Distilled Water and Tap Water as Factors in Taste Preference of the Rat

1966 ◽  
Vol 18 (1) ◽  
pp. 159-162 ◽  
Author(s):  
Paul Thomas Young

Schnorr and Brookshire demonstrated that naive rats reared from weaning on distilled water prefer distilled water to tap water; Ss reared on tap water also prefer distilled water, which result approaches statistical significance. This preference for distilled water is directly opposed to findings of Young and Falk who demonstrated a preference for tap water. The present paper is an analysis and interpretation of these experiments along with data from two further studies of taste preference.

1965 ◽  
Vol 17 (1) ◽  
pp. 191-194 ◽  
Author(s):  
John A. Schnorr ◽  
Kenneth H. Brookshire

Albino rats were permitted to drink either distilled water or tap water from two bottles. Animals with prior experience with distilled water in the home cage showed a consistent preference for distilled water which increased over test sessions; Ss having prior experience with tap water did not show statistically reliable preference behavior. Amount of water deprivation during the test session and length of test session were not significant variables. It was concluded that previous results showing a preference for tap water reflect the operation of several variables including prior experience, but the present experiment casts doubt on interpretations, suggesting that tap water is in some general way more palatable or that tap water and distilled water may be equated when interpreting experiments on taste preference.


2021 ◽  
pp. 014556132098606
Author(s):  
Nguyen Quynh Anh ◽  
Pawin Numthavaj ◽  
Thongchai Bhongmakapat

Objectives: This study compared the cerumen dissolution activities of 7.5% sodium bicarbonate, 5% potassium hydroxide, 10% lactic acid, 3% salicylic acid, 10% glycolic acid, and distilled water. Methods: An in vitro study was conducted with 36 cerumen samples. The cerumenolytic activities of the 6 agents were assessed by recording the degree of cerumen disintegration using digital photography at 15 minutes, 30 minutes, 1 hour, 2 hours, and 12 hours. The undissolved cerumen that remained after 12 hours was removed from the solutions and weighed after drying. Results: Potassium hydroxide showed the fastest cerumenolytic activity, dissolving a moderate amount of cerumen at 30 minutes, while glycolic acid and salicylic acid caused no visible changes in the cerumen samples. Samples treated with potassium hydroxide and sodium bicarbonate exhibited higher degrees of disintegration compared to samples treated with distilled water (odds ratio and 95% CI: 273.237 [0.203-367 470.4] and 1.129 [0.002-850.341], respectively). The greatest reduction in cerumen weight was associated with the use of sodium bicarbonate; however, this result did not reach statistical significance. Conclusions: Among the solutions tested, 5% potassium hydroxide showed the fastest dissolution activity, yielding moderate disintegration within only 30 minutes. In terms of residual cerumen weight within 12 hours, all solutions exhibited equivalent effectiveness in the disintegration of cerumen.


1966 ◽  
Vol 19 (2) ◽  
pp. 445-446 ◽  
Author(s):  
Paul Thomas Young

Further discussion of the Schnorr and Brookshire study of the preference between distilled water and tap water, with comments and suggestions.


2019 ◽  
Vol 230 (12) ◽  
Author(s):  
Agnieszka Dąbska

AbstractThe research goal was to investigate the hydraulic conductivity of compacted lime-softening sludge as a material to be applied to landfill liners. In doing so, the effect of compaction and moulding moisture content on the sludge hydraulic conductivity was assessed. An approximate polynomial k10mean at hydraulic gradients ≥30 for degree of compaction (0.95–1.05) and moulding moisture content (28%–36%) was determined. The results of short-term tap water permeation tests revealed that all hydraulic conductivity values were less than 2.5•10–8 m/s. A lowest hydraulic conductivity of 6.5•10–9 m/s, as well as a corresponding moisture content of 31% were then established. The long-term hydraulic conductivity was measured with tap water, distilled water, NaOH and HCl solutions and municipal waste leachate. The factors of permeating liquids and permeation time significantly affected the initial hydraulic conductivity. The long-term hydraulic conductivity increased for NaOH and HCl solutions and decreased for tap and distilled water. A significant reduction of hydraulic conductivity was observed for leachate permeation. The investigated material met the requirements for the liner systems of inert landfill sites regardless of pH and the limit value for hazardous and non-hazardous waste landfills.


1979 ◽  
Vol 42 (8) ◽  
pp. 654-655 ◽  
Author(s):  
BARBARA L. GREEN ◽  
WARREN LITSKY

Two different cartridge-type water treatment systems were evaluated for use in the microbiology laboratory, employing the Distilled Water Suitability Test (DWST). The Milli-Q system fed by distilled water and the Milli-R/Q system fed by tap water both produced water acceptable for microbiological use as measured by the DWST. Concentrations of ionic species (as measured by conductivity) in Milli-Q and Milli-R/Q products were significantly lower than in the double distilled control water.


1970 ◽  
Vol 48 (9) ◽  
pp. 592-597 ◽  
Author(s):  
G. Norris Melville ◽  
W. T. Josenhans ◽  
W. T. Ulmer

Effects of increased water content of inspired air at 21–38 °C on specific airway resistance (sRaw) in 107 healthy subjects were measured with a body plethysmograph. Mean sRaw increased insignificantly at 23 °C with 92% relative humidity (water content, 20.7 g∙m−3) for up to 71 h but became significant at 6 h with water content 25 g∙m−3. Increases were greater when evaporated tap water was inhaled than when distilled water was used. It is postulated that the increase in sRaw is due to mucosal swelling and to contaminants in tap water. A theory of respiratory "water elimination" is proposed to replace the concept of respiratory water loss.


