CANADIAN WILTSHIRE BACON: VI. QUANTITATIVE BACTERIOLOGICAL STUDIES ON PRODUCT

1940 ◽  
Vol 18d (5) ◽  
pp. 202-210 ◽  
Author(s):  
N. E. Gibbons
Keyword(s):  
Growth Rate ◽  
Surface Layer ◽  
Filter Paper ◽  
Bacterial Load ◽  
Nutrient Agar ◽  
Initial Load ◽  
Different Types ◽  
Visible Growth ◽  
Number Of Bacteria ◽  
Growth Of Bacteria

Surface counts of bacteria on the ribs of bacon showed that nutrient agar containing 4% salt incubated at 20 °C. gave the maximum number. In sampling the surface of a side of bacon, it was found that the removal of the surface layer of tissue yielded more accurate values than methods based on the removal of organisms by swabs or filter paper impressions.On the average, the bacterial load on the anterior ribs was greater than on the posterior ribs. Although there were significant differences in the number of bacteria on sides from the same plant, the greatest variation was between sides from different plants.A visible growth of bacteria or "slime" becomes evident on the average when the logarithm of the number of organisms per sq. cm. exceeds 7.2. Nevertheless, certain sides may appear slimy at log 6.7 per sq. cm., while others will not show this condition at log 8.0 per sq. cm. This variation in the number of organisms present at the visible slime level may result from differences in the flora, different types of growth of the same organism, or variability in the method of detection.The number of bacteria on the side was found to be correlated with the age of the sides from cure or from packing. The growth rate is slow during the first 8 to 10 days from packing, after which it increases. Sides having an initial load of 100,000 organisms per sq. cm. at packing may be expected to remain free from slime for 20 to 25 days, if stored at 1.1 °C. No correlation was obtained between the number of bacteria in the curing pickle and the number on the product.

CONTINUOUS CULTURE OF BRUCELLA ABORTUS S.19

1961 ◽  
Vol 7 (4) ◽  
pp. 491-505 ◽  
Author(s):  
Andreas H. W. Hauschild ◽  
Hilliard Pivnick
Keyword(s):  
Growth Rate ◽  
Continuous Culture ◽  
Dilution Rate ◽  
Brucella Abortus ◽  
Specific Growth ◽  
Limiting Factor ◽  
Continuous Growth ◽  
Viable Cells ◽  
Metabolic Products ◽  
Growth Of Bacteria

An apparatus is described for the continuous growth of bacteria. Brucella abortus S.19 has been grown in continuous culture for periods up to 3 weeks with populations up to 2 × 1011viable cells per ml and without the establishment of nonsmooth variants.Concentrations between 3 × 109and 2 × 1011cells per ml could be maintained as a function of the dilution rate without the requirement of a known limiting factor in the medium. In a series of steady-state conditions, the specific growth rate increased steadily up to 0.28 hour−1with decreasing population levels.Incidence of mutants was governed by the dilution rate and could also be reduced by various chelating substances.In continuous growth combined with continuous dialysis, population levels were approximately twice those obtained in continuous growth without dialysis. The effect of dialysis appears to be the continuous removal of growth-limiting metabolic products.

scholarly journals The laboratory tests of hybrid layers combining hardfacing and nitriding dedicated to increase the durability of forging tools in hot forging processes

2019 ◽  
Vol 91 (2) ◽  
Author(s):  
Paweł Widomski ◽  
Zbigniew Gronostajski ◽  
Marcin Kaszuba ◽  
Jagoda Kowalska ◽  
Mariusz Pawełczyk
Keyword(s):  
Surface Layer ◽  
Chemical Composition ◽  
Laboratory Tests ◽  
Hot Forging ◽  
Composition Analysis ◽  
Wear Resistant ◽  
Gas Nitriding ◽  
Use Wear ◽  
Different Types ◽  
Hybrid Layers

