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Sample records for surface composition dry

  1. Effects of composite surface coating and pre-drying on the properties of kabanosy dry sausage.

    Science.gov (United States)

    Tyburcy, Andrzej; Kozyra, Daniel

    2010-10-01

    Coating of dry sausages with renewable materials could be an alternative to vacuum packaging. In this study kabanosy dry sausage was coated with a composite emulsion and stored for 7 or 15 days at 4-6 degrees C. Effects of different emulsion formulas (0.5 or 1% w/w of kappa-carrageenan and 5 or 10% w/w of glycerol) and pre-drying of coated sausages (at 50 degrees C for 1.5h) were investigated. Carrageenan concentration had a significant effect (Pemulsion adsorbed on the sausage surface but little influence on the barrier properties of the coatings. At both glycerol concentration levels, coatings had no visible cracks and were easily removed from the sausage surface after 7 and 15 days of storage. The colour values of coatings (L*, a*, and b*) changed along with the decreasing water activity during storage. Pre-drying of coated sausages reduced peeled product weight loss after storage. The financial analysis showed that among coatings tested the best proved to be the emulsion containing (w/w): 5% glycerol, 5% gelatin, 0.5% carrageenan, 20% lard, 20% beeswax, and 50% water. Copyright (c) 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.

  2. The impact of atomization on the surface composition of spray-dried milk droplets.

    Science.gov (United States)

    Foerster, Martin; Gengenbach, Thomas; Woo, Meng Wai; Selomulya, Cordelia

    2016-04-01

    The dominant presence of fat at the surface of spray-dried milk powders has been widely reported in the literature and described as resulting in unfavourable powder properties. The mechanism(s) causing this phenomenon are yet to be clearly identified. A systematic investigation of the component distribution in atomized droplets and spray-dried particles consisting of model milk systems with different fat contents demonstrated that atomization strongly influences the final surface composition. Cryogenic flash-freezing of uniform droplets from a microfluidic jet nozzle directly after atomization helped to distinguish the influence of the atomization stage from the drying stage. It was confirmed that the overrepresentation of fat on the surface is independent of the atomization technique, including a pressure-swirl single-fluid spray nozzle and a pilot-scale rotary disk spray dryer commonly used in industry. It is proposed that during the atomization stage a disintegration mechanism along the oil-water interface of the fat globules causes the surface predominance of fat. X-ray photoelectron spectroscopic measurements detected the outermost fat layer and some adjacent protein present on both atomized droplets and spray-dried particles. Confocal laser scanning microscopy gave a qualitative insight into the protein and fat distribution throughout the cross-sections, and confirmed the presence of a fat film along the particle surface. The film remained on the surface in the subsequent drying stage, while protein accumulated underneath, driven by diffusion. The results demonstrated that atomization induces component segregation and fat-rich surfaces in spray-dried milk powders, and thus these cannot be prevented by adjusting the spray drying conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Effects of Wet and Dry Finishing and Polishing on Surface Roughness and Microhardness of Composite Resins

    Science.gov (United States)

    Nasoohi, Negin; Hoorizad, Maryam

    2017-01-01

    Objectives: This study aimed to assess the effect of wet and dry finishing and polishing on microhardness and roughness of microhybrid and nanohybrid composites. Materials and Methods: Thirty samples were fabricated of each of the Polofil Supra and Aelite Aesthetic All-Purpose Body microhybrid and Grandio and Aelite Aesthetic Enamel nanohybrid composite resins. Each group (n=30) was divided into three subgroups of D, W and C (n=10). Finishing and polishing were performed dry in group D and under water coolant in group W. Group C served as the control group and did not receive finishing and polishing. Surface roughness of samples was measured by a profilometer and their hardness was measured by a Vickers hardness tester. Data were analyzed using two-way ANOVA (Pcomposites (Pcomposites (Pcomposites (Pcomposite resins. PMID:29104597

  4. Wear of Polished Steel Surfaces in Dry Friction Linear Contact on Polimer Composites with Glass Fibres

    Directory of Open Access Journals (Sweden)

    D. Rus

    2013-12-01

    Full Text Available It is generally known that the friction and wear between polymers and polished steel surfaces has a special character, the behaviour to friction and wear of a certain polymer might not be valid for a different polymer, moreover in dry friction conditions. In this paper, we study the reaction to wear of certain polymers with short glass fibres on different steel surfaces, considering the linear friction contact, observing the friction influence over the metallic surfaces wear. The paper includes also its analysis over the steel’s wear from different points of view: the reinforcement content influence and tribological parameters (load, contact pressure, sliding speed, contact temperature, etc.. Thus, we present our findings related to the fact that the abrasive component of the friction force is more significant than the adhesive component, which generally is specific to the polymers’ friction. Our detections also state that, in the case of the polyamide with 30% glass fibres, the steel surface linear wear rate order are of 10-4 mm/h, respectively the order of volumetric wear rate is of 10-6 cm3 /h. The resulting volumetric wear coefficients are of the order (10-11 – 10-12 cm3/cm and respectively linear wear coefficients of 10-9 mm/cm.

  5. Sustaining dry surfaces under water

    DEFF Research Database (Denmark)

    Jones, Paul R.; Hao, Xiuqing; Cruz-Chu, Eduardo R.

    2015-01-01

    Rough surfaces immersed under water remain practically dry if the liquid-solid contact is on roughness peaks, while the roughness valleys are filled with gas. Mechanisms that prevent water from invading the valleys are well studied. However, to remain practically dry under water, additional...... mechanisms need consideration. This is because trapped gas (e.g. air) in the roughness valleys can dissolve into the water pool, leading to invasion. Additionally, water vapor can also occupy the roughness valleys of immersed surfaces. If water vapor condenses, that too leads to invasion. These effects have...... not been investigated, and are critically important to maintain surfaces dry under water.In this work, we identify the critical roughness scale, below which it is possible to sustain the vapor phase of water and/or trapped gases in roughness valleys – thus keeping the immersed surface dry. Theoretical...

  6. AlSiTiN and AlSiCrN multilayer coatings: Effects of structure and surface composition on tribological behavior under dry and lubricated conditions

    International Nuclear Information System (INIS)

    Faga, Maria Giulia; Gautier, Giovanna; Cartasegna, Federico; Priarone, Paolo C.; Settineri, Luca

    2016-01-01

    Graphical abstract: - Highlights: • The demand for high performance nanostructured coatings has been increasing. • AlSiTiN and AlSiCrN nanocomposite coatings were deposited by PVD technique. • Coatings were analyzed in terms of structure, hardness and adhesion. • Tribological properties under dry and lubricated conditions were studied. • The effects of surface and bulk properties on friction evolution were assessed. - Abstract: Nanocomposite coatings have been widely studied over the last years because of their high potential in several applications. The increased interest for these coatings prompted the authors to study the tribological properties of two nanocomposites under dry and lubricated conditions (applying typical MQL media), in order to assess the influence of the surface and bulk properties on friction evolution. To this purpose, multilayer and nanocomposite AlSiTiN and AlSiCrN coatings were deposited onto tungsten carbide-cobalt (WC-Co) samples. Uncoated WC-Co materials were used as reference. Coatings were analyzed in terms of hardness and adhesion. The structure of the samples was assessed by X-ray diffraction (XRD), while the surface composition was studied by XPS analysis. Friction tests were carried out under both dry and lubricated conditions using an inox ball as counterpart. Both coatings showed high hardness and good adhesion to the substrate. As far as the friction properties are concerned, in dry conditions the surface properties affect the sliding contact at the early beginning, while bulk structure and tribolayer formation determine the main behavior. Only AlSiTiN coating shows a low and stable coefficient of friction (COF) under dry condition, while the use of MQL media results in a rapid stabilization of the COF for all the materials.

  7. Dry deposition on urban surfaces

    International Nuclear Information System (INIS)

    Roed, J.

    1985-01-01

    In order to facilitate developing a model for deposition in urban areas, beryllium-7, created by cosmic radiation and fall-out cesium-137, have been used as tracers in measurements designed to find the dry deposition velocity on building surfaces. A literature review has revealed that very little work has been done on deposition in urban areas; therefore, a major effort on meausring the deposition parameter is needed to construct reliable models in this field. Deposition velocities in the range from 0.001-0.04 cm/s have been found. (author)

  8. PHBV/PLLA-based composite scaffolds fabricated using an emulsion freezing/freeze-drying technique for bone tissue engineering: surface modification and in vitro biological evaluation

    International Nuclear Information System (INIS)

    Sultana, Naznin; Wang Min

    2012-01-01

    Tissue engineering combines living cells with biodegradable materials and/or bioactive components. Composite scaffolds containing biodegradable polymers and nanosized osteoconductive bioceramic with suitable properties are promising for bone tissue regeneration. In this paper, based on blending two biodegradable and biocompatible polymers, namely poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and poly(l-lactic acid) (PLLA) with incorporated nano hydroxyapatite (HA), three-dimensional composite scaffolds with controlled microstructures and an interconnected porous structure, together with high porosity, were fabricated using an emulsion freezing/freeze-drying technique. The influence of various parameters involved in the emulsion freezing/freeze-drying technique was studied for the fabrication of good-quality polymer scaffolds based on PHBV polymers. The morphology, mechanical properties and crystallinity of PHBV/PLLA and HA in PHBV/PLLA composite scaffolds and PHBV polymer scaffolds were studied. The scaffolds were coated with collagen in order to improve wettability. During in vitro biological evaluation study, it was observed that SaOS-2 cells had high attachment on collagen-coated scaffolds. Significant improvement in cell proliferation and alkaline phosphatase activity for HA-incorporated composite scaffolds was observed due to the incorporation of HA. After 3 and 7 days of culture on all scaffolds, SaOS-2 cells also had normal morphology and growth. These results indicated that PHBV/PLLA-based scaffolds fabricated via an emulsion freezing/freeze-drying technique were favorable sites for osteoblastic cells and are promising for the applications of bone tissue engineering.

  9. Effect of drying temperatures on the proximate composition and ...

    African Journals Online (AJOL)

    Results of the proximate composition showed that the nutritional qualities of the dried eggs were retained during drying thus the drying temperature did not affect the quality of eggs. The moisture contents of the dried whole egg, dried egg yolk and dried egg white at the different temperatures range from 6.25 -7.23%, ...

  10. Dry cooling systems with plastic surfaces

    International Nuclear Information System (INIS)

    Roma, Carlo; Leonelli, Vincenzo

    1975-01-01

    Research and experiments made on dry cooling systems with plastic surfaces are described. The demonstration program planned in Italy for a 100Gcal/h dry cooling system is exposed, and an installation intended for a large 1300Mwe nuclear power station is described with reference to the assembly (exploitation and maintenance included). The performance and economic data relating to this installation are also exposed [fr

  11. Surface decontamination using dry ice snow

    International Nuclear Information System (INIS)

    Ryu, Jungdong; Park, Kwangheon; Lee, Bumsik; Kim Yangeun

    1999-01-01

    An adjustable nozzle for controlling the size of dry ice snow was developed. The converging/diverging nozzle can control the size of snows from sub-microns to 10 micron size. Using the nozzle, a surface decontamination device was made. The removal mechanisms of surface contaminants are mechanical impact, partial dissolving and evaporation process, and viscous flow. A heat supply system is added for the prevention of surface ice layer formation. The cleaning power is slightly dependent on the size of snow. Small snows are the better in viscous flow cleaning, while large snows are slightly better in dissolving and sublimation process. Human oils like fingerprints on glass were easy to remove. Decontamination ability was tested using a contaminated pump-housing surface. About 40 to 80% of radioactivity was removed. This device is effective in surface-decontamination of any electrical devices like detector, controllers which cannot be cleaned in aqueous solution. (author)

  12. Cassava Sun Drying Performance on Various Surfaces and Drying ...

    African Journals Online (AJOL)

    Traditional processing methods that include ... The traditional sun drying method is very inefficient as the product can take 2-. 3 days to dry. .... using a digital balance (Ohaus Corporation type). The same applied .... preservation and marketing.

  13. Gelcasting compositions having improved drying characteristics and machinability

    Science.gov (United States)

    Janney, Mark A.; Walls, Claudia A. H.

    2001-01-01

    A gelcasting composition has improved drying behavior, machinability and shelf life in the dried and unfired state. The composition includes an inorganic powder, solvent, monomer system soluble in the solvent, an initiator system for polymerizing the monomer system, and a plasticizer soluble in the solvent. Dispersants and other processing aides to control slurry properties can be added. The plasticizer imparts an ability to dry thick section parts, to store samples in the dried state without cracking under conditions of varying relative humidity, and to machine dry gelcast parts without cracking or chipping. A method of making gelcast parts is also disclosed.

  14. Dry deposition to vegetated surfaces: parametric dependencies

    International Nuclear Information System (INIS)

    Underwood, B.Y.

    1987-12-01

    The dry deposition velocity of airborne pollutants to vegetated surfaces depends on the physico-chemical form of the pollutant, on meteorological conditions (windspeed, atmospheric stability) and on characteristics of the surface cover. This report examines these dependencies, drawing on experimental data and on information from theoretical analyses. A canopy model is outlined which uses first-order closure of the equations for turbulent transport of momentum (or matter), with losses of momentum (or matter) to individual canopy elements parameterised in terms of the mean windspeed: the model has previously been tested against experimental data on an artificial 'grass' canopy. The model is used to elucidate the features of the dependence of deposition velocity on windspeed and on whether the pollutant is in gaseous or particulate form: in the former case, the dependence on the molecular diffusivity of the gas is shown; in the latter case, dependencies on particle diameter and density are deduced. The predictions are related to available measurements. Additional hypotheses are introduced to treat the influence of atmospheric stability on deposition, and the analysis is used to shed light on the somewhat confusing picture that has emerged from past experimental studies. In considering the dependence of deposition velocity on the structural properties of the vegetation, it is established that more parameters than the single one conventionally used -aerodynamic roughness length - are needed to characterise the surface cover. Some indications of the extent of variation in deposition velocity from one type of vegetation to another are elicited from the model. (author)

  15. Dry Eye Management: Targeting the Ocular Surface Microenvironment.

    Science.gov (United States)

    Zhang, Xiaobo; M, Vimalin Jeyalatha; Qu, Yangluowa; He, Xin; Ou, Shangkun; Bu, Jinghua; Jia, Changkai; Wang, Junqi; Wu, Han; Liu, Zuguo; Li, Wei

    2017-06-29

    Dry eye can damage the ocular surface and result in mild corneal epithelial defect to blinding corneal pannus formation and squamous metaplasia. Significant progress in the treatment of dry eye has been made in the last two decades; progressing from lubricating and hydrating the ocular surface with artificial tear to stimulating tear secretion; anti-inflammation and immune regulation. With the increase in knowledge regarding the pathophysiology of dry eye, we propose in this review the concept of ocular surface microenvironment. Various components of the microenvironment contribute to the homeostasis of ocular surface. Compromise in one or more components can result in homeostasis disruption of ocular surface leading to dry eye disease. Complete evaluation of the microenvironment component changes in dry eye patients will not only lead to appropriate diagnosis, but also guide in timely and effective clinical management. Successful treatment of dry eye should be aimed to restore the homeostasis of the ocular surface microenvironment.

  16. Dry Eye Management: Targeting the Ocular Surface Microenvironment

    Science.gov (United States)

    Zhang, Xiaobo; Jeyalatha M, Vimalin; Qu, Yangluowa; He, Xin; Ou, Shangkun; Bu, Jinghua; Jia, Changkai; Wang, Junqi; Wu, Han; Liu, Zuguo

    2017-01-01

    Dry eye can damage the ocular surface and result in mild corneal epithelial defect to blinding corneal pannus formation and squamous metaplasia. Significant progress in the treatment of dry eye has been made in the last two decades; progressing from lubricating and hydrating the ocular surface with artificial tear to stimulating tear secretion; anti-inflammation and immune regulation. With the increase in knowledge regarding the pathophysiology of dry eye, we propose in this review the concept of ocular surface microenvironment. Various components of the microenvironment contribute to the homeostasis of ocular surface. Compromise in one or more components can result in homeostasis disruption of ocular surface leading to dry eye disease. Complete evaluation of the microenvironment component changes in dry eye patients will not only lead to appropriate diagnosis, but also guide in timely and effective clinical management. Successful treatment of dry eye should be aimed to restore the homeostasis of the ocular surface microenvironment. PMID:28661456

  17. Effect of surface roughness on drying speed of drying lamellas in ...

    African Journals Online (AJOL)

    Lamellas, which are defined as top layers of multilayer parquet and favourable to wood veneer can be dried in jet ventilated automatic veneer roller dryer due to short drying period. The objective of this study is to determine the effect of surface roughness on the drying speed of the veneer roller dryer. Quercus spp.

  18. Effect of smoking and sun drying on proximate composition of ...

    African Journals Online (AJOL)

    Effect of smoking and sun drying on proximate composition of Diplotaxodon fish species (Ndunduma) from lake Malawi, Malawi. ... African Journal of Food, Agriculture, Nutrition and Development ... The fish were washed then weighed and thereafter, smoked in a traditional smoking kiln and sun dried on reed mats.

  19. Municipal Sewage Sludge Drying Treatment by an Composite Modifier

    OpenAIRE

    Na Wei

    2012-01-01

    A sludge composite modifier (SCM) which comprises a mixture of three cementitious components was proposed for sludge drying and stabilization. Effect of SCM components on sludge moisture content was analyzed using uniform design and the optimum composition of SCM was determined by computer-aided modeling and optimization. To compare the drying effect of SCM, quicklime, and Portland cement, the effects of material content and curing time on moisture content of sludge were also studied. The res...

  20. Composite Dry Structure Cost Improvement Approach

    Science.gov (United States)

    Nettles, Alan; Nettles, Mindy

    2015-01-01

    This effort demonstrates that by focusing only on properties of relevance, composite interstage and shroud structures can be placed on the Space Launch System vehicle that simultaneously reduces cost, improves reliability, and maximizes performance, thus providing the Advanced Development Group with a new methodology of how to utilize composites to reduce weight for composite structures on launch vehicles. Interstage and shroud structures were chosen since both of these structures are simple in configuration and do not experience extreme environments (such as cryogenic or hot gas temperatures) and should represent a good starting point for flying composites on a 'man-rated' vehicle. They are used as an example only. The project involves using polymer matrix composites for launch vehicle structures, and the logic and rationale behind the proposed new methodology.

  1. Dry deposition of particles to ocean surfaces

    NARCIS (Netherlands)

    Larsen, S.E.; Edson, J.B.; Hummelshoj, P.; Jensen, N.O.; Leeuw, G. de; Mestayer, P.G.

    1995-01-01

    Dry deposition of atmospheric particles mainly depends on wind speed and particle diameter. The dry deposition velocity, Vd, is found to vary by a factor of 100-1,000 with diameter in a likely diameter range, adding uncertainty to deposition estimates, because the diameter distribution for many

  2. Resistance of surface-dried virus to common disinfection procedures

    NARCIS (Netherlands)

    Terpstra, F. G.; van den Blink, A. E.; Bos, L. M.; Boots, A. G. C.; Brinkhuis, F. H. M.; Gijsen, E.; van Remmerden, Y.; Schuitemaker, H.; van 't Wout, A. B.

    2007-01-01

    It is believed that surface-dried viruses can remain infectious and may therefore pose a threat to public health. To help address this issue, we studied 0.1 N NaOH and 0.1% hypochlorite for their capacity to inactivate surface-dried lipid-enveloped (LE) [human immunodeficiency virus (HIV), bovine

  3. Spherical nanostructured Si/C composite prepared by spray drying technique for lithium ion batteries anode

    International Nuclear Information System (INIS)

    Chen Libao; Xie Xiaohua; Wang Baofeng; Wang Ke; Xie Jingying

    2006-01-01

    Spherical nanostructured Si/C composite was prepared by spray drying technique, followed by heat treatment, in which nanosized silicon and fine graphite particles were homogeneously embedded in carbon matrix pyrolyzed by phenol formaldehyde resin. Cyclic voltammetry tests showed two pairs of redox peaks corresponding to lithiation and delithiation of Si/C composite. The Si/C composite exhibited a reversible capacity of 635 mAh g -1 and good cycle performance used in lithium ion batteries. To improve cycle performance of this Si/C composite further, the carbon-coated Si/C composite was synthesized by the second spray drying and heat treatment processing. The cycle performance of carbon-coated Si/C composite was improved significantly, which was attributed to the formation of stable SEI passivation layers on the outer surface of carbon shell which protected the bared silicon from exposing to electrolyte directly

  4. Spherical nanostructured Si/C composite prepared by spray drying technique for lithium ion batteries anode

    Energy Technology Data Exchange (ETDEWEB)

    Chen Libao [Energy Science and Technology Laboratory, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Xie Xiaohua [Energy Science and Technology Laboratory, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Wang Baofeng [Department of Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Wang Ke [Energy Science and Technology Laboratory, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Xie Jingying [Energy Science and Technology Laboratory, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China) and Graduate School of Chinese Academy of Sciences, Beijing 100049 (China)]. E-mail: jyxie@mail.sim.ac.cn

    2006-07-15

    Spherical nanostructured Si/C composite was prepared by spray drying technique, followed by heat treatment, in which nanosized silicon and fine graphite particles were homogeneously embedded in carbon matrix pyrolyzed by phenol formaldehyde resin. Cyclic voltammetry tests showed two pairs of redox peaks corresponding to lithiation and delithiation of Si/C composite. The Si/C composite exhibited a reversible capacity of 635 mAh g{sup -1} and good cycle performance used in lithium ion batteries. To improve cycle performance of this Si/C composite further, the carbon-coated Si/C composite was synthesized by the second spray drying and heat treatment processing. The cycle performance of carbon-coated Si/C composite was improved significantly, which was attributed to the formation of stable SEI passivation layers on the outer surface of carbon shell which protected the bared silicon from exposing to electrolyte directly.

  5. Regional variation in Caribbean dry forest tree species composition

    Science.gov (United States)

    Janet Franklin; Julie Ripplinger; Ethan H. Freid; Humfredo Marcano-Vega; David W. Steadman

    2015-01-01

    How does tree species composition vary in relation to geographical and environmental gradients in a globally rare tropical/subtropical broadleaf dry forest community in the Caribbean? We analyzed data from 153 Forest Inventory and Analysis (FIA) plots from Puerto Rico and the U.S. Virgin Islands (USVI), along with 42 plots that we sampled in the Bahamian Archipelago (...

  6. Low surface damage dry etched black silicon

    Science.gov (United States)

    Plakhotnyuk, Maksym M.; Gaudig, Maria; Davidsen, Rasmus Schmidt; Lindhard, Jonas Michael; Hirsch, Jens; Lausch, Dominik; Schmidt, Michael Stenbæk; Stamate, Eugen; Hansen, Ole

    2017-10-01

    Black silicon (bSi) is promising for integration into silicon solar cell fabrication flow due to its excellent light trapping and low reflectance, and a continuously improving passivation. However, intensive ion bombardment during the reactive ion etching used to fabricate bSi induces surface damage that causes significant recombination. Here, we present a process optimization strategy for bSi, where surface damage is reduced and surface passivation is improved while excellent light trapping and low reflectance are maintained. We demonstrate that reduction of the capacitively coupled plasma power, during reactive ion etching at non-cryogenic temperature (-20 °C), preserves the reflectivity below 1% and improves the effective minority carrier lifetime due to reduced ion energy. We investigate the effect of the etching process on the surface morphology, light trapping, reflectance, transmittance, and effective lifetime of bSi. Additional surface passivation using atomic layer deposition of Al2O3 significantly improves the effective lifetime. For n-type wafers, the lifetime reaches 12 ms for polished and 7.5 ms for bSi surfaces. For p-type wafers, the lifetime reaches 800 μs for both polished and bSi surfaces.

  7. Low surface damage dry etched black silicon

    DEFF Research Database (Denmark)

    Plakhotnyuk, Maksym M.; Gaudig, Maria; Davidsen, Rasmus Schmidt

    2017-01-01

    Black silicon (bSi) is promising for integration into silicon solar cell fabrication flow due to its excellent light trapping and low reflectance, and a continuously improving passivation. However, intensive ion bombardment during the reactive ion etching used to fabricate bSi induces surface dam...

  8. Municipal Sewage Sludge Drying Treatment by an Composite Modifier

    Directory of Open Access Journals (Sweden)

    Na Wei

    2012-01-01

    Full Text Available A sludge composite modifier (SCM which comprises a mixture of three cementitious components was proposed for sludge drying and stabilization. Effect of SCM components on sludge moisture content was analyzed using uniform design and the optimum composition of SCM was determined by computer-aided modeling and optimization. To compare the drying effect of SCM, quicklime, and Portland cement, the effects of material content and curing time on moisture content of sludge were also studied. The results showed that the optimum ratio of modifier component was slag/cement clinker/dihydrate gypsum = 0.64/0.292/0.068 and the moisture content of SCM-stabilized sludge decreased with the increasing material content and extending curing time. Besides, the experimental results showed that optimized SCM behaved better than quicklime and Portland cement in sludge semi-drying and XRD analysis revealed that the main hydrated product of stabilization was ettringite, which played an important role in the effective drying process. Sewage sludge stabilized using SCM could be used as an effective landfill cover.

  9. Dry sliding behavior of aluminum alloy 8011 with 12% fly ash composites

    Science.gov (United States)

    Magibalan, S.; Senthilkumar, P.; Palanivelu, R.; Senthilkumar, C.; Shivasankaran, N.; Prabu, M.

    2018-05-01

    This research focused on the fabrication of aluminum alloy 8011 with 12% fly ash (FA) composite (AA8011%–12% FA) using the stir casting method. A three-level central composite design experiment was developed using response surface methodology with various parameters such as load, time, and sliding velocity varied in the range of 5 to 15 N, 5 to 15 min, and 1.5 to 4.5 m.s‑1, respectively. Dry sliding wear tests were performed as per the experimental design using a pin on disc at room temperature. The obtained regression result indicated that the developed model performed well in relating the wear process parameters and predicted the wear behavior of the composite. The surface plot showed that the wear rate increases with increase in load, time, and sliding velocity. Hardness was evaluated by Vickers hardness testing machine. Moreover, the surface morphology of the worn-out composite was examined using a scanning electron microscope.

  10. Gas Composition Transients in the Cold Vacuum Drying (CVD) Facility

    International Nuclear Information System (INIS)

    PACKER, M.J.

    2000-01-01

    The purpose of this document is to evaluate selected problems involving the prediction of transient gas compositions during Cold Vacuum Drying operations. The problems were evaluated to answer specific design questions. The document is formatted as a topical report with each section representing a specific problem solution. The problem solutions are reported in the calculation format specified in HNF-1613, Rev. 0, EP 7.6

  11. Intensifying drying process with creation of functional plant compositions

    Directory of Open Access Journals (Sweden)

    Zh. Petrova

    2015-05-01

    Full Text Available Introduction. The process of drying agricultural raw products is associated with loss of bioactive substances by the products exposed to heat, light, oxygen, or рН medium. It is reasonable to enhance the table beet processing technology in order to achieve maximum betanin conservation at lower energy consumption. Materials and methods. Table beets, rhubarbs, lemons, and tomatoes were dried at temperature of 50 to 100 ºС, air speed of 1.5 to 3.5 m/s, heat carrier water content of 7 to 15 g/kg, and layer thickness of 2 to 20 mm. The betanіn content was determined via absorption spectra, using the optical density value at 540 nm wavelength. A differential microcalorimeter was used for measuring evaporation heat consumption. Results and discussion.The effect of raw product pre-drying preparation was studied. With no preliminary preparation, the loss of betanin after drying reaches 66 %. The preliminary preparation technology we have developed includes boiling whole root crops with optimal selection of acid medium and allows us to reduce the betanin loss down to 6 %. Regretfully, the process requires large energy consumption. Low energy consumption pre-drying preparation method was developed for antioxidant raw products with thermal processing replaced by blending. The betanin loss, in this case, does not exceed 5 %. Optimal drying temperature of betanin-containing raw stock, after its preliminary processing, is 60 °С. It allows to keep up to 95 % of betanіn. Specific heat consumption for water evaporation out of the developed table beet based antioxidant plant compositions, with addition of rhubarb and lemon, is less by 4 to 5 % as compared to the initial components. Conclusions. Dependence of betanin loss in plant raw stock on the material temperature and composition components, in the course of their pre-drying preparation, was found. It was also found that water evaporation heat, for some antioxidant plant compositions developed, is less

  12. Clusterin Seals the Ocular Surface Barrier in Mouse Dry Eye.

    Science.gov (United States)

    Bauskar, Aditi; Mack, Wendy J; Mauris, Jerome; Argüeso, Pablo; Heur, Martin; Nagel, Barbara A; Kolar, Grant R; Gleave, Martin E; Nakamura, Takahiro; Kinoshita, Shigeru; Moradian-Oldak, Janet; Panjwani, Noorjahan; Pflugfelder, Stephen C; Wilson, Mark R; Fini, M Elizabeth; Jeong, Shinwu

    2015-01-01

    Dry eye is a common disorder caused by inadequate hydration of the ocular surface that results in disruption of barrier function. The homeostatic protein clusterin (CLU) is prominent at fluid-tissue interfaces throughout the body. CLU levels are reduced at the ocular surface in human inflammatory disorders that manifest as severe dry eye, as well as in a preclinical mouse model for desiccating stress that mimics dry eye. Using this mouse model, we show here that CLU prevents and ameliorates ocular surface barrier disruption by a remarkable sealing mechanism dependent on attainment of a critical all-or-none concentration. When the CLU level drops below the critical all-or-none threshold, the barrier becomes vulnerable to desiccating stress. CLU binds selectively to the ocular surface subjected to desiccating stress in vivo, and in vitro to the galectin LGALS3, a key barrier component. Positioned in this way, CLU not only physically seals the ocular surface barrier, but it also protects the barrier cells and prevents further damage to barrier structure. These findings define a fundamentally new mechanism for ocular surface protection and suggest CLU as a biotherapeutic for dry eye.

  13. Clusterin Seals the Ocular Surface Barrier in Mouse Dry Eye.

    Directory of Open Access Journals (Sweden)

    Aditi Bauskar

    Full Text Available Dry eye is a common disorder caused by inadequate hydration of the ocular surface that results in disruption of barrier function. The homeostatic protein clusterin (CLU is prominent at fluid-tissue interfaces throughout the body. CLU levels are reduced at the ocular surface in human inflammatory disorders that manifest as severe dry eye, as well as in a preclinical mouse model for desiccating stress that mimics dry eye. Using this mouse model, we show here that CLU prevents and ameliorates ocular surface barrier disruption by a remarkable sealing mechanism dependent on attainment of a critical all-or-none concentration. When the CLU level drops below the critical all-or-none threshold, the barrier becomes vulnerable to desiccating stress. CLU binds selectively to the ocular surface subjected to desiccating stress in vivo, and in vitro to the galectin LGALS3, a key barrier component. Positioned in this way, CLU not only physically seals the ocular surface barrier, but it also protects the barrier cells and prevents further damage to barrier structure. These findings define a fundamentally new mechanism for ocular surface protection and suggest CLU as a biotherapeutic for dry eye.

  14. Influence of Ear Surface Area on Heat Tolerance of Composite ...

    African Journals Online (AJOL)

    Relative importance of ear surface area on heat tolerance of composite rabbit population was evaluated. The study was conducted during the dry and rainy seasons, climatic data were recorded to obtain categorical heat stress index. Physiological parameters, growth performance, ear length and ear width of the rabbits ...

  15. Pluto's surface composition and atmosphere

    Science.gov (United States)

    Young, L. A.; Gladstone, R.; Summers, M. E.; Strobel, D. F.; Kammer, J.; Hinson, D. P.; Grundy, W. M.; Cruikshank, D. P.; Protopapa, S.; Schmitt, B.; Stern, A.; Weaver, H. A., Jr.; Olkin, C.; Ennico Smith, K.

    2017-12-01

    New Horizons studied Pluto's N2-dominated neutral atmosphere through radio (at 4.2 cm with the REX radio experiment), solar and stellar occultations and airglow (at 52-187 nm with the Alice ultraviolet spectrograph), and imaging (with the LORRI and MVIC visible-wavelength cameras). It studied the plasma environment and solar wind interaction with in situ instruments (PEPPSI and SWAP). Contemporaneous observations of Pluto's atmosphere from Earth included a ground-based stellar occultation and ALMA observations of gaseous CO and HCN. Joint analysis of these datasets reveal a variable boundary layer; a stable lower atmosphere; radiative heating and cooling; haze production and hydrocarbon chemistry; diffusive equilibrium; and slower-than-expected escape. New Horizons studied Pluto's surface composition with the LEISA near-infrared spectral imager from 1.25 to 2.5 micron. Additional compositional information at higher spatial resolution came from the MVIC 4-channel color imager, which included a channel centered at 0.89 micron specifically designed to detect solid CH4. These instruments allow mapping of the volatiles N2, CO, and CH4, the surface expression of the H2O bedrock, and the dark, reddish material presumed to be tholins. These observations reveal a large equatorial basin (informally named Sptunik Planitia), filled with N2 ice with minor amounts of CO and CH4, surrounded by hills of CH4 and H2O ice. Broadly speaking, composition outside of Sptunik Planitia follows latitudinal banding, with dark, mainly volatile free terrains near the equator, with N2, CO, and CH4 at mid-northern latitudes, and mainly CH4 at high northern latitudes. Deviations from these broad trends are seen, and point to complex surface-atmosphere interactions at diurnal, seasonal, perennial, and million-year timescales.

  16. Surface characteristics analysis of dry EDMed AISI D2 steel using modified tool design

    Energy Technology Data Exchange (ETDEWEB)

    Pragadish, N.; Kumar, M. Pradeep [Anna University, Chennai (China)

    2015-04-15

    A modified tool design is proposed which helps in drilling holes without any central core, and also enables the effective removal of the debris particles. Experiments were conducted on AISI D2 Steel using copper electrode as tool in both conventional EDM and dry EDM processes and the performance of both processes is compared. Experiments were designed using Taguchi's L27 orthogonal array. Discharge current (I), gap voltage (V), pulse on time (T{sub ON}), gas pressure (P) and tool rotational speed (N) were chosen as the various input parameters, and their effect on the material removal rate (MRR), surface roughness (SR), surface morphology, microstructure and elemental composition of the machined surface is analyzed. The experimental results show better surface characteristics in the surface machined under dry EDM process.

  17. Surface characteristics analysis of dry EDMed AISI D2 steel using modified tool design

    International Nuclear Information System (INIS)

    Pragadish, N.; Kumar, M. Pradeep

    2015-01-01

    A modified tool design is proposed which helps in drilling holes without any central core, and also enables the effective removal of the debris particles. Experiments were conducted on AISI D2 Steel using copper electrode as tool in both conventional EDM and dry EDM processes and the performance of both processes is compared. Experiments were designed using Taguchi's L27 orthogonal array. Discharge current (I), gap voltage (V), pulse on time (T ON ), gas pressure (P) and tool rotational speed (N) were chosen as the various input parameters, and their effect on the material removal rate (MRR), surface roughness (SR), surface morphology, microstructure and elemental composition of the machined surface is analyzed. The experimental results show better surface characteristics in the surface machined under dry EDM process.

  18. A new dry-surface biofilm model: An essential tool for efficacy testing of hospital surface decontamination procedures.

    Science.gov (United States)

    Almatroudi, Ahmad; Hu, Honghua; Deva, Anand; Gosbell, Iain B; Jacombs, Anita; Jensen, Slade O; Whiteley, Greg; Glasbey, Trevor; Vickery, Karen

    2015-10-01

    The environment has been shown to be a source of pathogens causing infections in hospitalised patients. Incorporation of pathogens into biofilms, contaminating dry hospital surfaces, prolongs their survival and renders them tolerant to normal hospital cleaning and disinfection procedures. Currently there is no standard method for testing efficacy of detergents and disinfectants against biofilm formed on dry surfaces. The aim of this study was to develop a reproducible method of producing Staphylococcus aureus biofilm with properties similar to those of biofilm obtained from dry hospital clinical surfaces, for use in efficacy testing of decontamination products. The properties (composition, architecture) of model biofilm and biofilm obtained from clinical dry surfaces within an intensive care unit were compared. The CDC Biofilm Reactor was adapted to create a dry surface biofilm model. S. aureus ATCC 25923 was grown on polycarbonate coupons. Alternating cycles of dehydration and hydration in tryptone soy broth (TSB) were performed over 12 days. Number of biofilm bacteria attached to individual coupons was determined by plate culture and the coefficient of variation (CV%) calculated. The DNA, glycoconjugates and protein content of the biofilm were determined by analysing biofilm stained with SYTO 60, Alexa-488-labelled Aleuria aurantia lectin and SyproOrange respectively using Image J and Imaris software. Biofilm architecture was analysed using live/dead staining and confocal microscopy (CM) and scanning electron microscopy (SEM). Model biofilm was compared to naturally formed biofilm containing S. aureus on dry clinical surfaces. The CDC Biofilm reactor reproducibly formed a multi-layered, biofilm containing about 10(7) CFU/coupon embedded in thick extracellular polymeric substances. Within run CV was 9.5% and the between run CV was 10.1%. Protein was the principal component of both the in vitro model biofilm and the biofilms found on clinical surfaces. Continued

  19. Tribological Investigation of SiC/Al Composite under Dry Sliding Friction

    Directory of Open Access Journals (Sweden)

    DAI Liquan

    2016-12-01

    Full Text Available The effect of sliding distances on aluminum matrix composite reinforced by silicon carbide particle with volume fraction of 9% was investigated. Friction behavior and wear resistance of the composite with distances of 5000 r, 10000 r and 20000 r were studied under dry sliding conditions of the same speed and load(200 r/min, 45 N. The results show that the friction coefficient in long-range sliding process displays three stages:wearing zone, stable zone and accelerating zone. The matrix surface produces severe adhesion because of the rising temperature and then leads plastic areas, in which both friction coefficient and wear rate are increased.

  20. Nanoparticle motion on the surface of drying droplets

    Science.gov (United States)

    Zhao, Mingfei; Yong, Xin

    2018-03-01

    Advances in solution-based printing and surface patterning techniques for additive manufacturing demand a clear understanding of particle dynamics in drying colloidal droplets and its relationship with deposit structure. Although the evaporation-driven deposition has been studied thoroughly for the particles dispersed in the bulk of the droplet, few investigations have focused on the particles strongly adsorbed to the droplet surface. We modeled the assembly and deposition of the surface-active particles in a drying sessile droplet with a pinned contact line by the multiphase lattice Boltzmann-Brownian dynamics method. The particle trajectory and its area density profile characterize the assembly dynamics and deposition pattern development during evaporation. While the bulk-dispersed particles continuously move to the contact line, forming the typical "coffee-ring" deposit, the interface-bound particles migrate first toward the apex and then to the contact line as the droplet dries out. To understand this unexpected behavior, we resolve the droplet velocity field both in the bulk and within the interfacial region. The simulation results agree well with the analytical solution for the Stokes flow inside an evaporating droplet. At different stages of evaporation, our study reveals that the competition between the tangential surface flow and the downward motion of the evaporating liquid-vapor interface governs the dynamics of the interface-bound particles. In particular, the interface displacement contributes to the particle motion toward the droplet apex in a short phase, while the outward advective flow prevails at the late stage of drying and carries the particles to the contact line. The final deposit of the surface-adsorbed particles exhibits a density enhancement at the center, in addition to a coffee ring. Despite its small influence on the final deposit in the present study, the distinct dynamics of surface-active particles due to the interfacial confinement

  1. Organic composition in the dry season rainwater of Guangzhou, China.

    Science.gov (United States)

    Xu, Tao; Song, Zhiguang; Liu, Junfeng; Wang, Cuiping; Wei, Jianrong; Chen, Heng

    2008-02-01

    This paper reports the results from a study of the organic composition of rainwater collected at Tianhe district of Guangzhou city, P.R. China, during the dry season. Several special setups of a pyrex bottle with a glass funnel were used for the collection of the rainwater. Three fractions (aliphatics, PAHs and fatty acids) were separated from the total extracted organic compounds and identified with GC-MS. The molecular diagnostic ratios were utilized for the source reconciliation. The aliphatic hydrocarbon and the biomarkers (triterpanes and steranes) distribution show a characteristic of the petrochemical source in the rainwater samples. The PAHs diagnostic ratios [e.g. MP/P, MPI, Fl/ (Fl + Py)] indicated vehicular emissions. The fatty acids ratios (e.g. C(18:1)/C(18:0) and C(18:2)/C(18:0)) reflect the contribution of cooking emissions, while the higher plant waxes play little part. Moreover, the values of MP/P, MPI, BaA/(BaA + CT) and BeP/(BeP + BaP) reflected the origin of the long-distance transportation to some extent. On the whole, for the dry season rainwater, all molecular diagnostic ratios indicated the complexity of the organic composition of the rain, which have the characteristics of both a local emission contribution and a long-distance transportation contribution.

  2. Tensile bond strength of hydroxyethyl methacrylate dentin bonding agent on dentin surface at various drying techniques

    Directory of Open Access Journals (Sweden)

    Kun Ismiyatin

    2010-06-01

    Full Text Available Background: There are several dentin surface drying techniques to provide a perfect resin penetration on dentin. There are two techniques which will be compared in this study. The first technique was by rubbing dentin surface gently using cotton pellet twice, this technique is called blot dry technique. The second technique is by air blowing dentin surface for one second and continued by rubbing dentin surface gently using moist cotton. Purpose: This experiment was aimed to examine the best dentin surface drying techniques after 37% phosphoric acid etching to obtain the optimum tensile bond strength between hydroxyethyl methacrylate (HEMA and dentin surface. Method: Bovine teeth was prepared flat to obtain the dentin surface and than was etched using 37% phosphoric acid for 15 seconds. After etching the dentin was cleaned using 20 cc plain water and dried with blot dry techniques (group I, or dried with air blow for one second (group II, or dried with air blow for one second, and continued with rubbing gently using moist cotton pellet (group III, and without any drying as control group (group IV. After these drying, the dentin surfaces were applied with resin dentin bonding agent and put into plunger facing the composite mould. The antagonist plunger was filled with composite resin. After 24 hours, therefore bond strength was measured using Autograph. Result: Data obtained was analyzed using One-Way ANOVA with 95% confidence level and continued with LSD test on p≤0.05. The result showed that the highest tensile bond strength was on group I, while the lowest on group IV. Group II and IV, III and IV, II and III did not show signigicant difference (p>0.05. Conclusion: Dentin surface drying techniques through gentle rubbing using cotton pellet twice (blot dry technique gave the greatest tensile bond strength.Latar belakang masalah: Tehnik pengeringan permukaan dentin agar resin dapat penetrasi dengan sempurna adalah dengan cara pengusapan secara

  3. Particle dry deposition to water surfaces: Processes and consequences

    DEFF Research Database (Denmark)

    Pryor, S.C.; Barthelmie, R.J.

    2000-01-01

    flux to coastal waters, atmosphere-surface exchange represents a significant component of the total flux and may be particularly critical during the summertime when both the riverine input and ambient nutrient concentrations are often at a minimum. In this chapter, we present an overview...... of the physical and chemical processes which dictate the quantity (and direction) of atmosphere-surface fluxes of trace chemicals to (and above) water surfaces with particular emphasis on the role of particles. Dry deposition (transfer to the surface in the absence of precipitation) of particles is determined...... efforts to simulate and measure fluxes close to the coastline. These arise in part from the complexity of atmospheric flow in this region where energy and chemical fluxes are highly inhomogeneous in space and time and thermally generated atmospheric circulations are commonplace. (C) 2000 Elsevier Science...

  4. Influence of drying method on the surface energy of cellulose nanofibrils determined by inverse gas chromatography

    Science.gov (United States)

    Yucheng Peng; Douglas J. Gardner; Yousoo Han; Zhiyong Cai; Mandla A. Tshabalala

    2013-01-01

    Research and development of the renewable nanomaterial cellulose nanofibrils (CNFs) has received considerable attention. The effect of drying on the surface energy of CNFs was investigated. Samples of nanofibrillated cellulose (NFC) and cellulose nanocrystals (CNC) were each subjected to four separate drying methods: air-drying, freeze-drying, spray-drying, and...

  5. Enhancement of convective drying by application of airborne ultrasound - a response surface approach.

    Science.gov (United States)

    Beck, Svenja M; Sabarez, Henry; Gaukel, Volker; Knoerzer, Kai

    2014-11-01

    Drying is one of the oldest and most commonly used processes in the food manufacturing industry. The conventional way of drying is by forced convection at elevated temperatures. However, this process step often requires a very long treatment time, is highly energy consuming and detrimental to the product quality. Therefore, an investigation of whether the drying time and temperature can be reduced with the assistance of an airborne ultrasound intervention is of interest. Previous studies have shown that contact ultrasound can accelerate the drying process. It is assumed that mechanical vibrations, creating micro channels in the food matrix or keeping these channels from collapsing upon drying, are responsible for the faster water removal. In food samples, due to their natural origin, drying is also influenced by fluctuations in tissue structure, varying between different trials. For this reason, a model food system with thermo-physical properties and composition (water, cellulose, starch, fructose) similar to those of plant-based foods has been used in this study. The main objective was, therefore, to investigate the influence of airborne ultrasound conditions on the drying behaviour of the model food. The impact of airborne ultrasound at various power levels, drying temperature, relative humidity of the drying air, and the air speed was analysed. To examine possible interactions between these parameters, the experiments were designed with a Response Surface Method using Minitab 16 Statistical Software (Minitab Inc., State College, PA, USA). In addition, a first attempt at improving the process conditions and performance for better suitability and applicability in industrial scale processing was undertaken by non-continuous/intermittent sonication. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Surface fixation of dried blood by glutaraldehyde and peracetic acid.

    Science.gov (United States)

    Kampf, G; Bloss, R; Martiny, H

    2004-06-01

    The difficulties of successful prion inactivation by chemical agents has led to changes in recommendations regarding the reprocessing of instruments including flexible endoscopes. One of the changes is the preference for peracetic acid instead of glutaraldehyde in order to avoid fixation of organic material, but the surface fixation by various active agents has not been fully investigated. We used a standardized amount of dried blood soil on metal carriers (on average 22 mg). One part of the carriers was exposed to different disinfectants (four based on peracetic acid, three based on glutaraldehyde, two based on quaternary ammonium compounds (QAC), one based on QAC and amines, one based on phenols and one cleaning agent) and air dried. The difference compared with the non-exposed soiled carrier was taken as the measure of blood removal by exposure to the disinfectants. In addition the other part of the carriers was exposed to a cleaning agent and air dried. The cleaning agent itself was capable of removing more than 99% of the dried blood and served as a control for non-fixation. The rate of fixation of dried blood was calculated as the ratio of the weight of residual soil on 'soiled, disinfected and cleaned' carriers and on 'soiled and disinfected' carriers. All experiments were repeated eight times. Blood removal varied between 90.3% +/- 1.5% (phenol-based disinfectant) and peracetic acid. No other preparations showed a potential for blood fixation (peracetic acid, and support the evidence that effective cleaning should precede the chemical disinfection. Copyright 2004 The Hospital Infection Society

  7. Modeling seasonal surface temperature variations in secondary tropical dry forests

    Science.gov (United States)

    Cao, Sen; Sanchez-Azofeifa, Arturo

    2017-10-01

    Secondary tropical dry forests (TDFs) provide important ecosystem services such as carbon sequestration, biodiversity conservation, and nutrient cycle regulation. However, their biogeophysical processes at the canopy-atmosphere interface remain unknown, limiting our understanding of how this endangered ecosystem influences, and responds to the ongoing global warming. To facilitate future development of conservation policies, this study characterized the seasonal land surface temperature (LST) behavior of three successional stages (early, intermediate, and late) of a TDF, at the Santa Rosa National Park (SRNP), Costa Rica. A total of 38 Landsat-8 Thermal Infrared Sensor (TIRS) data and the Surface Reflectance (SR) product were utilized to model LST time series from July 2013 to July 2016 using a radiative transfer equation (RTE) algorithm. We further related the LST time series to seven vegetation indices which reflect different properties of TDFs, and soil moisture data obtained from a Wireless Sensor Network (WSN). Results showed that the LST in the dry season was 15-20 K higher than in the wet season at SRNP. We found that the early successional stages were about 6-8 K warmer than the intermediate successional stages and were 9-10 K warmer than the late successional stages in the middle of the dry season; meanwhile, a minimum LST difference (0-1 K) was observed at the end of the wet season. Leaf phenology and canopy architecture explained most LST variations in both dry and wet seasons. However, our analysis revealed that it is precipitation that ultimately determines the LST variations through both biogeochemical (leaf phenology) and biogeophysical processes (evapotranspiration) of the plants. Results of this study could help physiological modeling studies in secondary TDFs.

  8. Facile Dry Surface Cleaning of Graphene by UV Treatment

    Science.gov (United States)

    Kim, Jin Hong; Haidari, Mohd Musaib; Choi, Jin Sik; Kim, Hakseong; Yu, Young-Jun; Park, Jonghyurk

    2018-05-01

    Graphene has been considered an ideal material for application in transparent lightweight wearable electronics due to its extraordinary mechanical, optical, and electrical properties originating from its ordered hexagonal carbon atomic lattice in a layer. Precise surface control is critical in maximizing its performance in electronic applications. Graphene grown by chemical vapor deposition is widely used but it produces polymeric residue following wet/chemical transfer process, which strongly affects its intrinsic electrical properties and limits the doping efficiency by adsorption. Here, we introduce a facile dry-cleaning method based on UV irradiation to eliminate the organic residues even after device fabrication. Through surface topography, Raman analysis, and electrical transport measurement characteristics, we confirm that the optimized UV treatment can recover the clean graphene surface and improve graphene-FET performance more effectively than thermal treatment. We propose our UV irradiation method as a systematically controllable and damage-free post process for application in large-area devices.

  9. Tribological behaviors of UHMWPE composites with different counter surface morphologies

    Science.gov (United States)

    Wang, Yanzhen; Yin, Zhongwei; Li, Hulin; Gao, Gengyuan

    2017-12-01

    The influence of counter surface morphologies on hybrid glass fiber (GF) and carbon fiber (CF) filled ultrahigh molecular weight polyethylene (UHMWPE) were studied under various contact pressure and sliding speed against GCr15 steel in dry condition. The goals were to investigate the tribological behavior of GF/CF/UHMWPE composite as a kind of water lubricated journal bearing material. The friction and wear behavior of composites were examined using a pin-on-disc tribometer. The morphologies of the worn surface were examined by scanning electron microscopy (SEM) and laser 3D micro-imaging and profile measurement. Generally, the wear rate and friction coefficient of composites increase as the increment of counter surface roughness. The friction coefficient increases firstly and then decrease with an increase in sliding speed and contact pressure for counterface with Ra=0.2 and 3.5 μm, while the friction coefficient decreased for counterface with Ra=0.6 μm.

  10. A mechanical model for surface layer formation on self-lubricating ceramic composites

    NARCIS (Netherlands)

    Song, Jiupeng; Valefi, Mahdiar; de Rooij, Matthias B.; Schipper, Dirk J.

    2010-01-01

    To predict the thickness of a self-lubricating layer on the contact surface of ceramic composite material containing a soft phase during dry sliding test, a mechanical model was built to calculate the material transfer of the soft second phase in the composite to the surface. The tribological test,

  11. Composite shear bond strength to dry and wet enamel with three self-etch adhesives

    Directory of Open Access Journals (Sweden)

    Shafiee F

    2006-01-01

    Full Text Available Background and Aim: The bonding mechanisms of self etching primers, based upon the simultaneous etching and priming of dentin, simplifies the bonding technique, but the efficiency of these systems is still controversial. This study compared the shear bond strength of three self etch adhesive systems in dry and wet conditions. Materials and Method: In this experimental study, 77 intact bovine lower incisors with flat 600 grit sanded enamel surface were fixed in acrylic molds and divided into 7 groups, of 11 teeth. The enamel surfaces were treated according to a special procedure as follows: Group 1: Prompt L-Pop (PLP in dry condition, Group 2: Prompt L-Pop in wet condition, Group 3: Clearfield SE Bond (CSEB in dry condition, Group 4: Clearfield SE Bond in wet condition, Group 5: iBond (iB in dry condition, Group 6: iBond in wet condition, Group 7: Margin Bond (Control in dry condition. Surfaces were air dried for ten seconds, or blot dried in wet condition. Composite resin was bonded on the enamel and built up by applying a cylindric teflon split mold (4 mm height 2mm diameter. After 24 hours storage in dionized water at room temperature, all specimens were thermocycled and shear bond test was employed by a universal testing machine (Instron with a cross-head speed of 1mm/min. The shear bond strength was recorded in MPa and data were analyzed with ANOVA and Scheffe statistical tests. P<0.05 was considered as statistically significant. The mode of failure was examined under a stereomicroscope. Results: 1- Shear bond strength of CSEB in dry condition (21.5 ± 4.8 MPa was significantly higher than PLP and iB groups (p<0.0001. 2- Shear bond strength of iB and PLP groups in dry condition (9.60 ± 2.2, 9.49 ± 3 MPa were significantly lower than CSEB and control (2.99 ± 5.1 MPa (P<0.0001. 3- There was no significant difference between PLP and iB groups in dry condition (P=1. 4- Shear bond strength of CSEB in wet condition (21.8 ± 3 MPa was

  12. Fretting and wear behaviors of Ni/nano-WC composite coatings in dry and wet conditions

    International Nuclear Information System (INIS)

    Benea, Lidia; Başa, Sorin-Bogdan; Dănăilă, Eliza; Caron, Nadège; Raquet, Olivier; Ponthiaux, Pierre; Celis, Jean-Pierre

    2015-01-01

    Highlights: • The friction and wear properties of Ni/nano-WC composite were studied. • Nano-WC reinforcement decreased friction coefficient in dry and wet conditions. • Nano-WC reinforcement fraction was seen to be 12 wt.%. • Nanohardness increased by 27% compared to nickel without WC reinforcements. • Ennoblement of OCP corresponding to the Ni/nano-WC composite coating. - Abstract: The fretting and wear behaviors of Ni/nano-WC composite coatings were studied by considering the effect of fretting frequency of 1 Hz during 10,000 cycles, at different applied loads in dry or wet conditions. The studies were performed on a ball-on-disk tribometer and the results were compared with pure Ni coating. The nanohardness of pure Ni and Ni/nano-WC composite coatings was tested by nanoindentation technique. To evaluate the wet wear (tribocorrosion) behavior the open circuit potential (OCP) was measured before, during and after the fretting tests at room temperature in the solution that simulates the primary water circuit of Pressurized Water Reactors (PWRs). The results show that Ni/nano-WC composite coatings exhibited a low friction coefficient, high nanohardness and wear resistance compared with pure Ni coatings under similar experimental conditions. Ni/nano-WC composite coatings were obtained on stainless steel support by electrochemical codeposition of nano-sized WC particles (diameter size of ∼60 nm) with nickel, from a standard nickel Watts plating bath. The surface morphology and the composition of the coatings were characterized by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX) respectively

  13. Tribological behavior of the carbon fiber reinforced polyphenylene sulfide (PPS) composite coating under dry sliding and water lubrication

    International Nuclear Information System (INIS)

    Xu Haiyan; Feng Zhizhong; Chen Jianmin; Zhou Huidi

    2006-01-01

    Carbon fiber reinforced polyphenylene sulphide (PPS) composite coatings (the mass fraction of the carbon fiber varied from 1 to 5 wt%) were prepared by flame spraying. The microstructure and physical properties of the composite coating were studied. The friction and wear characteristics of the PPS coating and carbon fiber reinforced PPS composite coating under dry- and water-lubricated sliding against stainless steel were comparatively investigated using a block-ring tester. The composite coatings showed lower friction coefficient and higher wear rate than pure PPS coatings under dry sliding. Under water-lubricated condition, the composite coatings showed better wear resistance than under dry. Under water-lubricated condition the tribological behaviors of the 3 wt% carbon fiber reinforced composite coating also were investigated under different sliding speed and load. The result showed that the sliding speed had little effect on the tribological properties, but the load affected greatly on that of the composite coatings. The morphologies of the worn surfaces of the composite coatings and the counterpart steel were analyzed by means of scanning electron microscopy (SEM), coupled with an energy-dispersive X-ray spectrometer (EDS) for compositional analysis

  14. Effect of drying methods on the chemical composition of three ...

    African Journals Online (AJOL)

    Three methods of drying (oven, sun and smoke) were used to dry Bonga spp., Sardinella spp. and Heterotis niloticus. The physico-chemical and minerals contents of the sample were determined using standard methods. Oven dried H. niloticus recorded the highest (16.42%) moisture content while the least moisture content ...

  15. Dry deposition on smooth and rough urban surfaces

    International Nuclear Information System (INIS)

    Roed, J.

    1987-01-01

    Following the Chernobyl accident, dry deposition velocities on smooth surfaces indoors and outdoors have been measured in Denmark. Internal wall surfaces gave deposition velocities of 0.0008-0.0009 cm/s for 131I and 0.0001-0.0002 cm/s for 134Cs and 103Ru. Internal floor surfaces gave higher values for the deposition velocities: for 131I, 0.002 cm/s and for 134Cs and 103Ru, 0.0005-0.0013 cm/s. The deposition velocities on vertical and horizontal external surfaces were nearly equal. Those for 131I were found as 0.02-0.03 cm/s and for 137Cs as 0.001-0.002 cm/s. On external rough surfaces such as grass and corrugated roof material the deposition velocities for 134Cs and 103Ru were 0.03-0.05 cm/s. For iodine, however, deposition velocities were higher for clipped grass (2 cm/s) than for roof material (0.2-0.4 cm/s). The results show that internal deposition velocities are considerably lower than those on external smooth surfaces, and that the deposition velocities on rough surfaces are an order of magnitude higher than on smooth surfaces. It was also shown that the deposition velocities of iodine are considerably higher than those of cesium and ruthenium. This work was supported by EEC Radiation Protection Programme No B16-107-DK and by NKA, The Nordic Liaison Committee for Atomic Energy. (author)

  16. Adhesive Wear Performance of CFRP Multilayered Polyester Composites Under Dry/wet Contact Conditions

    Science.gov (United States)

    Danaelan, D.; Yousif, B. F.

    The tribo-performance of a new engineering composite material based on coconut fibers was investigated. In this work, coconut fibers reinforced polyester (CFRP) composites were developed. The tribo-experiments were conducted by using pin-on-disc machine under dry and wet sliding contact condition against smooth stainless steel counterface. Worn surfaces were observed using optical microscope. Friction coefficient and specific wear rate were presented as a function of sliding distance (0-0.6 km) at different sliding velocities (0.1-0.28 m/s). The effect of applied load and sliding velocity was evaluated. The results showed that all test parameters have significant influence on friction and wear characteristics of the composites. Moreover, friction coefficient increased as the normal load and speed increased, the values were about 0.7-0.9 under dry contact condition. Meanwhile, under wet contact condition, there was a great reduction in the friction coefficient, i.e. the values were about 0.1-0.2. Furthermore, the specific wear rates were found to be around 2-4 (10-3) mm3/Nm under dry contact condition and highly reduced under wet condition. In other words, the presence of water as cleaner and polisher assisted to enhance the adhesive wear performance of CFRP by about 10%. The images from optical microscope showed evidence of adhesive wear mode with transition to abrasive wear mode at higher sliding velocities due to third body abrasion. On the other hand, optical images for wet condition showed less adhesive wear and smooth surfaces.

  17. Effect of bagasse ash reinforcement on dry sliding wear behaviour of polymer matrix composites

    International Nuclear Information System (INIS)

    Aigbodion, V.S.; Hassan, S.B.; Agunsoye, J.O.

    2012-01-01

    Highlights: → The influence of wear parameters on the wear rate of RLDPE were investigated. → The predicted wear rate of the RLDPE and it composites were found to lie close to that experimentally observed ones. → The results showed that the addition of bagasse ash as filler materials in RLDPE composites increase the wear resistance. -- Abstract: The tribological behaviour of recycled low density polyethylene (RLDPE) polymer composites with bagasse ash particles as a reinforcement was studied using a pin-on-disc wear rig under dry sliding conditions. The influence of wear parameters like, applied load, sliding speed, sliding distance and percentage of bagasse ash fillers, on the wear rate were investigated. A plan of experiments was performed to acquire data in a controlled way. Scanning electron microscope was used to analyse the worn surface of the samples. Linear regression equation and analysis of variance (ANOVA) were employed to investigate the influence of process parameters on the wear rate of the samples. The predicted wear rate of the RLDPE and it composites were found to lie close to that experimentally observed ones. The confirmation of the experiments conducted using ANOVA to verify the optimal testing parameters show that sliding speed and applied load had significant effect on the wear rate. The results showed that the addition of bagasse ash as filler materials in RLDPE composites increase the wear resistance of the composite greatly.

  18. Multimodal imaging of ocular surface of dry eye subjects

    Science.gov (United States)

    Zhang, Aizhong; Salahura, Gheorghe; Kottaiyan, Ranjini; Yoon, Geunyoung; Aquavella, James V.; Zavislan, James M.

    2016-03-01

    To study the relationship between the corneal lipid layer and the ocular surface temperature (OST), we conducted a clinical trial for 20 subjects. Subjects were clinically screened prior to the trial. Of the 20 subjects, 15 have Meibomian gland dysfunction (MGD), and 5 have aqueous-deficient dry eye (ADDE). A custom, circularly polarized illumination video tearscope measured the lipid layer thickness of the ocular tear film. A long-wave infrared video camera recorded the dynamic thermal properties of the ocular team film. The results of these two methods were analyzed and compared. Using principal component analysis (PCA) of the lipid layer distribution, we find that the 20 subjects could be categorized into five statistically significant groups, independent of their original clinical classification: thin (6 subjects), medium (5 subjects), medium and homogenous (3 subjects), thick (4 subjects), and very thick (2 subjects) lipids, respectively. We also conducted PCA of the OST data, and recategorized the subjects into two thermal groups by k-means clustering: one includes all ADDE subjects and some MGD subjects; the other includes the remaining MGD subjects. By comparing these two methods, we find that dry eye subjects with thin ( 40 nm), there is no strong correlation between the lipid layer thickness and heterogeneity and the OST patterns.

  19. Stretchable, Adhesion-Tunable Dry Adhesive by Surface Wrinkling

    KAUST Repository

    Jeong, Hoon Eui

    2010-02-16

    We introduce a simple yet robust method of fabricating a stretchable, adhesion-tunable dry adhesive by combining replica molding and surface wrinkling. By utilizing a thin, wrinkled polydimethyl siloxane (PDMS) sheet with a thickness of 1 mm with built-in micropillars, active, dynamic control of normal and shear adhesion was achieved. Relatively strong normal (∼10.8 N/cm2) and shear adhesion (∼14.7 N/cm2) forces could be obtained for a fully extended (strained) PDMS sheet (prestrain of∼3%), whereas the forces could be rapidly reduced to nearly zero once the prestrain was released (prestrain of ∼0.5%). Moreover, durability tests demonstrated that the adhesion strength in both the normal and shear directions was maintained over more than 100 cycles of attachment and detachment. © 2010 American Chemical Society.

  20. Stretchable, Adhesion-Tunable Dry Adhesive by Surface Wrinkling

    KAUST Repository

    Jeong, Hoon Eui; Kwak, Moon Kyu; Suh, Kahp Y.

    2010-01-01

    We introduce a simple yet robust method of fabricating a stretchable, adhesion-tunable dry adhesive by combining replica molding and surface wrinkling. By utilizing a thin, wrinkled polydimethyl siloxane (PDMS) sheet with a thickness of 1 mm with built-in micropillars, active, dynamic control of normal and shear adhesion was achieved. Relatively strong normal (∼10.8 N/cm2) and shear adhesion (∼14.7 N/cm2) forces could be obtained for a fully extended (strained) PDMS sheet (prestrain of∼3%), whereas the forces could be rapidly reduced to nearly zero once the prestrain was released (prestrain of ∼0.5%). Moreover, durability tests demonstrated that the adhesion strength in both the normal and shear directions was maintained over more than 100 cycles of attachment and detachment. © 2010 American Chemical Society.

  1. The effect of drying on the nutritional composition of fresh and dried ...

    African Journals Online (AJOL)

    A study was carried out to identify some nutritional properties of Moringa Oeifera leaf and to compare the nutritional qualities of fresh and dried leaves of Moringa Oleifera.Two samples each of fresh and dried Moringa Oeifera leaves were used for the experiment and the mean values in their nutritional qualities compared.

  2. Ambient pressure dried tetrapropoxysilane-based silica aerogels with high specific surface area

    Science.gov (United States)

    Parale, Vinayak G.; Han, Wooje; Jung, Hae-Noo-Ree; Lee, Kyu-Yeon; Park, Hyung-Ho

    2018-01-01

    In the present paper, we report the synthesis of tetrapropoxysilane (TPOS)-based silica aerogels with high surface area and large pore volume. The silica aerogels were prepared by a two-step sol-gel process followed by surface modification via a simple ambient pressure drying approach. In order to minimize drying shrinkage and obtain hydrophobic aerogels, the surface of the alcogels was modified using trichloromethylsilane as a silylating agent. The effect of the sol-gel compositional parameters on the polymerization of aerogels prepared by TPOS, one of the precursors belonging to the Si(OR)4 family, was reported for the first time. The oxalic acid and NH4OH concentrations were adjusted to achieve good-quality aerogels with high surface area, low density, and high transparency. Controlling the hydrolysis and condensation reactions of the TPOS precursor turned out to be the most important factor to determine the pore characteristics of the aerogel. Highly transparent aerogels with high specific surface area (938 m2/g) and low density (0.047 g/cm3) could be obtained using an optimized TPOS/MeOH molar ratio with appropriate concentrations of oxalic acid and NH4OH.

  3. Management of Surface Drying Temperature to Increase Antioxidant Capacity of Thyme Leaf Extracts (Thymus vulgaris L.)

    OpenAIRE

    RODRIGUEZ CORTINA, JADER; Melo, E.C.; Mulet Pons, Antonio; Bon Corbín, José

    2014-01-01

    [EN] Thyme leaves are an important source of essential oils with antioxidant activity; these compounds are located in trichomes on the leaf surface. The drying conditions affect not only the drying time but also the antioxidant activity. In the literature, a drying temperature of 70 ºC appears to be the best for drying thyme leaves according to their antioxidant capacity. Considering drying periods at different temperature also could be quality beneficial. From these considerations, the goal ...

  4. Hybrid response surface methodology-artificial neural network optimization of drying process of banana slices in a forced convective dryer.

    Science.gov (United States)

    Taheri-Garavand, Amin; Karimi, Fatemeh; Karimi, Mahmoud; Lotfi, Valiullah; Khoobbakht, Golmohammad

    2018-06-01

    The aim of the study is to fit models for predicting surfaces using the response surface methodology and the artificial neural network to optimize for obtaining the maximum acceptability using desirability functions methodology in a hot air drying process of banana slices. The drying air temperature, air velocity, and drying time were chosen as independent factors and moisture content, drying rate, energy efficiency, and exergy efficiency were dependent variables or responses in the mentioned drying process. A rotatable central composite design as an adequate method was used to develop models for the responses in the response surface methodology. Moreover, isoresponse contour plots were useful to predict the results by performing only a limited set of experiments. The optimum operating conditions obtained from the artificial neural network models were moisture content 0.14 g/g, drying rate 1.03 g water/g h, energy efficiency 0.61, and exergy efficiency 0.91, when the air temperature, air velocity, and drying time values were equal to -0.42 (74.2 ℃), 1.00 (1.50 m/s), and -0.17 (2.50 h) in the coded units, respectively.

  5. Dry sliding wear behavior of heat treated hybrid metal matrix composite using Taguchi techniques

    International Nuclear Information System (INIS)

    Kiran, T.S.; Prasanna Kumar, M.; Basavarajappa, S.; Viswanatha, B.M.

    2014-01-01

    Highlights: • ZA-27 alloy is used as matrix material and reinforced with SiC and Gr particles. • Heat treatment was carried out for all specimen. • Dry sliding wear test was done on pin-on-disc apparatus by Taguchi technique. • ZA-27/9SiC–3Gr showed superior wear resistance over the base alloy. • Ceramic mixed mechanical layer on contact surface of composite was formed. - Abstract: Dry sliding wear behavior of zinc based alloy and composite reinforced with SiCp (9 wt%) and Gr (3 wt%) fabricated by stir casting method was investigated. Heat treatment (HT) and aging of the specimen were carried out, followed by water quenching. Wear behavior was evaluated using pin on disc apparatus. Taguchi technique was used to estimate the parameters affecting the wear significantly. The effect of HT was that it reduced the microcracks, residual stresses and improved the distribution of microconstituents. The influence of various parameters like applied load, sliding speed and sliding distance on wear behavior was investigated by means and analysis of variance (ANOVA). Further, correlation between the parameters was determined by multiple linear regression equation for each response. It was observed that the applied load significantly influenced the wear volume loss (WVL), followed by sliding speed implying that increase in either applied load or sliding speed increases the WVL. Whereas for composites, sliding distance showed a negative influence on wear indicating that increase in sliding distance reduces WVL due to the presence of reinforcements. The wear mechanism of the worn out specimen was analyzed using scanning electron microscopy. The analysis shows that the formation and retention of ceramic mixed mechanical layer (CMML) plays a major role in the dry sliding wear resistance

  6. Surface composition and surface properties of water hyacinth ...

    African Journals Online (AJOL)

    Surface composition and surface properties of water hyacinth ( Eichhornia ... (2/1, v/v) followed by ethanol, using Fourier Transform Infra-red (FT-IR) spectroscopy, ... polar organic solvents and non-polar n-alkane hydrocarbons is discussed.

  7. Visualizing Composite Data on the Lexis Surface

    DEFF Research Database (Denmark)

    Schöley, Jonas; Willekens, Frans

    The analysis of composite data is a topic inherent to demography. In recent times, due to a growing catalogue of detailed population data, it became feasible to consider populations not only structured by time, age or sex, but by any number of interesting criteria. This “inflation” of data...... dimensions produces challenges in visualizing the data. To aid the understanding of age-structured timelines of compositions we seek to extend the Lexis surface plot from 1-dimensional continuous data to multidimensional composite data. We apply different strategies for visualizing composite data...

  8. Preparation of polymer-organo clay nano composites through the spray drying process

    International Nuclear Information System (INIS)

    Bernardo, Paulo R.A.; Pessan, Luiz A.; Carvalho, Antonio J.F. de; Vidotti, Suel E.

    2011-01-01

    The objective of the work was the study and preparation of polymer nano composites with montmorillonite organo clays (MMT) through the spray drying process. A new technique was proposed and tested to obtaining polymer nano composites, based on the use of the spray drying process to produce a nano composite with high clay content. The process consisted of the following stages: clay intercalation in water solution, with after addition of polyvinyl alcohol (PVOH) and a hydro soluble polyester ionomer (GEROLPS20) as exfoliation agents; spray drying the mixture obtained; incorporation powder in EVOH, PET e PP matrix. The effects of exfoliation agent on morphological and thermal properties of the nano composites were studied by XRD, transmission electron microscopy (TEM) and TGA. The results demonstrate that the process of spray drying is an innovative way to obtain a nano composite with high clay content. (author)

  9. The chemical composition and in vitro dry matter digestibility of ...

    African Journals Online (AJOL)

    The mean IVDMD of maize residues obtained by means of a whole plant maize harvester was found to be relatively high (IVDMD = 55.6±7.0%) while the crude protein (CP) (46±10 g/kg dry matter (DM)) and phosphorus (P) (1.2±0.5 g/kg DM) concentrations were below the maintenance requirement for dry gestating beef ...

  10. Effect of different drying methods on the composition of steviol glycosides in Stevia rebaudiana Bertoni leaves

    Science.gov (United States)

    Aranda-González, Irma; Betancur-Ancona, David; Chel-Guerrero, Luis; Moguel-Ordóñez, Yolanda

    2017-01-01

    Drying techniques can modify the composition of certain plant compounds. Therefore, the aim of the study was to assess the effect of different drying methods on steviol glycosides in Stevia rebaudiana Bertoni leaves. Four different drying methods were applied to Stevia rebaudiana Bertoni leaves, which were then subjected to aqueous extraction. Radiation or convection drying was performed in stoves at 60°C, whereas shade or sun drying methods were applied at 29.7°C and 70% of relative humidity. Stevioside, rebaudioside A, rebaudioside B, rebaudioside C, rebaudioside D, dulcoside A, and steviolbioside were quantified by a validated HPLC method. Among steviol glycosides, the content (g 100 g-1 dry basis) of stevioside, rebaudioside A, rebaudioside B, and rebaudioside C varied according to the drying method. The total glycoside content was higher in sun-dried samples, with no significant differences compared to shade or convection drying, whereas radiation drying adversely affected the content of rebaudioside A and rebaudioside C (p <0.01) and was therefore a method lowering total glycoside content. The effect of the different drying methods was also reflected in the proportion of the sweetener profile. Convection drying could be suitable for modern food processing industries while shadow or sun drying may be a low-cost alternative for farmers.

  11. Influence of drying and irradiation on the composition of volatile compounds of thyme (Thymus vulgaris L.)

    International Nuclear Information System (INIS)

    Venskutonis, R.; Poll, L.; Larsen, M.

