject over ten years. This transition is characterized by a continuous and reversible evolution of the thickness of the film of pentane with temperature from a thick (but finite film) to a macroscopic film. The critical wetting transition occurs when the Hamaker constant of the system, which gives the net interaction between the two interfaces bounding the wetting layer of pentane in terms of the van der Waals forces, changes sign. A theoretical approach based on the Cahn-Landau theory, which takes into account long range forces (van der Waals forces), enables us to explain the mechanism of the critical wetting transition and to show that a first-order wetting transition should precede it. Because of their similar dispersive properties, linear alkanes could all be able to show such a succession of transitions. An ellipsometry study performed on a brine/hexane/vapor system confirms that a discontinuous transition from a thin microscopic film to a thick but finite adsorbed film takes place. THis study demonstrates that the wetting of alkanes on water is determined by subtle interplay between short range and long range forces, which can lead to an intermediary state between partial and complete wetting. (author)

Study of wet blasting of components in nuclear power stations

International Nuclear Information System (INIS)

Hall, J.

1999-12-01

This report looks at the method of wet blasting radioactive components in nuclear power stations. The wet blaster uses pearl shaped glass beads with the dimensions of 150-250 μm mixed with water as blasting media. The improved design, providing outer operator's positions with proper radiation protection and more efficient blasting equipment has resulted in a lesser dose taken by the operators. The main reason to decontaminate components in nuclear power plants is to enable service on these components. On components like valves, pump shafts, pipes etc. oxides form and bind radiation. These components are normally situated at some distance from the reactor core and will mainly suffer from radiation from so called activation products. When a component is to be decontaminated it can be decontaminated to a radioactive level where it will be declassified. This report has found levels ranging from 150-1000 Bq/kg allowing declassification of radioactive materials. This difference is found between different countries and different organisations. The report also looks at the levels of waste generated using wet blasting. This is done by tracking the contamination to determine where it collects. It is either collected in the water treatment plant or collected in the blasting media. At Barsebaeck the waste levels, from de-contaminating nearly 800 components in one year, results in a waste volume of about 0,250 m 3 . This waste consists of low and medium level waste and will cost about 3 600 EURO to store. The conclusions of the report are that wet blasting is an indispensable way to treat contaminated components in modern nuclear power plants. The wet blasting equipment can be improved by using a robot enabling the operators to remotely treat components from the outer operator's positions. There they will benefit from better radiation protection thus further reduce their taken dose. The wet blasting equipment could also be used to better control the levels of radioactivity on

Study of wet blasting of components in nuclear power stations

Energy Technology Data Exchange (ETDEWEB)

Hall, J

1999-12-01

This report looks at the method of wet blasting radioactive components in nuclear power stations. The wet blaster uses pearl shaped glass beads with the dimensions of 150-250 {mu}m mixed with water as blasting media. The improved design, providing outer operator's positions with proper radiation protection and more efficient blasting equipment has resulted in a lesser dose taken by the operators. The main reason to decontaminate components in nuclear power plants is to enable service on these components. On components like valves, pump shafts, pipes etc. oxides form and bind radiation. These components are normally situated at some distance from the reactor core and will mainly suffer from radiation from so called activation products. When a component is to be decontaminated it can be decontaminated to a radioactive level where it will be declassified. This report has found levels ranging from 150-1000 Bq/kg allowing declassification of radioactive materials.This difference is found between different countries and different organisations. The report also looks at the levels of waste generated using wet blasting. This is done by tracking the contamination to determine where it collects. It is either collected in the water treatment plant or collected in the blasting media. At Barsebaeck the waste levels, from de-contaminating nearly 800 components in one year, results in a waste volume of about 0,250 m{sup 3}. This waste consists of low and medium level waste and will cost about 3 600 EURO to store. The conclusions of the report are that wet blasting is an indispensable way to treat contaminated components in modern nuclear power plants. The wet blasting equipment can be improved by using a robot enabling the operators to remotely treat components from the outer operator's positions. There they will benefit from better radiation protection thus further reduce their taken dose. The wet blasting equipment could also be used to better control the levels of

Westinghouse containment filtered venting system wet scrubber technology

International Nuclear Information System (INIS)

Kristensson, S.; Nilsson, P-O.

2014-01-01

Following the Fukushima event Westinghouse has further developed and enhanced its filtered containment venting system (FCVS) product line. The filtration efficiency of the proven FILTRA-MVSS system installed at all Swedish NPPs as well as at the Muhelberg plant in Switzerland has been enhanced and a new wet scrubber design, SVEN (Safety Venting), based on the FILTRA-MVSS tradition, developed. To meet increased filtration requirements for organic iodine these two wet scrubber products have been complemented with a zeolite module. The offering of a select choice of products allows for a better adjustment to the specific constraints and needs of each nuclear power station that is planning for the installation of such a system. The FILTRA-MVSS (MVSS=Multi Venturi Scrubber System) is a wet containment filtered vent system that uses multiple venturies to create an interaction between the vent gases and the scrubber media allowing for removal of aerosols and gaseous iodines in a very efficient manner. The FILTRA-MVSS was originally developed to meet stringent requirements on autonomy and maintained filtration efficiency over a wide range of venting conditions. The system was jointly developed in the late 80's by ABB Atom and ABB Flaekt, today Westinghouse and Alstom. Following installations in Sweden and Switzerland the system was further developed by replacement of the gravel-bed moisture separator with a standard demister and by addition of a set of sintered metal fibre filter cartridges placed after the moisture separator step. The system is today offered as a modular steel tank design to simplify installation at site. To reduce complexity and delivery time Westinghouse has developed an alternative design in which the venturi module is replaced by a submerged metal fibre filter cartridges module. This new wet scrubber design, SVEN (patent pending), provides a flexible, compact, and lower weight system, while still preserving and even enhancing the filtration

A constructed wet meadow model for forested lands in the Southwest

Science.gov (United States)

Dave Pawelek; Roy Jemison; Daniel Neary

1999-01-01

Improving primary roads in the Zuni Mountains of New Mexico must take into consideration the wet meadows and upland areas. This study looks at spring flow rates, erosion, channels and changes in plant cover and composition. The goal is to help planners design environmentally sensitive roadways for wet meadow areas.

Making Activated Carbon by Wet Pressurized Pyrolysis

Science.gov (United States)

Fisher, John W.; Pisharody, Suresh; Wignarajah, K.; Moran, Mark

2006-01-01

A wet pressurized pyrolysis (wet carbonization) process has been invented as a means of producing activated carbon from a wide variety of inedible biomass consisting principally of plant wastes. The principal intended use of this activated carbon is room-temperature adsorption of pollutant gases from cooled incinerator exhaust streams. Activated carbon is highly porous and has a large surface area. The surface area depends strongly on the raw material and the production process. Coconut shells and bituminous coal are the primary raw materials that, until now, were converted into activated carbon of commercially acceptable quality by use of traditional production processes that involve activation by use of steam or carbon dioxide. In the wet pressurized pyrolysis process, the plant material is subjected to high pressure and temperature in an aqueous medium in the absence of oxygen for a specified amount of time to break carbon-oxygen bonds in the organic material and modify the structure of the material to obtain large surface area. Plant materials that have been used in demonstrations of the process include inedible parts of wheat, rice, potato, soybean, and tomato plants. The raw plant material is ground and mixed with a specified proportion of water. The mixture is placed in a stirred autoclave, wherein it is pyrolized at a temperature between 450 and 590 F (approximately between 230 and 310 C) and a pressure between 1 and 1.4 kpsi (approximately between 7 and 10 MPa) for a time between 5 minutes and 1 hour. The solid fraction remaining after wet carbonization is dried, then activated at a temperature of 500 F (260 C) in nitrogen gas. The activated carbon thus produced is comparable to commercial activated carbon. It can be used to adsorb oxides of sulfur, oxides of nitrogen, and trace amounts of hydrocarbons, any or all of which can be present in flue gas. Alternatively, the dried solid fraction can be used, even without the activation treatment, to absorb

Measurement and analysis of the re-wetting front velocity during quench cooling of hot horizontal tubes

Energy Technology Data Exchange (ETDEWEB)

Takrouri, Kifah, E-mail: takroukj@mcmaster.ca [Department of Engineering Physics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4L7 (Canada); Luxat, John, E-mail: luxatj@mcmaster.ca [Department of Engineering Physics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4L7 (Canada); Hamed, Mohamed [Thermal Processing Laboratory (TPL), Department of Mechanical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4L7 (Canada)

2017-01-15

Highlights: • Two phase flow & re-wetting front velocity were studied for quench of hot tubes. • The velocity decreased as temperature difference between tube and coolant decreased. • Increasing surface curvature was found to decrease the re-wetting front velocity. • Increasing tube thermal conductivity decreased the velocity. • Correlations were developed to predict the front velocity. - Abstract: When a liquid is put into contact with a hot dry surface, there exists a maximum temperature called the re-wetting temperature below which the liquid is in actual contact with the surface. Re-wetting occurs after destabilization of a vapor film that exists between the hot surface and the liquid. If re-wetting is established at a location on the hot surface, a wet patch appears at that location and starts to spread to cover and cool the entire surface. The outer edge of the wet patch is called the re-wetting front and can proceed only if the surface ahead of it cools down to the re-wetting temperature. Study of re-wetting heat transfer is very important in nuclear reactor safety for limiting the extent of core damage during the early stages of severe accidents after loss of coolant accidents LOCA and is essential for predicting the rate at which the coolant cools an overheated core. One of the important parameters in re-wetting cooling is the velocity at which the re-wetting front moves on the surface. In this study, experimental tests were carried out to investigate the re-wetting front velocity on hot horizontal cylindrical tubes being cooled by a vertical rectangular water multi-jet system. Effects of initial surface temperature in the range 400–740 °C, water subcooling in the range 15–80 °C and jet velocity in the range 0.17–1.43 m/s on the re-wetting front velocity were investigated. The two-phase flow behavior was observed by using a high-speed camera. The re-wetting front velocity was found to increase by increasing water subcooling, decreasing

The effect of moisture content on the explosively driven fragmentation of wet sand

International Nuclear Information System (INIS)

Xue, K

2014-01-01

A comprehensive model is established to account for the instability onset of rapidly expanding granular shells subject to the explosion loadings generated by the detonation of the central explosives. The moisture content strongly influences the shock interactions in the wet particle beds and the ensuing evolvement of the granular compacts. A material model for granular materials which can account for the degree of saturation was incorporated into a nonlinear dynamic simulation program to investigate the moisture effect on the shock responses of wet granular materials. In conjunction with our instability model, the predicted instability diameters of the expanding dry/wet granular shells are in a good agreement with the experimental results. Particularly the postponed instability onset of the wet granular shell found both experimentally and analytically can largely be attributed to the significantly greater kinetic energy obtained by wet particles thanks to less energy of shock wave consumed in compacting the granular material.

Formative Assessment Probes: Wet Jeans

Science.gov (United States)

Keeley, Page

2015-01-01

Picture a wet towel or a puddle of water on a hot, sunny day. An hour later, the towel is dry and the puddle no longer exists. What happened to the water? Where did it go? These are questions that reveal myriad interesting student ideas about evaporation and the water cycle--ideas that provide teachers with a treasure trove of data they can use to…

Nutrient Removal of Grey Water from Wet Market Using Sequencing Batch Reactor

International Nuclear Information System (INIS)

Omar Danial; Mohd Razman Salim; Salmiati

2016-01-01

Fresh water scarcity has become an important issue in this world today. Water reuse is known as one of the strategies to overcome this problem. Grey water is one of the sources of reused water. Several researches were carried out on water reuse, but limited attention was focused on reusing grey water from wet market, which contains high nutrient and organic matters. This study was carried out on nutrient removal from grey water using sequencing batch reactor (SBR). The grey water sample was taken from a wet market (Pasar Peladang, Skudai). About 1L of grey water was fed into the reactor with a total volume of 4L. Anoxic-aerobic phase were divided with a ratio of 30 % - 70 % of total time respectively. Mixing was maintained at 30 rpm during the start of each cycle until settling phase to achieve uniform condition. Influent and effluent were set for 30 minutes. The SBR was operated with 3 cycles/ day, temperature 30 degree Celsius, cycle time 8 hours and hydraulic retention time (HRT) 1.2 days. Aeration at 35 L/ min was induced for ammonia conversion and assisting nitrification.. The results show that the bacteria growing in alternating anoxic/ aerobic systems could remove organic substrates and nutrient. The COD, Total Nitrogen and Total Phosphorus removal efficiencies were maximum at the levels of 94 %, 88 % and 70 % respectively. Anaerobic-Aerobic-Anoxic phase was proposed to increase the removal percentage. (author)

Investigations of metal leaching from mobile phone parts using TCLP and WET methods.

Science.gov (United States)

Yadav, Satyamanyu; Yadav, Sudesh

2014-11-01

Metal leaching from landfills containing end-of-life or otherwise discarded mobile phones poses a threat to the environment as well as public health. In the present study, the metal toxicity of printed wire boards (PWBs), plastics, liquid crystal displays (LCDs) and batteries of mobile phones was assessed using the Toxicity Characteristics Leaching Procedures (TCLP) and the Waste Extraction Test (WET). The PWBs failed TCLP for Pb and Se, and WET for Pb and Zn. In WET, the two PWB samples for Pb and Zn and the battery samples for Co and Cu failed the test. Furthermore, the PWBS for Ni and the battery samples for Ni and Co failed the WET in their TCLP leachates. Both, Ni and Co are the regulatory metals in only WET and not covered under TCLP. These observations indicate that the TCLP seems to be a more aggressive test than the WET for the metal leaching from the mobile phone parts. The compositional variations, nature of leaching solution (acetate in TCLP and citrate in WET) and the redox conditions in the leaching solution of the PWBs resulted in different order of metals with respect to their amounts of leaching from PWBs in TCLP (Fe > Pb > Zn > Ni > Co > Cu) and WET (Zn > Fe > Ni > Pb > Cu). The metal leaching also varied with the make, manufacturing year and part of the mobile phone tested. PWBs, plastics and batteries should be treated as hazardous waste. Metal leaching, particularly of Se and Pb, from mobile phones can be harmful to the environment and human health. Therefore, a scientifically sound and environmentally safe handling and disposal management system needs to be evolved for the mobile phone disposal. Copyright © 2014 Elsevier Ltd. All rights reserved.

Wetted surface area of recreational boats

NARCIS (Netherlands)

Bakker J; van Vlaardingen PLA; ICH; VSP

2018-01-01

The wetted surface area of recreational craft is often treated with special paint that prevents growth of algae and other organisms. The active substances in this paint (antifouling) are also emitted into the water. The extent of this emission is among others determined by the treated surface area.

New advances in wet scrubbing improvement efficiencies

Energy Technology Data Exchange (ETDEWEB)

Keen, A.R. [Altech Group, Toronto, ON (Canada)

2000-07-01

Wet scrubbing systems are the most versatile and cost efficient of all air pollution abatement technologies. This paper presented System REITHER{sup TM} which is a new generation of venturi scrubber. The advantages of this design are that it is simple and compact, has high removal efficiencies for sub-micron dusts or aerosols and it is flexible to handle any mass flow rate. It also provides high and constant reliability, is easy to control and has the potential to absorb gaseous pollutants. Another advantage is that it can handle corrosive streams through corrosion resistant materials. Innovations in wet scrubbing have made it possible to provide reliable and efficient separation of fine particles, corrosive aerosols and gases. New technology provides industrial engineers with a cost effective option when control air emissions is required. 1 fig.

Environmentally friendly and breathable wet-laid hydroentangled nonwovens for personal hygiene care with excellent water absorbency and flushability

Science.gov (United States)

Deng, Chao; Liu, Wanjun; Zhang, Yinjiang; Huang, Chen; Zhao, Yi; Jin, Xiangyu

2018-04-01

Developing wet-laid papers with a good wet strength remains a longstanding challenge in the papermaking industry. In this study, hydroentanglement, a mechanical bonding technique is developed to consolidate the wet-laid fibre web. The results indicate that wet tensile strength, ductile stretching property, softness, air permeability and water absorbency of the wet-laid fibre web are significantly improved by hydroentanglement. In addition, the abrasion test shows that the dusting off rate of wet-laid fibre web can be effectively reduced through hydroentanglement. Moreover, the disintegration experiment proves that wet-laid hydroentangled nonwovens could be easily dispersed when compared with conventional carded hydroentangled nonwovens. Therefore, the new wet-laid hydroentangled nonwovens can maintain excellent performance in a wet state, showing a great potential for personal hygiene applications.

Defect-induced wetting on BaF 2(111) and CaF 2(111) at ambient conditions

Science.gov (United States)

Cardellach, M.; Verdaguer, A.; Fraxedas, J.

2011-12-01

The interaction of water with freshly cleaved (111) surfaces of isostructural BaF2 and CaF2 single crystals at ambient conditions (room temperature and under controlled humidity) has been studied using scanning force microscopy in different operation modes and optical microscopy. Such surfaces exhibit contrasting behaviors for both materials: while on BaF2(111) two-dimensional water layers are formed after accumulation at step edges, CaF2(111) does not promote the formation of such layers. We attribute such opposed behavior to lattice match (mismatch) between hexagonal water ice and the hexagonal (111) surfaces of BaF2(CaF2). Optical microscope images reveal that this behavior also determines the way the surfaces become wetted at a macroscopic level.

Review of wet environment types on Mars with focus on duration and volumetric issues.

Science.gov (United States)

Kereszturi, Akos

2012-06-01

The astrobiological significance of certain environment types on Mars strongly depends on the temperature, duration, and chemistry of liquid water that was present there in the past. Recent works have focused on the identification of signs of ancient water on Mars, as it is more difficult to estimate the above-mentioned parameters. In this paper, two important factors are reviewed, the duration and the volume of water at different environment types on past and present Mars. Using currently available information, we can only roughly estimate these values, but as environment types show characteristic differences in this respect, it is worth comparing them and the result may have importance for research in astrobiology. Impact-induced and geothermal hydrothermal systems, lakes, and valley networks were in existence on Mars over the course of from 10(2) to 10(6) years, although they would have experienced substantially different temperature regimes. Ancient oceans, as well as water in outflow channels and gullies, and at the microscopic scale as interfacial water layers, would have had inherently different times of duration and overall volume: oceans may have endured from 10(4) to 10(6) years, while interfacial water would have had the smallest volume and residence time of liquid phase on Mars. Martian wet environments with longer residence times of liquid water are believed to have existed for that amount of time necessary for life to develop on Earth between the Late Heavy Bombardment and the age of the earliest fossil record. The results of this review show the necessity for more detailed analysis of conditions within geothermal heat-induced systems to reconstruct the conditions during weathering and mineral alteration, as well as to search for signs of reoccurring wet periods in ancient crater lakes.

Process Analytical Technology for High Shear Wet Granulation: Wet Mass Consistency Reported by In-Line Drag Flow Force Sensor Is Consistent With Powder Rheology Measured by At-Line FT4 Powder Rheometer.

Science.gov (United States)

Narang, Ajit S; Sheverev, Valery; Freeman, Tim; Both, Douglas; Stepaniuk, Vadim; Delancy, Michael; Millington-Smith, Doug; Macias, Kevin; Subramanian, Ganeshkumar

2016-01-01

Drag flow force (DFF) sensor that measures the force exerted by wet mass in a granulator on a thin cylindrical probe was shown as a promising process analytical technology for real-time in-line high-resolution monitoring of wet mass consistency during high shear wet granulation. Our previous studies indicated that this process analytical technology tool could be correlated to granulation end point established independently through drug product critical quality attributes. In this study, the measurements of flow force by a DFF sensor, taken during wet granulation of 3 placebo formulations with different binder content, are compared with concurrent at line FT4 Powder Rheometer characterization of wet granules collected at different time points of the processing. The wet mass consistency measured by the DFF sensor correlated well with the granulation's resistance to flow and interparticulate interactions as measured by FT4 Powder Rheometer. This indicated that the force pulse magnitude measured by the DFF sensor was indicative of fundamental material properties (e.g., shear viscosity and granule size/density), as they were changing during the granulation process. These studies indicate that DFF sensor can be a valuable tool for wet granulation formulation and process development and scale up, as well as for routine monitoring and control during manufacturing. Copyright © 2016. Published by Elsevier Inc.

40 CFR 427.110 - Applicability; description of the wet dust collection subcategory.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of the wet dust collection subcategory. 427.110 Section 427.110 Protection of Environment ENVIRONMENTAL PROTECTION... (particulates) from atmospheric emissions by means of wet scrubbers. ...

A novel nano-hydroxyapatite – PMMA hybrid scaffolds adopted by conjugated thermal induced phase separation (TIPS) and wet-chemical approach: Analysis of its mechanical and biological properties

Energy Technology Data Exchange (ETDEWEB)

Radha, G. [National Centre for Nanoscience and Nanotechnology, University of Madras, Guindy campus, Chennai 600025 (India); Balakumar, S., E-mail: balasuga@yahoo.com [National Centre for Nanoscience and Nanotechnology, University of Madras, Guindy campus, Chennai 600025 (India); Venkatesan, Balaji; Vellaichamy, Elangovan [Department of Biochemistry, University of Madras, Guindy campus, Chennai 600025 (India)

2017-04-01

In this study, we report the preparation of nano-hydroxyapatite (nHAp) incorporated poly(methyl methacrylate) (PMMA) scaffolds by conjugated thermal induced phase separation (TIPS) and wet-chemical approach, which essentially facilitates the enhancement of both mechanical as well as biological properties of the scaffolds. The dissolution of PMMA was accomplished by acetone (Ace scaffold), ethanol-water (E-W scaffold) and isopropanol-water (I-W scaffold) mixtures as solvents. The existence of nHAp in PMMA matrix was investigated systematically. The porosity of ~ 57.89% was achieved from Ace scaffold that was higher degree compared to both I-W and E-W scaffolds. On the other hand, the dense porous architecture of I-W scaffold exhibited superior hardness of ~ 65.6 HR ‘D’ than that of the Ace and E-W scaffolds. All the fabricated samples demonstrated enhanced in vitro bioactivity with respect to increasing immersion period as a result of flower-like in vitro apatite layer formation. The MTT assay was carried out for 1 day and 3 day culture using Saos-2 osteoblast-like cells, which showed better cell proliferation with increasing culture period owing to the interconnected pore architecture of scaffolds and the rational hemocompatibility as per the ASTM standard F756-00. - Highlights: • Conjugated TIPS – wet chemical derived strategy was adopted for PMMA-nHAp composite scaffolds preparation. • TIPS method was carried out by varying solvents such as acetone, isopropanol-water and ethanol-water mixtures. • The impact of solvents on porosity and mechanical properties has been explored. • The existence of nHAp in PMMA has improved in-vitro bioactivity through apatitic-flowers formation. • Hemocompatibility of the scaffolds are in agreement with ASTM standards.