In response to the growing need to use wear-resistant layers that increase durability of tools in forging pro-cesses, hybrid layers have been proposed that combine hardfacing with nitriding treatment. This article presents the results of laboratory tests of surface wear-resistant layers made with a new hybrid technology Gas-Shielded Metal Arc surfacing (hardfacing) with ZeroFlow gas nitriding. Specimens made with hardfacing or nitriding were prepared and examined. Analysis covered the thorough microstructure study, EDX chemical composition analysis and microhardness analysis. In experiment, 3 different types of nitrided layers were proposed for alpha, gamma prim and epsilon nitrides in the surface layer. The results of metallographic research in the surface layer was presented. The analysis of chemical composition in the particular overlay welds was performed to determine the content of alloying elements in the particular overlay welds. The susceptibility to nitriding of used weld materials as well as the ability to form particular types of nitrides on selected welded substrates was also tested.

Effectiveness of Surface Treatment With Blasted Bioceramic Materials on Implants Surfaces

2021 ◽  
Author(s):  
Suet Yeo Soo ◽  
Nikolaos Silikas
Keyword(s):  
Surface Layer ◽  
Surface Treatment ◽  
Calcium Oxide ◽  
Surface Deposition ◽  
Commercially Pure ◽  
Different Types ◽  
Implant Integration ◽  
Surface Morphologies ◽  
Scanning Electron ◽  
Blasting Method

Hydroxyapatite (HA) and other forms of bioceramics coatings had been reported to stimulate bone healing, which helps in initial implant integration. This study was to evaluate the effectiveness of air blasting with two combinations of bioceramic powders (hydroxyapatite and calcium oxide) on the selected implant surfaces for surface deposition. Five different types of implant disks were tested, namely Commercially pure (Cp), Sandblasted (SB), Sandblasted and etched(SBE), SLActive®, Roxolid®. The studied samples were blasted with apatite abrasive bioceramic powders, 95% Hydroxyapatite (HA)/5% Calcium Oxide (CaO) and 90% Hydroxyapatite (HA)/10% Calcium Oxide (CaO). The surface and elemental differences between the blasted samples were compared using a Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopy (EDS). Results after surface treatment had demonstrated changes in surface morphologies; most evidently on the Cp implant discs. All treated surfaces revealed a non-uniform distribution of the treatment on the surface layer, with dispersed patches of bioceramic powders over the surfaces. The experimental blasting method used in this study has demonstrated the ability to deposit bioceramic materials on different implant surfaces.

scholarly journals Continuous Estimation of the Crack Growth Rate during Rotating‒Bending Fatigue Testing

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 275 ◽  
Author(s):  
Gabriela Martinez-Cazares ◽  
Rafael Mercado-Solis ◽  
Yaneth Bedolla-Gil ◽  
Diego Lozano
Keyword(s):  
Growth Rate ◽  
Crack Growth Rate ◽  
Crack Growth ◽  
Fatigue Testing ◽  
Crack Nucleation ◽  
Bending Fatigue ◽  
Initial Load ◽  
Rotating Bending Fatigue ◽  
Rotating Bending ◽  
Continuous Estimation

A method for estimating the crack growth rate in steel during rotating‒bending fatigue testing is presented. Constant deflection tests were conducted in which the initial load remained constant prior to crack nucleation, when it decreased as the crack grew. In the proposed approach, steel samples were sharp-notched to produce a characteristic circular fracture upon loading and the final fracture area was correlated with a ratio of the load prior to fracture and the initial load. In this method, the deflection imposed is a function of a material’s elastic modulus rather than its yield strength and the correlation obtained to estimate the average crack length as a function of the instantaneous load is independent of the applied stress or steel grade.

Molecular Dynamics Simulation of Vapor Condensation on Nanotubes

2013 ◽  
Author(s):  
Donguk Suh ◽  
Kenji Yasuoka ◽  
Xiao Cheng Zeng
Keyword(s):  
Molecular Dynamics ◽  
Growth Rate ◽  
Significant Variation ◽  
Homogeneous Nucleation ◽  
Vapor Condensation ◽  
Dynamics Simulation ◽  
Condensation Process ◽  
Silicon Nanotubes ◽  
Aspect Ratios ◽  
Different Types

