Science.gov

Sample records for hand-held semiconductor cdznte-based

  1. Hand held explosives detection system

    DOEpatents

    Conrad, Frank J.

    1992-01-01

    The present invention is directed to a sensitive hand-held explosives detection device capable of detecting the presence of extremely low quantities of high explosives molecules, and which is applicable to sampling vapors from personnel, baggage, cargo, etc., as part of an explosives detection system.

  2. Hand-held medical robots.

    PubMed

    Payne, Christopher J; Yang, Guang-Zhong

    2014-08-01

    Medical robots have evolved from autonomous systems to tele-operated platforms and mechanically-grounded, cooperatively-controlled robots. Whilst these approaches have seen both commercial and clinical success, uptake of these robots remains moderate because of their high cost, large physical footprint and long setup times. More recently, researchers have moved toward developing hand-held robots that are completely ungrounded and manipulated by surgeons in free space, in a similar manner to how conventional instruments are handled. These devices provide specific functions that assist the surgeon in accomplishing tasks that are otherwise challenging with manual manipulation. Hand-held robots have the advantages of being compact and easily integrated into the normal surgical workflow since there is typically little or no setup time. Hand-held devices can also have a significantly reduced cost to healthcare providers as they do not necessitate the complex, multi degree-of-freedom linkages that grounded robots require. However, the development of such devices is faced with many technical challenges, including miniaturization, cost and sterility, control stability, inertial and gravity compensation and robust instrument tracking. This review presents the emerging technical trends in hand-held medical robots and future development opportunities for promoting their wider clinical uptake. PMID:24927713

  3. Microfluidic MEMS hand-held flow cytometer

    NASA Astrophysics Data System (ADS)

    Grafton, Meggie M. G.; Maleki, Teimour; Zordan, Michael D.; Reece, Lisa M.; Byrnes, Ron; Jones, Alan; Todd, Paul; Leary, James F.

    2011-02-01

    Due to a number of recent technological advances, a hand-held flow cytometer can be achieved by use of semiconductor illuminators, optical sensors (all battery powered) and sensitive cell markers such as immuno-quantum dot (Qdot) labels. The specific application described is of a handheld blood analyzer that can quickly process a drop of whole, unfractionated human peripheral blood by real-time, on-chip magnetic separation of white blood cells (WBCs) and red blood cells (RBCs) and further fluorescence analysis of Qdot labeled WBC subsets. Various microfluidic patterns were fabricated in PDMS and used to characterize flow of single cells and magnetic deflection of magnetically labeled cells. An LED excitation, avalanche photodiode detection system (SensL Technologies, Ltd., Cork, Ireland) was used for immuno-Qdot detection of WBC subsets. A static optical setup was used to determine the sensitivity of the detection system. In this work we demonstrate: valve-less, on-chip magnetic sorting of immunomagnetically labeled white blood cells, bright Qdot labeling of lymphocytes, and counting of labeled white blood cells. Comparisons of these results with conventional flow cytometric analyses are reported. Sample preparation efficiency was determined by labeling of isolated white blood cells. Appropriate flow rates were determined for optical detection and confirmed with flowing particles. Several enabling technologies required for a truly portable, battery powered, hand-held flow cytometer for use in future point-of-care diagnostic devices have been demonstrated. The combining of these technologies into an integrated handheld instrument is in progress and results on whole blood cell analysis are to be reported in another paper.

  4. Choosing a Hand-Held Inventory Device

    ERIC Educational Resources Information Center

    Green, Lois; Hughes, Janet; Neff, Verne; Notartomas, Trish

    2008-01-01

    In spring of 2006, a task force was charged to look at the feasibility of acquiring hand-held inventory devices for the Pennsylvania State University Libraries (PSUL). The task force's charge was not to look at the whole concept of doing an inventory, but rather to focus on the feasibility of acquiring hand-held devices to use in an inventory.…

  5. Hand-held multiple system gas chromatograph

    DOEpatents

    Yu, Conrad M.

    2001-01-01

    A multiple parallel hand-held gas chromatograph (GC) system which includes several independent GCs. Each independent GC has its own injector, separation column, detector and oven and the GCs are mounted in a light weight hand-held assembly. Each GC operates independently and simultaneously. Because of different coatings in different separation columns, different retention times for the same gas will be measured. Thus, for a GC system with multiple parallel GCs, the system can measure, in a short period, different retention times and provide a cross-reference in the determination of the measured gas and to become a two-dimensional system for direct field use.

  6. High performance hand-held gas chromatograph

    SciTech Connect

    Yu, C.M.

    1998-04-28

    The Microtechnology Center of Lawrence Livermore National Laboratory has developed a high performance hand-held, real time detection gas chromatograph (HHGC) by Micro-Electro-Mechanical-System (MEMS) technology. The total weight of this hand-held gas chromatograph is about five lbs., with a physical size of 8{close_quotes} x 5{close_quotes} x 3{close_quotes} including carrier gas and battery. It consumes about 12 watts of electrical power with a response time on the order of one to two minutes. This HHGC has an average effective theoretical plate of about 40k. Presently, its sensitivity is limited by its thermal sensitive detector at PPM. Like a conventional G.C., this HHGC consists mainly of three major components: (1) the sample injector, (2) the column, and (3) the detector with related electronics. The present HHGC injector is a modified version of the conventional injector. Its separation column is fabricated completely on silicon wafers by means of MEMS technology. This separation column has a circular cross section with a diameter of 100 pm. The detector developed for this hand-held GC is a thermal conductivity detector fabricated on a silicon nitride window by MEMS technology. A normal Wheatstone bridge is used. The signal is fed into a PC and displayed through LabView software.

  7. Hand-held and automated breast ultrasound

    SciTech Connect

    Bassett, L.W.; Gold, R.H.; Kimme-Smith, C.

    1985-01-01

    The book is a guide for physicians and technologists who use US as an adjunct to mammography; it carefully outlines the pros and cons of US of the breast and its role in the diagnosis of benign and malignant diseases. After an introduction that discusses the philosophy of breast US, the chapters cover the physics of US and instrumentation (both hand-held transducers as well as automated water path scanners), then proceed to a discussion of the normal breast. Sections on benign disorders, malignant lesions, and pitfalls of diagnosis are followed by quiz cases.

  8. A hand-held immaterial volumetric display

    NASA Astrophysics Data System (ADS)

    Sand, Antti; Rakkolainen, Ismo

    2014-03-01

    We have created an ultralight, movable, "immaterial" fogscreen. It is based on the fogscreen mid-air imaging technology. The hand-held unit is roughly the size and weight of an ordinary toaster. If the screen is tracked, it can be swept in the air to create mid-air slices of volumetric objects, or to show augmented reality (AR) content on top of real objects. Interfacing devices and methodologies, such as hand and gesture trackers, camera-based trackers and object recognition, can make the screen interactive. The user can easily interact with any physical object or virtual information, as the screen is permeable. Any real objects can be seen through the screen, instead of e.g., through a video-based augmented reality screen. It creates a mixed reality setup where both the real world object and the augmented reality content can be viewed and interacted with simultaneously. The hand-held mid-air screen can be used e.g., as a novel collaborating or classroom tool for individual students or small groups.

  9. 30 CFR 57.14116 - Hand-held power tools.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Hand-held power tools. 57.14116 Section 57... Equipment Safety Devices and Maintenance Requirements § 57.14116 Hand-held power tools. (a) Power drills, disc sanders, grinders and circular and chain saws, when used in the hand-held mode shall be...

  10. 30 CFR 56.7053 - Moving hand-held drills.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Moving hand-held drills. 56.7053 Section 56.7053 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Jet Piercing Drilling § 56.7053 Moving hand-held drills. Before hand-held drills are moved from...

  11. 30 CFR 57.14116 - Hand-held power tools.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Hand-held power tools. 57.14116 Section 57... Equipment Safety Devices and Maintenance Requirements § 57.14116 Hand-held power tools. (a) Power drills, disc sanders, grinders and circular and chain saws, when used in the hand-held mode shall be...

  12. 30 CFR 56.14116 - Hand-held power tools.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Hand-held power tools. 56.14116 Section 56... Equipment Safety Devices and Maintenance Requirements § 56.14116 Hand-held power tools. (a) Power drills, disc sanders, grinders and circular and chain saws, when used in the hand-held mode shall be...

  13. 30 CFR 56.7053 - Moving hand-held drills.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Moving hand-held drills. 56.7053 Section 56.7053 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Jet Piercing Drilling § 56.7053 Moving hand-held drills. Before hand-held drills are moved from...

  14. 30 CFR 57.12033 - Hand-held electric tools.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Hand-held electric tools. 57.12033 Section 57.12033 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Surface and Underground § 57.12033 Hand-held electric tools. Hand-held electric tools shall not...

  15. 30 CFR 57.12033 - Hand-held electric tools.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Hand-held electric tools. 57.12033 Section 57.12033 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Surface and Underground § 57.12033 Hand-held electric tools. Hand-held electric tools shall not...

  16. 30 CFR 57.14116 - Hand-held power tools.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Hand-held power tools. 57.14116 Section 57... Equipment Safety Devices and Maintenance Requirements § 57.14116 Hand-held power tools. (a) Power drills, disc sanders, grinders and circular and chain saws, when used in the hand-held mode shall be...

  17. 30 CFR 56.14116 - Hand-held power tools.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Hand-held power tools. 56.14116 Section 56... Equipment Safety Devices and Maintenance Requirements § 56.14116 Hand-held power tools. (a) Power drills, disc sanders, grinders and circular and chain saws, when used in the hand-held mode shall be...

  18. 30 CFR 56.14116 - Hand-held power tools.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Hand-held power tools. 56.14116 Section 56... Equipment Safety Devices and Maintenance Requirements § 56.14116 Hand-held power tools. (a) Power drills, disc sanders, grinders and circular and chain saws, when used in the hand-held mode shall be...

  19. 30 CFR 57.12033 - Hand-held electric tools.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Hand-held electric tools. 57.12033 Section 57.12033 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Surface and Underground § 57.12033 Hand-held electric tools. Hand-held electric tools shall not...

  20. 30 CFR 57.12033 - Hand-held electric tools.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Hand-held electric tools. 57.12033 Section 57.12033 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Surface and Underground § 57.12033 Hand-held electric tools. Hand-held electric tools shall not...

  1. 30 CFR 57.12033 - Hand-held electric tools.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Hand-held electric tools. 57.12033 Section 57.12033 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Surface and Underground § 57.12033 Hand-held electric tools. Hand-held electric tools shall not...

  2. 30 CFR 56.7053 - Moving hand-held drills.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Moving hand-held drills. 56.7053 Section 56.7053 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Jet Piercing Drilling § 56.7053 Moving hand-held drills. Before hand-held drills are moved from...

  3. 30 CFR 57.14116 - Hand-held power tools.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Hand-held power tools. 57.14116 Section 57... Equipment Safety Devices and Maintenance Requirements § 57.14116 Hand-held power tools. (a) Power drills, disc sanders, grinders and circular and chain saws, when used in the hand-held mode shall be...

  4. 30 CFR 57.14116 - Hand-held power tools.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Hand-held power tools. 57.14116 Section 57... Equipment Safety Devices and Maintenance Requirements § 57.14116 Hand-held power tools. (a) Power drills, disc sanders, grinders and circular and chain saws, when used in the hand-held mode shall be...

  5. 30 CFR 56.14116 - Hand-held power tools.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Hand-held power tools. 56.14116 Section 56... Equipment Safety Devices and Maintenance Requirements § 56.14116 Hand-held power tools. (a) Power drills, disc sanders, grinders and circular and chain saws, when used in the hand-held mode shall be...

  6. 30 CFR 56.7053 - Moving hand-held drills.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Moving hand-held drills. 56.7053 Section 56.7053 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Jet Piercing Drilling § 56.7053 Moving hand-held drills. Before hand-held drills are moved from...

  7. 30 CFR 56.14116 - Hand-held power tools.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Hand-held power tools. 56.14116 Section 56... Equipment Safety Devices and Maintenance Requirements § 56.14116 Hand-held power tools. (a) Power drills, disc sanders, grinders and circular and chain saws, when used in the hand-held mode shall be...

  8. 30 CFR 56.7053 - Moving hand-held drills.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Moving hand-held drills. 56.7053 Section 56.7053 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Jet Piercing Drilling § 56.7053 Moving hand-held drills. Before hand-held drills are moved from...

  9. [Hand-held echocardiography in clinical practice].

    PubMed

    Mondillo, Sergio; Galderisi, Maurizio

    2005-05-01

    In the last years the industry has created echocardiographic portable machines of reduced size, available for a growing number of operators. After the first experiences of the '70s, hand-held echocardiography (HHE) is earned interesting commercial positions. The transportability of these machines allows to perform examinations outside the echo-lab and provides diagnostic information in heterogeneous locations such as intensive care unit, emergency room and outpatient structures, at the bedside and even in ambulance. HHE can be useful for detection of several pathologies including aortic aneurysms and left ventricular hypertrophy, regional wall motion abnormalities, pericardial and pleural effusion. To date, four main kinds of HHE can be distinguished: a first, high-cost variety, including miniaturized machines, equipped with instrumentations of standard echocardiography and even new softwares for tissue Doppler and myocardial contrast echocardiography; a second kind of machines of high level but not miniaturized; a third (intermediate level and low cost), and a fourth one (basic level and very low cost), including "cardioscopes" corresponding to the ultrasound stethoscope, able to complete efficaciously the clinical examination. The introduction of HHE opens controversy about its diagnostic accuracy, the opportunity to establish the clinical scenario where it should be utilized and the identification of the potential users and the needed competence level. Preliminary experiences show the possibility of improving and anticipating the diagnosis of several cardiac diseases but also the need to plan specific ultrasound training to avoid inappropriate use of HHE. PMID:15934422

  10. Clear differences in hand-held dermoscopes.

    PubMed

    Blum, Andreas; Jaworski, Simone

    2006-12-01

    In order to correctly evaluate melanocytic and non-melanocytic skin tumors using a hand-held dermoscope, it is essential to have adequate magnification and illumination to allow the differential structures to be clearly seen. One example of a dysplastic compound melanocytic nevus and a thin malignant melanoma were examined with five different handheld dermoscopes (Heine Delta 10, Heine Delta 20, Dermogenius and Dermlite Foto 37 with and without glass plate) in order to assess the image quality. The magnification was identical in all dermoscopes. In the newer dermoscopes (Heine Delta 20, Dermogenius and Dermlite Foto 37 with and without glass plate) the light sources were clearly improved, as now 6 or 24 LEDs, respectively, are employed. This distinctly improved the image quality with regard to color and visible differential structures compared to the dermoscope (Heine Delta 10) with only one light source. Clear differences is assessing differential structures were seen in one dermoscope (Dermlite Foto 37 without glass plate). Using this dermoscope without any glass plate or liquid between the dermoscope and the skin, exophytic tumors were better visualized in a three-dimensional fashion but fewer differential structures were seen. PMID:17176414

  11. Hand-Held Devices Detect Explosives and Chemical Agents

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Ion Applications Inc., of West Palm Beach, Florida, partnered with Ames Research Center through Small Business Innovation Research (SBIR) agreements to develop a miniature version ion mobility spectrometer (IMS). While NASA was interested in the instrument for detecting chemicals during exploration of distant planets, moons, and comets, the company has incorporated the technology into a commercial hand-held IMS device for use by the military and other public safety organizations. Capable of detecting and identifying molecules with part-per-billion sensitivity, the technology now provides soldiers with portable explosives and chemical warfare agent detection. The device is also being adapted for detecting drugs and is employed in industrial processes such as semiconductor manufacturing.

  12. 30 CFR 57.7053 - Moving hand-held drills.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Moving hand-held drills. 57.7053 Section 57.7053 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Rotary Jet Piercing Drilling-Surface and Underground § 57.7053 Moving hand-held drills. Before...

  13. 30 CFR 57.7053 - Moving hand-held drills.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Moving hand-held drills. 57.7053 Section 57.7053 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Rotary Jet Piercing Drilling-Surface and Underground § 57.7053 Moving hand-held drills. Before...

  14. 30 CFR 57.7053 - Moving hand-held drills.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Moving hand-held drills. 57.7053 Section 57.7053 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Rotary Jet Piercing Drilling-Surface and Underground § 57.7053 Moving hand-held drills. Before...

  15. 30 CFR 57.7053 - Moving hand-held drills.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Moving hand-held drills. 57.7053 Section 57.7053 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Rotary Jet Piercing Drilling-Surface and Underground § 57.7053 Moving hand-held drills. Before...

  16. 30 CFR 57.7053 - Moving hand-held drills.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Moving hand-held drills. 57.7053 Section 57.7053 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Rotary Jet Piercing Drilling-Surface and Underground § 57.7053 Moving hand-held drills. Before...

  17. Electronic, Hand-Held, Wireless Text-And-Graphics Viewer

    NASA Technical Reports Server (NTRS)

    Palumbo, Daniel L.

    1994-01-01

    Proposed electronic, hand-held, wireless viewer presents written material to reader in way that closely resembles that of paper reading material. Viewer presents text and graphics like those normally found in books, newspapers, and magazines. Its hand-held and wireless features enable it to be used in positions and areas where books and magazines are normally used. Device consists primarily of two parts: the receiver/information store and viewing screen.

  18. Automated Hand-Held UXO Detection, Classification & Discrimination Sensor

    SciTech Connect

    Bell, Thomas H.

    2000-06-12

    The research focused on procedures for target discrimination and classification using hand-held EMI sensors. The idea is to have a small, portable sensor that can be operated in a sweep or similar pattern in front of the operator, and that is capable of distinguishing between buried UXO and clutter on the spot. Curing Phase 1, we developed the processing techniques for distinguishing between buried UXO and clutter using the EM61-HH hand-held metal detector.

  19. Hand held phase-shifting diffraction moire interferometer

    DOEpatents

    Deason, Vance A.; Ward, Michael B.

    1994-01-01

    An interferometer in which a coherent beam of light is generated within a remote case and transmitted to a hand held unit tethered to said remote case, said hand held unit having optical elements for directing a pair of mutually coherent collimated laser beams at a diffraction grating. Data from the secondary or diffracted beams are then transmitted to a separate video and data acquisition system for recording and analysis for load induced deformation or for identification purposes. Means are also provided for shifting the phase of one incident beam relative to the other incident beam and being controlled from within said remote case.

  20. Hand held phase-shifting diffraction Moire interferometer

    DOEpatents

    Deason, V.A.; Ward, M.B.

    1994-09-20

    An interferometer is described in which a coherent beam of light is generated within a remote case and transmitted to a hand held unit tethered to said remote case, said hand held unit having optical elements for directing a pair of mutually coherent collimated laser beams at a diffraction grating. Data from the secondary or diffracted beams are then transmitted to a separate video and data acquisition system for recording and analysis for load induced deformation or for identification purposes. Means are also provided for shifting the phase of one incident beam relative to the other incident beam and being controlled from within said remote case. 4 figs.

  1. Epilepsy Forewarning Using A Hand-Held Device

    SciTech Connect

    Hively, LM

    2005-02-21

    Over the last decade, ORNL has developed and patented a novel approach for forewarning of a large variety of machine and biomedical events. The present implementation uses desktop computers to analyze archival data. This report describes the next logical step in this effort, namely use of a hand-held device for the analysis.

  2. 30 CFR 56.12033 - Hand-held electric tools.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Hand-held electric tools. 56.12033 Section 56.12033 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity §...

  3. 30 CFR 56.12033 - Hand-held electric tools.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Hand-held electric tools. 56.12033 Section 56.12033 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity §...

  4. Hand-Held Ultrasonic Instrument for Reading Matrix Symbols

    NASA Technical Reports Server (NTRS)

    Schramm, Harry F.; Kula, John P.; Gurney, John W.; Lior, Ephraim D.

    2008-01-01

    A hand-held instrument that would include an ultrasonic camera has been proposed as an efficient means of reading matrix symbols. The proposed instrument could be operated without mechanical raster scanning. All electronic functions from excitation of ultrasonic pulses through final digital processing for decoding matrix symbols would be performed by dedicated circuitry within the single, compact instrument housing.

  5. 30 CFR 56.12033 - Hand-held electric tools.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Hand-held electric tools. 56.12033 Section 56.12033 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity §...

  6. 30 CFR 56.12033 - Hand-held electric tools.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Hand-held electric tools. 56.12033 Section 56.12033 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity §...

  7. 30 CFR 56.12033 - Hand-held electric tools.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Hand-held electric tools. 56.12033 Section 56.12033 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity §...

  8. Hand-held Calculators: Past, Present, and Future

    ERIC Educational Resources Information Center

    Bell, Max; And Others

    1977-01-01

    Recommendations of several publications with regard to the use of hand-held calculators in the mathematics curriculum are presented. Relevant portions of the NACOME and Euclid Conference reports are cited as well as a report to NSF and recommendations from an NIE/NSF conference. Recommendations support expanded use of, and research concerning,…

  9. Hand-held radiometry: A set of notes developed for use at the Workshop of Hand-held radiometry

    NASA Technical Reports Server (NTRS)

    Jackson, R. D.; Pinter, P. J., Jr.; Reginato, R. J.; Idso, S. B. (Principal Investigator)

    1980-01-01

    A set of notes was developed to aid the beginner in hand-held radiometry. The electromagnetic spectrum is reviewed, and pertinent terms are defined. View areas of multiband radiometers are developed to show the areas of coincidence of adjacent bands. The amounts of plant cover seen by radiometers having different fields of view are described. Vegetation indices are derived and discussed. Response functions of several radiometers are shown and applied to spectrometer data taken over 12 wheat plots, to provide a comparison of instruments and bands within and among instruments. The calculation of solar time is reviewed and applied to the calculation of the local time of LANDSAT satellite overpasses for any particular location in the Northern Hemisphere. The use and misuse of hand-held infrared thermometers are discussed, and a procedure for photographic determination of plant cover is described. Some suggestions are offered concerning procedures to be followed when collecting hand-held spectral and thermal data. A list of references pertinent to hand-held radiometry is included.

  10. Engineering issues for hand-held sensing devices, with examples

    NASA Astrophysics Data System (ADS)

    Freiwald, David A.; Freiwald, Joyce

    1994-03-01

    It is now U.S. defense policy that there will be no new platform starts. The emphasis for platforms will be on O&M cost reduction, life-extension improvements, and force-multiplier- device upgrades. There is also an increasing emphasis on hand-held force-multiplier devices for individuals, which is the focus of this paper. Engineering issues include operations analysis, weight, cube, cost, prime power, ease of use, data storage, reliability, fault tolerance, data communications and human factors. Two examples of hand-held devices are given. Applications include USMC, Army, SOCOM, DEA, FBI, SS, Border Patrol and others. Barriers to adoption of such technology are also discussed.

  11. Introducing a hand-held urinal service in secondary care.

    PubMed

    Pomfret, Ian; Vickerman, Julie; Tonge, Pauline

    Chorley & South Ribble Primary Care Trust's multiprofessional continence service was established in 2000 (Pomfret, 2001). An integral part of this service development was the creation of a community-based, hand-held urinal library. There are 28 female hand-held urinals available in the UK and many more for males. Some of the urinals are available on prescription and others have to be purchased by the patient. The urinal library allows patients in the community to use the urinals before they are prescribed or buy them, because it is only by using them that they will know that the product will be suitable. The service is proving to be hugely successful. PMID:15895500

  12. A Cheap, Semiquantitative Hand-Held Conductivity Tester.

    ERIC Educational Resources Information Center

    Zawacky, Susan K. S.

    1995-01-01

    Describes a design for a hand-held conductivity tester powered by a 9V battery that gives semi-quantitative results for aqueous electrolyte solutions of concentrations ranging from 0.001 M to 0.1 M. The tester uses a bar-graph LED driven by an LM3914 integrated circuit to indicate the level of conductivity. A list of parts, procedures, and results…

  13. Vibration and impulsivity analysis of hand held olive beaters.

    PubMed

    Deboli, Roberto; Calvo, Angela; Preti, Christian

    2016-07-01

    To provide more effective evaluations of hand arm vibration syndromes caused by hand held olive beaters, this study focused on two aspects: the acceleration measured at the tool pole and the analysis of the impulsivity, using the crest factor. The signals were frequency weighted using the weighting curve Wh as described in the ISO 5349-1 standard. The same source signals were also filtered by the Wh-bl filter (ISO/TS 15694), because the weighting filter Wh (unlike the Wh-bl filter) could underestimate the effect of high frequency vibration on vibration-induced finger disorders. Ten (experienced) male operators used three beater models (battery powered) in the real olive harvesting condition. High vibration total values were obtained with values never lower than 20 m(-2). Concerning the crest factor, the values ranged from 5 to more than 22. This work demonstrated that the hand held olive beaters produced high impulsive loads comparable to the industry hand held tools. PMID:26615333

  14. Distributing Data from Desktop to Hand-Held Computers

    NASA Technical Reports Server (NTRS)

    Elmore, Jason L.

    2005-01-01

    A system of server and client software formats and redistributes data from commercially available desktop to commercially available hand-held computers via both wired and wireless networks. This software is an inexpensive means of enabling engineers and technicians to gain access to current sensor data while working in locations in which such data would otherwise be inaccessible. The sensor data are first gathered by a data-acquisition server computer, then transmitted via a wired network to a data-distribution computer that executes the server portion of the present software. Data in all sensor channels -- both raw sensor outputs in millivolt units and results of conversion to engineering units -- are made available for distribution. Selected subsets of the data are transmitted to each hand-held computer via the wired and then a wireless network. The selection of the subsets and the choice of the sequences and formats for displaying the data is made by means of a user interface generated by the client portion of the software. The data displayed on the screens of hand-held units can be updated at rates from 1 to

  15. Hand-held portable microarray reader for biodetection

    DOEpatents

    Thompson, Deanna Lynn; Coleman, Matthew A; Lane, Stephen M; Matthews, Dennis L; Albala, Joanna; Wachsmann-Hogiu, Sebastian

    2013-04-23

    A hand-held portable microarray reader for biodetection includes a microarray reader engineered to be small enough for portable applications. The invention includes a high-powered light-emitting diode that emits excitation light, an excitation filter positioned to receive the excitation light, a slide, a slide holder assembly for positioning the slide to receive the excitation light from the excitation filter, an emission filter positioned to receive the excitation light from the slide, a lens positioned to receive the excitation light from the emission filter, and a CCD camera positioned to receive the excitation light from the lens.

  16. Development of dual sensor hand-held detector

    NASA Astrophysics Data System (ADS)

    Sezgin, Mehmet

    2010-04-01

    In this paper hand-held dual sensor detector development requirements are considered dedicated to buried object detection. Design characteristics of such a system are categorized and listed. Hardware and software structures, ergonomics, user interface, environmental and EMC/EMI tests to be applied and performance test issues are studied. Main properties of the developed system (SEZER) are presented, which contains Metal Detector (MD) and Ground Penetrating Radar (GPR). The realized system has ergonomic structure and can detect both metallic and non-metallic buried objects. Moreover classification of target is possible if it was defined to the signal processing software in learning phase.

  17. A hand-held triangulation sensor for small features measurement

    NASA Astrophysics Data System (ADS)

    Abramovich, Gil; Harding, Kevin

    2010-11-01

    This paper describes progressive generations of hand held triangulation sensors for measuring small features, from edge breaks to corrosion pits. We describe the design considerations, ergonomics, packaging and interface between the device and part, such as the sensor tip and optional fixtures. We then present a customized design to address different types of surface features and defects. Next, we present the calibration concept, and its execution. The paper closes by summarizing system performance evaluation experiments and their results. It was shown that the system is capable of measuring edges down to a radius of 250 microns at a repeatability of 50 microns.

  18. Hand-held terminal antennas for personal satellite communications

    NASA Technical Reports Server (NTRS)

    Caballero, J. E.; Badenes, J.; Fernandez, J.; Martin-Pascual, C.; Municio, F.

    1995-01-01

    This paper deals with two hand-held antenna types operating with geostationary and medium earth orbit (GEO and MEO) satellite systems. They could be applied to the low earth orbit (LEO) and highly elliptical orbit (HEO) systems respectively doing the appropriate frequency scale designs. The first one is a lambda/2 (1/2 turn) quadrifilar helix (quasi-hemispherical coverage), and the second one is a self-diplexed antenna made of a circular patch and a short-circuited ring patch in stacked configuration (zenithal coverage).

  19. A hand-held EPR scanner for transcutaneous oximetry

    NASA Astrophysics Data System (ADS)

    Wolfson, Helen; Ahmad, Rizwan; Twig, Ygal; Blank, Aharon; Kuppusamy, Periannan

    2015-03-01

    Cutaneous (skin) oxygenation is an important prognostic factor for the treatment of chronic wounds, skin cancer, diabetes side effects, and limb amputation. Currently, there are no reliable methods for measuring this parameter. Oximetry, using electron paramagnetic resonance (EPR) spectroscopy, is emerging as a potential tool for clinical oximetry, including cutaneous applications. The problem with EPR oximetry, however, is that the conventional EPR design requires the use of a large magnet that can generate homogeneous field across the sample, making it unattractive for clinical practice. We present a novel approach that makes use of a miniature permanent magnet, combined with a small microwave resonator, to enable the acquisition of EPR signals from paramagnetic species placed on the skin. The instrumentation consists of a hand-held, modular, cylindrical probehead with overall dimensions of 36-mm diameter and 24-mm height, with 150-g weight. The probehead includes a Halbach array of 16 pieces (4×4×8 mm3) of Sm-Co permanent magnet and a loop-gap resonator (2.24 GHz). Preliminary measurements using a Hahn-echo pulse sequence (800 echos in 20 ms) showed a signalto- noise ratio of ~70 compared to ~435 in a homogenous magnet under identical settings. Further work is in progress to improve the performance of the probehead and to optimize the hand-held system for clinical use

  20. Bone age maturity assessment using hand-held device

    NASA Astrophysics Data System (ADS)

    Ratib, Osman M.; Gilsanz, Vicente; Liu, Xiaodong; Boechat, M. I.

    2004-04-01

    Purpose: Assessment of bone maturity is traditionally performed through visual comparison of hand and wrist radiograph with existing reference images in textbooks. Our goal was to develop a digital index based on idealized hand Xray images that can be incorporated in a hand held computer and used for visual assessment of bone age for patients. Material and methods: Due to the large variability in bone maturation in normals, we generated a set of "ideal" images obtained by computer combinations of images from our normal reference data sets. Software for hand-held PDA devices was developed for easy navigation through the set of images and visual selection of matching images. A formula based on our statistical analysis provides the standard deviation from normal based on the chronological age of the patient. The accuracy of the program was compared to traditional interpretation by two radiologists in a double blind reading of 200 normal Caucasian children (100 boys, 100 girls). Results: Strong correlations were present between chronological age and bone age (r > 0.9) with no statistical difference between the digital and traditional assessment methods. Determinations of carpal bone maturity in adolescents was slightly more accurate using the digital system. The users did praise the convenience and effectiveness of the digital Palm Index in clinical practice. Conclusion: An idealized digital Palm Bone Age Index provides a convenient and effective alternative to conventional atlases for the assessment of skeletal maturity.

  1. Hand held data collection and monitoring system for nuclear facilities

    DOEpatents

    Brayton, D.D.; Scharold, P.G.; Thornton, M.W.; Marquez, D.L.

    1999-01-26

    Apparatus and method is disclosed for a data collection and monitoring system that utilizes a pen based hand held computer unit which has contained therein interaction software that allows the user to review maintenance procedures, collect data, compare data with historical trends and safety limits, and input new information at various collection sites. The system has a means to allow automatic transfer of the collected data to a main computer data base for further review, reporting, and distribution purposes and uploading updated collection and maintenance procedures. The hand held computer has a running to-do list so sample collection and other general tasks, such as housekeeping are automatically scheduled for timely completion. A done list helps users to keep track of all completed tasks. The built-in check list assures that work process will meet the applicable processes and procedures. Users can hand write comments or drawings with an electronic pen that allows the users to directly interface information on the screen. 15 figs.

  2. Hand held data collection and monitoring system for nuclear facilities

    DOEpatents

    Brayton, Darryl D.; Scharold, Paul G.; Thornton, Michael W.; Marquez, Diana L.

    1999-01-01

    Apparatus and method is disclosed for a data collection and monitoring system that utilizes a pen based hand held computer unit which has contained therein interaction software that allows the user to review maintenance procedures, collect data, compare data with historical trends and safety limits, and input new information at various collection sites. The system has a means to allow automatic transfer of the collected data to a main computer data base for further review, reporting, and distribution purposes and uploading updated collection and maintenance procedures. The hand held computer has a running to-do list so sample collection and other general tasks, such as housekeeping are automatically scheduled for timely completion. A done list helps users to keep track of all completed tasks. The built-in check list assures that work process will meet the applicable processes and procedures. Users can hand write comments or drawings with an electronic pen that allows the users to directly interface information on the screen.

  3. Ultratrace detector for hand-held gas chromatography

    DOEpatents

    Andresen, Brian D.; Miller, Fred S.

    1999-01-01

    An ultratrace detector system for hand-held gas chromatography having high sensitivity, for example, to emissions generated during production of weapons, biological compounds, drugs, etc. The detector system is insensitive to water, air, helium, argon, oxygen, and C0.sub.2. The detector system is basically composed of a hand-held capillary gas chromatography (GC), an insulated heated redox-chamber, a detection chamber, and a vapor trap. For example, the detector system may use gas phase redox reactions and spectral absorption of mercury vapor. The gas chromatograph initially separates compounds that percolate through a bed of heated mercuric oxide (HgO) in a silica--or other metal--aerogel material which acts as an insulator. Compounds easily oxidized by HgO liberate atomic mercury that subsequently pass through a detection chamber which includes a detector cell, such as quartz, that is illuminated with a 254 nm ultra-violet (UV) mercury discharge lamp which generates the exact mercury absorption bands that are used to detect the liberated mercury atoms. Atomic mercury strongly absorbs 254 nm energy is therefore a specific signal for reducing compounds eluting from the capillary GC, whereafter the atomic mercury is trapped for example, in a silicon-aerogel trap.

  4. Hand-Held Reader for Colorimetric Sensor Arrays.

    PubMed

    Askim, Jon R; Suslick, Kenneth S

    2015-08-01

    An inexpensive hand-held device for analysis of colorimetric sensor arrays (CSAs) has been developed. The device makes use of a contact image sensor (CIS), technology commonly used in business card scanners, to rapidly collect low-noise colorimetric data for chemical sensing. The lack of moving parts and insensitivity to vibration allow for lower noise and improved scan rates compared to other digital imaging techniques (e.g., digital cameras, flatbed scanners); signal-to-noise ratios are a factor of 3-10 higher than currently used methods, and scan rates are up to 250 times faster without compromising sensitivity. The device is capable of real-time chemical analysis at scan rates up to 48 Hz. PMID:26177346

  5. A Smart Haptic Hand-Held Device for Neurosurgical Microdissection.

    PubMed

    Payne, Christopher J; Marcus, Hani J; Yang, Guang-Zhong

    2015-09-01

    Microneurosurgery requires dexterity, precision and delicate force application in order to be carried out safely and effectively. Neurosurgeons must apply sufficient force in order to carry out microsurgical procedures effectively but not excessive force such that iatrogenic injury occurs. This paper presents a smart hand-held microsurgical instrument that indicates to the surgeon when a force-threshold has been exceeded by providing vibrotactile feedback. Many existing haptic-feedback systems, particularly master-slave robotic platforms, are large, highly complex, and costly. By comparison, the proposed device is compact, fail-safe and low cost. Two psychophysical user studies were carried out to assess the proposed vibrotactile force-threshold feedback system. A cadaveric pilot study was carried out to evaluate the device in a microdissection task. In all the studies performed, the haptic dissector device has shown to be effective in providing real-time feedback in terms of force application during microsurgical tasks. PMID:25631207

  6. Comparative Geometrical Investigations of Hand-Held Scanning Systems

    NASA Astrophysics Data System (ADS)

    Kersten, T. P.; Przybilla, H.-J.; Lindstaedt, M.; Tschirschwitz, F.; Misgaiski-Hass, M.

    2016-06-01

    An increasing number of hand-held scanning systems by different manufacturers are becoming available on the market. However, their geometrical performance is little-known to many users. Therefore the Laboratory for Photogrammetry & Laser Scanning of the HafenCity University Hamburg has carried out geometrical accuracy tests with the following systems in co-operation with the Bochum University of Applied Sciences (Laboratory for Photogrammetry) as well as the Humboldt University in Berlin (Institute for Computer Science): DOTProduct DPI-7, Artec Spider, Mantis Vision F5 SR, Kinect v1 + v2, Structure Sensor and Google's Project Tango. In the framework of these comparative investigations geometrically stable reference bodies were used. The appropriate reference data were acquired by measurement with two structured light projection systems (AICON smartSCAN and GOM ATOS I 2M). The comprehensive test results of the different test scenarios are presented and critically discussed in this contribution.

  7. Self-contained, hand-held optical spectrometer

    SciTech Connect

    Baird, W.; Nogar, N.S.

    1994-12-31

    The authors describe the design(s) and performance of a self-contained, portable (hand-held) optical spectrometer. The current instrument is based on a miniaturized monochromator, diode array detector, Peltier cooler and microprocessor control. It can be used either in absorption mode, or in a fluorescence-excitation mode (using an on-board UV penlamp). The unit contains an on-board computer, control pad and LCD display, and can write data to a demountable data key. On-board batteries allow operation for up to three hours in data acquisition mode, or up to twenty-four hours in stand-by mode. The instrument may couple to the sample either fiber-optically, or directly with a light-tight coupling unit. The authors also describe second generation instruments incorporating monolithic optical devices and/or interference filters. In general, these instruments can be made more compact, but at some cost in versatility and information content.

  8. Center of percussion of hand-held implements

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2004-05-01

    The center of percussion is commonly regarded as a sweet spot when referring to a baseball bat or a tennis racquet because it is assumed that there will be no sudden motion of the handle with respect to the hand if the corresponding axis of rotation passes through the hand. A problem with this interpretation is that the hand extends over a finite length of the handle and exerts an opposing reaction force on the handle. The hand also changes the total mass and moment of inertia of the system, while the arm restricts free motion of the hand. Experimental results are presented showing that the axis of rotation passes through the hand or the wrist for all the usual impact points on a hand-held implement. As a result, the impact point that feels best is usually the node of the fundamental vibration mode, not the center of percussion.

  9. Productivity enhancements using hand-held computers: a case study.

    PubMed

    Bruns, B J

    1991-01-01

    In closing, the benefits of computerizing the equipment control information system have been assessed qualitatively and, to an extent, quantitatively. We have seen a drastic improvement in the operation of the clinical engineering department. Equipment repair and inspection results are readily accessible for technician use. Equipment service reports are typed and easy to read. Accountability of repair parts are immediately available for restocking and financial needs. Feedback reports are generated on a regular and timely basis. We have shown a reduction of around 12 minutes in the inspection procedure. This time has been directly linked to the automation of the inspection process using hand-held computers. The cost of automation was inexpensive, as the hand-held computers cost around 500 dollars per unit. Currently, the devices are used by any technician who performs inspections outside the department. The units time the inspection process and record the inspection result. We have interfaced the units to portable bar-code printers that produce an inspection label on-site. In the future, bar-code wands and guns will be used to streamline the data entry process of the inspection. A reduction in the number of incorrectly typed ECNs will improve the integrity of the database. The use of bar-codes will eventually spread to the parts' system. This will improve tracking, ordering, and inventorying repair parts. The plan is to improve the documentation of these parts and ease the analysis of new equipment needs, manufacturer reliability, and contract evaluations. At the present, we are addressing the problem of preparation time.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2032064

  10. Hand-held echocardiography: its use and usefulness.

    PubMed

    Mondillo, Sergio; Giannotti, Giovanna; Innelli, Pasquale; Ballo, Pier Carlo; Galderisi, Maurizio

    2006-07-28

    In recent years, several echocardiographic hand-held devices have been developed and are now available for a growing number of cardiologists. After the first clinical use 25 years ago, hand-held echocardiography (HHE) is now earning important commercial positions. Their transportability permits echo performance out the echo-labs and offers the possibility to make diagnosis in intensive care unit, emergency room, outpatient clinic, at the bedside, and even in ambulance. Experiences in the clinical setting have demonstrated the ability of HHE to detect multiple diseases including abdominal aortic aneurysms, left ventricular hypertrophy, regional wall motion abnormalities, pericardial and pleural effusions. At the present time, four varieties of HHE have to be recognized: the first includes high-cost, miniaturized machines, similar to the most advanced instrumentations, provided by new tools and imaging transfer systems; a second intermediate, middle-cost variety encompasses devices corresponding to standard echocardiography, but not miniaturized; according to the definition of the American Society of Echocardiography, a third and a fourth category comprise machines of weight lower than 2.7 kg, battery supplied and appropriately defined as "portable cardioschopes", which can be utilized as a technical refinement of physical examination. The use of HHE opens main controversy concerning their diagnostic accuracy, the opportunity to establish in which clinical settings they should be used and the identification of both potential users and required competence level. Preliminary experiences show the possibility to improve and anticipate diagnosis of several cardiovascular diseases but also the need to plan specific ultrasound training to avoid incorrect use of HHE. PMID:16087257

  11. 30 CFR 77.402 - Hand-held power tools; safety devices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Hand-held power tools; safety devices. 77.402... COAL MINES Safeguards for Mechanical Equipment § 77.402 Hand-held power tools; safety devices. Hand-held power tools shall be equipped with controls requiring constant hand or finger pressure to...

  12. 30 CFR 75.1724 - Hand-held power tools; safety devices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Hand-held power tools; safety devices. 75.1724... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1724 Hand-held power tools; safety devices. Hand-held power tools shall be equipped with controls requiring...

  13. 49 CFR 392.82 - Using a hand-held mobile telephone.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 5 2013-10-01 2013-10-01 false Using a hand-held mobile telephone. 392.82 Section... COMMERCIAL MOTOR VEHICLES Limiting the Use of Electronic Devices § 392.82 Using a hand-held mobile telephone. (a)(1) No driver shall use a hand-held mobile telephone while driving a CMV. (2) No motor...

  14. 30 CFR 75.1724 - Hand-held power tools; safety devices.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Hand-held power tools; safety devices. 75.1724... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1724 Hand-held power tools; safety devices. Hand-held power tools shall be equipped with controls requiring...

  15. 49 CFR 392.82 - Using a hand-held mobile telephone.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 5 2012-10-01 2012-10-01 false Using a hand-held mobile telephone. 392.82 Section... COMMERCIAL MOTOR VEHICLES Limiting the Use of Electronic Devices § 392.82 Using a hand-held mobile telephone. (a)(1) No driver shall use a hand-held mobile telephone while driving a CMV. (2) No motor...

  16. 47 CFR 15.519 - Technical requirements for hand held UWB systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Technical requirements for hand held UWB... DEVICES Ultra-Wideband Operation § 15.519 Technical requirements for hand held UWB systems. (a) UWB devices operating under the provisions of this section must be hand held, i.e., they are relatively...

  17. 30 CFR 75.1724 - Hand-held power tools; safety devices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Hand-held power tools; safety devices. 75.1724... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1724 Hand-held power tools; safety devices. Hand-held power tools shall be equipped with controls requiring...

  18. 30 CFR 77.402 - Hand-held power tools; safety devices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Hand-held power tools; safety devices. 77.402... COAL MINES Safeguards for Mechanical Equipment § 77.402 Hand-held power tools; safety devices. Hand-held power tools shall be equipped with controls requiring constant hand or finger pressure to...

  19. 30 CFR 77.402 - Hand-held power tools; safety devices.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Hand-held power tools; safety devices. 77.402... COAL MINES Safeguards for Mechanical Equipment § 77.402 Hand-held power tools; safety devices. Hand-held power tools shall be equipped with controls requiring constant hand or finger pressure to...

  20. 47 CFR 15.519 - Technical requirements for hand held UWB systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Technical requirements for hand held UWB... DEVICES Ultra-Wideband Operation § 15.519 Technical requirements for hand held UWB systems. (a) UWB devices operating under the provisions of this section must be hand held, i.e., they are relatively...

  1. 30 CFR 77.402 - Hand-held power tools; safety devices.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Hand-held power tools; safety devices. 77.402... COAL MINES Safeguards for Mechanical Equipment § 77.402 Hand-held power tools; safety devices. Hand-held power tools shall be equipped with controls requiring constant hand or finger pressure to...

  2. 30 CFR 75.1724 - Hand-held power tools; safety devices.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Hand-held power tools; safety devices. 75.1724... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1724 Hand-held power tools; safety devices. Hand-held power tools shall be equipped with controls requiring...

  3. 47 CFR 15.519 - Technical requirements for hand held UWB systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Technical requirements for hand held UWB... DEVICES Ultra-Wideband Operation § 15.519 Technical requirements for hand held UWB systems. (a) UWB devices operating under the provisions of this section must be hand held, i.e., they are relatively...

  4. 47 CFR 15.519 - Technical requirements for hand held UWB systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Technical requirements for hand held UWB... DEVICES Ultra-Wideband Operation § 15.519 Technical requirements for hand held UWB systems. (a) UWB devices operating under the provisions of this section must be hand held, i.e., they are relatively...

  5. 47 CFR 15.519 - Technical requirements for hand held UWB systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Technical requirements for hand held UWB... DEVICES Ultra-Wideband Operation § 15.519 Technical requirements for hand held UWB systems. (a) UWB devices operating under the provisions of this section must be hand held, i.e., they are relatively...

  6. 30 CFR 75.1724 - Hand-held power tools; safety devices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Hand-held power tools; safety devices. 75.1724... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1724 Hand-held power tools; safety devices. Hand-held power tools shall be equipped with controls requiring...

  7. 30 CFR 77.402 - Hand-held power tools; safety devices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Hand-held power tools; safety devices. 77.402... COAL MINES Safeguards for Mechanical Equipment § 77.402 Hand-held power tools; safety devices. Hand-held power tools shall be equipped with controls requiring constant hand or finger pressure to...

  8. 49 CFR 392.82 - Using a hand-held mobile telephone.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 5 2014-10-01 2014-10-01 false Using a hand-held mobile telephone. 392.82 Section... COMMERCIAL MOTOR VEHICLES Limiting the Use of Electronic Devices § 392.82 Using a hand-held mobile telephone. (a)(1) No driver shall use a hand-held mobile telephone while driving a CMV. (2) No motor...

  9. 75 FR 32803 - Notice of Issuance of Final Determination Concerning a GTX Mobile+ Hand Held Computer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-09

    ... Mobile+ Hand Held Computer AGENCY: U.S. Customs and Border Protection, Department of Homeland Security... Mobile+ hand held computer. Based upon the facts presented, CBP has concluded in the final determination that Canada is the country of origin of the GTX Mobile+ hand held computer for purposes of...

  10. Cordless hand-held optical 3D sensor

    NASA Astrophysics Data System (ADS)

    Munkelt, Christoph; Bräuer-Burchardt, Christian; Kühmstedt, Peter; Schmidt, Ingo; Notni, Gunther

    2007-07-01

    A new mobile optical 3D measurement system using phase correlation based fringe projection technique will be presented. The sensor consist of a digital projection unit and two cameras in a stereo arrangement, whereby both are battery powered. The data transfer to a base station will be done via WLAN. This gives the possibility to use the system in complicate, remote measurement situations, which are typical in archaeology and architecture. In the measurement procedure the sensor will be hand-held by the user, illuminating the object with a sequence of less than 10 fringe patterns, within a time below 200 ms. This short sequence duration was achieved by a new approach, which combines the epipolar constraint with robust phase correlation utilizing a pre-calibrated sensor head, containing two cameras and a digital fringe projector. Furthermore, the system can be utilized to acquire the all around shape of objects by using the phasogrammetric approach with virtual land marks introduced by the authors 1, 2. This way no matching procedures or markers are necessary for the registration of multiple views, which makes the system very flexible in accomplishing different measurement tasks. The realized measurement field is approx. 100 mm up to 400 mm in diameter. The mobile character makes the measurement system useful for a wide range of applications in arts, architecture, archaeology and criminology, which will be shown in the paper.

  11. Use of the hand-held calculator in office ultrasound.

    PubMed

    Christenson, D; McCown, R B

    1984-09-01

    Office ultrasonographers may use various fetal measurements for indices of fetal growth. One index predicts birth weight from biparietal diameter (BPD) and abdominal circumference from a set of reference tables generated by a computer-assisted analysis. An inexpensive hand-held programmable calculator may be used instead of the reference table to estimate birth weight. It produces results by direct calculation from the original equation after BPD and abdominal circumference are entered as data. A step-by-step program for a representative calculator is provided, along with data entry instructions. The program also will calculate the head-to-abdomen circumference ratio. Other functions that could be placed on pocket calculators include fetal brain-weight calculations or gestational age determinations from limb measurements. Because it is possible to represent any graph or data point set as a polynominal equation, entering the equation into a programmable calculator can eliminate tedious searches through charts and graphs. A table or graph can use only two measured parameters at a time, representing their complex relationship with a result. It is not possible to represent a result in terms of more than two parameters using a single graph or chart. A calculator permits complex calculations relating more than two parameters by the office practitioner as well as the researcher. PMID:6462574

  12. Hand-Held Units for Short-Range Wireless Biotelemetry

    NASA Technical Reports Server (NTRS)

    Miranda, Felix A.; Simons, Rainee N.

    2008-01-01

    Special-purpose hand-held radiotransceiver units have been proposed as means of short-range radio powering and interrogation of surgically implanted microelectromechanical sensors and actuators. These units are based partly on the same principles as those of the units described in "Printed Multi- Turn Loop Antennas for RF Biotelemetry" (LEW-17879-1), NASA Tech Briefs, Vol. 31, No. 6 (June 2007), page 48. Like the previously reported units, these units would make it unnecessary to have wire connections between the implanted devices and the external equipment used to activate and interrogate them. Like a unit of the previously reported type, a unit of the type now proposed would include a printed-circuit antenna on a dielectric substrate. The antenna circuitry would include integrated surface-mount inductors for impedance tuning. Circuits for processing the signals transmitted and received by the antenna would be included on the substrate. During operation, the unit would be positioned near (but not in electrical contact with) a human subject, in proximity to a microelectromechanical sensor or actuator that has been surgically implanted in the subject. It has been demonstrated that significant electromagnetic coupling with an implanted device could be established at a distance of as much as 4 in. (.10 cm). During operation in the interrogation mode, the antenna of the unit would receive a radio telemetry signal transmitted by the surgically implanted device. The antenna substrate would have dimensions of approximately 3.25 by 3.75 inches (approximately 8.3 by 9.5 cm). The substrate would have a thickness of the order of 30 mils (of the order of a somewhat less than a millimeter). The substrate would be made of low-radiofrequency- loss dielectric material that could be, for example, fused quartz, alumina, or any of a number of commercially available radio-frequency dielectric composite materials. The antenna conductors would typically be made of copper or a

  13. Portable Hand-Held Electrochemical Sensor for the Transuranics

    SciTech Connect

    Dale D. Russell, William B. Knowlton, Ph.D.; Russel Hertzog, Ph.D

    2005-11-25

    sensitive detector for uranium. Millimeter scale electrodes, operated by a hand-held instrument assembled in this lab and operated in the voltammetric mode, were transported to the DOE-Nevada test site (Las Vegas, NV) where field detection and quantitation of plutonium, uranium, and a mixture of these two elements was also demonstrated. Several probe designs were prepared, built and tested including probes with movable protective windows. A miniature, battery powered potentiostat was designed, built and demonstrated for use in a hand-held field portable instrument. This work was performed largely by undergraduates who gained valuable research experience, and many of them have continued on to graduate schools. In addition, they all gained exposure to and appreciation for national security research, in particular non-proliferation research. Four graduate students participated and one earned the MS degree on this project.

  14. Direction-Sensitive Hand-Held Gamma-Ray Spectrometer

    SciTech Connect

    Mukhopadhyay, S.

    2012-10-04

    A novel, light-weight, hand-held gamma-ray detector with directional sensitivity is being designed. The detector uses a set of multiple rings around two cylindrical surfaces, which provides precise location of two interaction points on two concentric cylindrical planes, wherefrom the source location can be traced back by back projection and/or Compton imaging technique. The detectors are 2.0 × 2.0 mm europium-doped strontium iodide (SrI2:Eu2+) crystals, whose light output has been measured to exceed 120,000 photons/MeV, making it one of the brightest scintillators in existence. The crystal’s energy resolution, less than 3% at 662 keV, is also excellent, and the response is highly linear over a wide range of gamma-ray energies. The emission of SrI2:Eu2+ is well matched to both photo-multiplier tubes and blue-enhanced silicon photodiodes. The solid-state photomultipliers used in this design (each 2.0 × 2.0 mm) are arrays of active pixel sensors (avalanche photodiodes driven beyond their breakdown voltage in reverse bias); each pixel acts as a binary photon detector, and their summed output is an analog representation of the total photon energy, while the individual pixel accurately defines the point of interaction. A simple back-projection algorithm involving cone-surface mapping is being modeled. The back projection for an event cone is a conical surface defining the possible location of the source. The cone axis is the straight line passing through the first and second interaction points.

  15. Hand-Held Color Meters Based on Interference Filters

    NASA Technical Reports Server (NTRS)

    Snyder, G. Jeffrey; Fleurial, Jean-Pierre; Caillat, Thierry; Chen, Gang; Yang, Rong Gui

    2004-01-01

    Small, inexpensive, hand-held optoelectronic color-measuring devices based on metal-film/dielectric-film interference filters are undergoing development. These color meters could be suitable for use in a variety of applications in which there are requirements to quantify or match colors for aesthetic purposes but there is no need for the high spectral resolution of scientific-grade spectrometers. Such applications typically occur in the paint, printing, and cosmetic industries, for example. The figure schematically depicts a color meter of this type being used to measure the color of a sample in terms of the spectrum of light reflected from the sample. Light from a white source (for example, a white light-emitting diode) passes through a collimating lens to the sample. Another lens collects some of the light reflected from the sample and focuses the light onto the input end of optical fiber. Light emerging from the output end of the optical fiber illuminates an array of photodetectors covered with metal/dielectric-film interference filters like those described in Metal/Dielectric-film Interference Color Filters (NPO-20217), NASA Tech Briefs, Vol. 23, No. 2 (February 1999), page 70. Typically, these are wide-band-pass filters, as shown at the bottom of the figure. The photodetector array need not be of any particular design: it could be something as simple as an assembly containing several photodiodes or something as elaborate as an active-pixel sensor or other imaging device. What is essential is that each of the photodetectors or each of several groups of photodetectors is covered with a metal/dielectric-film filter of a different color. In most applications, it would be desirable to have at least three different filters, each for a spectral band that contains one of the three primary additive red, green, and blue colors. In some applications, it may be necessary to have more than three different color filters in order to characterize subtle differences in color

  16. Hand Held Device for Wireless Powering and Interrogation of Biomems Sensors and Actuators

    NASA Technical Reports Server (NTRS)

    Miranda, Felix Antonio (Inventor); Simons, Rainee N (Inventor)

    2007-01-01

    A compact, hand-held device for wireless powering, interrogation and data retrieval from at least one implanted sensor. The hand-held device includes an antenna for powering an implanted sensor and for receiving data from the implanted sensor to the hand-held device for at least one of storage, display or analysis. The hand-held device establishes electromagnetic coupling with a low radiating radio frequency power inductor in the implanted sensor at a predefined separation and the antenna geometry allows for the antenna to power, interrogate and retrieve data from the implanted sensor without strapping the hand-held device to a human body housing the implanted sensor The hand-held device optionally allows for activation of the implanted sensor only during interrogation and data retrieval.

  17. 16 CFR 1225.2 - Requirements for hand-held infant carriers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... approves this incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Requirements for hand-held infant carriers... ACT REGULATIONS SAFETY STANDARD FOR HAND-HELD INFANT CARRIERS (Eff. 6-6-14) § 1225.2 Requirements...

