An Experimental Investigation of the Role of Radiation in Laboratory Bench-Top Experiments in Thermal Physics

ERIC Educational Resources Information Center

Twomey, Patrick; O'Sullivan, Colm; O'Riordan, John

2009-01-01

A simple undergraduate experiment designed to study cooling purely by radiation and cooling by a combination of convection and radiation is described. Results indicate that the contribution from radiative cooling in normal laboratory experiments is more significant than students often realize, even in the case of forced cooling. (Contains 1…

Size Exclusion Chromatography: An Experiment for High School and Community College Chemistry and Biotechnology Laboratory Programs

ERIC Educational Resources Information Center

Brunauer, Linda S.; Davis, Kathryn K.

2008-01-01

A simple multiday laboratory exercise suitable for use in a high school or community college chemistry course or a biotechnology advanced placement biology course is described. In this experiment students gain experience in the use of column chromatography as a tool for the separation and characterization of biomolecules, thus expanding their…

Time Trials--An AP Physics Challenge Lab

ERIC Educational Resources Information Center

Jones, David

2009-01-01

I have come to the conclusion that for high school physics classroom and laboratory experiences, simpler is better! In this paper I describe a very simple and effective lab experience that my AP students have thoroughly enjoyed year after year. I call this lab exercise "Time Trials." The experiment is simple in design and it is a lot of fun for…

Birdcage volume coils and magnetic resonance imaging: a simple experiment for students.

PubMed

Vincent, Dwight E; Wang, Tianhao; Magyar, Thalia A K; Jacob, Peni I; Buist, Richard; Martin, Melanie

2017-01-01

This article explains some simple experiments that can be used in undergraduate or graduate physics or biomedical engineering laboratory classes to learn how birdcage volume radiofrequency (RF) coils and magnetic resonance imaging (MRI) work. For a clear picture, and to do any quantitative MRI analysis, acquiring images with a high signal-to-noise ratio (SNR) is required. With a given MRI system at a given field strength, the only means to change the SNR using hardware is to change the RF coil used to collect the image. RF coils can be designed in many different ways including birdcage volume RF coil designs. The choice of RF coil to give the best SNR for any MRI study is based on the sample being imaged. The data collected in the simple experiments show that the SNR varies as inverse diameter for the birdcage volume RF coils used in these experiments. The experiments were easily performed by a high school student, an undergraduate student, and a graduate student, in less than 3 h, the time typically allotted for a university laboratory course. The article describes experiments that students in undergraduate or graduate laboratories can perform to observe how birdcage volume RF coils influence MRI measurements. It is designed for students interested in pursuing careers in the imaging field.

Mass Spectrometry for the Masses

ERIC Educational Resources Information Center

Persinger, Jared D.; Hoops, Geoffrey, C.; Samide, Michael J.

2004-01-01

A simple, qualitative experiment is developed for implementation, where the gas chromatography-mass spectrometry (GC-MS) plays an important role, into the laboratory curriculum of a chemistry course designed for nonscience majors. This laboratory experiment is well suited for the students as it helps them to determine the validity of their…

A Unit Cell Laboratory Experiment: Marbles, Magnets, and Stacking Arrangements

ERIC Educational Resources Information Center

Collins, David C.

2011-01-01

An undergraduate first-semester general chemistry laboratory experiment introducing face-centered, body-centered, and simple cubic unit cells is presented. Emphasis is placed on the stacking arrangement of solid spheres used to produce a particular unit cell. Marbles and spherical magnets are employed to prepare each stacking arrangement. Packing…

ORGANIC CONTAMINANT DISTRIBUTION IN SEDIMENTS, POLYCHAETES (NEREIS VIRENS) AND THE AMERICAN LOBSTER, HOMARUS AMERICANUS IN A LABORATORY FOOD CHAIN EXPERIMENT

EPA Science Inventory

A laboratory experiment was conducted to investigate the transfer of organic contaminants from an environmentally contaminated marine sediment through a simple marine food chain. The infaunal polychaete, Nereis virens, was exposed to contaminated sediment collected from the Passa...

Simple Laboratory Exercise for Induction of Beta-Mannanase from "Aspergillus niger"

ERIC Educational Resources Information Center

Mulimani, V. H.; Naganagouda, K.

2010-01-01

This laboratory experiment was designed for Biochemistry, Biotechnology, Microbiology, and Food Technology students of undergraduate and postgraduate courses. The experiment shows the advantages of using agricultural waste, copra mannan as potent inducer of [beta]-mannanase. The students were able to compare the enzyme induction by commercial…

A New Application for Radioimmunoassay: Measurement of Thermodynamic Constants.

ERIC Educational Resources Information Center

Angstadt, Carol N.; And Others

1983-01-01

Describes a laboratory experiment in which an equilibrium radioimmunoassay (RIA) is used to estimate thermodynamic parameters such as equilibrium constants. The experiment is simple and inexpensive, and it introduces a technique that is important in the clinical chemistry and research laboratory. Background information, procedures, and results are…

Using Modern Solid-State Analytical Tools for Investigations of an Advanced Carbon Capture Material: Experiments for the Inorganic Chemistry Laboratory

ERIC Educational Resources Information Center

Wriedt, Mario; Sculley, Julian P.; Aulakh, Darpandeep; Zhou, Hong-Cai

2016-01-01

A simple and straightforward synthesis of an ultrastable porous metal-organic framework (MOF) based on copper(II) and a mixed N donor ligand system is described as a laboratory experiment for chemistry undergraduate students. These experiments and the resulting analysis are designed to teach students basic research tools and procedures while…

Development and Implementation of a Simple, Engaging Acid Rain Neutralization Experiment and Corresponding Animated Instructional Video for Introductory Chemistry Students

ERIC Educational Resources Information Center

Rand, Danielle; Yennie, Craig J.; Lynch, Patrick; Lowry, Gregory; Budarz, James; Zhu, Wenlei; Wang, Li-Qiong

2016-01-01

Here we describe an acid rain neutralization laboratory experiment and its corresponding instructional video. This experiment has been developed and implemented for use in the teaching laboratory of a large introductory chemistry course at Brown University. It provides a contextually relevant example to introduce beginner-level students with…

The Biochemistry of the Muscle Contraction Process: An Undergraduate Laboratory Experiment Using Viscosity to Follow the Progress of a Reaction.

ERIC Educational Resources Information Center

Belliveau, James F.; And Others

1981-01-01

Describes an undergraduate laboratory experiment using viscosity to follow the progress of the contractile process in muscles. This simple, short experiment illustrates the action of ATP as the source of energy in the contractile process and the catalytic effect of calcium ions as a control in the energy producing process. (CS)

A Simple Laboratory Class Using a "Pseudomonas aeruginosa" Auxotroph to Illustrate UV-Mutagenic Killing, DNA Photorepair and Mutagenic DNA Repair

ERIC Educational Resources Information Center

Sobrero, Patricio; Valverde, Claudio

2013-01-01

A simple and cheap laboratory class is proposed to illustrate the lethal effect of UV radiation on bacteria and the operation of different DNA repair mechanisms. The class is divided into two sessions, an initial 3-hour experimental session and a second 2-hour analytical session. The experimental session involves two separate experiments: one…

Validating the Goldstein-Wehner Law for the Stratified Positive Column of DC Discharge in an Undergraduate Laboratory

ERIC Educational Resources Information Center

Lisovskiy, V. A.; Koval, V. A.; Artushenko, E. P.; Yegorenkov, V. D.

2012-01-01

In this paper we suggest a simple technique for validating the Goldstein-Wehner law for a stratified positive column of dc glow discharge while studying the properties of gas discharges in an undergraduate laboratory. To accomplish this a simple device with a pre-vacuum mechanical pump, dc source and gas pressure gauge is required. Experiments may…

Advanced Undergraduate Experiments in Thermoanalytical Chemistry.

ERIC Educational Resources Information Center

Hill, J. O.; Magee, R. J.

1988-01-01

Describes several experiments using the techniques of thermal analysis and thermometric titrimetry. Defines thermal analysis and several recent branches of the technique. Notes most of the experiments use simple equipment and standard laboratory techniques. (MVL)

A Simple Experiment Demonstrating the Allosteric Regulation of Yeast Pyruvate Kinase.

ERIC Educational Resources Information Center

Taber, Richard L.; Campbell, Angela; Spencer, Scott

1998-01-01

Explains the procedures used to determine the regulatory properties of yeast pyruvate kinase. Involves a partial purification using PEG precipitation that can be done in one laboratory period with simple equipment. (DDR)

LETTERS AND COMMENTS: Permeability measurements in undergraduate vacuum laboratories: a simple experiment using a He leak detector

NASA Astrophysics Data System (ADS)

dos Santos, J. M. F.; Veloso, J. F. C. A.; Monteiro, C. M. B.

2004-01-01

We describe a simple experiment intended for didactic laboratory vacuum classes of undergraduate courses, using a helium leak detector. The helium throughput flowing into the vacuum volume due to the permeability of materials can be taken as a real leak, which can be measured with the helium leak detector. The experiment allows students to perform actual measurements of helium permeability constants of different materials, and access the dependence of the helium permeability throughput on the material thickness, area and helium pressure differential. As an example, a set of measurements are presented for Kapton foils, exhibiting results that are in good agreement with those presented in the literature.

A Laboratory Experiment to Demonstrate the Principles of Sedimentation in a Centrifuge: Estimation of Radius and Settling Velocity of Bacteria

ERIC Educational Resources Information Center

Riley, Erin; Felse, P. Arthur

2017-01-01

Centrifugation is a major unit operation in chemical and biotechnology industries. Here we present a simple, hands-on laboratory experiment to teach the basic principles of centrifugation and to explore the shear effects of centrifugation using bacterial cells as model particles. This experiment provides training in the use of a bench-top…

Using Mole Ratios of Electrolytic Products of Water for Analysis of Household Vinegar: An Experiment for the Undergraduate Physical Chemistry Laboratory

ERIC Educational Resources Information Center

Dabke, Rajeev B.; Gebeyehu, Zewdu

2012-01-01

A simple 3-h physical chemistry undergraduate experiment for the quantitative analysis of acetic acid in household vinegar is presented. The laboratory experiment combines titration concept with electrolysis and an application of the gas laws. A vinegar sample was placed in the cathode compartment of the electrolysis cell. Electrolysis of water…

Geophysical Fluid Dynamics Laboratory Open Days at the Woods Hole Oceanographic Institution

NASA Astrophysics Data System (ADS)

Hyatt, Jason; Cenedese, Claudia; Jensen, Anders

2015-11-01

This event was hosted for one week for two consecutive years in 2013 and 2014. It targeted postdocs, graduate students, K-12 students and local community participation. The Geophysical Fluid Dynamics Laboratory at the Woods Hole Oceanographic Institution hosted 10 hands-on demonstrations and displays, with something for all ages, to share the excitement of fluid mechanics and oceanography. The demonstrations/experiments spanned as many fluid mechanics problems as possible in all fields of oceanography and gave insight into using fluids laboratory experiments as a research tool. The chosen experiments were `simple' yet exciting for a 6 year old child, a high school student, a graduate student, and a postdoctoral fellow from different disciplines within oceanography. The laboratory is a perfect environment in which to create excitement and stimulate curiosity. Even what we consider `simple' experiments can fascinate and generate interesting questions from both a 6 year old child and a physics professor. How does an avalanche happen? How does a bath tub vortex form? What happens to waves when they break? How does a hurricane move? Hands-on activities in the fluid dynamics laboratory helped students of all ages in answering these and other intriguing questions. The laboratory experiments/demonstrations were accompanied by `live' videos to assist in the interpretation of the demonstrations. Posters illustrated the oceanographic/scientific applicability and the location on Earth where the dynamics in the experiments occur. Support was given by the WHOI Doherty Chair in Education.

Quantum Dots in a Polymer Composite: A Convenient Particle-in-a-Box Laboratory Experiment

ERIC Educational Resources Information Center

Rice, Charles V.; Giffin, Guinevere A.

2008-01-01

Semiconductor quantum dots are at the forefront of materials science chemistry with applications in biological imaging and photovoltaic technologies. We have developed a simple laboratory experiment to measure the quantum-dot size from fluorescence spectra. A major roadblock of quantum-dot based exercises is the particle synthesis and handling;…

X-Ray Diffraction of Intermetallic Compounds: A Physical Chemistry Laboratory Experiment

ERIC Educational Resources Information Center

Varberg, Thomas D.; Skakuj, Kacper

2015-01-01

Here we describe an experiment for the undergraduate physical chemistry laboratory in which students synthesize the intermetallic compounds AlNi and AlNi3 and study them by X-ray diffractometry. The compounds are synthesized in a simple one-step reaction occurring in the solid state. Powder X-ray diffractograms are recorded for the two compounds…

Solubility and Solubility Product Determination of a Sparingly Soluble Salt: A First-Level Laboratory Experiment

ERIC Educational Resources Information Center

Bonomo, Raffaele P.; Tabbi, Giovanni; Vagliasindi, Laura I.

2012-01-01

A simple experiment was devised to let students determine the solubility and solubility product, "K"[subscript sp], of calcium sulfate dihydrate in a first-level laboratory. The students experimentally work on an intriguing equilibrium law: the constancy of the product of the ion concentrations of a sparingly soluble salt. The determination of…

Experimenting with Synthesis and Analysis of Cationic Gemini Surfactants in a Second-Semester General Chemistry Laboratory

ERIC Educational Resources Information Center

Anzovino, Mary E.; Greenberg, Andrew E.; Moore, John W.

2015-01-01

A laboratory experiment is described in which students synthesize a variety of cationic gemini surfactants and analyze their efficacy as fabric softeners. Students perform a simple organic synthesis reaction and two analytical tests (one qualitative and one quantitative), and use the class data to assess the synthesized products. The experiment…

Dipeptide Structural Analysis Using Two-Dimensional NMR for the Undergraduate Advanced Laboratory

ERIC Educational Resources Information Center

Gonzalez, Elizabeth; Dolino, Drew; Schwartzenburg, Danielle; Steiger, Michelle A.

2015-01-01

A laboratory experiment was developed to introduce students in either an organic chemistry or biochemistry lab course to two-dimensional nuclear magnetic resonance (2D NMR) spectroscopy using simple biomolecules. The goal of this experiment is for students to understand and interpret the information provided by a 2D NMR spectrum. Students are…

A Laboratory Experiment, Based on the Maillard Reaction, Conducted as a Project in Introductory Statistics

ERIC Educational Resources Information Center

Kravchuk, Olena; Elliott, Antony; Bhandari, Bhesh

2005-01-01

A simple laboratory experiment, based on the Maillard reaction, served as a project in Introductory Statistics for undergraduates in Food Science and Technology. By using the principles of randomization and replication and reflecting on the sources of variation in the experimental data, students reinforced the statistical concepts and techniques…

STRUCTURED LEARNING AND TRAINING ENVIRONMENTS--A PREPARATION LABORATORY FOR ADVANCED MAMMALIAN PHYSIOLOGY.

ERIC Educational Resources Information Center

FIEL, NICHOLAS J.; JOHNSTON, RAYMOND F.

A PREPARATION LABORATORY WAS DESIGNED TO FAMILIARIZE STUDENTS IN ADVANCED MAMMALIAN PHYSIOLOGY WITH LABORATORY SKILLS AND TECHNIQUES AND THUS SHORTEN THE TIME THEY SPEND IN SETTING UP ACTUAL EXPERIMENTS. THE LABORATORY LASTS 30 MINUTES, IS FLEXIBLE AND SIMPLE OF OPERATION, AND DOES NOT REQUIRE A PROFESSOR'S PRESENCE. THE BASIC TRAINING UNIT IS THE…

Determination of Absolute Zero Using a Computer-Based Laboratory

ERIC Educational Resources Information Center

Amrani, D.

2007-01-01

We present a simple computer-based laboratory experiment for evaluating absolute zero in degrees Celsius, which can be performed in college and undergraduate physical sciences laboratory courses. With a computer, absolute zero apparatus can help demonstrators or students to observe the relationship between temperature and pressure and use…

Considerations on the Retrieval of Plume Particle Properties from the AFRPL Transmissometer and Polarization-Scattering Experiments.

DTIC Science & Technology

1984-08-01

transmissometer experiment. In these measure - ments, simple transmission measurements of laser radiation through a diameter of the plume are made. With...Air Force Rocket Propulsion Laboratory4{AFRPL). In one experiment, simple laser transmission measurements are made over a full diameter line of sight...consist of measure - ments of the polarization of laser radiation which has been scattered by plume particulates. The analysis is presented in Section

A Simple LIBS (Laser-Induced Breakdown Spectroscopy) Laboratory Experiment to Introduce Undergraduates to Calibration Functions and Atomic Spectroscopy

ERIC Educational Resources Information Center

Chinni, Rosemarie C.

2012-01-01

This laboratory experiment introduces students to a different type of atomic spectroscopy: laser-induced breakdown spectroscopy (LIBS). LIBS uses a laser-generated spark to excite the sample; once excited, the elemental emission is spectrally resolved and detected. The students use LIBS to analyze a series of standard synthetic silicate samples…

Sol-Gel Synthesis of a Biotemplated Inorganic Photocatalyst: A Simple Experiment for Introducing Undergraduate Students to Materials Chemistry

ERIC Educational Resources Information Center

Boffa, Vittorio; Yue, Yuanzheng; He, Wen

2012-01-01

As part of a laboratory course, undergraduate students were asked to use baker's yeast cells as biotemplate in preparing TiO[subscript 2] powders and to test the photocatalytic activity of the resulting materials. This laboratory experience, selected because of the important environmental implications of soft chemistry and photocatalysis, provides…

UV-Vis Spectrophotometric Analysis and Quantification of Glyphosate for an Interdisciplinary Undergraduate Laboratory

ERIC Educational Resources Information Center

Felton, Daniel E.; Ederer, Martina; Steffens, Timothy; Hartzell, Patricia L.; Waynant, Kristopher V.

2018-01-01

Glyphosate (N-(phosphonomethyl)glycine) is the most widely used herbicide on earth. A simple assay to quantify glyphosate concentrations in environmental samples was developed as part of an interdisciplinary effort linking introductory laboratory courses in chemistry, biology, and microbiology. In this 3 h laboratory experiment, students used…

The Computer as Lab Partner.

ERIC Educational Resources Information Center

Nicklin, R. C.

1985-01-01

Microcomputers can record laboratory measurements which human laboratory partners can never collect. Simple, harder, and general-purpose interfaces are discussed, with suggestions for several experiments involving an exercise bike, acceleration, and pendulums. Additional applications with pH meters, spectrophotometers, and chromatographs are also…

Experiments in Special Relativity Using Compton Scattering of Gamma Rays.

ERIC Educational Resources Information Center

Egelstaff, P. A.; And Others

1981-01-01

Some simple undergraduate laboratory experiments are described, which verify the energy-momentum relationship of special relativity. These experiments have been designed either to be used as classroom demonstrations or to be carried out by second-year students. (Author/JN)

The RC Circuit--A Multipurpose Laboratory Experiment.

ERIC Educational Resources Information Center

Wood, Herbert T.

1993-01-01

Describes an experiment that demonstrates the use of Kirchoff's rules in the analysis of electrical circuits. The experiment also involves the solution of a linear nonhomogeneous differential equation that is slightly different from the standard one for the simple RC circuit. (ZWH)

Determination of Al Content in Commercial Samples through Stoichiometry: A Simple Experiment for an Advanced High-School Chemistry Olympiad Preparatory Course

ERIC Educational Resources Information Center

de Lima, Kassio M. G.; da Silva, Amison R. L.; de Souza, Joao P. F.; das Neves, Luiz S.; Gasparotto, Luiz H. S.

2014-01-01

Stoichiometry has always been a puzzling subject. This may be partially due to the way it is introduced to students, with stoichiometric coefficients usually provided in the reaction. If the stoichiometric coefficients are not given, students find it very difficult to solve problems. This article describes a simple 4-h laboratory experiment for…

A Simple Laboratory Experiment to Determine the Kinetics of Mutarotation of D-Glucose Using a Blood Glucose Meter

ERIC Educational Resources Information Center

Perles, Carlos E.; Volpe, Pedro L. O.

2008-01-01

A simple commercial blood glucose meter is used to follow the kinetics of mutarotation of D-glucose in aqueous solution. The results may be compared with those obtained using an automatic polarimeter, if this is available This experiment is proposed for use by students in a general chemistry, biology, organic chemistry, and physical chemistry…

Case-Study Investigation of Equine Maternity via PCR-RFLP: A Biochemistry Laboratory Experiment

PubMed Central

Millard, Julie T.; Chuang, Edward; Lucas, James S.; Nagy, Erzsebet E.; Davis, Griffin T.

2013-01-01

A simple and robust biochemistry laboratory experiment is described that uses restriction fragment length polymorphism (RFLP) of polymerase chain reaction (PCR) products to verify the identity of a potentially valuable horse. During the first laboratory period, students purify DNA from equine samples and amplify two loci of mitochondrial DNA. During the second laboratory period, students digest PCR products with restriction enzymes and analyze the fragment sizes through agarose gel electrophoresis. An optional step of validating DNA extracts through realtime PCR can expand the experiment to three weeks. This experiment, which has an engaging and versatile scenario, provides students with exposure to key principles and techniques of molecular biology, bioinformatics, and evolution in a forensic context. PMID:24363455

An easy-to-build remote laboratory with data transfer using the Internet School Experimental System

NASA Astrophysics Data System (ADS)

Schauer, František; Lustig, František; Dvořák, Jiří; Ožvoldová, Miroslava

2008-07-01

The present state of information communication technology makes it possible to devise and run computer-based e-laboratories accessible to any user with a connection to the Internet, equipped with very simple technical means and making full use of web services. Thus, the way is open for a new strategy of physics education with strongly global features, based on experiment and experimentation. We name this strategy integrated e-learning, and remote experiments across the Internet are the foundation for this strategy. We present both pedagogical and technical reasoning for the remote experiments and outline a simple system based on a server-client approach, and on web services and Java applets. We give here an outline of the prospective remote laboratory system with data transfer using the Internet School Experimental System (ISES) as hardware and ISES WEB Control kit as software. This approach enables the simple construction of remote experiments without building any hardware and virtually no programming, using a paste and copy approach with typical prebuilt blocks such as a camera view, controls, graphs, displays, etc. We have set up and operate at present seven experiments, running round the clock, with more than 12 000 connections since 2005. The experiments are widely used in practical teaching of both university and secondary level physics. The recording of the detailed steps the experimentor takes during the measurement enables detailed study of the psychological aspects of running the experiments. The system is ready for a network of universities to start covering the basic set of physics experiments. In conclusion we summarize the results achieved and experiences of using remote experiments built on the ISES hardware system.

Principles of Radio: A Laboratory Experiment

ERIC Educational Resources Information Center

Kraftmakher, Yaakov

2002-01-01

An experiment is proposed for learning the principles of radio. A simple radio receiver illustrates amplitude modulation and demodulation, the selectivity of a receiver and the features of a directional antenna. Both normal and computerized versions of the experiment are described. The computerized experiment employs the "ScienceWorkshop"…

The Implementation of Problem-Solving Based Laboratory Activities to Teach the Concept of Simple Harmonic Motion in Senior High School

NASA Astrophysics Data System (ADS)

Iradat, R. D.; Alatas, F.

2017-09-01

Simple harmonic motion is considered as a relatively complex concept to be understood by students. This study attempts to implement laboratory activities that focus on solving contextual problems related to the concept. A group of senior high school students participated in this pre-experimental method from a group’s pretest-posttest research design. Laboratory activities have had a positive impact on improving students’ scientific skills, such as, formulating goals, conducting experiments, applying laboratory tools, and collecting data. Therefore this study has added to the theoretical and practical knowledge that needs to be considered to teach better complicated concepts in physics learning.

Remote Control and Data Acquisition: A Case Study

NASA Technical Reports Server (NTRS)

DeGennaro, Alfred J.; Wilkinson, R. Allen

2000-01-01

This paper details software tools developed to remotely command experimental apparatus, and to acquire and visualize the associated data in soft real time. The work was undertaken because commercial products failed to meet the needs. This work has identified six key factors intrinsic to development of quality research laboratory software. Capabilities include access to all new instrument functions without any programming or dependence on others to write drivers or virtual instruments, simple full screen text-based experiment configuration and control user interface, months of continuous experiment run-times, order of 1% CPU load for condensed matter physics experiment described here, very little imposition of software tool choices on remote users, and total remote control from anywhere in the world over the Internet or from home on a 56 Kb modem as if the user is sitting in the laboratory. This work yielded a set of simple robust tools that are highly reliable, resource conserving, extensible, and versatile, with a uniform simple interface.

Synthesis and Spectra of Vanadium Complexes.

ERIC Educational Resources Information Center

Ophardt, Charles E.; Stupgia, Sean

1984-01-01

Describes an experiment which illustrates simple synthetic techniques, redox principles in synthesis reactions, interpretation of visible spectra using Orgel diagrams, and the spectrochemical series. The experiment is suitable for the advanced undergraduate inorganic chemistry laboratory. (JN)

Are Radishes Really Allelopathic to Lettuce?

ERIC Educational Resources Information Center

Santaniello, Catherine M.; Koning, Ross E.

1996-01-01

Presents an experiment that challenges the claim that sprouting radish seedlings release chemicals into the environment that inhibit germination of lettuce seeds. Reports that although no simple allelopathic demonstration was observed, the experiment provides fertile ground for further experimentation in inquiry-based laboratory experiences. (JRH)

Operating Experience Review of the INL HTE Gas Monitoring System

DOE Office of Scientific and Technical Information (OSTI.GOV)

L. C. Cadwallader; K. G. DeWall

2010-06-01

This paper describes the operations of several types of gas monitors in use at the Idaho National Laboratory (INL) High Temperature Electrolysis Experiment (HTE) laboratory. The gases monitored at hydrogen, carbon monoxide, carbon dioxide, and oxygen. The operating time, calibration, and unwanted alarms are described. The calibration session time durations are described. Some simple statistics are given for the reliability of these monitors and the results are compared to operating experiences of other types of monitors.

Characterizing oxidative flow reactor SOA production and OH radical exposure from laboratory experiments of complex mixtures (engine exhaust) and simple precursors (monoterpenes)

NASA Astrophysics Data System (ADS)

Michael Link, M. L.; Friedman, B.; Ortega, J. V.; Son, J.; Kim, J.; Park, G.; Park, T.; Kim, K.; Lee, T.; Farmer, D.

2016-12-01

Recent commercialization of the Oxidative Flow Reactor (OFR, occasionally described in the literature as a "Potential Aerosol Mass") has created the opportunity for many researchers to explore the mechanisms behind OH-driven aerosol formation on a wide range of oxidative timescales (hours to weeks) in both laboratory and field measurements. These experiments have been conducted in both laboratory and field settings, including simple (i.e. single component) and complex (multi-component) precursors. Standard practices for performing OFR experiments, and interpreting data from the measurements, are still being developed. Measurement of gas and particle phase chemistry, from oxidation products generated in the OFR, through laboratory studies on single precursors and the measurement of SOA from vehicle emissions on short atmospheric timescales represent two very different experiments in which careful experimental design is essential for exploring reaction mechanisms and SOA yields. Two parameters essential in experimental design are (1) the role of seed aerosol in controlling gas-particle partitioning and SOA yields, and (2) the accurate determination of OH exposure during any one experiment. We investigated the role of seed aerosol surface area in controlling the observed SOA yields and gas/particle composition from the OH-initiated oxidation of four monoterpenes using an aerosol chemical ionization time-of-flight mass spectrometer and scanning mobility particle sizer. While the OH exposure during laboratory experiments is simple to constrain, complex mixtures such as diesel exhaust have high estimated OH reactivity values, and thus require careful consideration. We developed methods for constraining OH radical exposure in the OFR during vehicle exhaust oxidation experiments. We observe changes in O/C ratios and highly functionalized species over the temperature gradient employed in the aerosol-CIMS measurement. We relate this observed, speciated chemistry to the volatility of the aerosol, and compare observed SOA yields to other OFR and smog chamber SOA generation methods. Additionally, estimates of OH radical exposure in the OFR during different vehicle experiments of varying fuel type and speed were observed to vary as determined from a high-NOx and variable humidity calibration set.

Some More Simple Laser Experiments for the Undergraduate Laboratory

ERIC Educational Resources Information Center

Yap, F. Y.

1969-01-01

Describes three elementary optics experiments using a laser instead of conventional light sources. Experiments illustrate the Fresnel-Arago law, elliptical polarization, double refraction and polarization in calcite, and interference by a Fresnel biprism. Because of the high intensity of the laser beam, these experiments lend themselves very well…

Simple Recipes for Prebiotic Soup: A High School or Undergraduate Chemistry Laboratory

NASA Astrophysics Data System (ADS)

Martinez-Meeler, Marisol; Aljinovic, Nika; Swain, Dorothy

2003-06-01

A lab activity demonstrating Stanley Miller‘s prebiotic soup experiments is described. This lab activity, which uses only simple, readily available materials and equipment, would be suitable for use in a high school or introductory college chemistry class. The activity starts by asking students to consider some of the debated issues surrounding research into the chemical origins of life on Earth. It continues by having the students set up a simple apparatus that sends an electrical spark through a mixture of methane, ammonia, and water. The experiment concludes (the following week) by having students analyze their reaction products and design their own variation on the experiment.

Simple Experiments in Psychology.

ERIC Educational Resources Information Center

Ray, Wilbert S.

This material, developed for use in secondary schools, is a programmed-type learning package consisting of an "Instructor's Manual", a "Student's Introduction", and a "Laboratory Manual". The general goal of the program is to teach students to distinguish between reliable and unreliable information. The "Laboratory Manual" contains nine simple…

Working with Enzymes - Where Is Lactose Digested? An Enzyme Assay for Nutritional Biochemistry Laboratories

NASA Astrophysics Data System (ADS)

Pope, Sandi R.; Tolleson, Tonya D.; Williams, R. Jill; Underhill, Russell D.; Deal, S. Todd

1998-06-01

At Georgia Southern University, we offer a sophomore-level introductory biochemistry course that is aimed at nutrition and chemistry education majors. The laboratory portion of this course has long lacked an experimental introduction to enzymes. We have developed a simple enzyme assay utilizing lactase enzyme from crushed LactAid tablets and a 5% lactose solution ("synthetic milk"). In the experiment, the students assay the activity of the enzyme on the "synthetic milk" at pHs of approximately 1, 6, and 8 with the stated goal of determining where lactose functions in the digestive tract. The activity of the lactase may be followed chromatographically or spectrophotometrically. The experiment, which is actually a simple pH assay, is easily implemented in allied health chemistry laboratory courses and readily lends itself to adaptation for more complex kinetic assays in upper-level biochemistry laboratory courses. The experimental details, including a list of required supplies and hints for implementation, are provided.

Isostasy for Geoscience Labs.

ERIC Educational Resources Information Center

Diecchio, Richard Joseph

1995-01-01

Presents simple laboratory experiments to help students understand the principle of buoyancy and mass balance. Buoyancy experiments can simulate lithospheric mass balance, crustal loading and unloading, and can be used to model differences between the oceanic and continental lithosphere. (MKR)

Simple Demonstration of the Seebeck Effect

ERIC Educational Resources Information Center

Molki, Arman

2010-01-01

In this article we propose a simple and low-cost experimental set-up through which science educators can demonstrate the Seebeck effect using a thermocouple and an instrumentation amplifier. The experiment can be set up and conducted during a 1-hour laboratory session. (Contains 3 tables and 3 figures.)

Experimental Control of Simple Pendulum Model

ERIC Educational Resources Information Center

Medina, C.

2004-01-01

This paper conveys information about a Physics laboratory experiment for students with some theoretical knowledge about oscillatory motion. Students construct a simple pendulum that behaves as an ideal one, and analyze model assumption incidence on its period. The following aspects are quantitatively analyzed: vanishing friction, small amplitude,…

Operating experience review of an INL gas monitoring system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cadwallader, Lee C.; DeWall, K. G.; Herring, J. S.

2015-03-12

This article describes the operations of several types of gas monitors in use at the Idaho National Laboratory (INL) High Temperature Electrolysis Experiment (HTE) laboratory. The gases monitored in the lab room are hydrogen, carbon monoxide, carbon dioxide, and oxygen. The operating time, calibration, and both actual and unwanted alarms are described. The calibration session time durations are described. In addition, some simple calculations are given to estimate the reliability of these monitors and the results are compared to operating experiences of other types of monitors.

On the Application of Simple Experiments to the Teaching of ChE Thermodynamics

ERIC Educational Resources Information Center

McNeil, Kenneth M.

1978-01-01

This article describes the undergraduate ChE thermodynamics course at Drexel University and the reasons for incorporating a series of laboratory experiments into the course. Included is a list of lecture topics and a description of each of the experiments. (BB)

An Undergraduate Laboratory Experiment Using a Simple Photoassisted Fuel Cell to Remediate Simulated Wastewater

ERIC Educational Resources Information Center

Touati, Faiza; McGuigan, Kevin G.; Cassidy, John

2007-01-01

A simple method of casting with a Ti[O[subscript]2]/polyvinylchloride (PVC) composite layer was used to describe the behavior of coated electrodes. The system demonstrated that even with low energy light sources, an enhancement of the oxidation efficiency is possible.

Simple Analysis of Historical Lime Mortars

ERIC Educational Resources Information Center

Pires, Joa~o

2015-01-01

A laboratory experiment is described in which a simple characterization of a historical lime mortar is made by the determination of its approximate composition by a gravimetric method. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) are also used for the qualitative characterization of the lime mortar components. These…

Diffusion of Salt in Tap Water

ERIC Educational Resources Information Center

Booth, C.; And Others

1978-01-01

A simple experiment is described to measure the diffusion coefficient of a solute in a fluid. Laboratory-made floats are used to monitor the density changes associated with diffusion behavior. The experiment is ideally suited for undergraduate project work. (BB)

Friedel-Crafts Acylation: An Experiment Incorporating Spectroscopic Structure Determination.

ERIC Educational Resources Information Center

Schatz, Paul F.

1979-01-01

Describes a laboratory experiment which demonstrates manipulation of highly reactive chemicals, use of a gas trap, and simple and reduced pressure distillation. Student must characterize starting material and product with nuclear magnetic resonance and infrared spectroscopy. (Author/SA)

The Synthetic Experiment: E. B. Titchener's Cornell Psychological Laboratory and the Test of Introspective Analysis.

PubMed

Evans, Rand B

2017-01-01

Beginning in 1 9a0, a major thread of research was added to E. B. Titchener's Cornell laboratory: the synthetic experiment. Titchener and his graduate students used introspective analysis to reduce a perception, a complex experience, into its simple sensory constituents. To test the validity of that analysis, stimulus patterns were selected to reprodiuce the patterns of sensations found in the introspective analyses. If the original perception can be reconstructed in this way, then the analysis was considered validated. This article reviews development of the synthetic method in E. B. Titchener's laboratory at Cornell University and examines its impact on psychological research.

Thought Experiments in Physics Education: A Simple and Practical Example.

ERIC Educational Resources Information Center

Lattery, Mark J.

2001-01-01

Uses a Galilean thought experiment to enhance learning in a college-level physical science course. Presents both modern and historical perspectives of Galileo's work. As a final project, students explored Galileo's thought experiment in the laboratory using modern detectors with satisfying results. (Contains 25 references.) (Author/ASK)

A Laboratory Exercise with Related Rates.

ERIC Educational Resources Information Center

Sworder, Steven C.

A laboratory experiment, based on a simple electric circuit that can be used to demonstrate the existence of real-world "related rates" problems, is outlined and an equation for voltage across the capacitor terminals during discharge is derived. The necessary materials, setup methods, and experimental problems are described. A student laboratory…

Notes on Experiments.

ERIC Educational Resources Information Center

Physics Education, 1989

1989-01-01

Described are the purposes, laboratory set-ups, and procedures of four classroom experiments: ultrasound speedometer; vibrating-bar depth gauge; folding three-dimensional model of equipotential surfaces; and a simple optical system for the reconstruction of images from computer-generated holograms. Diagrams and pictures are provided. (YP)

Implementing Computer Based Laboratories

NASA Astrophysics Data System (ADS)

Peterson, David

2001-11-01

Physics students at Francis Marion University will complete several required laboratory exercises utilizing computer-based Vernier probes. The simple pendulum, the acceleration due to gravity, simple harmonic motion, radioactive half lives, and radiation inverse square law experiments will be incorporated into calculus-based and algebra-based physics courses. Assessment of student learning and faculty satisfaction will be carried out by surveys and test results. Cost effectiveness and time effectiveness assessments will be presented. Majors in Computational Physics, Health Physics, Engineering, Chemistry, Mathematics and Biology take these courses, and assessments will be categorized by major. To enhance the computer skills of students enrolled in the courses, MAPLE will be used for further analysis of the data acquired during the experiments. Assessment of these enhancement exercises will also be presented.

A Simple Molecular Dynamics Lab to Calculate Viscosity as a Function of Temperature

ERIC Educational Resources Information Center

Eckler, Logan H.; Nee, Matthew J.

2016-01-01

A simple molecular dynamics experiment is described to demonstrate transport properties for the undergraduate physical chemistry laboratory. The AMBER package is used to monitor self-diffusion in "n"-hexane. Scripts (available in the Supporting Information) make the process considerably easier for students, allowing them to focus on the…

Introducing Students to Surface Modification and Phase Transfer of Nanoparticles with a Laboratory Experiment

ERIC Educational Resources Information Center

Alkilany, Alaaldin M.; Mansour, Sara; Amro, Hamza M.; Pelaz, Beatriz; Soliman, Mahmoud G.; Hinman, Joshua G.; Dennison, Jordan M.; Parak, Wolfgang J.; Murphy, Catherine J.

2017-01-01

A simple, reliable, and cost-effective experiment is presented in which students synthesized citrate-capped gold nanoparticles (GNPs), functionalized them with poly(ethylene glycol) (PEG), and transferred the PEG-GNPs from water to the organic phase dichloromethane. The experiment introduces students to nanotechnology with foci on important…

An Experiment on a Physical Pendulum and Steiner's Theorem

ERIC Educational Resources Information Center

Russeva, G. B.; Tsutsumanova, G. G.; Russev, S. C.

2010-01-01

Introductory physics laboratory curricula usually include experiments on the moment of inertia, the centre of gravity, the harmonic motion of a physical pendulum, and Steiner's theorem. We present a simple experiment using very low cost equipment for investigating these subjects in the general case of an asymmetrical test body. (Contains 3 figures…

Applying Statistics in the Undergraduate Chemistry Laboratory: Experiments with Food Dyes.

ERIC Educational Resources Information Center

Thomasson, Kathryn; Lofthus-Merschman, Sheila; Humbert, Michelle; Kulevsky, Norman

1998-01-01

Describes several experiments to teach different aspects of the statistical analysis of data using household substances and a simple analysis technique. Each experiment can be performed in three hours. Students learn about treatment of spurious data, application of a pooled variance, linear least-squares fitting, and simultaneous analysis of dyes…

Assessing Uncertainties in a Simple and Cheap Experiment

ERIC Educational Resources Information Center

de Souza, Paulo A., Jr.; Brasil, Gutemberg Hespanha

2009-01-01

This paper describes how to calculate measurement uncertainties using as a practical example the assessment of the thickness of ping-pong balls and their material density. The advantages of a randomized experiment are also discussed. This experiment can be reproduced in the physics laboratory for undergraduate students. (Contains 7 tables, 1…

Analysis of Currently Available Analgesic Tablets by Modern Liquid Chromatography: An Undergraduate Laboratory Introduction to HPLC.

ERIC Educational Resources Information Center

Kagel, R. A.; Farwell, S. O.

1983-01-01

Background information, procedures, and results, are provided for an undergraduate experiment in which analgesic tablets are analyzed using liquid chromatography. The experiment, an improved, modified version of the Waters Associates Inc. experiment, is simple to prepare, requiring little glassware and minimal sample manipulation by students. (JN)

What’s in a drop? Correlating observations and outcomes to guide macromolecular crystallization experiments

PubMed Central

Luft, Joseph R.; Wolfley, Jennifer R.; Snell, Edward H.

2011-01-01

Observations of crystallization experiments are classified as specific outcomes and integrated through a phase diagram to visualize solubility and thereby direct subsequent experiments. Specific examples are taken from our high-throughput crystallization laboratory which provided a broad scope of data from 20 million crystallization experiments on 12,500 different biological macromolecules. The methods and rationale are broadly and generally applicable in any crystallization laboratory. Through a combination of incomplete factorial sampling of crystallization cocktails, standard outcome classifications, visualization of outcomes as they relate chemically and application of a simple phase diagram approach we demonstrate how to logically design subsequent crystallization experiments. PMID:21643490

A Simple, Low-Cost, Data-Logging Pendulum Built from a Computer Mouse

ERIC Educational Resources Information Center

Gintautas, Vadas; Hubler, Alfred

2009-01-01

Lessons and homework problems involving a pendulum are often a big part of introductory physics classes and laboratory courses from high school to undergraduate levels. Although laboratory equipment for pendulum experiments is commercially available, it is often expensive and may not be affordable for teachers on fixed budgets, particularly in…

Combining a Standard Fischer Esterification Experiment with Stereochemical and Molecular-Modeling Concepts

ERIC Educational Resources Information Center

Clausen, Thomas P.

2011-01-01

The Fisher esterification reaction is ideally suited for the undergraduate organic laboratory because it is easy to carry out and often involves a suitable introduction to basic laboratory techniques including extraction, distillation, and simple spectroscopic (IR and NMR) analyses. Here, a Fisher esterification reaction is described in which the…

Synthesis of a Photoluminescent and Triboluminescent Copper(I) Compound: An Experiment for an Advanced Inorganic Chemistry Laboratory

ERIC Educational Resources Information Center

Marchetti, Fabio; Di Nicola, Corrado; Pettinari, Riccardo; Timokhin, Ivan; Pettinari, Claudio

2012-01-01

A simple synthesis is proposed from inexpensive reactants of a copper(I) derivative that exhibits strong photoluminescence and, in the crystalline form, exhibits strong triboluminescence. This laboratory provides an opportunity for introducing students to the phenomenon of triboluminescence. (Contains 1 scheme and 4 figures.)

The mass-luminosity relation in an introductory astronomy lab

NASA Astrophysics Data System (ADS)

LoPresto, Michael C.

2016-11-01

Exposing students in general education science courses of lower mathematical levels to experiments that make use of quantitative skills such as collecting and analyzing data is very important because they provide examples of how science is actually done. Experiments with relatively simple procedures that are also interesting and engaging which serve this purpose can be hard to find. This can especially be true for introductory college astronomy courses; however, courses of this type often do still have a laboratory component because most students, regardless of major, are required to take at least one laboratory science course. When required to work with data in a quantitative fashion, the difficulty students with lower mathematical skills often have is that any actual physical meaning of an experiment can become completely lost in a procedure that, to them, seems to be purely an exercise in complex mathematics and for which they have resorted to simply following by rote, from which, perhaps needless to say, they are likely to learn little or nothing. I have seen this happen numerous times and it has inspired me to focus on attempting to develop meaningful laboratory experiences for students of lower mathematical level courses, such as introductory astronomy and conceptual physics, that involve both the gathering and analysis of numerical data. What follows is a simple experiment of this type on the mass-luminosity relation for stars on the main sequence of the Hertzsprung-Russell diagram that has proven useful for an introductory astronomy laboratory course.

Laboratory Experiments on the Electrochemical Remediation of the Environment. Part 7: Microscale Production of Ozone

ERIC Educational Resources Information Center

Ibanez, Jorge G.; Mayen-Mondragon, Rodrigo; Moran-Moran, M. T.; Alatorre-Ordaz, Alejandro; Mattson, Bruce; Eskestrand, Scot

2005-01-01

Ozone is a powerful oxidant and disinfectant, which can be used to clean environment as well as obtain pure drinking water. A series of experiments to produce and test ozone with simple equipment and material are presented.

A Simple Adsorption Experiment

ERIC Educational Resources Information Center

Guirado, Gonzalo; Ayllon, Jose A.

2011-01-01

The study of adsorption phenomenon is one of the most relevant and traditional physical chemistry experiments performed by chemistry undergraduate students in laboratory courses. In this article, we describe an easy, inexpensive, and straightforward way to experimentally determine adsorption isotherms using pieces of filter paper as the adsorbent…

Dynamics of animal movement in an ecological context: dragonfly wing damage reduces flight performance and predation success.

PubMed

Combes, S A; Crall, J D; Mukherjee, S

2010-06-23

Much of our understanding of the control and dynamics of animal movement derives from controlled laboratory experiments. While many aspects of animal movement can be probed only in these settings, a more complete understanding of animal locomotion may be gained by linking experiments on relatively simple motions in the laboratory to studies of more complex behaviours in natural settings. To demonstrate the utility of this approach, we examined the effects of wing damage on dragonfly flight performance in both a laboratory drop-escape response and the more natural context of aerial predation. The laboratory experiment shows that hindwing area loss reduces vertical acceleration and average flight velocity, and the predation experiment demonstrates that this type of wing damage results in a significant decline in capture success. Taken together, these results suggest that wing damage may take a serious toll on wild dragonflies, potentially reducing both reproductive success and survival.

Virtually-Enhanced Fluid Laboratories for Teaching Meteorology

NASA Astrophysics Data System (ADS)

Marshall, J.; Illari, L.

2015-12-01

The Weather in a Tank (WIAT) project aims to offer instructors a repertoire of rotating tank experiments, and a curriculum in fluid dynamics, to better assist students in learning how to move between phenomena in the real world and basic principles of rotating fluid dynamics which play a central role in determining the climate of the planet. Despite the increasing use of laboratory experiments in teaching meteorology, however, we are aware that many teachers and students do not have access to suitable apparatus and so cannot benefit from them. Here we describe a 'virtually-enhanced' laboratory that we hope could be very effective in getting across a flavor of the experiments and bring them to a wider audience. In the pedagogical spirit of WIAT we focus on how simple underlying principles, illustrated through laboratory experiments, shape the observed structure of the large-scale atmospheric circulation.

Teaching Beer's Law and Absorption Spectrophotometry with a Smart Phone: A Substantially Simplified Protocol

ERIC Educational Resources Information Center

Kuntzleman, Thomas S.; Jacobson, Erik C.

2016-01-01

A very simple protocol for teaching Beer's Law and absorption spectrophotometry using a smart phone is described. Materials commonly found in high school chemistry laboratories or even around the house may be used. Data collection and analysis is quick and easy. Despite the simple nature of the experiment, excellent results can be achieved.

Special Relativity in the School Laboratory: A Simple Apparatus for Cosmic-Ray Muon Detection

ERIC Educational Resources Information Center

Singh, P.; Hedgeland, H.

2015-01-01

We use apparatus based on two Geiger-Müller tubes, a simple electronic circuit and a Raspberry Pi computer to illustrate relativistic time dilation affecting cosmic-ray muons travelling through the atmosphere to the Earth's surface. The experiment we describe lends itself to both classroom demonstration to accompany the topic of special relativity…

A Simple and Affordable TTL Processor for the Classroom

ERIC Educational Resources Information Center

Feinberg, Dave

2007-01-01

This paper presents a simple 4 bit computer processor design that may be built using TTL chips for less than $65. In addition to describing the processor itself in detail, we discuss our experience using the laboratory kit and its associated machine instruction set to teach computer architecture to high school students. (Contains 3 figures and 5…

Which Method Is Most Precise; Which Is Most Accurate? An Undergraduate Experiment

ERIC Educational Resources Information Center

Jordan, A. D.

2007-01-01

A simple experiment, the determination of the density of a liquid by several methods, is presented. Since the concept of density is a familiar one, the experiment is suitable for the introductory laboratory period of a first- or second-year course in physical or analytical chemistry. The main objective of the experiment is to familiarize students…

The dumbest experiment in space. [problems in laboratory apparatus adaption to space environment

NASA Technical Reports Server (NTRS)

Prouty, C. R.

1981-01-01

A simple conceptual experiment is used to illustrate (1) the fundamentals of performing an experiment, including the theoretical concept, the experiment design, the performance of the experiment, and the recording of observations; (2) the increasing challenges posed by performance of the same experiment in a location remote from the experimenter, such as additional planning and equipment and their associated cost increases; and (3) the significant growth of difficulties to be overcome when the simple experiment is performed in a highly restrictive environment, such as a spacecraft in orbit, with someone else remotely operating the experiment. It is shown that performing an experiment in the remote, hostile environment of space will pose difficulties equaling or exceeding those of the experiment itself, entailing mastery of a widening range of disciplines.

A Grand Sale: $12 for a Dozen Experiments in CRE.

ERIC Educational Resources Information Center

Guo-Tai, Zhang; Shau-Drang, Hau

1984-01-01

Introduces a procedure for a whole class of experiments which require very simple and inexpensive equipment and which illustrate one of the basic problems of chemical reaction engineering. The reactions are designed to allow development of a kinetic rate equation from laboratory data. (JM)

A Simple Experiment for Determining Vapor Pressure and Enthalpy of Vaporization of Water.

