scholarly journals Postharvest Decay Risk Associated with Hydrocooling Tomatoes

Plant Disease ◽  
2000 ◽  
Vol 84 (12) ◽  
pp. 1314-1318 ◽  
Author(s):  
Clément Vigneault ◽  
Jerry A. Bartz ◽  
Steven A. Sargent
Keyword(s):  
Water Uptake ◽  
Cold Water ◽  
Tap Water ◽  
Water Pressure ◽  
Cooling Water ◽  
Erwinia Carotovora ◽  
Free Chlorine ◽  
Continuous Coverage ◽  
Decay Risk ◽  
A Cell

Tomatoes (breaker stage) hydrocooled with a cell suspension of Erwinia carotovora subsp. carotovora containing 50 to 200 mg of free chlorine per liter (ppm) (10°C, pH 7) remained decay free during a 10-day storage at 20°C. Sporadic disease appeared during storage of tomatoes similarly cooled with chlorinated water containing spores of Rhizopus stolonifer. In contrast, when chlorine was omitted from the pathogen suspensions, 50 to 100% of the fruit became diseased. A laboratory-scale shower hydrocooler reduced fruit temperatures from 35 to 15°C within 13.3 min, whereas a flume cooler produced the same temperature reduction in 10.5 min. In both systems, tomatoes increased in weight during cooling, evidence for water uptake. Larger weight increases occurred among tomatoes cooled in the shower than in the flume. An upward instead of downward orientation of stem scars under the shower streams led to significantly larger weight increases, presumably because pores in the stem scar were continuously flooded with water. Tomatoes intermittently submerged in cold water (10 2-min immersions followed by 30-s pauses) absorbed significantly less water than those continuously submerged for 20 min. Hydrocooling appears to be a viable method for rapid cooling of tomatoes. Technical refinements in the hydrocooling process that prevent continuous coverage of fruit surfaces by water should reduce water uptake and the associated risk of pathogen internalization. Maintenance of free chlorine at up to 200 ppm in the cooling water and prevention of direct water pressure on fruit should minimize decay risks. No evidence of phytotoxicity was observed among fruit infiltrated with 200 ppm of chlorine. These tomatoes ripened similarly to those that were not cooled or were cooled in tap water.

scholarly journals Analysis of Soil Water Response to Grass Transpiration

2013 ◽  
Vol 1 (No. 3) ◽  
pp. 85-98
Author(s):  
Dohnal Michal ◽  
Dušek Jaromír ◽  
Vogel Tomáš ◽  
Herza Jiří
Keyword(s):  
Soil Water ◽  
Water Uptake ◽  
Preferential Flow ◽  
Water Movement ◽  
Control Volume ◽  
Water Pressure ◽  
Lower Boundary ◽  
Root Water Uptake ◽  
Water Dynamics ◽  
Soil Water Dynamics

This paper focuses on numerical modelling of soil water movement in response to the root water uptake that is driven by transpiration. The flow of water in a lysimeter, installed at a grass covered hillslope site in a small headwater catchment, is analysed by means of numerical simulation. The lysimeter system provides a well defined control volume with boundary fluxes measured and soil water pressure continuously monitored. The evapotranspiration intensity is estimated by the Penman-Monteith method and compared with the measured lysimeter soil water loss and the simulated root water uptake. Variably saturated flow of water in the lysimeter is simulated using one-dimensional dual-permeability model based on the numerical solution of the Richards’ equation. The availability of water for the root water uptake is determined by the evaluation of the plant water stress function, integrated in the soil water flow model. Different lower boundary conditions are tested to compare the soil water dynamics inside and outside the lysimeter. Special attention is paid to the possible influence of the preferential flow effects on the lysimeter soil water balance. The adopted modelling approach provides a useful and flexible framework for numerical analysis of soil water dynamics in response to the plant transpiration.

Experimental Analysis of Water/Oil Displacement Tests in Horizontal Pipe

SPE Journal ◽  
2021 ◽  
pp. 1-18
Author(s):  
Roberto Fernando Leuchtenberger ◽  
Jorge Luiz Biazussi ◽  
William Monte Verde ◽  
Marcelo de Souza Castro ◽  
Antonio Carlos Bannwart
Keyword(s):  
Viscous Liquid ◽  
High Speed ◽  
Cold Water ◽  
Tap Water ◽  
Logistic Function ◽  
Oil Field ◽  
Injection Velocity ◽  
Internal Diameter ◽  
Oil Viscosity ◽  
Horizontal Pipe