1948 ◽  
Vol 26f (2) ◽  
pp. 91-104 ◽  
Author(s):  
C. K. Johns

Using Staphylococcus aureus and Eschericha coli as test organisms, the influence of various concentrations of skim milk on the germicidal potency of Roccal and of Dalglish hypochlorite solutions was studied. Both germicides retained their activity in the presence of unexpectedly high concentrations of skim milk, especially against S. aureus. Small concentrations frequently showed a slight potentiating effect in both laboratory and plant tests. The effectiveness of the hypochlorite fell off sharply beyond a certain concentration, while that of Roccal declined more gradually. Solutions of Roccal prepared with tap water were decidedly less active against E. coli than those prepared with distilled water. With the hypochlorite, tap water solutions were equally effective. Against S. aureus, a similar difference was noted although to a lesser extent. Added skim milk depressed the germicidal action of tap water solutions of Roccal to a greater extent than for distilled water solutions, while for the hypochlorite the reverse held true.


Weed Science ◽  
1979 ◽  
Vol 27 (1) ◽  
pp. 38-41 ◽  
Author(s):  
P. W. Stahlman ◽  
W. M. Phillips

Several inorganic salts added to the spray solution reduced the herbicidal activity of glyphosate [N-(phosphonomethyl)glycine]. Of the salts tested, iron and aluminum reduced herbicidal activity most. Reductions by calcium and zinc were moderately severe; by magnesium, moderate; by potassium and sodium, none. The reduction in phytotoxicity seems to be caused by cations, but factors other than valence also may be involved.Reduction in phytotoxicity was related to salt concentration and spray volume. Glyphosate at 0.84 kg/ha in 93 to 374 L/ha distilled water killed test plants. Tap water was an equally effective carrier at 93 and 187 L/ha volumes, but was significantly less effective at the 374 L/ha volume. Activity decreased as the molar concentration of CaCl2 increased to 0.01. Herbicidal activity was eliminated at 0.01 M and 374 L/ha; however, concentrations of CaCl2 exceeding 0.04 M reversed the trend and reacted similarly to a 0.005 M solution, which approximates the minimum hardness of most ground waters in Kansas.


1986 ◽  
Vol 32 (112) ◽  
pp. 397-403 ◽  
Author(s):  
R. Ettema ◽  
J.A. Schaefer

AbstractSeries of experiments were conducted with the aim of determining the influences of the following factors on freeze-bonding between contacting ice blocks in floating ice rubble: pressure normal to the contact plane, period and area of contact, and salinity of the water in which freeze-bonding occurred. Freeze-bonding between ice blocks in air was also investigated. The experiments were conducted with water and air temperatures of about 0°C and normal pressures, between ice blocks, up to 4 kPa. This range of normal pressures may occur hydrostatically between ice blocks in layers of floating ice rubble up to about 10 m thick, or in 2-3 m thick layers which are in a passive Rankine state of pressure. The experiments show that stronger freeze-bonds develop between ice blocks in distilled water, tap water, and water from the Iowa River than develop between ice blocks contacting in air at 0°C. However, stronger freeze-bonds developed in air at 0°C than developed between ice blocks in 0°C saline (NaCl) solutions with salinities in excess of 12.5% by weight. The strength of freeze-bonding increased linearly with contact period for ice blocks in distilled, tap, and river waters, but did not increase with contact period for ice blocks contacting in saline solutions or in air. The results of the experiments are useful contributions to explanations of the shear-strength behavior of a layer of floating ice rubble. For example, thicker layers of ice rubble may show greater cohesive behavior, because normal pressures and thus freeze-bond strengths increase with layer thickness.


2014 ◽  
Vol 59 (3) ◽  
pp. 243-254 ◽  
Author(s):  
Kanayo Chukwuka ◽  
Maxwell Obiakara ◽  
Israel Ogunsumi

Screen house experiments were carried out to examine the effects of aqueous leaf extracts of Tithonia diversifolia (Ti) and Vernonia amygdalina (Ve), as well as NPK fertilizer (15-15-15) on the germination, growth and development of maize. Fresh leaves were collected, washed with tap water, chopped and pounded, soaked in distilled water and filtered. The two filtrates were used to prepare extracts at 50 and 100% w/v. Four maize seeds were placed in Petri dishes laid out in a completely randomized design with five replicates. In every Petri dish 10 ml of extract per treatment was added. A control experiment with distilled water was also set up. Also, in a completely randomized design with four replicates, 4-week-old potted maize plants were treated with 500 ml of each extract as well as with 1.52 g of NPK fertilizer. The results showed that the germination percentage of the seeds followed the order Ti50 - Control - Ve50. The seeds treated with aqueous extracts of T. diversifolia and V. amygdalina at 100% w/v produced lower but equal germination percentage. The seedling radicle growth was significantly inhibited by the aqueous extracts of Ti100, Ve50 and Ve100 (p?0.05). The inhibition was dose-dependent and more pronounced in seeds treated with extracts of V. amygdalina. The aqueous extract of T. diversifolia (50% w/v) and control influenced radicle growth substantially. All the extracts inhibited the plumule development compared to the control. On the other hand, growth, development and yield were not significantly affected by the plant extracts.


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