ERIC Educational Resources Information Center

Levinson, Gerald S.

1982-01-01

Laboratory procedures, calculations, and sample results are described for a freshman chemistry experiment in which the Clausius-Clapeyron equation is introduced as a means of describing the variation of vapor pressure with temperature and for determining enthalpy of vaporization. (Author/SK)

Simple Epoxide Formation for the Organic Laboratory Using Oxone

ERIC Educational Resources Information Center

Broshears, Williams C.; Esteb, John J.; Richter, Jeremy; Wilson, Anne M.

2004-01-01

Epoxide chemistry is widely used in organic synthesis and regularly discussed in organic chemistry textbooks. An experiment to generate dimethyldioxirane in situ from acetone using Oxone is explained.

An Authentic Research Experience for Undergraduates on a Budget: Using Data from Simple Experiments to Develop Mini-Research Proposals

ERIC Educational Resources Information Center

Robertson, Katherine

2016-01-01

The benefits of undergraduate research are well documented, and many colleges and universities include a senior research requirement for graduation. In addition, most science curricula attempt to include discoverystyle, laboratory components to prepare students for their research experiences and to expose them to research methods in different…

Electromagnetic Faraday generator and its application

NASA Astrophysics Data System (ADS)

Mayer, V. V.; Varaksina, E. I.

2017-07-01

This paper presents a simple electromagnetic generator meant for use in students’ experiments. This apparatus provides realization of a series of experiments demonstrating the principles of electricity generation and the conversion of electricity to other forms of energy with practical application. The experiments can be reproduced in a school laboratory and can be recommended for students’ project activity.

Laboratory Exercise for Studying the Morphology of Heat-Denatured and Amyloid Aggregates of Lysozyme by Atomic Force Microscopy

ERIC Educational Resources Information Center

Gokalp, Sumeyra; Horton, William; Jónsdóttir-Lewis, Elfa B.; Foster, Michelle; Török, Marianna

2018-01-01

To facilitate learning advanced instrumental techniques, essential tools for visualizing biomaterials, a simple and versatile laboratory exercise demonstrating the use of Atomic Force Microscopy (AFM) in biomedical applications was developed. In this experiment, the morphology of heat-denatured and amyloid-type aggregates formed from a low-cost…

Using Visible Spectrophotometers and pH Measurements to Study Speciation in a Guided-Inquiry Laboratory

ERIC Educational Resources Information Center

Otto, William H.; Larive, Cynthia K.; Mason, Susan L.; Robinson, Janet B.; Heppert Joseph A.; Ellis, James D.

2005-01-01

An experiment to perform a simple initial investigation that illustrates concepts of speciation and equilibrium, using the instrument and chemical resources in the laboratory is presented. The investigation showed that the presence of multiple chemical species in a reaction mixture (phenol red solution) reflects the acid and base conditions…

A Simple Student Laboratory on Osmotic Flow, Osmotic Pressure, and the Reflection Coefficient.

ERIC Educational Resources Information Center

Feher, Joseph J.; Ford, George D.

1995-01-01

Describes a laboratory exercise containing a practical series of experiments that novice students can perform within two hours. The exercise provides a confirmation of van't Hoff's law while placing more emphasis on osmotic flow than pressure. Students can determine parameters such as the reflection coefficient which stress the interaction of both…

Experiments with Helium-Filled Balloons

ERIC Educational Resources Information Center

Zable, Anthony C.

2010-01-01

The concepts of Newtonian mechanics, fluids, and ideal gas law physics are often treated as separate and isolated topics in the typical introductory college-level physics course, especially in the laboratory setting. To bridge these subjects, a simple experiment was developed that utilizes computer-based data acquisition sensors and a digital gram…

Applications of Chemiluminescence in the Teaching of Experimental Design

ERIC Educational Resources Information Center

Krawczyk, Tomasz; Slupska, Roksana; Baj, Stefan

2015-01-01

This work describes a single-session laboratory experiment devoted to teaching the principles of factorial experimental design. Students undertook the rational optimization of a luminol oxidation reaction, using a two-level experiment that aimed to create a long-lasting bright emission. During the session students used only simple glassware and…

Experimental Confirmation of Lenz's Law

ERIC Educational Resources Information Center

Mayer, V. V.; Varaksina, E. I.

2017-01-01

The paper presents a series of experiments that demonstrate the phenomenon of electromagnetic induction. These make it possible to determine the direction of the induced current and so confirm Lenz's Law. The simple experiments can be reproduced in a school laboratory and can be recommended for students' project activity.

A Better 2-D Mechanical Energy Conservation Experiment

ERIC Educational Resources Information Center

Paesler, Michael

2012-01-01

A variety of simple classical mechanics energy conservation experiments are used in teaching laboratories. Typical one-dimensional (1-D) setups may involve falling balls or oscillating springs. Many of these can be quite satisfying in that students can confirm--within a few percent--that mechanical energy is conserved. Students generally have…

Experimental confirmation of Lenz’s law

NASA Astrophysics Data System (ADS)

Mayer, V. V.; Varaksina, E. I.

2017-11-01

The paper presents a series of experiments that demonstrate the phenomenon of electromagnetic induction. These make it possible to determine the direction of the induced current and so confirm Lenz’s Law. The simple experiments can be reproduced in a school laboratory and can be recommended for students’ project activity.

Use of a Simple, Colorimetric Assay to Demonstrate Conditions for Induction of Nitrate Reductase in Plants.

ERIC Educational Resources Information Center

Harley, Suzanne M.

1993-01-01

Nitrate assimilation by plants provides an excellent system for demonstrating control of gene expression in a eukaryotic organism. Describes an assay method that allows students to complete experiments designed around the measurement of nitrate reductase within a three-hour laboratory experiment. (PR)

A Comprehensive Real-World Distillation Experiment

ERIC Educational Resources Information Center

Kazameas, Christos G.; Keller, Kaitlin N.; Luyben, William L.

2015-01-01

Most undergraduate mass transfer and separation courses cover the design of distillation columns, and many undergraduate laboratories have distillation experiments. In many cases, the treatment is restricted to simple column configurations and simplifying assumptions are made so as to convey only the basic concepts. In industry, the analysis of a…

An Approach to Poiseuille's Law in an Undergraduate Laboratory Experiment

ERIC Educational Resources Information Center

Sianoudis, I. A.; Drakaki, E.

2008-01-01

The continuous growth of computer and sensor technology allows many researchers to develop simple modifications and/or refinements to standard educational experiments, making them more attractive and comprehensible to students and thus increasing their educational impact. In the framework of this approach, the present study proposes an alternative…

Low-cost nonlinear optics experiment for undergraduate instructional laboratory and lecture demonstration

NASA Astrophysics Data System (ADS)

Turchiello, Rozane de F.; Pereira, Luiz A. A.; Gómez, Sergio L.

2017-07-01

This paper presents a simple and affordable experiment on the thermal lens effect, suitable for an undergraduate educational laboratory or as a tabletop demonstration in a lecture on nonlinear optics. Such an experiment exploits the formation of a lens in an absorbing medium illuminated by a laser beam with a Gaussian intensity profile. As an absorber, we use a commercial soy sauce, which exhibits a strong thermal lensing effect. Additionally, we show how to measure the radius of a Gaussian beam using the knife-edge method, and how to estimate the focal length of the induced thermal lens.

Audiovisual Speech Web-Lab: an Internet teaching and research laboratory.

PubMed

Gordon, M S; Rosenblum, L D

2001-05-01

Internet resources now enable laboratories to make full-length experiments available on line. A handful of existing web sites offer users the ability to participate in experiments and generate usable data. We have integrated this technology into a web site that also provides full discussion of the theoretical and methodological aspects of the experiments using text and simple interactive demonstrations. The content of the web site (http://www.psych.ucr.edu/avspeech/lab) concerns audiovisual speech perception and its relation to face perception. The site is designed to be useful for users of multiple interests and levels of expertise.

Inexpensive Laboratory Model with Many Applications.

ERIC Educational Resources Information Center

Archbold, Norbert L.; Johnson, Robert E.

1987-01-01

Presents a simple, inexpensive and realistic model which allows introductory geology students to obtain subsurface information through a simulated drilling experience. Offers ideas on additional applications to a variety of geologic situations. (ML)

Chocolate--A Sweet Conundrum.

ERIC Educational Resources Information Center

Beckett, Stephen

1988-01-01

Presented is a brief history of manufacturing chocolate and an outline of production methods. Describes laboratory techniques used to monitor liquid chocolate viscosity. Discusses a simple experiment which can be performed in the classroom. (Author/CW)

Relationship between a solar drying model of red pepper and the kinetics of pure water evaporation (1)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Passamai, V.; Saravia, L.

1997-05-01

Drying of red pepper under solar radiation was investigated, and a simple model related to water evaporation was developed. Drying experiments at constant laboratory conditions were undertaken where solar radiation was simulated by a 1,000 W lamp. In this first part of the work, water evaporation under radiation is studied and laboratory experiments are presented with two objectives: to verify Penman`s model of evaporation under radiation, and to validate the laboratory experiments. Modifying Penman`s model of evaporation by introducing two drying conductances as a function of water content, allows the development of a drying model under solar radiation. In themore » second part of this paper, the model is validated by applying it to red pepper open air solar drying experiments.« less

Determination of Rest Mass Energy of the Electron by a Compton Scattering Experiment

ERIC Educational Resources Information Center

Prasannakumar, S.; Krishnaveni, S.; Umesh, T. K.

2012-01-01

We report here a simple Compton scattering experiment which may be carried out in graduate and undergraduate laboratories to determine the rest mass energy of the electron. In the present experiment, we have measured the energies of the Compton scattered gamma rays with a NaI(Tl) gamma ray spectrometer coupled to a 1 K multichannel analyzer at…

Oxidation of Borneol to Camphor Using Oxone and Catalytic Sodium Chloride: A Green Experiment for the Undergraduate Organic Chemistry Laboratory

ERIC Educational Resources Information Center

Lang, Patrick T.; Harned, Andrew M.; Wissinger, Jane E.

2011-01-01

A new green oxidation procedure was developed for the undergraduate organic teaching laboratories using Oxone and a catalytic quantity of sodium chloride for the conversion of borneol to camphor. This simple 1 h, room temperature reaction afforded high quality and yield of product, was environmentally friendly, and produced negligible quantities…

Flotation of Mineral and Dyes: A Laboratory Experiment for Separation Method Molecular Hitchhikers

ERIC Educational Resources Information Center

Rappon, Tim; Sylvestre, Jarrett A.; Rappon, Manit

2016-01-01

Flotation as a method of separation is widely researched and is applied in many industries. It has been used to address a wide range of environmental issues including treatment of wastewater, recovery of heavy metals for recycling, extraction of minerals in mining, and so forth. This laboratory attempts to show how such a simple method can be used…

Resistivity in Play-Doh: Time and Color Variations

ERIC Educational Resources Information Center

Fuse, Christopher; August, Brandon; Cannaday, Ashley; Barker, Casey

2013-01-01

The study of electricity and magnetism is fundamental to all first-year physics courses. Developing simple electricity laboratory experiences that are open ended and inquiry based can be difficult. We wished to create a lab experiment where the students have some control over the experimental design, data analysis is required, and students…

A Novel General Chemistry Laboratory: Creation of Biomimetic Superhydrophobic Surfaces through Replica Molding

ERIC Educational Resources Information Center

Verbanic, Samuel; Brady, Owen; Sanda, Ahmed; Gustafson, Carolina; Donhauser, Zachary J.

2014-01-01

Biomimetic replicas of superhydrophobic lotus and taro leaf surfaces can be made using polydimethylsiloxane. These replicas faithfully reproduce the microstructures of the leaves' surface and can be analyzed using contact angle goniometry, self-cleaning experiments, and optical microscopy. These simple and adaptable experiments were used to…

The Pea Seedling as a Model of Normal and Abnormal Morphogenesis

ERIC Educational Resources Information Center

Kurkdjian, Armen; And Others

1974-01-01

Describes several simple and inexpensive experiments designed to facilitate the study of normal and abnormal morphogenesis in the biology laboratory. Seedlings of the common garden pea are used in the experiments, and abnormal morphogenesis (tumors) are induced by a virulent strain of the crown-gall organism, Agrobacterium tumefaciens. (JR)

Analysis of the RNA Content of the Yeast "Saccharomyces Cerevisiae"

ERIC Educational Resources Information Center

Deutch, Charles E.; Marshall, Pamela A.

2008-01-01

In this article, the authors describe an interconnected set of relatively simple laboratory experiments in which students determine the RNA content of yeast cells and use agarose gel electrophoresis to separate and analyze the major species of cellular RNA. This set of experiments focuses on RNAs from the yeast "Saccharomyces cerevisiae", a…

Low carbon steel: Metallurgical structure vs. mechanical properties

NASA Technical Reports Server (NTRS)

Shull, Robert D.

1990-01-01

The objective is to provide a low cost, simple experiment for either demonstration purposes or as a laboratory experiment that will teach the student the importance of the thermal-mechanical history of a metallic alloy in determining that material's mechanical behavior. Hairpins are subjected to various treatments. The experimental equipment and procedures are discussed.

Cavity Ring down Spectroscopy Experiment for an Advanced Undergraduate Laboratory

ERIC Educational Resources Information Center

Stacewicz, T.; Wasylczyk, P.; Kowalczyk, P.; Semczuk, M.

2007-01-01

A simple experiment is described that permits advanced undergraduates to learn the principles and applications of the cavity ring down spectroscopy technique. The apparatus is used for measurements of low concentrations of NO[subscript 2] produced in air by an electric discharge. We present the setup, experimental procedure, data analysis and some…

Scaling up Effects in the Organic Laboratory

ERIC Educational Resources Information Center

Persson, Anna; Lindstrom, Ulf M.

2004-01-01

A simple and effective way of exposing chemistry students to some of the effects of scaling up an organic reaction is described. It gives the student an experience that may encounter in an industrial setting.

A "Stationery" Kinetics Experiment.

ERIC Educational Resources Information Center

Hall, L.; Goberdhansingh, A.

1988-01-01

Describes a simple redox reaction that occurs between potassium permanganate and oxalic acid that can be used to prepare an interesting disappearing ink for demonstrating kinetics for introductory chemistry. Discusses laboratory procedures and factors that influence disappearance times. (CW)

Ranking protective coatings: Laboratory vs. field experience

NASA Astrophysics Data System (ADS)

Conner, Jeffrey A.; Connor, William B.

1994-12-01

Environmentally protective coatings are used on a wide range of gas turbine components for survival in the harsh operating conditions of engines. A host of coatings are commercially available to protect hot-section components, ranging from simple aluminides to designer metallic overlays and ceramic thermal barrier coatings. A variety of coating-application processes are available, and they range from simple pack cementation processing to complex physical vapor deposition, which requires multimillion dollar facilities. Detailed databases are available for most coatings and coating/process combinations for a range of laboratory tests. Still, the analysis of components actually used in engines often yields surprises when compared against predicted coating behavior from laboratory testing. This paper highlights recent work to develop new laboratory tests that better simulate engine environments. Comparison of in-flight coating performance as well as industrial and factory engine testing on a range of hardware is presented along with laboratory predictions from standard testing and from recently developed cyclic burner-rig testing.

Dynamics of animal movement in an ecological context: dragonfly wing damage reduces flight performance and predation success

PubMed Central

Combes, S. A.; Crall, J. D.; Mukherjee, S.

2010-01-01

Much of our understanding of the control and dynamics of animal movement derives from controlled laboratory experiments. While many aspects of animal movement can be probed only in these settings, a more complete understanding of animal locomotion may be gained by linking experiments on relatively simple motions in the laboratory to studies of more complex behaviours in natural settings. To demonstrate the utility of this approach, we examined the effects of wing damage on dragonfly flight performance in both a laboratory drop–escape response and the more natural context of aerial predation. The laboratory experiment shows that hindwing area loss reduces vertical acceleration and average flight velocity, and the predation experiment demonstrates that this type of wing damage results in a significant decline in capture success. Taken together, these results suggest that wing damage may take a serious toll on wild dragonflies, potentially reducing both reproductive success and survival. PMID:20236968

Predictive modelling of flow in a two-dimensional intermediate-scale, heterogeneous porous media

USGS Publications Warehouse

Barth, Gilbert R.; Hill, M.C.; Illangasekare, T.H.; Rajaram, H.

2000-01-01

To better understand the role of sedimentary structures in flow through porous media, and to determine how small-scale laboratory-measured values of hydraulic conductivity relate to in situ values this work deterministically examines flow through simple, artificial structures constructed for a series of intermediate-scale (10 m long), two-dimensional, heterogeneous, laboratory experiments. Nonlinear regression was used to determine optimal values of in situ hydraulic conductivity, which were compared to laboratory-measured values. Despite explicit numerical representation of the heterogeneity, the optimized values were generally greater than the laboratory-measured values. Discrepancies between measured and optimal values varied depending on the sand sieve size, but their contribution to error in the predicted flow was fairly consistent for all sands. Results indicate that, even under these controlled circumstances, laboratory-measured values of hydraulic conductivity need to be applied to models cautiously.To better understand the role of sedimentary structures in flow through porous media, and to determine how small-scale laboratory-measured values of hydraulic conductivity relate to in situ values this work deterministically examines flow through simple, artificial structures constructed for a series of intermediate-scale (10 m long), two-dimensional, heterogeneous, laboratory experiments. Nonlinear regression was used to determine optimal values of in situ hydraulic conductivity, which were compared to laboratory-measured values. Despite explicit numerical representation of the heterogeneity, the optimized values were generally greater than the laboratory-measured values. Discrepancies between measured and optimal values varied depending on the sand sieve size, but their contribution to error in the predicted flow was fairly consistent for all sands. Results indicate that, even under these controlled circumstances, laboratory-measured values of hydraulic conductivity need to be applied to models cautiously.

A Simple Experiment to Explore Standing Waves in a Flexible Corrugated Sound Tube

NASA Astrophysics Data System (ADS)

Amorim, Maria Eva; Sousa, Teresa Delmira; Carvalho, P. Simeão; Sousa, Adriano Sampaioe

2011-09-01

Sound tubes, pipes, and singing rods are used as musical instruments and as toys to perform amusing experiments. In particular, corrugated tubes present unique characteristics with respect to the sounds they can produce; that is why they have been studied so intensively, both at theoretical and experimental levels.1-4 Experimental studies usually involve expensive and sophisticated equipment that is out of reach of school laboratory facilities.3-6 In this paper we show how to investigate quantitatively the sounds produced by a flexible sound tube corrugated on the inside by using educational equipment readily available in school laboratories, such as the oscilloscope, the microphone, the anemometer, and the air pump. We show that it is possible for students to study the discontinuous spectrum of sounds produced by a flexible corrugated tube and go even further, computing the speed of sound in air with a simple experimental procedure.

Identification of Gas Components in Lighter by Gas Chromatography: An Experiment of the Undergraduate Instrumental Analysis Laboratory Which Can Be Used with Distance Learning Applications

ERIC Educational Resources Information Center

Yavuz, Soner; Morgil, Inci

2006-01-01

In the applications of instrumental analysis lessons, advanced instruments with the needed experiments are needed. During the lessons it is a fact that the more experiments are performed, the more learning will be. For this reason, experiments that do not last long and should be performed with more simple instruments and that increase students"…

Simple Laboratory Experiment for Illustrating Soil Respiration.

ERIC Educational Resources Information Center

Hattey, J. A.; Johnson, G. V.

1997-01-01

Describes an experiment to illustrate the effect of food source and added nutrients (N) on microbial activity in the soil. Supplies include air-dried soil, dried plant material, sources of carbon and nitrogen, a trap such as KOH, colored water, and a 500-mL Erlenmeyer flask. Includes a diagram of an incubation chamber to demonstrate microbial…

Methylene Blue-Ascorbic Acid: An Undergraduate Experiment in Kinetics.

ERIC Educational Resources Information Center

Snehalatha, K. C.; And Others

1997-01-01

Describes a laboratory exercise involving methylene blue and L-ascorbic acid in a simple clock reaction technique to illustrate the basic concepts of chemical kinetics. If stock solutions are supplied and each type of experiment takes no more than half an hour, the entire investigation can be completed in three practical sessions of three hours…

A Simple Experiment in the Separation of a Solid-Phase Mixture and Infrared Spectroscopy for Introductory Chemistry

ERIC Educational Resources Information Center

Szalay, Paul S.

2008-01-01

This experiment was developed as a means of incorporating instrumental analyses into an introductory chemistry laboratory. A two-component solid mixture of caffeine and ibuprofen is separated through a series of solution extractions and precipitation and their relative amounts measured. These compounds were chosen because the combination of…

MANUAL OF LECTURE DEMONSTRATIONS, LABORATORY EXPERIMENTS, AND OBSERVATIONAL EQUIPMENT FOR TEACHING ELEMENTARY METEOROLOGY IN SCHOOLS AND COLLEGES.

ERIC Educational Resources Information Center

NEUBERGER, HANS; NICHOLAS, GEORGE

INCLUDED IN THIS MANUAL WRITTEN FOR SECONDARY SCHOOL AND COLLEGE TEACHERS ARE DESCRIPTIONS OF DEMONSTRATION MODELS, EXPERIMENTS PERTAINING TO SOME OF THE FUNDAMENTAL AND APPLIED METEOROLOGICAL CONCEPTS, AND INSTRUCTIONS FOR MAKING SIMPLE WEATHER OBSERVATIONS. THE CRITERIA FOR SELECTION OF TOPICS WERE EASE AND COST OF CONSTRUCTING APPARATUS AS WELL…

Fourier Theory Explanation for the Sampling Theorem Demonstrated by a Laboratory Experiment.

ERIC Educational Resources Information Center

Sharma, A.; And Others

1996-01-01

Describes a simple experiment that uses a CCD video camera, a display monitor, and a laser-printed bar pattern to illustrate signal sampling problems that produce aliasing or moiri fringes in images. Uses the Fourier transform to provide an appropriate and elegant means to explain the sampling theorem and the aliasing phenomenon in CCD-based…

Relationship between a solar drying model of red pepper and the kinetics of pure water evaporation (2)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Passamai, V.; Saravia, L.

1997-05-01

In part one, a simple drying model of red pepper related to water evaporation was developed. In this second part the drying model is applied by means of related experiments. Both laboratory and open air drying experiments were carried out to validate the model and simulation results are presented.

Special relativity in the school laboratory: a simple apparatus for cosmic-ray muon detection

NASA Astrophysics Data System (ADS)

Singh, P.; Hedgeland, H.

2015-05-01

We use apparatus based on two Geiger-Müller tubes, a simple electronic circuit and a Raspberry Pi computer to illustrate relativistic time dilation affecting cosmic-ray muons travelling through the atmosphere to the Earth’s surface. The experiment we describe lends itself to both classroom demonstration to accompany the topic of special relativity and to extended investigations for more inquisitive students.

Bell's Theorem and Einstein's `Spooky Actions' from a Simple Thought Experiment

NASA Astrophysics Data System (ADS)

Kuttner, Fred; Rosenblum, Bruce

2010-02-01

In 1964 John Bell proved a theorem2 allowing the experimental test of whether what Einstein derided as "spooky actions at a distance" actually exist. We will see that they do. Bell's theorem can be displayed with a simple, nonmathematical thought experiment suitable for a physics course at any level. And a simple, semi-classical derivation of the quantum theory result can be given for physics students. These entanglement phenomena are today applied in industrial laboratories and are increasingly discussed in the popular literature. Unfortunately, they are also misappropriated by the purveyors of pseudoscience, something physicists have a responsibility to address.3 Students can be intrigued by the quantum strangeness physics has encountered at a boundary of our discipline.

P.S.

ERIC Educational Resources Information Center

South Australian Science Teachers Journal, 1973

1973-01-01

Presents ideas from readers on techniques and equipment that might be useful in teaching secondary school science. Suggests how to construct cheap wall charts, modify a vacuum cleaner into a blower, construct a stereo microscope lamp holder, and outlines simple physics laboratory experiments. (JR)

A visual understanding of optical rotation using corn syrup

NASA Astrophysics Data System (ADS)

Nixon, M.; Hughes, I. G.

2017-07-01

In this paper a visual demonstration of optical rotation is presented, with content appropriate for use in a lecture demonstration as well as quantitative techniques suitable for an undergraduate-laboratory experiment. Linearly polarised lasers of various wavelengths are propagated through a glass tube containing corn syrup. The rotation of the plane of polarisation of the light is visible with the naked eye, making the experiment dramatic and engaging and aiding understanding of the phenomenon of optical rotation. In addition, we present a simple approach to quantitatively analyse data using only equipment commonly found in undergraduate teaching laboratories.

Thermodynamics of the Rhodamine B Lactone--Zwitterion Equilibrium.

ERIC Educational Resources Information Center

Hinckley, Daniel A.; Seybold, Paul G.

1987-01-01

Discusses the benefits of thermochromic transformations for studying thermodynamic properties. Describes an experiment that uses a commercially available dye, attains equilibrium rapidly, employs a simple, single-beam spectrophotometer, and is suitable for both physical chemistry and introductory chemistry laboratories. (TW)

Some Insights Regarding a Popular Introductory Gas Law Experiment

ERIC Educational Resources Information Center

DePierro, Ed; Garafalo, Fred

2005-01-01

The Dumas method provides a relatively simple way to determine the molar mass of volatile chemical compounds. A potential source of error in the Dumas molar mass method as it is often practiced in introductory chemistry laboratories is reported.

Simple Flame Test Techniques Using Cotton Swabs

ERIC Educational Resources Information Center

Sanger, Michael J.; Phelps, Amy J.; Banks, Catherine

2004-01-01

Three alternative methods for performing flame tests using cheaply and easily available cotton swabs are described. These flame tests are useful for chemical demonstrations or laboratory experiments because they are quick and easy to perform with easy cleanup and disposal methods.

A Laboratory Experiment of the Purification of Catalase.

ERIC Educational Resources Information Center

Busquets, Montserrat; Franco, Rafael

1986-01-01

Describes a simple method for purifying catalase for the study of proteins. Procedures are systematically and diagramatically presented. Also identifies polyacrylamide gel electrophoresis, kinetic studies, and apparent molecular weight determination as possible techniques to be used in studying proteins. (ML)

Chemoenzymatic Synthesis of an Enantiomerically Pure Lactone: A Three-Step Synthesis for Undergraduate Organic Chemistry Laboratory

NASA Astrophysics Data System (ADS)

McClure, Cynthia K.; Chenault, H. Keith

1996-05-01

A three-step laboratory sequence for the undergraduate organic laboratory is described. This series of experiments requires a student to use the product from one reaction as the starting material for a subsequent reaction, and thus the affords the student a "real world" experience of multistep synthesis. Thermal extrusion of sulfur dioxide from sulfolene is used to generate 1,3-butadiene in situ for a Diels-Alder cyclization with maleic anhydride. The anhydride is then reduced to the diol with lithium aluminum hydride. Oxidation of the diol to the chiral lactone is catalyzed by horse-liver alcohol dehydrogenase. This enzymatic oxidation illustrates in situ cofactor regeneration and allows students to measure simple enzyme kinetics.

Synthesis and Self-Assembly of the "Tennis Ball" Dimer and Subsequent Encapsulation of Methane. An Advanced Organic Chemistry Laboratory Experiment

NASA Astrophysics Data System (ADS)

Hof, Fraser; Palmer, Liam C.; Rebek, Julius, Jr.

2001-11-01

While important to the biological and materials sciences, noncovalent interactions, self-folding, and self-assembly often receive little discussion in the undergraduate chemistry curriculum. The synthesis and NMR characterization of a molecular "tennis ball" in an advanced undergraduate organic chemistry laboratory is a simple and effective way to introduce the relevance of these concepts. In appropriate solvents, the monomer dimerizes through a seam of eight hydrogen bonds with encapsulation of a guest molecule and symmetry reminiscent of a tennis ball. The entire experiment can be completed in three lab periods, however large-scale synthetic preparation of the starting monomer by a teaching assistant would reduce the laboratory to a single lab period for NMR studies.

Robust 1-Bit Compressive Sensing via Binary Stable Embeddings of Sparse Vectors

DTIC Science & Technology

2011-04-15

funded by Mitsubishi Electric Research Laboratories. †ICTEAM Institute, ELEN Department, Université catholique de Louvain (UCL), B-1348 Louvain-la-Neuve...reduced to a simple comparator that tests for values above or below zero, enabling extremely simple, efficient, and fast quantization. A 1-bit quantizer is...these two terms appears to be significantly different, according to the previously discussed experiments. To test the hypothesis that this term is the key

Binary Solid-Liquid Phase Diagram of Phenol and t-Butanol: An Undergraduate Physical Chemistry Experiment

ERIC Educational Resources Information Center

Xu, Xinhua; Wang, Xiaogang; Wu, Meifen

2014-01-01

The determination of the solid-liquid phase diagram of a binary system is always used as an experiment in the undergraduate physical chemistry laboratory courses. However, most phase diagrams investigated in the lab are simple eutectic ones, despite the fact that complex binary solid-liquid phase diagrams are more common. In this article, the…

Achieving Very Low Levels of Detection: An Improved Surface-Enhanced Raman Scattering Experiment for the Physical Chemistry Teaching Laboratory

ERIC Educational Resources Information Center

McMillan, Brian G.

2016-01-01

This experiment was designed and successfully introduced to complement the nanochemistry taught to undergraduate students in a useful and interesting way. Colloidal Ag nanoparticles were synthesized by a simple, room-temperature method, and the resulting suspension was then used to study the surface-enhanced Raman scattering (SERS) of methylene…

Experimental and numerical modeling of shrub crown fire initiation

Treesearch

Watcharapong Tachajapong; Jesse Lozano; Shakar Mahalingam; Xiangyang Zhou; David Weise

2009-01-01

The transition of fire from dry surface fuels to wet shrub crown fuels was studied using laboratory experiments and a simple physical model to gain a better understanding of the transition process. In the experiments, we investigated the effects of varying vertical distances between surface and crown fuels (crown base height), and of the wind speed on crown fire...

Determination and Comparison of Carbonyl Stretching Frequency of a Ketone in Its Ground State and the First Electronic Excited State

ERIC Educational Resources Information Center

Bandyopadhyay, Subhajit; Roy, Saswata

2014-01-01

This paper describes an inexpensive experiment to determine the carbonyl stretching frequency of an organic keto compound in its ground state and first electronic excited state. The experiment is simple to execute, clarifies some of the fundamental concepts of spectroscopy, and is appropriate for a basic spectroscopy laboratory course. The…

Spectroscopic Properties of Some Simple Esters: A Practical Application of Synthesis and Spectroscopy in the Undergraduate Organic Laboratory

ERIC Educational Resources Information Center

Brown, David P.; Durutlic, Haris; Juste, Didier

2004-01-01

Experiments are conducted for spectroscopic analysis of the allyl esters of some aromatic carboxylic acids. It is understood that these experiments allow the students to monitor the effect of hydrogen bonding on the IR stretching frequencies for the hydroxyl and carbonyl groups and also provide them with an excellent opportunity to examine the…

A Mechanistic Design Approach for Graphite Nanoplatelet (GNP) Reinforced Asphalt Mixtures for Low-Temperature Applications

DOT National Transportation Integrated Search

2018-01-01

This report explores the application of a discrete computational model for predicting the fracture behavior of asphalt mixtures at low temperatures based on the results of simple laboratory experiments. In this discrete element model, coarse aggregat...

A Simple Tubular Reactor Experiment.

ERIC Educational Resources Information Center

Hudgins, Robert R.; Cayrol, Bertrand

1981-01-01

Using the hydrolysis of crystal violet dye by sodium hydroxide as an example, the theory, apparatus, and procedure for a laboratory demonstration of tubular reactor behavior are described. The reaction presented can occur at room temperature and features a color change to reinforce measured results. (WB)

Sensitive Electroanalysis Using Solid Electrodes.

ERIC Educational Resources Information Center

Wang, Joseph

1982-01-01

A hydrodynamic modulation voltammetry (HMV) experiment involving use of simple hydrodynamic modulation procedures is described. Competing with time/equipment restrictions of most teaching laboratories (stopped-stirring and stopped-flow volumetry), students perform both batch and flow analyses and are introduced to analytical flow systems and the…

Toward Active Control of Noise from Hot Supersonic Jets

DTIC Science & Technology

2013-11-15

several laboratory - and full- scale data sets. Two different scaling scenarios are presented for the practising scientist to choose from. The first...As will be detailed below, this simple proof-of-concept experiment yielded good quality data that reveals details about the large-scale 3D structure...the light-field. Co-PI Thurow has recently designed and assembled a plenoptic camera in his laboratory with its key attributes being its compact

Unveiling Angular Momentum

NASA Astrophysics Data System (ADS)

Robinson, Stephen

2015-03-01

Angular momentum is a notoriously difficult concept to grasp. Visualization often requires three-dimensional pictures of vectors pointing in seemingly arbitrary directions. A simple student-run laboratory experiment coupled with intuitive explanations by an instructor can clear up some of the inherent ambiguity of rotational motion. Specifically, the precessional period of a suspended spinning bicycle wheel can be related to the spinning frequency through a simple algebraic expression. An explanation of this precession apart from the concept of angular momentum will be given.

Synthesis of Silver Nanoprisms with Variable Size and Investigation of Their Optical Properties: A First-Year Undergraduate Experiment Exploring Plasmonic Nanoparticles

ERIC Educational Resources Information Center

Frank, Andrew J.; Cathcart, Nicole; Maly, Kenneth E.; Kitaev, Vladimir

2010-01-01

A robust and reasonably simple experiment is described that introduces students to the visualization of nanoscale properties and is intended for a first-year laboratory. Silver nanoprisms (NPs) that display different colors due to variation of their plasmonic absorption with respect to size are prepared. Control over the size of the silver…

A Simple Calorimetric Experiment that Highlights Aspects of Global Heat Retention and Global Warming

ERIC Educational Resources Information Center

Burley, Joel D.; Johnston, Harold S.

2007-01-01

In this laboratory experiment, general chemistry students measure the heating curves for three different systems: (i) 500 g of room-temperature water heated by a small desk lamp, (ii) 500 g of an ice-water mixture warmed by conduction with room-temperature surroundings, and (iii) 500 g of an ice-water mixture heated by a small desk lamp and by…

Determination of the Effect of Various Modes of Cooking on the Vitamin C Content of a Common Food, Green Pepper: An Introductory Biochemistry Experiment.

ERIC Educational Resources Information Center

Johnson, Eric R.

1988-01-01

Describes a laboratory experiment that measures the amount of ascorbic acid destroyed by food preparation methods (boiling and steaming). Points out that aqueous extracts of cooked green pepper samples can be analyzed for ascorbic acid by a relatively simple redox titration. Lists experimental procedure for four methods of preparation. (MVL)

Synthesis of an Imidazolidinone Organocatalyst and Its Application in a Diels-Alder Cycloaddition: A Multistep Experiment for the Organic Teaching Laboratory

ERIC Educational Resources Information Center

Murphy, John J.; Driver, Ross B.; Walsh, Ria; Stephens, John C.

2016-01-01

The development of novel, high-yielding, and selective methodologies for the asymmetric synthesis of stereocenters is at the forefront of modern synthetic chemistry research. Organocatalysis can now be viewed as a viable alternative to the use of the sometimes toxic transition-metal catalysts. In this experiment, the simple synthesis of an achiral…

Laboratory Measurements of the Sound Generated by Breaking Waves

DTIC Science & Technology

1991-12-01

these techniques have not yet proven effective for studying the dynamics of breaking. The primary motivation for the research 3 presented in this...experiments described in this thesis were motivated by the fact that these preliminary experiments described above demonstrated that the simple I...1991. The research was motivated by the fact that preliminary measurements by Melville, Loewen, Felizardo, Jessup and Buckingham (1988) demonstrated

Food Choice in the Common Snail (Helix Aspersa).

ERIC Educational Resources Information Center

Gill, John; Howell, Pauline

1985-01-01

The easily obtained common snail shows interesting dietary preferences which can be the source of several simple experiments. Specific student instructions are given for quantitative and comparative studies using cabbage, lettuce, carrot, rutabaga, and onion. Suggestions for laboratory setup and further work are included. (DH)

An accelerating precursor to predict "time-to-failure" in creep and volcanic eruptions

NASA Astrophysics Data System (ADS)

Hao, Shengwang; Yang, Hang; Elsworth, Derek

2017-09-01

Real-time prediction by monitoring of the evolution of response variables is a central goal in predicting rock failure. A linear relation Ω˙Ω¨-1 = C(tf - t) has been developed to describe the time to failure, where Ω represents a response quantity, C is a constant and tf represents the failure time. Observations from laboratory creep failure experiments and precursors to volcanic eruptions are used to test the validity of the approach. Both cumulative and simple moving window techniques are developed to perform predictions and to illustrate the effects of data selection on the results. Laboratory creep failure experiments on granites show that the linear relation works well during the final approach to failure. For blind prediction, the simple moving window technique is preferred because it always uses the most recent data and excludes effects of early data deviating significantly from the predicted trend. When the predicted results show only small fluctuations, failure is imminent.

A new method of measuring gravitational acceleration in an undergraduate laboratory program

NASA Astrophysics Data System (ADS)

Wang, Qiaochu; Wang, Chang; Xiao, Yunhuan; Schulte, Jurgen; Shi, Qingfan

2018-01-01

This paper presents a high accuracy method to measure gravitational acceleration in an undergraduate laboratory program. The experiment is based on water in a cylindrical vessel rotating about its vertical axis at a constant speed. The water surface forms a paraboloid whose focal length is related to rotational period and gravitational acceleration. This experimental setup avoids classical source errors in determining the local value of gravitational acceleration, so prevalent in the common simple pendulum and inclined plane experiments. The presented method combines multiple physics concepts such as kinematics, classical mechanics and geometric optics, offering the opportunity for lateral as well as project-based learning.

Measuring the Earth’s magnetic field dip angle using a smartphone-aided setup: a simple experiment for introductory physics laboratories

NASA Astrophysics Data System (ADS)

Arabasi, Sameer; Al-Taani, Hussein

2017-03-01

Measurement of the Earth’s magnetic field dip angle is a widely used experiment in most introductory physics laboratories. In this paper we propose a smartphone-aided setup that takes advantage of the smartphone’s magnetometer sensor to measure the Earth’s magnetic field dip angle. This set-up will help students visualize the vector nature of the Earth’s magnetic field, especially high school and first year college students who are not quite experienced with vectors. This set-up is affordable and easy to use and could be easily produced by any high school or college physics instructor.

Measuring the coefficient of restitution and more: a simple experiment to promote students’ critical thinking and autonomous work

NASA Astrophysics Data System (ADS)

González, Manuel Á.; González, Miguel Á.; Vegas, Jesús; Llamas, César

2017-09-01

A simple experiment on the determination of the coefficient of restitution of different materials is taken as the basis of an extendable work that can be done by students in an autonomous way. On the whole, the work described in this paper would involve concepts of kinematics, materials science, air drag and buoyancy, and would help students to think of physics as a whole subject instead of a set of, more or less, isolated parts. The experiment can be done either in teaching laboratories or as an autonomous work by students at home. Students’ smartphones and cheap balls of different materials are the only experimental materials required to do the experiment. The proposed work also permits the students to analyse the limitations of a physical model used in the experiment by analysing the approximations considered in it, and then enhancing their critical thinking.

Chem 13 News, Number 72, November 1975.

ERIC Educational Resources Information Center

Friesen, R. J., Ed.; And Others

This newsletter contains student experiments and demonstrations suitable for secondary chemistry instruction as well as laboratory safety tips, book reviews and several activities involving the chemistry of winemaking and crime detection. Articles include those on carbon disulfide bonding, the electrolysis of sodium chloride, a simple and accurate…

Friedel-Crafts Alkylation Using Elemental Aluminum Catalyst: An Undergraduate Laboratory Experiment.

ERIC Educational Resources Information Center

Meeks, B. Spencer; Lucas, Anita R.

1989-01-01

Provides methodology for carrying out the synthesis of sec-butyltoluene by the Friedel-Crafts alkylation of toluene. Suggests using simple elemental aluminum as the catalyst in place of AlCl3 or amalgamated aluminum. Notes satisfactory results for both macro- and microscale operations. (MVL)

Sensitive Small Area Photometer

ERIC Educational Resources Information Center

Levenson, M. D.

1970-01-01

Describes a simple photometer capable of measuring small light intensities over small areas. The inexpensive, easy-to- construct instrument is intended for use in a student laboratory to measure the light intensities in a diffraction experiment from single or multiple slits. Typical experimental results are presented along with the theoretical…

Characterization of Coals and Lignites by Thermo-Magneto-Gravimetric Analysis.

ERIC Educational Resources Information Center

Rowe, M. W.

1983-01-01

Describes an inexpensive means for determining proximate analysis of coal, and by use of this data, its energy content. Pyrite content is also obtained by utilizing magnetic properties of iron. The simple device used makes the experiment suitable for the undergraduate laboratory. (Author/JN)

Ultrasound Imaging in Teaching Cardiac Physiology

ERIC Educational Resources Information Center

Johnson, Christopher D.; Montgomery, Laura E. A.; Quinn, Joe G.; Roe, Sean M.; Stewart, Michael T.; Tansey, Etain A.

2016-01-01

This laboratory session provides hands-on experience for students to visualize the beating human heart with ultrasound imaging. Simple views are obtained from which students can directly measure important cardiac dimensions in systole and diastole. This allows students to derive, from first principles, important measures of cardiac function, such…

Effect of Population Heterogenization on the Reproducibility of Mouse Behavior: A Multi-Laboratory Study

PubMed Central

Richter, S. Helene; Garner, Joseph P.; Zipser, Benjamin; Lewejohann, Lars; Sachser, Norbert; Touma, Chadi; Schindler, Britta; Chourbaji, Sabine; Brandwein, Christiane; Gass, Peter; van Stipdonk, Niek; van der Harst, Johanneke; Spruijt, Berry; Võikar, Vootele; Wolfer, David P.; Würbel, Hanno

2011-01-01

In animal experiments, animals, husbandry and test procedures are traditionally standardized to maximize test sensitivity and minimize animal use, assuming that this will also guarantee reproducibility. However, by reducing within-experiment variation, standardization may limit inference to the specific experimental conditions. Indeed, we have recently shown in mice that standardization may generate spurious results in behavioral tests, accounting for poor reproducibility, and that this can be avoided by population heterogenization through systematic variation of experimental conditions. Here, we examined whether a simple form of heterogenization effectively improves reproducibility of test results in a multi-laboratory situation. Each of six laboratories independently ordered 64 female mice of two inbred strains (C57BL/6NCrl, DBA/2NCrl) and examined them for strain differences in five commonly used behavioral tests under two different experimental designs. In the standardized design, experimental conditions were standardized as much as possible in each laboratory, while they were systematically varied with respect to the animals' test age and cage enrichment in the heterogenized design. Although heterogenization tended to improve reproducibility by increasing within-experiment variation relative to between-experiment variation, the effect was too weak to account for the large variation between laboratories. However, our findings confirm the potential of systematic heterogenization for improving reproducibility of animal experiments and highlight the need for effective and practicable heterogenization strategies. PMID:21305027

A Systematic Experimental Test of the Ideal Gas Equation for the General Chemistry Laboratory

NASA Astrophysics Data System (ADS)

Blanco, Luis H.; Romero, Carmen M.

1995-10-01

A set of experiments that examines each one of the terms of the ideal gas equation is described. Boyle's Law, Charles-Gay Lussac's Law, Amonton's Law, the number of moles or Molecular Weight, and the Gas Constant are studied. The experiments use very simple, easy to obtain equipment and common gases, mainly air. The results gathered by General Chemistry College students are satisfactory.

Solar Hot Water Heating by Natural Convection.

ERIC Educational Resources Information Center

Noble, Richard D.

1983-01-01

Presents an undergraduate laboratory experiment in which a solar collector is used to heat water for domestic use. The working fluid is moved by natural convection so no pumps are required. Experimental apparatus is simple in design and operation so that data can be collected quickly and easily. (Author/JN)

A Simple Method for Measuring Ground-Level Ozone in the Atmosphere

ERIC Educational Resources Information Center

Seeley, John V.; Seeley, Stacy K.; Bull, Arthur W.; Fehir, Richard J., Jr.; Cornwall, Susan; Knudsen, Gabriel A.

2005-01-01

An iodometric assay that allows the ground-level ozone concentration to be determined with an inexpensive sampling apparatus and a homemade photometer is described. This laboratory experiment applies a variety of different fundamental concepts including oxidation-reduction chemistry, the ideal gas law, and spectroscopic analysis and also provides…

Readily Made Solvated Electrons

ERIC Educational Resources Information Center

Ibanez, Jorge G.; Guerra-Millan, Francisco J.; Hugerat, Muhamad; Vazquez-Olavarrieta, Jorge L.; Basheer, Ahmad; Abu-Much, Riam

2011-01-01

The existence of solvated electrons has been known for a long time. Key methods for their production (i.e., photoionization of reducing ions, water radiolysis, and the reaction between H[middle dot] and OH[superscript -]) are unsuitable for most school laboratories. We describe a simple experiment to produce liquid ammonia and solvated electrons…

Preparation and Luminescence Thermochromism of Tetranuclear Copper(I)-Pyridine-Iodide Clusters

ERIC Educational Resources Information Center

Parmeggiani, Fabio; Sacchetti, Alessandro

2012-01-01

A simple and straightforward synthesis of a tetranuclear copper(I)-pyridine-iodide cluster is described as a laboratory experiment for advanced inorganic chemistry undergraduate students. The product is used to demonstrate the fascinating and visually impressive phenomenon of luminescence thermochromism: exposed to long-wave UV light, the…

New Approaches to Data Acquisitions in a Torsion Pendulum Experiment

ERIC Educational Resources Information Center

Jiang, Daya; Xiao, Jinghua; Li, Haihong; Dai, Qionglin

2007-01-01

In this paper, two simple non-contact and cost-effective methods to acquire data in the student laboratory are applied to investigate the motion of a torsion pendulum. The first method is based on a Hall sensor, while the second makes use of an optical mouse.

Scottish Schools Science Equipment Research Centre.

ERIC Educational Resources Information Center

1972

This newsletter is composed of brief notes in the various areas of science. Biology Notes include hazards of tasting Phenylthiocarbamide in laboratory experiments, the use of Albustic and Clinistix test papers for protein and glucose determinations, the measurement of the respiratory quotient, and the construction of a simple respirometer. Physics…

Using Artificial Nests to Study Nest Predation in Birds

ERIC Educational Resources Information Center

Belthoff, James R.

2005-01-01

A simple and effective field exercise that demonstrates factors affecting predation on bird nests is described. With instructor guidance, students in high school biology or college-level biology, ecology, animal behavior, wildlife management or ornithology laboratory courses can collaborate to design field experiments related to nest depredation.

A Novel W-Tube for Microscale Experiments in Chemistry

ERIC Educational Resources Information Center

Gupta, H. O.

2007-01-01

A simple W-shaped apparatus was developed by bending glass tubing to contain all of the chemicals involved and to limit the quantities to microscale. The W-tubes were tested by the teachers and students from a few schools to demonstrate its great utility and convenience in microscale chemistry laboratory.

Hall Effect in a Moving Liquid

ERIC Educational Resources Information Center

Di Lieto, Alberto; Giuliano, Alessia; Maccarrone, Francesco; Paffuti, Giampiero

2012-01-01

A simple experiment, suitable for performing in an undergraduate physics laboratory, illustrates electromagnetic induction through the water entering into a cylindrical rubber tube by detecting the voltage developed across the tube in the direction transverse both to the flow velocity and to the magnetic field. The apparatus is a very simple…

Metabolic Myopathies and Physical Activity: When Fatigue Is More Than Simple Exertion.

ERIC Educational Resources Information Center

Tarnopolsky, Mark A.

2002-01-01

When patients experience fatigue and muscle cramps beyond exercise adaptation, physicians should consider metabolic myopathies. The most common conditions seen in active patients are myoadenylate deaminase deficiency and disorders such as McArdle's disease. Targeted family histories and basic laboratory studies help rule out conditions mimicking…

Sequential Dependencies in Driving

ERIC Educational Resources Information Center

Doshi, Anup; Tran, Cuong; Wilder, Matthew H.; Mozer, Michael C.; Trivedi, Mohan M.

2012-01-01

The effect of recent experience on current behavior has been studied extensively in simple laboratory tasks. We explore the nature of sequential effects in the more naturalistic setting of automobile driving. Driving is a safety-critical task in which delayed response times may have severe consequences. Using a realistic driving simulator, we find…

Measurement of Refractive Index Gradients by Deflection of a Laser Beam

ERIC Educational Resources Information Center

Barnard, A. J.; Ahlborn, B.

1975-01-01

In this simple experiment for an undergraduate laboratory a laser beam is passed through the mixing zone of two liquids with different refractive indices. The spatial variation of the refractive index, at different times during the mixing, can be determined from the observed deflection of the beam. (Author)

The Study of a Simple Redox Reaction as an Experimental Approach to Chemical Kinetics.

