Inactivation Rates of Cronobacter spp. and Selected Other Bacterial Strains in Powdered Infant Formulae Stored at Different Temperatures

2010 ◽  
Vol 73 (5) ◽  
pp. 839-848 ◽  
Author(s):  
M. C. KANDHAI ◽  
M. W. REIJ ◽  
M. van SCHOTHORST ◽  
L. G. M. GORRIS ◽  
M. H. ZWIETERING
Keyword(s):  
Distribution Model ◽  
Effect Of Temperature ◽  
Powdered Infant Formula ◽  
Bacterial Cells ◽  
Bacterial Strains ◽  
Infant Formulae ◽  
Different Temperatures ◽  
D Values ◽  
Log Linear ◽  
Increasing Temperature

The aim of this study was to determine the survival of two strains of Cronobacter (Enterobacter sakazakii) and six other bacterial strains inoculated into dry powdered infant formula (PIF) stored for 22 weeks at several temperatures between 7 and 42°C. The experimental setup involved a relatively high initial concentration of bacteria, around 104 CFU/g of powder, and enumeration of survivors with a minimum detection level of 100 CFU/g. For all strains tested, it was found that the number of bacterial cells decreased faster with increasing temperature. Cronobacter spp. cells generally survived better at high temperatures (37 and 42°C) than the other bacteria, while such a difference in survival was not apparent at other temperatures. To describe the effect of temperature on survival, both the Weibull distribution model and the log-linear model were tested. At 22°C, decline rates of 0.011 and 0.008 log units per day were found for Cronobacter sakazakii ATCC 29544 and Cronobacter strain MC10, respectively. Assuming a linear relationship between log-transformed D-values and temperature, z-values estimated for C. sakazakii ATCC 29544 and Cronobacter MC10 were 13.3 and 23.5°C, respectively. Such differences found in resistance among Cronobacter spp. would be relevant to consider when establishing quantitative risk assessments on consumer risks related to PIF.

Transport kinetics of methanol in hydroxyethyl methacrylate homopolymer and its copolymers

2004 ◽  
Vol 19 (11) ◽  
pp. 3359-3363 ◽  
Author(s):  
C-S. Tsai ◽  
Sanboh Lee ◽  
Tinh Nguyen
Keyword(s):  
Continuous Phase ◽  
Transport Processes ◽  
Hydroxyethyl Methacrylate ◽  
Nominal Thickness ◽  
Methacrylate Copolymers ◽  
Different Temperatures ◽  
Free Energy Of Mixing ◽  
D Values ◽  
Increasing Temperature ◽  
Kinetics Of

The kinetics of methanol transport in 2-hydroxyethyl methacrylate (HEMA) homopolymer and 75/25 and 50/50 mol fraction HEMA/DHPMA (2,3-dihydroxypropyl methacrylate) copolymers at five different temperatures has been investigated using the sorption experiment technique. A combined case I and case II diffusion model was used to describe the transport processes. Four replicates for each temperature of each material having a nominal thickness of 0.1 mm were immersed in methanol maintained at 35, 40, 45, 50, and 55 °C, and the mass uptake as a function of time was measured gravimetrically. Experimental results are found to be in good agreement with model prediction at all temperatures and for all three materials. Both the diffusion coefficients of case I transport and velocity of case II transport increase with increasing temperature. D values at low temperatures (35 and 40 °C), which are in the 10−9 cm2/s range, of the HEMA homopolymer are less than those of the copolymers. On the other hand, the activation energies of case I transport of the copolymers are substantially higher than those of the HEMA homopolymer; however, the level of DHPMA loading in the copolymer does not seem to affect the activation energy. In addition, thermodynamic heat and free energy of mixing values indicate heat is released when HEMA/DHPMA copolymers are exposed to methanol and that the solvent/copolymer systems exist as a continuous phase. In contrast, the methanol/HEMA homopolymer system exists as separate phases.

scholarly journals The effect of temperature on persistence of SARS-CoV-2 on common surfaces

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Shane Riddell ◽  
Sarah Goldie ◽  
Andrew Hill ◽  
Debbie Eagles ◽  
Trevor W. Drew
Keyword(s):  
Uv Light ◽  
Risk Mitigation ◽  
Survival Rates ◽  
Environmental Stability ◽  
Effect Of Temperature ◽  
Viral Loads ◽  
Different Temperatures ◽  
C 30 ◽  
D Values