  18. Hand-held based near-infrared optical imaging devices: a review.

    PubMed

    Erickson, Sarah J; Godavarty, Anuradha

    2009-06-01

    Near-infrared (NIR) optical imaging is a non-invasive and non-ionizing modality that is emerging as a diagnostic/prognostic tool for breast cancer and other applications related to functional brain mapping. In recent years, hand-held based optical imaging devices are developed for clinical translation of the technology, as opposed to the various bulky optical imagers available. Herein, we review the different hand-held based NIR devices developed to date, in terms of the measurement techniques implemented (continuous wave, time or frequency-domain), the imaging methods used, and the specific applications towards which they were applied. The advantages and disadvantages of the different hand-held optical devices are described and also compared with respect to a novel hand-held based device currently developed in our Optical Imaging Laboratory towards three-dimensional tomography studies. PMID:19054704

  19. Computer implemented method, and apparatus for controlling a hand-held tool

    NASA Technical Reports Server (NTRS)

    Wagner, Kenneth William (Inventor); Taylor, James Clayton (Inventor)

    1999-01-01

    The invention described here in is a computer-implemented method and apparatus for controlling a hand-held tool. In particular, the control of a hand held tool is for the purpose of controlling the speed of a fastener interface mechanism and the torque applied to fasteners by the fastener interface mechanism of the hand-held tool and monitoring the operating parameters of the tool. The control is embodied in intool software embedded on a processor within the tool which also communicates with remote software. An operator can run the tool, or through the interaction of both software, operate the tool from a remote location, analyze data from a performance history recorded by the tool, and select various torque and speed parameters for each fastener.

  20. Enhancing Mathematical Concepts through Leading Questions and Hand-Held Data Collection Tools.

    ERIC Educational Resources Information Center

    Laughbaum, Edward D.

    Hand-held data collection technology allows for access to real-world data collection--at any other time and almost any place. Is the use of data and its collection desirable to the mathematical learning process? The answer is a resounding yes! Not only can significant mathematical ideas be taught in the process; colleagues are also helped in the…

  1. Droplet size characterization of hand-held atomization equipment typically used in vector control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The atomization characteristics from four hand-held sprayers (Leco P-1, Colt ULV Aerosol Generator, UlVAFAN MK2, Turbair ElectraFan 12) and a Stihl SR400 backpack sprayer were evaluated using water- and oil-based solutions. The effects on droplet size spectrum for three insecticides (Tempo SC Ultra...

  2. Online Responses towards Parental Rearing Styles Regarding Hand-Held Devices

    ERIC Educational Resources Information Center

    Geng, Gretchen; Disney, Leigh

    2014-01-01

    This article reviewed the literature on parental rearing styles and used responses from an online discussion forum to investigate people's opinions towards parental rearing styles and strategies when children use hand-held devices. Critical discourse analysis (CDA) was used as an analysis method via micro, meso and macro multi-level…

  3. 77 FR 40637 - Honeywell International, Scanning and Mobility Division, Formerly Known as Hand Held Products...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-10

    ... in the Federal Register on June 17, 2011 (Vol. 76 FR 117). At the request of the state workforce... 17, 2011 (Vol. 76 FR 117). In order to ensure that the worker group is properly identified, the... Known as Hand Held Products, Inc., Including On-Site Leased Workers From Manpower, Skaneatelles...

  4. Hand-Held Model of a Sarcomere to Illustrate the Sliding Filament Mechanism in Muscle Contraction

    ERIC Educational Resources Information Center

    Jittivadhna, Karnyupha; Ruenwongsa, Pintip; Panijpan, Bhinyo

    2009-01-01

    From our teaching of the contractile unit of the striated muscle, we have found limitations in using textbook illustrations of sarcomere structure and its related dynamic molecular physiological details. A hand-held model of a striated muscle sarcomere made from common items has thus been made by us to enhance students' understanding of the…

  5. Using Hand-Held Calculators in Sixth Grade Classes. A Brief Report of an Educational Project.

    ERIC Educational Resources Information Center

    Barrett, Ray; Keefe, Michael

    This brief report describes an exploratory pilot project in which sixth-grade students used hand-held calculators throughout the school year. The report includes guidelines on the purchase and use of calculators as well as advice on gaining community support for such a project. Issues related to classroom management are discussed; in particular,…

  6. 75 FR 27504 - Substantial Product Hazard List: Hand-Held Hair Dryers

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-17

    ... compliance with UL 859. An additional 42 companies are listed in the Intertek ETL Listed Mark Product... Certifications directory and another four firms are listed in the Intertek ETL Listed Mark Product Directory as... additional 42 suppliers listed in the Intertek ETL Listed Mark Product Directory as supplying hand-held...

  7. Hand-held transendoscopic robotic manipulators: A transurethral laser prostate surgery case study

    PubMed Central

    Hendrick, Richard J.; Mitchell, Christopher R.; Herrell, S. Duke; Webster, Robert J.

    2016-01-01

    Natural orifice endoscopic surgery can enable incisionless approaches, but a major challenge is the lack of small and dexterous instrumentation. Surgical robots have the potential to meet this need yet often disrupt the clinical workflow. Hand-held robots that combine thin manipulators and endoscopes have the potential to address this by integrating seamlessly into the clinical workflow and enhancing dexterity. As a case study illustrating the potential of this approach, we describe a hand-held robotic system that passes two concentric tube manipulators through a 5 mm port in a rigid endoscope for transurethral laser prostate surgery. This system is intended to catalyze the use of a clinically superior, yet rarely attempted, procedure for benign prostatic hyperplasia. This paper describes system design and experiments to evaluate the surgeon’s functional workspace and accuracy using the robot. Phantom and cadaver experiments demonstrate successful completion of the target procedure via prostate lobe resection. PMID:27570361

  8. An efficient solid modeling system based on a hand-held 3D laser scan device

    NASA Astrophysics Data System (ADS)

    Xiong, Hanwei; Xu, Jun; Xu, Chenxi; Pan, Ming

    2014-12-01

    The hand-held 3D laser scanner sold in the market is appealing for its port and convenient to use, but price is expensive. To develop such a system based cheap devices using the same principles as the commercial systems is impossible. In this paper, a simple hand-held 3D laser scanner is developed based on a volume reconstruction method using cheap devices. Unlike convenient laser scanner to collect point cloud of an object surface, the proposed method only scan few key profile curves on the surface. Planar section curve network can be generated from these profile curves to construct a volume model of the object. The details of design are presented, and illustrated by the example of a complex shaped object.

  9. Early Childhood Vision Screening in Hawai'i Utilizing a Hand-Held Screener.

    PubMed

    Chang, Duane A; Ede, Roger C; Chow, Dominic C; Souza, Ryan D; Gangcuangco, Louie Mar A; Hanks, Nancy; Nakamoto, Beau K; Mitchell, Brooks; Masutani, Alison T; Fisk, Sam; Shikuma, Cecilia M; Dill, Jan E

    2015-09-01

    The goal of early childhood vision screening is to detect subnormal vision and amblyopic risk factors that threaten visual development so that treatment can be initiated early to yield the highest benefit. Hand-held, portable, instrument-based vision screening devices can be used in children as young as 6 months of age. We assessed the feasibility of hand-held photoscreeners to screen for vision disorders in pre-school children in Hawai'i. A total of 137 preschool children on O'ahu in the "Tutu and Me"/Partners in Development program were screened at 6 different locations using the Plusoptix S12 hand-held photoscreener. Once technical issues were resolved, screening was fast and well tolerated. Possible vision abnormalities were found in 11 of the 137 children (8%). Poor compliance for follow-up with formal vision examination limited our ability to confirm these abnormalities. We conclude that photoscreening has the potential to facilitate early childhood vision screening in Hawai'i. The optimal referral criteria for use in Hawai'i will need to be determined after considering the age of the screening population and the available medical resources in Hawai'i. Early detection of treatable eye disorders has far-reaching benefits for the visual development and long term health and well-being of children. A comprehensive early childhood vision screening program in Hawai'i utilizing automated hand-held photoscreeners may have public health value. Such a program should integrate referral to an eye care professional for confirmation and management of vision disorders of at-risk children found on screening. PMID:26468424

  10. Rapid detection of Escherichia coli in water using a hand-held fluorescence detector.

    PubMed

    Wildeboer, Dirk; Amirat, Linda; Price, Robert G; Abuknesha, Ramadan A

    2010-04-01

    The quantification of pathogenic bacteria in an environmental or clinical sample commonly involves laboratory-based techniques and results are not obtained for 24-72 h after sampling. Enzymatic analysis of microbial activity in water and other environmental samples using fluorescent synthetic substrates are well-established and highly sensitive methods in addition to providing a measure of specificity towards indicative bacteria. The enzyme beta-d-glucuronidase (GUD) is a specific marker for Escherichia coli and 4-methylumbelliferone-beta-D-glucuronide (MUG) a sensitive substrate for determining the presence of E. coli in a sample. However, currently used procedures are laboratory-based and require bench-top fluorimeters for the measurement of fluorescence resulting from the enzyme-substrate reaction. Recent developments in electronic engineering have led to the miniaturisation of fluorescence detectors. We describe the use of a novel hand-held fluorimeter to directly analyse samples obtained from the River Thames for the presence of E. coli. The results obtained by the hand-held detector were compared with those obtained with an established fluorescent substrate assay and by quantifying microbial growth on a chromogenic medium. Both reference methods utilised filtration of water samples. The miniaturised fluorescence detector was used and incubation times reduced to 30 min making the detection system portable and rapid. The developed hand-held system reliably detected E. coli as low as 7 cfu/mL river water sample. Our study demonstrates that new hand-held fluorescence measurement technology can be applied to the rapid and convenient detection of bacteria in environmental samples. This enables rapid monitoring to be carried out on-site. The technique described is generic and it may, therefore, be used in conjunction with different fluorescent substrates which allows the assessment of various target microorganisms in biological samples. PMID:20153013

  11. Protein Crystals Grown in the hand-held Protein Crystallization Apparatus for Microgravity (PCAM)

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Crystals grown in the hand-held Protein Crystallization Apparatus for Microgravity (PCAM) onboard STS-61C. The PCAM has a pedestal in the center of a circular chamber, the surrounding chamber holds an absorbent reservoir that contains a solution of the precipitant. Vapor pressure differences between the protein solution and the reservoir solution force water to move from the protein solution to the reservoir. As protein concentrations increase, protein crystals begin to nucleate and grow.

  12. Using hand-held point and shoot video cameras in clinical education.

    PubMed

    Stoten, Sharon

    2011-02-01

    Clinical educators are challenged to design and implement creative instructional strategies to provide employees with optimal clinical practice learning opportunities. Using hand-held video cameras to capture patient encounters or skills demonstrations involves employees in active learning and can increase dialogue between employees and clinical educators. The video that is created also can be used for evaluation and feedback. Hands-on experiences may energize employees with different talents and styles of learning. PMID:21323214

  13. Planning of directionally drilled wells in the offshore Wilmington field using the hand-held calculator

    SciTech Connect

    Clark, D.D.; Barth, J.W.

    1983-02-01

    As of July 1982, 901 wells have been directionally drilled in the Long Beach Unit of the East Wilmington Field from 4 man-made islands and land based drilling sites. As more wells are added to each site the planning of new well courses has become more complex. The hand held calculator with Long Beach Unit developed programs has been an aid in laying out new wells which will avoid existing cased boreholes.

  14. Note: A hand-held high-Tc superconducting quantum interference device operating without shielding.

    PubMed

    He, D F

    2011-02-01

    By improving the compensation circuit, a hand-held high-Tc rf superconducting quantum interference devices (SQUID) system was developed. It could operate well when moving in unshielded environment. To check the operation, it was used to do eddy-current testing by hand moving the SQUID, and the artificial defect under 6 mm aluminum plate could be successfully detected in shielded environment. PMID:21361649

  15. Hand-held resonance sensor for tissue stiffness measurements—a theoretical and experimental analysis

    NASA Astrophysics Data System (ADS)

    Jalkanen, Ville

    2010-05-01

    A piezoelectric transducer in a feedback circuit operating in a resonance state is the basis of a resonance sensor. Upon contact with a soft object a change in the resonance frequency reflects the acoustic impedance. Together with force measurement it is possible to obtain the elastic stiffness of the object. The aim of this study was to evaluate the concept of a hand-held resonance sensor for tissue stiffness measurement. A time derivative analysis of the force and the frequency change showed that a stiffness-sensitive parameter was independent of the impression speed. Soft tissue phantoms of gelatin were used in an experimental validation of the theory. A force indentation method was used as a reference method for assessing the gelatin's elastic stiffness. Results from the hand-held measurements showed that the stiffness parameter accurately measured the elastic stiffness of the gelatin (R2 = 0.94, p < 0.05). The stiffness parameter was weakly (on average R2 = 0.15) and non-significantly (p > 0.05, 14 out of 17) dependent on an impression speed parameter. On average, a small amount of the total variance was explained by the impression speed. In conclusion, soft tissue stiffness can be objectively measured with free-hand measurement with a resonance sensor. This study contributes a theoretical analysis and an experimental demonstration of the concept of a hand-held resonance sensor for stiffness measurements.

  16. Noise reduction techniques in the design of a pneumatic-driven hand held power tool

    NASA Astrophysics Data System (ADS)

    Skinner, Christian M.

    2005-09-01

    Pneumatic-driven hand-held power tools generate noise in the workplace. Current legislation in Europe and the USA aims at protecting workers against noise exposure. In the United States, the Occupational Safety and Health Administration (OSHA) requires that employers create a hearing conservation program if the noise exposure exceeds 85 dB(A). In the European Community under the Directive 2003/10/EC, employers are required to provide hearing protection if the noise exposure within the working environment exceeds 80 dB(A) and must require hearing protection to be worn if the noise exposure exceeds 85 dB(A). This paper examines the sources of noise which contribute to the overall noise from a hand-held power tool. A test plan was developed to identify these individual sources of noise and to determine if structure-borne noise or airborne noise is the dominant source relative to the overall noise level. The measurements were performed per International Standards Organization (ISO) 15744. This paper will describe the methodology used to identify the noise sources and reduce the overall noise of a hand-held power tool.

  17. A hand-held electronic tongue based on fluorometry for taste assessment of tea.

    PubMed

    Chang, Kuang-Hua; Chen, Richie L C; Hsieh, Bo-Chuan; Chen, Po-Chung; Hsiao, Hsien-Yi; Nieh, Chi-Hua; Cheng, Tzong-Jih

    2010-12-15

    A hand-held electronic tongue was developed for determining taste levels of astringency and umami in tea infusions. The sensing principles are based on quenching the fluorescence of 3-aminophthalate by tannin, and the fluorogenic reaction of o-phthalaldehyde (OPA) with amino acids to determine astringency and umami levels, respectively. Both reactions were measured by a single fluorescence sensing system with same excitation and emission wavelengths (340/425 nm). This work describes in detail the design, fabrication, and performance evaluation of a hand-held fluorometer with an ultra-violet light emitted diode (UVLED) and a photo-detector with a filter built-in. The dimension and the weight of proposed electronic tongue prototype are only 120×60×65 mm(3) and 150 g, respectively. The detection limits of this prototype for theanine and tannic acid were 0.2 μg/ml and 1 μg/ml, respectively. Correlation coefficients of this prototype compared with a commercial fluorescence instrument are both higher than 0.995 in determinations of tannin acid and theanine. Linear detection ranges of the hand-held fluorometer for tannic acid and theanine are 1-20 μg/ml and 0.2-10 μg/ml (CV<5%, n=3), respectively. A specified taste indicator for tea, defined as ratio of umami to astringency, was adopted here to effectively distinguish flavour quality of partially fermented Oolong teas. PMID:20728331

  18. A hand-held micro surgical device for contact force regulation against involuntary movements.

    PubMed

    Seulki Kyeong; Dongjune Chang; Yunjoo Kim; Gwang Min Gu; Seungkey Lee; Soohoa Jeong; Jung Kim

    2015-08-01

    Involuntary movements such as heart beating in surgical environment and surgeon's tremor disturb a micro surgical manipulation and cause a risk of patient wound. Although the delicate operation is performed by a skilled surgeon, the sensitivity of the surgeon is limited to quantify the range of safe contact forces. In this paper, we developed a compact hand-held surgical device to maintain a required contact force to maintain a required contact force using a custom force sensor and a linear delta mechanism. The custom optical force sensor measured the contact force of the device tip and the linear delta mechanism compensated undesired forces to maintain a consistent contact force. The proposed device is consisted of force sensing unit and actuating unit. The device was improved from our previous Linear Delta mechanism based prototype in terms of size, weight, and force sensing capability. The developed device was validated by investigation of contact force accuracy in a fixed condition and a hand-held condition. In hand-held condition, the visual feedback of the current contact force was provided, and the performance of the contact force regulation was investigated by comparing the root mean square (RMS) contact force errors and standard deviation in with and without control cases. The fluctuation (less than 50 mN) of the force regulation control of the device showed the feasibility of the device for the use in delicate operations. PMID:26736400

  19. 78 FR 20695 - Walk-Through Metal Detectors and Hand-Held Metal Detectors Test Method Validation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-05

    ... Office of Justice Programs Walk-Through Metal Detectors and Hand-Held Metal Detectors Test Method... detectors and hand-held metal detectors. In order to ensure that the test methods in the standards are properly documented, NIJ is requesting proposals (including price quotes) for test method...

  20. Advanced hand-held mine detector and mine detection neutralization and route marking system overview

    NASA Astrophysics Data System (ADS)

    Burch, Ian A.; Allsopp, David J.

    2000-08-01

    An overview of the UK MOD Applied Research Program for Land Mine Detection. The Defense Evaluation and Research Agency carries out and manages the whole of the UK MOD's Counter Minewarfare Applied Research program both within its own laboratories and in partnership with industrial and academic research organizations. This paper will address two specific counter Minewarfare programs, the Advanced Hand Held Mine Detector which started in April 1995 and the Mine Detection Neutralization and Route Marking System which started in April 1997. Both are multi-sensor systems, incorporating between the metal detection, ground penetrating radar, nuclear quadrupole resonance, ultra-wideband radar, and polarized thermal imaging.

  1. Applications of a hand-held GPS receiver in South American rain forests

    NASA Technical Reports Server (NTRS)

    Baksh, Michael

    1991-01-01

    A hand-held Global Positioning System receiver was used to determine the precise locations of villages, houses, gardens, and other cultural and environmental features in poorly mapped South American rain forests. The Magellan NAV 1000 unit profides extremely accurate latitude and longitude information, but determination of altitude is problematical. Overall, the receiver effectively allows anthropologists to obtain essential locational data useful for categorizing land uses, mapping tribal boundaries, and other applications in regions where environmental conditions are harsh and/or accessibility is difficult.

  2. Hand-held electronic teaching-aid for demonstrating MRI concepts.

    PubMed

    Malko, J A; Nelson, R C

    1989-11-01

    We describe a hand-held electronic teaching-aid for magnetic resonance imaging (MRI), which can be used to demonstrate the dependence of signal intensity on changing pulse sequence parameters (TR and TE), the dependence of intensity on changing tissue parameters (T1 and T2), and the ideas of "T1-weighting" and "T2-weighting" as they relate to image contrast. The device was specifically designed to be easy to use and readily accessible to residents-in-training and MR neophytes. PMID:2807811

  3. Environmental applications of hand-held photography taken from the space shuttle

    SciTech Connect

    Muehlberger, W.R.

    1996-07-01

    Astronauts have been taking photographs of earth since 1965, years before unmanned satellites began systematic coverage. The trained eye of an intelligent observer permits the rapid identification of a feature or an anomaly so that it can be the central focus of the photograph, rather than one of an endless stream of information from an unmanned satellite through which the interpreter has to sort and pick. This paper describes some of the environmental uses of hand-held photography since the launch of the first Space Shuttle in April, 1981.

  4. Rapid Diagnosis of an Ulnar Fracture with Portable Hand-Held Ultrasound

    NASA Technical Reports Server (NTRS)

    Kirkpatrick, Andrew W.; Brown, Ross; Diebel, Lawrence N.; Nicolaou, Savvas; Marshburn, Tom; Dulchavsky, Scott A.

    2002-01-01

    Orthopedic fractures are a common injury in operational activities, injuries that often occur in isolated or hostile environments. Clinical ultrasound devices have become more user friendly and lighter allowing them to be easily transported with forward medical teams. The bone-soft tissue interface has a very large acoustic impedance, with a high reflectance that can be used to visualize breaks in contour including fractures. Herein reported is a case of an ulnar fracture that was quickly visualized in the early phase of a multi-system trauma resuscitation with a hand-held ultrasound device. The implications for operational medicine are discussed.

  5. Hand-held spectral radiometer to estimate gramineous biomass. [with interfaced pocket calculator solution

    NASA Technical Reports Server (NTRS)

    Pearson, R. L.; Miller, L. D.; Tucker, C. J.

    1976-01-01

    A simple hand-held instrument has been designed and constructed to nondestructively estimate above-ground gramineous biomass using radiometric measurements. The prototype unit consists of a modified two-channel digital radiometer interfaced to a pocket calculator. A digital interface was constructed to join electronically and control the radiometer and calculator to enable the radiometer-calculator system to solve a linear conversion solution from radiometric units to estimated biomass. This instrument has been used to estimate radiometrically gramineous biomass in a more efficient fashion with a high degree of accuracy.

  6. Area estimation in pharmacokinetic studies using a hand-held programmable calculator.

    PubMed

    Bury, R W

    1984-01-01

    A short program for area analysis in pharmacokinetic studies using the Hewlett-Packard HP41C hand-held programmable calculator is described. Area under the concentration-time curve is calculated firstly within defined time limits and then with extrapolation to infinite time using the slope constant of the terminal phase. Input of concentration-time data is simple and there is no limit on the number of time-concentration co-ordinates which can be entered for area calculation. PMID:6735513

  7. Pre-participation cardiovascular screening: is community screening using hand-held cardiac ultrasound feasible?

    PubMed

    Mitchell, A R J; Hurry, R; Le Page, P; MacLachlan, H

    2015-06-01

    We evaluated the feasibility and costs of utilising hand-held cardiac ultrasound (HHCU) as part of a community-based pre-participation cardiovascular screening programme. Ninety-seven school children were screened using a personal history, a physical examination, a resting 12-lead electrocardiogram (ECG) and a HHCU. A consultant cardiologist independently reviewed and reported the data. Previously undiagnosed cardiovascular abnormalities were identified in nine participants (9%). An additional three participants (3%) were diagnosed with hypertension. The nine abnormalities were identified at a cost of £460 per finding, with a cost of £43 per participant screened. The marginal cost of adding a HHCU to the personal history, physical examination and ECG was £16 per participant. Pre-participation screening in the community using hand-held echocardiography is practical and inexpensive. The additional sensitivity and specificity provided by the ultrasound may enhance screening programmes, thereby reducing false positives and the need for expensive follow-up testing. PMID:26693333

  8. Hand-Held Sunphotometers for High School Student Construction and Measuring Aerosol Optical Thickness

    NASA Technical Reports Server (NTRS)

    Almonor, Linda; Baldwin, C.; Craig, R.; Johnson, L. P.

    2000-01-01

    Science education is taking the teaching of science from a traditional (lecture) approach to a multidimensional sense-making approach which allows teachers to support students by providing exploratory experiences. Using projects is one way of providing students with opportunities to observe and participate in sense-making activity. We created a learning environment that fostered inquiry-based learning. Students were engaged in a variety of Inquiry activities that enabled them to work in cooperative planning teams where respect for each other was encouraged and their ability to grasp, transform and transfer information was enhanced. Summer, 1998: An air pollution workshop was conducted for high school students in the Medgar Evers College/Middle College High School Liberty Partnership Summer Program. Students learned the basics of meteorology: structure and composition of the atmosphere and the processes that cause weather. The highlight of this workshop was the building of hand-held sunphotometers, which measure the intensity of the sunlight striking the Earth. Summer, 1999: high school students conducted a research project which measured the mass and size of ambient particulates and enhanced our ability to observe through land based measurements changes in the optical depth of ambient aerosols over Brooklyn. Students used hand held Sunphotometers to collect data over a two week period and entered it into the NASA GISS database by way of the internet.

  9. Hand-held optoacoustic probe for three-dimensional imaging of human morphology and function

    NASA Astrophysics Data System (ADS)

    Deán-Ben, X. Luís.; Razansky, Daniel

    2014-03-01

    We report on a hand-held imaging probe for real-time optoacoustic visualization of deep tissues in three dimensions. The proposed solution incorporates a two-dimensional array of ultrasonic sensors densely distributed on a spherical surface, whereas illumination is performed coaxially through a cylindrical cavity in the array. Visualization of three-dimensional tomographic data at a frame rate of 10 images per second is enabled by parallel recording of 256 time-resolved signals for each individual laser pulse along with a highly efficient GPUbased real-time reconstruction. A liquid coupling medium (water), enclosed in a transparent membrane, is used to guarantee transmission of the optoacoustically generated waves to the ultrasonic detectors. Excitation at multiple wavelengths further allows imaging spectrally distinctive tissue chromophores such as oxygenated and deoxygenated haemoglobin. The performance is showcased by video-rate tracking of deep tissue vasculature and three-dimensional measurements of blood oxygenenation in a healthy human volunteer. The flexibility provided by the hand-held hardware design, combined with the real-time operation, makes the developed platform highly usable for both small animal research and clinical imaging in multiple indications, including cancer, inflammation, skin and cardiovascular diseases, diagnostics of lymphatic system and breast

  10. Neurosurgical hand-held optical coherence tomography (OCT) forward-viewing probe

    NASA Astrophysics Data System (ADS)

    Sun, Cuiru; Lee, Kenneth K. C.; Vuong, Barry; Cusimano, Michael; Brukson, Alexander; Mariampillai, Adrian; Standish, Beau A.; Yang, Victor X. D.

    2012-02-01

    A prototype neurosurgical hand-held optical coherence tomography (OCT) imaging probe has been developed to provide micron resolution cross-sectional images of subsurface tissue during open surgery. This new ergonomic hand-held probe has been designed based on our group's previous work on electrostatically driven optical fibers. It has been packaged into a catheter probe in the familiar form factor of the clinically accepted Bayonet shaped neurosurgical non-imaging Doppler ultrasound probes. The optical design was optimized using ZEMAX simulation. Optical properties of the probe were tested to yield an ~20 um spot size, 5 mm working distance and a 3.5 mm field of view. The scan frequency can be increased or decreased by changing the applied voltage. Typically a scan frequency of less than 60Hz is chosen to keep the applied voltage to less than 2000V. The axial resolution of the probe was ~15 um (in air) as determined by the OCT system. A custom-triggering methodology has been developed to provide continuous stable imaging, which is crucial for clinical utility. Feasibility of this probe, in combination with a 1310 nm swept source OCT system was tested and images are presented to highlight the usefulness of such a forward viewing handheld OCT imaging probe. Knowledge gained from this research will lay the foundation for developing new OCT technologies for endovascular management of cerebral aneurysms and transsphenoidal neuroendoscopic treatment of pituitary tumors.

  11. Pre-participation cardiovascular screening: is community screening using hand-held cardiac ultrasound feasible?

    PubMed Central

    Hurry, R; Le Page, P; MacLachlan, H

    2015-01-01

    We evaluated the feasibility and costs of utilising hand-held cardiac ultrasound (HHCU) as part of a community-based pre-participation cardiovascular screening programme. Ninety-seven school children were screened using a personal history, a physical examination, a resting 12-lead electrocardiogram (ECG) and a HHCU. A consultant cardiologist independently reviewed and reported the data. Previously undiagnosed cardiovascular abnormalities were identified in nine participants (9%). An additional three participants (3%) were diagnosed with hypertension. The nine abnormalities were identified at a cost of £460 per finding, with a cost of £43 per participant screened. The marginal cost of adding a HHCU to the personal history, physical examination and ECG was £16 per participant. Pre-participation screening in the community using hand-held echocardiography is practical and inexpensive. The additional sensitivity and specificity provided by the ultrasound may enhance screening programmes, thereby reducing false positives and the need for expensive follow-up testing. PMID:26693333

  12. Algorithms for a hand-held miniature x-ray fluorescence analytical instrument

    SciTech Connect

    Elam, W.T.; Newman, D.; Ziemba, F.

    1998-12-31

    The purpose of this joint program was to provide technical assistance with the development of a Miniature X-ray Fluorescence (XRF) Analytical Instrument. This new XRF instrument is designed to overcome the weaknesses of spectrometers commercially available at the present time. Currently available XRF spectrometers (for a complete list see reference 1) convert spectral information to sample composition using the influence coefficients technique or the fundamental parameters method. They require either a standard sample with composition relatively close to the unknown or a detailed knowledge of the sample matrix. They also require a highly-trained operator and the results often depend on the capabilities of the operator. In addition, almost all existing field-portable, hand-held instruments use radioactive sources for excitation. Regulatory limits on such sources restrict them such that they can only provide relatively weak excitation. This limits all current hand-held XRF instruments to poor detection limits and/or long data collection times, in addition to the licensing requirements and disposal problems for radioactive sources. The new XRF instrument was developed jointly by Quantrad Sensor, Inc., the Naval Research Laboratory (NRL), and the Department of Energy (DOE). This report describes the analysis algorithms developed by NRL for the new instrument and the software which embodies them.

  13. Stabilized, hand-held, gamma-ray verification instrument for special nuclear materials

    SciTech Connect

    Fehlau, P.E.; Wiig, G.

    1988-01-01

    For many years, Los Alamos has developed intelligent, hand-held, search instruments for use by non-specialists to search for special nuclear materials (SNM). The instruments sense SNM by detecting its emitted radiation with scintillation detectors monitored by digital alarm circuitry. Now, we have developed a new hand-held instrument that can verify the presence or absence of particular radioisotopes by analyzing gamma-ray spectra. The new instrument is similar to recent, microprocessor-based, search instruments, but has LED detector stabilization, three adjustable regions-of-interest, and additional operating programs for spectrum analysis. We call the new instrument an SNM verification instrument. Its spectrum analysis capability can verify the presence or absence of specific plutonium isotopes in containers or verify the presence of uranium and its enrichment. The instrument retains the search capability, light weight, and low-power requirement of its predecessors. Its ready portability, detector stabilization, and simple operation allow individuals with little technical training to verify the contents of SNM containers. 5 refs., 5 figs.

  14. Curvelet filter based prescreener for explosive hazard detection in hand-held ground penetrating radar

    NASA Astrophysics Data System (ADS)

    White, Julie L.; Anderson, Derek T.; Ball, John E.; Parker, Brian

    2016-05-01

    Explosive hazards, above and below ground, are a serious threat to civilians and soldiers. In an attempt to mitigate these threats, different forms of explosive hazard detection (EHD) exist; e.g., multi-sensor hand-held platforms, downward looking and forward looking vehicle mounted platforms, etc. Robust detection of these threats resides in the processing and fusion of different data from multiple sensing modalities, e.g., radar, infrared, electromagnetic induction (EMI), etc. Herein, we focus on a new energy-based prescreener in hand-held ground penetrating radar (GPR). First, we Curvelet filter B-scan signal data using either Reverse-Reconstruction followed by Enhancement (RRE) or selectivity with respect to wedge information in the Curvelet transform. Next, we aggregate the result of a bank of matched filters and run a size contrast filter with Bhattacharyya distance. Alarms are then combined using weighted mean shift clustering. Results are demonstrated in the context of receiver operating characteristics (ROC) curve performance on data from a U. S. Army test site that contains multiple target and clutter types, burial depths and times of the day.

  15. The Complimentary Role of Methoxy-Isobutyl-Isonitrile and Hand-Held Gamma Probe in Adamantinoma

    PubMed Central

    Maharaj, Masha; Korowlay, Nisaar; Ellmann, Prof

    2016-01-01

    Adamantinoma is a rare locally aggressive osteolytic tumor that is found 90% of the time in the diaphysis of the tibia with the remaining lesions found in the fibula and long tubular bones. A case of adamantinoma of the tibia is presented. The added value of nuclear medicine investigations in the workup of this patient is described. A three-phase whole body 99mTc-methylene diphosphonate bone and a whole body 99mTc-methoxy-isobutyl-isonitrile scans were complimentary in the demarcation of viable bone tumor and the assessment of the remainder of the bone and soft tissue to exclude other sites. Intra-operative assistance with a hand-held gamma probe, guided the biopsy of the most metabolically active tumor tissue. Histology revealed a biphasic tumor composed of epithelial and fibrous components, in keeping with an adamantinoma. PMID:26912979

  16. Application of hand-held and portable infrared spectrometers in bovine milk analysis.

    PubMed

    Santos, Poliana M; Pereira-Filho, Edenir R; Rodriguez-Saona, Luis E

    2013-02-13

    A simple and fast method for the detection and quantification of milk adulteration was developed using portable and hand-held infrared (IR) spectrometers. Milk samples were purchased from local supermarkets (Columbus, OH, USA) and spiked with tap water, whey, hydrogen peroxide, synthetic urine, urea, and synthetic milk in different concentrations. Spectral data were collected using mid-infrared (MIR) and near-infrared (NIR) spectrometers. Soft independent modeling of class analogy (SIMCA) classification models exhibited tight and well-separated clusters allowing the discrimination of control from adulterated milk samples. Partial least-squares regression (PLSR) was used to estimate adulteration levels, and results showed high coefficients of determination (R(2)) and low standard errors of prediction (SEP). Classification and quantification models indicated that the tested MIR systems were superior to NIR systems in monitoring milk adulteration. This method can be potentially used as an alternative to traditional methods due to their simplicity, sensitivity, low energy cost, and portability. PMID:23339381

  17. Hand-Held Dynamometry Isometric Torque Reference Values for Children and Adolescents

    PubMed Central

    Maltais, Désirée B.; Lepage, Céline; Saulnier, Joanne; Crête, Mélanie

    2015-01-01

    Purpose: To establish hand-held dynamometry (HHD) maximal isometric muscle torque (MIT) reference values for children and adolescents who are developing typically. Methods: The MIT of 10 upper and lower limb muscle groups was assessed in 351 Caucasian youth (4 years 2 months to 17 years) using a standardized HHD protocol, previously shown to be feasible, valid, and reliable. Results: The mean MIT and 95% confidence interval of the mean for all muscle groups, for each of the 14 age groups (1 year age span for each group), and for each sex, were reported in both absolute (Nm) and normalized (Nm/kg) values. Conclusion: These HHD reference values may be helpful in the identification of muscle strength impairments in several pediatric populations, especially when bilateral impairments are present. PMID:26397089

  18. Cost effective spectral sensor solutions for hand held and field applications

    NASA Astrophysics Data System (ADS)

    Reetz, Edgar; Correns, Martin; Notni, Gunther

    2015-05-01

    Optical spectroscopy is without doubt one of the most important non-contact measurement principles. It is used in a wide range of applications from bio-medical to industrial fields. One recent trend is to miniaturize spectral sensors to address new areas of application. The most common spectral sensor type is based on diffraction gratings, while other types are based on micro mechanical systems (MEMS) or filter technologies. The authors represent the opinion that there is a potentially wide spread field of applications for spectrometers, but the market limits the range of applications since they cannot keep up with targeted cost requirements for consumer products. The present article explains an alternative approach for miniature multichannel spectrometer to enhance robustness for hand held field applications at a cost efficient price point.

  19. Detection of Depleted Uranium in Soil Using Portable Hand-Held Instruments

    SciTech Connect

    Coleman, R.L.

    1999-11-13

    The Measurement Applications and Development Group at the Oak Ridge National Laboratory (ORNL) has collected and analyzed data with the purpose of evaluating the in-situ detection capabilities of common hand-held detectors for depleted uranium ({sup 238}U) in soil. Measurements were collected with one each of the following detectors: a FIDLER operated in a gross (full spectrum) mode, a FIDLER operated in a spectrum specific (windowed) mode, a 1.25'' x 1.5'' cylindrical NaI detector operated with a gross count rate system, and both open and closed-window pancake-type detectors. Representative samples were then collected at the same location and later analyzed at an ORNL laboratory. This report presents a correlation between the measurements and the soil concentration results and should be helpful to anyone interested in estimating measurement sensitivities for depleted uranium in soil.

  20. Determining risk of heart disease and obesity with a hand-held programmable calculator.

    PubMed

    Everett, W D

    1989-10-01

    Two sets of programs are presented which aid the practicing flight surgeon to quickly assess risk of cardiovascular disease or calculate percent body fat. Risk of cardiovascular disease is easily computed using the Framingham Risk Equation and relating it to the average risk and minimal risk of a patient the same age. A "cardiovascular age" is also computed. Body composition determinations can be done quickly using only circumference measurements and recognized military formulas. Confidence intervals about the estimate and U.S. Air Force maximum allowable weights are computed. For males a maximum weight for health is computed. The programs presented were written for a simple, hand-held calculator. The calculator was selected because it is portable, inexpensive, can be used in a small clinic anywhere in the world, and requires no computer expertise, bringing sophisticated research statistical methods to the everyday clinical practice of aerospace medicine. PMID:2818379

  1. Prospective evaluation of hand-held focused abdominal sonography for trauma (FAST) in blunt abdominal trauma

    PubMed Central

    Kirkpatrick, Andrew W.; Sirois, Marco; Laupland, Kevin B.; Goldstein, Leanelle; Brown, David Ross; Simons, Richard K.; Dulchavsky, Scott; Boulanger, Bernard R.

    2005-01-01

    Background Ultrasonography (US) has become indispensable in assessing the status of the injured patient. Although hand-held US equipment is now commercially available and may expand the availability and speed of US in assessing the trauma patient, it has not been subjected to controlled evaluation in early trauma care. Methods A 2.4-kg hand-held (HH) US device was used to perform focused abdominal sonography for trauma (FAST) on blunt trauma victims at 2 centres. Results were compared with the “truth” as determined through formal FAST examinations (FFAST), CT, operative findings and serial examination. The ability of HHFAST to detect free fluid, intra-abdominal injuries and injuries requiring therapeutic interventions was assessed. Results HHFAST was positive in 80% of 313 patients who needed surgery or angiography. HHFAST test performances (sensitivity, specificity, positive and negative predictive values, likelihood ratios of positive and negative test results) were 77%, 99%, 96%, 94%, 95%, 95 and 0.2, respectively, for free fluid, and 64%, 99%, 96%, 89%, 90%, 74 and 0.4, respectively, for documented injuries. HHFAST missed or gave an indeterminate result in 8 (3%) of 270 patients with injuries who required therapeutic intervention and 25 (9%) of 270 patients who did not require intervention. FFAST performance was comparable. Conclusions HHFAST performed by clinicians detects intraperitoneal fluid with a high degree of accuracy. All FAST examinations are valuable tests when positive. They will miss some injuries, but the majority of the injuries missed do not require therapy. HHFAST provides an early extension of the physical examination but should be complemented by the selective use of CT, rather than formal repeat US. PMID:16417051

  2. Rapid Visuomotor Corrective Responses during Transport of Hand-Held Objects Incorporate Novel Object Dynamics.

    PubMed

    Diamond, Jonathan S; Nashed, Joseph Y; Johansson, Roland S; Wolpert, Daniel M; Flanagan, J Randall

    2015-07-22

    Numerous studies have shown that people are adept at learning novel object dynamics, linking applied force and motion, when performing reaching movements with hand-held objects. Here we investigated whether the control of rapid corrective arm responses, elicited in response to visual perturbations, has access to such newly acquired knowledge of object dynamics. Participants first learned to make reaching movements while grasping an object subjected to complex load forces that depended on the distance and angle of the hand from the start position. During a subsequent test phase, we examined grip and load force coordination during corrective arm movements elicited (within ∼150 ms) in response to viewed sudden lateral shifts (1.5 cm) in target or object position. We hypothesized that, if knowledge of object dynamics is incorporated in the control of the corrective responses, grip force changes would anticipate the unusual load force changes associated with the corrective arm movements so as to support grasp stability. Indeed, we found that the participants generated grip force adjustments tightly coupled, both spatially and temporally, to the load force changes associated with the arm movement corrections. We submit that recently learned novel object dynamics are effectively integrated into sensorimotor control policies that support rapid visually driven arm corrective actions during transport of hand held objects. Significance statement: Previous studies have demonstrated that the motor system can learn, and make use of, internal models of object dynamics to generate feedforward motor commands. However, it is not known whether such internal models are incorporated into rapid, automatic arm movement corrections that compensate for errors that arise during movement. Here we demonstrate, for the first time, that internal models of novel object dynamics are integrated into rapid corrective arm movements made in response to visuomotor perturbations that, importantly, do

  3. Detection of Francisella tularensis within Infected Mouse Tissues by Using a Hand-Held PCR Thermocycler

    PubMed Central

    Emanuel, Peter A.; Bell, Ryan; Dang, Jessica L.; McClanahan, Rebecca; David, John C.; Burgess, Robert J.; Thompson, Joseph; Collins, Lisa; Hadfield, Ted

    2003-01-01

    The diagnosis of human cases of tularemia often relies upon the demonstration of an antibody response to Francisella tularensis or the direct culturing of the bacteria from the patient. Antibody response is not detectable until 2 weeks or more after infection, and culturing requires special media and suspicion of tularemia. In addition, handling live Francisella poses a risk to laboratory personnel due to the highly infectious nature of this pathogen. In an effort to develop a rapid diagnostic assay for tularemia, we investigated the use of TaqMan 5′ hydrolysis fluorogenic PCR to detect the organism in tissues of infected mice. Mice were infected to produce respiratory tularemia. The fopA and tul4 genes of F. tularensis were amplified from infected spleen, lung, liver, and kidney tissues sampled over a 5-day period. The samples were analyzed using the laboratory-based Applied Biosystems International 7900 and the Smiths Detection-Edgewood BioSeeq, a hand-held portable fluorescence thermocycler designed for use in the field. A comparison of culturing and PCR for detection of bacteria in infected tissues shows that culturing was more sensitive than PCR. However, the results for culture take 72 h, whereas PCR results were available within 4 h. PCR was able to detect infection in all the tissues tested. Lung tissue showed the earliest response at 2 days when tested with the ABI 7900 and in 3 days when tested with the BioSeeq. The results were in agreement between the ABI 7900 and the BioSeeq when presented with the same sample. Template preparation may account for the loss of sensitivity compared to culturing techniques. The hand-held BioSeeq thermocycler shows promise as an expedient means of forward diagnosis of infection in the field. PMID:12574268

  4. Development of a hand-held 3D photoacoustic imaging system for breast cancer detection

    NASA Astrophysics Data System (ADS)

    Al-Aabed, Hazem; Roumeliotis, Michael; Carson, Jeffrey J. L.

    2010-06-01

    Photoacoustic (PA) imaging is a non-invasive imaging modality that employs non-ionizing near infrared (NIR) laser light to obtain optical images of tissues with depth penetration and resolution comparable to ultrasound imaging. PA images are created by illuminating tissues with a short laser pulse (~10 ns), which causes optically absorbing structures to heat up slightly, but so rapidly that conditions of thermal and stress confinement are met and the structure emits a pressure wave at ultrasonic frequencies. Detection of the pressure waves at the tissue surface with an ultrasound transducer array provides the data needed to reconstruct the distribution of light-absorbing structures within the tissue. Since it is recognized that cancerous breast lesions absorb light to a greater degree than surrounding normal tissue, PA imaging is a viable candidate for detection of lesions within the intact human breast. Therefore, we have constructed a transportable PA imaging system suitable for breast imaging. The system incorporates a hand-held transducer array with 30 detector elements arranged on a ring. Laser light is delivered coaxially in relation to the ring using a fiber optic light guide. The supporting hardware includes a NIR tuneable laser, transducer cabling, 30 preamplifiers, 30 independent data acquisition channels with onboard memory, and a computer with control and image reconstruction software. Initial tests with the transducer array suggest that it has sufficient sensitivity to detect optically absorbent objects on the order of 1- mm at a depth of 2 cm. It is anticipated that a small hand-held PA imaging unit will be amenable to patient work-up and would complement standard ultrasound imaging.

  5. Haemoassist--a hand-held electronic patient diary for haemophilia home care.

    PubMed

    Mondorf, W; Siegmund, B; Mahnel, R; Richter, H; Westfeld, M; Galler, A; Pollmann, H

    2009-03-01

    On-demand or prophylactic home-treatment is currently the treatment of choice for haemophilia patients. To allow physicians to monitor the amount of factor concentrates administered, the patients document each factor injection in a paper-diary. Nevertheless, because of the fact that most patients visit their physicians only two to four times a year, there could be considerable delay in detecting medication problems. The aim of this pilot study was to assess whether an electronic documentation tool could successfully replace traditional paper-diaries for haemophilia A patients and enable the physician to have a timely overview of the patient's treatment. An electronic, hand-held documentation tool, Haemoassist, was developed. In this study, patients using prophylaxis and on-demand therapies documented their factor consumption both electronically and on paper-diaries. Documentations were compared and descriptively evaluated. Patients also completed a survey to evaluate the feasibility and gather their opinions on the Haemoassist system. Ten patients from two haemophilia treatment centres in Germany submitted a total of 548 records via hand-held device during the observation period, from March 2006 to February 2007. Comparison of electronic and paper-based records showed differing responses among patients with some patients entering more electronic and some others more paper-based documentations. In the questionnaires on feasibility and usefulness of Haemoassist, three patients preferred the electronic tool, two patients wanted to continue using paper-based diaries, and one had no preference. The study shows that an electronic documentation system is feasible for haemophilia patients and provides the physician with the opportunity to more closely monitor patients. However, not all patients seem to be qualified for using an electronic tool, and the tool has to run reliably without major errors for ensuring reliability and acceptability. In the future, Haemoassist might

  6. Musculoskeletal Disorders of the Upper Extremities Due to Extensive Usage of Hand Held Devices

    PubMed Central

    2014-01-01

    Objective The use of hand held devices (HHD) such as mobile phones, game controls, tablets, portable media players and personal digital assistants have increased dramatically in past decade. While sending a text message or using the controls of the HHD the users need to use their thumb and other palm muscles extensively. The objective of this study was to describe the risk factors and clinical features of the musculoskeletal disorders (MSDs) arising due to usage of hand held devices and to evaluate the effectiveness of a sequenced rehabilitation protocol. Methods A retrospective report analysis of 70 subjects, who were diagnosed to have a MSD affecting the upper extremities, was conducted. Medical charts from a tertiary level rehabilitation centre from 2005–2013 were analysed. All the subjects reported pain in their upper extremities following extensive usage of HHD and were examined and diagnosed to have a MSD by an orthopaedic and rehabilitation physician. After the assessment and diagnosis, all the patients underwent rehabilitation using a sequenced protocol. Results All the subjects reported pain in the thumb and forearm with associated burning, numbness and tingling around the thenar aspect of the hand, and stiffness of wrist and hand. 43 subjects had symptoms on the right side; 9 on left and 18 had bilateral symptoms. Correlation was found between hand dominance and MSD. 33 subjects complained of onset of symptoms following extensive text messaging. All the subjects were diagnosed to have tendinosis of Extensor Pollicis Longus and Myofascial Pain Syndrome affecting the 1st interossei, thenar group of muscles and Extensor Digitorum Communis. 23 of the subjects were senior executives, among these 7 were CEO’s of major multinational companies in India. All the subjects recovered completely following the rehabilitation. Conclusions The study concluded that mobile phones and gadgets that promoted the predominant usage of thumb or only one finger while texting

  7. A new hand-held optical reflectometer to measure enamel erosion: correlation with surface hardness and calcium release

    PubMed Central

    Carvalho, Thiago Saads; Baumann, Tommy; Lussi, Adrian

    2016-01-01

    In the present study, the surface reflection intensity (SRI) was measured from enamel with different induced erosion degrees using a hand-held pen-size reflectometer (Hand-Held) and a Table-Top reflectometer. To validate the Hand-Held reflectometer, we correlated its optical signals with the change of surface microhardness (SMH), and amount of calcium released from the enamel samples during erosion. We used 124 tooth enamel specimens that were exposed to an erosive challenge of either 1, 2, 4, 6, 8, or 10 minutes. SRI and SMH were measured before and after the erosive challenge and we also measured the amount of calcium released to the citric acid. Relative SRI loss (rSRIloss) and relative SMH loss (rSMHloss) were calculated. rSRIloss from the Hand-Held and the Table-Top reflectometers were similar and significantly correlated to rSMHloss and calcium release. The regression analyses showed a significant association between rSRIloss from both reflectometers and rSMHloss and calcium, showing that both reflectometers can be used to measure erosive demineralization of enamel. The Hand-Held reflectometer is capable of assessing in vitro erosion, correlating to other commonly used methods. It is small, easy to handle and provides fast measurement, being a possible candidate to measure erosion in clinical studies. PMID:27121129

  8. Three-dimensional multispectral hand-held optoacoustic imaging with microsecond-level delayed laser pulses

    NASA Astrophysics Data System (ADS)

    Deán-Ben, X. L.; Bay, Erwin; Razansky, Daniel

    2015-03-01

    Three-dimensional hand-held optoacoustic imaging comes with important advantages that prompt the clinical translation of this modality, with applications envisioned in cardiovascular and peripheral vascular disease, disorders of the lymphatic system, breast cancer, arthritis or inflammation. Of particular importance is the multispectral acquisition of data by exciting the tissue at several wavelengths, which enables functional imaging applications. However, multispectral imaging of entire three-dimensional regions is significantly challenged by motion artefacts in concurrent acquisitions at different wavelengths. A method based on acquisition of volumetric datasets having a microsecond-level delay between pulses at different wavelengths is described in this work. This method can avoid image artefacts imposed by a scanning velocity greater than 2 m/s, thus, does not only facilitate imaging influenced by respiratory, cardiac or other intrinsic fast movements in living tissues, but can achieve artifact-free imaging in the presence of more significant motion, e.g., abrupt displacements during handheld-mode operation in a clinical environment.

  9. InfraCAM (trade mark): A Hand-Held Commercial Infrared Camera Modified for Spaceborne Applications

    NASA Technical Reports Server (NTRS)

    Manitakos, Daniel; Jones, Jeffrey; Melikian, Simon

    1996-01-01

    In 1994, Inframetrics introduced the InfraCAM(TM), a high resolution hand-held thermal imager. As the world's smallest, lightest and lowest power PtSi based infrared camera, the InfraCAM is ideal for a wise range of industrial, non destructive testing, surveillance and scientific applications. In addition to numerous commercial applications, the light weight and low power consumption of the InfraCAM make it extremely valuable for adaptation to space borne applications. Consequently, the InfraCAM has been selected by NASA Lewis Research Center (LeRC) in Cleveland, Ohio, for use as part of the DARTFire (Diffusive and Radiative Transport in Fires) space borne experiment. In this experiment, a solid fuel is ignited in a low gravity environment. The combustion period is recorded by both visible and infrared cameras. The infrared camera measures the emission from polymethyl methacrylate, (PMMA) and combustion products in six distinct narrow spectral bands. Four cameras successfully completed all qualification tests at Inframetrics and at NASA Lewis. They are presently being used for ground based testing in preparation for space flight in the fall of 1995.

  10. Hand-held hyperspectral imager for chemical/biological and environmental applications

    NASA Astrophysics Data System (ADS)

    Hinnrichs, Michele; Piatek, Bob

    2004-03-01

    A small, hand held, battery operated imaging infrared spectrometer, Sherlock, has been developed by Pacific Advanced Technology and was field tested in early 2003. The Sherlock spectral imaging camera has been designed for remote gas leak detection, however, the architecture of the camera is versatile enough that it can be applied to numerous other applications such as homeland security, chemical/biological agent detection, medical and pharmaceutical applications as well as standard research and development. This paper describes the Sherlock camera, theory of operations, shows current applications and touches on potential future applications for the camera. The Sherlock has an embedded Power PC and performs real-time-image processing function in an embedded FPGA. The camera has a built in LCD display as well as output to a standard monitor, or NTSC display. It has several I/O ports, ethernet, firewire, RS232 and thus can be easily controlled from a remote location. In addition, software upgrades can be performed over the ethernet eliminating the need to send the camera back to the factory for a retrofit. Using the USB port a mouse and key board can be connected and the camera can be used in a laboratory environment as a stand alone imaging spectrometer.

  11. Hand held analog television over WiMAX executed in SW

    NASA Astrophysics Data System (ADS)

    Iancu, Daniel; Ye, Hua; Senthilvelan, Murugappan; Kotlyar, Vladimir; Glossner, John; Moudgill, Mayan; Agrawal, Sitij; Jinturkar, Sanjay; Iancu, Andrei; Ramadurai, Vaidyanathan; Nacer, Gary; Stanley, Stuart; Sima, Mihai; Takala, Jarmo

    2007-02-01

    This paper describes a device capable of performing the following tasks: it samples and decodes the composite video analog TV signal, it encodes the resulting RGB data into a MPEG-4 stream and sends it over a WiMAX link. On the other end of the link a similar device receives the WiMAX signal, in either TDD or FDD mode, decodes the MPEG data and displays it on the LCD display. The device can be a hand held device, such as a mobile phone or a PDA. The algorithms for the analog TV, WiMAX physical layer, WiMAX MAC and the MPEG encoder/decoder are executed entirely in software in real time, using the Sandbridge Technologies' low power SB3011 digital signal processor. The SB3011 multithreaded digital signal processor includes four DSP cores with eight threads each, and one ARM processor. The execution of the algorithms requires the entire four cores for the FDD mode. The WiMAX MAC is executed on the ARM processor.

  12. Hand-Held Instrument Fights Acne, Tops Over-the-Counter Market

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Tyrell Inc., a Houston-based medical technologies company, was able to access engineering support in redesigning a heating element for a hand-held acne-fighting device through SATOP, NASA's Space Alliance Technology Outreach Program. SATOP put Tyrell in contact with The Boeing Company, which assessed the design and made several major contributions. The product, named Zeno, is now the highest selling over-the-counter medical device for the treatment of acne, and in 2006, Zeno was named the "SATOP Texas, Success Story of the Year." Zeno employs proprietary ClearPoint technology to provide relief of mild to moderate inflammatory acne by delivering a precisely controlled low-level dosage of heat to the blemish, causing the bacteria at the root of more than 90 percent of acne to self-destruct. Within its first year on the market, Zeno was cited by various publications for several awards, including Allure's 2005 "Best of Beauty," Marie Claire's "10 Best Gadgets for Girls," and Popular Science's 2005 "Best of What's New." A variation of the Zeno for use in treating herpetic lesions such as cold sores, by killing the virus that causes them, is currently undergoing FDA trials.

  13. Overview of passive and active vision techniques for hand-held 3D data acquistion

    NASA Astrophysics Data System (ADS)

    Mada, Sreenivasa K.; Smith, Melvyn L.; Smith, Lyndon N.; Midha, Prema S.

    2003-03-01

    The digitization of the 3D shape of real objects is a rapidly expanding discipline, with a wide variety of applications, including shape acquisition, inspection, reverse engineering, gauging and robot navigation. Developments in computer product design techniques, automated production, and the need for close manufacturing tolerances will be facts of life for the foreseeable future. A growing need exists for fast, accurate, portable, non-contact 3D sensors. However, in order for 3D scanning to become more commonplace, new methods are needed for easily, quickly and robustly acquiring accurate full geometric models of complex objects using low cost technology. In this paper, a brief survey is presented of current scanning technologies available for acquiring range data. An overview is provided of current 3D-shape acquisition using both active and passive vision techniques. Each technique is explained in terms of its configuration, principle of operation, and the inherent advantages and limitations. A separate section then focuses on the implications of scannerless scanning for hand held technology, after which the current status of 3D acquisition using handheld technology, together with related issues concerning implementation, is considered more fully. Finally, conclusions for further developments in handheld devices are discussed. This paper may be of particular benefit to new comers in this field.