ERIC Educational Resources Information Center

Elias, Horst; Zipp, Arden P.

1988-01-01

Recommends using iodide ions and peroxodisulfate ions for studying rate laws instead of the standard iodine clock for kinetic study. Presents the methodology and a discussion of the kinetics involved for a laboratory experiment for a high school or introductory college course. (ML)

Extrasolar Planets in the Classroom

ERIC Educational Resources Information Center

George, Samuel J.

2011-01-01

The field of extrasolar planets is still, in comparison with other astrophysical topics, in its infancy. There have been about 300 or so extrasolar planets detected and their detection has been accomplished by various different techniques. Here we present a simple laboratory experiment to show how planets are detected using the transit technique.…

Implementing a laboratory automation system: experience of a large clinical laboratory.

PubMed

Lam, Choong Weng; Jacob, Edward

2012-02-01

Laboratories today face increasing pressure to automate their operations as they are challenged by a continuing increase in workload, need to reduce expenditure, and difficulties in recruitment of experienced technical staff. Was the implementation of a laboratory automation system (LAS) in the Clinical Biochemistry Laboratory at Singapore General Hospital successful? There is no simple answer, so the following topics comparing and contrasting pre- and post-LAS have been explored: turnaround time (TAT), laboratory errors, and staff satisfaction. The benefits and limitations of LAS from the laboratory experience were also reviewed. The mean TAT for both stat and routine samples decreased post-LAS (30% and 13.4%, respectively). In the 90th percentile TAT chart, a 29% reduction was seen in the processing of stat samples on the LAS. However, no significant difference in the 90th percentile TAT was observed with routine samples. It was surprising to note that laboratory errors increased post-LAS. Considerable effort was needed to overcome the initial difficulties associated with adjusting to a new system, new software, and new working procedures. Although some of the known advantages and limitations of LAS have been validated, the claimed benefits such as improvements in TAT, laboratory errors, and staff morale were not evident in the initial months.

Synthesis of Dichlorophosphinenickel(II) Compounds and Their Catalytic Activity in Suzuki Cross-Coupling Reactions: A Simple Air-Free Experiment for Inorganic Chemistry Laboratory

ERIC Educational Resources Information Center

Thananatthanachon, Todsapon; Lecklider, Michelle R.

2017-01-01

In this experiment, students perform an air-free synthesis of three dichlorophosphinenickel(II) compounds, NiCl[subscript 2](PPh[subscript 3])[subscript 2], NiCl[subscript 2](PCy[subscript 3])[subscript 2], and NiCl[subscript 2](DPPE), using NiCl[subscript 2]·6H[subscript 2]O and the appropriate phosphine as the precursors. These colorful nickel…

Bayesian model calibration of ramp compression experiments on Z

NASA Astrophysics Data System (ADS)

Brown, Justin; Hund, Lauren

2017-06-01

Bayesian model calibration (BMC) is a statistical framework to estimate inputs for a computational model in the presence of multiple uncertainties, making it well suited to dynamic experiments which must be coupled with numerical simulations to interpret the results. Often, dynamic experiments are diagnosed using velocimetry and this output can be modeled using a hydrocode. Several calibration issues unique to this type of scenario including the functional nature of the output, uncertainty of nuisance parameters within the simulation, and model discrepancy identifiability are addressed, and a novel BMC process is proposed. As a proof of concept, we examine experiments conducted on Sandia National Laboratories' Z-machine which ramp compressed tantalum to peak stresses of 250 GPa. The proposed BMC framework is used to calibrate the cold curve of Ta (with uncertainty), and we conclude that the procedure results in simple, fast, and valid inferences. Sandia National Laboratories is a multi-mission laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Virtual and remote robotic laboratory using EJS, MATLAB and LabVIEW.

PubMed

Chaos, Dictino; Chacón, Jesús; Lopez-Orozco, Jose Antonio; Dormido, Sebastián

2013-02-21

This paper describes the design and implementation of a virtual and remote laboratory based on Easy Java Simulations (EJS) and LabVIEW. The main application of this laboratory is to improve the study of sensors in Mobile Robotics, dealing with the problems that arise on the real world experiments. This laboratory allows the user to work from their homes, tele-operating a real robot that takes measurements from its sensors in order to obtain a map of its environment. In addition, the application allows interacting with a robot simulation (virtual laboratory) or with a real robot (remote laboratory), with the same simple and intuitive graphical user interface in EJS. Thus, students can develop signal processing and control algorithms for the robot in simulation and then deploy them on the real robot for testing purposes. Practical examples of application of the laboratory on the inter-University Master of Systems Engineering and Automatic Control are presented.

Virtual and Remote Robotic Laboratory Using EJS, MATLAB and Lab VIEW

PubMed Central

Chaos, Dictino; Chacón, Jesús; Lopez-Orozco, Jose Antonio; Dormido, Sebastián

2013-01-01

This paper describes the design and implementation of a virtual and remote laboratory based on Easy Java Simulations (EJS) and LabVIEW. The main application of this laboratory is to improve the study of sensors in Mobile Robotics, dealing with the problems that arise on the real world experiments. This laboratory allows the user to work from their homes, tele-operating a real robot that takes measurements from its sensors in order to obtain a map of its environment. In addition, the application allows interacting with a robot simulation (virtual laboratory) or with a real robot (remote laboratory), with the same simple and intuitive graphical user interface in EJS. Thus, students can develop signal processing and control algorithms for the robot in simulation and then deploy them on the real robot for testing purposes. Practical examples of application of the laboratory on the inter-University Master of Systems Engineering and Automatic Control are presented. PMID:23429578

Shrink-film microfluidic education modules: Complete devices within minutes.

PubMed

Nguyen, Diep; McLane, Jolie; Lew, Valerie; Pegan, Jonathan; Khine, Michelle

2011-06-01

As advances in microfluidics continue to make contributions to diagnostics and life sciences, broader awareness of this expanding field becomes necessary. By leveraging low-cost microfabrication techniques that require no capital equipment or infrastructure, simple, accessible, and effective educational modules can be made available for a broad range of educational needs from middle school demonstrations to college laboratory classes. These modules demonstrate key microfluidic concepts such as diffusion and separation as well as "laboratory on-chip" applications including chemical reactions and biological assays. These modules are intended to provide an interdisciplinary hands-on experience, including chip design, fabrication of functional devices, and experiments at the microscale. Consequently, students will be able to conceptualize physics at small scales, gain experience in computer-aided design and microfabrication, and perform experiments-all in the context of addressing real-world challenges by making their own lab-on-chip devices.

An Effective and Economical Photometer for Classroom Demonstrations and Laboratory Use

ERIC Educational Resources Information Center

Butterfield, Anthony E.; Young, Colin C.

2012-01-01

We present a simple, effective, and inexpensive spectrophotometer design that may be used in a stand-alone teaching module, and to enhance various unit operations experiments. The spectrophotometers described performed as well as a commercial option at estimating cell concentration in a bioreactor and tracking a first-order reaction. Such devices…

A Simple and Low-Cost Ultramicroelectrode Fabrication and Characterization Method for Undergraduate Students

ERIC Educational Resources Information Center

Sur, Ujjal Kumar; Dhason, A.; Lakshminarayanan, V.

2012-01-01

A laboratory experiment is described in which students fabricate disk-shaped gold and platinum microelectrodes with diameters of 10-50 [mu]m by sealing sodalime glass with metal microwires. The electrodes are characterized by performing cyclic voltammetry in aqueous and acetonitrile solution. Commercial microelectrodes are expensive (cost depends…

Case Study: From Gummy Bears to Celery Stalks--Diffusion and Osmosis

ERIC Educational Resources Information Center

Bonney, Kevin M.

2014-01-01

This article describes an interrupted case study that intersperses information about diffusion and osmosis with content review and knowledge application questions, as well as a simple experiment that can be conducted without the use of a laboratory. The case study was developed for use in an introductory undergraduate biology course. The case…

Hands-on Science: Does It Matter What Students' Hands Are On?

ERIC Educational Resources Information Center

Triona, Lara M.; Klahr, David

2007-01-01

Hands-on science typically uses physical materials to give students first-hand experience in scientific methodologies, but the recent availability of virtual laboratories raises an important question about whether what students' hands are on matters to their learning. The overall findings of two articles that employed simple comparisons of…

The Use of Paramecium to Observe the Toxic Effect of Cigarette Smoke.

ERIC Educational Resources Information Center

Bardell, David

1986-01-01

Describes a laboratory experiment in which Paramecium caudatum was used to demonstrate the toxic effect of cigarette smoke on the cilia of epithelium cells lining the trachea and bronchi of smokers. Provides background information and explains the procedure, including how to make a simple mechanical smoking device. (TW)

Making and Using a Sensing Polymeric Material for Cu[superscript 2+

ERIC Educational Resources Information Center

Paddock, Jean R.; Maghasi, Anne T.; Heineman, William R.; Seliskar, Carl J.

2005-01-01

A simple chemical sensor-related experiment rooted in the synthesis of polymeric materials for use in either an advanced high-school or undergraduate college laboratory is presented. Students are introduced to and combine to the concepts of the chemical sensor, polymer chemistry, spectroscopy, metal chelates, and quantitative analytical methods.

Mirages in a Bottle

ERIC Educational Resources Information Center

Lopez-Arias, T.; Calza, G.; Gratton, L. M.; Oss, S.

2009-01-01

A simple experiment is presented to visualize inferior and superior mirages in the laboratory. A quantitative analysis is done using ray tracing with both photographic and computational techniques. The mirage's image, as seen by the eye or the camera lens, can be used to analyse the deflection and inversion of light rays. (Contains 6 footnotes, 1…

Application of a simple power law for transport ratio with bimodal distributions of spherical grains under oscillatory forcing

NASA Astrophysics Data System (ADS)

Holway, Kevin; Thaxton, Christopher S.; Calantoni, Joseph

2012-11-01

Morphodynamic models of coastal evolution require relatively simple parameterizations of sediment transport for application over larger scales. Calantoni and Thaxton (2008) [6] presented a transport parameterization for bimodal distributions of coarse quartz grains derived from detailed boundary layer simulations for sheet flow and near sheet flow conditions. The simulation results, valid over a range of wave forcing conditions and large- to small-grain diameter ratios, were successfully parameterized with a simple power law that allows for the prediction of the transport rates of each size fraction. Here, we have applied the simple power law to a two-dimensional cellular automaton to simulate sheet flow transport. Model results are validated with experiments performed in the small oscillating flow tunnel (S-OFT) at the Naval Research Laboratory at Stennis Space Center, MS, in which sheet flow transport was generated with a bed composed of a bimodal distribution of non-cohesive grains. The work presented suggests that, under the conditions specified, algorithms that incorporate the power law may correctly reproduce laboratory bed surface measurements of bimodal sheet flow transport while inherently incorporating vertical mixing by size.

A proton medical accelerator by the SBIR route — an example of technology transfer

NASA Astrophysics Data System (ADS)

Martin, R. L.

1989-04-01

Medical facilities for radiation treatment of cancer with protons have been established in many laboratories throughout the world. Essentially all of these have been designed as physics facilities, however, because of the requirement for protons up to 250 MeV. Most of the experience in this branch of accelerator technology lies in the national laboratories and a few large universities. A major issue is the transfer of this technology to the commercial sector to provide hospitals with simple, reliable and relatively inexpensive accelerators for this application. The author has chosen the SBIR route to accomplish this goal. ACCTEK Associates has received grants from the National Cancer Institute for development of the medical accelerator and beam delivery systems. Considerable encouragement and help has been received from Argonne National Laboratory and the Department of Energy. The experiences to date and the pros and cons on this approach to commercializing medical accelerators are described.

Introductory analysis of Bénard Marangoni convection

NASA Astrophysics Data System (ADS)

Maroto, J. A.; Pérez-Muñuzuri, V.; Romero-Cano, M. S.

2007-03-01

We describe experiments on Bénard-Marangoni convection which permit a useful understanding of the main concepts involved in this phenomenon such as, for example, Bénard cells, aspect ratio, Rayleigh and Marangoni numbers, Crispation number and critical conditions. In spite of the complexity of convection theory, we carry out a simple and introductory analysis which has the additional advantage of providing very suggestive experiments. As a consequence, we recommend our device for use as a laboratory experiment for undergraduate students of the thermodynamics of nonlinear and fluid physics.

Definition of Throw-Away Detectors (TADs) and VLF antenna for the AMPS laboratory

NASA Technical Reports Server (NTRS)

Koons, H. C.; Fennell, J. F.

1975-01-01

A Throw Away Detector (TAD)/subsatellite to be used as an experiment platform for the test flights to map the EMI from the shuttle and during the AMPS science flights is defined. A range of instrument platforms of varying capabilities is examined with emphasis on the EMI test vehicle. The operational support requirements of TAD/subsatellites are determined. The throw away detector is envisioned as a simple instrument package for supporting specific experiments.

A Simple Laboratory Scale Model of Iceberg Dynamics and its Role in Undergraduate Education

NASA Astrophysics Data System (ADS)

Burton, J. C.; MacAyeal, D. R.; Nakamura, N.

2011-12-01

Lab-scale models of geophysical phenomena have a long history in research and education. For example, at the University of Chicago, Dave Fultz developed laboratory-scale models of atmospheric flows. The results from his laboratory were so stimulating that similar laboratories were subsequently established at a number of other institutions. Today, the Dave Fultz Memorial Laboratory for Hydrodynamics (http://geosci.uchicago.edu/~nnn/LAB/) teaches general circulation of the atmosphere and oceans to hundreds of students each year. Following this tradition, we have constructed a lab model of iceberg-capsize dynamics for use in the Fultz Laboratory, which focuses on the interface between glaciology and physical oceanography. The experiment consists of a 2.5 meter long wave tank containing water and plastic "icebergs". The motion of the icebergs is tracked using digital video. Movies can be found at: http://geosci.uchicago.edu/research/glaciology_files/tsunamigenesis_research.shtml. We have had 3 successful undergraduate interns with backgrounds in mathematics, engineering, and geosciences perform experiments, analyze data, and interpret results. In addition to iceberg dynamics, the wave-tank has served as a teaching tool in undergraduate classes studying dam-breaking and tsunami run-up. Motivated by the relatively inexpensive cost of our apparatus (~1K-2K dollars) and positive experiences of undergraduate students, we hope to serve as a model for undergraduate research and education that other universities may follow.

Measurement of the sound absorption coefficient for an advanced undergraduate physics laboratory

NASA Astrophysics Data System (ADS)

Macho-Stadler, E.; Elejalde-García, M. J.

2017-09-01

We present a simple experiment that allows advanced undergraduates to learn the basics of the acoustic properties of materials. The impedance tube-standing wave method is applied to study the normal absorption coefficient of acoustics insulators. The setup includes a tube, a speaker, a microphone, a digital function generator and an oscilloscope, material available in an undergraduate laboratory. Results of the change of the absorption coefficient with the frequency, the sample thickness and the sample density are analysed and compared with those obtained with a commercial system.

Apparatus and methodology for fire gas characterization by means of animal exposure

NASA Technical Reports Server (NTRS)

Marcussen, W. H.; Hilado, C. J.; Furst, A.; Leon, H. A.; Kourtides, D. A.; Parker, J. A.; Butte, J. C.; Cummins, J. M.

1976-01-01

While there is a great deal of information available from small-scale laboratory experiments and for relatively simple mixtures of gases, considerable uncertainty exists regarding appropriate bioassay techniques for the complex mixture of gases generated in full-scale fires. Apparatus and methodology have been developed based on current state of the art for determining the effects of fire gases in the critical first 10 minutes of a full-scale fire on laboratory animals. This information is presented for its potential value and use while further improvements are being made.

Genotypic variability enhances the reproducibility of an ecological study.

PubMed

Milcu, Alexandru; Puga-Freitas, Ruben; Ellison, Aaron M; Blouin, Manuel; Scheu, Stefan; Freschet, Grégoire T; Rose, Laura; Barot, Sebastien; Cesarz, Simone; Eisenhauer, Nico; Girin, Thomas; Assandri, Davide; Bonkowski, Michael; Buchmann, Nina; Butenschoen, Olaf; Devidal, Sebastien; Gleixner, Gerd; Gessler, Arthur; Gigon, Agnès; Greiner, Anna; Grignani, Carlo; Hansart, Amandine; Kayler, Zachary; Lange, Markus; Lata, Jean-Christophe; Le Galliard, Jean-François; Lukac, Martin; Mannerheim, Neringa; Müller, Marina E H; Pando, Anne; Rotter, Paula; Scherer-Lorenzen, Michael; Seyhun, Rahme; Urban-Mead, Katherine; Weigelt, Alexandra; Zavattaro, Laura; Roy, Jacques

2018-02-01

Many scientific disciplines are currently experiencing a 'reproducibility crisis' because numerous scientific findings cannot be repeated consistently. A novel but controversial hypothesis postulates that stringent levels of environmental and biotic standardization in experimental studies reduce reproducibility by amplifying the impacts of laboratory-specific environmental factors not accounted for in study designs. A corollary to this hypothesis is that a deliberate introduction of controlled systematic variability (CSV) in experimental designs may lead to increased reproducibility. To test this hypothesis, we had 14 European laboratories run a simple microcosm experiment using grass (Brachypodium distachyon L.) monocultures and grass and legume (Medicago truncatula Gaertn.) mixtures. Each laboratory introduced environmental and genotypic CSV within and among replicated microcosms established in either growth chambers (with stringent control of environmental conditions) or glasshouses (with more variable environmental conditions). The introduction of genotypic CSV led to 18% lower among-laboratory variability in growth chambers, indicating increased reproducibility, but had no significant effect in glasshouses where reproducibility was generally lower. Environmental CSV had little effect on reproducibility. Although there are multiple causes for the 'reproducibility crisis', deliberately including genetic variability may be a simple solution for increasing the reproducibility of ecological studies performed under stringently controlled environmental conditions.

Check the Lambert-Beer-Bouguer law: a simple trick to boost the confidence of students toward both exponential laws and the discrete approach to experimental physics

NASA Astrophysics Data System (ADS)

Di Capua, R.; Offi, F.; Fontana, F.

2014-07-01

Exponential decay is a prototypical functional behaviour for many physical phenomena, and therefore it deserves great attention in physics courses at an academic level. The absorption of the electromagnetic radiation that propagates in a dissipative medium provides an example of the decay of light intensity, as stated by the law of Lambert-Beer-Bourguer. We devised a very simple experiment to check this law. The experimental setup, its realization, and the data analysis of the experiment are definitely simple. Our main goal was to create an experiment that is accessible to all students, including those in their first year of academic courses and those with poorly equipped laboratories. As illustrated in this paper, our proposal allowed us to develop a deep discussion about some general mathematical and numerical features of exponential decay. Furthermore, the special setup of the absorbing medium (sliced in finite thickness slabs) and the experimental outcomes allow students to understand the transition from the discrete to the continuum approach in experimental physics.

Integrating laboratory creep compaction data with numerical fault models: A Bayesian framework

USGS Publications Warehouse

Fitzenz, D.D.; Jalobeanu, A.; Hickman, S.H.

2007-01-01

We developed a robust Bayesian inversion scheme to plan and analyze laboratory creep compaction experiments. We chose a simple creep law that features the main parameters of interest when trying to identify rate-controlling mechanisms from experimental data. By integrating the chosen creep law or an approximation thereof, one can use all the data, either simultaneously or in overlapping subsets, thus making more complete use of the experiment data and propagating statistical variations in the data through to the final rate constants. Despite the nonlinearity of the problem, with this technique one can retrieve accurate estimates of both the stress exponent and the activation energy, even when the porosity time series data are noisy. Whereas adding observation points and/or experiments reduces the uncertainty on all parameters, enlarging the range of temperature or effective stress significantly reduces the covariance between stress exponent and activation energy. We apply this methodology to hydrothermal creep compaction data on quartz to obtain a quantitative, semiempirical law for fault zone compaction in the interseismic period. Incorporating this law into a simple direct rupture model, we find marginal distributions of the time to failure that are robust with respect to errors in the initial fault zone porosity. Copyright 2007 by the American Geophysical Union.

Radionuclide migration: laboratory experiments with isolated fractures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rundberg, R.S.; Thompson, J.L.; Maestas, S.

Laboratory experiments examining flow and element migration in rocks containing isolated fractures have been initiated at the Los Alamos National Laboratory. Techniques are being developed to establish simple fracture flow systems which are appropriate to models using analytical solutions to the matrix diffusion-flow equations, such as those of I. Neretnieks [I. Neretnieks, Diffusion in the Rock Matrix: An Important Factor in Radionuclide Retardation? J. Geophys. Res. 85, 4379 (1980).] These experiments are intended to be intermediate steps toward larger scale field experiments where it may become more difficult to establish and control the parameters important to nuclide migration in fracturedmore » media. Laboratory experiments have been run on fractures ranging in size from 1 to 20 cm in length. The hydraulic flow in these fractures was studied to provide the effective apertures. The flows established in these fracture systems are similar to those in the granite fracture flow experiments of Witherspoon et al. [P.A. Witherspoon, J.S.Y. Wang, K. Iwai, and J.E. Gale, Validity of Cubic Law for Fluid Flow in a Deformable Rock Fracture, Lawrence Berkeley Laboratory report LBL-9557 (October 1979).] Traced solutions containing {sup 85}Sr and {sup 137}Cs were flowed through fractures in Climax Stock granite and welded tuff (Bullfrog and Tram members, Yucca Mountain, Nevada Test Site). The results of the elutions through granite agree with the matrix diffusion calculations based on independent measurements of K/sub d/. The results of the elutions through tuff, however, agree only if the K/sub d/ values used in the calculations are lower than the K/sub d/ values measured using a batch technique. This trend has been previously observed in chromatographic column experiments with tuff. 5 figures, 3 tables.« less

Portable Conduction Velocity Experiments Using Earthworms for the College and High School Neuroscience Teaching Laboratory

ERIC Educational Resources Information Center

Shannon, Kyle M.; Gage, Gregory J.; Jankovic, Aleksandra; Wilson, W. Jeffrey; Marzullo, Timothy C.

2014-01-01

The earthworm is ideal for studying action potential conduction velocity in a classroom setting, as its simple linear anatomy allows easy axon length measurements and the worm's sparse coding allows single action potentials to be easily identified. The earthworm has two giant fiber systems (lateral and medial) with different conduction velocities…

Organocatalytic Ring-Opening Polymerization of Trimethylene Carbonate to Yield a Biodegradable Polycarbonate

ERIC Educational Resources Information Center

Chan, Julian M. W.; Zhang, Xiangyi; Brennan, Megan K.; Sardon, Haritz; Engler, Amanda C.; Fox, Courtney H.; Frank, Curtis W.; Waymouth, Robert M.; Hedrick, James L.

2015-01-01

In this laboratory experiment, students work in pairs to synthesize a simple aliphatic polycarbonate via ring-opening polymerization of trimethylene carbonate using 1,8-diazabicyclo[5.4.0]undec-7-ene and thiourea as organocatalysts. Following polymer isolation, students cool the material in a dry ice/acetone bath to observe its glass-transition…

Egg-Citing! Isolation of Protoporphyrin IX from Brown Eggshells and Its Detection by Optical Spectroscopy and Chemiluminescence

ERIC Educational Resources Information Center

Dean, Michelle L.; Miller, Tyson A.; Bruckner, Christian

2011-01-01

A simple and cost-effective laboratory experiment is described that extracts protoporphyrin IX from brown eggshells. The porphyrin is characterized by UV-vis and fluorescence spectroscopy. A chemiluminescence reaction (peroxyoxalate ester fragmentation) is performed that emits light in the UV region. When the porphyrin extract is added as a fluor…

Dyes, Fibers, and Paper: A Botany Lab Exercise for Non-Biology Majors

ERIC Educational Resources Information Center

Egan, Todd P.; Meekins, J. Forrest; Maluso, Diane

2004-01-01

This laboratory exercise affords students a hands-on experience learning about traditional dyes, fiber strength, and paper making. It is economical, simple to prepare, provides satisfactory results, and is student friendly. Dyes were extracted from plant leaves, stems, roots, and fruits. Hard-boiled eggs were place in the dyes for 15 minutes to…

A Simple Flotation De-Linking Experiment for the Recycling of Paper

ERIC Educational Resources Information Center

Venditti, Richard A.

2004-01-01

A laboratory exercise for the flotation de-linking of wastepaper is described, which consists of disintegrating printed wastepaper in a blender and then removing the ink or toner contaminants by pumping air bubbles through suspension using an aquarium pump or other source of air bubbles. The exercise has proven extremely reliable and consistent in…

Fluorescence Aggregation-Caused Quenching versus Aggregation-Induced Emission: A Visual Teaching Technology for Undergraduate Chemistry Students

ERIC Educational Resources Information Center

Ma, Xiaofeng; Sun, Rui; Cheng, Jinghui; Liu, Jiaoyan; Gou, Fei; Xiang, Haifeng; Zhou, Xiangge

2016-01-01

A laboratory experiment visually exploring two opposite basic principles of fluorescence of aggregation-caused quenching (ACQ) and aggregation-induced emission (AIE) is demonstrated. The students would prepared two salicylaldehyde-based Schiff bases through a simple one-pot condensation reaction of one equiv of 1,2-diamine with 2 equiv of…

Introducing High School Students to NMR Spectroscopy through Percent Composition Determination Using Low-Field Spectrometers

ERIC Educational Resources Information Center

Bonjour, Jessica L.; Pitzer, Joy M.; Frost, John A.

2015-01-01

Mole to gram conversions, density, and percent composition are fundamental concepts in first year chemistry at the high school or undergraduate level; however, students often find it difficult to engage with these concepts. We present a simple laboratory experiment utilizing portable nuclear magnetic resonance spectroscopy (NMR) to determine the…

Observing and Understanding Arterial and Venous Circulation Differences in a Physiology Laboratory Activity

ERIC Educational Resources Information Center

Altermann, Caroline; Gonçalves, Rithiele; Lara, Marcus Vinícius S.; Neves, Ben-Hur S.; Mello-Carpes, Pâmela B.

2015-01-01

The purpose of the present article is to describe three simple practical experiments that aim to observe and discuss the anatomic and physiological functions and differences between arteries and veins as well as the alterations observed in skin blood flow in different situations. For this activity, students were divided in small groups. In each…

Waste-to-Energy Laboratory. Grades 8-12.

ERIC Educational Resources Information Center

HAZWRAP, The Hazardous Waste Remedial Actions Program.

This brochure contains an activity for grades 8-12 students that focuses on the reuse of waste as an energy source by burning and converting it into energy. For this experiment students construct a calorimeter from simple recyclable material. The calorimeter is used to measure the amount of energy stored in paper and yard waste that could be used…

Fire spread characteristics determined in the laboratory

Treesearch

Richard C. Rothermel; Hal E. Anderson

1966-01-01

Fuel beds of ponderosa pine needles and white pine needles were burned under controlled environmental conditions to determine the effects of fuel moisture and windspeed upon the rate of fire spread. Empirical formulas are presented to show the effect of these parameters. A discussion of rate of spread and some simple experiments show how fuel may be preheated before...

Melde's experiment with an aquarium aerator. Rich dynamics with inexpensive apparatus

NASA Astrophysics Data System (ADS)

Graham, Mark

1998-05-01

As the basis for understanding music, quantum mechanics, and optical phenomena, standing waves are tremendously important, but instructors with a shoestring budget may not be able to do laboratories for them. However with simple modification of an inexpensive aquarium aerator costing a few dollars, instructors can take that shoestring and make standing waves.

Isolation of Biliverdin Ixa, as Its Dimethyl Ester, from Emu Eggshells

ERIC Educational Resources Information Center

Halepas, Steven; Hamchand, Randy; Lindeyer, Samuel E. D.; Bru¨ckner, Christian

2017-01-01

A laboratory experiment is described that extracts the tetrapyrrolic teal-colored biliverdin IXa, as its dimethyl ester, from commercially available emu eggshells. The extraction of ~10 mg samples of biliverdin is simple and requires two 3 h lab periods: A two-step acid digestion and liquid-liquid extraction, followed by short silica gel flash…

Model Experiment of Thermal Runaway Reactions Using the Aluminum-Hydrochloric Acid Reaction

ERIC Educational Resources Information Center

Kitabayashi, Suguru; Nakano, Masayoshi; Nishikawa, Kazuyuki; Koga, Nobuyoshi

2016-01-01

A laboratory exercise for the education of students about thermal runaway reactions based on the reaction between aluminum and hydrochloric acid as a model reaction is proposed. In the introductory part of the exercise, the induction period and subsequent thermal runaway behavior are evaluated via a simple observation of hydrogen gas evolution and…

Investigating Convective Heat Transfer with an Iron and a Hairdryer

ERIC Educational Resources Information Center

Gonzalez, Manuel I.; Lucio, Jesus H.

2008-01-01

A simple experimental set-up to study free and forced convection in undergraduate physics laboratories is presented. The flat plate of a domestic iron has been chosen as the hot surface, and a hairdryer is used to generate an air stream around the plate. Several experiments are proposed and typical numerical results are reported. An analysis and…

Games and Machine Learning: A Powerful Combination in an Artificial Intelligence Course

ERIC Educational Resources Information Center

Wallace, Scott A.; McCartney, Robert; Russell, Ingrid

2010-01-01

Project MLeXAI [Machine Learning eXperiences in Artificial Intelligence (AI)] seeks to build a set of reusable course curriculum and hands on laboratory projects for the artificial intelligence classroom. In this article, we describe two game-based projects from the second phase of project MLeXAI: Robot Defense--a simple real-time strategy game…

Cooperative action of coherent groups in broadly heterogeneous populations of interacting chemical oscillators

PubMed Central

Mikhailov, A. S.; Zanette, D. H.; Zhai, Y. M.; Kiss, I. Z.; Hudson, J. L.

2004-01-01

We present laboratory experiments on the effects of global coupling in a population of electrochemical oscillators with a multimodal frequency distribution. The experiments show that complex collective signals are generated by this system through spontaneous emergence and joint operation of coherently acting groups representing hierarchically organized resonant clusters. Numerical simulations support these experimental findings. Our results suggest that some forms of internal self-organization, characteristic for complex multiagent systems, are already possible in simple chemical systems. PMID:15263084

Integrating teaching and research in the field and laboratory settings

NASA Astrophysics Data System (ADS)

Wang, L.; Kaseke, K. F.; Daryanto, S.; Ravi, S.

2015-12-01

Field observations and laboratory measurements are great ways to engage students and spark students' interests in science. Typically these observations are separated from rigorous classroom teaching. Here we assessed the potential of integrating teaching and research in the field and laboratory setting in both US and abroad and worked with students without strong science background to utilize simple laboratory equipment and various environmental sensors to conduct innovative projects. We worked with students in Namibia and two local high school students in Indianapolis to conduct leaf potential measurements, soil nutrient extraction, soil infiltration measurements and isotope measurements. The experience showed us the potential of integrating teaching and research in the field setting and working with people with minimum exposure to modern scientific instrumentation to carry out creative projects.

Experiments with the low melting indium-bismuth alloy system

NASA Technical Reports Server (NTRS)

Krepski, Richard P.

1992-01-01

The following is a laboratory experiment designed to create an interest in and to further understanding of materials science. The primary audience for this material is the junior high school or middle school science student having no previous familiarity with the material, other than some knowledge of temperature and the concepts of atoms, elements, compounds, and chemical reactions. The objective of the experiment is to investigate the indium-bismuth alloy system. Near the eutectic composition, the liquidus is well below the boiling point of water, allowing simple, minimal hazard casting experiments. Such phenomena as metal oxidation, formation of intermetallic compound crystals, and an unusual volume increase during solidification could all be directly observed. A key concept for students to absorb is that properties of an alloy (melting point, mechanical behavior) may not correlate with simple interpolation of properties of the pure components. Discussion of other low melting metals and alloys leads to consideration of environmental and toxicity issues, as well as providing some historical context. Wetting behavior can also be explored.

The metallic sphere in a uniform ac magnetic field: A simple and precise experiment for exploring eddy currents and non-destructive testing

NASA Astrophysics Data System (ADS)

Honke, Michael L.; Bidinosti, Christopher P.

2018-06-01

We describe a very simple experiment that utilizes standard laboratory equipment to measure the electromagnetic response of a metallic sphere exposed to a uniform ac magnetic field. Measurements were made for a variety of non-magnetic and magnetic metals, and in all cases the results fit very well with theory over the four orders of frequency (25 Hz to 102 kHz) explored here. Precise values of magnetic permeability and electrical conductivity can be extracted from fits to the data given the sphere radius only. The same apparatus is also used to explore the effects of geometry on eddy current generation as well as to demonstrate non-destructive testing through measurements on coins of different composition.

Electrophysiology for biomedical engineering students: a practical and theoretical course in animal electrocorticography.

PubMed

Albarracín, Ana L; Farfán, Fernando D; Coletti, Marcos A; Teruya, Pablo Y; Felice, Carmelo J

2016-09-01

The major challenge in laboratory teaching is the application of abstract concepts in simple and direct practical lessons. However, students rarely have the opportunity to participate in a laboratory that combines practical learning with a realistic research experience. In the Biomedical Engineering career, we offer short and optional courses to complement studies for students as they initiate their Graduation Project. The objective of these theoretical and practical courses is to introduce students to the topics of their projects. The present work describes an experience in electrophysiology to teach undergraduate students how to extract cortical information using electrocorticographic techniques. Students actively participate in some parts of the experience and then process and analyze the data obtained with different signal processing tools. In postlaboratory evaluations, students described the course as an exceptional opportunity for students interested in following a postgraduate science program and fully appreciated their contents. Copyright © 2016 The American Physiological Society.

Shrink-film microfluidic education modules: Complete devices within minutes

PubMed Central

Nguyen, Diep; McLane, Jolie; Lew, Valerie; Pegan, Jonathan; Khine, Michelle

2011-01-01

As advances in microfluidics continue to make contributions to diagnostics and life sciences, broader awareness of this expanding field becomes necessary. By leveraging low-cost microfabrication techniques that require no capital equipment or infrastructure, simple, accessible, and effective educational modules can be made available for a broad range of educational needs from middle school demonstrations to college laboratory classes. These modules demonstrate key microfluidic concepts such as diffusion and separation as well as “laboratory on-chip” applications including chemical reactions and biological assays. These modules are intended to provide an interdisciplinary hands-on experience, including chip design, fabrication of functional devices, and experiments at the microscale. Consequently, students will be able to conceptualize physics at small scales, gain experience in computer-aided design and microfabrication, and perform experiments—all in the context of addressing real-world challenges by making their own lab-on-chip devices. PMID:21799715

Acoustic impulse response method as a source of undergraduate research projects and advanced laboratory experiments.

PubMed

Robertson, W M; Parker, J M

2012-03-01

A straightforward and inexpensive implementation of acoustic impulse response measurement is described utilizing the signal processing technique of coherent averaging. The technique is capable of high signal-to-noise measurements with personal computer data acquisition equipment, an amplifier/speaker, and a high quality microphone. When coupled with simple waveguide test systems fabricated from commercial PVC plumbing pipe, impulse response measurement has proven to be ideal for undergraduate research projects-often of publishable quality-or for advanced laboratory experiments. The technique provides important learning objectives for science or engineering students in areas such as interfacing and computer control of experiments; analog-to-digital conversion and sampling; time and frequency analysis using Fourier transforms; signal processing; and insight into a variety of current research areas such as acoustic bandgap materials, acoustic metamaterials, and fast and slow wave manipulation. © 2012 Acoustical Society of America

Astronaut James S. Voss Performs Tasks in the Destiny Laboratory

NASA Technical Reports Server (NTRS)

2001-01-01

Astronaut James S. Voss, Expedition Two flight engineer, works with a series of cables on the EXPRESS Rack in the United State's Destiny laboratory on the International Space Station (ISS). The EXPRESS Rack is a standardized payload rack system that transports, stores, and supports experiments aboard the ISS. EXPRESS stands for EXpedite the PRocessing of Experiments to the Space Station, reflecting the fact that this system was developed specifically to maximize the Station's research capabilities. The EXPRESS Rack system supports science payloads in several disciplines, including biology, chemistry, physics, ecology, and medicine. With the EXPRESS Rack, getting experiments to space has never been easier or more affordable. With its standardized hardware interfaces and streamlined approach, the EXPRESS Rack enables quick, simple integration of multiple payloads aboard the ISS. The system is comprised of elements that remain on the ISS, as well as elements that travel back and forth between the ISS and Earth via the Space Shuttle.

Effects of the Physical Laboratory versus the Virtual Laboratory in Teaching Simple Electric Circuits on Conceptual Achievement and Attitudes Towards the Subject

ERIC Educational Resources Information Center

Tekbiyik, Ahmet; Ercan, Orhan

2015-01-01

Current study examined the effects of virtual and physical laboratory practices on students' conceptual achievement in the subject of electricity and their attitudes towards simple electric circuits. Two groups (virtual and physical) selected through simple random sampling was taught with web-aided material called "Electricity in Our…

Safety in the Chemical Laboratory: Laboratory Air Quality: Part I. A Concentration Model.

ERIC Educational Resources Information Center

Butcher, Samuel S.; And Others

1985-01-01

Offers a simple model for estimating vapor concentrations in instructional laboratories. Three methods are described for measuring ventilation rates, and the results of measurements in six laboratories are presented. The model should provide a simple screening tool for evaluating worst-case personal exposures. (JN)

Oscillations in a half-empty bottle

NASA Astrophysics Data System (ADS)

Bourges, Andréane; Chardac, Amélie; Caussarieu, Aude; Plihon, Nicolas; Taberlet, Nicolas

2018-02-01

When a half-empty bottle of water is pushed to roll on a flat surface, the oscillations of the fluid inside the bottle induce an overall jerky motion. These velocity fluctuations of the bottle are studied through simple laboratory experiments accessible to undergraduate students and can help them to grasp fundamental concepts in mechanics and hydrodynamics. We first demonstrate through an astute experiment that the rotation of the fluid and the bottle is decoupled. The equations of motion are then derived using a mechanical approach, while the hydrodynamics of the fluid motion is explained. Finally, the theory is tested against two benchmark experiments.

"Student Lab"-on-a-Chip: Integrating Low-Cost Microfluidics into Undergraduate Teaching Labs to Study Multiphase Flow Phenomena in Small Vessels

ERIC Educational Resources Information Center

Young, Edmond W. K.; Simmons, Craig A.

2009-01-01

We describe a simple, low-cost laboratory session to demonstrate the Fahraeus-Lindqvist effect, a microphase flow phenomenon that occurs in small blood vessels and alters the effective rheological properties of blood. The experiments are performed by flowing cells through microchannels fabricated by soft lithography and characterization of cell…

Students Become Scientists at Science Skills Boot Camp | Poster

Cancer.gov

At the 2016 Science Skills Boot Camp (SSBC), a one-day training program designed for NIH summer interns with little or no prior research experience, students gathered to learn about basic research and laboratory skills. The boot camp provided a unique opportunity for interns to expand their knowledge of simple bench techniques, scientific papers, and ways to communicate their

Kinetics and Mechanism of Iodide Oxidation by Iron(III): A Clock Reaction Approach

ERIC Educational Resources Information Center

Bauer, Jurica; Tomisic, Vladislav; Vrkljan, Petar B. A.

2008-01-01

A simple method for studying the kinetics of a chemical reaction is described and the significance of reaction orders in deducing reaction mechanisms is demonstrated. In this student laboratory experiment, oxidation of iodide by iron(III) ions in an acidic medium is transformed into a clock reaction. By means of the initial rates method, it is…

Coordination Complexes as Catalysts: The Oxidation of Anthracene by Hydrogen Peroxide in the Presence of VO(acac)[subscript 2

ERIC Educational Resources Information Center

Charleton, Kimberly D. M.; Prokopchuk, Ernest M.

2011-01-01

A laboratory experiment aimed at students who are studying coordination chemistry of transition-metal complexes is described. A simple vanadyl acetylacetonate complex can be used as a catalyst in the hydrogen peroxide oxidation of anthracene to produce anthraquinone. The reaction can be performed under a variety of reaction conditions, ideally by…

Students Become Scientists at Science Skills Boot Camp | Poster

Cancer.gov

At the 2016 Science Skills Boot Camp (SSBC), a one-day training program designed for NIH summer interns with little or no prior research experience, students gathered to learn about basic research and laboratory skills. The boot camp provided a unique opportunity for interns to expand their knowledge of simple bench techniques, scientific papers, and ways to communicate their research.

Carbon Dioxide Absorbers: An Engaging Experiment for the General Chemistry Laboratory

ERIC Educational Resources Information Center

Ticich, Thomas M.

2011-01-01

A simple and direct method for measuring the absorption of carbon dioxide by two different substances is described. Lithium hydroxide has been used for decades to remove the gas from enclosed living spaces, such as spacecraft and submarines. The ratio of the mass of carbon dioxide absorbed to the mass of lithium hydroxide used obtained from this…

Flexural Vibration Test of a Cantilever Beam with a Force Sensor: Fast Determination of Young's Modulus

ERIC Educational Resources Information Center

Digilov, Rafael M.

2008-01-01

We describe a simple and very inexpensive undergraduate laboratory experiment for fast determination of Young's modulus at moderate temperatures with the aid of a force sensor. A strip-shaped specimen rigidly bolted to the force sensor forms a clamped-free cantilever beam. Placed in a furnace, it is subjected to free-bending vibrations followed by…

A Laboratory Experiment to Measure the Built-In Potential of a P-N Junction by a Photosaturation Method

ERIC Educational Resources Information Center

Ikram, I. Mohamed; Rabinal, M. K.; Mulimani, B. G.

2009-01-01

Here, we propose a simple method for measuring the built-in potential and its temperature dependence of a photodiode by a photosaturation technique. The experimental design facilitates both current-voltage and null voltage measurements as a function of white light intensity. This method gives the built-in potential directly; as a result its…

A Laboratory Activity on the Eddy Current Brake

ERIC Educational Resources Information Center

Molina-Bolivar, J. A.; Abella-Palacios, A. J.

2012-01-01

The aim of this paper is to introduce a simple and low-cost experimental setup that can be used to study the eddy current brake, which considers the motion of a sliding magnet on an inclined conducting plane in terms of basic physical principles. We present a set of quantitative experiments performed to study the influence of the geometrical and…

Using Latex Balls and Acrylic Resin Plates to Investigate the Stacking Arrangement and Packing Efficiency of Metal Crystals

ERIC Educational Resources Information Center

Ohashi, Atsushi

2015-01-01

A high-school third-year or undergraduate first-semester general chemistry laboratory experiment introducing simple-cubic, face-centered cubic, body-centered cubic, and hexagonal closest packing unit cells is presented. Latex balls and acrylic resin plates are employed to make each atomic arrangement. The volume of the vacant space in each cell is…

A Simple Experiment for Determining the Elastic Constant of a Fine Wire

ERIC Educational Resources Information Center

Freeman, W. Larry; Freda, Ronald F.

2007-01-01

Many general physics laboratories involve the use of springs to demonstrate Hooke's law, and much ado is made about how this can be used as a model for describing the elastic characteristics of materials at the molecular or atomic level. In recent years, the proliferation of computers, and appropriate sensors, have made it possible to demonstrate…

UV Catalysis, Cyanotype Photography, and Sunscreens

NASA Astrophysics Data System (ADS)

Lawrence, Glen D.; Fishelson, Stuart

1999-09-01

This laboratory experiment is intended for a chemistry course for non-science majors. The experiment utilizes one of the earliest photographic processes, the cyanotype process, to demonstrate UV catalysis of chemical reactions. In addition to making photographic prints from negatives, the process can be used to test the effectiveness of sunscreens and the relative efficacy of the SPF (sun protection factor) rating of sunscreens. This is an inexpensive process, requiring solutions of ammonium ferric citrate and potassium ferricyanide, with options to use hydrogen peroxide and ammonium hydroxide solutions. Students can prepare their own UV-sensitized paper with the indicated chemicals and watch the photographic image appear as it is exposed to sunlight or fluorescent UV lamps in a light box designed for use in this experiment. The laboratory experiment should stimulate discussion of UV catalysis, photographic processes and photochemistry, sunscreens, and UV damage to biological organisms. The chemicals used are relatively nontoxic, and the procedure is simple enough to be used by groups of diverse ages and abilities.

Condensation Processes in Astrophysical Environments

NASA Technical Reports Server (NTRS)

Nuth, Joseph A., III; Rietmeijer, Frans J. M.; Hill, Hugh G. M.

2002-01-01

Astrophysical systems present an intriguing set of challenges for laboratory chemists. Chemistry occurs in regions considered an excellent vacuum by laboratory standards and at temperatures that would vaporize laboratory equipment. Outflows around Asymptotic Giant Branch (AGB) stars have timescales ranging from seconds to weeks depending on the distance of the region of interest from the star and, on the way significant changes in the state variables are defined. The atmospheres in normal stars may only change significantly on several billion-year timescales. Most laboratory experiments carried out to understand astrophysical processes are not done at conditions that perfectly match the natural suite of state variables or timescales appropriate for natural conditions. Experimenters must make use of simple analog experiments that place limits on the behavior of natural systems, often extrapolating to lower-pressure and/or higher-temperature environments. Nevertheless, we argue that well-conceived experiments will often provide insights into astrophysical processes that are impossible to obtain through models or observations. This is especially true for complex chemical phenomena such as the formation and metamorphism of refractory grains under a range of astrophysical conditions. Data obtained in our laboratory has been surprising in numerous ways, ranging from the composition of the condensates to the thermal evolution of their spectral properties. None of this information could have been predicted from first principals and would not have been credible even if it had.

Studying three-phase supply in school

NASA Astrophysics Data System (ADS)

Singhal, Amit Kumar; Arun, P.

2009-07-01

The power distributions of nearly all major countries have accepted three-phase distribution as a standard. With increasing power requirements of instrumentation today even a small physics laboratory requires a three-phase supply. While physics students are given an introduction to this in passing, no experimental work is done with three-phase supply due to the possibility of accidents while working with such large power. We believe a conceptual understanding of three-phase supply would be useful for physics students, with hands-on experience using a simple circuit that can be assembled even in a high school laboratory.

Hawking-like radiation does not require a trapped region.

PubMed

Barceló, Carlos; Liberati, Stefano; Sonego, Sebastiano; Visser, Matt

2006-10-27

We discuss the issue of quasiparticle production by "analogue black holes" with particular attention paid to the possibility of reproducing Hawking radiation in a laboratory. By constructing simple geometric acoustic models, we obtain a somewhat unexpected result: We show that, in order to obtain a stationary and Planckian emission of quasiparticles, it is not necessary to create a trapped region in the acoustic spacetime (corresponding to a supersonic regime in the fluid flow). It is sufficient to set up a dynamically changing flow asymptotically approaching a sonic regime with sufficient rapidity in laboratory time. This result is generic to curved-space quantum field theory, the "analogue spacetimes" we consider providing a guide to physical intuition, and a possible route to laboratory experiments.

Education and Outreach with the Northwest Indiana Robotic Telescope

NASA Astrophysics Data System (ADS)

Rengstorf, Adam W.; Slavin, S. D.

2011-01-01

The Northwest Indiana Robotic (NIRo) Telescope is being used to completely revise the introductory astronomy laboratory experiments at Purdue University Calumet (PUC). The NIRo telescope is a new 20-inch RC telescope. It was dedicated in Aug 2010, is designed to be operated remotely and/or robotically, and is located 30 miles south of PUC's campus in rural Lake county, IN. A suite of laboratory experiments is being developed and piloted during the 2010-2011 academic year. Lab experiments will progress from introductions to instruments and software, through simple data visualization and analysis, to developing and submitting an observing plan to complete multi-week laboratories. Experiments for both the solar system course and the stars & galaxies are being developed. Students in the solar system course will request and analyze images for such experiments as recreating Aristarchus’ relative size & distance calculations, establishing an observing strategy to monitor the Galilean satellites & determine Jupiter's mass, an ongoing `asteroid hunt', Martian retrograde motion, and Venusian phases. The stars & galaxies course will complete labs on galaxy morphology, eclipsing binaries, building an HR-diagram, cluster aging, and distances to Cepheid variables. The main outreach component is the development of a primary education program. In conjunction with the PUC School of Education and area middle-school science teachers, we are in the process of identifying the subset of laboratory ideas best suited to the State of Indiana Earth & Space Science teaching standards from grades 6 - 8. These laboratories are being developed into finished data products, curricula, and learning modules appropriate for the middle school classroom. The middle school classroom will be able to request observations and retrieve reduced images via an internet portal, currently in development. This project has been funded by NSF award #DUE-0736592.

A Simple Laboratory Exercise Illustrating Active Transport in Yeast Cells.

ERIC Educational Resources Information Center

Stambuk, Boris U.

