Search

The USArray Transportable Array (TA), a component of the National Science Foundation's EarthScope Initiative, has proven to be a successful model for large-scale real-time monitoring networks. Approximately 400 stations are [...]

For this month's installment, guest authors Barth and Saunders discuss the present state of size-exclusion chromatography (SEC) columns for the separation of synthetic polymers and biopolymers. A comprehensive review of [...]

This article analyzes the legal status of unmanned instruments (particularly, floats and gliders) for observation purposes in the ocean environment. These new kinds of instruments are being deployed by the thousands into the oceans, not the least as part of the Argo Project of the International Oceanographic Commission. Their uncontrolled drifting has raised legal questions, especially when such instruments enter waters subject to the jurisdiction of foreign states. The authors argue that the current international legal framework is insufficient to address the pertinent issues, and that a new legal regime is needed. Keywords Argo Project, floats, marine scientific research, scientific instruments

Volcanologists are throwing new sensors and instruments at a problem of immense societal importance: predicting when a volcano near an inhabited area may erupt. The results are encouraging but far from consistent, After 2 decades of slumber, Alaska's Redoubt volcano was growing restless. Earthquakes rattled the mountain as magma welled up through the crest. But would the magma rend the surface or [...]

This article examines the history of photometric instruments and the debate that surrounded how they should be used. The author explores the work of 19th century scientist Richard Potter, who had used the photometer to measure the reflective power of metallic and glass mirros, and the criticisms he received from wave theorists for his usage of the photometer, who claimed he used an incorrect measuring procedure.

Microplate fluorometers in laboratories have steadily become popular in laboratories. These devices, which come in various types and dynamic ranges, can effectively determine fluorescence intensity, absorbance and luminescence. Several microplate fluorometers are available on the market. These devices come in different filter capacities, sensitivity, light sources, read times, software configurations, and fluorescence modes.

Our objective was to develop a technique for cannulating the terminal ileum in pregnant sows and to evaluate the usefulness of this procedure in digestibility studies in pregnant and lactating sows. A simple T-cannula was inserted into the terminal ileum approximately 15 cm cranial to the ileo-cecal valve in a total of 15 multiparous sows at d 40 ([+ or -] 5 d) of pregnancy. All cannulated sows recovered quickly after the surgery and within 3 d they were eating normally. Elevated body temperatures were not registered in any sows, and clinical problems related to the surgery were not observed. At farrowing, normal litters were born, and number of stillborn pigs, number of live born pigs, and daily litter weight gain were not affected by the cannulations (P > .05). Of the 15 sows originally cannulated, 11 sows were used for collection of digesta during gestation and the following lactating period. Eight sows were rebred after weaning, and five sows were rebred after the second lactation period and kept for another cycle. Blockage of the cannulas never occurred, and no serious problems were associated with digesta collections. The experiment demonstrated that pregnant sows can be prepared with a simple T-cannula in the distal ileum and that the cannula can be maintained in sows throughout the reproductive cycle. Hence, the procedure provides a tool for obtaining digesta from pregnant and lactating sows for nutrition studies. Key Words: Sows, Cannulation

Instruments such as the electron microscope win acceptance through the development of practices that integrate the instrument with existing scientific culture and knowledge. The development of electron microscopy during wartime illustrates how conservative elements, such as RCA and its scientists, influence scientific acceptance of a technique or instrument. Scientific instrument practice quickly develops continuities and traditions that channel and direct the vision of proper use of electron microscopes or other breakthrough devices.

Teachers in tropical schools have to cope with both a lack of materials and tight funding. Chemistry teachers faced with such a challenge can produce self-made teaching equipment at a low cost. Some suggestions on how to teach chemistry at schools in developing countries without the use of modern laboratory equipment are presented. They include the production of ink from natural materials, experiments in thin layer chromatography and reduction of iron ore using traditional methods.

Advanced chemistry students at the undergraduate level or beginning graduate students can learn by using two-photon ionization spectrometry (TPIS) of alkali atoms in flames. An enjoyable one-session new experiment to introduce students to pulsed laser-based instrumentation with this optogalvanic technique has been developed. Students and instructors will have to go beyond the typical black-box approach to using an instrument because stand-alone instruments for multiphoton ionization spectrometry are not yet commercially available. Apparatus, hazards, results, and the mechanism are discussed.

A study of the use of seismometers in middle and high school classrooms shows that the existence of the National Science Education Standards would either increase or not effect how much they would use scientific equipment in the classroom. The study showed that the impact of standardized tests did not increase rote memorization.

It is common for scientific equipment that is no longer required at one institution to be reused elsewhere. Many scientists are constantly aware of the possibilities of purchasing used equipment cheaply, or even borrowing or recycling it if necessary. However, they find that this can take up a lot of their time.