    1996-01-01

    An investigation of the influence of air-drying, freeze-drying, γ- and β-irradiation and storage for up to 10 months on the composition of volatile compounds in thyme herb (Thymus vulgaris L.) is presented. Altogether, 70 constituents were identified (53 positively and 17 tentatively), including those considered most important for thyme flavour. Quantitative results did not reveal significant differences in the composition of irradiated and non-irradiated samples, and the reduction of the amount of some volatile compounds after drying was comparable for air-dried and freeze-dried herb. The largest changes in flavour composition were observed during storage, especially the reduction in the concentration of monoterpene hydrocarbons

  12. The volatile oil composition of fresh and air-dried buds of Cannabis sativa.

    Science.gov (United States)

    Ross, S A; ElSohly, M A

    1996-01-01

    The composition of the steam-distilled volatile oil of fresh and air-dried, indoor-grown marijuana was studied by GC/FID and GC/MS. In all, 68 components were detected of which 57 were fully identified. Drying of the plant material had no effect on the qualitative composition of the oil and did not affect the ability of individuals familiar with marijuana smell to recognize the odor.

  13. Visualizing compositional data on the Lexis surface

    DEFF Research Database (Denmark)

    Schöley, Jonas; Willekens, Frans

    2017-01-01

    the visualizations for compliance with multiple desired criteria. Results: Compositional data can effectively be visualized on the Lexis surface. A key feature of the classical Lexis surface plot – to show age, period, and cohort patterns – is retained in the domain of compositions. The optimal choice among the four...... and demonstrate the usefulness of the techniques by performing an exploratory analysis of age-specific French cause-of-death patterns across the 20th century. We identify strengths and weaknesses of the four proposed techniques. We contribute a technique to construct the ternary-balance colour scheme from within...

  14. Chemical composition and in vitro dry matter digestibility of Moringa ...

    African Journals Online (AJOL)

    The effect of caecal inoculum of rabbit on in vitro gas production and dry matter digestibility of Moringa oleifera, Azadirachta indica and Aspilia africana leaf meals at different levels of 0%, 15% and 30%. Leave samples were analyzed for crude protein (CP), lignin (ADL), acid (ADF) and neutral (NDF) detergent fibres.

  15. The Effect of Ocular Surface Regularity on Contrast Sensitivity and Straylight in Dry Eye

    OpenAIRE

    Koh, Shizuka; Maeda, Naoyuki; Ikeda, Chikako; Asonuma, Sanae; Ogawa, Mai; Hiraoka, Takahiro; Oshika, Tetsuro; Nishida, Kohji

    2017-01-01

    Purpose: To investigate the association between visual function and ocular surface regularity in dry eye.Methods: We enrolled 52 eyes of 52 dry eye patients (34 dry eyes with superficial punctate keratopathy [SPK] in the central corneal region [central SPK] and 18 dry eyes without central SPK) and 20 eyes of 20 normal control subjects. All eyes had a best-corrected distance visual acuity better than 20/20. We measured two indices of contrast sensitivity function under photopic conditions: con...

  16. Visualizing compositional data on the Lexis surface

    Directory of Open Access Journals (Sweden)

    Jonas Schöley

    2017-02-01

    Full Text Available Background: The Lexis surface plot is an established visualization tool in demography. Its presentutility, however, is limited to the domain of one-dimensional magnitudes such as ratesand counts. Visualizing proportions among three or more groups on a period-age grid isan unsolved problem. Objective: We seek to extend the Lexis surface plot to the domain of compositional data. Methods: We propose four techniques for visualizing group compositions on a period-age grid. Todemonstrate the techniques we use data on age-specific cause-of-death compositions inFrance from 1925 to 1999. We compare the visualizations for compliance with multipledesired criteria. Results: Compositional data can effectively be visualized on the Lexis surface. A key feature ofthe classical Lexis surface plot - to show age, period, and cohort patterns - is retainedin the domain of compositions. The optimal choice among the four proposed techniquesdepends primarily on the number of groups making up the composition and whether ornot the plot should be readable by people with impaired colour vision. Contribution: We introduce techniques for visualizing compositional data on a period-age grid to thefield of demography and demonstrate the usefulness of the techniques by performingan exploratory analysis of age-specific French cause-of-death patterns across the 20thcentury. We identify strengths and weaknesses of the four proposed techniques. We contribute a technique to construct the ternary-balance colour scheme from within a per-ceptually uniform colour space. Comments: A full-colour representation is key to understanding the paper. Therefore, we recommend that you read it on screen or print a colour version.

  17. Surface composition of Mercury from reflectance spectrophotometry

    Science.gov (United States)

    Vilas, Faith

    1988-01-01

    The controversies surrounding the existing spectra of Mercury are discussed together with the various implications for interpretations of Mercury's surface composition. Special attention is given to the basic procedure used for reducing reflectance spectrophotometry data, the factors that must be accounted for in the reduction of these data, and the methodology for defining the portion of the surface contributing the greatest amount of light to an individual spectrum. The application of these methodologies to Mercury's spectra is presented.

  18. Ultraviolet Light Surface Treatment as an Environmentally Benign Process for Production, Maintenance and Repair of Military Composite Structures

    National Research Council Canada - National Science Library

    Drzal, Lawrence T

    2002-01-01

    The principal objective of this work is to develop a low-cost, high-speed, environmentally benign, dry surface treatment method for production, and repair of military composite structures using ultraviolet (UV...

  19. Influence of warm air-drying on enamel bond strength and surface free-energy of self-etch adhesives.

    Science.gov (United States)

    Shiratsuchi, Koji; Tsujimoto, Akimasa; Takamizawa, Toshiki; Furuichi, Tetsuya; Tsubota, Keishi; Kurokawa, Hiroyasu; Miyazaki, Masashi

    2013-08-01

    We examined the effect of warm air-drying on the enamel bond strengths and the surface free-energy of three single-step self-etch adhesives. Bovine mandibular incisors were mounted in self-curing resin and then wet ground with #600 silicon carbide (SiC) paper. The adhesives were applied according to the instructions of the respective manufacturers and then dried in a stream of normal (23°C) or warm (37°C) air for 5, 10, and 20 s. After visible-light irradiation of the adhesives, resin composites were condensed into a mold and polymerized. Ten samples per test group were stored in distilled water at 37°C for 24 h and then the bond strengths were measured. The surface free-energies were determined by measuring the contact angles of three test liquids placed on the cured adhesives. The enamel bond strengths varied according to the air-drying time and ranged from 15.8 to 19.1 MPa. The trends for the bond strengths were different among the materials. The value of the γS⁺ component increased slightly when drying was performed with a stream of warm air, whereas that of the γS⁻ component decreased significantly. These data suggest that warm air-drying is essential to obtain adequate enamel bond strengths, although increasing the drying time did not significantly influence the bond strength. © 2013 Eur J Oral Sci.

  20. floristic composition and structure of the dry afromontane forest at ...

    African Journals Online (AJOL)

    ADMIN

    Key words/phrases: Bale Mountains, floristic composition, plant community, vegetation structure. INTRODUCTION .... from ground was estimated for each tree and shrub species by ...... and environmental factors characterizing coffee forests in ...

  1. Controlled surface segregation leads to efficient coke-resistant nickel/platinum bimetallic catalysts for the dry reforming of methane

    KAUST Repository

    Li, Lidong; Zhou, Lu; Ould-Chikh, Samy; Anjum, Dalaver; Kanoun, Mohammed; Scaranto, Jessica; Hedhili, Mohamed Nejib; Khalid, Syed; Laveille, Paco; D'Souza, Lawrence; Clo, Alain M.; Basset, Jean-Marie

    2015-01-01

    Surface composition and structure are of vital importance for heterogeneous catalysts, especially for bimetallic catalysts, which often vary as a function of reaction conditions (known as surface segregation). The preparation of bimetallic catalysts with controlled metal surface composition and structure is very challenging. In this study, we synthesize a series of Ni/Pt bimetallic catalysts with controlled metal surface composition and structure using a method derived from surface organometallic chemistry. The evolution of the surface composition and structure of the obtained bimetallic catalysts under simulated reaction conditions is investigated by various techniques, which include CO-probe IR spectroscopy, high-angle annular dark-field scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy, extended X-ray absorption fine structure analysis, X-ray absorption near-edge structure analysis, XRD, and X-ray photoelectron spectroscopy. It is demonstrated that the structure of the bimetallic catalyst is evolved from Pt monolayer island-modified Ni nanoparticles to core-shell bimetallic nanoparticles composed of a Ni-rich core and a Ni/Pt alloy shell upon thermal treatment. These catalysts are active for the dry reforming of methane, and their catalytic activities, stabilities, and carbon formation vary with their surface composition and structure. The reform of reforming: A series of alumina-supported Ni/Pt bimetallic nanoparticles (NPs) with controlled surface composition and structure are prepared. Remarkable surface segregation for these bimetallic NPs is observed upon thermal treatment. These bimetallic NPs are active catalysts for CO2 reforming of CH4, and their catalytic activities, stabilities, and carbon formation vary with their surface composition and structure.

  2. Controlled surface segregation leads to efficient coke-resistant nickel/platinum bimetallic catalysts for the dry reforming of methane

    KAUST Repository

    Li, Lidong

    2015-02-03

    Surface composition and structure are of vital importance for heterogeneous catalysts, especially for bimetallic catalysts, which often vary as a function of reaction conditions (known as surface segregation). The preparation of bimetallic catalysts with controlled metal surface composition and structure is very challenging. In this study, we synthesize a series of Ni/Pt bimetallic catalysts with controlled metal surface composition and structure using a method derived from surface organometallic chemistry. The evolution of the surface composition and structure of the obtained bimetallic catalysts under simulated reaction conditions is investigated by various techniques, which include CO-probe IR spectroscopy, high-angle annular dark-field scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy, extended X-ray absorption fine structure analysis, X-ray absorption near-edge structure analysis, XRD, and X-ray photoelectron spectroscopy. It is demonstrated that the structure of the bimetallic catalyst is evolved from Pt monolayer island-modified Ni nanoparticles to core-shell bimetallic nanoparticles composed of a Ni-rich core and a Ni/Pt alloy shell upon thermal treatment. These catalysts are active for the dry reforming of methane, and their catalytic activities, stabilities, and carbon formation vary with their surface composition and structure. The reform of reforming: A series of alumina-supported Ni/Pt bimetallic nanoparticles (NPs) with controlled surface composition and structure are prepared. Remarkable surface segregation for these bimetallic NPs is observed upon thermal treatment. These bimetallic NPs are active catalysts for CO2 reforming of CH4, and their catalytic activities, stabilities, and carbon formation vary with their surface composition and structure.

  3. Amino acid composition of protein-enriched dried pasta

    OpenAIRE

    Vidrih, Rajko; Filip, Sebastjan

    2016-01-01

    Today, obesity is one of the major health problems, a so-called epidemic of the developed world. Obesity arises through an imbalance between energy intake and energy expenditure, so it is important for products to have a balanced nutritional composition. The aim of this study is to prepare high-protein pasta with high nutritional quality, with emphasis on its amino acid composition, as ordinary durum pasta lacks lysine and threonine. Ordinary durum wheat pasta contains, on average, 77 % carbo...

  4. Effectiveness of Disinfectants in Killing Enterobacter sakazakii in Suspension, Dried on the Surface of Stainless Steel, and in a Biofilm▿

    OpenAIRE

    Kim, Hoikyung; Ryu, Jee-Hoon; Beuchat, Larry R.

    2006-01-01

    The effectiveness of 13 disinfectants used in hospitals, day-care centers, and food service kitchens in killing Enterobacter sakazakii in suspension, dried on the surface of stainless steel, and in biofilm was determined. E. sakazakii exhibited various levels of resistance to the disinfectants, depending on the composition of the disinfectants, amount and type of organic matrix surrounding cells, and exposure time. Populations of planktonic cells suspended in water (7.22 to 7.40 log CFU/ml) d...

  5. Spray Drying of Spinach Juice: Characterization, Chemical Composition, and Storage.

    Science.gov (United States)

    Çalışkan Koç, Gülşah; Nur Dirim, Safiye

    2017-12-01

    The 1st aim of this study is to determine the influence of inlet and outlet air temperatures on the physical and chemical properties of obtained powders from spinach juice (SJ) with 3.2 ± 0.2 °Brix (°Bx). Second, the effect of 3 different drying agents (maltodextrin, whey powder, and gum Arabic) on the same properties was investigated for the selected inlet/outlet temperatures (160/100 °C) which gives the minimum moisture content and water activity values. For this purpose, the total soluble solid content of SJ was adjusted to 5.0 ± 0.2 °Bx with different drying agents. Finally, the effects of different storage conditions (4, 20, and 30 °C) on the physical and chemical properties of spinach powders (SPs) produced at selected conditions were examined. A pilot scale spray dryer was used at 3 different inlet/outlet air temperatures (160 to 200 °C/80 to 100 °C) where the outlet air temperature was controlled by regulating the feed flow rate. Results showed that the moisture content, water activity, browning index, total chlorophyll, and total phenolic contents of the SP significantly decreased and pH and total color change of the SP significantly increased by the addition of different drying agents (P < 0.05). In addition, the changes in the above-mentioned properties were determined during the storage period, at 3 different temperatures. It was also observed that the vitamin C, β-carotene, chlorophyll, and phenolic compounds retention showed first-order degradation kinetic with activation energy of 32.6840, 10.2736, 27.7031, and 28.2634 kJ/K.mol, respectively. © 2017 Institute of Food Technologists®.

  6. Dry Sliding Wear Behavior of Spark Plasma Sintered Fe-Based Bulk Metallic Glass/Graphite Composites

    Directory of Open Access Journals (Sweden)

    Xiulin Ji

    2016-09-01

    Full Text Available Bulk metallic glass (BMG and BMG-graphite composites were fabricated using spark plasma sintering at the sintering temperature of 575 °C and holding time of 15 min. The sintered composites exhibited partial crystallization and the presence of distributed porosity and graphite particles. The effect of graphite reinforcement on the tribological properties of the BMG/graphite composites was investigated using dry ball-on-disc sliding wear tests. The reinforcement of graphite resulted in a reduction in both the wear rate and the coefficient of friction as compared to monolithic BMG samples. The wear surfaces of BMG/graphite composites showed regions of localized wear loss due to microcracking and fracture, as was also the case with the regions covered with graphite-rich protective film due to smearing of pulled off graphite particles.

  7. Dry Stream Reaches in Carbonate Terranes: Surface Indicators of Ground-Water Reservoirs

    Science.gov (United States)

    Brahana, J.V.; Hollyday, E.F.

    1988-01-01

    In areas where dry stream reaches occur, subsurface drainage successfully competes with surface drainage, and sheet-like dissolution openings have developed parallel to bedding creating the ground-water reservoir. Union Hollow in south-central Tennessee is the setting for a case study that illustrates the application of the dry stream reach technique. In this technique, dry stream reach identification is based on two types of readily acquired information: remotely sensed black and white infrared aerial photography; and surface reconnaissance of stream channel characteristics. Test drilling in Union Hollow subsequent to identification of the dry reach proved that a localized ground-water reservoir was present.

  8. Volatile composition and sensory profile of shiitake mushrooms as affected by drying method.

    Science.gov (United States)

    Politowicz, Joanna; Lech, Krzysztof; Lipan, Leontina; Figiel, Adam; Carbonell-Barrachina, Ángel A

    2018-03-01

    One of the best preservation method for long-term storage is drying. In this work, the influence of different drying methods on aroma and sensory profile of shiitake mushroom was evaluated. The drying methods tested were: convective drying (CD), freeze-drying (FD), vacuum-microwave drying (VMD), and a combination of convective pre-drying and vacuum-microwave finish-drying (CPD-VMFD). The volatile composition of fresh and dried shiitake mushrooms was analysed by SPME, GC-MS and GC-FID, and showed the presence of 71 volatile compounds, most of them present in all dried samples but with quantitative variation. The major volatile compounds in fresh shiitake were 1-octen-3-ol (20.2%), 2-octanone (20.7%), 1,2,4-trithiolane (9.8%), and 1,2,3,5,6-pentathiepane (8.2%). Drying of shiitake mushrooms caused significant losses of C8 compounds and cyclic sulfur compounds, such as 1,2,4-trithiolane (V31) and 1,2,4,5-tetrathiane (V57). Samples dried at CD 80 °C implied a relative short drying time (120 min), had the highest contents of total volatiles (1594 μg 100 g -1 ) and cyclic sulfur compounds (e.g. V57 126 μg 100 g -1 ), and the highest intensity of most of the key positive sensory attributes, such as inner colour (7.0), fresh shiitake flavour (6.7), and sponginess (6.2). The best dehydration methods, resulting in the highest total concentrations of volatile compounds and high intensity of key sensory attributes were FD (if vacuum and liquid nitrogen facilities are available) and CD at 80 °C (for companies with vacuum and liquid nitrogen facilities). © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  9. Influence of ash on the fiber composition of dried dairy manures

    International Nuclear Information System (INIS)

    Reeves, J.B.; Van Kessel, J.A.S.

    2002-01-01

    The ash content of dried dairy manures is a significant source of error in the determination of their fiber composition. - The objective of this work was to examine the role of ash in the compositional analysis of dried dairy manures. Ninety-nine dairy manures obtained from Connecticut, Maryland, New York, Pennsylvania and Virginia were dried at 60 deg. C, and ground to 20 mesh. Samples were analyzed for neutral and acid detergent fiber, acid detergent lignin, total carbon, total nitrogen, and ash. In addition, cellulose and hemicellulose were computed by difference. Results indicated that high ash contents (8-52% of dry matter) can dramatically and unpredictably alter various measures of fiber composition and are a significant source of error in the determination of manure composition and how it relates to mineralization or other compositional influenced factors. Also, while the ash content of the dried intact manure can easily be determined, it is difficult to estimate the ash contribution to the individual fiber determinations, especially if sequential assays are performed

  10. Temperature processes at two sliding surfaces subjected to dry friction

    Czech Academy of Sciences Publication Activity Database

    Půst, Ladislav; Pešek, Luděk; Cibulka, Jan; Bula, Vítězslav

    2012-01-01

    Roč. 63, 5/6 (2012), s. 277-292 ISSN 0039-2472 R&D Projects: GA ČR GA101/09/1166 Institutional support: RVO:61388998 Keywords : dry friction * vibration damping * experimental set * increase of temperature * lost energy Subject RIV: BI - Acoustics

  11. Modeling Dry Deposition of Aerosol Particles on Rough Surfaces

    Czech Academy of Sciences Publication Activity Database

    Hussein, T.; Smolík, Jiří; Kerminen, V.-M.; Kulmala, M.

    2012-01-01

    Roč. 46, č. 1 (2012), s. 44-59 ISSN 0278-6826 Institutional research plan: CEZ:AV0Z40720504 Keywords : aerosol particles * dry deposition * transport Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.780, year: 2012

  12. Constraints on Europa's Ocean Composition Imposed by Its Surface Composition

    Science.gov (United States)

    Johnson, P. V.; Hodyss, R. P.; Vu, T. H.; Choukroun, M.

    2017-12-01

    Of the non-terrestrial environments within our Solar System, Europa's global liquid water ocean is arguably the most likely to be habitable. As such, understanding the habitability of Europa's ocean is of great interest to astrobiology and is the focus of missions currently being considered for further exploration of Europa. However, direct analysis of the ocean is unlikely in the foreseeable future. As such, our best means of constraining the subsurface ocean composition and its subsequent habitability currently is by further study of Europa's surface chemical composition. Recently, there has been a body of work published that looks at the chemistry of frozen brines representing putative ocean compositions. Here we take a simplified model of a four ionic component (Na, Mg, SO4, Cl) solution and map out what minerals are formed upon freezing as a function of relative ionic concentration, pH, etc. A `flow-chart' of the freezing sequence was developed based on both published and recently acquired experimental results. In performing this exercise, we are able to begin making meaningful links between observations of the surface chemistry and the chemical environment of the internal ocean.

  13. Surface Preparation for Microdebonding Analysis of Composites

    International Nuclear Information System (INIS)

    Kahraman, Ramazan; Mandell, J. F.

    1999-01-01

    The bond strength between fibers and matrix is an essential property of all composite materials and it must be measured accurately to be able to correlate it with the composite behavior. There are several factors affecting its measurement. This paper discusses the polishing and load application aspects of the indentation test technique for fibre-matrix bond strength determination in polymer and ceramic matrix composites. Different polishing procedures are suggested for polymer and ceramic surfaces for obtaining a smooth surface which is a must for the test results to be reliable. The geometry of the fibers tested was also found to affect the analysis results. For best results, fibers with similar size and which are similarly surrounded by other fibers should be tested. Care should be taken during load application on a fiber for the loading probe not to approach the fiber circumference. The force should be applied in a small increments as possible, however starting from a high enough level to prevent fiber breakage due to surface damage from several loading steps. (Author)

  14. Influence of Solvent Composition on the Performance of Spray-Dried Co-Amorphous Formulations

    DEFF Research Database (Denmark)

    Mishra, Jaya; Rades, Thomas; Löbmann, Korbinian

    2018-01-01

    Ball-milling is usually used to prepare co-amorphous drug–amino acid (AA) mixtures. In this study, co-amorphous drug–AA mixtures were produced using spray-drying, a scalable industrially preferred preparation method. The influence of the solvent type and solvent composition was investigated....... Mixtures of indomethacin (IND) and each of the three AAs arginine, histidine, and lysine were ball-milled and spray-dried at a 1:1 molar ratio, respectively. Spray-drying was performed at different solvent ratios in (a) ethanol and water mixtures and (b) acetone and water mixtures. Different ratios...... that using spray-drying as a preparation method, all IND–AA mixtures could be successfully converted into the respective co-amorphous forms, irrespective of the type of solvent used, but depending on the solvent mixture ratios. Both ball-milled and spray-dried co-amorphous samples showed an enhanced...

  15. Laser Surface Treatment and Modification of Aluminum Alloy Matrix Composites

    Science.gov (United States)

    Abbass, Muna Khethier

    2018-02-01

    The present work aimed to study the laser surface treatment and modification of Al-4.0%Cu-1.0%Mg alloy matrix composite reinforced with 10%SiC particles produced by stir casting. The specimens of the base alloy and composite were irradiated with an Nd:YAG laser of 1000 mJ, 1064 nm and 3 Hz . Dry wear test using the pin-on -disc technique at different sliding times (5-30 min) at a constant applied load and sliding speed were performed before and after laser treatment. Micro hardness and wear resistance were increased for all samples after laser hardening treatment. The improvement of these properties is explained by microstructural homogenization and grain refinement of the laser treated surface. Modification and refinement of SiC particles and grain refinement in the microstructure of the aluminum alloy matrix (α-Al) were observed by optical and SEM micrographs. The highest increase in hardness was 21.4% and 26.2% for the base alloy and composite sample respectively.

  16. (90377) SEDNA: INVESTIGATION OF SURFACE COMPOSITIONAL VARIATION

    International Nuclear Information System (INIS)

    Barucci, M. A.; De Bergh, C.; Merlin, F.; Morea Dalle Ore, C.; Cruikshank, D.; Alvarez-Candal, A.; Dumas, C.

    2010-01-01

    The dwarf planet (90377) Sedna is one of the most remote solar system objects accessible to investigations. To better constrain its surface composition and to investigate the possible heterogeneity of the surface of Sedna, several observations have been carried out at ESO-VLT with the powerful spectrometer SINFONI observing simultaneously the H and K bands. The analyzed spectra (obtained in 2005, 2007, and 2008) show a non-uniform spectral signature, particularly in the K band. Spectral modeling using the Shkuratov radiative transfer code for surface scattering has been performed using the various sets of data, including previous observations at visible wavelengths and photometry at 3.6 and 4.5 μm by the Spitzer Space Telescope. The visible and near-infrared spectra can be modeled with organic materials (triton and titan tholin), serpentine, and H 2 O ice in fairly significant amounts, and CH 4 , N 2 , and C 2 H 6 in varying trace amounts. One of the spectra obtained in 2005 October shows a different signature in the K band and is best modeled with CH 3 OH in place of CH 4 , with reduced amounts of serpentine and with the addition of olivine. The compositional surface heterogeneity can give input on the past history as well clues to the origin of this peculiar, distant object.

  17. Measurements of dry-deposition rates on various earth surfaces by 212Pb

    International Nuclear Information System (INIS)

    Osaki, S.; Sugihara, S.; Maeda, Y.

    2004-01-01

    Dry deposition rates of 212 Pb on a coniferous forest (Japanese cedar) and a broad-leaf forest (Pasania edulis) have been measured. Those on various kinds of grass fields, various states on artificial surface such as water, paper, and standing paper have been also measured. The dry deposition rates depend on the characteristics of depositing particles and the conditions of deposited surfaces. Dry deposition rates on the forest of Japanese cedar are highest because of the complex and adhesive surface of the leaves. Those on various grass fields are roughly depend on the logarithm of the height of their grasses. The total deposition rates of 7 Be do not depend on the densities or heights of the grasses. 7 Be may be not kept on their leaves or surface soil for a long time. The dry deposition rates of on artificial surface, e.g. paper and water surfaces make clear the mechanism on dry deposition, and suggest that more chances of collision and more adhesive of the surface are important for the dry deposition. About 90% of all deposition on the artificial paper grass was attached on the standing paper. On water surface, 60% of the rate of paper grass was attached, but only about 20% were attached on a dry paper plate. The aerosol particles are deposited by collision with the surface, therefore the deposition velocity depends on the chance of collision and the characteristics of the surface. Therefore the dry deposition rates on forests are larger and those of coniferous forest are largest. (author)

  18. 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.

  19. Analysis of the Pathogenic Factors and Management of Dry Eye in Ocular Surface Disorders.

    Science.gov (United States)

    Nebbioso, Marcella; Del Regno, Paola; Gharbiya, Magda; Sacchetti, Marta; Plateroti, Rocco; Lambiase, Alessandro

    2017-08-13

    The tear film represents the interface between the eye and the environment. The alteration of the delicate balance that regulates the secretion and distribution of the tear film determines the dry eye (DE) syndrome. Despite having a multifactorial origin, the main risk factors are female gender and advanced age. Likewise, morphological changes in several glands and in the chemical composition of their secretions, such as proteins, mucins, lipidics, aqueous tears, and salinity, are highly relevant factors that maintain a steady ocular surface. Another key factor of recurrence and onset of the disease is the presence of local and/or systemic inflammation that involves the ocular surface. DE syndrome is one of the most commonly encountered diseases in clinical practice, and many other causes related to daily life and the increase in average life expectancy will contribute to its onset. This review will consider the disorders of the ocular surface that give rise to such a widespread pathology. At the end, the most recent therapeutic options for the management of DE will be briefly discussed according to the specific underlying pathology.

  20. Volatile composition and sensory profile of Cantharellus cibarius Fr. as affected by drying method.

    Science.gov (United States)

    Politowicz, Joanna; Lech, Krzysztof; Sánchez-Rodríguez, Lucía; Szumny, Antoni; Carbonell-Barrachina, Ángel A

    2017-12-01

    In this work, the influence of different drying methods on the aroma composition and sensory quality of chanterelle mushrooms (Cantharellus cibarius Fr.) was evaluated. The drying methods tested were convective drying (CD), freeze drying (FD), vacuum microwave drying (VMD) and a combination of convective pre-drying and vacuum microwave finish drying (CPD-VMFD). Analyses of fresh and dried chanterelle samples by HS-SPME and GC/MS and GC-FID showed the presence of 39 volatile compounds at different concentrations. The most abundant compounds in fresh chanterelle were 1-hexanol (33.4 μg per 100 g dry basis (db)), 1-octen-3-ol (80.2 μg per 100 g db) and 2-octen-1-ol (19.3 μg per 100 g db). The results showed that fresh and dried chanterelle contained very low levels of aroma compounds; however, the highest contents of volatile compounds were found in samples after (i) CD at 80 °C (129 μg per 100 g db), (ii) CPD-VMFD at 70 °C-480/240 W (136 μg per 100 g db) and (iii) CPD-VMFD at 80 °C-480/240 W (136 μg per 100 g db). The best dehydration methods, which resulted in high contents of volatile compounds and appropriate sensory quality, according to descriptive sensory analysis and PCA tools, were CD at 70 and 80 °C. Besides, these methods led to spongy dried mushrooms with high intensities of fresh, mushroom ID, with proper color and without intense shrinkage. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  1. Goblet cells contribute to ocular surface immune tolerance—implications for dry eye disease

    NARCIS (Netherlands)

    Barbosa, Flavia L.; Xiao, Yangyan; Bian, Fang; Coursey, Terry G.; Ko, Byung Yi; Clevers, Hans; de Paiva, Cintia S.; Pflugfelder, Stephen C.

    2017-01-01

    Conjunctival goblet cell (GC) loss in dry eye is associated with ocular surface inflammation. This study investigated if conjunctival GCs contribute to ocular surface immune tolerance. Antigens applied to the ocular surface, imaged by confocal microscopy, passed into the conjunctival stroma through

  2. Goblet Cells Contribute to Ocular Surface Immune Tolerance-Implications for Dry Eye Disease

    NARCIS (Netherlands)

    Barbosa, Flavia L; Xiao, Yangyan; Bian, Fang; Coursey, Terry G; Ko, Byung Yi; Clevers, Hans; de Paiva, Cintia S; Pflugfelder, Stephen C

    2017-01-01

    Conjunctival goblet cell (GC) loss in dry eye is associated with ocular surface inflammation. This study investigated if conjunctival GCs contribute to ocular surface immune tolerance. Antigens applied to the ocular surface, imaged by confocal microscopy, passed into the conjunctival stroma through

  3. Inflammation in dry eye.

    Science.gov (United States)

    Stern, Michael E; Pflugfelder, Stephen C

    2004-04-01

    Dry eye is a condition of altered tear composition that results from a diseased or dysfunctional lacrimal functional unit. Evidence suggests that inflammation causes structural alterations and/or functional paralysis of the tear-secreting glands. Changes in tear composition resulting from lacrimal dysfunction, increased evaporation and/or poor clearance have pro-inflammatory effects on the ocular surface. This inflammation is responsible in part for the irritation symptoms, ocular surface epithelial disease, and altered corneal epithelial barrier function in dry eye. Anti-inflammatory therapies for dry eye target one or more of the inflammatory mediators/pathways that have been identified in dry eye.

  4. Preliminary Effects of Oral Uridine on the Ocular Surface in Dry Eye Patients

    OpenAIRE

    Chang, Ki Cheol; Oh, Joo Youn; In, Youn Seok; Kim, Mee Kum; Shin, Ki Cheul; Wee, Won Ryang; Lee, Jin Hak; Park, Myung Gyu

    2009-01-01

    We designed a randomized, double blinded, 3-months controlled prospective clinical study to investigate effects of oral uridine on the ocular surface in dry eye patients. Twenty-seven patients who diagnosed as dry eye with lower than 5 mm of wetting in the Schirmer strip, with corneal epithelial erosion and who completely followed-up till 3 months were enrolled. Corneal-conjunctival fluorescein staining, non-anesthetic Schirmer test, impression cytology, and Ocular Surface Disease Index (OSDI...

  5. Presence or absence of ocular surface inflammation directs clinical and therapeutic management of dry eye.

    Science.gov (United States)

    Sambursky, Robert

    2016-01-01

    The presence of clinically significant inflammation has been confirmed in the tears of 40%-65% of patients with symptoms of dry eye. Ocular surface inflammation may lead to tear film instability, epithelial cell irregularities, and permeability, resulting in chronic symptomatic pain and fluctuating vision as well as negative surgical outcomes. A retrospective single center medical chart review of 100 patients was conducted. All patients were tested with the InflammaDry test to determine if patients exhibited elevated levels of matrix metalloproteinase 9 (MMP-9). InflammaDry-positive patients were started on a combination of cyclosporine 0.05% twice daily, 2,000-4,000 mg oral omega-3 fatty acids, and frequent artificial tear replacement. InflammaDry-negative patients were started on 2,000-4,000 mg of oral omega-3 fatty acids and frequent artificial tear replacement. Each patient was retested at ~90 days. A symptom questionnaire was performed at the initial visit and at 90 days. 60% of the patients with dry eye symptoms tested positive for elevated MMP-9 at the initial visit. 78% of all patients returned for follow-up at ~90 days including 80% (48/60) of the previously InflammaDry-positive patients and 75% (30/40) of the previously InflammaDry-negative patients. A follow-up symptom questionnaire reported at least 75% symptomatic improvement in 65% (31/48) of the originally InflammaDry-positive patients and in 70% (21/30) of the initially InflammaDry-negative patients. Symptomatic improvement of at least 50% was reported in 85% (41/48) of previously InflammaDry-positive patients and 86% (26/30) of previously InflammaDry-negative patients. Following treatment, 54% (26/48) of previously InflammaDry-positive patients converted to a negative InflammaDry result. Identifying which symptomatic dry eye patients have underlying inflammation may predict patient responses to treatment and influence clinical management strategies.

  6. Producing of multicomponent and composite surface layers

    International Nuclear Information System (INIS)

    Wierzchon, T.; Bielinski, P.; Michalski, A.

    1995-01-01

    The paper presents a new method of producing multicomponent and composite layers on steel substrate. The combination of nickel plating with glow-discharge bordering or impulse-plasma deposition method gives an opportunity to obtain good properties of surface layers. The results of examinations of carbon 45 (0.45%C) steel, nickel plated and then borided under glow discharge conditions or covered with TiN layers are presented. The corrosion and friction wear resistance of such layers are markedly higher than for layer produced on non nickel plated substrates. (author). 19 refs, 5 figs

  7. OPTIMIZATION OF MICROWAVE AND AIR DRYING CONDITIONS OF QUINCE (CYDONIA OBLONGA, MILLER USING RESPONSE SURFACE METHODOLOGY

    Directory of Open Access Journals (Sweden)

    Cem Baltacioglu

    2015-03-01

    Full Text Available Effects of slice thickness of quince (Cydonia oblonga Miller , microwave incident power and air drying temperature on antioxidant activity and total phenolic content of quince were investigated during drying in microwave and air drying. Optimum conditions were found to be: i for microwave drying, 285 W and 4.14 mm thick (maximum antioxidant activity and 285 W and 6.85 mm thick (maximum total phenolic content, and ii for air drying, 75 ºC and 1.2 mm thick (both maximum antioxidant activity and total phenolic content. Drying conditions were optimized by using the response surface methodology. 13 experiments were carried out considering incident microwave powers from 285 to 795 W, air temperature from 46 to 74 ºC and slice thickness from 1.2 to 6.8 mm.

  8. Phenomenological study of aerosol dry deposition in urban area: surface properties, turbulence and local meteorology influences

    International Nuclear Information System (INIS)

    Roupsard, P.

    2013-01-01

    Aerosol dry deposition is not much known for urban areas due to the lack of data. Knowledge on this phenomenon is necessary to understand pollutant fluxes in cities and to estimate inhabitant exposition to ionizing radiation of radioactive aerosols. A data providing could enable to enhance dry deposition models for these areas. An original experimental approach is performed to study submicron aerosol dry deposition on urban surfaces. Wind tunnel coupled to in situ experiments give results to study different physical phenomenon governing dry deposition. Dry deposition velocities are measured using aerosol tracers. These data are associated to turbulent and meteorological measured conditions. This database permits to classify the principal physical phenomenon for each experiment type. Finally, different phenomenon must be considered for chronic and acute exposition of urban surfaces to atmospheric particles. (author)

  9. Tribological properties of three-dimensional braided carbon/Kevlar/epoxy hybrid composites under dry and lubricated conditions

    International Nuclear Information System (INIS)

    Wan, Y.Z.; Huang, Y.; He, F.; Li, Q.Y.; Lian, J.J.

    2007-01-01

    This paper presents a study of the tribological properties of three-dimensional (3-D) braided carbon/Kevlar/epoxy hybrid composites. Their specific wear rate and the coefficient of friction were examined as a function of operating conditions (load and sliding distance) under dry and lubricated conditions. In addition, the 3-D braided hybrid composites with varying carbon to Kevlar fiber volume ratio were tested to assess hybrid effects. It was found that the friction and wear rate decreased with sliding distance and then leveled off under dry and lubricated conditions. Different changing patterns with normal load were observed under two different sliding conditions. Furthermore, it was noted that negative hybrid effects on the wear resistance and the friction coefficient were identified for the current 3-D braided hybrid system. The composite with a carbon to Kevlar ratio of 3:2 was found to have the least wear and friction among all 3-D braided hybrid composites studied. Worn surfaces were observed by scanning electron microscope (SEM) and wear mechanisms were discussed in this study

  10. Effects of extrusion cooking on the chemical composition and functional properties of dry bean powders

    Science.gov (United States)

    This study aimed to investigate the impacts of extrusion cooking on the chemical composition and functional properties of bean powders from four bean varieties. The raw bean powders were extruded under eight different conditions, and the extrudates were then dried and ground (particle size = 0.5 mm)...

  11. Controls on surface soil drying rates observed by SMAP and simulated by the Noah land surface model

    Science.gov (United States)

    Shellito, Peter J.; Small, Eric E.; Livneh, Ben

    2018-03-01

    Drydown periods that follow precipitation events provide an opportunity to assess controls on soil evaporation on a continental scale. We use SMAP (Soil Moisture Active Passive) observations and Noah simulations from drydown periods to quantify the role of soil moisture, potential evaporation, vegetation cover, and soil texture on soil drying rates. Rates are determined using finite differences over intervals of 1 to 3 days. In the Noah model, the drying rates are a good approximation of direct soil evaporation rates, and our work suggests that SMAP-observed drying is also predominantly affected by direct soil evaporation. Data cover the domain of the North American Land Data Assimilation System Phase 2 and span the first 1.8 years of SMAP's operation. Drying of surface soil moisture observed by SMAP is faster than that simulated by Noah. SMAP drying is fastest when surface soil moisture levels are high, potential evaporation is high, and when vegetation cover is low. Soil texture plays a minor role in SMAP drying rates. Noah simulations show similar responses to soil moisture and potential evaporation, but vegetation has a minimal effect and soil texture has a much larger effect compared to SMAP. When drying rates are normalized by potential evaporation, SMAP observations and Noah simulations both show that increases in vegetation cover lead to decreases in evaporative efficiency from the surface soil. However, the magnitude of this effect simulated by Noah is much weaker than that determined from SMAP observations.

  12. Explore the influence of agglomeration on electrochemical performance of an amorphous MnO2/C composite by controlling drying process

    Science.gov (United States)

    Cui, Mangwei; Kang, Litao; Shi, Mingjie; Xie, Lingli; Wang, Xiaomin; Zhao, Zhe; Yun, Shan; Liang, Wei

    2017-09-01

    Amorphous MnO2/C composite is prepared by a facile redox reaction between potassium permanganate (KMnO4) and commercial black pen ink. Afterwards, two different drying processes, air drying or freeze drying, are employed to adjust the agglomeration state of particles in samples and explore its influence on capacitive performance. Experimental results indicate that the air-dried sample demonstrates much better cycling stability than the freeze-dried one (capacity retention at 5000 cycles: 70.9 vs. 60.7%), probably because of the relatively strong agglomeration between particles in this sample. Nevertheless, strong agglomeration seems to deteriorate the specific capacitance (from 492 down to 440.5 F/g at 1 A/g) due to the decrease of porosity and specific surface area. This study suggests that agglomeration of primary particles plays an important role to balance the specific capacitance and cycling stability for electrode materials.

  13. Optimization of surface roughness parameters in dry turning

    OpenAIRE

    R.A. Mahdavinejad; H. Sharifi Bidgoli

    2009-01-01

    Purpose: The precision of machine tools on one hand and the input setup parameters on the other hand, are strongly influenced in main output machining parameters such as stock removal, toll wear ratio and surface roughnes.Design/methodology/approach: There are a lot of input parameters which are effective in the variations of these output parameters. In CNC machines, the optimization of machining process in order to predict surface roughness is very important.Findings: From this point of view...

  14. Behavior of aircraft antiskid braking systems on dry and wet runway surfaces: Hydromechanically controlled system

    Science.gov (United States)

    Tanner, J. A.; Stubbs, S. M.; Smith, E. G.

    1981-01-01

    The investigation utilized one main gear wheel, brake, and tire assembly of a McDonnell Douglas DC-9 series 10 airplane. The landing-gear strut was replaced by a dynamometer. During maximum braking, average braking behavior indexes based upon brake pressure, brake torque, and drag-force friction coefficient developed by the antiskid system were generally higher on dry surfaces than on wet surfaces. The three braking behavior indexes gave similar results but should not be used interchangeably as a measure of the braking of this antiskid sytem. During the transition from a dry to a flooded surface under heavy braking, the wheel entered into a deep skid but the antiskid system reacted quickly by reducing brake pressure and performed normally during the remainder of the run on the flooded surface. The brake-pressure recovery following transition from a flooded to a dry surface was shown to be a function of the antiskid modulating orifice.

  15. Dry friction of microstructured polymer surfaces inspired by snake skin

    Directory of Open Access Journals (Sweden)

    Martina J. Baum

    2014-07-01

    Full Text Available The microstructure investigated in this study was inspired by the anisotropic microornamentation of scales from the ventral body side of the California King Snake (Lampropeltis getula californiae. Frictional properties of snake-inspired microstructured polymer surface (SIMPS made of epoxy resin were characterised in contact with a smooth glass ball by a microtribometer in two perpendicular directions. The SIMPS exhibited a considerable frictional anisotropy: Frictional coefficients measured along the microstructure were about 33% lower than those measured in the opposite direction. Frictional coefficients were compared to those obtained on other types of surface microstructure: (i smooth ones, (ii rough ones, and (iii ones with periodic groove-like microstructures of different dimensions. The results demonstrate the existence of a common pattern of interaction between two general effects that influence friction: (1 molecular interaction depending on real contact area and (2 the mechanical interlocking of both contacting surfaces. The strongest reduction of the frictional coefficient, compared to the smooth reference surface, was observed at a medium range of surface structure dimensions suggesting a trade-off between these two effects.

  16. Dry friction of microstructured polymer surfaces inspired by snake skin.

    Science.gov (United States)

    Baum, Martina J; Heepe, Lars; Fadeeva, Elena; Gorb, Stanislav N

    2014-01-01

    The microstructure investigated in this study was inspired by the anisotropic microornamentation of scales from the ventral body side of the California King Snake (Lampropeltis getula californiae). Frictional properties of snake-inspired microstructured polymer surface (SIMPS) made of epoxy resin were characterised in contact with a smooth glass ball by a microtribometer in two perpendicular directions. The SIMPS exhibited a considerable frictional anisotropy: Frictional coefficients measured along the microstructure were about 33% lower than those measured in the opposite direction. Frictional coefficients were compared to those obtained on other types of surface microstructure: (i) smooth ones, (ii) rough ones, and (iii) ones with periodic groove-like microstructures of different dimensions. The results demonstrate the existence of a common pattern of interaction between two general effects that influence friction: (1) molecular interaction depending on real contact area and (2) the mechanical interlocking of both contacting surfaces. The strongest reduction of the frictional coefficient, compared to the smooth reference surface, was observed at a medium range of surface structure dimensions suggesting a trade-off between these two effects.

  17. Dry Sliding Friction and Wear Studies of Fly Ash Reinforced AA-6351 Metal Matrix Composites

    Directory of Open Access Journals (Sweden)

    M. Uthayakumar

    2013-01-01

    Full Text Available Fly ash particles are potentially used in metal matrix composites due to their low cost, low density, and availability in large quantities as waste by-products in thermal power plants. This study describes multifactor-based experiments that were applied to research and investigation on dry sliding wear system of stir-cast aluminum alloy 6351 with 5, 10, and 15 wt.% fly ash reinforced metal matrix composites (MMCs. The effects of parameters such as load, sliding speed, and percentage of fly ash on the sliding wear, specific wear rate, and friction coefficient were analyzed using Grey relational analysis on a pin-on-disc machine. Analysis of variance (ANOVA was also employed to investigate which design parameters significantly affect the wear behavior of the composite. The results showed that the applied load exerted the greatest effect on the dry sliding wear followed by the sliding velocity.

  18. Evaluation of dry sliding wear behavior of silicon particles reinforced aluminum matrix composites

    International Nuclear Information System (INIS)

    Sun Zhiqiang; Zhang Di; Li Guobin

    2005-01-01

    This paper reports a study on the wear property of powder metallurgy aluminum matrix composites 9Si/Al-Cu-Mg. A on rock wear-testing machine is used to evaluate the wear property of the composites, in which a GCrl5 steel ring is used as the counter face material. The wear behavior of the composites under different conditions is studied. The optical microscope and scanning electron microscope are used to analyze the worn surfaces and the subsurface of the composites in order to research the wear mechanism of the composites. Results indicate that the weight loss of the composite were lower than that of the matrix alloy

  19. Dry Deposition, Surface Production and Dynamics of Aerosols in the Marine Boundary Layer

    DEFF Research Database (Denmark)

    Fairall, C.W.; Larsen, Søren Ejling

    1984-01-01

    A model of downward aerosol panicle flux characterized by dry deposition velocity, Vd, due to Slinn and Slinn (1980) is generalized to the case of nonzero surface concentration (absorbing surface with a surface source). A more general expression for the flux at some reference height is developed ...... produced as droplets at the surface and ‘continental’ background aerosols brought into the boundary layer at the top by entrainment and gravitational settling. Estimates of Si are provided....

  20. The pathology of dry eye: the interaction between the ocular surface and lacrimal glands.

    Science.gov (United States)

    Stern, M E; Beuerman, R W; Fox, R I; Gao, J; Mircheff, A K; Pflugfelder, S C

    1998-11-01

    Most dry-eye symptoms result from an abnormal, nonlubricative ocular surface that increases shear forces under the eyelids and diminishes the ability of the ocular surface to respond to environmental challenges. This ocular-surface dysfunction may result from immunocompromise due to systemic autoimmune disease or may occur locally from a decrease in systemic androgen support to the lacrimal gland as seen in aging, most frequently in the menopausal female. Components of the ocular surface (cornea, conjunctiva, accessory lacrimal glands, and meibomian glands), the main lacrimal gland, and interconnecting innervation act as a functional unit. When one portion is compromised, normal lacrimal support of the ocular surface is impaired. Resulting immune-based inflammation can lead to lacrimal gland and neural dysfunction. This progression yields the OS symptoms associated with dry eye. Restoration of lacrimal function involves resolution of lymphocytic activation and inflammation. This has been demonstrated in the MRL/lpr mouse using systemic androgens or cyclosporine and in the dry-eye dog using topical cyclosporine. The efficacy of cyclosporine may be due to its immunomodulatory and antiinflammatory (phosphatase inhibitory capability) functions on the ocular surface, resulting in a normalization of nerve traffic. Although the etiologies of dry eye are varied, common to all ocular-surface disease is an underlying cytokine/receptor-mediated inflammatory process. By treating this process, it may be possible to normalize the ocular surface/lacrimal neural reflex and facilitate ocular surface healing.

  1. Tear Osmolarity and Correlation With Ocular Surface Parameters in Patients With Dry Eye.

    Science.gov (United States)

    Mathews, Priya M; Karakus, Sezen; Agrawal, Devika; Hindman, Holly B; Ramulu, Pradeep Y; Akpek, Esen K

    2017-11-01

    To analyze the distribution of tear film osmolarity in patients with dry eye and its association with other ocular surface parameters. Tear osmolarity and other quantitative dry eye parameters were obtained from patients with 1) clinically significant dry eye (significant symptoms and ocular surface staining, n = 131), 2) symptoms-only dry eye (significant symptoms but no significant ocular surface staining, n = 52), and 3) controls (no significant symptoms or staining, n = 42). Tear osmolarity varied significantly across groups (P = 0.01), with patients with clinically significant dry eye having the highest tear osmolarity (312.0 ± 16.9 mOsm/L), control patients having the lowest tear osmolarity (305.6 ± 9.7 mOsm/L), and patients with symptoms-only dry eye falling in between (307.4 ± 5.6 mOsm/L). Patients with clinically significant dry eye also tended to have a greater intereye difference in osmolarity (12.0 ± 13.4) than did the individuals with symptoms-only dry eye (9.1 ± 12.4) and controls (9.0 ± 7.4) (P = 0.06). In multivariable regression models, higher tear osmolarity was associated with higher Ocular Surface Disease Index, discomfort subscore (P = 0.02), and higher corneal and conjunctival staining scores (P eye tear osmolarity was not correlated with the corresponding tear film breakup time or Schirmer test (P > 0.05 for both). Individuals with symptomatic dry eye that is not yet clinically significant seem to have higher and more variable osmolarity measurements than controls, potentially indicating that changes in osmolarity precede clinical findings.

  2. Optimization of surface integrity in dry hard turning using RSM

    Indian Academy of Sciences (India)

    This paper investigates the effect of different cutting parameters (cutting ... with coated carbide tool under different settings of cutting parameters. ... procedure of response surface methodology (RSM) to determine optimal ..... The numerical opti- .... and analysis of experiments, New Delhi, A. K. Ghosh, PHI Learning Private.

  3. Splash Dynamics of Watercolors on Dry, Wet, and Cooled Surfaces

    Science.gov (United States)

    Baron, David; Vaidya, Ashwin; Su, Haiyan

    2015-11-01

    In his classic study in 1908, A.M. Worthington gave a thorough account of splashes and their formation through visualization experiments. In more recent times, there has been renewed interest in this subject, and much of the underlying physics behind Worthington's experiments has now been clarified. One specific set of such recent studies, which motivates this paper, concerns the fluid dynamics behind Jackson Pollock's drip paintings. The physical processes and the mathematical structures hidden in his works have received serious attention and made the scientific pursuit of art a compelling area of exploration. Our work explores the interaction of watercolors with watercolor paper. Specifically, we conduct experiments to analyze the settling patterns of droplets of watercolor paint on wet and frozen paper. Variations in paint viscosity, paper roughness, paper temperature, and the height of a released droplet are examined from time of impact, through its transient stages, until its final, dry state. Observable phenomena such as paint splashing, spreading, fingering, branching, rheological deposition, and fractal patterns are studied in detail and classified in terms of the control parameters.

  4. Dry friction of microstructured polymer surfaces inspired by snake skin

    OpenAIRE

    Martina J. Baum; Lars Heepe; Elena Fadeeva; Stanislav N. Gorb

    2014-01-01

    Summary The microstructure investigated in this study was inspired by the anisotropic microornamentation of scales from the ventral body side of the California King Snake (Lampropeltis getula californiae). Frictional properties of snake-inspired microstructured polymer surface (SIMPS) made of epoxy resin were characterised in contact with a smooth glass ball by a microtribometer in two perpendicular directions. The SIMPS exhibited a considerable frictional anisotropy: Frictional coefficients ...

  5. Influence of Solvent Composition on the Performance of Spray-Dried Co-Amorphous Formulations

    Directory of Open Access Journals (Sweden)

    Jaya Mishra

    2018-04-01

    Full Text Available Ball-milling is usually used to prepare co-amorphous drug–amino acid (AA mixtures. In this study, co-amorphous drug–AA mixtures were produced using spray-drying, a scalable industrially preferred preparation method. The influence of the solvent type and solvent composition was investigated. Mixtures of indomethacin (IND and each of the three AAs arginine, histidine, and lysine were ball-milled and spray-dried at a 1:1 molar ratio, respectively. Spray-drying was performed at different solvent ratios in (a ethanol and water mixtures and (b acetone and water mixtures. Different ratios of these solvents were chosen to study the effect of solvent mixtures on co-amorphous formulation. Residual crystallinity, thermal properties, salt/partial salt formation, and powder dissolution profiles of the IND–AA mixtures were investigated and compared to pure crystalline and amorphous IND. It was found that using spray-drying as a preparation method, all IND–AA mixtures could be successfully converted into the respective co-amorphous forms, irrespective of the type of solvent used, but depending on the solvent mixture ratios. Both ball-milled and spray-dried co-amorphous samples showed an enhanced dissolution rate and maintained supersaturation compared to the crystalline and amorphous IND itself. The spray-dried samples resulting in co-amorphous samples were stable for at least seven months of storage.

  6. Native Liquid Extraction Surface Analysis Mass Spectrometry: Analysis of Noncovalent Protein Complexes Directly from Dried Substrates

    Science.gov (United States)

    Martin, Nicholas J.; Griffiths, Rian L.; Edwards, Rebecca L.; Cooper, Helen J.

    2015-08-01

    Liquid extraction surface analysis (LESA) mass spectrometry is a promising tool for the analysis of intact proteins from biological substrates. Here, we demonstrate native LESA mass spectrometry of noncovalent protein complexes of myoglobin and hemoglobin from a range of surfaces. Holomyoglobin, in which apomyoglobin is noncovalently bound to the prosthetic heme group, was observed following LESA mass spectrometry of myoglobin dried onto glass and polyvinylidene fluoride surfaces. Tetrameric hemoglobin [(αβ)2 4H] was observed following LESA mass spectrometry of hemoglobin dried onto glass and polyvinylidene fluoride (PVDF) surfaces, and from dried blood spots (DBS) on filter paper. Heme-bound dimers and monomers were also observed. The `contact' LESA approach was particularly suitable for the analysis of hemoglobin tetramers from DBS.

  7. Drop drying on surfaces determines chemical reactivity - the specific case of immobilization of oligonucleotides on microarrays

    Science.gov (United States)

    2013-01-01

    Background Drop drying is a key factor in a wide range of technical applications, including spotted microarrays. The applied nL liquid volume provides specific reaction conditions for the immobilization of probe molecules to a chemically modified surface. Results We investigated the influence of nL and μL liquid drop volumes on the process of probe immobilization and compare the results obtained to the situation in liquid solution. In our data, we observe a strong relationship between drop drying effects on immobilization and surface chemistry. In this work, we present results on the immobilization of dye labeled 20mer oligonucleotides with and without an activating 5′-aminoheptyl linker onto a 2D epoxysilane and a 3D NHS activated hydrogel surface. Conclusions Our experiments identified two basic processes determining immobilization. First, the rate of drop drying that depends on the drop volume and the ambient relative humidity. Oligonucleotides in a dried spot react unspecifically with the surface and long reaction times are needed. 3D hydrogel surfaces allow for immobilization in a liquid environment under diffusive conditions. Here, oligonucleotide immobilization is much faster and a specific reaction with the reactive linker group is observed. Second, the effect of increasing probe concentration as a result of drop drying. On a 3D hydrogel, the increasing concentration of probe molecules in nL spotting volumes accelerates immobilization dramatically. In case of μL volumes, immobilization depends on whether the drop is allowed to dry completely. At non-drying conditions, very limited immobilization is observed due to the low oligonucleotide concentration used in microarray spotting solutions. The results of our study provide a general guideline for microarray assay development. They allow for the initial definition and further optimization of reaction conditions for the immobilization of oligonucleotides and other probe molecule classes to different

  8. 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.

  9. Effect of the Machined Surfaces of AISI 4337 Steel to Cutting Conditions on Dry Machining Lathe

    Science.gov (United States)

    Rahim, Robbi; Napid, Suhardi; Hasibuan, Abdurrozzaq; Rahmah Sibuea, Siti; Yusmartato, Y.

    2018-04-01

    The objective of the research is to obtain a cutting condition which has a good chance of realizing dry machining concept on AISI 4337 steel material by studying surface roughness, microstructure and hardness of machining surface. The data generated from the experiment were then processed and analyzed using the standard Taguchi method L9 (34) orthogonal array. Testing of dry and wet machining used surface test and micro hardness test for each of 27 test specimens. The machining results of the experiments showed that average surface roughness (Raavg) was obtained at optimum cutting conditions when VB 0.1 μm, 0.3 μm and 0.6 μm respectively 1.467 μm, 2.133 μm and 2,800 μm fo r dry machining while which was carried out by wet machining the results obtained were 1,833 μm, 2,667 μm and 3,000 μm. It can be concluded that dry machining provides better surface quality of machinery results than wet machining. Therefore, dry machining is a good choice that may be realized in the manufacturing and automotive industries.

  10. Presence or absence of ocular surface inflammation directs clinical and therapeutic management of dry eye

    Directory of Open Access Journals (Sweden)

    Sambursky R

    2016-11-01

    Full Text Available Robert Sambursky Coastal Eye Institute, Cornea and Comprehensive Ophthalmology, Bradenton, FL, USA Background: The presence of clinically significant inflammation has been confirmed in the tears of 40%–65% of patients with symptoms of dry eye. Ocular surface inflammation may lead to tear film instability, epithelial cell irregularities, and permeability, resulting in chronic symptomatic pain and fluctuating vision as well as negative surgical outcomes.Patients and methods: A retrospective single center medical chart review of 100 patients was conducted. All patients were tested with the InflammaDry test to determine if patients exhibited elevated levels of matrix metalloproteinase 9 (MMP-9. InflammaDry-positive patients were started on a combination of cyclosporine 0.05% twice daily, 2,000–4,000 mg oral omega-3 fatty acids, and frequent artificial tear replacement. InflammaDry-negative patients were started on 2,000–4,000 mg of oral omega-3 fatty acids and frequent artificial tear replacement. Each patient was retested at ~90 days. A symptom questionnaire was performed at the initial visit and at 90 days.Results: 60% of the patients with dry eye symptoms tested positive for elevated MMP-9 at the initial visit. 78% of all patients returned for follow-up at ~90 days including 80% (48/60 of the previously InflammaDry-positive patients and 75% (30/40 of the previously InflammaDry-negative patients. A follow-up symptom questionnaire reported at least 75% symptomatic improvement in 65% (31/48 of the originally InflammaDry-positive patients and in 70% (21/30 of the initially InflammaDry-negative patients. Symptomatic improvement of at least 50% was reported in 85% (41/48 of previously InflammaDry-positive patients and 86% (26/30 of previously InflammaDry-negative patients. Following treatment, 54% (26/48 of previously InflammaDry-positive patients converted to a negative InflammaDry result.Conclusion: Identifying which symptomatic dry eye

  11. Method for attaining rosemary essential oil with differential composition from dried or fresh material.

    Science.gov (United States)

    Zheljazkov, Valtcho D; Astatkie, Tess; Zhalnov, Ivan; Georgieva, Tonya D

    2015-01-01

    Rosemary (Rosemarinus officinalis L.) is a well-known medicinal and essential oil plant, utilized by humankind since ancient times. The objective was to determine the effect of steam distillation time (DT) and material (dry or fresh biomass) on essential oil yield, composition, and bioactivity; and to develop regression models that can predict oil yield and composition at specific DT. The oil yield (content) from dry biomass was higher (0.43%) than that from fresh biomass (0.35%) and ranged from 0.18% in the 1.25 min DT to 0.51% in the 40 min DT. There was no yield advantage in extending the DT beyond 40 min, which is much shorter than the DT used by industry. In this study, the antioxidant capacity of the rosemary oil using the ORACoil method was 4,108 μmolVE/L. Rosemary oil did not exhibit significant antileishmanial, antimalarial, or antimicrobial activity. In general, the low-boiling constituents eluted earlier than the higher boiling constituents of the essential oil, resulting in a great variation of essential oil composition obtained at different DT. The most important constituents are α-pinene, eucalyptol, and camphor. The highest α-pinene concentration in the oil (30.4%) was obtained from dry biomass at 2.5 min DT; eucalyptol (23.3% of the total oil) from fresh biomass at 2.5 min DT; and camphor (15.9% of the total oil) from fresh biomass at 160 min DT. The DT could be used as an inexpensive tool to alter essential oil composition of the essential oil from fresh or dried rosemary biomass, and to produce rosemary oils with elevated or lowered concentration of specific targeted oil constituents to meet specific market demands.

  12. HEAT TREATMENTS OF HIGH TEMPERATURE DRIED NORWAY SPRUCE BOARDS: SACCHARIDES AND FURFURALS IN SAPWOOD SURFACES

    Directory of Open Access Journals (Sweden)

    Olov Karlsson,

    2012-02-01

    Full Text Available Carbohydrates that migrate to wood surfaces in sapwood during drying might influence properties such as mould susceptibility and colour. Sugars on the surface of Norway spruce boards during various heat treatments were studied. Samples (350mmx125mmx25mm were double-stacked, facing sapwood-side outwards, and dried at 110oC to a target moisture content (MC of 40%. Dried sub-samples (80 mm x 125 mm x 25 mm were stacked in a similar way and further heated at 110oC and at 130oC for 12, 24, and 36 hours, respectively. Glucose, fructose, and sucrose as well as 5-hydroxymethylfurfural (HMF and furfural in the sapwood surface layer of treated wood were analysed using HPLC (RI- and UV-detectors. Carbohydrates degraded to a lower extent at 110oC than at 130oC. Furfural and to a larger extent HMF increased with treatment period and temperature. Heat treatment led to a decrease in lightness and hue of the sapwood surface of sub-samples, while chroma increased somewhat. Furthermore, considerably faster degradation (within a few minutes of the carbohydrates on the surface of the dried spruce boards was observed when single sub-samples were conductively hot pressed at 200oC. Treatment period and initial MC influenced the presence of the carbohydrates in wood surface as well as colour change (Eab of the hot pressed sub-samples.

  13. Comparison of two methods for composite score generation in dry eye syndrome.

    Science.gov (United States)

    See, Craig; Bilonick, Richard A; Feuer, William; Galor, Anat

    2013-09-19

    To compare two methods of composite score generation in dry eye syndrome (DES). Male patients seen in the Miami Veterans Affairs eye clinic with normal eyelid, corneal, and conjunctival anatomy were recruited to participate in the study. Patients filled out the Dry Eye Questionnaire 5 (DEQ5) and underwent measurement of tear film parameters. DES severity scores were generated by independent component analysis (ICA) and latent class analysis (LCA). A total of 247 men were included in the study. Mean age was 69 years (SD 9). Using ICA analysis, osmolarity was found to carry the largest weight, followed by eyelid vascularity and meibomian orifice plugging. Conjunctival injection and tear breakup time (TBUT) carried the lowest weights. Using LCA analysis, TBUT was found to be best at discriminating healthy from diseased eyes, followed closely by Schirmer's test. DEQ5, eyelid vascularity, and conjunctival injection were the poorest at discrimination. The adjusted correlation coefficient between the two generated composite scores was 0.63, indicating that the shared variance was less than 40%. Both ICA and LCA produced composite scores for dry eye severity, with weak to moderate agreement; however, agreement for the relative importance of single diagnostic tests was poor between the two methods.

  14. Augmented dried versus cryopreserved amniotic membrane as an ocular surface dressing.

    Directory of Open Access Journals (Sweden)

    Claire L Allen

    Full Text Available Dried amniotic membrane (AM can be a useful therapeutic adjunct in ophthalmic surgery and possesses logistical advantages over cryopreserved AM. Differences in preservation techniques can significantly influence the biochemical composition and physical properties of AM, potentially affecting clinical efficacy. This study was established to investigate the biochemical and structural effects of drying AM in the absence and presence of saccharide lyoprotectants and its biocompatibility compared to cryopreserved material.AM was cryopreserved or dried with and without pre-treatment with trehalose or raffinose and the antioxidant epigallocatechin (EGCG. Structural and visual comparisons were assessed using electron microscopy. Localisation, expression and release of AM biological factors were determined using immunoassays and immunofluorescence. The biocompatibility of the AM preparations co-cultured with corneal epithelial cell (CEC or keratocyte monolayers were assessed using cell proliferation, cytotoxicity, apoptosis and migration assays.Drying devitalised AM epithelium, but less than cryopreservation and cellular damage was reduced in dried AM pre-treated with trehalose or raffinose. Dried AM alone, and with trehalose or raffinose showed greater factor retention efficiencies and bioavailability compared to cryopreserved AM and demonstrated a more sustained biochemical factor time release in vitro. Cellular health assays showed that dried AM with trehalose or raffinose are compatible and superior substrates compared to cryopreserved AM for primary CEC expansion, with increased proliferation and reduced LDH and caspase-3 levels. This concept was supported by improved wound healing in an immortalised human CEC line (hiCEC co-cultured with dried and trehalose or raffinose membranes, compared to cryopreserved and fresh AM.Our modified preservation process and our resultant optimised dried AM has enhanced structural properties and biochemical stability

  15. Case control study of dry eye and related ocular surface abnormalities in Ibadan, Nigeria.

    Science.gov (United States)

    Bekibele, C O; Baiyeroju, A M; Ajaiyeoba, A; Akang, E E U; Ajayi, B G K

    2010-02-01

    Tear instability is associated with symptoms of ocular discomfort and irritation. Many patients with dry eyes remain untreated due to improper diagnoses. To identify symptoms and surface abnormalities associated with dry eyes. One hundred and fifty-six eyes of 78 subjects attending the Eye Clinic of the University College Hospital Ibadan were screened for dry eyes/tear instability using rose Bengal stain (graded 0-9), tear break-up time (TBUT), Schirmer's 1 tests, tear meniscus height and a standardised symptoms questionnaire. Grades 4-9 rose Bengal staining were considered as positive dry eye and were compared with grades 0-3 staining eyes as negative controls. Mean tear meniscus height, Schirmer's test and TBUT were lower among cases than their corresponding control eyes. The difference between the mean Schirmer's test values of cases and their controls were statistically significant (P = 0.00 for right eyes and P = 0.002 for left eyes). Rose Bengal grades were inversely correlated with the mean Schirmer's values (Pearson correlation -0.429, P = 0.05 for right eyes and -0.335, P = 0.03 for left eyes) and TBUT (Pearson correlation -0.316, P = 0.05 for right eyes and -0.212, P = 0.06 for left eyes). About 95.8% of the cases were symptomatic, as opposed to 70.4% of the controls (P = 0.01, Fisher's exact test) and 95.8% of dry right eyes compared to 61.1% of their controls had ocular surface abnormalities (P = 0.001), while 89.5% of dry left eyes compared to 62.7% of controls had surface abnormalities (P = 0.07). A close relationship exists between ocular irritation symptoms, surface abnormalities and functional evidence of tear instability. Such patients should be treated empirically or screened for dry eyes.

  16. Investigation of equilibrium and kinetics of Cr(VI) adsorption by dried Bacillus cereus using response surface methodology.

    Science.gov (United States)

    Yang, Kai; Zhang, Jing; Yang, Tao; Wang, Hongyu

    2016-01-01

    In this study, response surface methodology (RSM) based on three-variable-five-level central composite rotatable design was used to analyze the effects of combined and individual operating parameters (biomass dose, initial concentration of Cr(VI) and pH) on the Cr(VI) adsorption capacity of dried Bacillus cereus. A quadratic polynomial equation was obtained to predict the adsorbed Cr(VI) amount. Analysis of variance showed that the effect of biomass dose was the key factor in the removal of Cr(VI). The maximum adsorbed Cr(VI) amount (30.93 mg g(-1)) was found at 165.30 mg L(-1), 2.96, and 3.01 g L(-1) for initial Cr(VI) concentration, pH, and biosorbent dosage, respectively. The surface chemical functional groups and microstructure of unloaded and Cr(VI)-loaded dried Bacillus cereus were identified by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), respectively. Besides, the results gained from these studies indicated that Langmuir isotherm and the second-order rate expression were suitable for the removal of Cr(VI) from wastewater. The results revealed RSM was an effective method for optimizing biosorption process, and dried Bacillus cereus had a remarkable performance on the removal of Cr(VI) from wastewater.

  17. High Temperature Dry Sliding Friction and Wear Performance of Laser Cladding WC/Ni Composite Coating

    Directory of Open Access Journals (Sweden)

    YANG Jiao-xi

    2016-06-01

    Full Text Available Two different types of agglomerate and angular WC/Ni matrix composite coatings were deposited by laser cladding. The high temperature wear resistance of these composite coatings was tested with a ring-on-disc MMG-10 apparatus. The morphologies of the worn surfaces were observed using a scanning electron microscopy (SEM equipped with an energy dispersive spectroscopy (EDS for elemental composition. The results show that the high temperature wear resistance of the laser clad WC/Ni-based composite coatings is improved significantly with WC mass fraction increasing. The 60% agglomerate WC/Ni composite coating has optimal high temperature wear resistance. High temperature wear mechanism of 60% WC/Ni composite coating is from abrasive wear of low temperature into composite function of the oxidation wear and abrasive wear.

  18. A comparative effect of various surface chemical treatments on the resin composite-composite repair bond strength

    Directory of Open Access Journals (Sweden)

    Shaloo Gupta

    2015-01-01

    Full Text Available Aim: The aim of this in vitro study was an attempt to investigate the effect of different surface treatments on the bond strength between pre-existing composite and repair composite resin. Materials and Methods: Forty acrylic blocks were prepared in a cuboidal mould. In each block, a well of 5 mm diameter and 5 mm depth was prepared to retain the composite resin (Filtek™ Z350, 3M/ESPE. Aging of the composite discs was achieved by storing them in water at 37°C for 1 week, and after that were divided into 5 groups (n = 8 according to surface treatment: Group I- 37% phosphoric acid, Group II-10% hydrofluoric acid, Group III-30% citric acid, Group IV-7% maleic acid and Group V- Adhesive (no etchant. The etched surfaces were rinsed and dried followed by application of bonding agent (Adper™ Single Bond 2. 3M/ESPE. The repair composite was placed on aged composite, light-cured for 40 seconds and stored in water at 37°C for 1 week. Shear bond strength between the aged and the new composite resin was determined with a universal testing machine (crosshead speed of 0.5 mm/min. Statistical Analysis: The compressive shear strengths were compared for differences using ANOVA test followed by Tamhane′s T2 post hoc analysis. Results: The surface treatment with 10% hydrofluoric acid showed the maximum bond strength followed by 30% citric acid, 7% maleic acid and 37% phosphoric acid in decreasing order. Conclusion: The use of 10% hydrofluoric acid can be a good alternative for surface treatment in repair of composite resin restoration as compared to commonly used 37% orthophosphoric acid.

  19. Thermal analysis of dry eye subjects and the thermal impulse perturbation model of ocular surface.

    Science.gov (United States)

    Zhang, Aizhong; Maki, Kara L; Salahura, Gheorghe; Kottaiyan, Ranjini; Yoon, Geunyoung; Hindman, Holly B; Aquavella, James V; Zavislan, James M

    2015-03-01

    In this study, we explore the usage of ocular surface temperature (OST) decay patterns to distinguished between dry eye patients with aqueous deficient dry eye (ADDE) and meibomian gland dysfunction (MGD). The OST profiles of 20 dry eye subjects were measured by a long-wave infrared thermal camera in a standardized environment (24 °C, and relative humidity (RH) 40%). The subjects were instructed to blink every 5 s after 20 ∼ 25 min acclimation. Exponential decay curves were fit to the average temperature within a region of the central cornea. We find the MGD subjects have both a higher initial temperature (p model, referred to as the thermal impulse perturbation (TIP) model. We conclude that long-wave-infrared thermal imaging is a plausible tool in assisting with the classification of dry eye patient. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Improved Formulations for Air-Surface Exchanges Related to National Security Needs: Dry Deposition Models

    Energy Technology Data Exchange (ETDEWEB)

    Droppo, James G.

    2006-07-01

    The Department of Homeland Security and others rely on results from atmospheric dispersion models for threat evaluation, event management, and post-event analyses. The ability to simulate dry deposition rates is a crucial part of our emergency preparedness capabilities. Deposited materials pose potential hazards from radioactive shine, inhalation, and ingestion pathways. A reliable characterization of these potential exposures is critical for management and mitigation of these hazards. A review of the current status of dry deposition formulations used in these atmospheric dispersion models was conducted. The formulations for dry deposition of particulate materials from am event such as a radiological attack involving a Radiological Detonation Device (RDD) is considered. The results of this effort are applicable to current emergency preparedness capabilities such as are deployed in the Interagency Modeling and Atmospheric Assessment Center (IMAAC), other similar national/regional emergency response systems, and standalone emergency response models. The review concludes that dry deposition formulations need to consider the full range of particle sizes including: 1) the accumulation mode range (0.1 to 1 micron diameter) and its minimum in deposition velocity, 2) smaller particles (less than .01 micron diameter) deposited mainly by molecular diffusion, 3) 10 to 50 micron diameter particles deposited mainly by impaction and gravitational settling, and 4) larger particles (greater than 100 micron diameter) deposited mainly by gravitational settling. The effects of the local turbulence intensity, particle characteristics, and surface element properties must also be addressed in the formulations. Specific areas for improvements in the dry deposition formulations are 1) capability of simulating near-field dry deposition patterns, 2) capability of addressing the full range of potential particle properties, 3) incorporation of particle surface retention/rebound processes, and

  1. Diversity patterns, environmental drivers and changes in vegetation composition in dry inter-Andean valleys

    DEFF Research Database (Denmark)

    Quintana, Catalina; Girardello, Marco; Barfod, Anders

    2016-01-01

    Aims We studied diversity, patterns of endemism and turnover of vegetation composition in dry inter-Andean valleys (DIAVs) where little is known about the influence of the abiotic drivers controlling plant species composition and occurrences, and the life forms that contribute most to α- and β...... species with low abundance (e.g. 30 individuals ha−1), including four endemic species. Most of the endemic species were locally rare, and most of them were restricted to southern valleys...... results further highlight the influence of disturbance, water availability and low temperature on plant species composition and occurrence. We also found significant, contrasting patterns in responses to environmental drivers, when analyzing our data separately by life form. Our results show...

  2. Speciated particle dry deposition to the sea surface: Results from ASEPS '97

    DEFF Research Database (Denmark)

    Pryor, S.C.; Barthelmie, R.J.; Geernaert, L.L.S.