Summary Production shutdowns occur often throughout the life cycle of an oil field. In offshore fields, shutdown situations are accompanied by an intense heat exchange between pipeline and cold water, which exponentially increases oil viscosity. Such an event may lead to serious difficulty to restart the production, or even render it unfeasible, especially for heavy oil fields. Therefore, a preventive procedure is required to remove the ultraviscous oil from pipelines and risers; for example, by pumping diesel or methanol in a flush procedure. Designing an efficient cleanup procedure is therefore essential in terms of time, amount of fluid injected, and pumping system requirements. However, the amount of research published in this area is limited. In this paper, we propose a comprehensive analysis on how the displacement of a viscous liquid by a less-viscous liquid occurs in a pipeline through footages in different segments, varying the injection velocity. Two mineral oils with different viscosities and tap water were used as working fluids for this study. The experimental setup was built with a horizontal 10-m-long acrylic pipe with 19-mm internal diameter. Two high-speed cameras were placed both in the inlet and outlet segments. Our results demonstrate how water displaces viscous oil in a pipeline, showing different flow configurations as superficial water velocity increases, depending on the oil viscosity and distance from the inlet. A dimensionless analysis was performed by a combination of the forces that govern the flow and dimensionless groups found in literature. The results show an expected area of optimum values regarding cleaning time according to flow configuration. A unidimensional model using a logistic function was proposed and showed a good agreement with the experimental data. The model itself proven to be an easy tool for industry and academic purposes, supporting even more robust and elaborated models in the future. NOTE: Supplemental material is available with this paper and is available online under the Supplementary Data heading at https://doi.org/10.2118/205356-PA.

scholarly journals THE ISOLATION OF A CELL MEMBRANE FRACTION FROM RAT LIVER

1960 ◽  
Vol 8 (2) ◽  
pp. 413-422 ◽  
Author(s):  
David M. Neville
Keyword(s):  
Rat Liver ◽  
Membrane Fraction ◽  
Cell Membranes ◽  
Cold Water ◽  
Sucrose Solution ◽  
Nuclear Membranes ◽  
A Cell ◽  
Liver Homogenates ◽  
Cell Fragments ◽  
Crude Membrane Fraction

A procedure is described for isolating cell membranes from rat liver homogenates. 20 gm. of rat liver was homogenized in a Dounce homogenizer in ice cold water buffered to pH 7.5 with NaHCO3, rupturing all of the cells and most nuclei. The diluted homogenate was filtered through cheesecloth to remove precipitated nucleoprotein and centrifuged at 1500 g, 10 minutes, to sediment a crude membrane fraction. The membrane containing sediment was recentrifuged 3 times in conical tubes (1220 g, 10 minutes), the top layer of the 2-layered sediment being retained. Flotation in a sucrose solution d = 1.22 freed the preparation from contaminating cell fragments and nuclear membranes not previously disintegrated. The floating material ∼0.4 ml. was quite homogeneous and consisted of thin amorphous membranes. Electron micrographs revealed numerous double profiles similar in shape and dimensions to apposed liver cell membranes in intact tissue.

scholarly journals Polysaccharides from Basidiocarps of Cultivating Mushroom Pleurotus ostreatus: Isolation and Structural Characterization

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2740 ◽  
Author(s):  
Ekaterina Baeva ◽  
Roman Bleha ◽  
Ekaterina Lavrova ◽  
Leonid Sushytskyi ◽  
Jana Čopíková ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Pleurotus Ostreatus ◽  
Cold Water ◽  
Water Soluble ◽  
Hot Water ◽  
Biologically Active ◽  
Alkaline Extract ◽  
A Cell ◽  
Oyster Mushrooms

Oyster mushrooms are an interesting source of biologically active glucans and other polysaccharides. This work is devoted to the isolation and structural characterization of polysaccharides from basidiocarps of the cultivated oyster mushroom, Pleurotus ostreatus. Five polysaccharidic fractions were obtained by subsequent extraction with cold water, hot water and two subsequent extractions with 1 m sodium hydroxide. Branched partially methoxylated mannogalactan and slightly branched (1→6)-β-d-glucan predominated in cold- and hot-water-soluble fractions, respectively. Alternatively, these polysaccharides were obtained by only hot water extraction and subsequent two-stage chromatographic separation. The alkali-soluble parts originating from the first alkali extraction were then fractionated by dissolution in dimethyl sulfoxide (DMSO). The polysaccharide insoluble in DMSO was identified as linear (1→3)-α-d-glucan, while branched (1→3)(1→6)-β-d-glucans were found to be soluble in DMSO. The second alkaline extract contained the mentioned branched β-d-glucan together with some proteins. Finally, the alkali insoluble part was a cell wall complex of chitin and β-d-glucans.