Researchers can utilize system software tools to increase work efficiency while minimizing costs and complexities associated with lab administrations. These tools supported detailed technical information on client installation and inventory, upgrades, remote troubleshooting, and software distribution. They include Microsoft's Zero Administration Kits, UniPress Software's S to Infinity and Blue Ocean Software's Track-It!.

The German-manufactured PHYWE apparatus offers a more efficient means of measuring velocity-of-light than many other methods and is easy to demonstrate to students of all study levels. The apparatus is a small black box with a transmitter/receiver, lens, and cables. It can be quickly set up and operated. An explanation of how it functions will enhance student understanding of light speed and measurement.

Very high density sensing arrays are described as the arrays containing the smallest feature sizes and the highest densities. Very high density sensing arrays are used in many fields including diagnostics, the environment, industrial processing, fundamental science and many others.

The officials from scientific societies, academic organizations and industrial groups have protested against the Department of Commerce's (DOC's) 'deemed policy' as the changes might limit the ability of foreign researchers and students in the US to use equipment and software that are on federal controlled technology lists. The DOC has established an independent advisory committee made up from the academic and industrial communities to review the policy, so that they can come up with significant recommendations.

A new experimental apparatus called the 'chaotic sparking pendulum', that reveals chaotic two-dimensional orbits of a pendulum sliding over a set of magnets is developed. Schematic representation of the experimental setup and the forces acting in the pendulum bob is described.

The numerous instruments and measurements used by the scientists are considered to be the basis of the development of many theories and concepts of modern science, as they are capable of producing many new effects. Instrumentation also helps in unifying the various fields of science by giving rise to interrelated ideas and concepts, which helps the user to understand others works and thus provides a guarantee of objectivity and reliability in science.

Part II: The Sample-Introduction System Part II of Robert Thomas' series on inductively coupled plasma mass spectrometry looks at one of the most critical areas of the instrument -- the […]

In this study, an automatic algorithm for monitoring areas of cold cloud tops within mesoscale convective systems that produced floods in Greece is developed. The technique is based on Meteosat infrared and water vapor images. The purpose of the algorithm is the estimation and monitoring of a variety of characteristics associated with propagating convective systems. The algorithm is capable of locating convective regions, tracking them until the point of dissipation, and taking into account the eventual splitting or merging of clouds that takes place during the lifetime of the system. The operability of the algorithm for the two most intense heavy rainfall events that occurred recently in Greece is examined and assessed.

We report on electrically driven amplified spontaneous emission and lasing in tetracene single crystals using field-effect electrodes for efficient electron and hole injection. For laser action, feedback is provided by reflections at the cleaved edges of the crystal resulting in a Fabry-Perot resonator. Increasing the injected current density above a certain threshold value results in the decreasing of the spectral width of the emission from 120 millielectron volts to less than 1 millielectron volt because of gain narrowing and eventually laser action. High electron and hole mobilities as well as balanced charge carrier injection lead to improved exciton generation in these gate-controlled devices. Moreover, the effect of charge-induced absorption is substantially reduced in high-quality single crystals compared with amorphous organic materials., Semiconductor lasers are widely used in modern science and technology. Compared with conventional inorganic semiconductors, organic semiconductors offer potential advantages with respect to easy processing, lower cost, and flexibility. Hence, [...]

Most of the important advances in scientific knowledge have followed improvements in experimental techniques. Tools created by physical scientists and engineers are leading to new discoveries in science and technology. [...]

Author(s): David W. Piston (corresponding author) [1] As head of Vanderbilt University's core microscopy labs, I recently met a colleague and his student to discuss their confusing results from an [...]

The intimate association of chemistry and light ranges from fireworks displays and the color of solutions and precipitates to the spectroscopic analysis of new and unknown substances. The advent of [...]

Nuclear magnetic resonance (NMR) applications to medical science began nearly 30 year ago with proton NMR measurements on cells, excised frog muscles, arms of living humans, and the living rat [...]

An apparatus using air flow as analogous to electric current flow helps students understand the concepts of electricity better. The apparatus helps first-year students derive the relationships among voltage, current, and resistance. They can easily determine how changing one variable and keeping the other constant will influence the third. The apparatus is useful in explaining other concepts, such as the lack of air flow through the manometer and the movement of electric charge from high potential to low potential.

Thermo Fisher Scientific Inc., says its new viscometer line features three models, each of which is suited for a unique user requirement: the Thermo Scientific Haake Viscotester E ('the expert [...]

South Africa's only World Anti-Doping Agency-accredited laboratory, the Free State University Sports Doping Laboratory, will conduct the testing for the FIFA World Cup using AB SCIEX's (Foster City, California) LC-MS-MS [...]