Adhesion of Aeromonas hydrophila to Water Distribution System Pipes after Different Contact Times

1998 ◽  
Vol 61 (10) ◽  
pp. 1321-1329 ◽  
Author(s):  
MAFU AKIER ASSANTA ◽  
DENIS ROY ◽  
DIANE MONTPETIT
Keyword(s):  
Stainless Steel ◽  
Surface Energy ◽  
Aeromonas Hydrophila ◽  
Distribution System ◽  
Water Distribution ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Extracellular Materials ◽  
And Storage ◽  
Storage Temperatures

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.

Attachment of Listeria monocytogenes to Stainless Steel, Glass, Polypropylene, and Rubber Surfaces After Short Contact Times

1990 ◽  
Vol 53 (9) ◽  
pp. 742-746 ◽  
Author(s):  
AKIER ASSANTA MAFU ◽  
DENIS ROY ◽  
JACQUES GOULET ◽  
PIERRE MAGNY
Keyword(s):  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Short Contact ◽  
Scanning Electron Microscopy Technique ◽  
Microscopy Technique ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Extracellular Materials ◽  
Storage Temperatures ◽  
Scanning Electron

This study was carried out to investigate the attachment capabilities of Listeria monocytogenes strain Scott A to stainless steel, glass, polypropylene, and rubber surfaces after short contact times at ambient (20°C) and cold storage temperatures (4°C) using scanning electron microscopy technique. Surface energy value of each surface was estimated by contact angle measurements. All surfaces displayed many possible harborages for L. monocytogenes attachment. Our results indicated that L. monocytogenes cells could attach to all surface types at both temperatures after contact times as short as 20 min or 1 h. Extracellular materials could be observed on the surfaces especially polypropylene and glass incubated at 4 and 20°C for 1 h respectively.

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
Keyword(s):  
Stainless Steel ◽  
Surface Energy ◽  
Water Distribution ◽  
Stainless Steel Surface ◽  
Ambient Temperatures ◽  
Waterborne Pathogen ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Arcobacter Butzleri ◽  
Extracellular Fibrils

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).

Assessment of Lisbon drinking water distribution network biofilm colonization and associated hazards

2008 ◽  
Vol 8 (4) ◽  
pp. 421-426
Author(s):  
J. Menaia ◽  
M. Benoliel ◽  
A. Lopes ◽  
C. Neto ◽  
E. Ferreira ◽  
...  
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Network ◽  
Storage Tanks ◽  
Water Pipe ◽  
Cultural Methods ◽  
Drinking Water Distribution ◽  
And Storage

Concerns arise from the possible occurrence of pathogens in drinking water pipe biofilms and storage tank sediments. In these studies, biofilm samples from pipes and sediments from storage tanks of the Lisbon drinking water distribution system were analyzed. Protein determinations and heterotrophic counts on pipe biofilm samples were used to assess the Lisbon network sessile colonization intensity and distribution. Indicator and pathogenic microorganisms were analyzed in pipe biofilm samples, as well as in storage tanks biofilm and sediments, by using cultural methods and PCR, to assess risks. Results have shown that the Lisbon network sessile colonization is relatively weak in intensity. In addition, no meaningful hazards were apparent for both the network biofilm and the storage tanks biofilm and sediments.

Surface Energy and Wetting Behaviour of Plasma Etched Porous SiCOH Surfaces and Plasma Etch Residue Cleaning Solutions

2009 ◽  
Vol 145-146 ◽  
pp. 319-322 ◽  
Author(s):  
Nicole Ahner ◽  
Matthias Schaller ◽  
Christin Bartsch ◽  
Eugene Baryschpolec ◽  
Stefan E. Schulz
Keyword(s):  
Surface Energy ◽  
Dielectric Materials ◽  
Solid Surfaces ◽  
Plasma Etch ◽  
Surface Energies ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Additional Process ◽  
Low K ◽  
Etch Residue

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.

The deformation and fracture of β-HMX

1982 ◽  
Vol 383 (1785) ◽  
pp. 399-407 ◽  
Keyword(s):  
Surface Energy ◽  
Compressive Loading ◽  
Mechanical Deformation ◽  
Angle Measurements ◽  
A Value ◽  
Deformation And Fracture ◽  
Deformation Properties ◽  
Contact Angle Measurements ◽  
Micro Indentation ◽  
Secondary Explosive

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.

scholarly journals Tailoring the Composition and Properties of Sprayed CuSbS2Thin Films by Using Polymeric Additives

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Ionut Popovici ◽  
Anca Duta
Keyword(s):  
Thin Films ◽  
Contact Angle ◽  
Ir Spectroscopy ◽  
Surface Energy ◽  
Hydrophilic Polymers ◽  
Film Morphology ◽  
Angle Measurements ◽  
Polymeric Additives ◽  
Contact Angle Measurements ◽  
Spray Pyrolysis Deposition

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.

scholarly journals Cell Morphology on Poly(methyl methacrylate) Microstructures as Function of Surface Energy

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Matthias Katschnig ◽  
Boris Maroh ◽  
Natascha Andraschek ◽  
Sandra Schlögl ◽  
Ulrike Zefferer ◽  
...  
Keyword(s):  
Contact Angle ◽  
Cell Adhesion ◽  
Surface Energy ◽  
Methyl Methacrylate ◽  
Cell Elongation ◽  
Cell Phenotype ◽  
Critical Surface ◽  
Poly Methyl Methacrylate ◽  
Angle Measurements ◽  
Contact Angle Measurements

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.

scholarly journals Student of Water Tanks Characteristics for Residential and Commerical Buildings in Oman

2020 ◽  
Author(s):  
Ahmed Rashid Said Al Ismaili ◽  
Adeel H. Suhail
Keyword(s):  
Stainless Steel ◽  
Distribution System ◽  
Water Distribution ◽  
The Other ◽  
Human Consumption ◽  
Water Tank ◽  
Steel Tank ◽  
Water Tanks ◽  
Selection Of ◽  
Stainless Steel Tank

Water tank is an important element in water distribution system. The project is studied the characteristics of water tanks and the main objective of it to identify the selection criteria for the water tank. Furthermore, Selection of water tank is a challenge for many individuals and companies. The study is gathers information from many sources such as literature reviews, companies, questionnaire and experts in order to reach to the main important characteristic of water tanks. The selection of water tank depends heavily on the applications. As a result, it found that the best type of storage tanks for sweet water used for human consumption are two types, one of which is polyvinyl chloride to store a quantity of less than five cubic meters and the other is stainless steel tank to store more than five cubic meters. The study found that the best reservoir for irrigation and sewage uses is the carbon steel tank. On the other hand, the study found that the stainless-steel tank is best suited for storage of seawater, which requires a material that can withstand corrosion.

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