  14. Randomized controlled pilot trial of a hand-held patient-oriented, insulin regimen optimizer.

    PubMed

    Holman, R R; Smale, A D; Pemberton, E; Riefflin, A; Nealon, J L

    1996-01-01

    A robust, hand-held, patient-oriented insulin regimen optimizer (POIRO) has been developed. Relevant information is entered by selecting appropriate items from choices displayed on a touch-sensitive screen rather than a conventional keyboard. All data items are recorded, together with their time and date of entry, and may be recalled at any time with glucose values displayed graphically to provide an overview of glycaemic control. When requested, an integral, hybrid, statistical and rule-based expert system program uses all available data to suggest an optimum insulin dose within physician determined, pre-set limits. POIRO has been formally evaluated in a randomized crossover pilot trial, comparing two 3 week periods with and without decision support, in six patients with type 1 diabetes. Mean (SE) pre-prandial blood glucose levels were significantly lower during the period when decision support was available (7.5 (0.4) versus 8.9 (0.4) mmol/l, p = 0.015) with no increase in the frequency or severity of hypoglycaemia. The device, which was well received by the patients, may offer a relatively inexpensive method of providing expert diabetic advice at a distance. The persistence of improved glycaemic control, even after decision support was switched off, suggests the device could be used intermittently by patients and may have educational value. PMID:9179835

  15. An Ungrounded Hand-Held Surgical Device Incorporating Active Constraints with Force-Feedback

    PubMed Central

    Payne, Christopher J.; Kwok, Ka-Wai; Yang, Guang-Zhong

    2014-01-01

    This paper presents an ungrounded, hand-held surgical device that incorporates active constraints and force-feedback. Optical tracking of the device and embedded actuation allow for real-time motion compensation of a surgical tool as an active constraint is encountered. The active constraints can be made soft, so that the surgical tool tip motion is scaled, or rigid, so as to altogether prevent the penetration of the active constraint. Force-feedback is also provided to the operator so as to indicate penetration of the active constraint boundary by the surgical tool. The device has been evaluated in detailed bench tests to quantify its motion scaling and force-feedback capabilities. The combined effects of force-feedback and motion compensation are demonstrated during palpation of an active constraint with rigid and soft boundaries. A user study evaluated the combined effect of motion compensation and force-feedback in preventing penetration of a rigid active constraint. The results have shown the potential of the device operating in an ungrounded setup that incorporates active constraints with force-feedback. PMID:24744963

  16. Initial Usability Testing of a Hand-held Electronic Logbook Prototype for the Human Research Facility

    NASA Technical Reports Server (NTRS)

    Berman, Andrea H.; Whitmore, Mihriban

    1996-01-01

    The Apple(R) Newton(TM) MessagePad 110 was flown aboard the KC-135 reduced gravity aircraft for microgravity usability testing. The Newton served as the initial hand-held electronic logbook prototype for the International Space Station (ISS) Human Research Facility (HRF). Subjects performed three different tasks with the Newton: (1) using the stylus to tap on different sections of the screen in order to launch an application and to select options within it; (2) using the stylus to write, and; (3) correcting handwriting recognition errors in a handwriting-intensive application. Subjects rated handwriting in microgravity 'Borderline' and had great difficulties finding a way in which to adequately restrain themselves at the lower body in order to have their hands free for the Newton. Handwriting recognition was rated 'Unacceptable,' but this issue is hardware-related and not unique to the microgravity environment. It is suggested that the restraint and handwriting issues are related and require further joint research with the current Handheld Electronic Logbook prototype: the Norand Pen*key Model #6300.

  17. Background adaptive division filtering for hand-held ground penetrating radar

    NASA Astrophysics Data System (ADS)

    Lee, Matthew A.; Anderson, Derek T.; Ball, John E.; White, Julie L.

    2016-05-01

    The challenge in detecting explosive hazards is that there are multiple types of targets buried at different depths in a highlycluttered environment. A wide array of target and clutter signatures exist, which makes detection algorithm design difficult. Such explosive hazards are typically deployed in past and present war zones and they pose a grave threat to the safety of civilians and soldiers alike. This paper focuses on a new image enhancement technique for hand-held ground penetrating radar (GPR). Advantages of the proposed technique is it runs in real-time and it does not require the radar to remain at a constant distance from the ground. Herein, we evaluate the performance of the proposed technique using data collected from a U.S. Army test site, which includes targets with varying amounts of metal content, placement depths, clutter and times of day. Receiver operating characteristic (ROC) curve-based results are presented for the detection of shallow, medium and deeply buried targets. Preliminary results are very encouraging and they demonstrate the usefulness of the proposed filtering technique.

  18. Spring wheat-leaf phytomass and yield estimates from airborne scanner and hand-held radiometer measurements

    NASA Technical Reports Server (NTRS)

    Aase, J. K.; Siddoway, F. H.; Millard, J. P.

    1984-01-01

    An attempt has been made to relate hand-held radiometer measurements, and airborne multispectral scanner readings, with both different wheat stand densities and grain yield. Aircraft overflights were conducted during the tillering, stem extension and heading period stages of growth, while hand-held radiometer readings were taken throughout the growing season. The near-IR/red ratio was used in the analysis, which indicated that both the aircraft and the ground measurements made possible a differentiation and evaluation of wheat stand densities at an early enough growth stage to serve as the basis of management decisions. The aircraft data also corroborated the hand-held radiometer measurements with respect to yield prediction. Winterkill was readily evaluated.

  19. Hands-free versus hand-held cell phone conversation on a braking response by young drivers.

    PubMed

    Hendrick, Joy L; Switzer, Jamie R

    2007-10-01

    As some states allow motorists to use hands-free cell phones only while driving, this study was done to examine some braking responses to see if conversing on these two types of cell phones affects quick responding. College-age drivers (n=25) completed reaction time trials in go/no-go situations under three conditions: control (no cell phone or conversation), and conversing on hands-free and hand-held cell phones. Their task involved moving the right foot from one pedal to another as quickly as possible in response to a visual signal in a lab setting. Significantly slower reaction times, movement times, and total response times were found for both cell phone conditions than for the control but no differences between hands-free and hand-held phone conditions. These findings provide additional support that talking on cell phones, regardless if it is hands-free or hand-held, reduces speed of information processing. PMID:18065072

  20. Moving a hand-held object: Reconstruction of referent coordinate and apparent stiffness trajectories

    PubMed Central

    Ambike, Satyajit; Zhou, Tao; Zatsiorsky, Vladimir M.; Latash, Mark L.

    2015-01-01

    This study used the framework of the referent configuration hypothesis and slow changes in the external conditions during vertical oscillation of a hand-held object to infer the characteristics of hypothetical control variables. The study had two main objectives: (1) to show that hypothetical control variables, namely, referent coordinates and apparent stiffness of vertical hand position and grip force can be measured in an experiment; and (2) to establish relation(s) between these control variables that yield the classic grip-force-load-force coupling. Healthy subjects gripped a handle and performed vertical oscillations between visual targets at one of five metronome-prescribed frequencies. A Hapticmaster robot was used to induce slow changes in the vertical force applied to the handle, while the size of the handle was changed slowly leading to changes in the grip aperture. The subjects were instructed not to react to possible changes in the external forces. A linear, second-order model was used to reconstruct the referent coordinate and apparent stiffness values for each phase of the vertical oscillation cycle using across-cycle regressions. The reconstructed time profiles of the referent coordinates and apparent stiffness showed consistent trends across subjects and movement frequencies. To validate the method, these values were used to predict the vertical force and the grip force applied to the handle for movement cycles that were not utilized in the reconstruction process. Analysis of the coupling between the four variables, two referent coordinates and two apparent stiffness values, revealed a single strong constraint reflecting the coupling between the grip force and vertical force. We view these data as providing experimental support for the idea of controlling natural, multi-muscle actions with shifts in a low-dimensional set of referent coordinates. PMID:25896800

  1. Consumer product safety: Risk assessment of exposure to asbestos emissions from hand-held hair dryers

    NASA Astrophysics Data System (ADS)

    Hallenbeck, William H.

    1981-01-01

    The United States Consumer Product Safety Commission (CPSC) is concerned that consumer exposure to asbestos from consumer products may present an unreasonable risk of injury. Recently, CPSC has obtained agreement by industry to cease production and distribution of hair dryers containing asbestos heat insulation. CPSC intends to broaden its investigation by selecting consumer products containing asbestos for “priority attention.” The Commission does not intend to make quantitative estimates of cancer risks posed by exposure to asbestos fibers in making regulatory decisions. This position may lead to a serious waste of resources for the Commission, industry, and society. The Commission should focus its initial attention on those products for which the release of asbestos is significant enough to cause an unreasonable health risk. To make a risk assessment for a particular use of asbestos, CPSC must acquire or request data on asbestos emissions and define “unreasonable risk to health.” In an attempt to give some meaning to the phrase “risk assessment,” the primary goal of this paper is to present a detailed risk assessment of exposure to asbestos from hand-held hair dryers. Several scenarios of use are presented using various assumptions regarding time of operation, mixing of fibers in a small room, rate of fiber emission, and time of exposure. The worst case analysis of the health risk of exposure to hair dryer emissions is based on several conservative assumptions and shows that the increased number of deaths per year due to respiratory cancer is 4 for the entire United States population. A more representative case analysis shows the increased number of deaths to be on the order of 0.15 per year.

  2. A hand-held mosaicked multispectral imaging device for early stage pressure ulcer detection.

    PubMed

    Qi, Hairong; Kong, Linghua; Wang, Chao; Miao, Lidan

    2011-10-01

    The use of a custom filter mosaic overlaying a CMOS/CCD sensor represents a novel idea to multispectral imaging. The innovation provides simple, miniaturized, low cost instrumentation that has many potential biological applications which require a hand-held detector. This makes it extremely adaptable and can serve as an integrated component to distributed diagnosis and home healthcare (D2H2). A mosaicked sensor is a monolithic array of many sensors, arranged in a geometric pattern with each sensor covered by an optical filter sensitive to a specified wavelength. In this way, only one spectral component is sensed at each pixel and the other spectral components must be estimated from neighbors. Although with great potential, one challenge faced by this device, however, is the reconstruction of the high-resolution full-spectral image from the low-resolution input. Due to the physical limitations in fabrication and the usage of the multispectral filter mosaic, two types of degradations exist, including filter misalignment and the missing spectral components, that must be corrected using intelligent algorithms to take full advantage of the hardware capability of the device. In this paper, we first describe a custom geometric correction method to restore the image from the misalignment distortion. We then present a binary tree-based generic demosaicking algorithm to efficiently estimate the missing special components and reconstruct a high-resolution full-spectral image. We choose early detection of pressure ulcer as a targeting area as early stage pressure ulcers and other subcutaneous lesions are nearly invisible in clinical settings, particularly so for dark pigmented skin. We show how the geometric correction and demosaicking algorithms successfully reconstruct a full-spectral image from which apparent contrast enhancement between damaged skin and the normal skin is observed. PMID:20703688

  3. Radioisotope guided surgery with imaging probe, a hand-held high-resolution gamma camera

    NASA Astrophysics Data System (ADS)

    Soluri, A.; Trotta, C.; Scopinaro, F.; Tofani, A.; D'Alessandria, C.; Pasta, V.; Stella, S.; Massari, R.

    2007-12-01

    Since 1997, our group of Physics together with Nuclear Physicians studies imaging probes (IP), hand-held, high-resolution gamma cameras for radio-guided surgery (RGS). Present work is aimed to verify the usefulness of two updated IP in different surgical operations. Forty patients scheduled for breast cancer sentinel node (SN) biopsy, five patients with nodal recurrence of thyroid cancer, seven patients with parathyroid adenomas, five patients with neuroendocrine tumours (NET), were operated under the guide of IP. We used two different IP with field of view of 1 and 4 in. 2, respectively and intrinsic spatial resolution of about 2 mm. Radioisotopes were 99mTc, 123I and 111In. The 1 in. 2 IP detected SN in all the 40 patients and more than one node in 24, whereas anger camera (AC) failed locating SN in four patients and detected true positive second nodes in only nine patients. The 4 in. 2 IP was used for RGS of thyroid, parathyroid and NETs. It detected eight latero-cervical nodes. In the same patients, AC detected five invaded nodes. Parathyroid adenomas detected by IP were 10 in 7 patients, NET five in five patients. One and 4 in. 2 IPs showed usefulness in all operations. Initial studies on SN biopsy were carried out on small series of patients to validate IP and to demonstrate the effectiveness and usefulness of IP alone or against conventional probes. We propose the use of the IP as control method for legal documentation and surgeon strategy guide before and after lesion(s) removal.

  4. Reproducibility of corneal astigmatism measurements with a hand held keratometer in preschool children.

    PubMed Central

    Harvey, E M; Miller, J M; Dobson, V

    1995-01-01

    AIMS--To evaluate the overall accuracy and reproducibility of the Alcon portable autokeratometer (PAK) measurements in infants and young children. METHODS--The accuracy of the Alcon PAK in measuring toric reference surfaces (1, 3, 5, and 7 D) under various suboptimal measurement conditions was assessed, and the reproducibility of PAK measurements of corneal astigmatism in newborn infants (n = 5), children (n = 19, age 3-5 years), and adults (n = 14) was evaluated. RESULTS--Measurements of toric reference surfaces indicated (a) no significant effect of distance (17-30 mm) on accuracy of measurements, (b) no systematic relation between amount of toricity and accuracy of measurements, (c) no systematic relation between angle of measurement and accuracy, (d) no difference in accuracy of measurements when the PAK is hand held in comparison with when it is mounted, (e) no difference in accuracy of measurements when axis of toricity is oriented obliquely than when it is oriented horizontally, with respect to the PAK, and (f) a small positive bias (+0.16 D) in measurement of spherical equivalent. The PAK did not prove useful for screening newborns. However, measurements were successfully obtained from 18/19 children and 14/14 adults. There was no significant difference in median measurement deviation (deviation of a subject's five measurements from his/her mean) between children (0.21 D) and adults (0.13 D). CONCLUSIONS--The PAK produces accurate measurements of surface curvature under a variety of suboptimal conditions. Variability of PAK measurements in preschool children is small enough to suggest that it would be useful for screening for corneal astigmatism in young children. PMID:8534668

  5. Moving a hand-held object: Reconstruction of referent coordinate and apparent stiffness trajectories.

    PubMed

    Ambike, S; Zhou, T; Zatsiorsky, V M; Latash, M L

    2015-07-01

    This study used the framework of the referent configuration hypothesis and slow changes in the external conditions during vertical oscillation of a hand-held object to infer the characteristics of hypothetical control variables. The study had two main objectives: (1) to show that hypothetical control variables, namely, referent coordinates and apparent stiffness of vertical hand position and grip force can be measured in an experiment; and (2) to establish relation(s) between these control variables that yield the classic grip-force-load-force coupling. Healthy subjects gripped a handle and performed vertical oscillations between visual targets at one of five metronome-prescribed frequencies. A HapticMaster robot was used to induce slow changes in the vertical force applied to the handle, while the size of the handle was changed slowly leading to changes in the grip aperture. The subjects were instructed not to react to possible changes in the external forces. A linear, second-order model was used to reconstruct the referent coordinate and apparent stiffness values for each phase of the vertical oscillation cycle using across-cycle regressions. The reconstructed time profiles of the referent coordinates and apparent stiffness showed consistent trends across subjects and movement frequencies. To validate the method, these values were used to predict the vertical force and the grip force applied to the handle for movement cycles that were not utilized in the reconstruction process. Analysis of the coupling between the four variables, two referent coordinates and two apparent stiffness values, revealed a single strong constraint reflecting the coupling between the grip force and vertical force. We view these data as providing experimental support for the idea of controlling natural, multi-muscle actions with shifts in a low-dimensional set of referent coordinates. PMID:25896800

  6. A field evaluation of the predictive value of a hand-held drum pressure detection device.

    PubMed

    Pannell, Michael A; Brandt, Michael T; Boatright, Daniel T

    2004-05-01

    According to Environmental Protection Agency estimates, 20% of hazardous waste drums currently managed in the 6500 known, uncontrolled Superfund removal or remediation sites contain some degree of elevated internal pressurization. This estimate increases to 90% during the summer months, and, overall, up to 5% of the drums stored in active treatment, storage, and disposal facilities may be pressurized. The ability to identify pressurized drums in real-time would enhance worker health and safety, reduce the potential for environmental contamination, and minimize property damage. A prototype hand-held drum pressure detection device was field tested at an active Resource Conservation and Recovery Act mixed waste operation using acoustic resonance spectroscopy technology to identify pressurized drums. The waste operation used a drum venting system that measured the actual drum pressure of retrieved drums. Drum venting system data were analyzed to quantify the ability of the drum pressure detection device to correctly identify drums with elevated internal pressure. After 456 drums were measured, the dichotomous pressure data (pressurized vs. nonpressurized) were analyzed. The relationship between the drum venting system and drum pressure detection device pressure data was found to be statistically significant. With alpha and beta values of 0.05, the negative predictive value was 0.94, the positive predictive value was 0.47, the sensitivity was 0.82, and the specificity was 0.77. Although capable of identifying nonpressurized drums, this instrument may not be appropriate for general use. Study results and critical improvements necessary to improve the instrument's predictive value, specificity, and sensitivity are presented. PMID:15238340

  7. Guiding Brain Tumor Resection Using Surface-Enhanced Raman Scattering Nanoparticles and a Hand-Held Raman Scanner

    PubMed Central

    2015-01-01

    The current difficulty in visualizing the true extent of malignant brain tumors during surgical resection represents one of the major reasons for the poor prognosis of brain tumor patients. Here, we evaluated the ability of a hand-held Raman scanner, guided by surface-enhanced Raman scattering (SERS) nanoparticles, to identify the microscopic tumor extent in a genetically engineered RCAS/tv-a glioblastoma mouse model. In a simulated intraoperative scenario, we tested both a static Raman imaging device and a mobile, hand-held Raman scanner. We show that SERS image-guided resection is more accurate than resection using white light visualization alone. Both methods complemented each other, and correlation with histology showed that SERS nanoparticles accurately outlined the extent of the tumors. Importantly, the hand-held Raman probe not only allowed near real-time scanning, but also detected additional microscopic foci of cancer in the resection bed that were not seen on static SERS images and would otherwise have been missed. This technology has a strong potential for clinical translation because it uses inert gold–silica SERS nanoparticles and a hand-held Raman scanner that can guide brain tumor resection in the operating room. PMID:25093240

  8. Reliability of measurements of hip abduction strength obtained with a hand-held dynamometer.

    PubMed

    Ieiri, Akira; Tushima, Eiki; Ishida, Kazuhiro; Inoue, Masahiro; Kanno, Taiki; Masuda, Takeshi

    2015-02-01

    This study aimed to evaluate intrarater and interrater reliability when measuring hip abductor strength in the supine position using a hand-held dynamometer (HHD) (Study 1), and to elucidate the relationships between measured values and examiners' physical characteristics (Study 2). Three healthy examiners (1 female, 24 y.o. and 2 males 23 and 27 y.o) and 12 subjects (6 females, 24.5 ± 2.8 years and 6 males, 27.7 ± 3.5 years) participated in Study 1, and 20 healthy examiners (7 females, 22.3 ± 1.3 years and 13 males, 29.4 ± 8.2 years) and 2 subjects (1 female, 24 y.o. and 1 male 27 y.o) participated in Study 2. All healthy examiners were hospital employees. Hip abductor strength was measured by HHD with hand fixation and with belt fixation, and examiner age, sex, height, weight, BMI, and dominant hand grip strength were evaluated. The intraclass correlation coefficient (ICC) (1,1), a measure of intrarater reliability, was 0.89-0.95 with hand fixation and 0.96-0.97 with belt fixation. ICC (2,1), a measure of interrater reliability, was 0.76-0.79 and 0.90-0.93, respectively. In subjects with high muscle strength (the examiner's hand was moved), the examiner's dominant hand grip strength affected muscle strength values with hand fixation (standardized partial regression coefficient = 0.78, determination coefficient R(2 )= 0.61, p < 0.01). In subjects with low muscle strength (the examiner's hand was not moved), no variables had effect. When the muscle strength of the subject is weak, both methods can be used. When the muscle strength of the subject is strong, it is necessary to adjust the value obtained by the examiner's dominant hand grip strength in the hand fixation method. PMID:25264015

  9. Hand-held analyser based on microchip electrophoresis with contactless conductivity detection for measurement of chemical warfare agent degradation products

    NASA Astrophysics Data System (ADS)

    Duran, Karolina-Petkovic; Zhu, Yonggang; Chen, Chuanpin; Swallow, Anthony; Stewart, Robert; Hoobin, Pam; Leech, Patrick; Ovenden, Simon

    2008-12-01

    This paper reports on the development of a hand-held device for on-site detection of organophosphonate nerve agent degradation products. This field-deployable analyzer relies on efficient microchip electrophoresis separation of alkyl methylphosphonic acids and their sensitive contactless conductivity detection. Miniaturized, low-powered design is coupled with promising analytical performance for separating the breakdown products of chemical warfare agents such as Soman, Sarin and VX . The detector has a detection limit of about 10 μg/mL and has a good linear response in the range 10-300 μg/mL concentration range. Applicability to environmental samples is demonstrated .The new hand-held analyzer offers great promise for converting conventional ion chromatography or capillary electrophoresis sophisticated systems into a portable forensic laboratory for faster, simpler and more reliable on-site screening.

  10. Analysis of the reliability of the make test in young adults by using a hand-held dynamometer

    PubMed Central

    Kim, Seong-Gil; Lim, Dong-Ho; Cho, Yong Ho

    2016-01-01

    [Purpose] The purpose of this study was to analyze intra-rater and inter-rater reliabilities of the make test, a manual muscle testing measurement method, using a hand-held dynamometer in Korean young adults. [Subjects and Methods] A total of 42 university students participated in this study. The make test, a manual muscle testing method, was conducted. A hand-held dynamometer was used to measure elbow joint flexion during the make test. [Results] Both intra-rater (the intraclass correlation coefficient=0.992) and inter-rater reliabilities (the intraclass correlation coefficient=0.949) were excellent, with values over 0.9. [Conclusion] The make test is a useful manual muscle testing method with high intra-rater and inter-rater reliability.

  11. Simultaneous hand-held contact color fundus and SD-OCT imaging for pediatric retinal diseases (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Ruggeri, Marco; Hernandez, Victor; De Freitas, Carolina; Relhan, Nidhi; Silgado, Juan; Manns, Fabrice; Parel, Jean-Marie

    2016-03-01

    Hand-held wide-field contact color fundus photography is currently the standard method to acquire diagnostic images of children during examination under anesthesia and in the neonatal intensive care unit. The recent development of portable non-contact hand-held OCT retinal imaging systems has proved that OCT is of tremendous help to complement fundus photography in the management of pediatric patients. Currently, there is no commercial or research system that combines color wide-field digital fundus and OCT imaging in a contact-fashion. The contact of the probe with the cornea has the advantages of reducing motion experienced by the photographer during the imaging and providing fundus and OCT images with wider field of view that includes the periphery of the retina. In this study we produce proof of concept for a contact-type hand-held unit for simultaneous color fundus and OCT live view of the retina of pediatric patients. The front piece of the hand-held unit consists of a contact ophthalmoscopy lens integrating a circular light guide that was recovered from a digital fundus camera for pediatric imaging. The custom-made rear piece consists of the optics to: 1) fold the visible aerial image of the fundus generated by the ophthalmoscopy lens on a miniaturized level board digital color camera; 2) conjugate the eye pupil to the galvanometric scanning mirrors of an OCT delivery system. Wide-field color fundus and OCT images were simultaneously obtained in an eye model and sequentially obtained on the eye of a conscious 25 year-old human subject with healthy retina.

  12. Robotic hand-held surgical device: evaluation of end-effector's kinematics and development of proof-of-concept prototypes.

    PubMed

    Zahraee, Ali Hassan; Szewczyk, Jérome; Paik, Jamie Kyujin; Morel, Guillaume

    2010-01-01

    We are working towards the development of a robotic hand-held surgical device for laparoscopic interventions that enhances the surgeons' dexterity. In this paper, the kinematics of the end effector is studied. Different choices of kinematics are compared during an evaluation campaign using a virtual reality simulator to find the optimal one: the Yaw-Roll (YR) kinematics. A proof of concept prototype is made based on the results. PMID:20879429

  13. The Hewlett-Packard HP-41CV Hand-Held Computer as a Medium for Teaching Mathematics to Fire Control Systems Repairers. Research Report 1408.

    ERIC Educational Resources Information Center

    Boldovici, John A.; Scott, Thomas D.

    A study compared the benefits of using the Hewlett-Packard HP-41CV hand-held computer, as opposed to conventional training without computers, in teaching mathematics to fire control systems repairers. Thirty soldiers in a course to train fire control systems repairers received training in technical mathematics using the hand-held computer, whereas…

  14. Use of a hand-held, metered-dose aerosol delivery device to administer pirbuterol acetate to horses with 'heaves'.

    PubMed

    Derksen, F J; Olszewski, M; Robinson, N E; Berney, C; Lloyd, J W; Hakala, J; Matson, C; Ruth, D

    1996-07-01

    Aerosol administration of bronchodilators to horses is recommended for treatment of certain airway diseases such as 'heaves'. We have developed a novel, hand-held, metered-dose inhaler and we sought to determine the bronchodilator efficacy of the beta 2 adrenoceptor agonist pirbuterol delivered by this device to horses affected with 'heaves'. To induce airway obstruction, 6 heaves-susceptible horses were stabled, bedded on straw and fed hay. When the maximum change in pleural pressure during tidal breathing (delta Pplmax) was greater than 20 cmH2O on 2 consecutive days, pulmonary function was measured before and 5, 10 and 30 min, as well as 1, 2, 3, 4, 5, 6 and 7 h after administration of aerosol pirbuterol. Pirbuterol was administered using a metered canister and the hand-held delivery device that was inserted into the left nostril. Either vehicle or pirbuterol acetate (400, 600, 800, 1200 or 1600 micrograms) was administered to each horse. Relief of airway obstruction indicated by changes in pulmonary function was observed within 5 min after administration of both vehicle and pirbuterol. Significant decreases in delta Pplmax and pulmonary resistance (RL) and an increase in dynamic compliance (Cdyn) persisted for the 7 h duration of the experiment. Comparison of the effect of vehicle and pirbuterol at each time period showed that pirbuterol decreased RL and delta Pplmax significantly for up to 1 h. The optimal dose was determined to be 600 micrograms. Immediate response to treatment, magnitude of drug effect and lack of side effects indicated that aerosol pirbuterol is an effective and safe bronchodilator in horses with 'heaves'. The hand-held, metered-dose aerosol delivery device was very convenient and extremely effective and is, therefore, recommended for delivery of therapeutic aerosols to horses. PMID:8818596

  15. Rapid prediction of total petroleum hydrocarbons in soil using a hand-held mid-infrared field instrument.

    PubMed

    Webster, Grant T; Soriano-Disla, José M; Kirk, Joel; Janik, Leslie J; Forrester, Sean T; McLaughlin, Mike J; Stewart, Richard J

    2016-11-01

    This manuscript reports on the performance of a hand-held diffuse reflectance (mid)-infrared Fourier transform (DRIFT) spectrometer for the prediction of total petroleum hydrocarbons (TPH) in three different diesel-contaminated soils. These soils include: a carbonate dominated clay, a kaolinite dominated clay and a loam from Padova Italy, north Western Australia and southern Nigeria, respectively. Soils were analysed for TPH concentration using a standard laboratory methods and scanned in DRIFT mode with the hand-held spectrometer to determine TPH calibration models. Successful partial least square regression (PLSR) predictions, with coefficient of determination (R(2)) ~0.99 and root mean square error (RMSE) <200mg/kg, were obtained for the low range TPH concentrations of 0 to ~3,000mg/kg. These predictions were carried out using a set of independent samples for each soil type. Prediction models were also tested for the full concentration range (0-60,000mg/kg) for each soil type model with R(2) and RMSE values of ~0.99 and <1,255mg/kg, respectively. Furthermore, a number of intermediate concentration range models were also generated for each soil type with similar R(2) values of ~0.99 and RMSE values <800mg/kg. This study shows the capability of using a portable mid-infrared (MIR) DRIFT spectrometer for predicting TPH in a variety of soil types and the potential for being a rapid in-field screening method for TPH concentration levels at common regulatory thresholds. A novel hand-held mid-infrared instrument can accurately detect TPH across different soil types and concentrations, which paves the way for a variety of applications in the field. PMID:27591631

  16. Catalog of Space Shuttle Earth Observations Hand-Held Photography: Space Transportation System (STS) 41-6 Mission

    NASA Technical Reports Server (NTRS)

    Nowakowski, Barbara S.; Palmer, Wesley F.

    1985-01-01

    This document catalogs Space Shuttle hand-held Earth observations photography which was collected on the Space Transportation System (STS) 41-G mission of October 1984. The catalog includes the following data for each of 2480 frames: geographical name, feature description, latitude and longitude, percentage of cloud cover, look direction and tilt, lens focal length, exposure evaluation, stereopairs, and orbit number. The catalog is a product of the Space Shuttle Earth Observations Project, Solar System Exploration Division, Space and Life Sciences Directorate, of the National Aeronautics and Space Administration, Lyndon B. Johnson Space Center.

  17. Intraoperative detection of radiolabeled compounds using a hand held gamma probe

    NASA Astrophysics Data System (ADS)

    Ricard, Marcel

    2001-02-01

    Scintillation cameras in Nuclear Medicine allow external detection of cancerous lesions after administration of a specific radiopharmaceutical to the patient. In some particular cases the affinity of the tracer is sufficient to consider the use of an intraoperative probe which enables the surgeon to identify radioactive tissues. A radiopharmaceutical consists of a radioisotope bound to a carrier molecule. The radioactive emissions must represent certain criteria in terms of half-life and energy to be detected during an operation. In the field of intraoperative detection radionuclides like 99mTc, 111In, 125I and 131I fall into this category. Their energy, which ranges from some 10 to 364 keV, cannot be properly detected by a single type of detector. Two technologies have been developed to yield detectors which are handy and sufficiently sensitive: semiconductor CdTe or CdZnTe to detect low energies and scintillator CsI(Tl) for higher energies. Today the intraoperative detection has been evaluated in the case of several pathologies such as osteoid osteoma, colorectal cancer, neuroblastoma, reoperation of differentiated thyroid carcinoma and localization of sentinel node in breast cancer and cutaneous melanoma. Obviously, the results obtained are not comparable from one indication to the other. Nevertheless, the surgeons have noted a considerable advantage in using the intraoperative probe in the case of neuroblastoma and thyroid surgery, especially when the reoperation is difficult or the localizations are ectopic or unusual. As regards the sentinel node, this concept represents a major new opportunity in the field of intraoperative detection and the results actually reported in the literature demonstrate that, when it is detected, elective node excision renders the staging of the disease more accurate. In conclusion, intraoperative detection supplies the surgeon with additional knowledge to be used in correlation with the patient's medical history.

  18. Analysis of Accuracy in Pointing with Redundant Hand-held Tools: A Geometric Approach to the Uncontrolled Manifold Method

    PubMed Central

    Campolo, Domenico; Widjaja, Ferdinan; Xu, Hong; Ang, Wei Tech; Burdet, Etienne

    2013-01-01

    This work introduces a coordinate-independent method to analyse movement variability of tasks performed with hand-held tools, such as a pen or a surgical scalpel. We extend the classical uncontrolled manifold (UCM) approach by exploiting the geometry of rigid body motions, used to describe tool configurations. In particular, we analyse variability during a static pointing task with a hand-held tool, where subjects are asked to keep the tool tip in steady contact with another object. In this case the tool is redundant with respect to the task, as subjects control position/orientation of the tool, i.e. 6 degrees-of-freedom (dof), to maintain the tool tip position (3dof) steady. To test the new method, subjects performed a pointing task with and without arm support. The additional dof introduced in the unsupported condition, injecting more variability into the system, represented a resource to minimise variability in the task space via coordinated motion. The results show that all of the seven subjects channeled more variability along directions not directly affecting the task (UCM), consistent with previous literature but now shown in a coordinate-independent way. Variability in the unsupported condition was only slightly larger at the endpoint but much larger in the UCM. PMID:23592956

  19. Potential Air Contamination During CO{sub 2} Angiography Using a Hand-Held Syringe: Theoretical Considerations and Gas Chromatography

    SciTech Connect

    Cho, David R.; Cho, Kyung J. Hawkins, Irvin F.

    2006-08-15

    Purpose. To assess air contamination in the hand-held syringes currently used for CO{sub 2} delivery and to determine whether there is an association between their position and the rate of air contamination. Methods. Assessment of air contamination in the syringe (20 ml) included theoretical modeling, mathematical calculation, and gas chromatography (GC). The model was used with Fick's first law to calculate the diffusion of CO{sub 2} and the amount of air contamination. For GC studies, the syringes were placed in the upright, horizontal, and inverted positions and gas samples were obtained after 5, 10, 20, 30, and 60 min. All trials with each position for each sampling time were performed five times. Results. The amounts of air contamination with time calculated mathematically were 5-10% less than those of GC. With the diffusivity of air-CO{sub 2} at 0.1599 cm{sup 2}/sec (9.594 cm{sup 2}/min), air contamination was calculated to be 60% at 60 min. With GC air contamination was 13% at 5 min, 31% at 20 min, 43% at 30 min, and 68% at 60 min. There was no difference in air contamination between the different syringe positions. Conclusion. Air contamination occurs in hand-held syringes filled with CO{sub 2} when they are open to the ambient air. The amounts of air contamination over time are similar among syringes placed in the upright, horizontal, and inverted positions.

  20. Intraoperative gamma hand-held probe navigation in resection of osteoid osteoma tumor--report of two cases.

    PubMed

    Cengić, Tomislav; Corluka, Stipe; Petrović, Tadija; Baranović, Senka; Kovacić, Ksenija; Kolundzić, Robert

    2013-06-01

    Two cases of osteoid osteoma tumor (OO) are presented and our early experience with intraoperative gamma probing to localize OO during surgery is reported. The concept of radioguided surgery was developed 60 years ago and the gamma detection probe technology for radioguided biopsy and/or resection of bone lesions has been applied since the early 1980s. Bone scintigraphy is very important for initial diagnosis of OO with almost 100% sensitivity. The bone scan finding is specific, with so called double density appearance, very intense accumulation of radiopharmaceutical in the nidus and therefore great difference between the nidus and the surrounding healthy bone, thus making possible to treat this lesion with probe guided surgery. Three phase bone scintigraphy and single photon emission computed tomography were conducted in our patients for initial diagnosis of OO. A second bone scintigraphy was performed before surgery. The surgery followed 12-15 hours later by intraoperative nidus detection with a hand-held gamma probe. Gamma hand-held probe is a system that detects gamma photons. The count rate in the nidus area on the day of surgery was 3 to 4 times higher than in the healthy bone area. Drilling was performed until the counts decreased to the level of the surrounding bone counts, thereby confirming complete excision. This is the method of choice for minimizing bone resection, the risk of pathologic fracture, the need of bone grafting, and reducing the period of convalescence. Evidence for the treatment efficiency is pain disappearance after the surgery. PMID:24053090

  1. Direct Analysis of Nonvolatile Chemical Compounds on Surfaces Using a Hand-Held Mass Spectrometer with Synchronized Discharge Ionization Function.

    PubMed

    Wang, Xiao; Zhou, Xiaoyu; Ouyang, Zheng

    2016-01-01

    Synchronized discharge ionization (SDI) was previously developed for hand-held mass spectrometers with discontinuous atmospheric pressure interfaces. The function of SDI has been demonstrated for analysis of volatile organic compounds in air at high sensitivity, which is attributed to the fact that ions were produced next to the ion trap mass analyzer inside the vacuum manifold. In this study, a simple sampling device was designed and fitted to a hand-held mass spectrometer to characterize its potential in direct analysis of low-volatility chemicals on surfaces. Nine chemicals of vapor pressures ranging from 10(-4) to 10(-8) Torr (at room temperature), including pesticides, illicit drugs, and explosives, were selected to evaluate and demonstrate the analytical capability of the designed system. Compounds of vapor pressures below 10(-7) Torr, such as tetryl, cocaine, and tetrahydrocannabinol (THC), have been successfully detected. Direct analysis of pesticides from fruit and explosives from a large surface area has also been demonstrated. Tandem mass analysis was performed, which helped to confirm the analyte identity as well as to improve the signal-to-noise ratio (S/N). PMID:26618852

  2. A new hand-held microfluidic cytometer for evaluating irradiation damage by analysis of the damaged cells distribution

    NASA Astrophysics Data System (ADS)

    Wang, Junsheng; Fan, Zhiqiang; Zhao, Yile; Song, Younan; Chu, Hui; Song, Wendong; Song, Yongxin; Pan, Xinxiang; Sun, Yeqing; Li, Dongqing

    2016-03-01

    Space radiation brings uneven damages to cells. The detection of the distribution of cell damage plays a very important role in radiation medicine and the related research. In this paper, a new hand-held microfluidic flow cytometer was developed to evaluate the degree of radiation damage of cells. The device we propose overcomes the shortcomings (e.g., large volume and high cost) of commercial flow cytometers and can evaluate the radiation damage of cells accurately and quickly with potential for onsite applications. The distribution of radiation-damaged cells is analyzed by a simultaneous detection of immunofluorescence intensity of γ-H2AX and resistance pulse sensor (RPS) signal. The γ-H2AX fluorescence intensity provides information of the degree of radiation damage in cells. The ratio of the number of cells with γ-H2AX fluorescence signals to the total numbers of cells detected by RPS indicates the percentage of the cells that are damaged by radiation. The comparison experiment between the developed hand-held microfluidic flow cytometer and a commercial confocal microscope indicates a consistent and comparable detection performance.

  3. A new hand-held microfluidic cytometer for evaluating irradiation damage by analysis of the damaged cells distribution.

    PubMed

    Wang, Junsheng; Fan, Zhiqiang; Zhao, Yile; Song, Younan; Chu, Hui; Song, Wendong; Song, Yongxin; Pan, Xinxiang; Sun, Yeqing; Li, Dongqing

    2016-01-01

    Space radiation brings uneven damages to cells. The detection of the distribution of cell damage plays a very important role in radiation medicine and the related research. In this paper, a new hand-held microfluidic flow cytometer was developed to evaluate the degree of radiation damage of cells. The device we propose overcomes the shortcomings (e.g., large volume and high cost) of commercial flow cytometers and can evaluate the radiation damage of cells accurately and quickly with potential for onsite applications. The distribution of radiation-damaged cells is analyzed by a simultaneous detection of immunofluorescence intensity of γ-H2AX and resistance pulse sensor (RPS) signal. The γ-H2AX fluorescence intensity provides information of the degree of radiation damage in cells. The ratio of the number of cells with γ-H2AX fluorescence signals to the total numbers of cells detected by RPS indicates the percentage of the cells that are damaged by radiation. The comparison experiment between the developed hand-held microfluidic flow cytometer and a commercial confocal microscope indicates a consistent and comparable detection performance. PMID:26983800

  4. A new hand-held microfluidic cytometer for evaluating irradiation damage by analysis of the damaged cells distribution

    PubMed Central

    Wang, Junsheng; Fan, Zhiqiang; Zhao, Yile; Song, Younan; Chu, Hui; Song, Wendong; Song, Yongxin; Pan, Xinxiang; Sun, Yeqing; Li, Dongqing

    2016-01-01

    Space radiation brings uneven damages to cells. The detection of the distribution of cell damage plays a very important role in radiation medicine and the related research. In this paper, a new hand-held microfluidic flow cytometer was developed to evaluate the degree of radiation damage of cells. The device we propose overcomes the shortcomings (e.g., large volume and high cost) of commercial flow cytometers and can evaluate the radiation damage of cells accurately and quickly with potential for onsite applications. The distribution of radiation-damaged cells is analyzed by a simultaneous detection of immunofluorescence intensity of γ-H2AX and resistance pulse sensor (RPS) signal. The γ-H2AX fluorescence intensity provides information of the degree of radiation damage in cells. The ratio of the number of cells with γ-H2AX fluorescence signals to the total numbers of cells detected by RPS indicates the percentage of the cells that are damaged by radiation. The comparison experiment between the developed hand-held microfluidic flow cytometer and a commercial confocal microscope indicates a consistent and comparable detection performance. PMID:26983800

  5. US-ROK Action Sheet 34: Safeguards Application of a Hand-held Mechanically Cooled Germanium Spectrometer

    SciTech Connect

    Dreyer, J.; Burks, M.; Ham, Y.; Kwak, S.

    2015-10-20

    This report summarizes results of Action Sheet 34 - for the cooperative efforts on the field testing and evaluation of a high-resolution, hand-held, gamma-ray spectrometer, known as SPG (Spectroscopic Planar Germanium), for safeguards application such as short notice inspections, UF6 analysis, enrichment determination, and other potential applications. The Spectroscopic Planar Germanium (SPG) has been demonstrated IAEA Physical Inventory Verification (PIV) in South Korea. This field test was a success and the feedback provided by KINAC, IAEA, and national laboratory staff was used to direct efforts to improve the instrument this year. Key points in this report include measurement results from PIV, analysis of spectra with commercially available Ortec U235 and PC-FRAM, and completion of tripod and tungsten collimator and integration of user feedback.

  6. SHIELDING AND DETECTOR RESPONSE CALCULATIONS PERTAINING TO CATEGORY 1 QUANTITIES OF PLUTONIUM AND HAND-HELD PLASTIC SCINTILLATORS

    SciTech Connect

    Couture, A.

    2013-06-07

    Nuclear facilities sometimes use hand-held plastic scintillator detectors to detect attempts to divert special nuclear material in situations where portal monitors are impractical. MCNP calculations have been performed to determine the neutron and gamma radiation field arising from a Category I quantity of weapons-grade plutonium in various shielding configurations. The shields considered were composed of combinations of lead and high-density polyethylene such that the mass of the plutonium plus shield was 22.7 kilograms. Monte-Carlo techniques were also used to determine the detector response to each of the shielding configurations. The detector response calculations were verified using field measurements of high-, medium-, and low- energy gamma-ray sources as well as a Cf-252 neutron source.

  7. 3D Scan of Ornamental Column (huabiao) Using Terrestrial LiDAR and Hand-held Imager

    NASA Astrophysics Data System (ADS)

    Zhang, W.; Wang, C.; Xi, X.

    2015-08-01

    In ancient China, Huabiao was a type of ornamental column used to decorate important buildings. We carried out 3D scan of a Huabiao located in Peking University, China. This Huabiao was built no later than 1742. It is carved by white marble, 8 meters in height. Clouds and various postures of dragons are carved on its body. Two instruments were used to acquire the point cloud of this Huabiao, a terrestrial LiDAR (Riegl VZ-1000) and a hand-held imager (Mantis Vision F5). In this paper, the details of the experiment were described, including the differences between these two instruments, such as working principle, spatial resolution, accuracy, instrument dimension and working flow. The point clouds obtained respectively by these two instruments were compared, and the registered point cloud of Huabiao was also presented. These should be of interest and helpful for the research communities of archaeology and heritage.

  8. HAND-HELD GAMMA-RAY SPECTROMETER BASED ON HIGH-EFFICIENCY FRISCH-RING CdZnTe DETECTORS.

    SciTech Connect

    CUI,Y.

    2007-05-01

    Frisch-ring CdZnTe detectors have demonstrated good energy resolution, el% FWHM at 662 keV, and good efficiency for detecting gamma rays. This technique facilitates the application of CdZnTe materials for high efficiency gamma-ray detection. A hand-held gamma-ray spectrometer based on Frisch-ring detectors is being designed at Brookhaven National Laboratory. It employs an 8x8 CdZnTe detector array to achieve a high volume of 19.2 cm3, so that detection efficiency is significantly improved. By using the front-end ASICs developed at BNL, this spectrometer has a small profile and high energy resolution. The spectrometer includes signal processing circuit, digitization and storage circuit, high-voltage module, and USB interface. In this paper, we introduce the details of the system structure and report our test results with it.

  9. Hand-Held Gamma-Ray Spectrometer Based on High-Efficiency Frisch-Ring Cdznte Detectors

    SciTech Connect

    Cui, Y.; Bolotnikov, A; Camarda, G; Hossain, A; James, R; DeGeronimo, G; Fried, J; O'Connor, P; Kargar, A; et. al.

    2008-01-01

    Frisch-ring CdZnTe detectors have demonstrated both good energy resolution, <1% FWHM at 662 keV, and good efficiency in detecting gamma rays, highlighting the strong potential of CdZnTe materials for such applications. We are designing a hand-held gamma-ray spectrometer based on Frisch-ring detectors at Brookhaven National Laboratory. It employs an 8 times 8 CdZnTe detector array to achieve a high volume of 19.2 cm3, so greatly improving detection efficiency. By using the front-end application-specific integrated circuits (ASICs) developed at BNL, this spectrometer has a small profile and high energy-resolution. It includes a signal processing circuit, digitization and storage circuits, a high-voltage module, and a universal serial bus (USB) interface. In this paper, we detail the system's structure and report the results of our tests with it.

  10. Estimation of Potential Gradient from Discharge Current through Hand-Held Metal Piece from Charged Human Body

    NASA Astrophysics Data System (ADS)

    Taka, Yoshinori; Fujiwara, Osamu

    Electrostatic discharge (ESD) events due to metal objects electrified with low voltages give a fatal electromagnetic interference to high-tech information equipment. In order to elucidate the mechanism, with a 6-GHz digital oscilloscope, we previously measured the discharge current due to collision of a hand-held metal piece from a charged human body, and gave a current calculation model. In this study, based on the calculation model, a method was presented for deriving a gap potential gradient from the measured discharge current. Measurements of the discharge currents were made for charge voltages from 200V to 1000V. The corresponding potential gradients were estimated, which were validated in comparison with an empirical formula based on the Paschen's law together with other researcher's experimental results.

  11. Drift from the Use of Hand-Held Knapsack Pesticide Sprayers in Boyacá (Colombian Andes).

    PubMed

    García-Santos, Glenda; Feola, Giuseppe; Nuyttens, David; Diaz, Jaime

    2016-05-25

    Offsite pesticide losses in tropical mountainous regions have been little studied. One example is measuring pesticide drift soil deposition, which can support pesticide risk assessment for surface water, soil, bystanders, and off-target plants and fauna. This is considered a serious gap, given the evidence of pesticide-related poisoning in those regions. Empirical data of drift deposition of a pesticide surrogate, Uranine tracer, within one of the highest potato-producing regions in Colombia, characterized by small plots and mountain orography, is presented. High drift values encountered in this study reflect the actual spray conditions using hand-held knapsack sprayers. Comparison between measured and predicted drift values using three existing empirical equations showed important underestimation. However, after their optimization based on measured drift information, the equations showed a strong predictive power for this study area and the study conditions. The most suitable curve to assess mean relative drift was the IMAG calculator after optimization. PMID:26479088

  12. Rapid and accurate determination of total lung capacity (TLC) from routine chest radiograms using a programmable hand-held calculator.

    PubMed

    Rodgers, R P; Tannen, R

    1983-01-01

    Since its appearance in 1960, the method of Barnhard and associates for the determination of total lung capacity (TLC) from routine chest radiograms has been widely studied in normal and diseased subjects. The method appears to be as accurate as the current definitive procedure, total body plethysmography. The method is in routine use in major medical institutions where the procedure has been automated, but the method does not seem to have gained the wide use it deserves. This is likely due to the tedium of the technique when performed manually--a single determination can require 30 min. We present here an implementation of the Barnhard method for the HP41-C hand-held programmable calculator. In conjunction with the use of a transparent reticle used for obtaining the required measurements, the program allows a single measurement to be made in under 12 minutes. We hope this technique will make radiographic TLC measurements more broadly accessible to the medical profession. PMID:6872526

  13. The GSFC Mark-2 three band hand-held radiometer. [thematic mapper for ground truth data collection

    NASA Technical Reports Server (NTRS)

    Tucker, C. J.; Jones, W. H.; Kley, W. A.; Sundstrom, G. J.

    1980-01-01

    A self-contained, portable, hand-radiometer designed for field usage was constructed and tested. The device, consisting of a hand-held probe containing three sensors and a strap supported electronic module, weighs 4 1/2 kilograms. It is powered by flashlight and transistor radio batteries, utilizes two silicon and one lead sulfide detectors, has three liquid crystal displays, sample and hold radiometric sampling, and its spectral configuration corresponds to LANDSAT-D's thematic mapper bands. The device was designed to support thematic mapper ground-truth data collection efforts and to facilitate 'in situ' ground-based remote sensing studies of natural materials. Prototype instruments were extensively tested under laboratory and field conditions with excellent results.

  14. Assessment of Lower Limb Muscle Strength and Power Using Hand-Held and Fixed Dynamometry: A Reliability and Validity Study

    PubMed Central

    Perraton, Luke G.; Bower, Kelly J.; Adair, Brooke; Pua, Yong-Hao; Williams, Gavin P.; McGaw, Rebekah

    2015-01-01

    Introduction Hand-held dynamometry (HHD) has never previously been used to examine isometric muscle power. Rate of force development (RFD) is often used for muscle power assessment, however no consensus currently exists on the most appropriate method of calculation. The aim of this study was to examine the reliability of different algorithms for RFD calculation and to examine the intra-rater, inter-rater, and inter-device reliability of HHD as well as the concurrent validity of HHD for the assessment of isometric lower limb muscle strength and power. Methods 30 healthy young adults (age: 23±5yrs, male: 15) were assessed on two sessions. Isometric muscle strength and power were measured using peak force and RFD respectively using two HHDs (Lafayette Model-01165 and Hoggan microFET2) and a criterion-reference KinCom dynamometer. Statistical analysis of reliability and validity comprised intraclass correlation coefficients (ICC), Pearson correlations, concordance correlations, standard error of measurement, and minimal detectable change. Results Comparison of RFD methods revealed that a peak 200ms moving window algorithm provided optimal reliability results. Intra-rater, inter-rater, and inter-device reliability analysis of peak force and RFD revealed mostly good to excellent reliability (coefficients ≥ 0.70) for all muscle groups. Concurrent validity analysis showed moderate to excellent relationships between HHD and fixed dynamometry for the hip and knee (ICCs ≥ 0.70) for both peak force and RFD, with mostly poor to good results shown for the ankle muscles (ICCs = 0.31–0.79). Conclusions Hand-held dynamometry has good to excellent reliability and validity for most measures of isometric lower limb strength and power in a healthy population, particularly for proximal muscle groups. To aid implementation we have created freely available software to extract these variables from data stored on the Lafayette device. Future research should examine the reliability

  15. Cellphone-Based Hand-Held Microplate Reader for Point-of-Care Testing of Enzyme-Linked Immunosorbent Assays.

    PubMed

    Berg, Brandon; Cortazar, Bingen; Tseng, Derek; Ozkan, Haydar; Feng, Steve; Wei, Qingshan; Chan, Raymond Yan-Lok; Burbano, Jordi; Farooqui, Qamar; Lewinski, Michael; Di Carlo, Dino; Garner, Omai B; Ozcan, Aydogan

    2015-08-25

    Standard microplate based enzyme-linked immunosorbent assays (ELISA) are widely utilized for various nanomedicine, molecular sensing, and disease screening applications, and this multiwell plate batched analysis dramatically reduces diagnosis costs per patient compared to nonbatched or nonstandard tests. However, their use in resource-limited and field-settings is inhibited by the necessity for relatively large and expensive readout instruments. To mitigate this problem, we created a hand-held and cost-effective cellphone-based colorimetric microplate reader, which uses a 3D-printed opto-mechanical attachment to hold and illuminate a 96-well plate using a light-emitting-diode (LED) array. This LED light is transmitted through each well, and is then collected via 96 individual optical fibers. Captured images of this fiber-bundle are transmitted to our servers through a custom-designed app for processing using a machine learning algorithm, yielding diagnostic results, which are delivered to the user within ∼1 min per 96-well plate, and are visualized using the same app. We successfully tested this mobile platform in a clinical microbiology laboratory using FDA-approved mumps IgG, measles IgG, and herpes simplex virus IgG (HSV-1 and HSV-2) ELISA tests using a total of 567 and 571 patient samples for training and blind testing, respectively, and achieved an accuracy of 99.6%, 98.6%, 99.4%, and 99.4% for mumps, measles, HSV-1, and HSV-2 tests, respectively. This cost-effective and hand-held platform could assist health-care professionals to perform high-throughput disease screening or tracking of vaccination campaigns at the point-of-care, even in resource-poor and field-settings. Also, its intrinsic wireless connectivity can serve epidemiological studies, generating spatiotemporal maps of disease prevalence and immunity. PMID:26159546

  16. A new miniature hand-held solar-blind reagentless standoff chemical, biological, and explosives (CBE) sensor

    NASA Astrophysics Data System (ADS)

    Hug, W. F.; Reid, R. D.; Bhartia, R.; Lane, A. L.

    2008-04-01

    Improvised explosive devices (IEDs), vehicle-borne improvised explosive devices (VBIEDs), and suicide bombers are a major threat to many countries and their citizenry. The ability to detect trace levels of these threats with a miniature, hand-held, reagentless, standoff sensor represents a major improvement in the state of the art of CBE surface sensors. Photon Systems, Inc., in collaboration with Jet Propulsion Laboratory, recently demonstrated a new technology hand-held sensor for reagentless, close-range, standoff detection and identification of trace levels CBE materials on surfaces. This targeted ultraviolet CBE (TUCBE) sensor is the result of an Army Phase I STTR program. The resulting 5lb, 5W, flashlight-sized sensor can discriminate CBE from background materials using a combination of deep UV excited resonance Raman (RR) and laser induced native fluorescence (LINF) emissions resulting from excitation by a new technology deep UV laser. Detection and identification is accomplished in less than 1ms. Standoff excitation of suspicious packages, vehicles, persons, and other objects that may contain hazardous materials is accomplished using wavelengths below 250nm where Raman and native fluorescence emissions occupy distinctly different wavelength regions. This enables simultaneous detection of RR and LINF emissions with no interferences. The sensor employs fused RR/LINF chemometric methods to extract the identity of targeted materials from background clutter. Photon Systems has demonstrated detection and identification of 100ng/cm2 of explosives materials at a distance of 1 meter using a sensor with 3.8 cm optical aperture. Expansion of the optical aperture to 38 cm in a lantern-sized sensor will enable similar detection and identification of CBE materials at standoff distances of 10 meters. As a result of excitation and detection in the deep UV and the use of a gated detection system, the sensor is solar blind and can operate in full daylight conditions.

  17. Hand-held portable desorption atmospheric pressure chemical ionization ion source for in situ analysis of nitroaromatic explosives.

    PubMed

    Jjunju, Fred P M; Maher, Simon; Li, Anyin; Syed, Sarfaraz U; Smith, Barry; Heeren, Ron M A; Taylor, Stephen; Cooks, R Graham

    2015-10-01

    A novel, lightweight (0.6 kg), solvent- and gas-cylinder-free, hand-held ion source based on desorption atmospheric pressure chemical ionization has been developed and deployed for the analysis of nitroaromatic explosives on surfaces in open air, offering portability for in-field analysis. A small, inexpensive, rechargeable lithium polymer battery was used to power the custom-designed circuitry within the device, which generates up to ±5 kV dc voltage to ignite a corona discharge plasma in air for up to 12 h of continuous operation, and allowing positive- and negative-ion mass spectrometry. The generated plasma is pneumatically transported to the surface to be interrogated by ambient air at a rate of 1-3.5 L/min, compressed using a small on-board diaphragm pump. The plasma source allows liquid or solid samples to be examined almost instantaneously without any sample preparation in the open environment. The advantages of low carrier gas and low power consumption (<6 W), as well as zero solvent usage, have aided in developing the field-ready, hand-held device for trigger-based, "near-real-time" sampling/ionization. Individual nitroaromatic explosives (such as 2,4,6-trinitrotoluene) can be easily detected in amounts as low as 5.8 pg with a linear dynamic range of at least 10 (10-100 pg), a relative standard deviation of ca. 7%, and an R(2) value of 0.9986. Direct detection of several nitroaromatic compounds in a complex mixture without prior sample preparation is demonstrated, and their identities are confirmed by tandem mass spectrometry fragmentation patterns. PMID:26329926

  18. Lava effusion rates from hand-held thermal infrared imagery: an example from the June 2003 effusive activity at Stromboli

    NASA Astrophysics Data System (ADS)

    Harris, Andrew; Dehn, Jon; Patrick, Matt; Calvari, Sonia; Ripepe, Maurizio; Lodato, Luigi

    2005-12-01

    A safe, easy and rapid method to calculate lava effusion rates using hand-held thermal image data was developed during June 2003 at Stromboli Volcano (Italy). We used a Forward Looking Infrared Radiometer (FLIR) to obtain images of the active lava flow field on a daily basis between May 31 and June 16, 2003. During this time the flow field geometry and size (where flows typically a few hundred meters long were emplaced on a steep slope) meant that near-vertical images of the whole flow field could be captured in a single image obtained from a helicopter hovering, at an altitude of 750 m and ˜1 km off shore. We used these images to adapt a thermally based effusion rate method, previously applied to low and high spatial resolution satellite data, to allow automated extraction of effusion rates from the hand-held thermal infrared imagery. A comparison between a thermally-derived (0.23 0.87 m3 s-1) and dimensionally-derived effusion rate (0.56 m3 s-1) showed that the thermally-derived range was centered on the expected value. Over the measurement period, the mean effusion rate was 0.38±0.25 m3 s-1, which is similar to that obtained during the 1985 86 effusive eruption and the time-averaged supply rate calculated for normal (non-effusive) Strombolian activity. A short effusive pulse, reaching a peak of ˜1.2 m3 s-1, was recorded on June 3, 2003. One explanation of such a peak would be an increase in driving pressure due to an increase in the height of the magma contained in the central column. We estimate that this pulse would require the magma column to attain a height of ˜190 m above the effusive vent, which is approximately the elevation difference between the vent and the floor of the NE crater. Our approach gives an easy-to-apply method that has the potential to provide effusion rate time series with a high temporal resolution.

