Attachment of Arcobacter butzleri, a New Waterborne Pathogen, to Water Distribution Pipe Surfaces

2002 ◽  
Vol 65 (8) ◽  
pp. 1240-1247 ◽  
Author(s):  
MAFU AKIER ASSANTA ◽  
DENIS ROY ◽  
MARIE-JOSÉE LEMAY ◽  
DIANE MONTPETIT

The capability of Arcobacter butzleri to attach to various water distribution pipe surfaces, such as stainless steel, copper, and plastic, was evaluated using scanning electron microscopy. Our results indicated that Arcobacter cells could easily attach to all surface types and the number of attached cells depended on the length of exposure and temperatures (4 and 20°C). Extracellular fibrils were also observed on the stainless steel surface, especially after 72 h of contact times at both refrigeration and ambient temperatures. In addition, the surface energy value of each material was estimated by contact angle measurements using water, α-bromonaphthalene, and dimethylsulfoxide. The surface energy of A. butzleri was 58.6 mJ·m−2 and the surface energy values of the three surfaces studied showed that plastic had a low energy surface (26.1 mJ·m−2) as did copper (45.8 mJ·m−2) and stainless steel (65.7 mJ·m−2).

1998 ◽  
Vol 61 (10) ◽  
pp. 1321-1329 ◽  
Author(s):  
MAFU AKIER ASSANTA ◽  
DENIS ROY ◽  
DIANE MONTPETIT

Scanning electron microscopy observation was used to investigate the ability of Aeromonas hydrophila to attach to various water distribution pipe surfaces, such as stainless Steel, copper, and polybutylene, after different contact times at ambient and storage temperatures. Surface energy value of each surface was estimated by contact angle measurements using water, α-bromonaphthalene, and dimethyl sulfoxide. Our results indicated that Aeromonas cells could easily attach to all surface types after exposures as short as 1 or 4 h at both temperatures (4 and 20°C). Polybutylene, a low-energy surface (41.2 mJ-m−2), followed by stainless Steel (65.7 mJ-m−2), was most colonized by Aeromonas cells, whereas few cells were observed on copper, which has a surface energy of 45.8 mJ-m−2. Extracellular materials could also be observed on polybutylene surfaces, especially after 1 and 4 h of exposure at the refrigeration temperature.


2009 ◽  
Vol 145-146 ◽  
pp. 319-322 ◽  
Author(s):  
Nicole Ahner ◽  
Matthias Schaller ◽  
Christin Bartsch ◽  
Eugene Baryschpolec ◽  
Stefan E. Schulz

The removal of plasma etch residues by wet cleaning is an alternative or additional process to plasma processes, which are known to degrade low-k and ultralow-k dielectric materials. Besides Cu/low-k compatibility wetting is an important issue for wet cleaning. Surface energy of solid and liquid is the key to understand the wetting behaviour. In this study we examined the energetic character of plasma etched/stripped solid surfaces, etch polymers and several cleaning solutions by contact angle measurements. The results show, that variations of the etching process can heavily change the energetic character of the solid. Calculating the surface energies of solid and liquid provides the possibility to make a prediction if a cleaning liquid will wet the surface which has to be cleaned.


A study has been made of the mechanical deformation properties of β-HMX, an important secondary explosive. It is shown that under compressive loading twinning takes place on the (101)-plane. At low loads, this twinning is elastic and usually precedes fracture. Cleavage in β-HMX takes place on the {011}-planes. The fracture surface energy of 0.06 J m -2 has been determined by a micro-indentation technique. This compares with a value of 0.045 J m -2 obtained for the thermodynamic surface energy from contact-angle measurements. The values suggest that there is relatively little energy loss by plastic deformation associated with crack propagation in HMX compared with, for example, the secondary explosives PETN and RDX. Despite this brittleness the twin deformation allows β-HMX to undergo large changes of shape: the significance of this in plastic-bonded explosives is commented on.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Ionut Popovici ◽  
Anca Duta

CuSbS2thin films were obtained by spray pyrolysis deposition, using polymeric additives for controlling the surface properties and film’s composition. Ternary crystalline chalcostibite compounds have been obtained without any postdeposition treatments. XRD spectra and IR spectroscopy were used to characterize films composition and interactions between components. Films morphology and surface energy were investigated using AFM microscopy and contact angle measurements. Hydrophobic and hydrophilic polymers strongly influence the composition and film morphology.