Uncertainty associated with convective wet removal of entrained aerosols in a global climate model

Directory of Open Access Journals (Sweden)

B. Croft

2012-11-01

Full Text Available The uncertainties associated with the wet removal of aerosols entrained above convective cloud bases are investigated in a global aerosol-climate model (ECHAM5-HAM under a set of limiting assumptions for the wet removal of the entrained aerosols. The limiting assumptions for the wet removal of entrained aerosols are negligible scavenging and vigorous scavenging (either through activation, with size-dependent impaction scavenging, or with the prescribed fractions of the standard model. To facilitate this process-based study, an explicit representation of cloud-droplet-borne and ice-crystal-borne aerosol mass and number, for the purpose of wet removal, is introduced into the ECHAM5-HAM model. This replaces and is compared with the prescribed cloud-droplet-borne and ice-crystal-borne aerosol fraction scavenging scheme of the standard model.

A 20% to 35% uncertainty in simulated global, annual mean aerosol mass burdens and optical depth (AOD is attributed to different assumptions for the wet removal of aerosols entrained above convective cloud bases. Assumptions about the removal of aerosols entrained above convective cloud bases control modeled upper tropospheric aerosol concentrations by as much as one order of magnitude.

Simulated aerosols entrained above convective cloud bases contribute 20% to 50% of modeled global, annual mean aerosol mass convective wet deposition (about 5% to 10% of the total dry and wet deposition, depending on the aerosol species, when including wet scavenging of those entrained aerosols (either by activation, size-dependent impaction, or with the prescribed fraction scheme. Among the simulations, the prescribed fraction and size-dependent impaction schemes yield the largest global, annual mean aerosol mass convective wet deposition (by about two-fold. However, the prescribed fraction scheme has more vigorous convective mixed-phase wet removal (by two to five-fold relative to the size-dependent impaction

Uncertainty associated with convective wet removal of entrained aerosols in a global climate model

Science.gov (United States)

Croft, B.; Pierce, J. R.; Martin, R. V.; Hoose, C.; Lohmann, U.

2012-11-01

The uncertainties associated with the wet removal of aerosols entrained above convective cloud bases are investigated in a global aerosol-climate model (ECHAM5-HAM) under a set of limiting assumptions for the wet removal of the entrained aerosols. The limiting assumptions for the wet removal of entrained aerosols are negligible scavenging and vigorous scavenging (either through activation, with size-dependent impaction scavenging, or with the prescribed fractions of the standard model). To facilitate this process-based study, an explicit representation of cloud-droplet-borne and ice-crystal-borne aerosol mass and number, for the purpose of wet removal, is introduced into the ECHAM5-HAM model. This replaces and is compared with the prescribed cloud-droplet-borne and ice-crystal-borne aerosol fraction scavenging scheme of the standard model. A 20% to 35% uncertainty in simulated global, annual mean aerosol mass burdens and optical depth (AOD) is attributed to different assumptions for the wet removal of aerosols entrained above convective cloud bases. Assumptions about the removal of aerosols entrained above convective cloud bases control modeled upper tropospheric aerosol concentrations by as much as one order of magnitude. Simulated aerosols entrained above convective cloud bases contribute 20% to 50% of modeled global, annual mean aerosol mass convective wet deposition (about 5% to 10% of the total dry and wet deposition), depending on the aerosol species, when including wet scavenging of those entrained aerosols (either by activation, size-dependent impaction, or with the prescribed fraction scheme). Among the simulations, the prescribed fraction and size-dependent impaction schemes yield the largest global, annual mean aerosol mass convective wet deposition (by about two-fold). However, the prescribed fraction scheme has more vigorous convective mixed-phase wet removal (by two to five-fold relative to the size-dependent impaction scheme) since nearly all

Molecular dynamics simulation of wetting behaviors of Li on W surfaces

Energy Technology Data Exchange (ETDEWEB)

Sun, Xuegui [College of Materials Science and Engineering, Hunan University, Changsha 410082 (China); Xiao, Shifang [Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha 410082 (China); Deng, Huiqiu, E-mail: hqdeng@hnu.edu.cn [Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha 410082 (China); Hu, Wangyu, E-mail: wyuhu@hnu.edu.cn [College of Materials Science and Engineering, Hunan University, Changsha 410082 (China)

2017-04-15

A modified analytic embedded atom potential has been developed for the Li-W system. The potential has been fitted to physical quantities derived from density functional theory calculations. It is shown that the new potential is capable of reproducing the solubility of solid solution for Li-W systems. The wetting behaviors between solid tungsten and liquid Li are examined by using molecular dynamics simulations. The MD simulation results for the Li droplet wetting on the W surface illustrated that our MAEAM potential model has a good forecasting ability for the contact angle of liquid Li on W the cleaning surface above the wetting temperature. And the results of Li film dewetting from the W surfaces are consistent with relative experimental results. It is believed that the potential can be used to investigate the surfaces wettability of liquid Li on W substrate. We also simulated the lithium droplet on grooved surface. It is shown that the grooving W surfaces can obviously improve the wetting of liquid Li on W surfaces.

The wet compression technology for gas turbine power plants: Thermodynamic model

International Nuclear Information System (INIS)

Bracco, Stefano; Pierfederici, Alessandro; Trucco, Angela

2007-01-01

This paper examines from a thermodynamic point of view the effects of wet compression on gas turbine power plants, particularly analysing the influence of ambient conditions on the plant performance. The results of the mathematical model, implemented in 'Matlab' software, have been compared with the simulation results presented in literature and in particular the values of the 'evaporative rate', proposed in Araimo et al. [L. Araimo, A. Torelli, Thermodynamic analysis of the wet compression process in heavy duty gas turbine compressors, in: Proceedings of the 59th ATI Annual Congress, Genova, 2004, pp. 1249-1263; L. Araimo, A. Torelli, Wet compression technology applied to heavy duty gas turbines - GT power augmentation and efficiency upgrade, in: Proceedings of the 59th ATI Annual Congress, Genova, 2004, pp. 1265-1277] by 'Gas Turbines Department' of Ansaldo Energia S.p.A., have been taken into account to validate the model. The simulator permits to investigate the effects of the fogging and wet compression techniques and estimate the power and efficiency gain of heavy duty gas turbines operating in hot and arid conditions

Imaging and etching, soft x-ray microscopy on whole wet cells

International Nuclear Information System (INIS)

Gilbert, J.R.; Pine, J.

1993-01-01

The authors have produced images of whole wet tissue culture cells with the Stony Brook/BNL scanning transmission x-ray microscope (STXM). For fixed cells the authors have taken images at theoretical resolutions of ∼50-75nm, and in practice have measured FWHM of features down to near 100nm, without any exotic image processing. For unfixed (i.e., initially live) cells the authors have imaged with 100nm pixels and measured features down to 250nm. In order to do this the authors have developed, tested and used a wet cell for maintaining fixed or live cells on the STXM stage during imaging. The design of the wet cell and the culture substrates that go with it make the STXM compatible with almost all standard systems for surface adherent tissue culture. The authors will show some new images of whole wet fixed and unfixed cells, with visible sub-micron features. The authors will also report data that helps to characterize the tissue damage due to x-ray absorption during STXM imaging

Incorporating full-scale experience into advanced limestone wet FGD designs

International Nuclear Information System (INIS)

Rader, P.C.; Bakke, E.

1992-01-01

Utilities choosing flue gas desulfurization as a strategy for compliance with Phase I of the 1990 Clean Air Act Amendments will largely turn to limestone wet scrubbing as the most cost-effective, least-risk option. State-of-the-art single absorber wet scrubbing systems can be designed to achieve: SO 2 removal efficiencies in excess of 95 %, system availabilities in excess of 98%, and byproducts which can be marketed or land filled. As a result of varying fuel characteristics, site considerations, and owner preferences, FGD plants for large central power stations are typically custom-designed. To avoid the risks associated with new, first-of-a-kind technologies, utilities have preferred to purchase FGD systems from suppliers with proven utility experience and reference plants as close as possible to the design envisioned. As the market for FGD systems is regulatory driven, the demand has shifted geographically in response to national environmental policies. Although limestone wet scrubbing has emerged as the overwhelming choice for SO 2 emission control in coal-fired power stations, the technology has evolved and been adapted to suit local and regional technical and economic situations. Global suppliers are able to benefit from experience and technological advances in the world market. With market units in the U.S., Denmark, Italy, Sweden, and Germany active in the design and supply of wet FGD plants, ABB has a unique ability to incorporate knowledge and experience gained throughout the industrialized world to acid rain retrofit projects in the U.S. This paper describes the design of advanced limestone wet scrubbing systems for application to acid rain retrofits. Specifically, the evolution of advanced design concepts from a global experience base is discussed

Dynamic Wetting and Dewetting: Comparison of Experiment with Theories

Directory of Open Access Journals (Sweden)

Orlova Evgeniya.G.

2016-01-01

Full Text Available The dynamics wetting/dewetting of a metal surface by distilled water drop was studied experimentally. The advancing and receding dynamic contact angles were obtained as a function of a contact line speed. The hydrodynamic and molecular-kinetic models have been applied to the experimental data to interpret the obtained results. The independent variables of the molecular-kinetic and hydrodynamic models, and the determination coefficient were determined by fitting procedure. The receding contact angles are found to be fitted better to the wetting models in comparison with the advancing dynamic contact angles.

Wet gas flow modeling for a vertically mounted Venturi meter

International Nuclear Information System (INIS)

Xu, Lijun; Zhou, Wanlu; Li, Xiaomin

2012-01-01

Venturi meters are playing an increasingly important role in wet gas metering in natural gas and oil industries. Due to the effect of liquid in a wet gas, the differential pressure over the converging section of a Venturi meter is higher than that when a pure gas flows through with the same flow rate. This phenomenon is referred to as over-reading. Thus, a correction for the over-reading is required. Most of the existing wet gas models are more suitable for higher pressure (>2 MPa) than lower pressure ( 0.5) than lower quality (<0.5) in recent years. However, conditions of lower pressure and lower quality also widely exist in the gas and oil industries. By comparing the performances of eight existing wet gas models in low-pressure range of 0.26–0.86 MPa and low-quality range of 0.07–0.36 with a vertically mounted Venturi meter of diameter ratio 0.45, de Leeuw's model was proven to perform best. Derived from de Leeuw's model, a modified model with better performance for the low-pressure and low-quality ranges was obtained. Experimental data showed that the root mean square of the relative errors of the over-reading was 2.30%. (paper)

Infrared and swelling study of the hydration-induced phase transition of wet-spun hyaluronate films

Science.gov (United States)

Hoppe, A. D.; Marlowe, R. L.; Lee, S. A.; Powell, J. W.; Rupprecht, A.

1997-03-01

The hydration properties of wet-spun films of hyaluronate (HA) with four different counterions (Li^+, Cs^+, Mg^2+, and Ca^2+) have been studied using optical microscopy, optical birefringence and infrared (IR) spectroscopy. Small pieces of these films were found to be optically birefringent up to hydration levels near 90 % relative humidity (RH). All four kinds of films then became optically isotropic and display dramatic changes in size. These changes are consistent with the occurrence of an order-disorder (o-d) transition. IR spectroscopy of the backbone region (from 800 to 1000 cm-1) suggests that the Li^+, Cs^+ and Ca^2+ films are very similar. Two IR bands in this region are observed at low RH and show no dependence on hydration until the o-d transition. The IR spectra of CaHA show five bands in this region. These five bands are observed to 95 % RH.

Molecular Structure and Dynamics of Water on Pristine and Strained Phosphorene: Wetting and Diffusion at Nanoscale.

Science.gov (United States)

Zhang, Wei; Ye, Chao; Hong, Linbi; Yang, Zaixing; Zhou, Ruhong

2016-12-06

Phosphorene, a newly fabricated two-dimensional (2D) nanomaterial, has emerged as a promising material for biomedical applications with great potential. Nonetheless, understanding the wetting and diffusive properties of bio-fluids on phosphorene which are of fundamental importance to these applications remains elusive. In this work, using molecular dynamics (MD) simulations, we investigated the structural and dynamic properties of water on both pristine and strained phosphorene. Our simulations indicate that the diffusion of water molecules on the phosphorene surface is anisotropic, with strain-enhanced diffusion clearly present, which arises from strain-induced smoothing of the energy landscape. The contact angle of water droplet on phosphorene exhibits a non-monotonic variation with the transverse strain. The structure of water on transverse stretched phosphorene is demonstrated to be different from that on longitudinal stretched phosphorene. Moreover, the contact angle of water on strained phosphorene is proportional to the quotient of the longitudinal and transverse diffusion coefficients of the interfacial water. These findings thereby offer helpful insights into the mechanism of the wetting and transport of water at nanoscale, and provide a better foundation for future biomedical applications of phosphorene.

Designer-Wet Micromodels for Studying Potential Changes in Wettability during Microbial Enhanced Oil Recovery

Science.gov (United States)

Armstrong, R. T.; Wildenschild, D.

2010-12-01

Microbial Enhanced Oil Recovery (MEOR) is a process where microorganisms are used for tertiary recovery of oil. Some bacteria can facilitate the mobilization of oil through the production of amphiphilic compounds called biosurfactants that reduce the interfacial tension (IFT) between immiscible phases. Additionally, most bacteria have an inclination to colonize surfaces and form biofilm, which can change a reservoir's wetting properties or clog preferential flow paths. Herein, we aim to understand changes in wettability during MEOR under mixed wettability conditions within silicon etched micromodels and to identify the type of oil field (i.e. based on wettability) in which MEOR is likely to be most profitable. To quantify porous media wettability, macro-scale indexes (obtained with techniques such as the Carter or Amott methods) are used regularly. However, these measurements lack the capability for characterization of changes in wettability during MEOR treatment, and only provide macro-scale information. In an effort to understand micro-scale temporal and spatial changes in wettability we measure interfacial curvature from stereo microscope images using level set methods. Curvature, from the perspective of the oil phase, is positive for a concave interface (i.e. water-wet surface) and negative for a convex interface (i.e. oil-wet surface). Thus, shifts in the radius of curvature distribution (i.e. from positive to negative or conversely) are indicative of wettability changes. Both curvature distributions using level-set methods and the Carter method are used to characterize wettability before and after microbial treatment. In preliminary studies aimed at understanding wettability changes due to microbial surface interactions by Bacillus mojavensis JF-2, oil droplets were placed on glass slides suspended in growth media and the resulting contact angle was measured over time. Results showed that a water-wet surface will become more water wet as JF-2 accumulated in

Atmospheric wet deposition of mercury in North America

Energy Technology Data Exchange (ETDEWEB)

Sweet, C.W.; Prestbo, E.; Brunette, B.

1999-07-01

Currently, 39 states in the US and 5 Canadian provinces have issued advisories about the dangers of eating mercury-contaminated fish taken from waters within their boundaries. The problem is most severe in the Great Lakes region, the Northeast US states, the Canadian maritime provinces, and in south Florida where many lakes and streams contain fish with concentrations of 1 ppm or higher. For many rural and remote locations, atmospheric deposition is the primary source of mercury. In 1995, the National Atmospheric Deposition Program (NADP) initiated a program to monitor total mercury and methylmercury (MMHg) in wet deposition (rain and snow) in North America. In this program, the Mercury Deposition Network (MDN), individual monitoring sites are funded and operated by a variety of local, state, and federal agencies. However, sampling and analysis are coordinated through a central laboratory so that all of the samples are collected and analyzed using the same protocols. Weekly wet-only precipitation samples are collected using an all-glass sampling train and special handling techniques. Analysis is by cold vapor atomic fluorescence spectrometry using USEPA Method 1631 for total mercury. Nearly 40 MDN sites are in operation in 1999. Most of the sites are in the eastern US and Canada. During 1996 and 1997, the volume-weighted mean concentration of total mercury in precipitation collected at 22 sites ranged from 6.0 to 18.9 ng/L. Annual deposition varied between 2.1 and 25.3 {micro} g/m{sup 2}. The average weekly wet deposition of total mercury is more than three times higher in the summer (June-August) than in the winter (December-February). This increase is due to both higher amounts of precipitation and higher concentrations of mercury in precipitation during the summer. The highest values for mercury concentration in precipitation and wet deposition of mercury were measured in the southeastern US.

Non-condensible gas fraction predictions using wet and dry bulb temperature measurements

International Nuclear Information System (INIS)

Bowman, J.; Griffith, P.

1983-03-01

A technique is presented whereby non-condensible gas mass fractions in a closed system can be determined using wet bulb and dry bulb temperature and system pressure measurements. This technique would have application in situations where sampling techniques could not be used. Using an energy balance about the wet bulb wick, and expression is obtained which relates the vapor concentration difference between the wet bulb wick and the free stream to the wet and dry bulb temperature difference and a heat to mass transfer coefficient ratio. This coefficient ratio was examined for forced and natural convection flows. This analysis was verified with forced and natural convection tests over the range of pressure and temperature from 50 to 557 psig and 415 to 576 0 F. All the data could best be fit by the natural convection analysis. This is useful when no information about the flow field is known

A kinetic model of municipal sludge degradation during non-catalytic wet oxidation.

Science.gov (United States)

Prince-Pike, Arrian; Wilson, David I; Baroutian, Saeid; Andrews, John; Gapes, Daniel J

2015-12-15

Wet oxidation is a successful process for the treatment of municipal sludge. In addition, the resulting effluent from wet oxidation is a useful carbon source for subsequent biological nutrient removal processes in wastewater treatment. Owing to limitations with current kinetic models, this study produced a kinetic model which predicts the concentrations of key intermediate components during wet oxidation. The model was regressed from lab-scale experiments and then subsequently validated using data from a wet oxidation pilot plant. The model was shown to be accurate in predicting the concentrations of each component, and produced good results when applied to a plant 500 times larger in size. A statistical study was undertaken to investigate the validity of the regressed model parameters. Finally the usefulness of the model was demonstrated by suggesting optimum operating conditions such that volatile fatty acids were maximised. Copyright © 2015 Elsevier Ltd. All rights reserved.

A WET TALE: TOXICITY OF COMPLEX EFFLUENTS

Science.gov (United States)

This course covers standards, regulations, policy, guidance and technical aspects of implementing the whole effluent toxicity program. The curriculum incorporates rationale and information on WET test requirements from USEPA documents, such as the Technical Support Document for W...

Borneol Is a TRPM8 Agonist that Increases Ocular Surface Wetness.

Directory of Open Access Journals (Sweden)

Gui-Lan Chen

Full Text Available Borneol is a compound widely used in ophthalmic preparations in China. Little is known about its exact role in treating eye diseases. Here we report that transient receptor potential melastatin 8 (TRPM8 channel is a pharmacological target of borneol and mediates its therapeutic effect in the eyes. Ca2+ measurement and electrophysiological recordings revealed that borneol activated TRPM8 channel in a temperature- and dose-dependent manner, which was similar to but less effective than the action of menthol, an established TRPM8 agonist. Borneol significantly increased tear production in guinea pigs without evoking nociceptive responses at 25°C, but failed to induce tear secretion at 35°C. In contrast, menthol evoked tearing response at both 25 and 35°C. TRPM8 channel blockers N-(3-Aminopropyl-2-[(3-methylphenylmethoxy]-N-(2-thienylmethylbenzamide hydrochloride (AMTB and N-(4-tert-butylphenyl-4-(3-chloropyridin-2-ylpiperazine-1-carboxamide (BCTC abolished borneol- and menthol-induced tear secretion. Borneol at micromolar concentrations did not affect the viability of human corneal epithelial cells. We conclude that borneol can activate the cold-sensing TRPM8 channel and modestly increase ocular surface wetness, which suggests it is an active compound in ophthalmic preparations and particularly useful in treating dry eye syndrome.

Extreme Wetting-Resistant Multiscale Nano-/Microstructured Surfaces for Viscoelastic Liquid Repellence

Directory of Open Access Journals (Sweden)

Aoythip Chunglok

2016-01-01

Full Text Available We demonstrate exceptional wetting-resistant surfaces capable of repelling low surface tension, non-Newtonian, and highly viscoelastic liquids. Theoretical analysis and experimental result confirm that a higher level of multiscale roughness topography composed of at least three structural length scales, ranging from nanometer to supermicron sizes, is crucial for the reduction of liquid-solid adhesion hysteresis. With Cassie-Baxter nonwetting state satisfied at all roughness length scales, the surface has been proven to effectively repel even highly adhesive liquid. Practically, this high-level hierarchical structure can be achieved through fractal-like structures of silica aggregates induced by siloxane oligomer interparticle bridges. The induced aggregation and surface functionalization of the silica particles can be performed simultaneously within a single reaction step, by utilizing trifunctional fluoroalkylsilane precursors that largely form a disordered fluoroalkylsiloxane grafting layer under the presence of sufficient native moisture preadsorbed at the silica surface. Spray-coating deposition of a particle surface layer on a precoated primer layer ensures facile processability and scalability of the fabrication method. The resulting low-surface-energy multiscale roughness exhibits outstanding liquid repellent properties, generating equivalent lotus effect for highly viscous and adhesive natural latex concentrate, with apparent contact angles greater than 160°, and very small roll-off angles of less than 3°.

Effect of rubber polarity on selective wetting of carbon nanotubes in ternary blends

OpenAIRE

Le, H.H.; Parsaker, M.; Sriharish, M.N.; Henning, S.; Menzel, M.; Wiessner, S.; Das, A.; Do, Q.K.; Heinrich, G.; Radusch, H.J.

2015-01-01

Based on atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) analysis of the rubber-filler gel (wetting concept) the kinetics of selective wetting of carbon nanotubes (CNTs) in ternary styrene butadiene rubber (SBR)/butadiene rubber (BR)/natural rubber (NR) blends was qualitatively and quantitatively characterized. Almost all CNTs are found to be wetted by the non-polar NR but not by the other non-polar rubber like BR or weakly polar SBR. It was proposed that phos...

Facts and fallacies in wet deposition modelling

International Nuclear Information System (INIS)

ApSimon, H.M.; Goddard, A.J.H.; Manning, P.M.; Simms, K.