  19. Centimeter-scale secondary information on hydraulic conductivity using a hand-held air permeameter on borehole cores.

    NASA Astrophysics Data System (ADS)

    Rogiers, B.; Winters, P.; Huysmans, M.; Beerten, K.; Mallants, D.; Gedeon, M.; Batelaan, O.; Dassargues, A.

    2012-04-01

    Saturated hydraulic conductivity (Ks) is one of the most important parameters determining groundwater flow and contaminant transport in both unsaturated and saturated porous media. Determining the small-scale variability of this parameter is key to evaluate implications on effective parameters at the larger scale. Moreover, for stochastic simulations of groundwater flow and contaminant transport, accurate models on the spatial variability of Ks are very much needed. While several well-established laboratory methods exist for determining Ks, investigating the small-scale variability remains a challenge. If several tens to hundreds of metres of borehole core has to be hydraulically characterised at the centimetre to decimetre scale, several hundreds to thousands of Ks measurements are required, which makes it very costly and time-consuming should traditional methods be used. With reliable air permeameters becoming increasingly available from the late 80's, a fast and effective indirect method exists to determine Ks. Therefore, the use of hand-held air permeameter measurements for determining very accurate small-scale heterogeneity about Ks is very appealing. Very little is known, however, on its applicability for borehole cores that typically carry a small sediment volume. Therefore, the method was tested on several borehole cores of different size, originating from the Campine basin, Northern Belgium. The studied sediments are of Miocene to Pleistocene age, with a marine to continental origin, and consist of sand to clayey sand with distinct clay lenses, resulting in a Ks range of 7 orders of magnitude. During previous studies, two samples were taken from borehole cores each two meters for performing constant head lab permeameter tests. This data is now used as a reference for the air permeameter measurements that are performed with a resolution of 5 centimetres. Preliminary results indicate a very good correlation between the previously gathered constant head Ks

  20. Towards the hand-held mass spectrometer: design considerations, simulation, and fabrication of micrometer-scaled cylindrical ion traps

    NASA Astrophysics Data System (ADS)

    Blain, Matthew G.; Riter, Leah S.; Cruz, Dolores; Austin, Daniel E.; Wu, Guangxiang; Plass, Wolfgang R.; Cooks, R. Graham

    2004-08-01

    Breakthrough improvements in simplicity and reductions in the size of mass spectrometers are needed for high-consequence fieldable applications, including error-free detection of chemical/biological warfare agents, medical diagnoses, and explosives and contraband discovery. These improvements are most likely to be realized with the reconceptualization of the mass spectrometer, rather than by incremental steps towards miniaturization. Microfabricated arrays of mass analyzers represent such a conceptual advance. A massively parallel array of micrometer-scaled mass analyzers on a chip has the potential to set the performance standard for hand-held sensors due to the inherit selectivity, sensitivity, and universal applicability of mass spectrometry as an analytical method. While the effort to develop a complete micro-MS system must include innovations in ultra-small-scale sample introduction, ion sources, mass analyzers, detectors, and vacuum and power subsystems, the first step towards radical miniaturization lies in the design, fabrication, and characterization of the mass analyzer itself. In this paper we discuss design considerations and results from simulations of ion trapping behavior for a micrometer scale cylindrical ion trap (CIT) mass analyzer (internal radius r0 = 1 [mu]m). We also present a description of the design and microfabrication of a 0.25 cm2 array of 106 one-micrometer CITs, including integrated ion detectors, constructed in tungsten on a silicon substrate.

  1. Task difficulty and inertial properties of hand-held tools: An assessment of their concurrent effects on precision aiming.

    PubMed

    Silva, Paula L; Bootsma, Reinoud J; Figueiredo, Priscilla Rezende Pereira; Avelar, Bruna Silva; de Andrade, André Gustavo Pereira; Fonseca, Sérgio T; Mancini, Marisa Cotta

    2016-08-01

    Aiming hand-held tools at targets in space entails adjustments in the dynamical organization of aiming patterns according to the required precision. We asked whether and how these adjustments are modified by the tool's mass distribution. Twelve participants performed reciprocal aiming movements with a 50-cm long wooden probe. Kinematic patterns of probe movements were used as a window into the behavioral dynamic underlying performance of a reciprocal aiming task. We crossed three levels of task difficulty (IDs 2.8, 4.5 and 6.1) with two types of probe varying in their mass distribution (proximal vs distal loading). Movement duration was affected by task difficulty and probe loading (shorter for larger targets and proximal probe loading). Progressive deviations from a sinusoidal movement pattern were observed as task difficulty increased. Such deviations were more pronounced with proximal probe loading. Results point to a higher degree of non-linearity in aiming dynamics when the probe was loaded proximally, which might reflect employment of additional perceptual-motor processes to control the position of its less stable tip at the vicinity of the targets. More generally, the effects of probe loading on aiming pattern and dynamics suggest that perceptual-motor processes responding to task level constraints are sensitive to, and not independent from, biomechanical, end-effector constraints. PMID:27219738

  2. Four dimensional hybrid ultrasound and optoacoustic imaging via passive element optical excitation in a hand-held probe

    SciTech Connect

    Fehm, Thomas Felix; Razansky, Daniel; Deán-Ben, Xosé Luís

    2014-10-27

    Ultrasonography and optoacoustic imaging share powerful advantages related to the natural aptitude for real-time image rendering with high resolution, the hand-held operation, and lack of ionizing radiation. The two methods also possess very different yet highly complementary advantages of the mechanical and optical contrast in living tissues. Nonetheless, efficient integration of these modalities remains challenging owing to the fundamental differences in the underlying physical contrast, optimal signal acquisition, and image reconstruction approaches. We report on a method for hybrid acquisition and reconstruction of three-dimensional pulse-echo ultrasound and optoacoustic images in real time based on passive ultrasound generation with an optical absorber, thus avoiding the hardware complexity of active ultrasound generation. In this way, complete hybrid datasets are generated with a single laser interrogation pulse, resulting in simultaneous rendering of ultrasound and optoacoustic images at an unprecedented rate of 10 volumetric frames per second. Performance is subsequently showcased in phantom experiments and in-vivo measurements from a healthy human volunteer, confirming general clinical applicability of the method.

  3. Four dimensional hybrid ultrasound and optoacoustic imaging via passive element optical excitation in a hand-held probe

    NASA Astrophysics Data System (ADS)

    Fehm, Thomas Felix; Deán-Ben, Xosé Luís; Razansky, Daniel

    2014-10-01

    Ultrasonography and optoacoustic imaging share powerful advantages related to the natural aptitude for real-time image rendering with high resolution, the hand-held operation, and lack of ionizing radiation. The two methods also possess very different yet highly complementary advantages of the mechanical and optical contrast in living tissues. Nonetheless, efficient integration of these modalities remains challenging owing to the fundamental differences in the underlying physical contrast, optimal signal acquisition, and image reconstruction approaches. We report on a method for hybrid acquisition and reconstruction of three-dimensional pulse-echo ultrasound and optoacoustic images in real time based on passive ultrasound generation with an optical absorber, thus avoiding the hardware complexity of active ultrasound generation. In this way, complete hybrid datasets are generated with a single laser interrogation pulse, resulting in simultaneous rendering of ultrasound and optoacoustic images at an unprecedented rate of 10 volumetric frames per second. Performance is subsequently showcased in phantom experiments and in-vivo measurements from a healthy human volunteer, confirming general clinical applicability of the method.

  4. Characteristics of the SAR distributions in a head exposed to electromagnetic fields radiated by a hand-held portable radio

    SciTech Connect

    Watanabe, Soichi; Taki, Masao; Nojima, Toshio; Fujiwara, Osamu

    1996-10-01

    This paper presents characteristics of the specific absorption rate (SAR) distributions calculated by the finite-difference time-domain (FDTD) method using a heterogeneous and realistic head model and a realistic hand-held portable radio model. The difference between the SAR distributions produced by a 1/4-wavelength monopole antenna and those produced by a 1/2-wavelength dipole antenna is investigated. The dependence of the maximum local SAR on the distance d{sub a} between the auricle of the head and the antenna of the radio is evaluated. It is shown that the maximum local SAR decreases as the antenna length extends from 1/4 to 1/2 of the wavelength. The maximum local SAR`s in a head model with auricles are larger than those in one without auricles. The dependence of the SAR on the electrical inhomogeneity of the tissues in the head model is not significant with regard to the surface distribution and the maximum local SAR when the radio is near the head. It is also shown that the maximum local SAR is not strongly dependent on the position of the hand when the hand does not shade the antenna. Furthermore, the SAR`s experimentally measured in a homogeneous head phantom are compared with the calculated SAR`s.

  5. Numerical analysis of gas and micro-particle interactions in a hand-held shock-tube device.

    PubMed

    Liu, Y; Kendall, M A F

    2006-12-01

    A unique hand-held gene gun is employed for ballistically delivering biomolecules to key cells in the skin and mucosa in the treatment of the major diseases. One of these types of devices, called the Contoured Shock Tube (CST), delivers powdered micro-particles to the skin with a narrow and highly controllable velocity distribution and a nominally uniform spatial distribution. In this paper, we apply a numerical approach to gain new insights in to the behavior of the CST prototype device. The drag correlations proposed by Henderson (1976), Igra and Takayama (1993) and Kurian and Das (1997) were applied to predict the micro-particle transport in a numerically simulated gas flow. Simulated pressure histories agree well with the corresponding static and Pitot pressure measurements, validating the CFD approach. The calculated velocity distributions show a good agreement, with the best prediction from Igra & Takayama correlation (maximum discrepancy of 5%). Key features of the gas dynamics and gas-particle interaction are discussed. Statistic analyses show a tight free-jet particle velocity distribution is achieved (570 +/- 14.7 m/s) for polystyrene particles (39 +/- 1 microm), representative of a drug payload. PMID:16917664

  6. ECG boy: low-cost medical instrumentation using mass-produced, hand-held entertainment computers. A preliminary report.

    PubMed

    Rohde, M M; Bement, S L; Lupa, R S

    1998-01-01

    A prototype low-cost, portable ECG monitor, the "ECG Boy," is described. A mass produced hand-held video game platform is the basis for a complete three-lead, driven right-leg electrocardiogram (ECG). The ECG circuitry is planned to fit in a standard modular cartridge that is inserted in a production Nintendo "Gameboy." The combination is slightly smaller than a paperback book and weighs less than 500 g. The unit contains essential safety features such as optical isolation and is powered by 9-V and AA batteries. Functionally, the ECG Boy permits viewing ECG recordings in real time on the integrated screen. The user can select both the lead displayed on the screen and the time scale used. A 1-mV reference allows for calibration. Other ECG enhancements such as data transmission via telephone can be easily and inexpensively added to this system. The ECG Boy is intended as a proof of concept for a new class of low-cost biomedical instruments. Rising health care costs coupled with tightened funding have created an acute demand for low-cost medical equipment that satisfies safety and quality standards. A mass-produced microprocessor-based platform designed for the entertainment market can keep costs low while providing a functional basis for a biomedical instrument. PMID:9800006

  7. The Fluostick, a real hand-held system for near-infrared fluorescence image-guided surgery

    NASA Astrophysics Data System (ADS)

    Dorval, Paul; Mangeret, Norman; Guillermet, Stephanie; Righini, Christian Adrien; Barabino, Gabriele; Rizo, Philippe; Poulet, Patrick

    2014-02-01

    Near-infrared fluorescence image-guided surgery, FIGS, has lately shown a huge potential in oncologic and lymphatic related surgeries. In some indications such as liver or heart surgery, fluorescence-reachable anatomic structures are limited by the access to the surgical field. Nevertheless, most of the systems available on the market are too large to image the sides of cavities. Small devices are clearly required to improve workability of fluorescence imaging systems. The current work describes the development of an instrument and the results of its evaluation. In order to image narrow area, we developed a small size device consisting of an optical head connected to a control box. The whole system, optical head, control box and software, receives a CE mark for clinical procedures. Building on existing technologies, we simplified the fluorescence imaging system. It consists of a custom charged-coupled device camera, a high color rendering index visible LED illumination and a Class1 Laser fluorophore excitation. With a curved shape of 25x35x150mm, the optical head was designed as a true hand-held probe. The field of view varies from 5x3.75cm to 2x1.5cm. The device is able to collect and display the signal of 5pmol of IndoCyanine Green (ICG) with a spatial resolution down to 70μm at 25 frames per second. The system has been evaluated in pre-clinical and clinical procedures. The preclinical studies confirmed the ability of the system to visualize tumors in mice models. Clinical evaluations includes lymphedema investigations and surgical resections of tumors in colorectal cancer.

  8. Development of a low-cost hand-held system for optical coherence tomography imaging (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Pande, Paritosh; Shelton, Ryan L.; Monroy, Guillermo L.; Nolan, Ryan M.; Boppart, Stephen A.

    2016-03-01

    We report the development of a low-cost hand-held optical coherence imaging system. The proposed system is based on the principle of linear optical coherence tomography (Linear OCT), a technique which was proposed in the early 2000s as a simpler alternative to the conventional time-domain and Fourier-domain OCT. In our design, as in the traditional Michaelson interferometer, light from a broadband source is split into sample and reference beams. Unlike in a Michaelson interferometer though, upon return, a tilt is introduced to the reference beam before it is combined with the sample beam to illuminate a detector array. The resulting fringe pattern encodes information about the relative time-of-flight of photons between the sample and reference arms, which can be decoded by standard signal processing techniques to obtain depth resolved reflectivity profiles of the sample. The axial resolution and the SNR of our system was measured to be approximately 5.2 μm and 80 dB, respectively. The performance of the proposed system was compared with a standard state-of-the-art Fourier-domain low coherence interferometry (LCI) system by imaging several biological and non-biological samples. The results of this study indicate that the proposed low-cost system might be a suitable choice for applications where the imaging depth and SNR can be traded for lower cost and simpler optical design. Two potentially useful applications of the proposed imaging system could be for imaging the human tympanic membrane (TM) for diagnosing middle ear pathologies, and to visualize the sub-surface features of materials for non-destructive evaluation and quality inspection.

  9. Limitations of Condensed Teaching Strategies to Develop Hand-Held Cardiac Ultrasonography Skills in Internal Medicine Residents.

    PubMed

    Wilkinson, Jeffrey S; Barake, Walid; Smith, Chris; Thakrar, Amar; Johri, Amer M

    2016-08-01

    Advances in ultrasonographic technology have allowed for hand-held cardiac ultrasonography (HHCU) units that fit into a physician's laboratory coat. Recently, studies to educate internal medicine residents have shown promise. The optimal duration and methodology for teaching HHCU skills has not been established. Over a 1-year period, internal medicine residents were recruited during their cardiology ward rotation into a single-centre nonblinded randomized trial. The 2 condensed teaching strategies were (1) a conventional ward-based program and (2) a technology-driven simulation-based strategy. Outcomes were evaluated by (1) an objective structured clinical examination (OSCE) to evaluate interpretation ability (assessing both type I and type II error rates) and (2) demonstration of HHCU skills graded by 2 level III echocardiographers. Twenty-four internal medicine residents were randomized. After teaching, the conventional teaching group had a significant absolute increase in the ability to make a singular correct diagnosis (20%; P < 0.001). In the technology arm, making a singular correct diagnosis increased 24% from baseline (P = 0.001). Interpretation skill was not significantly different between groups. The false-positive rate increased by an absolute 14% and 17% in the conventional and technology groups, respectively (P = 0.079 and P = 0.008). Our findings suggest that HHCU interpretation skills improve after either a conventional ward-based or a technology-driven approach. However, our study emphasizes the important limitations of both teaching programs, because we detected a trend toward an increase in the false-positive rate after both approaches. This suggests that a short duration of training may not be sufficient for HHCU to be performed in a safe manner. PMID:26860772

  10. Visualisation of liver tumours using hand-held real-time strain imaging: results of animal experiments

    PubMed Central

    Melodelima, D; Chenot, J; Souchon, R; Rivoire, M; Chapelon, J-Y

    2012-01-01

    Objective Surgical resection is the only curative option for colorectal hepatic metastases. Intra-operative localisation of these metastases during hepatic resection is performed by intra-operative B-mode imaging and palpation. Because liver metastases are stiffer than normal tissues, elastography may be a useful complement to B-mode imaging. This paper reports quantitative measures of the image quality attained during intra-operative real-time elastographic visualisation of liver metastasis. Methods VX2 tumours were implanted in the liver of eight rabbits and were scanned in vivo. Measurements of the tumour dimensions obtained via elastography were compared with those obtained using B-mode imaging and with gross pathology. Results Measurements of tumour diameters were similar when obtained by intra-operative elastography and pathological measurement methods (mean difference±standard deviation, 0.1±0.9 mm). The contrast between tumours and normal tissues was significantly higher (p<0.05) in elastograms (26±10 dB contrast) than in sonograms (1±1 dB contrast). Sensitivity and specificity for detecting tumours using intra-operative elastography were 100% and 88%, respectively, and positive and negative predictive values were 89% and 100%, respectively. In two cases elastograms were able to detect a tumour that was ambiguous in B-mode images. Conclusion Combined hand-held B-mode/strain imaging may provide additional information that is relevant for detection of liver metastases that may be missed by standard B-mode imaging alone, such as small and/or isoechoic tumours. PMID:22253340

  11. Electrochemical detection of harmful algae and other microbial contaminants in coastal waters using hand-held biosensors.

    PubMed

    LaGier, Michael J; Fell, Jack W; Goodwin, Kelly D

    2007-06-01

    Standard methods to identify microbial contaminants in the environment are slow, laborious, and can require specialized expertise. This study investigated electrochemical detection of microbial contaminants using commercially available, hand-held instruments. Electrochemical assays were developed for a red tide dinoflagellate (Karenia brevis), fecal-indicating bacteria (Enterococcus spp.), markers indicative of human sources of fecal pollution (human cluster Bacteroides and the esp gene of Enterococcus faecium), bacterial pathogens (Escherichia coli 0157:H7, Salmonella spp., Campylobacter jejuni, Staphylococcus aureus), and a viral pathogen (adenovirus). For K. brevis, two assay formats (Rapid PCR-Detect and Hybrid PCR-Detect) were tested and both provided detection limits of 10 genome equivalents for DNA isolated from K. brevis culture and amplified by PCR. Sensitivity with coastal water samples was sufficient to detect K. brevis that was "present" (

  12. Short-term measurement of linear growth in preterm infants: validation of a hand-held knemometer.

    PubMed

    Michaelsen, K F; Skov, L; Badsberg, J H; Jørgensen, M

    1991-11-01

    A hand-held electronic knemometer, resembling a pair of callipers, for measuring knee-heel length in preterm infants was developed to improve the accuracy of measuring linear growth velocity in infants. The measuring system is based on a magnetic encoder and has a resolution of 0.01 mm. The knee-heel length is recorded automatically when the pressure applied on the heel reaches a preset value. The result of a measurement sequence is expressed as the average of five sequential readings. The error of one measurement sequence was 0.82 mm, corresponding to a coefficient of variation of 0.8% or 2 d of growth in knee-heel length. It includes the technical error and an error component due to the correlation of the readings within a series. The estimated error on the measurement of the knee-heel growth velocity (expressed as mm/d), measured over a 3-wk period, was 0.04 mm, corresponding to a coefficient of variation of 8%. Longitudinal growth data from 11 healthy preterm infants (birth weight 918-1482 g) are presented. Knee-heel length velocity from birth until day of regained birth weight was similar to the velocity during the following weeks, showing that there was no deceleration of growth immediately after birth. In conclusion, the method is accurate and gentle in measuring linear growth velocity over short periods and can be useful in monitoring the progress of ill infants and in growth studies of preterm and mature infants, in which linear growth is a more relevant short-term outcome than weight gain. PMID:1754302

  13. Respirable crystalline silica dust exposure during concrete finishing (grinding) using hand-held grinders in the construction industry.

    PubMed

    Akbar-Khanzadeh, Farhang; Brillhart, Randall L

    2002-04-01

    Studies reporting the findings of exposure to crystalline silica dust during concrete finishing in construction settings are scarce due to the dynamic nature of the activity and the existence of many confounding factors. This study was initiated to explore the issue. A total of 49 personal respirable dust samples were collected during concrete finishing while workers used hand-held grinders. Only 15 (31%) of the grinders were equipped with local exhaust ventilation (LEV) systems. The confounding factors (e.g. wind velocity, wind direction, relative humidity and ambient temperature) were determined. To make the sampling task-specific, air sampling was activated only during actual grinding. Task-specific sampling times during each work shift ranged from 10 to 200 min. The concentration of total respirable particulate ranged from 0.34 to 81 mg/m3, with a mean +/- SD of 18.6 +/- 20.4 mg/m3, and the concentration of crystalline silica in the samples ranged from 0.02 to 7.1 mg/m3, with a mean +/- SD of 1.16 +/- 1.36 mg/m3. LEV on the grinders reduced the silica dust level significantly (P < 0.01) compared to grinders without LEV. Increased wind velocity also reduced the silica dust concentration significantly (P < 0.03). Working upwind reduced the exposure to silica dust compared to working downwind, but the difference was not statistically significant. The time-weighted average concentration of silica dust in 69% of the samples exceeded the current recommended threshold limit value of 0.05 mg/m3, indicating a strong need to devise methods for controlling workers' exposure to crystalline silica dust during concrete finishing activities. PMID:12176721

  14. Validation of a hand-held X-ray absorptiometer caliper against computerized tomography for in vivo soft tissue composition analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objective: To develop and validate a hand-held caliper which uses a dual-energy radioactive source to monitor regional changes in mid-thigh muscle mass and % fat. Methods: Optimum photon energies were determined by minimization of uncertainties in fat content measurements due to photon count statist...

  15. Beyond Textbook Illustrations: Hand-Held Models of Ordered DNA and Protein Structures as 3D Supplements to Enhance Student Learning of Helical Biopolymers

    ERIC Educational Resources Information Center

    Jittivadhna, Karnyupha; Ruenwongsa, Pintip; Panijpan, Bhinyo

    2010-01-01

    Textbook illustrations of 3D biopolymers on printed paper, regardless of how detailed and colorful, suffer from its two-dimensionality. For beginners, computer screen display of skeletal models of biopolymers and their animation usually does not provide the at-a-glance 3D perception and details, which can be done by good hand-held models. Here, we…

  16. Intra-operative ultrasound hand-held strain imaging for the visualization of ablations produced in the liver with a toroidal HIFU transducer: first in vivo results

    PubMed Central

    Chenot, Jérémy; Melodelima, David; N'Djin, William Apoutou; Souchon, Rémi; Rivoire, Michel; Chapelon, Jean-Yves

    2010-01-01

    The use of hand-held ultrasound strain imaging for intra-operative real-time visualization of HIFU ablations produced in the liver by a toroidal transducer was investigated. A linear 12 MHz ultrasound imaging probe was used to obtain radiofrequency signals. Using a fast cross-correlation algorithm, strain images were calculated and displayed at 60 frames/s, allowing the use of hand-held strain imaging intra-operatively. Fourteen HIFU lesions were produced in 4 pigs. Intra-operative strain imaging of HIFU ablations in the liver was feasible owing to the high frame rate. The correlation between dimensions measured on gross pathology and dimensions measured on B-mode images and on strain images were R = 0.72 and R = 0.94 respectively. The contrast between ablated and non-ablated tissue was significantly higher (p<0.05) in the strain images (22 dB) than in the B-mode images (9 dB). Strain images allowed equivalent or improved definition of ablated regions when compared with B-mode images. Real-time intra-operative hand-held strain imaging seems to be a promising complement to conventional B-Mode imaging for the guidance of HIFU ablations produced in the liver during an open procedure. These results support that hand-held strain imaging outperforms conventional B-mode ultrasound and could potentially be used for assessment of thermal therapies. PMID:20479514

  17. Evaluating the Reliability of a Novel Neck-Strength Assessment Protocol for Healthy Adults Using Self-Generated Resistance with a Hand-Held Dynamometer

    PubMed Central

    Beaudet, Danielle; Greenbaum, Marla; Hellyer, Leah; Tritton, Amanda; Walton, Dave

    2015-01-01

    ABSTRACT Purpose: To evaluate the intra- and inter-session test–retest agreement of a novel neck-strength assessment protocol using a hand-held dynamometer. Background: A literature review found a lack of neck-strength assessment protocols that are both portable and reliable. Hand-held dynamometry is a portable and inexpensive method of assessing muscle strength, but it is not commonly used for neck-strength assessment. Methods: A hand-held dynamometer was used to evaluate neck strength in 30 healthy participants. The device measured maximum force in cervical flexion, extension, side flexion, side flexion with rotation, and pure rotation, using the ipsilateral hand to apply isometric resistance over 3 seconds. Three measurements were taken over 6–8 days. Results: Test–retest intra-class correlation coefficients (ICCs) showed high reliability, ranging from 0.94 to 0.97 for all tested directions from Trial 1 to Trial 2 (intra-session reliability, ICC [2,1], absolute). ICC values demonstrated good to high inter-session reliability, ranging from 0.87 to 0.95 for all tested directions from Trial 1 to Trial 3 (ICC [2,1], absolute). Conclusion: The results suggest that the five test positions of the neck and upper-quadrant strength assessment protocol can be performed using hand-held dynamometry with good to high reliability. PMID:25931654

  18. So the Kids Are Busy, What Now? Teacher Perceptions of the Use of Hand-Held Game Consoles in West Australian Primary Classrooms

    ERIC Educational Resources Information Center

    O'Rourke, John; Main, Susan; Ellis, Michelle

    2013-01-01

    Games technology in the form of hand-held game consoles (HGCs) when focussed on specific academic skill development has the capacity to engage students in learning and in turn produce positive academic results. This current research explores teacher perceptions of the implementation of HGCs to enhance the development of mental maths skills (namely…

  19. The Status of Hand Held Calculators in Secondary Mathematics: An Examination of Issues and Uses in the Classroom throughout the Mid-Hudson Valley Region.

    ERIC Educational Resources Information Center

    Ostapczuk, Edward D.

    In light of research findings on how calculators can enhance mathematics learning, this study investigated the uses of hand held, non-programmable, scientific calculators in secondary mathematics education throughout the Mid-Hudson Valley (New York). The study gathered data from 18 high school principals and 25 mathematics teachers in 32 school…

  20. Determination of soluble solids content and titratable acidity of intact fruit and juice of Satsuma mandarin using a hand-held NIR instrument in transmittance mode

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Determination of soluble solids content (SSC) and titratable acidity (TA) of intact fruit and juice of Satsuma mandarin was investigated using a hand-held NIR instrument “NIR-Gun” in transmittance mode. The resulting calibration equation measured SSC of intact fruit and juice with a standard error o...

  1. Field-calibration of a hand-held TDR for determining soil moisture in an irrigated and a rainfed biofuel feedstock production system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural soil emissions of temperature-forcing greenhouse gases such as carbon dioxide, methane, and nitrous oxide are tightly coupled to soil moisture status. To determine the suitability of a rapid measurement method for soil volumetric water content (VWC; m3 m-3), a hand-held time-domain ref...

  2. Inter-Tester Reliability and Precision of Manual Muscle Testing and Hand-Held Dynamometry in Lower Limb Muscles of Children with Spina Bifida

    ERIC Educational Resources Information Center

    Mahony, Kate; Hunt, Adrienne; Daley, Deborah; Sims, Susan; Adams, Roger

    2009-01-01

    Reliability and measurement precision of manual muscle testing (MMT) and hand-held dynamometry (HHD) were compared for children with spina bifida. Strength measures were obtained of the hip flexors, hip abductors, and knee extensors of 20 children (10 males, 10 females; mean age 9 years 10 months; range: 5 to 15 years) by two experienced physical…

  3. An Examination of Hand-Held Computer-Assisted Instruction on Subtraction Skills for Second Grade Students with Learning and Behavioral Disabilities

    ERIC Educational Resources Information Center

    Nordness, Philip D.; Haverkost, Ann; Volberding, Annette

    2011-01-01

    The effect of a mathematic flashcard application on a hand-held computing device was examined across three individual second grade students with learning and behavioral disabilities. All of the students improved their subtraction scores by an average of 17% as measured by the district-created, curriculum-based assessment. The results of this study…

  4. Maintaining radiation exposures as low as reasonably achievable (ALARA) for dental personnel operating portable hand-held x-ray equipment.

    PubMed

    McGiff, Thomas J; Danforth, Robert A; Herschaft, Edward E

    2012-08-01

    Clinical experience indicates that newly available portable hand-held x-ray units provide advantages compared to traditional fixed properly installed and operated x-ray units in dental radiography. However, concern that hand-held x-ray units produce higher operator doses than fixed x-ray units has caused regulatory agencies to mandate requirements for use of hand-held units that go beyond those recommended by the manufacturer and can discourage the use of this technology. To assess the need for additional requirements, a hand-held x-ray unit and a pair of manikins were used to measure the dose to a simulated operator under two conditions: exposures made according to the manufacturer's recommendations and exposures made according to manufacturer's recommendation except for the removal of the x-ray unit's protective backscatter shield. Dose to the simulated operator was determined using an array of personal dosimeters and a pair of pressurized ion chambers. The results indicate that the dose to an operator of this equipment will be less than 0.6 mSv y⁻¹ if the device is used according to the manufacturer's recommendations. This suggests that doses to properly trained operators of well-designed, hand-held dental x-ray units will be below 1.0 mSv y⁻¹ (2% of the annual occupational dose limit) even if additional no additional operational requirements are established by regulatory agencies. This level of annual dose is similar to those reported as typical dental personnel using fixed x-ray units and appears to satisfy the ALARA principal for this class of occupational exposures. PMID:22739973

  5. Improving the accuracy of hand-held X-ray fluorescence spectrometers as a tool for monitoring brominated flame retardants in waste polymers.

    PubMed

    Guzzonato, A; Puype, F; Harrad, S J

    2016-09-01

    An optimised method for Br quantification as a metric of brominated flame retardant (BFR) concentrations present in Waste Electrical and Electronic Equipment (WEEE) polymers is proposed as an alternative to the sophisticated, yet time consuming GC-MS methods currently preferred. A hand-held X-ray fluorescence (XRF) spectrometer was validated with Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). Customized standard materials of specific BFRs in a styrenic polymer were used to perform an external calibration for hand-held XRF ranging from 0.08 to 12 wt% of Br, and cross-checking with LA-ICP-MS having similar LODs (0.0004 wt% for LA-ICP-MS and 0.0011 wt% for XRF). The "thickness calibration" developed here for hand-held XRF and the resulting correction, was applied to 28 real samples and showed excellent (R(2) = 0.9926) accordance with measurements obtained via LA-ICP-MS. This confirms the validity of hand-held XRF as an accurate technique for the determination of Br in WEEE plastics. This is the first use of solid standards to develop a thickness-corrected quantitative XRF measurement of Br in polymers using LA-ICP-MS for method evaluation. Thermal desorption gas chromatography mass spectrometry (TD-GC-MS) was used to confirm the presence of specific BFRs in WEEE polymer samples. We propose that expressing limit values for BFRs in waste materials in terms of Br rather than BFR concentration (based on a conservative assumption about the BFR present), presents a practical solution to the need for an accurate, yet rapid and inexpensive technique capable of monitoring compliance with limit values in situ. PMID:27281541

  6. Motion-compensated hand-held common-path Fourier-domain optical coherence tomography probe for image-guided intervention

    PubMed Central

    Huang, Yong; Liu, Xuan; Song, Cheol; Kang, Jin U.

    2012-01-01

    A motion-compensated, hand-held, common-path, Fourier-domain optical coherence tomography imaging probe has been developed for image-guided intervention during microsurgery. A hand-held prototype instrument was achieved by integrating an imaging fiber probe inside a stainless steel needle and attached to the ceramic shaft of a piezoelectric motor housed in an aluminum handle. The fiber probe obtains A-scan images. The distance information was extracted from the A-scans to track the sample surface distance and a fixed distance was maintained by a feedback motor control which effectively compensated hand tremor and target movements in the axial direction. Real-time data acquisition, processing, motion compensation, and image visualization and saving were implemented on a custom CPU-GPU hybrid architecture. We performed 10× zero padding to the raw spectrum to obtain 0.16 µm position accuracy with a compensation rate of 460 Hz. The root-mean-square error of hand-held distance variation from target position was measured to be 2.93 µm. We used a cross-correlation maximization-based shift correction algorithm for topology correction. To validate the system, we performed free-hand OCT M-scan imaging using various samples. PMID:23243562

  7. Efficacy and learning curve of a hand-held echocardiography device in an oncology outpatient clinic: Expanding the use of echoscopic heart examination beyond cardiology

    PubMed Central

    PéREZ DE ISLA, LEOPOLDO PÉREZ; MORENO, FERNANDO; GARCIA SAEZ, JOSE ANGEL GARCIA; CLAVERO, MATIAS; MORENO, NUNO; AGUADO DE LA ROSA, CARLOS AGUADO; DE AGUSTIN, JOSE ALBERTO; GOMEZ DE DIEGO, JOSE JUAN GOMEZ; COBOS, MIGUEL ANGEL; SALTIJERAL, ADRIANA; MACAYA, CARLOS; GARCIA-FERNANDEZ, MIGUEL ANGEL

    2015-01-01

    Certain chemotherapy drugs for breast cancer may induce cardiotoxicity and these patients should be echocardiographically monitored. The performance of a focused echocardiographic evaluation (echoscopy) at the patient's location by a non-cardiologist appears to be feasible. The aim of the present study was to assess the accuracy of echoscopy performed by medical oncologists in an outpatient clinic using hand-held echocardiography devices. The study cohort comprised consecutive unselected patients who attended an oncology outpatient clinic. Two medical oncologists attended a one-week training period, which included theoretical and practical teaching by an expert cardiologist. Every subject underwent two echo examinations. The first examination was performed by an oncologist using a hand-held echo device and the second was performed by a cardiologist using a ‘premium’ device. Out of the 101 enrolled patients, 32 were men (31.7%) and the mean age was 56.03±16.88 years. There was a good global agreement [intra-class correlation coefficient (ICC): 0.65 for left ventricular ejection fraction (LVEF)]. When the results were analyzed depending on the period of time when the echo studies were performed, a clear and short learning curve was observed: LVEF started at ICC=0.58 and increased to 0.66 and 0.77 in the second and third period, respectively. There were extremely few clinically significant differences and a learning curve was also evident. In conclusion, cardiac echoscopy performed by an oncologist with a hand-held device may lead to a similar clinical management as a study performed by an expert cardiologist with a ‘premium’ system in patients under chemotherapy following a short training period. PMID:26171188

  8. Portable computing for taking part of the lab to the sample types of applications. From hand held personal digital assistants to smart phones for mobile spectrometry

    NASA Astrophysics Data System (ADS)

    Weagant, Scott; Karanassios, Vassili

    2015-06-01

    The use of portable hand held computing devices for the acquisition of spectrochemical data is briefly discussed using examples from the author's laboratory. Several network topologies are evaluated. At present, one topology that involves a portable computing device for data acquisition and spectrometer control and that has wireless access to the internet at one end and communicates with a smart phone at the other end appears to be better suited for "taking part of the lab to the sample" types of applications. Thus, spectrometric data can be accessed from anywhere in the world.

  9. Development of a high-speed VCSEL OCT system for real-time imaging of conscious patients larynx using a hand-held probe (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Rangarajan, Swathi; Chou, Li-Dek; Coughlan, Carolyn; Sharma, Giriraj; Wong, Brian J. F.; Ramalingam, Tirunelveli S.

    2016-02-01

    Fourier domain optical coherence tomography (FD-OCT) is a noninvasive imaging modality that has previously been used to image the human larynx. However, differences in anatomical geometry and short imaging range of conventional OCT limits its application in a clinical setting. In order to address this issue, we have developed a gradient-index (GRIN) lens rod-based hand-held probe in conjunction with a long imaging range 200 kHz Vertical-Cavity Surface Emitting Lasers (VCSEL) swept-source optical coherence tomography (SS-OCT) system for high speed real-time imaging of the human larynx in an office setting. This hand-held probe is designed to have a long and dynamically tunable working distance to accommodate the differences in anatomical geometry of human test subjects. A nominal working distance (~6 cm) of the probe is selected to have a lateral resolution <100 um within a depth of focus of 6.4 mm, which covers more than half of the 12 mm imaging range of the VCSEL laser. The maximum lateral scanning range of the probe at 6 cm working distance is approximately 8.4 mm, and imaging an area of 8.5 mm by 8.5 mm is accomplished within a second. Using the above system, we will demonstrate real-time cross-sectional OCT imaging of larynx during phonation in vivo in human and ex-vivo in pig vocal folds.

  10. Into the Wild: Neuroergonomic Differentiation of Hand-Held and Augmented Reality Wearable Displays during Outdoor Navigation with Functional Near Infrared Spectroscopy

    PubMed Central

    McKendrick, Ryan; Parasuraman, Raja; Murtza, Rabia; Formwalt, Alice; Baccus, Wendy; Paczynski, Martin; Ayaz, Hasan

    2016-01-01

    Highly mobile computing devices promise to improve quality of life, productivity, and performance. Increased situation awareness and reduced mental workload are two potential means by which this can be accomplished. However, it is difficult to measure these concepts in the “wild”. We employed ultra-portable battery operated and wireless functional near infrared spectroscopy (fNIRS) to non-invasively measure hemodynamic changes in the brain’s Prefrontal cortex (PFC). Measurements were taken during navigation of a college campus with either a hand-held display, or an Augmented reality wearable display (ARWD). Hemodynamic measures were also paired with secondary tasks of visual perception and auditory working memory to provide behavioral assessment of situation awareness and mental workload. Navigating with an augmented reality wearable display produced the least workload during the auditory working memory task, and a trend for improved situation awareness in our measures of prefrontal hemodynamics. The hemodynamics associated with errors were also different between the two devices. Errors with an augmented reality wearable display were associated with increased prefrontal activity and the opposite was observed for the hand-held display. This suggests that the cognitive mechanisms underlying errors between the two devices differ. These findings show fNIRS is a valuable tool for assessing new technology in ecologically valid settings and that ARWDs offer benefits with regards to mental workload while navigating, and potentially superior situation awareness with improved display design. PMID:27242480

  11. Into the Wild: Neuroergonomic Differentiation of Hand-Held and Augmented Reality Wearable Displays during Outdoor Navigation with Functional Near Infrared Spectroscopy.

    PubMed

    McKendrick, Ryan; Parasuraman, Raja; Murtza, Rabia; Formwalt, Alice; Baccus, Wendy; Paczynski, Martin; Ayaz, Hasan

    2016-01-01

    Highly mobile computing devices promise to improve quality of life, productivity, and performance. Increased situation awareness and reduced mental workload are two potential means by which this can be accomplished. However, it is difficult to measure these concepts in the "wild". We employed ultra-portable battery operated and wireless functional near infrared spectroscopy (fNIRS) to non-invasively measure hemodynamic changes in the brain's Prefrontal cortex (PFC). Measurements were taken during navigation of a college campus with either a hand-held display, or an Augmented reality wearable display (ARWD). Hemodynamic measures were also paired with secondary tasks of visual perception and auditory working memory to provide behavioral assessment of situation awareness and mental workload. Navigating with an augmented reality wearable display produced the least workload during the auditory working memory task, and a trend for improved situation awareness in our measures of prefrontal hemodynamics. The hemodynamics associated with errors were also different between the two devices. Errors with an augmented reality wearable display were associated with increased prefrontal activity and the opposite was observed for the hand-held display. This suggests that the cognitive mechanisms underlying errors between the two devices differ. These findings show fNIRS is a valuable tool for assessing new technology in ecologically valid settings and that ARWDs offer benefits with regards to mental workload while navigating, and potentially superior situation awareness with improved display design. PMID:27242480

  12. Hand-Held High-Resolution Fluorescence Imaging System for Fluorescence-Guided Surgery of Patient and Cell-Line Pancreatic Tumors Growing Orthotopically in Nude Mice

    PubMed Central

    Hiroshima, Yukihiko; Maawy, Ali; Sato, Sho; Murakami, Takashi; Uehara, Fuminari; Miwa, Shinji; Yano, Shuya; Momiyama, Masashi; Chishima, Takashi; Tanaka, Kuniya; Bouvet, Michael; Endo, Itaru; Hoffman, Robert M.

    2014-01-01

    Background In this study, we investigated the advantages for fluorescence-guided surgery (FGS) in mice of a portable hand-sized imaging system compared to a large chamber fluorescing imaging system or a long-working-distance fluorescence microscope. Methods Mouse models of human pancreatic cancer for FGS included (1) MiaPaCa-2-expressing green fluorescent protein (GFP), (2) BxPC3 labeled with anti-CEA antibody conjugated with Alexa 488, (3) patient-derived orhotopic xenograft (PDOX)™ labeled with anti-CA19-9 antibody conjugated with Alexa 488. Results Each device could clearly detect the primary MiaPaCa-2-GFP. tumor and any residual tumor after FGS. In the BxPC3 model labeled with Alexa 488-conjugated anti-CEA, each device could detect the primary tumor, but the MVX10 could not clearly detect the residual tumor remaining after FGS while the other devices could. In the PDOX™ model labeled with Alexa 488 conjugated with anti CA19-9, only the portable hand-held device could distinguish the residual tumor from the background, and complete resection of the residual tumor was achieved under fluorescence navigation. Conclusions The results described in the present report suggest the hand-held mobile imaging system can be able to be applied to the clinic for FGS due to its convenient size and high sensitivity and help make FGS widely-used. PMID:24373959

  13. Hand-held Raman sensor head for in-situ characterization of meat quality applying a microsystem 671 nm diode laser

    NASA Astrophysics Data System (ADS)

    Schmidt, Heinar; Sowoidnich, Kay; Maiwald, Martin; Sumpf, Bernd; Kronfeldt, Heinz-Detlef

    2009-05-01

    A hand-held Raman sensor head was developed for the in-situ characterization of meat quality. As light source, a microsystem based external cavity diode laser module (ECDL) emitting at 671 nm was integrated in the sensor head and attached to a miniaturized optical bench which contains lens optics for excitation and signal collection as well as a Raman filter stage for Rayleigh rejection. The signal is transported with an optical fiber to the detection unit which was in the initial phase a laboratory spectrometer with CCD detector. All elements of the ECDL are aligned on a micro optical bench with 13 x 4 mm2 footprint. The wavelength stability is provided by a reflection Bragg grating and the laser has an optical power of up to 200 mW. However, for the Raman measurements of meat only 35 mW are needed to obtain Raman spectra within 1 - 5 seconds. Short measuring times are essential for the hand-held device. The laser and the sensor head are characterized in terms of stability and performance for in-situ Raman investigations. The function is demonstrated in a series of measurements with raw and packaged pork meat as samples. The suitability of the Raman sensor head for the quality control of meat and other products will be discussed.

  14. Thresholds of whole-blood β-hydroxybutyrate and glucose concentrations measured with an electronic hand-held device to identify ovine hyperketonemia.

    PubMed

    Pichler, M; Damberger, A; Schwendenwein, I; Gasteiner, J; Drillich, M; Iwersen, M

    2014-03-01

    Metabolic disorders, especially hyperketonemia, are very common in dairy sheep. The whole-blood concentrations of β-hydroxybutyrate (BHBA) and glucose can be determined by commercially available electronic hand-held devices, which are used in human medicine and for the detection of ketosis in dairy cows. The aim of this study was to evaluate the suitability of the hand-held device Precision Xceed (PX; Abbott Diabetes Care Inc., Abbott Park, IL) to detect hyperketonemia in ewes. An additional objective of this study was to evaluate the agreement between samples obtained by minimal invasive venipuncture of an ear vein and measurements of whole-blood samples from the jugular vein (vena jugularis, v. jug.). Blood samples taken from the v. jug. were collected from 358 ewes on 4 different farms. These samples and a blood drop obtained from an ear vein were analyzed simultaneously on farm with the PX. For method comparison, the samples obtained from the v. jug. were also analyzed by standard methods, which served as the gold standard at the Central Laboratory of the University of Veterinary Medicine Vienna, Austria. The correlation coefficients between the serum BHBA concentration and the concentrations measured with the hand-held meter in the whole blood from an ear vein and the v. jug. were 0.94 and 0.96, respectively. The correlation coefficients of plasma and whole-blood glucose concentration were 0.68 for the v. jug. and 0.47 for the ear vein. The mean glucose concentration was significantly lower in animals classified as hyperketonemic (BHBA ≥ 1.6 mmol/L) compared with healthy ewes. Whole-blood concentrations of BHBA and glucose measured with the PX from v. jug. showed a constant negative bias of 0.15 mmol/L and 8.4 mg/dL, respectively. Hence, a receiver operating characteristic analysis was performed to determine thresholds for the PX to detect hyperketonemia in ewes. This resulted in thresholds for moderate ketosis of BHBA concentrations of 0.7 mmol/L in blood

  15. A non-resonant, frequency up-converted electromagnetic energy harvester from human-body-induced vibration for hand-held smart system applications

    NASA Astrophysics Data System (ADS)

    Halim, Miah A.; Park, Jae Y.

    2014-03-01

    We present a non-resonant, frequency up-converted electromagnetic energy harvester that generates significant power from human-body-induced vibration, e.g., hand-shaking. Upon excitation, a freely movable non-magnetic ball within a cylinder periodically hits two magnets suspended on two helical compression springs located at either ends of the cylinder, allowing those to vibrate with higher frequencies. The device parameters have been designed based on the characteristics of human hand-shaking vibration. A prototype has been developed and tested both by vibration exciter (for non-resonance test) and by manual hand-shaking. The fabricated device generated 110 μW average power with 15.4 μW cm-3 average power density, while the energy harvester was mounted on a smart phone and was hand-shaken, indicating its ability in powering portable hand-held smart devices from low frequency (<5 Hz) vibrations.

  16. Suitability of capillary blood obtained by a minimally invasive lancet technique to detect subclinical ketosis in dairy cows by using 3 different electronic hand-held devices.

    PubMed

    Kanz, P; Drillich, M; Klein-Jöbstl, D; Mair, B; Borchardt, S; Meyer, L; Schwendenwein, I; Iwersen, M

    2015-09-01

    The objective of this study was to evaluate the suitability of capillary blood obtained by a minimally invasive lancet technique to detect subclinical ketosis in 49 prepartum and 191 postpartum Holstein-Friesian cows using 3 different electronic hand-held devices [FreeStyle Precision (FSP, Abbott), GlucoMen LX Plus (GLX, A. Menarini), NovaVet (NOV, Nova Biomedical)]. The β-hydroxybutyrate (BHBA) concentration in serum harvested from coccygeal blood samples was analyzed in a laboratory and used as a reference value. Capillary samples were obtained from the skin of the exterior vulva by using 1 of 3 different lancets. In all samples, the concentration of BHBA was immediately analyzed with all 3 hand-held devices used in random order. All lancets used in the study were eligible for capillary blood collection but differed in the total number of incisions needed. Spearman correlation coefficients between the BHBA concentrations in capillary blood and the reference test were highly significant with 83% for the FSP, 73% for the NOV, and 63% for the GLX. Using capillary blood, the FSP overestimated the mean BHBA concentration compared with the reference test (+0.08 mmol/L), whereas the GLX and NOV underestimated the mean concentration (-0.07 and -0.01 mmol/L). When a BHBA concentration of 1.2 mmol/L in serum was used to define subclinical ketosis, the corresponding analyses of receiver operating characteristics resulted in optimized thresholds for capillary blood of 1.1 mmol/L for the NOV and GLX devices, and of 1.0 mmol/L for the FSP. Based on these thresholds, sensitivities (Se) and specificities (Sp) were 89 and 84% for the NOV, 80 and 89% for the GLX, and 100 and 76% for the FSP. Based on a serum BHBA concentration of 1.4 mmol/L, analyses of receiver operating characteristics resulted in optimized cut-offs of 1.4 mmol/L for the FSP (Se 100%, Sp 92%), 1.3 mmol/L for the NOV (Se 80%, Sp 95%), and 1.1 mmol/L (Se 90%, Sp 85%) for the GLX. Using these optimized thresholds

  17. A common-path optical coherence tomography distance-sensor based surface tracking and motion compensation hand-held microsurgical tool

    NASA Astrophysics Data System (ADS)

    Zhang, Kang; Gehlbach, Peter; Kang, Jin U.

    2011-03-01

    Microsurgery requires constant attention to the involuntary motion due to physiological tremors. In this work, we demonstrated a simple and compact hand-held microsurgical tool capable of surface tracking and motion compensation based on common-path optical coherence tomography (CP-OCT) distance-sensor to improve the accuracy and safety of microsurgery. This tool is miniaturized into a 15mm-diameter plastic syringe and capable of surface tracking at less than 5 micrometer resolution. A phantom made with Intralipid layers is used to simulate a real tissue surface and a single-fiber integrated micro-dissector works as a surgical tip to perform tracking and accurate incision on the phantom surface. The micro-incision depth is evaluated after each operation through a fast 3D scanning by the Fourier domain OCT system. The results using the surface tracking and motion compensation tool show significant improvement compared to the results by free-hand.

  18. Beyond textbook illustrations: Hand-held models of ordered DNA and protein structures as 3D supplements to enhance student learning of helical biopolymers.

    PubMed

    Jittivadhna, Karnyupha; Ruenwongsa, Pintip; Panijpan, Bhinyo

    2010-11-01

    Textbook illustrations of 3D biopolymers on printed paper, regardless of how detailed and colorful, suffer from its two-dimensionality. For beginners, computer screen display of skeletal models of biopolymers and their animation usually does not provide the at-a-glance 3D perception and details, which can be done by good hand-held models. Here, we report a study on how our students learned more from using our ordered DNA and protein models assembled from colored computer-printouts on transparency film sheets that have useful structural details. Our models (reported in BAMBED 2009), having certain distinguished features, helped our students to grasp various aspects of these biopolymers that they usually find difficult. Quantitative and qualitative learning data from this study are reported. PMID:21567863

  19. Development of a Minimum Performance Standard for Hand-Held Fire Extinguishers as a Replacement for Halon 1211 on Civilian Transport Category Aircraft

    NASA Astrophysics Data System (ADS)

    Webster, Harry

    2002-08-01

    One or more Halon 1211 hand-held fire extinguishers are specified in Federal Aviation Regulation (FAR) Part 25.851 as a requirement on transport category aircraft with 31 or more seats. Halon 1211 has been linked to the destruction of the ozone layer and production of new Halon 1211 has been halted per the Montreal Protocol in 1993. The phase out of Halon 1211, as the hand-held firefighting agent of choice, for civilian transport category aircraft has necessitated the development of a Minimum Performance Standard (MPS) to evaluate replacement agents. The purpose of the MPS is to insure that there is no reduction in safety, both in terms of effectiveness in fighting onboard fires and toxicity to the passengers and crew. The MPS specifies two new tests that replacement agents must pass in addition to requiring national certifications such as provided by Underwriters Laboratories. The first test evaluates the "flooding" characteristics of the agent against a hidden in-flight fire. This test determines the ability of a streaming agent to function as a flooding agent. The second test evaluates the performance of the agent in fighting a terrorist fire scenario and the associated toxicity hazard. This test measures the agent's ability to extinguish a triple-seat fire in an aircraft cabin under in-flight conditions and the toxicity characteristics of both the neat agent and the products of decomposition. This MPS will insure that the replacement agents will meet or exceed the performance of Halon 1211 both in fighting fires and maintaining a safe breathing environment in aircraft cabins.

  20. Hand-held UXO Discriminator

    SciTech Connect

    Gasperikova, E.; Smith, J.T.; Kappler, K.N.; Ratti, A.; Morrison, H.F.; Becker, A.

    2010-04-01

    With prior funding (UX-1225, MM-0437, and MM-0838), we have successfully designed and built a cart-mounted Berkeley UXO Discriminator (BUD) and demonstrated its performance at various test sites (e.g., Gasperikova et al., 2007, 2009). It is a multi-transmitter multi-receiver active electromagnetic system that is able to discriminate UXO from scrap at a single measurement position, hence eliminates equirement of a very accurate sensor location. The cart-mounted system comprises of three orthogonal transmitters and eight pairs of differenced receivers (Smith et al., 2007). Receiver coils are located on ymmetry lines through the center of the system and see identical fields during the on-time of the pulse in all of the transmitter coils. They can then be wired in opposition to produce zero output during the n-ime of the pulses in three orthogonal transmitters. Moreover, this configuration dramatically reduces noise in the measurements by canceling the background electromagnetic fields (these fields are uniform ver the scale of the receiver array and are consequently nulled by the differencing operation), and by canceling the noise contributed by the tilt of the receivers in the Earth's magnetic field, and therefore reatly enhances receivers sensitivity to the gradients of the target.

  1. Hand-Held Power Clamp

    NASA Technical Reports Server (NTRS)

    Clancy, J. P.

    1985-01-01

    Tool furnishes large pushing or pulling forces. Device includes two clamping blocks, two clamping plates, and a motor-driven linear actuator with selflocking screw shaft. Power clamp exerts opening or closing force at push of switch. Tool approximately 1 m long. Originally designed to secure payload aboard Space Shuttle, operated with one hand to apply opening or closing force of up to 1,000 lb (4,400 N). Clamp has potential applications as end effector for industrial robots and in rescue work to push or pull wreckage with great force.

  2. Hand-held survey probe

    DOEpatents

    Young, Kevin L [Idaho Falls, ID; Hungate, Kevin E [Idaho Falls, ID

    2010-02-23

    A system for providing operational feedback to a user of a detection probe may include an optical sensor to generate data corresponding to a position of the detection probe with respect to a surface; a microprocessor to receive the data; a software medium having code to process the data with the microprocessor and pre-programmed parameters, and making a comparison of the data to the parameters; and an indicator device to indicate results of the comparison. A method of providing operational feedback to a user of a detection probe may include generating output data with an optical sensor corresponding to the relative position with respect to a surface; processing the output data, including comparing the output data to pre-programmed parameters; and indicating results of the comparison.

  3. A new integrated approach for characterizing the soil electromagnetic properties and detecting landmines using a hand-held vector network analyzer

    NASA Astrophysics Data System (ADS)

    Lopera, Olga; Lambot, Sebastien; Slob, Evert; Vanclooster, Marnik; Macq, Benoit; Milisavljevic, Nada

    2006-05-01

    The application of ground-penetrating radar (GPR) in humanitarian demining labors presents two major challenges: (1) the development of affordable and practical systems to detect metallic and non-metallic antipersonnel (AP) landmines under different conditions, and (2) the development of accurate soil characterization techniques to evaluate soil properties effects and determine the performance of these GPR-based systems. In this paper, we present a new integrated approach for characterizing electromagnetic (EM) properties of mine-affected soils and detecting landmines using a low cost hand-held vector network analyzer (VNA) connected to a highly directive antenna. Soil characterization is carried out using the radar-antenna-subsurface model of Lambot et al.1 and full-wave inversion of the radar signal focused in the time domain on the surface reflection. This methodology is integrated to background subtraction (BS) and migration to enhance landmine detection. Numerical and laboratory experiments are performed to show the effect of the soil EM properties on the detectability of the landmines and how the proposed approach can ameliorate the GPR performance.

  4. The use of hand-held 35 mm color infrared imagery for estimates of suspended solids - A progress report. [in water pollution monitoring

    NASA Technical Reports Server (NTRS)

    Miller, W. F.; Whisler, F. D.; Robinette, H. R.; Finnie, D.; Cannon, T.

