"Determining the distribution coefficient of caffeine" Essays and Research Papers

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    Extraction of caffeine from Lipton tea leaves Maria Gianna Beatrice L. Cancio*‚ Joe Mari Isabella B. Caringal‚ Rowena A. Chiang‚ Patricia Deanne del Valle Department of Biological Sciences‚ College of Science‚ University of Santo Tomas‚ España‚ Manila‚ Philippines Abstract Caffeine was extracted from Lipton tea leaves by multiple extraction techniques namely solid to liquid extraction and liquid to liquid extraction; the purification by sublimation and melting point determination. Three

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    establish a correlation between caffeine intake and the effects it has on both the pulse and respiration rates of an individual after undergoing moderate-intense cardiovascular exercise. Caffeine itself is one of the most heavily consumed drugs on the planet; it is estimated that over 90% of Americans consume caffeine daily (Richard Lovett‚ 2005‚ New Scientist iss. 2518) and is the most widely used stimulant in the world (Arcerio‚ P‚ Ormsbee‚ J‚ 2009‚ pg. 1). Caffeine stimulates the brain and behaviour

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    The Production Process Pre-Production Pre-production is a fairly loose term which refers to the tasks undertaken before production begins. Exactly what is included in this stage depends on the medium and situation. For a small video company‚ pre-production may refer to everything that happens before shooting begins‚ for example‚ meeting with the client‚ research‚ storyboarding‚ location planning‚ etc. For feature films‚ pre-production is more specific and only begins when other milestones have

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    are the affects of stimulants like (Caffeine and Amphitemine) on the study and learning habits for college students? Caffeine is a central nervous system (CNS) stimulant with a charge that rise energy‚ mood‚ awareness‚ concentration‚ and wakefulness. Caffeine is the most widely used drug in the world. Caffeine can be found in teas‚ coffee‚ energy drink and chocolate caffeine is also very popular among student‚ as a supplement and as a study aid. Drinking caffeine can have many effects‚ both positive

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    In this lab‚ caffeine was extracted from black tea‚ and green tea through a vacuum filtration‚ and a rotovap. The melting point of the sample of black tea was 219.12-236.05 ˚c‚ and for the green tea it was 176.22-227.6 ˚c. The % error of the melting point indicates how much error there was from the melting point taken experimentally. The % error of the melting point for black tea was 0.44%‚ and for green tea it is 3.15%.Since the theoretical melting point of caffeine is between 235-237 ˚c‚ we can

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    Extraction of Caffeine from Tea Leaves Santos‚ Raphael‚ Samson‚ Nonia Carla‚ *Tabora‚ Brylle‚ Tan‚ Kate Michal Department of Biological Sciences‚ University of Santo Tomas‚ Manila‚ Philippines Abstract Tea leaves are natural products that are harvested from agriculture. Caffeine‚ on the other hand‚ is a stimulant that has been shown to speed up the time of reaction‚ increase alertness‚ and improve one’s concentration. What we did in this experiment was to extract the alkaloid caffeine content from

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    Report The effect of caffeine on long-term memory Introduction: What is caffeine? Caffeine is one of the commonly consumed or most ingested stimulant or psychoactive substance in the world‚ known for it’s effect on vigilance and alertness level (A. Smith‚ 2002) or at least perceived to jolt our tired brains‚ when consumed in normal or moderate quantity. Caffeine is available to us from various sources like coffee‚ tea‚ cocoa‚ soft drinks and other such products. Caffeine is basically 1‚3‚7-trimethylxanthine

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    Practical 1.1 Introduction: Caffeine belongs to a class of compounds called methylxanthines and can block a receptor on the surface of heart muscle cells for adenosine. In fact‚ it is caffeine’s blockade of the A1 adenosine receptor in the heart that causes the heart to pound after a significant caffeine dose. Caffeine and similar compounds also inhibit a class of enzymes known as cyclic nucleotide phosphodiesterases. These enzymes are‚ in part responsible for degrading a stimulatory signal produced

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    The Distribution of Alu Genotypes in a Group of Level 4 Students The Distribution of Alu Genotypes Introduction DNA is mostly found in the nucleus of nearly every cell in the human body‚ it contains the biological instructions that make us unique. Located on the genome at different locations are short‚ identifiable sequences known as Alu insertion polymorphisms. The application of Alu elements has recently become used in forensic identification and paternity testing. Alu elements are found

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    Nicoleta Nedelcu Caffeine-induced effects on heart rate in zebrafish embryos and possible mechanisms of action Observation Caffeine is found in coffee‚ tea leaves‚ cocoa beans‚ and kola nuts. It is used in prescription and over the counter drugs. It increases blood pressure‚ mental alertness‚ and gastrointestinal motility. Cardiovascular development with caffeine and other small molecules can be studied relatively easy using zebrafish. The cardiovascular system is complete in two days after fertilization

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