WorldWideScience

Sample records for flip chip bonding

  1. Developments of optimum flip-chip bonding process

    Science.gov (United States)

    Jang, Dong H.; Kang, Sa Y.; Lee, Y. M.; Oh, S. Y.

    1997-08-01

    Flip-chip soldering is the critical technology for solving the current issues of electronic packaging industries that require the high I/O's. In order to increase the manufacturing ability of flip-chip technology, however, yield and reliability tissues should overcome. In this study, optimum flip-chip bonding process has been developed by using the test chips that had the electroplated solder bumps. Test chips are composed of three different types that are i) peripheral array pad chip, ii) peripheral array pad chip, and iii) area array pad chip. Each test chip has the daisy chain to consider the effect of reliability test. The electrical resistance was measured before and after reliability test. Based on these measurement, failure mode resulted from the moisture absorption was studied using scanning acoustic microscope. To achieve an optimum reflow profile of solder bump, correct temperature profile was set up with respect to the resin base flux. Different bonding forces were tested. Four underfill encapsulants were evaluated for minimum voids that caused the severe defects after reliability test. Also, the gap heights were measured with respect to applied bonding force after underfill was performed. Results from the moisture absorption and thermal cycling were discussed for flip-chip bonding on BT-resin substrates. The test vehicles using flip-chip technology have passed moisture preconditioning and temperature cycling tests.

  2. Seamless integration of CMOS and microfluidics using flip chip bonding

    Science.gov (United States)

    Welch, David; Blain Christen, Jennifer

    2013-03-01

    We demonstrate the microassembly of PDMS (polydimethylsiloxane) microfluidics with integrated circuits made in complementary metal-oxide-semiconductor (CMOS) processes. CMOS-sized chips are flip chip bonded to a flexible polyimide printed circuit board (PCB) with commercially available solder paste patterned using a SU-8 epoxy. The average resistance of each flip chip bond is negligible and all connections are electrically isolated. PDMS is attached to the flexible polyimide PCB using a combination of oxygen plasma treatment and chemical bonding with 3-aminopropyltriethoxysilane. The total device has a burst pressure of 175 kPA which is limited by the strength of the flip chip attachment. This technique allows the sensor area of the die to act as the bottom of the microfluidic channel. The SU-8 provides a barrier between the pad ring (electrical interface) and the fluids; post-processing is not required on the CMOS die. This assembly method shows great promise for developing analytic systems which combine the strengths of microelectronics and microfluidics into one device.

  3. Photodiodes integration on a suspended ridge structure VOA using 2-step flip-chip bonding method

    Science.gov (United States)

    Kim, Seon Hoon; Kim, Tae Un; Ki, Hyun Chul; Kim, Doo Gun; Kim, Hwe Jong; Lim, Jung Woon; Lee, Dong Yeol; Park, Chul Hee

    2015-01-01

    In this works, we have demonstrated a VOA integrated with mPDs, based on silica-on-silicon PLC and flip-chip bonding technologies. The suspended ridge structure was applied to reduce the power consumption. It achieves the attenuation of 30dB in open loop operation with the power consumption of below 30W. We have applied two-step flipchip bonding method using passive alignment to perform high density multi-chip integration on a VOA with eutectic AuSn solder bumps. The average bonding strength of the two-step flip-chip bonding method was about 90gf.

  4. Reliability of flip-chip bonded RFID die using anisotropic conductive paste hybrid material

    Institute of Scientific and Technical Information of China (English)

    Jun-Sik LEE; Jun-Ki KIM; Mok-Soon KIM; Namhyun KANG; Jong-Hyun LEE

    2011-01-01

    A reliability of flip-chip bonded die as a function of anisotropic conductive paste (ACP) hybrid materials. bonding conditions, and antenna pattern materials was investigated during the assembly of radio frequency identification(RFID) inlay. The optimization condition for flip-chip bonding was determined from the behavior of bonding strength. Under the optimized condition,the shear strength for the antenna printed with paste-type Ag ink was larger than that for Cu antenna. Furthermore, an identification distance was varied from the antenna materials. Comparing with the Ag antenna pattern, the as-bonded die on Cu antenna showed a larger distance of identification, However, the long-term reliability of inlay using the Cu antenna was decreased significantly as a function of aging time at room temperature because of the bended shape of Cu antenna formed during the flip-chip bonding process.

  5. Tin-Silver Alloys for Flip-Chip Bonding Studied with a Rotating Cylinder Electrode

    DEFF Research Database (Denmark)

    Tang, Peter Torben; Pedersen, E.H.; Bech-Nielsen, G.;

    1999-01-01

    Electrodeposition of solder for flip-chip bonding is studied in the form of a pyrophosphate/iodide tin-silver alloy bath. The objective is to obtain a uniform alloy composition, with 3.8 At.% silver, over a larger area. This specific alloy will provide an eutectic solder melting at 221°C (or 10°C...

  6. Flip Chip Bonding of a Quartz MEMS-Based Vibrating Beam Accelerometer

    Directory of Open Access Journals (Sweden)

    Jinxing Liang

    2015-09-01

    Full Text Available In this study, a novel method to assemble a micro-accelerometer by a flip chip bonding technique is proposed and demonstrated. Both the main two parts of the accelerometer, a double-ended tuning fork and a base-proof mass structure, are fabricated using a quartz wet etching process on Z cut quartz wafers with a thickness of 100 μm and 300 μm, respectively. The finite element method is used to simulate the vibration mode and optimize the sensing element structure. Taking advantage of self-alignment function of the flip chip bonding process, the two parts were precisely bonded at the desired joint position via AuSn solder. Experimental demonstrations were performed on a maximum scale of 4 × 8 mm2 chip, and high sensitivity up to 9.55 Hz/g with a DETF resonator and a Q value of 5000 in air was achieved.

  7. Flip Chip Bonding of a Quartz MEMS-Based Vibrating Beam Accelerometer.

    Science.gov (United States)

    Liang, Jinxing; Zhang, Liyuan; Wang, Ling; Dong, Yuan; Ueda, Toshitsugu

    2015-09-02

    In this study, a novel method to assemble a micro-accelerometer by a flip chip bonding technique is proposed and demonstrated. Both the main two parts of the accelerometer, a double-ended tuning fork and a base-proof mass structure, are fabricated using a quartz wet etching process on Z cut quartz wafers with a thickness of 100 μm and 300 μm, respectively. The finite element method is used to simulate the vibration mode and optimize the sensing element structure. Taking advantage of self-alignment function of the flip chip bonding process, the two parts were precisely bonded at the desired joint position via AuSn solder. Experimental demonstrations were performed on a maximum scale of 4 × 8 mm² chip, and high sensitivity up to 9.55 Hz/g with a DETF resonator and a Q value of 5000 in air was achieved.

  8. MICROELECTRONICS: Flip the Chip.

    Science.gov (United States)

    Wong, C P; Luo, S; Zhang, Z

    2000-12-22

    As integrated circuit fabrication advances rapidly and the market for faster, lighter, smaller, yet less expensive electronic products accelerates, electronic packaging faces its own challenges. In this Perspective, Wong, Luo, and Zhang describe recent advances in flip chip packaging. This technology has many advantages over the conventional wire bonding technology and offers the possibility of low-cost electronic assembly for modern electronic products.

  9. Development of a Fluxless Flip Chip Bonding Process for Optical Military Electronics

    Energy Technology Data Exchange (ETDEWEB)

    Girardi, Michael

    2007-11-11

    As military electronics tend to become lighter, smaller, thinner, and lower cost, the use of flip chip technology is becoming more common place to meet system requirements, yet survive environments. This paper explores the development of an optical flip chip application and details the selection/qualification of the substrate. The selected assembly consists of a procured 1x12 Vertical Cavity Surface Emitting Laser (VCSEL) die, having 80um diameter eutectic AuSn solder bumps at 250um pitch and flip chip bonded to a .006” thick 99.6% alumina substrate with .006” diameter thru holes and metallized with 500Å WTi, under minimum 2.0-3.0μm (80-120μ”) thin film deposited Au. An 8 run, 3 factor, 2 level Full Factorial Design of Experiments (DOE) was completed on procured detector arrays and procured ceramic substrates using the Suss Microtec FC150. The optimum settings for the peak temperature, peak time and final die z-height were selected using the ANOVA results and interaction plots. Additional studies were completed to qualify in-house produced substrates. An epoxy glob-top encapsulant was selected to dissipate stress on the flip chip solder joints and to enhance thermal shock performance.