    1975-01-01

    A cost-effective aerial surveillance technique is proposed for detection and identification of suspended solids which would be operational for both governmental monitoring organizations and private individuals operating catfish farms. Sixteen catfish ponds were flown daily for seven days using two hand-held 35 mm cameras with both Kodachrome X and Ektachrome infrared film. Hue, value, and chroma designations were recorded for each pond on each date by three interpreters, and the accepted color was that recorded by at least two of the interpreters, or if there was a three hue range, the median was accepted. Relations between suspended solids and color designations were analyzed graphically, and chroma was discarded due to an apparent lack of correlation. The data obtained were then analyzed by multiple regression. Significant correlations were revealed between hue and value and total and inorganic suspended solids. If perfected, this technique could be developed to sufficent accuracy for large-scale reconnaissance surveys to monitor the quality of rivers and streams.

  5. An Approach to Precise Nitrogen Management Using Hand-Held Crop Sensor Measurements and Winter Wheat Yield Mapping in a Mediterranean Environment

    PubMed Central

    Quebrajo, Lucía; Pérez-Ruiz, Manuel; Rodriguez-Lizana, Antonio; Agüera, Juan

    2015-01-01

    Regardless of the crop production system, nutrients inputs must be controlled at or below a certain economic threshold to achieve an acceptable level of profitability. The use of management zones and variable-rate fertilizer applications is gaining popularity in precision agriculture. Many researchers have evaluated the application of final yield maps and geo-referenced geophysical measurements (e.g., apparent soil electrical conductivity-ECa) as a method of establishing relatively homogeneous management zones within the same plot. Yield estimation models based on crop conditions at certain growth stages, soil nutrient statuses, agronomic factors, moisture statuses, and weed/pest pressures are a primary goal in precision agriculture. This study attempted to achieve the following objectives: (1) to investigate the potential for predicting winter wheat yields using vegetation measurements (the Normalized Difference Vegetation Index—NDVI) at the beginning of the season, thereby allowing for a yield response to nitrogen (N) fertilizer; and (2) evaluate the feasibility of using inexpensive optical sensor measurements in a Mediterranean environment. A field experiment was conducted in two commercial wheat fields near Seville, in southwestern Spain. Yield data were collected at harvest using a yield monitoring system (RDS Ceres II-volumetric meter) installed on a combine. Wheat yield and NDVI values of 3498 ± 481 kg ha−1 and 0.67 ± 0.04 nm nm−1 (field 1) and 3221 ± 531 kg ha−1 and 0.68 ± 0.05 nm nm−1 (field 2) were obtained. In both fields, the yield and NDVI exhibited a strong Pearson correlation, with rxy = 0.64 and p < 10−4 in field 1 and rxy = 0.78 and p < 10−4 in field 2. The preliminary results indicate that hand-held crop sensor-based N management can be applied to wheat production in Spain and has the potential to increase agronomic N-use efficiency on a long-term basis. PMID:25756861

  6. VALIDATION OF ANSI N42.34 AMERICAN NATIONAL STANDARD PERFORMANCE CRITERIA FOR HAND-HELD INSTRUMENTS FOR THE DETECTION AND IDENTIFICATION OF RADIONUCLIDES

    SciTech Connect

    Lorier, T.

    2014-09-03

    SRNL’s validation of ANSI N42.34-D6 for the Domestic Nuclear Detection Office (DNDO) was performed utilizing one hand-held instrument (or RID) – the FLIR identiFINDER 2. Each section of the standard was evaluated via a walk-through or test. NOTE: In Table 1, W = walk-through and T = test, as directed by the Domestic Nuclear Detection Office (DNDO). For a walk-through, the experiment was either setup or reviewed for setup; for a test, the N42.34-D6 procedures were followed with some exceptions and comments noted. SRNL is not fully able to evaluate a RID against Sections 7 (Environmental), 8 (Electromagnetic), and 9 (Mechanical) of N42.34, so those portions of this validation were done in collaboration with Qualtest, Inc. in Orlando, Florida. The walk-throughs and tests of Sections 7, 8, and 9 were performed in Qualtest, Inc. facilities with SRNL providing radiological sources as necessary. Where applicable, assessment results and findings of the walk-throughs and tests were recorded on datasheets and a validation summary is provided. A general comment pertained to test requirements found in another standard and referenced in N42.34-D6. For example, step 1 of the test method in section 8.1.2 states “RF test set up information can be found in IEC 61000-4-3.” It is recommended that any information from other standards necessary for conducting the tests within N42.34 should be posted in N42.34 for simplicity and to prevent the user from having to peruse other documents. Another general comment, as noted by Qualtest, is that a tolerance reference is not listed for each test in sections 7-9. Overall, the N42.34-D6 was proven to be practicable, but areas for improvement and recommendations were identified for consideration prior to final ballot submittal.

  7. Hand-held echocardiography in the setting of pre-operative cardiac evaluation of patients undergoing non-cardiac surgery: results from a randomized pilot study.

    PubMed

    Cavallari, Ilaria; Mega, Simona; Goffredo, Costanza; Patti, Giuseppe; Chello, Massimo; Di Sciascio, Germano

    2015-06-01

    Transthoracic echocardiography is not a routine test in the pre-operative cardiac evaluation of patients undergoing non-cardiac surgery but may be considered in those with known heart failure and valvular heart disease or complaining cardiac symptoms. In this setting, hand-held echocardiography (HHE) could find a potential application as an alternative to standard echocardiography in selected patients; however, its utility in this context has not been investigated. The aim of this pilot study was to evaluate the conclusiveness of HHE compared to standard echocardiography in this subset of patients. 100 patients scheduled for non-cardiac surgery were randomized to receive a standard exam with a Philips Ie33 or a bedside evaluation with a pocket-size imaging device (Opti-Go, Philips Medical System). The primary endpoint was the percentage of satisfactory diagnosis at the end of the examination referred as conclusiveness. Secondary endpoints were the mean duration time and the mean waiting time to perform the exams. No significant difference in terms of conclusiveness between HHE and standard echo was found (86 vs 96%; P = 0.08). Mean duration time of the examinations was 6.1 ± 1.2 min with HHE and 13.1 ± 2.6 min with standard echocardiography (P < 0.001). HHE resulted in a consistent save of waiting time because it was performed the same day of clinical evaluation whereas patients waited 10.1 ± 6.1 days for a standard echocardiography (P < 0.001). This study suggests the potential role of HHE for pre-operative evaluation of selected patients undergoing non-cardiac surgery, since it provided similar information but it was faster and earlier performed compared to standard echocardiography. PMID:25985940

  8. A feasibility study to develop a diabetes prevention program for young adults with prediabetes using digital platforms and a hand held device

    PubMed Central

    Cha, EunSeok; Kim, Kevin H.; Umpierrez, Guillermo; Dawkins, Colleen R.; Bello, Morenike K.; Lerner, Hannah; Narayan, K.M. Venkat; Dunbar, Sandra B.

    2014-01-01

    Purpose The purpose of the pilot study was to examine the feasibility and preliminary efficacy of an age-specific diabetes prevention program in young adults with prediabetes. Methods One group pretest-posttest design was conducted. The inclusion criteria were young adults age 18–29 years with prediabetes [either Impaird fasting glucose [IFG] (100–125 mg/dL), or an A1C of 5.7%–6.4%]. Fifteen participants were enrolled in this study. A technology based lifestyle coaching program focused on diet and physical activity and incorporating a hand-held device and digital platforms was developed and tested. Psychosocial factors (health literacy, illness perception, self-efficacy, therapeutic efficacy) based on social cognitive theory, changes in diet and physical activity, and cardiometabolic risk factors were assessed at baseline and week 12 after intervention. A paired-samples t-test was performed to examine changes between baseline and post-intervention on each psychosocial and physical variable. Results Participants (n= 13 completers) were mean age 24.4 yrs [SD: 2.2], 23.1% male, and 53.8% were African American. Overall, the participants were satisfied with the intervention (M = 4.15 on a 5-point Likert scale). Between pre and post testing, BMI and A1C decreased from 41.0 ±7.3 to 40.1±7.0 and 6.0% ± .5 to 5.6% ± .5, respectively, while fasting glucose did not significantly change (92.6±11 mg/dl to 97.6 ±14.3 mg/dl). Conclusion The intervention resulted in reduced A1C and a trend for decreased BMI in obese sedentary young adults with prediabetes after 12 weeks of intervention. Further study through a randomized clinical trial with a longer intervention period is warranted. PMID:24950683

  9. Performance status of a small robot-mounted or hand-held, solar-blind, standoff chemical, biological, and explosives (CBE) sensor

    NASA Astrophysics Data System (ADS)

    Hug, W. F.; Reid, R. D.; Bhartia, R.; Lane, A. L.

    2009-05-01

    Photon Systems and JPL are continuing development of a new technology robot-mounted or hand-held sensor for reagentless, short-range, standoff detection and identification of trace levels CBE materials on surfaces. This deep ultraviolet CBE sensor is the result of ongoing Army STTR and DTRA programs. The evolving 6 lb, 15W, lantern-size sensor can discriminate CBE from background clutter materials using a combination of deep UV excited resonance Raman (RR) and laser induced native fluorescence (LINF) emissions resulting from excitation by a new technology deep UV laser. Standoff excitation of suspicious packages, vehicles, persons, and other objects that may contain hazardous materials is accomplished using wavelengths below 250nm where RR and LINF emissions occupy distinctly different wavelength regions. This enables simultaneous detection of RR and LINF emissions with no spectral overlap or interference of LINF over RR or RR over LINF. The new eye-safe targeted ultraviolet chemical, biological, and explosives (TUCBE) sensor can detect and identify less than 1 μg/cm2 of explosives or 104 bacterial spores at 10 meters standoff, or 10 ng/cm2 of explosives or 102 bacterial spores/cm2 at 1 meter standoff. Detection and identification requires less than 1 ms and has a sample rate up to 20 Hz. Lower concentrations of contamination can be detected and identified as closer ranges and higher concentrations at longer ranges. The sensor is solar blind and can be operated in full daylight conditions as a result of excitation and detection in the deep UV and the use of a gated detection system.

  10. Specific absorption rate levels measured in a phantom head exposed to radio frequency transmissions from analog hand-held mobile phones

    SciTech Connect

    Anderson, V.; Joyner, K.H.

    1995-05-01

    Electric fields (E-fields) induced within a phantom head from exposure to three different advanced mobile phone system (AMPS) hand-held telephones were measured using an implantable E-Field probe. Measurements were taken in the eye nearest the phone and along a lateral scan through the brain from its center to the side nearest the phone. During measurement, the phones were positioned alongside the phantom head as in typical use and were configured to transmit at maximum power (600 mW nominal). The specific absorption rate (SAR) was calculated from the in situ E-field measurements, which varied significantly between phone models and antenna configuration. The SARs induced in the eye ranged from 0.007 to 0.21 W/kg. Metal-framed spectacles enhanced SAR levels in the eye by 9--29%. In the brain, maximum levels were recorded at the measurement point closest to the phone and ranged from 0.12 to 0.83 W/kg. These SARs are below peak spatial limits recommended in the US and Australian national standards and the IRPA guidelines for safe exposure to radio frequency (RF) electromagnetic fields. Furthermore, a detailed thermal analysis of the eye indicated only a 0.022 C maximum steady-state temperature rise in the eye from a uniform SAR loading of 0.21 W/kg. A more approximate thermal analysis in the brain also indicated only a small maximum temperature rise of 0.034 C for a local SAR loading of 0.83 W/kg.

  11. Interpretation of laboratory tests using a programmable hand-held calculator: calculation of posterior probability and relative risk on the basis of prior probability and sensitivity, specificity and result of the test.

    PubMed

    van de Merwe, J P

    1984-01-01

    A program is presented for the Hewlett-Packard HP- 41C programmable hand-held calculator that calculates the posterior probability and relative risk of an event (e.g. a disease) on the basis of prior probability (prevalence) and sensitivity, specificity and result of the test. PMID:6370577

  12. Point-of-care screening for left ventricular hypertrophy and concentric geometry using hand-held cardiac ultrasound in hypertensive patients

    PubMed Central

    Stoica, Roxana; Heller, Eliot N; Bella, Jonathan N

    2011-01-01

    Background: The introduction of the hand-held cardiac ultrasound (HCU) may potentially increase detection of LV hypertrophy in hypertensive patients. However, whether point-of-care screening for LV hypertrophy and concentric LV geometry by HCU in hypertensive patients is feasible and comparable to that of standard state-of-the-art echocardiography (SE) evaluation remains to be elucidated. Methods and Results: Accordingly, one hundred consecutive patients (66 female, mean age=58±13 years, 32% African-American, mean body mass index=31±8 kg/m2) with the diagnosis of hypertension underwent both HCU and SE examinations in tandem. A cardiology fellow-in-training performed the HCU exam while a cardiac sonographer performed the SE. 37% of hypertensive patients had electrocardiographic LV hypertrophy by Sokolow-Lyon or Cornell voltage criteria. Mean LV mass was 210±42 g with the HCU and 209±40 g with SE. Mean relative wall thickness was 0.45±0.05 by the HCUD and 0.44±0.05 by SE. There was excellent correlation between LV mass and relative wall thickness measurements by HCU and SE (r=0.985, SEE=6.8 g and r=0.762, SEE=0.33, respectively, both p<0.001). The prevalence of LV hypertrophy using prognostically-validated partition values for LV mass/height2.7 of 46.7 and 49.2 g/m2.7 in women and men, respectively was 76% by HCU and 78% by SE (p=NS), with excellent agreement (92%, κ=0.774, p<0.001). Agreement for detection of concentric LV geometry (relative wall thickness>0.43) was also excellent (88%, κ =0.756, p<0.001). Agreement for LV hypertrophy and concentric geometry detection between the cardiology fellow-in-training and sonographer was excellent (κ =0.786, p<0.001). Conclusion: Point-of-care screening for LV hypertrophy and concentric LV geometry by HCU is feasible and correlates very well with that of SE. HCU may allow for immediate point-of-care assessment and treatment of cardiac target organ damage in hypertensive patients. PMID:22254192

  13. An approach to precise nitrogen management using hand-held crop sensor measurements and winter wheat yield mapping in a Mediterranean environment.

    PubMed

    Quebrajo, Lucía; Pérez-Ruiz, Manuel; Rodriguez-Lizana, Antonio; Agüera, Juan

    2015-01-01

    Regardless of the crop production system, nutrients inputs must be controlled at or below a certain economic threshold to achieve an acceptable level of profitability. The use of management zones and variable-rate fertilizer applications is gaining popularity in precision agriculture. Many researchers have evaluated the application of final yield maps and geo-referenced geophysical measurements (e.g., apparent soil electrical conductivity-ECa) as a method of establishing relatively homogeneous management zones within the same plot. Yield estimation models based on crop conditions at certain growth stages, soil nutrient statuses, agronomic factors, moisture statuses, and weed/pest pressures are a primary goal in precision agriculture. This study attempted to achieve the following objectives: (1) to investigate the potential for predicting winter wheat yields using vegetation measurements (the Normalized Difference Vegetation Index-NDVI) at the beginning of the season, thereby allowing for a yield response to nitrogen (N) fertilizer; and (2) evaluate the feasibility of using inexpensive optical sensor measurements in a Mediterranean environment. A field experiment was conducted in two commercial wheat fields near Seville, in southwestern Spain. Yield data were collected at harvest using a yield monitoring system (RDS Ceres II-volumetric meter) installed on a combine. Wheat yield and NDVI values of 3498 ± 481 kg ha(-1) and 0.67 ± 0.04 nm nm(-1) (field 1) and 3221 ± 531 kg ha(-1) and 0.68 ± 0.05 nm nm(-1) (field 2) were obtained. In both fields, the yield and NDVI exhibited a strong Pearson correlation, with r(xy) = 0.64 and p < 10(-4) in field 1 and r(xy) = 0.78 and p < 10(-4) in field 2. The preliminary results indicate that hand-held crop sensor-based N management can be applied to wheat production in Spain and has the potential to increase agronomic N-use efficiency on a long-term basis. PMID:25756861

  14. Layered semiconductor neutron detectors

    DOEpatents

    Mao, Samuel S; Perry, Dale L

    2013-12-10

    Room temperature operating solid state hand held neutron detectors integrate one or more relatively thin layers of a high neutron interaction cross-section element or materials with semiconductor detectors. The high neutron interaction cross-section element (e.g., Gd, B or Li) or materials comprising at least one high neutron interaction cross-section element can be in the form of unstructured layers or micro- or nano-structured arrays. Such architecture provides high efficiency neutron detector devices by capturing substantially more carriers produced from high energy .alpha.-particles or .gamma.-photons generated by neutron interaction.

  15. Can Satellite-Based Sensors, Hand-Held Thermal Imagers and Thermal Infrared Radiometers Calculate Reliable Eruption Rates at Active Lava Flows, Domes and Lakes?

    NASA Astrophysics Data System (ADS)

    Harris, A. J.

    2004-12-01

    Thermal data provide viable means of extracting eruption rates at active lava flows, domes and lakes. The initial algorithm, developed since 1994, uses total heat flux (Q), extracted from satellite-sensor-derived thermal images of the active lava body to extract eruption rate (E) using E = Q / ρ [c Δ T + f L]. Here ρ and c are lava density and specific heat capacity, Δ T is lava cooling, f is fractional crystallization and L is latent heat of crystallization. Later it was shown that this reduces to a linear relationship: E = a Q + b, where a and b are defined by values assumed for ρ , c, Δ T, f, and L. We present three case studies that: (1) demonstrate the variety of thermal data and activity styles that can be used in this approach, and (2) validate the approach through cross-checks with independent, field-based data: (I) Stromboli: Satellite and thermal imager-based lava flow eruption rates. A safe, easy and rapid method to calculate lava effusion rates using hand-held thermal image data was developed in June 2003 at Stromboli (Italy). FLIR data were used as input to the thermal effusion rate model, previously applied to satellite data, allowing automated effusion rate extraction. A comparison between a thermally-derived (0.2 - 0.9 m3/s) and dimensionally-derived (i.e. channel depth x width x velocity) effusion rate (0.6 m3/s) showed excellent agreement. In addition, the comparison between FLIR-derived effusion rates and satellite (AVHRR) derived values showed a good correlation (R = 0.9). (II) Santiaguito: Satellite-derived eruption rates for a lava dome A time series of 21 Landsat ETM+ and TM images acquired during 1986-2003, were used to calculate eruption rates at Santiaguito dome (Guatemala) to yield a time-averaged effusion rate of 0.4 m3/s. Field-based flow dimension and velocity measurements during 1987 and 2000-03 yielded a values of 0.6±0.3 and 0.5±0.2 m3/s which compared with an ETM+ derived values of 0.7±0.1 and 0.5±0.1 m3/s, respectively

  16. Hand-held triangulation laser profilometer with audio output for blind people Profilométre laser à triangulation tenu en main avec sortie sonare pour non-voyants

    NASA Astrophysics Data System (ADS)

    Farcy, R.; Damaschini, R.

    1998-06-01

    We describe a device currently under industrial development which will give to the blind a means of three-dimensional space perception. It consists of a 350 g hand-held triangulating laser telemeter including electronic parts and batteries, with auditory feedback either inside the apparatus or close to the ear. The microprocessor unit converts in real time the distance measured by the telemeter into a musical note. Scanning the space with an adequate movement of the hand produces musical lines corresponding to the profiles of the environment. We discuss the optical configuration of the system relative to our first year of clinical experimentation.

  17. Feasibility, double-blind, randomised, placebo-controlled, multi-centre trial of hand-held NB-UVB phototherapy for the treatment of vitiligo at home (HI-Light trial: Home Intervention of Light therapy)

    PubMed Central

    2014-01-01

    Background Hand-held NB-UVB units are lightweight devices that may overcome the need to treat vitiligo in hospital-based phototherapy cabinets, allowing early treatment at home that may enhance the likelihood of successful repigmentation. The pilot Hi-Light trial examined the feasibility of conducting a large multi-centre randomised controlled trial (RCT) on the use of such devices by exploring recruitment, adherence, acceptability, and patient education. Methods This was a feasibility, double-blind, multi-centre, parallel group randomised placebo-controlled trial of hand-held NB-UVB phototherapy for the treatment of vitiligo at home. The overall duration of the trial was seven months; three months recruitment and four months treatment. Participants were randomly allocated to active or placebo groups (2:1 ratio). The primary outcome measure was the proportion of eligible participants who were willing to be randomised. The secondary outcomes included proportion of participants expressing interest in the trial and fulfilling eligibility criteria, withdrawal rates and missing data, proportion of participants adhering to and satisfied with the treatment, and incidence of NB-UVB short-term adverse events. Results Eighty-three percent (45/54) of vitiligo patients who expressed interest in the trial were willing to be randomised. Due to time and financial constraints, only 29/45 potential participants were booked to attend a baseline hospital visit. All 29 (100%) potential participants were confirmed as being eligible and were subsequently randomised. Willingness to participate in the study for General Practice (family physicians) surgeries and hospitals were 40% and 79%, respectively; 86% (25/29) of patients adhered to the treatment and 65% (7/11) of patients in the active group had some degree of repigmentation. Only one patient in the active group reported erythema grade 3 (3%). Both devices (Dermfix 1000 NB-UVB and Waldmann NB-UVB 109) were acceptable to participants

  18. Micro-fluidic (Lab-on the- Chip) PCR Array Cartridge for Biological Screening in a Hand Held Device: FInal Report for CRADA no 264. PNNL-T2-258-RU with CombiMatrix Corp

    SciTech Connect

    Rainina, Evguenia I.

    2010-10-31

    The worldwide emergence of both new and old diseases resulting from human expansion and also human and materials mobility has and will continue to place stress on both medical and clinical diagnostics. The classical approach to bioagents detection involves the use of differential metabolic assays to determine species type in the case of most bacteria, or the use of cell culture and electron microscopy to diagnose viruses and some bacteria that are intracellular parasites. The long-term goal in bioagent detection is to develop a hand-held instrument featuring disposable cartridges which contain all the necessary reagents, reaction chambers, waste chambers, and micro-fluidics to extract, concentrate, amplify, and analyze nucleic acids. This GIPP project began development of a sensory platform using nucleic-acid based probes. Although research was not completed, initial findings indicated that an advanced sensing device could theoretically be built on a DNA/RNA-based technology platform.

  19. Effectiveness of prehospital wireless transmission of electrocardiograms to a cardiologist via hand-held device for patients with acute myocardial infarction (from the Timely Intervention in Myocardial Emergency, NorthEast Experience [TIME-NE]).

    PubMed

    Adams, George L; Campbell, Paul T; Adams, John M; Strauss, David G; Wall, Karen; Patterson, Janet; Shuping, Kathy B; Maynard, Charles; Young, Dwayne; Corey, Craig; Thompson, Alan; Lee, Benjamin A; Wagner, Galen S

    2006-11-01

    Percutaneous coronary intervention for patients with ST-segment elevation myocardial infarction (STEMI) decreases morbidity and mortality if performed within the first 2 hours of symptom onset. However, the American College of Cardiology/American Heart Association guideline for percutaneous coronary intervention door-to-balloon time (<90 minutes) in patients with STEMI is a infrequently accomplished goal. This study enrolled 277 patients with STEMI who were self-transported or transported by emergency medical services to NorthEast Medical Center for primary percutaneous coronary intervention. This study tested the hypothesis that prehospital wireless transmission of an electrocardiogram to a cardiologist's hand-held device results in shorter emergency department door-to-reperfusion time. A comparison was made between patients whose electrocardiogram was successfully transmitted during the intervention phase with (1) patients transported by the emergency medical services in the preintervention, (2) patients self-transported in the intervention phase, and (3) patients whose wireless transmission failed in the intervention phase. During the preintervention phase (2001 to 2003), 48 patients were enrolled. During the intervention phase (2003 to 2005), the following patients were enrolled: 101 self-transported patients, 24 patients with successful electrocardiographic transmission, and 19 patients for whom transmission failed. The median door-to-reperfusion time for patients with successful electrocardiographic transmission was 50 minutes, which was significantly shorter than a preintervention time of 101 minutes (p <0.0001), an intervention phase self-transport time of 96 minutes (p <0.0001), and a failed transmission time of 78 minutes (p <0.0001). In conclusion, prehospital wireless electrocardiographic transmission to a cardiologist's hand-held device significantly decreased emergency department door-to-reperfusion time, thus achieving the American College of

  20. Using a Hand-Held Electronic Calculator

    ERIC Educational Resources Information Center

    North, Roger

    1975-01-01

    The arithmetic needed for complex calculation using an electronic calculator is explained and exemplified. Problems involving square roots, number theory, Fibonacci numbers, and electrical resistances are solved. (SD)

  1. Hand-held microwave search detector

    NASA Astrophysics Data System (ADS)

    Daniels, David J.; Philippakis, Mike

    2005-05-01

    This paper describes the further development of a patented, novel, low cost, microwave search detector using noise radar technology operating in the 27-40GHz range of frequencies, initially reported in SPIE 2004. Initial experiments have shown that plastic explosives, ceramics and plastic material hidden on the body can be detected with the system. This paper considers the basic physics of the technique and reports on the development of a initial prototype system for hand search of suspects and addresses the work carried out on optimisation of PD and FAR. The radar uses a novel lens system and the design and modelling of this for optimum depth of field of focus will be reported.

  2. Hand-held optical fuel pin scanner

    DOEpatents

    Kirchner, Tommy L.; Powers, Hurshal G.

    1987-01-01

    An optical scanner for indicia arranged in a focal plane perpendicular to an optical system including a rotatable dove prism. The dove prism transmits a rotating image to a stationary photodiode array.

  3. Hand-held optical fuel pin scanner

    DOEpatents

    Kirchner, T.L.; Powers, H.G.

    1980-12-07

    An optical scanner for indicia arranged in a focal plane perpendicular to an optical system including a rotatable dove prism. The dove prism transmits a rotating image to a stationary photodiode array.

  4. Hand-held Pressure Gauge Calibrator

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Farmers rely on the accuracy of pressure gauges to ensure desired rates of pesticide sprays or irrigation water when applied. However, the pressure gauges tend to start failing in a few years. Defective pressure gauges can cause either over or under application of pesticides or water. Therefore, ...

  5. Hand-held instrument should relieve hematoma pressure

    NASA Technical Reports Server (NTRS)

    Raggio, L. J.; Robertson, T. L.

    1967-01-01

    Portable instrument relieves hematomas beneath fingernails and toenails without surgery. This device simplifies the operative procedure with an instant variable heating tip, adjustable depth settings and interchangeable tip sizes for cauterizing small areas and relieving pressurized clots.

  6. Hand-Held Video for Clinical Skills Teaching

    ERIC Educational Resources Information Center

    Edwards, Mark; Jones, Steve; Murphy, Fiona

    2007-01-01

    In health care education a balance needs to be struck between theoretical and practical teaching. Undergraduates typically split their time between clinical placement and university-based teaching blocks. A proportion of the time spent in preparation for clinical practice placements will be spent in the classroom or in simulation suites. The…

  7. Hand held sample tube manipulator, system and method

    DOEpatents

    Kenny, Donald V [Liberty Township, OH; Smith, Deborah L [Liberty Township, OH; Severance, Richard A [late of Columbus, OH

    2001-01-01

    A manipulator apparatus, system and method for measuring analytes present in sample tubes. The manipulator apparatus includes a housing having a central bore with an inlet end and outlet end; a plunger mechanism with at least a portion thereof slideably disposed for reciprocal movement within the central bore, the plunger mechanism having a tubular gas channel with an inlet end and an outlet end, the gas channel inlet end disposed in the same direction as said inlet end of the central bore, wherein the inlet end of said plunger mechanism is adapted for movement so as to expel a sample tube inserted in the bore at the outlet end of the housing, the inlet end of the plunger mechanism is adapted for connection to gas supply; a first seal is disposed in the housing for sealing between the central bore and the plunger mechanism; a second seal is disposed at the outlet end of the housing for sealing between the central bore and a sample tube; a holder mounted on the housing for holding the sample tube; and a biasing mechanism for returning the plunger mechanism to a starting position.

  8. Measuring the Moon's orbit using a hand-held camera

    NASA Astrophysics Data System (ADS)

    Oostra, Benjamin

    2014-04-01

    This paper describes a way to measure the Moon's distance and orbital eccentricity using a digital camera. The method consists of taking photographs of the Moon and measuring the size of the lunar disk in each picture. On a series of images taken on the same night, the effect of the Earth's size is evident and thus the distance to the Moon can be computed. A larger series of images, covering several weeks, demonstrates that the Moon's orbit is not perfectly circular.

  9. AUTOMATION OF EXPERIMENTS WITH A HAND-HELD PROGRAMMABLE CALCULATOR

    EPA Science Inventory

    Technological developments have dramatically reduced the cost of data collection, experimental control and computation. Products are now available which allow automation of experiments both in the laboratory and in the field at substantially lower cost and with less technical exp...

  10. Semiconductor photoelectrochemistry

    NASA Technical Reports Server (NTRS)

    Buoncristiani, A. M.; Byvik, C. E.

    1983-01-01

    Semiconductor photoelectrochemical reactions are investigated. A model of the charge transport processes in the semiconductor, based on semiconductor device theory, is presented. It incorporates the nonlinear processes characterizing the diffusion and reaction of charge carriers in the semiconductor. The model is used to study conditions limiting useful energy conversion, specifically the saturation of current flow due to high light intensity. Numerical results describing charge distributions in the semiconductor and its effects on the electrolyte are obtained. Experimental results include: an estimate rate at which a semiconductor photoelectrode is capable of converting electromagnetic energy into chemical energy; the effect of cell temperature on the efficiency; a method for determining the point of zero zeta potential for macroscopic semiconductor samples; a technique using platinized titanium dioxide powders and ultraviolet radiation to produce chlorine, bromine, and iodine from solutions containing their respective ions; the photoelectrochemical properties of a class of layered compounds called transition metal thiophosphates; and a technique used to produce high conversion efficiency from laser radiation to chemical energy.

  11. Semiconductor sensors

    NASA Technical Reports Server (NTRS)

    Gatos, Harry C. (Inventor); Lagowski, Jacek (Inventor)

    1977-01-01

    A semiconductor sensor adapted to detect with a high degree of sensitivity small magnitudes of a mechanical force, presence of traces of a gas or light. The sensor includes a high energy gap (i.e., .about. 1.0 electron volts) semiconductor wafer. Mechanical force is measured by employing a non-centrosymmetric material for the semiconductor. Distortion of the semiconductor by the force creates a contact potential difference (cpd) at the semiconductor surface, and this cpd is determined to give a measure of the force. When such a semiconductor is subjected to illumination with an energy less than the energy gap of the semiconductors, such illumination also creates a cpd at the surface. Detection of this cpd is employed to sense the illumination itself or, in a variation of the system, to detect a gas. When either a gas or light is to be detected and a crystal of a non-centrosymmetric material is employed, the presence of gas or light, in appropriate circumstances, results in a strain within the crystal which distorts the same and the distortion provides a mechanism for qualitative and quantitative evaluation of the gas or the light, as the case may be.

  12. Semiconductor processing

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The primary thrust of the semiconductor processing is outlined. The purpose is to (1) advance the theoretical basis for bulk growth of elemental and compound semiconductors in single crystal form, and (2) to develop a new experimental approaches by which semiconductor matrices with significantly improved crystalline and chemical perfection can be obtained. The most advanced approaches to silicon crystal growth is studied. The projected research expansion, directed toward the capability of growth of 4 inch diameter silicon crystals was implemented. Both intra and interdepartmental programs are established in the areas of process metallurgy, heat transfer, mass transfer, and systems control. Solutal convection in melt growth systems is also studied.

  13. Semiconductor Cubing

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Through Goddard Space Flight Center and Jet Propulsion Laboratory Small Business Innovation Research contracts, Irvine Sensors developed a three-dimensional memory system for a spaceborne data recorder and other applications for NASA. From these contracts, the company created the Memory Short Stack product, a patented technology for stacking integrated circuits that offers higher processing speeds and levels of integration, and lower power requirements. The product is a three-dimensional semiconductor package in which dozens of integrated circuits are stacked upon each other to form a cube. The technology is being used in various computer and telecommunications applications.

  14. Photoelectrosynthesis at semiconductor electrodes

    SciTech Connect

    Nozik, A. J.

    1980-12-01

    The general principles of photoelectrochemistry and photoelectrosynthesis are reviewed and some new developments in photoelectrosynthesis are discussed. Topics include energetics of semiconductor-electrolyte interfaces(band-edge unpinning); hot carrier injection at illuminated semiconductor-electrolyte junctions; derivatized semiconductor electrodes; particulate photoelectrochemical systems; layered compounds and other new materials; and dye sensitization. (WHK)

  15. Photorefractive Semiconductors and Applications

    NASA Technical Reports Server (NTRS)

    Chen, Li-Jen; Luke, Keung L.

    1993-01-01

    Photorefractive semiconductors are attractive for information processing, becuase of fast material response, compatibility with semiconductor lasers, and availability of cross polarization diffraction for enhancing signal-to-noise ration. This paper presents recent experimental results on information processing using photorefractive GaAs, InP and CdTe, including image processing with semiconductor lasers.

  16. Unitary lens semiconductor device

    DOEpatents

    Lear, K.L.

    1997-05-27

    A unitary lens semiconductor device and method are disclosed. The unitary lens semiconductor device is provided with at least one semiconductor layer having a composition varying in the growth direction for unitarily forming one or more lenses in the semiconductor layer. Unitary lens semiconductor devices may be formed as light-processing devices such as microlenses, and as light-active devices such as light-emitting diodes, photodetectors, resonant-cavity light-emitting diodes, vertical-cavity surface-emitting lasers, and resonant cavity photodetectors. 9 figs.

  17. Unitary lens semiconductor device

    DOEpatents

    Lear, Kevin L.

    1997-01-01

    A unitary lens semiconductor device and method. The unitary lens semiconductor device is provided with at least one semiconductor layer having a composition varying in the growth direction for unitarily forming one or more lenses in the semiconductor layer. Unitary lens semiconductor devices may be formed as light-processing devices such as microlenses, and as light-active devices such as light-emitting diodes, photodetectors, resonant-cavity light-emitting diodes, vertical-cavity surface-emitting lasers, and resonant cavity photodetectors.

  18. Organic semiconductor lasers as integrated light sources for optical sensor systems

    NASA Astrophysics Data System (ADS)

    Punke, Martin; Woggon, Thomas; Stroisch, Marc; Ebenhoch, Bernd; Geyer, Ulf; Karnutsch, Christian; Gerken, Martina; Lemmer, Uli; Bruendel, Mathias; Wang, Jing; Weimann, Thomas

    2007-09-01

    We demonstrate the feasibility of organic semiconductor lasers as light sources for lab-on-a-chip systems. These lasers are based on a 1D- or 2D-photonic crystal resonator structure providing optical feedback in the active laser material that is deposited on top, e.g. aluminum tris(8-hydroxyquinoline) (Alq 3) doped with the laser dye 4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM). We investigated different fabrication methods for the resonator structures, like thermal nanoimprint, UV nanoimprint, and laser interference lithography. Different substrate materials commonly used in lab-on-a-chip systems, e.g. PMMA, Topas, and Ormocer were deployed. By changing the distributed feedback grating periodicity, we demonstrate a tuning range for a single material system of more than 120 nm. The investigated organic semiconductor lasers are optically pumped. External optical pumping provides a feasible way for one-time-use chips. Our recent success of pumping organic lasers with a low-cost laser diode also renders hand-held systems possible. As a further step towards the integration of organic lasers in sensor systems, we demonstrate the coupling of an organic laser into polymeric waveguides which can be combined with microfluidic channels. The integrated organic lasers and the waveguides are both fabricated on the same polished PMMA substrate using thermal nanoimprint lithography and deep-UV modification, respectively. We could demonstrate the guiding of the laser light in single-mode waveguides.

  19. The Physics of Semiconductors

    NASA Astrophysics Data System (ADS)

    Grundmann, Marius

    The historic development of semiconductor physics and technology began in the second half of the 19th century. Interesting discussions of the early history of the physics and chemistry of semiconductors can be found in treatises of G. Busch [2] and Handel [3]. The history of semiconductor industry can be followedin the text of Morris [4] and Holbrook et al. [5]. In 1947, the realization of the transistor was the impetus to a fast-paced development that created the electronics and photonics industries. Products founded on the basis of semiconductor devices such as computers (CPUs, memories), optical-storage media (lasers for CD, DVD), communication infrastructure (lasers and photodetectors for optical-fiber technology, high frequency electronics for mobile communication), displays (thin film transistors, LEDs), projection (laser diodes) and general lighting (LEDs) are commonplace. Thus, fundamental research on semiconductors and semiconductor physics and its offspring in the form of devices has contributed largely to the development of modern civilization and culture.

  20. Semiconductor microcavity lasers

    SciTech Connect

    Gourley, P.L.; Wendt, J.R.; Vawter, G.A.; Warren, M.E.; Brennan, T.M.; Hammons, B.E.

    1994-02-01

    New kinds of semiconductor microcavity lasers are being created by modern semiconductor technologies like molecular beam epitaxy and electron beam lithography. These new microcavities exploit 3-dimensional architectures possible with epitaxial layering and surface patterning. The physical properties of these microcavities are intimately related to the geometry imposed on the semiconductor materials. Among these microcavities are surface-emitting structures which have many useful properties for commercial purposes. This paper reviews the basic physics of these microstructured lasers.

  1. Semiconductor bridge (SCB) detonator

    DOEpatents

    Bickes, Jr., Robert W.; Grubelich, Mark C.

    1999-01-01

    The present invention is a low-energy detonator for high-density secondary-explosive materials initiated by a semiconductor bridge igniter that comprises a pair of electrically conductive lands connected by a semiconductor bridge. The semiconductor bridge is in operational or direct contact with the explosive material, whereby current flowing through the semiconductor bridge causes initiation of the explosive material. Header wires connected to the electrically-conductive lands and electrical feed-throughs of the header posts of explosive devices, are substantially coaxial to the direction of current flow through the SCB, i.e., substantially coaxial to the SCB length.

  2. Semiconductor bridge (SCB) detonator

    DOEpatents

    Bickes, R.W. Jr.; Grubelich, M.C.

    1999-01-19

    The present invention is a low-energy detonator for high-density secondary-explosive materials initiated by a semiconductor bridge (SCB) igniter that comprises a pair of electrically conductive lands connected by a semiconductor bridge. The semiconductor bridge is in operational or direct contact with the explosive material, whereby current flowing through the semiconductor bridge causes initiation of the explosive material. Header wires connected to the electrically-conductive lands and electrical feed-throughs of the header posts of explosive devices, are substantially coaxial to the direction of current flow through the SCB, i.e., substantially coaxial to the SCB length. 3 figs.

  3. Interconnected semiconductor devices

    DOEpatents

    Grimmer, Derrick P.; Paulson, Kenneth R.; Gilbert, James R.

    1990-10-23

    Semiconductor layer and conductive layer formed on a flexible substrate, divided into individual devices and interconnected with one another in series by interconnection layers and penetrating terminals.

  4. ELECTRONIC WASTE GENERATED BY HAND HELD WIRELESS DEVICES WITH A FOCUS ON CELL PHONES

    EPA Science Inventory

    Characterization of wireless products; identify cell phone composition (particularly toxic components), document end of life programs for cell phones in the U.S. and Europe, examine provisions in the draft European Union Waste Electronic Equipment document. Project will include ...

  5. Preoperative distraction in children: hand-held videogames vs clown therapy.

    PubMed

    Messina, M; Molinaro, F; Meucci, D; Angotti, R; Giuntini, L; Cerchia, E; Bulotta, A L; Brandigi, E

    2014-01-01

    Anxiety in children undergoing surgery is characterized by feelings of tension, apprehension, nervousness and fear which may manifest differently. Postoperative behavioural changes such as nocturnal enuresis, feeding disorders, apathy, and sleep disturbances may stem from postoperative anxiety. Some Authors pointed out that over 60% of children undergoing surgery are prone to developing behavioural alterations 2 weeks after surgery. Variables such as age, temperament and anxiety both in children and parents are considered predictors of such changes.1 Studies were published describing how psycho-behavioural interventions based on play, learning and entertainment in preparing children for surgery, may reduce preoperative anxiety. Clown-therapy is applied in the most important paediatric facilities and has proved to diminish children's emotional distress and sufferance, as well as consumption of both analgesics and sedatives and to facilitate the achievement of therapeutic goals. The aim of our study was to evaluate the efficacy of clown-therapy during the child's hospital stay, with a view to optimizing treatment and care, preventing behavioural alterations and enhancing the child's overall life quality. PMID:25669889

  6. Development of hand-held nondestructive detection device for assessing meat freshness

    NASA Astrophysics Data System (ADS)

    Wei, Wensong; Peng, Yankun; Qiao, Lu

    2016-05-01

    Meat freshness is directly related to the health of consumers, and total volatile basic nitrogen (TVB-N) content is an important reference index for evaluating pork freshness. This paper attempted to measure TVB-N content for assessing pork meat freshness using a new self-developed portable and low cost detection device designed by ourselves basing on near infrared technique. The front-end part of this device was an integrated detection component containing a mini probe which was about 5cm in diameter circle. In the signal acquiring component, silicon photodiode detector was embedded in the center of light source in probe and spectral response range was 400-1100nm to receive diffuse light from pork meat surface in mini probe. The main circuits in this device included stabilized current supply circuit which was used to provide a stable power supply for each LED light source in probe and signal processing circuit which was utilized to complete signal amplification and A/D conversion, In addition, another vital function of the signal processing circuit was to analysis detection signals from mini probe in the detection component. For verifying this device performance, 58 pork samples with different freshness attributes and Multiple Linear Regression (MLR) mathematical method and ratio data processing algorithm were employed to build pork TVB-N content prediction model, and comparing with results from raw data model, the correlation coefficient of prediction and validation of TVB-N were 0.8027 and 0.7291 respectively, and the accuracy of predicting pork freshness was about 78.6%. This work demonstrates that it has the potential in nondestructive detection of TVB-N content in pork meat using this device, which can simplify related instruments design structure and reduce their development cost in future.

  7. Transforming an Introductory Linear Algebra Course with a TI-92 Hand-Held Computer.

    ERIC Educational Resources Information Center

    Quesada, Antonio R.

    2003-01-01

    Describes how the introduction of the TI-92 transformed a traditional first semester linear algebra course into a matrix-oriented course that emphasized conceptual understanding, relevant applications, and numerical issues. Indicates an increase in students' overall performance as they found the calculator very useful, believed it helped them…

  8. Hand-held computers in healthcare: what software programs are available?

    PubMed

    Gillingham, Wayne; Holt, Alec; Gillies, John

    2002-09-27

    The technology sector of healthcare is entering a new evolutionary phase. The medical community has an obligation to the public to provide the safest, most effective healthcare possible. This is more achievable with the use of computer technology at the point of care, and small, portable devices could fulfil this role. A PriceWaterhouse Coopers 2001 survey on information technology in physician practices found that 60% of respondents say that physicians in their organisation use personal digital assistants (PDAs), compared with 26% in the 2000 technology survey. This trend is expected to continue to the point where these devices will have their position on a physician s desk next to the stethoscope. Once this electronic evolution occurs, doctors will be able to practice medicine with greater ease and safety. In our opinion, the new generation of PDA mobile devices will be the tools to enable a transformation of healthcare to a paperless, wireless world. This article focuses on uses of PDAs in healthcare, whether by the registrar, consultant, nurse, student, teacher, patient, medical or surgical director. Current PDA healthcare software is categorised and discussed in the following five groups: 1) reference/text book; 2) calculator; 3) patient management/logbook; 4) personal clinical/study notebook; 5) utility software. PMID:12386664

  9. Measurement of Visual Reaction Times Using Hand-held Mobile Devices

    NASA Technical Reports Server (NTRS)

    Mulligan, Jeffrey B.; Arsintescu, Lucia; Flynn-Evans, Erin

    2015-01-01

    Modern mobile devices provide a convenient platform for collecting research data in the field. But,because the working of these devices is often cloaked behind multiple layers of proprietary system software, it can bedifficult to assess the accuracy of the data they produce, particularly in the case of timing. We have been collecting datain a simple visual reaction time experiment, as part of a fatigue testing protocol known as the Psychomotor Vigilance Test (PVT). In this protocol, subjects run a 5-minute block consisting of a sequence of trials in which a visual stimulus appears after an unpredictable variable delay. The subject is required to tap the screen as soon as possible after the appearance of the stimulus. In order to validate the reaction times reported by our program, we had subjects perform the task while a high-speed video camera recorded both the display screen, and a side view of the finger (observed in a mirror). Simple image-processing methods were applied to determine the frames in which the stimulus appeared and disappeared, and in which the finger made and broke contact with the screen. The results demonstrate a systematic delay between the initial contact by the finger and the detection of the touch by the software, having a value of 80 +- 20 milliseconds.

  10. Reliability and Accuracy of Six Hand-Held Blood Lactate Analysers

    PubMed Central

    Bonaventura, Jacinta M.; Sharpe, Ken; Knight, Emma; Fuller, Kate L.; Tanner, Rebecca K.; Gore, Christopher J.

    2015-01-01

    The reliability and accuracy of five portable blood lactate (BLa) analysers (Lactate Pro, Lactate Pro2, Lactate Scout+, Xpress™, and Edge) and one handheld point-of-care analyser (i-STAT) were compared to a criterion (Radiometer ABL90). Two devices of each brand of analyser were assessed using 22 x 6 mL blood samples taken from five subjects at rest and during exercise who generated lactate ranging ~1-23 mM. Each sample was measured simultaneously ~6 times on each device. Reliability was assessed as the within-sample standard deviation (wsSD) of the six replicates; accuracy as the bias compared with the ABL90; and overall error (the root mean squared error (√MSE)) was calculated as the square root of (wsSD2 and bias2). The √MSE indicated that both the Edge and Xpress had low total error (~0-2 mM) for lactate concentrations <15 mM, whereas the Edge and Lactate Pro2 were the better of the portable analysers for concentrations >15 mM. In all cases, bias (negative) was the major contribution to the √MSE. In conclusion, in a clinical setting where BLa is generally <15 mM the Edge and Xpress devices are relevant, but for athlete testing where peak BLa is important for training prescription the Edge and Lactate Pro2 are preferred. Key points The reliability of five common portable blood lactate analysers were generally <0.5 mM for concentrations in the range of ~1.0-10 mM. For all five portable analysers, the analytical error within a brand was much smaller than the biological variation in blood lactate (BLa). Compared with a criterion blood lactate analyser, there was a tendency for all portable analysers to under-read (i.e. a negative bias), which was particularly evident at the highest concentrations (BLa ~15-23 mM). The practical application of these negative biases would overestimate the ability of the athlete and prescribe a training intensity that would be too high. PMID:25729309

  11. Use of hand held devices in a Western Australian health sector.

    PubMed

    Patel, Keyurkumar J; Gururajan, Raj

    2006-01-01

    This paper outlines the results of wireless development for a private healthcare provider in Western Australia. The case study is presented here discusses the software methodology used, problems encountered in developing the software application and then delivering it. Furthermore, the important issues associated with integration of new software with existing modules, human factors that impeded some aspects of development and issues associated with rigorous testing to ensure user requirements are also discussed. PMID:17945883

  12. [Design of hand-held heart rate variability acquisition and analysis system].

    PubMed

    Li, Kaiyuan; Wang, Buqing; Wang, Weidong

    2012-07-01

    A design of handheld heart rate variability acquisition and analysis system is proposed. The system collects and stores the patient's ECG every five minutes through both hands touching on the electrodes, and then -uploads data to a PC through USB port. The system uses software written in LabVIEW to analyze heart rate variability parameters, The parameters calculated function is programmed and generated to components in Matlab. PMID:23189641

  13. The Rosetta phone: a hand-held device for automatic translation of signs in natural images

    NASA Astrophysics Data System (ADS)

    Jafri, Syed Ali Raza; Mikkilineni, Aravind K.; Boutin, Mireille; Delp, Edward J.

    2008-02-01

    When traveling in a region where the local language is not written using the Roman alphabet, translating written text (e.g., documents, road signs, or placards) is a particularly difficult problem since the text cannot be easily entered into a translation device or searched using a dictionary. To address this problem, we are developing the "Rosetta Phone," a handheld device (e.g., PDA or mobile telephone) capable of acquiring a picture of the text, identifying the text within the image, and producing both an audible and a visual English interpretation of the text. We started with English, as a developement language, for which we achieved close to 100% accuracy in identifying and reading text. We then modified the system to be able to read and translate words written using the Arabic character set. We currently achieve approximately 95% accuracy in reading words from a small directory of town names.

  14. Reliability and accuracy of six hand-held blood lactate analysers.

    PubMed

    Bonaventura, Jacinta M; Sharpe, Ken; Knight, Emma; Fuller, Kate L; Tanner, Rebecca K; Gore, Christopher J

    2015-03-01

    The reliability and accuracy of five portable blood lactate (BLa) analysers (Lactate Pro, Lactate Pro2, Lactate Scout+, Xpress™, and Edge) and one handheld point-of-care analyser (i-STAT) were compared to a criterion (Radiometer ABL90). Two devices of each brand of analyser were assessed using 22 x 6 mL blood samples taken from five subjects at rest and during exercise who generated lactate ranging ~1-23 mM. Each sample was measured simultaneously ~6 times on each device. Reliability was assessed as the within-sample standard deviation (wsSD) of the six replicates; accuracy as the bias compared with the ABL90; and overall error (the root mean squared error (√MSE)) was calculated as the square root of (wsSD(2) and bias(2)). The √MSE indicated that both the Edge and Xpress had low total error (~0-2 mM) for lactate concentrations <15 mM, whereas the Edge and Lactate Pro2 were the better of the portable analysers for concentrations >15 mM. In all cases, bias (negative) was the major contribution to the √MSE. In conclusion, in a clinical setting where BLa is generally <15 mM the Edge and Xpress devices are relevant, but for athlete testing where peak BLa is important for training prescription the Edge and Lactate Pro2 are preferred. Key pointsThe reliability of five common portable blood lactate analysers were generally <0.5 mM for concentrations in the range of ~1.0-10 mM.For all five portable analysers, the analytical error within a brand was much smaller than the biological variation in blood lactate (BLa).Compared with a criterion blood lactate analyser, there was a tendency for all portable analysers to under-read (i.e. a negative bias), which was particularly evident at the highest concentrations (BLa ~15-23 mM).The practical application of these negative biases would overestimate the ability of the athlete and prescribe a training intensity that would be too high. PMID:25729309

  15. Recent developments in space shuttle remote sensing, using hand-held film cameras

    NASA Technical Reports Server (NTRS)

    Amsbury, David L.; Bremer, Jeffrey M.

    1992-01-01

    The authors report on the advantages and disadvantages of a number of camera systems which are currently employed for space shuttle remote sensing operations. Systems discussed include the modified Hasselbad, the Rolleiflex 6008, the Linkof 5-inch format system, and the Nikon F3/F4 systems. Film/filter combinations (color positive films, color infrared films, color negative films and polarization filters) are presented.

  16. Miniaturized hand held microwave interference scanning system for NDE of dielectric armor and armor systems

    SciTech Connect

    Schmidt, Karl F.; Little, Jack R.; Ellingson, William A.; Meitzler, Thomas J.; Green, William

    2011-06-23

    Inspection of ceramic-based armor has advanced through development of a microwave-based, portable, non-contact NDE system. Recently, this system was miniaturized and made wireless for maximum utility in field applications. The electronic components and functionality of the laboratory system are retained, with alternative means of position input for creation of scan images. Validation of the detection capability was recently demonstrated using specially fabricated surrogates and ballistic impact-damaged specimens. The microwave data results have been compared to data from laboratory-based microwave interferometry systems and digital x-ray imaging. The microwave interference scanning has been shown to reliably detect cracks, laminar features and material property variations. The authors present details of the system operation, descriptions of the test samples used and recent results obtained.

  17. Raynaud's phenomenon in different groups of workers using hand-held vibrating tools.

    PubMed

    Harazin, B; Langauer-Lewowicka, H

    1996-05-01

    The dose-effect relationship showed in the Annex A of the ISO standard 5349-1986 can be used for preventing vibration-induced white fingers (VWF) because it allows to calculate the latent period for the lowest risk of VWF. The aim of this study was to assess the risk of VWF in three different occupational groups of workers whose members operated the same vibrating power tools and the same industrial processes throughout the workday. Each occupational group was employed in two foundries and they were considered to be very stable with a low turnover rate. The mean frequency-weighted acceleration magnitudes measured from pneumatic rammers (25.3 +/- 3.3 ms-2) where three times higher than from chipping hammers (8.4 +/- 3.8 ms-2) and six times higher than from grinders (3.8 +/- 1.1 ms-2). Medical examinations were carried out in 102 men consisting of 22 chippers, 42 rammers and 38 grinders. The results of this study showed that the relationship between lifetime exposure to hand-arm vibration and the vascular disorders can be predicted quite well using the Annex A of ISO standard only in one occupational group, that is, in chippers. Thirty-six percent of chippers reported blanching symptoms, but only five percent of the rammers and three percent of the grinders had these vascular disturbances. Our results may be explained by the fact that vibration received by an operator depends on the manner in which the tool is used. In a foundry three following work processes are performed: preparing forms in ramming mix, cleaning and grinding of castings during which different forces are used by operators. It seems very likely that the energy absorbtion in the hands and arms of chippers must be stronger than in other studied groups. PMID:8996728

  18. 77 FR 73354 - Safety Standard for Hand-Held Infant Carriers

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-10

    ... instructional literature of the proposed rule should be directed to the Office of Information and Regulatory... change, including any personal identifiers, contact information, or other personal information provided, to: http://www.regulations.gov . Do not submit confidential business information, trade...

  19. Voice Recognition Software and a Hand-Held Translation Machine for Second-Language Learning.

    ERIC Educational Resources Information Center

    Myers, Marie J.

    2000-01-01

    Presents the results of a research project subsidized by the Social Sciences and Humanities Research Council in Canada. The research constitutes one project of a number in a strategic research network "EvNet" on the evaluation of computer technologies. The focus here is on the impact of voice recognition software on the language development of…

  20. CHARACTERIZATION OF EMISSIONS FROM HAND-HELD TWO-STROKE ENGINES

    EPA Science Inventory

    Despite their extremely high organic and particulate matter emission rates, two-stroke engines remain among the least studied of engine types. Such studies are rare because they are costly to perform. Results reported in this paper were obtained using a facility that shares e...

  1. Capillary - Discharge Based Hand-Held Detector For Chemical Vapor Monitoring

    DOEpatents

    Duan, Yixiang

    2005-05-31

    A handheld/portable detector for chemical vapor monitoring includes a housing and a discharge chamber that is established therein. The plasma discharge has a relatively small volume, e.g., in the micro-liter range. A first electrode and a second electrode are disposed within the discharge chamber and a discharge gap is established therebetween. A sample gas tube is in fluid communication with the discharge chamber and provides a sample gas to the discharge chamber. Also, a plasma gas tube is in fluid communication with the discharge chamber and provides a plasma gas thereto. Accordingly, the plasma gas can be used to maintain microplasma discharge between the electrodes and the sample gas can be introduced into the microplasma discharge. A spectrometer optically connected to the handheld/portable detector is used to measure the radiation emitted by the sample gas when subjected to the microplasma discharge.

  2. Hand-held, mechanically cooled, radiation detection system for gamma-ray spectroscopy

    DOEpatents

    Burks, Morgan Thomas; Eckels, Joel Del

    2010-06-08

    In one embodiment, a radiation detection system is provided including a radiation detector and a first enclosure encapsulating the radiation detector, the first enclosure including a low-emissivity infra-red (IR) reflective coating used to thermally isolate the radiation detector. Additionally, a second enclosure encapsulating the first enclosure is included, the first enclosure being suspension mounted to the second enclosure. Further, a cooler capable of cooling the radiation detector is included. Still yet, a first cooling interface positioned on the second enclosure is included for coupling the cooler and the first enclosure. Furthermore, a second cooling interface positioned on the second enclosure and capable of coupling the first enclosure to a cooler separate from the radiation detection system is included. Other embodiments are also presented.

  3. 78 FR 27441 - NIJ Evaluation of Hand-Held Cell Phone Detector Devices

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-10

    ... operation, and Operate using Radio Frequency (RF) and/or Non-Linear Junction Detection (NLJD) technology.... Letters of Understanding may be obtained from and should be submitted to Jack flame, National Institute...