Investigation of chlorine wall decay in an old, decommissioned metallic pipe using a pipe section reactor

2020 ◽  
Vol 20 (3) ◽  
pp. 953-962
Author(s):  
R. Tonev ◽  
G. Dimova
Keyword(s):  
Reaction Rate ◽  
Rate Coefficient ◽  
Tap Water ◽  
Decay Rates ◽  
Free Chlorine ◽  
Reaction Rate Coefficient ◽  
Pipe Section ◽  
Reaction Coefficient ◽  
Bulk Reaction ◽  
Series Of Experiments

Abstract The study investigates the kinetics of free chlorine depletion in tap water from the Sofia distribution network. The overall decay rates, the bulk reaction rate coefficient, the wall reaction rate coefficient and the influence of mass transfer have been determined in a laboratory pipe section reactor (PSR), testing an old decommissioned metallic pipe. In total, 23 series of experiments were performed under different initial free chlorine concentrations and different hydraulic conditions. The applicability of different chlorine decay mathematical models has been investigated. A new model was proposed, combining zero order bulk reactions and first order wall reactions, describing the laboratory results with Nash-Sutcliffe efficiency coefficients over 0.99. The obtained values for the wall reaction coefficient vary in the range 0.008–0.030 m/h, decreasing exponentially with increasing initial chlorine concentration.

Vacuum Cooling of Cooked Mussels (Perna perna)

2006 ◽  
Vol 12 (1) ◽  
pp. 19-25 ◽  
Author(s):  
E. Huber ◽  
L. P. Soares ◽  
B. A. M. Carciofi ◽  
H. Hense ◽  
J. B. Laurindo
Keyword(s):  
Weight Loss ◽  
Cold Water ◽  
Temperature Drop ◽  
Relative Weight ◽  
Cooling Water ◽  
Hot Water ◽  
Process Time ◽  
Promising Alternative ◽  
Industrial Processing ◽  
Vacuum Cooling

Mussels pass through a thermal treatment during industrial processing with hot water or steam and then are pre-cooled before the manual extraction of the meat. This pre-cooling is classically accomplished by the immersion of the cooked mussels in cold water. In this work, vacuum cooling of mussels after the cooking stage was used as a technique to quickly decrease the product temperature and to avoid a possible microbial contamination by the cooling water or by manipulation. In about 3 minutes, mussels were cooled from about 90 °C to 20 °C. The relative weight loss during the vacuum cooling of the whole sample (meat and shell) was about 8% of the initial sample’s weight, for temperatures drop cited above. In this way, there was a 8.7 0.26 °C temperature drop for each 1% of weight loss. For separated meat (without shell), the ratio was 7.5 0.30 ºC per 1% weight loss, which agreed with the literature for vacuum cooling of meats in general. A simple numerical simulation was able to determine weight loss during the vacuum cooling process, providing data that agreed very well with experimental results. The vacuum cooling technique is a promising alternative for processing pre-cooked mussels, because process time is shortened and cross-contamination risk is significantly reduced in the cooling stage. The water loss is not a serious problem when the cooled mussels are canned in brine.

The Engine Fault Diagnosis Based on Time Domain and Frequency Domain

2014 ◽  
Vol 936 ◽  
pp. 2243-2246 ◽  
Author(s):  
Zhu Ting Yao ◽  
Hong Xia Pan
Keyword(s):  
Fault Diagnosis ◽  
Frequency Domain ◽  
Time Domain ◽  
Water Pressure ◽  
Cooling Water ◽  
Experimental System ◽  
Vibration Signal ◽  
Cylinder Block ◽  
Fuel Temperature ◽  
Multiple Faults

Engine is as a power machine, the operating status is good or bad, directly affects the working status of equipment. The status monitoring and fault diagnosis is very necessary to ensure that the equipment runs in its best, and improves equipment maintenance quality and efficiency. The engine failure shows the complexity and diversity of the interaction and complex relationship between the various subsystems of the engine, that is the fault of complexity, ambiguity, correlation, relativity and multiple faults coexistence. The available information are much in the engine diagnosis, for example, the vibration signal from bearings, cylinder head or cylinder block surface; oil, cooling water, pressure of intake, exhaust and fuel; temperature signal; noise, speed or oil-sample signals. In this paper, an engine as an example, engine fault diagnosis experimental system is built, the normal state, left one and right six cylinders off the oil, air filter blockage (inlet wood blockage is 30%, the inlet has screen cloth.) in the load of 2565Nm, and the speeds of 1500r/min, 1800r/min, 2200r/min are studied. The experimental results analysis, feature extraction and fault diagnosis are finished based on the time domain and frequency domain. Keywords: engine, fault diagnosis, time domain, frequency domain.