  10. Tin-Silver Alloys for Flip-Chip Bonding Studied with a Rotating Cylinder Electrode

    DEFF Research Database (Denmark)

    Tang, Peter Torben; Pedersen, E.H.; Bech-Nielsen, G.

    1999-01-01

    below pure tin). Depositions on a rotating cylinder electrode (with current screen), followed by composition measurements, provided useful information on the relationship between current density and alloy composition. Preliminary experiments with alloy plating on silicon substrates, with and without......Electrodeposition of solder for flip-chip bonding is studied in the form of a pyrophosphate/iodide tin-silver alloy bath. The objective is to obtain a uniform alloy composition, with 3.8 At.% silver, over a larger area. This specific alloy will provide an eutectic solder melting at 221°C (or 10°C...... photoresist, have shown a stable and promising alternative to pure tin and tin-lead alloys for flip-chip bonding applications....

  11. Indium bump array fabrication on small CMOS circuit for flip-chip bonding

    Institute of Scientific and Technical Information of China (English)

    Huang Yuyang; Zhang Yuxiang; Yin Zhizhen; Cui Guoxin; Liu H C; Bian Lifeng; Yang Hui; Zhang Yaohui

    2011-01-01

    We demonstrate a novel method for indium bump fabrication on a small CMOS circuit chip that is to be flip-chip bonded with a GaAs/AlGaAs multiple quantum well spatial light modulator.A chip holder with a via hole is used to coat the photoresist for indium bump lift-off.The 1000 μm-wide photoresist edge bead around the circuit chip can be reduced to less than 500μm,which ensures the integrity of the indium bump array.64 × 64 indium arrays with 20 μm-high,30 μm-diameter bumps are successfully formed on a 5 × 6.5 mm2 CMOS chip.

  12. Flip-chip bonding of vertical-cavity surface-emitting lasers using laser-induced forward transfer

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, K. S., E-mail: Kaur.Kamalpreet@elis.ugent.be; Missinne, J.; Van Steenberge, G. [Centre for Microsystems Technology, imec/Ghent University, Technologiepark 914A, B-9052 Gent (Belgium)

    2014-02-10

    This letter reports the use of the Laser-Induced Forward Transfer (LIFT) technique for the fabrication of indium micro-bumps for the flip-chip (FC) bonding of single vertical-cavity surface-emitting laser chips. The FC bonded chips were electrically and optically characterized, and the successful functioning of the devices post-bonding is demonstrated. The die shear and life-time tests carried out on the bonded chips confirmed the mechanical reliability of the LIFT-assisted FC bonded assemblies.

  13. Fluxless Bonding Processes Using Silver-Indium System for High Temperature Electronics and Silver Flip-Chip Interconnect Technology

    OpenAIRE

    Wu, Yuan-Yun

    2015-01-01

    In this dissertation, fluxless silver (Ag)-indium (In) binary system bonding and Ag solid-state bonding are used between different bonded pairs which have large thermal expansion coefficient (CTE) mismatch and flip-chip interconnect bonding application. In contrast to the conventional soldering process, fluxless bonding technique eliminates contamination and reliability problems caused by flux to fabricate high quality joints. Due to large CTE mismatch, high quality joints are important to ma...

  14. A Novel Magnetic Bead-based Biosensor Using Flip Chip Bonding Techniques

    Institute of Scientific and Technical Information of China (English)

    Bin Wang; Xiang Chen; Qinghui Jin; Jianlong Zhao; Yuansen Xu

    2006-01-01

    Based on flip-chip packaging, a novel approach towards integrated magnetic bio-separator was designed. The magnetic field and the force on the bead were simulated and analyzed, leading to the optimization of the fabrication parameters of the micro-magnetic unit. The planar coil as an electromagnet was fabricated through electroplating on a single seed layer.The PDMS microfluidic channel was bonded on the inverse side after Si etching. The results presented in this paper provide a novel design and fabrication to approach a microfluidic bio-separation system with magnetic beads.

  15. Advanced flip chip packaging

    CERN Document Server

    Lai, Yi-Shao; Wong, CP

    2013-01-01

    Advanced Flip Chip Packaging presents past, present and future advances and trends in areas such as substrate technology, material development, and assembly processes. Flip chip packaging is now in widespread use in computing, communications, consumer and automotive electronics, and the demand for flip chip technology is continuing to grow in order to meet the need for products that offer better performance, are smaller, and are environmentally sustainable. This book also: Offers broad-ranging chapters with a focus on IC-package-system integration Provides viewpoints from leading industry executives and experts Details state-of-the-art achievements in process technologies and scientific research Presents a clear development history and touches on trends in the industry while also discussing up-to-date technology information Advanced Flip Chip Packaging is an ideal book for engineers, researchers, and graduate students interested in the field of flip chip packaging.

  16. Development of gold based solder candidates for flip chip assembly

    DEFF Research Database (Denmark)

    Chidambaram, Vivek; Hald, John; Hattel, Jesper Henri

    2009-01-01

    Flip chip technology is now rapidly replacing the traditional wire bonding interconnection technology in the first level packaging applications due to the miniaturization drive in the microelectronics industry. Flip chip assembly currently involves the use of high lead containing solders for inte......Flip chip technology is now rapidly replacing the traditional wire bonding interconnection technology in the first level packaging applications due to the miniaturization drive in the microelectronics industry. Flip chip assembly currently involves the use of high lead containing solders...

  17. Application of Underfill for Flip-Chip Package Using Ultrasonic Bonding

    Science.gov (United States)

    Noh, Bo-In; Koo, Ja-Myeong; Jo, Jung-Lae; Jung, Seung-Boo

    2008-05-01

    In this study, the reliability of flip-chip (FC) packages with various underfills using ultrasonic bonding was evaluated in temperature and humidity (TH) tests. Fatigue cracks began at the interface between the Au bumps and glass substrate and then propagated through the interface with increasing dwell time in the TH test. The initial electrical resistance of Au bumps with lower viscosity underfill was lower than that of Au bumps with higher viscosity underfill. Entrapped underfill between the Au bumps and glass substrate or void formation between the Au bumps in FC packages was caused by high viscosity of the underfill. As the dwell time of the TH test increased, the electrical resistance of the FC packages increased. The fatigue life of an FC package with underfill that has a higher glass transition temperature (Tg) and lower coefficient of thermal expansion (CTE) value was higher than that of an FC package with underfill with lower Tg and a higher CTE value. Therefore, the properties of underfill affect the fatigue life of FC packages with underfill using ultrasonic bonding.

  18. Numerical Analysis of Warpage Induced by Thermo-Compression Bonding Process of Cu Pillar Bump Flip Chip Package

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Oh Young; Jung, Hoon Sun; Lee, Jung Hoon; Choa, Sung-Hoon [Seoul Nat’l Univ. of Science and Technology, Seoul (Korea, Republic of)

    2017-06-15

    In flip chip technology, the conventional solder bump has been replaced with a copper (Cu) pillar bump owing to its higher input/output (I/O) density, finer pitch, and higher reliability. However, Cu pillar bump technology faces several issues, such as interconnect shorting and higher low-k stress due to stiffer Cu pillar structure when the conventional reflow process is used. Therefore, the thermal compression bonding (TCB) process has been adopted in the flip chip attachment process in order to reduce the package warpage and stress. In this study, we investigated the package warpage induced during the TCB process using a numerical analysis. The warpage of the TCB process was compared with that of the reflow process.