  4. HAND-HELD SENSOR FOR REMOTELY MAPPING CARBON DIOXIDE POLLUTION SOURCES - PHASE I

    EPA Science Inventory

    In 2007, the U.S. Supreme Court ruled that carbon dioxide (CO2) is a pollutant under the federal Clean Air Act.  The ruling allows the U.S. Environmental Protection Agency (EPA) to regulate CO2 emissions.  Such regulation will entail monitoring a wid...

  5. Interference from a hand held radiofrequency remote control causing discharge of an implantable defibrillator.

    PubMed

    Man, K C; Davidson, T; Langberg, J J; Morady, F; Kalbfleisch, S J

    1993-08-01

    A 46-year-old man with a history of sustained monomorphic ventricular tachycardia underwent an implantation of a third generation multiprogrammable implantable cardioverter defibrillator. One year post implant, while manipulating a remote control to a radiofrequency modulated toy car, the patient experienced a defibrillator discharge not preceded by an arrhythmia prodrome. Subsequent interrogation of the defibrillator revealed that a 34-joule shock had been delivered and had been preceded by RR intervals ranging from 141-406 msec, consistent with sensing lead noise. The remote control utilizes a 12-volt battery and has a carrier frequency of 75.95 MHz and a modulating frequency of 50 Hz. Evaluation of the remote control and defibrillator interaction revealed that the remote control was able to trigger tachyarrhythmia sensing and reproduce the clinical episode. Interference was present only when the remote control was within 8 cm of the pulse generator and at specific angles relative to the device and only when the antenna length was > 45 cm. Interference was eliminated when a ground wire was attached to the antenna and when an aluminium shield was placed between the pulse generator and the remote control. This case report suggests that patients with third generation multiprogrammable defibrillators should be cautioned against close contact with potential sources of electromagnetic interference, such as remote control units. PMID:7690947

  6. DNA extraction-free quantification of Dehalococcoides spp. in groundwater using a hand-held device.

    PubMed

    Stedtfeld, Robert D; Stedtfeld, Tiffany M; Kronlein, Maggie; Seyrig, Gregoire; Steffan, Robert J; Cupples, Alison M; Hashsham, Syed A

    2014-12-01

    Nucleic acid amplification of biomarkers is increasingly used to measure microbial activity and predict remedial performance in sites with trichloroethene (TCE) contamination. Field-based genetic quantification of microorganisms associated with bioremediation may help increase accuracy that is diminished through transport and processing of groundwater samples. Sterivex cartridges and a previously undescribed mechanism for eluting biomass was used to concentrate cells. DNA extraction-free loop mediated isothermal amplification (LAMP) was monitored in real-time with a point of use device (termed Gene-Z). A detection limit of 10(5) cells L(–1) was obtained, corresponding to sensitivity between 10 to 100 genomic copies per reaction for assays targeting the Dehalococcoides spp. specific 16S rRNA gene and vcrA gene, respectively. The quantity of Dehalococcoides spp. genomic copies measured from two TCE contaminated groundwater samples with conventional means of quantification including filtration, DNA extraction, purification, and qPCR was comparable to the field ready technique. Overall, this method of measuring Dehalococcoides spp. and vcrA genes in groundwater via direct amplification without intentional DNA extraction and purification is demonstrated, which may provide a more accurate mechanism of predicting remediation rates. PMID:25360694

  7. Use of Electronic Hand-held Devices for Collection of Savannah River Site Environmental Data - 13329

    SciTech Connect

    Marberry, Hugh; Moore, Winston

    2013-07-01

    Savannah River Nuclear Solutions has begun using Xplore Tablet PC's to collect data in the field for soil samples, groundwater samples, air samples and round sheets at the Savannah River Site (SRS). EPA guidelines for groundwater sampling are incorporated into the application to ensure the sample technician follows the proper protocol. The sample technician is guided through the process for sampling and round sheet data collection by a series of menus and input boxes. Field measurements and well stabilization information are entered into the tablet for uploading into Environmental Restoration Data Management System (ERDMS). The process helps to eliminate input errors and provides data integrity. A soil sample technician has the ability to collect information about location of sample, field parameter, describe the soil sample, print bottle labels, and print chain of custody for the sample that they have collected. An air sample technician has the ability to provide flow, pressure, hours of operation, print bottle labels and chain of custody for samples they collect. Round sheets are collected using the information provided in the various procedures. The data are collected and uploaded into ERDMS. The equipment used is weather proof and hardened for the field use. Global Positioning System (GPS) capabilities are integrated into the applications to provide the location where samples were collected and to help sample technicians locate wells that are not visited often. (authors)

  8. GOES Satellite Data Validation Via Hand-held 4 LED Sun Photometer at Norfolk State University

    NASA Technical Reports Server (NTRS)

    Reynolds, Arthur, Jr.; Jackson, Tyrone; Reynolds, Kevin; Davidson, Cassy; Coope-Pabis, Barbara

    2005-01-01

    Sun photometry is a passive means of measuring a quantity of light radiation. The GIFTS- IOMI/GLOBE Water Vapor/Haze Sun photometer contains four light emitting diodes (LEDs), which are used to convert photocurrent to voltage. The intensity of the incoming and outgoing radiation as detected on the Earth s surface can be affected by aerosols and gases in the atmosphere. The focus of this research is primarily on aerosol and water vapor particles that absorb and reemit energy. Two LEDs in the photometer correspond to light scattered at 530 nm (green spectrum) and 620 nm (red spectrum). They collect data pertaining to aerosols that scatter light. The other two LEDs detect the light scattered by water vapor at wavelengths of 820 nm and 920 nm. The water vapor measurements will be compared to data collected by the Geostationary Observation Environmental Satellite (GOES). Before a comparison can be made, the extraterrestrial constant (ET), which is intrinsic to each sun photometer, must be measured. This paper will present determination of the ET constant, from which the aerosol optical thickness (AOT) can be computed for comparison to the GOES satellite to ascertain the reliability of the sun photometer.

  9. 78 FR 73415 - Safety Standard for Hand-Held Infant Carriers

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-06

    .... 3501-3521). The preamble to the proposed rule (77 FR at 73363 through 73364) discussed the information... provides information on how to obtain a copy of the ASTM standard or to inspect a copy of the standard at... to provide tracking information, as well as hazard warnings. The voluntary standard also includes:...

  10. Ice patterns and hydrothermal plumes, Lake Baikal, Russia - Insights from Space Shuttle hand-held photography

    NASA Technical Reports Server (NTRS)

    Evans, Cynthia A.; Helfert, Michael R.; Helms, David R.

    1992-01-01

    Earth photography from the Space Shuttle is used to examine the ice cover on Lake Baikal and correlate the patterns of weakened and melting ice with known hydrothermal areas in the Siberian lake. Particular zones of melted and broken ice may be surface expressions of elevated heat flow in Lake Baikal. The possibility is explored that hydrothermal vents can introduce local convective upwelling and disrupt a stable water column to the extent that the melt zones which are observed in the lake's ice cover are produced. A heat flow map and photographs of the lake are overlaid to compare specific areas of thinned or broken ice with the hot spots. The regions of known hydrothermal activity and high heat flow correlate extremely well with circular regions of thinned ice, and zones of broken and recrystallized ice. Local and regional climate data and other sources of warm water, such as river inlets, are considered.

  11. Distributing Data to Hand-Held Devices in a Wireless Network

    NASA Technical Reports Server (NTRS)

    Hodges, Mark; Simmons, Layne

    2008-01-01

    ADROIT is a developmental computer program for real-time distribution of complex data streams for display on Web-enabled, portable terminals held by members of an operational team of a spacecraft-command-and-control center who may be located away from the center. Examples of such terminals include personal data assistants, laptop computers, and cellular telephones. ADROIT would make it unnecessary to equip each terminal with platform- specific software for access to the data streams or with software that implements the information-sharing protocol used to deliver telemetry data to clients in the center. ADROIT is a combination of middleware plus software specific to the center. (Middleware enables one application program to communicate with another by performing such functions as conversion, translation, consolidation, and/or integration.) ADROIT translates a data stream (voice, video, or alphanumerical data) from the center into Extensible Markup Language, effectuates a subscription process to determine who gets what data when, and presents the data to each user in real time. Thus, ADROIT is expected to enable distribution of operations and to reduce the cost of operations by reducing the number of persons required to be in the center.

  12. Unusual pattern of injury caused by a pyrotechnic hand held signal flare.

    PubMed

    Oliver, D W; Ragbir, M; Saxby, P J

    1997-07-01

    The case is reported of a man shot with a distress flare from a range of about 3 m. The flare caused a large cavity deep in the pectoral muscles. There should be a high index of suspicion about the extent of the injury in all types of penetrating trauma. PMID:9248919

  13. Unusual pattern of injury caused by a pyrotechnic hand held signal flare.

    PubMed Central

    Oliver, D W; Ragbir, M; Saxby, P J

    1997-01-01

    The case is reported of a man shot with a distress flare from a range of about 3 m. The flare caused a large cavity deep in the pectoral muscles. There should be a high index of suspicion about the extent of the injury in all types of penetrating trauma. Images Figure 1 Figure 2 Figure 3 PMID:9248919

  14. Advanced sampling techniques for hand-held FT-IR instrumentation

    NASA Astrophysics Data System (ADS)

    Arnó, Josep; Frunzi, Michael; Weber, Chris; Levy, Dustin

    2013-05-01

    FT-IR spectroscopy is the technology of choice to identify solid and liquid phase unknown samples. The challenging ConOps in emergency response and military field applications require a significant redesign of the stationary FT-IR bench-top instruments typically used in laboratories. Specifically, field portable units require high levels of resistance against mechanical shock and chemical attack, ease of use in restrictive gear, extreme reliability, quick and easy interpretation of results, and reduced size. In the last 20 years, FT-IR instruments have been re-engineered to fit in small suitcases for field portable use and recently further miniaturized for handheld operation. This article introduces the HazMatID™ Elite, a FT-IR instrument designed to balance the portability advantages of a handheld device with the performance challenges associated with miniaturization. In this paper, special focus will be given to the HazMatID Elite's sampling interfaces optimized to collect and interrogate different types of samples: accumulated material using the on-board ATR press, dispersed powders using the ClearSampler™ tool, and the touch-to-sample sensor for direct liquid sampling. The application of the novel sample swipe accessory (ClearSampler) to collect material from surfaces will be discussed in some detail. The accessory was tested and evaluated for the detection of explosive residues before and after detonation. Experimental results derived from these investigations will be described in an effort to outline the advantages of this technology over existing sampling methods.

  15. Spin injection into semiconductors

    NASA Astrophysics Data System (ADS)

    Oestreich, M.; Hübner, J.; Hägele, D.; Klar, P. J.; Heimbrodt, W.; Rühle, W. W.; Ashenford, D. E.; Lunn, B.

    1999-03-01

    The injection of spin-polarized electrons is presently one of the major challenges in semiconductor spin electronics. We propose and demonstrate a most efficient spin injection using diluted magnetic semiconductors as spin aligners. Time-resolved photoluminescence with a Cd0.98Mn0.02Te/CdTe structure proves the feasibility of the spin-alignment mechanism.

  16. Semiconductor materials: From gemstone to semiconductor

    NASA Astrophysics Data System (ADS)

    Nebel, Christoph E.

    2003-07-01

    For diamond to be a viable semiconductor it must be possible to change its conductivity by adding impurities - known as dopants. With the discovery of a new dopant that generates electron conductivity at room temperature, diamond emerges as an electronic-grade material.

  17. Isotopically controlled semiconductors

    SciTech Connect

    Haller, E.E.

    2004-11-15

    A review of recent research involving isotopically controlled semiconductors is presented. Studies with isotopically enriched semiconductor structures experienced a dramatic expansion at the end of the Cold War when significant quantities of enriched isotopes of elements forming semiconductors became available for worldwide collaborations. Isotopes of an element differ in nuclear mass, may have different nuclear spins and undergo different nuclear reactions. Among the latter, the capture of thermal neutrons which can lead to neutron transmutation doping, can be considered the most important one for semiconductors. Experimental and theoretical research exploiting the differences in all the properties has been conducted and will be illustrated with selected examples. Manuel Cardona, the longtime editor-in-chief of Solid State Communications has been and continues to be one of the major contributors to this field of solid state physics and it is a great pleasure to dedicate this review to him.

  18. Network connectivity enhancement by exploiting all optical multicast in semiconductor ring laser

    NASA Astrophysics Data System (ADS)

    Siraj, M.; Memon, M. I.; Shoaib, M.; Alshebeili, S.

    2015-03-01

    The use of smart phone and tablet applications will provide the troops for executing, controlling and analyzing sophisticated operations with the commanders providing crucial documents directly to troops wherever and whenever needed. Wireless mesh networks (WMNs) is a cutting edge networking technology which is capable of supporting Joint Tactical radio System (JTRS).WMNs are capable of providing the much needed bandwidth for applications like hand held radios and communication for airborne and ground vehicles. Routing management tasks can be efficiently handled through WMNs through a central command control center. As the spectrum space is congested, cognitive radios are a much welcome technology that will provide much needed bandwidth. They can self-configure themselves, can adapt themselves to the user requirement, provide dynamic spectrum access for minimizing interference and also deliver optimal power output. Sometimes in the indoor environment, there are poor signal issues and reduced coverage. In this paper, a solution utilizing (CR WMNs) over optical network is presented by creating nanocells (PCs) inside the indoor environment. The phenomenon of four-wave mixing (FWM) is exploited to generate all-optical multicast using semiconductor ring laser (SRL). As a result same signal is transmitted at different wavelengths. Every PC is assigned a unique wavelength. By using CR technology in conjunction with PC will not only solve network coverage issue but will provide a good bandwidth to the secondary users.

  19. Method of doping a semiconductor

    DOEpatents

    Yang, Chiang Y.; Rapp, Robert A.

    1983-01-01

    A method for doping semiconductor material. An interface is established between a solid electrolyte and a semiconductor to be doped. The electrolyte is chosen to be an ionic conductor of the selected impurity and the semiconductor material and electrolyte are jointly chosen so that any compound formed from the impurity and the semiconductor will have a free energy no lower than the electrolyte. A potential is then established across the interface so as to allow the impurity ions to diffuse into the semiconductor. In one embodiment the semiconductor and electrolyte may be heated so as to increase the diffusion coefficient.

  20. GUARD RING SEMICONDUCTOR JUNCTION

    DOEpatents

    Goulding, F.S.; Hansen, W.L.

    1963-12-01

    A semiconductor diode having a very low noise characteristic when used under reverse bias is described. Surface leakage currents, which in conventional diodes greatly contribute to noise, are prevented from mixing with the desired signal currents. A p-n junction is formed with a thin layer of heavily doped semiconductor material disposed on a lightly doped, physically thick base material. An annular groove cuts through the thin layer and into the base for a short distance, dividing the thin layer into a peripheral guard ring that encircles the central region. Noise signal currents are shunted through the guard ring, leaving the central region free from such currents. (AEC)

  1. Superconductivity in doped semiconductors

    NASA Astrophysics Data System (ADS)

    Bustarret, E.

    2015-07-01

    A historical survey of the main normal and superconducting state properties of several semiconductors doped into superconductivity is proposed. This class of materials includes selenides, tellurides, oxides and column-IV semiconductors. Most of the experimental data point to a weak coupling pairing mechanism, probably phonon-mediated in the case of diamond, but probably not in the case of strontium titanate, these being the most intensively studied materials over the last decade. Despite promising theoretical predictions based on a conventional mechanism, the occurrence of critical temperatures significantly higher than 10 K has not been yet verified. However, the class provides an enticing playground for testing theories and devices alike.

  2. Amorphous semiconductor solar cell

    DOEpatents

    Dalal, Vikram L.

    1981-01-01

    A solar cell comprising a back electrical contact, amorphous silicon semiconductor base and junction layers and a top electrical contact includes in its manufacture the step of heat treating the physical junction between the base layer and junction layer to diffuse the dopant species at the physical junction into the base layer.

  3. Kansas Advanced Semiconductor Project

    SciTech Connect

    Baringer, P.; Bean, A.; Bolton, T.; Horton-Smith, G.; Maravin, Y.; Ratra, B.; Stanton, N.; von Toerne, E.; Wilson, G.

    2007-09-21

    KASP (Kansas Advanced Semiconductor Project) completed the new Layer 0 upgrade for D0, assumed key electronics projects for the US CMS project, finished important new physics measurements with the D0 experiment at Fermilab, made substantial contributions to detector studies for the proposed e+e- international linear collider (ILC), and advanced key initiatives in non-accelerator-based neutrino physics.

  4. Chemically Derivatized Semiconductor Photoelectrodes.

    ERIC Educational Resources Information Center

    Wrighton, Mark S.

    1983-01-01

    Deliberate modification of semiconductor photoelectrodes to improve durability and enhance rate of desirable interfacial redox processes is discussed for a variety of systems. Modification with molecular-based systems or with metals/metal oxides yields results indicating an important role for surface modification in devices for fundamental study…

  5. Physics of Organic Semiconductors

    NASA Astrophysics Data System (ADS)

    Brütting, Wolfgang

    2004-05-01

    Organic semiconductors are of steadily growing interest as active components in electronics and optoelectronics. Due to their flexibility, low cost and ease-of-production they represent a valid alternative to conventional inorganic semiconductor technology in a number of applications, such as flat panel displays and illumination, plastic integrated circuits or solar energy conversion. Although first commercial applications of this technology are being realized nowadays, there is still the need for a deeper scientific understanding in order to achieve optimum device performance.This special issue of physica status solidi (a) tries to give an overview of our present-day knowledge of the physics behind organic semiconductor devices. Contributions from 17 international research groups cover various aspects of this field ranging from the growth of organic layers and crystals, their electronic properties at interfaces, their photophysics and electrical transport properties to the application of these materials in different devices like organic field-effect transistors, photovoltaic cells and organic light-emitting diodes.Putting together such a special issue one soon realizes that it is simply impossible to fully cover the whole area of organic semiconductors. Nevertheless, we hope that the reader will find the collection of topics in this issue useful for getting an up-to-date review of a field which is still developing very dynamically.

  6. Semiconductor radiation detector

    DOEpatents

    Patt, Bradley E.; Iwanczyk, Jan S.; Tull, Carolyn R.; Vilkelis, Gintas

    2002-01-01

    A semiconductor radiation detector is provided to detect x-ray and light photons. The entrance electrode is segmented by using variable doping concentrations. Further, the entrance electrode is physically segmented by inserting n+ regions between p+ regions. The p+ regions and the n+ regions are individually biased. The detector elements can be used in an array, and the p+ regions and the n+ regions can be biased by applying potential at a single point. The back side of the semiconductor radiation detector has an n+ anode for collecting created charges and a number of p+ cathodes. Biased n+ inserts can be placed between the p+ cathodes, and an internal resistor divider can be used to bias the n+ inserts as well as the p+ cathodes. A polysilicon spiral guard can be implemented surrounding the active area of the entrance electrode or surrounding an array of entrance electrodes.

  7. Doped semiconductor nanocrystal junctions

    NASA Astrophysics Data System (ADS)

    Borowik, Ł.; Nguyen-Tran, T.; Roca i Cabarrocas, P.; Mélin, T.

    2013-11-01

    Semiconductor junctions are the basis of electronic and photovoltaic devices. Here, we investigate junctions formed from highly doped (ND≈1020-1021cm-3) silicon nanocrystals (NCs) in the 2-50 nm size range, using Kelvin probe force microscopy experiments with single charge sensitivity. We show that the charge transfer from doped NCs towards a two-dimensional layer experimentally follows a simple phenomenological law, corresponding to formation of an interface dipole linearly increasing with the NC diameter. This feature leads to analytically predictable junction properties down to quantum size regimes: NC depletion width independent of the NC size and varying as ND-1/3, and depleted charge linearly increasing with the NC diameter and varying as ND1/3. We thus establish a "nanocrystal counterpart" of conventional semiconductor planar junctions, here however valid in regimes of strong electrostatic and quantum confinements.

  8. Light amplification using semiconductors

    SciTech Connect

    Dupuis, R.D.

    1987-06-01

    During the summer of 1953, John von Neumann discussed his ideas concerning light amplification using semiconductors with Edward Teller. In September of that year, von Neumann sent a manuscript containing his ideas and calculations on this subject to Teller for his comments. To the best of our knowledge, von Neumann did not take time to work further on these ideas, and the manuscript remained unpublished. These previously unpublished writings of John von Neumann on the subject of light amplification in semiconductors are printed as a service to the laser community. While von Neumann's original manuscript and his letter to Teller are available to anyone who visits the Library of Congress, it is much more convenient to have this paper appear in an archival journal.

  9. Isotopically controlled semiconductors

    SciTech Connect

    Haller, Eugene E.

    2006-06-19

    The following article is an edited transcript based on the Turnbull Lecture given by Eugene E. Haller at the 2005 Materials Research Society Fall Meeting in Boston on November 29, 2005. The David Turnbull Lectureship is awarded to recognize the career of a scientist who has made outstanding contributions to understanding materials phenomena and properties through research, writing, and lecturing, as exemplified by the life work of David Turnbull. Haller was named the 2005 David Turnbull Lecturer for his 'pioneering achievements and leadership in establishing the field of isotopically engineered semiconductors; for outstanding contributions to materials growth, doping and diffusion; and for excellence in lecturing, writing, and fostering international collaborations'. The scientific interest, increased availability, and technological promise of highly enriched isotopes have led to a sharp rise in the number of experimental and theoretical studies with isotopically controlled semiconductor crystals. This article reviews results obtained with isotopically controlled semiconductor bulk and thin-film heterostructures. Isotopic composition affects several properties such as phonon energies, band structure, and lattice constant in subtle, but, for their physical understanding, significant ways. Large isotope-related effects are observed for thermal conductivity in local vibrational modes of impurities and after neutron transmutation doping. Spectacularly sharp photoluminescence lines have been observed in ultrapure, isotopically enriched silicon crystals. Isotope multilayer structures are especially well suited for simultaneous self- and dopant-diffusion studies. The absence of any chemical, mechanical, or electrical driving forces makes possible the study of an ideal random-walk problem. Isotopically controlled semiconductors may find applications in quantum computing, nanoscience, and spintronics.

  10. Tunable semiconductor lasers

    NASA Technical Reports Server (NTRS)

    Taghavi-Larigani, Shervin (Inventor); Vanzyl, Jakob J. (Inventor); Yariv, Amnon (Inventor)

    2006-01-01

    Tunable semiconductor lasers are disclosed requiring minimized coupling regions. Multiple laser embodiments employ ring resonators or ring resonator pairs using only a single coupling region with the gain medium are detailed. Tuning can be performed by changing the phase of the coupling coefficient between the gain medium and a ring resonator of the laser. Another embodiment provides a tunable laser including two Mach-Zehnder interferometers in series and a reflector coupled to a gain medium.

  11. Semiconductor Ion Implanters

    SciTech Connect

    MacKinnon, Barry A.; Ruffell, John P.

    2011-06-01

    In 1953 the Raytheon CK722 transistor was priced at $7.60. Based upon this, an Intel Xeon Quad Core processor containing 820,000,000 transistors should list at $6.2 billion. Particle accelerator technology plays an important part in the remarkable story of why that Intel product can be purchased today for a few hundred dollars. Most people of the mid twentieth century would be astonished at the ubiquity of semiconductors in the products we now buy and use every day. Though relatively expensive in the nineteen fifties they now exist in a wide range of items from high-end multicore microprocessors like the Intel product to disposable items containing 'only' hundreds or thousands like RFID chips and talking greeting cards. This historical development has been fueled by continuous advancement of the several individual technologies involved in the production of semiconductor devices including Ion Implantation and the charged particle beamlines at the heart of implant machines. In the course of its 40 year development, the worldwide implanter industry has reached annual sales levels around $2B, installed thousands of dedicated machines and directly employs thousands of workers. It represents in all these measures, as much and possibly more than any other industrial application of particle accelerator technology. This presentation discusses the history of implanter development. It touches on some of the people involved and on some of the developmental changes and challenges imposed as the requirements of the semiconductor industry evolved.

  12. Semiconductor Ion Implanters

    NASA Astrophysics Data System (ADS)

    MacKinnon, Barry A.; Ruffell, John P.

    2011-06-01

    In 1953 the Raytheon CK722 transistor was priced at 7.60. Based upon this, an Intel Xeon Quad Core processor containing 820,000,000 transistors should list at 6.2 billion! Particle accelerator technology plays an important part in the remarkable story of why that Intel product can be purchased today for a few hundred dollars. Most people of the mid twentieth century would be astonished at the ubiquity of semiconductors in the products we now buy and use every day. Though relatively expensive in the nineteen fifties they now exist in a wide range of items from high-end multicore microprocessors like the Intel product to disposable items containing `only' hundreds or thousands like RFID chips and talking greeting cards. This historical development has been fueled by continuous advancement of the several individual technologies involved in the production of semiconductor devices including Ion Implantation and the charged particle beamlines at the heart of implant machines. In the course of its 40 year development, the worldwide implanter industry has reached annual sales levels around 2B, installed thousands of dedicated machines and directly employs thousands of workers. It represents in all these measures, as much and possibly more than any other industrial application of particle accelerator technology. This presentation discusses the history of implanter development. It touches on some of the people involved and on some of the developmental changes and challenges imposed as the requirements of the semiconductor industry evolved.

  13. Theory of hydrogen in semiconductors

    SciTech Connect

    Walle, C.G. van de

    1998-12-31

    This paper treats the subject of hydrogen in semiconductors from various perspectives. First, a brief historical overview is given. Then, some basic principles governing the interaction between hydrogen and semiconductors are outlined. Finally, specific examples will emphasize the impact of hydrogen on technological applications. While the general treatment applies to interactions of hydrogen with any semiconductor, the applications will focus mainly on hydrogen interacting with silicon.

  14. New developments in power semiconductors

    NASA Technical Reports Server (NTRS)

    Sundberg, G. R.

    1983-01-01

    This paper represents an overview of some recent power semiconductor developments and spotlights new technologies that may have significant impact for aircraft electric secondary power. Primary emphasis will be on NASA-Lewis-supported developments in transistors, diodes, a new family of semiconductors, and solid-state remote power controllers. Several semiconductor companies that are moving into the power arena with devices rated at 400 V and 50 A and above are listed, with a brief look at a few devices.

  15. Method of passivating semiconductor surfaces

    DOEpatents

    Wanlass, M.W.

    1990-06-19

    A method is described for passivating Group III-V or II-VI semiconductor compound surfaces. The method includes selecting a passivating material having a lattice constant substantially mismatched to the lattice constant of the semiconductor compound. The passivating material is then grown as an ultrathin layer of passivating material on the surface of the Group III-V or II-VI semiconductor compound. The passivating material is grown to a thickness sufficient to maintain a coherent interface between the ultrathin passivating material and the semiconductor compound. In addition, a device formed from such method is also disclosed.

  16. Method of passivating semiconductor surfaces

    DOEpatents

    Wanlass, Mark W.

    1990-01-01

    A method of passivating Group III-V or II-VI semiconductor compound surfaces. The method includes selecting a passivating material having a lattice constant substantially mismatched to the lattice constant of the semiconductor compound. The passivating material is then grown as an ultrathin layer of passivating material on the surface of the Group III-V or II-VI semiconductor compound. The passivating material is grown to a thickness sufficient to maintain a coherent interface between the ultrathin passivating material and the semiconductor compound. In addition, a device formed from such method is also disclosed.

  17. Semiconductor nanorod liquid crystals

    SciTech Connect

    Li, Liang-shi; Walda, Joost; Manna, Liberato; Alivisatos, A. Paul

    2002-01-28

    Rodlike molecules form liquid crystalline phases with orientational order and positional disorder. The great majority of materials in which liquid crystalline phases have been observed are comprised of organic molecules or polymers, even though there has been continuing and growing interest in inorganic liquid crystals. Recent advances in the control of the sizes and shapes of inorganic nanocrystals allow for the formation of a broad class of new inorganic liquid crystals. Here we show the formation of liquid crystalline phases of CdSe semiconductor nanorods. These new liquid crystalline phases may have great importance for both application and fundamental study.

  18. Semiconductor cooling apparatus

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A. (Inventor); Gaier, James R. (Inventor)

    1993-01-01

    Gas derived graphite fibers generated by the decomposition of an organic gas are joined with a suitable binder. This produces a high thermal conductivity composite material which passively conducts heat from a source, such as a semiconductor, to a heat sink. The fibers may be intercalated. The intercalate can be halogen or halide salt, alkaline metal, or any other species which contributes to the electrical conductivity improvement of the graphite fiber. The fibers are bundled and joined with a suitable binder to form a high thermal conductivity composite material device. The heat transfer device may also be made of intercalated highly oriented pyrolytic graphite and machined, rather than made of fibers.

  19. Semiconductor superlattice photodetectors

    NASA Technical Reports Server (NTRS)

    Chuang, S. L.; Hess, K.; Coleman, J. J.; Leburton, J. P.

    1984-01-01

    A superlattice photomultiplier and a photodetector based on the real space transfer mechanism were studied. The wavelength for the first device is of the order of a micron or flexible corresponding to the bandgap absorption in a semiconductor. The wavelength for the second device is in the micron range (about 2 to 12 microns) corresponding to the energy of the conduction band edge discontinuity between an Al/(sub x)Ga(sub 1-x)As and GaAs interface. Both devices are described.

  20. Semiconductor structure and devices

    NASA Technical Reports Server (NTRS)

    Dinkel, Nancy A. (Inventor); Goldstein, Bernard (Inventor); Ettenberg, Michael (Inventor)

    1987-01-01

    Semiconductor devices such as lasers which include a substrate with a channel therein with a clad layer overlying the substrate and filling the channel exhibit irregularities such as terraces in the surface of the clad layer which are detrimental to device performance. These irregularities are substantially eliminated by forming the channel in a surface of a buffer layer greater than about 4 micrometers thick on the substrate and forming the clad layer over the buffer layer and the channel. CW lasers incorporating the principles of the invention exhibit the highest output power in a single spatial mode and maximum output power which have been observed to date.

  1. Isotopically controlled semiconductors

    SciTech Connect

    Haller, Eugene E.

    2001-12-21

    Semiconductor bulk crystals and multilayer structures with controlled isotopic composition have attracted much scientific and technical interest in the past few years. Isotopic composition affects a large number of physical properties, including phonon energies and lifetimes, bandgaps, the thermal conductivity and expansion coefficient and spin-related effects. Isotope superlattices are ideal media for self-diffusion studies. In combination with neutron transmutation doping, isotope control offers a novel approach to metal-insulator transition studies. Spintronics, quantum computing and nanoparticle science are emerging fields using isotope control.

  2. Composite Semiconductor Substrates

    NASA Technical Reports Server (NTRS)

    Nouhi, Akbar; Radhakrishnan, Gouri; Katz, Joseph; Koliwad, Kris

    1989-01-01

    Epitaxial structure of three semiconductor materials - silicon, gallium arsenide, and cadmium telluride - makes possible integrated monolithic focal-plane arrays of photodectors. Silicon layer contains charge-coupled devices, gallium arsenide layer contains other fast electronic circuitry, and cadmium telluride layer serves as base for array of mercury cadmium telluride infrared sensors. Technique effectively combines two well-established techniques; metalorganic chemical-vapor deposition (MOCVD) and molecular-beam epitaxy (MBE). Multilayer structure includes HgCdTe light sensors with Si readout devices and GaAs signal-processing circuits. CdTe layer provides base for building up HgCdTe layer.

  3. The Kingdom of Semiconductors

    NASA Astrophysics Data System (ADS)

    Bellac, Michel Le

    2014-11-01

    In this chapter, we move on to the case of fermions, and we shall find out that fermions are no less interesting than bosons! In practice, electrons are the most important example of fermions, because they are responsible for electrical conductivity in metals and semiconductors. It is impossible to understand a phenomenon as familiar as electrical conductivity without appealing to quantum physics. Two properties play a fundamental role: first the propagation of electron waves in crystal lattices, and second the Pauli exclusion principle, which is a consequence of the fermionic character of the electrons. In Section 6.1, we introduce electron wave propagation in crystals which gives rise to the phenomenon of energy bands, and we describe the filling of these bands according to the Pauli principle. These results will be used in Section 6.2 to describe the electronic properties of semiconductors, on which almost all our modern technology (laser diodes, optical fiber communication, computers, smartphones and so forth) is grounded. Finally, in Sections 6.3 and 6.4, we shall describe the principles of light emitting diodes (LEDs) and laser diodes.

  4. Doped semiconductor nanocrystal junctions

    SciTech Connect

    Borowik, Ł.; Mélin, T.; Nguyen-Tran, T.; Roca i Cabarrocas, P.

    2013-11-28

    Semiconductor junctions are the basis of electronic and photovoltaic devices. Here, we investigate junctions formed from highly doped (N{sub D}≈10{sup 20}−10{sup 21}cm{sup −3}) silicon nanocrystals (NCs) in the 2–50 nm size range, using Kelvin probe force microscopy experiments with single charge sensitivity. We show that the charge transfer from doped NCs towards a two-dimensional layer experimentally follows a simple phenomenological law, corresponding to formation of an interface dipole linearly increasing with the NC diameter. This feature leads to analytically predictable junction properties down to quantum size regimes: NC depletion width independent of the NC size and varying as N{sub D}{sup −1/3}, and depleted charge linearly increasing with the NC diameter and varying as N{sub D}{sup 1/3}. We thus establish a “nanocrystal counterpart” of conventional semiconductor planar junctions, here however valid in regimes of strong electrostatic and quantum confinements.

  5. Doping semiconductor nanocrystals.

    PubMed

    Erwin, Steven C; Zu, Lijun; Haftel, Michael I; Efros, Alexander L; Kennedy, Thomas A; Norris, David J

    2005-07-01

    Doping--the intentional introduction of impurities into a material--is fundamental to controlling the properties of bulk semiconductors. This has stimulated similar efforts to dope semiconductor nanocrystals. Despite some successes, many of these efforts have failed, for reasons that remain unclear. For example, Mn can be incorporated into nanocrystals of CdS and ZnSe (refs 7-9), but not into CdSe (ref. 12)--despite comparable bulk solubilities of near 50 per cent. These difficulties, which have hindered development of new nanocrystalline materials, are often attributed to 'self-purification', an allegedly intrinsic mechanism whereby impurities are expelled. Here we show instead that the underlying mechanism that controls doping is the initial adsorption of impurities on the nanocrystal surface during growth. We find that adsorption--and therefore doping efficiency--is determined by three main factors: surface morphology, nanocrystal shape, and surfactants in the growth solution. Calculated Mn adsorption energies and equilibrium shapes for several nanocrystals lead to specific doping predictions. These are confirmed by measuring how the Mn concentration in ZnSe varies with nanocrystal size and shape. Finally, we use our predictions to incorporate Mn into previously undopable CdSe nanocrystals. This success establishes that earlier difficulties with doping are not intrinsic, and suggests that a variety of doped nanocrystals--for applications from solar cells to spintronics--can be anticipated. PMID:16001066

  6. Semiconductor cylinder fiber laser

    NASA Astrophysics Data System (ADS)

    Sandupatla, Abhinay; Flattery, James; Kornreich, Philipp

    2015-12-01

    We fabricated a fiber laser that uses a thin semiconductor layer surrounding the glass core as the gain medium. This is a completely new type of laser. The In2Te3 semiconductor layer is about 15-nm thick. The fiber laser has a core diameter of 14.2 μm, an outside diameter of 126 μm, and it is 25-mm long. The laser mirrors consist of a thick vacuum-deposited aluminum layer at one end and a thin semitransparent aluminum layer deposited at the other end of the fiber. The laser is pumped from the side with either light from a halogen tungsten incandescent lamp or a blue light emitting diode flash light. Both the In2Te3 gain medium and the aluminum mirrors have a wide bandwidth. Therefore, the output spectrum consists of a pedestal from a wavelength of about 454 to 623 nm with several peaks. There is a main peak at 545 nm. The main peak has an amplitude of 16.5 dB above the noise level of -73 dB.

  7. Isotopically engineered semiconductors

    NASA Astrophysics Data System (ADS)

    Haller, E. E.

    1995-04-01

    Scientific interest, technological promise, and increased availability of highly enriched isotopes have led to a sharp rise in the number of experimental and theoretical studies with isotopically controlled semiconductor crystals. This review of mostly recent activities begins with an introduction to some past classical experiments which have been performed on isotopically controlled semiconductors. A review of the natural isotopic composition of the relevant elements follows. Some materials aspects resulting in part from the high costs of enriched isotopes are discussed next. Raman spectroscopy studies with a number of isotopically pure and deliberately mixed Ge bulk crystals show that the Brillouin-zone-center optical phonons are not localized. Their lifetime is almost independent of isotopic disorder, leading to homogeneous Raman line broadening. Studies with short period isotope superlattices consisting of alternating layers of n atomic planes of 70Ge and 74Ge reveal a host of zone-center phonons due to Brillouin-zone folding. At n≳40 one observes two phonon lines at frequencies corresponding to the bulk values of the two isotopes. In natural diamond, isotope scattering of the low-energy phonons, which are responsible for the thermal conductivity, is very strongly affected by small isotope disorder. Isotopically pure 12C diamond crystals exhibit thermal conductivities as high as 410 W cm-1 K-1 at 104 K, leading to projected values of over 2000 W cm-1 K-1 near 80 K. The changes in phonon properties with isotopic composition also weakly affect the electronic band structures and the lattice constants. The latter isotope dependence is most relevant for future standards of length based on crystal lattice constants. Capture of thermal neutrons by isotope nuclei followed by nuclear decay produces new elements, resulting in a very large number of possibilities for isotope selective doping of semiconductors. This neutron transmutation of isotope nuclei, already used

  8. Semiconductor devices incorporating multilayer interference regions

    DOEpatents

    Biefeld, R.M.; Drummond, T.J.; Gourley, P.L.; Zipperian, T.E.

    1987-08-31

    A semiconductor high reflector comprising a number of thin alternating layers of semiconductor materials is electrically tunable and may be used as a temperature insensitive semiconductor laser in a Fabry-Perot configuration. 8 figs.

  9. Semiconductor devices incorporating multilayer interference regions

    DOEpatents

    Biefeld, Robert M.; Drummond, Timothy J.; Gourley, Paul L.; Zipperian, Thomas E.

    1990-01-01

    A semiconductor high reflector comprising a number of thin alternating layers of semiconductor materials is electrically tunable and may be used as a temperature insensitive semiconductor laser in a Fabry-Perot configuration.

  10. Fibre ring cavity semiconductor laser

    SciTech Connect

    Duraev, V P; Medvedev, S V

    2013-10-31

    This paper presents a study of semiconductor lasers having a polarisation maintaining fibre ring cavity. We examine the operating principle and report main characteristics of a semiconductor ring laser, in particular in single- and multiple-frequency regimes, and discuss its application areas. (lasers)

  11. Process for producing chalcogenide semiconductors

    DOEpatents

    Noufi, R.; Chen, Y.W.

    1985-04-30

    A process for producing chalcogenide semiconductor material is disclosed. The process includes forming a base metal layer and then contacting this layer with a solution having a low pH and containing ions from at least one chalcogen to chalcogenize the layer and form the chalcogenide semiconductor material.

  12. Process for producing chalcogenide semiconductors

    DOEpatents

    Noufi, Rommel; Chen, Yih-Wen

    1987-01-01

    A process for producing chalcogenide semiconductor material is disclosed. The process includes forming a base metal layer and then contacting this layer with a solution having a low pH and containing ions from at least one chalcogen to chalcogenize the layer and form the chalcogenide semiconductor material.

  13. Variable temperature semiconductor film deposition

    DOEpatents

    Li, X.; Sheldon, P.

    1998-01-27

    A method of depositing a semiconductor material on a substrate is disclosed. The method sequentially comprises (a) providing the semiconductor material in a depositable state such as a vapor for deposition on the substrate; (b) depositing the semiconductor material on the substrate while heating the substrate to a first temperature sufficient to cause the semiconductor material to form a first film layer having a first grain size; (c) continually depositing the semiconductor material on the substrate while cooling the substrate to a second temperature sufficient to cause the semiconductor material to form a second film layer deposited on the first film layer and having a second grain size smaller than the first grain size; and (d) raising the substrate temperature, while either continuing or not continuing to deposit semiconductor material to form a third film layer, to thereby anneal the film layers into a single layer having favorable efficiency characteristics in photovoltaic applications. A preferred semiconductor material is cadmium telluride deposited on a glass/tin oxide substrate already having thereon a film layer of cadmium sulfide.

  14. Variable temperature semiconductor film deposition

    DOEpatents

    Li, Xiaonan; Sheldon, Peter

    1998-01-01

    A method of depositing a semiconductor material on a substrate. The method sequentially comprises (a) providing the semiconductor material in a depositable state such as a vapor for deposition on the substrate; (b) depositing the semiconductor material on the substrate while heating the substrate to a first temperature sufficient to cause the semiconductor material to form a first film layer having a first grain size; (c) continually depositing the semiconductor material on the substrate while cooling the substrate to a second temperature sufficient to cause the semiconductor material to form a second film layer deposited on the first film layer and having a second grain size smaller than the first grain size; and (d) raising the substrate temperature, while either continuing or not continuing to deposit semiconductor material to form a third film layer, to thereby anneal the film layers into a single layer having favorable efficiency characteristics in photovoltaic applications. A preferred semiconductor material is cadmium telluride deposited on a glass/tin oxide substrate already having thereon a film layer of cadmium sulfide.

  15. Physics with isotopically controlled semiconductors

    SciTech Connect

    Haller, E. E.

    2010-07-15

    This paper is based on a tutorial presentation at the International Conference on Defects in Semiconductors (ICDS-25) held in Saint Petersburg, Russia in July 2009. The tutorial focused on a review of recent research involving isotopically controlled semiconductors. Studies with isotopically enriched semiconductor structures experienced a dramatic expansion at the end of the Cold War when significant quantities of enriched isotopes of elements forming semiconductors became available for worldwide collaborations. Isotopes of an element differ in nuclear mass, may have different nuclear spins and undergo different nuclear reactions. Among the latter, the capture of thermal neutrons which can lead to neutron transmutation doping, is the most prominent effect for semiconductors. Experimental and theoretical research exploiting the differences in all the properties has been conducted and will be illustrated with selected examples.

  16. Functionalization of Semiconductor Nanoparticles

    NASA Astrophysics Data System (ADS)

    Baraton, M.-I.

    Functionalization of nanoparticles surface by attachment of organic entities is used to achieve and tailor many new properties, such as lubrication, optical response, chemical sensing, or biocompatibility. But because at the nanometer scale the surface properties significantly contribute to the overall properties, the consequences of the surface modifications have to be thoroughly evaluated. This paper demonstrates the relevance of Fourier transform infrared spectroscopy to the study of the surface reactions leading to the functionalization, and of the stability of the functionalized surface under the expected working conditions. In the case of semiconductor nanoparticles, this technique additionally allows the analysis of the impact of the functionalization on the electrical properties. This will be illustrated by the case study of tin oxide nanoparticles for chemical gas sensors. The correlation between surface chemistry and electrical properties is critical to optimize the nanoparticles functionalization for the targeted properties.

  17. Hydrogen on semiconductor surfaces

    SciTech Connect

    Schaefer, J.A.; Balster, T.; Polyakov, V.; Rossow, U.; Sloboshanin, S.; Starke, U.; Tautz, F.S.

    1998-12-31

    The authors review structural and electronic aspects of the reaction of hydrogen with semiconductor surfaces. Among others, they address the Si(100), Ge{sub x}Si{sub 1{minus}x}(100), GaAs(100), InP(100), SiC(100), SiC(0001) and SiC(000{bar 1}) surfaces. It is demonstrated that high resolution electron energy loss spectroscopy (HREELS) in conjunction with a number of other surface sensitive techniques like low energy electron diffraction (LEED) and photoelectron spectroscopy (XPS/UPS) can yield important information about the surface atomic structure, the effects of hydrogen passivation and etching and on electronic properties of the surfaces. 67 refs., 7 figs., 3 tabs.

  18. Photocatalysis Using Semiconductor Nanoclusters

    SciTech Connect

    Thurston, T.R.; Wilcoxon,J.P.

    1999-01-21

    We report on experiments using nanosize MoS{sub 2} to photo-oxidize organic pollutants in water using visible light as the energy source. We have demonstrated that we can vary the redox potentials and absorbance characteristics of these small semiconductors by adjusting their size, and our studies of the photooxidation of organic molecules have revealed that the rate of oxidation increases with increasing bandgap (i.e. more positive valence band and more negative conduction band potentials). Because these photocatalysis reactions can be performed with the nanoclusters fully dispersed and stable in solution, liquid chromatography can be used to determine both the intermediate reaction products and the state of the nanoclusters during the reaction. We have demonstrated that the MoS{sub 2} nanoclusters remain unchanged during the photooxidation process by this technique. We also report on studies of MoS{sub 2} nanoclusters deposited on TiO{sub 2} powder.

  19. Semiconductor nanowire lasers

    NASA Astrophysics Data System (ADS)

    Eaton, Samuel W.; Fu, Anthony; Wong, Andrew B.; Ning, Cun-Zheng; Yang, Peidong

    2016-06-01

    The discovery and continued development of the laser has revolutionized both science and industry. The advent of miniaturized, semiconductor lasers has made this technology an integral part of everyday life. Exciting research continues with a new focus on nanowire lasers because of their great potential in the field of optoelectronics. In this Review, we explore the latest advancements in the development of nanowire lasers and offer our perspective on future improvements and trends. We discuss fundamental material considerations and the latest, most effective materials for nanowire lasers. A discussion of novel cavity designs and amplification methods is followed by some of the latest work on surface plasmon polariton nanowire lasers. Finally, exciting new reports of electrically pumped nanowire lasers with the potential for integrated optoelectronic applications are described.

  20. Semiconductor radiation detector

    DOEpatents

    Bell, Zane W.; Burger, Arnold

    2010-03-30

    A semiconductor detector for ionizing electromagnetic radiation, neutrons, and energetic charged particles. The detecting element is comprised of a compound having the composition I-III-VI.sub.2 or II-IV-V.sub.2 where the "I" component is from column 1A or 1B of the periodic table, the "II" component is from column 2B, the "III" component is from column 3A, the "IV" component is from column 4A, the "V" component is from column 5A, and the "VI" component is from column 6A. The detecting element detects ionizing radiation by generating a signal proportional to the energy deposited in the element, and detects neutrons by virtue of the ionizing radiation emitted by one or more of the constituent materials subsequent to capture. The detector may contain more than one neutron-sensitive component.

  1. Semiconductor Nanocrystals for Biological Imaging

    SciTech Connect

    Fu, Aihua; Gu, Weiwei; Larabell, Carolyn; Alivisatos, A. Paul

    2005-06-28

    Conventional organic fluorophores suffer from poor photo stability, narrow absorption spectra and broad emission feature. Semiconductor nanocrystals, on the other hand, are highly photo-stable with broad absorption spectra and narrow size-tunable emission spectra. Recent advances in the synthesis of these materials have resulted in bright, sensitive, extremely photo-stable and biocompatible semiconductor fluorophores. Commercial availability facilitates their application in a variety of unprecedented biological experiments, including multiplexed cellular imaging, long-term in vitro and in vivo labeling, deep tissue structure mapping and single particle investigation of dynamic cellular processes. Semiconductor nanocrystals are one of the first examples of nanotechnology enabling a new class of biomedical applications.

  2. Electric currents and fields induced in cells in the human brain by radiation from hand-held cellular telephones

    NASA Astrophysics Data System (ADS)

    King, Ronold W. P.

    2000-01-01

    After a review of recent work on the interaction of electromagnetic fields from cellular telephones with the human head, the structural and radiating properties of two common types of transceivers are determined. These include the impedance and current amplitude distribution of the antennas. The tangential electric field maintained by the antennas on the adjacent surface of the head is next determined. From this, the electric field propagating through the skull into the brain is analyzed and, from it, the electric field in spherical and long cylindrical cells is determined. It ranges from 27 to 13.5 V/m in the first 3 cm inside the skull. Of interest is the fact that the induced field in the interior of all cells, regardless of their shape, is the same as the incident field in the brain. It is hoped that biomedical scientists will review these results and determine possible biological effects.

  3. The Rubble Rescue Radar (RRR): A low power hand-held microwave device for the detection of trapped human personnel

    SciTech Connect

    Haddad, W.S.

    1997-04-10

    Each year, innocent human lives are lost in collapsed structures as a result of both natural and man-made disasters. We have developed a prototype device, called the Rubble Rescue Radar (RRR) as a aid to workers trying to locate trapped victims in urban search and rescue operations. The RRR is a motion sensor incorporating Micropower Impulse Radar and is capable of detecting human breathing motions through reinforced concrete. It is lightweight, and designed to be handled by a single operator for local searches in areas where trapped victims are expected. Tests of the first prototype device were conducted on site at LLNL using a mock rubble pile consisting of a reinforced concrete pipe with two concrete floor slabs placed against one side, and random concrete and asphalt debris piled against the other. This arrangement provides safe and easy access for instruments and/or human subjects. Breathing signals of a human subject were recorded with the RRR through one floor slab plus the wall of the pipe, two slabs plus the wall of the pipe, and the random rubble plus the wall of the pipe. Breathing and heart beat signals were also recorded of a seated human subject at a distance of 1 meter with no obstructions. Results and photographs of the experimental work are presented, and a design concept for the next generation device is described.

  4. In vitro validation of a hand-held optical reflectometer to measure clinically observed erosive tooth wear.

    PubMed

    Carvalho, Thiago Saads; Assunção, Cristiane Meira; Jost, Fabian; Bürgin, Walter Bruno; Rodrigues, Jonas Almeida; Lussi, Adrian

    2016-08-01

    In this study, we analyzed a newly developed optical reflectometer for measuring erosive tooth wear (ETW) in vitro. Three examiners independently assessed the labial surface of 80 deciduous canines and 75 permanent incisors. One examiner performed visual examinations (BEWE), and the other two used the optical pen-size reflectometer to measure surface reflection intensity (SRI) on the same labial surfaces. The examinations were made in duplicate with at least 1 week interval. Intra- and inter-rater agreements were calculated using weighted kappa analysis for BEWE, and intra-class correlation coefficients (ICC) as well as Bland-Altman plots for SRI. The teeth were separated into without (BEWE 0) or with (BEWE 1-3) ETW, and SRI cut-off points were calculated. Intra-rater agreement for the visual examination was 0.46 and 0.82 for deciduous and permanent teeth, respectively. Inter-rater and intra-rater agreement for SRI were good (ICC > 0.7; p < 0.001). SRI measurements produced high specificity values for deciduous and permanent teeth (≥0.74 and ≥ 0.84, respectively), and lower sensitivity values (≥0.37 and ≥ 0.64, respectively), but permanent teeth had generally higher SRI values (p < 0.05). We observed a significant association between BEWE and SRI (p < 0.05). The optical pen-size reflectometer was able to adequately differentiate ETW on permanent teeth, with highly reliable and reproducible measurements, but ETW on deciduous teeth was less accurately differentiated. The reflectometer is a good candidate for clinical research. PMID:27184156

  5. Cellphone-based hand-held microplate reader for point-of-care ELISA testing (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Berg, Brandon; Cortazar, Bingen; Tseng, Derek; Ozkan, Haydar; Feng, Steve; Wei, Qingshan; Chan, Raymond Y.; Burbano, Jordi; Farooqui, Qamar; Lewinski, Michael; Di Carlo, Dino; Garner, Omai B.; Ozcan, Aydogan

    2016-03-01

    Enzyme-linked immunosorbent assay (ELISA) in a microplate format has been a gold standard first-line clinical test for diagnosis of various diseases including infectious diseases. However, this technology requires a relatively large and expensive multi-well scanning spectrophotometer to read and quantify the signal from each well, hindering its implementation in resource-limited-settings. Here, we demonstrate a cost-effective and handheld smartphone-based colorimetric microplate reader for rapid digitization and quantification of immunoserology-related ELISA tests in a conventional 96-well plate format at the point of care (POC). This device consists of a bundle of 96 optical fibers to collect the transmitted light from each well of the microplate and direct all the transmission signals from the wells onto the camera of the mobile-phone. Captured images are then transmitted to a remote server through a custom-designed app, and both quantitative and qualitative diagnostic results are returned back to the user within ~1 minute per 96-well plate by using a machine learning algorithm. We tested this mobile-phone based micro-plate reader in a clinical microbiology lab using FDA-approved mumps IgG, measles IgG, and herpes simplex virus IgG (HSV-1 and HSV-2) ELISA tests on 1138 remnant patient samples (roughly 50% training and 50% testing), and achieved an overall accuracy of ~99% or higher for each ELISA test. This handheld and cost-effective platform could be immediately useful for large-scale vaccination monitoring in low-infrastructure settings, and also for other high-throughput disease screening applications at POC.

  6. A prototype hand-held tri-modal instrument for in vivo ultrasound, photoacoustic, and fluorescence imaging

    NASA Astrophysics Data System (ADS)

    Kang, Jeeun; Chang, Jin Ho; Wilson, Brian C.; Veilleux, Israel; Bai, Yanhui; DaCosta, Ralph; Kim, Kang; Ha, Seunghan; Lee, Jong Gun; Kim, Jeong Seok; Lee, Sang-Goo; Kim, Sun Mi; Lee, Hak Jong; Ahn, Young Bok; Han, Seunghee; Yoo, Yangmo; Song, Tai-Kyong

    2015-03-01

    Multi-modality imaging is beneficial for both preclinical and clinical applications as it enables complementary information from each modality to be obtained in a single procedure. In this paper, we report the design, fabrication, and testing of a novel tri-modal in vivo imaging system to exploit molecular/functional information from fluorescence (FL) and photoacoustic (PA) imaging as well as anatomical information from ultrasound (US) imaging. The same ultrasound transducer was used for both US and PA imaging, bringing the pulsed laser light into a compact probe by fiberoptic bundles. The FL subsystem is independent of the acoustic components but the front end that delivers and collects the light is physically integrated into the same probe. The tri-modal imaging system was implemented to provide each modality image in real time as well as co-registration of the images. The performance of the system was evaluated through phantom and in vivo animal experiments. The results demonstrate that combining the modalities does not significantly compromise the performance of each of the separate US, PA, and FL imaging techniques, while enabling multi-modality registration. The potential applications of this novel approach to multi-modality imaging range from preclinical research to clinical diagnosis, especially in detection/localization and surgical guidance of accessible solid tumors.