    1999-01-01

    on Precipitation Scavenging and Atmosphere-Surface Exchange Processes. AMS, Richland, Washington, USA, 12pp.) model to calculate size-segregated dry deposition of particle inorganic nitrogen compounds to the western Baltic during the late Spring of 1997 based on data collected as part of the Air-Sea Exchange...

  3. Surface tension of compositions of polyhexametyleneguanidine hydrochloride - surfactants

    Directory of Open Access Journals (Sweden)

    S. Kumargaliyeva

    2012-12-01

    Full Text Available We made up songs bactericidal polyhexamethyleneguanidine hydrochloride (metacyde with the surface-active substances - anionic sodium dodecylsulfate, cationic cetylpyridinium bromide, and nonionic Tween-80 and measured the surface tension of water solutions. The study showed that the composition metacyde with surface-active agents have a greater surface activity than the individual components.

  4. Surface roughness of etched composite resin in light of composite repair

    NARCIS (Netherlands)

    Loomans, B.A.C.; Cardoso, M.V.; Opdam, N.J.M.; Roeters, F.J.M.; Munck, J. De; Huysmans, M.C.D.N.J.M.; Meerbeek, B. Van

    2011-01-01

    OBJECTIVES: In search for clinically effective composite repair protocols, the effect of various etching protocols on the surface roughness of composite resins with different filler composition were investigated. METHODS: Of two composite resins (hybrid-filled Clearfil AP-X; nano-filled Filtek

  5. Glass fibres reinforced polyester composites degradation monitoring by surface analysis

    Energy Technology Data Exchange (ETDEWEB)

    Croitoru, Catalin [“Transilvania” University of Brasov, Materials Engineering and Welding Department, Eroilor 29 Str., 500036 Brasov (Romania); Patachia, Silvia, E-mail: st.patachia@unitbv.ro [“Transilvania” University of Brasov, Product Design Environment and Mechatronics Department, Eroilor 29 Str., 500036 Brasov (Romania); Papancea, Adina [“Transilvania” University of Brasov, Product Design Environment and Mechatronics Department, Eroilor 29 Str., 500036 Brasov (Romania); Baltes, Liana; Tierean, Mircea [“Transilvania” University of Brasov, Materials Engineering and Welding Department, Eroilor 29 Str., 500036 Brasov (Romania)

    2015-12-15

    Highlights: • Glass fibre-reinforced polyester composites surface analysis by photographic method. • The composites are submitted to accelerated ageing by UV irradiation at 254 nm. • The UV irradiation promotes differences in the surface chemistry of the composites. • MB dye is differently adsorbed on surfaces with different degradation degrees. • Good correlation between the colouring degree and surface chemistry. - Abstract: The paper presents a novel method for quantification of the modifications that occur on the surface of different types of gel-coated glass fibre-reinforced polyester composites under artificial UV-ageing at 254 nm. The method implies the adsorption of an ionic dye, namely methylene blue, on the UV-aged composite, and computing the CIELab colour space parameters from the photographic image of the coloured composite's surface. The method significantly enhances the colour differences between the irradiated composites and the reference, in contrast with the non-coloured ones. The colour modifications that occur represent a good indicative of the surface degradation, alteration of surface hydrophily and roughness of the composite and are in good correlation with the ATR-FTIR spectroscopy and optical microscopy results. The proposed method is easier, faster and cheaper than the traditional ones.

  6. Effect of different drying techniques on bioactive components, fatty acid composition, and volatile profile of robusta coffee beans.

    Science.gov (United States)

    Dong, Wenjiang; Hu, Rongsuo; Chu, Zhong; Zhao, Jianping; Tan, Lehe

    2017-11-01

    This study investigated the effect of different drying techniques, namely, room-temperature drying (RTD), solar drying (SD), heat-pump drying (HPD), hot-air drying (HAD), and freeze drying (FD), on bioactive components, fatty acid composition, and the volatile compound profile of robusta coffee beans. The data showed that FD was an effective method to preserve fat, organic acids, and monounsaturated fatty acids. In contrast, HAD was ideal for retaining polyunsaturated fatty acids and amino acids. Sixty-two volatile compounds were identified in the differently dried coffee beans, representing 90% of the volatile compounds. HPD of the coffee beans produced the largest number of volatiles, whereas FD resulted in the highest volatile content. A principal component analysis demonstrated a close relationship between the HPD, SD, and RTD methods whereas the FD and HAD methods were significantly different. Overall, the results provide a basis for potential application to other similar thermal sensitive materials. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Modulation of dry tribological property of stainless steel by femtosecond laser surface texturing

    Science.gov (United States)

    Wang, Zhuo; Zhao, Quanzhong; Wang, Chengwei; Zhang, Yang

    2015-06-01

    We reported on the modification of tribological properties of stainless steel by femtosecond laser surface microstructuring. Regular arranged micro-grooved textures with different spacing were produced on the AISI 304L steel surfaces by an 800-nm femtosecond laser. The tribological properties of smooth surface and textured surface were investigated by carrying out reciprocating ball-on-flat tests against Al2O3 ceramic balls under dry friction. Results show that the spacing of micro-grooves had a significant impact on friction coefficient of textured surfaces. Furthermore, the wear behaviors of smooth and textured surface were also investigated. Femtosecond laser surface texturing had a marked potential for modulating friction and wear properties if the micro-grooves were distributed in an appropriate manner.

  8. Investigation on Failures of Composite Beam and Substrate Concrete due to Drying Shrinkage Property of Repair Materials

    Science.gov (United States)

    Pattnaik, Rashmi Ranjan

    2017-06-01

    A Finite Element Analysis (FEA) and an experimental study was conducted on composite beam of repair material and substrate concrete to investigate the failures of the composite beam due to drying shrinkage property of the repair materials. In FEA, the stress distribution in the composite beam due to two concentrate load and shrinkage of repair materials were investigated in addition to the deflected shape of the composite beam. The stress distributions and load deflection shapes of the finite element model were investigated to aid in analysis of the experimental findings. In the experimental findings, the mechanical properties such as compressive strength, split tensile strength, flexural strength, and load-deflection curves were studied in addition to slant shear bond strength, drying shrinkage and failure patterns of the composite beam specimens. Flexure test was conducted to simulate tensile stress at the interface between the repair material and substrate concrete. The results of FEA were used to analyze the experimental results. It was observed that the repair materials with low drying shrinkage are showing compatible failure in the flexure test of the composite beam and deform adequately in the load deflection curves. Also, the flexural strength of the composite beam with low drying shrinkage repair materials showed higher flexural strength as compared to the composite beams with higher drying shrinkage value of the repair materials even though the strength of those materials were more.

  9. Forest composition modifies litter dynamics and decomposition in regenerating tropical dry forest.

    Science.gov (United States)

    Schilling, Erik M; Waring, Bonnie G; Schilling, Jonathan S; Powers, Jennifer S

    2016-09-01

    We investigated how forest composition, litter quality, and rainfall interact to affect leaf litter decomposition across three successional tropical dry forests in Costa Rica. We monitored litter stocks and bulk litter turnover in 18 plots that exhibit substantial variation in soil characteristics, tree community structure, fungal communities (including forests dominated by ecto- or arbuscular mycorrhizal host trees), and forest age. Simultaneously, we decomposed three standard litter substrates over a 6-month period spanning an unusually intense drought. Decay rates of standard substrates depended on the interaction between litter identity and forest type. Decomposition rates were correlated with tree and soil fungal community composition as well as soil fertility, but these relationships differed among litter types. In low fertility soils dominated by ectomycorrhizal oak trees, bulk litter turnover rates were low, regardless of soil moisture. By contrast, in higher fertility soils that supported mostly arbuscular mycorrhizal trees, bulk litter decay rates were strongly dependent on seasonal water availability. Both measures of decomposition increased with forest age, as did the frequency of termite-mediated wood decay. Taken together, our results demonstrate that soils and forest age exert strong control over decomposition dynamics in these tropical dry forests, either directly through effects on microclimate and nutrients, or indirectly by affecting tree and microbial community composition and traits, such as litter quality.

  10. Measurements of dry deposition rates of 212Pb from aerosols on various natural and artificial surfaces

    International Nuclear Information System (INIS)

    Osaki, S.; Sugihara, S.; Maeda, Y.; Osaki, T.

    2007-01-01

    The dry deposition rates on various grass fields and two forests have been measured by the use of 212 Pb (T 1/2 = 10.6 hours). The deposition rate on grass fields (average: 7 mm x s -1 ) roughly depends on the logarithms of the heights or densities of the grasses. The dry deposition rates on a broadleaved forest (Lithocarpus edulis) and a coniferous forest (Cryptomeria Japonica) were also measured. The highest (ave. 26 mm x s -1 ) was on the forest of C. Japonica because of the dense and adhesive surfaces of the leaves. (author)

  11. Bacterial community composition and extracellular enzyme activity in temperate streambed sediment during drying and rewetting.

    Directory of Open Access Journals (Sweden)

    Elisabeth Pohlon

    Full Text Available Droughts are among the most important disturbance events for stream ecosystems; they not only affect stream hydrology but also the stream biota. Although desiccation of streams is common in Mediterranean regions, phases of dryness in headwaters have been observed more often and for longer periods in extended temperate regions, including Central Europe, reflecting global climate change and enhanced water withdrawal. The effects of desiccation and rewetting on the bacterial community composition and extracellular enzyme activity, a key process in the carbon flow of streams and rivers, were investigated in a typical Central European stream, the Breitenbach (Hesse, Germany. Wet streambed sediment is an important habitat in streams. It was sampled and exposed in the laboratory to different drying scenarios (fast, intermediate, slow for 13 weeks, followed by rewetting of the sediment from the fast drying scenario via a sediment core perfusion technique for 2 weeks. Bacterial community structure was analyzed using CARD-FISH and TGGE, and extracellular enzyme activity was assessed using fluorogenic model substrates. During desiccation the bacterial community composition shifted toward composition in soil, exhibiting increasing proportions of Actinobacteria and Alphaproteobacteria and decreasing proportions of Bacteroidetes and Betaproteobacteria. Simultaneously the activities of extracellular enzymes decreased, most pronounced with aminopeptidases and less pronounced with enzymes involved in the degradation of polymeric carbohydrates. After rewetting, the general ecosystem functioning, with respect to extracellular enzyme activity, recovered after 10 to 14 days. However, the bacterial community composition had not yet achieved its original composition as in unaffected sediments within this time. Thus, whether the bacterial community eventually recovers completely after these events remains unknown. Perhaps this community undergoes permanent changes

  12. Performance evaluation for different sensing surface of BICELLs bio-transducers for dry eye biomarkers

    Science.gov (United States)

    Laguna, M. F.; Holgado, M.; Santamaría, B.; López, A.; Maigler, M.; Lavín, A.; de Vicente, J.; Soria, J.; Suarez, T.; Bardina, C.; Jara, M.; Sanza, F. J.; Casquel, R.; Otón, A.; Riesgo, T.

    2015-03-01

    Biophotonic Sensing Cells (BICELLs) are demonstrated to be an efficient technology for label-free biosensing and in concrete for evaluating dry eye diseases. The main advantage of BICELLs is its capability to be used by dropping directly a tear into the sensing surface without the need of complex microfluidics systems. Among this advantage, compact Point of Care read-out device is employed with the capability of evaluating different types of BICELLs packaged on Biochip-Kits that can be fabricated by using different sensing surfaces material. In this paper, we evaluate the performance of the combination of three sensing surface materials: (3-Glycidyloxypropyl) trimethoxysilane (GPTMS), SU-8 resist and Nitrocellulose (NC) for two different biomarkers relevant for dry eye diseases: PRDX-5 and ANXA-11.

  13. Management type affects composition and facilitative processes in altoandine dry grassland

    Science.gov (United States)

    Catorci, Andrea; Cesaretti, Sabrina; Velasquez, Jose Luis; Burrascano, Sabina; Zeballos, Horacio

    2013-10-01

    We performed our study in the Dry Puna of the southern Peruvian Andes. Through a comparative approach we aimed to assess the effects of the two management systems, low grazing pressure by wild camelids vs. high grazing pressure by domestic livestock and periodic burning. Our general hypothesis was that the traditional high disturbance regime affects the dry Puna species diversity and composition through modifications of the magnitude of plant-plant-interactions and changes of the community structure due to shifts in species dominance. In 40 plots of 10 × 10 m, the cover value of each species was recorded and the species richness, floristic diversity, and community similarity of each treatment were compared. For each disturbance regime, differences of soil features (organic matter, carbon/nitrogen ratio, and potassium content) were tested. To evaluate plant-plant interactions, 4 linear transect divided into 500 plots of 10 × 10 cm were laid out and co-occurrence analysis was performed. We found that different disturbance regimes were associated with differences in the floristic composition, and that the high disturbance condition had lower species diversity and evenness. A decrease of tall species such as Festuca orthophylla and increase of dwarf and spiny Tetraglochin cristatum shrubs was observed as well. In addition, different disturbance intensities caused differences in the functional composition of the plant communities, since species with avoidance strategies are selected by high grazing pressure. High disturbance intensity was also associated to differences of soil features and to different clumped spatial structure of the dry Puna. Our results indicate also that: positive interactions are often species-specific mainly depending on the features of nurse and beneficiary species; the importance of positive interaction is higher at low grazing pressure than at high disturbance intensity; the magnitude and direction of the herbivory-mediated facilitation

  14. Immediate repair bond strengths of microhybrid, nanohybrid and nanofilled composites after different surface treatments

    NARCIS (Netherlands)

    Rinastiti, Margareta; Siswomihardjo, Widowati; Busscher, Henk J.; Ozcan, Mutlu

    Objectives: To evaluate immediate repair bond strengths and failure types of resin composites with and without surface conditioning and characterize the interacting composite surfaces by their surface composition and roughness. Methods: Microhybrid, nanohybrid and nanofilled resin composites were

  15. Chemical composition, antioxidant capacity, and sensory quality of dried jujube fruits as affected by cultivar and drying method.

    Science.gov (United States)

    Wojdyło, Aneta; Figiel, Adam; Legua, Pilar; Lech, Krzysztof; Carbonell-Barrachina, Ángel A; Hernández, Francisca

    2016-09-15

    The aim of this study was to determine the effect of different dying methods, such as convective drying (CD: 50, 60, 70 °C), vacuum-microwave drying (VMD: 120, 480, 480-120 W), a combination of convective pre-drying and vacuum-microwave finish drying [(CPD (60 °C)-VMFD (480-120 W)], and freeze-drying (FD) on key quality parameters of dried jujube fruits (cv. "GAL", "MSI", and "PSI"). The parameters studied included bioactive compounds (flavan-3-ols and flavonols, identified by LC-PDA-MS, and vitamin C), antioxidant capacity (ABTS and FRAP), and sensory attributes (e.g. hardness, jujube-ID, and sweetness). The best quality of the dried product (high contents of bioactive compounds and high intensity of key sensory attributes) was found in fruits treated by FD and VMD 480-120 W. The best cultivars were "PSI" and "GAL" from the point of view of bioactive content and sensory quality, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Dry sliding wear behavior of epoxy composite reinforced with short palmyra fibers

    International Nuclear Information System (INIS)

    Biswal, Somen; Satapathy, Alok

    2016-01-01

    The present work explores the possibility of using palmyra fiber as a replacement for synthetic fiber in conventional polymer composites for application against wear. An attempt has been made in this work to improve the sliding wear resistance of neat epoxy by reinforcing it with short palmyra fibers (SPF). Epoxy composites with different proportions (0, 4, 8 and 12 wt. %) of SPF are fabricated by conventional hand lay-up technique. Dry sliding wear tests are performed on the composite samples using a pin-on-disc test rig as per ASTM G 99-05 standards under various operating parameters. Design of experiment approach based on Taguchi's L16 Orthogonal Arrays is used for the analysis of the wear. This parametric analysis reveals that the SPF content is the most significant factor affecting the wear process followed by the sliding velocity. The sliding wear behavior of these composites under an extensive range of test conditions is predicted by a model based on the artificial neural network (ANN). A well trained ANN has been used to predict the sliding wear response of epoxy based composites over a wide range. (paper)

  17. Tyre contact length on dry and wet road surfaces measured by three-axial accelerometer

    Science.gov (United States)

    Matilainen, Mika; Tuononen, Ari

    2015-02-01

    We determined the tyre contact length on dry and wet roads by measuring the accelerations of the inner liner with a three-axial accelerometer. The influence of the tyre pressure, driving velocity, and tread depth on the contact length was studied in both types of road surface conditions. On dry asphalt the contact length was almost constant, regardless of the driving velocity. On wet asphalt the presence of water could be detected even at low driving velocities (e.g. 20 km/h for a worn tyre) as the contact length began to decrease from that found in the dry asphalt situation. In addition to improving the performance of active safety systems and driver warning systems, the contact length information could be beneficial for classifying and studying the aquaplaning behaviour of tyres.

  18. Effect of oven drying and storage on essential oil composition of clove (Syzygium aromaticum) from Toli-Toli

    Science.gov (United States)

    Murni, V. W.; Saepudin, E.; Cahyana, A. H.; Rahayu, D. U. C.; Hastuti, L. T.; Haib, J.

    2017-07-01

    The research about post-harvested clove is still limited especially in Indonesia, as the biggest producer of clove in the world. The present study was aimed to investigate the effect of drying process and storage on the composition of essential oil of Indonesian clove originated from Toli-Toli. The essential oil of fresh and dried clove was obtained by steam distillation and the composition of the oil was analyzed by gas chromatography-mass spectrometry (GC-MS). In all of the clove oil samples, eugenol was the major component, followed by caryophyllene and acetyleugenol. The drying method used was oven drying at 50°C until clove's moisture content reaches 13±1%. During the drying process, the content of phenylpropanoids such as eugenol, isoeugenol, and chavicol increased, while esters and monoterpenes decreased. The composition of clove oil was studied from dried clove after oven drying, then stored in the laboratory at room temperature for 4 months. There was slightly change on clove oil composition after 4 months of storage. The content of major components of clove like eugenol was higher while acetyleugenol was lower after 4 months of storage.

  19. Effects of solar radiation on grape (Vitis vinifera L.) composition and dried fruit colour

    International Nuclear Information System (INIS)

    Uhlig, B.A.

    1998-01-01

    Most sun-exposed fruit (Vitis vinifera L.) produced dark brown berries with low L-values, whereas most dried berries from shade fruit were acceptable in lightness although some had a green tinge. Fruit shaded by the natural vine canopy or exposed to direct solar radiation had similar drying ratios. However, berry weights were significantly higher in the shade than in the sun for both cultivars. The difference in berry weight between the two positions was less pronounced in the heat affected year. Solar radiation changed the composition of fresh berries and the colour of the dried fruit. The soluble-solid concentration was higher in fresh fruit exposed to direct solar radiation than in fruit grown in shaded conditions within the canopy. In the heat affected year the berries from both positions had the same soluble-solid concentrations, possibly due to dehydration of the fruit. No significant difference was found between the pH of sun fruit and shade fruit, but the titratable acidity was higher in shade fruit. Malate and tartrate concentrations in berry skin and the polyphenol oxidase activities had carotenoid concentrations in whole fresh berries were not significantly different for sun and shade fruit. Total phenol concentrations in berry skin were higher in sun fruit and chlorophyll concentrations in whole, fresh berries were higher in shade fruit. (author)

  20. Nutrients Composition in Fit Snacks Made from Ostrich, Beef and Chicken Dried Meat.

    Science.gov (United States)

    Zdanowska-Sąsiadek, Żaneta; Marchewka, Joanna; Horbańczuk, Jarosław Olav; Wierzbicka, Agnieszka; Lipińska, Paulina; Jóźwik, Artur; Atanasov, Atanas G; Huminiecki, Łukasz; Sieroń, Aleksander; Sieroń, Karolina; Strzałkowska, Nina; Stelmasiak, Adrian; De Smet, Stefaan; Van Hecke, Thomas; Hoffman, Louwrens C

    2018-05-25

    The aim of the study was to compare three types of meat snacks made from ostrich, beef, and chicken meat in relation to their nutrients content including fat, fatty acids, heme iron, and peptides, like anserine and carnosine, from which human health may potentially benefit. Dry meat samples were produced, from one type of muscle, obtained from ostrich ( m. ambiens ), beef ( m. semimembranosus ), and broiler chicken meat ( m. pectoralis major ). The composition of dried ostrich, beef, and chicken meat, with and without spices was compared. We show that meat snacks made from ostrich, beef, and chicken meat were characterized by high concentration of nutrients including proteins, minerals (heme iron especially in ostrich, than in beef), biologically active peptides (carnosine-in beef, anserine-in ostrich then in chicken meat). The, beneficial to human health, n -3 fatty acids levels differed significantly between species. Moreover, ostrich jerky contained four times less fat as compared to beef and half of that in chicken. In conclusion we can say that dried ostrich, beef, and chicken meat could be a good source of nutritional components.

  1. Nutrients Composition in Fit Snacks Made from Ostrich, Beef and Chicken Dried Meat

    Directory of Open Access Journals (Sweden)

    Żaneta Zdanowska-Sąsiadek

    2018-05-01

    Full Text Available The aim of the study was to compare three types of meat snacks made from ostrich, beef, and chicken meat in relation to their nutrients content including fat, fatty acids, heme iron, and peptides, like anserine and carnosine, from which human health may potentially benefit. Dry meat samples were produced, from one type of muscle, obtained from ostrich (m. ambiens, beef (m. semimembranosus, and broiler chicken meat (m. pectoralis major. The composition of dried ostrich, beef, and chicken meat, with and without spices was compared. We show that meat snacks made from ostrich, beef, and chicken meat were characterized by high concentration of nutrients including proteins, minerals (heme iron especially in ostrich, than in beef, biologically active peptides (carnosine—in beef, anserine—in ostrich then in chicken meat. The, beneficial to human health, n-3 fatty acids levels differed significantly between species. Moreover, ostrich jerky contained four times less fat as compared to beef and half of that in chicken. In conclusion we can say that dried ostrich, beef, and chicken meat could be a good source of nutritional components.

  2. The measurement of dry deposition and surface runoff to quantify urban road pollution in Taipei, Taiwan.

    Science.gov (United States)

    Wang, Yunn-Jinn; Chen, Chi-Feng; Lin, Jen-Yang

    2013-10-16

    Pollutants deposited on road surfaces and distributed in the environment are a source of nonpoint pollution. Field data are traditionally hard to collect from roads because of constant traffic. In this study, in cooperation with the traffic administration, the dry deposition on and road runoff from urban roads was measured in Taipei City and New Taipei City, Taiwan. The results showed that the dry deposition is 2.01-5.14 g/m(2) · day and 78-87% of these solids are in the 75-300 µm size range. The heavy metals in the dry deposited particles are mainly Fe, Zn, and Na, with average concentrations of 34,978, 1,519 and 1,502 ppm, respectively. Elevated express roads show the highest heavy metal concentrations. Not only the number of vehicles, but also the speed of the traffic should be considered as factors that influence road pollution, as high speeds may accelerate vehicle wear and deposit more heavy metals on road surfaces. In addition to dry deposition, the runoff and water quality was analyzed every five minutes during the first two hours of storm events to capture the properties of the first flush road runoff. The sample mean concentration (SMC) from three roads demonstrated that the first flush runoff had a high pollution content, notably for suspended solid (SS), chemical oxygen demand (COD), oil and grease, Pb, and Zn. Regular sweeping and onsite water treatment facilities are suggested to minimize the pollution from urban roads.

  3. Inflammatory Response to Lipopolysaccharide on the Ocular Surface in a Murine Dry Eye Model.

    Science.gov (United States)

    Simmons, Ken T; Xiao, Yangyan; Pflugfelder, Stephen C; de Paiva, Cintia S

    2016-05-01

    Toll-like receptor 4 (TLR4) alerts cells to the presence of bacteria by initiating an inflammatory response. We hypothesize that disruption of the ocular surface barrier in dry eye enhances TLR4 signaling. This study determined whether dry eye enhances expression of inflammatory mediators in response to topically applied TLR4 ligand. A single dose of lipopolysaccharide (LPS) or vehicle (endotoxin-free water) was applied to the cornea of nonstressed (NS) mice or mice subjected to 5 days of desiccating stress (DS). After 4 hours, corneal epithelium and conjunctiva were extracted to analyze expression of inflammatory mediators via PCR. Protein expression was confirmed by immunobead assay and immunostaining. Topically applied LPS increased expression of inflammatory mediators IL-1β, CXCL10, IL-12a, and IFN-γ in the conjunctiva, and IL-1β and CXCL10 in the cornea of NS mice compared to that in untreated controls. LPS in DS mice produced 3-fold increased expression of IL-1β in cornea and 2-fold increased expression in IL-12a in conjunctiva compared to that in LPS-treated control mice. LPS increased expression of inflammatory cytokines on the ocular surface. This expression was further increased in dry eye, which suggests that epithelial barrier disruption enhances exposure of LPS to TLR4+ cells and that the inflammatory response to endotoxin-producing commensal or pathogenic bacteria may be more severe in dry eye disease.

  4. COMPOSITE FRIEND SISAL / POLYESTER TREATED IN SURFACE

    Directory of Open Access Journals (Sweden)

    Jayna K. Dionisio Santos

    2011-09-01

    Full Text Available The use of composites in manufacturing equipment and products is taking a very important space in the industry in general. Moreover these materials have unique characteristics when analyzed separately from constituents who are part of them. However it is know that cares must be taken in their manufacture, as the use of appropriate process and the composition of each element, in addition to adherence fiber / matrix, which is a major factor in obtaining of the final mechanical strength of the product. One should also take into account whether the composites are environmentally friendly. For this reason, in this work, a composite partially ecological was made, using as reinforcement, a sisal woven and, as matrix, the polyester resin. Seeking to improve the adherence fiber / matrix, a treatment in sisal woven was performed with aqueous solution of sodium hydroxide (NaOH at a concentration of 3%. The composite subjected to this treatment presented, in bending test, a better mechanical performance, with an increase of 27% in the flexion strength and of 54% in maximum strain, but there was a reduction of about 15% in its flexural modulus.

  5. Change in dry matter and nutritive composition of Brachiaria humidicola grown in Ban Thon soil series

    Directory of Open Access Journals (Sweden)

    Jeerasak Chobtang

    2008-11-01

    Full Text Available This experiment was conducted to determine the change in dry matter and nutritive composition of Humidicola grass (Brachiaria humidicola grown in Ban Thon soil series (infertility soil as a function of growth age. One rai (0.16 ha of two-year-old pasture of fertilised Humidicola grass was uniformly cut and the regrowth samples were collected every twenty days. The samples were subjected to analysis for dry matter content and nutritive composition, i.e. crude protein, ash, calcium, phosphorus, neutral detergent fibre, acid detergent fibre, and acid detergent lignin. The results showed that while the yields of available forage and leaves increased curvilinearly (quadratic, p<0.05, the stem yield increased linearly (p<0.05 over sampling dates. The highest biomass accumulation rate was numerically observed between 40-60 days of regrowth. The concentrations of crude protein, ash, calcium and phosphorus decreased curvilinearly (quadratic, p<0.05 with advancing maturity and reached the lowest flat after 60 days of regrowth. The cell wall components, i.e. NDF, ADF and ADL, increased over the experimental period and reached the highest plateau at 40 days of regrowth. It was concluded that Humidicola grass should be grazed or preserved at the regrowth age of not over 60 days to maximise the utilisation of the grass.

  6. Evaluation of Nutritional Composition of The Dried Seaweed Ulva lactuca from Pameungpeuk Waters, Indonesia.

    Science.gov (United States)

    Rasyid, Abdullah

    2017-07-01

    The nutritional composition of the dried seaweed Ulva lactuca from Pameungpeuk waters, including proximate, vitamins, minerals, dietary fibre and heavy metal has been carried out. The objective of this present study is to know the nutritional composition of the dried seaweed U. lactuca for utilisation in human nutrition in the future. Results show that carbohydrate was the major component in the proximate analysis of U. lactuca in the present study. The carbohydrate content was 58.1%. Moisture, ash, protein and fat content were 16.9%, 11.2%, 13.6% and 0.19% respectively, while dietary fibre was 28.4%. The vitamin A content was examined in this study less than 0.5 IU/100 mg while vitamin B1 (thiamine) and vitamin B2 (riboflavin) were 4.87 mg/kg and 0.86 mg/kg respectively. The calcium content was 1828 mg/100 g higher than other minerals. The heavy metal content examined in this study were lower than the limit of the quality criteria applied to edible seaweeds sold in Indonesia. Based on the results of this study show that U. lactuca has potential to be developed as an alternative source of a healthy food for human in the future.

  7. Effects of contact cap dimension on dry adhesion of bioinspired mushroom-shaped surfaces

    Science.gov (United States)

    Wang, Yue; Shao, Jinyou; Ding, Yucheng; Li, Xiangming; Tian, Hongmiao; Hu, Hong

    2015-03-01

    Dry adhesion observed in small creatures, such as spiders, insects, and geckos, has many great advantages such as repeatability and strong adhesiveness. In order to mimic these unique performances, fibrillar surface with a mushroom shaped end has drawn lots of attentions because of its advantage in efficiently enhancing adhesion compared with other sphere or simple flat ends. Here, in order to study the effects of contact cap dimension on adhesion strength, patterned surfaces of mushroom-shaped micropillars with differing cap diameters are fabricated based on the conventional photolithography and molding. The normal adhesion strength of these dry adhesives with varying cap diameters is measured with home-built equipment. The strength increases with the rise of cap diameter, and interestingly it becomes strongest when the mushroom caps join together.

  8. Functional strategies of tropical dry forest plants in relation to growth form and isotopic composition

    Science.gov (United States)

    Santiago, L. S.; Silvera, K.; Andrade, J. L.; Dawson, T. E.

    2017-11-01

    Tropical dry forests (TDFs) undergo a substantial dry season in which plant species must endure several months of drought. Although TDFs support a diverse array of plant growth forms, it is not clear how they vary in mechanisms for coping with seasonal drought. We measured organic tissue stable isotopic composition of carbon (δ13C) and nitrogen (δ15N) across six plant growth forms including epiphytes, terrestrial succulents, trees, shrubs, herbs, and vines, and oxygen (δ18O) of four growth forms, to distinguish among patterns of resource acquisition and evaluate mechanisms for surviving annual drought in a lowland tropical dry forest in Yucatan, Mexico. Terrestrial succulent and epiphyte δ13C was around -14‰, indicating photosynthesis through the Crassulacean acid metabolism pathway, and along with one C4 herb were distinct from mean values of all other growth forms, which were between -26 and -29‰ indicating C3 photosynthesis. Mean tissue δ15N across epiphytes was -4.95‰ and was significantly lower than all other growth forms, which had values around +3‰. Tissue N concentration varied significantly among growth forms with epiphytes and terrestrial succulents having significantly lower values of about 1% compared to trees, shrubs, herbs and vines, which were around 3%. Tissue C concentration was highest in trees, shrubs and vines, intermediate in herbs and epiphytes and lowest in terrestrial succulents. δ18O did not vary among growth forms. Overall, our results suggest several water-saving aspects of resource acquisition, including the absolute occurrence of CAM photosynthesis in terrestrial succulents and epiphytes, high concentrations of leaf N in some species, which may facilitate CO2 drawdown by photosynthetic enzymes for a given stomatal conductance, and potentially diverse N sources ranging from atmospheric N in epiphytes with extremely depleted δ15N values, and a large range of δ15N values among trees, many of which are legumes and dry season

  9. Sputtering induced surface composition changes in copper-palladium alloys

    International Nuclear Information System (INIS)

    Sundararaman, M.; Sharma, S.K.; Kumar, L.; Krishnan, R.

    1981-01-01

    It has been observed that, in general, surface composition is different from bulk composition in multicomponent materials as a result of ion beam sputtering. This compositional difference arises from factors like preferential sputtering, radiation induced concentration gradients and the knock-in effect. In the present work, changes in the surface composition of copper-palladium alloys, brought about by argon ion sputtering, have been studied using Auger electron spectroscopy. Argon ion energy has been varied from 500 eV to 5 keV. Enrichment of palladium has been observed in the sputter-altered layer. The palladium enrichment at the surface has been found to be higher for 500 eV argon ion sputtering compared with argon ion sputtering at higher energies. Above 500 eV, the surface composition has been observed to remain the same irrespective of the sputter ion energy for each alloy composition. The bulk composition ratio of palladium to copper has been found to be linearly related to the sputter altered surface composition ratio of palladium to copper. These results are discussed on the basis of recent theories of alloy sputtering. (orig.)

  10. Presence or absence of ocular surface inflammation directs clinical and therapeutic management of dry eye

    OpenAIRE

    Sambursky, Robert

    2016-01-01

    Robert Sambursky Coastal Eye Institute, Cornea and Comprehensive Ophthalmology, Bradenton, FL, USA Background: The presence of clinically significant inflammation has been confirmed in the tears of 40%–65% of patients with symptoms of dry eye. Ocular surface inflammation may lead to tear film instability, epithelial cell irregularities, and permeability, resulting in chronic symptomatic pain and fluctuating vision as well as negative surgical outcomes.Patients and methods: A retro...

  11. Chemical, mechanical and biological properties of contemporary composite surface sealers.

    Science.gov (United States)

    Anagnostou, Maria; Mountouris, George; Silikas, Nick; Kletsas, Dimitris; Eliades, George

    2015-12-01

    To evaluate the chemical, mechanical, and biological properties of modern composite surface sealers (CSS) having different compositions. The CSS products tested were Biscover LV (BC), Durafinish (DF), G-Coat Plus (GC), and Permaseal (PS). The tests performed were: (A): degree of conversion (DC%) by ATR-FTIR spectroscopy; (B): thickness of O2-inhibition layer by transmission optical microscopy; (C): surface hardness, 10 min after irradiation and following 1 week water storage, employing a Vickers indenter (VHN); (D): color (ΔE*) and gloss changes (ΔGU) after toothbrush abrasion, using L*a*b* colorimetry and glossimetry; (E): accelerated wear (GC,PS only) by an OHSU wear simulator plus 3D profilometric analysis, and (F): cytotoxicity testing of aqueous CSS eluents on human gingival fibroblast cultures employing the methyl-(3)H thymidine DNA labeling method. Statistical analyses included 1-way (A, B, ΔE*, ΔGU) and 2-way (C, F) ANOVAs, plus Tukey post hoc tests. Student's t-test was used to evaluate the results of the accelerated wear test (α=0.05 for all). The rankings of the statistical significant differences were: (A) PS (64.9)>DF,BC,GC (56.1-53.9) DC%; (B) DF,PS (12.3,9.8)>GC,BC (5.2,4.8) μm; (C): GC (37.6)>BC,DF (32.6,31.1)>PS (26.6) VHN (10 min/dry) and BC,DF (29.3,28.7)>GC(26.5)>PS(21.6) VHN (1w/water), with no significant material/storage condition interaction; (D): no differences were found among GC,DF,BC,PS (0.67-1.11) ΔE*, with all values within the visually acceptable range and PS,BC (32.8,29.4)>GC,DF (19.4,12.9) ΔGU; (E): no differences were found between GC and PS in volume loss (0.10,0.11 mm(3)), maximum (113.9,130.5 μm) and mean wear depths (30.3,27.5 μm); (F): at 1% v/v concentration, DF showed toxicity (23% vital cells vs 95-102% for others). However, at 5% v/v concentration DF (0%) and BC (9%) were the most toxic, whereas GC (58%) and PS (56%) showed moderate toxicity. Important chemical, mechanical, and biological properties exist among

  12. Surface topography and contact mechanics of dry and wet human skin

    Directory of Open Access Journals (Sweden)

    Alexander E. Kovalev

    2014-08-01

    Full Text Available The surface topography of the human wrist skin is studied by using optical and atomic force microscopy (AFM methods. By using these techniques the surface roughness power spectrum is obtained. The Persson contact mechanics theory is used to calculate the contact area for different magnifications, for the dry and wet skin. The measured friction coefficient between a glass ball and dry and wet skin can be explained assuming that a frictional shear stress σf ≈ 13 MPa and σf ≈ 5 MPa, respectively, act in the area of real contact during sliding. These frictional shear stresses are typical for sliding on surfaces of elastic bodies. The big increase in friction, which has been observed for glass sliding on wet skin as the skin dries up, can be explained as result of the increase in the contact area arising from the attraction of capillary bridges. Finally, we demonstrated that the real contact area can be properly defined only when a combination of both AFM and optical methods is used for power spectrum calculation.

  13. Recent field studies of dry deposition to surfaces in plant canopies

    International Nuclear Information System (INIS)

    Lindberg, S.E.; Lovett, G.M.; Bondietti, E.A.; Davidson, C.I.

    1984-01-01

    A variety of field techniques were used to assess the dry deposition of sulfur. In a deciduous forest canopy in eastern Tennessee, inert petri plates and adjacent chestnut oak leaves showed similar SO 4 -2 deposition velocities of about 0.1 cm s -1 . In the same forest, statistical analysis of throughfall yielded a deposition velocity of 0.48 cm s -1 for total sulfur (SO 4 -2 plus SO 2 ). The throughfall technique appears useful for scaling individual surface measurements to larger spatial and temporal scales. On a grassy field in Illinois, flat Teflon plates, petri dishes, and dustfall buckets were exposed side by side. Measured sulfate deposition increased with increasing rim height on the collection surface, and deposition velocities ranged from 0.14 to 0.70 cm s -1 . Much of the deposition to these surfaces can be attributed to large-particle SO 4 -2 . Dry season (summer) deposition velocities of 7 Be in California were found to be similar to dry deposition velocities of 212 Pb in Tennessee, ranging from 0.18 to 0.35 cm s -1 . These natural radionuclides attach to submicron aerosols in the atmosphere and may be useful tracers of submicron SO 4 -2 deposition. 9 references, 5 figures, 4 tables

  14. Effect of natural and artificial drying of leaf biomassof Psidium guajava on the content and chemical composition of essential oil

    Directory of Open Access Journals (Sweden)

    Elizabeth Aparecida Josefi da Silva

    2016-10-01

    Full Text Available Psidium guajava L. is native to Central and South America. It is widely distributed and well adapted to Brazil, a producer of essential oils rich in terpenes. The objective of this study was to evaluate the effects of natural and artificial drying on the content and chemical composition of the essential oil of guava leaves (Psidium guajava L. grown in Rio Verde (GO. The two treatments consisted of drying fresh leaves either naturally in the shade or artificially at 40°C. Chemical composition was analyzed qualitatively and quantitatively by gas coupled with mass spectrometer chromatography (GC/MS and gas chromatography using a flame ionizer (GC-FID, respectively. The method of drying changed the content and chemical composition of the essential oil of guava leaves. Drying in the shade reduced the content and altered the constituents of the essential oil, whereas drying in an oven at 40°C, despite having reduced the amounts of the constituents, exhibited the highest essential oil content and increased the concentration of certain major constituents as compared to that in the natural shade drying method. The major components found in the essential oil of leaves regardless of the drying processes were trans-caryophyllene, ?-humulene, aromadendrene, ?-selinene, and selin-11-en-4?-ol. According to reports in the literature, these compounds possess fungicidal, insecticidal, antimicrobial, and anti-inflammatory activity, among others beneficial actions.

  15. Microhardness changes gradient of the duplex stainless steel (DSS surface layer after dry turning

    Directory of Open Access Journals (Sweden)

    G. Krolczyk

    2014-10-01

    Full Text Available The article presents the gradient of microhardness changes as a function of the distance from the material surface after turning with a wedge provided with a coating with a ceramic intermediate layer. The investigation comprised the influence of cutting speed on surface integrity microhardness in dry machining. The tested material was duplex stainless steel (DSS with two-phase, ferritic-austenitic structure. The tests have been performed under production conditions during machining of parts for electric motors and deep-well pumps.

  16. Nonhazardous solvent composition and method for cleaning metal surfaces

    International Nuclear Information System (INIS)

    Googin, J.M.; Simandl, R.F.; Thompson, L.M.

    1993-01-01

    A solvent composition for displacing greasy and oily contaminants as well as water and/or aqueous residue from metallic surfaces, especially surfaces of radioactive materials so that such surfaces can be wiped clean of the displaced contaminants, water and/or aqueous residue. The solvent composition consists essentially of a blend of nonpolar aliphatic hydrocarbon solvent having a minimum flash point of about 140 F and 2 to 25 volume percent of a polar solvent having a flash point sufficiently high so as to provide the solvent composition with a minimum flash point of at least 140 F. The solvent composition is nonhazardous so that when it is used to clean the surfaces of radioactive materials the waste in the form of paper or cloth wipes, lab coats and the like used in the cleaning operation is not considered to be mixed waste composed of a hazardous solvent and a radioactive material

  17. Surface composition of carburized tungsten trioxide and its catalytic activity

    International Nuclear Information System (INIS)

    Nakazawa, M.; Okamoto, H.

    1985-01-01

    The surface composition and electronic structure of carburized tungsten trioxide are investigated using x-ray photoelectron spectroscopy (XPS). The relationship between the surface composition and the catalytic activity for methanol electro-oxidation is clarified. The tungsten carbide concentration in the surface layer increases with the carburization time. The formation of tungsten carbide enhances the catalytic activity. On the other hand, the presence of free carbon or tungsten trioxide in the surface layer reduces the activity remarkably. It is also shown that, the higher the electronic density of states near the Fermi level, the higher the catalytic activity

  18. Durable superhydrophobic paper enabled by surface sizing of starch-based composite films

    Science.gov (United States)

    Chen, Gang; Zhu, Penghui; Kuang, Yudi; Liu, Yu; Lin, Donghan; Peng, Congxing; Wen, Zhicheng; Fang, Zhiqiang

    2017-07-01

    Superhydrophobic paper with remarkable durability is of considerable interest for its practical applications. In this study, a scalable, inexpensive, and universal surface sizing technique was implemented to prepare superhydrophobic paper with enhanced durability. A thin layer of starch-based composite, acting as a bio-binder, was first coated onto the paper surface by a sophisticated manufacturing technique called surface sizing, immediately followed by a spray coating of hexamethyl disilazane treated silica nanoparticles (HMDS-SiNPs) dispersed in ethanol on the surface of the wet starch-coated sheet, and the dual layers dried at the same time. Consequently, durable superhydrophobic paper with bi-layer structure was obtained after air drying. The as-prepared superhydrophobic paper not only exhibited a self-cleaning behavior, but also presented an enhanced durability against scratching, bending/deformation, as well as moisture. The universal surface sizing of starch-based composites may pave the way for the up-scaled and cost-effective production of durable superhydrophobic paper.

  19. Micro-tribological properties of hydroxyapatite-based composites in dry sliding

    International Nuclear Information System (INIS)

    Lu, Zhi; Liu, Yong; Liu, Bowei; Liu, Meiling

    2013-01-01

    Highlights: ► The micro-tribological properties of HA-based composites were investigated. ► The micro-scale test is greatly benefits to the analyses of the wear mechanism. ► A higher speed benefits the formation of the lubricating layer, when high in Cu. ► With increasing Cu, the wear mechanism shift from abrasive wear to adhesive wear. - Abstract: The micro-tribological properties of hydroxyapatite-based composites sliding against alumina balls were investigated by a ball-on-block tribometer. Surface properties of the HA-based composites were measured and examined by using atomic force microscopy and scanning electron microscopy. Running-in behavior during sliding tests was studied as a function of surface properties. The effects of copper fibers, initial surface roughness, and sliding velocity on the friction coefficient and the wear resistance were discussed. Results show that a lubricant layer benefits the tribological properties of the composites. With the increasing of Cu, the lubricant layer is more stable, and resistant to increase of the sliding velocity. At a Cu content of 15%, the wear curve is very stable even at a velocity of 900 rpm. The wear mechanism also changes from abrasive wear to adhesive wear. A model was quoted to describe the relationship between the wear resistant and the load

  20. Hot Surface Ignition of A Composite Fuel Droplet

    Directory of Open Access Journals (Sweden)

    Glushkov Dmitrii O.

    2015-01-01

    Full Text Available The present study examines the characteristics of conductive heating (up to ignition temperature of a composite fuel droplet based on coal, liquid petroleum products, and water. In this paper, we have established the difference between heat transfer from a heat source to a fuel droplet in case of conductive (hot surface and convective (hot gas heat supply. The Leidenfrost effect influences on heat transfer characteristics significantly due to the gas gap between a composite fuel droplet and a hot surface.

  1. Ocular surface temperature in patients with evaporative and aqueous-deficient dry eyes: a thermographic approach.

    Science.gov (United States)

    Matteoli, S; Favuzza, E; Mazzantini, L; Aragona, P; Cappelli, S; Corvi, A; Mencucci, R

    2017-07-26

    In recent decades infrared thermography (IRT) has facilitated accurate quantitative measurements of the ocular surface temperature (OST), applying a non-invasive procedure. The objective of this work was to develop a procedure based on IRT, which allows characterizing of the cooling of the ocular surface of patients suffering from dry eye syndrome, and distinguishing among patients suffering from aqueous deficient dry eye (ADDE) and evaporative dry eyes (EDE). All patients examined (34 females and 4 males, 23-84 years) were divided into two groups according to their Schirmer I result (⩽ 7 mm for ADDE and  >  7 mm for EDE), and the OST was recorded for 7 s at 30 Hz. For each acquisition, the temperatures of the central cornea (CC) as well as those of both temporal and nasal canthi were investigated. Findings showed that the maximum temperature variation (up to 0.75  ±  0.29 °C) was at the CC for both groups. Furthermore, patients suffering from EDE tended to have a higher initial OST than those with ADDE, explained by the greater quantity of the tear film, evenly distributed over the entire ocular surface, keeping the OST higher initially. Results also showed that EDE patients had an average cooling rate higher than those suffering from ADDE, confirming the excessive evaporation of the tear film. Ocular thermography paves the way to become an effective tool for differentiating between the two different etiologies of dry eye syndrome.

  2. The ocular surface and tear film and their dysfunction in dry eye disease.

    Science.gov (United States)

    Rolando, M; Zierhut, M

    2001-03-01

    The ocular surface, tear film, lacrimal glands, and eyelids act as a functional unit to preserve the quality of the refractive surface of the eye and to resist injury and protect the eye against changing bodily and environmental conditions. Events that disturb the homeostasis of this functional unit can result in a vicious cycle of ocular surface disease. The tear film is the most dynamic structure of the functional unit, and its production and turnover is essential to maintaining the health of the ocular surface. Classically, the tear film is reported to be composed of three layers: the mucin, aqueous, and lipid layers. The boundaries and real thickness of such layers is still under discussion. A dysfunction of any of these layers can result in dry eye disease.

  3. Negentropy Generation and Fractality in the Dry Friction of Polished Surfaces

    Directory of Open Access Journals (Sweden)

    Mordecai Segall

    2010-03-01

    Full Text Available We consider the Robin Hood model of dry friction to study entropy transfer during sliding. For the polished surface (steady state we study the probability distribution of slips and find an exponential behavior for all the physically relevant asperity interaction-distance thresholds. In addition, we characterize the time evolution of the sample by its spatial fractal dimension and by its entropy content. Starting from an unpolished surface, the entropy decreases during the Robin Hood process, until it reaches a plateau; thereafter the system fluctuates above the critical height. This validates the notion that friction increases information in the neighborhood of the contacting surface at the expense of losing information in remote regions. We explain the practical relevance of these results for engineering surface processing such as honing.

  4. Response surface optimization of lyoprotectant for Lactobacillus bulgaricus during vacuum freeze-drying.

    Science.gov (United States)

    Chen, He; Chen, Shiwei; Li, Chuanna; Shu, Guowei

    2015-01-01

    The individual and interactive effects of skimmed milk powder, lactose, and sodium ascorbate on the number of viable cells and freeze-drying survival for vacuum freeze-dried powder formulation of Lactobacillus bulgaricus were studied by response surface methodology, and the optimal compound lyoprotectant formulations were gained. It is shown that skim milk powder, lactose, and sodium ascorbate had a significant impact on variables and survival of cultures after freeze-drying. Also, their protective abilities could be enhanced significantly when using them as a mixture of 28% w/v skim milk, 24% w/v lactose, and 4.8% w/v sodium ascorbate. The optimal freeze-drying survival rate and the number of viable cells of Lactobacillus bulgaricus were observed to be (64.41±0.02)% and (3.22±0.02)×10(11) colony-forming units (CFU)/g using the optimal compound protectants, which were very close to the expected values 64.47% and 3.28×10(11) CFU/g.

  5. Drying Kinetics and Optimisation of Pectin Extraction from Banana Peels via Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Bee Lin Chua

    2018-01-01

    Full Text Available Banana peels which are the waste in abundance, are used to extract valuable pectin. The gelling ability of the pectin has gained attention in food and pharmaceutical industries. This research aims to select the best drying kinetic model for banana peels and also optimize the pectin extraction process using Box-Behnken response surface design (BBD. Determination of pectin gelling mechanism using degree of esterification (DE is also focused in this research. In this study, oven drying with temperature 50°C was chosen as the best drying temperature due to highest extraction yield. Furthermore, Page-Two-term model was selected as the best model to describe the drying kinetics of banana peels due to highest R2 value (0.9991 and lowest RMSE value (0.001. The optimal extraction conditions given by BBD were 75°C extraction temperature, 23 min extraction time and 1:33.3 g/ml solid-liquid ratio. Likewise, the DE for both pectins extracted using unoptimised and optimised conditions were 71.92±1.38% and 76.1±2.07% respectively. Both of the pectins were classified as high-methoxyl pectins. The pectin with higher DE also indicated that the rate of gel formation is higher. The results showed that the pectin yield and gelling time has successfully improved after optimised the pectin extraction process.

  6. Influence of additives on melt viscosity, surface tension, and film formation of dry powder coatings.

    Science.gov (United States)

    Sauer, Dorothea; McGinity, James W

    2009-06-01

    Limited information on thermally cured dry-powder coatings used for solid dosage forms has been available in the literature. The aim of this study was to characterize the film formation process of Eudragit L 100-55 dry-powder coatings and to investigate the influence of film additives on melt viscosity and surface tension. The coating process employed no liquids and the plasticizer was combined with the polymer using hot melt extrusion. Thermoanalytical methods including differential scanning calorimetry and thermogravimetric analysis (TGA) were used to investigate the thermal properties of the dry-coating formulations. The rheological behavior of the coating formulations were characterized with the extrusion torque, and the surface energy parameters were determined from contact angle measurements. The influence of the level of triethyl citrate (TEC) as plasticizer and polyethylene glycol (PEG) 3350 in the polymer film on film formation was investigated using a digital force tester. TGA confirmed thermal stability of all coating excipients at the investigated curing conditions. Increasing TEC levels and the addition of PEG 3350 as a low melting excipient in the coating reduced the viscosity of the polymer. Plasticization of the polymer with TEC increased the surface free energy, whereas the admixture of 10% PEG 3350 did not affect the surface free energy of Eudragit L 100-55. The spreading coefficient of the polymers over two sample tablet formulations was reduced with increasing surface free energy. During the curing process, puncture strength, and elongation of powder-cast films increased. The effect of curing time on the mechanical properties was dependent on the plasticizer content. The incorporation of TEC and PEG 3350 into the Eudragit L 100-55 powder coating formulation improved film formation. Mechanical testing of powder-cast films showed an increase of both elongation and puncture strength over the curing process as criterion for polymer particle fusion

  7. Sampling for Beryllium Surface Contamination using Wet, Dry and Alcohol Wipe Sampling

    Energy Technology Data Exchange (ETDEWEB)

    Kerr, Kent [Central Missouri State Univ., Warrensburg, MO (United States)

    2004-12-01

    This research project was conducted at the National Nuclear Security Administration's Kansas City Plant, operated by Honeywell Federal Manufacturing and Technologies, in conjunction with the Safety Sciences Department of Central Missouri State University, to compare relative removal efficiencies of three wipe sampling techniques currently used at Department of Energy facilities. Efficiencies of removal of beryllium contamination from typical painted surfaces were tested by wipe sampling with dry Whatman 42 filter paper, with water-moistened (Ghost Wipe) materials, and by methanol-moistened wipes. Test plates were prepared using 100 mm X 15 mm Pyrex Petri dishes with interior surfaces spray painted with a bond coat primer. To achieve uniform deposition over the test plate surface, 10 ml aliquots of solution containing 1 beryllium and 0.1 ml of metal working fluid were transferred to the test plates and subsequently evaporated. Metal working fluid was added to simulate the slight oiliness common on surfaces in metal working shops where fugitive oil mist accumulates over time. Sixteen test plates for each wipe method (dry, water, and methanol) were processed and sampled using a modification of wiping patterns recommended by OSHA Method 125G. Laboratory and statistical analysis showed that methanol-moistened wipe sampling removed significantly more (about twice as much) beryllium/oil-film surface contamination as water-moistened wipes (p< 0.001), which removed significantly more (about twice as much) residue as dry wipes (p <0.001). Evidence for beryllium sensitization via skin exposure argues in favor of wipe sampling with wetting agents that provide enhanced residue removal efficiency.

  8. Effects of past burning frequency on plant species structure and composition in dry dipterocarp forest

    Science.gov (United States)

    Wanthongchai, Dr.; Bauhus, Prof.; Goldammer, Prof.

    2009-04-01

    Anthropogenic burning in dry dipterocarp forests (DDF) has become a common phenomenon throughout Thailand. It is feared that too frequent fires may affect vegetation structure and composition and thus impact on ecosystem productivity. The aim of this study was to quantify the effects of prescribed fires on sites with different past burning regimes on vegetation structure and composition in the Huay Kha Khaeng Wildlife Sanctuary (HKK), Thailand. Fire frequency was determined from satellite images and ranged from frequent, infrequent, rare and unburned with fire occurrences of 7, 2, 1 and 0 out of the past 10 years, respectively. The pre-burn fuel loads, the overstorey and understorey vegetation structure and composition were determined to investigate the effects of the contrasting past burning regimes. The burning experiment was carried out, applying a three-strip head-fire burning technique. The vegetation structure and composition were sampled again one year after the fire to assess the fire impacts. Aboveground fine fuel loads increased with the length of fire-free interval. The woody plant structures of the frequently burned stand differed from those of the other less frequently burned stands. The species composition of the overstorey on the frequently burned site, in particular that of small sized trees (4.5-10 cm dbh), also differed significantly from that of the other sites. Whilst the ground vegetation including shrubs and herbs did not differ between the past burning regimes, frequent burning obviously promoted the proliferation of graminoid vegetation. There was no clear evidence showing that the prescribed fires affected the mortality of trees (dbh> 4.5 cm) on the sites of the different past burning regimes. The effects of prescribed burning on the understorey vegetation structures varied between the past burning regimes and the understorey vegetation type. Therefore, it is recommended that the DDF at HKK should be subjected to a prescribed fire frequency

  9. Surface modification of magnesium hydroxide sulfate hydrate whiskers using a silane coupling agent by dry process

    International Nuclear Information System (INIS)

    Zhu, Donghai; Nai, Xueying; Lan, Shengjie; Bian, Shaoju; Liu, Xin; Li, Wu

    2016-01-01

    Highlights: • Dry process was adopted to modify the surface of MHSH whiskers using silane. • Si−O−Mg bonds were formed directly by the reaction between Si−OC 2 H 5 and −OH of MHSH. • Dispersibility and compatibility of modified whiskers greatly improved in organic phase. • Thermal stability of whiskers was enhanced after modified. - Abstract: In order to improve the compatibility of magnesium hydroxide sulfate hydrate (MHSH) whiskers with polymers, the surface of MHSH whiskers was modified using vinyltriethoxysilane (VTES) by dry process. The possible mechanism of the surface modification and the interfacial interactions between MHSH whiskers and VTES, as well as the effect of surface modification, were studied. Scanning electronic microscopy (SEM), transmission electron microscopy (TEM) and X-ray powder diffraction (XRD) analyses showed that the agglomerations were effectively separated and a thin layer was formed on the surface of the whiskers after modification. Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) analyses showed that the VTES molecules were bound to the surface of MHSH whiskers after modification. Chemical bonds (Si−O−Mg) were formed by the reaction between Si−OC 2 H 5 or Si−OH and the hydroxyl group of MHSH whiskers. The effect of surface modification was evaluated by sedimentation tests, contact angle measurements and thermogravimetric analysis (TGA). The results showed that the surface of MHSH whiskers was transformed from hydrophilic to hydrophobic, and the dispersibility and the compatibility of MHSH whiskers were significantly improved in the organic phase. Additionally, the thermal stability of the VTES-modified MHSH whiskers was improved significantly.

  10. Surface characterization of lignocellulosics for composite manufacture

    Science.gov (United States)

    Iyer, Ananth V.

    The objectives of this research were to form moisture resistant wheat strawboards, either by altering the straw surface characteristics or by changing the chemistry of the polymeric 4, 4' diphenylmethane diisocyanate (PMDI)-based matrix and interface. Part I compared the surface characteristics of wheat, barley, oat, rice, kenaf, hemp and softwood particles. All cereal straws had two surfaces: epidermis and brittle-pith unlike one heterogeneous type observed for bast fibers and softwood particles. The epidermis of cereal straws was not wet by water or aqueous binders, whereas the pith surface allowed the penetration of water, but was not readily wetted by aqueous binders. Between the different surface treatments evaluated for wheat straw in Part II, NaOH selectively peeled-off the epidermis and pith layers. The treated straw particles were formable into strawboards using aqueous phenol-formaldehyde, urea-formaldehyde, and duroplastic acrylic acid binders with good internal bond strength (IBS) and adequate water resistance. In Part III it was shown that, decreasing straw particle sizes and bleaching worsened the mechanical properties of strawboards, but the moisture absorption properties of bleached strawboards were lower than the unbleached ones. Layering of straw particles in strawboards did not seem to affect their mechanical or moisture absorption properties. Part IV showed that the pith surface of wheat straw was fractured on curing with PMDI, providing hollow microcrevices for water accumulation. Furthermore, the cured PMDI formed a network polyurea/polyuretonimine/polycarbodiimide/polyisocyanurate polymer on straw surfaces whose properties dictated the properties of strawboards. Among the different mono-, bi-, and tri-functional alcohols, amines and carboxylic acids evaluated in Part V as H-donor substitutes to moisture for reaction with PMDI on straw surfaces, ethylene glycol, resorcinol, glycerin and citric acid provided IBS values greater than the ANSI

  11. Composition and physical properties of Enceladus' surface

    Science.gov (United States)

    Brown, R.H.; Clark, R.N.; Buratti, B.J.; Cruikshank, D.P.; Barnes, J.W.; Mastrapa, R.M.E.; Bauer, J.; Newman, S.; Momary, T.; Baines, K.H.; Bellucci, G.; Capaccioni, F.; Cerroni, P.; Combes, M.; Coradini, A.; Drossart, P.; Formisano, V.; Jaumann, R.; Langavin, Y.; Matson, D.L.; McCord, T.B.; Nelson, R.M.; Nicholson, P.D.; Sicardy, B.; Sotin, Christophe

    2006-01-01

    Observations of Saturn's satellite Enceladus using Cassini's Visual and Infrared Mapping Spectrometer instrument were obtained during three flybys of Enceladus in 2005. Enceladus' surface is composed mostly of nearly pure water ice except near its south pole, where there are light organics, CO2, and amorphous and crystalline water ice, particularly in the region dubbed the "tiger stripes." An upper limit of 5 precipitable nanometers is derived for CO in the atmospheric column above Enceladus, and 2% for NH 3 in global surface deposits. Upper limits of 140 kelvin (for a filled pixel) are derived for the temperatures in the tiger stripes.

  12. Influence of Freeze-Drying and Oven-Drying Post Blanching on the Nutrient Composition of the Edible Insect Ruspolia differens.

    Science.gov (United States)

    Fombong, Forkwa Tengweh; Van Der Borght, Mik; Vanden Broeck, Jozef

    2017-09-16

    The longhorn grasshopper, Ruspolia differens (Serville), plays an important role as a food source across Sub-Saharan Africa, where it is consumed as a delicacy in both rural and urban areas. The effect of two drying methods (freeze-drying and oven-drying), employed after blanching, on the proximate, fatty acid and mineral composition of the two most common morphs was determined. Ruspolia differens grasshoppers were harvested in Uganda and Kenya from wild swarms during the rainy periods of November-December 2016. Based on cuticular coloration, we identified three morphs, green, brown and purple, which occurred at a ratio of 65:33:2, respectively. Results indicated that these insects have a high lipid content of 36%, as well as significant protein levels ranging between 33% and 46% dry matter. Oleic acid (44%) and palmitic acid (28%) were the two most abundant fatty acids; while the presence of arachidonic acid (0.6%) and docosahexaenoic acid (0.21%) suggests that Ruspolia differens is also a source of polyunsaturated fatty acids. The observed amino acid profile showed similar trends in all morphs, and all essential amino acids were present. Calcium (896-1035 mg/100 g), potassium (779-816 mg/100 g) and phosphorus (652-685 mg/100 g) were quite high among the minerals. The presence of the trace elements iron (217-220 mg/100 g), zinc (14.2-14.6 mg/100 g), manganese (7.4-8.3 mg/100 g) and copper (1.66 mg/100 g) suggests that inclusion of these grasshoppers in human diets may aid in combatting micronutrient deficiencies. Oven-drying Ruspolia differens delivered the same nutritional quality as freeze-drying. Hence, both drying approaches can be adequately used to formulate insect-based food products without noticeable nutritional changes.

  13. Influence of Freeze-Drying and Oven-Drying Post Blanching on the Nutrient Composition of the Edible Insect Ruspolia differens

    Directory of Open Access Journals (Sweden)

    Forkwa Tengweh Fombong

    2017-09-01

    Full Text Available The longhorn grasshopper, Ruspolia differens (Serville, plays an important role as a food source across Sub-Saharan Africa, where it is consumed as a delicacy in both rural and urban areas. The effect of two drying methods (freeze-drying and oven-drying, employed after blanching, on the proximate, fatty acid and mineral composition of the two most common morphs was determined. Ruspolia differens grasshoppers were harvested in Uganda and Kenya from wild swarms during the rainy periods of November–December 2016. Based on cuticular coloration, we identified three morphs, green, brown and purple, which occurred at a ratio of 65:33:2, respectively. Results indicated that these insects have a high lipid content of 36%, as well as significant protein levels ranging between 33% and 46% dry matter. Oleic acid (44% and palmitic acid (28% were the two most abundant fatty acids; while the presence of arachidonic acid (0.6% and docosahexaenoic acid (0.21% suggests that Ruspolia differens is also a source of polyunsaturated fatty acids. The observed amino acid profile showed similar trends in all morphs, and all essential amino acids were present. Calcium (896–1035 mg/100 g, potassium (779–816 mg/100 g and phosphorus (652–685 mg/100 g were quite high among the minerals. The presence of the trace elements iron (217–220 mg/100 g, zinc (14.2–14.6 mg/100 g, manganese (7.4–8.3 mg/100 g and copper (1.66 mg/100 g suggests that inclusion of these grasshoppers in human diets may aid in combatting micronutrient deficiencies. Oven-drying Ruspolia differens delivered the same nutritional quality as freeze-drying. Hence, both drying approaches can be adequately used to formulate insect-based food products without noticeable nutritional changes.

  14. LSM Microelectrodes: Kinetics and Surface Composition

    DEFF Research Database (Denmark)

    Hansen, Karin Vels; Norrman, Kion; Jacobsen, Torben

    2015-01-01

    spectroscopy and cyclic voltammetry were performed on electrodes with diameters of 20–100 μm in oxygen, air and nitrogen both at open circuit voltage and at anodic and cathodic polarization. In situ conductance mapping, ex situ surface analysis by time-of-flight secondary ion mass spectrometry, and scanning...

  15. Intracellular water exchange for measuring the dry mass, water mass and changes in chemical composition of living cells.

    Directory of Open Access Journals (Sweden)

    Francisco Feijó Delgado

    Full Text Available We present a method for direct non-optical quantification of dry mass, dry density and water mass of single living cells in suspension. Dry mass and dry density are obtained simultaneously by measuring a cell's buoyant mass sequentially in an H2O-based fluid and a D2O-based fluid. Rapid exchange of intracellular H2O for D2O renders the cell's water content neutrally buoyant in both measurements, and thus the paired measurements yield the mass and density of the cell's dry material alone. Utilizing this same property of rapid water exchange, we also demonstrate the quantification of intracellular water mass. In a population of E. coli, we paired these measurements to estimate the percent dry weight by mass and volume. We then focused on cellular dry density - the average density of all cellular biomolecules, weighted by their relative abundances. Given that densities vary across biomolecule types (RNA, DNA, protein, we investigated whether we could detect changes in biomolecular composition in bacteria, fungi, and mammalian cells. In E. coli, and S. cerevisiae, dry density increases from stationary to exponential phase, consistent with previously known increases in the RNA/protein ratio from up-regulated ribosome production. For mammalian cells, changes in growth conditions cause substantial shifts in dry density, suggesting concurrent changes in the protein, nucleic acid and lipid content of the cell.

  16. Intracellular Water Exchange for Measuring the Dry Mass, Water Mass and Changes in Chemical Composition of Living Cells

    Science.gov (United States)

    Hecht, Vivian C.; Son, Sungmin; Li, Yingzhong; Knudsen, Scott M.; Olcum, Selim; Higgins, John M.; Chen, Jianzhu; Grover, William H.; Manalis, Scott R.

    2013-01-01

    We present a method for direct non-optical quantification of dry mass, dry density and water mass of single living cells in suspension. Dry mass and dry density are obtained simultaneously by measuring a cell’s buoyant mass sequentially in an H2O-based fluid and a D2O-based fluid. Rapid exchange of intracellular H2O for D2O renders the cell’s water content neutrally buoyant in both measurements, and thus the paired measurements yield the mass and density of the cell’s dry material alone. Utilizing this same property of rapid water exchange, we also demonstrate the quantification of intracellular water mass. In a population of E. coli, we paired these measurements to estimate the percent dry weight by mass and volume. We then focused on cellular dry density – the average density of all cellular biomolecules, weighted by their relative abundances. Given that densities vary across biomolecule types (RNA, DNA, protein), we investigated whether we could detect changes in biomolecular composition in bacteria, fungi, and mammalian cells. In E. coli, and S. cerevisiae, dry density increases from stationary to exponential phase, consistent with previously known increases in the RNA/protein ratio from up-regulated ribosome production. For mammalian cells, changes in growth conditions cause substantial shifts in dry density, suggesting concurrent changes in the protein, nucleic acid and lipid content of the cell. PMID:23844039

  17. Preliminary effects of oral uridine on the ocular surface in dry eye patients.

    Science.gov (United States)

    Chang, Ki Cheol; Oh, Joo Youn; In, Youn Seok; Kim, Mee Kum; Shin, Ki Cheul; Wee, Won Ryang; Lee, Jin Hak; Park, Myung Gyu

    2009-08-01

    We designed a randomized, double blinded, 3-months controlled prospective clinical study to investigate effects of oral uridine on the ocular surface in dry eye patients. Twenty-seven patients who diagnosed as dry eye with lower than 5 mm of wetting in the Schirmer strip, with corneal epithelial erosion and who completely followed-up till 3 months were enrolled. Corneal-conjunctival fluorescein staining, non-anesthetic Schirmer test, impression cytology, and Ocular Surface Disease Index (OSDI) were evaluated in the experimental and placebo groups at the baseline, 1 and 3 months after start of medication in a double blinded manner. Fluorescein stain score of the cornea was markedly decreased in oral uridine group compared to the placebo group at 3 months after medication (P=0.032, Mann-Whitney U test). The Schirmer wetting score for the oral uridine group was significantly increased (P=0.001, Wilcoxon signed rank test) at 3 months and its difference between two groups was statistically significant (P=0.030, Mann-Whitney U test). OSDI scores were significantly decreased at 1 and 3 months in treatment group. Oral uridine is effective in treatment of dry eyes.

  18. Tribological investigations of the applicability of surface functionalization for dry extrusion processes

    Science.gov (United States)

    Teller, Marco; Prünte, Stephan; Ross, Ingo; Temmler, André; Schneider, Jochen M.; Hirt, Gerhard

    2017-10-01

    Cold extrusion processes are characterized by large relative contact stresses combined with a severe surface enlargement of the workpiece. Under these process conditions a high risk for galling of workpiece material to the tool steel occurs especially in processing of aluminum and aluminum alloys. In order to reduce adhesive wear lubricants for separation of workpiece and tool surfaces are used. As a consequence additional process steps (e.g. preparation and cleaning of workpieces) are necessary. Thus, the realization of a dry forming process is aspired from an environmental and economic perspective. In this paper a surface functionalization with self-assembled-monolayers (SAM) of the tool steels AISI D2 (DIN 1.2379) and AISI H11 (DIN 1.2343) is evaluated by a process-oriented tribological test. The tribological experiment is able to resemble and scale the process conditions of cold extrusion related to relative contact stress and surface enlargement for the forming of pure aluminum (Al99.5). The effect of reduced relative contact stress, surface enlargement and relative velocity on adhesive wear and tool lifetime is evaluated. Similar process conditions are achievable by different die designs with decreased extrusion ratios and adjusted die angles. The effect of surface functionalization critically depends on the substrate material. The different microstructure and the resulting differences in surface chemistry of the two tested tool steels appear to affect the performance of the tool surface functionalization with SAM.

  19. Bromatological composition and dry matter digestibility of millet cultivars subjected to nitrogen doses

    Directory of Open Access Journals (Sweden)

    W.H.D. Buso

    2014-06-01

    Full Text Available The bromatological composition and in vitro dry matter digestibility of millet cultivars were assessed for different nitrogen doses and two sowing seasons in the Ceres municipality of Goiás state, Brazil. The treatments consisted of three millet cultivars (ADR-7010, ADR-500 and BRS-1501, four nitrogen (N doses (0, 50, 100 and 200kg ha-1 of N and two sowing seasons. Three replicates and a randomised block design with a 3 x 4 x 2 factorial scheme were used. Two cuttings were performed in each season when plants reached an average height of 0.70 cm. No significant interactions were observed between or among cultivars for N doses and dry matter (DM, crude protein (CP, neutral detergent fibre (NDF and acid detergent fibre (ADF contents. The DM, CP, NDF and ADF contents were significantly different between N doses. The DM and CP contents increased as the N dose increased to 100kg ha-1. The maximum DM and CP contents were 11.14 and 22.53%, respectively. The NDF and ADF contents were higher in the control treatment (60.11 and 30.01%, respectively. In addition, the lowest ADF and NDF concentrations occurred at an N dose of 50kg ha-1 (56.33 and 30.23%, respectively. The DM contents were higher for the February sowing, with an average of 10.59%. The highest CP and ADF contents were found for the December sowing (22.46 and 31.58%, respectively. No significant differences were found for millet cultivars, N doses or sowing seasons. A significant interaction was found between sowing season and millet cultivar. The BRS-1501 cultivar had a higher in vitro dry matter digestibility in the December/2010 sowing (73.88%.

  20. External Thermal Insulation Composite Systems: Critical Parameters for Surface Hygrothermal Behaviour

    Directory of Open Access Journals (Sweden)

    Eva Barreira

    2014-01-01

    Full Text Available External Thermal Insulation Composite Systems (ETICS are often used in Europe. Despite its thermal advantages, low cost, and ease of application, this system has serious problems of biological growth causing the cladding defacement. Recent studies pointed that biological growth is due to high values of surface moisture content, which mostly results from the combined effect of exterior surface condensation, wind-driven rain, and drying process. Based on numerical simulation, this paper points the most critical parameters involved in hygrothermal behaviour of ETICS, considering the influence of thermal and hygric properties of the external rendering, the effect of the characteristics of the façade, and the consequences of the exterior and interior climate on exterior surface condensation, wind-driven rain, and drying process. The model used was previously validated by comparison with the results of an “in situ” campaign. The results of the sensitivity analyses show that relative humidity and temperature of the exterior air, atmospheric radiation, and emissivity of the exterior rendering are the parameters that most influence exterior surface condensation. Wind-driven rain depends mostly on horizontal rain, building’s height, wind velocity, and orientation. The drying capacity is influenced by short-wave absorbance, incident solar radiation, and orientation.

  1. Storage conditions affect oxidative stability and nutritional composition of freeze-dried Nannochloropsis salina

    DEFF Research Database (Denmark)

    Safafar, Hamed; Langvad, Sten; Møller, Peter

    2017-01-01

    composition of microalgae biomass. In order to investigate the worsening of the nutritional quality of freeze dried biomass, a multifactorial storage experiment was conducted on a high EPA (eicosapentaenoic acid) Nannochloropsis salina biomass. The storage time (0–56 days), storage temperature (5, 20,and 40...... °C and packaging conditions (under vacuum and ambient pressure)used as main factors. During the 56 days of storage, both time and temperature strongly influenced the oxidation reactions which result in deterioration of bioactive compounds such as carotenoids, tocopherols, and EPA. Lipid deterioration......, or cosmetics requires the knowledge of the optimum storage conditions to prevent the value-added compounds from deterioration. Results of this study improve our understanding of the chemical deterioration under different storage conditions and can help the producers/customers to extend the shelf life...

  2. Microbial Quality and Proximate Composition of Dried Hibiscus sabdariffa Calyxes in Uyo, Eastern Nigeria

    Directory of Open Access Journals (Sweden)

    Adebayo-tayo, B. C.