  19. Advanced Flip Chips in Extreme Temperature Environments

    Science.gov (United States)

    Ramesham, Rajeshuni

    2010-01-01

    The use of underfill materials is necessary with flip-chip interconnect technology to redistribute stresses due to mismatching coefficients of thermal expansion (CTEs) between dissimilar materials in the overall assembly. Underfills are formulated using organic polymers and possibly inorganic filler materials. There are a few ways to apply the underfills with flip-chip technology. Traditional capillary-flow underfill materials now possess high flow speed and reduced time to cure, but they still require additional processing steps beyond the typical surface-mount technology (SMT) assembly process. Studies were conducted using underfills in a temperature range of -190 to 85 C, which resulted in an increase of reliability by one to two orders of magnitude. Thermal shock of the flip-chip test articles was designed to induce failures at the interconnect sites (-40 to 100 C). The study on the reliability of flip chips using underfills in the extreme temperature region is of significant value for space applications. This technology is considered as an enabling technology for future space missions. Flip-chip interconnect technology is an advanced electrical interconnection approach where the silicon die or chip is electrically connected, face down, to the substrate by reflowing solder bumps on area-array metallized terminals on the die to matching footprints of solder-wettable pads on the chosen substrate. This advanced flip-chip interconnect technology will significantly improve the performance of high-speed systems, productivity enhancement over manual wire bonding, self-alignment during die joining, low lead inductances, and reduced need for attachment of precious metals. The use of commercially developed no-flow fluxing underfills provides a means of reducing the processing steps employed in the traditional capillary flow methods to enhance SMT compatibility. Reliability of flip chips may be significantly increased by matching/tailoring the CTEs of the substrate

  20. Experiences in flip chip production of radiation detectors

    Science.gov (United States)

    Savolainen-Pulli, Satu; Salonen, Jaakko; Salmi, Jorma; Vähänen, Sami

    2006-09-01

    Modern imaging devices often require heterogeneous integration of different materials and technologies. Because of yield considerations, material availability, and various technological limitations, an extremely fine pitch is necessary to realize high-resolution images. Thus, there is a need for a hybridization technology that is able to join together readout amplifiers and pixel detectors at a very fine pitch. This paper describes radiation detector flip chip production at VTT. Our flip chip technology utilizes 25-μm diameter tin-lead solder bumps at a 50-μm pitch and is based on flux-free bonding. When preprocessed wafers are used, as is the case here, the total yield is defined only partly by the flip chip process. Wafer preprocessing done by a third-party silicon foundry and the flip chip process create different process defects. Wafer-level yield maps (based on probing) provided by the customer are used to select good readout chips for assembly. Wafer probing is often done outside of a real clean room environment, resulting in particle contamination and/or scratches on the wafers. Factors affecting the total yield of flip chip bonded detectors are discussed, and some yield numbers of the process are given. Ways to improve yield are considered, and finally guidelines for process planning and device design with respect to yield optimization are given.

  1. Experiences in flip chip production of radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Savolainen-Pulli, Satu [VTT, MEMS- and Micropackaging, P.O. Box 1000, Tietotie 3, Espoo, FI-02044 VTT (Finland)]. E-mail: satu.savolainen-pulli@vtt.fi; Salonen, Jaakko [VTT, MEMS- and Micropackaging, P.O. Box 1000, Tietotie 3, Espoo, FI-02044 VTT (Finland); Salmi, Jorma [VTT, MEMS- and Micropackaging, P.O. Box 1000, Tietotie 3, Espoo, FI-02044 VTT (Finland); Vaehaenen, Sami [VTT, MEMS- and Micropackaging, P.O. Box 1000, Tietotie 3, Espoo, FI-02044 VTT (Finland)

    2006-09-01

    Modern imaging devices often require heterogeneous integration of different materials and technologies. Because of yield considerations, material availability, and various technological limitations, an extremely fine pitch is necessary to realize high-resolution images. Thus, there is a need for a hybridization technology that is able to join together readout amplifiers and pixel detectors at a very fine pitch. This paper describes radiation detector flip chip production at VTT. Our flip chip technology utilizes 25-{mu}m diameter tin-lead solder bumps at a 50-{mu}m pitch and is based on flux-free bonding. When preprocessed wafers are used, as is the case here, the total yield is defined only partly by the flip chip process. Wafer preprocessing done by a third-party silicon foundry and the flip chip process create different process defects. Wafer-level yield maps (based on probing) provided by the customer are used to select good readout chips for assembly. Wafer probing is often done outside of a real clean room environment, resulting in particle contamination and/or scratches on the wafers. Factors affecting the total yield of flip chip bonded detectors are discussed, and some yield numbers of the process are given. Ways to improve yield are considered, and finally guidelines for process planning and device design with respect to yield optimization are given.

  2. Flip chip assembly of thinned chips for hybrid pixel detector applications

    CERN Document Server

    Fritzsch, T; Woehrmann, M; Rothermund, M; Huegging, F; Ehrmann, O; Oppermann, H; Lang, K.D

    2014-01-01

    There is a steady trend to ultra-thin microelectronic devices. Especially for future particle detector systems a reduced readout chip thickness is required to limit the loss of tracking precision due to scattering. The reduction of silicon thickness is performed at wafer level in a two-step thinning process. To minimize the risk of wafer breakage the thinned wafer needs to be handled by a carrier during the whole process chain of wafer bumping. Another key process is the flip chip assembly of thinned readout chips onto thin sensor tiles. Besides the prevention of silicon breakage the minimization of chip warpage is one additional task for a high yield and reliable flip chip process. A new technology using glass carrier wafer will be described in detail. The main advantage of this technology is the combination of a carrier support during wafer processing and the chip support during flip chip assembly. For that a glass wafer is glue-bonded onto the backside of the thinned readout chip wafer. After the bump depo...

  3. Microchannel cooling of face down bonded chips

    Science.gov (United States)

    Bernhardt, Anthony F.

    1993-01-01

    Microchannel cooling is applied to flip-chip bonded integrated circuits, in a manner which maintains the advantages of flip-chip bonds, while overcoming the difficulties encountered in cooling the chips. The technique is suited to either multichip integrated circuit boards in a plane, or to stacks of circuit boards in a three dimensional interconnect structure. Integrated circuit chips are mounted on a circuit board using flip-chip or control collapse bonds. A microchannel structure is essentially permanently coupled with the back of the chip. A coolant delivery manifold delivers coolant to the microchannel structure, and a seal consisting of a compressible elastomer is provided between the coolant delivery manifold and the microchannel structure. The integrated circuit chip and microchannel structure are connected together to form a replaceable integrated circuit module which can be easily decoupled from the coolant delivery manifold and the circuit board. The coolant supply manifolds may be disposed between the circuit boards in a stack and coupled to supplies of coolant through a side of the stack.

  4. Flip-chip assembly of VCSELs to silicon grating couplers via laser fabricated SU8 prisms.

    Science.gov (United States)

    Kaur, K S; Subramanian, A Z; Cardile, P; Verplancke, R; Van Kerrebrouck, J; Spiga, S; Meyer, R; Bauwelinck, J; Baets, R; Van Steenberge, G

    2015-11-02

    This article presents the flip-chip bonding of vertical-cavity surface-emitting lasers (VCSELs) to silicon grating couplers (GCs) via SU8 prisms. The SU8 prisms are defined on top of the GCs using non-uniform laser ablation process. The prisms enable perfectly vertical coupling from the bonded VCSELs to the GCs. The VCSELs are flip-chip bonded on top of the silicon GCs employing the laser-induced forward transfer (LIFT)-assisted thermocompression technique. An excess loss of transmission experiments performed on the bonded assemblies with clear eye openings up to 20 Gb/s are also presented.

  5. Flip-chip light emitting diode with resonant optical microcavity

    Science.gov (United States)

    Gee, James M.; Bogart, Katherine H.A.; Fischer, Arthur J.

    2005-11-29

    A flip-chip light emitting diode with enhanced efficiency. The device structure employs a microcavity structure in a flip-chip configuration. The microcavity enhances the light emission in vertical modes, which are readily extracted from the device. Most of the rest of the light is emitted into waveguided lateral modes. Flip-chip configuration is advantageous for light emitting diodes (LEDs) grown on dielectric substrates (e.g., gallium nitride LEDs grown on sapphire substrates) in general due to better thermal dissipation and lower series resistance. Flip-chip configuration is advantageous for microcavity LEDs in particular because (a) one of the reflectors is a high-reflectivity metal ohmic contact that is already part of the flip-chip configuration, and (b) current conduction is only required through a single distributed Bragg reflector. Some of the waveguided lateral modes can also be extracted with angled sidewalls used for the interdigitated contacts in the flip-chip configuration.