1987-01-01

Following a reactor accident, relatively high contamination at ground level can occur, even at quite long distances from the source, if the pollutant cloud encounters intense precipitation. To estimate such contamination and its extent properly, it is necessary to take into account the spatial and temporal structure of rain patterns and their motion. Currently, models of wet deposition are rather crude. Source meteorology is usually used and is clearly inadequate. Furthermore, no allowance is made for the dynamic nature of rainfall, which occurs as a result of vertical air motions and convergence; nor for the different scavenging mechanism operating in and below cloud. Meteorological information available on these aspects of wet deposition is reviewed, and their importance and inclusion in modelling and prediction of resulting ground contamination is indicated. Some of the pitfalls of simple modelling procedures are illustrated. (author)

40 CFR 406.10 - Applicability; description of the corn wet milling subcategory.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Applicability; description of the corn wet milling subcategory. 406.10 Section 406.10 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GRAIN MILLS POINT SOURCE CATEGORY Corn Wet Milling...

Discussion about the application of treatment process for dehydrated wet waste at nuclear power station

International Nuclear Information System (INIS)

Li Guanghua; Wu Qiang

2009-01-01

In nuclear power station, the most popular treatment about low level radioactive wet waste generated during the unit operating and maintenance is embedded by cement. For radioactive waste minimization, this article introduces a new treatment process to dehydrate and compress wet waste. According to the development and application of the treatment process for the wet waste, and comparing with the formerly treatment-the cement embedding, prove that the new treatment can meet the purpose for volume reduction of wet waste. (authors)

Biofuels and Bioproducts from Wet and Gaseous Waste Streams: Challenges and Opportunities

Energy Technology Data Exchange (ETDEWEB)

None, None

2017-01-09

This report draws together activities related to wet and gaseous waste feedstocks into a single document. It enables an amplified focus on feedstocks in the relevant technology and potential markets category. Also, this report helps to inform and support ongoing wet and gaseous resource recovery activities in the Bioenergy Technologies Office (BETO) and in the broader federal space. Historically, the office has identified wet and gaseous waste feedstocks as potentially advantageous, but has not pursued them with a sustained focus. This document seeks to position these waste streams appropriately alongside more traditional feedstocks in BETO efforts.

Rainforest-initiated wet season onset over the southern Amazon.

Science.gov (United States)

Wright, Jonathon S; Fu, Rong; Worden, John R; Chakraborty, Sudip; Clinton, Nicholas E; Risi, Camille; Sun, Ying; Yin, Lei

2017-08-08

Although it is well established that transpiration contributes much of the water for rainfall over Amazonia, it remains unclear whether transpiration helps to drive or merely responds to the seasonal cycle of rainfall. Here, we use multiple independent satellite datasets to show that rainforest transpiration enables an increase of shallow convection that moistens and destabilizes the atmosphere during the initial stages of the dry-to-wet season transition. This shallow convection moisture pump (SCMP) preconditions the atmosphere at the regional scale for a rapid increase in rain-bearing deep convection, which in turn drives moisture convergence and wet season onset 2-3 mo before the arrival of the Intertropical Convergence Zone (ITCZ). Aerosols produced by late dry season biomass burning may alter the efficiency of the SCMP. Our results highlight the mechanisms by which interactions among land surface processes, atmospheric convection, and biomass burning may alter the timing of wet season onset and provide a mechanistic framework for understanding how deforestation extends the dry season and enhances regional vulnerability to drought.

Impact of small-scale geometric roughness on wetting behavior.

Science.gov (United States)

Kumar, Vaibhaw; Errington, Jeffrey R

2013-09-24

We examine the extent to which small-scale geometric substrate roughness influences the wetting behavior of fluids at solid surfaces. Molecular simulation is used to construct roughness wetting diagrams wherein the progression of the contact angle is traced from the Cassie to Wenzel to impregnation regime with increasing substrate strength for a collection of systems with rectangularly shaped grooves. We focus on the evolution of these diagrams as the length scale of the substrate features approaches the size of a fluid molecule. When considering a series of wetting diagrams for substrates with fixed shape and variable feature periodicity, we find that the diagrams progressively shift away from a common curve as the substrate features become smaller than approximately 10 fluid diameters. It is at this length scale that the macroscopic models of Cassie and Wenzel become unreliable. Deviations from the macroscopic models are attributed to the manner in which the effective substrate-fluid interaction strength evolves with periodicity and the important role that confinement effects play for substrates with small periodicities.

Interplay of complete wetting, critical adsorption, and capillary condensation.

Science.gov (United States)

Drzewiński, A; Maciołek, A; Barasiński, A; Dietrich, S

2009-04-01

The excess adsorption Gamma in two-dimensional Ising strips (infinityxL), subject to identical boundary fields at both one-dimensional surfaces decaying in the orthogonal direction j as -h1j(-p), is studied for various values of p and along various thermodynamic paths below the bulk critical point by means of the density-matrix renormalization-group method. The crossover behavior between the complete-wetting and critical-adsorption regimes, occurring in semi-infinite systems, is strongly influenced by confinement effects. Along isotherms T=const the asymptotic power-law dependences on the external bulk field, which characterize these two regimes, are pre-empted by capillary condensation. Along the pseudo-first-order phase-coexistence line of the strips, which varies with temperature, we find a broad crossover regime in which both the thickness of the wetting film and Gamma increase as functions of the reduced temperature tau but do not follow any power law. Above the wetting temperature the order-parameter profiles are not slablike but exhibit wide interfacial variations and pronounced tails.

Review of BNFL's operational experience of wet type flasks

International Nuclear Information System (INIS)

McWilliam, D.S.

2004-01-01

BNFL International Transport's operational experience includes shipping 6000te of spent fuel from Japan to Sellafield, through its dedicated terminal at Barrow, and to Cogema La Hague. This fuel was shipped under the PNTL (Pacific Nuclear Transport Ltd) banner for which BNFL is responsible. PNTL owned and operated a fleet of 5 ships for Japanese business and a fleet of 80 wet and 58 dry flasks, for the transport of Light Water Reactor (LWR) spent fuel, from both Pressurised Water Reactors (PWR) and Boiling Water Reactors (BWR). ''Wet'' or ''dry'' flask is the common terminology used to distinguish between spent fuel flasks transporting fuel where the fuel is immersed in water, or spent fuel flasks that have been drained of water and dried. This paper concentrates on the wet type of flask utilised to transport fuel to Sellafield, that is the Excellox type (including similar type NTL derivatives). It aims to provide a summary of operational experience during handling at power stations, shipment, unloading at reprocessors and from scheduled maintenance

Two-Dimensional Wetting Transition Modeling with the Potts Model

Science.gov (United States)

Lopes, Daisiane M.; Mombach, José C. M.

2017-12-01

A droplet of a liquid deposited on a surface structured in pillars may have two states of wetting: (1) Cassie-Baxter (CB), the liquid remains on top of the pillars, also known as heterogeneous wetting, or (2) Wenzel, the liquid fills completely the cavities of the surface, also known as homogeneous wetting. Studies show that between these two states, there is an energy barrier that, when overcome, results in the transition of states. The transition can be achieved by changes in geometry parameters of the surface, by vibrations of the surface or by evaporation of the liquid. In this paper, we present a comparison of two-dimensional simulations of the Cassie-Wenzel transition on pillar-structured surfaces using the cellular Potts model (CPM) with studies performed by Shahraz et al. In our work, we determine a transition diagram by varying the surface parameters such as the interpillar distance ( G) and the pillar height ( H). Our results were compared to those obtained by Shahraz et al. obtaining good agreement.

Peracetic acid as an alternative disinfection technology for wet weather flows.

Science.gov (United States)

Coyle, Elizabeth E; Ormsbee, Lindell E; Brion, Gail M

2014-08-01

Rain-induced wet weather flows (WWFs) consist of combined sewer overflows, sanitary sewer overflows, and stormwater, all of which introduce pathogens to surface waters when discharged. When people come into contact with the contaminated surface water, these pathogens can be transmitted resulting in severe health problems. As such, WWFs should be disinfected. Traditional disinfection technologies are typically cost-prohibitive, can yield toxic byproducts, and space for facilities is often limited, if available. More cost-effective alternative technologies, requiring less space and producing less harmful byproducts are currently being explored. Peracetic acid (PAA) was investigated as one such alternative and this research has confirmed the feasibility and applicability of using PAA as a disinfectant for WWFs. Peracetic acid doses ranging from 5 mg/L to 15 mg/L over contact times of 2 to 10 minutes were shown to be effective and directly applicable to WWF disinfection.

Wetting behaviour and reactivity between liquid Gd and ZrO2 substrate

Directory of Open Access Journals (Sweden)

Turalska P.

2017-01-01

Full Text Available The wetting behavior and reactivity between molten pure Gd and polycrystalline 3YSZ substrate (ZrO2 stabilized with 3 wt% of Y2O3were experimentally determined by a sessile drop method using a classical contact heating coupled with drop pushing procedure. The test was performed under an inert flowing gas atmosphere (Ar at two temperatures of 1362°C and 1412°C. Immediately after melting (Tm=1341°C, liquid Gd did not wet the substrate forming a contact angle of θ=141°. The non-wetting to wetting transition (θ < 90° took place after about 110 seconds of interaction and was accompanied by a sudden decrease in the contact angle value to 67°. Further heating of the couple to 1412 °C did not affect wetting (θ=67°±1°. The solidified Gd/3YSZ couple was studied by means of optical microscopy and scanning electron microscopy coupled with X-ray energy dispersive spectroscopy. Structural investigations revealed that the wettability in the Gd/3YSZ system is of a reactive nature associated with the formation of a continuous layer of a wettable reaction product Gd2Zr2O7.

A thermal-driven silicon micro xy-stage integrated with piezoresistive sensors for nano-positioning

International Nuclear Information System (INIS)

Choi, Young-Soo; Zhang, Yan; Lee, Dong-Weon

2012-01-01

This paper describes a novel micro xy-stage, driven by double-hot arm horizontal thermal micro-actuators integrated with a piezoresistive sensor (PS) for low-voltage operation and precise control. This micro xy-stage structure is linked with chevron beams and optimized to amplify the displacement generated by the micro-actuators that provide a pull force to the movable platform. The PS employed for in situ displacement detection and feedback control is fabricated at the base of a cold arm, which minimizes the influence of temperature change induced by electro-thermal heating. The micro xy-stage structure is defined through the use of a simple micromachining process, released by backside wet etching with a special tool. For an input power of approximately 44 mW, each chevron actuator provides about 16 µm and the total displacement of the platform is close to 32 µm. The sensitivity of the PS is better than 1 mV µm −1 , obtained from the amplified voltage output of the Wheatstone bridge circuit. The potential applications of the proposed micro xy-stage lie in micro- or nano-manipulation, as well as the positioning of ultra-small objects in nanotechnology. (paper)

Random Vibration Testing of Advanced Wet Tantalum Capacitors

Science.gov (United States)

Teverovsky, Alexander

2015-01-01

Advanced wet tantalum capacitors allow for improved performance of power supply systems along with substantial reduction of size and weight of the systems that is especially beneficial for space electronics. Due to launch-related stresses, acceptance testing of all space systems includes random vibration test (RVT). However, many types of advanced wet tantalum capacitors cannot pass consistently RVT at conditions specified in MIL-PRF-39006, which impedes their use in space projects. This requires a closer look at the existing requirements, modes and mechanisms of failures, specifics of test conditions, and acceptance criteria. In this work, different lots of advanced wet tantalum capacitors from four manufacturers have been tested at step stress random vibration conditions while their currents were monitored before, during, and after the testing. It has been shown that the robustness of the parts and their reliability are mostly due to effective self-healing processes and limited current spiking or minor scintillations caused by RVT do not increase the risk of failures during operation. A simple model for scintillations events has been used to simulate current spiking during RVT and optimize test conditions. The significance of scintillations and possible effects of gas generation have been discussed and test acceptance criteria for limited current spiking have been suggested.

Environmental management system case study: textile wet processes

Energy Technology Data Exchange (ETDEWEB)

Nasreldin, A A [Engineering Researches and Industrial Technologies Council, Sudan Academy of Sciences, Khartoum (Sudan)

2008-10-15

Textile industry is one of the oldest industries, it started very early in the ancient ages, its grows and improves gradually at the first and then rapidly to satisfy other different need of the mankind, even for luxury purposes, this development caused damage to environment, then its need the treatment. Textile wet processes used significant quantities of water and various kind of chemicals marketed under the name textile auxiliaries, to enhance the appearance of the fabric, serviceability, and durability. The chemical contamination of textile wet processes can be a health risk for the mill workers, consumers and for the environment as well. A number of schemes have been proposed in different countries to control the textile wet processes to create better environment and protect the ecosystem from further degradation, the developing countries need to apply their designed policies from the beginning. A theoretical study for probability of application of environmental management system in textile industry, to prevent or eliminate textile industry pollution that considered as one of the largest polluters in Sudanese environment, especially after the government (industrial ministry) support and facilitate to textile industry development. Applying environmental management system can appreciably reduce the textile industry pollution as founded from the study.(Author)

Environmental management system case study: textile wet processes

International Nuclear Information System (INIS)

Nasreldin, A.A.

2008-10-01

Textile industry is one of the oldest industries, it started very early in the ancient ages, its grows and improves gradually at the first and then rapidly to satisfy other different need of the mankind, even for luxury purposes, this development caused damage to environment, then its need the treatment. Textile wet processes used significant quantities of water and various kind of chemicals marketed under the name textile auxiliaries, to enhance the appearance of the fabric, serviceability, and durability. The chemical contamination of textile wet processes can be a health risk for the mill workers, consumers and for the environment as well. A number of schemes have been proposed in different countries to control the textile wet processes to create better environment and protect the ecosystem from further degradation, the developing countries need to apply their designed policies from the beginning. A theoretical study for probability of application of environmental management system in textile industry, to prevent or eliminate textile industry pollution that considered as one of the largest polluters in Sudanese environment, especially after the government (industrial ministry) support and facilitate to textile industry development. Applying environmental management system can appreciably reduce the textile industry pollution as founded from the study.(Author)

Cosmetic Cleansing Oil Absorption by Soft Contact Lenses in Dry and Wet Conditions.

Science.gov (United States)

Tsukiyama, Junko; Miyamoto, Yuko; Kodama, Aya; Fukuda, Masahiko; Shimomura, Yoshikazu

2017-09-01

Previous reports showed that cosmetic cleansing oil for removing makeup, which contains mineral oil and surfactant, can deform some silicone hydrogel contact lenses (SHCLs) when applied directly to the lenses, although plasma-coated SHCLs (lotrafilcon A and B) were not affected. In the present study, we investigated hydrogel lenses and SHCLs in both wet and dry conditions. Several brands of hydrogel and SHCLs were immersed in a cleansing oil solution containing Sudan Black B for 5 min under wet and dry conditions. The lenses under the wet condition were simply picked up from the saline, whereas those under the dry condition were blotted with paper wipes. After immersing, the excess solution remaining on the lenses was removed by finger rubbing with a multipurpose solution. The lenses were then examined using a stereomicroscope, and their mean brightness was measured and compared. The cosmetic cleansing oil was not absorbed by the hydrogel lenses under wet or dry conditions. However, four of seven brands of SHCLs absorbed the cosmetic cleansing oil under both conditions (dry and wet), whereas asmofilcon A absorbed it only under the dry condition. Lotrafilcon B and delefilcon A did not absorb cleansing oil even under the dry condition. Hydrogel lenses resist cosmetic cleansing oil. However, SHCLs have different degrees of resistance depending on the lens material. Some SHCLs absorbed cosmetic cleansing oil more under dry conditions than under wet conditions.

Investigating spin-transfer torques induced by thermal gradients in magnetic tunnel junctions by using micro-cavity ferromagnetic resonance

Science.gov (United States)

Cansever, H.; Narkowicz, R.; Lenz, K.; Fowley, C.; Ramasubramanian, L.; Yildirim, O.; Niesen, A.; Huebner, T.; Reiss, G.; Lindner, J.; Fassbender, J.; Deac, A. M.

2018-06-01

Similar to electrical currents flowing through magnetic multilayers, thermal gradients applied across the barrier of a magnetic tunnel junction may induce pure spin-currents and generate ‘thermal’ spin-transfer torques large enough to induce magnetization dynamics in the free layer. In this study, we describe a novel experimental approach to observe spin-transfer torques induced by thermal gradients in magnetic multilayers by studying their ferromagnetic resonance response in microwave cavities. Utilizing this approach allows for measuring the magnetization dynamics on micron/nano-sized samples in open-circuit conditions, i.e. without the need of electrical contacts. We performed first experiments on magnetic tunnel junctions patterned into 6  ×  9 µm2 ellipses from Co2FeAl/MgO/CoFeB stacks. We conducted microresonator ferromagnetic resonance (FMR) under focused laser illumination to induce thermal gradients in the layer stack and compared them to measurements in which the sample was globally heated from the backside of the substrate. Moreover, we carried out broadband FMR measurements under global heating conditions on the same extended films the microstructures were later on prepared from. The results clearly demonstrate the effect of thermal spin-torque on the FMR response and thus show that the microresonator approach is well suited to investigate thermal spin-transfer-driven processes for small temperatures gradients, far below the gradients required for magnetic switching.

Optimisation of electronic interface properties of a-Si:H/c-Si hetero-junction solar cells by wet-chemical surface pre-treatment

Energy Technology Data Exchange (ETDEWEB)

Angermann, H. [Hahn-Meitner-Institut, Abt. Siliziumphotovoltaik, Kekulestrasse 5, D-12489 Berlin (Germany)], E-mail: angermann@hmi.de; Korte, L.; Rappich, J.; Conrad, E.; Sieber, I.; Schmidt, M. [Hahn-Meitner-Institut, Abt. Siliziumphotovoltaik, Kekulestrasse 5, D-12489 Berlin (Germany); Huebener, K.; Hauschild, J. [Freie Universitaet Berlin, FB Physik, Arnimallee 14, 14195 Berlin (Germany)

2008-08-30

The relation between structural imperfections at structured silicon surfaces, energetic distribution of interface state densities, recombination loss at a-Si:H/c-Si interfaces and solar cell characteristics have been intensively investigated using non-destructive, surface sensitive techniques, surface photovoltage (SPV) and photoluminescence (PL) measurements, atomic force microscopy (AFM) and electron microscopy (SEM). Sequences of wet-chemical oxidation and etching steps were optimised with respect to the etching behaviour of Si(111) pyramids. Special wet-chemical smoothing and oxide removal procedures for structured substrates were developed, in order to reduce the preparation-induced surface micro-roughness and density of electronically active defects. H-termination and passivation by wet-chemical oxides were used to inhibit surface contamination and native oxidation during the technological process. We achieved significantly lower micro-roughness, densities of surface states D{sub it}(E) and recombination loss at a-Si:H/c-Si interfaces on wafers with randomly distributed pyramids, compared to conventional pre-treatments. For amorphous-crystalline hetero-junction solar cells (ZnO/a-Si:H/c-Si/BSF/Al), the c-Si surface becomes part of the a-Si:H/c-Si interface, whose recombination activity determines cell performance. With textured substrates, the smoothening procedure results in a significant increase of short circuit current, fill factor and efficiency.

Optimisation of electronic interface properties of a-Si:H/c-Si hetero-junction solar cells by wet-chemical surface pre-treatment

International Nuclear Information System (INIS)

Angermann, H.; Korte, L.; Rappich, J.; Conrad, E.; Sieber, I.; Schmidt, M.; Huebener, K.; Hauschild, J.

2008-01-01

The relation between structural imperfections at structured silicon surfaces, energetic distribution of interface state densities, recombination loss at a-Si:H/c-Si interfaces and solar cell characteristics have been intensively investigated using non-destructive, surface sensitive techniques, surface photovoltage (SPV) and photoluminescence (PL) measurements, atomic force microscopy (AFM) and electron microscopy (SEM). Sequences of wet-chemical oxidation and etching steps were optimised with respect to the etching behaviour of Si(111) pyramids. Special wet-chemical smoothing and oxide removal procedures for structured substrates were developed, in order to reduce the preparation-induced surface micro-roughness and density of electronically active defects. H-termination and passivation by wet-chemical oxides were used to inhibit surface contamination and native oxidation during the technological process. We achieved significantly lower micro-roughness, densities of surface states D it (E) and recombination loss at a-Si:H/c-Si interfaces on wafers with randomly distributed pyramids, compared to conventional pre-treatments. For amorphous-crystalline hetero-junction solar cells (ZnO/a-Si:H/c-Si/BSF/Al), the c-Si surface becomes part of the a-Si:H/c-Si interface, whose recombination activity determines cell performance. With textured substrates, the smoothening procedure results in a significant increase of short circuit current, fill factor and efficiency

Wet gas compression. Experimental investigation of the aerodynamics within a centrifugal compressor exposed to wet gas

Energy Technology Data Exchange (ETDEWEB)

Gruener, Trond Gammelsaeter

2012-07-01

The demand for more efficient oil and gas production requires improved technology to increase production rates and enhance profitable operation. The centrifugal compressor is the key elements in the compression system. Preliminary studies of wet gas compressor concepts have demonstrated the benefits of wet gas boosting. An open-loop test facility was designed for single-stage wet gas compressor testing. Experimental investigators have been performed to reveal the impact of liquid on the aerodynamics of centrifugal compressor. The investigation consisted of two test campaigns with different impeller/diffuser configurations. Atmospheric air and water were used as experimental fluids. The two configurations showed a different pressure ratio characteristics when liquid as present. The results from test campaign A demonstrated a pronounced pressure ratio decrease at high flow and a minor pressure ration increase pressure ratio with reducing gas mass fraction (GMF). The deviation in pressure ratio characteristic for the two test campaigns was attributed to the volute operating characteristic. Both impeller/diffuser configurations demonstrated a reduction in maximum volume flow with decreasing GMF. The impeller pressure ratio was related to the diffuser and/or the volute performance). Air and water are preferable experimental fluids for safety reasons and because a less extensive facility design is required. An evaluation of the air/water tests versus hydrocarbon tests was performed in order to reveal whether the results were representative. Air/water tests at atmospheric conditions reproduced the general performance trend of hydrocarbon wet gas compressor tests with an analogous impeller at high pressures. Aerodynamic instability limits the operating range because of feasible severe damage of the compressor and adverse influence on the performance. It is essential to establish the surge margin at different operating conditions. A delayed instability inception was

Three-level cobblestone-like TiO2 micro/nanocones for dual-responsive water/oil reversible wetting without fluorination

Science.gov (United States)

Zhou, Chen; Li, Guoqiang; Li, Chuanzong; Zhang, Zhen; Zhang, Yachao; Wu, Sizhu; Hu, Yanlei; Zhu, Wulin; Li, Jiawen; Chu, Jiaru; Hu, Zhijia; Wu, Dong; Yu, Liandong

2017-10-01

In this work, a kind of three-level cobblestone-like anatase TiO2 microcone array was fabricated on titanium sheets by femtosecond laser-induced self-assembly. This three level structure consisted of cobblestone-like features (15-25 μm in height and 20-35 μm in diameter), ˜460 nm ripple-like features, and smaller particles (10-500 nm). The formation of microcone arrays can be ascribed to the interaction of alternant laser beam ablation. TiO2 surfaces display dual-responsive water/oil reversible wetting via heat treatment and selective UV irradiation without fluorination. It is indicated that three-level scale surface roughness can amplify the wetting character of the Ti surface, and the mechanism for reversible switching between extreme wettabilities is caused by the conversion between Ti-OH and Ti-O. Moreover, the double-faced superhydrophobic and double-faced superhydrophilic Ti samples were constructed, which exhibited stable superhydrophobicity and underwater superoleophobicity in water-oil solution, respectively, even when strongly shaken. Finally, we present the hybrid-patterned TiO2 surface and realized reversible switching pattern wettability.