    2009-01-01

    Full Text Available Dried Hibiscus sabdarifa calyxes collected from different markets in Uyo, Eastern Nigeria were evaluated for microbial quality, Aflatoxin contamination and proximate composition. The results showed that all the calyxes were contaminated with microorganism. The total bacteria count ranged from 5.0 x 10^3 to 8.1 x 10^4 cfu/g in which the highest count was obtained from dried calyxes from Itam Market. Coliform were not detected in most of the sample except samples from Uyo main market and Ikot Ekpene market in which the coliform level is below the acceptable limit. Salmonella/Shigella was not detected in the sample. The fungi count ranged from 3.4 x 10^4 to 7.3 x 10^4. The associated bacteria were Staphylococcus aureus, Bacillus subtilis, Bacillus sp. Enterococuss faecalis, Micrococcus sp. and Klebsiella sp. The associated fungi were Aspergillus flavus, A. terreus, A. glaucus, Penicillium citrinum, Fusarium oxysporum, Rhizopus sp. and Mucor sp. A. glaucus had the highest frequency of occurrence among the isolated fungi. Out of the sample obtained Aflatoxin B1 was detected in two samples and it ranged from 1.57 to 17.8 /µg/kg. The proximate analysis revealed that the crude protein ranged from 8.34 – 9.97%, crude fibre (7.26 – 7.82% and fat (8.51 – 9.26%. The moisture content ranged from 13.13 – 14.85%.

  3. The Prospective Health Assessment of Cataract Patients’ Ocular Surface (PHACO study: the effect of dry eye

    Directory of Open Access Journals (Sweden)

    Trattler WB

    2017-08-01

    Full Text Available William B Trattler,1 Parag A Majmudar,2 Eric D Donnenfeld,3 Marguerite B McDonald,4 Karl G Stonecipher,5 Damien F Goldberg6 On behalf of the PHACO Study Group 1Center for Excellence in Eye Care, Miami, FL, USA; 2Chicago Cornea Consultants, Chicago, IL, USA; 3Ophthalmic Consultants of Long Island, Garden City, NY, USA; 4Ophthalmic Consultants of Long Island, Lynbrook, NY, USA; 5University North Carolina School of Medicine, Chapel Hill, NC, USA; 6Wolstan & Goldberg Eye Associates, Torrance, CA, USA Purpose: To determine the incidence and severity of dry eye as determined by the International Task Force (ITF scale in patients being screened for cataract surgery.Patients and methods: This was a prospective, multi-center, observational study of 136 patients, at least 55 years of age, who were scheduled to undergo cataract surgery. The primary outcome measure was the incidence of dry eye as evaluated by grade on the ITF scale and secondary outcome measures include tear break-up time (TBUT, ocular surface disease index score, corneal staining with fluorescein, conjunctival staining with lissamine green, and a patient questionnaire to evaluate symptoms of dry eye.Results: Mean patient age was 70.7 years. A total of 73.5% of patients were Caucasian and 50% were female. Almost 60% had never complained of a foreign body sensation; only 13% complained of a foreign body sensation half or most of the time. The majority of patients (62.9% had a TBUT ≤5 seconds, 77% of eyes had positive corneal staining and 50% of the eyes had positive central corneal staining. Eighteen percent had Schirmer’s score with anesthesia ≤5 mm.Conclusion: The incidence of dry eye in patients scheduled to undergo cataract surgery in a real-world setting is higher than anticipated. Keywords: cataract surgery screening, dry eye, International Task Force scale, observational study

  4. Optical Properties and Surface Morphology of Nano-composite PMMA: TiO2 Thin Films

    International Nuclear Information System (INIS)

    Lyly Nyl Ismail; Ahmad Fairoz Aziz; Habibah Zulkefle

    2011-01-01

    There are two nano-composite PMMA: TiO 2 solutions were prepared in this research. First solution is nano-composite PMMA commercially available TiO 2 nanopowder and the second solution is nano-composite PMMA with self-prepared TiO 2 powder. The self-prepared TiO 2 powder is obtained by preparing the TiO 2 sol-gel. Solvo thermal method were used to dry the TiO 2 sol-gel and obtained TiO 2 crystal. Ball millers were used to grind the TiO 2 crystal in order to obtained nano sized powder. Triton-X was used as surfactant to stabilizer the composite between PMMA: TiO 2 . Besides comparing the nano-composite solution, we also studied the effect of the thin films thickness on the optical properties and surface morphology of the thin films. The thin films were deposited by sol-gel spin coating method on glass substrates. The optical properties and surface characterization were measured with UV-VIS spectrometer equipment and atomic force microscopy (AFM). The result showed that nano-composite PMMA with self prepared TiO 2 give high optical transparency than nano-composite PMMA with commercially available TiO 2 nano powder. The results also indicate as the thickness is increased the optical transparency are decreased. Both AFM images showed that the agglomerations of TiO 2 particles are occurred on the thin films and the surface roughness is increased when the thickness is increased. High agglomeration particles exist in the AFM images for nano-composite PMMA: TiO 2 with TiO 2 nano powder compare to the other nano-composite solution. (author)

  5. Crack path and fracture surface modifications in cement composites

    Directory of Open Access Journals (Sweden)

    Sajjad Ahmad

    2015-10-01

    Full Text Available There is a tremendous increase in the use of high strength and high performance self-consolidating cementitious composites due to their superior workability and mechanical strengths. Cement composites are quasi-brittle in nature and possess extremely low tensile strength as compared to their compressive strength. Due to the low tensile strength capacity, cracks develop in cementitious composites due to the drying shrinkage, plastic settlements and/or stress concentrations (due to external restrains and/or applied stresses etc. These cracks developed at the nanoscale may grow rapidly due to the applied stresses and join together to form micro and macro cracks. The growth of cracks from nanoscale to micro and macro scale is very rapid and may lead to sudden failure of the cement composites. The present paper reports the modifications in the crack growth pattern of the high performance cement composites to achieve enhanced ductility and toughness. The objective was accomplished by the incorporation of the micro sized inert particulates in the cement composite matrix. The results indicate that the incorporation of micro sized inert particles acted as the obstacles in the growth of the cracks thus improving the ductility and the energy absorption capacity of the self-consolidating cementitious composites.

  6. Continuous Natural Fiber Reinforced Thermoplastic Composites by Fiber Surface Modification

    Directory of Open Access Journals (Sweden)

    Patcharat Wongsriraksa

    2013-01-01

    Full Text Available Continuous natural fiber reinforced thermoplastic materials are expected to replace inorganic fiber reinforced thermosetting materials. However, in the process of fabricating the composite, it is difficult to impregnate the thermoplastic resin into reinforcement fiber because of the high melt viscosity. Therefore, intermediate material, which allows high impregnation during molding, has been investigated for fabricating continuous fiber reinforced thermoplastic composite by aligning resin fiber alongside reinforcing fiber with braiding technique. This intermediate material has been called “microbraid yarn (MBY.” Moreover, it is well known that the interfacial properties between natural fiber and resin are low; therefore, surface treatment on continuous natural fiber was performed by using polyurethane (PU and flexible epoxy (FLEX to improve the interfacial properties. The effect of surface treatment on the mechanical properties of continuous natural fiber reinforced thermoplastic composites was examined. From these results, it was suggested that surface treatment by PU with low content could produce composites with better mechanical properties.

  7. Surface characterization of current composites after toothbrush abrasion.

    Science.gov (United States)

    Takahashi, Rena; Jin, Jian; Nikaido, Toru; Tagami, Junji; Hickel, Reinhard; Kunzelmann, Karl-Heinz

    2013-01-01

    The present study was designed to evaluate the surface roughness and the gloss of current composites before and after toothbrush abrasion. We assessed forty dimensionally standardized composite specimens (n=8/group) from five composites: two nanohybrids (i. e., IPS Empress Direct Enamel and IPS Empress Direct Dentin), two microhybrids (i. e., Clearfil AP-X and Filtek Z250) and one organically modified ceramics (Admira). All of the specimens were polished with 4000-grid silicon carbide papers. Surface roughness was measured with a profilometer and gloss was measured with a glossmeter before and after powered toothbrush abrasion with a 1:1 slurry (dentifrice/tap water) at 12,000 strokes in a toothbrush simulator. There was a significant increase in the surface roughness and a reduction in gloss after toothbrush abrasion in all of the composites except Clearfil AP-X (pgloss (R(2)=0.191, p<0.001).

  8. Optimisation of phenolic extraction from Averrhoa carambola pomace by response surface methodology and its microencapsulation by spray and freeze drying.

    Science.gov (United States)

    Saikia, Sangeeta; Mahnot, Nikhil Kumar; Mahanta, Charu Lata

    2015-03-15

    Optimised of the extraction of polyphenol from star fruit (Averrhoa carambola) pomace using response surface methodology was carried out. Two variables viz. temperature (°C) and ethanol concentration (%) with 5 levels (-1.414, -1, 0, +1 and +1.414) were used to design the optimisation model using central composite rotatable design where, -1.414 and +1.414 refer to axial values, -1 and +1 mean factorial points and 0 refers to centre point of the design. The two variables, temperature of 40°C and ethanol concentration of 65% were the optimised conditions for the response variables of total phenolic content, ferric reducing antioxidant capacity and 2,2-diphenyl-1-picrylhydrazyl scavenging activity. The reverse phase-high pressure liquid chromatography chromatogram of the polyphenol extract showed eight phenolic acids and ascorbic acid. The extract was then encapsulated with maltodextrin (⩽ DE 20) by spray and freeze drying methods at three different concentrations. Highest encapsulating efficiency was obtained in freeze dried encapsulates (78-97%). The obtained optimised model could be used for polyphenol extraction from star fruit pomace and microencapsulates can be incorporated in different food systems to enhance their antioxidant property. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. The Measurement of Dry Deposition and Surface Runoff to Quantify Urban Road Pollution in Taipei, Taiwan

    Science.gov (United States)

    Wang, Yunn-Jinn; Chen, Chi-Feng; Lin, Jen-Yang

    2013-01-01

    Pollutants deposited on road surfaces and distributed in the environment are a source of nonpoint pollution. Field data are traditionally hard to collect from roads because of constant traffic. In this study, in cooperation with the traffic administration, the dry deposition on and road runoff from urban roads was measured in Taipei City and New Taipei City, Taiwan. The results showed that the dry deposition is 2.01–5.14 g/m2·day and 78–87% of these solids are in the 75–300 µm size range. The heavy metals in the dry deposited particles are mainly Fe, Zn, and Na, with average concentrations of 34,978, 1,519 and 1,502 ppm, respectively. Elevated express roads show the highest heavy metal concentrations. Not only the number of vehicles, but also the speed of the traffic should be considered as factors that influence road pollution, as high speeds may accelerate vehicle wear and deposit more heavy metals on road surfaces. In addition to dry deposition, the runoff and water quality was analyzed every five minutes during the first two hours of storm events to capture the properties of the first flush road runoff. The sample mean concentration (SMC) from three roads demonstrated that the first flush runoff had a high pollution content, notably for suspended solid (SS), chemical oxygen demand (COD), oil and grease, Pb, and Zn. Regular sweeping and onsite water treatment facilities are suggested to minimize the pollution from urban roads. PMID:24135820

  10. Mercury fluxes from air/surface interfaces in paddy field and dry land

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Jinshan [Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), College of Resources and Environment, Southwest University, No. 216, Tiansheng Street, Beibei, Chongqing 400715 (China); Wang Dingyong, E-mail: dywang@swu.edu.cn [Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), College of Resources and Environment, Southwest University, No. 216, Tiansheng Street, Beibei, Chongqing 400715 (China)] [Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing 400716 (China); Liu Xiao; Zhang Yutong [Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), College of Resources and Environment, Southwest University, No. 216, Tiansheng Street, Beibei, Chongqing 400715 (China)

    2011-02-15

    Research highlights: {yields} It was found that agricultural fields are important local atmospheric Hg sources in the region. {yields} The Hg emissions from dry cornfield were higher than those from the flooded rice paddy, higher mercury emissions in the warm season than the cold season, and during daytime than at night. {yields} Mercury evasion is strongly related to solar radiation which is important in the emission of Hg at both sites. - Abstract: In order to provide insight into the characteristics of Hg exchange in soil/water-air surface from cropland (including paddy field and dry land), Hg fluxes were measured in Chengjiang. Mercury fluxes were measured using the dynamic flux chamber method, coupled with a Lumex (registered) multifunctional Hg analyzer RA-915{sup +} (Lumex Ltd., Russia). The Hg fluxes from paddy field and dry land were alternatively measured every 30 min. Data were collected for 24-48 h once per month for 5 months. Mercury fluxes in both fields were synchronously measured under the same conditions to compare Hg emissions between paddy field and dry land over diurnal and seasonal periods and find out what factors affect Hg emission on each surface. These results indicated that air Hg concentrations at the monitoring site was double the value observed at the global background sites in Europe and North America. The Hg release fluxes were 46.5 {+-} 22.8 ng m{sup -2} h{sup -1} in the warm season, 15.5 {+-} 18.8 ng m{sup -2} h{sup -1} in the cold season for dry land, and 23.8 {+-} 15.6 ng m{sup -2} h{sup -1} in the warm season, 6.3 {+-} 11.9 ng m{sup -2} h{sup -1} in the cold season for paddy field. Solar radiation is important in the emission of Hg over both sites. Hg exchange at the soil/air and water/air interfaces showed temporal variations. The amount of Hg emission from dry land was higher than that from the paddy field, and the emission in daytime was higher than that at night. Moreover, Hg emissions from land covered by crops, was lower

  11. Identification of the compositional changes in Orthosiphon stamineus leaves triggered by different drying techniques using 1 H NMR metabolomics.

    Science.gov (United States)

    Pariyani, Raghunath; Ismail, Intan Safinar; Ahmad Azam, Amalina; Abas, Faridah; Shaari, Khozirah

    2017-09-01

    Java tea is a well-known herbal infusion prepared from the leaves of Orthosiphon stamineus (OS). The biological properties of tea are in direct correlation with the primary and secondary metabolite composition, which in turn largely depends on the choice of drying method. Herein, the impact of three commonly used drying methods, i.e. shade, microwave and freeze drying, on the metabolite composition and antioxidant activity of OS leaves was investigated using proton nuclear magnetic resonance ( 1 H NMR) spectroscopy combined with multivariate classification and regression analysis tools. A total of 31 constituents comprising primary and secondary metabolites belonging to the chemical classes of fatty acids, amino acids, sugars, terpenoids and phenolic compounds were identified. Shade-dried leaves were identified to possess the highest concentrations of bioactive secondary metabolites such as chlorogenic acid, caffeic acid, luteolin, orthosiphol and apigenin, followed by microwave-dried samples. Freeze-dried leaves had higher concentrations of choline, amino acids leucine, alanine and glutamine and sugars such as fructose and α-glucose, but contained the lowest levels of secondary metabolites. Metabolite profiling coupled with multivariate analysis identified shade drying as the best method to prepare OS leaves as Java tea or to include in traditional medicine preparation. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  12. The influence of sun drying process and prolonged storage on composition of essential oil from clove buds (Syzygium aromaticum)

    Science.gov (United States)

    Hastuti, L. T.; Saepudin, E.; Cahyana, A. H.; Rahayu, D. U. C.; Murni, V. W.; Haib, J.

    2017-07-01

    Clove (Syzygium aromaticum) is native to Indonesia and used as a spice in virtually all of the world's cuisine. Clove bud oil, a yellow liquid, is obtained from distillation of buds. The quality of oil is influenced by origin, post-harvest processing, pre-treatment before distillation, the distillation method, and post-distillation treatment. The objective of this study is to investigate the effect of drying process and prolonged storage on essential oil composition of clove bud from the Tolitoli, Indonesia. To determine the effect of drying, fresh clove bud was dried under sunlight until it reached moisture content 13±1 %. The effect of storage was studied in the oil extracted from clove bud that was stored in laboratory at 25 °C for 4 months. The essential oil of each treatment was obtained by steam distillation and its chemical composition was analyzed by GC/MS. The major components found in fresh and dried clove are as follows: eugenol, eugenyl acetate, and caryophyllene. Percentage of caryophyllene was slightly increase after drying but decrease during storage. While the content of eugenyl acetate decreased during drying and storage, the content of eugenol increased. The drying and storage also affect to the change on minor compounds of essential oil of clove.

  13. Surface functionalized hollow silica particles and composites

    KAUST Repository

    Rodionov, Valentin; Khanh, Vu Bao

    2017-01-01

    Composition comprising hollow spherical silica particles having outside particle walls and inside particle walls, wherein the particles have an average particle size of about 10 nm to about 500 nm and an average wall thickness of about 10 nm to about 50 nm; and wherein the particles are functionalized with at least one organic functional group on the outside particle wall, on the inside particle wall, or on both the outside and inside particle walls, wherein the organic functional group is in a reacted or unreacted form. The organic functional group can be epoxy. The particles can be mixed with polymer precursor or a polymer material such as epoxy to form a prepreg or a nanocomposite. Lightweight but strong materials can be formed. Low loadings of hollow particles can be used.

  14. Surface functionalized hollow silica particles and composites

    KAUST Repository

    Rodionov, Valentin

    2017-05-26

    Composition comprising hollow spherical silica particles having outside particle walls and inside particle walls, wherein the particles have an average particle size of about 10 nm to about 500 nm and an average wall thickness of about 10 nm to about 50 nm; and wherein the particles are functionalized with at least one organic functional group on the outside particle wall, on the inside particle wall, or on both the outside and inside particle walls, wherein the organic functional group is in a reacted or unreacted form. The organic functional group can be epoxy. The particles can be mixed with polymer precursor or a polymer material such as epoxy to form a prepreg or a nanocomposite. Lightweight but strong materials can be formed. Low loadings of hollow particles can be used.

  15. Mineralogy of the Martian Surface: Crustal Composition to Surface Processes

    Science.gov (United States)

    Mustard, John F.

    1999-01-01

    Over the course of this award we have: 1) Completed and published the results of a study of the effects of hyperfine particles on reflectance spectra of olivine and quartz, which included the development of scattering codes. Research has also progressed in the analysis of the effects of fine particle sizes on clay spectra. 2) Completed the analysis of the mineralogy of dark regions, showed the insitu compositions are highly correlated to the SNC meteorites, and determined that the martian mantle was depleted in aluminum prior to 2-3 GA ago; Studies of the mineralogic heterogeneity of surficial materials on Mars have also been conducted. and 3) Performed initial work on the study of the physical and chemical processes likely to form and modify duricrust. This includes assessments of erosion rates, solubility and transport of iron in soil environments, and models of pedogenic crust formation.

  16. A revised global ozone dry deposition estimate based on a new two-layer parameterisation for air-sea exchange and the multi-year MACC composition reanalysis

    Science.gov (United States)

    Luhar, Ashok K.; Woodhouse, Matthew T.; Galbally, Ian E.

    2018-03-01

    Dry deposition at the Earth's surface is an important sink of atmospheric ozone. Currently, dry deposition of ozone to the ocean surface in atmospheric chemistry models has the largest uncertainty compared to deposition to other surface types, with implications for global tropospheric ozone budget and associated radiative forcing. Most global models assume that the dominant term of surface resistance in the parameterisation of ozone dry deposition velocity at the oceanic surface is constant. There have been recent mechanistic parameterisations for air-sea exchange that account for the simultaneous waterside processes of ozone solubility, molecular diffusion, turbulent transfer, and first-order chemical reaction of ozone with dissolved iodide and other compounds, but there are questions about their performance and consistency. We present a new two-layer parameterisation scheme for the oceanic surface resistance by making the following realistic assumptions: (a) the thickness of the top water layer is of the order of a reaction-diffusion length scale (a few micrometres) within which ozone loss is dominated by chemical reaction and the influence of waterside turbulent transfer is negligible; (b) in the water layer below, both chemical reaction and waterside turbulent transfer act together and are accounted for; and (c) chemical reactivity is present through the depth of the oceanic mixing layer. The new parameterisation has been evaluated against dry deposition velocities from recent open-ocean measurements. It is found that the inclusion of only the aqueous iodide-ozone reaction satisfactorily describes the measurements. In order to better quantify the global dry deposition loss and its interannual variability, modelled 3-hourly ozone deposition velocities are combined with the 3-hourly MACC (Monitoring Atmospheric Composition and Climate) reanalysis ozone for the years 2003-2012. The resulting ozone dry deposition is found to be 98.4 ± 30.0 Tg O3 yr-1 for the ocean

  17. Surface roughness of composite resins subjected to hydrochloric acid.

    Science.gov (United States)

    Roque, Ana Carolina Cabral; Bohner, Lauren Oliveira Lima; de Godoi, Ana Paula Terossi; Colucci, Vivian; Corona, Silmara Aparecida Milori; Catirse, Alma Blásida Concepción Elizaur Benitez

    2015-01-01

    The purpose of this study was to determine the influence of hydrochloric acid on surface roughness of composite resins subjected to brushing. Sixty samples measuring 2 mm thick x 6 mm diameter were prepared and used as experimental units. The study presented a 3x2 factorial design, in which the factors were composite resin (n=20), at 3 levels: microhybrid composite (Z100), nanofilled composite (FiltekTM Supreme), nanohybrid composite (Ice), and acid challenge (n=10) at 2 levels: absence and presence. Acid challenge was performed by immersion of specimens in hydrochloric acid (pH 1.2) for 1 min, 4 times per day for 7 days. The specimens not subjected to acid challenge were stored in 15 mL of artificial saliva at 37 oC. Afterwards, all specimens were submitted to abrasive challenge by a brushing cycle performed with a 200 g weight at a speed of 356 rpm, totaling 17.8 cycles. Surface roughness measurements (Ra) were performed and analyzed by ANOVA and Tukey test (p≤0.05). Surface roughness values were higher in the presence (1.07±0.24) as compared with the absence of hydrochloric acid (0.72±0.04). Surface roughness values were higher for microhybrid (1.01±0.27) compared with nanofilled (0.68 ±0.09) and nanohybrid (0.48±0.15) composites when the specimens were not subjects to acid challenge. In the presence of hydrochloric acid, microhybrid (1.26±0.28) and nanofilled (1.18±0,30) composites presents higher surface roughness values compared with nanohybrid (0.77±0.15). The hydrochloric acid affected the surface roughness of composite resin subjected to brushing.

  18. Mechanical Properties and Tribological Behavior of In Situ NbC/Fe Surface Composites

    Science.gov (United States)

    Cai, Xiaolong; Zhong, Lisheng; Xu, Yunhua

    2017-01-01

    The mechanical properties and tribological behavior of the niobium carbide (NbC)-reinforced gray cast iron surface composites prepared by in situ synthesis have been investigated. Composites are comprised of a thin compound layer and followed by a deep diffusion zone on the surface of gray cast iron. The graded distributions of the hardness and elastic modulus along the depth direction of the cross section of composites form in the ranges of 6.5-20.1 and 159.3-411.2 GPa, respectively. Meanwhile, dry wear tests for composites were implemented on pin-on-disk equipment at sliding speed of 14.7 × 10-2 m/s and under 5 or 20 N, respectively. The result indicates that tribological performances of composites are considerably dependent on the volume fraction and the grain size of the NbC as well as the mechanical properties of the matrices in different areas. The surface compound layer presents the lowest coefficient of friction and wear rate, and exhibits the highest wear resistance, in comparison with diffusion zone and substrate. Furthermore, the worn morphologies observed reveal the dominant wear mechanism is abrasive wear feature in compound layer and diffusion zone.

  19. Sorption of Cu(II) Ions on Chitosan-Zeolite X Composites: Impact of Gelling and Drying Conditions.

    Science.gov (United States)

    Djelad, Amal; Morsli, Amine; Robitzer, Mike; Bengueddach, Abdelkader; di Renzo, Francesco; Quignard, Françoise

    2016-01-19

    Chitosan-zeolite Na-X composite beads with open porosity and different zeolite contents were prepared by an encapsulation method. Preparation conditions had to be optimised in order to stabilize the zeolite network during the polysaccharide gelling process. Composites and pure reference components were characterized using X-ray diffraction (XRD); scanning electron microscopy (SEM); N₂ adsorption-desorption; and thermogravimetric analysis (TG). Cu(II) sorption was investigated at pH 6. The choice of drying method used for the storage of the adsorbent severely affects the textural properties of the composite and the copper sorption effectiveness. The copper sorption capacity of chitosan hydrogel is about 190 mg·g(-1). More than 70% of this capacity is retained when the polysaccharide is stored as an aerogel after supercrititcal CO₂ drying, but nearly 90% of the capacity is lost after evaporative drying to a xerogel. Textural data and Cu(II) sorption data indicate that the properties of the zeolite-polysaccharide composites are not just the sum of the properties of the individual components. Whereas a chitosan coating impairs the accessibility of the microporosity of the zeolite; the presence of the zeolite improves the stability of the dispersion of chitosan upon supercritical drying and increases the affinity of the composites for Cu(II) cations. Chitosan-zeolite aerogels present Cu(II) sorption properties.

  20. Micro-Spherical Sulfur/Graphene Oxide Composite via Spray Drying for High Performance Lithium Sulfur Batteries

    Science.gov (United States)

    Tian, Yuan; Sun, Zhenghao; Zhang, Yongguang; Yin, Fuxing

    2018-01-01

    An efficient, industry-accepted spray drying method was used to synthesize micro-spherical sulfur/graphene oxide (S/GO) composites as cathode materials within lithium sulfur batteries. The as-designed wrapping of the sulfur-nanoparticles, with wrinkled GO composites, was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The unique morphological design of this material enabled superior discharge capacity and cycling performance, demonstrating a high initial discharge capacity of 1400 mAh g−1 at 0.1 C. The discharge capacity remained at 828 mAh g−1 after 150 cycles. The superior electrochemical performance indicates that the S/GO composite improves electrical conductivity and alleviates the shuttle effect. This study represents the first time such a facile spray drying method has been adopted for lithium sulfur batteries and used in the fabrication of S/GO composites. PMID:29346303

  1. What controls the isotopic composition of Greenland surface snow?

    Directory of Open Access Journals (Sweden)

    H. C. Steen-Larsen

    2014-02-01

    Full Text Available Water stable isotopes in Greenland ice core data provide key paleoclimatic information, and have been compared with precipitation isotopic composition simulated by isotopically enabled atmospheric models. However, post-depositional processes linked with snow metamorphism remain poorly documented. For this purpose, monitoring of the isotopic composition (δ18O, δD of near-surface water vapor, precipitation and samples of the top (0.5 cm snow surface has been conducted during two summers (2011–2012 at NEEM, NW Greenland. The samples also include a subset of 17O-excess measurements over 4 days, and the measurements span the 2012 Greenland heat wave. Our observations are consistent with calculations assuming isotopic equilibrium between surface snow and water vapor. We observe a strong correlation between near-surface vapor δ18O and air temperature (0.85 ± 0.11‰ °C−1 (R = 0.76 for 2012. The correlation with air temperature is not observed in precipitation data or surface snow data. Deuterium excess (d-excess is strongly anti-correlated with δ18O with a stronger slope for vapor than for precipitation and snow surface data. During nine 1–5-day periods between precipitation events, our data demonstrate parallel changes of δ18O and d-excess in surface snow and near-surface vapor. The changes in δ18O of the vapor are similar or larger than those of the snow δ18O. It is estimated using the CROCUS snow model that 6 to 20% of the surface snow mass is exchanged with the atmosphere. In our data, the sign of surface snow isotopic changes is not related to the sign or magnitude of sublimation or deposition. Comparisons with atmospheric models show that day-to-day variations in near-surface vapor isotopic composition are driven by synoptic variations and changes in air mass trajectories and distillation histories. We suggest that, in between precipitation events, changes in the surface snow isotopic composition are driven by these changes in near-surface

  2. The influence of surface type on the absorbed radiation by a human under hot, dry conditions

    Science.gov (United States)

    Hardin, A. W.; Vanos, J. K.

    2018-01-01

    Given the predominant use of heat-retaining materials in urban areas, numerous studies have addressed the urban heat island mitigation potential of various "cool" options, such as vegetation and high-albedo surfaces. The influence of altered radiational properties of such surfaces affects not only the air temperature within a microclimate, but more importantly the interactions of long- and short-wave radiation fluxes with the human body. Minimal studies have assessed how cool surfaces affect thermal comfort via changes in absorbed radiation by a human ( R abs) using real-world, rather than modeled, urban field data. The purpose of the current study is to assess the changes in the absorbed radiation by a human—a critical component of human energy budget models—based on surface type on hot summer days (air temperatures > 38.5∘C). Field tests were conducted using a high-end microclimate station under predominantly clear sky conditions over ten surfaces with higher sky view factors in Lubbock, Texas. Three methods were used to measure and estimate R abs: a cylindrical radiation thermometer (CRT), a net radiometer, and a theoretical estimation model. Results over dry surfaces suggest that the use of high-albedo surfaces to reduce overall urban heat gain may not improve acute human thermal comfort in clear conditions due to increased reflected radiation. Further, the use of low-cost instrumentation, such as the CRT, shows potential in quantifying radiative heat loads within urban areas at temporal scales of 5-10 min or greater, yet further research is needed. Fine-scale radiative information in urban areas can aid in the decision-making process for urban heat mitigation using non-vegetated urban surfaces, with surface type choice is dependent on the need for short-term thermal comfort, or reducing cumulative heat gain to the urban fabric.

  3. Effect of Particular Breed on the Chemical Composition, Texture, Color, and Sensorial Characteristics of Dry-cured Ham

    Directory of Open Access Journals (Sweden)

    Pil Nam Seong

    2014-08-01

    Full Text Available The present study demonstrates the impact of specific breed on the characteristics of dry-cured ham. Eighty thighs from Korean native pig (KNP, crossbreed (Landrace×Yorkshire♀×Duroc♂ (LYD, Berkshire (Ber, and Duroc (Du pig breeds (n = 10 for each breed were used for processing of dry-cured ham. The thighs were salted with 6% NaCl (w/w and 100 ppm NaNO2, and total processing time was 413 days. The effects of breed on the physicochemical composition, texture, color and sensory characteristics were assessed on the biceps femoris muscle of the hams. The results revealed that the highest weight loss was found in the dry-cured ham of LYD breed and the lowest weight loss was found in Ber dry-cured ham. The KNP dry-cured ham contain higher intramuscular fat level than other breed hams (p<0.05. It was observed that the dry-cured ham made from KNP breed had the lowest water activity value and highest salt content, while the LYD dry-cure ham had higher total volatile basic nitrogen content than the Ber and Du hams (p<0.05. Zinc, iron and total monounsaturated fatty acids levels were higher in KNP ham while polyunsaturated fatty acids levels were higher in Du ham when compared to other breed hams (p<0.05. Additionally, the KNP dry-cured ham possessed higher Commission International de l’Eclairage (CIE a* value, while the Du dry-cured ham had higher L*, CIE b* and hue angle values (p<0.05. Furthermore, breed significantly affected the sensory attributes of dry-cured hams with higher scores for color, aroma and taste found in KNP dry-cured ham as compared to other breed hams (p<0.05. The overall outcome of the study is that the breed has a potential effect on the specific chemical composition, texture, color and sensorial properties of dry-cured hams. These data could be useful for meat processors to select the suitable breeds for economical manufacturing of high quality dry-cured hams.

  4. Enhancement of the oxidation resistance of carbon fibres in C/C composites via surface treatments

    Energy Technology Data Exchange (ETDEWEB)

    Labruquere, S.; Pailler, R.; Naslain, R. [Bordeaux Univ., Pessac (France). Lab. des Composites Thermostructuraux; Desbat, B. [Lab. de Spectroscopie Moleculaire et Cristalline, Univ. of Bordeaux, Talence (France)

    1997-12-31

    Carbon-carbon (C/C) composites are commonly used in rockets and braking systems. However, the carbon reacts with oxygen, burning away rapidly at temperatures as low as 450 C. This work deals with the protection of carbon fibres from oxidation between 600 and 1000 C. Two kinds of methods were investigated to protect carbon fibres: (i) surface treatment with aqueous solutions (e.g. of H3PO4) and (ii) chemical vapour deposition (CVD) of SiC coatings. Oxidation resistance of the as treated preforms was studied under dry air atmosphere. (orig.) 2 refs.

  5. Key composition optimization of meat processed protein source by vacuum freeze-drying technology

    Directory of Open Access Journals (Sweden)

    Yan Ma

    2018-05-01

    Full Text Available Vacuum freeze-drying technology is a high technology content, a wide range of knowledge of technology in the field of drying technology is involved, it is also a method of the most complex drying equipment, the largest energy consumption, the highest cost of drying method, but due to the particularity of its dry goods: the freeze-drying food has the advantages of complex water performance is good, cooler and luster of freezing and drying food to maintain good products, less nutrient loss, light weight, easy to carry transportation, easy to long-term preservation, and on the quality is far superior to the obvious advantages of other dried food, making it become the forefront of drying technology research and development. The freeze-drying process of Chinese style ham and western Germany fruit tree tenderloin is studied in this paper, their eutectic point, melting point and collapse temperature, freeze-drying curve and its heat and mass transfer characteristics are got, then the precool temperature and the highest limiting temperature of sublimation interface are determined. The effect of system pressure on freeze-dried rate in freeze-drying process is discussed, and the method of regulating pressure circularly is determined. Keywords: Ham, Tenderloin, Vacuum freeze-dry, Processing, Optimization

  6. Dry matter production and chemical composition of Massai grass submitted to nitrogen rates and cutting heights

    Directory of Open Access Journals (Sweden)

    Giselle Abadia Campos Pereira

    2016-09-01

    Full Text Available The study was carried out in a greenhouse with a 4X4 factorial arrangement randomized block design in order to evaluate the effects of nitrogen rates (0, 50, 100 and 150 mg dm-3 associated with cutting heights (10, 15, 20 and 25 cm on dry matter production and the chemical composition of Massai grass. The seeding was done in pots with 11 kg of soil. 10 plants were kept per pot, and there were two cuts every 35 days. Nitrogen fertilization was split between the two cuts, where the first N application occurred after the uniformity cut and the second after the first cut. In each cut the plants were separated and weighed for botanical component evaluation: leaf blade and stem + sheath. After this, the samples were homogenized and analysed for dry matter (DM, crude protein (CP and neutral detergent fibre (NDF content. In the first cut, the N fertilization caused a linear increase in DM production of 0.058 g pot-1 per each 1 mg dm-3 of N applied, as well as causing an increase of 0.549% in CP percentage, a 0.0124 pot-1 g increase in CP production and a reduction of 0.055% in NDF. In the second cut, N rates promoted a quadratic effect on DM production. A maximum DM production of 16.48 g pot-1 with 107.27 mg dm-3 of N was observed while CP production content was increased by 0.0092 g pot-1 for each 1 mg dm-3 N applied. In terms of linear responses to DM and PB, as well as the use efficiency calculated for Massai grass, recommended N doses range between 50 and 100 g dm-3.

  7. Chemical composition and properties of spray-dried sugar beet concentrate obtained after ultrafiltration of diffusion juice

    Directory of Open Access Journals (Sweden)

    Regiec Piotr

    2015-03-01

    Full Text Available Ultrafiltration of diffusion juice is a method that can reduce environmental pollution during the production of sugar. A by-product (concentrate of ultrafiltration contains a large amount of sucrose, but due to its properties, it is difficult to manage. The aim of this study was to determine the effects of the temperature used during drying of diffusion juice concentrates on the content of certain components and characteristics of resultant preparations. Diffusion juice obtained from one of the Polish sugar plants was subjected to ultrafiltration and the obtained concentrates were dried in a spray dryer. In the dried samples, the following parameters were analyzed: dry mass, sucrose, total ash, protein, crude fiber and color. It has been declared that the degree of concentration and drying temperature influenced the chemical composition and the properties of the dehydrated diffusion juice concentrates. An increase in drying temperature was accompanied by the increased content of dry mass, protein, ash and fiber content in the preparations. The greater the degree of juice concentration, the greater was the content of dry mass, ash, and fiber. Inversely, the greater the degree of juice concentration, the lower the content of sucrose. The brightest color of the dehydrated product was observed at the drying temperature of 200°C. Spray-drying may be used for waste management after the diffusion juice membrane filtration, and the resultant preparations might be used in the production of feedstuff or food industry in general e.g. as sucrose source, in fermentation processes or in microorganisms propagation.

  8. Effect of Particular Breed on the Chemical Composition, Texture, Color, and Sensorial Characteristics of Dry-cured Ham.

    Science.gov (United States)

    Seong, Pil Nam; Park, Kuyng Mi; Kang, Sun Moon; Kang, Geun Ho; Cho, Soo Hyun; Park, Beom Young; Van Ba, Hoa

    2014-08-01

    The present study demonstrates the impact of specific breed on the characteristics of dry-cured ham. Eighty thighs from Korean native pig (KNP), crossbreed (Landrace×Yorkshire)♀×Duroc♂ (LYD), Berkshire (Ber), and Duroc (Du) pig breeds (n = 10 for each breed) were used for processing of dry-cured ham. The thighs were salted with 6% NaCl (w/w) and 100 ppm NaNO2, and total processing time was 413 days. The effects of breed on the physicochemical composition, texture, color and sensory characteristics were assessed on the biceps femoris muscle of the hams. The results revealed that the highest weight loss was found in the dry-cured ham of LYD breed and the lowest weight loss was found in Ber dry-cured ham. The KNP dry-cured ham contain higher intramuscular fat level than other breed hams (pham made from KNP breed had the lowest water activity value and highest salt content, while the LYD dry-cure ham had higher total volatile basic nitrogen content than the Ber and Du hams (pham while polyunsaturated fatty acids levels were higher in Du ham when compared to other breed hams (pham possessed higher Commission International de l'Eclairage (CIE) a* value, while the Du dry-cured ham had higher L*, CIE b* and hue angle values (phams with higher scores for color, aroma and taste found in KNP dry-cured ham as compared to other breed hams (pcolor and sensorial properties of dry-cured hams. These data could be useful for meat processors to select the suitable breeds for economical manufacturing of high quality dry-cured hams.

  9. Ocular surface immunity: homeostatic mechanisms and their disruption in dry eye disease.

    Science.gov (United States)

    Barabino, Stefano; Chen, Yihe; Chauhan, Sunil; Dana, Reza

    2012-05-01

    The tear film, lacrimal glands, corneal and conjunctival epithelia and Meibomian glands work together as a lacrimal functional unit (LFU) to preserve the integrity and function of the ocular surface. The integrity of this unit is necessary for the health and normal function of the eye and visual system. Nervous connections and systemic hormones are well known factors that maintain the homeostasis of the ocular surface. They control the response to internal and external stimuli. Our and others' studies show that immunological mechanisms also play a pivotal role in regulating the ocular surface environment. Our studies demonstrate how anti-inflammatory factors such as the expression of vascular endothelial growth factor receptor-3 (VEGFR-3) in corneal cells, immature corneal resident antigen-presenting cells, and regulatory T cells play an active role in protecting the ocular surface. Dry eye disease (DED) affects millions of people worldwide and negatively influences the quality of life for patients. In its most severe forms, DED may lead to blindness. The etiology and pathogenesis of DED remain largely unclear. Nonetheless, in this review we summarize the role of the disruption of afferent and efferent immunoregulatory mechanisms that are responsible for the chronicity of the disease, its symptoms, and its clinical signs. We illustrate current anti-inflammatory treatments for DED and propose that prevention of the disruption of immunoregulatory mechanisms may represent a promising therapeutic strategy towards controlling ocular surface inflammation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Chemical Controls of Ozone Dry Deposition to the Sea Surface Microlayer

    Science.gov (United States)

    Carpenter, L.; Chance, R.; Tinel, L.; Saint, A.; Sherwen, T.; Loades, D.; Evans, M. J.; Boxhall, P.; Hamilton, J.; Stolle, C.; Wurl, O.; Ribas-Ribas, M.; Pereira, R.

    2017-12-01

    Oceanic dry deposition of atmospheric ozone (O3) is both the largest and most uncertain O3 depositional sink, and is widely acknowledged to be controlled largely by chemical reactions in the sea surface microlayer (SML) involving iodide (I-) and dissolved organic material (DOM). These reactions not only determine how quickly O3 can be removed from the atmosphere, but also result in emissions of trace gases including volatile organic compounds and may constitute a source of secondary organic aerosols to the marine atmosphere. Iodide concentrations at the sea surface vary by approximately an order of magnitude spatially, leading to more than fivefold variation in ozone deposition velocities (and volatile iodine fluxes). Sea-surface temperature is a reasonable predictor of [I-], however two recent parameterisations for surface I- differ by a factor of two at low latitudes. The nature and reactivity of marine DOM to O3 is almost completely unknown, although studies have suggested approximately equivalent chemical control of I- and DOM on ozone deposition. Here we present substantial new measurements of oceanic I- in both bulk seawater and the overlying SML, and show improved estimates of the global sea surface iodide distribution. We also present analyses of water-soluble DOM isolated from the SML and bulk seawater, and corresponding laboratory studies of ozone uptake to bulk and SML seawater, with the aim of characterizing the reactivity of O3 towards marine DOM.

  11. Analysis of observed surface ozone in the dry season over Eastern Thailand during 1997-2012

    Science.gov (United States)

    Assareh, Nosha; Prabamroong, Thayukorn; Manomaiphiboon, Kasemsan; Theramongkol, Phunsak; Leungsakul, Sirakarn; Mitrjit, Nawarat; Rachiwong, Jintarat

    2016-09-01

    This study analyzed observed surface ozone (O3) in the dry season over a long-term period of 1997-2012 for the eastern region of Thailand and incorporated several technical tools or methods in investigating different aspects of O3. The focus was the urbanized and industrialized coastal areas recently recognized as most O3-polluted areas. It was found that O3 is intensified most in the dry-season months when meteorological conditions are favorable to O3 development. The diurnal variations of O3 and its precursors show the general patterns of urban background. From observational O3 isopleth diagrams and morning ratios of non-methane volatile organic compounds (NMVOC) and nitrogen oxides (NOx), the chemical regime of O3 formation was identified as VOC-sensitive, and the degree of VOC sensitivity tends to increase over the years, suggesting emission control on VOC to be suitable for O3 management. Both total oxidant analysis and back-trajectory modeling (together with K-means clustering) indicate the potential role of regional transport or influence in enhancing surface O3 level over the study areas. A meteorological adjustment with generalized linear modeling was performed to statistically exclude meteorological effects on the variability of O3. Local air-mass recirculation factor was included in the modeling to support the coastal application. The derived trends in O3 based on the meteorological adjustment were found to be significantly positive using a Mann-Kendall test with block bootstrapping.

  12. The effect of extrusion and drying on roller techniques concerning the rheological characteristics of rice-, corn-, sweet potato-, bean- and cassava root- and leaf- based composite flour

    Directory of Open Access Journals (Sweden)

    Johanna Aristizábal Galvis

    2013-01-01

    Full Text Available Promoting food security in Latin-America and the Caribbean is directly related to agricultural products. The region faces a food crisis which has reduced large population groups’ access to food. This work contributes to the study of obtaining precooked composite flour made from biofortified crops using protein, vitamin A and/or minerals. This study evaluated the effect of precooked flour’s composition and precooking on its solubility in water, water absorption capacity, consistency and viscosity; such flour was obtained by extrusion and drying on rollers. The composite flours were obtained from cassava roots, sweet potato tubers, corn, rice and bean grains and cassava leaves. Four composite flours were formulated taking four- to six-year-old children’s daily nutrient requirements (protein, iron, zinc and beta-carotenes as a basis. The extruder was operated at 90ºC, 300 rpm screw rotation speed, 17.64 g/min feed flow, with 30% moisture mixture. The dryer rollers were operated at 4 rpm roller rotation speed, 90ºC surface temperature and 1 mm separation between rollers. It was determined that flour dried on rollers led to more complete cooking and modified starch granule structure than precooking by extrusion, thereby producing flour having greater solubility in water, less water absorption, higher consistency and smaller viscosity, comparable to that of pattern flour.

  13. Key composition optimization of meat processed protein source by vacuum freeze-drying technology.

    Science.gov (United States)

    Ma, Yan; Wu, Xingzhuang; Zhang, Qi; Giovanni, Vigna; Meng, Xianjun

    2018-05-01

    Vacuum freeze-drying technology is a high technology content, a wide range of knowledge of technology in the field of drying technology is involved, it is also a method of the most complex drying equipment, the largest energy consumption, the highest cost of drying method, but due to the particularity of its dry goods: the freeze-drying food has the advantages of complex water performance is good, cooler and luster of freezing and drying food to maintain good products, less nutrient loss, light weight, easy to carry transportation, easy to long-term preservation, and on the quality is far superior to the obvious advantages of other dried food, making it become the forefront of drying technology research and development. The freeze-drying process of Chinese style ham and western Germany fruit tree tenderloin is studied in this paper, their eutectic point, melting point and collapse temperature, freeze-drying curve and its heat and mass transfer characteristics are got, then the precool temperature and the highest limiting temperature of sublimation interface are determined. The effect of system pressure on freeze-dried rate in freeze-drying process is discussed, and the method of regulating pressure circularly is determined.

  14. Reversible Compositional Control of Oxide Surfaces by Electrochemical Potentials

    KAUST Repository

    Mutoro, Eva

    2012-01-05

    Perovskite oxides can exhibit a wide range of interesting characteristics such as being catalytically active and electronically/ionically conducting, and thus, they have been used in a number of solid-state devices such as solid oxide fuel cells (SOFCs) and sensors. As the surface compositions of perovskites can greatly influence the catalytic properties, knowing and controlling their surface compositions is crucial to enhance device performance. In this study, we demonstrate that the surface strontium (Sr) and cobalt (Co) concentrations of perovskite-based thin films can be controlled reversibly at elevated temperatures by applying small electrical potential biases. The surface compositional changes of La 0.8Sr 0.2CoO 3-δ (LSC 113), (La 0.5Sr 0.5) 2CoO 4±δ (LSC 214), and LSC 214-decorated LSC 113 films (LSC 113/214) were investigated in situ by utilizing synchrotron-based X-ray photoelectron spectroscopy (XPS), where the largest changes of surface Sr were found for the LSC 113/214 surface. These findings offer the potential of reversibly controlling the surface functionality of perovskites. © 2011 American Chemical Society.

  15. Surface analysis of graphite fiber reinforced polyimide composites

    Science.gov (United States)

    Messick, D. L.; Progar, D. J.; Wightman, J. P.

    1983-01-01

    Several techniques have been used to establish the effect of different surface pretreatments on graphite-polyimide composites. Composites were prepared from Celion 6000 graphite fibers and the polyimide LARC-160. Pretreatments included mechanical abrasion, chemical etching and light irradiation. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used in the analysis. Contact angle of five different liquids of varying surface tensions were measured on the composites. SEM results showed polymer-rich peaks and polymer-poor valleys conforming to the pattern of the release cloth used durng fabrication. Mechanically treated and light irradiated samples showed varying degrees of polymer peak removal, with some degradation down to the graphite fibers. Minimal changes in surface topography were observed on concentrations of surface fluorine even after pretreatment. The light irradiation pretreatment was most effective at reducing surface fluorine concentrations whereas chemical pretreatment was the least effective. Critical surface tensions correlated directly with the surface fluorine to carbon ratios as calculated from XPS.

  16. Surface characterization of modern resin composites: a multitechnique approach.

    Science.gov (United States)

    Silikas, Nick; Kavvadia, Katerina; Eliades, George; Watts, David

    2005-04-01

    To characterize the surface properties of some modern resin composites employing a series of physicochemical methods. Specimens from three microhybrid (Palfique Estellite-PE, Z250 Filtek-ZF, Tetric Ceram-TC) and one nanofilled (Supreme Filtek-SF) conventionally photo-cured resin composites polished with Soflex disks were studied for the following properties: Surface chemical composition and degree of C=C conversion (FTIR), surface energetics (contact angles), surface texture (AFM), surface roughness (AFM, stylus profilometry) and gloss (60 degrees-, 20 degrees-angle specular gloss). Polar and non polar molecular groups were identified in all products including NH and CONH (SF, ZF, TC). SF and ZF demonstrated higher conversion than PE and TC (P 0.05) were found in critical surface tension, total work of adhesion and its polar and dispersion components, the latter being the highest in all products. AFM showed the smoothest surface texture in PE. The ranking of Sa, Sq, Ra and Rz roughness parameters was PEgloss measurements (PE, SF>ZF>TC, PTC, Pgloss differences. A positive correlation was found between Sa and Ra and a negative one between Sa and 20 degree-angle gloss.

  17. Gloss and surface roughness produced by polishing kits on resin composites.

    Science.gov (United States)

    Sadidzadeh, Ramtin; Cakir, Deniz; Ramp, Lance C; Burgess, John O

    2010-08-01

    To compare in vitro the surface roughness (Ra) and gloss (G) produced by three conventional and one experimental polishing kits on four resin composites. 24 discs were prepared (d = 12 mm, t = 4 mm) for each resin composite: Filtek Supreme Plus Body/A2 (FSB), Yellow Translucent (FST), Heliomolar/A2 (HM), and EsthetX/A2 (EX) following the manufacturers' instructions. They were finished with 320 grit silicon carbide paper for 80 seconds each. Polishing systems: Sof-Lex, Enhance-Pogo, Astropol and Experimental Discs/EXL-695, were applied following manufacturers' instructions. Each specimen was ultrasonically cleaned with distilled water and dried. Gloss and Ra were measured with a small area glossmeter (Novo-curve) and non-contact profilometer (Proscan 2000) following ISO 4288, respectively. The results were evaluated by two-way ANOVA followed by separate one-way ANOVA and Tukey/Kramer test (P = 0.05). There was a significant interaction of surface roughness and gloss between the composites and polishing systems (P gloss was obtained for FSB composite polished with the Experimental kit. The experimental polishing system produced smoothest surfaces (P gloss (P < 0.05).

  18. Visible and Near-IR Reflectance Spectra for Smectite, Sulfate And Perchlorate under Dry Conditions for Interpretation of Martian Surface Mineralogy

    Science.gov (United States)

    Morris, R.V.; Ming, W.; Golden, D.C.; Arvidson, R.E.; Wiseman, S.M.; Lichtenberg, K.A.; Cull, S.; Graff, T.G.

    2009-01-01

    Visible and near-IR (VNIR) spectral data for the martian surface obtained from orbit by the MRO-CRISM and OMEGA instruments are interpreted as having spectral signatures of H2O/OH-bearing phases, including smectites and other phyllosilicates, sulfates, and high-SiO2 phases [e.g., 1-4]. Interpretations of martian spectral signatures are based on and constrained by spectra that are obtained in the laboratory on samples with known mineralogical compositions and other physicochemical characteristics under, as appropriate, Mars-like environmental conditions (e.g., temperature, pressure, and humidity). With respect to environmental conditions, differences in the absolute concentration of atmospheric H2O can effect the hydration state and therefore the spectra signatures of smectite phyllosilicates (solvation H2O) and certain sulfates (hydration H2O) [e.g., 5-7]. We report VNIR spectral data acquired under humid (laboratory air) and dry (dry N2 gas) environments for two natural smectites (nontronite API-33A and saponite SapCa-1) to characterize the effect of solvation H2O on spectral properties. We also report spectral data for the thermal dehydration products of (1) melanterite (FeSO4.7H2O) in both air and dry N2 gas and (2) Mg-perchlorate (Mg(ClO4)2.6H2O) in dry N2 environments. Spectral measurements for samples dehydrated in dry N2 were made without exposing them to humid laboratory air.

  19. Data on color and chemical composition of dried scallop (Mizuhopecten yessoensis produced in different areas of Hokkaido, Japan

    Directory of Open Access Journals (Sweden)

    Hisaki Enda

    2018-02-01

    Full Text Available Dried scallop is used in Chinese, Japanese, and French cuisines for its unique flavor and taste. The quality of dried scallop is rated according to its clear, shiny brown color, developed by the Maillard reaction between sugars and amino acids. This article reports the colors, represented by L* and a* values, and chemical composition (water, salinity, Brix, proteins, and amino acids of dried scallop products. The dried scallops were produced in Tokoro, Sarufutsu, and Saroma in Hokkaido, Japan. The color of the dried scallops had values of 45.7–52.0 for L* and 2.31–5.08 for a*. The salinity of the products was 15.1–17.7%. The amino acid contents were 1350.8–1668.6 mg/100 g. The data collected here are provided in table format. The data can serve as a reference for commercial dried scallop products to determine product quality. Keywords: Quality of products, Dried scallop, Seasoning ingredient, Browning

  20. Experimental Tests on Bending Behavior of Profiled Steel Sheeting Dry Board Composite Floor with Geopolymer Concrete Infill

    Directory of Open Access Journals (Sweden)

    Mohd Isa Jaffar

    Full Text Available Abstract Profiled Steel Sheet Dry Board (PSSDB system is a lightweight composite structure comprises Profiled Steel Sheeting and Dry Board connected by self-drilling and self-tapping screws. This study introduced geopolymer concrete, an eco-friendly material without cement content as an infill material in the PSSDB floor system to highlight its effect onto the PSSDB (with full and half-size dry boards floor system's stiffness and strength. Experimental tests on various full scale PSSDB floor specimens were conducted under uniformly distributed transverse loads. Results illustrate that the rigidity of the panel with geopolymer concrete infill with half-size dry board (HBGPC increases by 43% relative to that of the panel with normal concrete infill with full-size dry board (FBNC. The developed finite-element modeling (FEM successfully predicts the behavior of FBGPC model with 94.8% accuracy. Geopolymer concrete infill and dry board size influence the strength panel, infill contact stiffness, and mid-span deflection of the profiled steel sheeting/dry board (PSSDB flooring system.

  1. Multi-response optimization of process parameters using Taguchi method and grey relational analysis during turning AA 7075/SiC composite in dry and spray cooling environments

    Directory of Open Access Journals (Sweden)

    P. C. Mishra

    2015-09-01

    Full Text Available Turning experiments were carried out on AA 7075/SiC composite workpiece in dry and spray cooling environments based on L16 Taguchi design of experiments. Multiple performance optimization of process parameters was performed using grey relational analysis. The performance characteristics considered were average surface roughness, cutting tool temperature and material removal rate. Uncoated carbide inserts were used for machining the workpiece in a high speed precision lathe. A grey relational grade obtained from grey relational analysis was used to optimize the process parameters. Optimal combination of process parameters was then determined by the Taguchi method using the grey relational grade as the performance index. Experimental results indicated that the turning in spray cooling environment was beneficial compared to that in dry environment for the quality response characteristics under consideration. Analysis of variance showed that feed was the most significant parameter for the multiple performance characteristics during turning in both the environments.

  2. Surface treated fly ash filled modified epoxy composites

    Directory of Open Access Journals (Sweden)

    Uma Dharmalingam

    2015-01-01

    Full Text Available Abstract Fly ash, an inorganic alumino silicate has been used as filler in epoxy matrix, but it reduces the mechanical properties due to its poor dispersion and interfacial bonding with the epoxy matrix. To improve its interfacial bonding with epoxy matrix, surface treatment of fly ash was done using surfactant sodium lauryl sulfate and silane coupling agent glycidoxy propyl trimethoxy silane. An attempt is also made to reduce the particle size of fly ash using high pressure pulverizer. To improve fly ash dispersion in epoxy matrix, the epoxy was modified by mixing with amine containing liquid silicone rubber (ACS. The effect of surface treated fly ash with varying filler loadings from 10 to 40% weight on the mechanical, morphological and thermal properties of modified epoxy composites was investigated. The surface treated fly ash was characterized by particle size analyzer and FTIR spectra. Morphological studies of surface treated fly ash filled modified epoxy composites indicate good dispersion of fillers in the modified epoxy matrix and improves its mechanical properties. Impact strength of the surface treated fly ash filled modified epoxy composites show more improvement than unmodified composites.

  3. The Origin of Mercury's Surface Composition, an Experimental Investigation

    Science.gov (United States)

    Boujibar, A.; Righter, K.; Rapp, J. F.; Ross, D. K.; Pando, K. M.; Danielson, L. R.; Fontaine, E.

    2016-01-01

    Introduction: Results from MESSENGER spacecraft have confirmed the reduced nature of Mercury, based on its high core/mantle ratio and its FeO-poor and S-rich surface. Moreover, high resolution images revealed large volcanic plains and abundant pyroclastic deposits, suggesting major melting stages of the Mercurian mantle. In addition, MESSENGER has provided the most precise data to date on major elemental compositions of Mercury's surface. These results revealed considerable chemical heterogeneities that suggested several stages of differentiation and re-melting processes. This interpretation was challenged by our experimental previous study, which showed a similar compositional variation in the melting products of enstatite chondrites, which are a possible Mercury analogue. However, these experimental melts were obtained over a limited range of pressure (1 bar to 1 gigapascal) and were not compared to the most recent elemental maps. Therefore, here we extend the experimental dataset to higher pressures and perform a more quantitative comparison with Mercury's surface compositions measured by MESSENGER. In particular, we test whether these chemical heterogeneities result from mixing between polybaric melts. Our experiments and models show that the majority of chemical diversity of Mercury's surface can result from melting of a primitive mantle compositionally similar to enstatite chondrites in composition at various depths and degrees of melting. The high-Mg region's composition is reproduced by melting at high pressure (3 gigapascals) (Tab. 1), which is consistent with previous interpretation as being a large degraded impact basin based on its low elevation and thin average crust. While low-Mg NVP (North Volcanic Plains) are the result of melting at low pressure (1 bar), intermediate-Mg NVP, Caloris Basin and Rachmaninoff result from mixing of a high-pressure (3 gigapascals) and low-pressure components (1 bar for Rachmaninoff and 1 gigapascal for the other regions

  4. Method and coating composition for protecting and decontaminating surfaces

    Science.gov (United States)

    Overhold, D C; Peterson, M D

    1959-03-10

    A protective coating useful in the decontamination of surfaces exposed to radioactive substances is described. This coating is placed on the surface before use and is soluble in water, allowing its easy removal in the event decontamination becomes necessary. Suitable coating compositions may be prepared by mixing a water soluble carbohydrate such as sucrose or dextrin, together with a hygroscopic agent such as calcium chloride or zinc chloride.

  5. Sliding-surface-liquefaction of sand-dry ice mixture and submarine landslides

    Science.gov (United States)

    Fukuoka, H.; Tsukui, A.

    2010-12-01

    In the historic records of off-shore mega-earthquakes along the subduction zone offshore Japan, there are a lot of witnesses about large-scale burning of flammable gas possibly ejected from sea floor. This gas was supposed to be the dissolved methane hydrates (MH), which have been found in the soundings of IODP and other oceanology projects. Since the vast distribution of the BSR in the continental margins, a lot of papers have been published which pointed out the possibilities of that gasification of those hydrates could have triggered gigantic submarine landslides. Global warming or large earthquake or magma intrusion may trigger extremely deep gigantic landslides in continental margins that which could cause catastrophic tsunami. However, recent triaxial compression tests on artificially prepared sand-MH-mixture samples revealed that the they have slightly higher strength than the ones of only sands and MH’s endothermal characteristics may resist against accelerating shear and large-displacement landslides as well. While, the stress-controlled undrained ring shear apparatuses have been developed by Sassa and Fukuoka at Disaster Prevention Research Institute, Kyoto University to reproduce subaerial landslides induced by earthquakes and rainfalls. Using the apparatuses, they found localized liquefaction phenomenon along the deep saturated potential sliding surface due to excess pore pressure generation during the grain crushing induced bulk volume change. This phenomenon was named as “sliding surface liquefaction.” Similar sudden large pore pressure generation was observed in pore pressure control test simulating rain-induced landslides. In this paper, authors examined the shear behavior of the dry sand-dry ice mixture under constant normal stress and shear speed control tests using the latest ring shear apparatus. Sample was mixture of silica sands and dry-ice pellets (frozen carbon-dioxide). Those mixtures are often used for studying the mechanism of the

  6. Strength and failure analysis of composite-to-composite adhesive bonds with different surface treatments

    Science.gov (United States)

    Paranjpe, Nikhil; Alamir, Mohammed; Alonayni, Abdullah; Asmatulu, Eylem; Rahman, Muhammad M.; Asmatulu, Ramazan

    2018-03-01

    Adhesives are widely utilized materials in aviation, automotive, energy, defense, and marine industries. Adhesive joints are gradually supplanting mechanical fasteners because they are lightweight structures, thus making the assembly lighter and easier. They also act as a sealant to prevent a structural joint from galvanic corrosion and leakages. Adhesive bonds provide high joint strength because of the fact that the load is distributed uniformly on the joint surface, while in mechanical joints, the load is concentrated at one point, thus leading to stress at that point and in turn causing joint failures. This research concentrated on the analysis of bond strength and failure loads in adhesive joint of composite-to-composite surfaces. Different durations of plasma along with the detergent cleaning were conducted on the composite surfaces prior to the adhesive applications and curing processes. The joint strength of the composites increased about 34% when the surface was plasma treated for 12 minutes. It is concluded that the combination of different surface preparations, rather than only one type of surface treatment, provides an ideal joint quality for the composites.

  7. Composition, physical properties and drying characteristics of seed oil of Citrullus lanatus

    Science.gov (United States)

    Idris, S. A.; Rashidi, A. R.; Muhammad, A.; Abdullah, M.; Elham, O. S. J.; Mamat, M. S.

    2017-09-01

    A study to investigate the effect of different drying methods for the pre-treatment process on the quality and quantity of oil extracted from Citrulllus lanatus seeds was conducted. The red type Citrulllus lanatus seeds from local supermarket in Shah Alam is used in this experiment. The amount of seed was divided into two portions; one portion was subjected to sun drying while the other portion was subjected to oven drying (at a temperature of 70°C). After the drying process, the seeds were ground in a laboratory grinder to turn them into powder. The ground seeds then will be fed to Supercritical Carbon Dioxide unit (SC-CO2) for extraction. Once the extracted oil is obtained, it will be analysed by using Gas Chromatography and Mass Spectrometer (GC-MS). Results indicated that the amount of the moisture content from the sun-dried was lower compared to oven-dried. The results also indicated that, there were no significant difference in the quantity of oil obtained from both samples of oven-dried and sun-dried. However, the acid value and other component content in the sample were higher in the sun-dried sample relative to the oven-dried sample. Linoleic acid is the only compound that was found in the oven-dried sample, whereas linoleic acid and oleic acid were found in the sun-dried sample. Based on the results, it shows that the drying effect were important when the quality of oil was to be considered. The other compounds like Naphtalenol, 9-17-Octadecadeinal, 2-Chloroethyl linoleate, and Carboxin also are found in the sun-dried sample. Other that that, drying method does not give any effect to the physical appearance of the extracted oil, as similar color and other physical appearance was produced by the both sample.

  8. Cerium Addition Improved the Dry Sliding Wear Resistance of Surface Welding AZ91 Alloy

    Directory of Open Access Journals (Sweden)

    Qingqiang Chen

    2018-02-01

    Full Text Available In this study, the effects of cerium (Ce addition on the friction and wear properties of surface welding AZ91 magnesium alloys were evaluated by pin-on-disk dry sliding friction and wear tests at normal temperature. The results show that both the friction coefficient and wear rate of surfacing magnesium alloys decreased with the decrease in load and increase in sliding speed. The surfacing AZ91 alloy with 1.5% Ce had the lowest friction coefficient and wear rate. The alloy without Ce had the worst wear resistance, mainly because it contained a lot of irregularly shaped and coarse β-Mg17Al12 phases. During friction, the β phase readily caused stress concentration and thus formed cracks at the interface between β phase and α-Mg matrix. The addition of Ce reduced the size and amount of Mg17Al12, while generating Al4Ce phase with a higher thermal stability. The Al-Ce phase could hinder the grain-boundary sliding and migration and reduced the degree of plastic deformation of subsurface metal. Scanning electron microscopy observation showed that the surfacing AZ91 alloy with 1.5% Ce had a total of four types of wear mechanism: abrasion, oxidation, and severe plastic deformation were the primary mechanisms; delamination was the secondary mechanism.

  9. Plasma facing surface composition during NSTX Li experiments

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, C.H., E-mail: cskinner@pppl.gov [Princeton Plasma Physics Laboratory, POB 451, Princeton, NJ 08543 (United States); Sullenberger, R. [Department of Mechanical and Aerospace Engineering, Princeton University, NJ 08540 (United States); Koel, B.E. [Department of Chemical and Biological Engineering, Princeton University, NJ 08540 (United States); Jaworski, M.A.; Kugel, H.W. [Princeton Plasma Physics Laboratory, POB 451, Princeton, NJ 08543 (United States)

    2013-07-15

    Lithium conditioned plasma facing surfaces have lowered recycling and enhanced plasma performance on many fusion devices. However, the nature of the plasma–lithium surface interaction has been obscured by the difficulty of in-tokamak surface analysis. We report laboratory studies of the chemical composition of lithium surfaces exposed to typical residual gases found in tokamaks. Solid lithium and a molybdenum alloy (TZM) coated with lithium have been examined using X-ray photoelectron spectroscopy, temperature programmed desorption, and Auger electron spectroscopy both in ultrahigh vacuum conditions and after exposure to trace gases. Lithium surfaces near room temperature were oxidized after exposure to 1–2 Langmuirs of oxygen or water vapor. The oxidation rate by carbon monoxide was four times less. Lithiated PFC surfaces in tokamaks will be oxidized in about 100 s depending on the tokamak vacuum conditions.

  10. Compressive strength measurements of hybrid dental composites treated with dry heat and light emitting diodes (LED post cure treatment

    Directory of Open Access Journals (Sweden)

    Jenny Krisnawaty

    2014-11-01

    Full Text Available Hybrid composites are mostly used on large cavities as restorative dental materials, whether it is used directly or indirectly. The mechanical properties of composite resin shall increase if it is treated with post cure treatment. The aim of this study is to evaluate compressive strength differences between dry heat and Light Emitting Diodes (LED treatment on the hybrid dental composite. A quasi-experimental was applied on this research with a total of 30 samples that were divided into two groups. Each sample was tested using LLOYD Universal Testing Machine with 1 mm/min speed to evaluate the compressive strength. The compressive strength results were marked when the sample was broken. The results of two groups were then analyzed using t-test statistical calculation. The results of this study show that post cure treatment on hybrid composite using LED light box (194.138 MPa was lower than dry heat treatment (227.339 MPa, which was also significantly different from statistical analysis. It can be concluded that compressive strength of LED light box was lower than dry heat post-cure treatment on the hybrid composite resin.

  11. Composite sampling of a Bacillus anthracis surrogate with cellulose sponge surface samplers from a nonporous surface.

    Directory of Open Access Journals (Sweden)

    Jenia A M Tufts

    Full Text Available A series of experiments was conducted to explore the utility of composite-based collection of surface samples for the detection of a Bacillus anthracis surrogate using cellulose sponge samplers on a nonporous stainless steel surface. Two composite-based collection approaches were evaluated over a surface area of 3716 cm2 (four separate 929 cm2 areas, larger than the 645 cm2 prescribed by the standard Centers for Disease Control (CDC and Prevention cellulose sponge sampling protocol for use on nonporous surfaces. The CDC method was also compared to a modified protocol where only one surface of the sponge sampler was used for each of the four areas composited. Differences in collection efficiency compared to positive controls and the potential for contaminant transfer for each protocol were assessed. The impact of the loss of wetting buffer from the sponge sampler onto additional surface areas sampled was evaluated. Statistical tests of the results using ANOVA indicate that the collection of composite samples using the modified sampling protocol is comparable to the collection of composite samples using the standard CDC protocol (p  =  0.261. Most of the surface-bound spores are collected on the first sampling pass, suggesting that multiple passes with the sponge sampler over the same surface may be unnecessary. The effect of moisture loss from the sponge sampler on collection efficiency was not significant (p  =  0.720 for both methods. Contaminant transfer occurs with both sampling protocols, but the magnitude of transfer is significantly greater when using the standard protocol than when the modified protocol is used (p<0.001. The results of this study suggest that composite surface sampling, by either method presented here, could successfully be used to increase the surface area sampled per sponge sampler, resulting in reduced sampling times in the field and decreased laboratory processing cost and turn-around times.

  12. CNT/PDMS composite flexible dry electrodes for long-term ECG monitoring.

    Science.gov (United States)

    Jung, Ha-Chul; Moon, Jin-Hee; Baek, Dong-Hyun; Lee, Jae-Hee; Choi, Yoon-Young; Hong, Joung-Sook; Lee, Sang-Hoon

    2012-05-01

    We fabricated a carbon nanotube (CNT)/ polydimethylsiloxane (PDMS) composite-based dry ECG electrode that can be readily connected to conventional ECG devices, and showed its long-term wearable monitoring capability and robustness to motion and sweat. While the dispersion of CNTs in PDMS is challenging, we optimized the process to disperse untreated CNTs within PDMS by mechanical force only. The electrical and mechanical characteristics of the CNT/PDMS electrode were tested according to the concentration of CNTs and its thickness. The performances of ECG electrodes were evaluated by using 36 types of electrodes which were fabricated with different concentrations of CNTs, and with a differing diameter and thickness. The ECG signals were obtained by using electrodes of diverse sizes to observe the effects of motion and sweat, and the proposed electrode was shown to be robust to both factors. The CNT concentration and diameter of the electrodes were critical parameters in obtaining high-quality ECG signals. The electrode was shown to be biocompatible from the cytotoxicity test. A seven-day continuous wearability test showed that the quality of the ECG signal did not degrade over time, and skin reactions such as itching or erythema were not observed. This electrode could be used for the long-term measurement of other electrical biosignals for ubiquitous health monitoring including EMG, EEG, and ERG.

  13. Dry deposition of submicron atmospheric aerosol over water surfaces in motion

    International Nuclear Information System (INIS)

    Nevenick, Calec

    2013-01-01

    Whether by chronic or accidental releases, the impact of a nuclear installation on the environment mainly depends on atmospheric transfers; and as the accidents at Chernobyl and Fukushima show, affect the contamination of surfaces and impacts in the medium and long-term on the environment and the population. In this context, this work focuses on the characterization and modeling of dry deposition of submicron aerosols on liquid surfaces in motion such as rivers. Unlike wet deposition which is conditioned by washout and rainout (rain and clouds), dry deposition is a phenomenon that depends entirely on the characteristics of aerosols, receiving surfaces, and air flow. In practice, the evaluation of dry deposition is based on the estimation of flux modeling as the product of particle concentration and deposition velocity which can vary over several orders of magnitude depending on the receiving surfaces (forest, snow, urban, grassland...). This topic is motivated by the virtual non-existence of studies on the mechanisms of dry deposition on continental water systems such as rivers; and respect for submicron aerosols. They have the lowest deposition efficiencies and filtration and the longer residence time in the atmosphere. In addition, they are potentially the most dangerous to living beings because they can penetrate deeper into the airway. Due to the lack of data on the dry deposition of submicron aerosols on a liquid surface in motion, the approach was based on two axes: 1) the acquisition of experimental deposition velocities and 2) the analysis and interpretation of results through modeling. The experiments were performed with uranine aerosols released into the IOA wind tunnel (Interface Ocean Atmosphere) of the Institute for Research on Non Equilibrium Phenomena which is configured to study the coupling between the air flow and water. These experiments have given many dry deposition velocities for different configurations characterized according to wind

  14. Dry deposition of submicron atmospheric aerosol over water surfaces in motion

    International Nuclear Information System (INIS)

    Calec, Nevenick

    2013-01-01

    Whether by chronic or accidental releases, the impact of a nuclear installation on the environment mainly depends on atmospheric transfers; and as the accidents at Chernobyl and Fukushima show, affect the contamination of surfaces and impacts in the medium and long-term on the environment and the population. In this context, this work focuses on the characterization and modeling of dry deposition of submicron aerosols on liquid surfaces in motion such as rivers. Unlike wet deposition which is conditioned by washout and rainout (rain and clouds), dry deposition is a phenomenon that depends entirely on the characteristics of aerosols, receiving surfaces, and air flow. In practice, the evaluation of dry deposition is based on the estimation of flux modeling as the product of particle concentration and deposition velocity which can vary over several orders of magnitude depending on the receiving surfaces (forest, snow, urban, grassland..). This topic is motivated by the virtual non-existence of studies on the mechanisms of dry deposition on continental water systems such as rivers; and respect for submicron aerosols. They have the lowest deposition efficiencies and filtration and the longer residence time in the atmosphere. In addition, they are potentially the most dangerous to living beings because they can penetrate deeper into the airway. Due to the lack of data on the dry deposition of submicron aerosols on a liquid surface in motion, the approach was based on two axes: 1) the acquisition of experimental deposition velocities and 2) the analysis and interpretation of results through modeling. The experiments were performed with uranine aerosols released into the IOA wind tunnel (Interface Ocean Atmosphere) of the Institute for Research on Non Equilibrium Phenomena which is configured to study the coupling between the air flow and water. These experiments have given many dry deposition velocities for different configurations characterized according to wind

  15. Analysis of surface hardness of artificially aged resin composites

    Directory of Open Access Journals (Sweden)

    Denise Cremonezzi Tornavoi

    2012-02-01

    Full Text Available This study evaluated the effect of artificially accelerated aging (AAA on the surface hardness of eight composite resins: Filtek Z250, Filtek Supreme, 4 Seasons, Herculite, P60, Tetric Ceram, Charisma, and Filtek Z100. Sixteen specimens were made from the test piece of each material, using an 8.0 × 2.0 mm teflon matrix. After 24 hours, eight specimens from each material were submitted to three surface hardness readings using a Shimadzu Microhardness Tester for 5 seconds at a load of 50 gf. The other eight specimens remained in the artificially accelerated aging machine for 382 hours and were submitted to the same surface hardness analysis. The means of each test specimen were submitted to the Kolmogorov-Smirnov test (p > 0.05, ANOVA and Tukey test (p < 0.05. With regard to hardness (F = 86.74, p < 0.0001 the analysis showed significant differences among the resin composite brands. But aging did not influence the hardness of any of the resin composites (F = 0.39, p = 0.53. In this study, there was interaction between the resin composite brand and the aging factors (F = 4.51, p < 0.0002. It was concluded that notwithstanding the type of resin, AAA did not influence surface hardness. However, with regard to hardness there was a significant difference among the resin brands.