  6. A Flip-Chip AlGaInP LED with GaN/Sapphire Transparent Substrate Fabricated by Direct Wafer Bonding

    Institute of Scientific and Technical Information of China (English)

    LIANG Ting; GUO Xia; GUAN Bao-Lu; GUO Jing; GU Xiao-Ling; LIN Qiao-Ming; SHEN Guang-Di

    2007-01-01

    A red-light AlGaInP light emitting diode(LED)is fabricated by,using direct wafer bonding technology.Taking N-GaN wafer as the transparent substrate,the red-light LED is flip-chiped onto a structured silicon submount.Electronic luminance(EL)test reveals that the luminance flux is 130% higher than that of the conventional LED made from the same LED wafer.Current-voltage(Ⅰ-Ⅴ)measurement indicates that the bonding processes do not impact the electrical property of AlGaInP LED in the small voltage region (V<1.5V).In the large voltage region (V>1.5 V),the Ⅰ-Ⅴ characteristic exhibits space-charge-limited currents characteristic due to the p-GaAs/n-GaN bonding interface.

  7. Characterization of Ni/SnPb-TiW/Pt Flip Chip Interconnections in Silicon Pixel Detector Modules

    CERN Document Server

    Karadzhinova, Aneliya; Härkönen, Jaakko; Luukka, Panja-riina; Mäenpää, Teppo; Tuominen, Eija; Haeggstrom, Edward; Kalliopuska, Juha; Vahanen, Sami; Kassamakov, Ivan

    2014-01-01

    In contemporary high energy physics experiments, silicon detectors are essential for recording the trajectory of new particles generated by multiple simultaneous collisions. Modern particle tracking systems may feature 100 million channels, or pixels, which need to be individually connected to read-out chains. Silicon pixel detectors are typically connected to readout chips by flip-chip bonding using solder bumps. High-quality electro-mechanical flip-chip interconnects minimizes the number of dead read-out channels in the particle tracking system. Furthermore, the detector modules must endure handling during installation and withstand heat generation and cooling during operation. Silicon pixel detector modules were constructed by flip-chip bonding 16 readout chips to a single sensor. Eutectic SnPb solder bumps were deposited on the readout chips and the sensor chips were coated with TiW/Pt thin film UBM (under bump metallization). The modules were assembled at Advacam Ltd, Finland. We studied the uniformity o...

  8. Polymer Flip Chips with Extreme Temperature Stability in Space Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the proposed SBIR Phase I program is to develop highly thermally and electrically conductive nanocomposites for space-based flip chips for...

  9. EVOLUTION OF MICROSTRUCTURE OF Sn-Ag-Cu LEAD-FREE FLIP CHIP SOLDER JOINTS DURING AGING PROCESS

    Institute of Scientific and Technical Information of China (English)

    Y.H. Tian; C.Q. Wang; W.F. Zhou

    2006-01-01

    Flip chip bonding has become a primary technology that has found application in the chip interconnection process in the electronic manufacturing industry in recent years. The solder joints of the flip chip bonding are small and consist of complicated microstructures such as Sn solution,eutectic mixture, and intermetallic compounds (IMCs), whose mechanical performance is quite different from the original solder bulk. The evolution of microstructure of the flip chip solder joints under thermal aging was analyzed. The results show that with an increase in aging time, coarsening of solder bulk matrix and AuSn4 IMCs occurred within the solder. The IMCs that are formed at the bottom side of the flip chip bond were different from those on the top side during the aging process. ( Cu, Ni, Au )6Sn5 were formed at the interfaces of both sides, and large complicated (Au, Ni,Cu)Sn4 IMCs appeared for some time near the bottom interface after aging, but they disappeared again and thus ( Cu, Ni,Au )6Sns IMC thickness increased considerably. The influence of reflow times during the flip chip bonding (as-bonded condition) on the characteristics of interfacial IMCs was weakened when subjected to the aging process.

  10. Low-loss highly tolerant flip-chip couplers for hybrid integration of Si3N4 and polymer waveguides

    NARCIS (Netherlands)

    Mu, J.; Alexoudi, T.; Yong, Y.S.; Vázquez-Córdova, S.A.; Dijkstra, M.; Worhoff, K.; Duis, J.; Garcia Blanco, S.M.

    2016-01-01

    In this letter, low-loss and highly fabrication-tolerant flip-chip bonded vertical couplers under single-mode condition are demonstrated for the integration of a polymer waveguide chip onto the Si3N4/SiO2 passive platform. The passively aligned vertical couplers have a lateral misalignment between p

  11. Identifying Professional Competencies of the Flip-Chip Packaging Engineer in Taiwan

    Science.gov (United States)

    Guu, Y. H.; Lin, Kuen-Yi; Lee, Lung-Sheng

    2014-01-01

    This study employed a literature review, expert interviews, and a questionnaire survey to construct a set of two-tier competencies for a flip-chip packaging engineer. The fuzzy Delphi questionnaire was sent to 12 flip-chip engineering experts to identify professional competencies that a flip-chip packaging engineer must have. Four competencies,…

  12. Electroplated solder alloys for flip chip interconnections

    Science.gov (United States)

    Annala, P.; Kaitila, J.; Salonen, J.

    1997-01-01

    Flip chip mounting of bare dice is gaining widespread use in microelectronics packaging. The main drivers for this technology are high packaging density, improved performance at high frequency, low parasitic effects and potentially high reliability and low cost. Many companies have made significant efforts to develop a technology for bump processing, bare die testing and underfill encapsulation to gain the benefit of all potential advantages. We have focussed on low cost bumping of fully processed silicon wafers to develop a flexible scheme for various reflow requirements. The bumping process is based on galvanic plating from an alloy solution or, alternatively, from several elemental plating baths. Sputtered Mo/Cu or Cr/Cu is used as a wettable base for electroplating. Excess base metal is removed by using the bumps as an etching mask. Variation of the alloy composition or the layer structure, allows the adjustment of the bump reflow temperature for the specific requirements of the assembly. Using binary tin-lead and ternary tin-lead-bismuth alloys, reflow temperatures from 100 °C (bismuth rich alloys) to above 300 °C (lead rich alloys) can be covered. The influence of the plating current density on the final alloy composition has been established by ion beam analysis of the plated layers and a series of reflow experiments. To control the plating uniformity and the alloy composition, a new cup plating system has been built with a random flow pattern and continuous adjustment of the current density. A well-controlled reflow of the bumps has been achieved in hot glycerol up to the eutectic point of tin-lead alloys. For high temperature alloys, high molecular weight organic liquids have been used. A tensile pull strength of 20 g per bump and resistance of 5 mΩ per bump have been measured for typical eutectic tin-lead bumps of 100 μm in diameter.

  13. Flip-chip integration of tilted VCSELs onto a silicon photonic integrated circuit.

    Science.gov (United States)

    Lu, Huihui; Lee, Jun Su; Zhao, Yan; Scarcella, Carmelo; Cardile, Paolo; Daly, Aidan; Ortsiefer, Markus; Carroll, Lee; O'Brien, Peter

    2016-07-25

    In this article we describe a cost-effective approach for hybrid laser integration, in which vertical cavity surface emitting lasers (VCSELs) are passively-aligned and flip-chip bonded to a Si photonic integrated circuit (PIC), with a tilt-angle optimized for optical-insertion into standard grating-couplers. A tilt-angle of 10° is achieved by controlling the reflow of the solder ball deposition used for the electrical-contacting and mechanical-bonding of the VCSEL to the PIC. After flip-chip integration, the VCSEL-to-PIC insertion loss is -11.8 dB, indicating an excess coupling penalty of -5.9 dB, compared to Fibre-to-PIC coupling. Finite difference time domain simulations indicate that the penalty arises from the relatively poor match between the VCSEL mode and the grating-coupler.

