Beaker Of Water Research Articles

Effectiveness of hypothermia prevention devices for preterm infants: A laboratory study.

Newborn hypothermia at birth remains as global challenge across all settings. The prevention of delivery room hypothermia at birth could potentially reduce neonatal morbidity and mortality. To compare the heat conservation efficacy of Neohelp and Neowrap and evaluate the heat production efficacy of trans-warmer infant mattress (TWM) in a laboratory setting. A beaker of water was heated at 60∘C was covered by Neohelp or two layers of Neowrap and left to cool in an open room for 90 minutes and calculated the decay constant. Using infra-red camera, we measured the maximum temperature and time taken to reach the temperature in the TWM. Neowrap took 863 seconds for the temperature to drop from 37∘C to 35∘C, compared with 941 seconds with Neohelp. When activated TWM reached a maximum temperature of 39.3 ± 0.1∘C. It took 30 seconds when the activator was placed in the centre, compared with 88 seconds when it was at the corner. Compared to Neowrap, Neohelp had better heat conservation properties. Activating the metal disk from the TWM center would deliver quicker heat.

К БИОЛОГИИ OENANTHE AQUATICA (L.) POIR. (UMBELLIFLORAE)

The results of experiments on seed germination and the initial stages of ontogenesis of the hygrohelophyte Oenanthe aquatica under laboratory conditions are presented. The features of fruit germination and the initial stages of ontogenesis of Oenanthe aquatica (L.) Poir were studied. It was revealed that mature fruits of O. aquatica do not have a dormant period. Germination of both freshly harvested fruits and those subjected to various storage conditions for 4 months (in laboratory conditions, refrigerator and freezer), showed a high percentage of laboratory germination from 90.6 to 100%. At the same time, storage of fruits in the freezer and in the refrigerator led to a decrease in the lag-time and germination period (in comparison with those of freshly picked fruits and fruits stored at room temperature). It was revealed that the fruits of O. aquatica germinate without a dormant period. It was shown that the development of O. aquatica seedling under laboratory conditions lasts about 30 days. The transition of a plant to a juvenile ontogenetic state occurs when the cotyledon leaves die off and is accompanied by the appearance of all the main plant organs. The sprout is a monopodially growing rosette shoot with main and adventitious roots. The juvenile plant is also represented by a uniaxial monopodial and anisotropic rosette shoot. The transition to an immature age-related state is characterized by the preservation of the rosette form of growth and the appearance of axillary buds on the shoot. In juvenile and immature age states, plants usually hibernate. It was revealed that already at the seedling stage, the polyvariance of ontogenesis is traced according to the rates of development of plants (growing in Petri dishes and floating on the surface of the water in beakers), associated with different rates of plant transition from the seedling phase to the juvenile age state.

Effect of Anaerobic Condition on the Induction of α-Amylase in Rice (Oryza sativa L.) Seeds

Rice has the unique ability to express α-amylase under anoxic conditions, a feature that is critical for successful anaerobic germination and growth. We examined α-amylase activity in 8 genotypes of rice (Oryza sativa L.) seed in laboratory condition, which showed different seedling establishment traits in field experiments, grown in anaerobic condition. There was tolerant check (Savita) and susceptible check (Sambha). Anaerobic condition was maintained by 10 cm water in beaker. Result emphasised that in tolerant genotypes amylase activity was significantly higher than susceptible check (Sambha) at different day intervals but optima were observed at 5th day. Maximum amylase activity was found in Sipulutpandon among all genotypes.

A floating water bridge produces water with excess charge

Excess positive and negative Bjerrum-defect like charge (protonic and ‘aterprotonic’, from ancient Greek ἄ'τερ, ‘without’) in anolyte and catholyte of high voltage electrolysis of highly pure water was found during the so-called ‘floating water bridge’ experiment. The floating water bridge is a special case of an electrohydrodynamic liquid bridge and constitutes an intriguing phenomenon that occurs when a high potential difference (~kV cm−1) is applied between two beakers of water. To obtain such results impedance spectroscopy was used. This measurement technique allows the depiction and simulation of complex aqueous systems as simple electric circuits. In the present work we show that there is an additional small contribution from the difference in conductivity between anolyte and catholyte which cannot be measured with a conductivity meter, but is clearly visible in an impedance spectrum.