  16. Phase spectral composition of wind generated ocean surface waves

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.

    A study of the composition of the phase spectra of wind generated ocean surface waves is carried out using wave records collected employing a ship borne wave recorder. It is found that the raw phase spectral estimates could be fitted by the Uniform...

  17. Spray drying of budesonide, formoterol fumarate and their composites-II. Statistical factorial design and in vitro deposition properties.

    Science.gov (United States)

    Tajber, L; Corrigan, O I; Healy, A M

    2009-02-09

    The aim of this study was to investigate the effect of changing spray drying parameters on the production of a budesonide/formoterol fumarate 100:6 (w/w) composite. The systems were spray dried as solutions from 95% ethanol/5% water (v/v) using a Büchi 191-Mini Spray Dryer. A 2(5-1) factorial design study was undertaken to assess the consequence of altering spray drying processing variables on particle characteristics. The processing parameters that were studied were inlet temperature, spray drier airflow rate, pump rate, aspirator setting and feed concentration. Each batch of the resulting powder was characterised in terms of thermal and micromeritic properties as well as an in vitro deposition by twin impinger analysis. Overall, the parameter that had the greatest influence on each response investigated was production yield - airflow (higher airflow giving greater yields), median particle size - airflow (higher airflow giving smaller particle sizes) and Carr's compressibility index - feed concentration (lower feed concentration giving smaller Carr's indices). A six- to seven-fold difference in respirable fraction can be observed by changing the spray drying process parameters. The co-spray dried composite system which displayed best in vitro deposition characteristics, showed a 2.6-fold increase in respirable fraction in the twin impinger experiments and better dose uniformity compared with the physical mix of micronised powders.

  18. Self-assembling peptide detergents stabilize isolated photosystem ion a dry surface for an extended time.

    Directory of Open Access Journals (Sweden)

    2005-07-01

    Full Text Available We used a class of designed peptide detergents to stabilize photosystem I (PS-I upon extended drying under N2 on a gold-coated-Ni-NTA glass surface. PS-I is a chlorophyll-containing membrane protein complex that is the primary reducer of ferredoxin and the electron acceptor of plastocyanin. We isolated the complex from the thylakoids of spinach chloroplasts using a chemical detergent. The chlorophyll molecules associated with the PS-I complex provide an intrinsic steady-state emission spectrum between 650 and 800 nm at -196.15 degrees C that reflects the organization of the pigment-protein interactions. In the absence of detergents, a large blue shift of the fluorescence maxima from approximately 735 nm to approximately 685 nm indicates a disruption in light-harvesting subunit organization, thus revealing chlorophyll-protein interactions. The commonly used membrane protein-stabilizing detergents, N-dodecyl-beta-D-maltoside and N-octyl-beta-D-glucoside, only partially stabilized the approximately 735-nm complex with approximately 685-nm spectroscopic shift. However, prior to drying, addition of the peptide detergent acetyl-AAAAAAK at increasing concentration significantly stabilized the PS-I complex. Moreover, in the presence of acetyl-AAAAAAK, the PS-I complex is stable in a dried form at room temperature for at least 3 wk. Another peptide detergent, acetyl-VVVVVVD, also stabilized the complex but to a lesser extent. These observations suggest that the peptide detergents may effectively stabilize membrane proteins in the solid-state. These designed peptide detergents may facilitate the study of diverse types of membrane proteins.

  19. Effect of processing history on the surface interfacial properties of budesonide in carrier-based dry-powder inhalers.

    Science.gov (United States)

    Shur, Jagdeep; Pitchayajittipong, Chonladda; Rogueda, Philippe; Price, Robert

    2013-08-01

    Influence of air-jet micronization, post-micronization conditioning and storage on the surface properties of budesonide in dry-powder inhaler formulations was investigated. Crystalline budesonide was air jet-micronized and conditioned using organic vapor. Particle engineering was also used to fabricate respirable particles of budesonide. Surface imaging by atomic force microscopy suggested that micronized material possessed process-induced surface disorder, which relaxed upon conditioning with organic vapor. Particle engineered material was devoid of such surface disorder. Surface interfacial properties of all batches were different and correlated to in vitro fine particle delivery. The surface properties and in vitro performance of the conditioned material changed upon storage of the budesonide at 44% relative humidity and 25°C, while the micronized and particle-engineered material remained stable. These data suggest that processing conditions of budesonide affected the surface properties of the material, which was demonstrated to have direct affect on dry-powder inhaler formulation performance.

  20. Meteorological and Land Surface Properties Impacting Sea Breeze Extent and Aerosol Distribution in a Dry Environment

    Science.gov (United States)

    Igel, Adele L.; van den Heever, Susan C.; Johnson, Jill S.

    2018-01-01

    The properties of sea breeze circulations are influenced by a variety of meteorological and geophysical factors that interact with one another. These circulations can redistribute aerosol particles and pollution and therefore can play an important role in local air quality, as well as impact remote sensing. In this study, we select 11 factors that have the potential to impact either the sea breeze circulation properties and/or the spatial distribution of aerosols. Simulations are run to identify which of the 11 factors have the largest influence on the sea breeze properties and aerosol concentrations and to subsequently understand the mean response of these variables to the selected factors. All simulations are designed to be representative of conditions in coastal sub tropical environments and are thus relatively dry, as such they do not support deep convection associated with the sea breeze front. For this dry sea breeze regime, we find that the background wind speed was the most influential factor for the sea breeze propagation, with the soil saturation fraction also being important. For the spatial aerosol distribution, the most important factors were the soil moisture, sea-air temperature difference, and the initial boundary layer height. The importance of these factors seems to be strongly tied to the development of the surface-based mixed layer both ahead of and behind the sea breeze front. This study highlights potential avenues for further research regarding sea breeze dynamics and the impact of sea breeze circulations on pollution dispersion and remote sensing algorithms.

  1. Effect of Particular Breed on the Chemical Composition, Texture, Color, and Sensorial Characteristics of Dry-cured Ham

    OpenAIRE

    Seong, Pil Nam; Park, Kuyng Mi; Kang, Sun Moon; Kang, Geun Ho; Cho, Soo Hyun; Park, Beom Young; Van Ba, Hoa

    2014-01-01

    The present study demonstrates the impact of specific breed on the characteristics of dry-cured ham. Eighty thighs from Korean native pig (KNP), crossbreed (Landrace×Yorkshire)♀×Duroc♂ (LYD), Berkshire (Ber), and Duroc (Du) pig breeds (n = 10 for each breed) were used for processing of dry-cured ham. The thighs were salted with 6% NaCl (w/w) and 100 ppm NaNO2, and total processing time was 413 days. The effects of breed on the physicochemical composition, texture, color and sensory characteri...

  2. Surface discoloration of composite resins: Effects of staining and bleaching.

    Science.gov (United States)

    Poggio, Claudio; Beltrami, Riccardo; Scribante, Andrea; Colombo, Marco; Chiesa, Marco

    2012-09-01

    The purpose of this in vitro study was to evaluate surface discoloration of three microhybrid composite resins (Esthet•X HD, Clearfil AP-X, Gradia Direct) and five nanohybrid composite resins (Ceram•X, GC Kalore, G-aenial, Grandio, GrandioSO), after staining and bleaching procedures. The composite resins were polymerized with a curing light (Celalux II, Voco, Cuxhaven, Germany) into 160 silicon molds (6,4 mm in diameter and 2 mm in thickness) to obtain identical specimens. Twenty samples for each composite resin were prepared. The specimens were polished using an automated polishing machine with the sequence of 600-, 800-, 1000-grit abrasive paper under water irrigation. The specimens were immersed in tea and distilled water: the specimens were dipped for 20 min, once a day (every 24 h), for 14 days into the drinks. The specimens were then bleached with carbamide peroxide at 17% (Perfect Bleach-Voco). The color of specimens was measured with a spectrophotometer according to the CIE L(*)a(*)b(*) system after light-polymerization of composite resin specimens, after 7 days, after 14 days, and after bleaching. The color difference h index (DEab(*)) between each measurement was calculated. Statistical analysis was made using analysis of variance (ANOVA). All specimens showed a significant increase in staining with a similar trend and no significant differences between microhybrid and nanohybrid composite resins. After whitening procedures, materials tested showed both significant and unsignificant differences of the h index. Microhybrid and nanohybrid composite resins had similar in vitro surface discoloration in tea. After bleaching, discoloration was removed from some composite resins tested.

  3. Elastic representation surfaces of unidirectional graphite/epoxy composites

    International Nuclear Information System (INIS)

    Kriz, R.D.; Ledbetter, H.M.

    1985-01-01

    Unidirectional graphite/epoxy composites exhibit high elastic anisotropy and unusual geometrical features in their elastic-property polar diagrams. From the five-component transverse-isotropic elastic-stiffness tensor we compute and display representation surfaces for Young's modulus, torsional modulus, linear compressibility, and Poisson's ratios. Based on Christoffel-equation solutions, we describe some unusual elastic-wave-surface topological features. Musgrave considered in detail the differences between phase-velocity and group-velocity surfaces arising from high elastic anisotropy. For these composites, we find effects similar to, but more dramatic than, Musgrave's. Some new, unexpected results for graphite/epoxy include: a shear-wave velocity that exceeds a longitudinal velocity in the plane transverse to the fiber; a wave that changes polarization character from longitudinal to transverse as the propagation direction sweeps from the fiber axis to the perpendicular axis

  4. Optimization of the Büchi B-90 spray drying process using central composite design for preparation of solid dispersions.

    Science.gov (United States)

    Gu, Bing; Linehan, Brian; Tseng, Yin-Chao

    2015-08-01

    A central composite design approach was applied to study the effect of polymer concentration, inlet temperature and air flow rate on the spray drying process of the Büchi B-90 nano spray dryer (B-90). Hypromellose acetate succinate-LF was used for the Design of Experiment (DoE) study. Statistically significant models to predict the yield, spray rate, and drying efficiency were generated from the study. The spray drying conditions were optimized according to the models to maximize the yield and efficiency of the process. The models were further validated using a poorly water-soluble investigational compound (BI064) from Boehringer Ingelheim Pharmaceuticals. The polymer/drug ratio ranged from 1/1 to 3/1w/w. The spray dried formulations were amorphous determined by differential scanning calorimetry and X-ray powder diffraction. The particle size of the spray dried formulations was 2-10 μm under polarized light microscopy. All the formulations were physically stable for at least 3h when suspended in an aqueous vehicle composed of 1% methyl cellulose. This study demonstrates that DoE is a useful tool to optimize the spray drying process, and the B-90 can be used to efficiently produce amorphous solid dispersions with a limited quantity of drug substance available during drug discovery stages. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Dry Sliding Wear Behavior of A356 Alloy/Mg2Sip Functionally Graded in-situ Composites: Effect of Processing Conditions

    Directory of Open Access Journals (Sweden)

    S.C. Ram

    2016-09-01

    Full Text Available In present study, the effect of dry sliding wear conditions of A356 alloy/Mg2Sip functionally graded in-situ composites developed by centrifugal casting method has been studied. A pure commercial A356 alloy (Al–7.5Si–0.3Mg was selected to be the matrix of the composites and primary Mg2Sip reinforcing particles were formed by in-situ chemical reaction with an average grain size of 40-47.8 µm. The Al–(Mg2Sip functionally graded metal matrix composites (FGMMC’s were synthesized by centrifugal casting technique with radial geometry, using two different mould rotating speeds ( 1200 and 1600 rpm. The X-ray diffraction (XRD characterization technique was carried out to confirm the in-situ formed Mg2Si particles in composites. Optical microscopy examination was carried out to reveals the grain refinement of Al-rich grains due to in-situ formed Mg2Si particles. Scanning electron microscope (SEM and Energy dispersive X-ray spectroscopy (EDS techniques were carried out to reveal the distribution of phases, morphological characteristics and confirmation of primary Mg2Si particles in the matrix. The sliding wear behavior was studied using a Pin-on-Disc set-up machine with sliding wear parameters: effect of loads (N, effect of sliding distances (m and effect of Mg on wear at room temperature with a high-carbon chromium steel disc (HRC-64 as counter surfaces. A good correlation was evidenced between the dry sliding behaviour of functionally graded in-situ composites and the distribution of Mg2Si reinforcing particles. Beside the above processing conditions, the dominant wear mechanisms of functionally graded in-situ composites have been correlated with the microstructures. The hardness and wear resistance properties of these composites increase with increasing volume percent of reinforced primary Si/Mg2Si particles toward inner zone of cast cylindrical shapes. The objective of this works was to study the tribological characteristics under dry sliding

  6. Dynamic Ocular Surface and Lacrimal Gland Changes Induced in Experimental Murine Dry Eye

    Science.gov (United States)

    Xiao, Bing; Wang, Yu; Reinach, Peter S.; Ren, Yueping; Li, Jinyang; Hua, Shanshan; Lu, Huihui; Chen, Wei

    2015-01-01

    Dry eye disease can be a consequence of lacrimal gland insufficiency in Sjögren’s Syndrome or increased tear film evaporation despite normal lacrimal gland function. To determine if there is a correlation between severity effects in these models and underlying pathophysiological responses, we compared the time dependent changes in each of these parameters that occur during a 6 week period. Dry eye was induced in 6-week-old female C57BL/6 mice by exposing them to an Intelligently Controlled Environmental System (ICES). Sixty mice were housed in ICES for 1, 2, 4 and 6 weeks respectively. Twelve were raised in normal environment and received subcutaneous injections of scopolamine hydrobromide (SCOP) 3 times daily for 5 days. Another sixty mice were housed in a normal environment and received no treatment. Corneal fluorescein staining along with corneal MMP-9 and caspase-3 level measurements were performed in parallel with the TUNEL assay. Interleukin-17(IL-17), IL-23, IL-6, IL-1, TNF-α, IFN-γ and TGF-β2 levels were estimated by real-time PCR measurements of conjunctival and lacrimal gland samples (LGs). Immunohistochemistry of excised LGs along with flow cytometry in cervical lymph nodes evaluated immune cell infiltration. Light and transmission electron microscopy studies evaluated LGs cytoarchitectural changes. ICES induced corneal epithelial destruction and apoptosis peaked at 2 weeks and kept stable in the following 4 weeks. In the ICES group, lacrimal gland proinflammatory cytokine level increases were much lower than those in the SCOP group. In accord with the lower proinflammatory cytokine levels, in the ICES group, lacrimal gland cytosolic vesicular density and size exceeded that in the SCOP group. ICES and SCOP induced murine dry eye effects became progressively more severe over a two week period. Subsequently, the disease process stabilized for the next four weeks. ICES induced local effects in the ocular surface, but failed to elicit lacrimal gland

  7. Dynamic ocular surface and lacrimal gland changes induced in experimental murine dry eye.

    Science.gov (United States)

    Xiao, Bing; Wang, Yu; Reinach, Peter S; Ren, Yueping; Li, Jinyang; Hua, Shanshan; Lu, Huihui; Chen, Wei

    2015-01-01

    Dry eye disease can be a consequence of lacrimal gland insufficiency in Sjögren's Syndrome or increased tear film evaporation despite normal lacrimal gland function. To determine if there is a correlation between severity effects in these models and underlying pathophysiological responses, we compared the time dependent changes in each of these parameters that occur during a 6 week period. Dry eye was induced in 6-week-old female C57BL/6 mice by exposing them to an Intelligently Controlled Environmental System (ICES). Sixty mice were housed in ICES for 1, 2, 4 and 6 weeks respectively. Twelve were raised in normal environment and received subcutaneous injections of scopolamine hydrobromide (SCOP) 3 times daily for 5 days. Another sixty mice were housed in a normal environment and received no treatment. Corneal fluorescein staining along with corneal MMP-9 and caspase-3 level measurements were performed in parallel with the TUNEL assay. Interleukin-17(IL-17), IL-23, IL-6, IL-1, TNF-α, IFN-γ and TGF-β2 levels were estimated by real-time PCR measurements of conjunctival and lacrimal gland samples (LGs). Immunohistochemistry of excised LGs along with flow cytometry in cervical lymph nodes evaluated immune cell infiltration. Light and transmission electron microscopy studies evaluated LGs cytoarchitectural changes. ICES induced corneal epithelial destruction and apoptosis peaked at 2 weeks and kept stable in the following 4 weeks. In the ICES group, lacrimal gland proinflammatory cytokine level increases were much lower than those in the SCOP group. In accord with the lower proinflammatory cytokine levels, in the ICES group, lacrimal gland cytosolic vesicular density and size exceeded that in the SCOP group. ICES and SCOP induced murine dry eye effects became progressively more severe over a two week period. Subsequently, the disease process stabilized for the next four weeks. ICES induced local effects in the ocular surface, but failed to elicit lacrimal gland

  8. Characterization of transfer layers on steel surfaces sliding against diamondlike carbon in dry nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Erdemir, A.; Bindal, C.; Pagan, J. [Argonne National Lab., IL (United States); Wilbur, P. [Colorado State Univ., Fort Collins, CO (United States). Dept. of Mechanical Engineering

    1995-03-01

    Transfer layers on sliding steel surfaces play important roles in tribological performance of diamondlike carbon films. This study investigated the nature of transfer layers formed on M50 balls during sliding against diamondlike carbon (DLC) films (1.5 {mu}m thick) prepared by ion-beam deposition. Long-duration sliding tests were performed with steel balls sliding against the DLC coatings in dry nitrogen at room temperature and zero humidity. Test results indicated that the friction coefficients of test pairs were initially 0.12 but decreased steadily with sliding distance to 0.02-0.03 and remained constant throughout the tests, which lasted for more than 250,000 sliding cycles (30 km). This low-friction regime appeared to coincide with the formation of a carbon-rich transfer layer on the sliding surfaces of M50 balls. Micro-laser-Raman spectroscopy and electron microscopy were used to elucidate the structure and chemistry of these transfer layers and to reveal their possible role in the wear and friction behavior of DLC-coated surfaces.

  9. Improving Dry Powder Inhaler Performance by Surface Roughening of Lactose Carrier Particles.

    Science.gov (United States)

    Tan, Bernice Mei Jin; Chan, Lai Wah; Heng, Paul Wan Sia

    2016-08-01

    This study investigated the impact of macro-scale carrier surface roughness on the performance of dry powder inhaler (DPI) formulations. Fluid-bed processing and roller compaction were explored as processing methods to increase the surface roughness (Ra) of lactose carrier particles. DPI formulations containing either (a) different concentrations of fine lactose at a fixed concentration of micronized drug (isoniazid) or (b) various concentrations of drug in the absence of fine lactose were prepared. The fine particle fraction (FPF) and aerodynamic particle size of micronized drug of all formulations were determined using the Next Generation Impactor. Fluid-bed processing resulted in a modest increase in the Ra from 562 to 907 nm while roller compaction led to significant increases in Ra > 1300 nm. The roller compacted carriers exhibited FPF > 35%, which were twice that of the smoothest carriers. The addition of up to 5%, w/w of fine lactose improved the FPF of smoother carriers by 60-200% whereas only lactose carrier particles by roller compaction was immensely beneficial to improving DPI performance, primarily due to increased surface roughness at the macro-scale.

  10. Photonic crystal structures on nonflat surfaces fabricated by dry lift-off soft UV nanoimprint lithography

    International Nuclear Information System (INIS)

    Sun, Tangyou; Xu, Zhimou; Xu, Haifeng; Zhao, Wenning; Wu, Xinghui; Liu, Sisi; Ma, Zhichao; He, Jian; Liu, Shiyuan; Peng, Jing

    2013-01-01

    The surface nonflatness induced from the material itself or the production atmosphere can lead to serious non-uniformity consequences in nanoimprint lithography (NIL) which is used for providing a low cost and high throughput nano-fabrication process. In this paper, soft UV NIL (SUNIL) processes are used for photonic crystal (PC) pattern transfer of a GaN-based light-emitting diode (LED) with patterned sapphire substrate (PSS). The results reveal a significant incompatibility between the conventional SUNIL and the nonflat p-GaN surface. Ellipse-shaped rather than circle-shaped PC structure is obtained on the p-GaN surface due the deformation of the soft mold in nonflat NIL. A dry lift-off (DLO) SUNIL is proposed to overcome the non-uniformity issue in nonflat NIL as well as the collapse problem of the free-standing pillar-shaped resist in wet lift-off. The photoluminescence enhancements of the LED fabricated by the DLO SUNIL method compared to those with conventional SUNIL and unpatterned LED are 1.41 fold and 3.48 fold, respectively. Further study shows that the DLO SUNIL is applicable in the fabrication of the PC structure with tunable duty cycle via one single initial PC mold. (paper)

  11. The Effect of Shoe Sole Tread Groove Depth on the Gait Parameters during Walking on Dry and Slippery Surface

    Directory of Open Access Journals (Sweden)

    M Ziaei

    2012-12-01

    Full Text Available Background: Prevention of slipping accidents requires provision of adequate friction through the use of suitable combinations of footwear and underfoot surfaces. Shoe sole tread groove is one of the important factors on friction coefficient during walking. Objective: To measure the effect of different shoe sole tread groove depths and different surfaces on the required quotient of friction (Q, heel strike velocity and occurrence time of ground reaction forces (GRF in stance phase during walking on slippery and dry surfaces. Methods: In this semi-experimental study, 22 healthy men were studied under different conditions. The studied independent variables were shoe groove depths (included 1, 2.5 and 5 mm and type of walking surface (dry and slippery. Biomechanical gait analysis was carried out with 396 single steps. Data were collected by motion analysis system and two force platform. Results: The occurrence time of GRF was significantly faster on dry surface than slippery surface (p<0.01. Q was significantly lower on slippery surface and with groove depths of 1 and 2.5 mm. The highest value of Q was observed with the deepest groove depth of 5 mm. Heel strike velocity did not differ significantly in the 6 conditions tested. Conclusion: Tread groove depth is a significant factor affecting the Q at the shoes-surface interface on dry and slippery floors. It seems that deeper groove is more appropriate for maintaining the stability during walking. The walking surface affects the occurrence time of GRF; the force components occur sooner on the dry than slippery surface.

  12. THE EFFECT OF VARIOUS PARAMETERS ON DRY SLIDING WEAR BEHAVIOR AND SUBSURFACE OF AGED HYBRID METAL MATRIX COMPOSITES USING TAGUCHI TECHNIQUE

    Directory of Open Access Journals (Sweden)

    B.M. Viswanatha

    2017-06-01

    Full Text Available The effects of applied load, sliding speed and sliding distance on the dry sliding wear behavior of aged Al-SiCp-Gr composites were investigated. The specimen were fabricated by stir-casting technique. The pin-on-disc wear testing machine was used to investigate the wear rate by design of experiments based on L27 using Taguchi technique. Sliding distance was the most important variable that influenced the wear rate followed by sliding speed and applied load. The worn out surfaces were analyzed by SEM and EDS to study the subsurface mechanism of wear. The addition of reinforcements showed improved tribological behavior of the composite than base alloy.

  13. Effect of gamma-irradiation on the fatty acid composition of salted, semi-dried Vietnamese scad and Bombay duck

    International Nuclear Information System (INIS)

    Vinh, P.Q.; Rao, V.S.; Adhikar, H.R.; Nair, P.M.

    1994-01-01

    Effect of gamma irradiation on the lipid and fatty acid composition of semi-dried Bombay duck (Harpodon nehcreus) and Vietnamese scad (Alepes mate) was studied. In both these dried fishes, c16:0 aand c18:1 were the predominant fatty acids and the fishes contained ignificant quantities of the n-3 polyunsaturated fatty acids (PUFAs), C20:5 and C22:6. Irradiation at a dose of 3 kGy, did not cause any alterations in the total lipid content and he overall lipid class profile in these fishes. However, in the Vietnamese scad, C18:3, C20:4 and C22:6 were significantly decreased in the irradiated samples. In spite of this decrease the irradiated semi-dried scad retained 82% of the initial amount of n-3 PUFAs

  14. Effect of surface coating with magnesium stearate via mechanical dry powder coating approach on the aerosol performance of micronized drug powders from dry powder inhalers.

    Science.gov (United States)

    Zhou, Qi Tony; Qu, Li; Gengenbach, Thomas; Larson, Ian; Stewart, Peter J; Morton, David A V

    2013-03-01

    The objective of this study was to investigate the effect of particle surface coating with magnesium stearate on the aerosolization of dry powder inhaler formulations. Micronized salbutamol sulphate as a model drug was dry coated with magnesium stearate using a mechanofusion technique. The coating quality was characterized by X-ray photoelectron spectroscopy. Powder bulk and flow properties were assessed by bulk densities and shear cell measurements. The aerosol performance was studied by laser diffraction and supported by a twin-stage impinger. High degrees of coating coverage were achieved after mechanofusion, as measured by X-ray photoelectron spectroscopy. Concomitant significant increases occurred in powder bulk densities and in aerosol performance after coating. The apparent optimum performance corresponded with using 2% w/w magnesium stearate. In contrast, traditional blending resulted in no significant changes in either bulk or aerosolization behaviour compared to the untreated sample. It is believed that conventional low-shear blending provides insufficient energy levels to expose host micronized particle surfaces from agglomerates and to distribute guest coating material effectively for coating. A simple ultra-high-shear mechanical dry powder coating step was shown as highly effective in producing ultra-thin coatings on micronized powders and to substantially improve the powder aerosolization efficiency.

  15. Fatty Acid Composition of Dried Fruits of Sclerocarya birrea, Diospyros blancoi and Landolphia kirkii

    Directory of Open Access Journals (Sweden)

    Athanasia O. Matemu

    2017-11-01

    Full Text Available Wild fruits are commonly consumed in the rural communities of South Africa. The information on their nutritionally important fatty acids is, however, limited. Three wild fruit species, Diospyros blancoi, Landolphia kirkii and Sclerocarya birrea from Limpopo Province were selected for evaluation of fatty acid content. Fatty acids composition of dried fruits of Diospyros blancoi (Db, Landolphia kirkii (Lk and ripe and/or overripe Sclerocarya birrea (Sb were evaluated by a gas chromatography-time of flight-mass spectrometer (GC-TOF-MS. Hexadecanoic acid (C16:0 was found in highest abundance in L. kirkii (57.73–73.55%, followed by S. birrea (55.92–71.31% and D. blancoi (46.31–62.05%, respectively. Octadecanoic acid (C18:0 was of second highest abundance, with 24.71–100% in D. blancoi, L. kirkii (31.03–41.60% and S. birrea (9.11–17.0%. The 9-octadecenoic acid (C18:1n-9 was the major unsaturated fatty acid in both S. birrea (5.33–18.82%, D. blancoi (8.22–8.92%, and L. kirkii (3.84–8.63%. The 9,-12-octadecadienoic acid (C18:2n-6 was the major unsaturated fatty acid in D. blancoi (22.34%. The 9,-12,-15-octadecatrienoic acid (C18:3n-3 was found in L. kirkii (3.51% and S. birrea (2.79%. From the results, saturated fatty acids were the most dominant, whereas mono- and poly-unsaturated fatty acids were the minor constituents. Therefore, presence of nutritionally important essential fatty acids from S. birrea, D. blancoi and L. kirkii has been shown.

  16. Determination of chemical composition, and storage on dried fermented goat milk product (Oggtt

    Directory of Open Access Journals (Sweden)

    Badriah O. Al-Abdulkarim

    2013-06-01

    Full Text Available A sample of dried fermented goat milk product (Oggtt obtained from the local market of Riyadh city in The Kingdom of Saudi Arabia, was stored for 6 months at 4 °C and subjected to chemical composition analysis before and after storage. The result showed that the sample moisture increased significantly (P ⩽ 0.05 after storage from 7% to 10%, total ash decreased non-significantly (P ⩽ 0.05 from 8% to 7.6%, total carbohydrates decreased non-significantly (P ⩽ 0.05 from 35.5% to 33.8%, protein increased non-significantly (P ⩽ 0.05 from 16 to 16.1 g/l, fat content was found to have the same values in all samples before and after storage at 5%, lactose increased (P ⩽ 0.05 non-significantly from 28.4% to 29%, acidity decreased (P ⩽ 0.05 significantly from 0.45% to 0.39%, and pH decreased (P ⩽ 0.05 non-significantly from 4.3% to 4%. On the other hand, mineral composition showed (P ⩽ 0.05 non-significant results before and after storage. Ca concentration decreased from 118 to 1149 mg/kg and K concentration increased from 185.8 to 1888 mg/kg. While Mg increased from 105 to 123 mg/kg, Zn increased from 8.3 to 8.6 mg/kg, Mn and Fe were found to have the same values of concentrations before and after storage which were 0.2 and 0.1 mg/kg, respectively. Accordingly, we can conclude that Oggtt is a stable product and have a good nutritional value in comparison to daily required amounts for healthy human life.

  17. Changes in composition and structure of a tropical dry forest following intermittent Cattle grazing

    Directory of Open Access Journals (Sweden)

    Margaret Stern

    2002-12-01

    Full Text Available In northwestern Costa Rica, cattle are being used as a "management tool" to reduce the amount of combustible material, mainly dominated by Hyparrhenia rufa, an African grass. This project is being developed within Parque Nacional Palo Verde and Reserva Biológica Lomas Barbudal, both of which fonn part of the only remaining tropical dry forests in Mesoamerica. To determine the short-term effects of cattle grazing on the natural vegetation, we compared the floristic composition within Palo Verde in an area under intermittent cattle grazing with an area that has not been grazed. There were significantly fewer plant species in the area with intermittent cattle grazing compared to the area with no grazing. Floristic composition of these two habitats was different as reflected by both Fisher's alpha values and the Shannon index of diversity, both of which were significantly higher in the ungrazed site. The ungrazed area contained more plant species and was more similar to mature forest. The structure of the vegetation was significantly different between the intermittently grazed and ungrazed sites with more small stems (1-5 cm dbh and fewer large stems (>5 cm dbh in the intermittently grazed habitat. These results indicate that cattle grazing has an impact on the dry forest by reducing the relative abundance and density of larger tree species and by changing the species composition and structure of the community. The current management plan implemented in Palo Verde and Lomas Barbudal is not appropriate because of the impact that cattle have on the structure of the natural vegetation and should not be considered a viable alternative in other protected areas of dry forest in the Neotropics. We suggest that alternative fire prevention measures be evaluated including hand-cutting H. rufa, the creation of more frequent and larger fire breaks, and the development of green breaks.En el noroeste de Costa Rica se utiliza ganado como una "herramienta de

  18. The Effect of Tear Supplementation on Ocular Surface Sensations during the Interblink Interval in Patients with Dry Eye.

    Directory of Open Access Journals (Sweden)

    Lóránt Dienes

    Full Text Available To investigate the characteristics of ocular surface sensations and corneal sensitivity during the interblink interval before and after tear supplementation in dry eye patients.Twenty subjects (41.88±14.37 years with dry eye symptoms were included in the dry eye group. Fourteen subjects (39.13±11.27 years without any clinical signs and/or symptoms of dry eye were included in the control group. Tear film dynamics was assessed by non-invasive tear film breakup time (NI-BUT in parallel with continuous recordings of ocular sensations during forced blinking. Corneal sensitivity to selective stimulation of corneal mechano-, cold and chemical receptors was assessed using a gas esthesiometer. All the measurements were made before and 5 min after saline and hydroxypropyl-guar (HP-guar drops.In dry eye patients the intensity of irritation increased rapidly after the last blink during forced blinking, while in controls there was no alteration in the intensity during the first 10 sec followed by an exponential increase. Irritation scores were significantly higher in dry eye patients throughout the entire interblink interval compared to controls (p0.05.Ocular surface irritation responses due to tear film drying are considerably increased in dry eye patients compared to normal subjects. Although tear supplementation improves the protective tear film layer, and thus reduce unpleasant sensory responses, the rapid rise in discomfort is still maintained and might be responsible for the remaining complaints of dry eye patients despite the treatment.

  19. Heat treatment effect on the microstructure, tensile properties and dry sliding wear behavior of A356-10%B4C cast composites

    International Nuclear Information System (INIS)

    Lashgari, H.R.; Zangeneh, Sh.; Shahmir, H.; Saghafi, M.; Emamy, M.

    2010-01-01

    In present paper, an attempt was made to examine the influence of T6 heat treatment (solution treatment at 540 o C for 5 h, quenching in hot water and artificial aging at 170 o C for 8 h) on the microstructure, tensile properties and dry sliding wear behavior of A356-10%B 4 C cast composites. The composite ingots were made by stir casting process. In this work, the matrix alloy and composite were characterized by optical microscope, scanning electron microscope equipped with energy dispersive X-ray spectroscopy, tensile tests and conventional pin-on-disk experiment. The obtained results showed that in Al-B 4 C composite, T6 treatment was a dominant factor on the hardness improvement in comparison with hardness increasing due to the addition of B 4 C hard particles. In addition, T6 treatment can contribute to the strong bonding between B 4 C and matrix alloy and also it can change eutectic silicon morphology from acicular to near spherical. This case can lead to higher strength and wear properties of heat treated metal matrix composites in comparison with unheat treated state. Observation of worn surfaces indicated detachment of mechanically mixed layer which can primarily due to the delamination wear mechanism under higher applied load.

  20. Mechanical performance and thermal stability of glass fiber reinforced silica aerogel composites based on co-precursor method by freeze drying

    Science.gov (United States)

    Zhou, Ting; Cheng, Xudong; Pan, Yuelei; Li, Congcong; Gong, Lunlun; Zhang, Heping

    2018-04-01

    In order to maintain the integrity, glass fiber (GF) reinforced silica aerogel composites were synthesized using methltrimethoxysilane (MTMS) and water glass co-precursor by freeze drying method. The composites were characterized by scanning electron microscopy, Brunauer-Emmett-Teller analysis, uniaxial compressive test, three-point bending test, thermal conductivity analysis, contact angle test, TG-DSC analysis. It was found that the molar ratio of MTMS/water glass could significantly affect the properties of composites. The bulk density and thermal conductivity first decreased and then increased with the increasing molar ratio. The composites showed remarkable mechanical strength and flexibility compared with pure silica aerogel. Moreover, when the molar ratio is 1.8, the composites showed high specific surface area (870.9 m2/g), high contact angle (150°), great thermal stability (560 °C) and low thermal conductivity (0.0248 W/m·K). These outstanding properties indicate that GF/aerogels have broad prospects in the field of thermal insulation.

  1. Air-drying paint compositions comprising carbohydrate-based polyesters and polyester preparation

    NARCIS (Netherlands)

    Oostveen, E.A.; Weijnen, J.; Haveren, van J.; Gillard, M.

    2003-01-01

    The invention relates to a polyester obtainable by transesterification or interesterification of:(i) a carbohydrate or an acyl ester thereof, (ii) an alkyl ester of a drying fatty acid, semi-drying fatty acid or mixture thereof; and (iii) an alkyl ester of a non aromatic polycarboxylic acid. The

  2. Associations between soil variables and vegetation structure and composition of Caribbean dry forests

    Science.gov (United States)

    Elvia M. Melendez-Ackerman; Julissa Rojas-Sandoval; Danny S. Fernandez; Grizelle Gonzalez; Hana Lopez; Jose Sustache; Mariely Morales; Miguel Garcia-Bermudez; Susan Aragon

    2016-01-01

    Soil–vegetation associations have been understudied in tropical dry forests when compared to the amount of extant research on this issue in tropical wet forests. Recent studies assert that vegetation in tropical dry forests is highly heterogeneous and that soil variability may be a contributing factor. In this study, we evaluated the relationship between soil variables...

  3. Ensiling as biological pretreatment of grass (Festulolium Hykor): The effect of composition, dry matter, and inocula on cellulose convertibility

    DEFF Research Database (Denmark)

    Ambye-Jensen, Morten; Johansen, Katja Salomon; Didion, Thomas

    2013-01-01

    Grass biomass is a prospective type of lignocellulosic biomass for bioenergy and fuel production, but the low dry matter in grass at harvest calls for new pretreatment strategies for cellulosic conversion. In this study, ensiling was tested as a biological pretreatment method of the high yielding...... grass variety Festulolium Hykor. The biomass was harvested in four cuts over a growing season. Three important factors of ensiling: biomass composition, dry matter (DM) at ensiling, and inoculation of lactic acid bacteria, were assessed in relation to subsequent enzymatic cellulose hydrolysis....... The organic acid profile after ensiling was dependant on the composition of the grass and the DM, rather than on the inocula. High levels of organic acids, notably lactic acid, produced during ensiling improved enzymatic cellulose convertibility in the grass biomass. Ensiling of less mature grass gave higher...

  4. Investigation of sizing - from glass fibre surface to composite interface

    DEFF Research Database (Denmark)

    Petersen, Helga Nørgaard; Kusano, Yukihiro

    significantly. The usage span wide, from furniture and car components to construction materials. Even though, the concept of composites is well known and widely applied, the fundamental principles of the interaction of the constituents, in the composites are still not fully understood. This thesis is a part...... of the sizing from the glass fibre surface to the interface in composites. Through soxhlet extraction with acetone it was possible to remove a part of the sizing from the glass fibres for analysis. By burning off the sizing at 565 ºC a higher mass loss was obtained than from the extraction, indicating...... increased after the removal of sizing by extraction but also when the sizing was removed by burning. This could partly be explained by the sizing being less dense than the glass fibres. For the burned glass fibres compactment of the glass structure also yields an increase in stiffness. The fibre strength...

  5. Mesoporous high surface area Ce0.9Gd0.1O1.95 synthesized by spray drying

    DEFF Research Database (Denmark)

    Lundberg, Mats; Wang, Hsiang-Jen; Blennow Tullmar, Peter

    2011-01-01

    Mesoporous gadolinium doped cerium dioxide with high surface area was produced by spray drying using Pluronic 123 as surfactant. The powder, when calcined at 400 °C, had a BET surface area of 136 m2 g−1 and was polycrystalline as confirmed by XRD and TEM. XEDS confirmed Ce, Gd and O, as the only......, corresponding to the crystallite size calculated from XRD data. The similar size range of the mesopores and the observed crystallite size indicates that the porosity is partly formed from intergranular mesoporosity. Using the spray drying method of a surfactant assisted liquid precursor solution it can...

  6. Trehalose protects against ocular surface disorders in experimental murine dry eye through suppression of apoptosis.

    Science.gov (United States)

    Chen, Wei; Zhang, Xiaobo; Liu, Mimi; Zhang, Jingna; Ye, Ya; Lin, Ying; Luyckx, Jacques; Qu, Jia

    2009-09-01

    The disaccharide trehalose is a key element involved in anhydrobiosis (the capability of surviving almost complete dehydration) in many organisms. Its presence also confers resistance to desiccation and high osmolarity in bacterial and human cells by protecting proteins and membranes from denaturation. The present study used a novel murine dry eye model induced by controlled low-humidity air velocity to determine whether topically applied trehalose could heal ocular surface epithelial disorders caused by ocular surface desiccation. In addition, the efficacy of 87.6 mM trehalose eyedrops was compared with that of 20% serum, the efficacy of which has been well documented. Mice ocular surface epithelial disorders were induced by exposure of murine eyes to continuous controlled low-humidity air velocity in an intelligently controlled environmental system (ICES) for 21 days, which accelerated the tear evaporation. The mice were then randomized into three groups: the control group received PBS (0.01 M) treatment; a second group received 87.6 mM trehalose eyedrops treatment; and the third group received mice serum eyedrops treatment. Each treatment was administered as a 10 microl dose every 6 h for 14 days. The resultant changes in corneal barrier function and histopathologic examination of cornea and conjunctiva were analyzed and the level of apoptosis on the ocular surface was assessed using active caspase-3. After 14 days of treatment, the corneal fluorescein staining area, the ruffling and desquamating cells on the apical corneal epithelium, as well as the apoptotic cells on ocular surface epithelium had significantly reduced in eyes treated with trehalose compared with those treated with serum and PBS. In contrast, after 14 days of treatment, improvements in the thickness of the corneal epithelium, the squamous metaplasia in conjunctival epithelium and the number of goblet cells of the conjunctiva were less marked in eyes treated with trehalose compared with serum

  7. Composition and color stability of carbon monoxide treated dried porcine blood.

    Science.gov (United States)

    Fontes, P R; Gomide, L A M; Fontes, E A F; Ramos, E M; Ramos, A L S

    2010-07-01

    Color stability of swine blood was studied over 12 weeks of storage in plastic bags, after pH (7.40, 6.70, or 6.00) adjustment, saturation with carbon monoxide (CO) and spray-drying. CO-treated dried blood presented a redder color and higher reflectance between 610 and 700 nm, compared to a brownish-red color and lower reflectance of untreated samples. As indicated by reflectance spectra, blood pH adjustment did not influence (P>0.05) the initial color of dried blood but influenced (Pvalues, which was more pronounced in polyethylene (OTR=4130 cm(3)/m(2)/day/atm) packaged samples. After 12 weeks of storage, CO-treated samples packaged in high OTR bags presented color indexes similar to those of the untreated dried samples. CO-treated samples packaged in nylon-polyethylene (OTR=30-60 cm(3)/m(2)/day/atm) bags showed a smaller rate of discoloration and color difference (DeltaE(*)) between the CO-treated and untreated samples. Even with some darkening, packaging CO-treated dry blood in low OTR bags still gives an acceptable reddish color after 12 weeks of storage while untreated dry blood has a brownish color just after drying. Copyright 2010 Elsevier Ltd. All rights reserved.

  8. Kenaf-polypropylene composites: effect of amphiphilic coupling agent on surface properties of fibres and composites

    CSIR Research Space (South Africa)

    Jacob John, Maya

    2010-10-01

    Full Text Available This paper presents an experimental study on the use of zein as a coupling agent in natural fibre composites. Kenaf nonwovens were treated with zein coupling agent, which is a protein extracted from corn. The surface characteristics of untreated...

  9. Bioactive carbon-PEEK composites prepared by chemical surface treatment.

    Science.gov (United States)

    Miyazaki, Toshiki; Matsunami, Chisato; Shirosaki, Yuki

    2017-01-01

    Polyetheretherketone (PEEK) has attracted much attention as an artificial intervertebral spacer for spinal reconstruction. Furthermore, PEEK plastic reinforced with carbon fiber has twice the bending strength of pure PEEK. However, the PEEK-based materials do not show ability for direct bone bonding, i.e., bioactivity. Although several trials have been conducted for enabling PEEK with bioactivity, few studies have reported on bioactive surface modification of carbon-PEEK composites. In the present study, we attempted the preparation of bioactive carbon-PEEK composites by chemical treatments with H 2 SO 4 and CaCl 2 . Bioactivity was evaluated by in vitro apatite formation in simulated body fluid (SBF). The apatite formation on the carbon-PEEK composite was compared with that of pure PEEK. Both pure PEEK and carbon-PEEK composite formed the apatite in SBF when they were treated with H 2 SO 4 and CaCl 2 ; the latter showed higher apatite-forming ability than the former. It is conjectured that many functional groups able to induce the apatite nucleation, such as sulfo and carboxyl groups, are incorporated into the dispersed carbon phase in the carbon-PEEK composites. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Cell surface damage and morphological changes in Oenococcus oeni after freeze-drying and incubation in synthetic wine.

    Science.gov (United States)

    Bravo-Ferrada, Bárbara Mercedes; Gonçalves, Sónia; Semorile, Liliana; Santos, Nuno C; Brizuela, Natalia; Elizabeth Tymczyszyn, E; Hollmann, Axel

    2018-04-28

    The aim of the present study was to evaluate the effects of freeze-drying in the presence of trehalose as a cryoprotectant, followed by incubation in synthetic wine, on surface damage, viability and l-malic acid consumption of the oenological strain Oenococcus oeni UNQOe 73.2. After freeze-drying, no significant differences were observed in the number of viable cells (for both acclimated and non-acclimated cultures) respect to the fresh culture. In contrast, loss of viability was observed after wine incubation for 24 h, being acclimated freeze-dried cells the best conditions for this. After the preservation process, small changes in cell morphology were observed by Atomic Force Microscopy (AFM). The Zeta potential and AFM showed that 24 h of wine incubation was enough to induce several cell surface modifications. Plate count data allowed us to establish that surface damage is an important factor for loss of viability, regardless of the acclimation treatment. Although the number of surviving O. oeni cells decreased dramatically after incubation in synthetic wine for 15 days, the consumption of l-malic acid was higher than 70%, with freeze-dried cells showing a better performance than fresh cultures. These results demonstrate that O. oeni freeze-dried cultures could be applied to direct wine inoculation, to conduct malolactic fermentation, maintaining its technological properties and reducing the time and costs of the winemaking process. Copyright © 2018. Published by Elsevier Inc.

  11. Experimental determination of surface heat transfer coefficient in a dry ice-ethanol cooling bath using a numerical approach.

    Science.gov (United States)

    Santos, M V; Sansinena, M; Zaritzky, N; Chirife, J

    BACKGROUND: Dry ice-ethanol bath (-78 degree C) have been widely used in low temperature biological research to attain rapid cooling of samples below freezing temperature. The prediction of cooling rates of biological samples immersed in dry ice-ethanol bath is of practical interest in cryopreservation. The cooling rate can be obtained using mathematical models representing the heat conduction equation in transient state. Additionally, at the solid cryogenic-fluid interface, the knowledge of the surface heat transfer coefficient (h) is necessary for the convective boundary condition in order to correctly establish the mathematical problem. The study was to apply numerical modeling to obtain the surface heat transfer coefficient of a dry ice-ethanol bath. A numerical finite element solution of heat conduction equation was used to obtain surface heat transfer coefficients from measured temperatures at the center of polytetrafluoroethylene and polymethylmetacrylate cylinders immersed in a dry ice-ethanol cooling bath. The numerical model considered the temperature dependence of thermophysical properties of plastic materials used. A negative linear relationship is observed between cylinder diameter and heat transfer coefficient in the liquid bath, the calculated h values were 308, 135 and 62.5 W/(m 2 K) for PMMA 1.3, PTFE 2.59 and 3.14 cm in diameter, respectively. The calculated heat transfer coefficients were consistent among several replicates; h in dry ice-ethanol showed an inverse relationship with cylinder diameter.

  12. Relationship Between Ocular Surface Disease Index, Dry Eye Tests, and Demographic Properties in Computer Users

    Directory of Open Access Journals (Sweden)

    Hüseyin Simavlı

    2014-03-01

    Full Text Available Objectives: The aim of the present study is to evaluate the ocular surface disease index (OSDI in computer users and to investigate the correlations of this index with dry eye tests and demographic properties. Materials and Methods: In this prospective study, 178 subjects with an age range of 20-40 years and who spent most of their daily life in front of the computers were included. All participants underwent a complete ophthalmologic examination including basal secretion test, tear break-up time test, and ocular surface staining. In addition, all patients completed the OSDI questionnaire. Results: A total of 178 volunteers (101 female, 77 male with a mean age of 28.8±4.5 years were included in the study. Mean time of computer use was 7.7±1.9 (5-14 hours/day, and mean computer use period was 71.1±39.7 (4-204 months. Mean OSDI score was 44.1±24.7 (0-100. There was a significant negative correlation between the OSDI score and tear break-up time test in the right (p=0.005 r=-0.21 and the left eyes (p=0.003 r=-0.22. There was a significant positive correlation between the OSDI score and gender (p=0.014 r=0.18 and daily computer usage time (p=0.008 r=0.2. In addition to this, there was a significant positive correlation between the OSDI score and ocular surface staining pattern in the right (p=0.03 r=0.16 and the left eyes (p=0.03 r=0.17. Age, smoking, type of computer, use of glasses, presence of symptoms, and basal secretion test were not found to be correlated with OSDI score. Conclusions: Long-term computer use causes ocular surface problems. The OSDI were found to be correlated with tear break-up time test, gender, daily computer usage time, and ocular surface staining pattern in computer users. (Turk J Ophthalmol 2014; 44: 115-8

  13. INFLUENCE OF BIOPREPARATIONS FROM DRY SOYBEAN AND SUNFLOWER LECITHINS ON SERUM LIPIDS COMPOSITION

    Directory of Open Access Journals (Sweden)

    H. V. Dziak

    2014-04-01

    Full Text Available Dry lecithin, which is a mixture of polar phospholipids, neutral lipids, free fatty acids, glycolipids, carbohydrates, and small amounts of moisture, is a promising object for biologic-hepatoprotectors creation. One of its pharmacological activity displays is its influence on serum lipids, in particular transport forms of these lipids. The influence of dry soy lecithin and sunflower on hyperlipoproteinemia ratio and other lipid disorders is studied. It is shown that low-fat dry soybean lecithin showed hypocholesterolemic activity against all studied forms of serum cholesterol. Nonfat dry sunflower lecithin had similar but somewhat less prominent effect. However reduced concentration of high density lipoprotein cholesterol under sunflower lecithin developed right before soya lecithin. Both lecithin prevented the development of dyslipidemia induced carbon tetrachloride.

  14. Amino Acid Composition of Protein-Enriched Dried Pasta: Is It Suitable for a Low-Carbohydrate Diet?

    Directory of Open Access Journals (Sweden)

    Rajko Vidrih

    2015-01-01

    Full Text Available Today, obesity is one of the major health problems, a so-called epidemic of the developed world. Obesity arises through an imbalance between energy intake and energy expenditure, so it is important for products to have a balanced nutritional composition. The aim of this study is to prepare high-protein pasta with high nutritional quality, with emphasis on its amino acid composition, as ordinary durum pasta lacks lysine and threonine. Ordinary durum wheat pasta contains, on average, 77 % carbohydrate, and can have even less than 10 % protein. It is therefore oft en excluded from normal energy-restricted diets, and especially from low-carbohydrate diets. In this study pasta that can satisfy the nutritional requirements of a low-carbohydrate diet and is suitable for daily use was developed and evaluated. Protein-enhanced pasta was produced by adding high amounts of plant protein extract (40 % dry matter without (plain high-protein pasta or with 3 % dried spinach powder (high-protein spinach pasta to durum wheat semolina. According to the sensory analysis data, the addition of 40 % of plant protein extract satisfied sensory and nutritional requirements, allowing further development and evaluation for possible marketing. This analysis shows that these high-protein neutral and spinach pasta contain 36.4 and 39.6 g of protein per 100 g of dry mass, 12.07 and 14.70 g of total essential amino acids per 100 g of dry mass, and a high content of branched-chain amino acids, i.e. 5.54 and 6.65 g per 100 g of dry mass, respectively. This therefore represents a true alternative to durum wheat pasta for low-carbohydrate diets.

  15. Amino Acid Composition of Protein-Enriched Dried Pasta:
Is It Suitable for a Low-Carbohydrate Diet?

    Science.gov (United States)

    Filip, Sebastjan; Vidrih, Rajko

    2015-09-01

    Today, obesity is one of the major health problems, a so-called epidemic of the developed world. Obesity arises through an imbalance between energy intake and energy expenditure, so it is important for products to have a balanced nutritional composition. The aim of this study is to prepare high-protein pasta with high nutritional quality, with emphasis on its amino acid composition, as ordinary durum pasta lacks lysine and threonine. Ordinary durum wheat pasta contains, on average, 77% carbohydrate, and can have even less than 10% protein. It is therefore often excluded from normal energy-restricted diets, and especially from low-carbohydrate diets. In this study pasta that can satisfy the nutritional requirements of a low-carbohydrate diet and is suitable for daily use was developed and evaluated. Protein-enhanced pasta was produced by adding high amounts of plant protein extract (40% dry matter) without (plain high-protein pasta) or with 3% dried spinach powder (high-protein spinach pasta) to durum wheat semolina. According to the sensory analysis data, the addition of 40% of plant protein extract satisfied sensory and nutritional requirements, allowing further development and evaluation for possible marketing. This analysis shows that these high-protein neutral and spinach pasta contain 36.4 and 39.6 g of protein per 100 g of dry mass, 12.07 and 14.70 g of total essential amino acids per 100 g of dry mass, and a high content of branched-chain amino acids, i.e. 5.54 and 6.65 g per 100 g of dry mass, respectively. This therefore represents a true alternative to durum wheat pasta for low-carbohydrate diets.

  16. Surface Corrosion and Microstructure Degradation of Calcium Sulfoaluminate Cement Subjected to Wet-Dry Cycles in Sulfate Solution

    Directory of Open Access Journals (Sweden)

    Wuman Zhang

    2017-01-01

    Full Text Available The hydration products of calcium sulfoaluminate (CSA cement are different from those of Portland cement. The degradation of CSA cement subjected to wet-dry cycles in sulfate solution was studied in this paper. The surface corrosion was recorded and the microstructures were examined by scanning electron microscopy (SEM. The results show that SO42-, Na+, Mg2+, and Cl− have an effect on the stability of ettringite. In the initial period of sulfate attack, salt crystallization is the main factor leading to the degradation of CSA cement specimens. The decomposition and the carbonation of ettringite will cause long-term degradation of CSA cement specimens under wet-dry cycles in sulfate solution. The surface spalling and microstructure degradation increase significantly with the increase of wet-dry cycles, sulfate concentration, and water to cement ratio. Magnesium sulfate and sodium chloride reduce the degradation when the concentration of sulfate ions is a constant value.

  17. Effect of different concentrations of sodium hyaluronate on the ocular surface change of dry eye in New Zealand rabbits

    Directory of Open Access Journals (Sweden)

    Shuang-Yong Wang

    2015-10-01

    Full Text Available AIM:To observe the effect of different concentrations of sodium hyaluronate on ocular surface change of dry eye. METHODS: New Zealand rabbits with dry eye was prepared and treated with 0.1% and 0.3% sodium hyaluronate drops fluid respectively, which were regarded as low concentration treatment group(group Band high concentration treatment group(group Crespectively. However, the rabbits treated with saline were regarded as control group(group A. And then, corneal fluorescein staining, Schirmer test, conjunctival goblet cells, mucin expression and histological changes were observed.RESULTS: On D7 and D14 after treatment, corneal fluorescein staining scores were lower in group B and group C than that in group A(PP PCONCLUSION: The sodium hyaluronate can improve ocular surface damage of dry eye in New Zealand rabbits. The high concentration of sodium hyaluronate has better effect than low concentration.

  18. Titan's Surface Composition from Cassini VIMS Solar Occultation Observations

    Science.gov (United States)

    McCord, Thomas; Hayne, Paul; Sotin, Christophe

    2013-04-01

    Titan's surface is obscured by a thick absorbing and scattering atmosphere, allowing direct observation of the surface within only a few spectral win-dows in the near-infrared, complicating efforts to identify and map geologi-cally important materials using remote sensing IR spectroscopy. We there-fore investigate the atmosphere's infrared transmission with direct measure-ments using Titan's occultation of the Sun as well as Titan's reflectance measured at differing illumination and observation angles observed by Cas-sini's Visual and Infrared Mapping Spectrometer (VIMS). We use two im-portant spectral windows: the 2.7-2.8-mm "double window" and the broad 5-mm window. By estimating atmospheric attenuation within these windows, we seek an empirical correction factor that can be applied to VIMS meas-urements to estimate the true surface reflectance and map inferred composi-tional variations. Applying the empirical corrections, we correct the VIMS data for the viewing geometry-dependent atmospheric effects to derive the 5-µm reflectance and 2.8/2.7-µm reflectance ratio. We then compare the cor-rected reflectances to compounds proposed to exist on Titan's surface. We propose a simple correction to VIMS Titan data to account for atmospheric attenuation and diffuse scattering in the 5-mm and 2.7-2.8 mm windows, generally applicable for airmass water ice for the majority of the low-to-mid latitude area covered by VIMS measurements. Four compositional units are defined and mapped on Titan's surface based on the positions of data clusters in 5-mm vs. 2.8/2.7-mm scatter plots; a simple ternary mixture of H2O, hydrocarbons and CO2 might explain the reflectance properties of these surface units. The vast equatorial "dune seas" are compositionally very homogeneous, perhaps suggesting transport and mixing of particles over very large distances and/or and very consistent formation process and source material. The composi-tional branch characterizing Tui Regio and Hotei Regio is

  19. Piezoelectric composite morphing control surfaces for unmanned aerial vehicles

    Science.gov (United States)

    Ohanian, Osgar J., III; Karni, Etan D.; Olien, Chris C.; Gustafson, Eric A.; Kochersberger, Kevin B.; Gelhausen, Paul A.; Brown, Bridget L.

    2011-04-01

    The authors have explored the use of morphing control surfaces to replace traditional servo-actuated control surfaces in UAV applications. The morphing actuation is accomplished using Macro Fiber Composite (MFC) piezoelectric actuators in a bimorph configuration to deflect the aft section of a control surface cross section. The resulting camber change produces forces and moments for vehicle control. The flexible piezoelectric actuators are damage tolerant and provide excellent bandwidth. The large amplitude morphing deflections attained in bench-top experiments demonstrate the potential for excellent control authority. Aerodynamic performance calculations using experimentally measured morphed geometries indicate changes in sectional lift coefficients that are superior to a servo-actuated hinged flap airfoil. This morphing flight control actuation technology could eliminate the need for servos and mechanical linkages in small UAVs and thereby increase reliability and reduce drag.

  20. Effect of wear parameters on dry sliding behavior of Fly Ash/SiC particles reinforced AA 2024 hybrid composites

    Science.gov (United States)

    Bhaskar Kurapati, Vijaya; Kommineni, Ravindra

    2017-09-01

    In the present work AA 2024 alloy reinforced with mixtures of SiC and Fly Ash (FA) particles of 70 µm (5, 10 and 15 wt. %) are fabricated using the stir casting method. Both reinforcements are added in equal weight proportions. The wear test specimens are prepared from both the alloy and composite castings in the dimensions of Ф 4 mm and 30 mm lengths by the wire cut EDM process. The dry sliding wear properties of the prepared composites at room temperature are estimated by pin-on-disc wear testing equipment. The wear characteristics of the composites are studied by conducting the dry sliding wear test over loads of 0.5 Kgf, 1.0 Kgf, 1.5 Kgf, a track diameter of 60 mm and sliding times of 15 min, 30 min, 45min. The experimental results shows that the wear decreases with an increase in the weight percentage of FA and SiC particles in the matrix. Additionally wear increases with an increase in load and sliding time. Further, it is found that the wear resistance of the AA2024-Hybrid composites is higher than that of the AA2024 matrix.

  1. Changes in antibiotic sensitivity and cell surface hydrophobicity in Escherichia coli injured by heating, freezing, drying or gamma radiation

    International Nuclear Information System (INIS)

    Mackey, B.M.

    1983-01-01

    Escherichia coli cells exposed to mild heating, freezing and thawing, drying or γ-radiation were sensitised to hydrophobic antibiotics and sodium deoxycholate but not to small hydrophilic antibiotics. These stress treatments also caused increases in cell surface hydrophobicity broadly reflecting the degree of sensitivity to hydrophobic antibiotics. (Auth.)

  2. A novel collagen film with micro-rough surface structure for corneal epithelial repair fabricated by freeze drying technique

    International Nuclear Information System (INIS)

    Liu, Yang; Ren, Li; Wang, Yingjun

    2014-01-01

    Highlights: • Collagen film with micro-rough surface is fabricated by freeze drying technique. • The film has suitable water uptake capability and toughness performance. • The film has good optical performance. • Human corneal epithelial cells studies confirmed the biocompatibility of the film. - Abstract: Corneal epithelial defect is a common disease and keratoplasty is a common treatment method. A collagen film with micro-rough surface was fabricated through a simple freeze drying technique in this study. Compared with the air-dried collagen film (AD-Col), this freeze-dried collagen film (FD-Col) has a more suitable water uptake capability (about 85.5%) and toughness performance. Both of the two films have good optical properties and the luminousness of them is higher than 80%. Besides, the adhesion and proliferation rate of human corneal epithelial cells on the micro-rough surface of FD-Col film is higher than that on the smooth surface of AD-Col film. The results indicate that this FD-Col film may have potential applications for corneal epithelial repair

  3. A novel collagen film with micro-rough surface structure for corneal epithelial repair fabricated by freeze drying technique

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yang [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou 510006 (China); Guangdong Province Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou 510006 (China); Ren, Li, E-mail: psliren@scut.edu.cn [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou 510006 (China); Guangdong Province Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou 510006 (China); Wang, Yingjun, E-mail: imwangyj@163.com [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou 510006 (China); Guangdong Province Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou 510006 (China)

    2014-05-01

    Highlights: • Collagen film with micro-rough surface is fabricated by freeze drying technique. • The film has suitable water uptake capability and toughness performance. • The film has good optical performance. • Human corneal epithelial cells studies confirmed the biocompatibility of the film. - Abstract: Corneal epithelial defect is a common disease and keratoplasty is a common treatment method. A collagen film with micro-rough surface was fabricated through a simple freeze drying technique in this study. Compared with the air-dried collagen film (AD-Col), this freeze-dried collagen film (FD-Col) has a more suitable water uptake capability (about 85.5%) and toughness performance. Both of the two films have good optical properties and the luminousness of them is higher than 80%. Besides, the adhesion and proliferation rate of human corneal epithelial cells on the micro-rough surface of FD-Col film is higher than that on the smooth surface of AD-Col film. The results indicate that this FD-Col film may have potential applications for corneal epithelial repair.

  4. The control mechanism of surface traps on surface charge behavior in alumina-filled epoxy composites

    International Nuclear Information System (INIS)

    Li, Chuanyang; Hu, Jun; Lin, Chuanjie; He, Jinliang

    2016-01-01

    To investigate the role surface traps play in the charge injection and transfer behavior of alumina-filled epoxy composites, surface traps with different trap levels are introduced by different surface modification methods which include dielectric barrier discharges plasma, direct fluorination, and Cr 2 O 3 coating. The resulting surface physicochemical characteristics of experimental samples were observed using atomic force microscopy, scanning electron microscopy and fourier transform infrared spectroscopy. The surface potential under dc voltage was detected and the trap level distribution was measured. The results suggest that the surface morphology of the experimental samples differs dramatically after treatment with different surface modification methods. Different surface trap distributions directly determine the charge injection and transfer property along the surface. Shallow traps with trap level of 1.03–1.11 eV and 1.06–1.13 eV introduced by plasma and fluorination modifications are conducive for charge transport along the insulating surface, and the surface potential can be modified, producing a smoother potential curve. The Cr 2 O 3 coating can introduce a large number of deep traps with energy levels ranging from 1.09 to 1.15 eV. These can prevent charge injection through the reversed electric field formed by intensive trapped charges in the Cr 2 O 3 coatings. (paper)

  5. The presence of undesirable mould species on the surface of dry sausages

    Directory of Open Access Journals (Sweden)

    Vesković-Moračanin Slavica M.

    2008-01-01

    Full Text Available Transition from manufacture to the industrial way of meat production and processing, as well as contemporary concept of food quality and safety, have led to the application of starter cultures. Their application leads towards the streamlining of the production process in the desired direction, quality improvement and its harmonization, and thereby to its standardization. Application of moulds in the meat industry is based on positive effects of their proteolytic and lipolytic egzoenzymes which, as a consequence, leads to the creation of characteristic sensory properties ('flavor' of fermented products. Penicillium nalgiovense is a typical representative of moulds used in the production of fermented sausages-salamis from our region. Samples of 'zimska salama' (dry sausage, produced with Penicillium nalgiovense, were evaluated as hygienically unacceptable. Their sensory properties changed due to contamination of this mould during the ripening process. Micological analysis discovered the presence of Penicillium aurantiogriseum, which is a frequent mould contaminant in the meat industry. At the same time, thin layer chromatography revealed no possibility of metabolic activity of this mould in the creation of mycotoxins. However, the presence of this mould on the surface of 'zimska salama' is considered as undesirable due to formation of 'off flavor' in products. Such product is considered as hygienically unacceptable and cannot be used for the human consumption.

  6. An applied investigation of corn-based distillers dried grains with solubles in the production of natural fiber-plastic composites

    Science.gov (United States)

    Castillo, Hugo Eudosio

    The main objective of this research was to examine uses for distillers dried grains with solubles (DDGS), a coproduct of ethanol production plant, in the fiber-reinforced plastic composites industry. Initially the effort intended to take advantage of the DDGS components, using chemical reactions, to produce coupling agents to improve the physical properties of the composite. Four different chemicals plus water were used to convert proteins into soluble amino acids. The results were not as expected, and appeared to show an early pyrolysis of DDGS components. This may be due to regeneration of proteins when pH of solutions is neutralized. Procedures were then investigated to utilize DDGS for different markets. Considering that oils and proteins of DDGS can thermally decompose, it seemed important to separate the major components and work with DDGS fiber alone. A procedure to extract oil from DDGS using ethanol and then to hydrolyze proteins with ethanol diluted with water, acid and sodium sulfite, was developed. The resulting DDGS fiber or residual material, with a low content of oil and proteins, was used as filler in a propylene matrix with a lubricant and coupling agent to make natural fiber plastic composites (NFPC). Composites containing wood flour (WPC) were prepared simultaneously with those of DDGS fiber to compare tensile properties and fracture surfaces of the specimens by scanning electron microscope (SEM). This study demonstrates that DDGS fiber can replace wood fiber as a filler in NFPC.

  7. Dry powder pulmonary delivery of cationic PGA-co-PDL nanoparticles with surface adsorbed model protein.

    Science.gov (United States)

    Kunda, Nitesh K; Alfagih, Iman M; Dennison, Sarah R; Somavarapu, Satyanarayana; Merchant, Zahra; Hutcheon, Gillian A; Saleem, Imran Y

    2015-08-15

    Pulmonary delivery of macromolecules has been the focus of attention as an alternate route of delivery with benefits such as; large surface area, thin alveolar epithelium, rapid absorption and extensive vasculature. In this study, a model protein, bovine serum albumin (BSA) was adsorbed onto cationic PGA-co-PDL polymeric nanoparticles (NPs) prepared by a single emulsion solvent evaporation method using a cationic surfactant didodecyldimethylammonium bromide (DMAB) at 2% w/w (particle size: 128.64±06.01 nm and zeta-potential: +42.32±02.70 mV). The optimum cationic NPs were then surface adsorbed with BSA, NP:BSA (100:4) ratio yielded 10.01±1.19 μg of BSA per mg of NPs. The BSA adsorbed NPs (5 mg/ml) were then spray-dried in an aqueous suspension of L-leucine (7.5 mg/ml, corresponding to a ratio of 1:1.5/NP:L-leu) using a Büchi-290 mini-spray dryer to produce nanocomposite microparticles (NCMPs) containing cationic NPs. The aerosol properties showed a fine particle fraction (FPF, dae<4.46 μm) of 70.67±4.07% and mass median aerodynamic diameter (MMAD) of 2.80±0.21 μm suggesting a deposition in the respiratory bronchiolar region of the lungs.The cell viability was 75.76±03.55% (A549 cell line) at 156.25 μg/ml concentration after 24 h exposure. SDS-PAGE and circular dichroism (CD) confirmed that the primary and secondary structure of the released BSA was maintained. Moreover, the released BSA showed 78.76±1.54% relative esterolytic activity compared to standard BSA. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Effect of distribution of striated laser hardening tracks on dry sliding wear resistance of biomimetic surface

    Science.gov (United States)

    Su, Wei; Zhou, Ti; Zhang, Peng; Zhou, Hong; Li, Hui

    2018-01-01

    Some biological surfaces were proved to have excellent anti-wear performance. Being inspired, Nd:YAG pulsed laser was used to create striated biomimetic laser hardening tracks on medium carbon steel samples. Dry sliding wear tests biomimetic samples were performed to investigate specific influence of distribution of laser hardening tracks on sliding wear resistance of biomimetic samples. After comparing wear weight loss of biomimetic samples, quenched sample and untreated sample, it can be suggested that the sample covered with dense laser tracks (3.5 mm spacing) has lower wear weight loss than the one covered with sparse laser tracks (4.5 mm spacing); samples distributed with only dense laser tracks or sparse laser tracks (even distribution) were proved to have better wear resistance than samples distributed with both dense and sparse tracks (uneven distribution). Wear mechanisms indicate that laser track and exposed substrate of biomimetic sample can be regarded as hard zone and soft zone respectively. Inconsecutive striated hard regions, on the one hand, can disperse load into small branches, on the other hand, will hinder sliding abrasives during wear. Soft regions with small range are beneficial in consuming mechanical energy and storing lubricative oxides, however, soft zone with large width (>0.5 mm) will be harmful to abrasion resistance of biomimetic sample because damages and material loss are more obvious on surface of soft phase. As for the reason why samples with even distributed bionic laser tracks have better wear resistance, it can be explained by the fact that even distributed laser hardening tracks can inhibit severe worn of local regions, thus sliding process can be more stable and wear extent can be alleviated as well.

  9. Dried Blood Spot Proteomics: Surface Extraction of Endogenous Proteins Coupled with Automated Sample Preparation and Mass Spectrometry Analysis

    Science.gov (United States)

    Martin, Nicholas J.; Bunch, Josephine; Cooper, Helen J.

    2013-08-01

    Dried blood spots offer many advantages as a sample format including ease and safety of transport and handling. To date, the majority of mass spectrometry analyses of dried blood spots have focused on small molecules or hemoglobin. However, dried blood spots are a potentially rich source of protein biomarkers, an area that has been overlooked. To address this issue, we have applied an untargeted bottom-up proteomics approach to the analysis of dried blood spots. We present an automated and integrated method for extraction of endogenous proteins from the surface of dried blood spots and sample preparation via trypsin digestion by use of the Advion Biosciences Triversa Nanomate robotic platform. Liquid chromatography tandem mass spectrometry of the resulting digests enabled identification of 120 proteins from a single dried blood spot. The proteins identified cross a concentration range of four orders of magnitude. The method is evaluated and the results discussed in terms of the proteins identified and their potential use as biomarkers in screening programs.

  10. Neutron radiography of aircraft composite flight control surfaces

    International Nuclear Information System (INIS)

    Lewis, W.J.; Bennett, L.G.I.; Chalovich, T.R.; Francescone, O.

    2001-01-01

    A small (20 kWth), safe, pool-type nuclear research reactor called the SLOWPOKE-2 is located at the Royal Military College of Canada (RMC). The reactor was originally installed for teaching, training, research and semi-routine analysis, specifically, neutron activation analysis. It was envisioned that the neutrons from the SLOWPOKE-2 could also be used for neutron radiography, and so a research program was initiated to develop this technology. Over a period of approximately 15 years, and through a series of successive modifications, a neutron radiography system (NRS) was developed. Once completed, several applications of the technology have been demonstrated, including the nondestructive examination of the composite flight control surfaces from the Canadian Air Force's primary jet fighter, the CF18 Hornet aircraft. An initial trial was setup to investigate the flight control surfaces of 3 aircraft, to determine the parameters for a final licensed system, and to compare the results to other nondestructive methods. Over 500 neutron radiographs were made for these first 3 aircraft, and moisture and corrosion were discovered in the honeycomb structure and hydration was found in the composite and adhesive layers. In comparison with other NDT methods, neutron radiography was the only method that could detect the small areas of corrosion and moisture entrapment. However, before examining an additional 7 aircraft, the recommended modifications to the NRS were undertaken. These modifications were necessary to accommodate the larger flight control surfaces safely by incorporating flexible conformable shielding. As well, to expedite inspections so that all flight control surfaces from one aircraft could be completed in less than two weeks, there was a need to decrease the exposure time by both faster film/conversion screen combinations and by incorporating the capability of near realtime, digital radioscopy. Finally, as there are no inspection specific image quality

  11. Optimization of Bacillus aerius strain JS-786 cell dry mass and its antifungal activity against Botrytis cinerea using response surface methodology

    Directory of Open Access Journals (Sweden)

    Shafi Jamil

    2017-01-01

    Full Text Available The optimization of fermentation conditions is necessary for field application of biological control agents. The present study was designed to optimize the fermentation conditions for the Bacillus aerius strain, JS-786 in terms of cell dry mass and its antifungal activity against Botrytis cinerea with response surface methodology. A strain of bacteria with strong antifungal activity was isolated from the phyllosphere of tomato plant and identified as B. aerius JS-786 based on the sequence homology of its 16S rRNA gene. After the success of preliminary antifungal activity tests, response surface methodology was used to optimize the fermentation conditions (medium pH, gelatin percentage, incubation period, rotatory speed and incubation temperature to maximize the cell dry mass and antifungal activity against B. cinerea. A 25 factorial central composite design was employed and multiple response optimization was used to determine the desirability of the operation. The results of regression analysis showed that at the individual level, all of the experimental parameters were significant for cell dry mass; significant results were obtained for antifungal activity pH, incubation period, rotatory speed and incubation temperature. The interactive effect of the incubation period, rotatory speed and incubation temperature was significant. Maximum cell dry mass (8.7 g/L and inhibition zone (30.4 mm were obtained at pH 6.4, gelatin 3.2%, incubation period 36.92 h, rotatory speed 163 rpm, and temperature 33.5°C. This study should help to formulate a more rational and cost-effective biological product both in terms of bacterial growth and antifungal activity.