  14. UBM Formation on Single Die/Dice for Flip Chip Applications

    OpenAIRE

    Jittinorasett, Suwanna

    1999-01-01

    This thesis presents the low cost process for UBM formation on aluminum pads of single die/dice for Flip Chip applications. The UBM (Under Bump Metallurgy) is required in solder bump structure to provide adhesion/diffusion barrier layer, solder wettable layer, and oxidation barrier layer between the bonding pads of the die and the bumps. Typically, UBM is deposited on the whole wafers by sputtering, evaporation, or electroless plating. These deposition techniques are not practical for UBM ...

  15. Underfill process development for lead free flip chip assembly

    Science.gov (United States)

    Chaware, Raghunandan

    Underfills are used to enhance the long-term reliability of the flip-chip solder joints. More specifically, the function of the underfill is to couple the chip to the substrate, wherein the shear stresses experienced by the solder joints are converted to bending stresses. The underfill flows under the die due to the influence of strong capillary forces. The flow of the underfill under the chip depends on various factors such as the viscosity of the underfill, contact angle, surface tension, temperature, underfill gap, substrate design, bump pattern, bump density, and size of the chip. The flow of underfill is also influenced by the cleanliness of the substrate, the cleanliness of the underside of the chip, and the flux residues. The interaction between the underfill and the substrate affects not only gap filling, but also the filleting of the underfill. Similarly, the underfill-flux interaction directly affects the quality of underfilling and the reliability of the flip chip assembly. In the case of lead free flip chip assembly, the major concerns vis-a-vis process development for a large chip with a small bump pitch (less than 190 mum) include lower throughput, voiding under the chip, and critical reliability performance. The principal objective of this research endeavor was to investigate the fundamental issues that relate to the process and reliability aspects of underfilling of lead free flip chip assemblies. In order to develop a robust underfilling process, the effect of different process parameters and their interaction with the material properties were studied. In order to improve the compatibility between the underfill and the flux, a new epoxy flux that was compatible with the lead free assembly process was developed. The performance of the epoxy was also compared with the performance of various rosin based fluxes. This study also helped in identifying the critical parameters that can affect the assembly yields. This research endeavor successfully

  16. Simulation des Underfill-Prozesses bei Flip Chip-Anwendungen

    OpenAIRE

    Häußermann, Tanja

    2009-01-01

    Flip Chips sind elektronische Bauteile, die über leitfähige Höcker, so genannte Bumps, mit der aktiven Seite nach unten direkt auf dem Träger kontaktiert werden. Am häufigsten werden die Chips mit Hilfe von Lotbumps mit organischen Substraten verbunden. Nach dem Löten wird der Spalt zwischen Chip und Substrat komplett mit einem nicht leitfähigen Klebstoff, dem so genannten Underfiller, aufgefüllt. Der flüssige Underfiller wird entlang einer oder mehrerer Chipkanten appliziert, durch Kapillarw...

  17. Optimization of Indium Bump Morphology for Improved Flip Chip Devices

    Science.gov (United States)

    Jones, Todd J.; Nikzad, Shouleh; Cunningham, Thomas J.; Blazejewski, Edward; Dickie, Matthew R.; Hoenk, Michael E.; Greer, Harold F.

    2011-01-01

    Flip-chip hybridization, also known as bump bonding, is a packaging technique for microelectronic devices that directly connects an active element or detector to a substrate readout face-to-face, eliminating the need for wire bonding. In order to make conductive links between the two parts, a solder material is used between the bond pads on each side. Solder bumps, composed of indium metal, are typically deposited by thermal evaporation onto the active regions of the device and substrate. While indium bump technology has been a part of the electronic interconnect process field for many years and has been extensively employed in the infrared imager industry, obtaining a reliable, high-yield process for high-density patterns of bumps can be quite difficult. Under the right conditions, a moderate hydrogen plasma exposure can raise the temperature of the indium bump to the point where it can flow. This flow can result in a desirable shape where indium will efficiently wet the metal contact pad to provide good electrical contact to the underlying readout or imager circuit. However, it is extremely important to carefully control this process as the intensity of the hydrogen plasma treatment dramatically affects the indium bump morphology. To ensure the fine-tuning of this reflow process, it is necessary to have realtime feedback on the status of the bumps. With an appropriately placed viewport in a plasma chamber, one can image a small field (a square of approximately 5 millimeters on each side) of the bumps (10-20 microns in size) during the hydrogen plasma reflow process. By monitoring the shape of the bumps in real time using a video camera mounted to a telescoping 12 magnifying zoom lens and associated optical elements, an engineer can precisely determine when the reflow of the bumps has occurred, and can shut off the plasma before evaporation or de-wetting takes place.

  18. Nondestructive diagnosis of flip chips based on vibration analysis using PCA-RBF

    Science.gov (United States)

    Su, Lei; Shi, Tielin; Liu, Zhiping; Zhou, Hongdi; Du, Li; Liao, Guanglan

    2017-02-01

    Flip chip technology combined with solder bump interconnection has been widely applied in IC package. The solder bumps are sandwiched between dies and substrates, leading to conventional techniques being difficult to diagnose the flip chips. Meanwhile, these conventional diagnosis methods are usually performed by human visual judgment. The human eye-fatigue can easily cause fault detection. Thus, it is difficult and crucial to detect the defects of flip chips automatically. In this paper, a nondestructive diagnosis system based on vibration analysis is proposed. The flip chip is excited by air-coupled ultrasounds and raw vibration signals are measured by a laser scanning vibrometer. Forty-two features are extracted for analysis, including ten time domain features, sixteen frequency domain features and sixteen wavelet packet energy features. Principal component analysis is used for feature reduction. Radial basis function neural network is adopted for classification and recognition. Flip chips in three states (good flip chips, flip chips with missing solder bumps and flip chips with open solder bumps) are utilized to validate the proposed method. The results demonstrate that this method is effective for defect inspection in flip chip package.

  19. Selective low temperature microcap packaging technique through flip chip and wafer level alignment

    Science.gov (United States)

    Pan, C. T.

    2004-04-01

    In this study, a new technique of selective microcap bonding for packaging 3-D MEMS (Micro Electro Mechanical Systems) devices is presented. Microcap bonding on a selected area of the host wafer was successfully demonstrated through flip chip and wafer level alignment. A passivation treatment was developed to separate the microcap from the carrier wafer. A thick metal nickel (Ni) microcap was fabricated by an electroplating process. Its stiffness is superior to that of thin film poly-silicon made by the surface micromachining technique. For the selective microcap packaging process, photo definable materials served as the intermediate adhesive layer between the host wafer and the metal microcap on the carrier wafer. Several types of photo definable material used as the adhesive layer were tested and characterized for bonding strength. The experimental result shows that excellent bonding strength at low bonding temperature can be achieved.

  20. Efficient, tunable flip-chip-integrated III-V/Si hybrid external-cavity laser array.

    Science.gov (United States)

    Lin, Shiyun; Zheng, Xuezhe; Yao, Jin; Djordjevic, Stevan S; Cunningham, John E; Lee, Jin-Hyoung; Shubin, Ivan; Luo, Ying; Bovington, Jock; Lee, Daniel Y; Thacker, Hiren D; Raj, Kannan; Krishnamoorthy, Ashok V

    2016-09-19

    We demonstrate a surface-normal coupled tunable hybrid silicon laser array for the first time using passively-aligned, high-accuracy flip chip bonding. A 2x6 III-V reflective semiconductor optical amplifier (RSOA) array with integrated total internal reflection mirrors is bonded to a CMOS SOI chip with grating couplers and silicon ring reflectors to form a tunable hybrid external-cavity laser array. Waveguide-coupled wall plug efficiency (wcWPE) of 2% and output power of 3 mW has been achieved for all 12 lasers. We further improved the performance by reducing the thickness of metal/dielectric stacks and achieved 10mW output power and 5% wcWPE with the same integration techniques. This non-invasive, one-step back end of the line (BEOL) integration approach provides a promising solution to high density laser sources for future large-scale photonic integrated circuits.