Shooting Fish in a Barrel: A Demonstration of the Refraction of Light

This is not a treatise on optics or the index of refraction. It is merely a demonstration that will surprise and engage many of your students. We have all put a pencil in a beaker of water and observed how it appears to bend.1 Not so much fun or engaging, is it? Why not illustrate this optical effect by taking your students spearfishing? Simulated spearfishing, to avoid the financial and legal ramifications.

BIOPRODUTOS A PARTIR DO ÓLEO VEGETAL RESIDUAL: DESENGRAXANTES BASEADOS EM RESÍDUOS DE ROCHAS E CARVÃO VEGETAL

Vegetable oils are widely used by the Brazilian population, whether domestic, commercial or industrial level. At the end of processing, the remaining oil is discarded, often incorrectly, or being released in effluents directly into the soil, making it a potentially polluting waste. The objective of this work is to obtain two alternative bioproducts such as mitigating the environmental impact caused by the improper disposal of waste vegetable oil. The processing starts with the dissolution of the solid soap in water in beaker and homogenized for 10 minutes to form a semisolid paste. Then was added 10g of residual charcoal powder, coal, granite, marble and/or other rocks, homogenizing for 3 minutes. The result of the processing described in the methods is a semi-solid paste, sandy exfoliating action and physical characteristic when used residual powder of marble and/or granite. When used residual charcoal powder, the result is a dark color and abrasive action. This work showed the possibility of obtaining two bioproducts as alternatives to mitigate the environmental impact caused by improper disposal of waste vegetable oil. The raw materials not expensive simplified procedures and routine equipment positively stimulate their production.

Effective Optimization of Temperature Uniformity and Power Efficiency in Two-ports Microwave Ovens

Microwave assisted chemical reaction is increasingly studied in recent years by using the modified domestic microwave oven to heating on chemical reaction in the laboratory scale study. But the problems of temperature distribution non-uniformity and low power efficiency in the heating process are becoming a new obstacle in the application of microwave chemistry. An optimized microwave oven with two sources is proposed in this paper from the view of feeding system to overcome these disadvantages. As water is usually concerned as important solvent and reactant, a beaker of water is used as heating load in this study. By modeling the process of heating water for 180 s, the standard deviation and the average temperature are compared between the domestic microwave oven and the optimized microwave oven with two sources. As a result, the power is utilized more efficiently as a 20.14% increase can be seen by using the optimized microwave oven under the same microwave power and more uniformity is obtained as a 11.23% increase is performed by the use of the optimized microwave oven under the same heating conditions.

Defusing Diffusion

Diffusion has often been taught in science courses as one of the primary ways by which molecules travel, particularly within organisms. For years, classroom teachers have used the same common demonstrations to illustrate this concept (e.g., placing drops of food coloring in a beaker of water). Most of the time, the main contributor to the motion in these demonstrations is not actually diffusion, but rather convection. Yet teachers, textbooks, and workbooks continue to cite these as examples of diffusion, despite having been adequately refuted. In order to reaffirm the refutations and promote greater awareness of the continued existence of these misconceptions among teachers, the authors designed an experiment to test the premise that typical classroom diffusion experiments are, in fact, examples of convection. Taking advantage of the free-fall environment through NASA’s Teaching from Space Microgravity Experience, we were able to show that the great majority of dispersion patterns depicted in these demonstrations are due to convection. Subsequently, we propose classroom activities that serve as more accurate demonstrations of diffusion.

Levy G, Hayes B, “Physiochemical Basis of the Buffered Acetylsalicylic Acid Controversy New Engl. J. Med. 262:1053–1058 (1960)”—The Backstory

Levy G, Hayes B, “Physiochemical Basis of the Buffered Acetylsalicylic Acid Controversy New Engl. J. Med. 262:1053–1058 (1960)”—The Backstory

Tracking the Oxidative and Nonoxidative Fates of Isotopically Labeled Nutrients in Animals

Exogenous nutrients do not diffuse throughout the body like a drop of dye in a beaker of water. Rather, they are allocated among tissues according to physiological rules determined by evolutionary history, physiological status, and environmental conditions. These rules also determine how endogenous nutrients are differentially mobilized and oxidized during the periods between meals. Metabolic tracers are emerging as powerful tools to address classic questions about the nutritional bioenergetics of animals. For example, which nutrients will be oxidized and which will be stored in the body? How are stored nutrients divided among the different organs and tissues? Which nutrients are mobilized between meals? When does an animal switch from one type of metabolic fuel to another? The answers to these questions surely differ among species, but also depend on complex interactions between the animal and its environment. Here I review the conceptual framework for using isotopically labeled tracers.