  12. The effect of petrographical composition of coals and bituminous sediments on the material and isotopic composition of dry natural gases from artificial recoalification reactions. 2

    International Nuclear Information System (INIS)

    Maass, I.; Huebner, H.; Nitzsche, H.-M.; Schuetze, H.; Zschiesche, M.

    1975-01-01

    Experimental results indicate that on the basis of the material and isotopic composition of natural gases conclusions can be drawn with regard to the character (humic or bituminous) of the parent rock. Thus, genetic relations assumed to exist between humic sediments (e.g. coal seams) and dry natural gases as well as bituminous rocks and wet natural gases are experimentally confirmed. In addition, from analyses of the materials approximate data can be derived on the degree of carbonization of coal or bituminous sediments in the main phase of gas separation. Furthermore, these analyses were used to elucidate the question whether authochthonous or allochthonous deposits are present. It could be shown that the maceral composition of coals and of the organo-petrographical inclusions in bituminous sediments determines the isotopic composition of methane in recoalification gases to a considerable degree. (author)

  13. Surface composition of biomedical components by ion beam analysis

    International Nuclear Information System (INIS)

    Kenny, M.J.; Wielunski, L.S.; Baxter, G.R.

    1991-01-01

    Materials used for replacement body parts must satisfy a number of requirements such as biocompatibility and mechanical ability to handle the task with regard to strength, wear and durability. When using a CVD coated carbon fibre reinforced carbon ball, the surface must be ion implanted with uniform dose of nitrogen ions in order to make it wear resistant. The mechanism by which the wear resistance is improved is one of radiation damage and the required dose of about 10 16 cm -2 can have a tolerance of about 20%. To implant a spherical surface requires manipulation of the sample within the beam and control system (either computer or manually operated) to enable uniform dose all the way from polar to equatorial regions on the surface. A manipulator has been designed and built for this purpose. In order to establish whether the dose is uniform, nuclear reaction analysis using the reaction 14 N(d,α) 12 C is an ideal method of profiling. By taking measurements at a number of points on the surface, the uniformity of nitrogen dose can be ascertained. It is concluded that both Rutherford Backscattering and Nuclear Reaction Analysis can be used for rapid analysis of surface composition of carbon based materials used for replacement body components. 2 refs., 2 figs

  14. Venus Surface Composition Constrained by Observation and Experiment

    Science.gov (United States)

    Gilmore, Martha; Treiman, Allan; Helbert, Jörn; Smrekar, Suzanne

    2017-11-01

    New observations from the Venus Express spacecraft as well as theoretical and experimental investigation of Venus analogue materials have advanced our understanding of the petrology of Venus melts and the mineralogy of rocks on the surface. The VIRTIS instrument aboard Venus Express provided a map of the southern hemisphere of Venus at ˜1 μm allowing, for the first time, the definition of surface units in terms of their 1 μm emissivity and derived mineralogy. Tessera terrain has lower emissivity than the presumably basaltic plains, consistent with a more silica-rich or felsic mineralogy. Thermodynamic modeling and experimental production of melts with Venera and Vega starting compositions predict derivative melts that range from mafic to felsic. Large volumes of felsic melts require water and may link the formation of tesserae to the presence of a Venus ocean. Low emissivity rocks may also be produced by atmosphere-surface weathering reactions unlike those seen presently. High 1 μm emissivity values correlate to stratigraphically recent flows and have been used with theoretical and experimental predictions of basalt weathering to identify regions of recent volcanism. The timescale of this volcanism is currently constrained by the weathering of magnetite (higher emissivity) in fresh basalts to hematite (lower emissivity) in Venus' oxidizing environment. Recent volcanism is corroborated by transient thermal anomalies identified by the VMC instrument aboard Venus Express. The interpretation of all emissivity data depends critically on understanding the composition of surface materials, kinetics of rock weathering and their measurement under Venus conditions. Extended theoretical studies, continued analysis of earlier spacecraft results, new atmospheric data, and measurements of mineral stability under Venus conditions have improved our understanding atmosphere-surface interactions. The calcite-wollastonite CO2 buffer has been discounted due, among other things, to

  15. Comparison of three-dimensional printing and vacuum freeze-dried techniques for fabricating composite scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Kai [Tianjin First Center Hospital, No. 24 Fukang Road, Tianjin, TJ 300192 (China); Li, Ruixin [Institute of Medical Equipment, Academy of Military and Medical Sciences, No. 106, Wandong Street, Hedong District, Tianjin 300000 (China); Jiang, Wenxue, E-mail: jiangortholivea@sina.cn [Tianjin First Center Hospital, No. 24 Fukang Road, Tianjin, TJ 300192 (China); Sun, Yufu [Tianjin First Center Hospital, No. 24 Fukang Road, Tianjin, TJ 300192 (China); Li, Hui [Tianjin Medical University General Hospital, No. 154 Anshan Road, Tianjin, TJ 300052 (China)

    2016-09-02

    In this study, the performances of different preparation methods of the scaffolds were analyzed for chondrocyte tissue engineering. Silk fibroin/collagen (SF/C) was fabricated using a vacuum freeze-dried technique and by 3D printing. The porosity, water absorption expansion rates, mechanical properties, and pore sizes of the resulting materials were evaluated. The proliferation and metabolism of the cells was detected at different time points using an MTT assay. Cell morphologies and distributions were observed by histological analysis and scanning electron microscopy (SEM). The porosity, water absorption expansion rate, and Young’s modulus of the material obtained via 3D printing were significantly higher than those obtained by the freeze-dried method, while the pore size did not differ significantly between the two methods. MTT assay results showed that the metabolism of cells seeded on the 3D printed scaffolds was more viable than the metabolism on the freeze-dried material. H&E staining of the scaffolds revealed that the number of cells in the 3D printed scaffold was higher in comparison to a similar measurement on the freeze-dried material. Consequently, stem cells grew well inside the 3D printed scaffolds, as measured by SEM, while the internal structure of the freeze-dried scaffold was disordered. Compared with the freeze-dried technique, the 3D printed scaffold exhibited better overall performance and was more suitable for cartilage tissue engineering. - Highlights: • Silk fibroin/collagen was fabricated using 3D printing. • Physical characterization and Cell compatibility were compared. • 3D printed scaffold exhibited better overall performance.

  16. Comparison of three-dimensional printing and vacuum freeze-dried techniques for fabricating composite scaffolds

    International Nuclear Information System (INIS)

    Sun, Kai; Li, Ruixin; Jiang, Wenxue; Sun, Yufu; Li, Hui

    2016-01-01

    In this study, the performances of different preparation methods of the scaffolds were analyzed for chondrocyte tissue engineering. Silk fibroin/collagen (SF/C) was fabricated using a vacuum freeze-dried technique and by 3D printing. The porosity, water absorption expansion rates, mechanical properties, and pore sizes of the resulting materials were evaluated. The proliferation and metabolism of the cells was detected at different time points using an MTT assay. Cell morphologies and distributions were observed by histological analysis and scanning electron microscopy (SEM). The porosity, water absorption expansion rate, and Young’s modulus of the material obtained via 3D printing were significantly higher than those obtained by the freeze-dried method, while the pore size did not differ significantly between the two methods. MTT assay results showed that the metabolism of cells seeded on the 3D printed scaffolds was more viable than the metabolism on the freeze-dried material. H&E staining of the scaffolds revealed that the number of cells in the 3D printed scaffold was higher in comparison to a similar measurement on the freeze-dried material. Consequently, stem cells grew well inside the 3D printed scaffolds, as measured by SEM, while the internal structure of the freeze-dried scaffold was disordered. Compared with the freeze-dried technique, the 3D printed scaffold exhibited better overall performance and was more suitable for cartilage tissue engineering. - Highlights: • Silk fibroin/collagen was fabricated using 3D printing. • Physical characterization and Cell compatibility were compared. • 3D printed scaffold exhibited better overall performance.

  17. Comparative study of chemistry compositions and antimicrobial potentials of essential oils and oleoresins from dried and fresh Mentha longifolia L.

    Directory of Open Access Journals (Sweden)

    Sunita Singh

    2015-12-01

    Full Text Available Objective: To investigate the chemical compositions and antimicrobial potentials of the essential oils and oleoresins obtained from fresh and dried Mentha longifolia L. Methods: Gas chromatography and gas chromatography-mass spectrometer techniques were used to determine the profiling of the essential oils and oleoresins. In order to determine the antimicrobial efficacy of the volatile oil and oleoresins, the pathogenic fungus Aspergillus niger (1884, Aspergillus flavus (2479, Fusarium monoliforme (1893, Fusarium graminearum (2088 and Penicillium viridicatum (2007 were undertaken whereas four pathogenic bacteria Bacillus subtilis (1790, Staphylococcus aureus (3103 (Gram-positive, Escherichia coli (1672, Pseudomonas aeruginosa (1942 (Gram-negative were selected for the present study. Food poisoned, inverted Petri plate, agar well diffusion and disk diffusion methods were employed for investigating antimicrobial potentials. Results: Piperitenone oxide, an oxygenated monoterpene, dominated the chemical compositions of essential oils and oleoresins whose compositions varied from 23.5%–87.8%. Both essential oils showed good antifungal activities against Aspergillus and Fusarium species. The antibacterial investigations revealed that Gram-positive bacteria were more sensitive to the essential oils. Conclusions: Drying the fresh herbal materials influences the chemical contents and the biological activities of the essential oils and oleoresins. Such results indicate that essential oils of Mentha longifolia L. can be possible candidates for further investigations to isolate and characterize their active principles as possible new natural preservatives.

  18. Structure and Composition of a Dry Mixed-Conifer Forest in Absence of Contemporary Treatments, Southwest, USA

    Directory of Open Access Journals (Sweden)

    Douglas Cram

    2017-09-01

    Full Text Available Dry mixed-conifer forests in the Southwest occupy an important ecological and hydrological role in upper watersheds. In the absence of reoccurring fire and silvicultural treatments over the last 50 years, we quantified forest structure and composition on prevailing north and south aspects of a dry mixed-conifer forest in southcentral New Mexico using mixed models and ordination analysis in preparation for an experiment in ecological restoration. Results indicated overstory and midstory were dominated by Douglas-fir (Pseudotsuga menziesii and shade tolerant/fire intolerant white fir (Abies concolor with interspersed mature aspen on north aspects, and Douglas-fir and Southwestern white pine (Pinus strobiformis on south aspects. Ponderosa pine (Pinus ponderosa, which was historically co-dominant with Douglas-fir on north and south aspects, was subdominant on south aspects and almost entirely absent on north aspects. Regeneration was dominated by white fir saplings and seedlings on north aspects while ponderosa pine was completely absent. South aspect saplings and seedlings were characterized by Douglas-fir and Southwestern white pine, but almost no ponderosa pine. Ordination analysis characterized the effect of aspect on species composition. Understanding contemporary forest structure and composition is important when planning for desired future conditions that are to be achieved through ecological restoration using silvicultural techniques designed to foster resilience.

  19. Drying effect on flavonoid composition and antioxidant activity of immature kumquat.

    Science.gov (United States)

    Lou, Shyi-Neng; Lai, Yi-Chun; Huang, Jia-De; Ho, Chi-Tang; Ferng, Lin-Huei A; Chang, Yung-Chung

    2015-03-15

    A seven flavonoids in hot water extract of immature kumquat (Citrus japonica var. margarita) were identified and quantified (mg/100g fresh fruit): 3',5'-di-C-β-glucopyranosylphloretin (DGPP, 285.9 ± 2.9 mg/100g), acacetin 8-C-neohesperidoside (margaritene, 136.2 ± 2.6 mg/100g), acacetin 6-C-neohesperidoside (isomargaritene, 119.1 ± 1.8 mg/100g), fortunellin (acacetin 7-O-neohesperidoside, 28.5 ± 0.7 mg/100g), apigenin 8-C-neohesperidoside (16.9 ± 0.1mg/100g), poncirin (isosakuranetin 7-O-neohesperidoside, 5.1 ± 0.1mg/100g), and rhoifolin (apigenin 7-O-neohesperidoside, 2.0 ± 0.1mg/100g). When immature kumquat was dried at 110 and 130°C for 0.5h, the antioxidant activity, total phenolic content and identified flavonoids increased. The UV absorbance of browning products of immature kumquat dried at 130°C for 1.5h increased dramatically, while the identified flavonoids decreased. Therefore, it was concluded that drying below 130°C for 1.0 h, could release phenolic compounds, which resulted in the increasing antioxidant activity. Drying at 130°C for 1.5h, it might be due to the effect of formed browning products. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. A structural model for composite rotor blades and lifting surfaces

    Science.gov (United States)

    Rehfield, Lawrence W.; Atilgan, Ali R.

    1987-01-01

    Composite material systems are currently candidates for aerospace structures, primarily for the design flexibiity they offer i.e., it is possible to tailor the material and manufacturing approach to the application. Two notable examples are the wing of the Grumman/USAF/DARPA X-29 and rotor blades under development by the U.S.A. Aerostructures Directorate (AVSCOM), Langley Research Center. A working definition of elastic or structural tailoring is the use of structural concept, fiber orientation, ply stacking sequence, and a blend of materials to achieve specific performance goals. In the design process, choices of materials and dimensions are made which produce specific response characteristics which permit the selected goals to be achieved. Common choices for tailoring goals are preventing instabilities or vibration resonances or enhancing damage tolerance. An essential, enabling factor in the design of tailored composite structures is structural modeling that accurately, but simply, characterizes response. The objective of this paper is to improve the single-cell beam model for composite rotor blades or lifting surfaces and to demonstrate its usefullness in applications.

  1. Compositional profile and variation of Distillers Dried Grains with Solubles from various origins with focus on non-starch polysaccharides

    DEFF Research Database (Denmark)

    Pedersen, Mads Brøgger; Dalsgaard, S.; Knudsen, Knud Erik Bach

    2014-01-01

    nutrients (e.g. protein, fat, fibre and minerals) after fermentation of starch to ethanol. Corn DDGS differentiated from wheat DDGS by a greater content of fat (P≤0.006), insoluble-NSP (Pcellulose (P=0.032), and arabinose/xylose (P....001). Wheat DDGS differentiated from corn DDGS by a greater content of ash (P=0.001), soluble-NSP (Plignin (P...Corn-, wheat- and mixed cereal Distillers' Dried Grains with Solubles (DDGS) were investigated for compositional variability among DDGS origins, ethanol plants, and the relationship between corn and corresponding DDGS. A total of 138 DDGS samples were analyzed by use of Near Infrared Reflectance...

  2. Chemical composition, anti-oxidative activity and in vitro dry matter degradability of Kinnow mandarin fruit waste

    Directory of Open Access Journals (Sweden)

    Ravleen Kour

    2014-10-01

    Full Text Available Aim: Fruit processing and consumption yield a significant amount of by-products as waste, which can be used as potential nutrient suppliers for livestock. “Kinnow” (Citrus nobilis Lour x Citrus deliciosa Tenora is one of the most important citrus fruit crops of North Indian States. Its residues are rich in carbohydrates but poor in protein and account for approximately 55-60% of the raw weight of the fruit. Present study assessed the chemical composition and anti-oxidative activity of Kinnow mandarin fruit waste (KMW and scrutinized the impact of dietary incorporation of variable levels of KMW on in vitro dry matter digestibility (IVDMD. Materials and Methods: Sun dried and ground KMW was analyzed for proximate composition, fibre fractions and calcium and phosphorus content. Antioxidant potential of KMW as total phenolic count and 1-diphenyl-2-picrylhydrazyl (DPPH scavenging activity was assayed in an alcoholic extract of KMW. The effect of inclusion of KMW at variable levels (0-40% in the isonitrogenous concentrate mixtures on in vitro degradability of composite feed (concentrate mixture:Wheat straw; 40:60 was also carried out. Results: KMW after sun-drying contained 92.05% dry matter. The crude protein content of 7.60% indicates it being marginal in protein content, whereas nitrogen free extract content of 73.69% suggests that it is primarily a carbonaceous feedstuff. This observation was also supported by low neutral detergent fiber and acid detergent fiber content of 26.35% and 19.50%, respectively. High calcium content (0.92% vis-à-vis low phosphorus content (0.08%, resulted in wide Ca:P ratio (11.5 in KMW. High anti-oxidative potential of KMW is indicated by total phenolic content values of 17.1±1.04 mg gallic acid equivalents/g and DPPH free radicle scavenging activity 96.2 μg/ml (effective concentration 50. Mean IVDMD% of all the composite rations was found to be comparable (p>0.05 irrespective of the level of KMW inclusion

  3. Dry transfer of chemical-vapor-deposition-grown graphene onto liquid-sensitive surfaces for tunnel junction applications

    International Nuclear Information System (INIS)

    Feng, Ying; Chen, Ke

    2015-01-01

    We report a dry transfer method that can tranfer chemical vapor deposition (CVD) grown graphene onto liquid-sensitive surfaces. The graphene grown on copper (Cu) foil substrate was first transferred onto a freestanding 4 μm thick sputtered Cu film using the conventional wet transfer process, followed by a dry transfer process onto the target surface using a polydimethylsiloxane stamp. The dry-transferred graphene has similar properties to traditional wet-transferred graphene, characterized by scanning electron microscopy, atomic force microscopy, Raman spectroscopy, and electrical transport measurements. It has a sheet resistance of 1.6 ∼ 3.4 kΩ/□, hole density of (4.1 ∼ 5.3) × 10 12 cm −2 , and hole mobility of 460 ∼ 760 cm 2 V −1 s −1 without doping at room temperature. The results suggest that large-scale CVD-grown graphene can be transferred with good quality and without contaminating the target surface by any liquid. Mg/MgO/graphene tunnel junctions were fabricated using this transfer method. The junctions show good tunneling characteristics, which demonstrates the transfer technique can also be used to fabricate graphene devices on liquid-sensitive surfaces. (paper)

  4. Optimization of microwave-assisted drying of Jerusalem artichokes (Helianthus tuberosus L. by response surface methodology and genetic algorithm

    Directory of Open Access Journals (Sweden)

    E. KARACABEY

    2016-03-01

    Full Text Available The objective of the present study was to investigate microwave-assisted drying of Jerusalem artichoke tubers to determine the effects of the processing conditions. Drying time (DT and effectivemoisture diffusivity (EMD were determined to evaluate the drying process in terms of dehydration performance, whereas the rehydration ratio (RhR was considered as a significant quality index. A pretreatment of soaking in a NaCl solution was applied before all trials. The output power of the microwave oven, slice thickness and NaCl concentration of the pretreatment solution werethe three investigated parameters. The drying process was accelerated by altering the conditions while obtaining a higher quality product. For optimization of the drying process, response surface methodology (RSM and genetic algorithms (GA were used. Model adequacy was evaluated for each corresponding mathematical expression developed for interested responses by RSM. The residual of the model obtained by GA was compared to that of the RSM model. The GA was successful in high-performance prediction and produced results similar to those of RSM. The analysis and results of the present study show that both RSM and GA models can be used in cohesion to gain insight into the bioprocessing system.

  5. Effect of Rare Earth Y on Properties of Nanosized 90W-7Ni-3Fe Composite Powder Fabricated by Spray Drying-Hydrogen Reduction

    Directory of Open Access Journals (Sweden)

    Y.-Z. Ma

    2008-01-01

    Full Text Available (W,Ni,Fe composite oxide powder synthesized by spray drying was reduced at 700∘C for 90 minutes in H2 atmosphere. The effect of rare earth Y on H2 reduction of (W,Ni,Fe composite oxide powder was studied. Phase composition, crystalline size, and particle morphology of the reduced powder have been measured by X-ray diffraction and scanning electron microscope (SEM. Fsss particle size and special surface area of the reduced powder were also measured and analyzed. The result showed that new phase Y(Ni0.75W0.25O3 appeared in the reduced powder and particle morphology was nearly spherical or polyhedron by Y additions. The higher the rare earth element content was, the bigger the influencing on particle morphology was. When the rare earth Y content was under 0.8%, with the increase of the rare earth element content, dBET, Fsss, and crystal sizes of the reduced powder decreased greatly.

  6. [Preparation of panax notoginseng saponins-tanshinone H(A) composite method for pulmonary delivery with spray-drying method and its characterization].

    Science.gov (United States)

    Wang, Hua-Mei; Fu, Ting-Ming; Guo, Li-Wei

    2013-02-01

    To prepare panax notoginseng saponins-tanshinone II(A) composite particles for pulmonary delivery, in order to explore a dry powder particle preparation method ensuring synchronized arrival of multiple components of traditional Chinese medicine compounds at absorption sites. Panax notoginseng saponins-tanshinone II(A) composite particles were prepared with spray-drying method, and characterized by scanning electron microscopy (SEM), confocal laser scanning microscope (CLSM), X-ray diffraction (XRD), infrared analysis (IR), dry laser particle size analysis, high performance liquid chromatography (HPLC) and the aerodynamic behavior was evaluated by a Next Generation Impactor (NGI). The dry powder particles produced had narrow particle size distribution range and good aerodynamic behavior, and could realize synchronized administration of multiple components. The spray-drying method is used to combine traditional Chinese medicine components with different physical and chemical properties in the same particle, and product into traditional Chinese medicine compound particles in line with the requirements for pulmonary delivery.

  7. Low Hysteresis Carbon Nanotube Transistors Constructed via a General Dry-Laminating Encapsulation Method on Diverse Surfaces.

    Science.gov (United States)

    Yang, Yi; Wang, Zhongwu; Xu, Zeyang; Wu, Kunjie; Yu, Xiaoqin; Chen, Xiaosong; Meng, Yancheng; Li, Hongwei; Qiu, Song; Jin, Hehua; Li, Liqiang; Li, Qingwen

    2017-04-26

    Electrical hysteresis in carbon nanotube thin-film transistor (CNTTFT) due to surface adsorption of H 2 O/O 2 is a severe obstacle for practical applications. The conventional encapsulation methods based on vacuum-deposited inorganic materials or wet-coated organic materials have some limitations. In this work, we develop a general and highly efficient dry-laminating encapsulation method to reduce the hysteresis of CNTTFTs, which may simultaneously realize the construction and encapsulation of CNTTFT. Furthermore, by virtue of dry procedure and wide compatibility of PMMA, this method is suitable for the construction of CNTTFT on diverse surface including both inorganic and organic dielectric materials. Significantly, the dry-encapsulated CNTTFT exhibits very low or even negligible hysteresis with good repeatability and air stability, which is greatly superior to the nonencapsulated and wet-encapsulated CNTTFT with spin-coated PMMA. The dry-laminating encapsulation strategy, a kind of technological innovation, resolves a significant problem of CNTTFT and therefore will be promising in facile transferring and packaging the CNT films for high-performance optoelectronic devices.

  8. Effect of Omega-3 Fatty Acids Dietary Supplementation on Ocular Surface and Tear Film in Diabetic Patients with Dry Eye.

    Science.gov (United States)

    Georgakopoulos, Constantine D; Makri, Olga E; Pagoulatos, Dionisios; Vasilakis, Panagiotis; Peristeropoulou, Politimi; Kouli, Vasiliki; Eliopoulou, Maria I; Psachoulia, Caterina

    2017-01-01

    The objective of this study was to investigate the effect of dietary supplementation with omega-3 fatty acids on ocular surface and tear film in patients with type 2 diabetes suffering from dry eye. Thirty-six patients suffering from type 2 diabetes and moderate to severe dry eye syndrome were included in the study. Patients were assigned to receive omega-3 long-chain polyunsaturated fatty acids for 3 months. Tear film break-up time test, Schirmer-I test, and conjunctival impression cytology analysis were performed on all patients at baseline and after 1 and 3 months. The subjective symptoms of dry eye were evaluated with the Ocular Surface Disease Index (OSDI) questionnaire at the same time points. Patients' average age was 65.57 ± 4.27 years and the mean duration of diabetes was 14.85 ± 5.4 years. There was a statistically significant increase in Schirmer-I test results and tear break-up time score after 3 months of supplementary intake of omega-3 fatty acids compared to baseline (p dry eye syndrome in patients with type 2 diabetes.

  9. Mineral and chemical composition of rock core and surface gas composition in Horonobe Underground Research Laboratory project. Phase 1

    International Nuclear Information System (INIS)

    Hiraga, Naoto; Ishii, Eiichi

    2008-02-01

    The following three kinds of analyses were conducted for the 1st phase of the Horonobe Underground Research Laboratory Project. Mineral composition analysis of core sample. Whole rock chemical composition analysis of core sample. Surface gas composition analysis. This document summarizes the results of these analyses. (author)

  10. Surface composition of Europa based on VLT observations

    Science.gov (United States)

    Ligier, N.; Poulet, F.; Carter, J.

    2016-12-01

    Jupiter's moon Europa may harbor a global salty ocean under an 80-170 km thick outer layer consisting of an icy crust (Anderson et al. 1998). Meanwhile, the 10-50 My old surface, dated by cratering rates (Pappalardo et al. 1999) implies rapid surface recycling and reprocessing that could result in tectonic activity (Kattenhorn et al. 2014) and plumes (Roth et al. 2014). The surface could thus exhibit fingerprints of chemical species, as minerals characteristics of an ocean-mantle interaction and/or organics of exobiological interest, directly originating from the subglacial ocean. In order to re-investigate the composition of Europa's surface, a global mapping campaign of the satellite was performed with the near-infrared integral field spectrograph SINFONI on the Very Large Telescope (VLT) in Chile. The high spectral binning of this instrument (0.5 nm) and large signal noise ratio in comparison to previous observations are adequate to detect sharp absorptions in the wavelength range 1.45-2.45 μm. In addition, the spatially resolved spectra we obtained over five epochs nearly cover the entire surface of Europa with a pixel scale of 12.5 by 25 m.a.s ( 35 by 70 km on Europa's surface), thus permitting a global scale study. Several icy and non-icy compounds were detected and mapped at <100 km resolution. They are unevenly distributed on the moon's surface. Amorphous and crystalline water ice are both present and, in spite of a particularly strong amorphization process likely engendered by the Io plasma torus, the crystalline form is found to be approximately twice as abundant as the amorphous ice based on the analysis of the 1.65 μm band. If the surface is dominated by small and mid-sized water ice grains (25-200 μm), crystalline water-ice grains exhibit spatial inhomogeneities in their distribution. The sulfuric acid hydrate distribution exhibits the typical "bullseye" feature on the trailing hemisphere. The presence of Mg-bearing chlorinated salts (chloride

  11. A fine surface roughness electroless Ni–P–PTFE composite modified stamper for light guide plate application

    International Nuclear Information System (INIS)

    Pan, K; Fu, C

    2010-01-01

    Electroless Ni–P–PTFE composite coating technology takes advantage of the beneficial properties from both Ni–P alloy and PTFE, such as good wear resistance, good anti-adhesion, dry lubrication, low coefficient of friction and good corrosion resistance. It has been applied in many mold industries. However, the Ni–P–PTFE composite coating suffers from bad surface roughness, when the PTFE particles incorporate into a Ni–P matrix. This severely hampers the technology to be applied to optical grade applications. In this paper, we propose a trick to generate a fine surface roughness (FSR) electroless Ni–P–PTFE composite to modify a nickel stamper. Using this new method, the nickel stamper can be covered by a Ni–P–PTFE functional layer and can keep the original surface property at the same time, namely the optical properties. We have chosen 4.5 inch (97 mm × 59 mm × 0.6 mm) light guide plates (LGPs) to demonstrate the effectiveness of the procedure. For the sake of comparison, the LGPs were produced by injection molding with three kinds of stampers including an original SUS430 master, an electroless Ni–P–PTFE composite coated nickel stamper and an FSR electroless Ni–P–PTFE composite modified stamper. We measured and discussed the optical performances at both the element level and system level, namely complete back light units.

  12. Microstructure, composition and performance of PVD coatings designed for successful dry high speed milling

    International Nuclear Information System (INIS)

    Muenz, W.-D.; Lembke, M.I.; Lewis, D.B.; Smith, I.J.

    2001-01-01

    Dry high speed machining (HSM), particularly dry high speed milling, demands hard coatings, which exhibit high toughness, high oxidation resistance, a limited amount of residual stress and excellent adhesion to the cemented carbide (CC) substrate. These requirements are met by TiAICrYN coatings grown by the combined cathodic arc/unbalanced magnetron deposition method. Fully sufficient adhesion is achieved by ion implantation of Cr into the CC prior deposition. Residual stress is controlled by an Y - free base layer; high oxidation resistance is provided by an Y - containing 3 μm thick hard coating with 29 GPa hardness and a residual stress well below -7 GPa. Under the influence of temperatures above 800 o C, Y segregates along the columns of TiAIN and plugs the in/out diffusion of elements. A top layer of Y - containing oxynitride reduces the friction against the work piece material (0.9 to 0.65). Cutting tools coated as such may be used for dry milling up to 25 k rpm in steels HRC > 60. (author)

  13. Surface ozone seasonality under global change: Influence from dry deposition and isoprene emissions at northern mid-latitudes

    Science.gov (United States)

    Clifton, O.; Paulot, F.; Fiore, A. M.; Horowitz, L. W.; Malyshev, S.; Shevliakova, E.; Correa, G. J. P.; Lin, M.

    2017-12-01

    Identifying the contributions of nonlinear chemistry and transport to observed surface ozone seasonal cycles over land using global models relies on an accurate representation of ozone uptake by vegetation (dry deposition). It is well established that in the absence of ozone precursor emission changes, a warming climate will increase surface ozone in polluted regions, and that a rise in temperature-dependent isoprene emissions would exacerbate this "climate penalty". However, the influence of changes in ozone dry deposition, expected to evolve with climate and land use, is often overlooked in air quality projections. With a new scheme that represents dry deposition within the NOAA GFDL dynamic vegetation land model (LM3) coupled to the NOAA GFDL atmospheric chemistry-climate model (AM3), we simulate the impact of 21st century climate and land use on ozone dry deposition and isoprene emissions. This dry deposition parameterization is a version of the Wesely scheme, but uses parameters explicitly calculated by LM3 that respond to climate and land use (e.g., stomatal conductance, canopy interception of water, leaf area index). The parameterization includes a nonstomatal deposition dependence on humidity. We evaluate climatological present-day seasonal cycles of ozone deposition velocities and abundances with those observed at northern mid-latitude sites. With a set of 2010s and 2090s decadal simulations under a high climate warming scenario (RCP8.5) and a sensitivity simulation with well-mixed greenhouse gases following RCP8.5 but air pollutants held at 2010 levels (RCP8.5_WMGG), we examine changes in surface ozone seasonal cycles. We build on our previous findings, which indicate that strong reductions in anthropogenic NOx emissions under RCP8.5 cause the surface ozone seasonal cycle over the NE USA to reverse, shifting from a summer peak at present to a winter peak by 2100. Under RCP8.5_WMGG, we parse the separate effects of climate and land use on ozone dry

  14. Comparison of Ant Community Diversity and Functional Group Composition Associated to Land Use Change in a Seasonally Dry Oak Forest.

    Science.gov (United States)

    Cuautle, M; Vergara, C H; Badano, E I

    2016-04-01

    Ants have been used to assess land use conversion, because they reflect environmental change, and their response to these changes have been useful in the identification of bioindicators. We evaluated ant diversity and composition associated to different land use change in a temperate forest (above 2000 m asl) in Mexico. The study was carried out in "Flor del Bosque" Park a vegetation mosaic of native Oak Forests and introduced Eucalyptus and grasslands. Species richness, dominance and diversity rarefaction curves, based on ant morphospecies and functional groups, were constructed and compared among the three vegetation types, for the rainy and the dry seasons of 2008-2009. Jaccard and Sorensen incidence-based indices were calculated to obtain similarity values among all the habitats. The Oak Forest was a rich dominant community, both in species and functional groups; the Eucalyptus plantation was diverse with low dominance. The most seasonality habitat was the grassland, with low species and high functional group diversity during the dry seasons, but the reverse pattern during the wet season. The Oak Forest was more similar to the Eucalyptus plantation than to the grassland, particularly during the dry season. Oak Forests are dominated by Cold Climate Specialists, specifically Prenolepis imparis (Say). The Eucalyptus and the grassland are characterized by generalized Myrmicinae, as Pheidole spp. and Monomorium ebenium (Forel). The conservation of the native Oak Forest is primordial for the maintenance of Cold Climate Specialist ant communities. The microclimatic conditions in this forest, probably, prevented the invasion by opportunistic species.

  15. OPTIMIZATION OF SURFACE ROUGHNESS OF AISI 304 AUSTENITIC STAINLESS STEEL IN DRY TURNING OPERATION USING TAGUCHI DESIGN METHOD

    Directory of Open Access Journals (Sweden)

    D. PHILIP SELVARAJ

    2010-09-01

    Full Text Available The present work is concentrated with the dry turning of AISI 304 Austenitic Stainless Steel (ASS. This paper presents the influence of cutting parameters like cutting speed, feed rate and depth of cut on the surface roughness of austenitic stainless steel during dry turning. A plan of experiments based on Taguchi’s technique has been used to acquire the data. An orthogonal array, the signal to noise (S/N ratio and the analysis of variance (ANOVA are employed to investigate the cutting characteristics of AISI 304 austenitic stainless steel bars using TiC and TiCN coated tungsten carbide cutting tool. Finally the confirmation tests that have been carried out to compare the predicted values with the experimental values confirm its effectiveness in the analysis of surface roughness.

  16. Topographic and Electrochemical Ti6Al4V Alloy Surface Characterization in Dry and Wet Reciprocating Sliding

    Directory of Open Access Journals (Sweden)

    Z. Doni

    2013-09-01

    Full Text Available This present paper shows the behavior of functional integrity of the state Ti6Al4V alloy under reciprocating sliding wear conditions in acomparative way for two different counter materials, steel and ceramicballs in dry and corrosive environment (3.5% NaCl. The surface integrity analysis of the dry reciprocating wear tests was based on the evolution of The roughness parameters with the applied load. In the case of reciprocating wear tests in corrosive environment the surface integrity analysis was based on electrochemical parameters. Comparative analysis of the evolution of the roughness parameters with the applied load shows a higher stability of the Ti6Al4V/Al2O3 contact pair, while from the point of view of the electrochemical parameters the Tribological properties are worse than Ti6Al4V/steel ball contact pair.

  17. Surface Composition of Trojan Asteroids from Thermal-Infrared Spectroscopy

    Science.gov (United States)

    Martin, A.; Emery, J. P.; Lindsay, S. S.

    2017-12-01

    Asteroid origins provide an effective means of constraining the events that dynamically shaped the solar system. Jupiter Trojan asteroids (hereafter Trojans) may help in determining the extent of radial mixing that occurred during giant planet migration. Previous studies aimed at characterizing surface composition show that Trojans have low albedo surfaces and fall into two distinct spectral groups the near infrared (NIR). Though, featureless in this spectral region, NIR spectra of Trojans either exhibit a red or less-red slope. Typically, red-sloped spectra are associated with organics, but it has been shown that Trojans are not host to much, if any, organic material. Instead, the red slope is likely due to anhydrous silicates. The thermal infrared (TIR) wavelength range has advantages for detecting silicates on low albedo asteroids such as Trojans. The 10 µm region exhibits strong features due to the Si-O fundamental molecular vibrations. We hypothesize that the two Trojan spectral groups have different compositions (silicate mineralogy). With TIR spectra from the Spitzer Space Telescope, we identify mineralogical features from the surface of 11 Trojan asteroids, five red and six less-red. Preliminary results from analysis of the 10 µm region indicate red-sloped Trojans have a higher spectral contrast compared to less-red-sloped Trojans. Fine-grain mixtures of crystalline pyroxene and olivine exhibit a 10 µm feature with sharp cutoffs between about 9 µm and 12 µm, which create a broad flat plateau. Amorphous phases, when present, smooth the sharp emission features, resulting in a dome-like shape. Further spectral analysis in the 10 µm, 18 µm, and 30 µm band region will be performed for a more robust analysis. If all Trojans come from the same region, it is expected that they share spectral and compositional characteristics. Therefore, if spectral analysis in the TIR reinforce the NIR spectral slope dichotomy, it is likely that Trojans were sourced from

  18. Effect of turning parameters on surface roughness of A356/5% SiC composite produced by electromagnetic stir casting

    Energy Technology Data Exchange (ETDEWEB)

    Dwivedi, S. P.; Kumar, Sudhir; Kumar, Ajay [Noida Institute of Engineering Technology, U.P (India)

    2012-12-15

    In the present investigation, A356 alloy 5 wt% SiC composite is fabricated by electromagnetic stir casting process. An attempt has been made to investigate the effect of CNC lathe process parameters like cutting speed, depth of cut, and feed rate on surface roughness during machining of A356 alloy 5 wt% SiC particulate metal-matrix composites in dry condition. Response surface methodology (Box Behnken Method) is chosen to design the experiments. The results reveal that cutting speed increases surface roughness decreases, whereas depth of cut and feed increase surface roughness increase. Optimum values of speed (190 m/min), feed (0.14 mm/rev) and depth of cut (0.20 mm) during turning of A356 alloy 5 wt% SiC composites to minimize the surface roughness (3.15>m) have been find out. The mechanical properties of A356 alloy 5 wt% SiC were also analyzed.

  19. Dynamics of shearing force and its correlations with chemical compositions and dry matter digestibility of stylo ( stem

    Directory of Open Access Journals (Sweden)

    Xuejuan Zi

    2017-12-01

    Full Text Available Objective The study explored the dynamics of shearing force and its correlation with chemical compositions and in vitro dry matter digestibility (IVDMD of stylo. Methods The shearing force, diameter, linear density, chemical composition, and IVDMD of different height stylo stem were investigated. Linear regression analysis was done to determine the relationships between the shearing force and cut height, diameter, chemical composition, or IVDMD. Results The results showed that shearing force of stylo stem increased with plant height increasing and the crude protein (CP content and IVDMD decreased but fiber content increased over time, resulting in decreased forage value. In addition, tall stem had greater shearing force than short stem. Moreover, shearing force is positively correlated with stem diameter, linear density and fiber fraction, but negatively correlated with CP content and IVDMD. Conclusion Overall, shearing force is an indicator more direct, easier and faster to measure than chemical composition and digestibility for evaluation of forage nutritive value related to animal performance. Therefore, it can be used to evaluate the nutritive value of stylo.

  20. Vegetation structure and composition of a tropical dry forest in regeneration in Bataclán (Cali, Colombia

    Directory of Open Access Journals (Sweden)

    Viviana Londoño Lemos

    2015-01-01

    Full Text Available Characterization of long-term vegetation in a tropical dry forest (TDF that is in the process of regeneration permits establishment of patterns of composition, structure and dynamics of plant communities and sheds light on the different stages of plant succession. In this study, the plant community of ecoparque Bataclán, Cali, Colombia was evaluated by determining its structure and composition in two regeneration strategies. One strategy consisted of natural regeneration with bamboo barriers and the other of natural regeneration without bamboo barriers. Three permanent plots of 500 m2 were established in each regeneration strategy (six plots in total. Composition and structure was determined, taking into account all the growth habits, with different sampling methods. We found no significant differences between vegetation structure and composition of the two strategies for forest regeneration. forty-one species belonging to 27 families were recorded (trees and shrubs 58.5 %, herbs 24.4 %, climbers or scandents 14.6 %, epiphytes 2.4 %. The dominant family was Melastomataceae and the dominant species was Miconia prasina. The orchidCatasetum ochraceum and the grass Thrasya petrosa were indicator species for high luminosity. We conclude that the plant community is in an early successional stage, where there is a mixture of planted and naturally regenerated species in the zone, characterized by pioneer species from TDF and other nearby life zones.

  1. Height, leaf nymber, chemical composition and dry matter production of Stylosanthes Campo Grande at different levels of potassium and zinco.

    Directory of Open Access Journals (Sweden)

    Françoise Mara Gomes

    2015-10-01

    Full Text Available The objective of this study was to determine plant height, total number of leaves, number of live leaves, chemical composition and dry mass production of Stylosanthes cv. Campo Grande at first cut and after 21 days of regrowth at different levels of potassium (K2O with and without zinc (Zn. The experiment was conducted using a randomized block design in a 4 x 2 factorial scheme consisting of four repetitions. Four levels of K2O (0, 120, 240 and 360 mg/dm3 with and without Zn (0 and 6 mg/dm3 were used. There was no effect of the interaction between K2O and Zn levels on the structural characteristics of Stylosanthes cv. Campo Grande, and no independent effects of the different levels of K2O and Zn were observed. The mean plant height, total number of leaves and number of live leaves were 21.2 cm, 30.2 and 27.2, respectively. Dry mass production did not differ between K2O and Zn levels, with a mean production of 3.7 g/pot. There was also no effect of the interaction between K2O and Zn levels on dry matter and neutral detergent fiber content, and no independent effects of the different levels of K2O and Zn were observed, with mean values of 29.3% and 46.9% dry matter, respectively. However, an effect of the interaction between K2O and Zn levels was observed for crude protein content, which exhibited a quadratic response. Re2growth increased linearly with increasing K2O levels. Although the highest crude protein content was obtained at zero levels of potassium and zinc, potassium fertilization is advantageous since it increases the regrowth of Stylosanthes cv. Campo Grande in 21 days.

  2. Dry eye evaluation and correlation analysis between tear film stability and corneal surface regularity after small incision lenticule extraction.

    Science.gov (United States)

    Zhang, Hui; Wang, Yan

    2017-09-22

    To investigate the dry eye after small incision lenticule extraction (SMILE) and explore the correlations between changes in the tear film stability, the tear secretion and the corneal surface regularity. Sixty-two eyes of 22 men and 13 women who underwent SMILE were included in this study. Corneal topography was measured to assess the index of surface variance (ISV) and the index of vertical asymmetry (IVA). Dry eye tests including subjective symptom questionnaire, tear breakup time (TBUT), corneal fluorescein staining and Schirmer's test (ST) were evaluated before and at 1 and 6 months postoperatively. TBUT was found to be significantly decreased from 9.8 ± 3.4 s preoperatively to 7.4 ± 3.8 s at 1 month and 6.5 ± 3.6 s at 6 months (both P short-TBUT type of dry eye. Corneal surface regularity indices might be helpful in the assessment of tear film stability following SMILE procedure.

  3. Evaluation of Alternative Peel Ply Surface Preparation Methods of SC-15 Epoxy / Fiberglass Composite Surfaces for Secondary Bonding

    Science.gov (United States)

    2014-01-01

    prepared composite surfaces. Examination of the surface compositions will show differences in makeup and identify any transfer of contaminants...by carefully brushing the specimen with a lint-free cloth followed by a high-pressure nitrogen gas stream. 3.2 X-ray Photospectroscopy (XPS

  4. Thermomechanical behavior of dry contacts in disc brake rotor with a grey cast iron composition

    Directory of Open Access Journals (Sweden)

    Belhocine Ali

    2013-01-01

    Full Text Available The main purpose of this study is to analysis the thermomechanical behavior of the dry contact between the brake disc and pads during the braking phase. The simulation strategy is based on the calculation code ANSYS11. The modeling of transient temperature in the disk is actually used to identify the factor of geometric design of the disk to install the ventilation system in vehicles. The thermal-structural analysis is then used coupling to determine the deformation established and the Von Mises stresses in the disk, the contact pressure distribution in pads. The results are satisfactory compared to those found in the literature.

  5. Surface protein composition of Aeromonas hydrophila strains virulent for fish: identification of a surface array protein

    International Nuclear Information System (INIS)

    Dooley, J.S.G.; Trust, T.J.

    1988-01-01

    The surface protein composition of members of a serogroup of Aeromonas hydrophila was examined. Immunoblotting with antiserum raised against formalinized whole cells of A. hydrophila TF7 showed a 52K S-layer protein to be the major surface protein antigen, and impermeant Sulfo-NHS-Biotin cell surface labeling showed that the 52K S-layer protein was the only protein accessible to the Sulfo-NHS-Biotin label and effectively masked underlying outer membrane (OM) proteins. In its native surface conformation the 52K S-layer protein was only weakly reactive with a lactoperoxidase 125 I surface iodination procedure. A UV-induced rough lipopolysaccharide (LPS) mutant of TF7 was found to produce an intact S layer, but a deep rough LPS mutant was unable to maintain an array on the cell surface and excreted the S-layer protein into the growth medium, indicating that a minimum LPS oligosaccharide size required for A. hydrophila S-layer anchoring. The native S layer was permeable to 125 I in the lactoperoxidase radiolabeling procedure, and two major OM proteins of molecular weights 30,000 and 48,000 were iodinated. The 48K species was a peptidoglycan-associated, transmembrane protein which exhibited heat-modifiable SDS solubilization behavior characteristic of a porin protein. A 50K major peptidoglycan-associated OM protein which was not radiolabeled exhibited similar SDS heat modification characteristics and possibly represents a second porin protein

  6. Surface Functionalization of Thin-Film Composite Membranes with Copper Nanoparticles for Antimicrobial Surface Properties

    KAUST Repository

    Ben-Sasson, Moshe

    2014-01-07

    Biofouling is a major operational challenge in reverse osmosis (RO) desalination, motivating a search for improved biofouling control strategies. Copper, long known for its antibacterial activity and relatively low cost, is an attractive potential biocidal agent. In this paper, we present a method for loading copper nanoparticles (Cu-NPs) on the surface of a thin-film composite (TFC) polyamide RO membrane. Cu-NPs were synthesized using polyethyleneimine (PEI) as a capping agent, resulting in particles with an average radius of 34 nm and a copper content between 39 and 49 wt.%. The positive charge of the Cu-NPs imparted by the PEI allowed a simple electrostatic functionalization of the negatively charged RO membrane. We confirmed functionalization and irreversible binding of the Cu-NPs to the membrane surface with SEM and XPS after exposing the membrane to bath sonication. We also demonstrated that Cu-NP functionalization can be repeated after the Cu-NPs dissolve from the membrane surface. The Cu-NP functionalization had minimal impact on the intrinsic membrane transport parameters. Surface hydrophilicity and surface roughness were also maintained, and the membrane surface charge became positive after functionalization. The functionalized membrane exhibited significant antibacterial activity, leading to an 80-95% reduction in the number of attached live bacteria for three different model bacterial strains. Challenges associated with this functionalization method and its implementation in RO desalination are discussed. © 2013 American Chemical Society.

  7. Surface Functionalization of Thin-Film Composite Membranes with Copper Nanoparticles for Antimicrobial Surface Properties

    KAUST Repository

    Ben-Sasson, Moshe; Zodrow, Katherine R.; Genggeng, Qi; Kang, Yan; Giannelis, Emmanuel P.; Elimelech, Menachem

    2014-01-01

    Biofouling is a major operational challenge in reverse osmosis (RO) desalination, motivating a search for improved biofouling control strategies. Copper, long known for its antibacterial activity and relatively low cost, is an attractive potential biocidal agent. In this paper, we present a method for loading copper nanoparticles (Cu-NPs) on the surface of a thin-film composite (TFC) polyamide RO membrane. Cu-NPs were synthesized using polyethyleneimine (PEI) as a capping agent, resulting in particles with an average radius of 34 nm and a copper content between 39 and 49 wt.%. The positive charge of the Cu-NPs imparted by the PEI allowed a simple electrostatic functionalization of the negatively charged RO membrane. We confirmed functionalization and irreversible binding of the Cu-NPs to the membrane surface with SEM and XPS after exposing the membrane to bath sonication. We also demonstrated that Cu-NP functionalization can be repeated after the Cu-NPs dissolve from the membrane surface. The Cu-NP functionalization had minimal impact on the intrinsic membrane transport parameters. Surface hydrophilicity and surface roughness were also maintained, and the membrane surface charge became positive after functionalization. The functionalized membrane exhibited significant antibacterial activity, leading to an 80-95% reduction in the number of attached live bacteria for three different model bacterial strains. Challenges associated with this functionalization method and its implementation in RO desalination are discussed. © 2013 American Chemical Society.

  8. Effect of Ground Surface Roughness on Atmospheric Dispersion and Dry Deposition of Cs-137 in the UAE Environment

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sungyeop; Beeley, Philip A. [Khalifa Univ. of Science, Abu Dhabi (United Arab Emirates); Kim, Sungyeop; Chang, Soonheung; Lee, Kunjai [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2013-05-15

    The site of nuclear power plant (NPP) in the UAE has several unique characteristics as a NPP on the desert environment near coastal region. Those characteristics are represented like below: · Arid ground surface · Low ground surface roughness length · Relatively simple (flat) terrain · Extremely low precipitation · Intense solar radiation and high temperature in day time · Sea breeze · Relatively high humidity of atmosphere · Etc. From the review of this desert environment in the UAE, low ground surface roughness is regarded as one of definitively different characteristics from that of other NPP sites. In this context, surface roughness is selected as independent variables for the sensitivity analyses in this research. Another important reason of this selection is that this parameters is less dependent on the day and night change than other parameters. With ground level concentration, dry deposition rate has been chosen as a dependent variable to be considered rather than wet deposition because UAE shows almost zero rainfall especially in summer. Lower ground level concentration of Cs-137 near the site and extremely lower dry deposition of Cs-137 are predicted in the UAE environment because of the lower ground surface roughness of the desert.

  9. Microwave and plasma-assisted modification of composite fiber surface topography

    Science.gov (United States)

    Paulauskas, Felix L [Knoxville, TN; White, Terry L [Knoxville, TN; Bigelow, Timothy S [Knoxville, TN

    2003-02-04

    The present invention introduces a novel method for producing an undulated surface on composite fibers using plasma technology and microwave radiation. The undulated surface improves the mechanical interlocking of the fibers to composite resins and enhances the mechanical strength and interfacial sheer strength of the composites in which they are introduced.

  10. Functional levels of floor surface roughness for the prevention of slips and falls: clean-and-dry and soapsuds-covered wet surfaces.

    Science.gov (United States)

    Kim, In-Ju; Hsiao, Hongwei; Simeonov, Peter

    2013-01-01

    Literature has shown a general trend that slip resistance performance improves with floor surface roughness. However, whether slip resistance properties are linearly correlated with surface topographies of the floors or what roughness levels are required for effective slip resistance performance still remain to be answered. This pilot study aimed to investigate slip resistance properties and identify functional levels of floor surface roughness for practical design applications in reducing the risk of slip and fall incidents. A theory model was proposed to characterize functional levels of surface roughness of floor surfaces by introducing a new concept of three distinctive zones. A series of dynamic friction tests were conducted using 3 shoes and 9 floor specimens under clean-and-dry as well as soapsuds-covered slippery wet environments. The results showed that all the tested floor-shoe combinations provided sufficient slip resistances performance under the clean-and-dry condition. A significant effect of floor type (surface roughness) on dynamic friction coefficient (DFC) was found in the soapsuds-covered wet condition. As compared to the surface roughness effects, the shoe-type effects were relatively small. Under the soapsuds-covered wet condition, floors with 50 μm in Ra roughness scale seemed to represent an upper bound in the functional range of floor surface roughness for slip resistance because further increase of surface roughness provided no additional benefit. A lower bound of the functional range for slip resistance under the soapsuds-covered wet condition was estimated from the requirement of DFC > 0.4 at Ra ≅ 17 μm. Findings from this study may have potential safety implications in the floor surface design for reducing slip and fall hazards. Published by Elsevier Ltd.

  11. Diquafosol sodium ophthalmic solution for the treatment of dry eye: clinical evaluation and biochemical analysis of tear composition.

    Science.gov (United States)

    Shigeyasu, Chika; Yamada, Masakazu; Akune, Yoko; Tsubota, Kazuo

    2015-11-01

    To evaluate the clinical efficacy of 3% diquafosol sodium ophthalmic solution for dry eye, and to analyze the concentration of tear proteins and mucin-like substances after the treatment. Fifty eyes of 25 patients with dry eye syndrome were prospectively enrolled. The patients were treated with diquafosol solution at a dose of 1 drop in each eye 6 times daily for 4 weeks. The parameters of clinical efficacy were tear osmolarity, tear breakup time (BUT), fluorescein staining scores for the cornea and conjunctiva, Schirmer test values, and subjective symptoms evaluated using the ocular surface disease index (OSDI). Tears collected with Schirmer test strips were analyzed by high-performance liquid chromatography, and the concentrations of the total protein and the 4 major tear proteins, namely, secretory IgA, lactoferrin, lipocalin-1, lysozyme, and N-acetyl-neuraminic acid (Neu5Ac), were measured. Neu5Ac is a major sialic acid, a marker of secretory mucins. The BUT, keratoconjunctival staining scores, and Schirmer test values were improved with statistical significance after the treatment with diquafosol solution, while changes in the other parameters, including tear osmolarity, corneal staining scores, and OSDI scores were not significant. The Neu5Ac concentration was significantly increased, which was not accompanied by changes in tear proteins. Topical application of diquafosol significantly improved the clinical parameters of the BUT, keratoconjunctival staining scores, and Schirmer test values and was accompanied by increased sialic acid content in the tears of patients with dry eye.

  12. Surface properties of thermally treated composite wood panels

    Science.gov (United States)

    Croitoru, Catalin; Spirchez, Cosmin; Lunguleasa, Aurel; Cristea, Daniel; Roata, Ionut Claudiu; Pop, Mihai Alin; Bedo, Tibor; Stanciu, Elena Manuela; Pascu, Alexandru

    2018-04-01

    Composite finger-jointed spruce and oak wood panels have been thermally treated under standard pressure and oxygen content conditions at two different temperatures, 180 °C and respectively 200 °C for short time periods (3 and 5 h). Due to the thermally-aided chemical restructuration of the wood components, a decrease in water uptake and volumetric swelling values with up to 45% for spruce and 35% for oak have been registered, comparing to the reference samples. In relation to water resistance, a 15% increase of the dispersive component of the surface energy has been registered for the thermal-treated spruce panels, which impedes water spreading on the surface. The thermal-treated wood presents superior resistance to accelerated UV exposure and subsequently, with up to 10% higher Brinell hardness values than reference wood. The proposed thermal treatment improves the durability of the finger-jointed wood through a more economically and environmental friendly method than traditional impregnation, with minimal degradative impact on the structural components of wood.

  13. Near Surface CO2 Triple Oxygen Isotope Composition

    Directory of Open Access Journals (Sweden)

    Sasadhar Mahata

    2016-02-01

    Full Text Available The isotopic composition of carbon dioxide in the atmosphere is a powerful tool for constraining its sources and sinks. In particular, the 17O oxygen anomaly [Δ17O = 1000 × ln(1 + δ17O/1000 - 0.516 × 1000 × ln(1 + δ18O/1000], with a value > 0.5‰ produced in the middle atmosphere, provides an ideal tool for probing the exchange of carbon dioxide between the biosphere/hydrosphere and atmosphere. The biosphere/hydrosphere and anthropogenic emissions give values ≤ 0.3‰. Therefore, any anomaly in near surface CO2 would reflect the balance between stratospheric input and exchange with the aforementioned surface sources. We have analyzed Δ17O values of CO2 separated from air samples collected in Taipei, Taiwan, located in the western Pacific region. The obtained mean anomaly is 0.42 ± 0.14‰ (1-σ standard deviation, in good agreement with model prediction and a published decadal record. Apart from typically used δ13C and δ18O values, the Δ17O value could provide an additional tracer for constraining the carbon cycle.

  14. Efficacy of a New Ocular Surface Modulator in Restoring Epithelial Changes in an In Vitro Model of Dry Eye Syndrome.

    Science.gov (United States)

    Barabino, Stefano; De Servi, Barbara; Aragona, Salvatore; Manenti, Demetrio; Meloni, Marisa

    2017-03-01

    So far tear substitutes have demonstrated a limited role in restoring ocular surface damage in dry eye syndrome (DES). The aim of this study was to assess the efficacy of a new ocular surface modulator in an in vitro model of human corneal epithelium (HCE) damaged by severe osmotic stress mirroring the features of dry eye conditions. A reconstructed HCE model challenged by the introduction of sorbitol in the culture medium for 16 h was used to induce an inflammatory pathway and to impair the tight junctions integrity determining a severe modification of the superficial layer ultrastructure. At the end of the overnight stress period in the treated HCE series, 30 μl of the ocular surface modulator (T-LysYal, Sildeha, Switzerland) and of hyaluronic acid (HA) in the control HCE series were applied for 24 h. The following parameters were quantified: scanning electron microscopy (SEM), trans-epithelial electrical resistance (TEER), immunofluorescence analysis of integrin β1 (ITG-β1), mRNA expression of Cyclin D-1 (CCND1), and ITG-β1. In the positive control after the osmotic stress the HCE surface damage was visible at the ultrastructural level with loss of cell-cell interconnections, intercellular matrix destruction, and TEER reduction. After 24 h of treatment with T-LysYal, HCE showed a significant improvement of the ultrastructural morphological organization and increased expression of ITG-β1 at the tissue level when compared to positive and control series. A significant increase of mRNA expression for ITG-β1 and CCND1 was shown in the HA-treated cells compared to T-LysYal. TEER measurement showed a significant reduction in all groups after 16 h without modifications after the treatment period. This study has shown the possibility of a new class of agents denominated ocular surface modulators to restore corneal cells damaged by dry eye conditions. Further in vivo studies are certainly necessary to confirm these results.

  15. The improvement of dry eye after cataract surgery by intraoperative using ophthalmic viscosurgical devices on the surface of cornea

    Science.gov (United States)

    He, Yuan; Li, Jia; Zhu, Jingfen; Jie, Ying; Wang, Ningli; Wang, Jun

    2017-01-01

    Abstract Backgroud: This study aimed to investigate the protective effect of intraoperative used hydroxypropyl methylcellulose (HPMC 2%) on the ocular surface after cataract surgery. Methods: A total of 149 eyes (149 patients) diagnosed with age-related cataract, age 69.19 ± 9.74 years, were enrolled in this prospective, parallel-design, continuous, randomised controlled study. Patients were randomly assigned to receive HPMC 2% (study group) or balanced salt solution (control group) during the surgery to moisturize the cornea surface. The Ocular Surface Disease Index, Schirmer test without topical anesthetics, tear break-up time, and corneal fluorescein staining were assessed preoperatively, 1 day, 1 week, and 1 month after the surgery, respectively. Results: The Schirmer test value of male patients in the study group at 1 week postoperation was higher than that of male patients in the control group (P = .019). For patients diagnosed with dry eye before the surgery, Schirmer test value in the male patients in the study group at 1 month after surgery was higher than that in the male patients in the control group (P = .037). Furthermore, for the cluster of preoperative dry eye patients whose surgical time was longer than median, corneal fluorescein staining of the patients in the study group was superior to that of the patients in the control group (P = .032). Conclusion: Intraoperative use of HPMC 2% on the cornea surface could improve clinical outcomes of tear film and ocular surface health to some degree, especially in the patients diagnosed with dry eye before the surgery, male patients, and patients whose surgical time was relatively longer. PMID:29390284

  16. Impact of Optimized Land Surface Parameters on the Land-Atmosphere Coupling in WRF Simulations of Dry and Wet Extremes

    Science.gov (United States)

    Kumar, S.; Santanello, J. A.; Peters-Lidard, C. D.; Harrison, K.

    2011-12-01

    Land-atmosphere (L-A) interactions play a critical role in determining the diurnal evolution of both planetary boundary layer (PBL) and land surface temperature and moisture budgets, as well as controlling feedbacks with clouds and precipitation that lead to the persistence of dry and wet regimes. Recent efforts to quantify the strength of L-A coupling in prediction models have produced diagnostics that integrate across both the land and PBL components of the system. In this study, we examine the impact of improved specification of land surface states, anomalies, and fluxes on coupled WRF forecasts during the summers of extreme dry (2006) and wet (2007) conditions in the U.S. Southern Great Plains. The improved land initialization and surface flux parameterizations are obtained through the use of a new optimization and uncertainty module in NASA's Land Information System (LIS-OPT), whereby parameter sets are calibrated in the Noah land surface model and classified according to the land cover and soil type mapping of the observations and the full domain. The impact of the calibrated parameters on the a) spinup of land surface states used as initial conditions, and b) heat and moisture fluxes of the coupled (LIS-WRF) simulations are then assessed in terms of ambient weather, PBL budgets, and precipitation along with L-A coupling diagnostics. In addition, the sensitivity of this approach to the period of calibration (dry, wet, normal) is investigated. Finally, tradeoffs of computational tractability and scientific validity (e.g.,. relating to the representation of the spatial dependence of parameters) and the feasibility of calibrating to multiple observational datasets are also discussed.

  17. Automated grading, upgrading, and cuttings prediction of surfaced dry hardwood lumber

    Science.gov (United States)

    Sang-Mook Lee; Phil Araman; A.Lynn Abbott; Matthew F. Winn

    2010-01-01

    This paper concerns the scanning, sawing, and grading of kiln-dried hardwood lumber. A prototype system is described that uses laser sources and a video camera to scan boards. The system automatically detects defects and wane, searches for optimal sawing solutions, and then estimates the grades of the boards that would result. The goal is to derive maximum commercial...

  18. Surface Compositions of Red Giant Stars in Globular Clusters

    Science.gov (United States)

    Cheng, Eric; Lau, Marie; Smith, Graeme; Chen, Brian

    2018-01-01

    Globular clusters (GCs) are excellent “laboratories” to study the formation and evolution of our galaxy. In order to understand, more specifically, the chemical compositions and stellar evolution of the stars in GCs, we ask whether or not deep internal mixing occurs in red giants or if in fact the compositions come from the primordial interstellar medium or previous generations of stars. It has been discovered that as a star evolves up the red giant branch, the surface carbon abundance decreases, which is evidence of deep internal mixing. We questioned whether these processes also affect O or Na abundance as a star evolves. We collected measurement data of red giants from GCs out of academic journals and sorted the data into catalogs. Then, we plotted the catalogs into figures, comparing surface O and Na each with stellar luminosity. Statistical tests were ran to quantify the amount of correlation between the variables. Out of 27 GCs, we concluded that eight show a positive correlation between Na and luminosity, and two show a negative correlation between O and luminosity. Properties of GCs were compared to determine if chemical distribution in stars depends on GCs as the self-enrichment scenario suggests. We created histograms of sodium distribution to test for bimodality to examine if there are separate trends in each GC. In six GCs, two different sequences of red giants appear for Na versus luminosity, suggesting evidence that the depth of mixing may differ among each red giant in a GC. This study has provided new evidence that the changing chemical abundances on the surfaces of red giants can be due to stellar evolutionary effects and deep internal mixing, which may not necessarily depend on the GC and may differ in depth among each red giant. Through this study, we learn more about stellar evolution which will eventually help us understand the origins of our universe. Most of this work was carried out by high school students working under the auspices of

  19. Impact of soils and cropping systems on composition of mineral elements of dry cacao beans

    Science.gov (United States)

    In view of its high economic value, cacao (Theobroma cacao L.) researchers are seeking technological innovations that increase production and improve the quality of cacao beans. The objective of this study was to characterize the mineral (P, K, Ca, Mg, Si, Fe, Mn, Zn, Cu, Cd, Ba) composition of caca...

  20. Soil drying effects on the carbon isotope composition of soil respiration

    Science.gov (United States)

    Stable isotopes are used widely as a tool for determining sources of carbon (C) fluxes in ecosystem C studies. Environmental factors that change over time, such as moisture, can create dynamic changes in the isotopic composition of C assimilated by plants, and offers a unique opp...

  1. Ion beam effects on the surface and near-surface composition of TaSi2

    International Nuclear Information System (INIS)

    Valeri, S.; Di Bona, A.; Ottaviani, G.; Procop, M.

    1991-01-01

    Low-energy (0.7-4.5 keV) ion bombardment effects on polycrystalline TaSi 2 at sputter steady state and in various intermediate steps have been investigated, in the temperature range up to 550degC, to determine the time and temperature dependence of the altered layer formation. This in turn enables a better knowledge of the synergistic effects of the processes mentioned above. At low temperatures (T≤410degC) the surface is silicon depleted, and the depletion is even more severe in the subsurface region up to a depth of several tens of angstroems; silicon preferential sputtering and radiation-enhanced segregation assisted by the displacement mixing-induced motion of atoms are assumed to be responsible for this composition profile, while thermally activated diffusion processes become operative above 410degC, reducing progressively the concentration gradient between the surface and the subsurface zone. The composition at different depths has been determined from Auger peaks for different kinetic energies, by varying the take-off angle and finally by sputter profiling at low in energy the high energy processed surfaces. Quantitative analysis has been performed by XPS and AES by using the elemental standard method. (orig.)

  2. Effect of magnesium content on the microstructure and dry sliding wear behavior of centrifugally cast functionally graded A356-Mg2Si in situ composites

    Science.gov (United States)

    Ram, Subhash Chandra; Chattopadhyay, K.; Chakrabarty, I.

    2018-04-01

    Functionally graded A356 alloy (Al–7.2Si–0.3Mg) –Mg2Si in situ composites have been synthesized via centrifugal casting route. Mg2Si particles tend to migrate towards the core of the tubular product by centrifugal force. The in situ formed Mg2Si particles in composites are characterized by x-ray diffraction (XRD) analysis, Energy dispersive spectrometry (EDS), Optical, Scanning Electron and Transmission Electron Microscopy. Apart from primary blocky Mg2Si particles the matrix contains other phases viz. Al-Si eutectic, pseudo-binary Al-Mg2Si eutectic and Al-Fe-Si intermetallics. Density is found to decrease and %porosity is increased with increase in volume fraction of Mg2Si. Maximum hardness was observed at the inner core region due to maximum segregation of Mg2Si particles and gradually decreases towards the outer periphery region. The dry sliding wear was evaluated with varying parameters such as normal loads (N) and sliding distances (m). A substantial increase in wear resistance at the inner core region is observed. From the worn surface characterization, the wear mechanisms have been explained.

  3. Effects of surface coating process conditions on the water permeation and salt rejection properties of composite polyamide reverse osmosis membranes

    KAUST Repository

    Louie, Jennifer Sarah

    2011-02-01

    The application of polymer surface coatings to improve the fouling resistance of reverse osmosis membranes tends to increase flow resistance across the membrane. This paper presents a systematic analysis on how membrane properties and performance are impacted by the coating process steps, and investigates how such effects could contribute to lower water flux. On one hand, simply pre-soaking dry aromatic polyamide composite membranes in aliphatic alcohols results in a significant increase in water flux, which is attributed to wetting of pores in the selective polyamide layer and to changes in the polymer structure. This flux increase was not readily reversible, based on a 300-h water permeation test. Conversely, drying a wetted membrane led to a decrease in water flux, which we hypothesize is caused by increased interchain hydrogen-bonding in the selective layer. This drop in water flux was not permanent; higher flux was observed if the same wetted/dried membrane was then re-soaked in ethanol prior to the water permeation experiment. An ethanol pre-soaking step also increased water flux of a PEBAX-coated membrane by nearly 70%. In contrast to the reduction in water flux caused by the specific treatment sequence of ethanol-swelling followed by drying, this same sequence actually increased gas transport. The eight- to ten-fold increase in Knudsen diffusion-based gas permeance after this pre-treatment was attributed to an increase in the number or size of membrane defects. © 2010 Elsevier B.V.

  4. Factors associated with long-term species composition in dry tropical forests of Central India

    Science.gov (United States)

    Agarwala, M.; DeFries, R. S.; Qureshi, Q.; Jhala, Y. V.

    2016-10-01

    The long-term future of species composition in forests depends on regeneration. Many factors can affect regeneration, including human use, environmental conditions, and species’ traits. This study examines the influence of these factors in a tropical deciduous forest of Central India, which is heavily used by local, forest-dependent residents for livestock grazing, fuel-wood extraction, construction and other livelihood needs. We measure size-class proportions (the ratio of abundance of a species at a site in a higher size class to total abundance in both lower and higher size classes) for 39 tree species across 20 transects at different intensities of human use. The size-class proportions for medium to large trees and for small to medium-sized trees were negatively associated with species that are used for local construction, while size class proportions for saplings to small trees were positively associated with those species that are fire resistant and negatively associated with livestock density. Results indicate that grazing and fire prevent non-fire resistant species from reaching reproductive age, which can alter the long term composition and future availability of species that are important for local use and ecosystem services. Management efforts to reduce fire and forest grazing could reverse these impacts on long-term forest composition.

  5. Dry Sliding Wear Charactristics of Aluminum 6061-T6, Magnesium AZ31 and Rock Dust Composite

    Science.gov (United States)

    Balachandar, R.; Balasundaram, R.; Rajkumar, G.

    2018-02-01

    In recent years, the use of aluminum composite is gaining popularity in a wide range of applications like automobiles, aerospace and constructions (both interior & exterior) panels etc., due to its high strength, low density characteristics. Various reinforcing materials are used with aluminum 6061-T6 in order to have better mechanical properties. The addition of 0.3% of magnesium AZ31 will increase the ultimate tensile strength by 25 %. The reinforcement of rock dust will decrease the density. Hence, in order to have an advantages of magnesium AZ31 and rock dust, in this work, these two constitutes are varied from 1% to 2% on the base material of Al6061-T6 in stir casting. To evaluate the wear characteristics, Pin on disc is used in these composites. The input parameters are speed, time & load. The output response is wear. To minimize the number of experiments, L9 orthogonal array is used. The test results showed that a composite of 97% of Al (6061-T6), 1% Mg (AZ31) & 2 % of rock dust produced less wear. To find the best value of operating parameter for each sample, ANN-GA is used.

  6. Creating surfactant nanoparticles for block copolymer composites through surface chemistry.

    Science.gov (United States)

    Kim, Bumjoon J; Bang, Joona; Hawker, Craig J; Chiu, Julia J; Pine, David J; Jang, Se Gyu; Yang, Seung-Man; Kramer, Edward J

    2007-12-04

    A simple strategy to tailor the surface of nanoparticles for their specific adsorption to and localization at block copolymer interfaces was explored. Gold nanoparticles coated by a mixture of low molecular weight thiol end-functional polystyrene (PS-SH) (Mn = 1.5 and 3.4 kg/mol) and poly(2-vinylpyridine) homopolymers (P2VP-SH) (Mn = 1.5 and 3.0 kg/mol) were incorporated into a lamellar poly(styrene-b-2-vinylpyridine) diblock copolymer (PS-b-P2VP) (Mn = 196 kg/mol). A library of nanoparticles with varying PS and P2VP surface compositions (FPS) and high polymer ligand areal chain densities was synthesized. The location of the nanoparticles in the PS-b-P2VP block copolymer was determined by transmission electron microscopy. Sharp transitions in particle location from the PS domain to the PS/P2VP interface, and subsequently to the P2VP domain, were observed at FPS = 0.9 and 0.1, respectively. This extremely wide window of FPS values where the polymer-coated gold nanoparticles adsorb to the interface suggests a redistribution of PS and P2VP polymers on the Au surface, inducing the formation of amphiphilic nanoparticles at the PS/P2VP interface. In a second and synthetically more challenging approach, gold nanoparticles were covered with a thiol terminated random copolymer of styrene and 2-vinylpyridine synthesized by RAFT polymerization. Two different random copolymers were considered, where the molecular weight was fixed at 3.5 kg/mol and the relative incorporation of styrene and 2-vinylpyridine repeat units varied (FPS = 0.52 and 0.40). The areal chain density of these random copolymers on Au is unfortunately not high enough to preclude any contact between the P2VP block of the block copolymer and the Au surface. Interestingly, gold nanoparticles coated by the random copolymer with FPS = 0.4 were dispersed in the P2VP domain, while those with FPS = 0.52 were located at the interface. A simple calculation for the adsorption energy to the interface of the nanoparticles

  7. Laboratory study of SO2 dry deposition on limestone and marble: Effects of humidity and surface variables

    Science.gov (United States)

    Spiker, E. C.; Hosker, R.P.; Weintraub, V.C.; Sherwood, S.I.

    1995-01-01

    The dry deposition of gaseous air pollutants on stone and other materials is influenced by atmospheric processes and the chemical characteristics of the deposited gas species and of the specific receptor material. Previous studies have shown that relative humidity, surface moisture, and acid buffering capability of the receptor surface are very important factors. To better quantify this behavior, a special recirculating wind tunnel/environmental chamber was constructed, in which wind speed, turbulence, air temperature, relative humidity, and concentrations of several pollutants (SO2, O3, nitrogen oxides) can be held constant. An airfoil sample holder holds up to eight stone samples (3.8 cm in diameter and 1 cm thick) in nearly identical exposure conditions. SO2 deposition on limestone was found to increase exponentially with increasing relative humidity (RH). Marble behaves similarly, but with a much lower deposition rate. Trends indicate there is little deposition below 20% RH on clean limestone and below 60% RH on clean marble. This large difference is due to the limestone's greater porosity, surface roughness, and effective surface area. These results indicate surface variables generally limit SO2 deposition below about 70% RH on limestone and below at least 95% RH on marble. Aerodynamic variables generally limit deposition at higher relative humidity or when the surface is wet.The dry deposition of gaseous air pollutants on stone and other materials is influenced by atmospheric processes and the chemical characteristics of the deposited gas species and of the specific receptor material. Previous studies have shown that relative humidity, surface moisture, and acid buffering capability of the receptor surface are very important factors. To better quantify this behavior, a special recirculating wind tunnel/environmental chamber was constructed, in which wind speed, turbulence, air temperature, relative humidity, and concentrations of several pollutants (SO2, O3

  8. Quantification of Gaseous Elemental Mercury Dry Deposition to Environmental Surfaces using Mercury Stable Isotopes in a Controlled Environment

    Science.gov (United States)

    Rutter, A. P.; Schauer, J. J.; Shafer, M. M.; Olson, M.; Robinson, M.; Vanderveer, P.; Creswell, J. E.; Parman, A.; Mallek, J.; Gorski, P.