  1. Flip chip bumping technology-Status and update

    Energy Technology Data Exchange (ETDEWEB)

    Juergen Wolf, M. [Fraunhofer IZM, Gustav-Meyer-Allee 25, 13355 Berlin (Germany)]. E-mail: juergen.Wolf@izm.fraunhofer.de; Engelmann, Gunter [Fraunhofer IZM, Gustav-Meyer-Allee 25, 13355 Berlin (Germany); Dietrich, Lothar [Fraunhofer IZM, Gustav-Meyer-Allee 25, 13355 Berlin (Germany); Reichl, Herbert [Fraunhofer IZM, Gustav-Meyer-Allee 25, 13355 Berlin (Germany)

    2006-09-01

    Flip chip technology is a key driver for new complex system architectures and high-density packaging, e.g. sensor or pixel devices. Bumped wafers/dice as key elements become very important in terms of general availability at low cost, high yield and quality level. Today, different materials, e.g. Au, Ni, AuSn, SnAg, SnAgCu, SnCu, etc., are used for flip chip interconnects and different bumping approaches are available. Electroplating is the technology of choice for high-yield wafer bumping for small bump sizes and pitches. Lead-free solder bumps require an increase in knowledge in the field of under bump metallization (UBM) and the interaction of bump and substrate metallization, the formation and growth of intermetallic compounds (IMCs) during liquid- and solid-phase reactions. Results of a new bi-layer UBM of Ni-Cu which is especially designed for small-sized lead-free solder bumps will be discussed.

  2. Repairable chip bonding/interconnect process

    Science.gov (United States)

    Bernhardt, Anthony F.; Contolini, Robert J.; Malba, Vincent; Riddle, Robert A.

    1997-01-01

    A repairable, chip-to-board interconnect process which addresses cost and testability issues in the multi-chip modules. This process can be carried out using a chip-on-sacrificial-substrate technique, involving laser processing. This process avoids the curing/solvent evolution problems encountered in prior approaches, as well is resolving prior plating problems and the requirements for fillets. For repairable high speed chip-to-board connection, transmission lines can be formed on the sides of the chip from chip bond pads, ending in a gull wing at the bottom of the chip for subsequent solder.

  3. Laser-induced forward transfer for flip-chip packaging of single dies.

    Science.gov (United States)

    Kaur, Kamal S; Van Steenberge, Geert

    2015-03-20

    Flip-chip (FC) packaging is a key technology for realizing high performance, ultra-miniaturized and high-density circuits in the micro-electronics industry. In this technique the chip and/or the substrate is bumped and the two are bonded via these conductive bumps. Many bumping techniques have been developed and intensively investigated since the introduction of the FC technology in 1960(1) such as stencil printing, stud bumping, evaporation and electroless/electroplating2. Despite the progress that these methods have made they all suffer from one or more than one drawbacks that need to be addressed such as cost, complex processing steps, high processing temperatures, manufacturing time and most importantly the lack of flexibility. In this paper, we demonstrate a simple and cost-effective laser-based bump forming technique known as Laser-induced Forward Transfer (LIFT)3. Using the LIFT technique a wide range of bump materials can be printed in a single-step with great flexibility, high speed and accuracy at RT. In addition, LIFT enables the bumping and bonding down to chip-scale, which is critical for fabricating ultra-miniature circuitry.

  4. The Numerical Analysis of Strain Behavior at Solder Joint and Interface of Flip Chip Package

    Institute of Scientific and Technical Information of China (English)

    S; C; Chen; Y; C; Lin

    2002-01-01

    The flip chip package is a kind of advanced electri ca l packages. Due to the requirement of miniaturization, lower weight, higher dens ity and higher performance in the advanced electric package, it is expected that flip chip package will soon be a mainstream technology. The silicon chip is dir ectly connected to printing circuit substrate by SnPb solder joints. Also, the u nderfill, a composite of polymer and silica particles, is filled in the gap betw een the chip and substrate around the solder joint...

  5. Wax-bonding 3D microfluidic chips

    KAUST Repository

    Gong, Xiuqing

    2013-10-10

    We report a simple, low-cost and detachable microfluidic chip incorporating easily accessible paper, glass slides or other polymer films as the chip materials along with adhesive wax as the recycling bonding material. We use a laser to cut through the paper or film to form patterns and then sandwich the paper and film between glass sheets or polymer membranes . The hot-melt adhesive wax can realize bridge bonding between various materials, for example, paper, polymethylmethacrylate (PMMA) film, glass sheets, or metal plate. The bonding process is reversible and the wax is reusable through a melting and cooling process. With this process, a three-dimensional (3D) microfluidic chip is achievable by vacuating and venting the chip in a hot-water bath. To study the biocompatibility and applicability of the wax-based microfluidic chip, we tested the PCR compatibility with the chip materials first. Then we applied the wax-paper based microfluidic chip to HeLa cell electroporation (EP ). Subsequently, a prototype of a 5-layer 3D chip was fabricated by multilayer wax bonding. To check the sealing ability and the durability of the chip, green fluorescence protein (GFP) recombinant Escherichia coli (E. coli) bacteria were cultured, with which the chemotaxis of E. coli was studied in order to determine the influence of antibiotic ciprofloxacin concentration on the E. coli migration.

  6. Molded underfill (MUF) encapsulation for flip-chip package: A numerical investigation

    Science.gov (United States)

    Azmi, M. A.; Abdullah, M. K.; Abdullah, M. Z.; Ariff, Z. M.; Saad, Abdullah Aziz; Hamid, M. F.; Ismail, M. A.

    2017-07-01

    This paper presents the numerical simulation of epoxy molding compound (EMC) filling in multi flip-chip packages during encapsulation process. The empty and a group flip chip packages were considered in the mold cavity in order to study the flow profile of the EMC. SOLIDWORKS software was used for three-dimensional modeling and it was incorporated into fluid analysis software namely as ANSYS FLUENT. The volume of fluid (VOF) technique was used for capturing the flow front profiles and Power Law model was applied for its rheology model. The numerical result are compared and discussed with previous experimental and it was shown a good conformity for model validation. The prediction of flow front was observed and analyzed at different filling time. The possibility and visual of void formation in the package is captured and the number of flip-chip is one factor that contributed to the void formation.

  7. AE (Acoustic Emission) for Flip-Chip CGA/FCBGA Defect Detection

    Science.gov (United States)

    Ghaffarian, Reza

    2014-01-01

    C-mode scanning acoustic microscopy (C-SAM) is a nondestructive inspection technique that uses ultrasound to show the internal feature of a specimen. A very high or ultra-high-frequency ultrasound passes through a specimen to produce a visible acoustic microimage (AMI) of its inner features. As ultrasound travels into a specimen, the wave is absorbed, scattered or reflected. The response is highly sensitive to the elastic properties of the materials and is especially sensitive to air gaps. This specific characteristic makes AMI the preferred method for finding "air gaps" such as delamination, cracks, voids, and porosity. C-SAM analysis, which is a type of AMI, was widely used in the past for evaluation of plastic microelectronic circuits, especially for detecting delamination of direct die bonding. With the introduction of the flip-chip die attachment in a package; its use has been expanded to nondestructive characterization of the flip-chip solder bumps and underfill. Figure 1.1 compares visual and C-SAM inspection approaches for defect detection, especially for solder joint interconnections and hidden defects. C-SAM is specifically useful for package features like internal cracks and delamination. C-SAM not only allows for the visualization of the interior features, it has the ability to produce images on layer-by-layer basis. Visual inspection; however, is only superior to C-SAM for the exposed features including solder dewetting, microcracks, and contamination. Ideally, a combination of various inspection techniques - visual, optical and SEM microscopy, C-SAM, and X-ray - need to be performed in order to assure quality at part, package, and system levels. This reports presents evaluations performed on various advanced packages/assemblies, especially the flip-chip die version of ball grid array/column grid array (BGA/CGA) using C-SAM equipment. Both external and internal equipment was used for evaluation. The outside facility provided images of the key features

  8. Observation of amorphous chromium in modified C4 flip chip solder joints after thermal stress testing

    Energy Technology Data Exchange (ETDEWEB)

    Hooghan, T.K.; Nakahara, S.; Hooghan, K.; Privette, R.W.; Bachman, M.A.; Moyer, R.S

    2003-08-01

    Flip chip reliability was evaluated using thermal stress tests at 150 deg. C. Electrical failures of flip chip devices were found to occur at the solder/under-bump-metallization interface by forming a porous amorphous chromium layer. The formation of the porous amorphous layer responsible for electrical failures resulted from the outdiffusion of copper atoms from a copper-chromium co-deposit, used as one of the under-bump-metallization layers. A strong interaction of Cu with the Sn component of the solder is the driving force of the Cu outdiffusion.