  7. An inexpensive method for kinematic calibration of a parallel robot by using one hand-held camera as main sensor.

    PubMed

    Traslosheros, Alberto; Sebastián, José María; Torrijos, Jesús; Carelli, Ricardo; Castillo, Eduardo

    2013-01-01

    This paper presents a novel method for the calibration of a parallel robot, which allows a more accurate configuration instead of a configuration based on nominal parameters. It is used, as the main sensor with one camera installed in the robot hand that determines the relative position of the robot with respect to a spherical object fixed in the working area of the robot. The positions of the end effector are related to the incremental positions of resolvers of the robot motors. A kinematic model of the robot is used to find a new group of parameters, which minimizes errors in the kinematic equations. Additionally, properties of the spherical object and intrinsic camera parameters are utilized to model the projection of the object in the image and thereby improve spatial measurements. Finally, several working tests, static and tracking tests are executed in order to verify how the robotic system behaviour improves by using calibrated parameters against nominal parameters. In order to emphasize that, this proposed new method uses neither external nor expensive sensor. That is why new robots are useful in teaching and research activities. PMID:23921827

  8. An Evaluation of the Implementation of Hand Held Health Records with Adults with Learning Disabilities: A Cluster Randomized Controlled Trial

    ERIC Educational Resources Information Center

    Turk, Vicky; Burchell, Sarah; Burrha, Sukhjinder; Corney, Roslyn; Elliott, Sandra; Kerry, Sally; Molloy, Catherine; Painter, Kerry

    2010-01-01

    Background: Personal health records were implemented with adults with learning disabilities (AWLD) to try to improve their health-care. Materials and Method: Forty GP practices were randomized to the Personal Health Profile (PHP) implementation or control group. Two hundred and one AWLD were interviewed at baseline and 163 followed up after 12…

  9. A Hand-held Fiber-optic Implement for the Site-specific Delivery of Photosensitizer and Singlet Oxygen

    PubMed Central

    Mahendran, Adaickapillai; Kopkalli, Yasemin; Ghosh, Goutam; Ghogare, Ashwini; Minnis, Mihaela; Kruft, Bonnie I.; Zamadar, Matibur; Aebisher, David; Davenport, Lesley; Greer, Alexander

    2012-01-01

    We have constructed a fiber optic device that internally flows triplet oxygen and externally produces singlet oxygen, causing a reaction at the (Z)-1,2-dialkoxyethene spacer group, freeing a pheophorbide sensitizer upon the fragmentation of a reactive dioxetane intermediate. The device can be operated and sensitizer photorelease observed using absorption and fluorescence spectroscopy. We demonstrate the preference of sensitizer photorelease when the probe tip is in contact with octanol or lipophilic media. A first-order photocleavage rate constant of 1.13 h−1 was measured in octanol where dye desorption was not accompanied by readsorption. When the probe tip contacts aqueous solution, the photorelease was inefficient because most of the dye adsorbed on the probe tip, even after the covalent ethene spacer bonds have been broken. The observed stability of the free sensitizer in lipophilic media is reasonable even though it is a pyropheophorbide-a derivative that carries a p-formylbenzylic alcohol substituent at the carboxylic acid group. In octanol or lipid systems, we found that the dye was not susceptible to hydrolysis to pyropheophorbide-a, otherwise a pH effect was observed in a binary methanol-water system (9:1) at pH below 2 or above 8. PMID:21790616

  10. A prototype hand-held tri-modal instrument for in vivo ultrasound, photoacoustic, and fluorescence imaging.

    PubMed

    Kang, Jeeun; Chang, Jin Ho; Wilson, Brian C; Veilleux, Israel; Bai, Yanhui; DaCosta, Ralph; Kim, Kang; Ha, Seunghan; Lee, Jong Gun; Kim, Jeong Seok; Lee, Sang-Goo; Kim, Sun Mi; Lee, Hak Jong; Ahn, Young Bok; Han, Seunghee; Yoo, Yangmo; Song, Tai-Kyong

    2015-03-01

    Multi-modality imaging is beneficial for both preclinical and clinical applications as it enables complementary information from each modality to be obtained in a single procedure. In this paper, we report the design, fabrication, and testing of a novel tri-modal in vivo imaging system to exploit molecular/functional information from fluorescence (FL) and photoacoustic (PA) imaging as well as anatomical information from ultrasound (US) imaging. The same ultrasound transducer was used for both US and PA imaging, bringing the pulsed laser light into a compact probe by fiberoptic bundles. The FL subsystem is independent of the acoustic components but the front end that delivers and collects the light is physically integrated into the same probe. The tri-modal imaging system was implemented to provide each modality image in real time as well as co-registration of the images. The performance of the system was evaluated through phantom and in vivo animal experiments. The results demonstrate that combining the modalities does not significantly compromise the performance of each of the separate US, PA, and FL imaging techniques, while enabling multi-modality registration. The potential applications of this novel approach to multi-modality imaging range from preclinical research to clinical diagnosis, especially in detection/localization and surgical guidance of accessible solid tumors. PMID:25832265

  11. Differentiation between diseases using a programmable hand-held calculator and Bayes' theorem: application to lower gastrointestinal tract disorders.

    PubMed

    van de Merwe, J P

    1984-01-01

    A program is presented for the Hewlett-Packard HP-41C programmable pocket calculator that computes posterior probabilities of more than 200 diseases on the basis of Bayes' theorem. Data for specific applications are stored in ASCII files. The program and data are retained in the non-volatile memory of the calculator. An example of the application of the program to six lower gastrointestinal tract disorders is given using data from the literature. PMID:6391801

  12. Semiconductor device PN junction fabrication using optical processing of amorphous semiconductor material

    SciTech Connect

    Sopori, Bhushan; Rangappan, Anikara

    2014-11-25

    Systems and methods for semiconductor device PN junction fabrication are provided. In one embodiment, a method for fabricating an electrical device having a P-N junction comprises: depositing a layer of amorphous semiconductor material onto a crystalline semiconductor base, wherein the crystalline semiconductor base comprises a crystalline phase of a same semiconductor as the amorphous layer; and growing the layer of amorphous semiconductor material into a layer of crystalline semiconductor material that is epitaxially matched to the lattice structure of the crystalline semiconductor base by applying an optical energy that penetrates at least the amorphous semiconductor material.

  13. Semiconductor technology program. Progress briefs

    NASA Technical Reports Server (NTRS)

    Bullis, W. M.

    1980-01-01

    Measurement technology for semiconductor materials, process control, and devices is reviewed. Activities include: optical linewidth and thermal resistance measurements; device modeling; dopant density profiles; resonance ionization spectroscopy; and deep level measurements. Standardized oxide charge terminology is also described.

  14. Metal-Insulator-Semiconductor Photodetectors

    PubMed Central

    Lin, Chu-Hsuan; Liu, Chee Wee

    2010-01-01

    The major radiation of the Sun can be roughly divided into three regions: ultraviolet, visible, and infrared light. Detection in these three regions is important to human beings. The metal-insulator-semiconductor photodetector, with a simpler process than the pn-junction photodetector and a lower dark current than the MSM photodetector, has been developed for light detection in these three regions. Ideal UV photodetectors with high UV-to-visible rejection ratio could be demonstrated with III–V metal-insulator-semiconductor UV photodetectors. The visible-light detection and near-infrared optical communications have been implemented with Si and Ge metal-insulator-semiconductor photodetectors. For mid- and long-wavelength infrared detection, metal-insulator-semiconductor SiGe/Si quantum dot infrared photodetectors have been developed, and the detection spectrum covers atmospheric transmission windows. PMID:22163382

  15. Semiconductor crystal high resolution imager

    NASA Technical Reports Server (NTRS)

    Levin, Craig S. (Inventor); Matteson, James (Inventor)

    2011-01-01

    A radiation imaging device (10). The radiation image device (10) comprises a subject radiation station (12) producing photon emissions (14), and at least one semiconductor crystal detector (16) arranged in an edge-on orientation with respect to the emitted photons (14) to directly receive the emitted photons (14) and produce a signal. The semiconductor crystal detector (16) comprises at least one anode and at least one cathode that produces the signal in response to the emitted photons (14).

  16. Impurity gettering in semiconductors

    DOEpatents

    Sopori, B.L.

    1995-06-20

    A process for impurity gettering in a semiconductor substrate or device such as a silicon substrate or device is disclosed. The process comprises hydrogenating the substrate or device at the back side thereof with sufficient intensity and for a time period sufficient to produce a damaged back side. Thereafter, the substrate or device is illuminated with electromagnetic radiation at an intensity and for a time period sufficient to cause the impurities to diffuse to the back side and alloy with a metal there present to form a contact and capture the impurities. The impurity gettering process also can function to simultaneously passivate defects within the substrate or device, with the defects likewise diffusing to the back side for simultaneous passivation. Simultaneously, substantially all hydrogen-induced damage on the back side of the substrate or device is likewise annihilated. Also taught is an alternate process comprising thermal treatment after hydrogenation of the substrate or device at a temperature of from about 500 C to about 700 C for a time period sufficient to cause the impurities to diffuse to the damaged back side thereof for subsequent capture by an alloying metal. 1 fig.

  17. Impurity gettering in semiconductors

    DOEpatents

    Sopori, Bhushan L.

    1995-01-01

    A process for impurity gettering in a semiconductor substrate or device such as a silicon substrate or device. The process comprises hydrogenating the substrate or device at the back side thereof with sufficient intensity and for a time period sufficient to produce a damaged back side. Thereafter, the substrate or device is illuminated with electromagnetic radiation at an intensity and for a time period sufficient to cause the impurities to diffuse to the back side and alloy with a metal there present to form a contact and capture the impurities. The impurity gettering process also can function to simultaneously passivate defects within the substrate or device, with the defects likewise diffusing to the back side for simultaneous passivation. Simultaneously, substantially all hydrogen-induced damage on the back side of the substrate or device is likewise annihilated. Also taught is an alternate process comprising thermal treatment after hydrogenation of the substrate or device at a temperature of from about 500.degree. C. to about 700.degree. C. for a time period sufficient to cause the impurities to diffuse to the damaged back side thereof for subsequent capture by an alloying metal.

  18. Semiconductor film Cherenkov lasers

    NASA Astrophysics Data System (ADS)

    Walsh, John E.

    1994-12-01

    The technical achievements for the project 'Semiconductor Film Cherenkov Lasers' are summarized. Described in the fourteen appendices are the operation of a sapphire Cherenkov laser and various grating-coupled oscillators. These coherent radiation sources were operated over the spectral range extending from 3 mm down to 400 micrometers. The utility of various types of open, multi-grating resonators and mode-locked operation were also demonstrated. In addition to these experiments, which were carried out with a 10-100 kV pulse generator, a low-energy (3-3.6 MeV) Van de Graaff generator and a low-energy RF linac (2.8 MeV) were used to investigate the properties of continuum incoherent Smith-Purcell radiation. It was shown that levels of intensity comparable to the infrared beam lines on a synchrotron could be obtained and thus that grating-coupled sources are potentially an important new source for Fourier transform spectroscopy. Finally, a scanning electron microscope was adapted for investigating mu-electron-beam-driven far-infrared sources. At the close of the project, spontaneous emission over the 288-800 micrometers band had been observed. Intensity levels were in accord with expectations based on theory. One or more of the Appendices address these topics in detail.

  19. Survey of cryogenic semiconductor devices

    SciTech Connect

    Talarico, L.J.; McKeever, J.W.

    1996-04-01

    Improved reliability and electronic performance can be achieved in a system operated at cryogenic temperatures because of the reduction in mechanical insult and in disruptive effects of thermal energy on electronic devices. Continuing discoveries of new superconductors with ever increasing values of T{sub c} above that of liquid nitrogen temperature (LNT) have provided incentive for developing semiconductor electronic systems that may also operate in the superconductor`s liquid nitrogen bath. Because of the interest in high-temperature superconductor (HTS) devices, liquid nitrogen is the cryogen of choice and LNT is the temperature on which this review is focused. The purpose of this survey is to locate and assemble published information comparing the room temperature (298 K), performance of commercially available conventional and hybrid semiconductor device with their performance at LNT (77K), to help establish their candidacy as cryogenic electronic devices specifically for use at LNT. The approach to gathering information for this survey included the following activities. Periodicals and proceedings were searched for information on the behavior of semiconductor devices at LNT. Telephone calls were made to representatives of semiconductor industries, to semiconductor subcontractors, to university faculty members prominent for their research in the area of cryogenic semiconductors, and to representatives of the National Aeronautics and Space Administration (NASA) and NASA subcontractors. The sources and contacts are listed with their responses in the introduction, and a list of references appears at the end of the survey.

  20. EDITORIAL: Oxide semiconductors

    NASA Astrophysics Data System (ADS)

    Kawasaki, M.; Makino, T.

    2005-04-01

    Blue or ultraviolet semiconducting light-emitting diodes have the potential to revolutionize illumination systems in the near-future. Such industrial need has propelled the investigation of several wide-gap semiconducting materials in recent years. Commercial applications include blue lasers for DVD memory and laser printers, while military applications are also expected. Most of the material development has so far been focused on GaN (band gap 3.5 eV at 2 K), and ZnSe (2.9 eV) because these two representative direct transition semiconductors are known to be bright emitting sources. GaN and GaN-based alloys are emerging as the winners in this field because ZnSe is subject to defect formation under high current drive. On the other hand, another II-VI compound, ZnO, has also excited substantial interest in the optoelectronics-oriented research communities because it is the brightest emitter of all, owing to the fact that its excitons have a 60 meV binding energy. This is compared with 26 meV for GaN and 20 meV for ZnSe. The stable excitons could lead to laser action based on their recombination even at temperatures well above room temperature. ZnO has additional major properties that are more advantageous than other wide-gap materials: availability of large area substrates, higher energy radiation stability, environmentally-friendly ingredients, and amenability to wet chemical etching. However, ZnO is not new to the semiconductor field as exemplified by several studies made during the 1960s on structural, vibrational, optical and electrical properties (Mollwo E 1982 Landolt-Boernstein New Series vol 17 (Berlin: Springer) p 35). In terms of devices, the luminescence from light-emitting diode structures was demonstrated in which Cu2O was used as the p-type material (Drapak I T 1968 Semiconductors 2 624). The main obstacle to the development of ZnO has been the lack of reproducible p-type ZnO. The possibility of achieving epitaxial p-type layers with the aid of thermal

  1. Wide-Bandgap Semiconductors

    SciTech Connect

    Chinthavali, M.S.

    2005-11-22

    With the increase in demand for more efficient, higher-power, and higher-temperature operation of power converters, design engineers face the challenge of increasing the efficiency and power density of converters [1, 2]. Development in power semiconductors is vital for achieving the design goals set by the industry. Silicon (Si) power devices have reached their theoretical limits in terms of higher-temperature and higher-power operation by virtue of the physical properties of the material. To overcome these limitations, research has focused on wide-bandgap materials such as silicon carbide (SiC), gallium nitride (GaN), and diamond because of their superior material advantages such as large bandgap, high thermal conductivity, and high critical breakdown field strength. Diamond is the ultimate material for power devices because of its greater than tenfold improvement in electrical properties compared with silicon; however, it is more suited for higher-voltage (grid level) higher-power applications based on the intrinsic properties of the material [3]. GaN and SiC power devices have similar performance improvements over Si power devices. GaN performs only slightly better than SiC. Both SiC and GaN have processing issues that need to be resolved before they can seriously challenge Si power devices; however, SiC is at a more technically advanced stage than GaN. SiC is considered to be the best transition material for future power devices before high-power diamond device technology matures. Since SiC power devices have lower losses than Si devices, SiC-based power converters are more efficient. With the high-temperature operation capability of SiC, thermal management requirements are reduced; therefore, a smaller heat sink would be sufficient. In addition, since SiC power devices can be switched at higher frequencies, smaller passive components are required in power converters. Smaller heat sinks and passive components result in higher-power-density power converters

  2. Optical pumping in semiconductors

    NASA Astrophysics Data System (ADS)

    Hermann, C.; Lampel, G.; Safarov, V. I.

    Optical Pumping in Semiconductors (OPS) arises from the transfer of angular momentum from light to the localized states of a semiconductor. Spin polarized electrons are thus excited in the conduction band; their polarization is convenient measured through the circular polarization of photoluminescence. This review gives an insight of the various studies based on OPS. After describing the first OPS experiment, we show that this technique allows the determination of band structure properties, and the optical detection of conduction electron spin resonance. The nuclei are polarized by hyperfine interaction, which permits the optical detection of nuclear resonance. A magnetic field transverse to the direction of light propagation produces an electronic depolarization analogous to the Hanle effect. The electron lifetime and spin relaxation time are measured under steady-state conditions by comparison to their Larmor frequency in this transverse field. By activation to Negative Electron Affinity of a GaAs surface, electrons oriented by OPS can be photoemitted into vacuum, leading to a highly spin-polarized beam : we describe a collision experiment in which such a beam transfers angular momentum to atoms. Le Pompage Optique dans les semiconducteurs (POS) provient du transfert de moment angulaire de la lumière vers les états délocalisés d'un semiconducteur. On excite ainsi dans la bande de conduction des électrons polarisés de spin, dont on mesure commodément la polarisation à partir de la polarisation circulaire de la photoluminescence. Cet article de revue présente un aperçu des différentes études fondées sur le POS. Après avoir décrit la première expérience de POS, nous montrons que par cette technique on peut déterminer des propriétés liées à la structure de bande, et détecter optiquement la résonance de spin des électrons de conduction. Les noyaux sont polarisés grâce au couplage hyperfin qui permet également la détection optique de la r

  3. Hydrogen in semiconductors and metals

    SciTech Connect

    Nickel, N.H.; Jackson, W.B.; Bowman, R.C.; Leisure, R.G.

    1998-12-31

    Major highlights of the conference include further understanding of the structure of extended hydrogen clusters in semiconductors, switchable optical properties of metal-hydride films, reversible changes in the magnetic coupling in metallic superlattices, and increased lifetime of integrated circuits due to deuterium device passivation. Continued progress has also been achieved in understanding hydrogenation of defects in compound semiconductors and on surfaces. Total energy calculations in semiconductors have progressed sufficiently to predict energetics and vibration frequencies as measured by experiment. Similarly, electronic structure calculations of hydrogen-metal systems provide a deeper understanding of stability, bonding, and phase changes. Various nuclear techniques have been refined to yield important information regarding the concentration and transport of hydrogen in condensed matter. Finally, the interaction of hydrogen to create thermal donors has been used to create deep p-n junctions without the need for deep diffusion of dopants. The volume has been organized along the order of presentation within the conference. Similar methods and subjects have been grouped together. The authors have attempted to keep similar metal and semiconductor papers together in order to further promote cross-fertilization between the fields. Major categories include hydrogen on surfaces, theory and thermodynamics, hydrogen transport phenomena, nuclear characterization techniques, compound semiconductors, metal bulk, devices and applications, bulk silicon, and carbon and carbon-like materials. Separate abstracts were prepared for most papers.

  4. Nonlinear optical interactions in semiconductors

    NASA Astrophysics Data System (ADS)

    Salour, M. M.

    1985-12-01

    The optical pumping technique in GaAs has led to the development of a novel and highly sensitive optical temperature sensor. Completed is the experiment on two photon optical pumping in ZnO. An external cavity semiconductor laser involving ZnO as a gain medium was demonstrated under two-photon excitation. This laser should have a major impact on the development of tunable blue-green radiation for submarine communication. Completed is a paper on heat buildup in semiconductor platelets. New lasers are used to explore elementary excitation in optical thin film layers of semiconductors. This has led to the first demonstration of the feasibility of room temperature operation of a tunable coherent source involving multiple quantum well material. Completed is the construction of a simple remote (non-contact) temperature sensor to directly measure heat buildup in semiconductor materials as a result of high power optical laser excitation. Finally, an experiment involving optical frequency mixing to probe electrodynamics in the GaAlAs multiple quantumwell and superlattice structures, utilizing two recently constructed tunabel laser systems,has been successful. Attempts were focused on observing a number of new optical effects including nonlinear absorption and transmission phenomena, enhanced spontaneous and stimulated light scattering processes, etc. The construction of an external cavity semiconductor HgCdTe has been successful.

  5. High mobility emissive organic semiconductor.

    PubMed

    Liu, Jie; Zhang, Hantang; Dong, Huanli; Meng, Lingqiang; Jiang, Longfeng; Jiang, Lang; Wang, Ying; Yu, Junsheng; Sun, Yanming; Hu, Wenping; Heeger, Alan J

    2015-01-01

    The integration of high charge carrier mobility and high luminescence in an organic semiconductor is challenging. However, there is need of such materials for organic light-emitting transistors and organic electrically pumped lasers. Here we show a novel organic semiconductor, 2,6-diphenylanthracene (DPA), which exhibits not only high emission with single crystal absolute florescence quantum yield of 41.2% but also high charge carrier mobility with single crystal mobility of 34 cm(2) V(-1) s(-1). Organic light-emitting diodes (OLEDs) based on DPA give pure blue emission with brightness up to 6,627 cd m(-2) and turn-on voltage of 2.8 V. 2,6-Diphenylanthracene OLED arrays are successfully driven by DPA field-effect transistor arrays, demonstrating that DPA is a high mobility emissive organic semiconductor with potential in organic optoelectronics. PMID:26620323

  6. High mobility emissive organic semiconductor

    PubMed Central

    Liu, Jie; Zhang, Hantang; Dong, Huanli; Meng, Lingqiang; Jiang, Longfeng; Jiang, Lang; Wang, Ying; Yu, Junsheng; Sun, Yanming; Hu, Wenping; Heeger, Alan J.

    2015-01-01

    The integration of high charge carrier mobility and high luminescence in an organic semiconductor is challenging. However, there is need of such materials for organic light-emitting transistors and organic electrically pumped lasers. Here we show a novel organic semiconductor, 2,6-diphenylanthracene (DPA), which exhibits not only high emission with single crystal absolute florescence quantum yield of 41.2% but also high charge carrier mobility with single crystal mobility of 34 cm2 V−1 s−1. Organic light-emitting diodes (OLEDs) based on DPA give pure blue emission with brightness up to 6,627 cd m−2 and turn-on voltage of 2.8 V. 2,6-Diphenylanthracene OLED arrays are successfully driven by DPA field-effect transistor arrays, demonstrating that DPA is a high mobility emissive organic semiconductor with potential in organic optoelectronics. PMID:26620323

  7. High mobility emissive organic semiconductor

    NASA Astrophysics Data System (ADS)

    Liu, Jie; Zhang, Hantang; Dong, Huanli; Meng, Lingqiang; Jiang, Longfeng; Jiang, Lang; Wang, Ying; Yu, Junsheng; Sun, Yanming; Hu, Wenping; Heeger, Alan J.

    2015-12-01

    The integration of high charge carrier mobility and high luminescence in an organic semiconductor is challenging. However, there is need of such materials for organic light-emitting transistors and organic electrically pumped lasers. Here we show a novel organic semiconductor, 2,6-diphenylanthracene (DPA), which exhibits not only high emission with single crystal absolute florescence quantum yield of 41.2% but also high charge carrier mobility with single crystal mobility of 34 cm2 V-1 s-1. Organic light-emitting diodes (OLEDs) based on DPA give pure blue emission with brightness up to 6,627 cd m-2 and turn-on voltage of 2.8 V. 2,6-Diphenylanthracene OLED arrays are successfully driven by DPA field-effect transistor arrays, demonstrating that DPA is a high mobility emissive organic semiconductor with potential in organic optoelectronics.

  8. Selenium semiconductor core optical fibers

    SciTech Connect

    Tang, G. W.; Qian, Q. Peng, K. L.; Wen, X.; Zhou, G. X.; Sun, M.; Chen, X. D.; Yang, Z. M.

    2015-02-15

    Phosphate glass-clad optical fibers containing selenium (Se) semiconductor core were fabricated using a molten core method. The cores were found to be amorphous as evidenced by X-ray diffraction and corroborated by Micro-Raman spectrum. Elemental analysis across the core/clad interface suggests that there is some diffusion of about 3 wt % oxygen in the core region. Phosphate glass-clad crystalline selenium core optical fibers were obtained by a postdrawing annealing process. A two-cm-long crystalline selenium semiconductor core optical fibers, electrically contacted to external circuitry through the fiber end facets, exhibit a three times change in conductivity between dark and illuminated states. Such crystalline selenium semiconductor core optical fibers have promising utility in optical switch and photoconductivity of optical fiber array.

  9. Device Concepts in Semiconductor Spintronics

    NASA Astrophysics Data System (ADS)

    Molenkamp, Laurens W.

    Semiconductor spintronics has now reached a stage where the basic physical mechanisms controlling spin injection and detection are understood. Moreover, some critical technological issues involved in the growth and lithography of the magnetic semiconductors have been solved. This has allowed us to explore the physics of meanwhile quite complex spintronic devices. The lectures will start with an introduction to spin transport in metals and semiconductors. Building upon this, I will discuss various simple devices that demonstrate this basic physics in action. Subsequently, more advanced devices will be covered. For example, I will discuss resonant tunneling diodes (RTDs) fabricated from paramagnetic II-VI semiconductors that can be operated as a voltage controlled spin-switch. A quantum dot version of these RTDs exhibits, unexpectedly, remanent magnetism at zero external field, which we interpret as resulting from tunneling through a single magnetic polaron. In the ferromagnetic semiconductor (Ga, Mn)As we have observed a very large spin valve effect due to domain wall pinning at sub-10 nm sized constrictions. Furthermore, we have found a novel magnetoresistance effect in this material, dubbed tunnel anisotropic magnetoresistance (TAMR), which is due to the strongly (magneto-)anisotropic density of states in a ferromagnetic semiconductor. The effect leads to the observation of a spin valve-like behavior in tunnel structures containg a single ferromagnetic layer and also dominates the spin-valve signal obtained from structures containing two (Ga, Mn)As layers, where the effect may cause resistance changes of five orders of magnitude. Note from Publisher: This article contains the abstract only.

  10. Exciton Transport in Organic Semiconductors

    NASA Astrophysics Data System (ADS)

    Menke, Stephen Matthew

    Photovoltaic cells based on organic semiconductors are attractive for their use as a renewable energy source owing to their abundant feedstock and compatibility with low-cost coating techniques on flexible substrates. In contrast to photovoltaic cells based traditional inorganic semiconductors, photon absorption in an organic semiconductor results in the formation of a coulombically bound electron-hole pair, or exciton. The transport of excitons, consequently, is of critical importance as excitons mediate the interaction between charge and light in organic photovoltaic cells (OPVs). In this dissertation, a strong connection between the fundamental photophysical parameters that control nanoscopic exciton energy transfer and the mesoscopic exciton transport is established. With this connection in place, strategies for enhancing the typically short length scale for exciton diffusion (L D) can be developed. Dilution of the organic semiconductor boron subphthalocyanine chloride (SubPc) is found to increase the LD for SubPc by 50%. In turn, OPVs based on dilute layers of SubPc exhibit a 30% enhancement in power conversion efficiency. The enhancement in power conversion efficiency is realized via enhancements in LD, optimized optical spacing, and directed exciton transport at an exciton permeable interface. The role of spin, energetic disorder, and thermal activation on L D are also addressed. Organic semiconductors that exhibit thermally activated delayed fluorescence and efficient intersystem and reverse intersystem crossing highlight the balance between singlet and triplet exciton energy transfer and diffusion. Temperature dependent measurements for LD provide insight into the inhomogeneously broadened exciton density of states and the thermal nature of exciton energy transfer. Additional topics include energy-cascade OPV architectures and broadband, spectrally tunable photodetectors based on organic semiconductors.

  11. A brief history of ... semiconductors

    NASA Astrophysics Data System (ADS)

    Jenkins, Tudor

    2005-09-01

    The development of studies in semiconductor materials is traced from its beginnings with Michael Faraday in 1833 to the production of the first silicon transistor in 1954, which heralded the age of silicon electronics and microelectronics. Prior to the advent of band theory, work was patchy and driven by needs of technology. However, the arrival of this successful quantum theory of solids, together with a concentration on the growth of pure silicon and germanium and an understanding of their properties, saw an explosion in activity in semiconductor studies that has continued to this day.

  12. Wide band gap semiconductor templates

    SciTech Connect

    Arendt, Paul N.; Stan, Liliana; Jia, Quanxi; DePaula, Raymond F.; Usov, Igor O.

    2010-12-14

    The present invention relates to a thin film structure based on an epitaxial (111)-oriented rare earth-Group IVB oxide on the cubic (001) MgO terminated surface and the ion-beam-assisted deposition ("IBAD") techniques that are amendable to be over coated by semiconductors with hexagonal crystal structures. The IBAD magnesium oxide ("MgO") technology, in conjunction with certain template materials, is used to fabricate the desired thin film array. Similarly, IBAD MgO with appropriate template layers can be used for semiconductors with cubic type crystal structures.

  13. Thermoelectric performance of granular semiconductors.

    SciTech Connect

    Glatz, A.; Beloborodov, I. S.; Materials Science Division; California State Univ.

    2009-01-01

    We study the effects of doping and confinement on the thermoelectric properties of nanocrystalline semiconductors. We calculate the thermopower and figure of merit for temperatures less than the charging energy. For weakly coupled semiconducting grains it is shown that the figure of merit is optimized for grain sizes of order 5 nm for typical materials, and that its value can be larger than one. Using the similarities between granular semiconductors and electron or Coulomb glasses allows for a quantitative description of inhomogeneous semiconducting thermoelectrics.

  14. Method of preparing nitrogen containing semiconductor material

    DOEpatents

    Barber, Greg D.; Kurtz, Sarah R.

    2004-09-07

    A method of combining group III elements with group V elements that incorporates at least nitrogen from a nitrogen halide for use in semiconductors and in particular semiconductors in photovoltaic cells.

  15. Semiconductor Reliability--Another Field for Physicists.

    ERIC Educational Resources Information Center

    Derman, Samuel; Anderson, Wallace T.

    1994-01-01

    Stresses that an important industrial area is product reliability, especially for semiconductors. Suggests that physics students would benefit from training in semiconductors: the many modes of failure, radiation effects, and electrical contact problems. (MVL)

  16. Semiconductor electrode with improved photostability characteristics

    DOEpatents

    Frank, Arthur J.

    1987-01-01

    An electrode is disclosed for use in photoelectrochemical cells having an electrolyte which includes an aqueous constituent. The electrode includes a semiconductor and a hydrophobic film disposed between the semiconductor and the aqueous constituent. The hydrophobic film is adapted to permit charges to pass therethrough while substantially decreasing the activity of the aqueous constituent at the semiconductor surface thereby decreasing the photodegradation of the semiconductor electrode.

  17. Semiconductor nanocrystal-based phagokinetic tracking

    DOEpatents

    Alivisatos, A Paul; Larabell, Carolyn A; Parak, Wolfgang J; Le Gros, Mark; Boudreau, Rosanne

    2014-11-18

    Methods for determining metabolic properties of living cells through the uptake of semiconductor nanocrystals by cells. Generally the methods require a layer of neutral or hydrophilic semiconductor nanocrystals and a layer of cells seeded onto a culture surface and changes in the layer of semiconductor nanocrystals are detected. The observed changes made to the layer of semiconductor nanocrystals can be correlated to such metabolic properties as metastatic potential, cell motility or migration.

  18. Semiconductor electrode with improved photostability characteristics

    DOEpatents

    Frank, A.J.

    1985-02-19

    An electrode is described for use in photoelectrochemical cells having an electrolyte which includes an aqueous constituent. The electrode consists of a semiconductor and a hydrophobic film disposed between the semiconductor and the aqueous constituent. The hydrophobic film is adapted to permit charges to pass therethrough while substantially decreasing the activity of the aqueous constituent at the semiconductor surface thereby decreasing the photodegradation of the semiconductor electrode.

  19. Diode having trenches in a semiconductor region

    DOEpatents

    Palacios, Tomas Apostol; Lu, Bin; Matioli, Elison de Nazareth

    2016-03-22

    An electrode structure is described in which conductive regions are recessed into a semiconductor region. Trenches may be formed in a semiconductor region, such that conductive regions can be formed in the trenches. The electrode structure may be used in semiconductor devices such as field effect transistors or diodes. Nitride-based power semiconductor devices are described including such an electrode structure, which can reduce leakage current and otherwise improve performance.

  20. Semiconductor devices having a recessed electrode structure

    SciTech Connect

    Palacios, Tomas Apostol; Lu, Bin; Matioli, Elison de Nazareth

    2015-05-26

    An electrode structure is described in which conductive regions are recessed into a semiconductor region. Trenches may be formed in a semiconductor region, such that conductive regions can be formed in the trenches. The electrode structure may be used in semiconductor devices such as field effect transistors or diodes. Nitride-based power semiconductor devices are described including such an electrode structure, which can reduce leakage current and otherwise improve performance.

  1. Semiconductor assisted metal deposition for nanolithography applications

    DOEpatents

    Rajh, Tijana; Meshkov, Natalia; Nedelijkovic, Jovan M.; Skubal, Laura R.; Tiede, David M.; Thurnauer, Marion

    2002-01-01

    An article of manufacture and method of forming nanoparticle sized material components. A semiconductor oxide substrate includes nanoparticles of semiconductor oxide. A modifier is deposited onto the nanoparticles, and a source of metal ions are deposited in association with the semiconductor and the modifier, the modifier enabling electronic hole scavenging and chelation of the metal ions. The metal ions and modifier are illuminated to cause reduction of the metal ions to metal onto the semiconductor nanoparticles.

  2. Semiconductor assisted metal deposition for nanolithography applications

    DOEpatents

    Rajh, Tijana; Meshkov, Natalia; Nedelijkovic, Jovan M.; Skubal, Laura R.; Tiede, David M.; Thurnauer, Marion

    2001-01-01

    An article of manufacture and method of forming nanoparticle sized material components. A semiconductor oxide substrate includes nanoparticles of semiconductor oxide. A modifier is deposited onto the nanoparticles, and a source of metal ions are deposited in association with the semiconductor and the modifier, the modifier enabling electronic hole scavenging and chelation of the metal ions. The metal ions and modifier are illuminated to cause reduction of the metal ions to metal onto the semiconductor nanoparticles.

  3. (Magnetic properties of doped semiconductors)

    SciTech Connect

    Not Available

    1990-01-01

    Research continued on the transport behavior of doped semiconductors on both sides of the metal-insulator transition, and the approach to the transition from both the insulating and the metallic side. Work is described on magneto resistance of a series of metallic Si:B samples and CdSe. (CBS)

  4. Conductive Container for Semiconductor Devices

    NASA Technical Reports Server (NTRS)

    Rice, J. T.

    1986-01-01

    Container for semiconductor components not only protects them against mechanical damage but ensures they are not harmed by electrostatic discharges. Container holds components in fixed positions so they can be serialized and identified from their locations. Suitable for holding components during both storing and shipping. Originally developed for microwave diodes, container concept readily adaptable to transistors and integrated circuits.

  5. Semiconductor-based optical refrigerator

    DOEpatents

    Epstein, Richard I.; Edwards, Bradley C.; Sheik-Bahae, Mansoor

    2002-01-01

    Optical refrigerators using semiconductor material as a cooling medium, with layers of material in close proximity to the cooling medium that carries away heat from the cooling material and preventing radiation trapping. In addition to the use of semiconducting material, the invention can be used with ytterbium-doped glass optical refrigerators.

  6. Electronic spectra of semiconductor nanocrystals

    SciTech Connect

    Alivisatos, A.P.

    1993-12-31

    Semiconductor nanocrystals smaller than the bulk exciton show substantial quantum confinement effects. Recent experiments including Stark effect, resonance Raman, valence band photoemission, and near edge X-ray adsorption will be used to put together a picture of the nanocrystal electronic states.

  7. Semiconductor technology program: Progress briefs

    NASA Technical Reports Server (NTRS)

    Galloway, K. F.; Scace, R. I.; Walters, E. J.

    1981-01-01

    Measurement technology for semiconductor materials, process control, and devices, is discussed. Silicon and silicon based devices are emphasized. Highlighted activities include semiinsulating GaAs characterization, an automatic scanning spectroscopic ellipsometer, linewidth measurement and coherence, bandgap narrowing effects in silicon, the evaluation of electrical linewidth uniformity, and arsenicomplanted profiles in silicon.

  8. Mechanical scriber for semiconductor devices

    DOEpatents

    Lin, Peter T.

    1985-01-01

    A mechanical scriber using a scribing tip, such as a diamond, provides controlled scriber forces with a spring-loaded compound lever arrangement. The scribing force and range of scribing depth are adjusted by a pair of adjustable micrometer heads. A semiconductor device, such as a multilayer solar cell, can be formed into scribed strips at each layer.

  9. Mechanical scriber for semiconductor devices

    DOEpatents

    Lin, P.T.

    1985-03-05

    A mechanical scriber using a scribing tip, such as a diamond, provides controlled scriber forces with a spring-loaded compound lever arrangement. The scribing force and range of scribing depth are adjusted by a pair of adjustable micrometer heads. A semiconductor device, such as a multilayer solar cell, can be formed into scribed strips at each layer. 5 figs.

  10. A Brief History of ... Semiconductors

    ERIC Educational Resources Information Center

    Jenkins, Tudor

    2005-01-01

    The development of studies in semiconductor materials is traced from its beginnings with Michael Faraday in 1833 to the production of the first silicon transistor in 1954, which heralded the age of silicon electronics and microelectronics. Prior to the advent of band theory, work was patchy and driven by needs of technology. However, the arrival…

  11. 2010 Defects in Semiconductors GRC

    SciTech Connect

    Shengbai Zhang

    2011-01-06

    Continuing its tradition of excellence, this Gordon Conference will focus on research at the forefront of the field of defects in semiconductors. The conference will have a strong emphasis on the control of defects during growth and processing, as well as an emphasis on the development of novel defect detection methods and first-principles defect theories. Electronic, magnetic, and optical properties of bulk, thin film, and nanoscale semiconductors will be discussed in detail. In contrast to many conferences, which tend to focus on specific semiconductors, this conference will deal with point and extended defects in a broad range of electronic materials. This approach has proved to be extremely fruitful for advancing fundamental understanding in emerging materials such as wide-band-gap semiconductors, oxides, sp{sup 2} carbon based-materials, and photovoltaic/solar cell materials, and in understanding important defect phenomena such as doping bottleneck in nanostructures and the diffusion of defects and impurities. The program consists of about twenty invited talks and a number of contributed poster sessions. The emphasis should be on work which has yet to be published. The large amount of discussion time provides an ideal forum for dealing with topics that are new and/or controversial.

  12. Semiconductor ac static power switch

    NASA Technical Reports Server (NTRS)

    Vrancik, J.

    1968-01-01

    Semiconductor ac static power switch has long life and high reliability, contains no moving parts, and operates satisfactorily in severe environments, including high vibration and shock conditions. Due to their resistance to shock and vibration, static switches are used where accidental switching caused by mechanical vibration or shock cannot be tolerated.

  13. Electron beam pumped semiconductor laser

    NASA Technical Reports Server (NTRS)

    Hug, William F. (Inventor); Reid, Ray D. (Inventor)

    2009-01-01

    Electron-beam-pumped semiconductor ultra-violet optical sources (ESUVOSs) are disclosed that use ballistic electron pumped wide bandgap semiconductor materials. The sources may produce incoherent radiation and take the form of electron-beam-pumped light emitting triodes (ELETs). The sources may produce coherent radiation and take the form of electron-beam-pumped laser triodes (ELTs). The ELTs may take the form of electron-beam-pumped vertical cavity surface emitting lasers (EVCSEL) or edge emitting electron-beam-pumped lasers (EEELs). The semiconductor medium may take the form of an aluminum gallium nitride alloy that has a mole fraction of aluminum selected to give a desired emission wavelength, diamond, or diamond-like carbon (DLC). The sources may be produced from discrete components that are assembled after their individual formation or they may be produced using batch MEMS-type or semiconductor-type processing techniques to build them up in a whole or partial monolithic manner, or combination thereof.

  14. Optical bistability in semiconductor microcavities

    SciTech Connect

    Baas, A.; Karr, J.Ph.; Giacobino, E.; Eleuch, H.

    2004-02-01

    We report the observation of polaritonic bistability in semiconductor microcavities in the strong-coupling regime. The origin of bistability is the polariton-polariton interaction, which gives rise to a Kerr-like nonlinearity. The experimental results are in good agreement with a simple model taking transverse effects into account.

  15. Semiconductor alloys - Structural property engineering

    NASA Technical Reports Server (NTRS)

    Sher, A.; Van Schilfgaarde, M.; Berding, M.; Chen, A.-B.

    1987-01-01

    Semiconductor alloys have been used for years to tune band gaps and average bond lengths to specific applications. Other selection criteria for alloy composition, and a growth technique designed to modify their structural properties, are presently considered. The alloys Zn(1-y)Cd(y)Te and CdSe(y)Te(1-y) are treated as examples.

  16. Amphoteric native defects in semiconductors

    SciTech Connect

    Walukiewicz, W.

    1989-05-22

    We show that a new concept of amphoteric native defects with strongly Fermi level dependent defect formation energy provides the basis for a unified explanation of a large variety of phenomena in semiconductors. Formation of Schottky barriers, particle irradiation induced compensation, doping-induced superlattice intermixing, and limits of free-carrier concentration find for the first time a common simple explanation.

  17. Semiconductor films on flexible iridium substrates

    DOEpatents

    Goyal, Amit

    2005-03-29

    A laminate semiconductor article includes a flexible substrate, an optional biaxially textured oxide buffer system on the flexible substrate, a biaxially textured Ir-based buffer layer on the substrate or the buffer system, and an epitaxial layer of a semiconductor. Ir can serve as a substrate with an epitaxial layer of a semiconductor thereon.

  18. Advanced Semiconductor Devices

    NASA Astrophysics Data System (ADS)

    Shur, Michael S.; Maki, Paul A.; Kolodzey, James

    2007-06-01

    I. Wide band gap devices. Wide-Bandgap Semiconductor devices for automotive applications / M. Sugimoto ... [et al.]. A GaN on SiC HFET device technology for wireless infrastructure applications / B. Green ... [et al.]. Drift velocity limitation in GaN HEMT channels / A. Matulionis. Simulations of field-plated and recessed gate gallium nitride-based heterojunction field-effect transistors / V. O. Turin, M. S. Shur and D. B. Veksler. Low temperature electroluminescence of green and deep green GaInN/GaN light emitting diodes / Y. Li ... [et al.]. Spatial spectral analysis in high brightness GaInN/GaN light emitting diodes / T. Detchprohm ... [et al.]. Self-induced surface texturing of Al2O3 by means of inductively coupled plasma reactive ion etching in Cl2 chemistry / P. Batoni ... [et al.]. Field and termionic field transport in aluminium gallium arsenide heterojunction barriers / D. V. Morgan and A. Porch. Electrical characteristics and carrier lifetime measurements in high voltage 4H-SiC PiN diodes / P. A. Losee ... [et al.]. Geometry and short channel effects on enhancement-mode n-Channel GaN MOSFETs on p and n- GaN/sapphire substrates / W. Huang, T. Khan and T. P. Chow. 4H-SiC Vertical RESURF Schottky Rectifiers and MOSFETs / Y. Wang, P. A. Losee and T. P. Chow. Present status and future Directions of SiGe HBT technology / M. H. Khater ... [et al.]Optical properties of GaInN/GaN multi-quantum Wells structure and light emitting diode grown by metalorganic chemical vapor phase epitaxy / J. Senawiratne ... [et al.]. Electrical comparison of Ta/Ti/Al/Mo/Au and Ti/Al/Mo/Au Ohmic contacts on undoped GaN HEMTs structure with AlN interlayer / Y. Sun and L. F. Eastman. Above 2 A/mm drain current density of GaN HEMTs grown on sapphire / F. Medjdoub ... [et al.]. Focused thermal beam direct patterning on InGaN during molecular beam epitaxy / X. Chen, W. J. Schaff and L. F. Eastman -- II. Terahertz and millimeter wave devices. Temperature-dependent microwave performance of

  19. Controlled growth of semiconductor crystals

    DOEpatents

    Bourret-Courchesne, E.D.

    1992-07-21

    A method is disclosed for growth of III-V, II-VI and related semiconductor single crystals that suppresses random nucleation and sticking of the semiconductor melt at the crucible walls. Small pieces of an oxide of boron B[sub x]O[sub y] are dispersed throughout the comminuted solid semiconductor charge in the crucible, with the oxide of boron preferably having water content of at least 600 ppm. The crucible temperature is first raised to a temperature greater than the melt temperature T[sub m1] of the oxide of boron (T[sub m1]=723 K for boron oxide B[sub 2]O[sub 3]), and the oxide of boron is allowed to melt and form a reasonably uniform liquid layer between the crucible walls and bottom surfaces and the still-solid semiconductor charge. The temperature is then raised to approximately the melt temperature T[sub m2] of the semiconductor charge material, and crystal growth proceeds by a liquid encapsulated, vertical gradient freeze process. About half of the crystals grown have a dislocation density of less than 1000/cm[sup 2]. If the oxide of boron has water content less than 600 ppm, the crucible material should include boron nitride, a layer of the inner surface of the crucible should be oxidized before the oxide of boron in the crucible charge is melted, and the sum of thicknesses of the solid boron oxide layer and liquid boron oxide layer should be at least 50 [mu]m. 7 figs.

  20. Controlled growth of semiconductor crystals

    DOEpatents

    Bourret-Courchesne, Edith D.

    1992-01-01

    A method for growth of III-V, II-VI and related semiconductor single crystals that suppresses random nucleation and sticking of the semiconductor melt at the crucible walls. Small pieces of an oxide of boron B.sub.x O.sub.y are dispersed throughout the comminuted solid semiconductor charge in the crucible, with the oxide of boron preferably having water content of at least 600 ppm. The crucible temperature is first raised to a temperature greater than the melt temperature T.sub.m1 of the oxide of boron (T.sub.m1 =723.degree. K. for boron oxide B.sub.2 O.sub.3), and the oxide of boron is allowed to melt and form a reasonably uniform liquid layer between the crucible walls and bottom surfaces and the still-solid semiconductor charge. The temperature is then raised to approximately the melt temperature T.sub.m2 of the semiconductor charge material, and crystal growth proceeds by a liquid encapsulated, vertical gradient freeze process. About half of the crystals grown have a dislocation density of less than 1000/cm.sup.2. If the oxide of boron has water content less than 600 ppm, the crucible material should include boron nitride, a layer of the inner surface of the crucible should be oxidized before the oxide of boron in the crucible charge is melted, and the sum of thicknesses of the solid boron oxide layer and liquid boron oxide layer should be at least 50 .mu.m.

  1. Fermi level dependent native defect formation: Consequences for metal--semiconductor and semiconductor--semiconductor interfaces

    SciTech Connect

    Walukiewicz, W.

    1988-07-01

    The amphoteric native defect model of the Schottky barrier formation is used to analyze the Fermi level pinning at metal/semiconductor interfaces for submonolayer metal coverages. It is assumed that the energy required for defect generation is released in the process of surface back-relaxation. Model calculations for metal/GaAs interfaces show a weak dependence of the Fermi level pinning on the thickness of metal deposited at room temperature. This weak dependence indicates a strong dependence of the defect formation energy on the Fermi level, a unique feature of amphoteric native defects. This result is in very good agreement with experimental data. It is shown that a very distinct asymmetry in the Fermi level pinning on p- and n-type GaAs observed at liquid nitrogen temperatures can be understood in terms of much different recombination rates for amphoteric native defects in those two types of materials. Also, it is demonstrated that the Fermi level stabilization energy, a central concept of the amphoteric defect system, plays a fundamental role in other phenomena in semiconductors such as semiconductor/semiconductor heterointerface intermixing and saturation of free carrier concentration.

  2. Fermi level dependent native defect formation: Consequences for metal-semiconductor and semiconductor-semiconductor interfaces

    SciTech Connect

    Walukiewicz, W.

    1988-02-01

    The amphoteric native defect model of the Schottky barrier formation is used to analyze the Fermi level pinning at metal/semiconductor interfaces for submonolayer metal coverages. It is assumed that the energy required for defect generation is released in the process of surface back-relaxation. Model calculations for metal/GaAs interfaces show a weak dependence of the Fermi level pinning on the thickness of metal deposited at room temperature. This weak dependence indicates a strong dependence of the defect formation energy on the Fermi level, a unique feature of amphoteric native defects. This result is in very good agreement with experimental data. It is shown that a very distinct asymmetry in the Fermi level pinning on p- and n-type GaAs observed at liquid nitrogen temperatures can be understood in terms of much different recombination rates for amphoteric native defects in those two types of materials. Also, it is demonstrated that the Fermi level stabilization energy, a central concept of the amphoteric defect system, plays a fundamental role in other phenomena in semiconductors such as semiconductor/semiconductor heterointerface intermixing and saturation of free carrier concentration. 33 refs., 6 figs.

  3. Preservation of surface features on semiconductor surfaces

    SciTech Connect

    Wilt, D.P.

    1989-02-14

    A semiconductor laser is described comprising a Group III-V compound semiconductor body having a major surface, p1 an optical grating on the major surface, a protective coating on the grating, the coating including a transition metal, a Group III-V compound semiconductor heterostructure formed on the coating, the heterostructure having the shape of a mesa and including a Group III-V compound semiconductor active layer, a current-blocking Group III-V compound semiconductor structure laterally adjacent the mesa and effective to direct the primary flow of current through the mesa during operation of the laser, and means forming electrical contact to the laser.

  4. Broad interband semiconductor laser diodes

    NASA Astrophysics Data System (ADS)

    Tan, Chee Loon

    A semiconductor laser is a diode device that emits light via stimulated emission. Conventionally, light emitted from a semiconductor laser is spatially coherent or narrowband. The fundamental mechanism of stimulated emission process in general leads only to a single wavelength emission. However, there are some lasers emit light with a broad spectrum or different distinct wavelength subjected to various operating conditions such as external grating configuration with semiconductor laser, diode-pumped self-Q-switch fiber laser, ultrashort pulse excitation, photonic crystal fiber, ultrabroadband solid-state lasers, semiconductor optical amplifier-based multiwavelength tunable fiber lasers, nonlinear crystal, broadband semiconductor laser etc. This type of broadband laser is vital in many practical applications such as optical telecommunications, spectroscopy measurement, imaging technology, etc. Recently, an ultra-broadband semiconductor laser that utilizes intersubband optical transitions via quantum cascade configuration has been realized. Laser action with a Fabry-Perot spectrum covering all wavelengths from 6 to 8 microm simultaneously is demonstrated with this approach. More recently, broadband emission results from interband optical transitions via quantum-dot/dash nanostructures have been demonstrated in a simple p-i-n laser diode structure. To date, this latest approach offers the simplest design by proper engineering of quantized energy states as well as utilizing the high inhomogeneity of the dot/dash nanostructures, which is inherent from self-assembled growth technology. In this dissertation, modeling of semiconductor InGaAs/GaAs quantum-dot broadband laser utilizing the properties of inhomogeneous and homogeneous broadening effects on lasing spectral will be discussed, followed by a detail analysis of another type of broad interband semiconductor laser, which is InAs/InGaAlAs quantum-dash broadband laser. Based on the device characterization results

  5. Back-side readout semiconductor photomultiplier

    SciTech Connect

    Choong, Woon-Seng; Holland, Stephen E

    2014-05-20

    This disclosure provides systems, methods, and apparatus related to semiconductor photomultipliers. In one aspect, a device includes a p-type semiconductor substrate, the p-type semiconductor substrate having a first side and a second side, the first side of the p-type semiconductor substrate defining a recess, and the second side of the p-type semiconductor substrate being doped with n-type ions. A conductive material is disposed in the recess. A p-type epitaxial layer is disposed on the second side of the p-type semiconductor substrate. The p-type epitaxial layer includes a first region proximate the p-type semiconductor substrate, the first region being implanted with p-type ions at a higher doping level than the p-type epitaxial layer, and a second region disposed on the first region, the second region being doped with p-type ions at a higher doping level than the first region.

  6. Semiconductor electrolyte photovoltaic energy converter

    NASA Technical Reports Server (NTRS)

    Anderson, W. W.; Anderson, L. B.

    1975-01-01

    Feasibility and practicality of a solar cell consisting of a semiconductor surface in contact with an electrolyte are evaluated. Basic components and processes are detailed for photovoltaic energy conversion at the surface of an n-type semiconductor in contact with an electrolyte which is oxidizing to conduction band electrons. Characteristics of single crystal CdS, GaAs, CdSe, CdTe and thin film CdS in contact with aqueous and methanol based electrolytes are studied and open circuit voltages are measured from Mott-Schottky plots and open circuit photo voltages. Quantum efficiencies for short circuit photo currents of a CdS crystal and a 20 micrometer film are shown together with electrical and photovoltaic properties. Highest photon irradiances are observed with the GaAs cell.

  7. Coherent magnetic semiconductor nanodot arrays

    PubMed Central

    2011-01-01

    In searching appropriate candidates of magnetic semiconductors compatible with mainstream Si technology for future spintronic devices, extensive attention has been focused on Mn-doped Ge magnetic semiconductors. Up to now, lack of reliable methods to obtain high-quality MnGe nanostructures with a desired shape and a good controllability has been a barrier to make these materials practically applicable for spintronic devices. Here, we report, for the first time, an innovative growth approach to produce self-assembled and coherent magnetic MnGe nanodot arrays with an excellent reproducibility. Magnetotransport experiments reveal that the nanodot arrays possess giant magneto-resistance associated with geometrical effects. The discovery of the MnGe nanodot arrays paves the way towards next-generation high-density magnetic memories and spintronic devices with low-power dissipation. PMID:21711627

  8. Dimensional crossover in semiconductor nanostructures.

    PubMed

    McDonald, Matthew P; Chatterjee, Rusha; Si, Jixin; Jankó, Boldizsár; Kuno, Masaru

    2016-01-01

    Recent advances in semiconductor nanostructure syntheses provide unprecedented control over electronic quantum confinement and have led to extensive investigations of their size- and shape-dependent optical/electrical properties. Notably, spectroscopic measurements show that optical bandgaps of one-dimensional CdSe nanowires are substantially (approximately 100 meV) lower than their zero-dimensional counterparts for equivalent diameters spanning 5-10 nm. But what, exactly, dictates the dimensional crossover of a semiconductor's electronic structure? Here we probe the one-dimensional to zero-dimensional transition of CdSe using single nanowire/nanorod absorption spectroscopy. We find that carrier electrostatic interactions play a fundamental role in establishing dimensional crossover. Moreover, the critical length at which this transition occurs is governed by the aspect ratio-dependent interplay between carrier confinement and dielectric contrast/confinement energies. PMID:27577091

  9. Hypersonic modes in nanophononic semiconductors.

    PubMed

    Hepplestone, S P; Srivastava, G P

    2008-09-01

    Frequency gaps and negative group velocities of hypersonic phonon modes in periodically arranged composite semiconductors are presented. Trends and criteria for phononic gaps are discussed using a variety of atomic-level theoretical approaches. From our calculations, the possibility of achieving semiconductor-based one-dimensional phononic structures is established. We present results of the location and size of gaps, as well as negative group velocities of phonon modes in such structures. In addition to reproducing the results of recent measurements of the locations of the band gaps in the nanosized Si/Si{0.4}Ge{0.6} superlattice, we show that such a system is a true one-dimensional hypersonic phononic crystal. PMID:18851224

  10. Optical conductivity for liquid semiconductors

    NASA Astrophysics Data System (ADS)

    Jain, Manish; Ko, Eunjung; Derby, J. J.; Chelikowsky, James

    2002-03-01

    We present calculations for the optical conductivity of several semiconductor liquids: SiGe, GaAs, CdTe, and ZnTe. We perform ab initio molecular dynamics for these liquids. The required interatomic forces are determined using the pseudopotential density functional method. We determine the optical conductivity by considering ensemble averages of the liquid state within the Kubo-Greenwood formalism. In the liquid phase, CdTe and ZnTe exhibit properties that are different from III-V and group IV semiconductors. CdTe and ZnTe remain semiconducting unlike SiGe and GaAs, which are metallic in the melt. These differences in optical conductivities are explained in terms of differences in the microstructure of the liquids. We also verify an empirical rule by Joffe and Regel. Their rule predicts the liquid will remain semiconducting if the short range order of the melt resembles that of the crystalline phase.

  11. Cameras for semiconductor process control

    NASA Technical Reports Server (NTRS)

    Porter, W. A.; Parker, D. L.

    1977-01-01

    The application of X-ray topography to semiconductor process control is described, considering the novel features of the high speed camera and the difficulties associated with this technique. The most significant results on the effects of material defects on device performance are presented, including results obtained using wafers processed entirely within this institute. Defects were identified using the X-ray camera and correlations made with probe data. Also included are temperature dependent effects of material defects. Recent applications and improvements of X-ray topographs of silicon-on-sapphire and gallium arsenide are presented with a description of a real time TV system prototype and of the most recent vacuum chuck design. Discussion is included of our promotion of the use of the camera by various semiconductor manufacturers.

  12. Compound semiconductor optical waveguide switch

    DOEpatents

    Spahn, Olga B.; Sullivan, Charles T.; Garcia, Ernest J.

    2003-06-10

    An optical waveguide switch is disclosed which is formed from III-V compound semiconductors and which has a moveable optical waveguide with a cantilevered portion that can be bent laterally by an integral electrostatic actuator to route an optical signal (i.e. light) between the moveable optical waveguide and one of a plurality of fixed optical waveguides. A plurality of optical waveguide switches can be formed on a common substrate and interconnected to form an optical switching network.

  13. Selective Etching of Semiconductor Glassivation

    NASA Technical Reports Server (NTRS)

    Casper, N.

    1982-01-01

    Selective etching technique removes portions of glassivation on a semi-conductor die for failure analysis or repairs. A periodontal needle attached to a plastic syringe is moved by a microprobe. Syringe is filled with a glass etch. A drop of hexane and vacuum pump oil is placed on microcircuit die and hexane is allowed to evaporate leaving a thin film of oil. Microprobe brings needle into contact with area of die to be etched.

  14. Etching Of Semiconductor Wafer Edges

    DOEpatents

    Kardauskas, Michael J.; Piwczyk, Bernhard P.