2000-01-01

Describes a simple laboratory activity illustrating the chemiosmotic principles of active transport in yeast cells. Demonstrates the energy coupling mechanism of active a-glucoside uptake by Saccaromyces cerevisiae cells with a colorimetric transport assay using very simple equipment. (Contains 22 references.) (Author/YDS)

Studying Equilibrium in the Chemical Reaction between Ferric and Iodide Ions in Solution Using a Simple and Inexpensive Approach

ERIC Educational Resources Information Center

Nikolaychuk, Pavel Anatolyevich; Kuvaeva, Alyona Olegovna

2016-01-01

A laboratory experiment on the study of the chemical equilibrium based on the reaction between ferric and iodide ions in solution with the formation of ferrous ions, free iodine, and triiodide ions is developed. The total concentration of iodide and triiodide ions in the reaction mixture during the reaction is determined by the argentometric…

Promoting 21st-Century Skills in the Science Classroom by Adapting Cookbook Lab Activities: The Case of DNA Extraction of Wheat Germ

ERIC Educational Resources Information Center

Alozie, Nonye M.; Grueber, David J.; Dereski, Mary O.

2012-01-01

How can science instruction engage students in 21st-century skills and inquiry-based learning, even when doing simple labs in the classroom? We collaborated with teachers in professional development workshops to transform "cookbook" activities into engaging laboratory experiences. We show how to change the common classroom activity of DNA…

Galileo and optical illusion

NASA Astrophysics Data System (ADS)

Parker, Gary D.

1986-03-01

Galileo's earliest telescopic measurements are of sufficient quality that their detailed analysis yields scientifically interesting and pedagogically useful results. An optical illusion strongly influences Galileo's observations of Jupiter's moons, as published in the Starry Messenger. A simple procedure identifies individual satellites with sufficient reliability to demonstrate that Galileo regularly underestimated satellite brightness and overestimated elongation when a satellite was very close to Jupiter. The probability of underestimation is a monotonically decreasing function of separation angle, both for Galileo and for viewers of a laboratory simulation of the Jupiter ``starfield'' viewed by Galileo. Analysis of Galileo's records and a simple simulation experiment appropriate to undergraduate courses clarify the scientific problems facing Galileo in interpreting his observations.

Challenges in Implementing a Biorisk Management Program at Universitas Indonesia: A Checklist Tool for Biorisk Management.

PubMed

Naroeni, Aroem; Bachtiar, Endang Winiati; Ibrahim, Fera; Bela, Budiman; Kusminanti, Yuni; Pujiriani, Ike; Lestari, Fatma

Rapid development and advancement of bioresearch at a university's laboratories can have both positive and negative implications for public health and the environment. Many research activities in which biological materials have been created, modified, stored, and manipulated require safety procedures to keep the negative effects on humans and the environment as low as possible. The Occupational Health, Safety and Environmental (OHS&E) Department of the University of Indonesia (UI) is trying to increase the awareness and responsibility of its university members and laboratory staffs who work with biohazard materials by creating a biorisk checklist. The checklist was developed based on WHO guidelines and the National University of Singapore (NUS) Laboratory Manual, which contains 311 questions about the management, administration, and handling of various hazards, recombinant experiments, and animal and plant experiments. A gap analysis was run against the checklist in 14 laboratories at the University of Indonesia Salemba campus, which daily works with highly infectious pathogens and high-risk agents. Overall result showed that none of these laboratories had met all of the checklist items, and there were only 2 laboratories that had implemented more than half of the items. This checklist was proven to be a simple tool for assessing laboratories that handle and store biohazard materials, and it could be used as a monitoring tool for biorisk programs as well. It also could be further developed as a laboratory software application to increase its effectiveness and its accuracy.

OGUMI—A new mobile application to conduct common-pool resource experiments in continuous time

PubMed Central

Nissen, Dennis

2017-01-01

OGUMI is an Android-based open source mobile application for conducting Common-Pool Resource Experiments, Choice Experiments, and Questionnaires in the field, in the laboratory, and online. A main feature of OGUMI is its capacity to capture real-time changes in human behaviour in response to a dynamically varying resource. OGUMI is simple (for example, likewise other existing software, it does not require expertise in behavioural game theory), stable, and extremely flexible with respect to the user-resource model running in the background. Here we present the motivation for the development of OGUMI and we discuss its main features with an example application. PMID:28582457

OGUMI-A new mobile application to conduct common-pool resource experiments in continuous time.

PubMed

Brandt, Gunnar; Kulesz, Micaela M; Nissen, Dennis; Merico, Agostino

2017-01-01

OGUMI is an Android-based open source mobile application for conducting Common-Pool Resource Experiments, Choice Experiments, and Questionnaires in the field, in the laboratory, and online. A main feature of OGUMI is its capacity to capture real-time changes in human behaviour in response to a dynamically varying resource. OGUMI is simple (for example, likewise other existing software, it does not require expertise in behavioural game theory), stable, and extremely flexible with respect to the user-resource model running in the background. Here we present the motivation for the development of OGUMI and we discuss its main features with an example application.

Covariation of metabolic rates and cell size in coccolithophores

NASA Astrophysics Data System (ADS)

Aloisi, G.

2015-08-01

Coccolithophores are sensitive recorders of environmental change. The size of their coccosphere varies in the ocean along gradients of environmental conditions and provides a key for understanding the fate of this important phytoplankton group in the future ocean. But interpreting field changes in coccosphere size in terms of laboratory observations is hard, mainly because the marine signal reflects the response of multiple morphotypes to changes in a combination of environmental variables. In this paper I examine the large corpus of published laboratory experiments with coccolithophores looking for relations between environmental conditions, metabolic rates and cell size (a proxy for coccosphere size). I show that growth, photosynthesis and, to a lesser extent, calcification covary with cell size when pCO2, irradiance, temperature, nitrate, phosphate and iron conditions change. With the exception of phosphate and temperature, a change from limiting to non-limiting conditions always results in an increase in cell size. An increase in phosphate or temperature (below the optimum temperature for growth) produces the opposite effect. The magnitude of the coccosphere-size changes observed in the laboratory is comparable to that observed in the ocean. If the biological reasons behind the environment-metabolism-size link are understood, it will be possible to use coccosphere-size changes in the modern ocean and in marine sediments to investigate the fate of coccolithophores in the future ocean. This reasoning can be extended to the size of coccoliths if, as recent experiments are starting to show, coccolith size reacts to environmental change proportionally to coccosphere size. The coccolithophore database is strongly biased in favour of experiments with the coccolithophore Emiliania huxleyi (E. huxleyi; 82 % of database entries), and more experiments with other species are needed to understand whether these observations can be extended to coccolithophores in general. I introduce a simple model that simulates the growth rate and the size of cells forced by nitrate and phosphate concentrations. By considering a simple rule that allocates the energy flow from nutrient acquisition to cell structure (biomass) and cell maturity (biological complexity, eventually leading to cell division), the model is able to reproduce the covariation of growth rate and cell size observed in laboratory experiments with E. huxleyi when these nutrients become limiting. These results support ongoing efforts to interpret coccosphere and coccolith size measurements in the context of climate change.

Heterosis Increases Fertility, Fecundity, and Survival of Laboratory-Produced F1 Hybrid Males of the Malaria Mosquito Anopheles coluzzii

PubMed Central

Ekechukwu, Nkiru E.; Baeshen, Rowida; Traorè, Sékou F.; Coulibaly, Mamadou; Diabate, Abdoulaye; Catteruccia, Flaminia; Tripet, Frédéric

2015-01-01

The success of vector control strategies aiming to decrease disease transmission via the release of sterile or genetically-modified male mosquitoes critically depends on mating between laboratory-reared males and wild females. Unfortunately, mosquito colonization, laboratory rearing, and genetic manipulations can all negatively affect male competitiveness. Heterosis is commonly used to produce domestic animals with enhanced vigor and homogenous genetic background and could therefore potentially improve the mating performance of mass-reared male mosquitoes. Here, we produced enhanced hybrid males of the malaria mosquito Anopheles coluzzii by crossing two strains colonized >35 and 8 years ago. We compared the amount of sperm and mating plug proteins they transferred to females, as well as their insemination rate, reproductive success and longevity under various experimental conditions. Across experiments, widespread adaptations to laboratory mating were detected in the older strain. In large-group mating experiments, no overall hybrid advantage in insemination rates and the amount of sperm and accessory gland proteins transferred to females was detected. Despite higher sperm activity, hybrid males did not appear more fecund. However, individual-male mating and laboratory-swarm experiments revealed that hybrid males, while inseminating fewer females than older inbred males, were significantly more fertile, producing larger mating plugs and drastically increasing female fecundity. Heterotic males also showed increased longevity. These results validate the use of heterosis for creating hybrid males with improved fitness from long-established inbred laboratory strains. Therefore, this simple approach could facilitate disease control strategies based on male mosquito releases with important ultimate benefits to human health. PMID:26497140

Friction Laws Derived From the Acoustic Emissions of a Laboratory Fault by Machine Learning

NASA Astrophysics Data System (ADS)

Rouet-Leduc, B.; Hulbert, C.; Ren, C. X.; Bolton, D. C.; Marone, C.; Johnson, P. A.

2017-12-01

Fault friction controls nearly all aspects of fault rupture, yet it is only possible to measure in the laboratory. Here we describe laboratory experiments where acoustic emissions are recorded from the fault. We find that by applying a machine learning approach known as "extreme gradient boosting trees" to the continuous acoustical signal, the fault friction can be directly inferred, showing that instantaneous characteristics of the acoustic signal are a fingerprint of the frictional state. This machine learning-based inference leads to a simple law that links the acoustic signal to the friction state, and holds for every stress cycle the laboratory fault goes through. The approach does not use any other measured parameter than instantaneous statistics of the acoustic signal. This finding may have importance for inferring frictional characteristics from seismic waves in Earth where fault friction cannot be measured.

Efficacy and security of ivermectin given orally to rats naturally infected with Syphacia spp., Giardia spp. and Hymenolepis nana.

PubMed

Foletto, V R S; Vanz, F; Gazarini, L; Stern, C A J; Tonussi, C R

2015-07-01

The results of this study show that the oral administration of ivermectin (48 mg/L) repeatedly for 72 h used in accordance with the present protocol is a safe and highly effective treatment for Giardia spp. and Hymenolepis nana in laboratory rat colonies. The drug can be easily and safely administered using drinking water. This simple regimen should control pinworm infection (Syphacia muris), a problem that can be endemic in laboratory colonies. Experiments using healthy animals are likely to generate more consistent results, thereby requiring a reduced number of animals per group. © The Author(s) 2014.

Roles, uses, and benefits of general aviation aircraft in aerospace engineering education

NASA Technical Reports Server (NTRS)

Odonoghue, Dennis P.; Mcknight, Robert C.

1994-01-01

Many colleges and universities throughout the United States offer outstanding programs in aerospace engineering. In addition to the fundamentals of aerodynamics, propulsion, flight dynamics, and air vehicle design, many of the best programs have in the past provided students the opportunity to design and fly airborne experiments on board various types of aircraft. Sadly, however, the number of institutions offering such 'airborne laboratories' has dwindled in recent years. As a result, opportunities for students to apply their classroom knowledge, analytical skills, and engineering judgement to the development and management of flight experiments on an actual aircraft are indeed rare. One major reason for the elimination of flight programs by some institutions, particularly the smaller colleges, is the prohibitive cost of operating and maintaining an aircraft as a flying laboratory. The purpose of this paper is to discuss simple, low-cost, relevant flight experiments that can be performed using readily available general aviation aircraft. This paper examines flight experiments that have been successfully conducted on board the NASA Lewis Research Center's T-34B aircraft, as part of the NASA/AIAA/University Flight Experiment Program for Students (NAUFEPS) and discusses how similar experiments could be inexpensively performed on other general aviation aircraft.

An open-source, extensible system for laboratory timing and control

NASA Astrophysics Data System (ADS)

Gaskell, Peter E.; Thorn, Jeremy J.; Alba, Sequoia; Steck, Daniel A.

2009-11-01

We describe a simple system for timing and control, which provides control of analog, digital, and radio-frequency signals. Our system differs from most common laboratory setups in that it is open source, built from off-the-shelf components, synchronized to a common and accurate clock, and connected over an Ethernet network. A simple bus architecture facilitates creating new and specialized devices with only moderate experience in circuit design. Each device operates independently, requiring only an Ethernet network connection to the controlling computer, a clock signal, and a trigger signal. This makes the system highly robust and scalable. The devices can all be connected to a single external clock, allowing synchronous operation of a large number of devices for situations requiring precise timing of many parallel control and acquisition channels. Provided an accurate enough clock, these devices are capable of triggering events separated by one day with near-microsecond precision. We have achieved precisions of ˜0.1 ppb (parts per 109) over 16 s.

Teaching radio astronomy with Affordable Small Radio Telescope (ASRT)

NASA Astrophysics Data System (ADS)

Joshi, Bhal Chandra

A simple, easy to build and portable radio telescope, called Affordable Small Radio Telescope (ASRT), has been developed by the Radio Physics Laboratory (RPL), a radio astronomy teaching unit associated with the National Centre for Radio Astrophysics (TIFR) and Inter-University Centre for Astronomy and Astrophysics (IUCAA), which are two premier astronomy institutes in India. ASRT consists of off-the-shelf available Direct to Home television dishes and is easy to assemble. Our design is scalable from simple very low cost telescope to more complex yet moderately costing instrument. ASRT provides a platform for demonstrating radio physics concepts through simple hands-on experiment as well as for carrying out solar monitoring by college/University students. The presentation will highlight the concept of ASRT and the different experiments that can be carried out using it. The solar monitoring observations will be discussed along-with details of methods for calibrating these measurements. The pedagogical usefulness of ASRT in introducing undergraduatephysics students to astrophysics, measurements and analysis methods used in radio astronomy will also be discussed. Use of ASRT in the last three years in the programs of RPL, namely the annual Radio Astronomy Winter School for College students (RAWSC) and Pulsar Observing for Students (POS) is also presented. This year a new program was initiated to form a virtual group of an ASRT community, which will not only share their measurements, but also think of improving the pedagogical usefulness of ASRT by innovative experiments. This initiative is presented with the best practices drawn from our experience in using ASRT as a tool for student training in space sciences. The talk will also point out future ideas in involving a larger body of students in simple radio astronomy experiments with the ASRT, which RPL is likely to nucleate as part of its mandate.

NMR Kinetics of the S[subscript N]2 Reaction between BuBr and I[superscript -]: An Introductory Organic Chemistry Laboratory Exercise

ERIC Educational Resources Information Center

Mobley, T. Andrew

2015-01-01

A simple organic chemistry experiment is described that investigates the kinetics of the reaction between 1-bromobutane (BuBr) and iodide (I[superscript -]) as followed by observing the disappearance of BuBr and the appearance of 1-iodobutane (BuI) using [superscript 1]H NMR spectroscopy. In small groups of three to four, students acquire data to…

Consecutive C[subscript 60] Fullerene Dissociation from Ir([eta][superscript 2]-C[subscript 60])(CO)(Cl)(PPh[subscript 3])[subscript 2] and the Oxidative Addition of Benzene

ERIC Educational Resources Information Center

Felix, Tamara; Cortes-Figueroa, Jose E.

2010-01-01

This laboratory activity is a mechanistic exploration of the interactions between electronically deficient organometallic compounds and solvent molecules. Simple kinetics experiments designed to explore the mechanism of C[subscript 60] fullerene-benzene exchange on Ir(([eta][superscript 2]-C[subscript 60])(CO)(Cl)(PPh[subscript 3])[subscript 2]…

Breadboard Amplifier: Building and Using Simple Electrophysiology Equipment.

PubMed

Crisp, Kevin M; Lin, Hunter; Prosper, Issa

2016-01-01

Electrophysiology is a valuable skill for the neuroscientist, but the learning curve for students can be steep. Here we describe a very simple electromyography (EMG) amplifier that can be built from scratch by students with no electronics experience in about 30 minutes, making it ideal for incorporating into a laboratory activity. With few parts and no adjustments except the gain, students can begin physiology experiments quickly while having the satisfaction of having built the equipment themselves. Because the output of the circuit goes to a computer sound card, students can listen to electrophysiological activity as they see it on the computer screen, a feature many of our students greatly appreciated. Various applications are discussed, including dual channel recording, using streaming media platforms with remote lab partners and acquiring data in the field on a smart phone. Our students reported that they enjoyed being able to build a working device and using it to record from their own muscles.

Building Diversified Multiple Trees for classification in high dimensional noisy biomedical data.

PubMed

Li, Jiuyong; Liu, Lin; Liu, Jixue; Green, Ryan

2017-12-01

It is common that a trained classification model is applied to the operating data that is deviated from the training data because of noise. This paper will test an ensemble method, Diversified Multiple Tree (DMT), on its capability for classifying instances in a new laboratory using the classifier built on the instances of another laboratory. DMT is tested on three real world biomedical data sets from different laboratories in comparison with four benchmark ensemble methods, AdaBoost, Bagging, Random Forests, and Random Trees. Experiments have also been conducted on studying the limitation of DMT and its possible variations. Experimental results show that DMT is significantly more accurate than other benchmark ensemble classifiers on classifying new instances of a different laboratory from the laboratory where instances are used to build the classifier. This paper demonstrates that an ensemble classifier, DMT, is more robust in classifying noisy data than other widely used ensemble methods. DMT works on the data set that supports multiple simple trees.

A simple model for estimating a magnetic field in laser-driven coils

DOE PAGES

Fiksel, Gennady; Fox, William; Gao, Lan; ...

2016-09-26

Magnetic field generation by laser-driven coils is a promising way of magnetizing plasma in laboratory high-energy-density plasma experiments. A typical configuration consists of two electrodes—one electrode is irradiated with a high-intensity laser beam and another electrode collects charged particles from the expanding plasma. The two electrodes are separated by a narrow gap forming a capacitor-like configuration and are connected with a conducting wire-coil. The charge-separation in the expanding plasma builds up a potential difference between the electrodes that drives the electrical current in the coil. A magnetic field of tens to hundreds of Teslas generated inside the coil has beenmore » reported. This paper presents a simple model that estimates the magnetic field using simple assumptions. Lastly, the results are compared with the published experimental data.« less

A simple wavelength division multiplexing system for active learning teaching

NASA Astrophysics Data System (ADS)

Zghal, Mourad; Ghalila, Hassen; Ben Lakhdar, Zohra

2009-06-01

The active learning project consists in a series of workshops for educators, researchers and students and promotes an innovative method of teaching physics using simple, inexpensive materials that can be fabricated locally. The objective of the project is to train trainers and inspire students to learn physics. The workshops are based on the use of laboratory work and hands-on activities in the classroom. The interpretation of these experiments is challenging for some students, and the experiments can lead to a significant amount of discussion. The workshops are organized within the framework of the project ``Active Learning in Optics and Photonics" (ALOP) mainly funded by UNESCO, with the support of ICTP (Abdus Salam International Centre for Theoretical Physics) and SPIE. ALOP workshops offer high school, college or university physics teachers the opportunity to improve their conceptual understanding of optics. These workshops usually run for five days and cover several of the topics usually found in any introductory university physics program. Optics and photonics are used as subject matter because it is relevant as well as adaptable to research and educational conditions in many developing countries [1]. In this paper, we will mainly focus on a specific topic of the ALOP workshops, namely optical communications and Wavelength Division Multiplexing technology (WDM). This activity was originally developed by Mazzolini et al [2]. WDM is a technology used in fibre-optic communications for transmitting two or more separate signals over a single fibre optic cable by using a separate wavelength for each signal. Multiple signals are carried together as separate wavelengths of light in a multiplexed signal. Simple and inexpensive WDM system was implemented in our laboratory using light emitting diodes or diode lasers, plastic optical fibres, a set of optical filters and lenses, prism or grating, and photodiodes. Transmission of audio signals using home-made, simple, inexpensive electronic circuits was also demonstrated. The experimental set-up was used during national ALOP workshops. Results are presented and discussed in this paper. Current explorations to further develop these and other closely-related experiments will also be described.

Space debris characterization in support of a satellite breakup model

NASA Technical Reports Server (NTRS)

Fortson, Bryan H.; Winter, James E.; Allahdadi, Firooz A.

1992-01-01

The Space Kinetic Impact and Debris Branch began an ambitious program to construct a fully analytical model of the breakup of a satellite under hypervelocity impact. In order to provide empirical data with which to substantiate the model, debris from hypervelocity experiments conducted in a controlled laboratory environment were characterized to provide information of its mass, velocity, and ballistic coefficient distributions. Data on the debris were collected in one master data file, and a simple FORTRAN program allows users to describe the debris from any subset of these experiments that may be of interest to them. A statistical analysis was performed, allowing users to determine the precision of the velocity measurements for the data. Attempts are being made to include and correlate other laboratory data, as well as those data obtained from the explosion or collision of spacecraft in low earth orbit.

Portable conduction velocity experiments using earthworms for the college and high school neuroscience teaching laboratory

PubMed Central

Shannon, Kyle M.; Gage, Gregory J.; Jankovic, Aleksandra; Wilson, W. Jeffrey

2014-01-01

The earthworm is ideal for studying action potential conduction velocity in a classroom setting, as its simple linear anatomy allows easy axon length measurements and the worm's sparse coding allows single action potentials to be easily identified. The earthworm has two giant fiber systems (lateral and medial) with different conduction velocities that can be easily measured by manipulating electrode placement and the tactile stimulus. Here, we present a portable and robust experimental setup that allows students to perform conduction velocity measurements within a 30-min to 1-h laboratory session. Our improvement over this well-known preparation is the combination of behaviorally relevant tactile stimuli (avoiding electrical stimulation) with the invention of minimal, low-cost, and portable equipment. We tested these experiments during workshops in both a high school and college classroom environment and found positive learning outcomes when we compared pre- and posttests taken by the students. PMID:24585472

Molecular Diagnostics of Fusion and Laboratory Plasmas

NASA Astrophysics Data System (ADS)

Fantz, U.

2005-05-01

The presence of molecules in the cold scrape-off layer of fusion experiments and industrial plasmas requires an understanding of the molecular dynamics in these low temperature plasmas. Suitable diagnostic methods can provide an insight in molecular processes in the plasma volume as well as for plasma surface interactions. A very simple but powerful technique is the molecular emission spectroscopy. Spectra are obtained easily, whereas interpretation might be very complex and relies on the availability of atomic and molecular data. Examples are given for hydrogen plasmas and plasmas with hydrocarbons which both are of importance in industrial applications as well as in fusion experiments.

Analyzing Oscillations of a Rolling Cart Using Smartphones and Tablets

NASA Astrophysics Data System (ADS)

Egri, Sándor; Szabó, Lóránt

2015-03-01

It is well known that "interactive engagement" helps students to understand basic concepts in physics.1 Performing experiments and analyzing measured data are effective ways to realize interactive engagement, in our view. Some experiments need special equipment, measuring instruments, or laboratories, but in this activity we advocate student use of mobile phones or tablets to take experimental data. Applying their own devices and measuring simple phenomena from everyday life can improve student interest, while still allowing precise analysis of data, which can give deeper insight into scientific thinking and provide a good opportunity for inquiry-based learning.2

Prebiotic organic microstructures.

PubMed

Bassez, Marie-Paule; Takano, Yoshinori; Kobayashi, Kensei

2012-08-01

Micro- and sub-micrometer spheres, tubules and fiber-filament soft structures have been synthesized in our experiments conducted with 3 MeV proton irradiations of a mixture of simple inorganic constituents, CO, N(2) and H(2)O. We analysed the irradiation products, with scanning electron microscopy (SEM) and atomic force microscopy (AFM). These laboratory organic structures produced a wide variety of proteinaceous and non-proteinaceous amino acids after HCl hydrolysis. The enantiomer analysis for D,L-alanine confirmed that the amino acids were abiotically synthesized during the laboratory experiment. We discuss the presence of CO(2) and the production of H(2) during exothermic processes of serpentinization and consequently we discuss the production of hydrothermal CO in a ferromagnesian silicate mineral environment. We also discuss the low intensity of the Earth's magnetic field during the Paleoarchaean Era and consequently we conclude that excitation sources arising from cosmic radiation were much more abundant during this Era. We then show that our laboratory prebiotic microstructures might be synthesized during the Archaean Eon, as a product of the serpentinization process of the rocks and of their mineral contents.

Fostering Elementary School Students' Understanding of Simple Electricity by Combining Simulation and Laboratory Activities

ERIC Educational Resources Information Center

Jaakkola, T.; Nurmi, S.

2008-01-01

Computer simulations and laboratory activities have been traditionally treated as substitute or competing methods in science teaching. The aim of this experimental study was to investigate if it would be more beneficial to combine simulation and laboratory activities than to use them separately in teaching the concepts of simple electricity. Based…

An Operationally Simple Sonogashira Reaction for an Undergraduate Organic Chemistry Laboratory Class

ERIC Educational Resources Information Center

Cranwell, Philippa B.; Peterson, Alexander M.; Littlefield, Benjamin T. R.; Russell, Andrew T.

2015-01-01

An operationally simple, reliable, and cheap Sonogashira reaction suitable for an undergraduate laboratory class that can be completed within a day-long (8 h) laboratory session has been developed. Cross-coupling is carried out between 2-methyl-3-butyn-2-ol and various aryl iodides using catalytic amounts of bis(triphenylphosphine)palladium(II)…

Chromatographic Separations Using Solid-Phase Extraction Cartridges: Separation of Wine Phenolics

NASA Astrophysics Data System (ADS)

Brenneman, Charles A.; Ebeler, Susan E.

1999-12-01

We describe a simple laboratory experiment that demonstrates the principles of chromatographic separation using solid-phase extraction columns and red wine. By adjusting pH and mobile phase composition, the wine is separated into three fractions of differing polarity. The content of each fraction can be monitored by UV-vis spectroscopy. When the experiment is combined with experiments involving HPLC or GC separations, students gain a greater appreciation for and understanding of the highly automated instrumental systems currently available. In addition, they learn about the chemistry of polyphenolic compounds, which are present in many foods and beverages and which are receiving much attention for their potentially beneficial health effects.

(Preoxidation cleaning optimization for crystalline silicon)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1991-01-01

A series of controlled experiments has been performed in Sandia's Photovoltaic Device Fabrication Laboratory to evaluate the effect of various chemical surface treatments on the recombination lifetime of crystalline silicon wafers subjected to a high-temperature dry oxidation. From this series of experiments we have deduced a relatively simple yet effective cleaning sequence. We have also evaluated the effect of different chemical damage-removal etches for improving the recombination lifetime and surface smoothness of mechanically lapped wafers. This paper presents the methodology used, the experimental results obtained, and our experience with using this process on a continuing basis over a period ofmore » many months. 7 refs., 4 figs., 1 tab.« less

Four experimental demonstrations of active vibration control for flexible structures

NASA Technical Reports Server (NTRS)

Phillips, Doug; Collins, Emmanuel G., Jr.

1990-01-01

Laboratory experiments designed to test prototype active-vibration-control systems under development for future flexible space structures are described, summarizing previously reported results. The control-synthesis technique employed for all four experiments was the maximum-entropy optimal-projection (MEOP) method (Bernstein and Hyland, 1988). Consideration is given to: (1) a pendulum experiment on large-amplitude LF dynamics; (2) a plate experiment on broadband vibration suppression in a two-dimensional structure; (3) a multiple-hexagon experiment combining the factors studied in (1) and (2) to simulate the complexity of a large space structure; and (4) the NASA Marshall ACES experiment on a lightweight deployable 45-foot beam. Extensive diagrams, drawings, graphs, and photographs are included. The results are shown to validate the MEOP design approach, demonstrating that good performance is achievable using relatively simple low-order decentralized controllers.

Technology Being Developed at Lawrence Berkeley National Laboratory: Ultra-Low- Emission Combustion Technologies for Heat and Power Generation

NASA Technical Reports Server (NTRS)

Cheng, Robert K.

2001-01-01

The Combustion Technologies Group at Lawrence Berkeley National Laboratory has developed simple, low-cost, yet robust combustion technologies that may change the fundamental design concept of burners for boilers and furnaces, and injectors for gas turbine combustors. The new technologies utilize lean premixed combustion and could bring about significant pollution reductions from commercial and industrial combustion processes and may also improve efficiency. The technologies are spinoffs of two fundamental research projects: An inner-ring burner insert for lean flame stabilization developed for NASA- sponsored reduced-gravity combustion experiments. A low-swirl burner developed for Department of Energy Basic Energy Sciences research on turbulent combustion.

How to Recognize Success and Failure: Practical Assessment of an Evolving, First-Semester Laboratory Program Using Simple, Outcome-Based Tools

ERIC Educational Resources Information Center

Gron, Liz U.; Bradley, Shelly B.; McKenzie, Jennifer R.; Shinn, Sara E.; Teague, M. Warfield

2013-01-01

This paper presents the use of simple, outcome-based assessment tools to design and evaluate the first semester of a new introductory laboratory program created to teach green analytical chemistry using environmental samples. This general chemistry laboratory program, like many introductory courses, has a wide array of stakeholders within and…

Elementary Reactions and Their Role in Gas-Phase Prebiotic Chemistry

PubMed Central

Balucani, Nadia

2009-01-01

The formation of complex organic molecules in a reactor filled with gaseous mixtures possibly reproducing the primitive terrestrial atmosphere and ocean demonstrated more than 50 years ago that inorganic synthesis of prebiotic molecules is possible, provided that some form of energy is provided to the system. After that groundbreaking experiment, gas-phase prebiotic molecules have been observed in a wide variety of extraterrestrial objects (including interstellar clouds, comets and planetary atmospheres) where the physical conditions vary widely. A thorough characterization of the chemical evolution of those objects relies on a multi-disciplinary approach: 1) observations allow us to identify the molecules and their number densities as they are nowadays; 2) the chemistry which lies behind their formation starting from atoms and simple molecules is accounted for by complex reaction networks; 3) for a realistic modeling of such networks, a number of experimental parameters are needed and, therefore, the relevant molecular processes should be fully characterized in laboratory experiments. A survey of the available literature reveals, however, that much information is still lacking if it is true that only a small percentage of the elementary reactions considered in the models have been characterized in laboratory experiments. New experimental approaches to characterize the relevant elementary reactions in laboratory are presented and the implications of the results are discussed. PMID:19564951

Using simple manipulatives to improve student comprehension of a complex biological process: protein synthesis.

PubMed

Guzman, Karen; Bartlett, John

2012-01-01

Biological systems and living processes involve a complex interplay of biochemicals and macromolecular structures that can be challenging for undergraduate students to comprehend and, thus, misconceptions abound. Protein synthesis, or translation, is an example of a biological process for which students often hold many misconceptions. This article describes an exercise that was developed to illustrate the process of translation using simple objects to represent complex molecules. Animations, 3D physical models, computer simulations, laboratory experiments and classroom lectures are also used to reinforce the students' understanding of translation, but by focusing on the simple manipulatives in this exercise, students are better able to visualize concepts that can elude them when using the other methods. The translation exercise is described along with suggestions for background material, questions used to evaluate student comprehension and tips for using the manipulatives to identify common misconceptions. Copyright © 2012 Wiley Periodicals, Inc.

Microscale Organic Laboratory: IV. A Simple and Rapid Procedure for Carrying Out Wittig Reactions.

ERIC Educational Resources Information Center

Pike, R. M.; And Others

1986-01-01

Describes two examples where synthetic salt-base mixtures are used in a microscale organic laboratory program as a simple and quick procedure for carrying out Wittig reactions. Both experimental procedures are outlined and discussed. (TW)

Laboratory Needs for Interstellar Ice Studies

NASA Astrophysics Data System (ADS)

Boogert, Abraham C. A.

2012-05-01

A large fraction of the molecules in dense interstellar and circumstellar environments is stored in icy grain mantles. The mantles are formed by a complex interplay between chemical and physical processes. Key questions on the accretion and desorption processes and the chemistry on the grain surfaces and within the icy mantles can only be answered by laboratory experiments. Recent infrared (2-30 micron) spectroscopic surveys of large samples of Young Stellar Objects (YSOs) and background stars tracing quiescent cloud material have shown that the ice band profiles and depths vary considerably as a function of environment. Using laboratory spectra in the identification process, it is clear that a rather complex mixture of simple species (CH3OH, CO2, H2O, CO) exists even in the quiescent cloud phase. Variations of the local physical conditions (CO freeze out) and time scales (CH3OH formation) appear to be key factors in the observed variations. Sublimation and thermal processing dominate as YSOs heat their environments. The identification of several ice absorption features is still disputed. I will outline laboratory work (e.g., on salts, PAHs, and aliphatic hydrocarbons) needed to further constrain the ice band identification as well as the thermal and chemical history of the carriers. Such experiments will also be essential to interpret future high spectral resolution SOFIA and JWST observations.

Dating thermal events at Cerro Prieto using fission track annealing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanford, S.J.; Elders, W..

1981-01-01

Data from laboratory experiments and geologic fading studies were compiled from published sources to produce lines of iso-annealing for apatite in time-temperature space. Fission track ages were calculated for samples from two wells at Cerro Prieto, one with an apparently simple and one with an apparently complex thermal history. Temperatures were estimated by empirical vitrinite reflectance geothermometry, fluid inclusion homogenization and oxygen isotope equilibrium. These estimates were compared with logs of measured borehole temperatures.

Effects of light at night on laboratory animals and research outcomes.

PubMed

Emmer, Kathryn M; Russart, Kathryn L G; Walker, William H; Nelson, Randy J; DeVries, A Courtney

2018-06-28

Light has substantial influences on the physiology and behavior of most laboratory animals. As such, lighting conditions within animal rooms are potentially significant and often underappreciated variables within experiments. Disruption of the light/dark cycle, primarily by exposing animals to light at night (LAN), disturbs biological rhythms and has widespread physiological consequences because of mechanisms such as melatonin suppression, sympathetic stimulation, and altered circadian clock gene expression. Thus, attention to the lighting environment of laboratory animals and maintaining consistency of a light/dark cycle is imperative for study reproducibility. Light intensity, as well as wavelength, photoperiod, and timing, are all important variables. Although modern rodent facilities are designed to facilitate appropriate light cycling, there are simple ways to modify rooms to prevent extraneous light exposure during the dark period. Attention to lighting conditions of laboratory animals by both researchers and research care staff ensures best practices for maintaining animal welfare, as well as reproducibility of research results. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

PaR-PaR Laboratory Automation Platform

DOE Office of Scientific and Technical Information (OSTI.GOV)

Linshiz, G; Stawski, N; Poust, S

2013-05-01

Labor-intensive multistep biological tasks, such as the construction and cloning of DNA molecules, are prime candidates for laboratory automation. Flexible and biology-friendly operation of robotic equipment is key to its successful integration in biological laboratories, and the efforts required to operate a robot must be much smaller than the alternative manual lab work. To achieve these goals, a simple high-level biology-friendly robot programming language is needed. We have developed and experimentally validated such a language: Programming a Robot (PaR-PaR). The syntax and compiler for the language are based on computer science principles and a deep understanding of biological workflows. PaR-PaRmore » allows researchers to use liquid-handling robots effectively, enabling experiments that would not have been considered previously. After minimal training, a biologist can independently write complicated protocols for a robot within an hour. Adoption of PaR-PaR as a standard cross-platform language would enable hand-written or software-generated robotic protocols to be shared across laboratories.« less

PaR-PaR laboratory automation platform.

PubMed

Linshiz, Gregory; Stawski, Nina; Poust, Sean; Bi, Changhao; Keasling, Jay D; Hillson, Nathan J

2013-05-17

Labor-intensive multistep biological tasks, such as the construction and cloning of DNA molecules, are prime candidates for laboratory automation. Flexible and biology-friendly operation of robotic equipment is key to its successful integration in biological laboratories, and the efforts required to operate a robot must be much smaller than the alternative manual lab work. To achieve these goals, a simple high-level biology-friendly robot programming language is needed. We have developed and experimentally validated such a language: Programming a Robot (PaR-PaR). The syntax and compiler for the language are based on computer science principles and a deep understanding of biological workflows. PaR-PaR allows researchers to use liquid-handling robots effectively, enabling experiments that would not have been considered previously. After minimal training, a biologist can independently write complicated protocols for a robot within an hour. Adoption of PaR-PaR as a standard cross-platform language would enable hand-written or software-generated robotic protocols to be shared across laboratories.

The use of a Nintendo Wii remote control in physics experiments

NASA Astrophysics Data System (ADS)

Abellán, F. J.; Arenas, A.; Núñez, M. J.; Victoria, L.

2013-09-01

In this paper we describe how a Nintendo Wii remote control (known as the Wiimote) can be used in the design and implementation of several undergraduate-level experiments in a physics laboratory class. An experimental setup composed of a Wiimote and a conveniently located IR LED allows the trajectory of one or several moving objects to be tracked and recorded accurately, in both long and short displacement. The authors have developed a user interface program to configure the operation of the acquisition system of such data. The two experiments included in this work are the free fall of a body with magnetic braking and the simple pendulum, but other physics experiments could have been chosen. The treatment of the data was performed using Bayesian inference.

Insights on landscape dynamics from tiny spheres in oil, or: How I learned to stop worrying and love the lab

NASA Astrophysics Data System (ADS)

Jerolmack, D. J.; Durian, D. J.; Ferdowsi, B.; Houssais, M.; Ortiz, C. P.

2016-12-01

As in most of Earth science, there is a tension in the design of sediment transport experiments between simplicity and the ability to isolate variables, and realism so that results maybe extrapolated to the field. This leads to tradeoffs in data acquisition, as "simple" experiments may be designed around the goal of maximizing observation of fundamental dynamics, while the dynamics of "realistic" experiments are typically more opaque. Here we present results from a series of "simple" sediment transport experiments involving a laminar shear flow over spherical plastic grains, where refractive-index matched scanning techniques are used to perform tomographic imaging of the sediment bed. This setup allows us to measure particle velocities over seven orders of magnitude - encompassing much of the range of natural flows from creeping soil to suspended load - and these measurements reveal new phenomena relevant for geomorphology and granular physics. We show that the onset of sediment transport is actually a continuous transition from creeping to bed load, and that sub-threshold creep in this laboratory "river" is similar to creep observed on hillslopes and in glassy materials. We also show that the transition from bed load to suspension can be modeled as a continuous transition from a dense to dilute granular flow, uniting sediment transport with granular rheology. We then perform experiments with bi-modal grains, which undergo granular segregation that delivers coarse grains from the subsurface to the surface. This results in armoring that is entirely consistent with observations of more realistic systems, but by a completely different mechanism from surface-transport based theories. Although these phenomena may likely be quantitatively or even qualitatively different in natural settings, they cannot be dismissed out of hand because experiments are "too simple". Indeed, most of our findings can be mapped to observations from more complicated experiments and also field studies. By embracing the control and resolution afforded by "simple" experiments, we allow the possibility to both determine the mechanistic underpinnings of transport, and to reveal fundamentally new dynamics that may change our perspective on how landscapes work.

A note on the contribution of multi-photon processes to radiative opacity

NASA Astrophysics Data System (ADS)

Pain, Jean-Christophe

2018-03-01

Recently, Bailey et al. performed iron opacity measurements on the Z machine at Sandia National Laboratory in conditions close to the ones of the base of the convective zone of the Sun. Such experiments have raised questions about the physical models commonly used in opacity codes. To understand the discrepancy between experiment and theory, More et al. investigated the role of two-photon processes. In the present work we show, by simple estimate and using hydrogenic formulas, that due to the intensity of the backlight radiation seen by the sample, such processes are likely to play an important role only for highly excited states.

Using Performance Assessment Model in Physics Laboratory to Increase Students’ Critical Thinking Disposition

NASA Astrophysics Data System (ADS)

Emiliannur, E.; Hamidah, I.; Zainul, A.; Wulan, A. R.

2017-09-01

Performance Assessment Model (PAM) has been developed to represent the physics concepts which able to be devided into five experiments: 1) acceleration due to gravity; 2) Hooke’s law; 3) simple harmonic motion; 4) work-energy concepts; and 5) the law of momentum conservation. The aim of this study was to determine the contribution of PAM in physics laboratory to increase students’ Critical Thinking Disposition (CTD) at senior high school. Subject of the study were 11th grade consist 32 students of a senior high school in Lubuk Sikaping, West Sumatera. The research used one group pretest-postest design. Data was collected through essay test and questionnaire about CTD. Data was analyzed using quantitative way with N-gain value. This study concluded that performance assessmet model effectively increases the N-gain at medium category. It means students’ critical thinking disposition significant increase after implementation of performance assessment model in physics laboratory.

Comparison of Refractory Performance in Black Liquor Gasifiers and a Smelt Test System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peascoe, RA

2001-09-25

Prior laboratory corrosion studies along with experience at the black liquor gasifier in New Bern, North Carolina, clearly demonstrate that serious material problems exist with the gasifier's refractory lining. Mullite-based and alumina-based refractories used at the New Bern facility suffered significant degradation even though they reportedly performed adequately in smaller scale systems. Oak Ridge National Laboratory's involvement in the failure analysis, and the initial exploration of suitable replacement materials, led to the realization that a simple and reliable, complementary method for refractory screening was needed. The development of a laboratory test system and its suitability for simulating the environment ofmore » black liquor gasifiers was undertaken. Identification and characterization of corrosion products were used to evaluate the test system as a rapid screening tool for refractory performance and as a predictor of refractory lifetime. Results from the test systems and pl ants were qualitatively similar.« less

Estimating Fault Friction From Seismic Signals in the Laboratory

NASA Astrophysics Data System (ADS)

Rouet-Leduc, Bertrand; Hulbert, Claudia; Bolton, David C.; Ren, Christopher X.; Riviere, Jacques; Marone, Chris; Guyer, Robert A.; Johnson, Paul A.

2018-02-01

Nearly all aspects of earthquake rupture are controlled by the friction along the fault that progressively increases with tectonic forcing but in general cannot be directly measured. We show that fault friction can be determined at any time, from the continuous seismic signal. In a classic laboratory experiment of repeating earthquakes, we find that the seismic signal follows a specific pattern with respect to fault friction, allowing us to determine the fault's position within its failure cycle. Using machine learning, we show that instantaneous statistical characteristics of the seismic signal are a fingerprint of the fault zone shear stress and frictional state. Further analysis of this fingerprint leads to a simple equation of state quantitatively relating the seismic signal power and the friction on the fault. These results show that fault zone frictional characteristics and the state of stress in the surroundings of the fault can be inferred from seismic waves, at least in the laboratory.

Breadboard Amplifier: Building and Using Simple Electrophysiology Equipment

PubMed Central

Crisp, Kevin M.; Lin, Hunter; Prosper, Issa

2016-01-01

Electrophysiology is a valuable skill for the neuroscientist, but the learning curve for students can be steep. Here we describe a very simple electromyography (EMG) amplifier that can be built from scratch by students with no electronics experience in about 30 minutes, making it ideal for incorporating into a laboratory activity. With few parts and no adjustments except the gain, students can begin physiology experiments quickly while having the satisfaction of having built the equipment themselves. Because the output of the circuit goes to a computer sound card, students can listen to electrophysiological activity as they see it on the computer screen, a feature many of our students greatly appreciated. Various applications are discussed, including dual channel recording, using streaming media platforms with remote lab partners and acquiring data in the field on a smart phone. Our students reported that they enjoyed being able to build a working device and using it to record from their own muscles. PMID:27385921

Hybrid nanosensor for colorimetric and ultrasensitive detection of nuclease contaminations

NASA Astrophysics Data System (ADS)

Cecere, Paola; Valentini, Paola; Pompa, Pier Paolo

2016-04-01

Nucleases are ubiquitous enzymes that degrade DNA or RNA, thus they can prejudice the good outcome of molecular biology experiments involving nucleic acids. We propose a colorimetric test for the naked-eye detection of nuclease contaminations. The system uses an hybrid nanosensor, based on gold nanoparticles functionalized with DNA probes. Our assay is rapid, instrument-free, simple and low-cost. Moreover, it reaches sensitivity equal or better than those of commercial kits, and presents a lot of advantageous aspects. Therefore, it is very competitive, with a real market potential. This test will be relevant in routine process monitoring in scientific laboratories, and in quality control in clinical laboratories and industrial processes, allowing the simultaneous detection of nucleases with different substrate specificities and large-scale screening.

Handling Metadata in a Neurophysiology Laboratory

PubMed Central

Zehl, Lyuba; Jaillet, Florent; Stoewer, Adrian; Grewe, Jan; Sobolev, Andrey; Wachtler, Thomas; Brochier, Thomas G.; Riehle, Alexa; Denker, Michael; Grün, Sonja

2016-01-01

To date, non-reproducibility of neurophysiological research is a matter of intense discussion in the scientific community. A crucial component to enhance reproducibility is to comprehensively collect and store metadata, that is, all information about the experiment, the data, and the applied preprocessing steps on the data, such that they can be accessed and shared in a consistent and simple manner. However, the complexity of experiments, the highly specialized analysis workflows and a lack of knowledge on how to make use of supporting software tools often overburden researchers to perform such a detailed documentation. For this reason, the collected metadata are often incomplete, incomprehensible for outsiders or ambiguous. Based on our research experience in dealing with diverse datasets, we here provide conceptual and technical guidance to overcome the challenges associated with the collection, organization, and storage of metadata in a neurophysiology laboratory. Through the concrete example of managing the metadata of a complex experiment that yields multi-channel recordings from monkeys performing a behavioral motor task, we practically demonstrate the implementation of these approaches and solutions with the intention that they may be generalized to other projects. Moreover, we detail five use cases that demonstrate the resulting benefits of constructing a well-organized metadata collection when processing or analyzing the recorded data, in particular when these are shared between laboratories in a modern scientific collaboration. Finally, we suggest an adaptable workflow to accumulate, structure and store metadata from different sources using, by way of example, the odML metadata framework. PMID:27486397

Handling Metadata in a Neurophysiology Laboratory.

PubMed

Zehl, Lyuba; Jaillet, Florent; Stoewer, Adrian; Grewe, Jan; Sobolev, Andrey; Wachtler, Thomas; Brochier, Thomas G; Riehle, Alexa; Denker, Michael; Grün, Sonja

2016-01-01

To date, non-reproducibility of neurophysiological research is a matter of intense discussion in the scientific community. A crucial component to enhance reproducibility is to comprehensively collect and store metadata, that is, all information about the experiment, the data, and the applied preprocessing steps on the data, such that they can be accessed and shared in a consistent and simple manner. However, the complexity of experiments, the highly specialized analysis workflows and a lack of knowledge on how to make use of supporting software tools often overburden researchers to perform such a detailed documentation. For this reason, the collected metadata are often incomplete, incomprehensible for outsiders or ambiguous. Based on our research experience in dealing with diverse datasets, we here provide conceptual and technical guidance to overcome the challenges associated with the collection, organization, and storage of metadata in a neurophysiology laboratory. Through the concrete example of managing the metadata of a complex experiment that yields multi-channel recordings from monkeys performing a behavioral motor task, we practically demonstrate the implementation of these approaches and solutions with the intention that they may be generalized to other projects. Moreover, we detail five use cases that demonstrate the resulting benefits of constructing a well-organized metadata collection when processing or analyzing the recorded data, in particular when these are shared between laboratories in a modern scientific collaboration. Finally, we suggest an adaptable workflow to accumulate, structure and store metadata from different sources using, by way of example, the odML metadata framework.

Ocean acidification alters fish populations indirectly through habitat modification

NASA Astrophysics Data System (ADS)

Nagelkerken, Ivan; Russell, Bayden D.; Gillanders, Bronwyn M.; Connell, Sean D.

2016-01-01

Ocean ecosystems are predicted to lose biodiversity and productivity from increasing ocean acidification. Although laboratory experiments reveal negative effects of acidification on the behaviour and performance of species, more comprehensive predictions have been hampered by a lack of in situ studies that incorporate the complexity of interactions between species and their environment. We studied CO2 vents from both Northern and Southern hemispheres, using such natural laboratories to investigate the effect of ocean acidification on plant-animal associations embedded within all their natural complexity. Although we substantiate simple direct effects of reduced predator-avoidance behaviour by fishes, as observed in laboratory experiments, we here show that this negative effect is naturally dampened when fish reside in shelter-rich habitats. Importantly, elevated CO2 drove strong increases in the abundance of some fish species through major habitat shifts, associated increases in resources such as habitat and prey availability, and reduced predator abundances. The indirect effects of acidification via resource and predator alterations may have far-reaching consequences for population abundances, and its study provides a framework for a more comprehensive understanding of increasing CO2 emissions as a driver of ecological change.

The UAH Spinning Terrella Experiment: A Laboratory Analog for the Earth's Magnetosphere

NASA Technical Reports Server (NTRS)

Sheldon, R. B.; Gallagher, D. L.; Craven, P. D.; Whitaker, Ann F. (Technical Monitor)

2001-01-01

The UAH Spinning Terrella Experiment has been modified to include the effect of a second magnet. This is a simple laboratory demonstration of the well-known double-dipole approximation to the Earth's magnetosphere. In addition, the magnet has been biassed $\\sim$-400V which generates a DC glow discharge and traps it in a ring current around the magnet. This ring current is easily imaged with a digital camera and illustrates several significant topological properties of a dipole field. In particular, when the two dipoles are aligned, and therefore repel, they emulate a northward IMF Bz magnetosphere. Such a geometry traps plasma in the high latitude cusps as can be clearly seen in the movies. Likewise, when the two magnets are anti-aligned, they emulate a southward IMF Bz magnetosphere with direct feeding of plasma through the x-line. We present evidence for trapping and heating of the plasma, comparing the dipole-trapped ring current to the cusp-trapped population. We also present a peculiar asymmetric ring current produced in by the plasma at low plasma densities. We discuss the similarities and dissimilarities of the laboratory analog to the collisionless Earth plasma, and implications for the interpretation of IMAGE data.