    2009-12-01

    Andrew P. Rutter (1) * *, James J, Schauer (1,2) *, Martin M. Shafer(1,2), Michael R. Olson (1), Michael Robinson (1), Peter Vanderveer (3), Joel Creswell (1), Justin L. Mallek (1), Andrew M. Parman (1) (1) Environmental Chemistry and Technology Program, 660 N. Park St, Madison, WI 53705. (2) Wisconsin State Laboratory of Hygiene, 2601 Agriculture Drive, Madison, WI 53718. (3) Biotron, University of Wisconsin - Madison, 2115 Observatory Drive, Madison, WI 53706 * Correspond author(jjschauer@wisc.edu) * *Presenting author (aprutter@wisc.edu) Abstract Gaseous elemental mercury (GEM) is the predominant component of atmospheric mercury outside of arctic depletion events, and locations where anthropogenic point sources are not influencing atmospheric concentrations. GEM constitutes greater than 99% of the mercury mass in most rural and remote locations. While dry and wet deposition of atmospheric mercury is thought to be dominated by oxidized mercury (a.k.a. reactive mercury), only small GEM uptake to environmental surfaces could impact the input of mercury to terrestrial and aquatic ecosystems. Dry deposition and subsequent re-emission of gaseous elemental mercury is a pathway from the atmosphere that remains only partially understood from a mechanistic perspective. In order to properly model GEM dry deposition and re-emission an understanding of its dependence on irradiance, temperature, and relative humidity must be measured and parameterized for a broad spectrum of environmental surfaces colocated with surrogate deposition surfaces used to make field based dry deposition measurements. Measurements of isotopically enriched GEM dry deposition were made with a variety of environmental surfaces in a controlled environment room at the University of Wisconsin Biotron. The experimental set up allowed dry deposition components which are not easily separated in the field to be decoupled. We were able to isolate surface transfer processes from variabilities caused by

  9. Comparison between dry deposition fluxes measured with water and solid surfaces, and estimated by an inferential model

    Energy Technology Data Exchange (ETDEWEB)

    Balestrini, R.; Consuma, A.; Polesello, S.; Tartari, G. [Istituto di Ricerca sulle Acque, Brugherio, MI (Italy)

    2000-08-01

    The quantification of the dry atmospheric input to natural surfaces is currently a complete task. In this study a water surface sampler (Das) was used contemporary to conventional solid surface samplers (wet and dry and bulk) to monitor the dry deposition in a densely inhabited and industrialised area. The dry contribution to the total deposition was 33-56% for sulfate, 11-39% for ammonium and 18-28% for nitrate ion, depending on the measurement technique. Among the three samplers, the Das one was the most efficient to collect sulfate, ammonium and nitrate. The comparison of the seasonal trends showed that the dry collector using a polyethylene surface, collected mainly aerosol particles of ammonium sulfate, while the aqueous surface of Das sampler was able to sample also the gaseous form of the pollutants. Sulfate and nitrate flux values determined from direct measurements were also compared with those obtained by a resistance model. The sulphate measured values fitted quite well with those predicted from the model showing similar seasonal variations. The quantitative differences observed in winter could be due to an increase in the acidity of water, used as collecting medium, which lowered the solubility of gaseous sulphur dioxide. In order to investigate the effect of water acidity on the deposition on a water body, a series of experiments were carried out. [Italian] La quantificazione della deposizione secca costituisce, ancora oggi, un'operazione complessa. Tre tipi di campionatori, rispettivamente con una superficie acquosa (Das) e con superfici solide in polietilene (wet and dry e bulk) sono stati impiegati per misurare la deposizione secca in un'area densamente antropizzata. Il contributo della deposizione secca alla deposizione totale e' risultato compreso tra 33 e 56% per i solfati, tra 11 e 39% per l'ammonio e tra 18 e il 28% per i nitrati, secondo la tecnica di campionamento. Il campionatore Das si e' dimostrato il piu

  10. Classification and mapping of the composition and structure of dry woodland and savanna in the eastern Okavango Delta

    Directory of Open Access Journals (Sweden)

    Michelle J. Tedder

    2013-02-01

    Full Text Available The dry woodland and savanna regions of the Okavango Delta form a transition zone between the Okavango Swamps and the Kalahari Desert and have been largely overlooked in terms of vegetation classification and mapping. This study focused on the species composition and height structure of this vegetation, with the aim of identifying vegetation classes and providing a vegetation map accompanied by quantitative data. Two hundred and fifty-six plots (50 m × 50 m were sampled and species cover abundance, total cover and structural composition were recorded. The plots were classified using agglomerative, hierarchical cluster analysis using group means and Bray-Curtis similarity and groups described using indicator species analysis. In total, 23 woody species and 28 grass species were recorded. Acacia erioloba and Colophospermum mopane were the most common woody species, whilst Urochloa mossambicensis, Panicum maximum, Dactyloctenium gigantiumand Eragrostis lehmanniana were the most widespread grasses. Eleven vegetation types were identified, with the most widespread being Short mixed mopane woodland, Tall mopane woodland and Tall mixed mopane woodland, covering 288.73 km2 (28%, 209.14 km2 (20% and 173.30 km2 (17% of the area, respectively. Despite their extensive area, these three vegetation types were the least species-rich, whilst Palm thornveld, Short mixed broadleaf woodland and Open mixed Acacia woodland were the most taxonomically variable. By contrast, Closed mixed Acacia woodland and Closed Acacia–Combretum woodland had the most limited distribution, accounting for less than 1% of the mapped area each.Conservation implications: The dry woodland and savanna vegetation of the Okavango Delta comprises a much wider suite of plant communities than the Acacia-dominated and Mopane-dominated classifications often used. This classification provided a more detailed understanding of this vegetation and essential background information for monitoring

  11. Time course of ocular surface and lacrimal gland changes in a new scopolamine-induced dry eye model.

    Science.gov (United States)

    Viau, Sabrina; Maire, Marie-Annick; Pasquis, Bruno; Grégoire, Stéphane; Fourgeux, Cynthia; Acar, Niyazi; Bretillon, Lionel; Creuzot-Garcher, Catherine P; Joffre, Corinne

    2008-06-01

    The aim of this study was to set up an animal model of dry eye showing disturbance in several components of the lacrimal functional unit, and to describe the time course of the appearance of clinical signs and inflammatory markers. Dry eye was induced in 6-week-old female Lewis rats by a systemic and continuous delivery of scopolamine via osmotic pumps implanted subcutaneously. We first determined the appropriate dose of scopolamine (6, 12.5, or 25 mg/day) for 28 days. In a second set of experiments, we determined markers after 1, 2, 3, 7, 10, 17, or 28 days of a 12.5-mg/day dose. Clinical signs of corneal dryness were evaluated in vivo using fluorescein staining. MHC II expression and mucin Muc5AC production were detected on the conjunctival epithelium using immunostaining. The level of IL-1beta, IL-6, TNF-alpha, and IFN-gamma mRNA was evaluated by real-time polymerase chain reaction in conjunctiva and exorbital lacrimal gland (LG). Lipids were extracted from the exorbital LG for fatty acid analysis. Daily scopolamine doses of 12.5 mg and 25 mg applied for a 28-day period induced keratitis, a decrease in Muc5AC immunostaining density in the conjunctival epithelium, and modifications in the fatty acid composition of the exorbital LG. Animals treated with a 12.5-mg/day dose of scopolamine exhibited an increase in corneal fluorescein staining after 2, 10, and 28 days. All animals exhibited unilateral or bilateral keratitis after 17 days. In the conjunctival epithelium, a significant decrease in Muc5AC immunostaining density was observed at early and late time points, and MHC II expression tended to be increased after 1, 7, 10, and 28 days, without reaching statistical significance. The levels of TNF-alpha, IL-1beta and IL-6 mRNA were increased with scopolamine treatment in both conjunctiva and exorbital LG. Arachidonic acid and the Delta5 desaturase index were significantly increased in the exorbital LG of dry eye animals at each time point. This systemic and

  12. Upregulation of NLRP3 Inflammasome in the Tears and Ocular Surface of Dry Eye Patients.

    Directory of Open Access Journals (Sweden)

    Liangliang Niu

    Full Text Available To evaluate the mRNA and protein expressions of NLRP3 inflammasome and its downstream inflammatory factors in human dry eye.We recruited 54 patients with Sjögren's syndrome dry eye (SSDE, 50 patients with non-Sjögren's syndrome dry eye (NSSDE, and 46 healthy controls. Tear film breakup time (TBUT, Schirmer I test, and fluorescein staining (FL were performed on all subjects. Tear samples were obtained to analyze the inflammatory cytokine levels of IL-1β and IL-18 via enzyme-linked immunosorbent (ELISA. Conjunctival impression cytology (CIC specimens were collected to detect the mRNA expression of NLRP3, caspase-1, IL-1β, and IL-18 using quantitative RT-PCR, and the protein expression of NLRP3 and caspase-1 by Western blotting.NLRP3 mRNA expression showed higher levels in both dry eye groups compared with controls, with a comparably significant elevation in the SSDE group (relative 2.47-fold upregulation, p<0.05. NLRP3 protein expression was also increased in SSDE group (relative1.94-fold upregulation compared with the controls. mRNA expression of caspase-1 was significantly upregulated in both SSDE (relative 1.44-fold upregulation, p<0.05 and NSSDE (relative 1.32-fold upregulation, p<0.05. Procaspase-1 protein level was increased in SSDE (relative 1.84-fold upregulation and NSSDE (relative 1.12-fold upregulation versus controls; and caspase-1 protein expression was also increased in SSDE (relative 1.49-fold upregulation and NSSDE (relative 1.17-fold upregulation compared with the controls. The patients with SSDE and NSSDE had higher IL-1β and IL-18 mRNA values and protein expressions than the controls did. The relative mRNA expression of IL-1β upregulated 3.59-fold (p<0.001 in SSDE and 2.13-fold (p<0.01 in NSSDE compared with the controls. IL-1β protein level also showed significant upregulation in SSDE (p=0.01; vs. controls groups. IL-18 mRNA expression levels were significantly upregulated in the SSDE (relative 2.97-fold upregulation, p

  13. Lipid oxidation and fatty acid composition in salt-dried yellow croaker ( Pseudosciaena polyactis) during processing

    Science.gov (United States)

    Cai, Qiuxing; Wu, Yanyan; Li, Laihao; Wang, Yueqi; Yang, Xianqing; Zhao, Yongqiang

    2017-10-01

    Lipid oxidation in salt-dried yellow croaker ( Pseudosciaena polyactis) was evaluated during processing with commonly used analytical indices, such as the peroxide value (POV), the thiobarbituric acid reactive substances (TBARS) value, and oxidative-relative lipoxygenase (LOX) activity. Additionally, fatty acids were analyzed using gas chromatography-mass spectrometry. Both POV and TBARS increased significantly ( P acids were identified. Combined eicosapentaenoic acid (EPA; C20:5n3) and docosahexaenoic acid (DHA; C22:6n3) content varied between (19.20 ± 0.37) mg g-1 and (23.45 ± 1.05) mg g-1. The polyunsaturated fatty acid/saturated fatty acid (PUFA/SFA) ratio in yellow croaker was 0.73-1.10, and the n-6/n-3 PUFA ratio was approximately 0.13-0.20. The contents of most fatty acids varied significantly ( P acids are potential markers for evaluating lipid oxidation in fish muscle because there was a significant correlation between these markers and TBARS and LOX activity ( P 0.931.

  14. Discrepancy between body surface area and body composition in cancer.

    Science.gov (United States)

    Stobäus, Nicole; Küpferling, Susanne; Lorenz, Marie-Luise; Norman, Kristina

    2013-01-01

    Calculation of cytostatic dose is typically based on body surface area (BSA) regardless of body composition. The aim of this study was to assess the discrepancy between BSA and low fat-free mass (FFM) by investigating the prevalence of low FFM with regard to BSA in 630 cancer patients. First, BSA was calculated according to DuBois and DuBois. Patients were divided into 6 categories with respect to their BSA. Each BSA category was further divided into 3 groups according to FFM: low (FFM), normal (-0.99 and 0.99 SD of mean FFM) or high (>1 SD of mean FFM), which was derived through bioelectric impedance analysis. FFM was reduced in 15.7% of patients, 69% had normal and 15.2% had high FFM. In patients with low FFM (i.e., more than-1 SD lower than the mean FFM within their BSA group), body mass index and fatigue were higher whereas functional status was reduced. Moreover, in the subcohort of patients receiving chemotherapy, absolute FFM [Hazard ratio (HR) = 0.970, P = 0.026] as well as the allocation to the low FFM group (HR = 1.644, P = 0.025) emerged as predictors of increased 1-yr mortality. In conclusion, there was a large discrepancy between FFM and BSA. Particularly women were affected by low FFM.

  15. Surface modified carbon nanoparticle papers and applications on polymer composites

    Science.gov (United States)

    Ouyang, Xilian

    Free-standing paper like materials are usually employed as protective layers, chemical filters, components of electrical batteries or supercapacitors, adhesive layers, and electronic or optoelectric components. Free-standing papers made from carbon nanoparticles have drawn increased interest because they have a variety of superior chemical and physical characteristics, such as light weight, high intrinsic mechanical properties, and extraordinary high electrical conductivity. Nanopapers fabricated from 1- D shape carbon nanofibers (CNFs) and carbon nanotubes (CNTs) are promising reinforcing materials for polymer composites, because the highly porous CNF and CNT nanopapers (porosity ˜80% and ˜70% respectively) can be impregnated with matrix polymers. In the first part of this work, polyaniline (PANI) was used to functionalize the surface of CNFs, and the resultant carbon nanopapers presented impressive mechanical strength and electrical conductivity that it could be used in the in-mold coating (IMC)/ injection molding process to achieve high electromagnetic interference (EMI) shielding effectiveness. Aniline modified (AF) CNT nanopapers were used as a 3D network in gas separation membranes. The resultant composite membranes demonstrated better and stable CO2 permeance and CO 2/H2 selectivity in a high temperature (107°C) and high pressure (15-30 atm) gas separation process, not achievable by conventional polymer membranes. In the second part, we demonstrated that 2-D graphene (GP) or graphene oxide (GO) nanosheets could be tightly packed into a film which was impermeable to most gases and liquids. GP or GO nanopapers could be coated on polymer composites. In order to achieve well-dispersed single-layer graphene in aqueous medium, we developed a facile approach to synthesize functional GP bearing benzenesulfonic acid groups which allow the preparation of nanopapers by water based assembly. With the optimized processing conditions, our best GP nanopapers could reach

  16. Body composition of lactating and dry Holstein cows estimated by deuterium dilution

    International Nuclear Information System (INIS)

    Martin, R.A.; Ehle, F.R.

    1986-01-01

    In three experiments patterns of water turnover and body composition estimated by deuterium oxide were studied in Holstein cows. In the first experiment, four lactating cows were infused with deuterium oxide, and blood samples were taken during 4-d collection. Milking was stopped; cows were reinfused with deuterium oxide and resampled. Slopes of deuterium oxide dilution curves indicated lactating cows turned water over more rapidly than nonlactating cows. In the second experiment with the same four cows, during 4-d collection, deuterium oxide concentrations in milk, urine, and feces showed dilution patterns similar to deuterium oxide in blood. Sampling milk may be an alternative to sampling blood. In the third experiment, 36 Holstein cows were fed 55, 65, or 75% alfalfa, smooth bromegrass, or equal parts of each forage as total mixed rations; remaining portions of rations were a grain mixture. Body composition was estimated at -1, 1, 2, 3, 4, and 5 mo postpartum. Empty body water, protein, mineral, fat, and fat percentage decreased from prepartum to postpartum. First calf heifers contained less empty body water, protein, and mineral than older cows. Cows fed diets with 55% forage had more body fat than those fed diets with 75% forage. Cows fed alfalfa-based diets had more gastrointestinal fill regardless of grain than cows fed diets that contained alfalfa and smooth bromegrass. Gastrointestinal fill of cows increased from prepartum to 5 mo postpartum

  17. Dry deposition fluxes and deposition velocities of trace metals in the Tokyo metropolitan area measured with a water surface sampler.

    Science.gov (United States)

    Sakata, Masahiro; Marumoto, Kohji

    2004-04-01

    Dry deposition fluxes and deposition velocities (=deposition flux/atmospheric concentration) for trace metals including Hg, Cd, Cu, Mn, Pb, and Zn in the Tokyo metropolitan area were measured using an improved water surface sampler. Mercury is deposited on the water surface in both gaseous (reactive gaseous mercury, RGM) and particulate (particulate mercury, Hg(p)) forms. The results based on 1 yr observations found that dry deposition plays a significant if not dominant role in trace metal deposition in this urban area, contributing fluxes ranging from 0.46 (Cd) to 3.0 (Zn) times those of concurrent wet deposition fluxes. The deposition velocities were found to be dependent on the deposition of coarse particles larger than approximately 5 microm in diameter on the basis of model calculations. Our analysis suggests that the 84.13% diameter is a more appropriate index for each deposited metal than the 50% diameter in the assumed undersize log-normal distribution, because larger particles are responsible for the flux. The deposition velocities for trace metals other than mercury increased exponentially with an increase in their 84.13% diameters. Using this regression equation, the deposition velocities for Hg(p) were estimated from its 84.13% diameter. The deposition fluxes for Hg(p) calculated from the estimated velocities tended to be close to the mercury fluxes measured with the water surface sampler during the study periods except during summer.

  18. Chemical composition and biological value of spray dried porcine blood by-products and bone protein hydrolysate for young chickens.

    Science.gov (United States)

    Jamroz, D; Wiliczkiewicz, A; Orda, J; Skorupińska, J; Słupczyńska, M; Kuryszko, J

    2011-10-01

    The chemical composition of spray dried porcine blood by-products is characterised by wide variation in crude protein contents. In spray dried porcine blood plasma (SDBP) it varied between 670-780 g/kg, in spray dried blood cells (SDBC) between 830-930 g/kg, and in bone protein hydrolysate (BPH) in a range of 740-780 g/kg. Compared with fish meal, these feeds are poor in Met and Lys. Moreover, in BPH deep deficits of Met, Cys, Thr and other amino acids were found. The experiment comprised 7 dietary treatments: SDBP, SDBC, and BPH, each at an inclusion rate of 20 or 40 g/kg diet, plus a control. The addition of 20 or 40 g/kg of the analysed meals into feeds for very young chickens (1-28 d post hatch) significantly decreased the body weight (BW) of birds. Only the treatments with 40 g/kg of SDBP and SDBC showed no significant difference in BW as compared with the control. There were no significant differences between treatments and type of meal for feed intake, haematocrit and haemoglobin concentrations in blood. Addition of bone protein and blood cell meals to feed decreased the IgG concentration in blood and caused shortening of the femur and tibia bones. However, changes in the mineral composition of bones were not significantly affected by the type of meal used. The blood by-products, which are rich in microelements, improved retention of Ca and Cu only. In comparison to control chickens, significantly better accretion of these minerals was found in treatments containing 20 g/kg of SDBP or 40 g/kg of SDBC. Great variability in apparent ileal amino acid digestibility in chickens was determined. In this respect, some significant differences related to the type of meal fed were confirmed for Asp, Pro, Val, Tyr and His. In general, the apparent ileal digestibility of amino acids was about 2-3 percentage units better in chickens fed on diets containing the animal by products than in control birds.

  19. Impact of oral vitamin D supplementation on the ocular surface in people with dry eye and/or low serum vitamin D.

    Science.gov (United States)

    Yang, Chih-Huang; Albietz, Julie; Harkin, Damien G; Kimlin, Michael G; Schmid, Katrina L

    2018-02-01

    To determine the possible association between serum vitamin D levels and dry eye symptoms, and the impact of an oral vitamin D supplement. Three linked studies were performed. (i) 29 older adult participants, (ii) 29 dry eyed participants, and (iii) 2-month vitamin D supplementation for 32 dry eyed/low serum vitamin D levelled participants. All participants were assessed by the Ocular Surface Diseases Index (OSDI) to determine dry eye symptoms, and the phenol red thread test (PRT) and/or Schirmer's tear test, tear meniscus height, non-invasive tear break up time, grading ocular surface redness and fluorescein staining of the cornea to detect the tear quality and ocular surface conditions. Blood samples were collected for serum vitamin D analysis and interleukin-6 (IL-6) levels. Among older adult participants, vitamin D levels were negatively correlated with dry eye symptoms, the severity of dry eye, and associated with tired eye symptom. Vitamin D levels of people with dry eye diagnosis were not correlated with OSDI scores and IL-6 levels; while IL-6 levels showed correlation with tear production. In supplement study, vitamin D levels increased by 29mol/l, while dry eye symptoms and grading of corneal staining appeared significant reductions. No significant changes in IL-6 levels. Low vitamin D levels (dry eye symptoms in older individuals but not those diagnosed with dry eye. Vitamin D supplement increased the vitamin D levels, and improved dry eye symptoms, the tear quality and ocular surface conditions. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  20. [Dry matter intake of South American camelids and its effects on the composition of feed rations].

    Science.gov (United States)

    Stölzl, Anna Maria; Lambertz, Christian; Moors, Eva; Stiehl, Jennifer; Gauly, Matthias

    2014-01-01

    The number of South American camelids (SAC) is increasing in Germany since decades. Due to a lack of scientifically based publications the knowledge about feeding SACs is still poor. Therefore, the aim of this study was to estimate the dry matter intake (DMI) of SACs as a basis for calculations of feed rations. Previous studies proposed a DMI of up to 3% of the body weight (BW) (Vaughan und Gauly, 2011). In the present study, eight llamas (Llama glama) were allocated to two groups of four animals each. The two groups were fed with hay of different qualities over a total period often weeks, which was divided into two runs of five weeks each. During the first run, group 1 was fed with hay 1 (15.1% crude protein; 8.5% crude ash; 3.1% crude fat; 52.6% NDF per kg DM) and group 2 with hay 2 (6.6% crude protein; 6.2% crude ash; 2.1% crude fat; 64.3% NDF per kg DM). After five weeks the groups were changed and group 1 received hay 2 and group 2 received hay 1. BW was measured at the start and end of each run (week zero, five and ten). The hay quality affected the DMI, but the animals did not compensate a lower feed quality with an increased DMI. The total DMI was 1.26% and 0.89% of the BW for hay 1 and hay 2, respectively, which was lower than expected in both groups. In conclusion, calculations of feed rations for SACs should be adjusted to the present findings of a lower DMI capability.

  1. Evaluation of the effect of various drying techniques on the composition of the psychoactive phenylpropylamino alkaloids of khat (Catha edulis Forsk chewing leaves

    Directory of Open Access Journals (Sweden)

    S. Chigome

    2013-09-01

    Full Text Available The study demonstrated that by freezing or drying under different conditions, cathinone could be detected in the khat (Catha edulis Forsk samples that have been harvested for more than four months. Freeze drying or freezing in the refrigerator (-20 oC yielded more than 73% of cathinone. Air drying, sun drying or oven drying at 60 oC resulted in a cathinone composition of 57%, 42% and 36%, respectively. The study confirmed that, freshly harvested tender leaves of khat contained exclusively of cathinone but upon sun drying, part of it decomposes to cathine and norephedrine leaving cathinone as a major component. Thus it is wrong to assume that sun drying the leaves can result complete conversion of cathinone to cathine and norephedrine. Furthermore, the results of the study confirmed that it was possible to preserve khat samples for longer periods after freeze drying or deep freezing without significant loss of cathinone.DOI: http://dx.doi.org/10.4314/bcse.v27i3.3

  2. The effect of drying temperatures on antioxidant activity, phenolic compounds, fatty acid composition and tocopherol contents in citrus seed and oils.

    Science.gov (United States)

    Al Juhaimi, Fahad; Özcan, Mehmet Musa; Uslu, Nurhan; Ghafoor, Kashif

    2018-01-01

    In this study, the effect of drying temperature on antioxidant activity, phenolic compounds, fatty acid composition and tocopherol content of citrus seeds and oils were studied. Kinnow mandarin seed, dried at 60 °C, exhibited the highest antioxidant activity. Orlendo orange seed had the maximum total phenolic content and α-tocopherol content, with a value of 63.349 mg/100 g and 28.085 mg/g (control samples), respectively. The antioxidant activity of Orlendo orange seed (63.349%) was higher than seeds of Eureka lemon (55.819%) and Kinnow mandarin (28.015%), while the highest total phenolic content was found in seeds of Kinnow mandarin, followed by Orlendo orange and Eureka lemon (113.132). 1.2-Dihydroxybenzene (13.171), kaempferol (10.780), (+)-catechin (9.341) and isorhamnetin (7.592) in mg/100 g were the major phenolic compounds found in Kinnow mandarin. Among the unsaturated fatty acids, linoleic acid was the most abundant acid in all oils, which varied from 44.4% (dried at 80 °C) to 46.1% (dried at 70 °C), from 39.0% (dried at 60 °C) to 40.0% (dried at 70 °C). The total phenolic content, antioxidant activity and phenolic compounds of citrus seeds and tocopherol content of seed oils were significantly affected by drying process and varied depending on the drying temperature.

  3. Analysis of surface roughness and cutting force during turning of Ti6Al4V ELI in dry environment

    Directory of Open Access Journals (Sweden)

    V. G. Sargade

    2016-04-01

    Full Text Available This paper investigates the effect of cutting parameters on the surface roughness and cutting force of titanium alloy Ti-6Al-4V ELI when turning using PVD TiAlN coated tool in dry environment. Taguchi L9 orthogonal array design of experiment was used for the turning experiment 2 factors and 3 levels. Turning parameters studied were cutting speed (50, 65, 80 m/min, feed rate (0.08, 0.15, 0.2 mm/rev and depth of cut 0.5 mm constant. Linear and second order model of the surface roughness and cutting force has been developed in terms of cutting speed and feed. The results show that the feed rate was the most impact factor controlling the cutting force and surface roughness produced. MINITAB 17software was used to develop a linear and second order model of surface roughness and cutting force. Optimum condition was at 66.97 m/min of cutting speed, 0.08 mm/rev of feed rate. Surface roughness 0.57μm and cutting force 54.02 N were obtained at the optimum condition. A good agreement between the experimental and predicted surface roughness and cutting force were observed.

  4. Year-round atmospheric wet and dry deposition of nitrogen and phosphorus on water and land surfaces in Nanjing, China.

    Science.gov (United States)

    Sun, Liying; Li, Bo; Ma, Yuchun; Wang, Jinyang; Xiong, Zhengqin

    2013-06-01

    The dry deposition of ammonium, nitrate, and total phosphorus (TP) to both water (DW) and land (DD) surfaces, along with wet deposition, were simultaneously monitored from March 2009 to February 2011 in Nanjing, China. Results showed that wet deposition of total phosphorus was 1.1 kg phosphorus ha (-1)yr(-1), and inorganic nitrogen was 28.7 kg nitrogen ha (-1)yr(-1), with 43% being ammonium nitrogen. Dry deposition of ammonium, nitrate, and total phosphorus, measured by the DW/DD method, was 7.5/2.2 kg nitrogen ha (-1)yr(-1), 6.3/ 4.9 kg nitrogen ha (-1)yr(-1), and 1.9/0.4 kg phosphorus ha (-1)yr(-1), respectively. Significant differences between the DW and DD methods indicated that both methods should be employed simultaneously when analyzing deposition to aquatic and terrestrial ecosystems in watershed areas. The dry deposition of ammonium, nitrate, and total phosphorus contributed 38%, 28%, and 63%, respectively, to the total deposition in the simulated aquatic ecosystem; this has significance for the field of water eutrophication control.

  5. Lower Lid Laxity is Negatively Correlated with Improvement of the Ocular Surface Disease Index in Dry Eye Treatment.

    Science.gov (United States)

    Oh, Seung Hoon; Lyu, Byul; Yim, Hye Bin; Lee, Na Young

    2016-01-01

    To compare the responses to dry eye treatment of patients sorted by the degree of lower lid laxity. Sixty patients were grouped into three groups according to the degree of lower lid laxity. Tear break-up time (TBUT), Schirmer test (ST) scores, ocular surface disease index (OSDI) scores, and changes in OSDI score in each group were compared, before and at 3 months after treatment. TBUT, ST, and OSDI scores were not different among the three groups at baseline. TBUT improved in each group at 3 months after treatment, and no differences between groups were found. ST scores were not increased after treatment, while OSDI were improved to 22.57 ± 5.243, 31.16 ± 11.353, and 37.85 ± 13.342 in the no, moderate, and high laxity groups, respectively; these improvements were statistically significant (p = 0.003, dry eye treatment, as assessed by change in OSDI score (p = 0.005 versus moderate laxity group, p = 0.005 versus no laxity group). Lower lid laxity is one of the factors contributing to the responses to dry eye treatment assessed by change in OSDI score, independent of TBUT and ST scores.

  6. Response Surface Optimization of Lyoprotectant from Amino Acids and Salts for Bifidobacterium Bifidum During Vacuum Freeze-Drying

    Directory of Open Access Journals (Sweden)

    Qi Kangru

    2017-12-01

    Full Text Available High quality probiotic powder can lay the foundation for the commercial production of functional dairy products. The freeze-drying method was used for the preservation of microorganisms, having a deleterious effect on the microorganisms viability. In order to reduce the damage to probiotics and to improve the survival rate of probiotics during freeze-drying, the Response Surface Methodology (RSM was adopted in this research to optimize lyoprotectant composed of amino acids (glycine, arginine and salts (NaHCO3 and ascorbic acid. Probiotic used was Bifidobacterium bifidum BB01. The regression model (p<0.05 was obtained by Box–Behnken experiment design, indicating this model can evaluate the freeze-drying survival rate of B. bifidum BB01 under different lyoprotectants. The results indicated these concentrations as optimal (in W/V: glycine 4.5%, arginine 5.5%, NaHCO3 0.8% and ascorbic acid 2.3%, respectively. Under these optimal conditions, the survival rate of lyophilized powder of B. bifidum BB01 was significantly increased by 80.9% compared to the control group (6.9±0.62%, the results were agreement with the model prediction value (88.7%.

  7. Fabrication of Al/Graphite/Al2O3 Surface Hybrid Nano Composite by Friction Stir Processing and Investigating The Wear and Microstructural Properties of The Composite

    Directory of Open Access Journals (Sweden)

    A. Mostafapour

    2012-10-01

    Full Text Available Friction stir processing was applied for fabricating an aluminum alloy based hybrid nano composite reinforced with nano sized Al2O3 and micro sized graphite particles. A mixture of Al2O3 and graphite particles was packed into a groove with 1 mm width and 4.5 mm depth, which had been cut in 5083 aluminum plate of 10 mm thick. Packed groove was subjected to friction stir processing in order to implement powder mixture into the aluminum alloy matrix. Microstructural properties were investigated by means of optical microscopy and scanning electron microscopy (SEM. It was found that reinforcement particle mixture was distributed uniformly in nugget zone. Wear resistance of composite was measured by dry sliding wear test. As a result, hybrid composite revealed significant reduction in wear rate in comparison with Al/AL2O3 composite produced by friction stir processing. Worn surface of the wear test samples were examined by SEM in order to determine wear mechanism.

  8. Statistical Analysis of the Effects of Drying Temperature and Pretreatment on the Proximate Composition of Dried Matured Green Plantain (Musa Paradisiaca

    Directory of Open Access Journals (Sweden)

    K.A. Yusuf

    2014-07-01

    Full Text Available Drying has been identified as the efficient means of ensuring continuous food supply to the growing population of any country and to enable the farmers produce more high quality marketable products. In this study, the effects of drying temperature and pretreatment on the quality of dried mature green plantain (Musa paradisiaca were studied using an electrically-powered cabinet dryer. The product was dried from an initial moisture content of 62% (w.b to a moisture content of 11.9% (w.b. A factorial experiment in a Randomized Complete Block Design (RCBD involving three levels of temperature (50, 60 and 70 0C; three levels of pretreatment (blanching, boiling and control and three replications were used. The quality analysis of the dried samples at different level of drying temperatures and pre-treatments was carried out for protein, fat, ash and fibre content and the data obtained were statistically analyzed using SPSS 16.0 software to determine the level of significance among the treatment factors on the dried samples. The protein, fat and fibre content decreased with increase in temperature but the ash content increased with increase in temperature. In pretreatments, control had the highest protein content of 4.27% at 60 0C, lowest fat content of 2.26% at 70 0 C and moderate fibre and ash contents of 0.68% and 1.82% respectively at 60 0C. Boiled sample also had the highest fat content of 4.27% at 50 0C, lowest fat content 2.26% at 70 0C and moderate fibre and ash contents of 0.88% and 1.73% respectively at 60 0C. lastly, blanched sample had the highest fat content of 4.11% at 50 0 C, lowest fat content 2.54% at 70 0C and moderate fibre and ash contents of 0.83% and 1.45% respectively at 60 0C.

  9. [Optimization of vacuum belt drying process of Gardeniae Fructus in Reduning injection by Box-Behnken design-response surface methodology].

    Science.gov (United States)

    Huang, Dao-sheng; Shi, Wei; Han, Lei; Sun, Ke; Chen, Guang-bo; Wu Jian-xiong; Xu, Gui-hong; Bi, Yu-an; Wang, Zhen-zhong; Xiao, Wei

    2015-06-01

    To optimize the belt drying process conditions optimization of Gardeniae Fructus extract from Reduning injection by Box-Behnken design-response surface methodology, on the basis of single factor experiment, a three-factor and three-level Box-Behnken experimental design was employed to optimize the drying technology of Gardeniae Fructus extract from Reduning injection. With drying temperature, drying time, feeding speed as independent variables and the content of geniposide as dependent variable, the experimental data were fitted to a second order polynomial equation, establishing the mathematical relationship between the content of geniposide and respective variables. With the experimental data analyzed by Design-Expert 8. 0. 6, the optimal drying parameter was as follows: the drying temperature was 98.5 degrees C , the drying time was 89 min, the feeding speed was 99.8 r x min(-1). Three verification experiments were taked under this technology and the measured average content of geniposide was 564. 108 mg x g(-1), which was close to the model prediction: 563. 307 mg x g(-1). According to the verification test, the Gardeniae Fructus belt drying process is steady and feasible. So single factor experiments combined with response surface method (RSM) could be used to optimize the drying technology of Reduning injection Gardenia extract.

  10. Adhesion enhancement of Al coatings on carbon/epoxy composite surfaces by atmospheric plasma

    International Nuclear Information System (INIS)

    Coulon, J.F.; Tournerie, N.; Maillard, H.

    2013-01-01

    Adhesion strengths between aluminium thin film coatings and manufactured carbon/epoxy composite surfaces were measured by assessing fracture tensile strengths using pull-off tests. The effect of the substrate roughness (nm to μm) of these composite surfaces on adhesion was studied by examining the surface free energies and adhesion strengths. The adhesion strengths of the coatings varied significantly. To improve the coating adhesion, each composite surface was treated with atmospheric plasma prior to deposition, which resulted in an increase in the surface free energy from approximately 40 mJ/m 2 to 70 mJ/m 2 because the plasma pretreatment led to the formation of hydrophilic C-O and C=O bonds on the composite surfaces, as demonstrated by X-ray photoelectron spectroscopy analyses. The adhesion strengths of the coatings were enhanced for all surface roughnesses studied. In our study, the effect of mechanical adhesion due to roughness was separated from the effect of modifying the chemical bonds with plasma activation. The adhesion ability of the pure resin was relatively weak. Increasing the surface roughness largely improved the adhesion of the resin surface. Plasma treatment of the pure resin also increased the surface adhesion. Our study shows that plasma activation effectively enhances the adhesion of manufactured composites, even when the surface roughness is on the order of microns. The ageing of the surface activation was also investigated, and the results demonstrate that atmospheric plasma has potential for use in the pretreatment of composite materials.

  11. Impact of metal matrix composite on the evolution and erosion performance characteristics of non lubricated-dry abrasive degradation of ternary composite coating for refineries system

    Science.gov (United States)

    Anawe, Paul Apeye Lucky; Fayomi, Ojo Sunday Isaac

    2018-06-01

    The application of rational design principles and process in electrodeposition can eliminate many engineering catastrophes related to corrosion and micromechanical failure in service. This has led to appreciate the need of surface modification on component for enhance life span. Admixed Zn-30Al-13Ti-chloride composite bath was electrolytically prepared and successfully deposited on UNS G10150 mild steel substrate by zinc dual anode deposition processes within an interval of applied current density, particle concentration and constant time. The codeposition of Zn-Al-Ti coating was studied in the presence of other bath ingredient. The effect of deposition current and particle concentration on structural property, adhesion behaviour, ideal crystal orientation, surface topography and electrochemical properties of Zn-Al-Ti alloy coating series on mild steel were analytically examined. The wear stability of the developed composite materials was examined via sliding reciprocating rig. The structural integrity was examined with scanning electron microscope equipped with EDS, X-ray diffraction; Atomic force microscope, dura scan micro-hardness tester and 3 μ metrohm Potentiostat/galvanostat. Interestingly the induced activity of the Zn-Al-Ti chloride composite alloy results into excellent structural modification and stable crystal precipitation within the structural interface as a result of Zn3Al, Zn2Ti and ZnAl3Ti2 intermetallic phase. The obtained results showed that the introduction of Ti particles in the presence of other bath additive in the plating bath mostly modified the surface and brings an increase in the microhardness, corrosion resistance and reduce wear deformation of Zn-Al-Ti chloride composite alloy.

  12. Emulsion drying synthesis of olivine LiFePO4/C composite and its electrochemical properties as lithium intercalation material

    International Nuclear Information System (INIS)

    Myung, Seung-Taek; Komaba, Shinichi; Hirosaki, Norimitsu; Yashiro, Hitoshi; Kumagai, Naoaki

    2004-01-01

    The electroactive LiFePO 4 /C nano-composite has been synthesized by an emulsion drying method. During burning-out the oily emulsion precipitates in an air-limited atmosphere at 300 deg. C, amorphous or low crystalline carbon was generated along with releasing carbon oxide gases, and trivalent iron as a cheap starting material was immediately reduced to the divalent one at this stage as confirmed by X-ray photoelectron spectroscopy, leading to a low crystalline LiFePO 4 /C composite. Heat-treatment of the low crystalline LiFePO 4 /C in an Ar atmosphere resulted in a well-ordered olivine structure, as refined by Rietveld refinement of the X-ray diffraction pattern. From secondary electron microscopic and scanning transmission electron microscopic observations with the corresponding elemental mapping images of iron and phosphorous, it was found that the LiFePO 4 powders are modified by fine carbon. The in situ formation of the nano-sized carbon during crystallization of LiFePO 4 brought about two advantages: (i) an optimized particle size of LiFePO 4 , and (ii) a uniform distribution of fine carbon in the product. These effects of the fine carbon on LiFePO 4 /C composite led to high capacity retention upon cycling at 25 and 50 deg. C and high rate capability, resulting from a great enhancement of electric conductivity as high as 10 -4 S cm -1 . That is, the obtained capacity was higher than 90 mAh (g-phosphate) -1 by applying a higher current density of about 1000 mA g -1 (11 C) at 50 deg. C

  13. PROXIMATE COMPOSITION AND TECHNOLOGICAL CHARACTERISTICS OF DRY PASTA INCORPORATED WITH MICRONIZED CORN PERICARP

    Directory of Open Access Journals (Sweden)

    JOÃO RENATO DE JESUS JUNQUEIRA

    2017-01-01

    Full Text Available Pastas are generally accepted all over the world, mainly because they are versatile, cheap and easy - to - prepare. They are not nutritionally balanced, since they provide mainly carbohydrates. As a result of this, it is important to use ingredients which could improve the nutritional deficiencies, without affecting the technological and sensorial characteristics. This study evaluated the effect of using wheat semolina and micronized corn pericarp (MCP, on the proximate composition, cooking quality and color of spaghetti type pasta. Spaghetti pasta was produced using wheat semolina with the incorporation of micronized corn pericarp, at levels of 0, 10, 20 and 30%. There were no significant differences (p > 0.05 between the formulated samples with regards to the contents of moisture and lipid, cooking time, weight gain and volume increase. As observed, supplementation with micronized corn pericarp presented significant difference on the contents of proteins, minerals, dietary fiber and solid soluble loss of the spaghetti pasta (p < 0.05. With increase in micronized corn pericarp concentration, the color difference became accentuated. The use of MCP appears to be viable, providing a nutritionally enriched product without further impairment on pasta quality.

  14. Remote compositional mapping of lunar titanium and surface maturity

    Science.gov (United States)

    Johnson, J. R.; Larson, S. M.; Singer, Robert B.

    1991-01-01

    Lunar ilmenite (FeTiO3) is a potential resource capable of providing oxygen for life support and spacecraft propellant for future lunar bases. Estimates of TiO2 content in mature mare soils can be made using an empirical relation between the 400/500 nm reflectance ratio and TiO2 wt percent. A TiO2 abundance map was constructed for the entire near-side lunar maria accurate to + or - 2 wt percent TiO2 using CCD images obtained at the Tumamoc Hill 0.5 m telescope in Tucson, employing bandpass filters centered at 400 and 560 nm. Highest TiO2 regions in the maria are located in western Mare Tranquillitatis. Greater contrast differences between regions on the lunar surface can be obtained using 400/730 nm ratio images. The relation might well be refined to accommodate this possibly more sensitive indicator of TiO2 content. Another potential lunar resource is solar wind-implanted He-3 which may be used as a fuel for fusion reactors. Relative soil maturity, as determined by agglutinate content, can be estimated from 950/560 nm ration images. Immature soils appear darker in this ratio since such soils contain abundant pyroxene grains which cause strong absorption centered near 950 nm due Fe(2+) crystal field transitions. A positive correlation exists between the amount of He-3 and TiO2 content in lunar soils, suggesting that regions high in TiO2 should also be high in He-3. Reflectance spectrophotometry in the region 320 to 870 nm was also obtained for several regions. Below about 340 nm, these spectra show variations in relative reflectance that are caused by as yet unassigned near-UV absorptions due to compositional differences.

  15. Galileo's Multiinstrument Spectral View of Europa's Surface Composition

    Science.gov (United States)

    Fanale, F.P.; Granahan, J.C.; McCord, T.B.; Hansen, G.; Hibbitts, C.A.; Carlson, R.; Matson, D.; Ocampo, A.; Kamp, L.; Smythe, W.; Leader, F.; Mehlman, R.; Greeley, R.; Sullivan, R.; Geissler, P.; Barth, C.; Hendrix, A.; Clark, B.; Helfenstein, P.; Veverka, J.; Belton, M.J.S.; Becker, K.; Becker, T.

    1999-01-01

    We have combined spectral reflectance data from the Solid State Imaging (SSI) experiment, the Near-Infrared Mapping Spectrometer (NIMS), and the Ultraviolet Spectrometer (UVS) in an attempt to determine the composition and implied genesis of non-H2O components in the optical surface of Europa. We have considered four terrains: (1) the "dark terrains" on the trailing hemisphere, (2) the "mottled terrain," (3) the linea on the leading hemisphere, and (4) the linea embedded in the dark terrain on the trailing hemisphere. The darker materials in these terrains exhibit remarkably similar spectra in both the visible and near infrared. In the visible, a downturn toward shorter wavelengths has been attributed to sulfur. The broad concentrations of dark material on the trailing hemisphere was originally thought to be indicative of exogenic sulfur implantation. While an exogenic cause is still probable, more recent observations by the UVS team at higher spatial resolution have led to their suggestions that the role of the bombardment may have primarily been to sputter away overlying ice and to reveal underlying endogenic non-H2O contaminants. If so, this might explain why the spectra in all these terrains are so similar despite the fact that the contaminants in the linea are clearly endogenic and those in the mottled terrain are almost certainly so. In the near infrared, all these terrains exhibit much more asymmetrical bands at 1.4 and 2.0 ??m at shorter wavelengths than spectra from elsewhere on Europa. It has been argued that this is because the water molecules are bound in hydrated salts. However, this interpretation has been challenged and it has also been argued that pure coarse ice can exhibit such asymmetric bands under certain conditions. The nature of this controversy is briefly discussed, as are theoretical and experimental studies bearing on this problem. ?? 1999 Academic Press.

  16. Ability of Shiga toxigenic Escherichia coli to survive within dry-surface biofilms and transfer to fresh lettuce.

    Science.gov (United States)

    Adator, Emelia Hornam; Cheng, Meining; Holley, Rick; McAllister, Tim; Narvaez-Bravo, Claudia

    2018-03-23

    Biofilms are known to play important roles in bacterial survival and persistence in food-processing environments. This study aimed to determine the ability of the top 7 STEC serotypes to form biofilms on polystyrene (POL) and stainless steel (SS) plates and to quantify their survival and transfer from dry-surface biofilms to lettuce pieces. The ability of 14 STEC strains to form biofilms on these two materials at different exposure times and temperatures was assessed using crystal violet, Congo red and SEM. At 10 °C all serotypes were weak biofilm producers on both surfaces. In contrast, serotypes O45-040, O45-445, O103-102, O103-670 and O157-R508 were strong biofilm producers at 25 °C. Strains O103-102, O103-670, O111-CFS, O111-053 and O157:H7-R508 were expressers of curli. Under scanning electron microscopy, strains O103-670, O111-CFS, O157-R508, and O121-083 formed more discernible multilayer, mature biofilms on SS coupons. Regardless of the surface (POL/SS), all STEC strains were able to transfer viable cells onto fresh lettuce within a short contact time (2 min) to varying degrees (up to 6.35 log cfu/g). On POL, viable cell of almost all serotypes exhibited decreased detachment (p = 0.001) over 6 days; while after 30 days on SS, serotypes O45-040, O103-102, O103-670, O111-053, O111-CFS, O121-083, O145-231 O157:H7-R508 and O157:H7-122 were transferred to lettuce. After enrichment, all 14 STEC strains were recovered from dry-surface biofilms on POL and SS plates after 30 days. Results demonstrated that the top 7 STEC remained viable within dry-surface biofilms for at least 30 days, transferring to lettuce within 2 min of exposure and acting as a source of adulteration. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

  17. METHANE DRY REFORMING OVER Ni SUPPORTED ON PINE SAWDUST ACTIVATED CARBON: EFFECTS OF SUPPORT SURFACE PROPERTIES AND METAL LOADING

    Directory of Open Access Journals (Sweden)

    Rafael García

    2015-05-01

    Full Text Available The influence of metal loading and support surface functional groups (SFG on methane dry reforming (MDR over Ni catalysts supported on pine-sawdust derived activated carbon were studied. Using pine sawdust as the catalyst support precursor, the smallest variety and lowest concentration of SFG led to best Ni dispersion and highest catalytic activity, which increased with Ni loading up to 3 Ni atoms nm-2. At higher Ni loading, the formation of large metal aggregates was observed, consistent with a lower "apparen" surface area and a decrease in catalytic activity. The H2/CO ratio rose with increasing reaction temperature, indicating that increasingly important side reactions were taking place in addition to MDR.

  18. Study of surface integrity AISI 4140 as result of hard, dry and high speed machining using CBN

    Science.gov (United States)

    Ginting, B.; Sembiring, R. W.; Manurung, N.

    2017-09-01

    The concept of hard, dry and high speed machining can be combined, to produce high productivity, with lower production costs in manufacturing industry. Hard lathe process can be a solution to reduce production time. In lathe hard alloy steels reported problems relating to the integrity of such surface roughness, residual stress, the white layer and the surface integrity. AISI 4140 material is used for high reliable hydraulic system components. This material includes in cold work tool steel. Consideration election is because this material is able to be hardened up to 55 HRC. In this research, the experimental design using CCD model fit with three factors, each factor is composed of two levels, and six central point, experiments were conducted with 1 replications. The experimental design research using CCD model fit.

  19. An Artificial Turf-Based Surrogate Surface Collector for the Direct Measurement of Atmospheric Mercury Dry Deposition

    Directory of Open Access Journals (Sweden)

    Naima L. Hall

    2017-02-01

    Full Text Available This paper describes the development of a new artificial turf surrogate surface (ATSS sampler for use in the measurement of mercury (Hg dry deposition. In contrast to many existing surrogate surface designs, the ATSS utilizes a three-dimensional deposition surface that may more closely mimic the physical structure of many natural surfaces than traditional flat surrogate surface designs (water, filter, greased Mylar film. The ATSS has been designed to overcome several complicating factors that can impact the integrity of samples with other direct measurement approaches by providing a passive system which can be deployed for both short and extended periods of time (days to weeks, and is not contaminated by precipitation and/or invalidated by strong winds. Performance characteristics including collocated precision, in-field procedural and laboratory blanks were evaluated. The results of these performance evaluations included a mean collocated precision of 9%, low blanks (0.8 ng, high extraction efficiency (97%–103%, and a quantitative matrix spike recovery (100%.

  20. Dry Phosphorus silicate glass etching and surface conditioning and cleaning for multi-crystalline silicon solar cell processing

    International Nuclear Information System (INIS)

    Kagilik, Ahmed S.

    2014-01-01

    As an alternative to the wet chemical etching method, dry chemical etching processes for Phosphorus silicate glass [PSG} layer removal using Trifluormethane/Sulfur Hexafluoride (CHF 3 / SF 6 ) gas mixture in commercial silicon-nitride plasma enhanced chemical vapour deposition (SiN-PECVD) system is applied. The dependence of the solar cell performance on the etching temperature is investigated and optimized. It is found that the SiN-PECVD system temperature variation has a significant impact on the whole solar cell characteristics. A dry plasma cleaning treatment of the Si wafer surface after the PSG removal step is also investigated and developed. The cleaning step is used to remove the polymer film which is formed during the PSG etching using both oxygen and hydrogen gases. By applying an additional cleaning step, the polymer film deposited on the silicon wafer surface after PSG etching is eliminated. The effect of different plasma cleaning conditions on solar cell performance is investigated. After optimization of the plasma operating conditions, the performance of the solar cell is improved and the overall gain in efficiency of 0.6% absolute is yielded compared to a cell without any further cleaning step. On the other hand, the best solar cell characteristics can reach values close to that achieved by the conventional wet chemical etching processes demonstrating the effectiveness of the additional O 2 /H 2 post cleaning treatment.(author)

  1. Molecular dimensions of dried glucose oxidase on a Au(1 1 1) surface studied by dynamic mode scanning force microscopy

    International Nuclear Information System (INIS)

    Otsuka, Ichiro; Yaoita, Masashi; Nagashima, Seiichi; Higano, Michi

    2005-01-01

    We have investigated the molecular dimensions of a dried single glucose oxidase (GO) molecule adsorbed on a Au(1 1 1) surface with the UHV non-contact atomic force microscopy (NC-AFM) and tapping mode atomic force microcopy (TMAFM). The smallest air-dried GO particles in a TMAFM-measured size distribution are found to be 10-11 nm wide and 0.3-0.4 nm high. We find each collapsed ellipsoidal feature with a groove in a NC-AFM image, which measured 12 nm x 10 nm x 0.5 nm. The lateral dimensions (12 nm x 10 nm) of the observed feature is close to those of a GO monomer measured by scanning tunneling microscopy (STM) [Quijin et al., 12.2 nm x 8.9 nm as the size of one wing of an opening butterfly (dimer) appeared in a STM image] and by contact mode AFM [Quinto et al., 14 nm x 8 nm]. Our value of the vertical dimension (0.5 nm) is consistent with AFM results and molecular dynamics simulations that suggest a surface-induced complete unfolding, showing the average diameter of amino acid residues

  2. Top-Down Proteomics and Direct Surface Sampling of Neonatal Dried Blood Spots: Diagnosis of Unknown Hemoglobin Variants

    Science.gov (United States)

    Edwards, Rebecca L.; Griffiths, Paul; Bunch, Josephine; Cooper, Helen J.

    2012-11-01

    We have previously shown that liquid microjunction surface sampling of dried blood spots coupled with high resolution top-down mass spectrometry may be used for screening of common hemoglobin variants HbS, HbC, and HbD. In order to test the robustness of the approach, we have applied the approach to unknown hemoglobin variants. Six neonatal dried blood spot samples that had been identified as variants, but which could not be diagnosed by current screening methods, were analyzed by direct surface sampling top-down mass spectrometry. Both collision-induced dissociation and electron transfer dissociation mass spectrometry were employed. Four of the samples were identified as β-chain variants: two were heterozygous Hb D-Iran, one was heterozygous Hb Headington, and one was heterozygous Hb J-Baltimore. The fifth sample was identified as the α-chain variant heterozygous Hb Phnom Penh. Analysis of the sixth sample suggested that it did not in fact contain a variant. Adoption of the approach in the clinic would require speed in both data collection and interpretation. To address that issue, we have compared manual data analysis with freely available data analysis software (ProsightPTM). The results demonstrate the power of top-down proteomics for hemoglobin variant analysis in newborn samples.

  3. Ocular surface immunity: Homeostatic mechanisms and their disruption in dry eye disease

    OpenAIRE

    Barabino, Stefano; Chen, Yihe; Chauhan, Sunil Kumar; Dana, Reza

    2012-01-01

    The tear film, lacrimal glands, corneal and conjunctival epithelia and Meibomian glands work together as a lacrimal functional unit (LFU) to preserve the integrity and function of the ocular surface. The integrity of this unit is necessary for the health and normal function of the eye and visual system. Nervous connections and systemic hormones are well known factors that maintain the homeostasis of the ocular surface. They control the response to internal and external stimuli. Our and others...

  4. Predicting the surface roughness in the dry machining of duplex stainless steel (DSS

    Directory of Open Access Journals (Sweden)

    G. Krolczyk

    2013-04-01

    Full Text Available This paper examines the influence of cutting parameters, namely cutting speed, feed and depth of cut onto surface roughness after DSS turning process. The study included developing a mathematical model to determine the surface roughness. Verification research has been carried out on CNC lathe; hence the test plan has been adjusted to the possibility of programmable machines controlling GE Fanuc Series 0-T. The comparison of results obtained by given experimental plan was performed in industrial company.

  5. Preparation and Evaluation of Surface Modified Lactose Particles for Improved Performance of Fluticasone Propionate Dry Powder Inhaler.

    Science.gov (United States)

    Singh, Deepak J; Jain, Rajesh R; Soni, P S; Abdul, Samad; Darshana, Hegde; Gaikwad, Rajiv V; Menon, Mala D

    2015-08-01

    Dry powder inhalers (DPI) are generally formulated by mixing micronized drug particles with coarse lactose carrier particles to assist powder handling during the manufacturing and powder aerosol delivery during patient use. In the present study, surface modified lactose (SML) particles were produced using force control agents, and their in vitro performance on dry powder inhaler (DPI) formulation of Fluticasone propionate was studied. With a view to reduce surface passivation of high surface free energy sites on the most commonly used DPI carrier, α- lactose monohydrate, effects of various force control agents such as Pluronic F-68, Cremophor RH 40, glyceryl monostearate, polyethylene glycol 6000, magnesium stearate, and soya lecithin were studied. DPI formulations prepared with SML showed improved flow properties, and atomic force microscopy (AFM) studies revealed decrease in surface roughness. The DSC and X-ray diffraction patterns of SML showed no change in the crystal structure and thermal behavior under the experimental conditions. The fine particle fraction (FPF) values of lactose modified with Pluronic F-68, Cremophor RH 40, glyceryl monostearate were improved, with increase in concentration up to 0.5%. Soya lecithin and PEG 6000 modified lactose showed decrease in FPF value with increase in concentration. Increase in FPF value was observed with increasing concentration of magnesium stearate. Two different DPI devices, Rotahaler(®) and Diskhaler(®), were compared to evaluate the performance of SML formulations. FPF value of all SML formulations were higher using both devices as compared to the same formulations prepared using untreated lactose. One month stability of SML formulations at 40°C/75% RH, in permeable polystyrene tubes did not reveal any significant changes in FPF values. SML particles can help in reducing product development hindrances and improve inhalational properties of DPI.

  6. The Use of Spray-Dried Mn3O4/C Composites as Electrocatalysts for Li–O2 Batteries

    Directory of Open Access Journals (Sweden)

    Hong-Kai Yang

    2016-11-01

    Full Text Available The electrocatalytic activities of Mn3O4/C composites are studied in lithium–oxygen (Li–O2 batteries as cathode catalysts. The Mn3O4/C composites are fabricated using ultrasonic spray pyrolysis (USP with organic surfactants as the carbon sources. The physical and electrochemical performance of the composites is characterized by X-ray diffraction, scanning electron microscopy, particle size analysis, Brunauer–Emmett–Teller (BET measurements, elemental analysis, galvanostatic charge–discharge methods and rotating ring-disk electrode (RRDE measurements. The electrochemical tests demonstrate that the Mn3O4/C composite that is prepared using Trition X-114 (TX114 surfactant has higher activity as a bi-functional catalyst and delivers better oxygen reduction reaction (ORR and oxygen evolution reaction (OER catalytic performance in Li–O2 batteries because there is a larger surface area and particles are homogeneous with a meso/macro porous structure. The rate constant (kf for the production of superoxide radical (O2•− and the propylene carbonate (PC-electrolyte decomposition rate constant (k for M3O4/C and Super P electrodes are measured using RRDE experiments and analysis in the 0.1 M tetrabutylammonium hexafluorophosphate (TBAPF6/PC electrolyte. The results show that TX114 has higher electrocatalytic activity for the first step of ORR to generate O2•− and produces a faster PC-electrolyte decomposition rate.

  7. Influence of surface roughness on streptococcal adhesion forces to composite resins

    NARCIS (Netherlands)

    Mei, Li; Busscher, Henk J; van der Mei, Henny C; Ren, Yijin

    OBJECTIVE: To determine streptococcal adhesion forces with composite resins with different surface roughness. METHODS: Polishing and grinding were applied to obtain smooth (roughness 20 nm), moderately rough (150 nm) and rough (350 nm) surfaces of two orthodontic, light-cured composites. Adhesion

  8. Modeling and Parameter Optimization for Surface Roughness and Residual Stress in Dry Turning Process

    Directory of Open Access Journals (Sweden)

    M. H. El-Axir

    2017-10-01

    Full Text Available The influence of some turning variables and tool overhang on surface roughness parameters and residual stress induced due to machining 6061-T6 aluminum alloy is investigated in this paper. Four input parameters (cutting speed, feed rate, depth of cut and tool overhang are considered. Tests are carried out by precision turning operation on a lathe. Design of experiment techniques, i.e. response surface methodology (RSM and Taguchi's technique have been used to accomplish the objective of the experimental study. Surface roughness parameters are measured using a portable surface roughness device while residual stresses are measured employing deflection-etching technique using electrochemical analysis. The results obtained reveal that feed and rotational speed play significant role in determining the average surface roughness. Furthermore, the depth of cut and tool overhang are less significant parameters, whereas tool overhang interacts with feed rate. The best result of surface roughness was obtained using low or medium values of overhang with low speed and /or feed rate. Minimum maximum tensile residual stress can be obtained with a combination of tool overhang of 37 mm with very low depth of cut, low rotational speed and feed rate of 0.188 mm/rev.

  9. Dry Etch Black Silicon with Low Surface Damage: Effect of Low Capacitively Coupled Plasma Power

    DEFF Research Database (Denmark)

    Iandolo, Beniamino; Plakhotnyuk, Maksym; Gaudig, Maria

    2017-01-01

    Black silicon fabricated by reactive ion etch (RIE) is promising for integration into silicon solar cells thanks to its excellent light trapping ability. However, intensive ion bombardment during the RIE induces surface damage, which results in enhanced surface recombination velocity. Here, we pr...... carrier lifetime thanks to reduced ion energy. Surface passivation using atomic layer deposition of Al2O3 improves the effective lifetime to 7.5 ms and 0.8 ms for black silicon n- and p-type wafers, respectively.......Black silicon fabricated by reactive ion etch (RIE) is promising for integration into silicon solar cells thanks to its excellent light trapping ability. However, intensive ion bombardment during the RIE induces surface damage, which results in enhanced surface recombination velocity. Here, we...... present a RIE optimization leading to reduced surface damage while retaining excellent light trapping and low reflectivity. In particular, we demonstrate that the reduction of the capacitively coupled power during reactive ion etching preserves a reflectance below 1% and improves the effective minority...

  10. Influence of Layup Sequence on the Surface Accuracy of Carbon Fiber Composite Space Mirrors

    Science.gov (United States)

    Yang, Zhiyong; Liu, Qingnian; Zhang, Boming; Xu, Liang; Tang, Zhanwen; Xie, Yongjie

    2018-04-01

    Layup sequence is directly related to stiffness and deformation resistance of the composite space mirror, and error caused by layup sequence can affect the surface precision of composite mirrors evidently. Variation of layup sequence with the same total thickness of composite space mirror changes surface form of the composite mirror, which is the focus of our study. In our research, the influence of varied quasi-isotropic stacking sequences and random angular deviation on the surface accuracy of composite space mirrors was investigated through finite element analyses (FEA). We established a simulation model for the studied concave mirror with 500 mm diameter, essential factors of layup sequences and random angular deviations on different plies were discussed. Five guiding findings were described in this study. Increasing total plies, optimizing stacking sequence and keeping consistency of ply alignment in ply placement are effective to improve surface accuracy of composite mirror.

  11. Visible and Near-IR Reflectance Spectra of Smectite Acquired Under Dry Conditions for Interpretation of Martian Surface Mineralogy

    Science.gov (United States)

    Morris, Richard V.; Achilles, Cherie N; Archer, Paul D.; Graff, Trevor G.; Agresti, David G.; Ming, Douglas W; Golden, Dadi C.; Mertzman, Stanley A.

    2011-01-01

    Visible and near-IR (VNIR) spectra from the MEx OMEGA and the MRO CRISM hyper-spectral imaging instruments have spectral features associated with the H2O molecule and M OH functional groups (M = Mg, Fe, Al, and Si). Mineralogical assignments of martian spectral features are made on the basis of laboratory VNIR spectra, which were often acquired under ambient (humid) conditions. Smectites like nontronite, saponite, and montmorillionite have interlayer H2O that is exchangeable with their environment, and we have acquired smectite reflectance spectra under dry environmental conditions for interpretation of martian surface mineralogy. We also obtained chemical, Moessbauer (MB), powder X-ray diffraction (XRD), and thermogravimetric (TG) data to understand variations in spectral properties. VNIR spectra were recorded in humid lab air at 25-35C, in a dynamic dry N2 atmosphere (50-150 ppmv H2O) after exposing the smectite samples (5 nontronites, 3 montmorillionites, and 1 saponite) to that atmosphere for up to approximately l000 hr each at 25-35C, approximately 105C, and approximately 215C, and after re-exposure to humid lab air. Heating at 105C and 215C for approximately 1000 hr is taken as a surrogate for geologic time scales at lower temperatures. Upon exposure to dry N2, the position and intensity of spectral features associated with M-OH were relatively insensitive to the dry environment, and the spectral features associated with H2O (e.g., approximately 1.90 micrometers) decreased in intensity and are sometimes not detectable by the end of the 215C heating step. The position and intensity of H2O spectral features recovered upon re-exposure to lab air. XRD data show interlayer collapse for the nontronites and Namontmorillionites, with the interlayer remaining collapsed for the latter after re-exposure to lab air. The interlayer did not collapse for the saponite and Ca-montmorillionite. TG data show that the concentration of H2O derived from structural OH was invariant

  12. Effect of Lamina Thickness of Prepreg on the Surface Accuracy of Carbon Fiber Composite Space Mirrors

    Science.gov (United States)

    Yang, Zhiyong; Tang, Zhanwen; Xie, Yongjie; Shi, Hanqiao; Zhang, Boming; Guo, Hongjun

    2018-02-01

    Composite space mirror can completely replicate the high-precision surface of mould by replication process, but the actual surface accuracy of the replication composite mirror always decreases. Lamina thickness of prepreg affects the layers and layup sequence of composite space mirror, and which would affect surface accuracy of space mirror. In our research, two groups of contrasting cases through finite element analyses (FEA) and comparative experiments were studied; the effect of different lamina thicknesses of prepreg and corresponding lay-up sequences was focused as well. We describe a special analysis model, validated process and result analysis. The simulated and measured surface figures both get the same conclusion. Reducing lamina thickness of prepreg used in replicating composite space mirror is propitious to optimal design of layup sequence for fabricating composite mirror, and could improve its surface accuracy.

  13. Influence of polishing on surface roughness following toothbrushing wear of composite resins.

    Science.gov (United States)

    Dalla-Vecchia, Karine Battestin; Taborda, Talita Damas; Stona, Deborah; Pressi, Heloísa; Burnett Júnior, Luiz Henrique; Rodrigues-Junior, Sinval Adalberto

    2017-01-01

    This study aimed to evaluate the influence of different polishing systems on the surface roughness of composite resins following procedures to simulate the effects of toothbrushing over time. Four currently available commercial composites were used to make 128 cylindrical specimens. The specimens were randomly allocated to polishing with a 1-step polisher or 1 of 3 multistep polishers (n = 8 per group). The baseline surface roughness was measured, and the specimens were submitted to 5000, 10,000, and 20,000 brushing cycles to represent toothbrushing throughout 6, 12, and 24 months, respectively. Results showed that surface roughness was influenced by the type of composite and polishing system and was not influenced by the simulated toothbrushing time. However, the surface roughness, as challenged by toothbrushing wear, was affected by the interaction among the composite, the polisher, and the toothbrushing time. The 1-step polisher produced the highest surface roughness and influenced toothbrushing wear resistance of some composites.

  14. Milk yield and composition, dry matter intake and blood parameters of Holstein cows fed ensiled apple pomace co-ensiled with broiler litter

    DEFF Research Database (Denmark)

    Osman Azizi, Osman; Karimi, Shahram; Sadeghi, Ghorbanali

    2014-01-01

    The present study was carried out to evaluate the effects of ensiled mixed apple pomace and broiler litter (EAPBL) on milk yield (MY) and composition, dry matter intake (DMI) and blood parameters at early lactation cow. Four multiparous early-lactating Holstein dairy cows were used in a 4×4 Latin...

  15. Effects of Diets Supplemented with Ensiled Mulberry Leaves and Sun-Dried Mulberry Fruit Pomace on the Ruminal Bacterial and Archaeal Community Composition of Finishing Steers

    NARCIS (Netherlands)

    Niu, Yuhong; Meng, Qingxiang; Li, Shengli; Ren, Liping; Zhou, Bo; Schonewille, Thomas; Zhou, Zhenming

    This study investigated the effects of ensiled mulberry leaves (EML) and sun-dried mulberry fruit pomace (SMFP) on the ruminal bacterial and archaeal community composition of finishing steers. Corn grain- and cotton meal-based concentrate was partially replaced with EML or SMFP. The diets had

  16. Evaluation of Drying Process on the Composition of Black Pepper Ethanolic Extract by High Performance Liquid Chromatography With Diode Array Detector

    Science.gov (United States)

    Namjoyan, Foroogh; Hejazi, Hoda; Ramezani, Zahra

    2012-01-01

    Background Black pepper (Piper nigrum) is one of the well-known spices extensively used worldwide especially in India, and Southeast Asia. The presence of alkaloids in the pepper, namely, piperine and its three stereoisomers, isopiperine, chavicine and isochavicine are well noticed. Objectives The current study evaluated the effect of lyophilization and oven drying on the stability and decomposition of constituents of black pepper ethanolic extract. Materials and Methods In the current study ethanolic extract of black pepper obtained by maceration method was dried using two methods. The effect of freeze and oven drying on the chemical composition of the extract especially piperine and its three isomers were evaluated by HPLC analysis of the ethanolic extract before and after drying processes using diode array detector. The UV Vis spectra of the peaks at piperine retention time before and after each drying methods indicated maximum absorbance at 341.2 nm corresponding to standard piperine. Results The results indicated a decrease in intensity of the chromatogram peaks at approximately all retention times after freeze drying, indicating a few percent loss of piperine and its isomers upon lyophilization. Two impurity peaks were completely removed from the extract. Conclusions In oven dried samples two of the piperine stereoisomers were completely removed from the extract and the intensity of piperine peak was increased. PMID:24624176

  17. Dry Etching of Copper Phthalocyanine Thin Films: Effects on Morphology and Surface Stoichiometry

    Directory of Open Access Journals (Sweden)

    Michael J. Brett

    2012-08-01

    Full Text Available We investigate the evolution of copper phthalocyanine thin films as they are etched with argon plasma. Significant morphological changes occur as a result of the ion bombardment; a planar surface quickly becomes an array of nanopillars which are less than 20 nm in diameter. The changes in morphology are independent of plasma power, which controls the etch rate only. Analysis by X-ray photoelectron spectroscopy shows that surface concentrations of copper and oxygen increase with etch time, while carbon and nitrogen are depleted. Despite these changes in surface stoichiometry, we observe no effect on the work function. The absorbance and X-ray diffraction spectra show no changes other than the peaks diminishing with etch time. These findings have important implications for organic photovoltaic devices which seek nanopillar thin films of metal phthalocyanine materials as an optimal structure.

  18. α-Melanocyte-stimulating hormone ameliorates ocular surface dysfunctions and lesions in a scopolamine-induced dry eye model via PKA-CREB and MEK-Erk pathways

    Science.gov (United States)

    Ru, Yusha; Huang, Yue; Liu, Huijuan; Du, Juan; Meng, Zhu; Dou, Zexia; Liu, Xun; Wei, Rui Hua; Zhang, Yan; Zhao, Shaozhen

    2015-01-01

    Dry eye is a highly prevalent, chronic, and multifactorial disease that compromises quality of life and generates socioeconomic burdens. The pathogenic factors of dry eye disease (DED) include tear secretion abnormalities, tear film instability, and ocular surface inflammation. An effective intervention targeting the pathogenic factors is needed to control this disease. Here we applied α-Melanocyte-stimulating hormone (α-MSH) twice a day to the ocular surface of a scopolamine-induced dry eye rat model. The results showed that α-MSH at different doses ameliorated tear secretion, tear film stability, and corneal integrity, and corrected overexpression of proinflammatory factors, TNF-α, IL-1β, and IFN-γ, in ocular surface of the dry eye rats. Moreover, α-MSH, at 10−4 μg/μl, maintained corneal morphology, inhibited apoptosis, and restored the number and size of conjunctival goblet cells in the dry eye rats. Mechanistically, α-MSH activated both PKA-CREB and MEK-Erk pathways in the dry eye corneas and conjunctivas; pharmacological blockade of either pathway abolished α-MSH’s protective effects, suggesting that both pathways are necessary for α-MSH’s protection under dry eye condition. The peliotropic protective functions and explicit signaling mechanism of α-MSH warrant translation of the α-MSH-containing eye drop into a novel and effective intervention to DED. PMID:26685899

  19. α-Melanocyte-stimulating hormone ameliorates ocular surface dysfunctions and lesions in a scopolamine-induced dry eye model via PKA-CREB and MEK-Erk pathways.

    Science.gov (United States)

    Ru, Yusha; Huang, Yue; Liu, Huijuan; Du, Juan; Meng, Zhu; Dou, Zexia; Liu, Xun; Wei, Rui Hua; Zhang, Yan; Zhao, Shaozhen

    2015-12-21

    Dry eye is a highly prevalent, chronic, and multifactorial disease that compromises quality of life and generates socioeconomic burdens. The pathogenic factors of dry eye disease (DED) include tear secretion abnormalities, tear film instability, and ocular surface inflammation. An effective intervention targeting the pathogenic factors is needed to control this disease. Here we applied α-Melanocyte-stimulating hormone (α-MSH) twice a day to the ocular surface of a scopolamine-induced dry eye rat model. The results showed that α-MSH at different doses ameliorated tear secretion, tear film stability, and corneal integrity, and corrected overexpression of proinflammatory factors, TNF-α, IL-1β, and IFN-γ, in ocular surface of the dry eye rats. Moreover, α-MSH, at 10(-4) μg/μl, maintained corneal morphology, inhibited apoptosis, and restored the number and size of conjunctival goblet cells in the dry eye rats. Mechanistically, α-MSH activated both PKA-CREB and MEK-Erk pathways in the dry eye corneas and conjunctivas; pharmacological blockade of either pathway abolished α-MSH's protective effects, suggesting that both pathways are necessary for α-MSH's protection under dry eye condition. The peliotropic protective functions and explicit signaling mechanism of α-MSH warrant translation of the α-MSH-containing eye drop into a novel and effective intervention to DED.

  20. Structure and coarsening at the surface of a dry three-dimensional aqueous foam.

    Science.gov (United States)

    Roth, A E; Chen, B G; Durian, D J

    2013-12-01

    We utilize total-internal reflection to isolate the two-dimensional surface foam formed at the planar boundary of a three-dimensional sample. The resulting images of surface Plateau borders are consistent with Plateau's laws for a truly two-dimensional foam. Samples are allowed to coarsen into a self-similar scaling state where statistical distributions appear independent of time, except for an overall scale factor. There we find that statistical measures of side number distributions, size-topology correlations, and bubble shapes are all very similar to those for two-dimensional foams. However, the size number distribution is slightly broader, and the shapes are slightly more elongated. A more obvious difference is that T2 processes now include the creation of surface bubbles, due to rearrangement in the bulk, and von Neumann's law is dramatically violated for individual bubbles. But nevertheless, our most striking finding is that von Neumann's law appears to holds on average, namely, the average rate of area change for surface bubbles appears to be proportional to the number of sides minus six, but with individual bubbles showing a wide distribution of deviations from this average behavior.