    2003-12-09

    A novel method of etching a plurality of semiconductor wafers is provided which comprises assembling said plurality of wafers in a stack, and subjecting said stack of wafers to dry etching using a relatively high density plasma which is produced at atmospheric pressure. The plasma is focused magnetically and said stack is rotated so as to expose successive edge portions of said wafers to said plasma.

  15. Hybrid ferromagnetic-semiconductor structures

    SciTech Connect

    Prinz, G.A. )

    1990-11-23

    Ultrahigh-vacuum growth techniques are now being used to grow single-crystal films of magnetic materials. These growth procedures, carried out in the same molecular beam epitaxy systems commonly used for the growth of semiconductor films, have yielded a variety of new materials and structures that may prove useful for integrated electronics and integrated optical device applications. Examples are given for growth on GaAs and ZnSe, including magnetic sandwiches and patterned structures. 14 refs., 9 figs.

  16. Conductivity in transparent oxide semiconductors

    NASA Astrophysics Data System (ADS)

    King, P. D. C.; Veal, T. D.

    2011-08-01

    Despite an extensive research effort for over 60 years, an understanding of the origins of conductivity in wide band gap transparent conducting oxide (TCO) semiconductors remains elusive. While TCOs have already found widespread use in device applications requiring a transparent contact, there are currently enormous efforts to (i) increase the conductivity of existing materials, (ii) identify suitable alternatives, and (iii) attempt to gain semiconductor-engineering levels of control over their carrier density, essential for the incorporation of TCOs into a new generation of multifunctional transparent electronic devices. These efforts, however, are dependent on a microscopic identification of the defects and impurities leading to the high unintentional carrier densities present in these materials. Here, we review recent developments towards such an understanding. While oxygen vacancies are commonly assumed to be the source of the conductivity, there is increasing evidence that this is not a sufficient mechanism to explain the total measured carrier concentrations. In fact, many studies suggest that oxygen vacancies are deep, rather than shallow, donors, and their abundance in as-grown material is also debated. We discuss other potential contributions to the conductivity in TCOs, including other native defects, their complexes, and in particular hydrogen impurities. Convincing theoretical and experimental evidence is presented for the donor nature of hydrogen across a range of TCO materials, and while its stability and the role of interstitial versus substitutional species are still somewhat open questions, it is one of the leading contenders for yielding unintentional conductivity in TCOs. We also review recent work indicating that the surfaces of TCOs can support very high carrier densities, opposite to the case for conventional semiconductors. In thin-film materials/devices and, in particular, nanostructures, the surface can have a large impact on the total

  17. Interfaces in semiconductor/metal radial superlattices

    SciTech Connect

    Deneke, Christoph; Sigle, Wilfried; Eigenthaler, Ulrike; Aken, Peter A. van; Schuetz, Gisela; Schmidt, Oliver G.

    2007-06-25

    Semiconductor/metal radial superlattices are produced by the roll-up of inherently strained InGaAs/Ti/Au as well as InAlGaAs/GaAs/Cr films. Cross sections of the obtained structures are prepared and investigated in detail by diverse transmission electron microscopy as well as microanalysis techniques. Special attention is paid to the interfaces of the semiconductor/metal hybrid superlattice. The study reveals amorphous, noncrystalline layers for the semiconductor/metal as well as for the metal/semiconductor interface. The chemical analysis suggests that the observed interlayers are oxides giving rise to a semiconductor/oxide/metal/oxide superlattice rather than a pure semiconductor/metal superlattice.

  18. 75 FR 49526 - Freescale Semiconductor, Inc., Technical Information Center, Tempe, AZ; Freescale Semiconductor...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-13

    ... Register on November 17, 2009 (74 FR 59249). At the request of the petitioners, the Department reviewed the... Employment and Training Administration Freescale Semiconductor, Inc., Technical Information Center, Tempe, AZ; Freescale Semiconductor, Inc., Technical Information Center, Woburn, MA; Amended Certification...

  19. Charge injection in doped organic semiconductors

    NASA Astrophysics Data System (ADS)

    Hosseini, A. R.; Wong, Man Hoi; Shen, Yulong; Malliaras, George G.

    2005-01-01

    The influence of doping on the process of charge injection from a metal electrode into a model organic semiconductor is investigated. The contact resistance, which is the relevant figure-of-merit, is found to decrease dramatically upon doping beyond what is expected from theory and seen in crystalline semiconductors. This phenomenon is understood in terms of broadening of the transport manifold in the organic semiconductor, induced by the dopants.

  20. Optical devices featuring textured semiconductor layers

    DOEpatents

    Moustakas, Theodore D.; Cabalu, Jasper S.

    2012-08-07

    A semiconductor sensor, solar cell or emitter, or a precursor therefor, has a substrate and one or more textured semiconductor layers deposited onto the substrate. The textured layers enhance light extraction or absorption. Texturing in the region of multiple quantum wells greatly enhances internal quantum efficiency if the semiconductor is polar and the quantum wells are grown along the polar direction. Electroluminescence of LEDs of the invention is dichromatic, and results in variable color LEDs, including white LEDs, without the use of phosphor.

  1. Optical devices featuring textured semiconductor layers

    DOEpatents

    Moustakas, Theodore D.; Cabalu, Jasper S.

    2011-10-11

    A semiconductor sensor, solar cell or emitter, or a precursor therefor, has a substrate and one or more textured semiconductor layers deposited onto the substrate. The textured layers enhance light extraction or absorption. Texturing in the region of multiple quantum wells greatly enhances internal quantum efficiency if the semiconductor is polar and the quantum wells are grown along the polar direction. Electroluminescence of LEDs of the invention is dichromatic, and results in variable color LEDs, including white LEDs, without the use of phosphor.

  2. High performance compound semiconductor SPAD arrays

    NASA Astrophysics Data System (ADS)

    Harmon, Eric S.; Naydenkov, Mikhail; Bowling, Jared

    2016-05-01

    Aggregated compound semiconductor single photon avalanche diode (SPAD) arrays are emerging as a viable alternative to the silicon photomultiplier (SiPM). Compound semiconductors have the potential to surpass SiPM performance, potentially achieving orders of magnitude lower dark count rates and improved radiation hardness. New planar processing techniques have been developed to enable compound semiconductor SPAD devices to be produced with pixel pitches of 11 - 25 microns, with thousands of SPADs per array.

  3. Stretchable semiconductor elements and stretchable electrical circuits

    DOEpatents

    Rogers, John A.; Khang, Dahl-Young; Menard, Etienne

    2009-07-07

    The invention provides methods and devices for fabricating printable semiconductor elements and assembling printable semiconductor elements onto substrate surfaces. Methods, devices and device components of the present invention are capable of generating a wide range of flexible electronic and optoelectronic devices and arrays of devices on substrates comprising polymeric materials. The present invention also provides stretchable semiconductor structures and stretchable electronic devices capable of good performance in stretched configurations.

  4. Sensor Detects Semiconductor Escaping From Ampoule

    NASA Technical Reports Server (NTRS)

    Watring, Dale A.; Johnson, Martin L.

    1994-01-01

    Electrical resistance and temperature change upon exposure to semiconductors. Sensor detects breakage of ampoule containing molten semiconductor. Chemical reaction between hot semiconductor material and wire causes step increase in electrical resistance and temperature of wire. Step increase in temperature and resistance of sensor indicates presence of hot GaAs. Sensor used to shut down furnace automatically if ampoule breaks and prevents further release of molton semiconductor, which could quickly breach surrounding thin wall of cartridge, damage furnace, and/or release toxic vapors into surrounding area.

  5. Wafer-fused semiconductor radiation detector

    DOEpatents

    Lee, Edwin Y.; James, Ralph B.

    2002-01-01

    Wafer-fused semiconductor radiation detector useful for gamma-ray and x-ray spectrometers and imaging systems. The detector is fabricated using wafer fusion to insert an electrically conductive grid, typically comprising a metal, between two solid semiconductor pieces, one having a cathode (negative electrode) and the other having an anode (positive electrode). The wafer fused semiconductor radiation detector functions like the commonly used Frisch grid radiation detector, in which an electrically conductive grid is inserted in high vacuum between the cathode and the anode. The wafer-fused semiconductor radiation detector can be fabricated using the same or two different semiconductor materials of different sizes and of the same or different thicknesses; and it may utilize a wide range of metals, or other electrically conducting materials, to form the grid, to optimize the detector performance, without being constrained by structural dissimilarity of the individual parts. The wafer-fused detector is basically formed, for example, by etching spaced grooves across one end of one of two pieces of semiconductor materials, partially filling the grooves with a selected electrical conductor which forms a grid electrode, and then fusing the grooved end of the one semiconductor piece to an end of the other semiconductor piece with a cathode and an anode being formed on opposite ends of the semiconductor pieces.

  6. Reflection technique for thermal mapping of semiconductors

    DOEpatents

    Walter, Martin J.

    1989-06-20

    Semiconductors may be optically tested for their temperatures by illuminating them with tunable monochromatic electromagnetic radiation and observing the light reflected off of them. A transition point will occur when the wavelength of the light corresponds with the actual band gap energy of the semiconductor. At the transition point, the image of the semiconductor will appreciably darken as the light is transmitted through it, rather than being reflected off of it. The wavelength of the light at the transition point corresponds to the actual band gap energy and the actual temperature of the semiconductor.

  7. Etching Semiconductors With Beams Of Reactive Atoms

    NASA Technical Reports Server (NTRS)

    Minton, Timothy K.; Giapis, Konstantinos P.; Moore, Teresa A.

    1995-01-01

    Method of etching semiconductors with energetic beams of electrically neutral, but chemically reactive, species undergoing development. Enables etching of straight walls into semiconductor substrates at edges of masks without damage to underlying semiconductor material. In addition to elimination of charge damage, technique reduces substrate bombardment damage because translational energy of neutral species in range 2-12 eV, below damage threshold of many semiconductor materials. Furthermore, low-energy neutrals cause no mask erosion allowing for etching features with very high aspect ratios.

  8. Hot Electron Effects in Semiconductors.

    NASA Astrophysics Data System (ADS)

    Moore, James Scott

    The high-field transport of electrons has been calculated for two semiconductor configurations: quasi -two-dimensional and bulk. All calculations are performed by solving the Boltzmann equation, assuming a displaced Maxwellian distribution function. In the case of quasi-two-dimensional semiconductors, this treatment is applied to a <100> inversion layer in silicon. Under a high electric field, energy levels become grouped into subbands, so that motion of carriers perpendicular to the surface becomes quantized; thus, the energy, momentum and population transfer relaxation rates appropriate to the individual levels must be considered in the calculations, along with their relation to velocity overshoot. Previous work was performed under the assumption that intervalley scattering is a local phenomenon, i.e., a function only of electron temperature of the initial valley. In the present work, this assumption has been relaxed, and the intervalley coupling of electron temperature is taken into account. dc and transient response characteristics for both uncoupled and coupled models are performed, and the results are compared. Due to the recent interest in GaAs/Al(,x)Ga(,1 -x)As superlattices, there exists a need for a theory of hot electron transport in these structures. Since GaAs is a polar semiconductor, a theory must first be derived for polar III-V compounds under inversion, the result then being easily extended to superlattices. In this work, such theory is derived but, due to the alignment of the subbands, the simultaneous balance equations cannot be solved numerically with the approach undertaken here (solution of the Boltzmann equation). A theory of transport in bulk III-V compounds is modified by some simplifying approximations to make the theory numerically tractable, this theory then being applied to model bulk III-V compounds (in particular dc and transient response characteristics), along with their ternary and quaternary alloys. These results are found to

  9. High-Performance Thermoelectric Semiconductors

    NASA Technical Reports Server (NTRS)

    Fleurial, Jean-Pierre; Caillat, Thierry; Borshchevsky, Alexander

    1994-01-01

    Figures of merit almost double current state-of-art thermoelectric materials. IrSb3 is semiconductor found to exhibit exceptional thermoelectric properties. CoSb3 and RhSb3 have same skutterudite crystallographic structure as IrSb3, and exhibit exceptional transport properties expected to contribute to high thermoelectric performance. These three compounds form solid solutions. Combination of properties offers potential for development of new high-performance thermoelectric materials for more efficient thermoelectric power generators, coolers, and detectors.

  10. Optic probe for semiconductor characterization

    DOEpatents

    Sopori, Bhushan L.; Hambarian, Artak

    2008-09-02

    Described herein is an optical probe (120) for use in characterizing surface defects in wafers, such as semiconductor wafers. The optical probe (120) detects laser light reflected from the surface (124) of the wafer (106) within various ranges of angles. Characteristics of defects in the surface (124) of the wafer (106) are determined based on the amount of reflected laser light detected in each of the ranges of angles. Additionally, a wafer characterization system (100) is described that includes the described optical probe (120).

  11. Semiconductor double quantum dot micromaser.

    PubMed

    Liu, Y-Y; Stehlik, J; Eichler, C; Gullans, M J; Taylor, J M; Petta, J R

    2015-01-16

    The coherent generation of light, from masers to lasers, relies upon the specific structure of the individual emitters that lead to gain. Devices operating as lasers in the few-emitter limit provide opportunities for understanding quantum coherent phenomena, from terahertz sources to quantum communication. Here we demonstrate a maser that is driven by single-electron tunneling events. Semiconductor double quantum dots (DQDs) serve as a gain medium and are placed inside a high-quality factor microwave cavity. We verify maser action by comparing the statistics of the emitted microwave field above and below the maser threshold. PMID:25593187

  12. Processing of insulators and semiconductors

    DOEpatents

    Quick, Nathaniel R.; Joshi, Pooran C.; Duty, Chad Edward; Jellison, Jr., Gerald Earle; Angelini, Joseph Attilio

    2015-06-16

    A method is disclosed for processing an insulator material or a semiconductor material. The method includes pulsing a plasma lamp onto the material to diffuse a doping substance into the material, to activate the doping substance in the material or to metallize a large area region of the material. The method may further include pulsing a laser onto a selected region of the material to diffuse a doping substance into the material, to activate the doping substance in the material or to metallize a selected region of the material.

  13. Semiconductor technology program. Progress briefs

    NASA Technical Reports Server (NTRS)

    Bullis, W. M. (Editor)

    1979-01-01

    The current status of NBS work on measurement technology for semiconductor materials, process control, and devices is reported. Results of both in-house and contract research are covered. Highlighted activities include modeling of diffusion processes, analysis of model spreading resistance data, and studies of resonance ionization spectroscopy, resistivity-dopant density relationships in p-type silicon, deep level measurements, photoresist sensitometry, random fault measurements, power MOSFET thermal characteristics, power transistor switching characteristics, and gross leak testing. New and selected on-going projects are described. Compilations of recent publications and publications in press are included.

  14. Microradiography with Semiconductor Pixel Detectors

    NASA Astrophysics Data System (ADS)

    Jakubek, Jan; Cejnarova, Andrea; Dammer, Jiří; Holý, Tomáš; Platkevič, Michal; Pospíšil, Stanislav; Vavřík, Daniel; Vykydal, Zdeněk

    2007-11-01

    High resolution radiography (with X-rays, neutrons, heavy charged particles, …) often exploited also in tomographic mode to provide 3D images stands as a powerful imaging technique for instant and nondestructive visualization of fine internal structure of objects. Novel types of semiconductor single particle counting pixel detectors offer many advantages for radiation imaging: high detection efficiency, energy discrimination or direct energy measurement, noiseless digital integration (counting), high frame rate and virtually unlimited dynamic range. This article shows the application and potential of pixel detectors (such as Medipix2 or TimePix) in different fields of radiation imaging.

  15. Heterogeneous Integration of Compound Semiconductors

    NASA Astrophysics Data System (ADS)

    Moutanabbir, Oussama; Gösele, Ulrich

    2010-08-01

    The ability to tailor compound semiconductors and to integrate them onto foreign substrates can lead to superior or novel functionalities with a potential impact on various areas in electronics, optoelectronics, spintronics, biosensing, and photovoltaics. This review provides a brief description of different approaches to achieve this heterogeneous integration, with an emphasis on the ion-cut process, also known commercially as the Smart-Cut™ process. This process combines semiconductor wafer bonding and undercutting using defect engineering by light ion implantation. Bulk-quality heterostructures frequently unattainable by direct epitaxial growth can be produced, provided that a list of technical criteria is fulfilled, thus offering an additional degree of freedom in the design and fabrication of heterogeneous and flexible devices. Ion cutting is a generic process that can be employed to split and transfer fine monocrystalline layers from various crystals. Materials and engineering issues as well as our current understanding of the underlying physics involved in its application to cleaving thin layers from freestanding GaN, InP, and GaAs wafers are presented.

  16. Organic semiconductors: fundamentals and applications

    NASA Astrophysics Data System (ADS)

    Kowalsky, W.; Becker, E.; Benstem, T.; Johannes, H.-H.; Metzdorf, D.; Neuner, H.; Schöbel, J.

    The first organic light emitting diodes (OLEDs) were demonstrated in 1987. To date they have been brought into marketable commodity. OLED matrix displays offer high contrast, wide viewing, angle and a broad temperature range at low power consumption. Due to the sensitivity of organic thin films, new structuring techniques had do be developed. In recent years in addition to advanced OLED activities, increasing effort has been put into the realization of organic integrated circuits for low-cost applications based on organic field-effect transistors. First transistors have shown the necessity to decrease operating voltage and to improve carrier mobility. Electrical current in organic devices is limited by the low conductivity of organic semiconductors and by energy barriers at the metal-organic semiconductor interface. Photoelectric measurements facilitate the determination of barrier height differences between various electrode setups. Further insight in the energy band alignment at organic heterointerfaces are gained by ultraviolet photoelectron spectroscopy. Energy transfer, in a doped OLED emitting layer can be investigated by time-resolved photo-luminescence measurements.

  17. Semiconductor foundry, lithography, and partners

    NASA Astrophysics Data System (ADS)

    Lin, Burn J.

    2002-07-01

    The semiconductor foundry took off in 1990 with an annual capacity of less than 0.1M 8-inch-equivalent wafers at the 2-mm node. In 2000, the annual capacity rose to more than 10M. Initially, the technology practiced at foundries was 1 to 2 generations behind that at integrated device manufacturers (IDMs). Presently, the progress in 0.13-mm manufacturing goes hand-in-hand with any of the IDMs. There is a two-order of magnitude rise in output and the progress of technology development outpaces IDMs. What are the reasons of the success? Is it possible to sustain the pace? This paper shows the quick rise of foundries in capacity, sales, and market share. It discusses the their uniqueness which gives rise to advantages in conjunction with challenges. It also shows the role foundries take with their customer partners and supplier partners, their mutual dependencies, as well as expectations. What role then does lithography play in the foundries? What are the lithographic challenges to sustain the pace of technology? The experience of technology development and transfer, at one of the major foundries, is used to illustrate the difficulties and progresses made. Looking into the future, as semiconductor manufacturing will become even more expensive and capital investment more prohibitive, we will make an attempt to suggest possible solutions.

  18. Method for fabricating semiconductor devices

    NASA Technical Reports Server (NTRS)

    Kaiser, William J. (Inventor); Grunthaner, Frank J. (Inventor); Hecht, Michael H. (Inventor); Bell, Lloyd D. (Inventor)

    1995-01-01

    A process for fabricating gold/gallium arsenide structures, in situ, on molecular beam epitaxially grown gallium arsenide. The resulting interface proves to be Ohmic, an unexpected result which is interpreted in terms of increased electrode interdiffusion. More importantly, the present invention surprisingly permits the fabrication of Ohmic contacts in a III-V semiconductor material at room temperature. Although it may be desireable to heat the Ohmic contact to a temperature of, for example, 200 degrees Centigrade if one wishes to further decrease the resistance of the contact, such low temperature annealing is much less likely to have any deleterious affect on the underlying substrate. The use of the term in situ herein, contemplates continuously maintaining an ultra-high vacuum, that is a vacuum which is at least 10.sup.-8 Torr, until after the metallization has been completed. An alternative embodiment of the present invention comprising an additional step, namely the termination of the gallium arsenide by a two monolayer thickness of epitaxial aluminum arsenide as a diffusion barrier, enables the recovery of Schottky barrier behavior, namely a rectified I-V characteristic. The present invention provides a significant breakthrough in the fabrication of III-V semiconductor devices wherein excellent Ohmic contact and Schottky barrier interfaces to such devices can be achieved simply and inexpensively and without requiring the high temperature processing of the prior art and also without requiring the use of exotic high temperature refractory materials as substitutes for those preferred contact metals such as gold, aluminum and the like.

  19. Frontier of transparent oxide semiconductors

    NASA Astrophysics Data System (ADS)

    Ohta, Hiromichi; Nomura, Kenji; Hiramatsu, Hidenori; Ueda, Kazushige; Kamiya, Toshio; Hirano, Masahiro; Hosono, Hideo

    2003-12-01

    Recent advancements of transparent oxide semiconductors (TOS) toward new frontiers of "oxide electronics" are reviewed based on our efforts, categorized as "novel functional materials", "heteroepitaxial growth techniques", and "device fabrications". Topics focused in this paper are: (1) highly conductive ITO thin film with atomically flat surface, (2) p-type TOS material ZnRh 2O 4, (3) deep-ultraviolet (DUV) transparent conductive oxide β-Ga 2O 3 thin film, (4) electrochromic oxyfuolide NbO 2F, (5) single-crystalline films of InGaO 3(ZnO) m grown by reactive solid-phase epitaxy, (6) p-type semiconductor LaCuOS/Se epitaxial films capable of emitting UV- and purple-light, (7) p-n homojunction based on bipolar CuInO 2, (8) transparent FET based on single-crystalline InGaO 3(ZnO) 5 films, and (9) UV-light emitting diode based on p-n heterojunction.

  20. Theoretical tools for semiconductors devices

    SciTech Connect

    Hagan, P.; Cox, R.; Randall, E.; Reyna, L.

    1996-10-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Future generations of Very Large Scale Integrated (VLSI) circuits require semiconducting devices that are much faster and smaller than current devices. Three-dimensional and transient effects are critical to the performance of these devices. Yet using Monte Carlo (MC) codes to perform time-dependent, three-dimensional simulations will not be feasible in the foreseeable future. Here we re-analyze the physics of semiconductors; use singular perturbation techniques to derive the reduced-dimensionality equations that accurately describe the semiconductor in the regimes corresponding to ultra-small ultra-fast devices; and validate the resulting theoretical models against MC simulations and experimental data. The objective of this project was to gain the capability of accurately simulating ultra-small ultra-fast devices in three spatial dimensions with the ultimate goal of transforming the design of advanced devices.

  1. Polaronic trapping in magnetic semiconductors

    NASA Astrophysics Data System (ADS)

    Raebiger, Hannes

    2012-02-01

    GaN doped with iron is an interesting candidate material for magnetic semiconductors, as p-d coupling between the localized Fe-d and extended N-p hole states is expected to facilitate long-range ferromagnetic alignment of the Fe spins [1]. This picture of extended states in GaN:Fe, however, falls apart due to a polaronic localization of the hole carriers nearby the Fe impurities. To elucidate the carrier localization in GaN:Fe and related iron doped III-V semiconductors, I present a systematic study using self-interaction corrected density-functional calculations [2]. These calculations predict three distinct scenarios. (i) Some systems do sustain extended host-like hole states, (ii) some exhibit polaronic trapping, (iii) and some exhibit carrier trapping at Fe-d orbitals. These behaviors are described in detail to give an insight as to how to distinguish them experimentally. I thank T. Fujita, C. Echeverria-Arrondo, and A. Ayuela for their collaboration.[4pt] [1] T. Dietl et al, Science, 287, 1019 (2000).[0pt] [2] S. Lany and A. Zunger, Phys. Rev. B, 80, 085202 (2009).

  2. Novel room temperature ferromagnetic semiconductors

    SciTech Connect

    Gupta, Amita

    2004-11-01

    Today's information world, bits of data are processed by semiconductor chips, and stored in the magnetic disk drives. But tomorrow's information technology may see magnetism (spin) and semiconductivity (charge) combined in one 'spintronic' device that exploits both charge and 'spin' to carry data (the best of two worlds). Spintronic devices such as spin valve transistors, spin light emitting diodes, non-volatile memory, logic devices, optical isolators and ultra-fast optical switches are some of the areas of interest for introducing the ferromagnetic properties at room temperature in a semiconductor to make it multifunctional. The potential advantages of such spintronic devices will be higher speed, greater efficiency, and better stability at a reduced power consumption. This Thesis contains two main topics: In-depth understanding of magnetism in Mn doped ZnO, and our search and identification of at least six new above room temperature ferromagnetic semiconductors. Both complex doped ZnO based new materials, as well as a number of nonoxides like phosphides, and sulfides suitably doped with Mn or Cu are shown to give rise to ferromagnetism above room temperature. Some of the highlights of this work are discovery of room temperature ferromagnetism in: (1) ZnO:Mn (paper in Nature Materials, Oct issue, 2003); (2) ZnO doped with Cu (containing no magnetic elements in it); (3) GaP doped with Cu (again containing no magnetic elements in it); (4) Enhancement of Magnetization by Cu co-doping in ZnO:Mn; (5) CdS doped with Mn, and a few others not reported in this thesis. We discuss in detail the first observation of ferromagnetism above room temperature in the form of powder, bulk pellets, in 2-3 mu-m thick transparent pulsed laser deposited films of the Mn (<4 at. percent) doped ZnO. High-resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS) spectra recorded from 2 to 200nm areas showed homogeneous distribution of Mn substituting

  3. High power semiconductor disk laser with a semiconductor-dielectric-metal compound mirror

    NASA Astrophysics Data System (ADS)

    Rantamäki, A.; Saarinen, E. J.; Lyytikäinen, J.; Lahtonen, K.; Valden, M.; Okhotnikov, O. G.

    2014-03-01

    We present optically pumped semiconductor disk lasers with a thin dielectric layer placed between the semiconductor distributed Bragg reflector and the metallization interface. The approach is shown to enhance the reflectivity of the semiconductor mirror while introducing a negligible penalty to the thermal resistance of the device. The design has potential for improving the performance of semiconductor disk lasers by avoiding highly pump-absorbing metal layers and allowing thinner mirror structures. The advantages are expected to be especially prominent for material systems that employ thick thermally insulating semiconductor mirrors.

  4. Semiconductor liquid-junction solar cell

    SciTech Connect

    Parkinson, B.A.

    1982-10-29

    A semiconductor liquid junction photocell in which the photocell is in the configuration of a light concentrator and in which the electrolytic solution both conducts current and facilitates the concentration of incident solar radiation onto the semiconductor. The photocell may be in the configuration of a non-imaging concentrator such as a compound parabolic concentrator, or an imaging concentrator such as a lens.

  5. Hybrid anode for semiconductor radiation detectors

    DOEpatents

    Yang, Ge; Bolotnikov, Aleksey E; Camarda, Guiseppe; Cui, Yonggang; Hossain, Anwar; Kim, Ki Hyun; James, Ralph B

    2013-11-19

    The present invention relates to a novel hybrid anode configuration for a radiation detector that effectively reduces the edge effect of surface defects on the internal electric field in compound semiconductor detectors by focusing the internal electric field of the detector and redirecting drifting carriers away from the side surfaces of the semiconductor toward the collection electrode(s).

  6. Energetics of the Semiconductor-Electrolyte Interface.

    ERIC Educational Resources Information Center

    Turner, John A.

    1983-01-01

    The use of semiconductors as electrodes for electrochemistry requires an understanding of both solid-state physics and electrochemistry, since phenomena associated with both disciplines are seen in semiconductor/electrolyte systems. The interfacial energetics of these systems are discussed. (JN)

  7. Photoelectroconversion by Semiconductors: A Physical Chemistry Experiment.

    ERIC Educational Resources Information Center

    Fan, Qinbai; And Others

    1995-01-01

    Presents an experiment designed to give students some experience with photochemistry, electrochemistry, and basic theories about semiconductors. Uses a liquid-junction solar cell and illustrates some fundamental physical and chemical principles related to light and electricity interconversion as well as the properties of semiconductors. (JRH)

  8. Stable surface passivation process for compound semiconductors

    DOEpatents

    Ashby, Carol I. H.

    2001-01-01

    A passivation process for a previously sulfided, selenided or tellurated III-V compound semiconductor surface. The concentration of undesired mid-gap surface states on a compound semiconductor surface is reduced by the formation of a near-monolayer of metal-(sulfur and/or selenium and/or tellurium)-semiconductor that is effective for long term passivation of the underlying semiconductor surface. Starting with the III-V compound semiconductor surface, any oxidation present thereon is substantially removed and the surface is then treated with sulfur, selenium or tellurium to form a near-monolayer of chalcogen-semiconductor of the surface in an oxygen-free atmosphere. This chalcogenated surface is then contacted with a solution of a metal that will form a low solubility chalcogenide to form a near-monolayer of metal-chalcogen-semiconductor. The resulting passivating layer provides long term protection for the underlying surface at or above the level achieved by a freshly chalcogenated compound semiconductor surface in an oxygen free atmosphere.

  9. Apparatus for edge etching of semiconductor wafers

    NASA Technical Reports Server (NTRS)

    Casajus, A.

    1986-01-01

    A device for use in the production of semiconductors, characterized by etching in a rapidly rotating etching bath is described. The fast rotation causes the surface of the etching bath to assume the form of a paraboloid of revolution, so that the semiconductor wafer adjusted at a given height above the resting bath surface is only attacked by etchant at the edges.

  10. Many-body effects in semiconductor lasers

    SciTech Connect

    Chow, W.W.

    1995-03-01

    A microscopic theory, that is based on the coupled Maxwell-semiconductor-Bloch equations, is used to investigate the effects of many-body Coulomb interactions in semiconductor laser devices. This paper describes two examples where the many-body effects play important roles. Experimental data supporting the theoretical results are presented.

  11. Preparation of a semiconductor thin film

    DOEpatents

    Pehnt, Martin; Schulz, Douglas L.; Curtis, Calvin J.; Ginley, David S.

    1998-01-01

    A process for the preparation of a semiconductor film. The process comprises depositing nanoparticles of a semiconductor material onto a substrate whose surface temperature during nanoparticle deposition thereon is sufficient to cause substantially simultaneous fusion of the nanoparticles to thereby coalesce with each other and effectuate film growth.

  12. Preparation of a semiconductor thin film

    DOEpatents

    Pehnt, M.; Schulz, D.L.; Curtis, C.J.; Ginley, D.S.

    1998-01-27

    A process is disclosed for the preparation of a semiconductor film. The process comprises depositing nanoparticles of a semiconductor material onto a substrate whose surface temperature during nanoparticle deposition thereon is sufficient to cause substantially simultaneous fusion of the nanoparticles to thereby coalesce with each other and effectuate film growth.

  13. Semiconductor switch geometry with electric field shaping

    DOEpatents

    Booth, Rex; Pocha, Michael D.

    1994-01-01

    An optoelectric switch is disclosed that utilizes a cylindrically shaped and contoured GaAs medium or other optically active semiconductor medium to couple two cylindrically shaped metal conductors with flat and flared termination points each having an ovoid prominence centrally extending there from. Coupling the truncated ovoid prominence of each conductor with the cylindrically shaped optically active semiconductor causes the semiconductor to cylindrically taper to a triple junction circular line at the base of each prominence where the metal conductor conjoins with the semiconductor and a third medium such as epoxy or air. Tapering the semiconductor at the triple junction inhibits carrier formation and injection at the triple junction and thereby enables greater current carrying capacity through and greater sensitivity of the bulk area of the optically active medium.

  14. Semiconductor switch geometry with electric field shaping

    DOEpatents

    Booth, R.; Pocha, M.D.

    1994-08-23

    An optoelectric switch is disclosed that utilizes a cylindrically shaped and contoured GaAs medium or other optically active semiconductor medium to couple two cylindrically shaped metal conductors with flat and flared termination points each having an ovoid prominence centrally extending there from. Coupling the truncated ovoid prominence of each conductor with the cylindrically shaped optically active semiconductor causes the semiconductor to cylindrically taper to a triple junction circular line at the base of each prominence where the metal conductor conjoins with the semiconductor and a third medium such as epoxy or air. Tapering the semiconductor at the triple junction inhibits carrier formation and injection at the triple junction and thereby enables greater current carrying capacity through and greater sensitivity of the bulk area of the optically active medium. 10 figs.

  15. Creating semiconductor metafilms with designer absorption spectra

    PubMed Central

    Kim, Soo Jin; Fan, Pengyu; Kang, Ju-Hyung; Brongersma, Mark L.

    2015-01-01

    The optical properties of semiconductors are typically considered intrinsic and fixed. Here we leverage the rapid developments in the field of optical metamaterials to create ultrathin semiconductor metafilms with designer absorption spectra. We show how such metafilms can be constructed by placing one or more types of high-index semiconductor antennas into a dense array with subwavelength spacings. It is argued that the large absorption cross-section of semiconductor antennas and their weak near-field coupling open a unique opportunity to create strongly absorbing metafilms whose spectral absorption properties directly reflect those of the individual antennas. Using experiments and simulations, we demonstrate that near-unity absorption at one or more target wavelengths of interest can be achieved in a sub-50-nm-thick metafilm using judiciously sized and spaced Ge nanobeams. The ability to create semiconductor metafilms with custom absorption spectra opens up new design strategies for planar optoelectronic devices and solar cells. PMID:26184335

  16. Moving liquids with light: Photoelectrowetting on semiconductors

    PubMed Central

    Arscott, Steve

    2011-01-01

    By linking semiconductor physics and wetting phenomena a brand new effect termed “photoelectrowetting-on-semiconductors” is demonstrated here for a conducting droplet resting on an insulator-semiconductor stack. Optical generation of carriers in the space-charge region of the underlying semiconductor alters the capacitance of the liquid-insulator-semiconductor stack; the result of this is a modification of the wetting contact angle of the droplet upon illumination using above band gap light. The effect is demonstrated using commercial silicon wafers, both n- and p-type having a doping range spanning four orders of magnitude (6×1014−8×1018 cm−3), coated with a commercial amorphous fluoropolymer insulating film (Teflon®). Impedance measurements confirm that the observations are semiconductor space-charge related effects. The impact of the work could lead to new silicon-based technologies in areas such as Laboratory-on-a-Chip, Microfluidics and Optofluidics. PMID:22355699

  17. Plasma Properties of an Exploding Semiconductor Igniter

    NASA Astrophysics Data System (ADS)

    McGuirk, J. S.; Thomas, K. A.; Shaffer, E.; Malone, A. L.; Baginski, T.; Baginski, M. E.

    1997-11-01

    Requirements by the automotive industry for low-cost, pyrotechnic igniters for automotive airbags have led to the development of several semiconductor devices. The properties of the plasma produced by the vaporization of an exploding semiconductor are necessary in order to minimize the electrical energy requirements. This work considers two silicon-based semiconductor devices: the semiconductor bridge (SCB) and the semiconductor junction igniter both consisting of etched silicon with vapor deposited aluminum structures. Electrical current passing through the device heats a narrow junction region to the point of vaporization creating an aluminum and silicon low-temperature plasma. This work will investigate the electrical characteristics of both devices and infer the plasma properties. Furthermore optical spectral measurements will be taken of the exploding devices to estimate the temperature and density of the plasma.

  18. Creating semiconductor metafilms with designer absorption spectra

    NASA Astrophysics Data System (ADS)

    Kim, Soo Jin; Fan, Pengyu; Kang, Ju-Hyung; Brongersma, Mark L.

    2015-07-01

    The optical properties of semiconductors are typically considered intrinsic and fixed. Here we leverage the rapid developments in the field of optical metamaterials to create ultrathin semiconductor metafilms with designer absorption spectra. We show how such metafilms can be constructed by placing one or more types of high-index semiconductor antennas into a dense array with subwavelength spacings. It is argued that the large absorption cross-section of semiconductor antennas and their weak near-field coupling open a unique opportunity to create strongly absorbing metafilms whose spectral absorption properties directly reflect those of the individual antennas. Using experiments and simulations, we demonstrate that near-unity absorption at one or more target wavelengths of interest can be achieved in a sub-50-nm-thick metafilm using judiciously sized and spaced Ge nanobeams. The ability to create semiconductor metafilms with custom absorption spectra opens up new design strategies for planar optoelectronic devices and solar cells.

  19. Creating semiconductor metafilms with designer absorption spectra.

    PubMed

    Kim, Soo Jin; Fan, Pengyu; Kang, Ju-Hyung; Brongersma, Mark L

    2015-01-01

    The optical properties of semiconductors are typically considered intrinsic and fixed. Here we leverage the rapid developments in the field of optical metamaterials to create ultrathin semiconductor metafilms with designer absorption spectra. We show how such metafilms can be constructed by placing one or more types of high-index semiconductor antennas into a dense array with subwavelength spacings. It is argued that the large absorption cross-section of semiconductor antennas and their weak near-field coupling open a unique opportunity to create strongly absorbing metafilms whose spectral absorption properties directly reflect those of the individual antennas. Using experiments and simulations, we demonstrate that near-unity absorption at one or more target wavelengths of interest can be achieved in a sub-50-nm-thick metafilm using judiciously sized and spaced Ge nanobeams. The ability to create semiconductor metafilms with custom absorption spectra opens up new design strategies for planar optoelectronic devices and solar cells. PMID:26184335

  20. Semiconductor Laser Low Frequency Noise Characterization

    NASA Technical Reports Server (NTRS)

    Maleki, Lute; Logan, Ronald T.

    1996-01-01

    This work summarizes the efforts in identifying the fundamental noise limit in semiconductor optical sources (lasers) to determine the source of 1/F noise and it's associated behavior. In addition, the study also addresses the effects of this 1/F noise on RF phased arrays. The study showed that the 1/F noise in semiconductor lasers has an ultimate physical limit based upon similar factors to fundamental noise generated in other semiconductor and solid state devices. The study also showed that both additive and multiplicative noise can be a significant detriment to the performance of RF phased arrays especially in regard to very low sidelobe performance and ultimate beam steering accuracy. The final result is that a noise power related term must be included in a complete analysis of the noise spectrum of any semiconductor device including semiconductor lasers.

  1. Method of making a semiconductor device assembly

    NASA Technical Reports Server (NTRS)

    Dholakia, Anil R. (Inventor); Trager, Louis (Inventor)

    1989-01-01

    The invention is a semiconductor device assembly and method of making the same. A mounting plate has positioning means for positioning the plate relative to a header, a first mounting surface of the plate is attached to the header and a semiconductor device is attached to a second mounting surface of the mounting plate. The assembly is made by forming the mounting plate, positioning the mounting plate relative to the header by the positioning means, attaching the first mounting surface to the header and the semiconductor device to the second mounting surface. Another method of making the assembly is by defining and etching a mounting plate and attaching the first mounting surface to the header and the semiconductor device to the second mounting surface. This assembly and process provides an efficient means for mounting semiconductor devices and in particular electro-optic devices such as lasers.

  2. Misconceptions of Emergent Semiconductor Phenomena

    NASA Astrophysics Data System (ADS)

    Nelson, Katherine G.

    The semiconductor field of Photovoltaics (PV) has experienced tremendous growth, requiring curricula to consider ways to promote student success. One major barrier to success students may face when learning PV is the development of misconceptions. The purpose of this work was to determine the presence and prevalence of misconceptions students may have for three PV semiconductor phenomena; Diffusion, Drift and Excitation. These phenomena are emergent, a class of phenomena that have certain characteristics. In emergent phenomena, the individual entities in the phenomena interact and aggregate to form a self-organizing pattern that can be observed at a higher level. Learners develop a different type of misconception for these phenomena, an emergent misconception. Participants (N=41) completed a written protocol. The pilot study utilized half of these protocols (n = 20) to determine the presence of both general and emergent misconceptions for the three phenomena. Once the presence of both general and emergent misconceptions was confirmed, all protocols (N=41) were analyzed to determine the presence and prevalence of general and emergent misconceptions, and to note any relationships among these misconceptions (full study). Through written protocol analysis of participants' responses, numerous codes emerged from the data for both general and emergent misconceptions. General and emergent misconceptions were found in 80% and 55% of participants' responses, respectively. General misconceptions indicated limited understandings of chemical bonding, electricity and magnetism, energy, and the nature of science. Participants also described the phenomena using teleological, predictable, and causal traits, indicating participants had misconceptions regarding the emergent aspects of the phenomena. For both general and emergent misconceptions, relationships were observed between similar misconceptions within and across the three phenomena, and differences in misconceptions were

  3. Electromechanical phenomena in semiconductor nanostructures

    NASA Astrophysics Data System (ADS)

    Lew Yan Voon, L. C.; Willatzen, M.

    2011-02-01

    Electromechanical phenomena in semiconductors are still poorly studied from a fundamental and an applied science perspective, even though significant strides have been made in the last decade or so. Indeed, most current electromechanical devices are based on ferroelectric oxides. Yet, the importance of the effect in certain semiconductors is being increasingly recognized. For instance, the magnitude of the electric field in an AlN/GaN nanostructure can reach 1-10 MV/cm. In fact, the basic functioning of an (0001) AlGaN/GaN high electron mobility transistor is due to the two-dimensional electron gas formed at the material interface by the polarization fields. The goal of this review is to inform the reader of some of the recent developments in the field for nanostructures and to point out still open questions. Examples of recent work that involves the piezoelectric and pyroelectric effects in semiconductors include: the study of the optoelectronic properties of III-nitrides quantum wells and dots, the current controversy regarding the importance of the nonlinear piezoelectric effect, energy harvesting using ZnO nanowires as a piezoelectric nanogenerator, the use of piezoelectric materials in surface acoustic wave devices, and the appropriateness of various models for analyzing electromechanical effects. Piezoelectric materials such as GaN and ZnO are gaining more and more importance for energy-related applications; examples include high-brightness light-emitting diodes for white lighting, high-electron mobility transistors, and nanogenerators. Indeed, it remains to be demonstrated whether these materials could be the ideal multifunctional materials. The solutions to these and other related problems will not only lead to a better understanding of the basic physics of these materials, but will validate new characterization tools, and advance the development of new and better devices. We will restrict ourselves to nanostructures in the current article even though the

  4. Optoelectronic bistability effect in semiconductors

    NASA Astrophysics Data System (ADS)

    Lagomarsino, Stefano

    2008-09-01

    A recombination bistability driven only by light irradiance, without any intervention of an externally imposed electric or magnetic field, is possible in doped semiconductors in which recombination is assured by multiply charged centers. This effect is allowed by the competition between two or more different recombination channels, providing that the shallower charged centers capture more likely charge carriers of the same polarity than the deep neutral ones, in spite of columbic repulsion. A close algebraic condition guaranteeing this effect is given, involving the trap parameters of the recombination centers. Deep multiple recombination centers in germanium, silicon, and silicon carbide are identified whose trap parameters make those materials good candidates to the realization of optoelectronic switching devices based on this effect.

  5. Boron doping a semiconductor particle

    SciTech Connect

    Stevens, G.D.; Reynolds, J.S.; Brown, L.K.

    1998-06-09

    A method of boron doping a semiconductor particle using boric acid to obtain a p-type doped particle. Either silicon spheres or silicon powder is mixed with a diluted solution of boric acid having a predetermined concentration. The spheres are dried, with the boron film then being driven into the sphere. A melt procedure mixes the driven boron uniformly throughout the sphere. In the case of silicon powder, the powder is metered out into piles and melted/fused with an optical furnace. Both processes obtain a p-type doped silicon sphere with desired resistivity. Boric acid is not a restricted chemical, is inexpensive, and does not pose any special shipping, handling, or disposal requirements. 2 figs.

  6. Mn-based ferromagnetic semiconductors

    NASA Astrophysics Data System (ADS)

    Dietl, Tomasz; Sawicki, Maciej

    2003-07-01

    The present status of research and prospects for device applications of ferromagnetic (diluted magnetic) semiconductors (DMS) is presented. We review the nature of the electronic states and the mechanisms of the carrier-mediated exchange interactions (mean-field Zener model) in p-type Mn-based III-V and II-VI compounds, highlighting a good correspondence of experimental findings and theoretical predictions. An account of the latest progress on the road of increasing the Currie point to above the room temperature is given for both families of compounds. We comment on a possibility of obtaining ferromagnetism in n-type materials, taking (Zn,Mn)O:Al as the example. Concerning technologically important issue of easy axis and domain engineering, we present theoretical predictions and experimental results on the temperature and carrier concentration driven change of magnetic anisotropy in (Ga,Mn)As.

  7. Phosphorus doping a semiconductor particle

    DOEpatents

    Stevens, G.D.; Reynolds, J.S.

    1999-07-20

    A method of phosphorus doping a semiconductor particle using ammonium phosphate is disclosed. A p-doped silicon sphere is mixed with a diluted solution of ammonium phosphate having a predetermined concentration. These spheres are dried with the phosphorus then being diffused into the sphere to create either a shallow or deep p-n junction. A good PSG glass layer is formed on the surface of the sphere during the diffusion process. A subsequent segregation anneal process is utilized to strip metal impurities from near the p-n junction into the glass layer. A subsequent HF strip procedure is then utilized to removed the PSG layer. Ammonium phosphate is not a restricted chemical, is inexpensive, and does not pose any special shipping, handling, or disposal requirement. 1 fig.

  8. Phosphorous doping a semiconductor particle

    DOEpatents

    Stevens, Gary Don; Reynolds, Jeffrey Scott

    1999-07-20

    A method (10) of phosphorus doping a semiconductor particle using ammonium phosphate. A p-doped silicon sphere is mixed with a diluted solution of ammonium phosphate having a predetermined concentration. These spheres are dried (16, 18), with the phosphorus then being diffused (20) into the sphere to create either a shallow or deep p-n junction. A good PSG glass layer is formed on the surface of the sphere during the diffusion process. A subsequent segregation anneal process is utilized to strip metal impurities from near the p-n junction into the glass layer. A subsequent HF strip procedure is then utilized to removed the PSG layer. Ammonium phosphate is not a restricted chemical, is inexpensive, and does not pose any special shipping, handling, or disposal requirement.

  9. Semiconductor electrochemistry of coal pyrite

    SciTech Connect

    Osseo-Asare, K.

    1992-05-01

    This project seeks to advance the fundamental understanding of the physicochemical processes occurring at the pyrite/aqueous interface, in the context of coal cleaning, coal desulfurization, and acid mine drainage. A novel approach to the study of pyrite aqueous electrochemistry is proposed, based on the use of both synthetic and natural (i.e. coal-derived) pyrite specimens, the utilization of pyrite both in the form of micro (i.e. colloidal and subcolloidal) and macro (i.e. rotating ring disk)-electrodes, and the application of in-situ direct electroanalytical and spectroelectrochemical characterization techniques. Central to this research is the recognition that pyrite is a semiconductor material. (Photo)electrochemical experiments will be conducted to unravel the mechanisms of anodic and cathodic processes such as those associated with pyrite decomposition and the reduction of oxidants such as molecular oxygen and the ferric ion.

  10. Boron doping a semiconductor particle

    DOEpatents

    Stevens, Gary Don; Reynolds, Jeffrey Scott; Brown, Louanne Kay

    1998-06-09

    A method (10,30) of boron doping a semiconductor particle using boric acid to obtain a p-type doped particle. Either silicon spheres or silicon powder is mixed with a diluted solution of boric acid having a predetermined concentration. The spheres are dried (16), with the boron film then being driven (18) into the sphere. A melt procedure mixes the driven boron uniformly throughout the sphere. In the case of silicon powder, the powder is metered out (38) into piles and melted/fused (40) with an optical furnace. Both processes obtain a p-type doped silicon sphere with desired resistivity. Boric acid is not a restricted chemical, is inexpensive, and does not pose any special shipping, handling, or disposal requirements.

  11. Semiconductor processing with excimer lasers

    SciTech Connect

    Young, R.T.; Narayan, J.; Christie, W.H.; van der Leeden, G.A.; Rothe, D.E.; Cheng, L.J.

    1983-01-01

    The advantages of pulsed excimer lasers for semiconductor processing are reviewed. Extensive comparisons of the quality of annealing of ion-implanted Si obtained with XeCl and ruby lasers have been made. The results indicate that irrespective of the large differences in the optical properties of Si at uv and visible wavelengths, the efficiency of usage of the incident energy for annealing is comparable for the two lasers. However, because of the excellent optical beam quality, the XeCl laser can provide superior control of the surface melting and the resulting junction depth. Furthermore, the concentrations of electrically active point defects in the XeCl laser annealed region are 2 to 3 orders of magnitude lower than that obtained from ruby or Nd:YAG lasers. All these results seem to suggest that XeCl lasers should be suitable for fabricating not only solar cells but also the more advanced device structures required for VLSI or VHSIC applications.

  12. Space station power semiconductor package

    NASA Technical Reports Server (NTRS)

    Balodis, Vilnis; Berman, Albert; Devance, Darrell; Ludlow, Gerry; Wagner, Lee

    1987-01-01

    A package of high-power switching semiconductors for the space station have been designed and fabricated. The package includes a high-voltage (600 volts) high current (50 amps) NPN Fast Switching Power Transistor and a high-voltage (1200 volts), high-current (50 amps) Fast Recovery Diode. The package features an isolated collector for the transistors and an isolated anode for the diode. Beryllia is used as the isolation material resulting in a thermal resistance for both devices of .2 degrees per watt. Additional features include a hermetical seal for long life -- greater than 10 years in a space environment. Also, the package design resulted in a low electrical energy loss with the reduction of eddy currents, stray inductances, circuit inductance, and capacitance. The required package design and device parameters have been achieved. Test results for the transistor and diode utilizing the space station package is given.

  13. Heating device for semiconductor wafers

    DOEpatents

    Vosen, Steven R.

    1999-01-01

    An apparatus for heat treating semiconductor wafers is disclosed. The apparatus includes a heating device which contains an assembly of light energy sources for emitting light energy onto a wafer. In particular, the light energy sources are positioned such that many different radial heating zones are created on a wafer being heated. For instance, in one embodiment, the light energy sources form a spiral configuration. In an alternative embodiment, the light energy sources appear to be randomly dispersed with respect to each other so that no discernable pattern is present. In a third alternative embodiment of the present invention, the light energy sources form concentric rings. Tuning light sources are then placed in between the concentric rings of light.

  14. Heating device for semiconductor wafers

    DOEpatents

    Vosen, S.R.

    1999-07-27

    An apparatus for heat treating semiconductor wafers is disclosed. The apparatus includes a heating device which contains an assembly of light energy sources for emitting light energy onto a wafer. In particular, the light energy sources are positioned such that many different radial heating zones are created on a wafer being heated. For instance, in one embodiment, the light energy sources form a spiral configuration. In an alternative embodiment, the light energy sources appear to be randomly dispersed with respect to each other so that no discernible pattern is present. In a third alternative embodiment of the present invention, the light energy sources form concentric rings. Tuning light sources are then placed in between the concentric rings of light. 4 figs.

  15. XAFS in dilute magnetic semiconductors.

    PubMed

    Sun, Zhihu; Yan, Wensheng; Yao, Tao; Liu, Qinghua; Xie, Yi; Wei, Shiqiang

    2013-10-14

    X-Ray absorption fine structure (XAFS) spectroscopy has experienced a rapid development in the last four decades and has proved to be a powerful structure characterization technique in the study of local environments in condensed matter. In this article, we first introduce the XAFS basic principles including theory, data analysis and experiment in some detail. Then we attempt to make a review on the applications of XAFS to the study of atomic and electronic structure in dilute magnetic semiconductor (DMS) systems. The power of XAFS in characterizing this interesting material system, such as determining the occupation sites and distribution of the dopants, detecting the presence of metal clusters or secondary phases, as well as identifying the defect types and dopant valence, will be illuminated by selected examples. This review should be of interest both to newcomers in the DMS field and to an interdisciplinary community of researchers working in synthesis, characterization and utilization of DMS materials. PMID:23884341

  16. Optical Properties of Semiconductor Nanocrystals

    NASA Astrophysics Data System (ADS)

    Gaponenko, S. V.

    1998-10-01

    Low-dimensional semiconductor structures, often referred to as nanocrystals or quantum dots, exhibit fascinating behavior and have a multitude of potential applications, especially in the field of communications. This book examines in detail the optical properties of these structures, gives full coverage of theoretical and experimental results, and discusses their technological applications. The author begins by setting out the basic physics of electron states in crystals (adopting a "cluster-to-crystal" approach), and goes on to discuss the growth of nanocrystals, absorption and emission of light by nanocrystals, optical nonlinearities, interface effects, and photonic crystals. He illustrates the physical principles with references to actual devices such as novel light-emitters and optical switches. The book covers a rapidly developing, interdisciplinary field. It will be of great interest to graduate students of photonics or microelectronics, and to researchers in electrical engineering, physics, chemistry, and materials science.

  17. Bistable amphoteric centers in semiconductors

    SciTech Connect

    Nikitina, A. G.; Zuev, V. V.

    2008-02-15

    It is shown that, at thermodynamic equilibrium, the release of charge carriers from the localized states of bistable amphoteric centers into quasi-free states depends on the degree of compensation. This brings about different functional dependences of the concentration of free charge carriers on temperature. It is found that, in uncompensated semiconductors, the concentration of free charge carriers follows the same dependence in the case of bistable amphoteric centers and bistable amphoteric U{sup -} centers, although the distributions of charge carriers over the charge states and configurations are different for these types of centers. The results can be used for interpreting various experimental data insufficiently explained in the context of the traditional approach.

  18. Self-compensation in semiconductors

    NASA Astrophysics Data System (ADS)

    Tsur, Y.; Riess, I.

    1999-09-01

    The problem of self-compensation of charged dopants is analyzed. Special emphasis is given to dopants in binary oxides. It is shown that one can determine the degree of self-compensation from the properties of the host material and dopant concentration alone. It is further shown that for a native p-type semiconductor, donors are compensated, mostly, by native ionic defects. On the other hand, doping with acceptors allows us to increase significantly the hole concentration, i.e., self-compensation is low under high doping levels. For a native n-type semiconductor the opposite is true, namely, extrinsic acceptors are mainly compensated by native ionic defects. It is shown that the changes in concentration of all the charged defects are simply related by a single factor, the doping factor f, or its power fk where k depends solely on the defect's charge. Quantitative calculations of f and defect concentrations are presented for Cu2O, which was used as a model material. It is found that for p-type Cu2O doping with donors results in f within the range of 1-10, depending on the dopant concentration and P(O2). This means that the hole concentration decreases and the electron concentration increases at most by a factor of 10. Therefore one does not expect to obtain a changeover from p- to n-type cuprous oxide by doping, under equilibrium conditions. Most of the donors are compensated by negative ionic defects. Self-compensation in the presence of amphoteric defects and Fermi level stabilization are discussed, using the former formalism.

  19. Room-temperature semiconductor heterostructure refrigeration

    NASA Astrophysics Data System (ADS)

    Chao, K. A.; Larsson, Magnus; Mal'shukov, A. G.

    2005-07-01

    With the proper design of semiconductor tunneling barrier structures, we can inject low-energy electrons via resonant tunneling, and take out high-energy electrons via a thermionic process. This is the operation principle of our semiconductor heterostructure refrigerator (SHR) without the need of applying a temperature gradient across the device. Even for the bad thermoelectric material AlGaAs, our calculation shows that at room temperature, the SHR can easily lower the temperature by 5-7K. Such devices can be fabricated with the present semiconductor technology. Besides its use as a kitchen refrigerator, the SHR can efficiently cool microelectronic devices.

  20. Diluted magnetic semiconductor nanowires exhibiting magnetoresistance

    DOEpatents

    Yang, Peidong; Choi, Heonjin; Lee, Sangkwon; He, Rongrui; Zhang, Yanfeng; Kuykendal, Tevye; Pauzauskie, Peter

    2011-08-23

    A method for is disclosed for fabricating diluted magnetic semiconductor (DMS) nanowires by providing a catalyst-coated substrate and subjecting at least a portion of the substrate to a semiconductor, and dopant via chloride-based vapor transport to synthesize the nanowires. Using this novel chloride-based chemical vapor transport process, single crystalline diluted magnetic semiconductor nanowires Ga.sub.1-xMn.sub.xN (x=0.07) were synthesized. The nanowires, which have diameters of .about.10 nm to 100 nm and lengths of up to tens of micrometers, show ferromagnetism with Curie temperature above room temperature, and magnetoresistance up to 250 Kelvin.