Heat Sink Issue: A Specific Safety Issue for NPP Site Selection and Evaluation in the Warm Countries With Extreme Climatic Conditions

2013 ◽  
Author(s):  
Andrei Rodionov ◽  
Jean-Marie Mattei
Keyword(s):  
Site Selection ◽  
Heat Sink ◽  
Cold Water ◽  
Safety Issue ◽  
Cooling Water ◽  
Water Source ◽  
Climatic Conditions ◽  
Spent Fuel ◽  
Regulatory Review ◽  
Human Environment

One of the major issues during the site selection and design of a NPP is the heat sink issue, i.e. installation and availability of reliable and efficient recipient of heat (air, water or both of them) in relation in particular with: • waste the heat removed from the condenser of the turbines during normal operational state, • waste the heat removed from all of the safety-related and non-safety-related equipment and systems during normal operational state, • waste the residual heat removed from nuclear reactor fuel (situated in reactor vessel or tubes), the decay heat removed from nuclear spent fuel (situated in spent fuel pool), and the heat removed from all of the safety-related equipment and systems during abnormal operational state and accident conditions. There are several “newcomer” countries that are situated in warm climate zones. In such countries, the cooling water design could be a challenge with regards to extreme water and air temperatures, air humidity, absence of an important reliable cold water source inside the country, etc. In addition, some specific items related to natural, industrial and human environment should be considered during the site evaluation, as for example, risk of intensive biota development, oil spills, siltation, low water level events, etc. This requires particular consideration of the heat sink issue for the site regulatory review during the licensing process. The article discusses the methodology for site regulatory review with regards to the heat sink issue and provides some practical advises on safety assessment and acceptance criteria to be considered.

Urinary responses to cold temperature during water immersion

1985 ◽  
Vol 248 (5) ◽  
pp. R560-R566 ◽  
Author(s):  
D. R. Knight ◽  
S. M. Horvath
Keyword(s):  
Sodium Excretion ◽  
Cold Water ◽  
Water Pressure ◽  
Water Immersion ◽  
Free Water ◽  
Cold Water Immersion ◽  
Cold Temperature ◽  
Ambient Water ◽  
Cold Temperatures ◽  
Diuretic Response

If cold temperature combines with ambient water pressure to stimulate the Henry-Gauer reflex in humans, then free water clearance (CH2O) should be greater during immersion in cold water (29.8 degrees C) than during exposure to cold air (14.8 degrees C) or immersion in thermoneutral water (35 degrees C). Urinary responses to these environments were compared with control measurements made during 6 h of sitting in thermoneutral air (27.6 degrees C). CH2O was not significantly greater in cold water than in the other environments. Rather, the diuretic response was characterized by an increased osmolar clearance (P less than 0.05). Cold temperature and water pressure additively raised urinary output during cold water immersion, with ambient water pressure accounting for two-thirds of the urinary water loss. An elevated rate of sodium excretion (P less than 0.05) began significantly earlier in cold water than in thermoneutral water. This effect of low temperature might have resulted from cold-induced vasoconstriction, since cold temperatures was observed to reduce the foot volume. Sodium excretion was inversely proportional to vital capacity, indicating a responsiveness of the kidney to expansion of the central blood volume. In addition to the effects of water pressure and cold temperature, urinary function was also sensitive to time. The rate of potassium excretion was significantly elevated at min 199 of exposure to all environments. Failure of CH2O to increase above control values indicated that the human diuretic response to cold water immersion is atypical for the Henry-Gauer reflex.

scholarly journals Water Quality as a Predictor of Legionella Positivity of Building Water Systems

Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 295 ◽  
Author(s):  
David Pierre ◽  
Julianne L. Baron ◽  
Xiao Ma ◽  
Frank P. Sidari ◽  
Marilyn M. Wagener ◽  
...  
Keyword(s):  
Water Quality ◽  
Cold Water ◽  
Water Systems ◽  
Quality Parameters ◽  
Free Chlorine ◽  
Hot Water ◽  
Water Quality Parameters ◽  
Plate Count ◽  
Poor Correlation ◽  
Distal Site

Testing drinking water systems for the presence of Legionella colonization is a proactive approach to assess and reduce the risk of Legionnaires’ disease. Previous studies suggest that there may be a link between Legionella positivity in the hot water return line or certain water quality parameters (temperature, free chlorine residual, etc.) with distal site Legionella positivity. It has been suggested that these measurements could be used as a surrogate for testing for Legionella in building water systems. We evaluated the relationship between hot water return line Legionella positivity and other water quality parameters and Legionella colonization in premise plumbing systems by testing 269 samples from domestic cold and hot water samples in 28 buildings. The hot water return line Legionella positivity and distal site positivity only demonstrated a 77.8% concordance rate. Hot water return line Legionella positivity compared to distal site positivity had a sensitivity of 55% and a specificity of 96%. There was poor correlation and a low positive predictive value between the hot water return line and distal outlet positivity. There was no correlation between Legionella distal site positivity and total bacteria (heterotrophic plate count), pH, free chlorine, calcium, magnesium, zinc, manganese, copper, temperature, total organic carbon, or incoming cold-water chlorine concentration. These findings suggest that hot water return line Legionella positivity and other water quality parameters are not predictive of distal site positivity and should not be used alone to determine the building’s Legionella colonization rate and effectiveness of water management programs.

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