Edge-to-Stem Variability in Wet-Canopy Evaporation From an Urban Tree Row

Science.gov (United States)

Van Stan, John T.; Norman, Zachary; Meghoo, Adrian; Friesen, Jan; Hildebrandt, Anke; Côté, Jean-François; Underwood, S. Jeffrey; Maldonado, Gustavo

2017-11-01

Evaporation from wet-canopy (E_C) and stem (E_S) surfaces during rainfall represents a significant portion of municipal-to-global scale hydrologic cycles. For urban ecosystems, E_C and E_S dynamics play valuable roles in stormwater management. Despite this, canopy-interception loss studies typically ignore crown-scale variability in E_C and assume (with few indirect data) that E_S is generally {<}2% of total wet-canopy evaporation. We test these common assumptions for the first time with a spatially-distributed network of in-canopy meteorological monitoring and 45 surface temperature sensors in an urban Pinus elliottii tree row to estimate E_C and E_S under the assumption that crown surfaces behave as "wet bulbs". From December 2015 through July 2016, 33 saturated crown periods (195 h of 5-min observations) were isolated from storms for determination of 5-min evaporation rates ranging from negligible to 0.67 mm h^{-1}. Mean E_S (0.10 mm h^{-1}) was significantly lower (p < 0.01) than mean E_C (0.16 mm h^{-1}). But, E_S values often equalled E_C and, when scaled to trunk area using terrestrial lidar, accounted for 8-13% (inter-quartile range) of total wet-crown evaporation (E_S+E_C scaled to surface area). E_S contributions to total wet-crown evaporation maximized at 33%, showing a general underestimate (by 2-17 times) of this quantity in the literature. Moreover, results suggest wet-crown evaporation from urban tree rows can be adequately estimated by simply assuming saturated tree surfaces behave as wet bulbs, avoiding problematic assumptions associated with other physically-based methods.

Water regime history drives responses of soil Namib Desert microbial communities to wetting events

Science.gov (United States)

Frossard, Aline; Ramond, Jean-Baptiste; Seely, Mary; Cowan, Don A.

2015-07-01

Despite the dominance of microorganisms in arid soils, the structures and functional dynamics of microbial communities in hot deserts remain largely unresolved. The effects of wetting event frequency and intensity on Namib Desert microbial communities from two soils with different water-regime histories were tested over 36 days. A total of 168 soil microcosms received wetting events mimicking fog, light rain and heavy rainfall, with a parallel “dry condition” control. T-RFLP data showed that the different wetting events affected desert microbial community structures, but these effects were attenuated by the effects related to the long-term adaptation of both fungal and bacterial communities to soil origins (i.e. soil water regime histories). The intensity of the water pulses (i.e. the amount of water added) rather than the frequency of wetting events had greatest effect in shaping bacterial and fungal community structures. In contrast to microbial diversity, microbial activities (enzyme activities) showed very little response to the wetting events and were mainly driven by soil origin. This experiment clearly demonstrates the complexity of microbial community responses to wetting events in hyperarid hot desert soil ecosystems and underlines the dynamism of their indigenous microbial communities.

Composition of corn dry-grind ethanol by-products: DDGS, wet cake, and thin stillage.

Science.gov (United States)

Kim, Youngmi; Mosier, Nathan S; Hendrickson, Rick; Ezeji, Thaddeus; Blaschek, Hans; Dien, Bruce; Cotta, Michael; Dale, Bruce; Ladisch, Michael R

2008-08-01

DDGS and wet distillers' grains are the major co-products of the dry grind ethanol facilities. As they are mainly used as animal feed, a typical compositional analysis of the DDGS and wet distillers' grains mainly focuses on defining the feedstock's nutritional characteristics. With an increasing demand for fuel ethanol, the DDGS and wet distillers' grains are viewed as a potential bridge feedstock for ethanol production from other cellulosic biomass. The introduction of DDGS or wet distillers' grains as an additional feed to the existing dry grind plants for increased ethanol yield requires a different approach to the compositional analysis of the material. Rather than focusing on its nutritional value, this new approach aims at determining more detailed chemical composition, especially on polymeric sugars such as cellulose, starch and xylan, which release fermentable sugars upon enzymatic hydrolysis. In this paper we present a detailed and complete compositional analysis procedure suggested for DDGS and wet distillers' grains, as well as the resulting compositions completed by three different research groups. Polymeric sugars, crude protein, crude oil and ash contents of DDGS and wet distillers' grains were accurately and reproducibly determined by the compositional analysis procedure described in this paper.

Variable selection based near infrared spectroscopy quantitative and qualitative analysis on wheat wet gluten

Science.gov (United States)

Lü, Chengxu; Jiang, Xunpeng; Zhou, Xingfan; Zhang, Yinqiao; Zhang, Naiqian; Wei, Chongfeng; Mao, Wenhua

2017-10-01

Wet gluten is a useful quality indicator for wheat, and short wave near infrared spectroscopy (NIRS) is a high performance technique with the advantage of economic rapid and nondestructive test. To study the feasibility of short wave NIRS analyzing wet gluten directly from wheat seed, 54 representative wheat seed samples were collected and scanned by spectrometer. 8 spectral pretreatment method and genetic algorithm (GA) variable selection method were used to optimize analysis. Both quantitative and qualitative model of wet gluten were built by partial least squares regression and discriminate analysis. For quantitative analysis, normalization is the optimized pretreatment method, 17 wet gluten sensitive variables are selected by GA, and GA model performs a better result than that of all variable model, with R2V=0.88, and RMSEV=1.47. For qualitative analysis, automatic weighted least squares baseline is the optimized pretreatment method, all variable models perform better results than those of GA models. The correct classification rates of 3 class of 30% wet gluten content are 95.45, 84.52, and 90.00%, respectively. The short wave NIRS technique shows potential for both quantitative and qualitative analysis of wet gluten for wheat seed.

Wetting in a colloidal liquid-gas system

NARCIS (Netherlands)

Wijting, W.K.; Besseling, N.A.M.; Cohen Stuart, M.A.

2003-01-01

We present first observations of wetting phenomena in depletion interaction driven, phase separated colloidal dispersions (coated silica-cyclohexane-polydimethylsiloxane). The contact angle of the colloidal liquid-gas interface at a solid substrate (coated glass) was determined for a series of

Nanoscale View of Dewetting and Coating on Partially Wetted Solids.

Science.gov (United States)

Deng, Yajun; Chen, Lei; Liu, Qiao; Yu, Jiapeng; Wang, Hao

2016-05-19

There remain significant gaps in our ability to predict dewetting and wetting despite the extensive study over the past century. An important reason is the absence of nanoscopic knowledge about the processes near the moving contact line. This experimental study for the first time obtained the liquid morphology within 10 nm of the contact line, which was receding at low speed (U dewetting far from a simple reverse of wetting. A complete scenario for dewetting and coating is provided.

Crystallisation of Gypsum and Prevention of Foaming in Wet Flue Gas Desulphurisation (FGD) Plants

DEFF Research Database (Denmark)

Hansen, Brian Brun

The aim of this project is to investigate two operational problems, which have been experienced during wet flue gas desulphurisation (FGD) operation, i.e. poor gypsum dewatering properties and foaming. The results of this work can be used for the optimization of wet FGD-plants in terms of reliabi......The aim of this project is to investigate two operational problems, which have been experienced during wet flue gas desulphurisation (FGD) operation, i.e. poor gypsum dewatering properties and foaming. The results of this work can be used for the optimization of wet FGD-plants in terms....... Experiments in a falling film wet FGD pilot plant have shown a strong non-linear behaviour (in a ln(n(l)) vs. l plot) at the lower end of the particle size range, compared to the well-known linear “mixed suspension mixed product removal (MSMPR)” model. A transient population balance model, fitted...

Effects of grazing intensity on small mammal population ecology in wet meadows

DEFF Research Database (Denmark)

Schmidt, Niels Martin; Olsen, Henrik; Bildsøe, Mogens

2005-01-01

Livestock grazing is common management practice in wet grasslands. However, knowledge of its effects on small mammals is limited. We studied the influence of grazing intensity on small mammals in general and field voles Microtus agrestis in particular in two Danish wet meadows, 1998-2000. General...

Large wet-type cooling towers and their influence on the environment

International Nuclear Information System (INIS)

Schiffers, A.

1977-01-01

Large wet-type cooling towers with natural draft are said to be ecologically beneficial today, especially concerning the heat emission from power plants. A description is given of the influence of such cooling towers on the environment and the possible climatic influences are considered in detail. Recent investigations have shown that wet-type cooling towers represent no danger of any kind for fauna and flora as to the bacterial radiation. Physical studies have shown that neither the emitted water vapour nor the heat emitted into the atmosphere, can significantly change the macroclimate and microclimate. At present, wet-type cooling towers cannot be replaced by dry-type or so-called hybrid-type cooling towers, the technical development of which for large units being not yet guaranteed. (orig.) [de

Wetting Behavior of Calcium Ferrite Slags on Cristobalite Substrates

Science.gov (United States)

Yang, Mingrui; Lv, Xuewei; Wei, Ruirui; Xu, Jian; Bai, Chenguang

2018-03-01

Calcium ferrite (CF) is a significant intermediate adhesive phase in high-basicity sinters. The wettability between calcium ferrite (CF) and gangue plays an important role in the assimilation process. The wettability of CF-based slags, in which a constant amount (2 mass pct.) of Al2O3, MgO, SiO2, and TiO2 was added, on solid SiO2 (cristobalite) substrates at 1523 K (1250 °C) was investigated. The interfacial microstructure and spreading mechanisms were discussed for each sample. All the tested slag samples exhibited good wettability on the SiO2 substrate. The initial apparent contact angles were in the range of 20 to 50 deg, while the final apparent contact angles were 5 deg. The wetting process could be divided into three stages on the basis of the change in diameter, namely the "linear spreading" stage, "spreading rate reduction" stage, and "wetting equilibrium" stage. It was found that the CF-SiO2 wetting system exhibits dissolutive wetting and the dissolution of SiO2 into slag influences its spreading process. The spreading rate increases with a decrease in the ratio of viscosity to interfacial tension, which is a result of the addition of Al2O3, MgO, SiO2, and TiO2. After cooling, a deep corrosion pit was formed in the substrate and a diffusion layer was generated in front of the residual slag zone; further, some SiO2 and Fe2O3 solid solutions precipitated in the slag.

On the annealing-induced enhancement of the interface properties of NiO:Cu/wet-SiOx/n-Si tunnelling junction solar cells

Science.gov (United States)

Yang, Xueliang; Liu, Wei; Chen, Jingwei; Sun, Yun

2018-04-01

Using metal oxides to form a carrier-selective interface on crystalline silicon (c-Si) has recently generated considerable interest for use with c-Si photovoltaics because of the potential to reduce cost. n-type oxides, such as MoO3, V2O5, and WO3, have been widely studied. In this work, a p-type oxide, Cu-doped NiO (NiO:Cu), is explored as a transparent hole-selective contact to n-Si. An ultrathin SiOx layer, fabricated by a wet-chemical method (wet-SiOx), is introduced at the NiO:Cu/n-Si interface to achieve a tunnelling junction solar cell. Interestingly, it was observed that the interface quality of the NiO:Cu/wet-SiOx/n-Si heterojunction was dramatically enhanced by post-deposition annealing (PDA) at a temperature of 200 °C. Our device exhibits an improved power conversion efficiency of 10.8%, which is the highest efficiency among NiO/Si heterojunction photo-electric devices to date. It is demonstrated that the 200 °C PDA treatment enhances the built-in field by a reduction in the interface density of states (Dit) but does not influence the work function of the NiO:Cu thin layer. This stable work function after the PDA treatment is in conflict with the changed built-in field according to the Schottky model. Thus, the Bardeen model is introduced for this physical insight: the enhancement of the built-in field originates from the unpinning of the Fermi levels of NiO:Cu and n-Si by the interface state reduction.

Phoenix's Wet Chemistry Laboratory Units

Science.gov (United States)

2008-01-01

This image shows four Wet Chemistry Laboratory units, part of the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) instrument on board NASA's Phoenix Mars Lander. This image was taken before Phoenix's launch on August 4, 2007. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

Topographical Anisotropy and Wetting of Ground Stainless Steel Surfaces

Directory of Open Access Journals (Sweden)

Cornelia Bellmann

2012-12-01

Full Text Available Microscopic and physico-chemical methods were used for a comprehensive surface characterization of different mechanically modified stainless steel surfaces. The surfaces were analyzed using high-resolution confocal microscopy, resulting in detailed information about the topographic properties. In addition, static water contact angle measurements were carried out to characterize the surface heterogeneity of the samples. The effect of morphological anisotropy on water contact angle anisotropy was investigated. The correlation between topography and wetting was studied by means of a model of wetting proposed in the present work, that allows quantifying the air volume of the interface water drop-stainless steel surface.

Predicting germination in semi-arid wildland seedbeds II. Field validation of wet thermal-time models

Science.gov (United States)

Jennifer K. Rawlins; Bruce A. Roundy; Dennis Eggett; Nathan. Cline

2011-01-01

Accurate prediction of germination for species used for semi-arid land revegetation would support selection of plant materials for specific climatic conditions and sites. Wet thermal-time models predict germination time by summing progress toward germination subpopulation percentages as a function of temperature across intermittent wet periods or within singular wet...

Surfactant-induced deposit structures in relation to the biological efficacy of glyphosate on easy- and difficult-to-wet weed species.

Science.gov (United States)

Kraemer, Thorsten; Hunsche, Mauricio; Noga, Georg

2009-08-01

Typical active ingredient (AI) residue patterns are formed during droplet drying on plant surfaces owing to the interaction of spray solution characteristics and leaf micromorphology. Currently, comparatively little is known about the influence of AI deposit patterns within a spray droplet residue area on the penetration and biological efficacy of glyphosate. A scanning electron microscope with energy dispersive X-ray microanalysis has been used to characterise residue patterns and to quantify the area ultimately covered by glyphosate within the droplet spread area. The easy-to-wet weed species Stellaria media L. and Viola arvensis L., as well as the difficult-to-wet Chenopodium album L. and Setaria viridis L., differing in their surface micromorphology, have been used. Rapeseed oil ethoxylates (RSO 5 or RSO 60) were added to glyphosate solutions to provide different droplet spread areas. Addition of RSO 5 enhanced droplet spread area more than RSO 60, and both caused distinct glyphosate residue patterns. The biological efficacy of treatment solutions showed no significant correlation with the area ultimately covered by glyphosate. The results have implications on herbicide uptake models. This study shows that droplet spread area does not correspond to the area ultimately covered by glyphosate, and that the latter does not affect glyphosate phytotoxicity.

Double-layer optical fiber coating analysis in MHD flow of an elastico-viscous fluid using wet-on-wet coating process

Directory of Open Access Journals (Sweden)

Zeeshan Khan

Full Text Available Modern optical fibers require a double-layer coating on the glass fiber in order to provide protection from signal attenuation and mechanical damage. The most important plastic resins used in wires and optical fibers are plastic polyvinyl chloride (PVC and low and high density polyethylene (LDPE/HDPE, nylon and Polysulfone. One of the most important things which affect the final product after processing is the design of the coating die. In the present study, double-layer optical fiber coating is performed using melt polymer satisfying Oldroyd 8-constant fluid model in a pressure type die with the effect of magneto-hydrodynamic (MHD. Wet-on-wet coating process is applied for double-layer optical fiber coating. The coating process in the coating die is modeled as a simple two-layer Couette flow of two immiscible fluids in an annulus with an assigned pressure gradient. Based on the assumptions of fully developed laminar and MHD flow, the Oldroyd 8-constant model of non-Newtonian fluid of two immiscible resin layers is modeled. The governing nonlinear equations are solved analytically by the new technique of Optimal Homotopy Asymptotic Method (OHAM. The convergence of the series solution is established. The results are also verified by the Adomian Decomposition Method (ADM. The effect of important parameters such as magnetic parameter Mi, the dilatant constant α, the Pseodoplastic constant β, the radii ratio δ, the pressure gradient Ω, the speed of fiber optics V, and the viscosity ratio κ on the velocity profiles, thickness of coated fiber optics, volume flow rate, and shear stress on the fiber optics are investigated. At the end the result of the present work is also compared with the experimental results already available in the literature by taking non-Newtonian parameters tends to zero. Keywords: Non-Newtonian fluid, Oldroyd 8-constant fluid, MHD flow, Double-layer fiber coating, OHAM, ADM, Wet-on-wet coating process

Effects of wet-cupping on blood pressure in hypertensive patients: a randomized controlled trial.

Science.gov (United States)

Aleyeidi, Nouran A; Aseri, Khaled S; Matbouli, Shadia M; Sulaiamani, Albaraa A; Kobeisy, Sumayyah A

2015-11-01

Although cupping remains a popular treatment modality worldwide, its efficacy for most diseases, including hypertension, has not been scientifically evaluated. We aimed to determine the efficacy of wet-cupping for high blood pressure, and the incidence of the procedure's side effects in the intervention group. This is a randomized controlled trial conducted in the General Practice Department at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, between May 2013 and February 2014. There were two groups (40 participants each): intervention group undergoing wet-cupping (hijama) in addition to conventional hypertension treatment, and a control group undergoing only conventional hypertension treatment. Three wet-cupping sessions were performed every other day. The mean systolic and diastolic blood pressures were measured using a validated automatic sphygmomanometer. The follow-up period was 8 weeks. Wet-cupping provided an immediate reduction of systolic blood pressure. After 4 weeks of follow-up, the mean systolic blood pressure in the intervention group was 8.4 mmHg less than in the control group (P=0.046). After 8 weeks, there were no significant differences in blood pressures between the intervention and control groups. In this study, wet-cupping did not result in any serious side effects. Wet-cupping therapy is effective for reducing systolic blood pressure in hypertensive patients for up to 4 weeks, without serious side effects. Wet-cupping should be considered as a complementary hypertension treatment, and further studies are needed. ClinicalTrials.gov Identifier NCT01987583.

To the vibrational over wetting and liquefaction effects in moistured soils

International Nuclear Information System (INIS)

Karimov, F.H.; Oripov, G.O.; Saidov, R.M.; Tojibekov, M.

2003-01-01

There is a lot of evidence of the dynamical effects in soils when they become wetted or during or after the earthquakes or explosions. There are some quantitative estimates for the vibrational wetting and liquefaction of soils under consideration. For the models in the present research the moistured sands and weak soils like losses are accepted. The first model is focusing on soil fractures sliding down under the action of vibrations, tightening of a hard phase, squeezing water phase out and thus bringing to soil liquefaction. The second is based on soil fractures plunging at the action of vibrations into the aquatic background. This mechanism seems to be more effective for the high degree moistured soils. The third mechanism is based on capillary phenomena in moistured porous medium. When inertia forces are large enough the resultant force, consisting of sliding down gravity component and inertia forces, overcomes friction and fracture becomes unstable. Both vibrations amplitude and frequency are the stability controlling factors, playing an important role in the vibrational wetting and liquefaction effects through porous water phase squeezing out or capillary lifting phenomena leading to the wetting or liquefaction of the medium. (author)

Microwave moisture sensing of wet bales

Science.gov (United States)

Sensing of moisture in very wet lint bales is unique due to the fact that moisture distribution is typically non-uniform and can in some instances be highly localized. This issue is even further complicated by the use of a sensor that reads only a portion of the bale and/or with a sensor that provid...

Characterization of wet aggregate stability of soils by ¹H-NMR relaxometry.

Science.gov (United States)

Buchmann, C; Meyer, M; Schaumann, G E

2015-09-01

For the assessment of soil structural stability against hydraulic stress, wet sieving or constant head permeability tests are typically used but rather limited in their intrinsic information value. The multiple applications of several tests is the only possibility to assess important processes and mechanisms during soil aggregate breakdown, e.g. the influences of soil fragment release or differential swelling on the porous systems of soils or soil aggregate columns. Consequently, the development of new techniques for a faster and more detailed wet aggregate stability assessment is required. (1)H nuclear magnetic resonance relaxometry ((1)H-NMR relaxometry) might provide these requirements because it has already been successfully applied on soils. We evaluated the potential of (1)H-NMR relaxometry for the assessment of wet aggregate stability of soils, with more detailed information on occurring mechanisms at the same time. Therefore, we conducted single wet sieving and constant head permeability tests on untreated and 1% polyacrylic acid-treated soil aggregates of different textures and organic matter contents, subsequently measured by (1)H-NMR relaxometry after percolation. The stability of the soil aggregates were mainly depending on their organic matter contents and the type of aggregate stabilization, whereby additional effects of clay swelling on the measured wet aggregate stability were identified by the transverse relaxation time (T2) distributions. Regression analyses showed that only the percentage of water stable aggregates could be determined accurately from percolated soil aggregate columns by (1)H-NMR relaxometry measurements. (1)H-NMR relaxometry seems a promising technique for wet aggregate stability measurements but should be further developed for nonpercolated aggregate columns and real soil samples. Copyright © 2014 John Wiley & Sons, Ltd.

Selective Oxidation and Reactive Wetting during Galvanizing of a CMnAl TRIP-Assisted Steel

Science.gov (United States)

Bellhouse, E. M.; McDermid, J. R.