Vapor condensation on silicon nanotubes has been simulated by classical molecular dynamics to understand how the nucleation and condensation process for pores is affected. Two different nanotube aspect ratios were examined to see if there are growth rate changes. The rate for the two different types of nanotubes did not show significant variation meaning that the aspect ratio is an insignificant factor to enhance condensation. This result is consistent with previous nanorod studies. The supersaturated vapor gathered both inside and outside of the tube. Unlike the growth rate, however, the occurrence of homogeneous nucleation was hindered contrary to other basic geometries in previous studies.

scholarly journals Factors influencing phagocytosis of Salmonella typhimurium by macrophages in murine schistosomiasis

1997 ◽  
Vol 30 (2) ◽  
pp. 101-106 ◽  
Author(s):  
Maria Imaculada Muniz-Junqueira ◽  
Aluízio Prata ◽  
Carlos Eduardo Tosta
Keyword(s):  
Salmonella Typhimurium ◽  
Schistosoma Mansoni ◽  
Bacterial Load ◽  
Concurrent Infection ◽  
Functional Limit ◽  
Phagocytic Capacity ◽  
Specific Antibodies ◽  
Factors Influencing ◽  
High Bacterial Load ◽  
Number Of Bacteria

We investigated the influence of Salmonella typhimurium load and specific antibodies on phagocytosis in schistosomiasis. Macrophages from Schistosoma mansoni-infected mice showed depressed capacity to increase the phagocytosis in the presence of a high bacterial load, due to a reduced involvement of these cells in phagocytosis and to a deficient ability to increase the number of phagocytosed bacteria. Normal and Salmonella-infected mice increased their phagocytic capacity when exposed to a high bacterial load. Antibody to Salmonella increased the phagocytic capacity of macrophages from Schistosoma-infected mice due to an increase in the number of bacteria phagocytosed but caused no modification in the number of macrophages engaged in phagocytosis. Our data indicate that macrophages from Schistosoma-infected mice work close to their functional limit, since no increase in phagocytosis was observed after increasing the bacterial load. Specific antibodies can improve their phagocytic capacity and, therefore, could help clearing concurrent infection.

scholarly journals Sources of Carbon to Deep-Sea Corals

Radiocarbon ◽  
1989 ◽  
Vol 31 (03) ◽  
pp. 533-543 ◽  
Author(s):  
Sheila Griffin ◽  
Ellen R M Druffel
Keyword(s):  
Growth Rate ◽  
Organic Matter ◽  
Deep Sea ◽  
Inorganic Carbon ◽  
Sea Water ◽  
Dissolved Inorganic Carbon ◽  
Growth Rings ◽  
Time Histories ◽  
Visible Growth ◽  
Deep Sea Corals

Radiocarbon measurements in deep-sea corals from the Little Bahama Bank were used to determine the source of carbon to the skeletal matrices. Specimens of Lophelia, Gerardia, Paragorgia johnsoni and Corallium noibe were sectioned according to visible growth rings and/or stem diameter. We determined that the source of carbon to the corals accreting organic matter was primarily from surface-derived sources. Those corals that accrete a calcerous skeleton were found to obtain their carbon solely from dissolved inorganic carbon (DIC) in sea water from the depth at which the corals grew. These results, in conjunction with growth-rate studies using short-lived radioisotopes, support the use of deep-sea corals to reconstruct time histories of transient and non-transient tracers at depth in the oceans.

scholarly journals Enhancing the Feasibility ofMicrocystis aeruginosaas a Feedstock for Bioethanol Production under the Influence of Various Factors

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Muhammad Imran Khan ◽  
Moon Geon Lee ◽  
Hyo Jin Seo ◽  
Jin Hyuk Shin ◽  
Tai Sun Shin ◽  
...  
Keyword(s):  
Growth Rate ◽  
Fermentation Process ◽  
Aminolevulinic Acid ◽  
Pichia Stipitis ◽  
Naphthalene Acetic Acid ◽  
Bioethanol Production ◽  
Algae Biomass ◽  
Pretreatment Method ◽  
Red Led ◽  
Different Types