  9. Reliability of an ultra-fine-pitch COF flip-chip package using non-conductive paste

    Science.gov (United States)

    Kim, Hae-Yeon; Min, Kyung-Eun; Lee, Jun-Sik; Lee, So-Jeong; Lee, Sung-Soo; Kim, Jun-Ki

    2016-01-01

    Ultra-fine-pitch chip-on-film (COF) packages such as display-drive-integrated circuit (DDI) modules are manufactured through an underfill process following Au-to-Sn thermo-compression bonding. As the interconnection pitch becomes finer and is reduced to less than 25 um, however, an alternative flip-chip technology, such as non-conductive paste (NCP) bonding, is needed in place of the capillary underfill process. In this study, new NCP formulations are investigated to achieve rapid curing at a temperature high enough to form a metallic bond between the bump and the pad. An appropriate curing agent was determined through a dielectric analysis (DEA). COF samples were prepared with a DDI chip 11,772 × 924 um in size and with a 38 um-thick polyimide flexible printed circuit by both NCP bonding and thermo-compressionunderfill processes. Pressure cooker tests lasting as long as 192 h revealed that the reliability of the NCP sample against high temperatures and high humidity levels exceeded somewhat that of the underfill sample. In thermal cycling test up to 500 cycles, however, the reliability of the NCP sample was inferior to that of the underfill sample. It was considered that unbonded faults and NCP trapping at the bump-to-pad joint were responsible for the premature failure of the NCP sample under a thermal cycling condition. [Figure not available: see fulltext.

  10. Heating rate and spin flip lifetime due to near field noise in layered superconducting atom chips

    CERN Document Server

    Fermani, Rachele; Zhang, Bo; Lim, Michael J; Dumke, Rainer

    2009-01-01

    We theoretically investigate the heating rate and spin flip lifetimes due to near field noise for atoms trapped close to layered superconducting structures. In particular, we compare the case of a gold layer deposited above a superconductor with the case of a bare superconductor. We study a niobium-based and a YBCO-based chip. For both niobium and YBCO chips at a temperature of 4.2 K, we find that the deposition of the gold layer can have a significant impact on the heating rate and spin flip lifetime, as a result of the increase of the near field noise. At a chip temperature of 77 K, this effect is less pronounced for the YBCO chip.

  11. High performance thin-film flip-chip InGaN-GaN light-emitting diodes

    Science.gov (United States)

    Shchekin, O. B.; Epler, J. E.; Trottier, T. A.; Margalith, T.; Steigerwald, D. A.; Holcomb, M. O.; Martin, P. S.; Krames, M. R.

    2006-08-01

    Data are presented on the operation of thin-film flip-chip InGaN /GaN multiple-quantum-well light-emitting diodes (LEDs). The combination of thin-film LED concept with flip-chip technology is shown to provide surface brightness and flux output advantages over conventional flip-chip and vertical-injection thin-film LEDs. Performance characteristics of blue, white, and green thin-film flip-chip 1×1mm2 LEDs are described. Blue (˜441nm) thin-film flip-chip LEDs are demonstrated with radiance of 191mW/mm2sr at 1A drive, more than two times brighter than conventional flip-chip LEDs. An encapsulated thin-film flip-chip blue LED lamp is shown to have external quantum efficiency of 38% at forward current of 350mA. A white lamp based on a YAG:Ce phosphor coated device exhibits luminous efficacy of 60lm/W at 350mA with peak efficiency of 96lm/W at 20mA and luminance of 38Mcd/m2 at 1A drive current. Green (˜517nm) devices exhibit luminance of 37Mcd/m2 at 1A.

  12. Application of robust color composite fringe in flip-chip solder bump 3-D measurement

    Science.gov (United States)

    Kuo, Chung-Feng Jeffrey; Wu, Han-Cheng

    2017-04-01

    This study developed a 3-D measurement system based on flip-chip solder bump, used fringes with different modulation intensities in color channels, in order to produce color composite fringe with robustness, and proposed a multi-channel composite phase unwrapping algorithm, which uses fringe modulation weights of different channels to recombine the phase information for better measurement accuracy and stability. The experimental results showed that the average measurement accuracy is 0.43μm and the standard deviation is 1.38 μm. The results thus proved that the proposed 3-D measurement system is effective in measuring a plane with a height of 50 μm. In the flip-chip solder bump measuring experiment, different fringe modulation configurations were tested to overcome the problem of reflective coefficient between the flip-chip base board and the solder bump. The proposed system has a good measurement results and robust stability in the solder bump measurement, and can be used for the measurement of 3-D information for micron flip-chip solder bump application.

  13. Cost effective flip chip assembly and interconnection technologies for large area pixel sensor applications

    Energy Technology Data Exchange (ETDEWEB)

    Fritzsch, T., E-mail: thomas.fritzsch@izm.fraunhofer.de [Fraunhofer IZM, Gustav-Meyer-Allee 25, Berlin 13355 (Germany); Jordan, R.; Oppermann, H. [Fraunhofer IZM, Gustav-Meyer-Allee 25, Berlin 13355 (Germany); Ehrmann, O. [Berlin Institute of Technology (TUB), Berlin 10623 (Germany); Toepper, M.; Baumgartner, T.; Lang, K.-D. [Fraunhofer IZM, Gustav-Meyer-Allee 25, Berlin 13355 (Germany)

    2011-09-11

    Much of the cost of manufacturing pixel detectors is due to bumping and flip chip assembly of the readout chips onto sensor tiles, even if it is done on wafer level. To address this issue, Fraunhofer IZM investigated two new technological approaches, namely screen printing using dry film resist and chip-to-wafer assembly. In the first approach, solder bumps with diameters of 80 and 25 {mu}m in pitches of 110 and 60 {mu}m, respectively, were produced by screen-printing solder paste using a photo-structured dry film resist. Results indicated that the technology is a viable high yield and low cost bumping process. The second approach was developed to decrease the number of manual handling steps in pixel module manufacturing, which is critical for reducing processing time and cost. Here, chip designs on 200 mm readout chip (ROC) wafers and 150 mm sensor wafers were especially adapted for chip-to-wafer assembly and to ensure that the interconnection yield and reliability could be tested. After bumping and dicing of the readout chip wafer and UBM plating on the sensor wafer, individual dice were flip chip mounted on the pre-diced sensor wafer. This paper describes the technological steps, key processing parameters and first results for both technologies.

  14. A two-dimensional simulation model for the molded underfill process in flip chip packaging

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Xue Ru; Young, Wen Bin [National Cheng Kung University, Tainan (China)

    2015-07-15

    The flip chip process involves the deposition of solder bumps on the chip surface and their subsequent direct attachment and connection to a substrate. Underfilling traditional flip chip packaging is typically performed following a two-step approach. The first step uses capillary force to fill the gap between the chip and the substrate, and the second step uses epoxy molding compound (EMC) to overmold the package. Unlike traditional flip chip packaging, the molded underfill (MUF) concept uses a single-step approach to simultaneously achieve both underfill and overmold. MUF is a simpler and faster process. In this study, a 2D numerical model is developed to simulate the front movement of EMC flow and the void formation for different geometric parameters. The 2D model simplifies the procedures of geometric modeling and reduces the modeling time for the MUF simulation. Experiments are conducted to verify the prediction results of the model. The effect on void formation for different geometric parameters is investigated using a 2D model.

  15. Flip-chip-type high-Tc gradiometer for biomagnetic measurements in unshielded environment

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A flip-chip-type gradiometer has been constructed with a 10 mm×5 mm planar DC-SQUID gradiometer fabricated on a SrTiO3 bicrystal substrate and a flux transformer made from a YBCO*/YBCO/CeO2/YSZ multilayer on a φ50.8 mm Si wafer. The coupling coefficient between the flux transformer and the planar gradiometer is 0.18. The transformer increases effectively the resolution of the gradiometer. A magnetic field gradient resolution of 73 fT·cm-1·Hz-1/2 in the white region and 596 fT·cm-1Hz-1/2 at 1 Hz has been obtained. High quality magnetocardiogram signals have been successfully measured by using this flip-chip-type gradiometer in an unshielded environment.