A Simple Low-Cost Lock-In Amplifier for the Laboratory

ERIC Educational Resources Information Center

Sengupta, Sandip K.; Farnham, Jessica M.; Whitten, James E.

2005-01-01

The creation of a simple, low-cost lock-in amplifier (LIA) suitable for use in the chemistry teaching laboratory is described. The use of integrated circuits and few components are necessary to adequately accomplish lock-in amplification limited the total cost of construction to under US$100.

Simple & Rapid Generation of Complex DNA Profiles for the Undergraduate Laboratory

ERIC Educational Resources Information Center

Kass, David H.

2007-01-01

Deoxyribonucleic acid (DNA) profiles can be generated by a variety of techniques incorporating different types of DNA markers. Simple methods are commonly utilized in the undergraduate laboratory, but with certain drawbacks. In this article, the author presents an advancement of the "Alu" dimorphism technique involving two tetraplex polymerase…

A simple technique for maintaining Stimulium adults, including onchocerciasis vectors, under artificial conditions.

PubMed

Raybould, J N; Mhiddin, H K

1974-01-01

The maintenance of Simulium adults in the laboratory is necessary for many experimental investigations and is a prerequisite to laboratory colonization. A simple technique for this purpose is described in which each fly is kept separately in a hole bored in a block of expanded polystyrene.

Microgravity Effects on Microbiology In Space Laboratories

NASA Technical Reports Server (NTRS)

Nelson, Emily S.; Juergensmeyer, Elizabeth; Juergensmeyer, Margaret

2000-01-01

Here we present a review of the effects of residual acceleration on microorganisms in space Laboratories. Residual acceleration in the microgravity environment is frequently ignored by microbiologists, although their experiments may be as sensitive to this acceleration as those designed by materials scientists and fluid physicists. Furthermore, analysis to date has been largely empirical and/or based on very simple theoretical models. As a result, the responses of single cells to the space environment are widely assumed to be taking place in "pure" microgravity. These responses vary widely and are not well understood. Some of this variation may be due to the range of microgravity conditions experience by organisms. In the future, as we move from visiting orbital environments to living and working there, we will undoubtedly bring microorganisms with us. It is also quite likely that the first extraterrestrial life we encounter will be single-celled organisms. Therefore, we would like to present a summary of the current knowledge base, and to challenge the space community to develop new approaches in understanding this important field.

Search for Chemical Biomarkers on Mars Using the Sample Analysis at Mars Instrument Suite on the Mars Science Laboratory

NASA Technical Reports Server (NTRS)

Glavin, D. P.; Conrad, P.; Dworkin, J. P.; Eigenbrode, J.; Mahaffy, P. R.

2011-01-01

One key goal for the future exploration of Mars is the search for chemical biomarkers including complex organic compounds important in life on Earth. The Sample Analysis at Mars (SAM) instrument suite on the Mars Science Laboratory (MSL) will provide the most sensitive measurements of the organic composition of rocks and regolith samples ever carried out in situ on Mars. SAM consists of a gas chromatograph (GC), quadrupole mass spectrometer (QMS), and tunable laser spectrometer to measure volatiles in the atmosphere and released from rock powders heated up to 1000 C. The measurement of organics in solid samples will be accomplished by three experiments: (1) pyrolysis QMS to identify alkane fragments and simple aromatic compounds; pyrolysis GCMS to separate and identify complex mixtures of larger hydrocarbons; and (3) chemical derivatization and GCMS extract less volatile compounds including amino and carboxylic acids that are not detectable by the other two experiments.

Laboratory and greenhouse assessment of phytoremediation of petroleum contaminated soils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banks, M.K.; Schwab, A.P.; Wang, X.

Phytoremediation of soils contaminated with petroleum and associated priority pollutants was evaluated in greenhouse and laboratory experiments. Mineralization of several PAHs was measured in rhizosphere soil, non-rhizosphere soil, and sterile soil amended with simulated root exudates. The least amount of mineralization was observed in sterile soil, but there were no differences among all other soils. Mineralization of 14 C-benzo[a]pyrene was determined in chambers to determine the effects of tall fescue on dissipation of this compound. After 180 days, the soils with fescue had more than twice the mineralization than soils without plants. In the soils with plants, evolution of 14CO2more » from the soil was five times greater than from the plant biomass. These experiments demonstrate that the presence of plants is a necessary part of the phytoremediation process. There appears to be no residual rhizosphere effect, and the simple exudation of organic compounds does not mimic fully the presence of roots.« less

Evaluation of bed load transport subject to high shear stress fluctuations

NASA Astrophysics Data System (ADS)

Cheng, Nian-Sheng; Tang, Hongwu; Zhu, Lijun

2004-05-01

Many formulas available in the literature for computing sediment transport rates are often expressed in terms of time mean variables such as time mean bed shear stress or flow velocity, while effects of turbulence intensity, e.g., bed shear stress fluctuation, on sediment transport were seldom considered. This may be due to the fact that turbulence fluctuation is relatively limited in laboratory open-channel flows, which are often used for conducting sediment transport experiments. However, turbulence intensity could be markedly enhanced in practice. This note presents an analytical method to compute bed load transport by including effects of fluctuations in the bed shear stress. The analytical results obtained show that the transport rate enhanced by turbulence can be expressed as a simple function of the relative fluctuation of the bed shear stress. The results are also verified using data that were collected recently from specifically designed laboratory experiments. The present analysis is applicable largely for the condition of a flat bed that is comprised of uniform sand particles subject to unidirectional flows.

Does linear separability really matter? Complex visual search is explained by simple search

PubMed Central

Vighneshvel, T.; Arun, S. P.

2013-01-01

Visual search in real life involves complex displays with a target among multiple types of distracters, but in the laboratory, it is often tested using simple displays with identical distracters. Can complex search be understood in terms of simple searches? This link may not be straightforward if complex search has emergent properties. One such property is linear separability, whereby search is hard when a target cannot be separated from its distracters using a single linear boundary. However, evidence in favor of linear separability is based on testing stimulus configurations in an external parametric space that need not be related to their true perceptual representation. We therefore set out to assess whether linear separability influences complex search at all. Our null hypothesis was that complex search performance depends only on classical factors such as target-distracter similarity and distracter homogeneity, which we measured using simple searches. Across three experiments involving a variety of artificial and natural objects, differences between linearly separable and nonseparable searches were explained using target-distracter similarity and distracter heterogeneity. Further, simple searches accurately predicted complex search regardless of linear separability (r = 0.91). Our results show that complex search is explained by simple search, refuting the widely held belief that linear separability influences visual search. PMID:24029822

Varying iron release from transferrin and lactoferrin proteins. A laboratory experiment.

PubMed

Carmona, Fernando; González, Ana; Sánchez, Manu; Gálvez, Natividad; Cuesta, Rafael; Capdevila, Mercè; Dominguez-Vera, Jose M

2017-11-01

Iron metabolism is an important subject of study for undergraduate students of chemistry and biochemistry. Relevant laboratory exercises are scarce in the literature but would be very helpful in assisting students grasp key concepts. The experiment described here deals with different iron release mechanisms of two protagonists in iron metabolism: serum transferrin (Tf) and lactoferrin (Lf). Despite having very similar structures and iron-binding sites, Tf releases practically all its iron at pH 5.5 while Lf requires a significantly lower pH of 3. This difference in behavior is directly related to their respective biological functions as Tf blood-borne iron into the cell, while Lf competes with pathogens to sequester iron in biological fluids at more acidic pHs.  During this experiment, the students will carry out iron loading and unloading on both human Lf and Tf and monitor the iron release at different pHs using UV-Vis spectroscopy. With this simple approach, the students will discover the different patterns of iron release of Tf and Lf and how this variance in behavior relates to their biological functions. Furthermore, this laboratory practice can be expanded to allow students to investigate a variety of iron proteins. © 2017 by The International Union of Biochemistry and Molecular Biology, 45(6):521-527, 2017. © 2017 The International Union of Biochemistry and Molecular Biology.

Mid- and far-infrared spectroscopic studies of the influence of temperature, ultraviolet photolysis and ion irradiation on cosmic-type ices.

PubMed

Moore, M H; Hudson, R L; Gerakines, P A

2001-03-15

Infrared (IR) studies of laboratory ices can provide information on the evolution of cosmic-type ices as a function of different simulated space environments involving thermal, ultraviolet (UV), or ion processing. Laboratory radiation experiments can lead to the formation of complex organic molecules. However, because of our lack of knowledge about UV photon and ion fluxes, and exposure lifetimes, it is not certain how well our simulations represent space conditions. Appropriate laboratory experiments are also limited by the absence of knowledge about the composition, density, and temperature of ices in different regions of space. Our current understanding of expected doses due to UV photons and cosmic rays is summarized here, along with an inventory of condensed-phase molecules identified on outer solar system surfaces, comets and interstellar grains. Far-IR spectra of thermally cycled H2O are discussed since these results reflect the dramatic difference between the amorphous and crystalline phases of H2O ice, the most dominant condensed-phase molecule in cosmic ices. A comparison of mid-IR spectra of products in proton-irradiated and UV-photolyzed ices shows that few differences are observed for these two forms of processing for the simple binary mixtures studied to date. IR identification of radiation products and experiments to determine production rates of new molecules in ices during processing are discussed. A new technique for measuring intrinsic IR band strengths of several unstable molecules is presented. An example of our laboratory results applied to Europa observations is included.

A new site for 85Kr measurements on groundwater samples

NASA Astrophysics Data System (ADS)

Lange, T.; Hebert, D.

2001-06-01

As a part of a new 85Kr laboratory, which is currently being established at the Institute of Applied Physics in Freiberg, Germany, a modified CO 2 extractor for krypton sampling is used. The operation principle is simple and contamination-safe with a reasonable effort. Continuously pumped under pressure, the water passes a Venturi-type nozzle and degasses due to relaxing. The extracted gas mixture then enters a recirculation system flowing through a CO 2 trap (NaOH), molecular sieves and a cooled charcoal trap, where krypton and other components are adsorbed. Remaining gases reenter the system at the Venturi-type nozzle. To keep the circulation alive an additional helium support is needed. In a simple field experiment, extraction efficiencies up to 0.8 for 222Rn have been measured.

Measurement of the line-of-sight velocity of high-altitude barium clouds A technique

NASA Technical Reports Server (NTRS)

Mende, S. B.; Harris, S. E.

1982-01-01

It is demonstrated that for maximizing the scientific output of future ionospheric and magnetospheric ion cloud release experiments a new type of instrument is required which will measure the line-of-sight velocity of the ion cloud by the Doppler technique. A simple instrument was constructed using a 5-cm diam solid Fabry-Perot etalon coupled to a low-light-level integrating TV camera. It was demonstrated that the system has both the sensitivity and spectral resolution for detection of ion clouds and measurement of their line-of-sight Doppler velocity. The tests consisted of (1) a field experiment using a rocket barium cloud release to check sensitivity, and (2) laboratory experiments to show the spectral resolving capabilities of the system. The instrument was found to be operational if the source was brighter than approximately 1 kR, and it had a wavelength resolution much better than 0.2 A, which corresponds to approximately 12 km/sec or in the case of barium ion an acceleration potential of 100 V. The instrument is rugged and, therefore, simple to use in field experiments or on flight instruments. The sensitivity limit of the instrument can be increased by increasing the size of the etalon.

Perform light and optic experiments in Augmented Reality

NASA Astrophysics Data System (ADS)

Wozniak, Peter; Vauderwange, Oliver; Curticapean, Dan; Javahiraly, Nicolas; Israel, Kai

2015-10-01

In many scientific studies lens experiments are part of the curriculum. The conducted experiments are meant to give the students a basic understanding for the laws of optics and its applications. Most of the experiments need special hardware like e.g. an optical bench, light sources, apertures and different lens types. Therefore it is not possible for the students to conduct any of the experiments outside of the university's laboratory. Simple optical software simulators enabling the students to virtually perform lens experiments already exist, but are mostly desktop or web browser based. Augmented Reality (AR) is a special case of mediated and mixed reality concepts, where computers are used to add, subtract or modify one's perception of reality. As a result of the success and widespread availability of handheld mobile devices, like e.g. tablet computers and smartphones, mobile augmented reality applications are easy to use. Augmented reality can be easily used to visualize a simulated optical bench. The students can interactively modify properties like e.g. lens type, lens curvature, lens diameter, lens refractive index and the positions of the instruments in space. Light rays can be visualized and promote an additional understanding of the laws of optics. An AR application like this is ideally suited to prepare the actual laboratory sessions and/or recap the teaching content. The authors will present their experience with handheld augmented reality applications and their possibilities for light and optic experiments without the needs for specialized optical hardware.

Production of organic compounds in plasmas: A comparison among electric sparks, laser-induced plasmas and UV light

NASA Technical Reports Server (NTRS)

Scattergood, T. W.; Mckay, C. P.; Borucki, W. J.; Giver, L. P.; Vanghyseghem, H.; Parris, J. E.; Miller, S. L.

1991-01-01

In order to study the production of organic compounds in plasmas (and shocks), various mixtures of N2, CH4, and H2, modeling the atmosphere of Titan, were exposed to discrete sparks, laser-induced plasmas (LIP) and ultraviolet light. The yields of HCN and simple hydrocarbons were measured and compared to those calculated from a simple quenched thermodynamic equilibrium model. The agreement between experiment and theory was fair for HCN and C2H2. However, the yields of C2H6 and other hydrocarbons were much higher than those predicted by the model. Our experiments suggest that photolysis by ultraviolet light from the plasma is an important process in the synthesis. This was confirmed by the photolysis of gas samples exposed to the light, but not to the plasma or shock waves. The results of these experiments demonstrate that, in addition to the well-known efficient synthesis of organic compounds in plasmas, the yields of saturated species, e.g., ethane, may be higher than predicted by theory and that LIP provide a convenient and clean way of simulating planetary lightning and impact plasmas in the laboratory.

Overview of NASA's microgravity combustion science and fire safety program

NASA Technical Reports Server (NTRS)

Ross, Howard D.

1993-01-01

The study of fundamental combustion processes in a microgravity environment is a relatively new scientific endeavor. A few simple, precursor experiments were conducted in the early 1970's. Today the advent of the U.S. space shuttle and the anticipation of the Space Station Freedom provide for scientists and engineers a special opportunity -- in the form of long duration microgravity laboratories -- and need -- in the form of spacecraft fire safety and a variety of terrestrial applications -- to pursue fresh insight into the basic physics of combustion. Through microgravity, a new range of experiments can be performed since: (1) Buoyancy-induced flows are nearly eliminated; (2) Normally obscured forces and flows may be isolated; (3) Gravitational settling or sedimentation is nearly eliminated; and (4) Larger time or length scales in experiments become permissible.

Experimental constraints on the origin of chondrules

NASA Astrophysics Data System (ADS)

Boynton, W. V.; Drake; Hildebrand; Jones; Lewis; Treiman; Wark

1987-11-01

Chrondule formation was an important (perhaps ubiguitous) process in the early solar system, yet their origins remain elusive. Some points, however, are clear. The precursor material of chondules (dust) was rapidly heated at rates of perhaps thousands of degrees per second and was cooled more slowly. It was proposed to investigate chondrule formation in the Space Station environment via a dust-box (a chamber in which dust can be suspended, heated, and cooled. A microgravity environment is conducive to this kind of experiment because of the significant retardation of settling rates compared with a terrestrial laboratory environment. These long-duration experiments might require the development of technologies to counteract even the small, but finite and permanent gravitation field of the Space Station. Simple, but interesting experiments on dust suspensions immediately present themselves.

The Effects of Neutral Gas Release on Vehicle Charging: Experiment and Theory

NASA Astrophysics Data System (ADS)

Walker, D. N.; Amatucci, W. E.; Bowles, J. H.; Fernsler, R. F.; Siefring, C. L.; Antoniades, J. A.; Keskinen, M. J.

1998-11-01

This paper describes an experimental and theoretical research effort related to the mitigation of spacecraft charging by Neutral Gas Release (NGR). The Space Power Experiments Aboard Rockets programs (SPEAR I and III) [Mandel et al., 1998; Berg et al., 1995] and other earlier efforts have demonstrated that NGR is an effective method of controlling discharges in space. The laboratory experimentswere conducted in the large volume Space Physics Simulation Chamber (SPSC) at the Naval Research Laboratory (NRL). A realistic near-earth space environment can be simulated in this device for whichminimumscalingneeds to be performedtorelate the data to space plasma regimes. This environment is similar to that encountered by LEO spacecraft, e.g., the Space Station, Shuttle, and high inclination satellites. The experimental arrangement consists of an aluminum cylinder which can be biased to high negative voltage (0.4 kV

Electrostatic dust transport and Apollo 17 LEAM experiment. [Lunar Ejecta And Meteorite

NASA Technical Reports Server (NTRS)

Rhee, J. W.; Berg, O. E.; Wolf, H.

1977-01-01

The Lunar Ejecta and Meteorite (LEAM) experiment has been in operation since December 1973 when it was deployed in the Taurus-Littrow region of the moon by the Apollo 17 crew. A specialized analysis based on more than twenty-two lunations of the impact data shows that all of the events recorded by the sensors during the terminator passages are essentially lunar surface microparticles carrying a high electrostatic charge. Charged lunar fines held in place by adhesive forces can be ejected into space if the electrostatic stress exceeds the adhesive strength. A simple laboratory test demonstrated that this soil transport can indeed take place at the lunar terminator and in the vicinity of it.

Territoriality and Conflict Avoidance Explain Asociality (Solitariness) of the Endosymbiotic Pea Crab Tunicotheres moseri

PubMed Central

Ambrosio, Louis J.; Baeza, J. Antonio

2016-01-01

Host monopolization theory predicts symbiotic organisms inhabiting morphologically simple, relatively small and scarce hosts to live solitarily as a result of territorial behaviors. We tested this prediction with Tunicotheres moseri, an endosymbiotic crab dwelling in the atrial chamber of the morphologically simple, small, and relatively scarce ascidian Styela plicata. As predicted, natural populations of T. moseri inhabit ascidian hosts solitarily with greater frequency than expected by chance alone. Furthermore, laboratory experiments demonstrated that intruder crabs take significantly longer to colonize previously infected compared to uninfected hosts, indicating as expected, that resident crabs exhibit monopolization behaviors. While territoriality does occur, agonistic behaviors employed by T. moseri do not mirror the overt behaviors commonly reported for other territorial crustaceans. Documented double and triple cohabitations in the field coupled with laboratory observations demonstrating the almost invariable success of intruder crabs colonizing occupied hosts, suggest that territoriality is ineffective in completely explaining the solitary social habit of this species. Additional experiments showed that T. moseri juveniles and adults, when searching for ascidians use chemical cues to avoid hosts occupied by conspecifics. This conspecific avoidance behavior reported herein is a novel strategy most likely employed to preemptively resolve costly territorial conflicts. In general, this study supports predictions central to host monopolization theory, but also implies that alternative behavioral strategies (i.e., conflict avoidance) may be more important than originally thought in explaining the host use pattern of symbiotic organisms. PMID:26910474

Territoriality and Conflict Avoidance Explain Asociality (Solitariness) of the Endosymbiotic Pea Crab Tunicotheres moseri.

PubMed

Ambrosio, Louis J; Baeza, J Antonio

2016-01-01

Host monopolization theory predicts symbiotic organisms inhabiting morphologically simple, relatively small and scarce hosts to live solitarily as a result of territorial behaviors. We tested this prediction with Tunicotheres moseri, an endosymbiotic crab dwelling in the atrial chamber of the morphologically simple, small, and relatively scarce ascidian Styela plicata. As predicted, natural populations of T. moseri inhabit ascidian hosts solitarily with greater frequency than expected by chance alone. Furthermore, laboratory experiments demonstrated that intruder crabs take significantly longer to colonize previously infected compared to uninfected hosts, indicating as expected, that resident crabs exhibit monopolization behaviors. While territoriality does occur, agonistic behaviors employed by T. moseri do not mirror the overt behaviors commonly reported for other territorial crustaceans. Documented double and triple cohabitations in the field coupled with laboratory observations demonstrating the almost invariable success of intruder crabs colonizing occupied hosts, suggest that territoriality is ineffective in completely explaining the solitary social habit of this species. Additional experiments showed that T. moseri juveniles and adults, when searching for ascidians use chemical cues to avoid hosts occupied by conspecifics. This conspecific avoidance behavior reported herein is a novel strategy most likely employed to preemptively resolve costly territorial conflicts. In general, this study supports predictions central to host monopolization theory, but also implies that alternative behavioral strategies (i.e., conflict avoidance) may be more important than originally thought in explaining the host use pattern of symbiotic organisms.

Attenuation of radiation from distributed gamma sources as a function of wall thickness of a concrete blockhouse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmoke, M. A.; Rexroad, R. E.; Tiller, H. J.

1963-06-15

The experiment described constitutes part of the shielding program conducted by Army Nuclear Defense Laboratory and was designed to experimentally verify theoretical calculations used to predict the amount of radiation protection afforded by above-ground structures in a fallout radiation field. This method requires the knowledge of some physical parameters of a structure such as mass thickness of the walls and the geometric orientation of the detectors within the structure. From this information, a reduction factor for any given structure may be calculated. This Laboratory's experimental program was initially begun by measuring the attenuation of a simple structure with no complicatingmore » internal or external geometries and will proceed to more complex structures with basements, interior partitions, and upper floors. (auth)« less

Determination of the static friction coefficient from circular motion

NASA Astrophysics Data System (ADS)

Molina-Bolívar, J. A.; Cabrerizo-Vílchez, M. A.

2014-07-01

This paper describes a physics laboratory exercise for determining the coefficient of static friction between two surfaces. The circular motion of a coin placed on the surface of a rotating turntable has been studied. For this purpose, the motion is recorded with a high-speed digital video camera recording at 240 frames s-1, and the videos are analyzed using Tracker video-analysis software, allowing the students to dynamically model the motion of the coin. The students have to obtain the static friction coefficient by comparing the centripetal and maximum static friction forces. The experiment only requires simple and inexpensive materials. The dynamics of circular motion and static friction forces are difficult for many students to understand. The proposed laboratory exercise addresses these topics, which are relevant to the physics curriculum.

Designing easy DNA extraction: Teaching creativity through laboratory practice.

PubMed

Susantini, Endang; Lisdiana, Lisa; Isnawati; Tanzih Al Haq, Aushia; Trimulyono, Guntur

2017-05-01

Subject material concerning Deoxyribose Nucleic Acid (DNA) structure in the format of creativity-driven laboratory practice offers meaningful learning experience to the students. Therefore, a laboratory practice in which utilizes simple procedures and easy-safe-affordable household materials should be promoted to students to develop their creativity. This study aimed to examine whether designing and conducting DNA extraction with household materials could foster students' creative thinking. We also described how this laboratory practice affected students' knowledge and views. A total of 47 students participated in this study. These students were grouped and asked to utilize available household materials and modify procedures using hands-on worksheet. Result showed that this approach encouraged creative thinking as well as improved subject-related knowledge. Students also demonstrated positive views about content knowledge, social skills, and creative thinking skills. This study implies that extracting DNA with household materials is able to develop content knowledge, social skills, and creative thinking of the students. © 2016 by The International Union of Biochemistry and Molecular Biology, 45(3):216-225, 2017. © 2016 The International Union of Biochemistry and Molecular Biology.

Developing and Implementing a Simple, Affordable Hydrogen Fuel Cell Laboratory in Introductory Chemistry

ERIC Educational Resources Information Center

Klara, Kristina; Hou, Ning; Lawman, Allison; Wu, Liheng; Morrill, Drew; Tente, Alfred; Wang, Li-Qiong

2014-01-01

A simple, affordable hydrogen proton exchange membrane (PEM) fuel cell laboratory was developed through a collaborative effort between faculty and undergraduate students at Brown University. It has been incorporated into the introductory chemistry curriculum and successfully implemented in a class of over 500 students per academic year for over 3…

A simple technique for maintaining Simulium adults, including onchocerciasis vectors, under artificial conditions*

PubMed Central

Raybould, John N.; Mhiddin, Haji K.

1974-01-01

The maintenance of Simulium adults in the laboratory is necessary for many experimental investigations and is a prerequisite to laboratory colonization. A simple technique for this purpose is described in which each fly is kept separately in a hole bored in a block of expanded polystyrene. ImagesFig. 1 PMID:4549353

Behavior of Shape Memory Epoxy Foams in Microgravity: Experimental Results of STS-134 Mission

NASA Astrophysics Data System (ADS)

Santo, Loredana; Quadrini, Fabrizio; Squeo, Erica Anna; Dolce, Ferdinando; Mascetti, Gabriele; Bertolotto, Delfina; Villadei, Walter; Ganga, Pier Luigi; Zolesi, Valfredo

2012-09-01

Shape memory epoxy foams were used for an experiment on the International Space Station to evaluate the feasibility of their use for building multi-functional composite structures. A small equipment was designed and built to simulate the actuation of simple devices in micro-gravity conditions: three different configurations (compression, bending and torsion) were chosen during the memory step of the foams so as to produce their recovery on ISS. Two systems were used for the experimentation to avoid damages of the flight model during laboratory tests; however a single ground experiment was performed also on the flight model before the mission. Micro-gravity does not affect the ability of the foams to recover their shape but it poses strong limits for the heating system design because of the difference in heat transfer on earth and in orbit. A full recovery of the foam samples was not achieved due to some limitations in the maximum allowable temperature on ISS for safety reasons: anyway a 70% recovery was also measured at a temperature of 110°C. Ground laboratory experiments showed that 100% recovery could be reached by increasing the maximum temperature to 120°C. Experiment results have provided many useful information for the designing of a new structural composite actuator by using shape memory foams.

Laboratory experiment of seismic cycles using compliant viscoelastic materials

NASA Astrophysics Data System (ADS)

Yamaguchi, T.

2016-12-01

It is well known that surface asperities at fault interfaces play an essential role in stick-slip friction. There have been many laboratory experiments conducted using rocks and some analogue materials to understand the effects of asperities and the underlying mechanisms. Among such materials, soft polymer gels have great advantages of slowing down propagating rupture front speed as well as shear wave speed: it facilitates observation of the dynamic rupture behavior. However, most experiments were done with bimaterial interfaces (combination of soft and hard materials) and there are few experiments with an identical (gel on gel) setup. Furthermore, there have been also few studies mentioning the link between local asperity contact and macroscopic dynamic rupture behavior. In this talk, we report our experimental studies on stick-slip friction between gels having controlled artificial asperities. We show that, depending on number density and configuration randomness of the asperities, the rupture behavior greatly changes: when the asperities are located periodically with optimum number densities, fast rupture propagation occurs, while slow and heterogeneous slip behavior is observed for samples having randomly located asperities. We discuss the importance of low frequency (large wavelength) excitation of the normal displacement contributing to weakening the fault interface. We also discuss the observed regular to slow slip transition with a simple model.

FY05 FM Dial Summary Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harper, Warren W.; Strasburg, Jana D.; Golovich, Elizabeth C.

2005-12-01

Pacific Northwest National Laboratory's Infrared Sensors team is focused on developing methods for standoff detection of nuclear proliferation. In FY05, PNNL continued the development of the FM DIAL (frequency-modulated differential absorption LIDAR) experiment. Additional improvements to the FM DIAL trailer provided greater stability during field campaigns which made it easier to explore new locations for field campaigns. In addition to the Hanford Townsite, successful experiments were conducted at the Marine Science Laboratory in Sequim, WA and the Nevada Test Site located outside Las Vegas, NV. The range of chemicals that can be detected by FM DIAL has also increased. Priormore » to FY05, distributed feedback quantum cascade lasers (DFB-QCL) were used in the FM DIAL experiments. With these lasers, only simple chemicals with narrow (1-2 cm-1) absorption spectra, such as CO2 and N2O, could be detected. Fabry-Perot (FP) QC lasers have much broader spectra (20-40 cm-1) which allows for the detection of larger chemicals and a wider array of chemicals that can be detected. A FP-QCL has been characterized and used during initial studies detecting DMMP (dimethyl methylphosphonate).« less

A simple scaled down system to mimic the industrial production of first generation fuel ethanol in Brazil.

PubMed

Raghavendran, Vijayendran; Basso, Thalita Peixoto; da Silva, Juliana Bueno; Basso, Luiz Carlos; Gombert, Andreas Karoly

2017-07-01

Although first-generation fuel ethanol is produced in Brazil from sugarcane-based raw materials with high efficiency, there is still little knowledge about the microbiology, the biochemistry and the molecular mechanisms prevalent in the non-aseptic fermentation environment. Learning-by-doing has hitherto been the strategy to improve the process so far, with further improvements requiring breakthrough technologies. Performing experiments at an industrial scale are often expensive, complicated to set up and difficult to reproduce. Thus, developing an appropriate scaled down system for this process has become a necessity. In this paper, we present the design and demonstration of a simple and effective laboratory-scale system mimicking the industrial process used for first generation (1G) fuel ethanol production in the Brazilian sugarcane mills. We benchmarked this system via the superior phenotype of the Saccharomyces cerevisiae PE-2 strain, compared to other strains from the same species: S288c, baker's yeast, and CEN.PK113-7D. We trust that such a system can be easily implemented in different laboratories worldwide, and will allow a better understanding of the S. cerevisiae strains that can persist and dominate in this industrial, non-aseptic and peculiar environment.

Using Crickets to Introduce Neurophysiology to Early Undergraduate Students

PubMed Central

Dagda, Ruben K.; Thalhauser, Rachael M.; Dagda, Raul; Marzullo, Timothy C.; Gage, Gregory J.

2013-01-01

Anatomy and physiology instructors often face the daunting task of teaching the principles of neurophysiology as part of a laboratory course with very limited resources. Teaching neurophysiology can be a difficult undertaking as sophisticated electrophysiology and data acquisition equipment is often financially out-of-reach for two-year institutions, and for many preparations, instructors need to be highly skilled in electrophysiology techniques when teaching hands-on laboratories. In the absence of appropriate laboratory tools, many undergraduate students have difficulty understanding concepts related to neurophysiology. The cricket can serve as a reliable invertebrate model to teach the basic concepts of neurophysiology in the educational laboratory. In this manuscript, we describe a series of hands-on, demonstrative, technologically simple, and affordable laboratory activities that will help undergraduate students gain an understanding of the principles of neurophysiology. By using the cerci ganglion and leg preparation, students can quantify extracellular neural activity in response to sensory stimulation, understand the principles of rate coding and somatotopy, perform electrical microstimulation to understand the threshold of sensory stimulation, and do pharmacological manipulation of neuronal activity. We describe the utility of these laboratory activities, provide a convenient protocol for quantifying extracellular recordings, and discuss feedback provided by undergraduate students with regards to the quality of the educational experience after performing the lab activities. PMID:24319394

Morpho-dynamics of mountain streams: from laboratory experiments to field observations

NASA Astrophysics Data System (ADS)

Mettra, François; Lane, Stuart Nicholas; Heyman, Joris; Ancey, Christophe

2017-04-01

Due to the complexity of mountain stream evolution and its causes, it is judicious to conduct flume experiments to better understand the morpho-dynamics of steep river channels. A series of long-term experiments under steady conditions revealed the high internal variability of transport processes (including erosion and deposition events). In particular, high fluctuations over time of the sediment volume stored in the channel (or released from the channel) were observed for the steepest channel experiments at intermittent transport conditions. These conditions imply an autogenic regulation of the sediment transport process. When these were extended to non-steady conditions, repeated flood events suggested a hysteresis effect on sediment transport but where the forcing frequency (of the repeated floods) plays an important role in the response of the channel system. The results are compared with preliminary field observations from continuous measurements in Swiss Alpine rivers. Simple mechanisms of steep river channel behavior are proposed.

The `Chocolate Experiment' - A Demonstration of Radiation Absorption by Different Colored Surfaces

NASA Astrophysics Data System (ADS)

Fung, Dennis

2015-12-01

In the typical "cookbook" experiment comparing the radiation absorption rates of different colored surfaces, students' hands are commonly used as a measurement instrument to demonstrate that dull black and silvery surfaces are good and poor absorbers of radiation, respectively. However, college students are often skeptical about using their bare hands in this experiment because they learned in early science lessons that skin is not a reliable detector of heat transfer. Moreover, when the experiment is conducted in a school laboratory, it is often difficult for students to perceive the slight differences in heat transfer on the dull black and silvery aluminum leaves attached to their hands. Rather than replacing students' bare hands with such sophisticated apparatus as a data logger and temperature probe, I suggest using a simple (and delicious!) low-cost instrument, i.e., chocolate, which simply melts when it receives radiation.

Towards a representation of priming on soil carbon decomposition in the global land biosphere model ORCHIDEE (version 1.9.5.2)

NASA Astrophysics Data System (ADS)

Guenet, Bertrand; Esteban Moyano, Fernando; Peylin, Philippe; Ciais, Philippe; Janssens, Ivan A.

2016-03-01

Priming of soil carbon decomposition encompasses different processes through which the decomposition of native (already present) soil organic matter is amplified through the addition of new organic matter, with new inputs typically being more labile than the native soil organic matter. Evidence for priming comes from laboratory and field experiments, but to date there is no estimate of its impact at global scale and under the current anthropogenic perturbation of the carbon cycle. Current soil carbon decomposition models do not include priming mechanisms, thereby introducing uncertainty when extrapolating short-term local observations to ecosystem and regional to global scale. In this study we present a simple conceptual model of decomposition priming, called PRIM, able to reproduce laboratory (incubation) and field (litter manipulation) priming experiments. Parameters for this model were first optimized against data from 20 soil incubation experiments using a Bayesian framework. The optimized parameter values were evaluated against another set of soil incubation data independent from the ones used for calibration and the PRIM model reproduced the soil incubations data better than the original, CENTURY-type soil decomposition model, whose decomposition equations are based only on first-order kinetics. We then compared the PRIM model and the standard first-order decay model incorporated into the global land biosphere model ORCHIDEE (Organising Carbon and Hydrology In Dynamic Ecosystems). A test of both models was performed at ecosystem scale using litter manipulation experiments from five sites. Although both versions were equally able to reproduce observed decay rates of litter, only ORCHIDEE-PRIM could simulate the observed priming (R2 = 0.54) in cases where litter was added or removed. This result suggests that a conceptually simple and numerically tractable representation of priming adapted to global models is able to capture the sign and magnitude of the priming of litter and soil organic matter.

Towards a representation of priming on soil carbon decomposition in the global land biosphere model ORCHIDEE (version 1.9.5.2)

NASA Astrophysics Data System (ADS)

Guenet, B.; Moyano, F. E.; Peylin, P.; Ciais, P.; Janssens, I. A.

2015-10-01

Priming of soil carbon decomposition encompasses different processes through which the decomposition of native (already present) soil organic matter is amplified through the addition of new organic matter, with new inputs typically being more labile than the native soil organic matter. Evidence for priming comes from laboratory and field experiments, but to date there is no estimate of its impact at global scale and under the current anthropogenic perturbation of the carbon cycle. Current soil carbon decomposition models do not include priming mechanisms, thereby introducing uncertainty when extrapolating short-term local observations to ecosystem and regional to global scale. In this study we present a simple conceptual model of decomposition priming, called PRIM, able to reproduce laboratory (incubation) and field (litter manipulation) priming experiments. Parameters for this model were first optimized against data from 20 soil incubation experiments using a Bayesian framework. The optimized parameter values were evaluated against another set of soil incubation data independent from the ones used for calibration and the PRIM model reproduced the soil incubations data better than the original, CENTURY-type soil decomposition model, whose decomposition equations are based only on first order kinetics. We then compared the PRIM model and the standard first order decay model incorporated into the global land biosphere model ORCHIDEE. A test of both models was performed at ecosystem scale using litter manipulation experiments from 5 sites. Although both versions were equally able to reproduce observed decay rates of litter, only ORCHIDEE-PRIM could simulate the observed priming (R2 = 0.54) in cases where litter was added or removed. This result suggests that a conceptually simple and numerically tractable representation of priming adapted to global models is able to capture the sign and magnitude of the priming of litter and soil organic matter.

Characterization of blocks impacts from acoustic emissions: insights from laboratory experiments

NASA Astrophysics Data System (ADS)

Farin, Maxime; Mangeney, Anne; de Rosny, Julien; Toussaint, Renaud; Shapiro, Nikolaï

2014-05-01

Rockfalls, debris flows and rock avalanches represent a major natural hazard for the population in mountainous, volcanic and coastal areas but their direct observation on the field is very dangerous. Recent studies showed that gravitational instabilities can be detected and characterized (volume, duration,...) thanks to the seismic signal they generate. In an avalanche, individual block bouncing and rolling on the ground are expected to generated signals of higher frequencies than the main flow spreading. The identification of the time/frequency signature of individual blocks in the recorded signal remains however difficult. Laboratory experiments were conducted to investigate the acoustic signature of diverse simple sources corresponding to grains falling over thin plates of plexiglas and glass and over rock blocks. The elastic energy emitted by a single bouncing bead into the support was first quantitatively estimated and compared to the potential energy of fall and to the potential energy change during the shock. We obtained simple scaling laws relating the impactor characteristics (size, height of fall, material,...) to the elastic energy and spectral content. Next, we consider the collapse of granular columns made of steel spherical beads onto hard substrates. Initially, these columns were held by a magnetic field allowing to suppress suddenly the cohesion between the beads, and thus to minimize friction effects that would arise from side walls. We varied systematically the column volume, the column aspect ratio (height over length) and the grain size. This is shown to affect the signal envelope and frequency content. In the experiments, accelerometers (1 Hz to 56 kHz) were used to record the signals in a wide frequency range. The experiments were also monitored optically using fast cameras. Eventually, we looked at what types of features in the signal are affected by individual impacts, rolling of beads or by the large scale geometry of the avalanche.

Data management in the modern structural biology and biomedical research environment.

PubMed

Zimmerman, Matthew D; Grabowski, Marek; Domagalski, Marcin J; Maclean, Elizabeth M; Chruszcz, Maksymilian; Minor, Wladek

2014-01-01

Modern high-throughput structural biology laboratories produce vast amounts of raw experimental data. The traditional method of data reduction is very simple-results are summarized in peer-reviewed publications, which are hopefully published in high-impact journals. By their nature, publications include only the most important results derived from experiments that may have been performed over the course of many years. The main content of the published paper is a concise compilation of these data, an interpretation of the experimental results, and a comparison of these results with those obtained by other scientists.Due to an avalanche of structural biology manuscripts submitted to scientific journals, in many recent cases descriptions of experimental methodology (and sometimes even experimental results) are pushed to supplementary materials that are only published online and sometimes may not be reviewed as thoroughly as the main body of a manuscript. Trouble may arise when experimental results are contradicting the results obtained by other scientists, which requires (in the best case) the reexamination of the original raw data or independent repetition of the experiment according to the published description of the experiment. There are reports that a significant fraction of experiments obtained in academic laboratories cannot be repeated in an industrial environment (Begley CG & Ellis LM, Nature 483(7391):531-3, 2012). This is not an indication of scientific fraud but rather reflects the inadequate description of experiments performed on different equipment and on biological samples that were produced with disparate methods. For that reason the goal of a modern data management system is not only the simple replacement of the laboratory notebook by an electronic one but also the creation of a sophisticated, internally consistent, scalable data management system that will combine data obtained by a variety of experiments performed by various individuals on diverse equipment. All data should be stored in a core database that can be used by custom applications to prepare internal reports, statistics, and perform other functions that are specific to the research that is pursued in a particular laboratory.This chapter presents a general overview of the methods of data management and analysis used by structural genomics (SG) programs. In addition to a review of the existing literature on the subject, also presented is experience in the development of two SG data management systems, UniTrack and LabDB. The description is targeted to a general audience, as some technical details have been (or will be) published elsewhere. The focus is on "data management," meaning the process of gathering, organizing, and storing data, but also briefly discussed is "data mining," the process of analysis ideally leading to an understanding of the data. In other words, data mining is the conversion of data into information. Clearly, effective data management is a precondition for any useful data mining. If done properly, gathering details on millions of experiments on thousands of proteins and making them publicly available for analysis-even after the projects themselves have ended-may turn out to be one of the most important benefits of SG programs.

Psychosocial stress based on public speech in humans: is there a real life/laboratory setting cross-adaptation?

PubMed

Jezova, D; Hlavacova, N; Dicko, I; Solarikova, P; Brezina, I

2016-07-01

Repeated or chronic exposure to stressors is associated with changes in neuroendocrine responses depending on the type, intensity, number and frequency of stress exposure as well as previous stress experience. The aim of the study was to test the hypothesis that salivary cortisol and cardiovascular responses to real-life psychosocial stressors related to public performance can cross-adapt with responses to psychosocial stress induced by public speech under laboratory setting. The sample consisted of 22 healthy male volunteers, which were either actors, more precisely students of dramatic arts or non-actors, students of other fields. The stress task consisted of 15 min anticipatory preparation phase and 15 min of public speech on an emotionally charged topic. The actors, who were accustomed to public speaking, responded with a rise in salivary cortisol as well as blood pressure to laboratory public speech. The values of salivary cortisol, systolic blood pressure and state anxiety were lower in actors compared to non-actors. Unlike non-actors, subjects with experience in public speaking did not show stress-induced rise in the heart rate. Evaluation of personality traits revealed that actors scored significantly higher in extraversion than the subjects in the non-actor group. In conclusion, neuroendocrine responses to real-life stressors in actors can partially cross-adapt with responses to psychosocial stress under laboratory setting. The most evident adaptation was at the level of heart rate responses. The public speech tasks may be of help in evaluation of the ability to cope with stress in real life in artists by simple laboratory testing.

Fluidized bed coal desulfurization

NASA Technical Reports Server (NTRS)

Ravindram, M.

1983-01-01

Laboratory scale experiments were conducted on two high volatile bituminous coals in a bench scale batch fluidized bed reactor. Chemical pretreatment and posttreatment of coals were tried as a means of enhancing desulfurization. Sequential chlorination and dechlorination cum hydrodesulfurization under modest conditions relative to the water slurry process were found to result in substantial sulfur reductions of about 80%. Sulfur forms as well as proximate and ultimate analyses of the processed coals are included. These studies indicate that a fluidized bed reactor process has considerable potential for being developed into a simple and economic process for coal desulfurization.

Foucault's method for measuring the speed of light with modern apparatus

NASA Astrophysics Data System (ADS)

Vörös, Zoltán; Weihs, Gregor

2015-05-01

In this paper, we introduce two simple and inexpensive, yet quite accurate versions of the well-known Foucault method for measuring the speed of light. In a compact footprint of just 20 cm by 270 cm with readily available laboratory items, a rotating mirror taken from a laser printer, and a webcam, we obtained c=296\\720+/- 3000 km s-1, and c=302\\295+/- 3000 km s-1, respectively, both within less than a per cent of the defined value. The experiment also prepares students for extracting data through image processing.

Spatiotemporal Dynamics of Bumblebees Foraging under Predation Risk

NASA Astrophysics Data System (ADS)

Lenz, Friedrich; Ings, Thomas C.; Chittka, Lars; Chechkin, Aleksei V.; Klages, Rainer

2012-03-01

We analyze 3D flight paths of bumblebees searching for nectar in a laboratory experiment with and without predation risk from artificial spiders. For the flight velocities we find mixed probability distributions reflecting the access to the food sources while the threat posed by the spiders shows up only in the velocity correlations. The bumblebees thus adjust their flight patterns spatially to the environment and temporally to predation risk. Key information on response to environmental changes is contained in temporal correlation functions, as we explain by a simple emergent model.

Proof of concept of a simple computer-assisted technique for correcting bone deformities.

PubMed

Ma, Burton; Simpson, Amber L; Ellis, Randy E

2007-01-01

We propose a computer-assisted technique for correcting bone deformities using the Ilizarov method. Our technique is an improvement over prior art in that it does not require a tracking system, navigation hardware and software, or intraoperative registration. Instead, we rely on a postoperative CT scan to obtain all of the information necessary to plan the correction and compute a correction schedule for the patient. Our laboratory experiments using plastic phantoms produced deformity corrections accurate to within 3.0 degrees of rotation and 1 mm of lengthening.

A new modelling approach for zooplankton behaviour

NASA Astrophysics Data System (ADS)

Keiyu, A. Y.; Yamazaki, H.; Strickler, J. R.

We have developed a new simulation technique to model zooplankton behaviour. The approach utilizes neither the conventional artificial intelligence nor neural network methods. We have designed an adaptive behaviour network, which is similar to BEER [(1990) Intelligence as an adaptive behaviour: an experiment in computational neuroethology, Academic Press], based on observational studies of zooplankton behaviour. The proposed method is compared with non- "intelligent" models—random walk and correlated walk models—as well as observed behaviour in a laboratory tank. Although the network is simple, the model exhibits rich behavioural patterns similar to live copepods.

Thawing of ice in porous space of building materials: Experimental monitoring and computational modelling

NASA Astrophysics Data System (ADS)

Kočí, Jan; Maděra, Jiří; Kočí, Václav; Hlaváčová, Zuzana; Černý, Robert

2017-11-01

A simple laboratory experiment for the determination of thermal response of a studied sample during thawing is described in the paper. The sample made of autoclaved aerated concrete was partially water saturated and frozen. Then, the temperature development during thawing was recorded, allowing to identify the time scale of the phase change process taking place inside the sample. The experimental data was then used in the inverse analysis, in order to find unknown parameters of the smoothed effective specific heat capacity model.

Estimating Fault Friction From Seismic Signals in the Laboratory

DOE PAGES

Rouet-Leduc, Bertrand; Hulbert, Claudia; Bolton, David C.; ...

2018-01-29

Nearly all aspects of earthquake rupture are controlled by the friction along the fault that progressively increases with tectonic forcing but in general cannot be directly measured. We show that fault friction can be determined at any time, from the continuous seismic signal. In a classic laboratory experiment of repeating earthquakes, we find that the seismic signal follows a specific pattern with respect to fault friction, allowing us to determine the fault's position within its failure cycle. Using machine learning, we show that instantaneous statistical characteristics of the seismic signal are a fingerprint of the fault zone shear stress andmore » frictional state. Further analysis of this fingerprint leads to a simple equation of state quantitatively relating the seismic signal power and the friction on the fault. Finally, these results show that fault zone frictional characteristics and the state of stress in the surroundings of the fault can be inferred from seismic waves, at least in the laboratory.« less

Estimating Fault Friction From Seismic Signals in the Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rouet-Leduc, Bertrand; Hulbert, Claudia; Bolton, David C.

Nearly all aspects of earthquake rupture are controlled by the friction along the fault that progressively increases with tectonic forcing but in general cannot be directly measured. We show that fault friction can be determined at any time, from the continuous seismic signal. In a classic laboratory experiment of repeating earthquakes, we find that the seismic signal follows a specific pattern with respect to fault friction, allowing us to determine the fault's position within its failure cycle. Using machine learning, we show that instantaneous statistical characteristics of the seismic signal are a fingerprint of the fault zone shear stress andmore » frictional state. Further analysis of this fingerprint leads to a simple equation of state quantitatively relating the seismic signal power and the friction on the fault. Finally, these results show that fault zone frictional characteristics and the state of stress in the surroundings of the fault can be inferred from seismic waves, at least in the laboratory.« less

The Effect of Combining Analogy-Based Simulation and Laboratory Activities on Turkish Elementary School Students' Understanding of Simple Electric Circuits

ERIC Educational Resources Information Center

Unlu, Zeynep Koyunlu; Dokme, Ibilge

2011-01-01

The purpose of this study was to investigate whether the combination of both analogy-based simulation and laboratory activities as a teaching tool was more effective than utilizing them separately in teaching the concepts of simple electricity. The quasi-experimental design that involved 66 seventh grade students from urban Turkish elementary…

A Simple System for Observing Dynamic Phase Equilibrium via an Inquiry-Based Laboratory or Demonstration

ERIC Educational Resources Information Center

Cloonan, Carrie A.; Andrew, Julie A.; Nichol, Carolyn A.; Hutchinson, John S.

2011-01-01

This article describes an activity that can be used as an inquiry-based laboratory or demonstration for either high school or undergraduate chemistry students to provide a basis for understanding both vapor pressure and the concept of dynamic phase equilibrium. The activity includes a simple setup to create a closed system of only water liquid and…

Co-variation of metabolic rates and cell-size in coccolithophores

NASA Astrophysics Data System (ADS)

Aloisi, G.