Microcystis aeruginosa, a freshwater microalga, is capable of producing and accumulating different types of sugars in its biomass which make it a good feedstock for bioethanol production. Present study aims to investigate the effect of different factors increasing growth rate and carbohydrates productivity ofM. aeruginosa. MF media (modified BG11 media) and additional ingredients such as aminolevulinic acid (2 mM), lysine (2.28 mM), alanine (1 mM), and Naphthalene acetic acid (1 mM) as cytokine promotedM. aeruginosagrowth and sugar contents.Salmonellashowed growth-assisting effect onM. aeruginosa. Enhanced growth rate and carbohydrates contents were observed inM. aeruginosaculture grown at 25°C under red LED light of 90 μmolm−2s−1intensity. More greenish and carbohydrates richM. aeruginosabiomass was prepared (final OD660 nm= 2.21 and sugar contents 10.39 mM/mL) as compared to control (maximum OD660 nm= 1.4 and sugar contents 3 mM/mL). The final algae biomass was converted to algae juice through a specific pretreatment method. The resulted algae Juice was used as a substrate in fermentation process. Highest yield of bioethanol (50 mM/mL) was detected whenBrettanomyces custersainus,Saccharomyces cerevisiae, andPichia stipitiswere used in combinations for fermentation process as compared to their individual fermentation. The results indicated the influence of different factors on the growth rate and carbohydrates productivity ofM. aeruginosaand its feasibility as a feedstock for fermentative ethanol production.

Aspects of Estimating Zooplankton Production from Phytoplankton Production

1969 ◽  
Vol 26 (2) ◽  
pp. 199-220 ◽  
Author(s):  
C. D. McAllister
Keyword(s):  
Growth Rate ◽  
Primary Productivity ◽  
Secondary Production ◽  
Relative Effect ◽  
Plant Production ◽  
Phytoplankton Production ◽  
Continuous Grazing ◽  
Different Types ◽  
Phytoplankton Growth Rate ◽  
Zooplankton Production

Primary productivity and zooplankton data from Ocean Station P are used to compare estimates of phytoplankton and herbivore production calculated on the assumption of continuous grazing by the animals with estimates obtained on the assumption of three different types of nocturnal grazing. Effective plant production, that corrected for the effects of grazing on the size of the phytoplankton stock and hence on the magnitude of the plant respiratory loss, was less than the measured production and was least under the assumption of continuous grazing. The small differences in effective production resulting from the choice of different grazing schemes resulted in large differences in estimates of secondary production. The relative effect of assuming different grazing schemes on the estimate of secondary production varied markedly with zooplankton respiration and with the phytoplankton growth rate.

Cleaning and Reflow of Pb-Sn C4 Solder Bumps

1995 ◽  
Vol 117 (4) ◽  
pp. 281-287 ◽  
Author(s):  
Caroline S. Lee ◽  
Doug C. Crafts ◽  
T. W. Eagar
Keyword(s):  
Growth Rate ◽  
Surface Layer ◽  
Reaction Rate ◽  
Diffusion Rate ◽  
Primary Component ◽  
Corrosion Layer ◽  
Dense Layer ◽  
Surface Corrosion ◽  
Solder Bumps ◽  
Electroplating Process

The Pb/Sn electroplating process for C4 technology requires the ability to etch Ball Limiting Metallurgy (BLM) in the presence of the Pb/Sn bumps. Upon etching, a surface corrosion layer is formed and an appropriate cleaning acid must be used to remove this layer prior to solder reflow of the bumps. It was found that the morphology of the surface layer formed upon etching on the Pb/Sn solder bumps is critically dependent on the concentration of the etchant. Using a gravimetric test, XPS and AES analysis, PbO containing small amounts of Sn and S, was identified to be the primary component of the surface. The thickness morphology, composition and the growth rate of the layer are critically dependent on the sulfur from the etchant. In H2O2-rich solutions, the surface appears to be loosely packed and the growth rate on the surface of the bump was found to be reaction-rate limited; whereas, in H2SO4-rich solutions, the diffusion rate is the controlling step informing the surface layer on the solder bumps, thus producing a thin and dense layer.

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