Abstract Background The rate at which COVID-19 has spread throughout the globe has been alarming. While the role of fomite transmission is not yet fully understood, precise data on the environmental stability of SARS-CoV-2 is required to determine the risks of fomite transmission from contaminated surfaces. Methods This study measured the survival rates of infectious SARS-CoV-2, suspended in a standard ASTM E2197 matrix, on several common surface types. All experiments were carried out in the dark, to negate any effects of UV light. Inoculated surfaces were incubated at 20 °C, 30 °C and 40 °C and sampled at various time points. Results Survival rates of SARS-CoV-2 were determined at different temperatures and D-values, Z-values and half-life were calculated. We obtained half lives of between 1.7 and 2.7 days at 20 °C, reducing to a few hours when temperature was elevated to 40 °C. With initial viral loads broadly equivalent to the highest titres excreted by infectious patients, viable virus was isolated for up to 28 days at 20 °C from common surfaces such as glass, stainless steel and both paper and polymer banknotes. Conversely, infectious virus survived less than 24 h at 40 °C on some surfaces. Conclusion These findings demonstrate SARS-CoV-2 can remain infectious for significantly longer time periods than generally considered possible. These results could be used to inform improved risk mitigation procedures to prevent the fomite spread of COVID-19.

scholarly journals Mineral Composition and Antioxidant Potential in the Common Poppy (Papaver rhoeas L.) Petal Infusions

2020 ◽  
Vol 199 (1) ◽  
pp. 371-381
Author(s):  
Janda Katarzyna ◽  
Jakubczyk Karolina ◽  
Kupnicka Patrycja ◽  
Bosiacki Mateusz ◽  
Gutowska Izabela
Keyword(s):  
Vitamin C ◽  
Mineral Content ◽  
Antioxidant Potential ◽  
Effect Of Temperature ◽  
Total Polyphenol ◽  
Spectrophotometric Methods ◽  
Inflammatory Conditions ◽  
Different Temperatures ◽  
The Common ◽  
Increasing Temperature

AbstractThe flowers of the common poppy are used for medicinal purposes, both internally and externally. They are reported to have antispasmodic and antitussive properties, to alleviate inflammatory conditions and soothe anxiety-related digestive problems. The aim of the study was to determine the antioxidant potential and the content of vitamin C, polyphenols, and minerals in infusions made from the petals of the common poppy at different temperatures. The infusions were made at various temperatures (25 °C, 70 °C, 80 °C, and 90 °C). The antioxidant potential and the content of polyphenols and vitamin C were determined by spectrophotometric methods. The mineral content was determined using the ICP-OES method. The total polyphenol content ranged from 135.2 to 137.24 ppm and that of vitamin C—from 15.47 to 15.78 mg/100 mL. The temperature of the water used to make the infusions did not appear to have a significant effect on these parameters. The temperature did, however, significantly affect the antioxidant potential of the infusions—the highest antioxidant activity (71.21% DPPH inhibition) was observed in the infusion prepared using water at 80 °C. The infusions included in the study contained a number of minerals. No significant effect of temperature was found for the content of K, Zn, Cu, Fe, and Ni in the infusions. On the other hand, the content of Ca in the infusions was significantly correlated with the increasing temperature of the water. It was concluded that poppy petal infusions may serve as a valuable dietary supplement, providing antioxidants and minerals required by the human body to function properly.

Use of BI-Pb-Sn-Cd Alloy in Self-neutralisation Mechanism for Sub-munitions

2015 ◽  
Vol 65 (6) ◽  
pp. 438 ◽  
Author(s):  
Qingyan Ma ◽  
Ya Zhang
Keyword(s):  
Failure Rate ◽  
Steel Wire ◽  
Health Hazard ◽  
Economic Loss ◽  
The Self ◽  
Effect Of Temperature ◽  
Military Operations ◽  
Different Temperatures ◽  
Soft Metal ◽  
Increasing Temperature

<p class="P1">Unexploded sub munitions for military operations posed economic loss and health hazard. The need for unexploded sub munitons to be rendered safe after a certain period of time was of importance to the militaty. In this work, a self-neutralizing sub-component using soft metal penetration principle was developed and incorporated to the existing sub munitions so as to include a self-neutralizing feature in such sub munitions. This study was also conducted to determine the potential to use a steel wire to cut BI-Pb-Sn-Cd alloy at different temperatures (-40 °C～40 °C). The effect of temperature on neutralisation time was evaluated in experiments. The experimental results indicated that the neutralisation time was dependent on temperature of soft metal and decreased with increasing temperature. While BI-Pb-Sn-Cd alloy with thickness of 0.75±0.01 mm and height of 2.40 ±0.02 mm was cut by steel wire with a diameter of 0.12 mm, self-neutrlisation of sub munitions was completed ranging from 1min5s to 143 h 2 min. It was concluded that self-neutralisation based on BI-Pb-Sn-Cd alloy could meet its setting requirements in the battlefield, and its failure rate reached less than 10% at between -40 °C and 40 °C, and the self-neutralisation time could be adjusted by the size of soft metal.</p>

scholarly journals The effect of temperature on tacticity for bulk thermal polymerization of styrene