2015-04-01

Coccolithophores are sensitive recorders of environmental change. The size of their coccosphere varies in the ocean along gradients of environmental conditions and provides a key for understanding the fate of this important phytoplankton group in the future ocean. But interpreting field changes in coccosphere size in terms of laboratory observations is hard, mainly because the marine signal reflects the response of multiple morphotypes to changes in a combination of environmental variables. In this paper I examine the large corpus of published laboratory experiments with coccolithophores looking for relations between environmental conditions, metabolic rates and cell size (a proxy for coccosphere size). I show that growth, photosynthesis, and to a lesser extent calcification, co-vary with cell size when pCO2, irradiance, temperature, nitrate, phosphate and iron conditions change. With the exception of phosphate and temperature, a change from limiting to non-limiting conditions always results in an increase in cell size. An increase in phosphate or temperature produces the opposite effect. The magnitude of the coccosphere size changes observed in the laboratory is comparable to that observed in the ocean. If the biological reasons behind the environment-metabolism-size link are understood, it will be possible to use coccosphere size changes in the modern ocean and in marine sediments to investigate the fate of coccolithophores in the future ocean. This reasoning can be extended to the size of coccoliths if, as recent experiments are starting to show, coccolith size reacts to environmental change proportionally to coccosphere size. I introduce a simple model that simulates the growth rate and the size of cells forced by nitrate and phosphate concentrations. By considering a simple rule that allocates the energy flow from nutrient acquisition to cell structure (biomass) and cell maturity (biological complexity, eventually leading to cell division), the model is able to reproduce the co-variation of growth rate and cell size observed in the laboratory when these nutrients become limiting. These results support ongoing efforts to interpret coccosphere and coccolith size measurements in the context of climate change.

Role of Hydrodynamic and Mineralogical Heterogeneities on Reactive Transport Processes.

NASA Astrophysics Data System (ADS)

Luquot, L.; Garcia-Rios, M.; soler Sagarra, J.; Gouze, P.; Martinez-Perez, L.; Carrera, J.

2017-12-01

Predicting reactive transport at large scale, i.e., Darcy- and field- scale, is still challenging considering the number of heterogeneities that may be present from nm- to pore-scale. It is well documented that conventional continuum-scale approaches oversimplify and/or ignore many important aspects of rock structure, chemical reactions, fluid displacement and transport, which, as a consequence, results in uncertainties when applied to field-scale operations. The changes in flow and reactive transport across the different spatial and temporal scales are of central concern in many geological applications such as groundwater systems, geo-energy, rock building heritage and geological storage... In this presentation, we will discuss some laboratory and numerical results on how local heterogeneities (structural, hydrodynamic and mineralogical) can affect the localization and the rate of the reaction processes. Different flow through laboratory experiments using various rock samples will be presented, from simple monomineral rocks such as limestone samples, and more complex rocks composed of different minerals with a large range of kinetic reactions. A new numerical approach based on multirate water mixing approach will be presented and applied to one of the laboratory experiment in order to analyze and distinguish the effect of the mineralogy distribution and the hydrodynamic heterogeneity on the total reaction rate.

How can plants tell which way is up?

NASA Technical Reports Server (NTRS)

Kiss, J. Z.; Weise, S. E.; Kiss, H. G.

2000-01-01

Many people think of plants as essentially sessile organisms that do not actively respond to their environment. What could be further from the truth! In fact, plants are capable of a variety of movements, including the dramatic nastic responses (such as Venus fly trap closure) and the less sensational tropisms. These latter movements are directed growth responses to some type of external stimulus such as gravity (gravitropism, formerly known as geotropism) or light (phototropism). This paper describes some interesting exercises that are derived from recent work, including research that has led to experiments performed on two Space Shuttle missions in 1997 (Kiss et al. 1998). The study of tropisms can be a useful way to introduce students to plant biology in high school and introductory college courses. In our experience, students are fascinated by plant movements when they are presented in lectures and find laboratory experiences on this topic quite engaging. Laboratory work on plant tropisms can also be used to introduce important concepts in science such as hypothesis testing, quantitative analysis, and the use of statistics. The laboratory exercises described in this paper involve the higher plant Arabidopsis thaliana, which has become an important organism in molecular biology research and is the focus of an international plant genome project. Based on the material presented here, a number of plant gravitropism laboratory exercises with Arabidopsis that are simple in terms of equipment/materials and procedures can be developed. These exercises are robust in that they work well even in the hands of introductory students, and they can be expanded according to the individual instructor's needs. This paper describes two exercises that have been performed by beginning college students, and these exercises can easily be performed in biology classes in most high school settings.

Metabolomics for undergraduates: Identification and pathway assignment of mitochondrial metabolites.

PubMed

Marques, Ana Patrícia; Serralheiro, Maria Luisa; Ferreira, António E N; Freire, Ana Ponces; Cordeiro, Carlos; Silva, Marta Sousa

2016-01-01

Metabolomics is a key discipline in systems biology, together with genomics, transcriptomics, and proteomics. In this omics cascade, the metabolome represents the biochemical products that arise from cellular processes and is often regarded as the final response of a biological system to environmental or genetic changes. The overall screening approach to identify all the metabolites in a given biological system is called metabolic fingerprinting. Using high-resolution and high-mass accuracy mass spectrometry, large metabolome coverage, sensitivity, and specificity can be attained. Although the theoretical concepts of this methodology are usually provided in life-science programs, hands-on laboratory experiments are not usually accessible to undergraduate students. Even if the instruments are available, there are not simple laboratory protocols created specifically for teaching metabolomics. We designed a straightforward hands-on laboratory experiment to introduce students to this methodology, relating it to biochemical knowledge through metabolic pathway mapping of the identified metabolites. This study focuses on mitochondrial metabolomics since mitochondria have a well-known, medium-sized cellular sub-metabolome. These features facilitate both data processing and pathway mapping. In this experiment, students isolate mitochondria from potatoes, extract the metabolites, and analyze them by high-resolution mass spectrometry (using an FT-ICR mass spectrometer). The resulting mass list is submitted to an online program for metabolite identification, and compounds associated with mitochondrial pathways can be highlighted in a metabolic network map. © 2015 The International Union of Biochemistry and Molecular Biology.

Gas Phase Chemistry and Molecular Complexity: How Far Do They Go?

NASA Astrophysics Data System (ADS)

Balucani, Nadia

2016-07-01

The accumulation of organic molecules of increasing complexity is believed to be an important step toward the emergence of life. But how massive organic synthesis could occur in primitive Earth, i.e. a water-dominated environment, is a matter of debate. Two alternative theories have been suggested so far: endogenous and exogenous synthesis. In the first theory, the synthesis of simple organic molecules having a strong prebiotic potential (simple prebiotic molecules SPMs, such as H2CO, HCN, HC3N, NH2CHO) occurred directly on our planet starting from simple parent molecules of the atmosphere, liquid water and various energy sources. Miller's experiment was a milestone in this theory, but it was later recognized that the complexity of a planet cannot be reproduced in a single laboratory experiment. Some SPMs have been identified in the N2-dominated atmosphere of Titan (a massive moon of Saturn), which is believed to be reminiscent of the primitive terrestrial atmosphere. As such, the atmosphere of Titan represents a planetary scale laboratory for the comprehension of SPM formation in an environment close enough to primitive Earth and is the current frontier in the endogenous theory exploration. In the exogenous theory, SPMs came from space, the carriers being comets, asteroids and meteorites. The rationale behind this suggestion is that plenty of SPMs have been observed in interstellar clouds (ISCs), including star-forming regions, and in small bodies like comets, asteroids and meteorites. Therefore, the basic idea is that SPMs were formed in the solar nebula, preserved during the early phases of the Solar System formation in the body of comets/asteroids/meteorites and finally delivered to Earth by cometary and meteoritic falls. In this contribution, the status of our knowledge on how SPMs can be formed in the gas phase, either in the primitive terrestrial atmosphere or in the cold nebula from which the Solar System originated, will be presented. Particular attention will be given to neutral-neutral reactions.

The shapes of fragments in hypervelocity impact experiments ranging from cratering to catastrophic disruption

NASA Astrophysics Data System (ADS)

Michikami, T.; Hagermann, A.; Kadokawa, T.; Yoshida, A.; Shimada, A.; Hasegawa, S.; Tsuchiyama, A.

2015-12-01

Laboratory impact experiments have found that the shapes of impact fragments as defined by axes a, b and c, these being the maximum dimensions of the fragment in three mutually orthogonal planes (a ≥ b ≥ c) are distributed around mean values of the axial ratios b/a ~0.7 and c/a ~0.5, i.e., corresponding to a : b: c in the simple proportion 2: √2: 1. The shape distributions of some boulders on asteroid Eros, the small- and fast-rotating asteroids (diameter < 200 m and rotation period < 1 h), and asteroids in young families, are similar to those of laboratory fragments in catastrophic disruption. However, the shapes of laboratory fragments were obtained from the experiments that　resulted in catastrophic disruption, a process that is different from impact cratering. In order to systematically investigate the shapes of fragments in the range from impact cratering to catastrophic disruption, impact experiments for basalt targets 5 to 15 cm in size were performed. A total of 28 impact experiments were carried out by a spherical nylon projectile (diameter 7.14 mm) perpendicularly into the target surface at velocities of 1.6 to 7.0 km/s. More than 13,000 fragments with b ≥ 4 mm generated in the impact experiments were measured. In the experiments, the mean value of c/a in each impact decreases with decreasing impact energy per unit target mass. For instance, the mean value of c/a in an impact cratering event is nearly 0.2, which is less than that c/a in a catastrophic disruption (~0.5). To apply the experimental results to real collisions on asteroids, we investigated the shapes of 21 arbitrarily selected boulders (> 8 m) on asteroid Itokawa. The mean value of c/a of these boulders is 0.46, which is similar to the value for catastrophic disruption. This implies that the parent body of Itokawa could have experienced a catastrophic disruption.

Development of Supersonic Combustion Experiments for CFD Modeling

NASA Technical Reports Server (NTRS)

Baurle, Robert; Bivolaru, Daniel; Tedder, Sarah; Danehy, Paul M.; Cutler, Andrew D.; Magnotti, Gaetano

2007-01-01

This paper describes the development of an experiment to acquire data for developing and validating computational fluid dynamics (CFD) models for turbulence in supersonic combusting flows. The intent is that the flow field would be simple yet relevant to flows within hypersonic air-breathing engine combustors undergoing testing in vitiated-air ground-testing facilities. Specifically, it describes development of laboratory-scale hardware to produce a supersonic combusting coaxial jet, discusses design calculations, operability and types of flames observed. These flames are studied using the dual-pump coherent anti- Stokes Raman spectroscopy (CARS) - interferometric Rayleigh scattering (IRS) technique. This technique simultaneously and instantaneously measures temperature, composition, and velocity in the flow, from which many of the important turbulence statistics can be found. Some preliminary CARS data are presented.

A Flight Demonstration of Plasma Rocket Propulsion

NASA Technical Reports Server (NTRS)

Petro, Andrew

1999-01-01

The Advanced Space Propulsion Laboratory at the Johnson Space Center has been engaged in the development of a magneto-plasma rocket for several years. This type of rocket could be used in the future to propel interplanetary spacecraft. One advantageous feature of this rocket concept is the ability to vary its specific impulse so that it can be operated in a mode which maximizes propellant efficiency or a mode which maximizes thrust. This presentation will describe a proposed flight experiment in which a simple version of the rocket will be tested in space. In addition to the plasma rocket, the flight experiment will also demonstrate the use of a superconducting electromagnet, extensive use of heat pipes, and possibly the transfer of cryogenic propellant in space.

Assessment of the MHD capability in the ATHENA code using data from the ALEX (Argonne Liquid Metal Experiment) facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roth, P.A.

1988-10-28

The ATHENA (Advanced Thermal Hydraulic Energy Network Analyzer) code is a system transient analysis code with multi-loop, multi-fluid capabilities, which is available to the fusion community at the National Magnetic Fusion Energy Computing Center (NMFECC). The work reported here assesses the ATHENA magnetohydrodynamic (MHD) pressure drop model for liquid metals flowing through a strong magnetic field. An ATHENA model was developed for two simple geometry, adiabatic test sections used in the Argonne Liquid Metal Experiment (ALEX) at Argonne National Laboratory (ANL). The pressure drops calculated by ATHENA agreed well with the experimental results from the ALEX facility. 13 refs., 4more » figs., 2 tabs.« less

Two-dimensional atmospheric transport and chemistry model - Numerical experiments with a new advection algorithm

NASA Technical Reports Server (NTRS)

Shia, Run-Lie; Ha, Yuk Lung; Wen, Jun-Shan; Yung, Yuk L.

1990-01-01

Extensive testing of the advective scheme proposed by Prather (1986) has been carried out in support of the California Institute of Technology-Jet Propulsion Laboratory two-dimensional model of the middle atmosphere. The original scheme is generalized to include higher-order moments. In addition, it is shown how well the scheme works in the presence of chemistry as well as eddy diffusion. Six types of numerical experiments including simple clock motion and pure advection in two dimensions have been investigated in detail. By comparison with analytic solutions, it is shown that the new algorithm can faithfully preserve concentration profiles, has essentially no numerical diffusion, and is superior to a typical fourth-order finite difference scheme.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seinfeld, John H.

This project addressed the following research need in the Atmospheric System Research (ASR) Science and Program Plan: "Measurements downwind of urban sources of aerosol particles and precursor gases have shown that the mass concentration of secondary organic aerosol (SOA) can be several-fold greater than can be explained on the basis of current model calculations using observed precursor concentrations. ASR will continue conducting laboratory experiments on both gas-phase and aqueous-phase SOA formation to characterize the particle formation and the organic gases that react to form new organic aerosol material on aerosol seeds. ASR will use these experiments to guide the developmentmore » of comprehensive chemical mechanisms... to guide the development of parameterizations that are simple enough to be applied to aerosol life cycle models."« less

Measuring the interaction force between a high temperature superconductor and a permanent magnet

NASA Astrophysics Data System (ADS)

Valenzuela, S. O.; Jorge, G. A.; Rodríguez, E.

1999-11-01

Repulsive and attractive forces are both possible between a superconducting sample and a permanent magnet, and they can give rise to magnetic levitation or free-suspension phenomena, respectively. We show experiments to quantify this magnetic interaction, which represents a promising field with regard to short-term technological applications of high temperature superconductors. The measuring technique employs an electronic balance and a rare-earth magnet that induces a magnetic moment in a melt-textured YBa2Cu3O7 superconductor immersed in liquid nitrogen. The simple design of the experiments allows a fast and easy implementation in the advanced physics laboratory with a minimum cost. Actual levitation and suspension demonstrations can be done simultaneously as a help to interpret magnetic force measurements.

Effects of Contaminated Fluids on Complex Moduli in Porous Rocks; Lab and Field.

NASA Astrophysics Data System (ADS)

Spetzler, H.; Snieder, R.; Zhang, J.

2006-12-01

The interaction between fluids and porous rocks has been measured in the laboratory and in a controlled field experiment. In the laboratory we measured the static and dynamic effect of various contaminated fluids on the wettability, capillary pressure and other flow properties on geometrically simple surfaces. The characteristics of the menisci were quantified by measuring the forces required to deform and move them. Rate dependent surface tension and contact angles describe the hysteresis of the contact line motion. Finally we used geometrically complex surfaces, i.e. real rocks, and observed similar behavior. Then we did a field experiment where we could controllably irrigate a test volume and observe changes in deformation. At low deformation rates, where viscous deformation of the fluid is negligible, the dynamic hystereses of menisci deformation become the dominant mechanism for changes in complex moduli of partially fluid saturated rocks. In the laboratory for contaminated samples we observe attenuation increasing from below 1 Hz to 1 mHz, the limit of our patience in making these measurements. In the field we used microseisms and solid Earth tides as low frequency deformation sources. In the case of the tides we compare changes in observed tilt with theoretical site specific tidal tilts. Preliminary theoretical modeling suggests that indeed small changes in the moduli should be observable in changes in tilt response. In this paper we present our laboratory results and the field data and analysis to date.

A Michelson-type radio interferometer for university education

NASA Astrophysics Data System (ADS)

Koda, Jin; Barrett, James; Shafto, Gene; Slechta, Jeff; Hasegawa, Tetsuo; Hayashi, Masahiko; Metchev, Stanimir

2016-04-01

We report development of a simple and affordable radio interferometer suitable as an educational laboratory experiment. The design of this interferometer is based on the Michelson and Pease stellar optical interferometer, but instead operates at the radio wavelength of ˜11 GHz (˜2.7 cm), requiring much less stringent optical accuracy in its design and use. We utilize a commercial broadcast satellite dish and feedhorn with two flat side mirrors that slide on a ladder, providing baseline coverage. This interferometer can resolve and measure the diameter of the Sun, even on a day with marginal weather. Commercial broadcast satellites provide convenient point sources for comparison to the Sun's extended disk. The mathematical background of an adding interferometer is presented, as is its design and development, including the receiver system, and sample measurements of the Sun. Results from a student laboratory report are shown. With the increasing importance of interferometry in astronomy, the lack of educational interferometers is an obstacle to training the future generation of astronomers. This interferometer provides the hands-on experience needed to fully understand the basic concepts of interferometry.

What Can Be Learned From a Laboratory Model of Conceptual Change? Descriptive Findings and Methodological Issues

NASA Astrophysics Data System (ADS)

Ohlsson, Stellan; Cosejo, David G.

2014-07-01

The problem of how people process novel and unexpected information— deep learning (Ohlsson in Deep learning: how the mind overrides experience. Cambridge University Press, New York, 2011)—is central to several fields of research, including creativity, belief revision, and conceptual change. Researchers have not converged on a single theory for conceptual change, nor has any one theory been decisively falsified. One contributing reason is the difficulty of collecting informative data in this field. We propose that the commonly used methodologies of historical analysis, classroom interventions, and developmental studies, although indispensible, can be supplemented with studies of laboratory models of conceptual change. We introduce re- categorization, an experimental paradigm in which learners transition from one definition of a categorical concept to another, incompatible definition of the same concept, a simple form of conceptual change. We describe a re-categorization experiment, report some descriptive findings pertaining to the effects of category complexity, the temporal unfolding of learning, and the nature of the learner's final knowledge state. We end with a brief discussion of ways in which the re-categorization model can be improved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luna, R. E.

This paper provides a simple model for estimating the release of respirable aerosols resulting from an attack on a spent fuel cask using a high energy density device (HEDD). Two primary experiments have provided data on potential releases from spent fuel casks under HEDD attack. Sandia National Laboratories (SNL) conducted the first in the early 1980's and the second was sponsored by Gessellshaft fur Anlagen- and Reaktorsicherheit (GRS) in Germany and conducted in France in 1994. Both used surrogate spent fuel assemblies in real casks. The SNL experiments used un-pressurized fuel pin assemblies in a single element cask while themore » GRS tests used pressurized fuel pin assemblies in a 9-element cask. Data from the two test programs is reasonably consistent, given the differences in the experiments, but the use of the test data for prediction of releases resulting from HEDD attack requires a method for accounting for the effects of pin pressurization release and the ratio of pin plenum gas release to cask free volume (VR). To account for the effects of VR and to link the two data sources, a simple model has been developed that uses both the SNL data and the GRS data as well as recent test data on aerosols produced in experiments with single pellets subjected to HEDD effects conducted under the aegis of the International Consortium's Working Group on Sabotage of Transport and Storage Casks (WGSTSC). (authors)« less

Following Glycolysis Using 13C NMR: An Experiment Adaptable to Different Undergraduate Levels

NASA Astrophysics Data System (ADS)

Mega, T. L.; Carlson, C. B.; Cleary, D. A.

1997-12-01

This paper describes a laboratory exercise where the glycolysis of [1-13C] glucose under anaerobic conditions was followed using 13C NMR spectroscopy. The exercise is described in terms of its suitability for a variety of different undergraduate levels, although the emphasis in this paper is on its use in a n advanced chemistry laboratory course. The kinetics of the loss of glucose and the production of ethanol were investigated and found not to fit simple first or second order kinetics. In addition, the relative reaction rates of the two anomeric forms of glucose were analyzed, and it was determined that the a anomeric form reacted faster than the β anomeric form. Using proton-coupled 13C NMR, some of the metabolites were identified including ethanol (major) and glycerol (minor). Reaction and spectroscopic details are included.

Stone-age mass spectrometry: the beginnings of "SIMS" at RCA Laboratories, Princeton

NASA Astrophysics Data System (ADS)

Honig, Richard E.

1995-05-01

This paper takes you back almost half a century, to the time when mass spectrometry was young and exciting, and research was exploring new frontiers every day. Our early experiments called "sputtering of surfaces by positive ion beams", now known as "SIMS", were carried out with the simple, yet flexible instrumentation available at that time and produced many interesting results that are still valid today. Since commercial equipment did not exist in those days, just about everything had to be designed and constructed in-house - hardware as well as circuitry. Thus progress was slow, but occasional malfunctioning of a component could be readily rectified. It is gratifying to see how SIMS has developed in the interim from our early feasibility studies into a major research effort carried out worldwide in many laboratories.

[Input of a laboratory in the management of patients with Ebola virus disease and in the training of health personnel: experience of the Forecariah Ebola treatment centre (Guinea) in 2015].

PubMed

Gaüzère, B-A; Ouellet, I; Nottebrock, D; Nied, J-C; Beya-Kadiebwe, B; Camara, A K; Camara, D; Camara, M L M; Camara, M; Soumah, A; Tounkara, M K; Monteil, V; Camara, A; Bauffe, F; Camara, A; Camara, I B; Simon, B; Jaspard, M; Tran-Minh, T; L'Hériteau, F

2016-10-01

Ebola virus disease (EVD) is associated with a high lethality rate even when the afflicted are provided with good support in an Ebola treatment center (ETC). Basic laboratory tests can help to better understand the pathophysiology of the disease, to guide treatment and to establish simple protocols and procedures tailored to the practice of medicine in the context of such precarious environment for caregivers. Based on a few clinical cases of patients treated in the ETC of Forecariah, Guinea, run by the French Red Cross, this article describes the difficult conditions associated with the provision of medical practice in this challenging environment, aiming to minimize the casualties in the EVD patient and to train the health staff.

Using Ice-Cooled Condensers in Chemistry Laboratory

NASA Astrophysics Data System (ADS)

Solomon, Sally; Brook, Bryan; Rutkowsky, Susan; Bennet, Joseph

2003-03-01

An ice-cooled condenser, consisting of a jacket built around a tube open to the atmosphere with an outlet for removal of melting ice, is designed for use in academic laboratory classes. The apparatus can be used in place of standard water cooled condensers in setups where refluxing or distillation is performed. With this simple, inexpensive device there is no need for access to running water. Potential flooding due to insecure tubing is no longer a problem. The ice-cooled accessory, produced with standard glass tubing and either 14/10 or 14/20 ground glass joints, is compatible with most commercially available microscale or small scale kits. The device may even be used with an Erlenmeyer flask and a stopper or cork. Two experiments using ordinary household chemicals are suggested, one requiring refluxing and the other distillation.

Dual-domain mass-transfer parameters from electrical hysteresis: theory and analytical approach applied to laboratory, synthetic streambed, and groundwater experiments

USGS Publications Warehouse

Briggs, Martin A.; Day-Lewis, Frederick D.; Ong, John B.; Harvey, Judson W.; Lane, John W.

2014-01-01

Models of dual-domain mass transfer (DDMT) are used to explain anomalous aquifer transport behavior such as the slow release of contamination and solute tracer tailing. Traditional tracer experiments to characterize DDMT are performed at the flow path scale (meters), which inherently incorporates heterogeneous exchange processes; hence, estimated “effective” parameters are sensitive to experimental design (i.e., duration and injection velocity). Recently, electrical geophysical methods have been used to aid in the inference of DDMT parameters because, unlike traditional fluid sampling, electrical methods can directly sense less-mobile solute dynamics and can target specific points along subsurface flow paths. Here we propose an analytical framework for graphical parameter inference based on a simple petrophysical model explaining the hysteretic relation between measurements of bulk and fluid conductivity arising in the presence of DDMT at the local scale. Analysis is graphical and involves visual inspection of hysteresis patterns to (1) determine the size of paired mobile and less-mobile porosities and (2) identify the exchange rate coefficient through simple curve fitting. We demonstrate the approach using laboratory column experimental data, synthetic streambed experimental data, and field tracer-test data. Results from the analytical approach compare favorably with results from calibration of numerical models and also independent measurements of mobile and less-mobile porosity. We show that localized electrical hysteresis patterns resulting from diffusive exchange are independent of injection velocity, indicating that repeatable parameters can be extracted under varied experimental designs, and these parameters represent the true intrinsic properties of specific volumes of porous media of aquifers and hyporheic zones.

Dual-domain mass-transfer parameters from electrical hysteresis: Theory and analytical approach applied to laboratory, synthetic streambed, and groundwater experiments

NASA Astrophysics Data System (ADS)

Briggs, Martin A.; Day-Lewis, Frederick D.; Ong, John B.; Harvey, Judson W.; Lane, John W.

2014-10-01

Models of dual-domain mass transfer (DDMT) are used to explain anomalous aquifer transport behavior such as the slow release of contamination and solute tracer tailing. Traditional tracer experiments to characterize DDMT are performed at the flow path scale (meters), which inherently incorporates heterogeneous exchange processes; hence, estimated "effective" parameters are sensitive to experimental design (i.e., duration and injection velocity). Recently, electrical geophysical methods have been used to aid in the inference of DDMT parameters because, unlike traditional fluid sampling, electrical methods can directly sense less-mobile solute dynamics and can target specific points along subsurface flow paths. Here we propose an analytical framework for graphical parameter inference based on a simple petrophysical model explaining the hysteretic relation between measurements of bulk and fluid conductivity arising in the presence of DDMT at the local scale. Analysis is graphical and involves visual inspection of hysteresis patterns to (1) determine the size of paired mobile and less-mobile porosities and (2) identify the exchange rate coefficient through simple curve fitting. We demonstrate the approach using laboratory column experimental data, synthetic streambed experimental data, and field tracer-test data. Results from the analytical approach compare favorably with results from calibration of numerical models and also independent measurements of mobile and less-mobile porosity. We show that localized electrical hysteresis patterns resulting from diffusive exchange are independent of injection velocity, indicating that repeatable parameters can be extracted under varied experimental designs, and these parameters represent the true intrinsic properties of specific volumes of porous media of aquifers and hyporheic zones.

A simple eccentric stirred tank mini-bioreactor: mixing characterization and mammalian cell culture experiments.

PubMed

Bulnes-Abundis, David; Carrillo-Cocom, Leydi M; Aráiz-Hernández, Diana; García-Ulloa, Alfonso; Granados-Pastor, Marisa; Sánchez-Arreola, Pamela B; Murugappan, Gayathree; Alvarez, Mario M

2013-04-01

In industrial practice, stirred tank bioreactors are the most common mammalian cell culture platform. However, research and screening protocols at the laboratory scale (i.e., 5-100 mL) rely primarily on Petri dishes, culture bottles, or Erlenmeyer flasks. There is a clear need for simple-easy to assemble, easy to use, easy to clean-cell culture mini-bioreactors for lab-scale and/or screening applications. Here, we study the mixing performance and culture adequacy of a 30 mL eccentric stirred tank mini-bioreactor. A detailed mixing characterization of the proposed bioreactor is presented. Laser induced fluorescence (LIF) experiments and computational fluid dynamics (CFD) computations are used to identify the operational conditions required for adequate mixing. Mammalian cell culture experiments were conducted with two different cell models. The specific growth rate and the maximum cell density of Chinese hamster ovary (CHO) cell cultures grown in the mini-bioreactor were comparable to those observed for 6-well culture plates, Erlenmeyer flasks, and 1 L fully instrumented bioreactors. Human hematopoietic stem cells were successfully expanded tenfold in suspension conditions using the eccentric mini-bioreactor system. Our results demonstrate good mixing performance and suggest the practicality and adequacy of the proposed mini-bioreactor. Copyright © 2012 Wiley Periodicals, Inc.

Laboratory Activity on Sample Handling and Maintaining a Laboratory Notebook through Simple pH Measurements

ERIC Educational Resources Information Center

Erdmann, Mitzy A.; March, Joe L.

2016-01-01

Sample handling and laboratory notebook maintenance are necessary skills but can seem abstract if not presented to students in context. An introductory exercise focusing on proper sample handling, data collection and laboratory notebook keeping for the general chemistry laboratory was developed to emphasize the importance of keeping an accurate…

Enabling systematic, harmonised and large-scale biofilms data computation: the Biofilms Experiment Workbench.

PubMed

Pérez-Rodríguez, Gael; Glez-Peña, Daniel; Azevedo, Nuno F; Pereira, Maria Olívia; Fdez-Riverola, Florentino; Lourenço, Anália

2015-03-01

Biofilms are receiving increasing attention from the biomedical community. Biofilm-like growth within human body is considered one of the key microbial strategies to augment resistance and persistence during infectious processes. The Biofilms Experiment Workbench is a novel software workbench for the operation and analysis of biofilms experimental data. The goal is to promote the interchange and comparison of data among laboratories, providing systematic, harmonised and large-scale data computation. The workbench was developed with AIBench, an open-source Java desktop application framework for scientific software development in the domain of translational biomedicine. Implementation favours free and open-source third-parties, such as the R statistical package, and reaches for the Web services of the BiofOmics database to enable public experiment deposition. First, we summarise the novel, free, open, XML-based interchange format for encoding biofilms experimental data. Then, we describe the execution of common scenarios of operation with the new workbench, such as the creation of new experiments, the importation of data from Excel spreadsheets, the computation of analytical results, the on-demand and highly customised construction of Web publishable reports, and the comparison of results between laboratories. A considerable and varied amount of biofilms data is being generated, and there is a critical need to develop bioinformatics tools that expedite the interchange and comparison of microbiological and clinical results among laboratories. We propose a simple, open-source software infrastructure which is effective, extensible and easy to understand. The workbench is freely available for non-commercial use at http://sing.ei.uvigo.es/bew under LGPL license. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Simple non-laboratory- and laboratory-based risk assessment algorithms and nomogram for detecting undiagnosed diabetes mellitus.

PubMed

Wong, Carlos K H; Siu, Shing-Chung; Wan, Eric Y F; Jiao, Fang-Fang; Yu, Esther Y T; Fung, Colman S C; Wong, Ka-Wai; Leung, Angela Y M; Lam, Cindy L K

2016-05-01

The aim of the present study was to develop a simple nomogram that can be used to predict the risk of diabetes mellitus (DM) in the asymptomatic non-diabetic subjects based on non-laboratory- and laboratory-based risk algorithms. Anthropometric data, plasma fasting glucose, full lipid profile, exercise habits, and family history of DM were collected from Chinese non-diabetic subjects aged 18-70 years. Logistic regression analysis was performed on a random sample of 2518 subjects to construct non-laboratory- and laboratory-based risk assessment algorithms for detection of undiagnosed DM; both algorithms were validated on data of the remaining sample (n = 839). The Hosmer-Lemeshow test and area under the receiver operating characteristic (ROC) curve (AUC) were used to assess the calibration and discrimination of the DM risk algorithms. Of 3357 subjects recruited, 271 (8.1%) had undiagnosed DM defined by fasting glucose ≥7.0 mmol/L or 2-h post-load plasma glucose ≥11.1 mmol/L after an oral glucose tolerance test. The non-laboratory-based risk algorithm, with scores ranging from 0 to 33, included age, body mass index, family history of DM, regular exercise, and uncontrolled blood pressure; the laboratory-based risk algorithm, with scores ranging from 0 to 37, added triglyceride level to the risk factors. Both algorithms demonstrated acceptable calibration (Hosmer-Lemeshow test: P = 0.229 and P = 0.483) and discrimination (AUC 0.709 and 0.711) for detection of undiagnosed DM. A simple-to-use nomogram for detecting undiagnosed DM has been developed using validated non-laboratory-based and laboratory-based risk algorithms. © 2015 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.

Overview of the Calcium-45 Beta Spectrum Measurement at Los Alamos National Laboratory

NASA Astrophysics Data System (ADS)

Royse, Camen; Nab/UNCB Teams Collaboration

2017-09-01

One smoking gun of BSM physics would be the observation of a non-zero Fierz interference term, a feature in the beta spectrum produced by scalar and tensor couplings. Calcium-45 is an almost ideal candidate with which to search for a Fierz term. It is a pure beta emitter with a low endpoint of 256 keV and a simple decay scheme, with a 7 / 2 - -> 7 / 2 - g.s. to g.s. branching ratio of 99.9981(11)%. Isospin selection rules ensure the decay is greater than about 98.5% pure Gamow-Teller and the integrated effect of the weak magnetism over the entire spectrum is expected to be only 0.13%. An experiment designed to precisely measure the beta spectrum of Ca-45 has been run over the past two summers at Los Alamos National Laboratory. The experiment is composed of a 4 π-capture magnetic spectrometer between two segmented arrays of hexagonal silicon detectors (similar to the Nab experiment), a helium gas cooling system, front end electronics and amplifiers, and a data acquisition system which synchronizes the timing from the signals coming from both detector arrays. Data is analyzed to account for the pile-up of signals and other physical and calibration factors. An overview of the design and execution of the experiment as divided into the above topics will be presented.

Incorporating an ERP Project into Undergraduate Instruction

PubMed Central

Nyhus, Erika; Curtis, Nancy

2016-01-01

Electroencephalogram (EEG) is a relatively non-invasive, simple technique, and recent advances in open source analysis tools make it feasible to implement EEG as a component in undergraduate neuroscience curriculum. We have successfully led students to design novel experiments, record EEG data, and analyze event-related potentials (ERPs) during a one-semester laboratory course for undergraduates in cognitive neuroscience. First, students learned how to set up an EEG recording and completed an analysis tutorial. Students then learned how to set up a novel EEG experiment; briefly, they formed groups of four and designed an EEG experiment on a topic of their choice. Over the course of two weeks students collected behavioral and EEG data. Each group then analyzed their behavioral and ERP data and presented their results both as a presentation and as a final paper. Upon completion of the group project students reported a deeper understanding of cognitive neuroscience methods and a greater appreciation for the strengths and weaknesses of the EEG technique. Although recent advances in open source software made this project possible, it also required access to EEG recording equipment and proprietary software. Future efforts should be directed at making publicly available datasets to learn ERP analysis techniques and making publicly available EEG recording and analysis software to increase the accessibility of hands-on research experience in undergraduate cognitive neuroscience laboratory courses. PMID:27385925

Phenomenology of wall-bounded Newtonian turbulence.

PubMed

L'vov, Victor S; Pomyalov, Anna; Procaccia, Itamar; Zilitinkevich, Sergej S

2006-01-01

We construct a simple analytic model for wall-bounded turbulence, containing only four adjustable parameters. Two of these parameters are responsible for the viscous dissipation of the components of the Reynolds stress tensor. The other two parameters control the nonlinear relaxation of these objects. The model offers an analytic description of the profiles of the mean velocity and the correlation functions of velocity fluctuations in the entire boundary region, from the viscous sublayer, through the buffer layer, and further into the log-law turbulent region. In particular, the model predicts a very simple distribution of the turbulent kinetic energy in the log-law region between the velocity components: the streamwise component contains a half of the total energy whereas the wall-normal and cross-stream components contain a quarter each. In addition, the model predicts a very simple relation between the von Kármán slope k and the turbulent velocity in the log-law region v+ (in wall units): v+=6k. These predictions are in excellent agreement with direct numerical simulation data and with recent laboratory experiments.

A SIMPLE METHOD FOR EVALUATING DATA FROM AN INTERLABORATORY STUDY

EPA Science Inventory

Large-scale laboratory-and method-performance studies involving more than about 30 laboratories may be evaluated by calculating the HORRAT ratio for each test sample (HORRAT=[experimentally found among-laboratories relative standard deviation] divided by [relative standard deviat...

Detection of Cherenkov Photons with Multi-Anode Photomultipliers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salazar, H.; Moreno, E.; Murrieta, T.

2006-09-25

The present paper describes the laboratory course given at the X Mexican Workshop on Particles and Fields. We describe the setup and procedure used to measure the Cherenkov circles produced by cosmic muons upon traversal of a simple glass radiator system. The main purpose of this exercise is to introduce the students to work with multi-anode photomultipliers such as the one used for this experiment (Hamamatsu R5900-M64), with which measurements requiring position sensitive detection of single photons can be successfully performed. We present a short introduction to multi-anode photomultipliers (MAPMT) and describe the setup and the procedure used to measuremore » the response of a MAPMT to a uniform source of light. Finally, we describe the setup and procedure used to measure the Cherenkov circles produced by cosmic muons upon traversal of a simple glass radiator system.« less

Hall effect in a moving liquid

NASA Astrophysics Data System (ADS)

Di Lieto, Alberto; Giuliano, Alessia; Maccarrone, Francesco; Paffuti, Giampiero

2012-01-01

A simple experiment, suitable for performing in an undergraduate physics laboratory, illustrates electromagnetic induction through the water entering into a cylindrical rubber tube by detecting the voltage developed across the tube in the direction transverse both to the flow velocity and to the magnetic field. The apparatus is a very simple example of an electromagnetic flowmeter, a device which is commonly used both in industrial and physiological techniques. The phenomenology observed is similar to that of the Hall effect in the absence of an electric current in the direction of motion of the carriers. The experimental results show a dependence on the intensity of the magnetic field and on the carrier velocity, in good agreement with the theory. Discussion of the system, based on classical electromagnetism, indicates that the effect depends only on the flow rate, and is independent both of the velocity profile and of the electrical conductivity of the medium.

Role of large-scale velocity fluctuations in a two-vortex kinematic dynamo.

PubMed

Kaplan, E J; Brown, B P; Rahbarnia, K; Forest, C B

2012-06-01

This paper presents an analysis of the Dudley-James two-vortex flow, which inspired several laboratory-scale liquid-metal experiments, in order to better demonstrate its relation to astrophysical dynamos. A coordinate transformation splits the flow into components that are axisymmetric and nonaxisymmetric relative to the induced magnetic dipole moment. The reformulation gives the flow the same dynamo ingredients as are present in more complicated convection-driven dynamo simulations. These ingredients are currents driven by the mean flow and currents driven by correlations between fluctuations in the flow and fluctuations in the magnetic field. The simple model allows us to isolate the dynamics of the growing eigenvector and trace them back to individual three-wave couplings between the magnetic field and the flow. This simple model demonstrates the necessity of poloidal advection in sustaining the dynamo and points to the effect of large-scale flow fluctuations in exciting a dynamo magnetic field.

Microgravity combustion science: A program overview

NASA Technical Reports Server (NTRS)

1989-01-01

The promise of microgravity combustion research is introduced by way of a brief survey of results, the available set of reduced gravity facilities, and plans for experimental capabilities in the Space Station era. The study of fundamental combustion processes in a microgravity environment is a relatively new scientific endeavor. A few simple, precursor experiments were conducted in the early 1970's. Today the advent of the U.S. space shuttle and the anticipation of the Space Station Freedom provide for scientists and engineers a special opportunity, in the form of long duration microgravity laboratories, and need, in the form of spacecraft fire safety and a variety of terrestrial applications, to pursue fresh insight into the basic physics of combustion. The microgravity environment enables a new range of experiments to be performed since buoyancy-induced flows are nearly eliminated, normally obscured forces and flows may be isolated, gravitational settling or sedimentation is nearly eliminated, and larger time or length scales in experiments become permissible. The range of experiments completed to date was not broad, but is growing. Unexpected phenomena have been observed often in microgravity combustion experiments, raising questions about the degree of accuracy and completion of our classical understanding and our ability to estimate spacecraft fire hazards. Because of the field's relative immaturity, instrumentation has been restricted primarily to high-speed photography. To better explain these findings, more sophisticated diagnostic instrumentation, similar to that evolving in terrestrial laboratories, is being developed for use on Space Station Freedom and, along the way, in existing microgravity facilities.

Experiments and simulations of flux rope dynamics in a plasma

NASA Astrophysics Data System (ADS)

Intrator, Thomas; Abbate, Sara; Ryutov, Dmitri

2005-10-01

The behavior of flux ropes is a key issue in solar, space and astrophysics. For instance, magnetic fields and currents on the Sun are sheared and twisted as they store energy, experience an as yet unidentified instability, open into interplanetary space, eject the plasma trapped in them, and cause a flare. The Reconnection Scaling Experiment (RSX) provides a simple means to systematically characterize the linear and non-linear evolution of driven, dissipative, unstable plasma-current filaments. Topology evolves in three dimensions, supports multiple modes, and can bifurcate to quasi-helical equilibria. The ultimate saturation to a nonlinear force and energy balance is the link to a spectrum of relaxation processes. RSX has adjustable energy density β1 to β 1, non-negligible equilibrium plasma flows, driven steady-state scenarios, and adjustable line tying at boundaries. We will show magnetic structure of a kinking, rotating single line tied column, magnetic reconnection between two flux ropes, and pictures of three braided flux ropes. We use computed simulation movies to bridge the gap between the solar physics scales and experimental data with computational modeling. In collaboration with Ivo Furno, Tsitsi Madziwa-Nussinovm Giovanni Lapenta, Adam Light, Los Alamos National Laboratory; Sara Abbate, Torino Polytecnico; and Dmitri Ryutov, Lawrence Livermore National Laboratory.

A practical workshop for generating simple DNA fingerprints of plants.

PubMed

Rouzière, A-S; Redman, J E

2011-01-01

Gel electrophoresis DNA fingerprints offer a graphical and visually appealing illumination of the similarities and differences between DNA sequences of different species and individuals. A polymerase chain reaction (PCR) and restriction digest protocol was designed to give high-school students the opportunity to generate simple fingerprints of plants thereby illustrating concepts and techniques in genetics and molecular biology. Three combinations of primers/restriction enzyme targeting chloroplast DNA were sufficient to generate patterns that enabled visual discrimination of plant species. The protocol was tested with a range of common fruit, vegetable, and herb plants that could be easily cultivated and handled in the laboratory. Toxic or hazardous materials such as ethidium bromide and liquid nitrogen were avoided. The protocol was validated as a university outreach workshop targeted at a group of up to 10 high-school students. In a teaching laboratory, students sampled plants, setup the PCR reaction and restriction digest using microliter pipettes, and loaded the digested samples on an agarose gel. The workshop was structured as 2 × 2.5-hour sessions on separate days. The main challenges stemmed from the speed and accuracy of pipetting, especially at the gel loading stage. Feedback from students was largely positive, with the majority reporting that they had both enjoyed and learnt from the experience. Copyright © 2010 Wiley Periodicals, Inc.

Geochemical field method for determination of nickel in plants

USGS Publications Warehouse

Reichen, L.E.

1951-01-01

The use of biogeochemical data in prospecting for nickel emphasizes the need for a simple, moderately accurate field method for the determination of nickel in plants. In order to follow leads provided by plants of unusual nickel content without loss of time, the plants should be analyzed and the results given to the field geologist promptly. The method reported in this paper was developed to meet this need. Speed is acquired by elimination of the customary drying and controlled ashing; the fresh vegetation is ashed in an open dish over a gasoline stove. The ash is put into solution with hydrochloric acid and the solution buffered. A chromograph is used to make a confined spot with an aliquot of the ash solution on dimethylglyoxime reagent paper. As little as 0.025% nickel in plant ash can be determined. With a simple modification, 0.003% can be detected. Data are given comparing the results obtained by an accepted laboratory procedure. Results by the field method are within 30% of the laboratory values. The field method for nickel in plants meets the requirements of biogeochemical prospecting with respect to accuracy, simplicity, speed, and ease of performance in the field. With experience, an analyst can make 30 determinations in an 8-hour work day in the field.

Assessment of Gaseous Oxidized Mercury Measurement Accuracy at an Atmospheric Mercury Network (AMNet) Site

NASA Astrophysics Data System (ADS)

Luke, W. T.

2016-12-01

Recent laboratory and field research has documented and explored the biases and inaccuracies of the measurement of gaseous oxidized mercury (GOM) compounds using KCl-coated denuders. We report on the development of a simple, automated GOM calibration source and its deployment at NOAA/Air Resources Laboratory's Atmospheric Mercury Network (AMNet) site at the Mauna Loa Observatory (MLO) on the island of Hawaii. NOAA/ARL has developed a permeation-tube based calibration source with an extremely simple flow path that minimizes surface adsorptive effects and losses. The source was used to inject HgBr2 into one of two side-by-side Tekran® mercury speciation systems at MLO to characterize GOM measurement accuracy under a variety of atmospheric conditions. Due to its unique topography and meteorology, MLO experiences katabatic (upslope/downslope) mesoscale flow superimposed on the synoptic trade wind circulation of the tropics. Water vapor, ozone, and other trace atmospheric constituents often display pronounced diurnal variations at the site, which frequently encounters air characteristic of the middle free troposphere at night, and of the tropical marine boundary layer during the day. Results presented here will assist in the better understanding of the biases underlying GOM measurements in global mercury monitoring networks and may allow the development of correction factors for ambient data.

Observing and understanding arterial and venous circulation differences in a physiology laboratory activity.

PubMed

Altermann, Caroline; Gonçalves, Rithiele; Lara, Marcus Vinícius S; Neves, Ben-Hur S; Mello-Carpes, Pâmela B

2015-12-01

The purpose of the present article is to describe three simple practical experiments that aim to observe and discuss the anatomic and physiological functions and differences between arteries and veins as well as the alterations observed in skin blood flow in different situations. For this activity, students were divided in small groups. In each group, a volunteer is recruited for each experiment. The experiments only require a sphygmomanometer, rubber bands, and a clock and allow students to develop a hypothesis to explain the different responses to the interruption of arterial and venous blood flow. At the end, students prepare a short report, and the results are discussed. This activity allows students to perceive the presence of physiology in their daily lives and helps them to understand the concepts related to the cardiovascular system and hemodynamics. Copyright © 2015 The American Physiological Society.

Impact vaporization: Late time phenomena from experiments

NASA Technical Reports Server (NTRS)

Schultz, P. H.; Gault, D. E.

1987-01-01

While simple airflow produced by the outward movement of the ejecta curtain can be scaled to large dimensions, the interaction between an impact-vaporized component and the ejecta curtain is more complicated. The goal of these experiments was to examine such interaction in a real system involving crater growth, ejection of material, two phased mixtures of gas and dust, and strong pressure gradients. The results will be complemented by theoretical studies at laboratory scales in order to separate the various parameters for planetary scale processes. These experiments prompt, however, the following conclusions that may have relevance at broader scales. First, under near vacuum or low atmospheric pressures, an expanding vapor cloud scours the surrounding surface in advance of arriving ejecta. Second, the effect of early-time vaporization is relatively unimportant at late-times. Third, the overpressure created within the crater cavity by significant vaporization results in increased cratering efficiency and larger aspect ratios.

International Space Station (ISS)

NASA Image and Video Library

2001-05-14

Astronaut James S. Voss, Expedition Two flight engineer, works with a series of cables on the EXPRESS Rack in the United State's Destiny laboratory on the International Space Station (ISS). The EXPRESS Rack is a standardized payload rack system that transports, stores, and supports experiments aboard the ISS. EXPRESS stands for EXpedite the PRocessing of Experiments to the Space Station, reflecting the fact that this system was developed specifically to maximize the Station's research capabilities. The EXPRESS Rack system supports science payloads in several disciplines, including biology, chemistry, physics, ecology, and medicine. With the EXPRESS Rack, getting experiments to space has never been easier or more affordable. With its standardized hardware interfaces and streamlined approach, the EXPRESS Rack enables quick, simple integration of multiple payloads aboard the ISS. The system is comprised of elements that remain on the ISS, as well as elements that travel back and forth between the ISS and Earth via the Space Shuttle.

On the nonlocal predictions of quantum optics

NASA Technical Reports Server (NTRS)

Marshall, Trevor W.; Santos, Emilio; Vidiella-Barranco, Antonio

1994-01-01

We give a definition of locality in quantum optics based upon Bell's work, and show that locality has been violated in no experiment performed up to now. We argue that the interpretation of the Wigner function as a probability density gives a very attractive local realistic picture of quantum optics provided that this function is nonnegative. We conjecture that this is the case for all states which can be realized in the laboratory. In particular, we believe that the usual representation of 'single photon states' by a Fock state of the Hilbert space is not correct and that a more physical, although less simple mathematically, representation involves density matrices. We study in some detail the experiment showing anticorrelation after a beam splitter and prove that it naturally involves a positive Wigner function. Our (quantum) predictions for this experiment disagree with the ones reported in the literature.

The role of fine needle aspiration cytology in medical-surgical missions.

PubMed

Reyes, Cesar V; Reyes, Elisa A

2009-01-01

To relate a 6-year, short-term experience of utilizing fine needle aspiration cytology (FNAC) during medical-surgical missions in the impoverished areas of the Philippines. FNAC is a simple, accurate, fast and economical procedure and requires the simplest devices to implement. During medical-surgical missions to the poorest areas in the Third World countries, where there is almost complete lack of tissue processing and frozen section evaluation, and scarcity of laboratory testing, FNAC becomes a practical technique to use. FNAC in these situations plays an important role as an alternative diagnostic modality to surgery. Our week-long mission experience for 6 different years of successful application of FNAC is described. While the mission volunteers have gained extremely rewarding experience in these limited mission works, FNAC has proven to be a very useful adjunct in the delivery of short-term health care during medical-surgical treatment even in a less-than-ideal setting.