2011-09-01

A transformation induced plasticity (TRIP)-assisted steel with 0.2 pct C, 1.5 pct Mn, and 1.5 pct Al was successfully galvanized using a thermal cycle previously shown to produce an excellent combination of strength and ductility. The steel surface chemistry and oxide morphology were determined as a function of process atmosphere oxygen partial pressure. For the 220 K (-53 °C) dew point (dp) + 20 pct H2 atmosphere, the oxide morphology was a mixture of films and nodules. For the 243 K (-30 °C) dp + 5 pct H2 atmosphere, nodules of MnO were found primarily at grain boundaries. For the 278 K (+5 °C) dp + 5 pct H2 atmosphere, nodules of metallic Fe were found on the surface as a result of alloy element internal oxidation. The steel surface chemistry and oxide morphology were then related to the reactive wetting behavior during continuous hot dip galvanizing. Good wetting was obtained using the two lower oxygen partial pressure process atmospheres [220 K dp and 243 K dp (-53 °C dp and -30 °C dp)]. An increase in the number of bare spots was observed when using the higher oxygen partial pressure process atmosphere (+5 °C dp) due to the increased thickness of localized oxide films.

Controlling the optical parameters of self-assembled silver films with wetting layers and annealing

Science.gov (United States)

Ciesielski, Arkadiusz; Skowronski, Lukasz; Trzcinski, Marek; Szoplik, Tomasz

2017-11-01

We investigated the influence of presence of Ni and Ge wetting layers as well as annealing on the permittivity of Ag films with thicknesses of 20, 35 and 65 nm. Most of the research on thin silver films deals with very small (wetting and capping material, post-process annealing). Our study, based on atomic force microscopy, ellipsometric and X-ray photoelectron spectroscopy measurements, shows that utilizing a wetting layer is comparable to increasing the thickness of the silver film. Both operations decrease the roughness-to-thickness ratio, thus decreasing the scattering losses and both narrow the Lorentz-shaped interband transition peak. However, while increasing silver thickness increases absorption on the free carriers, the use of wetting layers influences the self-assembled internal structure of silver films in such a way, that the free carrier absorption decreases. Wetting layers also introduce additional contributions from effects like segregation or diffusion, which evolve in time and due to annealing.

Evaluation of wet oxidation pretreatment for enzymatic hydrolysis of softwood

DEFF Research Database (Denmark)

Palonen, H.; Thomsen, A.B.; Tenkanen, M.

2004-01-01

The wet oxidation pretreatment (water, oxygen, elevated temperature, and pressure) of softwood (Picea abies) was investigated for enhancing enzymatic hydrolysis. The pretreatment was preliminarily optimized. Six different combinations of reaction time, temperature, and pH were applied......, and the compositions of solid and liquid fractions were analyzed. The solid fraction after wet oxidation contained 58-64% cellulose, 2-16% hemicellulose, and 24-30% lignin. The pretreatment series gave information about the roles of lignin and hemicellulose in the enzymatic hydrolysis. The temperature...

High index glass thin film processing for photonics and photovoltaic (PV) applications

Science.gov (United States)

Ogbuu, Okechukwu Anthony

To favorably compete with fossil-fuel technology, the greatest challenge for thin film solar-cells is to improve efficiency and reduce material cost. Thickness scaling to thin film reduces material cost but affects the light absorption in the cells; therefore a concept that traps incident photons and increases its optical path length is needed to boost absorption in thin film solar cells. One approach is the integration of low symmetric gratings (LSG), using high index material, on either the front-side or backside of 30 um thin c-Si cells. In this study, Multicomponent TeO2--Bi2O 3--ZnO (TBZ) glass thin films were prepared using RF magnetron sputtering under different oxygen flow rates. The influences of oxygen flow rate on the structural and optical properties of the resulting thin films were investigated. The structural origin of the optical property variation was studied using X-ray diffraction, X-ray photoelectron spectroscopy, Raman Spectroscopy, and transmission electron microscopy. The results indicate that TBZ glass thin film is a suitable material for front side LSG material photovoltaic and photonics applications due to their amorphous nature, high refractive index (n > 2), broad band optical transparency window, low processing temperature. We developed a simple maskless method to pattern sputtered tellurite based glass thin films using unconventional agarose hydrogel mediated wet etching. Conventional wet etching process, while claiming low cost and high throughput, suffers from reproducibility and pattern fidelity issues due to the isotropic nature of wet chemical etching when applied to glasses and polymers. This method overcomes these challenges by using an agarose hydrogel stamp to mediate a conformal etching process. In our maskless method, agarose hydrogel stamps are patterned following a standard soft lithography and replica molding process from micropatterned masters and soaked in a chemical etchant. The micro-scale features on the stamp are

Atmospheric corrosion Monitoring with Time-of-Wetness (TOW) sensor and Thin Film Electric Resistance (TFER) sensor

International Nuclear Information System (INIS)

Jung, Sung Won; Kim, Young Geun; Song, Hong Seok; Lee, Seung Min; Kho, Young Tai

2002-01-01

In this study, TOW sensor was fabricated with the same P. J. Serada's in NRC and was evaluated according to pollutant amount and wet/dry cycle. Laboratorily fabricated thin film electric resistance (TFER) probes were applied in same environment for the measurement of corrosion rate for feasibility. TOW sensor could not differentiate the wet and dry time especially at polluted environment like 3.5% NaCl solution. This implies that wet/dry time monitoring by means of TOW sensor need careful application on various environment. TFER sensor could produce instant atmospheric corrosion rate regardless of environment condition. And corrosion rate obtained by TFER sensor could be differentiated according to wet/dry cycle, wet/dry cycle time variation and solution chemistry. Corrosion behaviors of TFER sensor showed that corrosion could proceed even after wet cycle because of remained electrolyte at the surface

Effects of Dry-Milling and Wet-Milling on Chemical, Physical and Gelatinization Properties of Rice Flour

Directory of Open Access Journals (Sweden)

Jitranut Leewatchararongjaroen

2016-09-01

Full Text Available Rice flour from nine varieties, subjected to dry- and wet-milling processes, was determined for its physical and chemical properties. The results revealed that milling method had an effect on properties of flour. Wet-milling process resulted in flour with significantly lower protein and ash contents and higher carbohydrate content. Wet-milled flour also tended to have lower lipid content and higher amylose content. In addition, wet-milled rice flour contained granules with smaller average size compared to dry-milled samples. Swelling power at 90 °C of wet-milled samples was higher while solubility was significantly lower than those of dry-milled flour. Dry milling process caused the destruction of the crystalline structure and yielded flour with lower crystallinity compared to wet-milling process, which resulted in significantly lower gelatinization enthalpy.

‘Breath figures’ on leaf surfaces – formation and effects of microscopic leaf wetness

Directory of Open Access Journals (Sweden)

Jürgen eBurkhardt

2013-10-01

Full Text Available ‘Microscopic leaf wetness’ means minute amounts of persistent liquid water on leaf surfaces which are invisible to the naked eye. The water is mainly maintained by transpired water vapor condensing onto the leaf surface and to attached leaf surface particles. With an estimated average thickness of less than 1 µm, microscopic leaf wetness it is about 2 orders of magnitude thinner than morning dewfall. The most important physical processes which reduce the saturation vapor pressure and promote condensation are cuticular absorption and the deliquescence of hygroscopic leaf surface particles. Deliquescent salts form highly concentrated solutions. Depending on the amount and concentration of the dissolved ions, the physicochemical properties of microscopic leaf wetness can be considerably different from those of pure water. Microscopic leaf wetness can form continuous thin layers on hydrophobic leaf surfaces and in specific cases can act similar to surfactants, enabling a strong potential influence on the foliar exchange of ions. Microscopic leaf wetness can also enhance the dissolution, the emission, and the reaction of specific atmospheric trace gases e.g. ammonia, SO2, or ozone, leading to a strong potential role for microscopic leaf wetness in plant/atmosphere interaction. Due to its difficult detection, there is little knowledge about the occurrence and the properties of microscopic leaf wetness. However, based on the existing evidence and on physicochemical reasoning it can be hypothesized that microscopic leaf wetness occurs on almost any plant worldwide and often permanently, and that it significantly influences the exchange processes of the leaf surface with its neighboring compartments, i.e., the plant interior and the atmosphere. The omission of microscopic water in general leaf wetness concepts has caused far-reaching, misleading conclusions in the past.

Spatio-temporal dynamics and synoptic characteristics of wet and drought extremes in Northern Eurasia

Science.gov (United States)

Utkuzova, Dilyara; Khan, Valentina

2015-04-01

Synoptical-statistical analysis has been conducted using SPI index calculated for 478 stations with records from 1966 through 2013. Different parameters of SPI frequency distribution and long-term tendencies were calculated as well as spatial characteristics indicating drought and wetness propagation. Results of analysis demonstrate that during last years there is a tendency of increasing of the intensity of draught and wetness extremes over Russia. There are fewer droughts in the northern regions. The drought propagation for the European territory of Russia is decreasing in June and August, and increasing in July. The situation is opposite for the wetness tendencies. For the Asian territory of Russia, the drought propagation is significantly increasing in July along with decreasing wetness trend. Synoptic conditions favorable for the formation of wet and drought extremes were identified by comparing synoptic charts with the spatial patterns of SPI. For synoptic analysis, episodes of extremely wet (6 episodes for the APR and 7 episodes for the EPR) and drought (6 episodes for the APR and 6 for the EPR) events were classified using A. Katz' typology of weather regimes. For European part of Russia, extreme DROUGHT events are linked to the weather type named "MIXED", for Asian part of Russia - the type "CENTRAL". For European part of Russia, extreme WET events associated with "CENTRAL" type. There is a displacement of the planetary frontal zone into southward direction approximately for 5-25 degrees relatively to normal climatological position during WET extreme events linked to «EASTERN» classification type. Intercomparison of SPI calculated on the base of NOAA NCEP CPC CAMS for the same period and with the resolution 0,5 degree, month precipitation data, Era-Interim Daily fields archive for the period 1979-2014 with the resolution 0,5 degree reanalysis and observational precipitation data was done. The results of comparative analysis has been discussed.

Durability of spent nuclear fuels and facility components in wet storage

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-04-01

Wet storage continues to be the dominant option for the management of irradiated fuel elements and assemblies (fuel units). Fuel types addressed in this study include those used in: power reactors, research and test reactors, and defence reactors. Important decisions must be made regarding acceptable storage modes for a broad variety of fuel types, involving numerous combinations of fuel and cladding materials. A broadly based materials database has the following important functions: to facilitate solutions to immediate and pressing materials problems; to facilitate decisions on the most effective long term interim storage methods for numerous fuel types; to maintain and update a basis on which to extend the licenses of storage facilities as regulatory periods expire; to facilitate cost-effective transfer of numerous fuel types to final disposal. Because examinations of radioactive materials are expensive, access to materials data and experience that provide an informed basis to analyse and extrapolate materials behaviour in wet storage environments can facilitate identification of cost-effective approaches to develop and maintain a valuable materials database. Fuel storage options include: leaving the fuel in wet storage, placing the fuel in canisters with cover gases, stored underwater, or transferring the fuel to one of several dry storage modes, involving a range of conditioning options. It is also important to anticipate the condition of the various materials as periods of wet storage are extended or as decisions to transfer to dry storage are implemented. A sound basis for extrapolation is needed to assess fuel and facility component integrity over the expected period of wet storage. A materials database also facilitates assessment of the current condition of specific fuel and facility materials, with minimal investments in direct examinations. This report provides quantitative and semi-quantitative data on materials behaviour or references sources of data to

Durability of spent nuclear fuels and facility components in wet storage

International Nuclear Information System (INIS)

1998-04-01

Wet storage continues to be the dominant option for the management of irradiated fuel elements and assemblies (fuel units). Fuel types addressed in this study include those used in: power reactors, research and test reactors, and defence reactors. Important decisions must be made regarding acceptable storage modes for a broad variety of fuel types, involving numerous combinations of fuel and cladding materials. A broadly based materials database has the following important functions: to facilitate solutions to immediate and pressing materials problems; to facilitate decisions on the most effective long term interim storage methods for numerous fuel types; to maintain and update a basis on which to extend the licenses of storage facilities as regulatory periods expire; to facilitate cost-effective transfer of numerous fuel types to final disposal. Because examinations of radioactive materials are expensive, access to materials data and experience that provide an informed basis to analyse and extrapolate materials behaviour in wet storage environments can facilitate identification of cost-effective approaches to develop and maintain a valuable materials database. Fuel storage options include: leaving the fuel in wet storage, placing the fuel in canisters with cover gases, stored underwater, or transferring the fuel to one of several dry storage modes, involving a range of conditioning options. It is also important to anticipate the condition of the various materials as periods of wet storage are extended or as decisions to transfer to dry storage are implemented. A sound basis for extrapolation is needed to assess fuel and facility component integrity over the expected period of wet storage. A materials database also facilitates assessment of the current condition of specific fuel and facility materials, with minimal investments in direct examinations. This report provides quantitative and semi-quantitative data on materials behaviour or references sources of data to

Removal of Atmospheric Ethanol by Wet Deposition: A Global Flux Estimate

Science.gov (United States)

Felix, J. D. D.; Willey, J. D.; Avery, B.; Thomas, R.; Mullaugh, K.; Kieber, R. J.; Mead, R. N.; Helms, J. R.; Campos, L.; Shimizu, M. S.; Guibbina, F.

2017-12-01

Global ethanol fuel consumption has increased exponentially over the last two decades and the US plans to double annual renewable fuel production in the next five years as required by the renewable fuel standard. Regardless of the technology or feedstock used to produce the renewable fuel, the primary end product will be ethanol. Increasing ethanol fuel consumption will have an impact on the oxidizing capacity of the atmosphere and increase atmospheric concentrations of the secondary pollutant peroxyacetyl nitrate as well a variety of VOCs with relatively high ozone reactivities (e.g. ethanol, formaldehyde, acetaldehyde). Despite these documented effects of ethanol emissions on atmospheric chemistry, current global atmospheric ethanol budget models have large uncertainties in the magnitude of ethanol sources and sinks. The presented work investigates the global wet deposition sink by providing the first estimate of the global wet deposition flux of ethanol (2.4 ± 1.6 Tg/yr) based on empirical wet deposition data (219 samples collected at 12 locations). This suggests the wet deposition sink removes between 6 and 17% of atmospheric ethanol annually. Concentrations of ethanol in marine wet deposition (25 ± 6 nM) were an order of magnitude less than in the majority of terrestrial deposition (345 ± 280 nM). Terrestrial deposition collected in locations impacted by high local sources of biofuel usage and locations downwind from ethanol distilleries were an order of magnitude higher in ethanol concentration (3090 ± 448 nM) compared to deposition collected in terrestrial locations not impacted by these sources. These results indicate that wet deposition of ethanol is heavily influenced by local sources and ethanol emission impacts on air quality may be more significant in highly populated areas. As established and developing countries continue to rapidly increase ethanol fuel consumption and subsequent emissions, understanding the magnitude of all ethanol sources and

The Investigation of the Cavitation Phenomenon in the Laval Nozzle with Full and Partial Surface Wetting

Directory of Open Access Journals (Sweden)

Jablonská Jana

2017-04-01

Full Text Available The article deals with the cavitation phenomenon affected by full and partial wetting of the wall. For the numerical computation of flow in the Laval nozzle the Schnerr-Sauer cavitation model was tested and was used for cavitation research of flow within the nozzle considering partial surface wetting. The coefficient of wetting for various materials was determined using experimental, theoretical and numerical methods of fluid flow due to partial surface wetting.

Observed and simulated precipitation responses in wet and dry regions 1850–2100

International Nuclear Information System (INIS)

Liu Chunlei; Allan, Richard P

2013-01-01

Global warming is expected to enhance fluxes of fresh water between the surface and atmosphere, causing wet regions to become wetter and dry regions drier, with serious implications for water resource management. Defining the wet and dry regions as the upper 30% and lower 70% of the precipitation totals across the tropics (30° S–30° N) each month we combine observations and climate model simulations to understand changes in the wet and dry regions over the period 1850–2100. Observed decreases in precipitation over dry tropical land (1950–2010) are also simulated by coupled atmosphere–ocean climate models (−0.3%/decade) with trends projected to continue into the 21st century. Discrepancies between observations and simulations over wet land regions since 1950 exist, relating to decadal fluctuations in El Niño southern oscillation, the timing of which is not represented by the coupled simulations. When atmosphere-only simulations are instead driven by observed sea surface temperature they are able to adequately represent this variability over land. Global distributions of precipitation trends are dominated by spatial changes in atmospheric circulation. However, the tendency for already wet regions to become wetter (precipitation increases with warming by 3% K −1 over wet tropical oceans) and the driest regions drier (precipitation decreases of −2% K −1 over dry tropical land regions) emerges over the 21st century in response to the substantial surface warming. (letter)

Some tests of wet tropospheric calibration for the CASA Uno Global Positioning System experiment

Science.gov (United States)

Dixon, T. H.; Wolf, S. Kornreich

1990-01-01

Wet tropospheric path delay can be a major error source for Global Positioning System (GPS) geodetic experiments. Strategies for minimizing this error are investigted using data from CASA Uno, the first major GPS experiment in Central and South America, where wet path delays may be both high and variable. Wet path delay calibration using water vapor radiometers (WVRs) and residual delay estimation is compared with strategies where the entire wet path delay is estimated stochastically without prior calibration, using data from a 270-km test baseline in Costa Rica. Both approaches yield centimeter-level baseline repeatability and similar tropospheric estimates, suggesting that WVR calibration is not critical for obtaining high precision results with GPS in the CASA region.

Effect of rubber polarity on selective wetting of carbon nanotubes in ternary blends

Directory of Open Access Journals (Sweden)

H. H. Le

2015-11-01

Full Text Available Based on atomic force microscopy (AFM and Fourier transform infrared spectroscopy (FTIR analysis of the rubber-filler gel (wetting concept the kinetics of selective wetting of carbon nanotubes (CNTs in ternary styrene butadiene rubber (SBR/butadiene rubber (BR/natural rubber (NR blends was qualitatively and quantitatively characterized. Almost all CNTs are found to be wetted by the non-polar NR but not by the other non-polar rubber like BR or weakly polar SBR. It was proposed that phospholipids, which are linked to the α-terminal of NR can interact with the CNT surface through cation-π interactions forming strong bonding between NR and CNTs. Using the corrected surface tension value of NR, which involves the effect of phospholipids found in our previous work the selective wetting of CNTs in ternary rubber blends can be well predicted using the Z-model for a thermodynamic equilibrium state. By replacing the non-polar BR by a polar rubber like nitrile butadiene rubber (NBR as a blend component CNTs are wetted by NBR slightly more than by NR thanks to the strong interaction between CNTs and nitrile groups of NBR. SBR remains unbound to CNTs in both blends.

Density-wave fronts on the brink of wet granular condensation

Science.gov (United States)

Huang, Kai; Zippelius, Andreas; Sand lab @ University of Bayreuth Team

2017-11-01

From sand dunes to Faraday heaping, driven granular matter, i.e., large agglomeration of macroscopic particles, is rich pattern forming system. When a granular material is partially wet (e.g., wet sand on the beach), a different pattern forming scenario arises due to the cohesive particle-particle interactions. Here, we focus on the formation of density-wave fronts in an oscillated wet granular layer undergoing a gas-liquid-like transition. The threshold of the instability is governed by the amplitude of the vertical vibrations. Fronts, which are curved into a spiral shape, propagate coherently along the circular rim of the container with leading edges. They are stable beyond a critical distance from the container center. Based on the measurement of the critical distance and the rotation frequency, we propose a model for the pattern formation by considering the competition between the time scale for the collapse of cohesive particles and that of the energy injection resisting this process. Deutsche Forschungsgemeinschaft (Grant No. HU1939 4-1).

Wet gas metering with the v-cone and neural nets

Energy Technology Data Exchange (ETDEWEB)

Toral, Haluk; Cai, Shiqian; Peters, Robert

2005-07-01

The paper presents analysis of extensive measurements taken at NEL, K-Lab and CEESI wet gas test loops. Differential and absolute pressure signals were sampled at high frequency across V-Cone meters. Turbulence characteristics of the flow captured in the sampled signals were characterized by pattern recognition techniques and related to the fractions and flow rates of individual phases. The sensitivity of over-reading to first and higher order features of the high frequency signals were investigated qualitatively. The sensitivities were quantified by means of the saliency test based on back propagating neural nets. A self contained wet gas meter based on neural net characterization of first and higher order features of the pressure, differential pressure and capacitance signals was proposed. Alternatively, a wet gas meter based on a neural net model of just pressure sensor inputs (based on currently available data) and liquid Froude number was shown to offer an accuracy of under 5% if the Froude number could be estimated with 25% accuracy. (author) (tk)

Study progress of CCR3 in wet age-related macular degeneration

Directory of Open Access Journals (Sweden)

Xian-Wei Wu

2014-03-01

Full Text Available According to the study, chemokine receptor 3(CCR3in the eye is mainly distributed in retinal pigment epithelial cells, and also expressed in the choroidal vascular endothelial cells(CECs. The specificity of CCR3's high expression in wet age-related macular degeneration(AMDwas found, and it is proved that in wet-AMD patients, it plays an important role in the formation of choroidal neovascularization(CNV. In this paper, the structure, function, the problem of current research and the future direction of CCR3 were summarized. It is believed that with the further research on CCR3, it will not only help us to find a new method of wet-AMD diagnosis and treatment, but also may provide an important reference for other CNV disease research and new anti-CNV drugs.

WETTABILITY AND IMBIBITION: MICROSCOPIC DISTRIBUTION OF WETTING AND ITS CONSEQUENCES AT THE CORE AND FIELD SCALES

Energy Technology Data Exchange (ETDEWEB)

Jill S. Buckley; Norman R. Morrow; Chris Palmer; Purnendu K. Dasgupta

2003-02-01

The questions of reservoir wettability have been approached in this project from three directions. First, we have studied the properties of crude oils that contribute to wetting alteration in a reservoir. A database of more than 150 different crude oil samples has been established to facilitate examination of the relationships between crude oil chemical and physical properties and their influence on reservoir wetting. In the course of this work an improved SARA analysis technique was developed and major advances were made in understanding asphaltene stability including development of a thermodynamic Asphaltene Solubility Model (ASM) and empirical methods for predicting the onset of instability. The CO-Wet database is a resource that will be used to guide wettability research in the future. The second approach is to study crude oil/brine/rock interactions on smooth surfaces. Contact angle measurements were made under controlled conditions on mica surfaces that had been exposed to many of the oils in the CO-Wet database. With this wealth of data, statistical tests can now be used to examine the relationships between crude oil properties and the tendencies of those oils to alter wetting. Traditionally, contact angles have been used as the primary wetting assessment tool on smooth surfaces. A new technique has been developed using an atomic forces microscope that adds a new dimension to the ability to characterize oil-treated surfaces. Ultimately we aim to understand wetting in porous media, the focus of the third approach taken in this project. Using oils from the CO-Wet database, experimental advances have been made in scaling the rate of imbibition, a sensitive measure of core wetting. Application of the scaling group to mixed-wet systems has been demonstrated for a range of core conditions. Investigations of imbibition in gas/liquid systems provided the motivation for theoretical advances as well. As a result of this project we have many new tools for studying

Wetting of bituminized ion-exchangers under simulated repository conditions

International Nuclear Information System (INIS)

Aalto, H.; Valkiainen, M.