2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Matthias Katschnig ◽  
Boris Maroh ◽  
Natascha Andraschek ◽  
Sandra Schlögl ◽  
Ulrike Zefferer ◽  
...  

Whilst the significance of substrate topography as a regulator of cell function is well established, a systematic analysis of the principles underlying this is still unavailable. Here we evaluate the hypothesis that surface energy plays a decisive role in substrate-mediated modulation of cell phenotype by evaluation of cell behaviour on synthetic microstructures exhibiting pronounced differences in surface energy. These microstructures, specifically cubes and walls, were fabricated from a biocompatible base polymer, poly(methyl methacrylate), by variotherm injection molding. The dimensions of the cubes were 1 μm x 1 μm x 1 μm (height x width x length) with a periodicity of 1:1 and 1:5 and the dimensions of the walls 1 μm x 1 μm x 15 mm (height x width x length) with a periodicity of 1:1 and 1:5. Mold inserts were made by lithography and electroplating. The surface energy of the resultant microstructures was determined by static contact angle measurements. Light scanning microscopy of the morphology of NT2/D1 and MC3T3-E1 preosteoblast cells cultured on structured PMMA samples in both cases revealed a profound surface energy dependence. “Walls” appeared to promote significant cell elongation, whilst a lack of cell adhesion was observed on “cubes” with the lowest periodicity. Contact angle measurements on walls revealed enhanced surface energy anisotropy (55 mN/m max., 10 mN/m min.) causing a lengthwise spreading of the test liquid droplet, similar to cell elongation. Surface energy measurements for cubes revealed increased isotropic hydrophobicity (87° max., H2O). A critical water contact angle of ≤ 80° appears to be necessary for adequate cell adhesion. A “switch” for cell adhesion and subsequently cell growth could therefore be applied by, for example, adjusting the periodicity of hydrophobic structures. In summary cell elongation on walls and a critical surface energy level for cell adhesion could be produced for NT2/D1 and MC3T3-E1 cells by symmetrical and asymmetrical energy barrier levels. We, furthermore, propose a water-drop model providing a common physicochemical cause regarding similar cell/droplet geometries and cell adhesion on the investigated microstructures.


Author(s):  
C. Mathew Mate ◽  
Robert W. Carpick

The energies associated with surfaces—surface energy, interfacial energy, surface tension, and work of adhesion—drive many surface and interfacial phenomena including tribological ones such as adhesion and friction. This chapter discusses the physical origins of surface energies for liquids and solids, and how the concepts of capillary pressure, capillary condensation, wetting, and work of adhesion are derived from surface energy. Further, this chapter covers the different methods for measuring surface energies, including the most common method for solid surfaces: contact angle measurements of liquid droplets on surfaces. This chapter also introduces how surface energies and surface tensions lead to adhesion and adhesion hysteresis between contacting surfaces, which is followed up in the subsequent chapters on surface forces.


Coatings ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 334 ◽  
Author(s):  
Vilma Jonauske ◽  
Sandra Stanionyte ◽  
Shih-Wen Chen ◽  
Aleksej Zarkov ◽  
Remigijus Juskenas ◽  
...  

Sol-gel derived calcium hydroxyapatite (Ca10(PO4)6(OH)2; CHA) thin films were deposited on stainless steel substrates with transverse and longitudinal patterned roughness employing a spin-coating technique. Each layer in the preparation of CHA multilayers was separately annealed at 850 °C in air. Fabricated CHA coatings were placed in simulated body fluid (SBF) for 2, 3, and 4 weeks and investigated after withdrawal. For the evaluation of obtained and treated with SBF coatings, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), X-ray diffraction (XRD) analysis, Raman spectroscopy, XPS spectroscopy, scanning electron microscopy (SEM) analysis, and contact angle measurements were used. The tribological properties of the CHA coatings were also investigated in this study.


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