NOTE: Laboratory Studies of Catalysis of CO to Organics on Grain Analogs

NASA Astrophysics Data System (ADS)

Ferrante, R. F.; Moore, M. H.; Nuth, J. A.; Smith, T.

2000-05-01

Experiments simulating heterogeneous conversion of H 2 and CO into simple hydrocarbons in astrophysical environments have been performed, utilizing realistic cosmic grain analogs of Fe-doped silicates as Fischer-Tropsch-Type catalysts. Catalysis was studied for temperatures from 470-670 K and reactant gas mixtures of H 2/CO with a ratio of 2-100. The total gas pressure was near 0.5 bar. Maximum conversion rates of a few percentage points were achieved over a 3-h time period. Major products were methane, ethane, ethylene, carbon dioxide, and water. Products were identified by IR spectroscopy.

A design strategy for autonomous systems

NASA Technical Reports Server (NTRS)

Forster, Pete

1989-01-01

Some solutions to crucial issues regarding the competent performance of an autonomously operating robot are identified; namely, that of handling multiple and variable data sources containing overlapping information and maintaining coherent operation while responding adequately to changes in the environment. Support for the ideas developed for the construction of such behavior are extracted from speculations in the study of cognitive psychology, an understanding of the behavior of controlled mechanisms, and the development of behavior-based robots in a few robot research laboratories. The validity of these ideas is supported by some simple simulation experiments in the field of mobile robot navigation and guidance.

Pulsed source of ultra low-energy muons at RIKEN-RAL

NASA Astrophysics Data System (ADS)

Bakule, Pavel; Matsuda, Yasuyuki; Iwasaki, Masahiko; Miyake, Yasuhiro; Nagamine, Kanetada; Ikedo, Yutaka; Shimomura, Koichiro; Strasser, Patrick

2006-03-01

At RIKEN-RAL muon facility of the Rutherford Appleton Laboratory (UK) we have produced a pulsed LE-μ + beam with pulse duration of only 10 ns and performed μSR experiments to demonstrate the capability to measure high spin precession frequency signals. The yield of pulsed LE-μ + has been steadily improving over the past 3 years and currently rates of up to 20 μ + per second are observed at the sample position. The overall cooling efficiency from the surface muon beam is now comparable to moderating the muon beam to epithermal energies in simple van der Waals bound solids.

e-Science and data management resources on the Web.

PubMed

Gore, Sally A

2011-01-01

The way research is conducted has changed over time, from simple experiments to computer modeling and simulation, from individuals working in isolated laboratories to global networks of researchers collaborating on a single topic. Often, this new paradigm results in the generation of staggering amounts of data. The intensive use of data and the existence of networks of researchers characterize e-Science. The role of libraries and librarians in e-Science has been a topic of interest for some time now. This column looks at tools, resources, and projects that demonstrate successful collaborations between libraries and researchers in e-Science.

Field and laboratory determination of water-surface elevation and velocity using noncontact measurements

USGS Publications Warehouse

Nelson, Jonathan M.; Kinzel, Paul J.; Schmeeckle, Mark Walter; McDonald, Richard R.; Minear, Justin T.

2016-01-01

Noncontact methods for measuring water-surface elevation and velocity in laboratory flumes and rivers are presented with examples. Water-surface elevations are measured using an array of acoustic transducers in the laboratory and using laser scanning in field situations. Water-surface velocities are based on using particle image velocimetry or other machine vision techniques on infrared video of the water surface. Using spatial and temporal averaging, results from these methods provide information that can be used to develop estimates of discharge for flows over known bathymetry. Making such estimates requires relating water-surface velocities to vertically averaged velocities; the methods here use standard relations. To examine where these relations break down, laboratory data for flows over simple bumps of three amplitudes are evaluated. As anticipated, discharges determined from surface information can have large errors where nonhydrostatic effects are large. In addition to investigating and characterizing this potential error in estimating discharge, a simple method for correction of the issue is presented. With a simple correction based on bed gradient along the flow direction, remotely sensed estimates of discharge appear to be viable.

Effect of Unsaturated Flow Modes on Partitioning Dynamics of Gravity-Driven Flow at a Simple Fracture Intersection: Laboratory Study and Three-Dimensional Smoothed Particle Hydrodynamics Simulations

NASA Astrophysics Data System (ADS)

Kordilla, Jannes; Noffz, Torsten; Dentz, Marco; Geyer, Tobias; Tartakovsky, Alexandre M.

2017-11-01

In this work, we study gravity-driven flow of water in the presence of air on a synthetic surface intersected by a horizontal fracture and investigate the importance of droplet and rivulet flow modes on the partitioning behavior at the fracture intersection. We present laboratory experiments, three-dimensional smoothed particle hydrodynamics (SPH) simulations using a heavily parallelized code, and a theoretical analysis. The flow-rate-dependent mode switching from droplets to rivulets is observed in experiments and reproduced by the SPH model, and the transition ranges agree in SPH simulations and laboratory experiments. We show that flow modes heavily influence the "bypass" behavior of water flowing along a fracture junction. Flows favoring the formation of droplets exhibit a much stronger bypass capacity compared to rivulet flows, where nearly the whole fluid mass is initially stored within the horizontal fracture. The effect of fluid buffering within the horizontal fracture is presented in terms of dimensionless fracture inflow so that characteristic scaling regimes can be recovered. For both cases (rivulets and droplets), the flow within the horizontal fracture transitions into a Washburn regime until a critical threshold is reached and the bypass efficiency increases. For rivulet flows, the initial filling of the horizontal fracture is described by classical plug flow. Meanwhile, for droplet flows, a size-dependent partitioning behavior is observed, and the filling of the fracture takes longer. For the case of rivulet flow, we provide an analytical solution that demonstrates the existence of classical Washburn flow within the horizontal fracture.

Comparison of cooperative and non-cooperative adaptive optics reference performance for propagation with thermal blooming effects

NASA Astrophysics Data System (ADS)

Edwards, Brian E.; Nitkowski, Arthur; Lawrence, Ryan; Horton, Kasey; Higgs, Charles

2004-10-01

Atmospheric turbulence and laser-induced thermal blooming effects can degrade the beam quality of a high-energy laser (HEL) weapon, and ultimately limit the amount of energy deliverable to a target. Lincoln Laboratory has built a thermal blooming laboratory capable of emulating atmospheric thermal blooming and turbulence effects for tactical HEL systems. The HEL weapon emulation hardware includes an adaptive optics beam delivery system, which utilizes a Shack-Hartman wavefront sensor and a 349 actuator deformable mirror. For this experiment, the laboratory was configured to emulate an engagement scenario consisting of sea skimming target approaching directly toward the HEL weapon at a range of 10km. The weapon utilizes a 1.5m aperture and radiates at a 1.62 micron wavelength. An adaptive optics reference beam was provided as either a point source located at the target (cooperative) or a projected point source reflected from the target (uncooperative). Performance of the adaptive optics system was then compared between reference sources. Results show that, for operating conditions with a thermal blooming distortion number of 75 and weak turbulence (Rytov of 0.02 and D/ro of 3), cooperative beacon AO correction experiences Phase Compensation Instability, resulting in lower performance than a simple, open-loop condition. The uncooperative beacon resulted in slightly better performance than the open-loop condition.

Simple Technique for Dark-Field Photography of Immunodiffusion Bands

PubMed Central

Jensh, Ronald P.; Brent, Robert L.

1969-01-01

A simple dark-field photographic technique was developed which enables laboratory personnel with minimal photographic training to easily record antigen-antibody patterns on immunodiffusion plates. Images PMID:4979944

Signal detection via residence-time asymmetry in noisy bistable devices.

PubMed

Bulsara, A R; Seberino, C; Gammaitoni, L; Karlsson, M F; Lundqvist, B; Robinson, J W C

2003-01-01

We introduce a dynamical readout description for a wide class of nonlinear dynamic sensors operating in a noisy environment. The presence of weak unknown signals is assessed via the monitoring of the residence time in the metastable attractors of the system, in the presence of a known, usually time-periodic, bias signal. This operational scenario can mitigate the effects of sensor noise, providing a greatly simplified readout scheme, as well as significantly reduced processing procedures. Such devices can also show a wide variety of interesting dynamical features. This scheme for quantifying the response of a nonlinear dynamic device has been implemented in experiments involving a simple laboratory version of a fluxgate magnetometer. We present the results of the experiments and demonstrate that they match the theoretical predictions reasonably well.

Experiments with synchronized sCMOS cameras

NASA Astrophysics Data System (ADS)

Steele, Iain A.; Jermak, Helen; Copperwheat, Chris M.; Smith, Robert J.; Poshyachinda, Saran; Soonthorntham, Boonrucksar

2016-07-01

Scientific-CMOS (sCMOS) cameras can combine low noise with high readout speeds and do not suffer the charge multiplication noise that effectively reduces the quantum efficiency of electron multiplying CCDs by a factor 2. As such they have strong potential in fast photometry and polarimetry instrumentation. In this paper we describe the results of laboratory experiments using a pair of commercial off the shelf sCMOS cameras based around a 4 transistor per pixel architecture. In particular using a both stable and a pulsed light sources we evaluate the timing precision that may be obtained when the cameras readouts are synchronized either in software or electronically. We find that software synchronization can introduce an error of 200-msec. With electronic synchronization any error is below the limit ( 50-msec) of our simple measurement technique.

Experimental evolution and the dynamics of adaptation and genome evolution in microbial populations.

PubMed

Lenski, Richard E

2017-10-01

Evolution is an on-going process, and it can be studied experimentally in organisms with rapid generations. My team has maintained 12 populations of Escherichia coli in a simple laboratory environment for >25 years and 60 000 generations. We have quantified the dynamics of adaptation by natural selection, seen some of the populations diverge into stably coexisting ecotypes, described changes in the bacteria's mutation rate, observed the new ability to exploit a previously untapped carbon source, characterized the dynamics of genome evolution and used parallel evolution to identify the genetic targets of selection. I discuss what the future might hold for this particular experiment, briefly highlight some other microbial evolution experiments and suggest how the fields of experimental evolution and microbial ecology might intersect going forward.

Performance of the cometary experiment MUPUS on the body Earth

NASA Astrophysics Data System (ADS)

Marczewski, W.; Usowicz, B.; Schröer, K.; Seiferlin, K.; Spohn, T.

2003-04-01

Thermal experiment MUPUS for the Rosetta mission was extensively experience in field and laboratory conditions to predict its performance under physical processes available on the Earth. The goal was not guessing a cometary material in the ground but available behavior of thermal sensor responses monitoring mass and energy transfer. The processes expected on a comet are different in composition and environmental from those met on the Earth but basically similar in physics. Nature of energy powering the processes is also essentially the same - solar radiation. Several simple laboratory experiments with freezing and thawing with water ice, with mixture of water and oil and water layers strongly diverged by salinity revealed capability of recognition layered structure of the medium under test. More over effects of slow convection and latent heat related to the layers are also observed well. Cometary environment without atmosphere makes process of sublimation dominant. Open air conditions on the Earth may also offer a change of state in matter but between different phases. Learning temperature gradient in snow layers under thawing show that effects stimulated by a cause of daily cycling may be detected thermally. Results from investigations in snow made on Spitzbergen are good proofs on capability of the method. Relevance of thermal effects to heat powered processes of mass transport in the matter of ground is meaningful for the cometary experiment of MUPUS and for Earth sciences much concerned on water, gas and solid matter transport in the terrestrial ground. Results leading to energy balance studied on the Earth surface may be interesting also for the experiment on the comet and are to be discussed.

Bioturbation, advection, and diffusion of a conserved tracer in a laboratory flume

NASA Astrophysics Data System (ADS)

Work, P. A.; Moore, P. R.; Reible, D. D.

2002-06-01

Laboratory experiments indicating the relative influences of advection, diffusion, and bioturbation on transport of NaCl tracer between a stream and streambed are described. Data were collected in a recirculating flume housing a box filled with test sediments. Peclet numbers ranged from 0 to 1.5. Sediment components included a medium sand (d50 = 0.31 mm), kaolinite, and topsoil. Lumbriculus variegatus were introduced as bioturbators. Conductivity probes were employed to document the flux of the tracer solution out of the bed. Measurements are compared to one-dimensional effective diffusion models assuming one or two horizontal sediment layers. These simple models provide a good indication of tracer half-life in the bed if a suitable effective diffusion coefficient is chosen but underpredict initial flux and overpredict flux at long times. Organism activity was limited to the upper reaches of the sediment test box but eventually exerts a secondary influence on flux from deeper regions.

SOBA: sequence ontology bioinformatics analysis.

PubMed

Moore, Barry; Fan, Guozhen; Eilbeck, Karen

2010-07-01

The advent of cheaper, faster sequencing technologies has pushed the task of sequence annotation from the exclusive domain of large-scale multi-national sequencing projects to that of research laboratories and small consortia. The bioinformatics burden placed on these laboratories, some with very little programming experience can be daunting. Fortunately, there exist software libraries and pipelines designed with these groups in mind, to ease the transition from an assembled genome to an annotated and accessible genome resource. We have developed the Sequence Ontology Bioinformatics Analysis (SOBA) tool to provide a simple statistical and graphical summary of an annotated genome. We envisage its use during annotation jamborees, genome comparison and for use by developers for rapid feedback during annotation software development and testing. SOBA also provides annotation consistency feedback to ensure correct use of terminology within annotations, and guides users to add new terms to the Sequence Ontology when required. SOBA is available at http://www.sequenceontology.org/cgi-bin/soba.cgi.

Laboratory investigation on the role of tubular shaped micro resonators phononic crystal insertion on the absorption coefficient of profiled sound absorber

NASA Astrophysics Data System (ADS)

Yahya, I.; Kusuma, J. I.; Harjana; Kristiani, R.; Hanina, R.

2016-02-01

This paper emphasizes the influence of tubular shaped microresonators phononic crystal insertion on the sound absorption coefficient of profiled sound absorber. A simple cubic and two different bodies centered cubic phononic crystal lattice model were analyzed in a laboratory test procedure. The experiment was conducted by using transfer function based two microphone impedance tube method refer to ASTM E-1050-98. The results show that sound absorption coefficient increase significantly at the mid and high-frequency band (600 - 700 Hz) and (1 - 1.6 kHz) when tubular shaped microresonator phononic crystal inserted into the tested sound absorber element. The increment phenomena related to multi-resonance effect that occurs when sound waves propagate through the phononic crystal lattice model that produce multiple reflections and scattering in mid and high-frequency band which increases the sound absorption coefficient accordingly

Radiative Transfer Theory Verified by Controlled Laboratory Experiments

NASA Technical Reports Server (NTRS)

Mishchenko, Michael I.; Goldstein, Dennis H.; Chowdhary, Jacek; Lompado, Arthur

2013-01-01

We report the results of high-accuracy controlled laboratory measurements of the Stokes reflection matrix for suspensions of submicrometer-sized latex particles in water and compare them with the results of a numerically exact computer solution of the vector radiative transfer equation (VRTE). The quantitative performance of the VRTE is monitored by increasing the volume packing density of the latex particles from 2 to 10. Our results indicate that the VRTE can be applied safely to random particulate media with packing densities up to 2. VRTE results for packing densities of the order of 5 should be taken with caution, whereas the polarized bidirectional reflectivity of suspensions with larger packing densities cannot be accurately predicted. We demonstrate that a simple modification of the phase matrix entering the VRTE based on the so-called static structure factor can be a promising remedy that deserves further examination.

Space charge enhanced plasma gradient effects on satellite electric field measurements

NASA Technical Reports Server (NTRS)

Diebold, Dan; Hershkowitz, Noah; Dekock, J.; Intrator, T.; Hsieh, M-K.

1991-01-01

It has been recognized that plasma gradients can cause error in magnetospheric electric field measurements made by double probes. Space charge enhanced Plasma Gradient Induced Error (PGIE) is discussed in general terms, presenting the results of a laboratory experiment designed to demonstrate this error, and deriving a simple expression that quantifies this error. Experimental conditions were not identical to magnetospheric conditions, although efforts were made to insure the relevant physics applied to both cases. The experimental data demonstrate some of the possible errors in electric field measurements made by strongly emitting probes due to space charge effects in the presence of plasma gradients. Probe errors in space and laboratory conditions are discussed, as well as experimental error. In the final section, theoretical aspects are examined and an expression is derived for the maximum steady state space charge enhanced PGIE taken by two identical current biased probes.

Sonic-boom-induced building structure responses including damage.

NASA Technical Reports Server (NTRS)

Clarkson, B. L.; Mayes, W. H.

1972-01-01

Concepts of sonic-boom pressure loading of building structures and the associated responses are reviewed, and results of pertinent theoretical and experimental research programs are summarized. The significance of sonic-boom load time histories, including waveshape effects, are illustrated with the aid of simple structural elements such as beams and plates. Also included are discussions of the significance of such other phenomena as three-dimensional loading effects, air cavity coupling, multimodal responses, and structural nonlinearities. Measured deflection, acceleration, and strain data from laboratory models and full-scale building tests are summarized, and these data are compared, where possible, with predicted values. Damage complaint and claim experience due both to controlled and uncontrolled supersonic flights over communities are summarized with particular reference to residential, commercial, and historic buildings. Sonic-boom-induced building responses are compared with those from other impulsive loadings due to natural and cultural events and from laboratory simulation tests.

Miniaturized Sample Preparation and Rapid Detection of Arsenite in Contaminated Soil Using a Smartphone.

PubMed

Siddiqui, Mohd Farhan; Kim, Soocheol; Jeon, Hyoil; Kim, Taeho; Joo, Chulmin; Park, Seungkyung

2018-03-04

Conventional methods for analyzing heavy metal contamination in soil and water generally require laboratory equipped instruments, complex procedures, skilled personnel and a significant amount of time. With the advancement in computing and multitasking performances, smartphone-based sensors potentially allow the transition of the laboratory-based analytical processes to field applicable, simple methods. In the present work, we demonstrate the novel miniaturized setup for simultaneous sample preparation and smartphone-based optical sensing of arsenic As(III) in the contaminated soil. Colorimetric detection protocol utilizing aptamers, gold nanoparticles and NaCl have been optimized and tested on the PDMS-chip to obtain the high sensitivity with the limit of detection of 0.71 ppm (in the sample) and a correlation coefficient of 0.98. The performance of the device is further demonstrated through the comparative analysis of arsenic-spiked soil samples with standard laboratory method, and a good agreement with a correlation coefficient of 0.9917 and the average difference of 0.37 ppm, are experimentally achieved. With the android application on the device to run the experiment, the whole process from sample preparation to detection is completed within 3 hours without the necessity of skilled personnel. The approximate cost of setup is estimated around 1 USD, weight 55 g. Therefore, the presented method offers the simple, rapid, portable and cost-effective means for onsite sensing of arsenic in soil. Combined with the geometric information inside the smartphones, the system will allow the monitoring of the contamination status of soils in a nation-wide manner.

Robotics and neuroscience: a rhythmic interaction.

PubMed

Ronsse, Renaud; Lefèvre, Philippe; Sepulchre, Rodolphe

2008-05-01

At the crossing between motor control neuroscience and robotics system theory, the paper presents a rhythmic experiment that is amenable both to handy laboratory implementation and simple mathematical modeling. The experiment is based on an impact juggling task, requiring the coordination of two upper-limb effectors and some phase-locking with the trajectories of one or several juggled objects. We describe the experiment, its implementation and the mathematical model used for the analysis. Our underlying research focuses on the role of sensory feedback in rhythmic tasks. In a robotic implementation of our experiment, we study the minimum feedback that is required to achieve robust control. A limited source of feedback, measuring only the impact times, is shown to give promising results. A second field of investigation concerns the human behavior in the same impact juggling task. We study how a variation of the tempo induces a transition between two distinct control strategies with different sensory feedback requirements. Analogies and differences between the robotic and human behaviors are obviously of high relevance in such a flexible setup.

Laboratory Experiments to Investigate Breakout and Bifurcation of Lava Flows on Mars

NASA Astrophysics Data System (ADS)

Miyamoto, H.; Zimbelman, J. R.; Tokunaga, T.; Tosaka, H.

2001-05-01

Mars Orbiter Camera (MOC) images show that many lava flows on Mars have morphologies quite similar to aa lava flows. Such flows often have many lobes and branches that overlap each other, making a compound flow unit. These features cannot be explained by any simple flow model because longer effusion duration will simply make the flow longer, although actual lavas often will bifurcate to make additonal flow units. Similarly, formation of a lava tube is difficult to predict by a model that does not contain preset conditions for their formation. Treatment of the surface crust is very important to the flow morphology, especially for effusion over a long duration. To understand the effect of a crust on flow morphology, paraffin wax is especially useful in laboratory experiments. In our experiments, a flow on a constant slope typically progresses with a constant width at first. Then, the flow front cools to form a crust, which inhibits the progress of the flow. At that time, the flow sometimes becomes sinuous or ceases its movement. With a sufficient flux after that, uplift of thickness (inflation) can occur. Uplift sometimes attains a sufficient thickening to produce a breakout at the side of the flow, bifurcating to form a new cooling unit. Bifurcated flows do not always follow the main flow (some branches moved several cm away from the initial flow). The bifurcations continue to develop into a complicated flow field, given a sufficiently long duration of effusion. Although the movement of the flow with a surface crust is difficult to predict, our simple analysis suggests that the maximum thickness attained by the inflation (by fluid continuing to enter a stopped flow) before a breakout can occur is roughly estimated by a balance between the overpressure and the crust tensile strength. The maximum extent of a bifurcated flow after a breakout can probably be constrained, which will be a significant goal for future modeling of compound flows.

Numerical modeling of zero-offset laboratory data in a strong topographic environment: results for a spectral-element method and a discretized Kirchhoff integral method

NASA Astrophysics Data System (ADS)

Favretto-Cristini, Nathalie; Tantsereva, Anastasiya; Cristini, Paul; Ursin, Bjørn; Komatitsch, Dimitri; Aizenberg, Arkady M.

2014-08-01

Accurate simulation of seismic wave propagation in complex geological structures is of particular interest nowadays. However conventional methods may fail to simulate realistic wavefields in environments with great and rapid structural changes, due for instance to the presence of shadow zones, diffractions and/or edge effects. Different methods, developed to improve seismic modeling, are typically tested on synthetic configurations against analytical solutions for simple canonical problems or reference methods, or via direct comparison with real data acquired in situ. Such approaches have limitations, especially if the propagation occurs in a complex environment with strong-contrast reflectors and surface irregularities, as it can be difficult to determine the method which gives the best approximation of the "real" solution, or to interpret the results obtained without an a priori knowledge of the geologic environment. An alternative approach for seismics consists in comparing the synthetic data with high-quality data collected in laboratory experiments under controlled conditions for a known configuration. In contrast with numerical experiments, laboratory data possess many of the characteristics of field data, as real waves propagate through models with no numerical approximations. We thus present a comparison of laboratory-scaled measurements of 3D zero-offset wave reflection of broadband pulses from a strong topographic environment immersed in a water tank with numerical data simulated by means of a spectral-element method and a discretized Kirchhoff integral method. The results indicate a good quantitative fit in terms of time arrivals and acceptable fit in amplitudes for all datasets.

Safety in the Chemical Laboratory: Laboratory Air Quality: Part II. Measurements of Ventilation Rates.

ERIC Educational Resources Information Center

Butcher, Samuel S.; And Others

1985-01-01

Part I of this paper (SE 538 295) described a simple model for estimating laboratory concentrations of gas phase pollutants. In this part, the measurement of ventilation rates and applications of the model are discussed. The model can provide a useful starting point in planning for safer instructional laboratories. (JN)

A Microcosm of the Biomedical Research Experience for Upper-level Undergraduates

PubMed Central

2008-01-01

The skill set required of biomedical researchers continues to grow and evolve as biology matures as a natural science. Science necessitates creative yet critical thinking, persuasive communication skills, purposeful use of time, and adeptness at the laboratory bench. Teaching these skills can be effectively accomplished in an inquiry-based, active-learning environment at a primarily undergraduate institution. Cell Biology Techniques, an upper-level cell biology laboratory course at St. John Fisher College, features two independent projects that take advantage of the biology of the nematode Caenorhabditis elegans, a premier yet simple model organism. First, students perform a miniature epigenetic screen for novel phenotypes using RNA interference. The results of this screen combined with literature research direct students toward a singe gene that they attempt to subclone in the second project. The biology of the chosen gene/protein also becomes an individualized focal point with respect to the content of the laboratory. Progress toward course goals is evaluated using written, oral, and group-produced assignments, including a concept map. Pre- and postassessment indicates a significant increase in the understanding of broad concepts in cell biological research. PMID:18519612

An Inexpensive Biophysics Laboratory Apparatus for Acquiring Pulmonary Function Data with Clinical Applications

NASA Astrophysics Data System (ADS)

Harkay, Gregory

2001-11-01

Interest on the part of the Physics Department at KSC in developing a computer interfaced lab with appeal to biology majors and a need to perform a clinical pulmonological study to fulfill a biology requirement led to the author's undergraduate research project in which a recording spirometer (typical cost: $15K) was constructed from readily available materials and a typical undergraduate lab computer interface. Simple components, including a basic photogate circuit, CPU fan, and PVC couplings were used to construct an instrument for measuring flow rates as a function of time. Pasco software was used to build an experiment in which data was collected and integration performed such that one could obtain accurate values for FEV1 (forced expiratory volume for one second) and FVC (forced vital capacity) and their ratio for a large sample of subjects. Results were compared to published norms and subjects with impaired respiratory mechanisms identified. This laboratory exercise is one with which biology students can clearly identify and would be a robust addition to the repertoire for a HS or college physics or biology teaching laboratory.

[A simple apparatus for controllable drinking without leaks for laboratory rats].

PubMed

Huber, D

1989-01-01

A simple device for watering laboratory rats is described. It has been made by using commercially available glass tubing (DURAN 50) with outside diameters of 8 mm, 6 mm, and 3 mm, respectively. The tubes were fused at their tips. The drinking tube is fitted to a rubber stopper at the top of a 250 ml soft polyethylene bottle. By this way water-soluble drugs can be administered to rats with high precision.

MULPEX: A compact multi-layered polymer foil collector for micrometeoroids and orbital debris

NASA Astrophysics Data System (ADS)

Kearsley, A. T.; Graham, G. A.; Burchell, M. J.; Taylor, E. A.; Drolshagen, G.; Chater, R. J.; McPhail, D.

Detailed studies of preserved hypervelocity impact residues on spacecraft multi-layer insulation foils have yielded important information about the flux of small particles from different sources in low-Earth orbit (LEO). We have extended our earlier research on impacts occurring in LEO to design and testing of a compact capture device. MUlti- Layer Polymer EXperiment (MULPEX) is simple, cheap to build, lightweight, of no power demand, easy to deploy, and optimised for the efficient collection of impact residue for analysis on return to Earth. The capture medium is a stack of very thin (8 and 40 μm) polyimide foils, supported on poly-tetrafluoroethylene sheet frames, surrounded by a protective aluminium casing. The uppermost foil has a very thin metallic coating for thermal protection and resistance to atomic oxygen and ultra-violet exposure. The casing provides a simple detachable interface for deployment on the spacecraft, facing into the desired direction for particle collection. On return to the laboratory, the stacked foils are separated for examination in a variable pressure scanning electron microscope, without need for surface coating. Analysis of impact residue is performed using energy dispersive X-ray spectrometers. Our laboratory experiments, utilising buck-shot firings of analogues to micrometeoroids (35-38 μm olivine) and space debris (4 μm alumina and 1 mm stainless steel) in a light gas gun, have shown that impact residue is abundant within the foil layers, and preserves a record of the impacting particle, whether of micrometer or millimetre dimensions. Penetrations of the top foil are easily recognised, and act as a proxy for dimensions of the penetrating particle. Impact may cause disruption and melting, but some residue retains sufficient crystallographic structure to show clear Raman lines, diagnostic of the original mineral.

MULPEX: a compact multi-layered polymer foil collector for micrometeoroids and orbital debris.

NASA Astrophysics Data System (ADS)

Kearsley, A. T.; Graham, G. A.; Burchell, M. J.; Taylor, E. A.; Drolshagen, G.; Chater, R. J.; McPhail, D.

Detailed studies of preserved hypervelocity impact residues on spacecraft multi-layer insulation foils have yielded important information about the flux of small particles from different sources in low-Earth orbit (LEO). We have extended our earlier research on impacts occurring in LEO to design and testing of a compact capture device. MULPEX (MUlti-Layer Polymer EXperiment) is simple, cheap to build, lightweight, of no power demand, easy to deploy, and optimised for the efficient collection of impact residue for analysis on return to Earth. The capture medium is a stack of very thin (8 micron and 40 micron) polyimide foils, supported on poly-tetrafluoroethylene sheet frames, surrounded by a protective aluminium casing. The uppermost foil has a very thin metallic coating for thermal protection and resistance to atomic oxygen and ultra-violet exposure. The casing provides a simple detachable interface for deployment on the spacecraft, facing into the desired direction for particle collection. On return to the laboratory, the stacked foils are separated for examination in a variable pressure scanning electron microscope, without need for surface coating. Analysis of impact residue is performed using energy dispersive X-ray spectrometers. Our laboratory experiments, utilising buck-shot firings of analogues to micrometeoroids (35-38 micron olivine) and space debris (4 micron alumina and 1mm stainless steel) in a light gas gun, have shown that impact residue is abundant within the foil layers, and preserves a record of the impacting particle, whether of micrometer or millimetre dimensions. Penetrations of the top foil are easily recognised, and act as a proxy for dimensions of the penetrating particle. Impact may cause disruption and melting, but some residue retains sufficient crystallographic structure to show clear Raman lines, diagnostic of the original mineral.

Factors influencing the latency of simple reaction time

PubMed Central

Woods, David L.; Wyma, John M.; Yund, E. William; Herron, Timothy J.; Reed, Bruce

2015-01-01

Simple reaction time (SRT), the minimal time needed to respond to a stimulus, is a basic measure of processing speed. SRTs were first measured by Francis Galton in the 19th century, who reported visual SRT latencies below 190 ms in young subjects. However, recent large-scale studies have reported substantially increased SRT latencies that differ markedly in different laboratories, in part due to timing delays introduced by the computer hardware and software used for SRT measurement. We developed a calibrated and temporally precise SRT test to analyze the factors that influence SRT latencies in a paradigm where visual stimuli were presented to the left or right hemifield at varying stimulus onset asynchronies (SOAs). Experiment 1 examined a community sample of 1469 subjects ranging in age from 18 to 65. Mean SRT latencies were short (231, 213 ms when corrected for hardware delays) and increased significantly with age (0.55 ms/year), but were unaffected by sex or education. As in previous studies, SRTs were prolonged at shorter SOAs and were slightly faster for stimuli presented in the visual field contralateral to the responding hand. Stimulus detection time (SDT) was estimated by subtracting movement initiation time, measured in a speeded finger tapping test, from SRTs. SDT latencies averaged 131 ms and were unaffected by age. Experiment 2 tested 189 subjects ranging in age from 18 to 82 years in a different laboratory using a larger range of SOAs. Both SRTs and SDTs were slightly prolonged (by 7 ms). SRT latencies increased with age while SDT latencies remained stable. Precise computer-based measurements of SRT latencies show that processing speed is as fast in contemporary populations as in the Victorian era, and that age-related increases in SRT latencies are due primarily to slowed motor output. PMID:25859198

What dynamics can be expected for mixed states in two-slit experiments?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luis, Alfredo; Sanz, Ángel S., E-mail: asanz@iff.csic.es

2015-06-15

Weak-measurement-based experiments (Kocsis et al., 2011) have shown that, at least for pure states, the average evolution of independent photons in Young’s two-slit experiment is in compliance with the trajectories prescribed by the Bohmian formulation of quantum mechanics. But, what happens if the same experiment is repeated assuming that the wave function associated with each particle is different, i.e., in the case of mixed (incoherent) states? This question is investigated here by means of two alternative numerical simulations of Young’s experiment, purposely devised to be easily implemented and tested in the laboratory. Contrary to what could be expected a priori, itmore » is found that even for conditions of maximal mixedness or incoherence (total lack of interference fringes), experimental data will render a puzzling and challenging outcome: the average particle trajectories will still display features analogous to those for pure states, i.e., independently of how mixedness arises, the associated dynamics is influenced by both slits at the same time. Physically this simply means that weak measurements are not able to discriminate how mixedness arises in the experiment, since they only provide information about the averaged system dynamics. - Highlights: • The dynamics associated with mixture states in investigated by means of two simple Young’s two-slit models. • The models are prepared to be easily implemented and tested in the laboratory by means of weak measurements. • Bohmian mechanics has been generalized to encompass statistical mixtures. • Even for conditions of maximal mixedness numerical simulations show that the dynamics is strongly influenced by both slits. • Accordingly, weak measurements are unable to discriminate how mixedness arises in an experiment.« less

A Simple "Tubeless" Telescope

ERIC Educational Resources Information Center

Straulino, S.; Bonechi, L.

2010-01-01

Two lenses make it possible to create a simple telescope with quite large magnification. The set-up is very simple and can be reproduced in schools, provided the laboratory has a range of lenses with different focal lengths. In this article, the authors adopt the Keplerian configuration, which is composed of two converging lenses. This instrument,…

Measuring Networking as an Outcome Variable in Undergraduate Research Experiences

PubMed Central

Hanauer, David I.; Hatfull, Graham

2015-01-01

The aim of this paper is to propose, present, and validate a simple survey instrument to measure student conversational networking. The tool consists of five items that cover personal and professional social networks, and its basic principle is the self-reporting of degrees of conversation, with a range of specific discussion partners. The networking instrument was validated in three studies. The basic psychometric characteristics of the scales were established by conducting a factor analysis and evaluating internal consistency using Cronbach’s alpha. The second study used a known-groups comparison and involved comparing outcomes for networking scales between two different undergraduate laboratory courses (one involving a specific effort to enhance networking). The final study looked at potential relationships between specific networking items and the established psychosocial variable of project ownership through a series of binary logistic regressions. Overall, the data from the three studies indicate that the networking scales have high internal consistency (α = 0.88), consist of a unitary dimension, can significantly differentiate between research experiences with low and high networking designs, and are related to project ownership scales. The ramifications of the networking instrument for student retention, the enhancement of public scientific literacy, and the differentiation of laboratory courses are discussed. PMID:26538387

Driving forces: Slab subduction and mantle convection

NASA Technical Reports Server (NTRS)

Hager, Bradford H.

1988-01-01

Mantle convection is the mechanism ultimately responsible for most geological activity at Earth's surface. To zeroth order, the lithosphere is the cold outer thermal boundary layer of the convecting mantle. Subduction of cold dense lithosphere provides tha major source of negative buoyancy driving mantle convection and, hence, surface tectonics. There are, however, importnat differences between plate tectonics and the more familiar convecting systems observed in the laboratory. Most important, the temperature dependence of the effective viscosity of mantle rocks makes the thermal boundary layer mechanically strong, leading to nearly rigid plates. This strength stabilizes the cold boundary layer against small amplitude perturbations and allows it to store substantial gravitational potential energy. Paradoxically, through going faults at subduction zones make the lithosphere there locally weak, allowing rapid convergence, unlike what is observed in laboratory experiments using fluids with temperature dependent viscosities. This bimodal strength distribution of the lithosphere distinguishes plate tectonics from simple convection experiments. In addition, Earth has a buoyant, relatively weak layer (the crust) occupying the upper part of the thermal boundary layer. Phase changes lead to extra sources of heat and bouyancy. These phenomena lead to observed richness of behavior of the plate tectonic style of mantle convection.

Evaluating Amazon's Mechanical Turk as a Tool for Experimental Behavioral Research

PubMed Central

Crump, Matthew J. C.; McDonnell, John V.; Gureckis, Todd M.

2013-01-01

Amazon Mechanical Turk (AMT) is an online crowdsourcing service where anonymous online workers complete web-based tasks for small sums of money. The service has attracted attention from experimental psychologists interested in gathering human subject data more efficiently. However, relative to traditional laboratory studies, many aspects of the testing environment are not under the experimenter's control. In this paper, we attempt to empirically evaluate the fidelity of the AMT system for use in cognitive behavioral experiments. These types of experiment differ from simple surveys in that they require multiple trials, sustained attention from participants, comprehension of complex instructions, and millisecond accuracy for response recording and stimulus presentation. We replicate a diverse body of tasks from experimental psychology including the Stroop, Switching, Flanker, Simon, Posner Cuing, attentional blink, subliminal priming, and category learning tasks using participants recruited using AMT. While most of replications were qualitatively successful and validated the approach of collecting data anonymously online using a web-browser, others revealed disparity between laboratory results and online results. A number of important lessons were encountered in the process of conducting these replications that should be of value to other researchers. PMID:23516406

Laboratory study of polymer solutions used for mobility control during in situ NAPL recovery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martel, K.E.; Martel, R.; Lefebvre, R.

1998-12-31

The use of surfactant solutions for the in situ recovery of residual NAPL in aquifers is increasingly considered as a viable remediation technique. The injection of a few pore volumes of high-concentration surfactant solutions can mobilize or solubilize most of the residual NAPL contacted by the solutions. However, the washing solutions` physico-chemical properties (low density and high viscosity), combined with the natural porous media heterogeneity, can prevent a good sweep of the entire contaminated volume. The objective of this laboratory study is first to select and characterize polymers that would be suitable for aquifer restoration. Their experiments showed that amongmore » several polymers, xanthan gum is the most suitable for aquifer remediation. An evaluation of xanthan gum solution rheology was made in order to predict shear rates, xanthan gum concentrations, salinity, and temperature effects on solution viscosity. The second set of experiments were made with a sand box which was designed to reproduce a simple heterogeneous media consisting of layers of sand with different permeability. These tests illustrate the xanthan gum solution`s ability to increase surfactant solution`s sweep efficiency and limit viscous fingering.« less

Principles and implementations of electrolysis systems for water splitting

DOE PAGES

Xiang, Chengxiang; Papadantonakis, Kimberly M.; Lewis, Nathan S.

2016-02-12

Efforts to develop renewable sources of carbon-neutral fuels have brought a renewed focus to research and development of sunlight-driven water-splitting systems. Electrolysis of water to produce H 2 and O 2 gases is the foundation of such systems, is conceptually and practically simple, and has been practiced both in the laboratory and industrially for many decades. In this Focus article, the fundamentals of water splitting and practices which distinguish commercial water-electrolysis systems from simple laboratory-scale demonstrations are described.

United Nations Environment Programme Capacity Building Pilot Project--training and interlaboratory study on persistent organic pollutant analysis under the Stockholm Convention.

PubMed

de Boer, J; Leslie, H; van Leeuwen, S P J; Wegener, J-W; van Bavel, B; Lindström, G; Lahoutifard, N; Fiedler, H

2008-06-09

Within the framework of a United Nations Environment Programme (UNEP) Capacity Building Project for training of laboratory staff in developing countries on persistent organic pollutant (POP) analysis, an interlaboratory study was organised following an initial evaluation of the performance of laboratories (reality check) and a series of training sessions. The target compounds were polychlorinated biphenyls (PCB) and organochlorine pesticides (OCP). Seven laboratories from five countries (Ecuador, Uruguay, Kenya, Moldova, and Fiji) participated. Most of the laboratories had no experience in determining PCBs. Although chromatograms improved considerably after the training and installation of new gas chromatographic (GC) columns at participating laboratories, the level of performance in the interlaboratory study was essentially on par with the moderate performance level achieved by European POP laboratories in the 1980s. Only some individual results were within +/-20% of the target values. The relative standard deviations (R.S.D.s) in POP concentrations determined by laboratories in a sediment sample were >200% in a number of cases. The results for a certified herring sample were better with at least some R.S.D. values below 50% and most below 100%. Clean up was as one of the main sources of error. After inspection it was ascertained that training of laboratory staff and investments in simple consumables such as glassware and GC columns would help to improve the quality of the analysis more than major investments in expensive instrumentation. Creating an effective network of POP laboratories at different continents together with a series of interlaboratory studies and workshops is suggested to improve the measurements of POPs in these countries.

Notes: Water Flow and Chemical Retardation in Soils: A Simple Effective Laboratory Demonstration.

ERIC Educational Resources Information Center

Bowman, R. S.; And Others

1988-01-01

Describes a laboratory demonstration that illustrates principles of miscible displacement and chemical retardation in soils. Discusses how the experimental apparatus can be constructed from readily available materials. (TW)

Simple Exploration Apparatus for the Introductory Physics Laboratory

ERIC Educational Resources Information Center

Campbell, Thomas C.

1977-01-01

Discusses the laboratory portion of a beginning noncalculus physics course that uses concrete examples of abstract concepts. Describes the use of coffee cans to explain oscillations and plastic darts to illustrate collisions. (MLH)

Maui Space Surveillance System Satellite Categorization Laboratory

NASA Astrophysics Data System (ADS)

Deiotte, R.; Guyote, M.; Kelecy, T.; Hall, D.; Africano, J.; Kervin, P.

The MSSS satellite categorization laboratory is a fusion of robotics and digital imaging processes that aims to decompose satellite photometric characteristics and behavior in a controlled setting. By combining a robot, light source and camera to acquire non-resolved images of a model satellite, detailed photometric analyses can be performed to extract relevant information about shape features, elemental makeup, and ultimately attitude and function. Using the laboratory setting a detailed analysis can be done on any type of material or design and the results cataloged in a database that will facilitate object identification by "curve-fitting" individual elements in the basis set to observational data that might otherwise be unidentifiable. Currently the laboratory has created, an ST-Robotics five degree of freedom robotic arm, collimated light source and non-focused Apogee camera have all been integrated into a MATLAB based software package that facilitates automatic data acquisition and analysis. Efforts to date have been aimed at construction of the lab as well as validation and verification of simple geometric objects. Simple tests on spheres, cubes and simple satellites show promising results that could lead to a much better understanding of non-resolvable space object characteristics. This paper presents a description of the laboratory configuration and validation test results with emphasis on the non-resolved photometric characteristics for a variety of object shapes, spin dynamics and orientations. The future vision, utility and benefits of the laboratory to the SSA community as a whole are also discussed.

Induced dynamic nonlinear ground response at Gamer Valley, California

USGS Publications Warehouse

Lawrence, Z.; Bodin, P.; Langston, C.A.; Pearce, F.; Gomberg, J.; Johnson, P.A.; Menq, F.-Y.; Brackman, T.

2008-01-01

We present results from a prototype experiment in which we actively induce, observe, and quantify in situ nonlinear sediment response in the near surface. This experiment was part of a suite of experiments conducted during August 2004 in Garner Valley, California, using a large mobile shaker truck from the Network for Earthquake Engineering Simulation (NEES) facility. We deployed a dense accelerometer array within meters of the mobile shaker truck to replicate a controlled, laboratory-style soil dynamics experiment in order to observe wave-amplitude-dependent sediment properties. Ground motion exceeding 1g acceleration was produced near the shaker truck. The wave field was dominated by Rayleigh surface waves and ground motions were strong enough to produce observable nonlinear changes in wave velocity. We found that as the force load of the shaker increased, the Rayleigh-wave phase velocity decreased by as much as ???30% at the highest frequencies used (up to 30 Hz). Phase velocity dispersion curves were inverted for S-wave velocity as a function of depth using a simple isotropic elastic model to estimate the depth dependence of changes to the velocity structure. The greatest change in velocity occurred nearest the surface, within the upper 4 m. These estimated S-wave velocity values were used with estimates of surface strain to compare with laboratory-based shear modulus reduction measurements from the same site. Our results suggest that it may be possible to characterize nonlinear soil properties in situ using a noninvasive field technique.

X-ray pinhole camera setups used in the Atomki ECR Laboratory for plasma diagnostics.

PubMed

Rácz, R; Biri, S; Pálinkás, J; Mascali, D; Castro, G; Caliri, C; Romano, F P; Gammino, S

2016-02-01

Imaging of the electron cyclotron resonance (ECR) plasmas by using CCD camera in combination with a pinhole is a non-destructive diagnostics method to record the strongly inhomogeneous spatial density distribution of the X-ray emitted by the plasma and by the chamber walls. This method can provide information on the location of the collisions between warm electrons and multiple charged ions/atoms, opening the possibility to investigate the direct effect of the ion source tuning parameters to the plasma structure. The first successful experiment with a pinhole X-ray camera was carried out in the Atomki ECR Laboratory more than 10 years ago. The goal of that experiment was to make the first ECR X-ray photos and to carry out simple studies on the effect of some setting parameters (magnetic field, extraction, disc voltage, gas mixing, etc.). Recently, intensive efforts were taken to investigate now the effect of different RF resonant modes to the plasma structure. Comparing to the 2002 experiment, this campaign used wider instrumental stock: CCD camera with a lead pinhole was placed at the injection side allowing X-ray imaging and beam extraction simultaneously. Additionally, Silicon Drift Detector (SDD) and High Purity Germanium (HPGe) detectors were installed to characterize the volumetric X-ray emission rate caused by the warm and hot electron domains. In this paper, detailed comparison study on the two X-ray camera and detector setups and also on the technical and scientific goals of the experiments is presented.

Online versus offline: The Web as a medium for response time data collection.

PubMed

Chetverikov, Andrey; Upravitelev, Philipp

2016-09-01

The Internet provides a convenient environment for data collection in psychology. Modern Web programming languages, such as JavaScript or Flash (ActionScript), facilitate complex experiments without the necessity of experimenter presence. Yet there is always a question of how much noise is added due to the differences between the setups used by participants and whether it is compensated for by increased ecological validity and larger sample sizes. This is especially a problem for experiments that measure response times (RTs), because they are more sensitive (and hence more susceptible to noise) than, for example, choices per se. We used a simple visual search task with different set sizes to compare laboratory performance with Web performance. The results suggest that although the locations (means) of RT distributions are different, other distribution parameters are not. Furthermore, the effect of experiment setting does not depend on set size, suggesting that task difficulty is not important in the choice of a data collection method. We also collected an additional online sample to investigate the effects of hardware and software diversity on the accuracy of RT data. We found that the high diversity of browsers, operating systems, and CPU performance may have a detrimental effect, though it can partly be compensated for by increased sample sizes and trial numbers. In sum, the findings show that Web-based experiments are an acceptable source of RT data, comparable to a common keyboard-based setup in the laboratory.

Elimination profile of methylthiouracil in cows after oral administration.

PubMed

Heeremans, A; Ermens, A; De Wasch, K K; Van Peteghem, C; De Brabander, H F

1998-12-01

In addition to methods for the determination of residues, there is an important need for knowledge of the fate and excretion of growth promoting substances in fattening animals. In court, often simple questions are asked, such as, over what period of time can the drug be detected?, is it possible to find residues after 2 months, etc. These questions can only be answered by conducting animal experiments. Data on excretion and distribution of thiouracils in cows are rather scarce. At the beginning of the 1980s, animal experiments with methylthiouracil (MTU) were carried out in the Laboratory of Chemical Analysis. These experiments showed that treatment of cows with MTU results in the rapid appearance of the drug in plasma, urine and milk, whereas MTU selectively accumulates in the thyroid gland. The results of these experiments were only published in media with limited access (thesis, abstracts) and also there has been a considerable improvement in data handling with computer programs in the last 15 years. This investigation reinterprets the 'old' analytical data from animal experiments using a pharmacokinetic software package.

Dynamic cell culture system (7-IML-1)

NASA Technical Reports Server (NTRS)

Cogoli, Augusto

1992-01-01

This experiment is one of the Biorack experiments being flown on the International Microgravity Laboratory 1 (MIL-1) mission as part of an investigation studying cell proliferation and performance in space. One of the objectives of this investigation is to assess the potential benefits of bioprocessing in space with the ultimate goal of developing a bioreactor for continuous cell cultures in space. This experiment will test the operation of an automated culture chamber that was designed for use in a Bioreactor in space. The device to be tested is called the Dynamic Cell Culture System (DCCS). It is a simple device in which media are renewed or chemicals are injected automatically, by means of osmotic pumps. This experiment uses four Type I/O experiment containers. One DCCS unit, which contains a culture chamber with renewal of medium and a second chamber without a medium supply fits in each container. Two DCCS units are maintained under zero gravity conditions during the on-orbit period. The other two units are maintained under 1 gh conditions in a 1 g centrifuge. The schedule for incubator transfer is given.