2001-01-01

According to the present plans the spent nuclear fuel from four Finnish nuclear power units will be transferred after interim storage to the final disposal site where it will be encapsulated and disposed of in a final repository constructed into the bedrock at a depth of 500 meters. Low and medium level waste generated at nuclear power plants will be finally disposed of in caverns constructed in the bedrock at the power plant site. The safety of the final disposal is based on a multibarrier concept and the degree of safety is estimated by using predictive models. The properties of the waste form are taken into account in the design of the repository construction. Bitumen has been chosen as an immobilisation agent for the wet wastes at Olkiluoto Power Plant, where two BWR units, TVO 1 and TVO 2, have separate bituminization facilities designed by Asea-Atom. Properties of bituminized spent ion-exchange resins from Olkiluoto power plant have been studied by VTT Chemical Technology since the late 70's. These studies have concentrated mainly on determining the long-term behaviour of the bituminization product under the repository conditions. Current interest lies on wetted product as a diffusion barrier. For this purpose a microscopic method for the visualisation of the structure of the wetted product has been developed. The equilibration of the samples in simulated concrete groundwater is currently going on at a temperature of 5-8 deg. C. Preliminary results are presented in this paper. Diffusion experiments have been planned for the further characterising of the wetted product as a release barrier for radionuclides including modelling. (author)

Wetting morphologies and their transitions in grooved substrates

Energy Technology Data Exchange (ETDEWEB)

Seemann, Ralf; Bommer, Stefan; Herrmann, Carsten; Michler, Dominik [Experimental Physics, Saarland University, D-66123 Saarbruecken (Germany); Brinkmann, Martin; Herminghaus, Stephan; Khare, Krishnacharya; Kostourou, Konstantina; Gurevich, Evgeny [Max Planck Institute for Dynamics and Self-Organization, D-37073 Goettingen (Germany); Law, Bruce M; McBride, Sean, E-mail: r.seemann@physik.uni-saarland.de [Department of Physics, Kansas State University, Manhattan, KS 66506 (United States)

2011-05-11

When exposed to a partially wetting liquid, many natural and artificial surfaces equipped with complex topographies display a rich variety of liquid interfacial morphologies. In the present article, we focus on a few simple paradigmatic surface topographies and elaborate on the statics and dynamics of the resulting wetting morphologies. It is demonstrated that the spectrum of wetting morphologies increases with increasing complexity of the groove structure. On elastically deformable substrates, additional structures in the liquid morphologies can be observed, which are caused by deformations of the groove geometry in the presence of capillary forces. The emergence of certain liquid morphologies in grooves can be actively controlled by changes in wettability and geometry. For electrically conducting solid substrates, the apparent contact angle can be varied by electrowetting. This allows, depending on groove geometry, a reversible or irreversible transport of liquid along surface grooves. In the case of irreversible liquid transport in triangular grooves, the dynamics of the emerging instability is sensitive to the apparent hydrodynamic slip at the substrate. On elastic substrates, the geometry can be varied in a straightforward manner by stretching or relaxing the sample. The imbibition velocity in deformable grooves is significantly reduced compared to solid grooves, which is a result of the microscopic deformation of the elastic groove material close to the three phase contact line.

Level Set Approach to Anisotropic Wet Etching of Silicon

Directory of Open Access Journals (Sweden)

Branislav Radjenović

2010-05-01

Full Text Available In this paper a methodology for the three dimensional (3D modeling and simulation of the profile evolution during anisotropic wet etching of silicon based on the level set method is presented. Etching rate anisotropy in silicon is modeled taking into account full silicon symmetry properties, by means of the interpolation technique using experimentally obtained values for the etching rates along thirteen principal and high index directions in KOH solutions. The resulting level set equations are solved using an open source implementation of the sparse field method (ITK library, developed in medical image processing community, extended for the case of non-convex Hamiltonians. Simulation results for some interesting initial 3D shapes, as well as some more practical examples illustrating anisotropic etching simulation in the presence of masks (simple square aperture mask, convex corner undercutting and convex corner compensation, formation of suspended structures are shown also. The obtained results show that level set method can be used as an effective tool for wet etching process modeling, and that is a viable alternative to the Cellular Automata method which now prevails in the simulations of the wet etching process.

Rain-induced subsurface airflow and Lisse effect

Science.gov (United States)

Guo, Haipeng; Jiao, Jiu J.; Weeks, Edwin P.

2008-07-01

Water-level increase after rainfall is usually indicative of rainfall recharge to groundwater. This, however, may not be true if the Lisse effect occurs. This effect represents the water-level increase in a well driven by airflow induced by an advancing wetting front during highly intensive rains. The rainwater, which may behave like a low-permeability lid, seals the ground surface so that the air pressure beneath the wetting front is increased because of air compression due to downward movement of the wetting front. A rapid and substantial rise of the water level in the well screened below water table, which bears no relationship to groundwater recharge, can be induced when various factors such as soil properties and the rain-runoff condition combine favorably. A transient, three-dimensional and variably saturated flow model was employed to study the air and groundwater flows in the soil under rain conditions. The objectives of this paper are two-fold: to evaluate the reliability of the theory of the Lisse effect presented by Weeks to predict its magnitude in modeled situations that mimic the physical complexity of real aquifers, and to conduct parametric studies on the sensitivity of the water-level rise in the well to soil properties and the rain event. The simulation results reveal that the magnitude of the Lisse effect increases with the ponding depth. Soil permeability plays a key role in generating the Lisse effect. The water-level rise in the well is delayed relative to the air-pressure rise in the unsaturated zone when the soil permeability is low, and the maximum water-level rise is less than the maximum air pressure induced by rain infiltration. The simulation also explores the sensitivity of the Lisse effect to the van Genuchten parameters and the water table depth.

Rain‐induced subsurface airflow and Lisse effect

Science.gov (United States)

Guo, Haipeng; Jiao, Jiu J.; Weeks, Edwin P.

2008-01-01

Water‐level increase after rainfall is usually indicative of rainfall recharge to groundwater. This, however, may not be true if the Lisse effect occurs. This effect represents the water‐level increase in a well driven by airflow induced by an advancing wetting front during highly intensive rains. The rainwater, which may behave like a low‐permeability lid, seals the ground surface so that the air pressure beneath the wetting front is increased because of air compression due to downward movement of the wetting front. A rapid and substantial rise of the water level in the well screened below water table, which bears no relationship to groundwater recharge, can be induced when various factors such as soil properties and the rain‐runoff condition combine favorably. A transient, three‐dimensional and variably saturated flow model was employed to study the air and groundwater flows in the soil under rain conditions. The objectives of this paper are two‐fold: to evaluate the reliability of the theory of the Lisse effect presented by Weeks to predict its magnitude in modeled situations that mimic the physical complexity of real aquifers, and to conduct parametric studies on the sensitivity of the water‐level rise in the well to soil properties and the rain event. The simulation results reveal that the magnitude of the Lisse effect increases with the ponding depth. Soil permeability plays a key role in generating the Lisse effect. The water‐level rise in the well is delayed relative to the air‐pressure rise in the unsaturated zone when the soil permeability is low, and the maximum water‐level rise is less than the maximum air pressure induced by rain infiltration. The simulation also explores the sensitivity of the Lisse effect to the van Genuchten parameters and the water table depth.

Modeling study on axial wetting length of meniscus in vertical rectangular microgrooves

International Nuclear Information System (INIS)

Nie, Xuelei; Hu, Xuegong; Tang, Dawei

2013-01-01

In this work, the traditional model for predicting axial wetting length of meniscus in vertical microgrooves is introduced firstly. The traditional model may cause inaccurate results in predicting wetting length in vertical microgrooves because of the assumption of round meniscus in cross sections of microgrooves and the way of calculating curvature. In order to develop this model and make it more accurate, a revised micro-PIV system is built to test the meniscus shapes in cross sections of vertical and horizontal microgrooves, and the experimental results prove that the real shapes of meniscus are parabolic other than round. The fitting formulas of meniscus shapes are obtained with software Origin 7.5. Based on experimental results and fitting formulas, the traditional model is revised by changing the way to calculate curvature. In the modified model, the curvature for calculating axial wetting length of meniscus equals average curvature of meniscus in cross section of vertical microgrooves minus the average curvature of meniscus in cross section of horizontal microgrooves. It is proved that the modified model can predict the wetting length in vertical microgrooves better than the original model. The average difference between experiment and modified model is 2.5% while that between experiment and traditional model is 174.2%. The disadvantage of the modified model is that using the new model to predict wetting length needs to know the real shapes of meniscus in vertical and horizontal microgrooves. -- Highlights: ► An experimental system is designed to test the shapes of meniscus in microgrooves. ► The real shapes of meniscus in microgrooves are obtained for first time. ► The shapes of meniscus in microgrooves is compared and analyzed. ► The model for predicting wetting length of meniscus in microgrooves is developed

Wetting effect on optical sum frequency generation (SFG) spectra of D-glucose, D-fructose, and sucrose

Science.gov (United States)

Hieu, Hoang Chi; Li, Hongyan; Miyauchi, Yoshihiro; Mizutani, Goro; Fujita, Naoko; Nakamura, Yasunori

2015-03-01

We report a sum frequency generation (SFG) spectroscopy study of D-glucose, D-fructose and sucrose in the Csbnd H stretching vibration regime. Wetting effect on the SFG spectra was investigated. The SFG spectrum of D-glucose changed from that of α-D-glucose into those of α-D-glucose monohydrate by wetting. The SFG spectra showed evidence of a small change of β-D-fructopyranose into other anomers by wetting. SFG spectra of sucrose did not change by wetting. Assignments of the vibrational peaks in the SFG spectra of the three sugars in the dry and wet states were performed in the Csbnd H stretching vibration region near 3000 cm-1.

Nanowires and nanotubes from π-conjugated organic materials fabricated by template wetting

DEFF Research Database (Denmark)

Bordo, Kirill; Schiek, Manuela; Rubahn, Horst-Günter

2014-01-01

on the wetting conditions: for diluted PF8 solutions mostly nanotubes are obtained; while for concentrated PF8 solutions and PF8 melts, the formation of nanowires is dominating. Wetting of the template pores by P3HT solutions and melts leads to the formation of nanotubes. For the small-molecule material PTCDI-C8...

49 CFR 173.182 - Barium azide-50 percent or more water wet.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Barium azide-50 percent or more water wet. 173.182 Section 173.182 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS... Class 1 and Class 7 § 173.182 Barium azide—50 percent or more water wet. Barium azide—50 percent or more...

Effect of wetting on nucleation and growth of D2 in confinement

Science.gov (United States)

Zepeda-Ruiz, L. A.; Sadigh, B.; Shin, S. J.; Kozioziemski, B. J.; Chernov, A. A.

2018-04-01

We have performed a computational study to determine how the wetting of liquid deuterium to the walls of the material influences nucleation. We present the development of a pair-wise interatomic potential that includes zero-point motion of molecular deuterium. Deuterium is used in this study because of its importance to inertial confinement fusion and the potential to generate a superfluid state if the solidification can be suppressed. Our simulations show that wetting dominates undercooling compared to the pore geometries. We observe a transition from heterogeneous nucleation at the confining wall to homogeneous nucleation at the bulk of the liquid (and intermediate cases) as the interaction with the confining wall changes from perfect wetting to non-wetting. When nucleation is heterogeneous, the temperature needed for solidification changes by 4 K with decreasing deuterium-wall interaction, but it remains independent (and equal to the one from bulk samples) when homogeneous nucleation dominates. We find that growth and quality of the resulting microstructure also depends on the magnitude of liquid deuterium-wall interaction strength.

Gamma-irradiation of wet corn. Microbiological aspects

International Nuclear Information System (INIS)

Poisson, Jeanne; Cahagnier, B.

1973-01-01

In the course of a survey of several years work on microbiological decontamination and control of wet corn by gamma-irradiation the following factors are studied: inhibiting and selective effect of gamma-irradiation (100 to 500krads) on the microflora of grains; evolution of residual microflora of irradiated wet grains (moisture content about 35%), during storage experiments under ventilated or airtight conditions. Two important points emerge from those studies. The microflora which develops on irradiated sample is much less varied than that of the control sample. The microbial population of an irradiated sample rises up in a few days on a level with the initial one of the control, then goes on increasing while remaining, as a rule, slightly inferior to that of the control placed under the same conditions. This greatly lowers the practical interest of irradiation, which can only be used together with another treatment able to inhibit the quick growth of the residual microflora [fr

Removal of ammonia solutions used in catalytic wet oxidation processes.

Science.gov (United States)

Hung, Chang Mao; Lou, Jie Chung; Lin, Chia Hua

2003-08-01

Ammonia (NH(3)) is an important product used in the chemical industry, and is common place in industrial wastewater. Industrial wastewater containing ammonia is generally either toxic or has concentrations or temperatures such that direct biological treatment is unfeasible. This investigation used aqueous solutions containing more of ammonia for catalytic liquid-phase oxidation in a trickle-bed reactor (TBR) based on Cu/La/Ce composite catalysts, prepared by co-precipitation of Cu(NO(3))(2), La(NO(3))(2), and Ce(NO(3))(3) at 7:2:1 molar concentrations. The experimental results indicated that the ammonia conversion of the wet oxidation in the presence of the Cu/La/Ce composite catalysts was determined by the Cu/La/Ce catalyst. Minimal ammonia was removed from the solution by the wet oxidation in the absence of any catalyst, while approximately 91% ammonia removal was achieved by wet oxidation over the Cu/La/Ce catalyst at 230 degrees C with oxygen partial pressure of 2.0 MPa. Furthermore, the effluent streams were conducted at a liquid hourly space velocity of under 9 h(-1) in the wet catalytic processes, and a reaction pathway was found linking the oxidizing ammonia to nitric oxide, nitrogen and water. The solution contained by-products, including nitrates and nitrites. Nitrite selectivity was minimized and ammonia removal maximized when the feed ammonia solution had a pH of around 12.0.

The multidimensional causal factors of 'wet litter' in chicken-meat production.

Science.gov (United States)

Dunlop, Mark W; Moss, Amy F; Groves, Peter J; Wilkinson, Stuart J; Stuetz, Richard M; Selle, Peter H

2016-08-15

The problem of 'wet litter', which occurs primarily in grow-out sheds for meat chickens (broilers), has been recognised for nearly a century. Nevertheless, it is an increasingly important problem in contemporary chicken-meat production as wet litter and associated conditions, especially footpad dermatitis, have developed into tangible welfare issues. This is only compounded by the market demand for chicken paws and compromised bird performance. This review considers the multidimensional causal factors of wet litter. While many causal factors can be listed it is evident that the critical ones could be described as micro-environmental factors and chief amongst them is proper management of drinking systems and adequate shed ventilation. Thus, this review focuses on these environmental factors and pays less attention to issues stemming from health and nutrition. Clearly, there are times when related avian health issues of coccidiosis and necrotic enteritis cannot be overlooked and the development of efficacious vaccines for the latter disease would be advantageous. Presently, the inclusion of phytate-degrading enzymes in meat chicken diets is routine and, therefore, the implication that exogenous phytases may contribute to wet litter is given consideration. Opinion is somewhat divided as how best to counter the problem of wet litter as some see education and extension as being more beneficial than furthering research efforts. However, it may prove instructive to assess the practice of whole grain feeding in relation to litter quality and the incidence of footpad dermatitis. Additional research could investigate the relationships between dietary concentrations of key minerals and the application of exogenous enzymes with litter quality. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

Progress on lipid extraction from wet algal biomass for biodiesel production.

Science.gov (United States)

Ghasemi Naghdi, Forough; González González, Lina M; Chan, William; Schenk, Peer M

2016-11-01

Lipid recovery and purification from microalgal cells continues to be a significant bottleneck in biodiesel production due to high costs involved and a high energy demand. Therefore, there is a considerable necessity to develop an extraction method which meets the essential requirements of being safe, cost-effective, robust, efficient, selective, environmentally friendly, feasible for large-scale production and free of product contamination. The use of wet concentrated algal biomass as a feedstock for oil extraction is especially desirable as it would avoid the requirement for further concentration and/or drying. This would save considerable costs and circumvent at least two lengthy processes during algae-based oil production. This article provides an overview on recent progress that has been made on the extraction of lipids from wet algal biomass. The biggest contributing factors appear to be the composition of algal cell walls, pre-treatments of biomass and the use of solvents (e.g. a solvent mixture or solvent-free lipid extraction). We compare recently developed wet extraction processes for oleaginous microalgae and make recommendations towards future research to improve lipid extraction from wet algal biomass. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Effect of Dentin Wetness on the Bond Strength of Universal Adhesives

Directory of Open Access Journals (Sweden)

An-Na Choi

2017-10-01

Full Text Available The effects of dentin wetness on the bond strength and adhesive interface morphology of universal adhesives have been investigated using micro-tensile bond strength (μTBS testing and confocal laser scanning microscopy (CLSM. Seventy-two human third molars were wet ground to expose flat dentin surfaces. They were divided into three groups according to the air-drying time of the dentin surfaces: 0 (without air drying, 5, and 10 s. The dentin surfaces were then treated with three universal adhesives: G-Premio Bond, Single Bond Universal, and All-Bond Universal in self-etch or etch-and-rinse mode. After composite build up, a μTBS test was performed. One additional tooth was prepared for each group by staining the adhesives with 0.01 wt % of Rhodamine B fluorescent dye for CLSM analysis. The data were analyzed statistically using ANOVA and Tukey’s post hoc tests (α = 0.05. Two-way ANOVA showed significant differences among the adhesive systems and dentin moisture conditions. An interaction effect was also observed (p < 0.05. One-way ANOVA showed that All-Bond Universal was the only material influenced by the wetness of the dentin surfaces. Wetness of the dentin surface is a factor influencing the micro-tensile bond strength of universal adhesives.

Large-scale circulation departures related to wet episodes in northeast Brazil

Science.gov (United States)

Sikdar, D. N.; Elsner, J. B.

1985-01-01

Large scale circulation features are presented as related to wet spells over northeast Brazil (Nordeste) during the rainy season (March and April) of 1979. The rainy season season is devided into dry and wet periods, the FGGE and geostationary satellite data was averaged and mean and departure fields of basic variables and cloudiness were studied. Analysis of seasonal mean circulation features show: lowest sea level easterlies beneath upper level westerlies; weak meridional winds; high relative humidity over the Amazon basin and relatively dry conditions over the South Atlantic Ocean. A fluctuation was found in the large scale circulation features on time scales of a few weeks or so over Nordeste and the South Atlantic sector. Even the subtropical High SLP's have large departures during wet episodes, implying a short period oscillation in the Southern Hemisphere Hadley circulation.

Energy and exergy analysis of counter flow wet cooling towers

Directory of Open Access Journals (Sweden)

Saravanan Mani

2008-01-01

Full Text Available Cooling tower is an open system direct contact heat exchanger, where it cools water by both convection and evaporation. In this paper, a mathematical model based on heat and mass transfer principle is developed to find the outlet condition of water and air. The model is solved using iterative method. Energy and exergy analysis infers that inlet air wet bulb temperature is found to be the most important parameter than inlet water temperature and also variation in dead state properties does not affect the performance of wet cooling tower. .

Wet steam turbines for nuclear generating stations -design and operating experience

International Nuclear Information System (INIS)

Usher, J.

1977-01-01

Lecture to the Institution of Nuclear Engineers, 11 Jan. 1977. The object of this lecture was to give an account of some design features of large wet steam turbines and to show by describing some recent operational experience how their design concepts were fulfilled. Headings are as follows: effects of wet steam cycle on turbine layout and operation (H.P. turbine, L.P. turbine); turbine control and operation; water separators; and steam reheaters. (U.K.)

Flow boiling heat transfer on nanowire-coated surfaces with highly wetting liquid

International Nuclear Information System (INIS)

Shin, Sangwoo; Choi, Geehong; Kim, Beom Seok; Cho, Hyung Hee

2014-01-01

Owing to the recent advances in nanotechnology, one significant progress in energy technology is increased cooling ability. It has recently been shown that nanowires can improve pool boiling heat transfer due to the unique features such as enhanced wetting and enlarged nucleation sites. Applying such nanowires on a flow boiling, which is another major class of boiling phenomenon that is associated with forced convection, is yet immature and scarce despite its importance in various applications such as liquid cooling of energy, electronics and refrigeration systems. Here, we investigate flow boiling heat transfer on surfaces that are coated with SiNWs (silicon nanowires). Also, we use highly-wetting dielectric liquid, FC-72, as a working fluid. An interesting wetting behavior is observed where the presence of SiNWs reduces wetting and wicking that in turn leads to significant decrease of CHF (critical heat flux) compared to the plain surface, which opposes the current consensus. Also, the effects of nanowire length and Reynolds number on the boiling heat transfer are shown to be highly nonmonotonic. We attempt to explain such an unusual behavior on the basis of wetting, nucleation and forced convection, and we show that such factors are highly coupled in a way that lead to unusual behavior. - Highlights: • Observation of suppressed wettability in the presence of surface roughness (nanowires). • Significant reduction of critical heat flux in the presence of nanowires. • Nonmonotonic behavior of heat transfer coefficient vs. nanowire length and Reynolds number

Cervical spinal epidural abscess following acupuncture and wet-cupping therapy: A case report.

Science.gov (United States)

Yao, Yindan; Hong, Wenke; Chen, Huimin; Guan, Qiongfeng; Yu, Hu; Chang, Xianchao; Yu, Yaoping; Xu, Shanhu; Fan, Weinv

2016-02-01

Report of an uncommon complication of acupuncture and wet cupping. A 54-year-old man presented with neck pain and fever. Magnetic resonance imaging of the cervical spine revealed an epidural abscess at C4 to T2. The symptoms related to epidural abscess resolved partially after treatment with antibiotics. Acupuncture and wet-cupping therapy should be taken into consideration as a cause of spinal epidural abscesses in patients who present with neck pain and fever. Furthermore, acupuncture and wet-cupping practitioners should pay attention to hygienic measures. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Role of Surface Chemistry in Adhesion and Wetting of Gecko Toe Pads

Science.gov (United States)

Badge, Ila; Stark, Alyssa Y.; Paoloni, Eva L.; Niewiarowski, Peter H.; Dhinojwala, Ali

2014-10-01

An array of micron-sized setal hairs offers geckos a unique ability to walk on vertical surfaces using van der Waals interactions. Although many studies have focused on the role of surface morphology of the hairs, very little is known about the role of surface chemistry on wetting and adhesion. We expect that both surface chemistry and morphology are important, not only to achieve optimum dry adhesion but also for increased efficiency in self-cleaning of water and adhesion under wet conditions. Here, we used a plasma-based vapor deposition process to coat the hairy patterns on gecko toe pad sheds with polar and non-polar coatings without significantly perturbing the setal morphology. By a comparison of wetting across treatments, we show that the intrinsic surface of gecko setae has a water contact angle between 70-90°. As expected, under wet conditions, adhesion on a hydrophilic surface (glass) was lower than that on a hydrophobic surface (alkyl-silane monolayer on glass). Surprisingly under wet and dry conditions the adhesion was comparable on the hydrophobic surface, independent of the surface chemistry of the setal hairs. This work highlights the need to utilize morphology and surface chemistry in developing successful synthetic adhesives with desirable adhesion and self-cleaning properties.