Prospective Study of the Effect of Post-Brushing Rinsing Behaviour on Dental Caries

Previous studies have indicated that rinsing the mouth with a beaker of water after toothbrushing may compromise the caries reducing effect of fluoride toothpaste. A 3-year clinical trial of daily supervised brushing with fluoride toothpaste at school was used to test the effect of post-brushing rinsing with water on caries increment. A total of 407 children, mean age 11.8 years, attending three schools in Kaunas, Lithuania were enrolled following informed consent of the children and their parents. Caries was recorded at baseline and annually for 3 years. During the study, children in two schools (A and B) performed daily supervised brushing with a 1,500-ppm fluoride toothpaste. Children in school A rinsed their mouths thoroughly with a beaker of water after toothbrushing whereas children in school B were only permitted to spit out once after brushing. Furthermore, the children in these schools were supplied with toothpaste and toothbrushes for use at home and in school. A third school (C), without daily brushing and without supply of toothpaste, served as control. Compliance with the protocol was consistently better in school B. After 3 years 276 children were available for examination. Three-year DMFS increments, including non-cavitated lesions (mean, 95% CI), were: school A, 6.8 (5.3; 8.3); school B, 6.2 (4.6; 7.8), and school C, 12.4 (10.6; 14.1). Mean increments for schools A and B did not differ significantly but were both significantly lower than those of school C (p< 0.001). It is concluded that post-brushing rinsing with water, under the conditions of this study, does not significantly affect the caries reducing effect of a fluoride toothpaste.

Just Breathe: The Oxygen Content of Air

In this Activity, students place steel wool in a test tube that is then inverted in a beaker of water. Oxygen in the air trapped in the test tube reacts with iron to form rust, and the water level rises inside the test tube. Within 30-45 minutes, the majority of oxygen is consumed. By measuring the overall height of the test tube and the final height of the water in the test tube, students can arrive at a reasonably good estimate of the percent oxygen (volume) in the original air sample.

Just Breathe: The Oxygen Content of Air

In this Activity, students place steel wool in a test tube that is then inverted in a beaker of water. Oxygen in the air trapped in the test tube reacts with iron to form rust, and the water level ...

Vial Organic - Organic Chemistry Labs for High School and Junior College

Vial Organic is the most economical, safe, and time-effective method of performing organic chemistry experiments. Activities are carried out in low-cost, sealed vials. Vial Organic is extremely safe because only micro quantities of reactants are used, reactants are contained in tightly sealed vials, and only water baths are used for temperature control. Vial Organic laboratory activities are easily performed within one 50-minute class period. When heat is required, a simple hot-water bath is prepared from a beaker of water and an inexpensive immersion heater. The low cost, ease of use, and relatively short time requirement will allow organic chemistry to be experienced by more students with less confusion and intimidation.

Elf Atochem mentors science teachers

Chemist Robert Thompson moved a tennis ball in spurts through the cut-off leg of a pair of pantyhose, mimicking the way food passes through the alimentary canal. On the worktable he shared with two schoolteachers and colleague James J. Salitros, a beaker of water was tinged pink with dye that had oozed through an made from a dialysis membrane. experiment simulated nutrients passing through the wall of the intestine into the bloodstream. Thompson and Salitros were among the 17 chemists and three engineers from Elf Atochem North America's Technical Center in King of Prussia, Pa., who spent last week mentoring 20 elementary-school teachers in hands-on science. on-site program, which trains teachers from local school districts, was launched last year. The company provides significant resources, noted R&D chemist Richard S. Freedlander, who directed the program this year. Mentors are paid their full salary for the week. So are other scientists who take ...