Communicate science: an example of food related hands-on laboratory approach

NASA Astrophysics Data System (ADS)

D'Addezio, Giuliana; Marsili, Antonella; Vallocchia, Massimiliano

2014-05-01

The Laboratorio Didattica e Divulgazione Scientifica of the Istituto Nazionale di Geofisica e Vulcanologia (INGV's Educational and Outreach Laboratory) organized activity with kids to convey scientific knowledge and to promote research on Earth Science, focusing on volcanic and seismic hazard. The combination of games and learning in educational activity can be a valuable tool for study of complex phenomena. Hands-on activity may help in engage kids in a learning process through direct participation that significantly improves the learning performance of children. Making learning fun motivate audience to pay attention on and stay focused on the subject. We present the experience of the hand-on laboratory "Laboratorio goloso per bambini curiosi di scienza (a delicious hands-on laboratory for kids curious about science)", performed in Frascati during the 2013 European Researchers' Night, promoted by the European Commission, as part of the program organized by the Laboratorio Didattica e Divulgazione Scientifica in the framework of Associazione Frascati Scienza (http://www.frascatiscienza.it/). The hand-on activity were designed for primary schools to create enjoyable and unusual tools for learning Earth Science. During this activity kids are involved with something related to everyday life, such as food, through manipulation, construction and implementation of simple experiments related to Earth dynamics. Children become familiar with scientific concepts such as composition of the Earth, plates tectonic, earthquakes and seismic waves propagation and experience the effect of earthquakes on buildings, exploring their important implications for seismic hazard. During the activity, composed of several steps, participants were able to learn about Earth inner structure, fragile lithosphere, waves propagations, impact of waves on building ecc.., dealing with eggs, cookies, honey, sugar, polenta, flour, chocolate, candies, liquorice sticks, bread, pudding and sweets. The activity was successful as more than 500 kids of different ages participated with great enthusiasm, as well as they parents, and gave the chance to explore and manipulate even complex scientific arguments without getting the feeling of having doing this.

Measurement of lifespan in Drosophila melanogaster.

PubMed

Linford, Nancy J; Bilgir, Ceyda; Ro, Jennifer; Pletcher, Scott D

2013-01-07

Aging is a phenomenon that results in steady physiological deterioration in nearly all organisms in which it has been examined, leading to reduced physical performance and increased risk of disease. Individual aging is manifest at the population level as an increase in age-dependent mortality, which is often measured in the laboratory by observing lifespan in large cohorts of age-matched individuals. Experiments that seek to quantify the extent to which genetic or environmental manipulations impact lifespan in simple model organisms have been remarkably successful for understanding the aspects of aging that are conserved across taxa and for inspiring new strategies for extending lifespan and preventing age-associated disease in mammals. The vinegar fly, Drosophila melanogaster, is an attractive model organism for studying the mechanisms of aging due to its relatively short lifespan, convenient husbandry, and facile genetics. However, demographic measures of aging, including age-specific survival and mortality, are extraordinarily susceptible to even minor variations in experimental design and environment, and the maintenance of strict laboratory practices for the duration of aging experiments is required. These considerations, together with the need to practice careful control of genetic background, are essential for generating robust measurements. Indeed, there are many notable controversies surrounding inference from longevity experiments in yeast, worms, flies and mice that have been traced to environmental or genetic artifacts(1-4). In this protocol, we describe a set of procedures that have been optimized over many years of measuring longevity in Drosophila using laboratory vials. We also describe the use of the dLife software, which was developed by our laboratory and is available for download (http://sitemaker.umich.edu/pletcherlab/software). dLife accelerates throughput and promotes good practices by incorporating optimal experimental design, simplifying fly handling and data collection, and standardizing data analysis. We will also discuss the many potential pitfalls in the design, collection, and interpretation of lifespan data, and we provide steps to avoid these dangers.

Application of modern radiative transfer tools to model laboratory quartz emissivity

NASA Astrophysics Data System (ADS)

Pitman, Karly M.; Wolff, Michael J.; Clayton, Geoffrey C.

2005-08-01

Planetary remote sensing of regolith surfaces requires use of theoretical models for interpretation of constituent grain physical properties. In this work, we review and critically evaluate past efforts to strengthen numerical radiative transfer (RT) models with comparison to a trusted set of nadir incidence laboratory quartz emissivity spectra. By first establishing a baseline statistical metric to rate successful model-laboratory emissivity spectral fits, we assess the efficacy of hybrid computational solutions (Mie theory + numerically exact RT algorithm) to calculate theoretical emissivity values for micron-sized α-quartz particles in the thermal infrared (2000-200 cm-1) wave number range. We show that Mie theory, a widely used but poor approximation to irregular grain shape, fails to produce the single scattering albedo and asymmetry parameter needed to arrive at the desired laboratory emissivity values. Through simple numerical experiments, we show that corrections to single scattering albedo and asymmetry parameter values generated via Mie theory become more necessary with increasing grain size. We directly compare the performance of diffraction subtraction and static structure factor corrections to the single scattering albedo, asymmetry parameter, and emissivity for dense packing of grains. Through these sensitivity studies, we provide evidence that, assuming RT methods work well given sufficiently well-quantified inputs, assumptions about the scatterer itself constitute the most crucial aspect of modeling emissivity values.

Laboratory Demonstration of Axicon-Lens Coronagraph

NASA Astrophysics Data System (ADS)

Choi, Jaeho; Jea, Geonho

2018-01-01

The results of laboratory based experiments of the proposed coronagraph using axicon-lenses that is conjunction with a method of noninterferometric quantitative phase imaging for direct imaging of exoplanets is will present. The light source is passing through tiny holes drilled on the thin metal plate is used as the simulated stellar and its companions. Those diffracted light at the edge of the holes bears a similarity to the light from the bright stellar. Those images are evaginated about the optical axis after the maximum focal length of the first axicon lens. Then the evaginated images of have cut off using the motorized iris which means the suppressed the central stellar light preferentially. Various length between the holes which represent the angular distance are examined. The laboratory experimental results are shown that the axicon-lens coronagraph has feature of ability to achieve the smaller IWA than l/D and high-contrast direct imaging. The laboratory based axicon-lens coronagraph imaging support the symbolic computation results which has potential in direct imaging for finding exoplanet and various astrophysical activities. The setup of the coronagraph is simple to build and is durable to operate. Moreover it can be transported the planets images to a broadband spectrometric instrument that able to investigate the constituent of the planetary system.

Reinforced Superhydrophobic Coating on Silicone Rubber for Longstanding Anti-Icing Performance in Severe Conditions.

PubMed

Emelyanenko, Alexandre M; Boinovich, Ludmila B; Bezdomnikov, Alexey A; Chulkova, Elizaveta V; Emelyanenko, Kirill A

2017-07-19

We present a simple method for fabricating the superhydrophobic coatings on composite silicone rubber used for electrical outdoor applications. The coating is characterized by contact angles as high as 170° and is mechanically durable in contact with the aqueous phase. We discuss the impact of mechanical durability of the surface texture on the anti-icing performance of the coating on the basis of the experimental data on freezing delay of sessile aqueous droplets. A set of complementary data obtained in laboratory and outdoor experiments on freezing delay time, variation of wettability and practical work of adhesion for supercooled aqueous sessile droplets, impacting behavior of droplets at low negative temperatures, as well as the results of snow and ice accumulation in outdoor experiments indicate the very prospective icephobic properties of the developed coating.

Enhancement of magnetocaloric effect in the Gd 2Al phase by Co alloying

DOE PAGES

Huang, Z. Y.; Fu, H.; Hadimani, R. L.; ...

2014-11-14

We observe that Cu clusters grow on surface terraces of graphite as a result of physical vapor deposition in ultrahigh vacuum. We show that the observation is incompatible with a variety of models incorporating homogeneous nucleation and high level calculations of atomic-scale energetics. An alternative explanation, ion-mediated heterogeneous nucleation, is proposed and validated, both with theory and experiment. This serves as a case study in identifying when and whether the simple, common observation of metal clusters on carbon-rich surfaces can be interpreted in terms of homogeneous nucleation. We describe a general approach for making system-specific and laboratory-specific predictions.

Ambiguity produces attention shifts in category learning.

PubMed

Vadillo, Miguel A; Orgaz, Cristina; Luque, David; Nelson, James Byron

2016-04-01

It has been suggested that people and nonhuman animals protect their knowledge from interference by shifting attention toward the context when presented with information that contradicts their previous beliefs. Despite that suggestion, no studies have directly measured changes in attention while participants are exposed to an interference treatment. In the present experiments, we adapted a dot-probe task to track participants' attention to cues and contexts while they were completing a simple category learning task. The results support the hypothesis that interference produces a change in the allocation of attention to cues and contexts. © 2016 Vadillo et al.; Published by Cold Spring Harbor Laboratory Press.

The Physics of Protoplanetary Dust Agglomerates. X. High-velocity Collisions between Small and Large Dust Agglomerates as a Growth Barrier

NASA Astrophysics Data System (ADS)

Schräpler, Rainer; Blum, Jürgen; Krijt, Sebastiaan; Raabe, Jan-Hendrik

2018-01-01

In a protoplanetary disk, dust aggregates in the μm to mm size range possess mean collision velocities of 10–60 m s‑1 with respect to dm- to m-sized bodies. We performed laboratory collision experiments to explore this parameter regime and found a size- and velocity-dependent threshold between erosion and growth. By using a local Monte Carlo coagulation calculation and along with a simple semi-analytical timescale approach, we show that erosion considerably limits particle growth in protoplanetary disks and leads to a steady-state dust-size distribution from μm- to dm-sized particles.

Assessment of the MHD capability in the ATHENA code using data from the ALEX facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roth, P.A.

1989-03-01

The ATHENA (Advanced Thermal Hydraulic Energy Network Analyzer) code is a system transient analysis code with multi-loop, multi-fluid capabilities, which is available to the fusion community at the National Magnetic Fusion Energy Computing Center (NMFECC). The work reported here assesses the ATHENA magnetohydrodynamic (MHD) pressure drop model for liquid metals flowing through a strong magnetic field. An ATHENA model was developed for two simple geometry, adiabatic test sections used in the Argonne Liquid Metal Experiment (ALEX) at Argonne National Laboratory (ANL). The pressure drops calculated by ATHENA agreed well with the experimental results from the ALEX facility.

Analysis of the linearity of half periods of the Lorentz pendulum

NASA Astrophysics Data System (ADS)

Wickramasinghe, T.; Ochoa, R.

2005-05-01

We analyze the motion of the Lorentz pendulum, a simple pendulum whose length is changed at a constant rate k. We show both analytically and numerically that the half period Tn, the time between half oscillations as measured from midpoint to midpoint, increases linearly with the oscillation number n such that Tn+1-Tn≈kπ2/2g, where g is the acceleration due to gravity. A video camera is used to record the motion of the oscillating bob of the pendulum and verify the linearity of Tn with oscillation number. The theory and the experiment are suitable for an advanced undergraduate laboratory.

Dannie Heineman Prize for Mathematical Physics: Applying mathematical techniques to solve important problems in quantum theory

NASA Astrophysics Data System (ADS)

Bender, Carl

2017-01-01

The theory of complex variables is extremely useful because it helps to explain the mathematical behavior of functions of a real variable. Complex variable theory also provides insight into the nature of physical theories. For example, it provides a simple and beautiful picture of quantization and it explains the underlying reason for the divergence of perturbation theory. By using complex-variable methods one can generalize conventional Hermitian quantum theories into the complex domain. The result is a new class of parity-time-symmetric (PT-symmetric) theories whose remarkable physical properties have been studied and verified in many recent laboratory experiments.

Using Single Drop Microextraction for Headspace Analysis with Gas Chromatography

NASA Astrophysics Data System (ADS)

Riccio, Daniel; Wood, Derrick C.; Miller, James M.

2008-07-01

Headspace (HS) gas chromatography (GC) is commonly used to analyze samples that contain non-volatiles. In 1996, a new sampling technique called single drop microextraction, SDME, was introduced, and in 2001 it was applied to HS analysis. It is a simple technique that uses equipment normally found in the undergraduate laboratory, making it ideal for instructional use, especially to illustrate HS analysis or as an alternative to solid-phase microextraction (SPME) to which it is very similar. The basic principles and practice of HS-GC using SDME are described, including a complete review of the literature. Some possible experiments are suggested using water and N -methylpyrrolidone (NMP) as solvents.

Determining whether metals nucleate homogeneously on graphite: A case study with copper

DOE PAGES

Appy, David; Lei, Huaping; Han, Yong; ...

2014-11-05

In this study, we observe that Cu clusters grow on surface terraces of graphite as a result of physical vapor deposition in ultrahigh vacuum. We show that the observation is incompatible with a variety of models incorporating homogeneous nucleation and calculations of atomic-scale energetics. An alternative explanation, ion-mediated heterogeneous nucleation, is proposed and validated, both with theory and experiment. This serves as a case study in identifying when and whether the simple, common observation of metal clusters on carbon-rich surfaces can be interpreted in terms of homogeneous nucleation. We describe a general approach for making system-specific and laboratory-specific predictions.

Create your own science planning tool in 3 days with SOA

NASA Technical Reports Server (NTRS)

Streiffert, Barbara A.; Polanskey, Carol A.; O'Reilly, Taifun

2003-01-01

Scientific discovery and advancement of knowledge has been, and continues to be, the goal for space missions at Jet Propulsion Laboratory. Scientist must plan their observation/experiments to get the maximum data return in order to make those discoveries. However, each mission has different science objectives, a different spacecraft and different instrument payloads, as well as, different routes to different destinations with different spacecraft restrictions and characteristics. In the current reduced cost environment, manageable cost for mission planning software is a must. Science Opportunity Analyzer (SOA), a planning tool for scientists and mission planners, utilizes a simple approach to reduce cost and promote reusability.

Introducing Laboratory Safety.

ERIC Educational Resources Information Center

DeLorenzo, Ronald

1985-01-01

Presents a simple, 10-item quiz designed to make students aware that they must learn laboratory safety. The items include questions on acid/base accidents, several types of fire extinguishers, and safety glassses. Answers and some explanations are included. (DH)

Teacher Research Experience Programs = Increase in Student Achievement

NASA Astrophysics Data System (ADS)

Dubner, J.

2010-12-01

Columbia University's Summer Research Program for Science Teachers (SRP), founded in 1990, is one of the largest, best known university-based professional development programs for science teachers in the U.S. The program’s basic premise is simple: teachers cannot effectively teach science if they have not experienced it firsthand. For eight weeks in each of two consecutive summers, teachers participate as a member of a research team, led by a member of Columbia University’s research faculty. In addition to the laboratory experience, all teachers meet as a group one day each week during the summer for a series of pedagogical activities. A unique quality of the Summer Research Program is its focus on objective assessment of its impact on attitudes and instructional practices of participating teachers, on the performance of these teachers in their mentors’ laboratories, and most importantly, on the impact of their participation in the program on student interest and performance in science. SRP uses pass rate on the New York State Regents standardized science examinations as an objective measure of student achievement. SRP's data is the first scientific evidence of a connection between a research experience for teachers program and gains in student achievement. As a result of the research, findings were published in Science Magazine. The author will present an overview of Columbia's teacher research program and the results of the published program evaluation.

Cumulative culture in the laboratory: methodological and theoretical challenges.

PubMed

Miton, Helena; Charbonneau, Mathieu

2018-05-30

In the last decade, cultural transmission experiments (transmission chains, replacement, closed groups and seeded groups) have become important experimental tools in investigating cultural evolution. However, these methods face important challenges, especially regarding the operationalization of theoretical claims. In this review, we focus on the study of cumulative cultural evolution, the process by which traditions are gradually modified and, for technological traditions in particular, improved upon over time. We identify several mismatches between theoretical definitions of cumulative culture and their implementation in cultural transmission experiments. We argue that observed performance increase can be the result of participants learning faster in a group context rather than effectively leading to a cumulative effect. We also show that in laboratory experiments, participants are asked to complete quite simple tasks, which can undermine the evidential value of the diagnostic criterion traditionally used for cumulative culture (i.e. that cumulative culture is a process that produces solutions that no single individual could have invented on their own). We show that the use of unidimensional metrics of cumulativeness drastically curtail the variation that may be observed, which raises specific issues in the interpretation of the experimental evidence. We suggest several solutions to these mismatches (learning times, task complexity and variation) and develop the use of design spaces in experimentally investigating old and new questions about cumulative culture. © 2018 The Author(s).

Laboratory Experiments on Rotation and Alignment of the Analogs of Interstellar Dust Grains by Radiation

NASA Technical Reports Server (NTRS)

Abbas, M. M.; Craven, P. D.; Spann, J. F.; Tankosic, D.; LeClair, A.; Gallagher, D. L.; West, E. A.; Weingartner, J. C.; Witherow, W. K.; Tielens, A. G. G. M.

2004-01-01

The processes and mechanisms involved in the rotation and alignment of interstellar dust grains have been of great interest in astrophysics ever since the surprising discovery of the polarization of starlight more than half a century ago. Numerous theories, detailed mathematical models, and numerical studies of grain rotation and alignment with respect to the Galactic magnetic field have been presented in the literature. In particular, the subject of grain rotation and alignment by radiative torques has been shown to be of particular interest in recent years. However, despite many investigations, a satisfactory theoretical understanding of the processes involved in subject, we have carried out some unique experiments to illuminate the processes involved in the rotation of dust grains in the interstellar medium. In this paper we present the results of some preliminary laboratory experiments on the rotation of individual micron/submicron-sized, nonspherical dust grains levitated in an electrodynamic balance evacuated to pressures of approximately 10(exp -3) to 10(exp -5) torr. The particles are illuminated by laser light at 5320 A, and the grain rotation rates are obtained by analyzing the low-frequency (approximately 0 - 100 kHz) signal of the scattered light detected by a photodiode detector. The rotation rates are compared with simple theoretical models to retrieve some basic rotational parameters. The results are examined in light of the current theories of alignment.

In-group modulation of perceptual matching.

PubMed

Moradi, Zargol; Sui, Jie; Hewstone, Miles; Humphreys, Glyn W

2015-10-01

We report a novel effect of in-group bias on a task requiring simple perceptual matching of stimuli. Football fans were instructed to associate the badges of their favorite football team (in-group), a rival team (out-group), and neutral teams with simple geometric shapes. Responses to matching in-group stimuli were more efficient, and discriminability was enhanced, as compared to out-group stimuli (rival and neutral)-a result that occurred even when participants responded only to the (equally familiar) geometric shapes. Across individuals, the in-group bias on shape matching was correlated with measures of group satisfaction, and similar results were found when football fans performed the task, in the context of both the football ground and a laboratory setting. We also observed effects of in-group bias on the response criteria in some but not all of the experiments. In control studies, the advantage for in-group stimuli was not found in an independent sample of participants who were not football fans. This indicates that there was not an intrinsic advantage for the stimuli that were "in-group" for football fans. Also, performance did not differ for familiar versus unfamiliar stimuli without in-group associations. These findings indicate that group identification can affect simple shape matching.

A Fan-tastic Quantitative Exploration of Ohm's Law

NASA Astrophysics Data System (ADS)

Mitchell, Brandon; Ekey, Robert; McCullough, Roy; Reitz, William

2018-02-01

Teaching simple circuits and Ohm's law to students in the introductory classroom has been extensively investigated through the common practice of using incandescent light bulbs to help students develop a conceptual foundation before moving on to quantitative analysis. However, the bulb filaments' resistance has a large temperature dependence, which makes them less suitable as a tool for quantitative analysis. Some instructors show that light bulbs do not obey Ohm's law either outright or through inquiry-based laboratory experiments. Others avoid the subject altogether by using bulbs strictly for qualitative purposes and then later switching to resistors for a numerical analysis, or by changing the operating conditions of the bulb so that it is "barely" glowing. It seems incongruous to develop a conceptual basis for the behavior of simple circuits using bulbs only to later reveal that they do not follow Ohm's law. Recently, small computer fans were proposed as a suitable replacement of bulbs for qualitative analysis of simple circuits where the current is related to the rotational speed of the fans. In this contribution, we demonstrate that fans can also be used for quantitative measurements and provide suggestions for successful classroom implementation.

Simple Sodium Dodecyl Sulfate-Assisted Sample Preparation Method for LC-MS-based Proteomic Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Jianying; Dann, Geoffrey P.; Shi, Tujin

2012-03-10

Sodium dodecyl sulfate (SDS) is one of the most popular laboratory reagents used for highly efficient biological sample extraction; however, SDS presents a significant challenge to LC-MS-based proteomic analyses due to its severe interference with reversed-phase LC separations and electrospray ionization interfaces. This study reports a simple SDS-assisted proteomic sample preparation method facilitated by a novel peptide-level SDS removal protocol. After SDS-assisted protein extraction and digestion, SDS was effectively (>99.9%) removed from peptides through ion substitution-mediated DS- precipitation with potassium chloride (KCl) followed by {approx}10 min centrifugation. Excellent peptide recovery (>95%) was observed for less than 20 {mu}g of peptides.more » Further experiments demonstrated the compatibility of this protocol with LC-MS/MS analyses. The resulting proteome coverage from this SDS-assisted protocol was comparable to or better than those obtained from other standard proteomic preparation methods in both mammalian tissues and bacterial samples. These results suggest that this SDS-assisted protocol is a practical, simple, and broadly applicable proteomic sample processing method, which can be particularly useful when dealing with samples difficult to solubilize by other methods.« less

Simple and Rapid System for Two-Dimensional Gel Electrophoresis Technique: A Laboratory Exercise for High School Students

ERIC Educational Resources Information Center

Maurye, Praveen; Basu, Arpita; Biswas, Jayanta Kumar; Bandyopadhyay, Tapas Kumar; Naskar, Malay

2018-01-01

Polyacrylamide gel electrophoresis (PAGE) is the most classical technique favored worldwide for resolution of macromolecules in many biochemistry laboratories due to its incessant advanced developments and wide modifications. These ever-growing advancements in the basic laboratory equipments lead to emergence of many expensive, complex, and tricky…

Feasibility of a simple laboratory approach for determining temperature influence on SPMD–air partition coefficients of selected compounds

USGS Publications Warehouse

Cicenaite, Aurelija; Huckins, James N.; Alvarez, David A.; Cranor, Walter L.; Gale, Robert W.; Kauneliene, Violeta; Bergqvist, Per-Anders

2007-01-01

Semipermeable membrane devices (SPMDs) are a widely used passive sampling methodology for both waterborne and airborne hydrophobic organic contaminants. The exchange kinetics and partition coefficients of an analyte in a SPMD are mediated by its physicochemical properties and certain environmental conditions. Controlled laboratory experiments are used for determining the SPMD–air (Ksa's) partition coefficients and the exchange kinetics of organic vapors. This study focused on determining a simple approach for measuring equilibrium Ksa's for naphthalene (Naph), o-chlorophenol (o-CPh) and p-dichlorobenzene (p-DCB) over a wide range of temperatures. SPMDs were exposed to test chemical vapors in small, gas-tight chambers at four different temperatures (−16, −4, 22 and 40 °C). The exposure times ranged from 6 h to 28 d depending on test temperature. Ksa's or non-equilibrium concentrations in SPMDs were determined for all compounds, temperatures and exposure periods with the exception of Naph, which could not be quantified in SPMDs until 4 weeks at the −16 °C temperature. To perform this study the assumption of constant and saturated atmospheric concentrations in test chambers was made. It could influence the results, which suggest that flow through experimental system and performance reference compounds should be used for SPMD calibration.

Can simple tank changes benefit the welfare of laboratory zebrafish Danio rerio?

PubMed

Lee, C J; Tyler, C R; Paull, G C

2018-03-01

This study examined the effects of simple changes in the tank environment on the wellbeing of laboratory-maintained zebrafish Danio rerio. Groups of D. rerio were either housed in stable environments (where they were maintained in the same tanks throughout the study) or in environments subject to change (where they were periodically moved to novel but identical tanks) and the effects of these treatments on morphometry, reproductive success and aggressive behaviour assessed. No effect of simple tank changes was found on body condition, reproductive output or aggression, for the periods of time studied, indicating that more complex scenarios in housing tank conditions are required for significant welfare benefits for captive D. rerio. © 2018 The Fisheries Society of the British Isles.

Engineered nanomaterials: toward effective safety management in research laboratories.

PubMed

Groso, Amela; Petri-Fink, Alke; Rothen-Rutishauser, Barbara; Hofmann, Heinrich; Meyer, Thierry

2016-03-15

It is still unknown which types of nanomaterials and associated doses represent an actual danger to humans and environment. Meanwhile, there is consensus on applying the precautionary principle to these novel materials until more information is available. To deal with the rapid evolution of research, including the fast turnover of collaborators, a user-friendly and easy-to-apply risk assessment tool offering adequate preventive and protective measures has to be provided. Based on new information concerning the hazards of engineered nanomaterials, we improved a previously developed risk assessment tool by following a simple scheme to gain in efficiency. In the first step, using a logical decision tree, one of the three hazard levels, from H1 to H3, is assigned to the nanomaterial. Using a combination of decision trees and matrices, the second step links the hazard with the emission and exposure potential to assign one of the three nanorisk levels (Nano 3 highest risk; Nano 1 lowest risk) to the activity. These operations are repeated at each process step, leading to the laboratory classification. The third step provides detailed preventive and protective measures for the determined level of nanorisk. We developed an adapted simple and intuitive method for nanomaterial risk management in research laboratories. It allows classifying the nanoactivities into three levels, additionally proposing concrete preventive and protective measures and associated actions. This method is a valuable tool for all the participants in nanomaterial safety. The users experience an essential learning opportunity and increase their safety awareness. Laboratory managers have a reliable tool to obtain an overview of the operations involving nanomaterials in their laboratories; this is essential, as they are responsible for the employee safety, but are sometimes unaware of the works performed. Bringing this risk to a three-band scale (like other types of risks such as biological, radiation, chemical, etc.) facilitates the management for occupational health and safety specialists. Institutes and school managers can obtain the necessary information to implement an adequate safety management system. Having an easy-to-use tool enables a dialog between all these partners, whose semantic and priorities in terms of safety are often different.

"In situ" extraction of essential oils by use of Dean-Stark glassware and a Vigreux column inside a microwave oven: a procedure for teaching green analytical chemistry.

PubMed

Chemat, Farid; Perino-Issartier, Sandrine; Petitcolas, Emmanuel; Fernandez, Xavier

2012-08-01

One of the principal objectives of sustainable and green processing development remains the dissemination and teaching of green chemistry in colleges, high schools, and academic laboratories. This paper describes simple glassware that illustrates the phenomenon of extraction in a conventional microwave oven as energy source and a process for green analytical chemistry. Simple glassware comprising a Dean-Stark apparatus (for extraction of aromatic plant material and recovery of essential oils and distilled water) and a Vigreux column (as an air-cooled condenser inside the microwave oven) was designed as an in-situ extraction vessel inside a microwave oven. The efficiency of this experiment was validated for extraction of essential oils from 30 g fresh orange peel, a by-product in the production of orange juice. Every laboratory throughout the world can use this equipment. The microwave power is 100 W and the irradiation time 15 min. The method is performed at atmospheric pressure without added solvent or water and furnishes essential oils similar to those obtained by conventional hydro or steam distillation. By use of GC-MS, 22 compounds in orange peel were separated and identified; the main compounds were limonene (72.1%), β-pinene (8.4%), and γ-terpinene (6.9%). This procedure is appropriate for the teaching laboratory, does not require any special microwave equipment, and enables the students to learn the skills of extraction, and chromatographic and spectroscopic analysis. They are also exposed to a dramatic visual example of rapid, sustainable, and green extraction of an essential oil, and are introduced to successful sustainable and green analytical chemistry.

An overview of methods for developing bioenergetic and life history models for rare and endangered species

USGS Publications Warehouse

Petersen, J.H.; DeAngelis, D.L.; Paukert, C.P.

2008-01-01

Many fish species are at risk to some degree, and conservation efforts are planned or underway to preserve sensitive populations. For many imperiled species, models could serve as useful tools for researchers and managers as they seek to understand individual growth, quantify predator-prey dynamics, and identify critical sources of mortality. Development and application of models for rare species however, has been constrained by small population sizes, difficulty in obtaining sampling permits, limited opportunities for funding, and regulations on how endangered species can be used in laboratory studies. Bioenergetic and life history models should help with endangered species-recovery planning since these types of models have been used successfully in the last 25 years to address management problems for many commercially and recreationally important fish species. In this paper we discuss five approaches to developing models and parameters for rare species. Borrowing model functions and parameters from related species is simple, but uncorroborated results can be misleading. Directly estimating parameters with laboratory studies may be possible for rare species that have locally abundant populations. Monte Carlo filtering can be used to estimate several parameters by means of performing simple laboratory growth experiments to first determine test criteria. Pattern-oriented modeling (POM) is a new and developing field of research that uses field-observed patterns to build, test, and parameterize models. Models developed using the POM approach are closely linked to field data, produce testable hypotheses, and require a close working relationship between modelers and empiricists. Artificial evolution in individual-based models can be used to gain insight into adaptive behaviors for poorly understood species and thus can fill in knowledge gaps. ?? Copyright by the American Fisheries Society 2008.

A simple approach for human recombinant apolipoprotein E4 expression and purification.

PubMed

Argyri, Letta; Skamnaki, Vassiliki; Stratikos, Efstratios; Chroni, Angeliki

2011-10-01

We report a simple expression and purification procedure for the production of recombinant apolipoprotein E4 (apoE4), an important protein for the lipid homeostasis in humans that plays critical roles in the pathogenesis of cardiovascular and neurodegenerative diseases. Our approach is based on the expression of a thioredoxin-apoE4 fusion construct in bacterial cells and subsequent removal of the fused thioredoxin using the highly specific 3C protease, avoiding costly and laborious lipidation-delipidation steps used before. Our approach results in rapid, high-yield production of structurally and functionally competent apoE4 as evidenced by secondary structure measurements, thermal and chemical melting profiles and the kinetic profile of solubilization of dimyristoyl-phosphatidylcholine (DMPC) vesicles. This protocol is appropriate for laboratories with little experience in apolipoprotein biochemistry and will facilitate future studies on the role of apoE4 in the pathogenesis of cardiovascular disease and neurodegenerative diseases, including Alzheimer's disease. Copyright © 2011 Elsevier Inc. All rights reserved.

Production and condensation of organic gases in the atmosphere of Titan

NASA Technical Reports Server (NTRS)

Sagan, C.; Thompson, W. R.

1982-01-01

The rates and altitudes for the dissociation of atmospheric constituents on Titan are calculated for solar ultraviolet radiation, the solar wind, Saturn magnetospheric particles, the Saturn co-rotating plasma, and cosmic rays. Laboratory experiments show that a variety of simple gas phase organic molecules and more complex organic solids called tholins are produced by such irradiations of simulated Titanian atmospheres. Except for ultraviolet wavelengths longward of the methane photodissociation continuum, most dissociation events occur between about 3100 and 3600 km altitude, corresponding well to the region of EUV opacity detected by Voyager. For a wide variety of simple to moderately complex organic gases in the Titanian atmosphere, condensation occurs below the top of the main cloud deck at about 2825 km. It is proposed that such condensates, beginning with CH4 at about 2615 km, comprise the principal mass of the Titan clouds. There is a distinct tendency for the atmosphere of Titan to act as a fractional distillation device, molecules of greater complexity condensing out at higher altitudes.

Simple method for generating adjustable trains of picosecond electron bunches

NASA Astrophysics Data System (ADS)

Muggli, P.; Allen, B.; Yakimenko, V. E.; Park, J.; Babzien, M.; Kusche, K. P.; Kimura, W. D.

2010-05-01

A simple, passive method for producing an adjustable train of picosecond electron bunches is demonstrated. The key component of this method is an electron beam mask consisting of an array of parallel wires that selectively spoils the beam emittance. This mask is positioned in a high magnetic dispersion, low beta-function region of the beam line. The incoming electron beam striking the mask has a time/energy correlation that corresponds to a time/position correlation at the mask location. The mask pattern is transformed into a time pattern or train of bunches when the dispersion is brought back to zero downstream of the mask. Results are presented of a proof-of-principle experiment demonstrating this novel technique that was performed at the Brookhaven National Laboratory Accelerator Test Facility. This technique allows for easy tailoring of the bunch train for a particular application, including varying the bunch width and spacing, and enabling the generation of a trailing witness bunch.

Experimental research control software system

NASA Astrophysics Data System (ADS)

Cohn, I. A.; Kovalenko, A. G.; Vystavkin, A. N.

2014-05-01

A software system, intended for automation of a small scale research, has been developed. The software allows one to control equipment, acquire and process data by means of simple scripts. The main purpose of that development is to increase experiment automation easiness, thus significantly reducing experimental setup automation efforts. In particular, minimal programming skills are required and supervisors have no reviewing troubles. Interactions between scripts and equipment are managed automatically, thus allowing to run multiple scripts simultaneously. Unlike well-known data acquisition commercial software systems, the control is performed by an imperative scripting language. This approach eases complex control and data acquisition algorithms implementation. A modular interface library performs interaction with external interfaces. While most widely used interfaces are already implemented, a simple framework is developed for fast implementations of new software and hardware interfaces. While the software is in continuous development with new features being implemented, it is already used in our laboratory for automation of a helium-3 cryostat control and data acquisition. The software is open source and distributed under Gnu Public License.

Simple Preparation and NMR Analysis of mer and fac Isomers of Tris(1,1,1-trifluoro-2,4-pentanedionato)cobalt(III). An Experiment for the Inorganic Chemistry Laboratory

NASA Astrophysics Data System (ADS)

Jensen, Ashley W.; O'Brien, Brian A.

2001-07-01

A one-step procedure for the preparation of tris(1,1,1-trifluoro-2,4-pentanedionato)cobalt(III) from hydrated cobalt(II) carbonate and 10% hydrogen peroxide, in which tert-butyl alcohol is used as a component of the solvent, is described. The procedure is short, simple, and less hazardous than procedures reported in the literature, and the starting materials are readily available and inexpensive. The product is a mixture of mer and fac isomers that can be separated by silica gel chromatography with toluene as the eluent. Thin-layer chromatography is used to obtain a collective class sample of each isomer for 1H, 13C, and 19F NMR analysis. The NMR analyses clearly illustrate the threefold rotational symmetry of the fac isomer and the lack of symmetry of the mer isomer. Detailed NMR data are provided for each isomer.

Colour and luminance contrasts predict the human detection of natural stimuli in complex visual environments.

PubMed

White, Thomas E; Rojas, Bibiana; Mappes, Johanna; Rautiala, Petri; Kemp, Darrell J

2017-09-01

Much of what we know about human colour perception has come from psychophysical studies conducted in tightly-controlled laboratory settings. An enduring challenge, however, lies in extrapolating this knowledge to the noisy conditions that characterize our actual visual experience. Here we combine statistical models of visual perception with empirical data to explore how chromatic (hue/saturation) and achromatic (luminant) information underpins the detection and classification of stimuli in a complex forest environment. The data best support a simple linear model of stimulus detection as an additive function of both luminance and saturation contrast. The strength of each predictor is modest yet consistent across gross variation in viewing conditions, which accords with expectation based upon general primate psychophysics. Our findings implicate simple visual cues in the guidance of perception amidst natural noise, and highlight the potential for informing human vision via a fusion between psychophysical modelling and real-world behaviour. © 2017 The Author(s).

Educating Laboratory Science Learners at a Distance Using Interactive Television

ERIC Educational Resources Information Center

Reddy, Christopher

2014-01-01

Laboratory science classes offered to students learning at a distance require a methodology that allows for the completion of tactile activities. Literature describes three different methods of solving the distance laboratory dilemma: kit-based laboratory experience, computer-based laboratory experience, and campus-based laboratory experience,…

The Source Physics Experiments (SPE) at the Nevada National Security Site (NNSS): An Overview

NASA Astrophysics Data System (ADS)

Snelson, C. M.; Chipman, V.; White, R. L.; Emmitt, R.; Townsend, M.; Barker, D.; Lee, P.

2012-12-01

Understanding the changes in seismic energy as it travels from the near field to the far field is the ultimate goal in monitoring for explosive events of interest. This requires a clear understanding of explosion phenomenology as it relates to seismic, infrasound, and acoustic signals. Although there has been much progress in modeling these phenomena, this has been primarily based in the empirical realm. As a result, the logical next step in advancing the seismic monitoring capability of the United States is to conduct field tests that can expand the predictive capability of the physics-based modeling currently under development. The Source Physics Experiment at the Nevada National Security Site (SPE) is the first step in this endeavor to link the empirically based with the physics-based modeling. This is a collaborative project between National Security Technologies (NSTec), Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Sandia National Laboratories (SNL), the Defense Threat Reduction Agency (DTRA), and the Air Force Technical Applications Center (AFTAC). The test series require both the simple and complex cases to fully characterize the problem, which is to understand the transition of seismic energy from the near field to the far field; to understand the development of S-waves in explosives sources; and how anisotropy controls seismic energy transmission and partitioning. The current series is being conducted in a granite body called the Climax Stock. This location was chosen for several reasons, including the fairly homogenous granite; the location of previous nuclear tests in the same rock body; and generally the geology has been well characterized. The simple geology series is planned for 7 shots using conventional explosives in the same shot hole surrounded by Continuous Reflectometry for Radius vs. Time Experiment (CORRTEX), Time of Arrival (TOA), Velocity of Detonation (VOD), down-hole accelerometers, surface accelerometers, infrasound, and a suite of seismic sensors of various frequency bands from the near field to the far field. This allows for the use of a single test bed in the simple geology case instead of multiple tests beds to obtain the same results. The shots are planned at various depths to obtain a Green's function, scaled-depth of burial data, nominal depth of burial data and damage zone data. SPE1 was conducted in May 2011 as a 220 lb (100 kg) TNT equivalent calibration shot at a depth of 180 ft (55 m). SPE2 was conducted in October 2011 as a 2200 lb (1000 kg) TNT equivalent calibration shot at a depth of 150 ft (46 m). SPE3 was conducted in July 2012 as a 2200 lb (1000 kg) TNT equivalent calibration shot at a depth of 150 ft (46 m) in the damaged zone. Over 400 data channels were recorded for each of these shots and data recovery was about 95% with high signal to noise ratio. Once the simple geology site data has been utilized, a new test bed will be developed in a complex geology site to test these physics based models. Ultimately, the results from this project will provide the next advances in the science of monitoring to enable a physics-based predicative capability. This work was done by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy. DOE/NV/25946--1584

The relevance of a rules-based maize marketing policy: an experimental case study of Zambia.

PubMed

Abbink, Klaus; Jayne, Thomas S; Moller, Lars C

2011-01-01

Strategic interaction between public and private actors is increasingly recognised as an important determinant of agricultural market performance in Africa and elsewhere. Trust and consultation tends to positively affect private activity while uncertainty of government behaviour impedes it. This paper reports on a laboratory experiment based on a stylised model of the Zambian maize market. The experiment facilitates a comparison between discretionary interventionism and a rules-based policy in which the government pre-commits itself to a future course of action. A simple precommitment rule can, in theory, overcome the prevailing strategic dilemma by encouraging private sector participation. Although this result is also borne out in the economic experiment, the improvement in private sector activity is surprisingly small and not statistically significant due to irrationally cautious choices by experimental governments. Encouragingly, a rules-based policy promotes a much more stable market outcome thereby substantially reducing the risk of severe food shortages. These results underscore the importance of predictable and transparent rules for the state's involvement in agricultural markets.

Techniques for the measurements of the line of sight velocity of high altitude Barium clouds

NASA Technical Reports Server (NTRS)

Mende, S. B.

1981-01-01

It is demonstrated that for maximizing the scientific output of future ion cloud release experiments a new type of instrument is required which will measure the line of sight velocity of the ion cloud by the Doppler Technique. A simple instrument was constructed using a 5 cm diameter solid Fabry-Perot etalon coupled to a low light level integrating television camera. It was demonstrated that the system has both the sensitivity and spectral resolution for the detection of ion clouds and the measurement of their line of sight Doppler velocity. The tests consisted of (1) a field experiment using a rocket barium cloud release to check the sensitivity, (2) laboratory experiments to show the spectral resolving capabilities of the system. The instrument was found to be operational if the source was brighter than about 1 kilorayleigh and it had a wavelength resolution much better than .2A which corresponds to about 12 km/sec or an acceleration potential of 100 volts.

Two-Plasmon Decay: Simulations and Experiments on the NIKE Laser System

NASA Astrophysics Data System (ADS)

Phillips, Lee; Weaver, J. L.; Oh, J.; Schmitt, A. J.; Obenschain, S.; Colombant, D.

2009-11-01

NIKE is a Krf laser system at the Naval Research Laboratory used to explore hydrodynamic stability, equation of state, and other issues arising in the research toward inertial fusion energy. The relatively small KrF wavelength, according to widely used theories, raises the threshold of most parametric instabilities. We report on simulations performed using the FAST3d radiation hydrocode to design TPD experiments. By post-processing the results of the simulations we have designed experiments that have explored the use of simple threshold formulas (from developing theories) and help establish the soundness of our simulational approach. Turning to the targets proposed for ICF energy research, we have found that among the designs for the proposed Fusion Test Facility (Obenschain et al., Phys. Plasmas 13 056320 (2006)), are some that are below LPI thresholds. We have also studied high-gain KrF shock ignition designs and found that they are below LPI thresholds for most of the implosion, becoming susceptible to TPD only late in the pulse.

Assessing the Two-Plasmon Decay Threat Through Simulations and Experiments on the NIKE Laser System

NASA Astrophysics Data System (ADS)

Phillips, Lee; Weaver, J. L.; Oh, J.; Schmitt, A. J.; Obenschain, S.

2010-11-01

NIKE is a Krf laser system at the Naval Research Laboratory used to explore hydrodynamic stability, equation of state, and other physics problems arising in IFE research. The comparatively short KrF wavelength is expected to raise the threshold of most parametric instabilities. We report on simulations performed using the FAST3d radiation hydrocode to design TPD experiments that have have allowed us to explore the validity of simple threshold formulas and help establish the accuracy of our simulations. We have also studied proposed high-gain shock ignition designs and devised experiments that can approach the relevant scalelength-temperature regime, allowing us a potential experimental method to study the LPI threat to these designs by direct observation. Through FAST3d studies of shock-ignited and conventional direct-drive designs with KrF (248 nm) and 3rd harmonic (351nm) drivers, we examine the benefits of the shorter wavelength KrF light in reducing the LPI threat.

An Inexpensive Robotics Laboratory.

ERIC Educational Resources Information Center

Inigo, R. M.; Angulo, J. M.

1985-01-01

Describes the design and implementation of a simple robot manipulator. The manipulator has three degrees of freedom and is controlled by a general purpose microcomputer. The basis for the manipulator (which costs under $100) is a simple working model of a crane. (Author/JN)

A Simple Lab Exercise Demonstrating Koch's Postulates.

ERIC Educational Resources Information Center

Fulton, Michael M.

1981-01-01

Describes a laboratory exercise which applies Koch's Postulates to a plant disease, bacterial speck. Includes an explanation of Koch's Postulate, list of equipment needed, advance preparation, outline of the three-week activity, and variations of the laboratory exercise. (DS)

DO TIE LABORATORY BASED METHODS REALLY REFLECT FIELD CONDITIONS

EPA Science Inventory

Sediment Toxicity Identification and Evaluation (TIE) methods have been developed for both interstitial waters and whole sediments. These relatively simple laboratory methods are designed to identify specific toxicants or classes of toxicants in sediments; however, the question ...

SaDA: From Sampling to Data Analysis—An Extensible Open Source Infrastructure for Rapid, Robust and Automated Management and Analysis of Modern Ecological High-Throughput Microarray Data

PubMed Central

Singh, Kumar Saurabh; Thual, Dominique; Spurio, Roberto; Cannata, Nicola

2015-01-01

One of the most crucial characteristics of day-to-day laboratory information management is the collection, storage and retrieval of information about research subjects and environmental or biomedical samples. An efficient link between sample data and experimental results is absolutely important for the successful outcome of a collaborative project. Currently available software solutions are largely limited to large scale, expensive commercial Laboratory Information Management Systems (LIMS). Acquiring such LIMS indeed can bring laboratory information management to a higher level, but most of the times this requires a sufficient investment of money, time and technical efforts. There is a clear need for a light weighted open source system which can easily be managed on local servers and handled by individual researchers. Here we present a software named SaDA for storing, retrieving and analyzing data originated from microorganism monitoring experiments. SaDA is fully integrated in the management of environmental samples, oligonucleotide sequences, microarray data and the subsequent downstream analysis procedures. It is simple and generic software, and can be extended and customized for various environmental and biomedical studies. PMID:26047146

MEASUREMENT OF WIND SPEED FROM COOLING LAKE THERMAL IMAGERY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garrett, A; Robert Kurzeja, R; Eliel Villa-Aleman, E

2009-01-20

The Savannah River National Laboratory (SRNL) collected thermal imagery and ground truth data at two commercial power plant cooling lakes to investigate the applicability of laboratory empirical correlations between surface heat flux and wind speed, and statistics derived from thermal imagery. SRNL demonstrated in a previous paper [1] that a linear relationship exists between the standard deviation of image temperature and surface heat flux. In this paper, SRNL will show that the skewness of the temperature distribution derived from cooling lake thermal images correlates with instantaneous wind speed measured at the same location. SRNL collected thermal imagery, surface meteorology andmore » water temperatures from helicopters and boats at the Comanche Peak and H. B. Robinson nuclear power plant cooling lakes. SRNL found that decreasing skewness correlated with increasing wind speed, as was the case for the laboratory experiments. Simple linear and orthogonal regression models both explained about 50% of the variance in the skewness - wind speed plots. A nonlinear (logistic) regression model produced a better fit to the data, apparently because the thermal convection and resulting skewness are related to wind speed in a highly nonlinear way in nearly calm and in windy conditions.« less

Tolerance of nonindigenous cichlid fishes (Cichlasoma urophthalmus, Hemichromis letourneuxi) to low temperature: laboratory and field experiments in south Florida

USGS Publications Warehouse

Schofield, Pamela J.; Loftus, William F.; Kobza, Robert M.; Cook, Mark I.; Slone, Daniel H.

2010-01-01

The cold tolerance of two non-native cichlids (Hemichromis letourneuxi and Cichlasoma urophthalmus) that are established in south Florida was tested in the field and laboratory. In the laboratory, fishes were acclimated to two temperatures (24 and 28°C), and three salinities (0, 10, and 35 ppt). Two endpoints were identified: loss of equilibrium (11.5–13.7°C for C. urophthalmus; 10.8–12.5°C for H. letourneuxi), and death (9.5–11.1°C for C. urophthalmus; 9.1–13.3°C for H. letourneuxi). In the field, fishes were caged in several aquatic habitats during two winter cold snaps. Temperatures were lowest (4.0°C) in the shallow marsh, where no fish survived, and warmest in canals and solution-holes. Canals and ditches as shallow as 50 cm provided thermal refuges for these tropical fishes. Because of the effect on survival of different habitat types, simple predictions of ultimate geographic expansion by non-native fishes using latitude and thermal isoclines are insufficient for freshwater fishes.

SaDA: From Sampling to Data Analysis-An Extensible Open Source Infrastructure for Rapid, Robust and Automated Management and Analysis of Modern Ecological High-Throughput Microarray Data.

PubMed

Singh, Kumar Saurabh; Thual, Dominique; Spurio, Roberto; Cannata, Nicola

2015-06-03

One of the most crucial characteristics of day-to-day laboratory information management is the collection, storage and retrieval of information about research subjects and environmental or biomedical samples. An efficient link between sample data and experimental results is absolutely important for the successful outcome of a collaborative project. Currently available software solutions are largely limited to large scale, expensive commercial Laboratory Information Management Systems (LIMS). Acquiring such LIMS indeed can bring laboratory information management to a higher level, but most of the times this requires a sufficient investment of money, time and technical efforts. There is a clear need for a light weighted open source system which can easily be managed on local servers and handled by individual researchers. Here we present a software named SaDA for storing, retrieving and analyzing data originated from microorganism monitoring experiments. SaDA is fully integrated in the management of environmental samples, oligonucleotide sequences, microarray data and the subsequent downstream analysis procedures. It is simple and generic software, and can be extended and customized for various environmental and biomedical studies.

Solid Xenon Project

NASA Astrophysics Data System (ADS)

Balakishiyeva, Durdana N.; Mahapatra, Rupak; Saab, Tarek; Yoo, Jonghee

2010-08-01

Crystals like Germanium and Silicon need to be grown in specialized facilities which is time and money costly. It takes many runs to test the detector once it's manufactured and mishaps are very probable. It is of a great challenge to grow big germanium crystals and that's why stacking them up in a tower is the only way at the moment to increase testing mass. Liquid Noble gas experiments experiencing contamination problems, their predicted energy resolution at 10 keV and lower energy range is not as good as predicted. Every experiment is targeting one specific purpose, looking for one thing. Why not to design an experiment that is diverse and build a detector that can search for Dark Matter, Solar Axions, Neutrinoless Double Beta decay, etc. Solid Xenon detector is such detector. We designed a simple Xenon crystal growing chamber that was put together at Fermi National Accelerator Laboratory. The first phase of this experiment was to demonstrate that a good, crack free Xenon crystal can be grown (regardless of many failed attempts by various groups) and our first goal, 1 kg crystal, was successful.

Electronic test and calibration circuits, a compilation

NASA Technical Reports Server (NTRS)

1972-01-01

A wide variety of simple test calibration circuits are compiled for the engineer and laboratory technician. The majority of circuits were found inexpensive to assemble. Testing electronic devices and components, instrument and system test, calibration and reference circuits, and simple test procedures are presented.