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Farshid Ziaee ◽  
Mehdi Nekoomanesh ◽  
Hamid Salehi Mobarakeh ◽  
Hassan Arabi
Keyword(s):  
Thermal Polymerization ◽  
Effect Of Temperature ◽  
Polymerization Temperature ◽  
Deuterated Chloroform ◽  
Methylene Carbon ◽  
Aromatic Carbon ◽  
First Order ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
Better Than

AbstractThree types of polystyrenes were prepared at different temperatures of 50, 150 and 250°C by bulk thermal polymerization of styrene below 20 percent of conversion. The assignment of all stereosequences at pentad level of quaternary aromatic carbon and hexad level of methylene carbon of the polystyrenes were done using 13C Liquid NMR in deuterated chloroform at similar conditions. Bernoullian and first-order Markov statistics were calculated and the results were compared with experimental NMR results. It is shown that first-order Markov statistics fit slightly better than Bernoullian statistics for the assigned carbons. The results indicated that by increasing polymerization temperature the probability of meso addition (Pm) in polystyrene chains was enhanced. Pm was calculated for polystyrenes prepared at 50, 150 and 250°C and corresponding values were 0.378, 0.398 and 0.402 respectively. It was shown that by increasing temperature the polymerization is directed toward the Bernoullian propagation. By increasing the NMR acquisition temperature from 20 to 65°C higher resolution especially in quaternary aromatic carbon was achieved and the related peak was splitted to 16 peaks corresponding to a heptad level compared to 10 peaks in 20°C.

scholarly journals Temperature Coupling and ‘Trade-Off’ Phenomena in the Acoustic Communication System of the Cricket, Gryllus Bimaculatus De Geer (Gryllidae)

1985 ◽  
Vol 114 (1) ◽  
pp. 17-35 ◽  
Author(s):  
John A. Doherty
Keyword(s):  
Pattern Recognition ◽  
Dominant Frequency ◽  
Calling Song ◽  
Effect Of Temperature ◽  
Gryllus Bimaculatus ◽  
Trade Off ◽  
Temporal Properties ◽  
Syllable Duration ◽  
Different Temperatures ◽  
Increasing Temperature

The effects of ambient temperature on stridulation (calling song) in males, and phonotaxis in females, were studied in the chirping cricket, Gryllus bimaculatus. In the male, temperature had the greatest effect on the syllable and chirp repetition rates. Both increased linearly with increasing temperature between 15 and 24°C; there was no effect of temperature on these temporal properties at higher temperatures (24–33°C). Syllable duration, number of syllables per chirp and dominant frequency remained relatively unaffected by changes in temperature. Stridulation and phonotaxis were temperature coupled because the female at 15, 22 and 30°C responded best to synthetic songs with syllable and chirp repetition rates that matched these temporal properties of the male's calling song at the same temperature. The phonotactic behaviour of the female indicates that certain combinations of temporal properties in the male's calling Song improve the female's response at different temperatures, suggesting the presence of ‘trade-off’ phenomena in phonotaxis and pattern recognition in G. bimaculatus.

Effect of Temperature and Water Immersion on the Mechanical Properties of Coated Fabrics

2010 ◽  
Vol 129-131 ◽  
pp. 230-234
Author(s):  
Ying Ying Zhang ◽  
Qi Lin Zhang ◽  
Chuan Zhi Zhou ◽  
Ying Zhou
Keyword(s):  
Mechanical Properties ◽  
Water Immersion ◽  
Effect Of Temperature ◽  
C 23 ◽  
Different Temperatures ◽  
Temperature Induction ◽  
Effects Of Temperature ◽  
C 50 ◽  
Coated Fabrics ◽  
Increasing Temperature

As composite, the mechanical properties of coated fabrics are sensitive to environment. This paper presented mechanical properties under different environments. A list of uniaxial tests are carried out under different temperatures including -20°C, 0°C, 23°C, 50°C, and 70°C. First, the tensile behaviors at room temperature and the failure behaviors are studied. Then, the effects of temperature on mechanical properties are determined. Finally, the effects of water immersion on mechanical properties are discussed. Results show PTFE coated fabrics remained unchanged in varying temperature and humidity. The temperature has effects on the mechanical properties of PVC coated fabrics. With increasing temperature, the strength decrease and the strain at break increase. The temperature induction factors are proposed for the design and analysis. The water immersion has little effect on the mechanical properties because of the impervious coating.