Creating gradient wetting surfaces via electroless displacement of zinc-coated carbon steel by nickel ions

Science.gov (United States)

Xu, Chang; Liu, Huicong; Liang, Weitao; Zhu, Liqun; Li, Weiping; Chen, Haining

2018-03-01

Gradient wetting surfaces are getting increasing attention due to their wide application in multiple fields such as droplet movement and biosorption. However, the fabrication processes of full gradient wetting surfaces are still complex and costly. In present work, a facile and low-cost chemical immersion method was used to create a full gradient wetting surface. By controlling the displacement time in Ni2+ solution, the prepared surfaces perform hydrophilic to superhydrophilic. After being modified by stearic acid, the gradient hydrophilic surfaces convert into hydrophobic. The surface morphology, composition, and wetting behaviors of the as-prepared surfaces were systematically studied and discussed. The gradient wetting property could be attributed to the change in microroughness and surface energy. In addition, these surfaces also exhibited excellent self-cleaning and wax prevention properties. Furthermore, high stability and corrosion resistance were also found for these surfaces, which further highlight their promising practical applications in many fields.

The chronic toxicity of mineral oil-wet and synthetic liquid-wet cuttings on an estuarine fish, Fundulus grandis

International Nuclear Information System (INIS)

Jones, F.V.; Rushing, J.H.; Churan, M.A.

1991-01-01

One of the major factors concerning oil-wet cuttings discharges in the long-term effect on the aquatic environment. This paper investigates the survival and growth of the mud minnow, Fundulus grandis, when exposed to different concentrations of mineral oil-wet and synthetic liquid-wet cuttings in flow-through bioassay chambers. The test fluids were a low aromatic mineral oil-based mud (MOBM) and a synthetic liquid-based mud (SBM). Each test fluid was added to a container of dried water-based cuttings which contained minimum hydrocarbons. The fluid and cuttings were mixed to obtain the desired test concentrations. The study tested three concentrations (1%, 5%, and 8.4% by dry weight) of each fluid on the cuttings. Growth rates during the 3-day period were modest with fish in 1% MOBM losing weight. The highest percent growth rates were obtained with fish cultured in 5% SBM and the controls. However, overall growth was not significantly different between treatments. Mean growth did show a significant difference between controls and 5% SBM, and other treatments. The cuttings of the 5% and 8.4% concentrations of both treatments looked like paste. These pastes may have slowed the movement of organics off of the cuttings beds and affected biodegradability and growth rates. Cuttings in the controls and 1% concentrations stayed suspended in the water column longer when disturbed and looked more like loose gravel. Uptake of the MOBM occurred in the internal organs and tissue of fish. No such uptake was observed in the fish tissue with the SBM; a very low level of synthetic liquid was detected in one gut sample only. This may be the major reason for the variations noted in growth rates. Fish mortality during the study was related to the buildup of anaerobic conditions and insufficient aeration. Fish survival for the entire study was 94%

RETROFITTING CONTROL FACILITIES FOR WET-WEATHER FLOW TREATMENT

Science.gov (United States)

Available technologies were evaluated to demonstrate the technical feasibility and cost effectiveness of retrofitting existing facilities to handle wet-weather flow. Cost/benefit relationships were also compared to construction of new conventional control and treatment facilities...

Comparison of wet-only and bulk deposition at Chiang Mai (Thailand) based on rainwater chemical composition

Science.gov (United States)

Chantara, Somporn; Chunsuk, Nawarut

The chemical composition of 122 rainwater samples collected daily from bulk and wet-only collectors in a sub-urban area of Chiang Mai (Thailand) during August 2005-July 2006 has been analyzed and compared to assess usability of a cheaper and less complex bulk collector over a sophisticated wet-only collector. Statistical analysis was performed on log-transformed daily rain amount and depositions of major ions for each collector type. The analysis of variance (ANOVA) test revealed that the amount of rainfall collected from a rain gauge, bulk collector and wet-only collector showed no significant difference ( ∝=0.05). The volume weight mean electro-conductivity (EC) values of bulk and wet-only samples were 0.69 and 0.65 mS/m, respectively. The average pH of the samples from both types of collectors was 5.5. Scatter plots between log-transformed depositions of specific ions obtained from bulk and wet-only samples showed high correlation ( r>0.91). Means of log-transformed bulk deposition were 14% (Na + and K +), 13% (Mg 2+), 7% (Ca 2+), 4% (NO 3-), 3% (SO 42- and Cl -) and 2% (NH 4+) higher than that of wet-only deposition. However, multivariate analysis of variance (MANOVA) revealed that ion depositions obtained from bulk and wet-only collectors were not significantly different ( ∝=0.05). Therefore, it was concluded that a bulk collector can be used instead of a wet-only collector in a sub-urban area.

Nitride-based Schottky diodes and HFETs fabricated by photo-enhanced chemical wet etching

International Nuclear Information System (INIS)

Su, Y.K.; Chang, S.J.; Kuan, T.M.; Ko, C.H.; Webb, J.B.; Lan, W.H.; Cherng, Y.T.; Chen, S.C.

2004-01-01

Photo-enhanced chemical (PEC) wet etching technology was used to etch GaN and AlGaN epitaxial layers. It was found that the maximum etch rates were 510, 1960, 300, and 0 nm/mm for GaN, Al 0.175 Ga 0.825 N, Al 0.23 Ga 0.77 N, and Al 0.4 Ga 0.6 N, respectively. It was also found that we could achieve a high Al 0.175 Ga 0.825 N to GaN etch rate ratio of 12.6. Nitride-based Schottky diodes and heterostructure field effect transistors (HFETs) were also fabricated by PEC wet etching. It was found that we could achieve a saturated I D larger than 850 mA/mm and a maximum g m about 163 mS/mm from PEC wet etched HFET with a 0.5 μm gate length. Compared with dry etched devices, the leakage currents observed from the PEC wet etched devices were also found to be smaller

Calculating Soil Wetness, Evapotranspiration and Carbon Cycle Processes Over Large Grid Areas Using a New Scaling Technique

Science.gov (United States)

Sellers, Piers

2012-01-01

Soil wetness typically shows great spatial variability over the length scales of general circulation model (GCM) grid areas (approx 100 km ), and the functions relating evapotranspiration and photosynthetic rate to local-scale (approx 1 m) soil wetness are highly non-linear. Soil respiration is also highly dependent on very small-scale variations in soil wetness. We therefore expect significant inaccuracies whenever we insert a single grid area-average soil wetness value into a function to calculate any of these rates for the grid area. For the particular case of evapotranspiration., this method - use of a grid-averaged soil wetness value - can also provoke severe oscillations in the evapotranspiration rate and soil wetness under some conditions. A method is presented whereby the probability distribution timction(pdf) for soil wetness within a grid area is represented by binning. and numerical integration of the binned pdf is performed to provide a spatially-integrated wetness stress term for the whole grid area, which then permits calculation of grid area fluxes in a single operation. The method is very accurate when 10 or more bins are used, can deal realistically with spatially variable precipitation, conserves moisture exactly and allows for precise modification of the soil wetness pdf after every time step. The method could also be applied to other ecological problems where small-scale processes must be area-integrated, or upscaled, to estimate fluxes over large areas, for example in treatments of the terrestrial carbon budget or trace gas generation.

Wetting and layering transitions of a spin-1/2 Ising model in a random transverse field

International Nuclear Information System (INIS)

Bahmad, L.; Benyoussef, A.; El-Kenz, A.; Ez-Zahraouy, H.

2000-09-01

The effect of a random transverse field (RTF) on the wetting and layering transitions of a spin-1/2 Ising model, in the presence of bulk and surface fields, is studied within an effective field theory by using the differential operator technique. Indeed, the dependencies of the wetting temperature and wetting transverse field on the probability of the presence of a transverse field are established. For specific values of the surface field we show the existence of a critical probability p, above which wetting and layering transitions disappear. (author)

The microstructure of self-healed PVA ECC under wet and dry cycles

Directory of Open Access Journals (Sweden)

Jia Huan Yu

2010-06-01

Full Text Available Self-healing of ECC (Engineered Cementitious Composites subjected to cyclic wetting and drying regimes is investigated in this paper. ECC structures subjected to outdoor environmental conditions such as wind and rain runoff can be simulated by accelerated test method of wetting and drying cycles. Uniaxial tensile tests of ECC M45 and ECC 2.8FA specimen are conducted respectively. It is found that crack width of ECC 2.8FA is around 10 μm with increased amount of fly ash, while the crack width of ECC M45 is around 100 μm. New insights about the microstructure and chemical composition analysis of ECC specimens initially cracked to 2% strain and then self-healed under wet-dry cycles are presented.

A Wet Chemistry Laboratory Cell

Science.gov (United States)

2008-01-01

This picture of NASA's Phoenix Mars Lander's Wet Chemistry Laboratory (WCL) cell is labeled with components responsible for mixing Martian soil with water from Earth, adding chemicals and measuring the solution chemistry. WCL is part of the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) instrument suite on board the Phoenix lander. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

Interfacial reactions in the Sb–Sn/(Cu, Ni) systems: Wetting experiments

International Nuclear Information System (INIS)

Novakovic, R.; Lanata, T.; Delsante, S.; Borzone, G.

2012-01-01

Interfacial reactions in the Sb–Sn/Cu and Sb–Sn/Ni systems have been investigated by means of wetting experiments. The wetting behaviour of two lead-free alloys, namely, Sb 2.5 Sn 97.5 and Sb 14.5 Sn 85.5 (at.%), in contact with Cu and Ni-substrates has been studied in view of possible applications as high-temperature solders in the electronics industry. The contact angle measurements on Cu and Ni plates were performed by using a sessile drop apparatus. The solder/substrate interface was characterised by the SEM-EDS analyses. -- Highlights: ► Sb–Sn alloys are used as high temperature lead-free solders. ► Sb–Sn alloys have good wetting properties on Cu and Ni substrates. ► Interfacial reactions and products are important for joint properties. ► Interfacial reactions/products data can be used to study the phase diagrams.

Triaxial Wetting Test on Rockfill Materials under Stress Combination Conditions of Spherical Stress p and Deviatoric Stress q

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Yan-yi Zhang

2018-01-01

Full Text Available A GCTS medium-sized triaxial apparatus is used to conduct a single-line method wetting test on three kinds of rockfill materials of different mother rocks such as mixture of sandstone and slate, and dolomite and granite, and the test stress conditions is the combination of spherical stress p and deviatoric stress q. The test results show that (1 for wetting shear strain, the effects of spherical stress p and deviatoric stress q are equivalent, and wetting shear strain and deviatoric stress q show the power function relationship preferably. (2 For wetting volumetric strain, the effect of deviatoric stress q can be neglected because it is extremely insignificant, and spherical stress p is the main influencing factor and shows the power function relationship preferably. (3 The wetting strains decrease significantly with the increase in initial water content and sample density generally, but the excessively high dry density will increase the wetting deformation. Also, the wetting strains will decrease with the increase in the saturated uniaxial compressive strength and average softening coefficient of the mother rock. Based on the test results, a wetting strain model is proposed for rockfill materials. The verification results indicate that the model satisfactorily reflects the development law of wetting deformation.

Electric Resistance Tests on Compacted Clay Material under Dynamic Load Coupled with Dry-Wet Cycling

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Zheng Lu

2018-01-01

Full Text Available The study of compacted clay material under dynamic load coupled with dry-wet cycling is one of the most important areas in the field of transportation. In this paper, experiments in terms of compacted clay under dynamic load coupled with dry-wet cycling are performed, and synchronous resistivity tests are also conducted. According to the test results, the influences of cumulative plastic strain, dry-wet cycles, and amplitudes on the soil resistivity are analyzed. Then a new damage factor based on resistivity is proposed to evaluate the long-term performance of compacted clay material. The result of research shows that the evolution of the soil resistivity can be divided into two stages, which has a contrary tendency with that of cumulative plastic strain. The dry-wet cycles and amplitudes have a significant effect on the damage of the compacted soil, which indicates that the dry-wet cycling of compacted soil materials should not be ignored in road engineering, especially in rainy and humid areas.

Making cassava flour safe using the wetting method

African Journals Online (AJOL)

The wetting method is simple and easy to use, the traditional thick porridge ... correlation between the percentage monthly incidence of konzo and .... Brain. 1990; 113: 223–35. Banea JP, Bradbury JH, Mandombi C, Nahimana D, Denton. 12.

Evaluation of Wet Cupping Therapy: Systematic Review of Randomized Clinical Trials.

Science.gov (United States)

Al Bedah, Abdullah M N; Khalil, Mohamed K M; Posadzki, Paul; Sohaibani, Imen; Aboushanab, Tamer Shaaban; AlQaed, Meshari; Ali, Gazzaffi I M

2016-10-01

Wet cupping is a widely used traditional therapy in many countries, which justifies a continuous scientific evaluation of its efficacy and safety. To perform a systematic review to critically evaluate and update the available evidence of wet cupping in traditional and complementary medicine. Ten electronic databases were searched from their inceptions to February 2016. Included studies were randomized clinical trials (RCTs) that evaluated wet cupping against any type of control interventions in patients with any clinical condition, as well as healthy individuals. Cochrane risk of bias tool was used to appraise the included RCTs. Fourteen RCTs met the eligibility criteria. The included studies evaluated the following clinical conditions: nonspecific low back pain (NSLBP), hypertension, brachialgia, carpal tunnel syndrome (CTS), chronic neck pain, metabolic syndrome, migraine headaches, oxygen saturation in smokers with chronic obstructive pulmonary disease (COPD), and oral and genital ulcers due to Behçet disease. Two RCTs evaluated physiologic and biochemical parameters of healthy individuals. Overall, 9 RCTs favored wet cupping over various control interventions in NSLBP (n = 2), hypertension (n = 1), brachialgia (n = 1), CTS (n = 1), chronic neck pain (n = 2), oxygen saturation in smokers with COPD (n = 1), and oral and genital ulcers due to Behçet disease (n = 1). Five RCTs showed no statistically significant between-group differences: NSLBP (n = 1), metabolic syndrome (n = 1), migraine headaches (n = 1), and physiologic and biochemical parameters of healthy individuals (n = 2). Included RCTs had a variable risk of bias across all domains and suffered methodologic limitations. There is a promising evidence in favor of the use of wet cupping for musculoskeletal pain, specifically NSLBP, neck pain, CTS, and brachialgia. Better-quality trials are needed to generate solid evidence and firmly inform policy makers.

Stochastic Rotation Dynamics simulations of wetting multi-phase flows

Science.gov (United States)

Hiller, Thomas; Sanchez de La Lama, Marta; Brinkmann, Martin

2016-06-01

Multi-color Stochastic Rotation Dynamics (SRDmc) has been introduced by Inoue et al. [1,2] as a particle based simulation method to study the flow of emulsion droplets in non-wetting microchannels. In this work, we extend the multi-color method to also account for different wetting conditions. This is achieved by assigning the color information not only to fluid particles but also to virtual wall particles that are required to enforce proper no-slip boundary conditions. To extend the scope of the original SRDmc algorithm to e.g. immiscible two-phase flow with viscosity contrast we implement an angular momentum conserving scheme (SRD+mc). We perform extensive benchmark simulations to show that a mono-phase SRDmc fluid exhibits bulk properties identical to a standard SRD fluid and that SRDmc fluids are applicable to a wide range of immiscible two-phase flows. To quantify the adhesion of a SRD+mc fluid in contact to the walls we measure the apparent contact angle from sessile droplets in mechanical equilibrium. For a further verification of our wettability implementation we compare the dewetting of a liquid film from a wetting stripe to experimental and numerical studies of interfacial morphologies on chemically structured surfaces.

Understanding the edge effect in wetting: a thermodynamic approach.

Science.gov (United States)

Fang, Guoping; Amirfazli, A

2012-06-26

Edge effect is known to hinder spreading of a sessile drop. However, the underlying thermodynamic mechanisms responsible for the edge effect still is not well-understood. In this study, a free energy model has been developed to investigate the energetic state of drops on a single pillar (from upright frustum to inverted frustum geometries). An analysis of drop free energy levels before and after crossing the edge allows us to understand the thermodynamic origin of the edge effect. In particular, four wetting cases for a drop on a single pillar with different edge angles have been determined by understanding the characteristics of FE plots. A wetting map describing the four wetting cases is given in terms of edge angle and intrinsic contact angle. The results show that the free energy barrier observed near the edge plays an important role in determining the drop states, i.e., (1) stable or metastable drop states at the pillar's edge, and (2) drop collapse by liquid spilling over the edge completely or staying at an intermediate sidewall position of the pillar. This thermodynamic model presents an energetic framework to describe the functioning of the so-called "re-entrant" structures. Results show good consistency with the literature and expand the current understanding of Gibbs' inequality condition.

Wetting of refractory metals with copper base alloys

International Nuclear Information System (INIS)

Anikeev, E.F.; Kostikov, V.I.; Chepelenko, V.N.; Batov, V.M.

1978-01-01

The effect is studied of phosphorus upon the wetting of molybdenum, niobium and tantalum by an alloy of the system copper-silver (10%) as a function of contact time and phosphorus concentration. Experiments have been conducted in vacuum of 5x10 -4 mm Hg at 900 deg C. It is established that the introduction of phosphorus into a copper-silver alloy improves the wetting of molybdenum, niobium and tantalum. Formation of intermetallic compounds on the alloy-refractory metal interface can be avoided by adjusting the time of contact of the solder with molybdenum, niobium and tantalum. As a solder with 2.9% phosphorus spreads well over copper, it is suggested to use said solder for brazing copper and the investigated refractory metals in items intended for service at temperatures of up to 600 deg C

Evaluation of acoustic resonance at branch section in main steam line. Part 1. Effects of steam wetness on acoustic resonance

International Nuclear Information System (INIS)

Uchiyama, Yuta; Morita, Ryo

2011-01-01

The power uprating of the nuclear power plant (NPP) is conducted in United States, EU countries and so on, and also is planned in Japan. However, the degradation phenomena such as flow-induced vibration and wall thinning may increase or expose in the power uprate condition. In U.S. NPP, the dryer had been damaged by high cycle fatigue due to acoustic-induced vibration under a 17% extended power uprating (EPU) condition. This is caused by acoustic resonance at the stub pipes of safety relief valves (SRVs) in the main steam lines (MSL). Increased velocity by uprating excites the pressure fluctuations and makes large amplitude resonance. To evaluate the acoustic resonance at the stub pipes of SRVs in actual BWR, it is necessary to clarify the acoustic characteristics in steam flow. Although there are several previous studies about acoustic resonance, most of them are not steam flow but air flow. Therefore in this study, to investigate the acoustic characteristics in steam flow, we conducted steam flow experiments in each dry and wet steam conditions, and also nearly saturated condition. We measured pressure fluctuation at the top of the single stub pipe and in main steam piping. As a result, acoustic resonance in dry steam flow could be evaluated as same as that in air flow. It is clarified that resonance amplitude of fluctuating pressure at the top of the stub pipe in wet steam was reduced to one-tenth compared with that in dry. (author)

Spatial Variability of Wet Troposphere Delays Over Inland Water Bodies

Science.gov (United States)

Mehran, Ali; Clark, Elizabeth A.; Lettenmaier, Dennis P.

2017-11-01

Satellite radar altimetry has enabled the study of water levels in large lakes and reservoirs at a global scale. The upcoming Surface Water and Ocean Topography (SWOT) satellite mission (scheduled launch 2020) will simultaneously measure water surface extent and elevation at an unprecedented accuracy and resolution. However, SWOT retrieval accuracy will be affected by a number of factors, including wet tropospheric delay—the delay in the signal's passage through the atmosphere due to atmospheric water content. In past applications, the wet tropospheric delay over large inland water bodies has been corrected using atmospheric moisture profiles based on atmospheric reanalysis data at relatively coarse (tens to hundreds of kilometers) spatial resolution. These products cannot resolve subgrid variations in wet tropospheric delays at the spatial resolutions (of 1 km and finer) that SWOT is intended to resolve. We calculate zenith wet tropospheric delays (ZWDs) and their spatial variability from Weather Research and Forecasting (WRF) numerical weather prediction model simulations at 2.33 km spatial resolution over the southwestern U.S., with attention in particular to Sam Rayburn, Ray Hubbard, and Elephant Butte Reservoirs which have width and length dimensions that are of order or larger than the WRF spatial resolution. We find that spatiotemporal variability of ZWD over the inland reservoirs depends on climatic conditions at the reservoir location, as well as distance from ocean, elevation, and surface area of the reservoir, but that the magnitude of subgrid variability (relative to analysis and reanalysis products) is generally less than 10 mm.

Analysis of uncertainties in CRAC2 calculations: wet deposition and plume rise

International Nuclear Information System (INIS)

Ward, R.C.; Kocher, D.C.; Hicks, B.B.; Hosker, R.P. Jr.; Ku, J.Y.; Rao, K.S.