Convection in a Continuously Stratified Fluid

This paper begins by commemorating Count Rumford's observations of convection in 1797. Rumford investigated the effects of stewed apples, eiderdown, and other fibrous materials on retarding vertical circulation in liquids. In contrast to Count Rumford's historic experiments, the present paper describes a simple, visually instructive, physical chemistry experiment for demonstrating how a mathematical model can be applied to free convection in a vertically stratified salt solution. In the first part of the experiment, a linear salt concentration profile is created in a beaker of water at room temperature. The salt concentration (and density) is greatest at the bottom of the liquid. When the beaker containing the salt solution is then heated on a hot plate, a well defined convecting bottom layer forms almost immediately. The measured rate of growth in thickness of this convecting layer is compared to that predicted from a model based on density differences. The temperature of the liquid above the bottom conv...

The Relationship Between pH and Pco2 as the Basis for Simple Classroom Demonstration of Chemical Equilibrium in the Carbonate System

Measurement of the pH of water under various conditions of different PCO2 and total dissolved-salt concentration is a simple experiment that can be used to reinforce concepts of chemical equilibrium and to teach the fundamentals of the carbonate system. The pH is sensitive to dissolved-salt concentrations, and differences between distilled-deionized and tap water are readily measurable. In the carbonate system, pH is also sensitive to PCO2 and can readily be changed by blowing bubbles (exhaled breath) through a beaker of water. All of these phenomena can be readily explained using the equations of chemical equilibrium and the charge-balance equation and provide a graphic demonstration of the relationship between the important thermodynamic variables pH, PCO2, and dissolved-salt concentration.

Snapshots of uncertainty: A new tool for the indentification of students' conceptions of scientific phenomena

In preparation for an experiment to investigate the effectiveness of teaching conservation principles, we showed a large number of Grade 8 students two cubes of exactly the same size but with very different masses, and two other cubes of very different sizes but with the same mass (confirmed using scales). Students were then asked to predict the extent of the water level rise which would occur if each cube of each pair were to be placed in similar beakers of water and submerged. Initially almost all predicted on the basis of mass being the significant factor. A teaching sequence followed in which students interacted with different objects and measured water displacement. Following this they were retested on the same task and many now predicted that the rise of water level would depend only on the volume of the object being submerged. On the other hand some still stated that only mass would be important, and others believed a balance between the two would be the determining factor.

The relationship among bronchial blocker cuff inflation volume, proximal airway pressure, and seal of the bronchial blocker cuff

The resting volume and diameter of the bronchial blocker cuff (defined as inflation of the cuff to just its natural shape) of the Univent (Fuji Systems Corp, Tokyo, Japan) tube are 2 mL and 5 mm. However, much larger inflation volumes may be required to seal an adult mainstem bronchus and the surface area of contact between the resultant spherical or ellipsoid-shaped cuff and the wall of the mainstem bronchus may be small and susceptible to leak with the application of high proximal airway pressures. This experiment determined the relationship among airway diameter, proximal airway pressure, inflation volume of the bronchial blocker cuff, and leakage of air around the bronchial blocker cuff in an in vitro model. The experimental model consisted of silicon tubing of 12.8-, 16.0-, and 19.2-mm ID as the mainstem bronchus. The main tracheal cuff sealed the Univent tube into the proximal end of the mainstem bronchus and the bronchial blocker cuff was inflated with various volumes near the distal end of the mainstem bronchus. The space between the tracheal cuff and the bronchial blocker cuff was then progressively pressurized in either a static or pulsed manner. The very distal end of the bronchus was functionally submerged under a beaker of water so that a bronchial blocker cuff leak would be indicated by bubbling. It was found that the Univent bronchial blocker cuff sealed the 12.8- and 16.0-mm ID mainstem bronchi against airway pressures as great as 100 cmH 20, with inflation volumes that were within the manufacturer's recommendation of 6 to 7 mL. Clinically, there was little difference in the cuff volume required to seal the bronchial blocker cuffs of the 6.0- and 9.0-mm ID Univent tubes against static and pulsed proximal airway pressures of the same magnitude. If an intraoperative leak develops, then intra-cuff volume should be increased to 6 to 7 mL and, if the leak is still present, then the surgeon may need to rearrange the surgical field so that the relationship between the mainstem bronchus (a cylinder) and the bronchial blocker cuff (a sphere or ellipsoid shape) is no longer distorted.

Reactions of the alkali metals with water: A novel demonstration

This demonstration is a novel variation that is much safer to perform than the standard demonstration of simply dropping a small piece of alkali metal into a beaker of water.