The Influence of Temperature on the Galvanic Corrosion in Multi-Material System in Seawater

2015 ◽  
Vol 1101 ◽  
pp. 225-228
Author(s):  
Chun Li Wang ◽  
Jian Hua Wu
Keyword(s):  
Corrosion Behavior ◽  
Galvanic Corrosion ◽  
Effect Of Temperature ◽  
Material System ◽  
Ni Alloy ◽  
Different Temperatures ◽  
Influence Of Temperature On ◽  
Zero Resistance ◽  
Increasing Temperature ◽  
Surface Morphologies

The galvanic corrosion behavior of titanium (TA2)/Cu-Ni alloy (B10)/low alloy steel (921A) multi-material system has been studied using a zero-resistance ammeter (ZRA) in seawater at different temperatures. After the tests, the surface morphologies of the samples were detected by SEM. Results showed galvanic corrosion behavior of TA2/B10/921A fulfill the mixed potential theory, 921A acts as the anode and both TA2 and B10 act as the cathodes. The effect of temperature on the galvanic corrosion is important, the corrosion rate increases with increasing temperature.

scholarly journals Effect of Temperature on Diluate Water in Batch Electrodialysis Reversal

Separations ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 229
Author(s):  
Germán Eduardo Dévora-Isiordia ◽  
Alejandra Ayala-Espinoza ◽  
Luis Alberto Lares-Rangel ◽  
María Isela Encinas-Guzmán ◽  
Reyna Guadalupe Sánchez-Duarte ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Significant Degree ◽  
Operating Conditions ◽  
Limiting Current ◽  
Effect Of Temperature ◽  
Input Concentration ◽  
Limiting Current Density ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
The Cost

A high percentage of the agricultural wells in the state of Sonora are overexploited, thus generating a significant degree of saline intrusion and abandonment by nearby communities. In this paper, the effect of temperature on the final concentration of diluted water was evaluated with variations in voltage and input concentration in a batch electrodialysis reversal (EDR) process in order to find the optimal operating conditions, with an emphasis on reducing the energy consumption and cost of desalinated water. Thirty-six samples were prepared: eighteen samples of 2000 mg/L total dissolved solids (TDS) and eighteen samples of 5000 mg/L TDS; brackish well water of 639 mg/L TDS and synthetic salt were mixed to obtain these concentrations. Three different temperatures (25, 30, and 35 °C) and two different voltages (10 and 20 V) were tested for each sample after evaluating the limiting current density. The best salt removal occurred in the 20 V sets, with 18.34% higher removal for the 2000 mg/L TDS experiments and 25.05% for the 5000 mg/L experiments (average between the 25 to 35 °C tests). The temperature positively affected the EDR, especially in the experiments at 10 V, where increasing by 10 °C increased the efficiency by 10.83% and 24.69% for 2000 and 5000 mg/L TDS, respectively. The energy consumption was lower with increasing temperature (35 °C), as it decreased by 1.405% and 1.613% for the 2000 and 5000 mg/L TDS concentrations, respectively (average between the 10 and 20 V tests), thus decreasing the cost per m3 of water.

scholarly journals Degradation of Dazomet by Thermal Fenton and Photo-Fenton Processes under UV and Sun lights at Different Temperatures

2018 ◽  
Vol 15 (2) ◽  
pp. 158-168
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thermodynamic Functions ◽  
Reaction Rate ◽  
Uv Light ◽  
Reaction Rate Constant ◽  
Effect Of Temperature ◽  
Fenton Process ◽  
Fenton Reagents ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
Sun Light

In this research, the degradation of Dazomet has been studied by using thermal Fenton process and photo-Fenton processes under UV and lights sun. The optimum values of amounts of the Fenton reagents have been determined (0.07g FeSO4 .7H2O, 3.5µl H2O2) at 25 °C and at pH 7 where the degradation percentages of Dazomet were recorded high. It has been found that solar photo Fenton process was more effective in degradation of Dazomet than photo-Fenton under UV-light and thermal Fenton processes, the percentage of degradation of Dazomet by photo-Fenton under sun light are 88% and 100% at 249 nm and 281 nm respectively, while the percentages of degradation for photo-Fenton under UV-light are 87%, 96% and for thermal Fenton are 70% and 66.8% at 249 nm and 281 nm respectively. In this research the effect of temperature on all the reactions has been studied in the range 25°C-45°C, it has been noticed that the reaction rate constant (k) has increased with increasing temperature, and the best percentage degradation of Dazomet was at 45°C in all processes, so, the thermodynamic functions ?G*, ?H*, ?S* have been calculated

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