1984-01-01

We have studied the sensitivity of results from the CRAC2 computer code, which predicts health impacts from a reactor-accident scenario, to uncertainties in selected meteorological models and parameters. The sources of uncertainty examined include the models for plume rise and wet deposition and the meteorological bin-sampling procedure. An alternative plume-rise model usually had little effect on predicted health impacts. In an alternative wet-deposition model, the scavenging rate depends only on storm type, rather than on rainfall rate and atmospheric stability class as in the CRAC2 model. Use of the alternative wet-deposition model in meteorological bin-sampling runs decreased predicted mean early injuries by as much as a factor of 2 to 3 and, for large release heights and sensible heat rates, decreased mean early fatalities by nearly an order of magnitude. The bin-sampling procedure in CRAC2 was expanded by dividing each rain bin into four bins that depend on rainfall rate. Use of the modified bin structure in conjunction with the CRAC2 wet-deposition model changed all predicted health impacts by less than a factor of 2. 9 references

Moving contact lines in partial wetting: bridging the gap across the scales

Science.gov (United States)

Pahlavan, Amir; Cueto-Felgueroso, Luis; McKinley, Gareth; Juanes, Ruben

2017-11-01

The spreading and dewetting of liquid films on solid substrates is a common phenomenon in nature and industry from a snail secreting a mucosal film to printing and coating processes. A quantitative description of these phenomena, however, requires a detailed understanding of the flow physics at the nanoscale as the intermolecular interactions become important close to the contact line. Classical hydrodynamic theory describes wetting as an interplay between viscous and interfacial forces, neglecting the intermolecular interactions, leading to a paradox known as the moving contact line singularity. By contrast, molecular kinetic theory describes wetting as an activated process, neglecting the bulk hydrodynamics in the spreading viscous fluid film altogether. Here, we show that our recently developed model for thin liquid films in partial wetting, which properly incorporates the role of van der Waals interactions in a thin spreading fluid layer into a height-dependent surface tension, bridges the gap between these two approaches and leads to a unified framework for the description of wetting phenomena. We further use our model to investigate the instability and dewetting of nanometric liquid films, and show that it brings theoretical predictions closer to experimental observations.

Simulation of convection-driven wet-chemical etching

NARCIS (Netherlands)

Driesen, C.H.

1999-01-01

a wet-chemical etching process, the resulting etched shape is smaller than the originally designed shape at the mask. This is caused by the fact that, as soon as material next to the mask is dissolved, material under the mask will be dissolved too. This is the so-called undercut effect. During an

Adsorption and wetting : experiments, thermodynamics and molecular aspects

NARCIS (Netherlands)

Schlangen, L.J.M.

1995-01-01

Adsorption and wetting are related phenomena. In order to improve knowledge of both and their relations, experiments, thermodynamics and a theoretical interpretation have been connected, starring n-alkanes.

Starting from the Gibbs adsorption equation thermodynamic relations between

Characterization of silver nanoparticles prepared by wet chemical ...

African Journals Online (AJOL)

Results: The silver nanoparticles formed were spherical in shape with mean size of 10.3 nm. The ... antibacterial activity against various strains of bacteria. Keywords: Wet ..... Fang J, Zhong C, Mu R. The study of deposited silver particulate ...

Hydrological long-term dry and wet periods in the Xijiang River basin, South China

Directory of Open Access Journals (Sweden)

T. Fischer

2013-01-01

Full Text Available In this study, hydrological long-term dry and wet periods are analyzed for the Xijiang River basin in South China. Daily precipitation data of 118 stations and data on daily discharge at Gaoyao hydrological station at the mouth of the Xijiang River for the period 1961–2007 are used. At a 24-month timescale, the standardized precipitation index (SPI-24 for the six sub-basins of the Xijiang River and the standardized discharge index (SDI-24 for Gaoyao station are applied. The monthly values of the SPI-24 averaged for the Xijiang River basin correlate highly with the monthly values of the SDI-24. Distinct long-term dry and wet sequences can be detected.

The principal component analysis is applied and shows spatial disparities in dry and wet periods for the six sub-basins. The correlation between the SPI-24 of the six sub-basins and the first principal component score shows that 67% of the variability within the sub-basins can be explained by dry and wet periods in the east of the Xijiang River basin. The spatial dipole conditions (second and third principal component explain spatiotemporal disparities in the variability of dry and wet periods. All sub-basins contribute to hydrological dry periods, while mainly the northeastern sub-basins cause wet periods in the Xijiang River. We can also conclude that long-term dry events are larger in spatial extent and cover all sub-basins while long-term wet events are regional phenomena.

A spectral analysis is applied for the SPI-24 and the SDI-24. The results show significant peaks in periodicities of 11–14.7 yr, 2.8 yr, 3.4–3.7 yr, and 6.3–7.3 yr. The same periodic cycles can be found in the SPI-24 of the six sub-basins but with some variability in the mean magnitude. A wavelet analysis shows that significant periodicities have been stable over time since the 1980s. Extrapolations of the reconstructed SPI-24 and SDI-24 represent the continuation of observed significant periodicities

Effects of Surface Modification and Bulk Geometry on the Biotribological Behavior of Cross-Linked Polyethylene: Wear Testing and Finite Element Analysis.

Science.gov (United States)

Watanabe, Kenichi; Kyomoto, Masayuki; Saiga, Kenichi; Taketomi, Shuji; Inui, Hiroshi; Kadono, Yuho; Takatori, Yoshio; Tanaka, Sakae; Ishihara, Kazuhiko; Moro, Toru

2015-01-01

The wear and creep deformation resistances of polymeric orthopedic bearing materials are both important for extending their longevity. In this study, we evaluated the wear and creep deformation resistances, including backside damage, of different polyethylene (PE) materials, namely, conventional PE, cross-linked PE (CLPE), and poly(2-methacryloyloxyethyl phosphorylcholine)- (PMPC-) grafted CLPE, through wear tests and finite element analysis. The gravimetric and volumetric degrees of wear of disks (3 or 6 mm in thickness) of these materials against a cobalt-chromium-molybdenum alloy pin were examined using a multidirectional pin-on-disk tester. Cross-linking and PMPC grafting decreased the gravimetric wear of the PE disks significantly. The volumetric wear at the bearing surface and the volumetric penetration in the backside of the 3-mm thick PE disk were higher than those of the 6-mm thick PE disk, regardless of the bearing material. The geometrical changes induced in the PE disks consisted of creep, because the calculated internal von Mises stress at the bearing side of all disks and that at the backside of the 3-mm thick disks exceeded their actual yield strengths. A highly hydrated bearing surface layer, formed by PMPC grafting, and a cross-linking-strengthened substrate of adequate thickness are essential for increasing the wear and creep deformation resistances.

Changes in duration of dry and wet spells associated with air temperatures in Russia

Science.gov (United States)

Ye, Hengchun

2018-03-01

This study uses daily precipitation records from 517 Russian stations (1966-2010) to examine the relationships between continuous dry and wet day duration and surface air temperature for all four seasons. The study found that both mean and extreme durations of dry periods increase with air temperature at about 7.0% (0.24 day/°C) and 7.7% (0.86 day/°C) respectively, while those of wet periods decrease at about 1.3% (-0.02 day/°C) and 2.2% (-0.10 day/°C) respectively averaged over the entire study region during summer. An increase in the duration of dry periods with higher air temperature is also found in other seasons at locations with a mean seasonal air temperature of about -5 °C or higher. Opposite relationships of shorter durations of dry periods and longer wet periods associated with higher air temperature are observed over the northern part of the study region in winter. The changes in durations of both dry and wet periods have significant correlations with the changes in total dry and wet days but are about 2.5 times higher for dry periods and 0.5 times lower for wet periods. The study also found that locations with longer durations of dry periods experience faster rates of increase in air temperature, suggesting the likelihood of exacerbating drought severity in drier and/or warmer locations for all seasons.

Changes in Wetting Hysteresis During Bioremediation: Changes in fluid flow behavior monitored with low-frequency seismic attenuation

Science.gov (United States)

Wempe, W.; Spetzler, H.; Kittleson, C.; Pursley, J.

2003-12-01

We observed significant reduction in wetting hysteresis with time while a diesel-contaminated quartz crystal was dipped in and out of an oil-reducing bacteria solution. This wetting hysteresis is significantly greater than the wetting hysteresis when the diesel-contaminated quartz crystal is dipped in and out of (1) water, (2) diesel and (3) the bacterial food solution that does not contain bacteria. The reduction in wetting hysteresis of the bacteria solution on the quartz surface results from a reduction in the advancing contact angle formed at the air-liquid-quartz contact with time; the receding contact angle remains the same with time. Our results suggest that the bacteria solution moves across the quartz surface with less resistance after bioremediation has begun. These results imply that bioremediation may influence fluid flow behavior with time. For many fluid-solid systems there is a difference between the contact angle while a contact line advances and recedes across a solid surface; this difference is known as wetting hysteresis. Changes in wetting hysteresis can occur from changes in surface tension or the surface topography. Low contact angle values indicate that the liquid spreads or wets well, while high values indicate poor wetting or non-wetting. Contact angles are estimated in the lab by measuring the weight of the meniscus formed at the air-liquid-quartz interface and by knowing the fluid surface tension. In the lab, we have been able to use low-frequency seismic attenuation data to detect changes in the wetting characteristics of glass plates and of Berea sandstone. The accepted seismic attenuation mechanism is related to the loss of seismic energy due to the hysteresis of meniscus movement (wetting hysteresis) when a pore containing two fluids is stressed at very low frequencies (bioremediation progress using seismic attenuation data. We are measuring low-frequency seismic attenuation in the lab while flowing bacteria solution through Berea

Measurement of wetted area fraction in subcooled pool boiling of water using infrared thermography

International Nuclear Information System (INIS)

Kim, Hyungdae; Park, Youngjae; Buongiorno, Jacopo

2013-01-01

The wetted area fraction in subcooled pool boiling of water at atmospheric pressure is measured using the DEPIcT (DEtection of Phase by Infrared Thermography) technique. DEPIcT exploits the contrast in infrared (IR) light emissions between wet and dry areas on the surface of an IR-transparent heater to visualize the instantaneous distribution of the liquid and gas phases in contact with the heater surface. In this paper time-averaged wetted area fraction data in nucleate boiling are reported as functions of heat flux (from 30% up to 100% of the Critical Heat Flux) and subcooling (ΔT sub = 0, 5, 10, 30 and 50 °C). The results show that the wetted area fraction monotonically decreases with increasing heat flux and increases with increasing subcooling: both trends are expected. The range of time-averaged wetted area fractions is from 90%, at low heat flux and high subcooling, to 50% at high heat flux (right before CHF) and low subcooling. It is also shown that the dry areas are periodically rewetted by liquid sloshing on the surface at any subcooling and heat flux; however, the dry areas expand irreversibly at CHF

Wetted-region structure in horizontal unsaturated fractures: Water entry through the surrounding porous matrix

International Nuclear Information System (INIS)

Glass, R.J.; Norton, D.L.

1991-01-01

Small-scale processes that influence wetted structure within the plane of a horizontal fracture as the fracture wets or drains through the matrix are investigated. Our approach integrates both aperture-scale modeling and physical experimentation. Several types of aperture-scale models have been defined and implemented. A series of physical experimental systems that allow us to measure wetted-region structure as a function of system parameters and water pressure head in analogue fractures also have been designed. In our preliminary proof-of-concept experiment, hysteresis is clearly evident in the measured saturation/pressure relation, as is the process of air entrapment, which causes a reduction in the connected areas between blocks and the wetted region available for flow in the plane of the fracture. A percolation threshold where the system is quickly spanned, allowing fluid conduction in the fracture plane, is observed which is analogous to that found in the aperture-scale models. A fractal wetted and entrapped-region structure is suggested by both experiment and modeling. This structure implies that flow tortuosity for both flow in the fracture and for inter-block fluid transfer is a scale-dependent function of pressure head

Symmetric wetting heterogeneity suppresses fluid displacement hysteresis in granular piles

Science.gov (United States)

Moosavi, R.; Schröter, M.; Herminghaus, S.

2018-02-01

We investigate experimentally the impact of heterogeneity on the capillary pressure hysteresis in fluid invasion of model porous media. We focus on symmetric heterogeneity, where the contact angles the fluid interface makes with the oil-wet (θ1) and the water-wet (θ2) beads add up to π . While enhanced heterogeneity is usually known to increase hysteresis phenomena, we find that hysteresis is greatly reduced when heterogeneities in wettability are introduced. On the contrary, geometric heterogeneity (like bidisperse particle size) does not lead to such an effect. We provide a qualitative explanation of this surprising result, resting on rather general geometric arguments.

Preliminary comparison of three processes of AlN oxidation: dry, wet and mixed ones

Directory of Open Access Journals (Sweden)

Korbutowicz R.

2016-03-01

Full Text Available Three methods of AlN layers oxidation: dry, wet and mixed (wet with oxygen were compared. Some physical parameters of oxidized thin films of aluminum nitride (AlN layers grown on silicon Si(1 1 1 were investigated by means Energy-Dispersive X-ray Spectroscopy (EDS and Spectroscopic Ellipsometry (SE. Three series of the thermal oxidations processes were carried out at 1012 °C in pure nitrogen as carrying gas and various gas ambients: (a dry oxidation with oxygen, (b wet oxidation with water steam and (c mixed atmosphere with various process times. All the research methods have shown that along with the rising of the oxidation time, AlN layer across the aluminum oxide nitride transforms to aluminum oxide. The mixed oxidation was a faster method than the dry or wet ones.

Influence of wetting layer wave functions on carrier capture in quantum dots

DEFF Research Database (Denmark)

Markussen, Troels; Kristensen, Philip; Tromborg, Bjarne

2005-01-01

This work numerically solves the effective mass Schrodinger equation and shows that the capture times are strongly influenced by details of the continuum states not accounted for by the approximate wave functions. Results show that calculations of capture time for phonon mediated carrier capture...... from a wetting layer into a quantum dot depend critically on the approximations used for the wetting layer wave functions....

Direct measurement of the wetting front capillary pressure in a clay brick ceramic

Energy Technology Data Exchange (ETDEWEB)

Ioannou, Ioannis [Manchester Centre for Civil and Construction Engineering, UMIST, PO Box 88, Manchester M60 1QD (United Kingdom); Hall, Christopher [Centre for Materials Science and Engineering and School of Engineering and Electronics, University of Edinburgh, The King' s Buildings, Edinburgh EH9 3JL (United Kingdom); Wilson, Moira A [Manchester Centre for Civil and Construction Engineering, UMIST, PO Box 88, Manchester M60 1QD (United Kingdom); Hoff, William D [Manchester Centre for Civil and Construction Engineering, UMIST, PO Box 88, Manchester M60 1QD (United Kingdom); Carter, Margaret A [Manchester Centre for Civil and Construction Engineering, UMIST, PO Box 88, Manchester M60 1QD (United Kingdom)

2003-12-21

The absorption of a liquid into a rectangular bar of an initially dry porous material that is sealed on all surfaces except the inflow face is analysed in terms of Sharp Front theory. Sharp Front models are developed for both complete and incomplete displacement of air ahead of the advancing wetting front. Experiments are described from which a characteristic capillary potential of the material is obtained by measuring the equilibrium pressure of the air displaced and compressed ahead of the advancing wetting front. Results for the absorption of water and n-heptane by a fired clay brick ceramic suggest that this wetting front capillary pressure (or capillary potential) scales approximately with the surface tension and also that the permeability scales inversely with the liquid viscosity. The pressure of the air trapped in the wetted region is found to be the same as the pressure of the displaced air. For this material the wetting front capillary pressure for water at 20 C is 0.113 MPa, equivalent to a hydraulic tension head of 11.5 m and to a Young-Laplace pore diameter of 2.6 {mu}m. The capillary pressure so measured is apparently a fundamental percolation property of the material that can be interpreted as the air pressure at which liquid phase continuity and unsaturated conductivity both vanish. The method described can be applied generally to porous materials.

Direct measurement of the wetting front capillary pressure in a clay brick ceramic

International Nuclear Information System (INIS)

Ioannou, Ioannis; Hall, Christopher; Wilson, Moira A; Hoff, William D; Carter, Margaret A

2003-01-01

The absorption of a liquid into a rectangular bar of an initially dry porous material that is sealed on all surfaces except the inflow face is analysed in terms of Sharp Front theory. Sharp Front models are developed for both complete and incomplete displacement of air ahead of the advancing wetting front. Experiments are described from which a characteristic capillary potential of the material is obtained by measuring the equilibrium pressure of the air displaced and compressed ahead of the advancing wetting front. Results for the absorption of water and n-heptane by a fired clay brick ceramic suggest that this wetting front capillary pressure (or capillary potential) scales approximately with the surface tension and also that the permeability scales inversely with the liquid viscosity. The pressure of the air trapped in the wetted region is found to be the same as the pressure of the displaced air. For this material the wetting front capillary pressure for water at 20 C is 0.113 MPa, equivalent to a hydraulic tension head of 11.5 m and to a Young-Laplace pore diameter of 2.6 μm. The capillary pressure so measured is apparently a fundamental percolation property of the material that can be interpreted as the air pressure at which liquid phase continuity and unsaturated conductivity both vanish. The method described can be applied generally to porous materials

Two-dimensional LIF measurements of humidity and OH density resulting from evaporated water from a wet surface in plasma for medical use

International Nuclear Information System (INIS)

Yagi, Ippei; Ono, Ryo; Oda, Tetsuji; Takaki, Koichi

2015-01-01

In plasma medicine, plasma is applied to a wet surface and is often accompanied by dry-gas flow. The dry-gas flow affects water evaporation from the wet surface and influences production of reactive species derived from water vapor, such as OH radicals. In this study, the effect of the dry-gas flow on two-dimensional distributions of humidity and OH radical density are examined by measuring them using laser-induced fluorescence (LIF). First, humidity is measured when nitrogen flows from a quartz tube of 4 mm inner diameter onto distilled water and agar media from 5 mm distance. NO gas is added to the nitrogen as a tracer and humidity is obtained from the quenching rate of NO molecules measured using LIF. This measurement has a spatial resolution of 0.2 mm 3 and a temporal resolution of less than 220 ns. The two-dimensional humidity distribution shows that the dry-gas flow pushes away water vapor evaporating from the wet surface. As a result, a low-humidity region is formed near the quartz tube nozzle and a high-humidity region is formed near the wet surface. The thickness of the low-humidity region reduces with increasing gas flow rate. It is 0.1–0.5 mm for the flow rate of higher than 0.3 l min −1 . Next, the OH density is measured when a nanosecond pulsed streamer discharge is applied to a distilled water surface with dry-air flow. The OH density decreases with increasing gas flow rate due to decreased humidity. When the flow rate is lower than 0.1 l min −1 , the OH distribution is approximately uniform in the plasma region, while the humidity distribution shows a large gradient. The importance of the thin high-humidity region on the flux of reactive species onto the wet surface is discussed. (paper)

Drop spreading and penetration into pre-wetted powders

KAUST Repository

Marston, Jeremy; Sprittles, James E.; Zhu, Y.; Li, Erqiang; Vakarelski, Ivan Uriev; Thoroddsen, Sigurdur T

2013-01-01

We present results from an experimental study of the impact of liquid drops onto powder beds which are pre-wetted with the impacting liquid. Using high-speed video imaging, we study both the dynamics of the initial spreading regime and drainage

The Influence of Surface Anisotropy Crystalline Structure on Wetting of Sapphire by Molten Aluminum

Science.gov (United States)

Aguilar-Santillan, Joaquin

2013-05-01

The wetting of sapphire by molten aluminum was investigated by the sessile drop technique from 1073 K to 1473 K (800 °C to 1200 °C) at PO2 <10-15 Pa under Ar atmosphere. This study focuses on sapphire crystalline structure and its principle to the interface. The planes " a" and " b" are oxygen terminated structures and wet more by Al, whereas the " c" plane is an aluminum terminated structure. A wetting transition at 1273 K (1000 °C) was obtained and a solid surface tension proves the capillarity trends of the couple.

Wetting phase transition of two segregated Bose–Einstein condensates restricted by a hard wall

Energy Technology Data Exchange (ETDEWEB)

Thu, Nguyen Van [Department of Physics, Hanoi Pedagogical University No. 2, Hanoi (Viet Nam); Phat, Tran Huu [Vietnam Atomic Energy Commission, 59 Ly Thuong Kiet, Hanoi (Viet Nam); Song, Pham The, E-mail: thesong80@icloud.com [Tay Bac University, Son La (Viet Nam)

2016-04-01

Highlights: • System of two segregated Bose–Einstein condensates limited by a wall is studied. • Double-parabola approximation is applied to Gross–Pitaevskii theory. • Interface tension and wetting phase diagram are established. - Abstract: The wetting phase transition in the system of two segregated Bose–Einstein condensates (BECs) restricted by a hard wall is studied by means of the double-parabola approximation (DPA) applied to the Gross–Pitaevskii (GP) theory. We found the interfacial tension and the wetting phase diagram which depend weakly on the spatial restriction.

A Practical Irradiance Model for Bifacial PV Modules: Preprint

Energy Technology Data Exchange (ETDEWEB)

Marion, Bill; MacAlpine, Sara; Deline, Chris; Asgharzadeh, Amir; Toor, Fatima; Riley, Daniel; Stein, Joshua; Hansen, Clifford

2017-06-15

A model, suitable for a row or multiple rows of photovoltaic (PV) modules, is presented for estimating the backside irradiance for bifacial PV modules. The model, which includes the effects of shading by the PV rows, is based on the use of configuration factors (CFs) to determine the fraction of a source of irradiance that is received by the backside of the PV module. Backside irradiances are modeled along the sloped height of the PV module, but assumed not to vary along the length of the PV row. The backside irradiances are corrected for angle-of-incidence losses and may be added to the front side irradiance to determine the total irradiance resource for the PV cell. Model results are compared with the measured backside irradiances for NREL and Sandia PV systems, and with results when using the RADIANCE ray tracing program.

A Practical Irradiance Model for Bifacial PV Modules

Energy Technology Data Exchange (ETDEWEB)

Marion, Bill; MacAlpine, Sara; Deline, Chris; Asgharzadeh, Amir; Toor, Fatima; Riley, Daniel; Stein, Joshua; Hansen, Clifford

2017-06-21

A model, suitable for a row or multiple rows of photovoltaic (PV) modules, is presented for estimating the backside irradiance for bifacial PV modules. The model, which includes the effects of shading by the PV rows, is based on the use of configuration factors to determine the fraction of a source of irradiance that is received by the backside of the PV module. Backside irradiances are modeled along the sloped height of the PV module, but assumed not to vary along the length of the PV row. The backside irradiances are corrected for angle-of-incidence losses and may be added to the front side irradiance to determine the total irradiance resource for the PV cell. Model results are compared with the measured backside irradiances for NREL and Sandia PV systems, and with results when using ray tracing software.

Simulation of convection-driven wet-chemical etching

NARCIS (Netherlands)

Driesen, C.H.

1999-01-01

In a wet-chemical etching process, the resulting etched shape is smaller than the originally designed shape at the mask. This is caused by the fact that, as soon as material next to the mask is dissolved, material under the mask will be dissolved too. This is the so-called undercut effect. During an

Electrical and physical characterizations of the effects of oxynitridation and wet oxidation at the interface of SiO2/4H-SiC(0001) and (000\\bar{1})