  1. Allometric relationships for surface area and dry mass of young Norway spruce aboveground organs

    Czech Academy of Sciences Publication Activity Database

    Pokorný, Radek; Tomášková, Ivana

    53 2007, č. 12 (2007), s. 548-554 ISSN 1212-4834 R&D Projects: GA MŽP(CZ) SP/2D1/93/07 Institutional research plan: CEZ:AV0Z60870520 Keywords : allometry * biomass, * Picea abies * sapwood * surface area Subject RIV: GK - Forestry

  2. Potential Groundwater Recharge from the Infiltration of Surface Runoff in Cold and Dry Creeks, Phase 2

    International Nuclear Information System (INIS)

    Waichler, Scott R.

    2005-01-01

    Runoff from Cold and Dry Creeks may provide an important source of groundwater recharge on the Hanford Site. This report presents estimates of total volume and distribution of such recharge from extreme precipitation events. Estimates were derived using a simple approach that combined the Soil Conservation Service curve number runoff method and an exponential-decay channel infiltration model. Fifteen-minute streamflow data from four gaging stations, and hourly precipitation data from one climate station, were used to compute curve numbers and calibrate the infiltration model. All data were from several storms occurring during January 1995. Design storm precipitation depths ranging from 1.6 to 2.7 inches were applied with computed curve numbers to produce total runoff/recharge of 7,700 to 15,900 ac-ft, or approximately 10 times the average annual rate from this recharge source as determined in a previous study. Approximately two-thirds of the simulated recharge occurred in the lower stream reaches contained in the broad alluvial valley that parallels State Highway 240 near the Hanford 200 Area

  3. A Corrected Formulation of the Multilayer Model (MLM) for Inferring Gaseous Dry Deposition to Vegetated Surfaces

    Science.gov (United States)

    Saylor, Rick D.; Wolfe, Glenn M.; Meyers, Tilden P.; Hicks, Bruce B.

    2014-01-01

    The Multilayer Model (MLM) has been used for many years to infer dry deposition fluxes from measured trace species concentrations and standard meteorological measurements for national networks in the U.S., including the U.S. Environmental Protection Agency's Clean Air Status and Trends Network (CASTNet). MLM utilizes a resistance analogy to calculate deposition velocities appropriate for whole vegetative canopies, while employing a multilayer integration to account for vertically varying meteorology, canopy morphology and radiative transfer within the canopy. However, the MLM formulation, as it was originally presented and as it has been subsequently employed, contains a non-physical representation related to the leaf-level quasi-laminar boundary layer resistance that affects the calculation of the total canopy resistance. In this note, the non-physical representation of the canopy resistance as originally formulated in MLM is discussed and a revised, physically consistent, formulation is suggested as a replacement. The revised canopy resistance formulation reduces estimates of HNO3 deposition velocities by as much as 38% during mid-day as compared to values generated by the original formulation. Inferred deposition velocities for SO2 and O3 are not significantly altered by the change in formulation (less than 3%). Inferred deposition loadings of oxidized and total nitrogen from CASTNet data may be reduced by 10-20% and 5-10%, respectively, for the Eastern U. S. when employing the revised formulation of MLM as compared to the original formulation.

  4. Potential Groundwater Recharge from the Infiltration of Surface Runoff in Cold and Dry Creeks, Phase 2

    Energy Technology Data Exchange (ETDEWEB)

    Waichler, Scott R.

    2005-12-13

    Runoff from Cold and Dry Creeks may provide an important source of groundwater recharge on the Hanford Site. This report presents estimates of total volume and distribution of such recharge from extreme precipitation events. Estimates were derived using a simple approach that combined the Soil Conservation Service curve number runoff method and an exponential-decay channel infiltration model. Fifteen-minute streamflow data from four gaging stations, and hourly precipitation data from one climate station, were used to compute curve numbers and calibrate the infiltration model. All data were from several storms occurring during January 1995. Design storm precipitation depths ranging from 1.6 to 2.7 inches were applied with computed curve numbers to produce total runoff/recharge of 7,700 to 15,900 ac-ft, or approximately 10 times the average annual rate from this recharge source as determined in a previous study. Approximately two-thirds of the simulated recharge occurred in the lower stream reaches contained in the broad alluvial valley that parallels State Highway 240 near the Hanford 200 Area.

  5. Shear-bond-strength of orthodontic brackets to aged nano-hybrid composite-resin surfaces using different surface preparation.

    Science.gov (United States)

    Demirtas, Hatice Kubra; Akin, Mehmet; Ileri, Zehra; Basciftci, Faruk Ayhan

    2015-01-01

    The aim of this study was to evaluate the effects of different surface preparation methods on the shear bond strength (SBS) of orthodontic metal brackets to aged nano-hybrid resin composite surfaces in vitro. A total of 100 restorative composite resin discs, 6 mm in diameter and 3 mm thick, were obtained and treated with an ageing procedure. After ageing, the samples were randomly divided as follows according to surface preparation methods: (1)Control, (2)37% phosphoric acid gel, (3)Sandblasting, (4)Diamond bur, (5)Air-flow and 20 central incisor teeth were used for the control etched group. SBS test were applied on bonded metal brackets to all samples. SBS values and residual adhesives were evaluated. Analysis of variance showed a significant difference (porthodontic metal brackets to nano-hybrid composite resin surfaces.

  6. Humidity Sensing Properties of Surface Modified Polyaniline Metal Oxide Composites

    Directory of Open Access Journals (Sweden)

    S. C. Nagaraju

    2014-01-01

    Full Text Available Polyaniline- (PANI praseodymium Oxide (Pr2O3 composites have been synthesized by in situ polymerization method with different weight percentages. The synthesized composites have been characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The temperature dependent conductivity shows that the conductivity is due to the hopping of polarons and bipolarons. These composites show negative thermal coefficient (α behavior as a function of temperature, which is characteristic behavior of semiconducting materials. Sensor studies have been carried out by two-probe method and found that the sensitivity increases with increase in % RH. It is noticed that stability increase is due to the presence of Pr2O3 in polyaniline up to 30 wt%. A fast recovery and response time along with high sensitivity make these composites suitable for humidity sensors.

  7. DFT study on dry reforming of methane over Ni2Fe overlayer of Ni(1 1 1) surface

    Science.gov (United States)

    Xu, Li-li; Wen, Hong; Jin, Xin; Bing, Qi-ming; Liu, Jing-yao

    2018-06-01

    We reported the complete catalytic cycle of dry reforming of methane (DRM) on Ni2Fe overlayer of Ni(1 1 1) surface by periodic density functional theory (DFT) calculations. The pathways for dehydrogenation of CH4 and CO2 activation were located. Our results demonstrate that compared with pure Ni(1 1 1) surface, the introduction Fe into Ni increases the energy barrier of CH dissociation to carbon and hydrogen atoms, thereby suppressing coke deposition on the surface, while it promotes the H-induced CO2 activation pathway to form OH radical, and thus not only the surface oxygen but also OH are responsible for the oxidation of CHx (x = 0,1) on the Ni2Fe overlayer. The most favorable pathway of CH/C oxidation is found to be CH∗ + OH∗ → CHOH∗ → CHO∗ + H∗ → CO∗ + 2H∗, with the rate-limiting energy barrier of 1.12 eV. Furthermore, since Fe is oxidized partially to FeO leading to a partial dealloying under DRM conditions, we also studied the surface-carbon removal and the activity for the reforming of methane on the FeO ribbon supported Ni(1 1 1) (FeO/Ni) interface by DFT+U method. The surface C reacts with lattice oxygen of FeO to produce CO via a Mars-van Krevelen (MvK) mechanism, with a very lower energy barrier of 0.16 eV. The present results show that the introduction of Fe into Ni has a positive effect on the activity toward DRM and has an improved coke resistance.

  8. Stick-Jump (SJ) Evaporation of Strongly Pinned Nanoliter Volume Sessile Water Droplets on Quick Drying, Micropatterned Surfaces.

    Science.gov (United States)

    Debuisson, Damien; Merlen, Alain; Senez, Vincent; Arscott, Steve

    2016-03-22

    We present an experimental study of stick-jump (SJ) evaporation of strongly pinned nanoliter volume sessile water droplets drying on micropatterned surfaces. The evaporation is studied on surfaces composed of photolithographically micropatterned negative photoresist (SU-8). The micropatterning of the SU-8 enables circular, smooth, trough-like features to be formed which causes a very strong pinning of the three phase (liquid-vapor-solid) contact line of an evaporating droplet. This is ideal for studying SJ evaporation as it contains sequential constant contact radius (CCR) evaporation phases during droplet evaporation. The evaporation was studied in nonconfined conditions, and forced convection was not used. Micropatterned concentric circles were defined having an initial radius of 1000 μm decreasing by a spacing ranging from 500 to 50 μm. The droplet evaporates, successively pinning and depinning from circle to circle. For each pinning radius, the droplet contact angle and volume are observed to decrease quasi-linearly with time. The experimental average evaporation rates were found to decrease with decreasing pining radii. In contrast, the experimental average evaporation flux is found to increase with decreasing droplet radii. The data also demonstrate the influence of the initial contact angle on evaporation rate and flux. The data indicate that the total evaporation time of a droplet depends on the specific micropattern spacing and that the total evaporation time on micropatterned surfaces is always less than on flat, homogeneous surfaces. Although the surface patterning is observed to have little effect on the average droplet flux-indicating that the underlying evaporation physics is not significantly changed by the patterning-the total evaporation time is considerably modified by patterning, up to a factor or almost 2 compared to evaporation on a flat, homogeneous surface. The closely spaced concentric circle pinning maintains a large droplet radius and

  9. Self-assembling peptide detergents stabilize isolated photosystem I on a dry surface for an extended time.

    Directory of Open Access Journals (Sweden)

    Patrick Kiley

    2005-07-01

    Full Text Available We used a class of designed peptide detergents to stabilize photosystem I (PS-I upon extended drying under N2 on a gold-coated-Ni-NTA glass surface. PS-I is a chlorophyll-containing membrane protein complex that is the primary reducer of ferredoxin and the electron acceptor of plastocyanin. We isolated the complex from the thylakoids of spinach chloroplasts using a chemical detergent. The chlorophyll molecules associated with the PS-I complex provide an intrinsic steady-state emission spectrum between 650 and 800 nm at -196.15 degrees C that reflects the organization of the pigment-protein interactions. In the absence of detergents, a large blue shift of the fluorescence maxima from approximately 735 nm to approximately 685 nm indicates a disruption in light-harvesting subunit organization, thus revealing chlorophyll-protein interactions. The commonly used membrane protein-stabilizing detergents, N-dodecyl-beta-D-maltoside and N-octyl-beta-D-glucoside, only partially stabilized the approximately 735-nm complex with approximately 685-nm spectroscopic shift. However, prior to drying, addition of the peptide detergent acetyl-AAAAAAK at increasing concentration significantly stabilized the PS-I complex. Moreover, in the presence of acetyl-AAAAAAK, the PS-I complex is stable in a dried form at room temperature for at least 3 wk. Another peptide detergent, acetyl-VVVVVVD, also stabilized the complex but to a lesser extent. These observations suggest that the peptide detergents may effectively stabilize membrane proteins in the solid-state. These designed peptide detergents may facilitate the study of diverse types of membrane proteins.

  10. Corneal sensitivity, ocular surface health and tear film stability after punctal plug therapy of aqueous deficient dry eye

    Directory of Open Access Journals (Sweden)

    Azza Mohamed Ahmed Said

    2016-11-01

    Full Text Available AIM: To evaluate the effect of punctal occlusion using thermosensitive (smart plug versus silicone plug for management of aqueous deficient dry eye on corneal sensitivity, ocular surface health and tear film stability. METHODS: A comparative prospective interventional case study included 45 patients with bilateral severe form of aqueous deficient dry eye. In each patient, the smart plug was inserted in the lower punctum of the right eye which was considered as study group 1 and silicone plug was inserted in the lower punctum of the left eye of the same patient which was considered as study group 2. All patients were subjected to careful history taking and questionnaire for subjective assessment of severity of symptoms. Corneal sensitivity, corneal fluorescein, rose bengal staining, Schirmer’s I test, tear film break up time and conjunctival impression cytology were performed pre and 1, 3 and 6mo post plug insertion. RESULTS: A statistically significant improvement in subjective and objective manifestations occurred following treatment with both types of plugs (P<0.01. The thermosensitive plug caused significant overall improvement, decrease in frequency of application of tear substitutes and improvement of conjunctival impression cytology parameters in the inserted side (P<0.01. Canaliculitis was reported in two eyes (4.4% following punctal occlusion using thermosensitive plug (study group 1. Spontaneous plug loss occurred in 21 eyes (46.6% in the silicone plug group (study group 2. CONCLUSION: Improvement of subjective and objective manifestations of aqueous deficient dry eye occurs following punctal plug occlusion. Thermosensitive plug has good patient's compliance with fewer complications and lower rates of loss compared to the silicone plug.

  11. Effect of dry mycelium of Penicillium chrysogenum fertilizer on soil microbial community composition, enzyme activities and snap bean growth.

    Science.gov (United States)

    Wang, Bing; Liu, Huiling; Cai, Chen; Thabit, Mohamed; Wang, Pu; Li, Guomin; Duan, Ziheng

    2016-10-01

    The dry mycelium fertilizer (DMF) was produced from penicillin fermentation fungi mycelium (PFFM) following an acid-heating pretreatment to degrade the residual penicillin. In this study, it was applied into soil as fertilizer to investigate its effects on soil properties, phytotoxicity, microbial community composition, enzyme activities, and growth of snap bean in greenhouse. As the results show, pH, total nitrogen, total phosphorus, total potassium, and organic matter of soil with DMF treatments were generally higher than CON treatment. In addition, the applied DMF did not cause heavy metal and residual drug pollution of the modified soil. The lowest GI values (<0.3) were recorded at DMF8 (36 kg DMF/plat) on the first days after applying the fertilizer, indicating that severe phytotoxicity appeared in the DMF8-modified soil. Results of microbial population and enzyme activities illustrated that DMF was rapidly decomposed and the decomposition process significantly affected microbial growth and enzyme activities. The DMF-modified soil phytotoxicity decreased at the late fertilization time. DMF1 was considered as the optimum amount of DMF dose based on principal component analysis scores. Plant height and plant yield of snap bean were remarkably enhanced with the optimum DMF dose.

  12. Ozone production using a power modulated surface dielectric barrier discharge in dry synthetic air

    Czech Academy of Sciences Publication Activity Database

    Šimek, Milan; Pekárek, S.; Prukner, Václav

    2012-01-01

    Roč. 32, č. 4 (2012), s. 743-754 ISSN 0272-4324 R&D Projects: GA ČR(CZ) GA202/09/0176 Institutional research plan: CEZ:AV0Z20430508 Keywords : ozone * surface DBD * synthetic air * nitrogen oxides * production efficiency Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.728, year: 2012 http://www.springerlink.com/content/h7p1j46381150510/fulltext.pdf

  13. [Effect of thermal cycling on surface microstructure of different light-curing composite resins].

    Science.gov (United States)

    Lv, Da; Liu, Kai-Lei; Yao, Yao; Zhang, Wei-Sheng; Liao, Chu-Hong; Jiang, Hong

    2015-04-01

    To evaluate the effect of thermal cycling on surface microstructure of different light-curing composite resins. A nanofilled composite (Z350) and 4 microhybrid composites (P60, Z250, Spectrum, and AP-X) were fabricated from lateral to center to form cubic specimens. The lateral surfaces were abrased and polished before water storage and 40 000 thermal cycles (5/55 degrees celsius;). The mean surface roughness (Ra) were measured and compared before and after thermal cycling, and the changes of microstructure were observed under scanning electron microscope (SEM). Significant decreases of Ra were observed in the composites, especially in Spectrum (from 0.164±0.024 µm to 0.140±0.017 µm, Presins, and fissures occurred on Z350 following the thermal cycling. Water storage and thermal cycling may produce polishing effect on composite resins and cause fissures on nanofilled composite resins.

  14. Surface coatings of unsaturated polyester resin Kamper wood (Dry obalan ops spp.) by using UV radiation

    International Nuclear Information System (INIS)

    Sugiarto Danu; Yusuf Sudo Hadi; Novi Eka Putri

    1999-01-01

    Kamper wood (Dryobalanops spp.) has high contribution in wood working industry and most of them need surface coating process. Radiation curing of surface coating, especially the use of ultra-violet (UV) light have potential to give contribution in the wood finishing. The experiment on surface coating of kamper wood has been conducted by using UV-radiation. Unsaturated polyester resin with the commercial name of Yucalac type 157 was used as coating materials after being added with styrene monomer, some fillers and radical photoinitiator of 2-hydroxy-2-2-methyl-l- phenyl propanone. Four photoinitiator concentration levels of 1.5 ; 2 ; 2.5 and 3 % by weight of resin were used. The coating materials were coated onto the wood panel samples by using high pressure sprayer. The wood samples were then exposed to irradiation by using 80 Watts/cm UV-source with variable conveyor speed of 3 ; 4 ; 5 and 5.8 m/min. Formulation of coating materials, pendulum hardness, adhesion, and gloss of cured films were evaluated

  15. Surface roughness comparison of methacrylate and silorane-based composite resins after 40% hydrogen peroxide application

    Directory of Open Access Journals (Sweden)

    Rori Sasmita

    2018-01-01

    Full Text Available The change of the tooth colour could be restored with bleaching. The tooth bleaching will affects the surface roughness of the composite resins. Recently, the material basis for composite resins has developed, among others are methacrylate-based and silorane based composite resins. The objective of this study was to distinguish the surface roughness value of methacrylate-based composite resin and silorane based composite resins. This research was quasi-experimental. The sample used in this study were methacrylate and silorane based composite resins in discs form, with the size of 6 mm and the thickness of 3 mm, manufactured into 20 specimens and divided into 2 groups. The control group was immersed in the artificial saliva, and the treatment group was applied with 40% hydrogen peroxide. The result of the experiment analyzed using unpaired sample t-test showed significant differences in the average value of the surface roughness after the application of 40% hydrogen peroxide. The average value of methacrylate and silorane based composite resins were 2.744 μm and 3.417 μm, respectively. There was a difference in the surface roughness of methacrylate and silorane based composite resin compounds after the application of 40% hydrogen peroxide. The surface roughness value of the silorane-based composite resin was higher than the methacrylate-based.

  16. Behavior of aircraft antiskid braking systems on dry and wet runway surfaces - A velocity-rate-controlled, pressure-bias-modulated system

    Science.gov (United States)

    Stubbs, S. M.; Tanner, J. A.

    1976-01-01

    During maximum braking the average ratio of drag-force friction coefficient developed by the antiskid system to maximum drag-force friction coefficient available at the tire/runway interface was higher on dry surfaces than on wet surfaces. The gross stopping power generated by the brake system on the dry surface was more than twice that obtained on the wet surfaces. With maximum braking applied, the average ratio of side-force friction coefficient developed by the tire under antiskid control to maximum side-force friction available at the tire/runway interface of a free-rolling yawed tire was shown to decrease with increasing yaw angle. Braking reduced the side-force friction coefficient on a dry surface by 75 percent as the wheel slip ratio was increased to 0.3; on a flooded surface the coefficient dropped to near zero for the same slip ratio. Locked wheel skids were observed when the tire encountered a runway surface transition from dry to flooded, due in part to the response time required for the system to sense abrupt changes in the runway friction; however, the antiskid system quickly responded by reducing brake pressure and cycling normally during the remainder of the run on the flooded surface.

  17. Changes in soil water availability in vineyards can be traced by the carbon and nitrogen isotope composition of dried wines.

    Science.gov (United States)

    Spangenberg, Jorge E; Zufferey, Vivian

    2018-04-13

    The grapevine is one of the most important edible fruit plants cultivated worldwide, and it is highly sensitive to changes in the soil water content. We studied the total carbon and nitrogen contents and stable isotope compositions (C/N WSR , δ 13 C WSR and δ 15 N WSR values) of the solid residues obtained by freeze-drying wines produced from two white grapevine cultivars (Vitis vinifera L. cv Chasselas and Petite Arvine) field grown under different soil water regimes while maintaining other climatic and ecopedological conditions identical. These experiments simulated the more frequent and extended climate change-induced periods of soil water shortage. The wines were from the 2009-2014 vintages, produced using the same vinification procedure. The plant water status, reflecting soil water availability, was assessed by the predawn leaf water potential (Ψ pd ), monitored in the field during the growing seasons. For both wine varieties, the δ 13 C WSR values are highly correlated with Ψ pd values and record the soil water availability set by soil water holding capacity, rainfall and irrigation water supply. These relationships were the same as those observed for the carbon isotope composition of fruit sugars (i.e., must sugars) and plant water status. In Chasselas wines, the nitrogen content and δ 15 N WSR values decreased with soil water deficit, indicating control of the flux of soil-water soluble nutrients into plants by soil water availability. Such a correlation was not found for Petite Arvine, probably due to different N-metabolism processes in this genetically atypical cultivar. The results presented in this study confirm and generalize what was previously found for red wine (Pinot noir); the carbon isotope composition of wine solid residues is a reliable indicator of the soil and the plant water status and thus can be used to trace back local climatic conditions in the vineyard's region. In most wines (except Petite Arvine) the C/N WSR and δ 15 N WSR

  18. Thermal performance enhancement of erythritol/carbon foam composites via surface modification of carbon foam

    Science.gov (United States)

    Li, Junfeng; Lu, Wu; Luo, Zhengping; Zeng, Yibing

    2017-03-01

    The thermal performance of the erythritol/carbon foam composites, including thermal diffusivity, thermal capacity, thermal conductivity and latent heat, were investigated via surface modification of carbon foam using hydrogen peroxide as oxider. It was found that the surface modification enhanced the wetting ability of carbon foam surface to the liquid erythritol of the carbon foam surface and promoted the increase of erythritol content in the erythritol/carbon foam composites. The dense interfaces were formed between erythritol and carbon foam, which is due to that the formation of oxygen functional groups C=O and C-OH on the carbon surface increased the surface polarity and reduced the interface resistance of carbon foam surface to the liquid erythritol. The latent heat of the erythritol/carbon foam composites increased from 202.0 to 217.2 J/g through surface modification of carbon foam. The thermal conductivity of the erythritol/carbon foam composite before and after surface modification further increased from 40.35 to 51.05 W/(m·K). The supercooling degree of erythritol also had a large decrease from 97 to 54 °C. Additionally, the simple and effective surface modification method of carbon foam provided an extendable way to enhance the thermal performances of the composites composed of carbon foams and PCMs.

  19. A comparison study of the nutritional, mineral and volatile compositions of three dry forms of ginger rhizomes, and antioxidant properties of their ethanolic and aqueous extracts

    Directory of Open Access Journals (Sweden)

    Aicha Jelled

    2017-02-01

    Full Text Available Objective: To compare the most accessible dry forms of ginger rhizomes (Zingiber officinale used as a spice and as a remedy in order to choose the best ginger for medicinal purpose. Methods: Freshly air dried ginger, commercially dry rhizomes and ginger available in powder form are investigated in terms of nutritional values (proximate and mineral compositions and volatiles profile. Ethanolic and aqueous extracts (decoctions and infusions were prepared for total phenolic, flavonoid and tannin contents determination. Also, three standard tests were established in order to estimate the best extract with the better antioxidant potential. Results: The results showed unlike proximate composition revealing different nutritional values. In fact, freshly dried ginger contained much ash, while already dry samples contained much protein. In addition, mineral contents of studied samples indicated their dissimilar richness especially in Ca, Mg, Na, K, Cu, Fe, and Mn. Solid phase micro-extraction gave volatile profiles with many interesting compounds, only 26 from the 51 identified components were common to studied samples with bioactive compounds predominance in freshly dried sample. Also, the antioxidant potential established by three different tests was higher in already dry samples and was positively correlated with their higher contents in the determined phytochemicals. The ethanolic extracts showed higher antioxidant activities than aqueous extracts. Decoctions and infusions were almost similar proving that long cooking time did not affect ginger antioxidant potential. Conclusions: This work highlighted the benefits of traditional preparations of ginger as sources of bioactive compounds, namely antioxidants, and proved that the available commercial samples are not identical and encouraged analyzing samples before uses depending on needs.

  20. Development of a High Efficiency Dry Powder Inhaler: Effects of Capsule Chamber Design and Inhaler Surface Modifications

    Science.gov (United States)

    Behara, Srinivas R.B.; Farkas, Dale R.; Hindle, Michael; Longest, P. Worth

    2013-01-01

    Purpose The objective of this study was to explore the performance of a high efficiency dry powder inhaler (DPI) intended for excipient enhanced growth (EEG) aerosol delivery based on changes to the capsule orientation and surface modifications of the capsule and device. Methods DPIs were constructed by combining newly designed capsule chambers (CC) with a previously developed three-dimensional (3D) rod array for particle deagglomeration and a previously optimized EEG formulation. The new CCs oriented the capsule perpendicular to the incoming airflow and were analyzed for different air inlets at a constant pressure drop across the device. Modifications to the inhaler and capsule surfaces included use of metal dispersion rods and surface coatings. Aerosolization performance of the new DPIs was evaluated and compared with commercial devices. Results The proposed capsule orientation and motion pattern increased capsule vibrational frequency and reduced the aerosol MMAD compared with commercial/modified DPIs. The use of metal rods in the 3D array further improved inhaler performance. Coating the inhaler and capsule with PTFE significantly increased emitted dose (ED) from the optimized DPI. Conclusions High efficiency performance is achieved for EEG delivery with the optimized DPI device and formulation combination producing an aerosol with MMAD 90%, and ED > 80%. PMID:23949304

  1. Development of a high efficiency dry powder inhaler: effects of capsule chamber design and inhaler surface modifications.

    Science.gov (United States)

    Behara, Srinivas R B; Farkas, Dale R; Hindle, Michael; Longest, P Worth

    2014-02-01

    The objective of this study was to explore the performance of a high efficiency dry powder inhaler (DPI) intended for excipient enhanced growth (EEG) aerosol delivery based on changes to the capsule orientation and surface modifications of the capsule and device. DPIs were constructed by combining newly designed capsule chambers (CC) with a previously developed three-dimensional (3D) rod array for particle deagglomeration and a previously optimized EEG formulation. The new CCs oriented the capsule perpendicular to the incoming airflow and were analyzed for different air inlets at a constant pressure drop across the device. Modifications to the inhaler and capsule surfaces included use of metal dispersion rods and surface coatings. Aerosolization performance of the new DPIs was evaluated and compared with commercial devices. The proposed capsule orientation and motion pattern increased capsule vibrational frequency and reduced the aerosol MMAD compared with commercial/modified DPIs. The use of metal rods in the 3D array further improved inhaler performance. Coating the inhaler and capsule with PTFE significantly increased emitted dose (ED) from the optimized DPI. High efficiency performance is achieved for EEG delivery with the optimized DPI device and formulation combination producing an aerosol with MMAD  90%, and ED > 80%.

  2. Selected chemical composition changes in microwave-convective dried parsley leaves affected by ultrasound and steaming pre-treatments - An optimization approach.

    Science.gov (United States)

    Dadan, Magdalena; Rybak, Katarzyna; Wiktor, Artur; Nowacka, Malgorzata; Zubernik, Joanna; Witrowa-Rajchert, Dorota

    2018-01-15

    Parsley leaves contain a high amount of bioactive components (especially lutein), therefore it is crucial to select the most appropriate pre-treatment and drying conditions, in order to obtain high quality of dried leaves, which was the aim of this study. The optimization was done using response surface methodology (RSM) for the following factors: microwave power (100, 200, 300W), air temperature (20, 30, 40°C) and pre-treatment variant (ultrasound, steaming and dipping as a control). Total phenolic content (TPC), antioxidant activity, chlorophyll and lutein contents (using UPLC-PDA) were determined in dried leaves. The analysed responses were dependent on the applied drying parameters and the pre-treatment type. The possibility of ultrasound and steam treatment application was proven and the optimal processing conditions were selected. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Relationships between surface coverage ratio and powder mechanics of binary adhesive mixtures for dry powder inhalers.

    Science.gov (United States)

    Rudén, Jonas; Frenning, Göran; Bramer, Tobias; Thalberg, Kyrre; Alderborn, Göran

    2018-04-25

    The aim of this paper was to study relationships between the content of fine particles and the powder mechanics of binary adhesive mixtures and link these relationships to the blend state. Mixtures with increasing amounts of fine particles (increasing surface coverage ratios (SCR)) were prepared using Lactopress SD as carrier and micro particles of lactose as fines (2.7 µm). Indicators of unsettled bulk density, compressibility and flowability were derived and the blend state was visually examined by imaging. The powder properties studied showed relationships to the SCR characterised by stages. At low SCR, the fine particles predominantly gathered in cavities of the carriers, giving increased bulk density and unchanged or improved flow. Thereafter, increased SCR gave a deposition of particles at the enveloped carrier surface with a gradually more irregular adhesion layer leading to a reduced bulk density and a step-wise reduced flowability. The mechanics of the mixtures at a certain stage were dependent on the structure and the dynamics of the adhesion layer and transitions between the stages were controlled by the evolution of the adhesion layer. It is advisable to use techniques based on different types of flow in order to comprehensively study the mechanics of adhesive mixtures. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Optimization of a lignite-fired open pulverizing system boiler process based on variations in the drying agent composition

    International Nuclear Information System (INIS)

    Ma, Youfu; Zhang, Hua; Yuan, Yichao; Wang, Zhiyun

    2015-01-01

    This paper evaluates three lignite-fired OPSB (open pulverizing system boiler) processes, named OPSB-A, OPSB-B and OPSB-C, corresponding to three options of drying agents used for the pulverizing systems. OPSB-B is similar to our previous work [18] on drying agent composition. Performances of the three OPSBs were calculated and compared with a 600 MW lignite-fired boiler as the reference. The results showed that the coal savings of OPSB-A and OPSB-C were 5.41% and 4.06% in comparison with the reference boiler, whereas for OPSB-B, the savings was 2.57%. Accordingly, emissions of each OPSB could be reduced in proportion to the coal savings. Among the three OPSBs, OPSB-C showed the best performance of water recovery from mill-exhausts because it had the highest mill-exhaust water dew point of 73.2 °C, whereas the exhaust dew points of OPSB-A and OPSB-B were 63.9 °C and 70.9 °C, respectively. Both OPSB-C and OPSB-B are beneficial for achieving a high mill-exhaust humidity ratio, which facilitates water recovery from the mill-exhaust, and a low oxygen content in mill-exhaust, which improves the operating safety of the pulverizing systems, whereas OPSB-A is relatively inferior in these respects. The OPSB-C process is recommended for engineering applications because of its favorable overall performances. - Highlights: • Three lignite-fired OPSB processes are analyzed based on a conventional 600 MW boiler. • OPSB-A, OPSB-B and OPSB-C show coal savings of 5.41%, 2.57 and 4.06%, respectively. • All OPSBs have a great advantage of water recovery from the flue gas, especially OPSB-C. • OPSB-C process is recommended in view of its favorable overall performances

  5. Dried artichoke bracts in rabbits nutrition: effects on the carcass characteristics, meat quality and fatty-acid composition.

    Science.gov (United States)

    Dabbou, S; Gasco, L; Gai, F; Zoccarato, I; Rotolo, L; Dabbou Fekih, S; Brugiapaglia, A; Helal, A N; Peiretti, P G

    2014-09-01

    In this study, the effects of the inclusion of artichoke bracts (AB) in rabbit diets on the carcass characteristics and rabbit meat quality were studied. A total of 120 rabbits aged 38 days were used and divided into three groups that were fed with different isonitrogenous and isocaloric diets supplemented with AB at 0%, 5% and 10%. The animals were single housed in wire cages at a temperature of 22±2°C and had free access to clean drinking water. At 96 days of age, 12 rabbits/group were slaughtered in an experimental slaughterhouse without fasting. The carcass was weighed and the weights of the skin and full gastrointestinal tract were recorded. Carcasses were chilled at +4°C for 24 h in a refrigerated room. The chilled carcass weight (CCW), dressing out percentage (CCW as percentage of slaughter weight), and the ratio of the head and liver were determined as a percentage of CCW. The reference carcass weight was also calculated. Carcasses were halved and the two longissimus dorsi (LD) muscles were excised. The left LD muscle was divided into two parts. The fore part was used to measure pH, colour and cooking losses. The hind part of the left LD was vacuum-packed, frozen at -20°C and then freeze-dried. Proximate composition, fatty-acid profile and thiobarbituric acid-reactive substances values were determined on freeze-dried samples. Results showed that carcass characteristics, LD muscle traits and its oxidative status were not affected by the AB supplementation, except for the meat ether extract content that increased from 0.68% to 0.94% on fresh matter basis with the increase of the AB supplementation (P<0.01). The α-linolenic acid proportion decreased with the increase of the AB supplementation from 3.58% to 2.59% in the LD muscle and from 4.74% to 3.62% in the perirenal fat, whereas the n-6/n-3 ratio increased significantly with increasing AB inclusion from 7.15 to 10.20 in the LD muscle and from 6.68 to 9.35 in the perirenal fat (P<0.01). Furthermore, no

  6. Increasing surface albedo in the dry subtropical forests of South America: the role of agriculture expansion and management

    Science.gov (United States)

    Houspanossian, J.; Kuppel, S.; Gimenez, R.; Jobbagy, E. G.; Nosetto, M. D.

    2014-12-01

    The increase in surface albedo inherent to land clearing and cultivation (land-cover change, LCC) in the subtropical dry forests of the South American Chaco offsets part of the radiative forcing (RF) of the related carbon emissions. The magnitude of these albedo changes, however, is also dependent on shifts in agricultural practices (land-management change, LMC) and will influence the net effect on Earth's radiation balance as well as other potential feedbacks on climate. We quantified the surface albedo changes between 2001 and 2013 and the consequent shifts in the radiation balance resulting from LCC and LMC, using MODIS imagery a columnar radiation model parameterized with satellite data. Agricultural systems replacing dry forests presented a large variety of managements, ranging from pasture systems with remnant trees to different grain crops, displaying a wide range of phenologies. Cultivated lands showed higher and more variable albedo values (mean = 0.162, Standard Deviation = 0.013, n = 10,000 pixels) than the dry forests they replace (mean = 0.113, SD = 0.010, n = 10,000). These albedo contrasts resulted in a cooling RF of deforestation of -10.1 W m-2 on average, but both livestock and grain crop production systems showed large differences among the different land management options. For instance, livestock systems based on open pasture lands showed higher albedo change and RF (0.06 and -16.3 W m-2, respectively) than silvopastoral systems (0.02 and -4.4 W m-2). Similarly in cropping systems, the replacement of double-cropping by single summer crops, a widespread process in the region lately, resulted in higher albedo change (0.06 vs. 0.08) and RF (-16.3 vs. -22.3 W m-2). Although the effects of LCC on climate are widely acknowledged, those of LMC are still scarcely understood. In the Chaco region, the latter could play an important role and offer a yet-overlooked pathway to influence the radiative balance of our planet.

  7. Quantitative morphological and compositional evaluation of laboratory prepared aluminoborosilicate glass surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Yuxuan, E-mail: yg4@alfred.edu; Wren, Anthony W.; Mellott, Nathan P.

    2015-01-01

    Graphical abstract: - Highlights: • Aluminoborosilicate glass surfaces were prepared through both melting and polishing/etching and the surface composition and morphology were quantified as a function of processing method. • Glass surface morphology was quantified using PSD analysis, followed by both fractal and ABC model fitting, resulting in a comprehensive description of the spatial distribution of roughness. • All melt surfaces showed a depletion in Na, Ca, and B with respect to the bulk composition. Polished/etched surfaces showed a depletion in Na, B, and Al with respect to the bulk composition. • It was found that increasing heat treatment temperature of melt surfaces lead to a decrease in equivalent roughness and an increased spatial homogeneity of roughness while etching of polished ISG glass surfaces decreases the roughness and spatial distribution homogeneity of roughness. - Abstract: Surface finishing techniques including polishing, etching and heat treatment can modify the topography and the surface chemical composition of glasses. It is widely acknowledged that atomic force microscopy (AFM) can be used to quantify the morphology of surfaces, providing various parameters including average, peak-to-valley, and apparent root-mean-square roughness. Furthermore advanced power spectral density (PSD) analysis of AFM-derived surface profiles offers quantification of the spatial homogeneity of roughness values along different wavelengths, resulting in parameters including equivalent RMS, Hurst exponent, and fractal dimension. Outermost surface (∼8 nm) chemical composition can be quantitatively measured by X-ray photoelectron spectroscopy. In this paper, we first developed a series of surface finishing methods for an aluminoborosilicate glass system by polishing, etching or heat treatment. The chemical composition and environment of prepared glass surfaces were quantified by XPS and topographical analysis was carried out by fractal and k

  8. Effects of 35% Carbamide Peroxide Gel on Surface Roughness and Hardness of Composite Resins

    Directory of Open Access Journals (Sweden)

    F. Sharafeddin

    2010-03-01

    Full Text Available Objective: Bleaching agents may not be safe for dental materials. The purpose of this invitro study was to evaluate the effects of Opalescent Quick "in-office bleaching gel" containing 35% carbamide peroxide on the surface roughness and hardness of microfilled(Heliomolar and hybride (Spectrum TPH composite resins.Materials and Methods: Twenty specimens of Spectrum TPH composite resins and twenty Heliomolar composite resins were fabricated using a metallic ring (6.5 mm diameter and 2.5 mm thickness and light cured, then their surfaces were polished. Specimens of each composite resin were divided into two equal groups. Ten specimens of each type of composite were stored in water at 37°C as the control groups and 35% carbamide peroxide gel (Opalescence Quick as the other group for 30 minutes a week for 3 weeks. Then the specimens were subject to roughness and hardness tests.Results: This study revealed that using 35% carbamide peroxide bleaching gels had no significant effect on the surface roughness of Spectrum TPH "hybrid" and Heliomolar "microfilled" composite resins. The surface hardness of Spectrum TPH composite treated with the subject gel significantly increased compared to heliomolar, which had no significant change after treatment with this bleaching gel.Conclusion: If tooth color matching of the composite had been satisfactory after office bleaching with 35% carbamide peroxide gel, this material would have been acceptable because it has no adverse effect on Heliomolar and Spectrum TPH composite resins.

  9. Mechanical effects associated with surface loading of dry rock due to glaciation

    International Nuclear Information System (INIS)

    Wahi, K.K.; Hunter, R.L.

    1985-01-01

    Many scenarios of interest for a repository in the Pasco Basin begin with glaciation. Loading and unloading of joints and fractures due to the weight of ice sheets could affect the hydrologic properties of the host rock and surrounding units. Scoping calculations performed using two-dimensional numerical models with simplifying assumptions predict stress changes and uplift or subsidence caused by an advancing glacier. The magnitudes of surface uplift and subsidence predicted by the study agree well with previous independent predictions. Peak stress unloading near the repository horizon is a small fraction of the ambient stress. Any resultant aperture increase is likewise small. Based on the results of this study, mechanical loading caused by a glacier is expected to have a minimal effect on rock permeability, assuming that the excess compressive loads do not crush the rock. 13 refs., 3 figs., 1 tab

  10. Three-dimensional modeling of chloroprene rubber surface topography upon composition

    Energy Technology Data Exchange (ETDEWEB)

    Žukienė, Kristina, E-mail: kristina.zukiene@ktu.lt [Department of Clothing and Polymer Products Technology, Kaunas University of Technology, Studentu St. 56, LT-51424 Kaunas (Lithuania); Jankauskaitė, Virginija [Department of Clothing and Polymer Products Technology, Kaunas University of Technology, Studentu St. 56, LT-51424 Kaunas (Lithuania); Petraitienė, Stase [Department of Applied Mathematics, Kaunas University of Technology, Studentu 50, LT-51368 Kaunas (Lithuania)

    2014-02-15

    In this study the effect of polymer blend composition on the surface roughness has been investigated and simulated. Three-dimensional modeling of chloroprene rubber film surface upon piperylene-styrene copolymer content was conducted. The efficiency of various surface roughness modeling methods, including Monte Carlo, surface growth and proposed method, named as parabolas, were compared. The required parameters for modeling were obtained from atomic force microscopy topographical images of polymer films surface. It was shown that experimental and modeled surfaces have the same correlation function. The quantitative comparison of function parameters was made. It was determined that novel parabolas method is suitable for three-dimensional polymer blends surface roughness description.

  11. Modified titanium surface with gelatin nano gold composite increases osteoblast cell biocompatibility

    International Nuclear Information System (INIS)

    Lee, Young-Hee; Bhattarai, Govinda; Aryal, Santosh; Lee, Nan-Hee; Lee, Min-Ho; Kim, Tae-Gun; Jhee, Eun-Chung; Kim, Hak-Yong; Yi, Ho-Keun

    2010-01-01

    This study examined the gelatin nano gold (GnG) composite for surface modification of titanium in addition to insure biocompatibility on dental implants or biomaterials. The GnG composite was constructed by gelatin and hydrogen tetrachloroaurate in presence of reducing agent, sodium borohydrate (NabH 4 ). The GnG composite was confirmed by UV-VIS spectroscopy and transmission electron microscopy (TEM). A dipping method was used to modify the titanium surface by GnG composite. Surface was characterized by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). The MC-3T3 E1 cell viability was assessed by trypan blue and the expression of proteins to biocompatibility were analyzed by Western blotting. The GnG composite showed well dispersed character, the strong absorption at 530 nm, roughness, regular crystal and clear C, Na, Cl, P, and Au signals onto titanium. Further, this composite allowed MC-3T3 E1 growth and viability compared to gelatin and pure titanium. It induced ERK activation and the expression of cell adherent molecules, FAK and SPARC, and growth factor, VEGF. However, GnG decreased the level of SAPK/JNK. This shows that GnG composite coated titanium surfaces have a good biocompatibility for osteoblast growth and attachment than in intact by simple and versatile dipping method. Furthermore, it offers good communication between cell and implant surfaces by regulating cell signaling and adherent molecules, which are useful to enhance the biocompatibility of titanium surfaces.

  12. Effect of the surface roughness on interfacial properties of carbon fibers reinforced epoxy resin composites

    International Nuclear Information System (INIS)

    Song Wei; Gu Aijuan; Liang Guozheng; Yuan Li

    2011-01-01

    The effect of the surface roughness on interfacial properties of carbon fibers (CFs) reinforced epoxy (EP) resin composite is studied. Aqueous ammonia was applied to modify the surfaces of CFs. The morphologies and chemical compositions of original CFs and treated CFs (a-CFs) were characterized by Atomic Force Microscopy (AFM), and X-ray Photoelectron Spectroscopy (XPS). Compared with the smooth surface of original CF, the surface of a-CF has bigger roughness; moreover, the roughness increases with the increase of the treating time. On the other hand, no obvious change in chemical composition takes place, indicating that the treating mechanism of CFs by aqueous ammonia is to physically change the morphologies rather than chemical compositions. In order to investigate the effect of surface roughness on the interfacial properties of CF/EP composites, the wettability and Interfacial Shear Strength (IFSS) were measured. Results show that with the increase of the roughness, the wettabilities of CFs against both water and ethylene glycol improves; in addition, the IFSS value of composites also increases. These attractive phenomena prove that the surface roughness of CFs can effectively overcome the poor interfacial adhesions between CFs and organic matrix, and thus make it possible to fabricate advanced composites based on CFs.

  13. Inactivation of Escherichia coli O157:H7 in biofilm on food-contact surfaces by sequential treatments of aqueous chlorine dioxide and drying.

    Science.gov (United States)

    Bang, Jihyun; Hong, Ayoung; Kim, Hoikyung; Beuchat, Larry R; Rhee, Min Suk; Kim, Younghoon; Ryu, Jee-Hoon

    2014-11-17

    We investigated the efficacy of sequential treatments of aqueous chlorine and chlorine dioxide and drying in killing Escherichia coli O157:H7 in biofilms formed on stainless steel, glass, plastic, and wooden surfaces. Cells attached to and formed a biofilm on wooden surfaces at significantly (P ≤ 0.05) higher levels compared with other surface types. The lethal activities of sodium hypochlorite (NaOCl) and aqueous chlorine dioxide (ClO₂) against E. coli O157:H7 in a biofilm on various food-contact surfaces were compared. Chlorine dioxide generally showed greater lethal activity than NaOCl against E. coli O157:H7 in a biofilm on the same type of surface. The resistance of E. coli O157:H7 to both sanitizers increased in the order of wood>plastic>glass>stainless steel. The synergistic lethal effects of sequential ClO₂ and drying treatments on E. coli O157:H7 in a biofilm on wooden surfaces were evaluated. When wooden surfaces harboring E. coli O157:H7 biofilm were treated with ClO₂ (200 μg/ml, 10 min), rinsed with water, and subsequently dried at 43% relative humidity and 22 °C, the number of E. coli O157:H7 on the surface decreased by an additional 6.4 CFU/coupon within 6 h of drying. However, when the wooden surface was treated with water or NaOCl and dried under the same conditions, the pathogen decreased by only 0.4 or 1.0 log CFU/coupon, respectively, after 12 h of drying. This indicates that ClO₂ treatment of food-contact surfaces results in residual lethality to E. coli O157:H7 during the drying process. These observations will be useful when selecting an appropriate type of food-contact surfaces, determining a proper sanitizer for decontamination, and designing an effective sanitization program to eliminate E. coli O157:H7 on food-contact surfaces in food processing, distribution, and preparation environments. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Study On The Influence Of Different Drying Modes Over The Chemical Composition Of Organic Fruits Of Some Plum Cultivars

    OpenAIRE

    GEORGIEV, Diyan; GEORGIEVA, Mariya; BRASHLYANOVA, Boryana; Karabadzhov, Ognyan

    2014-01-01

    The change of some biochemical indicators of fruits of some plum cultivars was followed under the influence of different equipments and drying modes. In the first variant for the process of drying was used an alternative energy source – solar energy, and in the second one – a heat pump.The highest dry matter content was found in the fresh fruits of Mirabelle de Nancy – 25.50 %. In the alternative source of drying of fruits, Gabrovska cultivar had the highest content of biological active subst...

  15. Comparison of time-dependent changes in the surface hardness of different composite resins

    Science.gov (United States)

    Ozcan, Suat; Yikilgan, Ihsan; Uctasli, Mine Betul; Bala, Oya; Kurklu, Zeliha Gonca Bek

    2013-01-01

    Objective: The aim of this study was to evaluate the change in surface hardness of silorane-based composite resin (Filtek Silorane) in time and compare the results with the surface hardness of two methacrylate-based resins (Filtek Supreme and Majesty Posterior). Materials and Methods: From each composite material, 18 wheel-shaped samples (5-mm diameter and 2-mm depth) were prepared. Top and bottom surface hardness of these samples was measured using a Vicker's hardness tester. The samples were then stored at 37°C and 100% humidity. After 24 h and 7, 30 and 90 days, the top and bottom surface hardness of the samples was measured. In each measurement, the rate between the hardness of the top and bottom surfaces were recorded as the hardness rate. Statistical analysis was performed by one-way analysis of variance, multiple comparisons by Tukey's test and binary comparisons by t-test with a significance level of P = 0.05. Results: The highest hardness values were obtained from each two surfaces of Majesty Posterior and the lowest from Filtek Silorane. Both the top and bottom surface hardness of the methacrylate based composite resins was high and there was a statistically significant difference between the top and bottom hardness values of only the silorane-based composite, Filtek Silorane (P composite resin Filtek Silorane showed adequate hardness ratio, the use of incremental technic during application is more important than methacrylate based composites. PMID:24966724

  16. Pluto and Charon: Surface Colors and Compositions - A Hypothesis

    Science.gov (United States)

    Cruikshank, D. P.

    2016-01-01

    The surface of Pluto displays an array of colors ranging from yellow to red to brown, while the surface of Charon is largely gray with a north polar zone of red color similar to regions on Pluto. Pluto's surface shows layers of intensely colored material in tilted and transported blocks, and fractured geo-graphical units. This arrangement suggests episodes of formation or deposition of that material interspersed with episodes of emplacement of ices having little or no color. The ices identified on the surfaces of these two bodies (N2, CH4, CO, C2H6, H2O on Pluto, and H2O and NH3 on Charon) are colorless, as are nearly all ices in a powdery state. The colors on Pluto probably arise from the in situ formation of a macro-molecular carbonaceous material generated by energetic processing of the ices on the surface. Laboratory experiments producing refractory tholins particularly relevant to Pluto explored the chemistry of both UV and low-energy electron bombardment of a mix of Pluto ices (N2:CH4:CO = 100:1:1). We can term this Pluto ice tholin PIT. Water ice in the crystalline state characterizes Charon's surface, and while most of Charon's surface is neutral in color, with geometric albedo approximately 0.38, the polar zone and a light cover of fainter but similar reddish color over some surface regions suggest a common origin with the colored material on Pluto. NH3 or NH3 x nH2O was identified from disk-integrated Earth-based spectra, and a few concentrated NH3 exposures have been found in the New Horizons spectral images.

  17. Chemical composition of solar dried blood and the ruminal content and its effect on performance of Japanese quails.

    Science.gov (United States)

    Mishra, Jyotiprabha; Abraham, Robinson J J; Rao, V Appa; Rajini, R Asha; Mishra, B P; Sarangi, N R

    2015-01-01

    The aim was to determine the chemical composition of solar dried blood and rumen content (DBRC) and further ascertain the concentration at which DBRC could be included in Japanese quail diets without any adverse effect on its performance. Feeding trial on the effect of DBRC on performance of Japanese quails was studied up to 5 weeks. 252 numbers of day old (Nandanam Type III breed) Japanese quails were purchased from Poultry Research Station, Madhavaram and divided into 7 batches (control+ six treatments) each consisting of 36 birds. The DBRC was included at 0%, 5%, 10%, 15%, 20%, 25% and 30% in diets as control, treatment-1 (T1), treatment-2 (T2), treatment-3 (T3), treatment-4 (T4), treatment-5 (T5) and treatment-6 (T6) respectively in a completely randomized design to replace soybean meal in Japanese quail feed. The birds were provided with ad-labidum feed and drinking water ad-libitum during the entire experimental period. The crude protein (CP), crude fiber (CF), ether extract (EE) and ash contents of DBRC were 35.87%, 17.40%, 3.6% and 12.6%, respectively. The amount of essential amino acids and non-essential amino acid content were found to be 12.98 and 4.87 (g/100 g of feed) respectively in DBRC feed. Result showed that all birds fed DBRC diets performed better than the control group. Mortality was unaffected by dietary treatments. There was a significant difference (p<0.01) observed in weight gain in treatment groups compared to the control. Up to 30% DBRC could be incorporated in the diets of Japanese quails without any adverse effects on its performance.

  18. Polishing and toothbrushing alters the surface roughness and gloss of composite resins.

    Science.gov (United States)

    Kamonkhantikul, Krid; Arksornnukit, Mansuang; Takahashi, Hidekazu; Kanehira, Masafumi; Finger, Werner J

    2014-01-01

    This study aimed to investigate the surface roughness and gloss of composite resins after using two polishing systems and toothbrushing. Six composite resins (Durafill VS, Filtek Z250, Filtek Z350 XT, Kalore, Venus Diamond, and Venus Pearl) were evaluated after polishing with two polishing systems (Sof-Lex, Venus Supra) and after toothbrushing up to 40,000 cycles. Surface roughness (Ra) and gloss were determined for each composite resin group (n=6) after silicon carbide paper grinding, polishing, and toothbrushing. Two-way ANOVA indicated significant differences in both Ra and gloss between measuring stages for the composite resins tested, except Venus Pearl, which showed significant differences only in gloss. After polishing, the Filtek Z350 XT, Kalore, and Venus Diamond showed significant increases in Ra, while all composite resin groups except the Filtek Z350 XT and Durafill VS with Sof-Lex showed increases in gloss. After toothbrushing, all composite resin demonstrated increases in Ra and decreases in gloss.

  19. Patterns of forest composition and their long term environmental drivers in the tropical dry forest transition zone of southern Africa

    Directory of Open Access Journals (Sweden)

    Vera De Cauwer

    2016-09-01

    Full Text Available Background Tropical dry forests cover less than 13 % of the world’s tropical forests and their area and biodiversity are declining. In southern Africa, the major threat is increasing population pressure, while drought caused by climate change is a potential threat in the drier transition zones to shrub land. Monitoring climate change impacts in these transition zones is difficult as there is inadequate information on forest composition to allow disentanglement from other environmental drivers. Methods This study combined historical and modern forest inventories covering an area of 21,000 km2 in a transition zone in Namibia and Angola to distinguish late succession tree communities, to understand their dependence on site factors, and to detect trends in the forest composition over the last 40 years. Results The woodlands were dominated by six tree species that represented 84 % of the total basal area and can be referred to as Baikiaea - Pterocarpus woodlands. A boosted regression tree analysis revealed that late succession tree communities are primarily determined by climate and topography. The Schinziophyton rautanenii and Baikiaea plurijuga communities are common on slightly inclined dune or valley slopes and had the highest basal area (5.5 – 6.2 m2 ha−1. The Burkea africana - Guibourtia coleosperma and Pterocarpus angolensis – Dialium englerianum communities are typical for the sandy plateaux and have a higher proportion of smaller stems caused by a higher fire frequency. A decrease in overall basal area or a trend of increasing domination by the more drought and cold resilient B. africana community was not confirmed by the historical data, but there were significant decreases in basal area for Ochna pulchra and the valuable fruit tree D. englerianum. Conclusions The slope communities are more sheltered from fire, frost and drought but are more susceptible to human expansion. The community with the important timber tree P

  20. Multilayered nanoclusters of platinum and gold: insights on electrodeposition pathways, electrocatalysis, surface and bulk compositional properties

    CSIR Research Space (South Africa)

    Mkwizu, TS

    2013-06-01

    Full Text Available Electrochemical, surface and bulk compositional properties of multilayered nanoclusters of Pt and Au, electrochemically deposited on glassy carbon under conditions involving sequential surface–limited redox–replacement reactions (performed at open...

  1. Surface water connectivity drives richness and composition of Arctic lake fish assemblages

    Science.gov (United States)

    Laske, Sarah M.; Haynes, Trevor B.; Rosenberger, Amanda E.; Koch, Joshua C.; Wipfli, Mark S.; Whitman, Matthew; Zimmerman, Christian E.

    2016-01-01

    Surface water connectivity can influence the richness and composition of fish assemblages, particularly in harsh environments where colonisation factors and access to seasonal refugia are required for species persistence.

  2. Efficacy of polishing kits on the surface roughness and color stability of different composite resins.

    Science.gov (United States)

    Kocaagaoglu, H; Aslan, T; Gürbulak, A; Albayrak, H; Taşdemir, Z; Gumus, H

    2017-05-01

    Different polishing kits may have different effects on the composite resin surfaces. The aim of this study was to evaluate the surface roughness and color stability of four different composites which was applied different polishing technique. Thirty specimens were made for each composite resin group (nanohybrid, GrandioSo-GS; nanohybrid, Clearfil Majesty Esthetic-CME; hybrid, Valux Plus-VP; micro-hybrid, Ruby Comp-RC; [15 mm in diameter and 2 mm height]), with the different monomer composition and particle size from a total of 120 specimens. Each composite group was divided into three subgroups (n = 10). The first subgroup of the each composite subgroups served as control (C) and had no surface treatment. The second subgroup of the each composite resin groups was polished with finishing discs (Bisco Finishing Discs; Bisco Inc., Schaumburg, IL, USA). The third subgroup of the each composite resin was polished with polishing wheel (Enhance and PoGo, Dentsply, Konstanz, Germany). The surface roughness and the color differences measurement of the specimens were made and recorded. The data were compared using Kruskal-Wallis test, and regression analysis was used in order to examine the correlation between surface roughness and color differences of the specimens (α = 0.05). The Kruskal-Wallis test indicated significant difference among the composite resins in terms of ΔE (P composite resins in terms of surface roughness (P > 0.05). Result of the regression analysis indicated statistically significant correlation between Ra and ΔE values (P < 0.05, r2 = 0.74). The findings of the present study have clinical relevance in the choice of polishing kits used.

  3. Surface Roughness and Gloss of Actual Composites as Polished With Different Polishing Systems.

    Science.gov (United States)

    Rodrigues-Junior, S A; Chemin, P; Piaia, P P; Ferracane, J L

    2015-01-01

    This in vitro study evaluated the effect of polishing with different polishing systems on the surface roughness and gloss of commercial composites. One hundred disk-shaped specimens (10 mm in diameter × 2 mm thick) were made with Filtek P-90, Filtek Z350 XT, Opallis, and Grandio. The specimens were manually finished with #400 sandpaper and polished by a single operator using three multistep systems (Superfix, Diamond Pro, and Sof-lex), one two-step system (Polidores DFL), and one one-step system (Enhance), following the manufacturer's instructions. The average surface roughness (μm) was measured with a surface profilometer (TR 200 Surface Roughness Tester), and gloss was measured using a small-area glossmeter (Novo-Curve, Rhopoint Instrumentation, East Sussex, UK). Data were analyzed by two-way analysis of variance and Tukey's test (α=0.05). Statistically significant differences in surface roughness were identified by varying the polishing systems (pGloss was influenced by the composites (pone-step system, Enhance, produced the lowest gloss for all composites. Surface roughness and gloss were affected by composites and polishing systems. The interaction between both also influenced these surface characteristics, meaning that a single polishing system will not behave similarly for all composites. The multistep systems produced higher gloss, while the one-step system produced the highest surface roughness and the lowest gloss of all.

  4. Use of variance techniques to measure dry air-surface exchange rates

    Science.gov (United States)

    Wesely, M. L.

    1988-07-01

    The variances of fluctuations of scalar quantities can be measured and interpreted to yield indirect estimates of their vertical fluxes in the atmospheric surface layer. Strong correlations among scalar fluctuations indicate a similarity of transfer mechanisms, which is utilized in some of the variance techniques. The ratios of the standard deviations of two scalar quantities, for example, can be used to estimate the flux of one if the flux of the other is measured, without knowledge of atmospheric stability. This is akin to a modified Bowen ratio approach. Other methods such as the normalized standard-deviation technique and the correlation-coefficient technique can be utilized effectively if atmospheric stability is evaluated and certain semi-empirical functions are known. In these cases, iterative calculations involving measured variances of fluctuations of temperature and vertical wind velocity can be used in place of direct flux measurements. For a chemical sensor whose output is contaminated by non-atmospheric noise, covariances with fluctuations of scalar quantities measured with a very good signal-to-noise ratio can be used to extract the needed standard deviation. Field measurements have shown that many of these approaches are successful for gases such as ozone and sulfur dioxide, as well as for temperature and water vapor, and could be extended to other trace substances. In humid areas, it appears that water vapor fluctuations often have a higher degree of correlation to fluctuations of other trace gases than do temperature fluctuations; this makes water vapor a more reliable companion or “reference” scalar. These techniques provide some reliable research approaches but, for routine or operational measurement, they are limited by the need for fast-response sensors. Also, all variance approaches require some independent means to estimate the direction of the flux.

  5. Study of Surface Wear and Damage Induced by Dry Sliding of Tempered AISI 4140 Steel against Hardened AISI 1055 Steel

    Directory of Open Access Journals (Sweden)

    A. Elhadi

    2016-12-01

    Full Text Available In industry, the sliding mechanical systems are subject to friction and wear phenomena. These phenomena can be the origin of a reduction of the efficiency of the mechanical system even to be responsible for its incapacity. Generally, the materials of the parts which are moving relative (tribological couple of these systems are low alloy steels and carbon steels, thanks to their good mechanical and tribological properties. The present work aimed to study, the surface wear and damage induced by dry sliding of hard carbon steel AISI 1055 (disc against tempered low alloy steel AISI 4140 (pin with different hardness and applied loads was investigated. The results revealed that the interaction between the applied load and pin hardness result in complex thermo-mechanical behaviour of the worn surfaces. When a lower hardness pin is used, the main wear mechanisms observed on the discs were abrasion, adhesion, and oxidation. When a higher hardness pin is used, the wear of the discs is governed by delamination, oxidation, and plastic deformation. In particular, third-body wear occurs at high applied load resulting in higher wear rate of high hardness pins compared to low hardness pins.

  6. Effect of acid whey and freeze-dried cranberries on lipid oxidation and fatty acid composition of nitrite-/nitrate-free fermented sausage made from deer meat

    Directory of Open Access Journals (Sweden)

    Małgorzata Karwowska

    2017-01-01

    Full Text Available Objective This study evaluated the effect of acid whey and freeze-dried cranberries on the physicochemical characteristics, lipid oxidation and fatty acid composition of nitrite-free fermented sausage made from deer meat and pork fat. Antioxidant interactions between acid whey and cranberry compounds were also explored. Methods Four formulations of fermented venison sausage were prepared: F1 (control, F2 (with 5% liquid acid whey, F3 (with 0.06% of freeze-dried cranberries, and F4 (with 5% liquid acid whey and 0.06% of freeze-dried cranberries. Each sample was analyzed for pH, water activity (aw, heme iron content, 2-thiobarbituric acid reactive substances (TBARS value and conjugated dienes at the end of the manufacturing process and at 30 and 90 days of refrigerated storage. Fatty acid composition was measured once at the end of the manufacturing process. Results At the end of ripening, all samples presented statistically different values for a pH range of 4.47 to pH 4.59. The sum of the unsaturated fatty acids was higher, while the conjugated diene and the TBARS values were lower in sausages with freeze-dried cranberries as compared to the control sausage. The highest content of heme iron (21.52 mg/kg at day 90 was found in the sausage formulation with the addition of freeze-dried cranberries, which suggests that the addition of cranberries stabilized the porphyrin ring of the heme molecule during storage and thereby reduced the release of iron. The use of liquid acid whey in combination with cranberries appears to not be justified in view of the oxidative stability of the obtained products. Conclusion The results suggest that the application of freeze-dried cranberries can lower the intensity of oxidative changes during the storage of nitrite-free fermented sausage made from deer meat.

  7. Effects of 35% Carbamide Peroxide Gel on Surface Roughness and Hardness of Composite Resins

    OpenAIRE

    Sharafeddin, F.; Jamalipour, GR.

    2010-01-01

    Objective: Bleaching agents may not be safe for dental materials. The purpose of this in-vitro study was to evaluate the effects of Opalescent Quick ?in-office bleaching gel? containing 35% carbamide peroxide on the surface roughness and hardness of microfilled (Heliomolar) and hybride (Spectrum TPH) composite resins. Materials and Methods: Twenty specimens of Spectrum TPH composite resins and twenty Heliomolar composite resins were fabricated using a metallic ring (6.5 mm diameter and 2.5 mm...

  8. Simultaneous tuning of chemical composition and topography of copolymer surfaces: micelles as building blocks.

    Science.gov (United States)

    Zhao, Ning; Zhang, Xiaoyan; Zhang, Xiaoli; Xu, Jian

    2007-05-14

    A simple method is described for controlling the surface chemical composition and topography of the diblock copolymer poly(styrene)-b-poly(dimethylsiloxane)(PS-b-PDMS) by casting the copolymer solutions from solvents with different selectivities. The surface morphology and chemical composition were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively, and the wetting behavior was studied by water contact angle (CA) and sliding angle (SA) and by CA hysteresis. Chemical composition and morphology of the surface depend on solvent properties, humidity of the air, solution concentration, and block lengths. If the copolymer is cast from a common solvent, the resultant surface is hydrophobic, with a flat morphology, and dominated by PDMS on the air side. From a PDMS-selective solvent, the surface topography depends on the morphology of the micelles. Starlike micelles give rise to a featureless surface nearly completely covered by PDMS, while crew-cut-like micelles lead to a rough surface with a hierarchical structure that consists partly of PDMS. From a PS-selective solvent, however, surface segregation of PDMS was restricted, and the surface morphology can be controlled by vapor-induced phase separation. On the basis of the tunable surface roughness and PDMS concentration on the air side, water repellency of the copolymer surface could be tailored from hydrophobic to superhydrophobic. In addition, reversible switching behavior between hydrophobic and superhydrophobic can be achieved by exposing the surface to solvents with different selectivities.

  9. All-cellulose composites of regenerated cellulose fibres by surface selective dissolution

    NARCIS (Netherlands)

    Soykeabkaew, N.; Nishino, T.; Peijs, Ton

    2009-01-01

    All-cellulose composites of Lyocell and high modulus/strength cellulose fibres were successfully prepared using a surface selective dissolution method. The effect of immersion time of the fibres in the solvent during composite's preparation and the effect of the starting fibre's structure on their

  10. Effect of processing method on surface and weathering characteristics of wood-flour/HDPE composites

    Science.gov (United States)

    Nicole M. Stark; Laurent M. Matuana; Craig M. Clemons

    2004-01-01

    Wood-plastic lumber is promoted as a low maintenance high-durability product. When exposed to accelerated weathering, however, wood-plastic composites may experience a color change and/or loss in mechanical properties. Different methods of manufacturing wood-plastic composites lead to different surface characteristics, which can influence weathering, In this study, 50...

  11. Evaluation of surface detail reproduction, dimensional stability and gypsum compatibility of monophase polyvinyl-siloxane and polyether elastomeric impression materials under dry and moist conditions.

    Science.gov (United States)

    Vadapalli, Sriharsha Babu; Atluri, Kaleswararao; Putcha, Madhu Sudhan; Kondreddi, Sirisha; Kumar, N Suman; Tadi, Durga Prasad

    2016-01-01

    This in vitro study was designed to compare polyvinyl-siloxane (PVS) monophase and polyether (PE) monophase materials under dry and moist conditions for properties such as surface detail reproduction, dimensional stability, and gypsum compatibility. Surface detail reproduction was evaluated using two criteria. Dimensional stability was evaluated according to American Dental Association (ADA) specification no. 19. Gypsum compatibility was assessed by two criteria. All the samples were evaluated, and the data obtained were analyzed by a two-way analysis of variance (ANOVA) and Pearson's Chi-square tests. When surface detail reproduction was evaluated with modification of ADA specification no. 19, both the groups under the two conditions showed no significant difference statistically. When evaluated macroscopically both the groups showed statistically significant difference. Results for dimensional stability showed that the deviation from standard was significant among the two groups, where Aquasil group showed significantly more deviation compared to Impregum group (P < 0.001). Two conditions also showed significant difference, with moist conditions showing significantly more deviation compared to dry condition (P < 0.001). The results of gypsum compatibility when evaluated with modification of ADA specification no. 19 and by giving grades to the casts for both the groups and under two conditions showed no significant difference statistically. Regarding dimensional stability, both impregum and aquasil performed better in dry condition than in moist; impregum performed better than aquasil in both the conditions. When tested for surface detail reproduction according to ADA specification, under dry and moist conditions both of them performed almost equally. When tested according to macroscopic evaluation, impregum and aquasil performed significantly better in dry condition compared to moist condition. In dry condition, both the materials performed almost equally. In

  12. The effect of different polishing systems on surface roughness and gloss of various resin composites.

    Science.gov (United States)

    Da Costa, Juliana; Ferracane, Jack; Paravina, Rade D; Mazur, Rui Fernando; Roeder, Leslie

    2007-01-01

    The purpose of this in vitro study was to evaluate the surface finish and gloss of five direct resin composites polished with six polishing systems. One hundred and fifty disk-shaped composite specimens (D=10.0 mm, 2-mm-thick, N=30 per material) were made. One side of each specimen was finished with a 16-fluted carbide finishing bur and then polished. Five specimens of each resin composite were randomly assigned to one of the six polishing systems. The surface roughness and gloss were measured with a surface profilometer and a glossmeter. The results were analyzed by two-way analysis of variance and Tukey's t-test (pgloss values between the composites and the polishing systems (p gloss value was recorded for Supreme + Pogo; the lowest was recorded for Z100 + Jiffy. Pogo showed the highest gloss values for all composites. The nanofill (Supreme) and minifill (Esthet-X) composites presented a surface roughness comparable to a microfill (Durafill), independent of the polishing system used, and a gloss comparable to a microfill, when polished with a one-step system (Pogo). As compared with the multiple-step systems, the smoothest surfaces and the highest gloss values were achieved using the one-step system (Pogo) for all the evaluated composites.

  13. Effect of dry period length and dietary energy source on energy balance, milk yield, and milk composition of dairy cows

    NARCIS (Netherlands)

    Knegsel, van A.T.M.; Remmelink, G.J.; Jorjong, S.; Fievez, V.; Kemp, B.

    2014-01-01

    The objective of this study was to evaluate the effects of dry period length and dietary energy source in early lactation on milk production, feed intake, and energy balance (EB) of dairy cows. Holstein-Friesian dairy cows (60 primiparous and 108 multiparous) were randomly assigned to dry period

  14. Surface roughness of orthodontic band cements with different compositions

    Directory of Open Access Journals (Sweden)

    Françoise Hélène van de Sande

    2011-06-01

    Full Text Available OBJECTIVES: The present study evaluated comparatively the surface roughness of four orthodontic band cements after storage in various solutions. MATERIAL AND METHODS: Eight standardized cylinders were made from 4 materials: zinc phosphate cement (ZP, compomer (C, resin-modified glass ionomer cement (RMGIC and resin cement (RC. Specimens were stored for 24 h in deionized water and immersed in saline (pH 7.0 or 0.1 M lactic acid solution (pH 4.0 for 15 days. Surface roughness readings were taken with a profilometer (Surfcorder SE1200 before and after the storage period. Data were analyzed by two-way ANOVA and Tukey's test (comparison among cements and storage solutions or paired t-test (comparison before and after the storage period at 5% significance level. RESULTS: The values for average surface roughness were statistically different (pRMGIC>C>R (p0.05. Compared to the current threshold (0.2 µm related to biofilm accumulation, both RC and C remained below the threshold, even after acidic challenge by immersion in lactic acid solution. CONCLUSIONS: Storage time and immersion in lactic acid solution increased the surface roughness of the majority of the tested cements. RC presented the smoothest surface and it was not influenced by storage conditions.

  15. Chemical composition of the fruit of two species of tropical dry forest in the coastal region of Ecuador as food source for ruminants

    Directory of Open Access Journals (Sweden)

    Henrry Othón Intriago Mendoza

    2015-04-01

    Full Text Available Fodder species of trees in the coastal region of Manabí are an alternative food to cattle, especia-lly between the months of september and december when the pasture gets scarce. To evaluate their nutritional potential was made a compositional analysis of nutritional parameters to the fruits of Prosopis juliflora (Sw. DC. (Algarrobo and Guazuma ulmifolia Lam. (Guasmo. Botanical characters of these trees and compositional analysis results are described. Furthermore, a comparison of these results with those obtained by other authors by con-sidering the values of protein, fat, fiber, ash and moisture is performed. For the environmental conditions of tropical dry forest, the guasmo presents higher contents of protein, fat, ash and fiber carob, although both species are important in the diet of herbivores, especially in dry seasons as providers of usable nutrients favoring animal nutrition

  16. Protecting the ocular surface and improving the quality of life of dry eye patients: a study of the efficacy of an HP-guar containing ocular lubricant in a population of dry eye patients.

    Science.gov (United States)

    Rolando, Maurizio; Autori, Silvia; Badino, Francesco; Barabino, Stefano

    2009-06-01

    The aim of this study was to evaluate the efficacy of a non-Newtonian tear substitute containing 0.4% polyethylene glycol 400 (PEG 400) and 0.3% propylene glycol in an 0.18% hydroxypropyl-guar (HPG) containing vehicle (Systane Lubricant Eye Drops; Alcon) in reducing the signs and symptoms of dry eye, as well as its effect on ocular protection. Twenty patients with moderate to severe dry eye were enrolled in a 28-day prospective, randomized, controlled study. Subjects self-administered the HPG containing ocular lubricant four times daily (QID) over the study duration. After 28 days, the effect of the HPG containing ocular lubricant was evaluated by means of the Global Staining Score (a measure of the corneal and conjunctival staining), inter-blink tear film stability, Ocular Protection Index (OPI), and subjective symptoms. The HPG containing ocular lubricant produced statistically significant improvements compared with baseline in dry eye symptoms (P eye symptoms with the HPG containing ocular lubricant -- evident as early as the first follow-up visit (Day 7) and continued throughout the 28 days of the study with a concurrent, increase in OPI to a level greater than unity -- indicate that this preparation is a fast-acting, long-lasting, and effective treatment for dry eye. In concurrence with the results from previously published clinical studies, the HPG containing ocular lubricant has shown efficacy in alleviating the signs and symptoms of dry eye as well as affording improved ocular surface protection.

  17. Effect of air-temperature and diet composition on the drying process of pellets for japanese abalone (Haliotis discus hannai feeding

    Directory of Open Access Journals (Sweden)

    Antonio Vega-Gálvez

    2011-09-01

    Full Text Available The aim of this research was to study the effect of air-temperature and diet composition on the mass transfer kinetics during the drying process of pellets used for Japanese Abalone (Haliotis discus hannai feeding. In the experimental design, three temperatures were used for convective drying, as well as three different diet compositions (Diets A, B and C, in which the amount of fishmeal, spirulin, algae, fish oil and cornstarch varied. The water diffusion coefficient of the pellets was determined using the equation of Fick's second law, which resulted in values between 0.84-1.94×10-10 m²/s. The drying kinetics was m