  16. Flip-chip-type high- T_c gradiometer for biomagnetic measurements in unshielded environment

    Institute of Scientific and Technical Information of China (English)

    田永君; 王天生; 陈珂; 漆汉宏; 陈烈; 郑东宁; Sven; LINZEN; Frank; SCHMIDL; Paul; SEIDEL

    2000-01-01

    A flip-chip-type gradiometer has been constructed with a 10 mm × 5 mm planar DC-SQUID gradiometer fabricated on a SrTiO3 bicrystal substrate and a flux transformer made from a YB-CO* /YBCO/CeO2/YSZ multilayer on a φ50.8 mm Si wafer. The coupling coefficient between the flux transformer and the planar gradiometer is 0.18. The transformer increases effectively the resolution of the gradiometer. A magnetic field gradient resolution of 73 fT·cm-1·Hz-1/2 in the white region and 596 fT·cm-1Hz-1/2 at 1 Hz has been obtained. High quality magnetocardiogram signals have been successfully measured by using this flip-chip-type gradiometer in an unshielded environment.

  17. Effect of aluminum trace dimension on electro-migration failure in flip-chip package

    Science.gov (United States)

    Liu, Peisheng; Fan, Guangming; Liu, Yahong; Yang, Longlong; Miao, Xiaoyong

    2017-03-01

    A 3D model of flip-chip package is established and thermal-electrical coupling is analyzed. The effect of the width of Aluminum (Al) trace on electro-migration mechanism is also studied. Reducing rates of the hot-spot temperature, the max Joule heating, the max temperature gradient and the max current density are defined to research the effects of the Al trace thickness and the UBM thickness on electro-migration.

  18. Experiment-Based Computational Investigation of Thermomechanical Stresses in Flip Chip BGA Using the ATC4.2 Test Vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Burchett, Steven N.; Nguyen, Luu; Peterson, David W.; Sweet, James N.

    1999-08-02

    Stress measurement test chips were flip chip assembled to organic BGA substrates containing micro-vias and epoxy build-up interconnect layers. Mechanical degradation observed during temperature cycling was correlated to a damage theory developed based on 3D finite element method analysis. Degradation included die cracking, edge delamination and radial fillet cracking.

  19. A numerical study of void nucleation and growth in a flip chip assembly process

    Science.gov (United States)

    Lee, Sangil; Zhou, Hao Min; Baldwin, Daniel F.

    2010-09-01

    In this study, we develop mathematical models and numerical simulations of void nucleation and growth induced by the chemical reaction in the flip chip package assembly process using a no-flow underfill. During the thermal assembly process, the underfill chemically reacts to the oxidation of solders I/O on the chip, achieving interconnection between chip and substrate. The chemical reaction causes a large number of voids in the thermal reflow process. The voids have been considered as a critical defect, reducing the life of the thermal reliability. This study investigates the mechanism of void nucleation and growth based on classical bubble nucleation theory and bubble dynamics, respectively. This knowledge can provide a theoretical foundation to achieve a void-free assembly process and high reliability performance.

  20. An Introduction to Flip-Chip Packaging Technology%倒装芯片封装技术概论

    Institute of Scientific and Technical Information of China (English)

    张文杰; 朱朋莉; 赵涛; 孙蓉; 汪正平

    2014-01-01

    As the high density package is moving towards miniaturization, high I/O density, better thermal and high reliable system, the conventional wire bonding technology can not satisfy the product need already. The advanced lfip chip technology is highly expected due to its high area array I/O interconnection, short signal path, high thermal dissipation, high electrical and thermal performance. In order to enhance the reliability of a flip-chip on organic board package, underifll is used between the chip and the substrate to redistribute the thermo-mechanical stress created by the coefifcient of thermal expansion (CTE) mismatch between the silicon chip and organic substrate. However, the conventional underifll relies on the capillary lfow of the underifll material and has many disadvantages. In order to overcome these disadvantages, no-lfow underifll has been invented to improve the lfip-chip underifll process. This paper reviews the development of lfip-chip technology and expounds the behavior of lfow and no-lfow underifll.%高密度电子封装正朝着小型化、高I/O 密度、更好的散热性和高的可靠性方向发展,传统引线键合技术已经无法满足要求。先进的倒装芯片封装技术由于具有较高的单位面积内 I/O 数量、短的信号路径、高的散热性、良好的电学和热力学性能,在电子封装中被广泛关注。底部填充胶被填充在芯片与基板之间的间隙,来降低芯片与基板热膨胀系数不匹配产生的应力,提高封装的稳定性。然而,流动底部填充胶依赖于胶的毛细作用进行填充,存在很多缺点。为了克服这些缺点,出现了非流动底部填充胶,以改善倒装芯片底部填充工艺。文章回顾了倒装芯片封装技术的发展,阐述了流动和非流动底部填充胶的施胶方式和性质。

  1. Validating theoretical calculations of thermomechanical stress and deformation using the ATC4.1 flip-chip test vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, D.W.; Sweet, J.N.; Burchett, S.N.

    1997-08-01

    Two closed form analytical solutions for tri-material thermomechanical stress and deformation, along with one-quarter section finite element model (FEM), were validated using an in-situ CMOS piezoresistive stress measurement test chip that has been repatterened into a fine pitch area array flip-chip. A special printed circuit board substrate for the test chip was designed at Sandia and fabricated by the Hadco Corp. The flip-chip solder attach (FCA) and underfill was performed by a SEMATECH member company. The measured incremental stresses produced by the underfill are reported and discussed for two underfill materials used in this experiment. Detailed comparisons between theory and experiment are presented and discussed.

  2. Investigation of high extraction efficiency flip-chip GaN-based light-emitting diodes

    Institute of Scientific and Technical Information of China (English)

    DA XiaoLi; SHEN GuangDi; XU Chen; ZOU DeShu; ZHU YanXu; ZHANG JianMing

    2009-01-01

    In order to obtain higher light output power, the flip-chip structure Is used. We studied the ratio of the light of GaN sides before and after fabricating metal reflector on p-GaN. The SiO2/SiNx dielectric film reflectors were deposited through plasma enhance chemical vapor deposition following the fabrication of metal reflector, and then the dielectric film reflectors on the electrodes were etched in order to expose the electrodes to the air. It is found that comparing with the flip-chip GaN-LED without dielectric film reflectors, light output power can be increased by as high as 10.2% after the deposition of 2 pairs of SiO2/SiNx dielectric film reflectors on GaN-LEDs, which cover the sidewalls and the areas without the metal reflector. This result indicates that the high reflector formed by multi-layer dielectric films is useful to enhance the light output power of GaN-based LED, which reflects light from step sidewalls and p-GaN without metal reflector to internal, and then light emits from the surface.

  3. High-Sensitivity Low-Noise Miniature Fluxgate Magnetometers Using a Flip Chip Conceptual Design

    Directory of Open Access Journals (Sweden)

    Chih-Cheng Lu

    2014-07-01

    Full Text Available This paper presents a novel class of miniature fluxgate magnetometers fabricated on a print circuit board (PCB substrate and electrically connected to each other similar to the current “flip chip” concept in semiconductor package. This sensor is soldered together by reversely flipping a 5 cm × 3 cm PCB substrate to the other identical one which includes dual magnetic cores, planar pick-up coils, and 3-D excitation coils constructed by planar Cu interconnections patterned on PCB substrates. Principles and analysis of the fluxgate sensor are introduced first, and followed by FEA electromagnetic modeling and simulation for the proposed sensor. Comprehensive characteristic experiments of the miniature fluxgate device exhibit favorable results in terms of sensitivity (or “responsivity” for magnetometers and field noise spectrum. The sensor is driven and characterized by employing the improved second-harmonic detection technique that enables linear V-B correlation and responsivity verification. In addition, the double magnitude of responsivity measured under very low frequency (1 Hz magnetic fields is experimentally demonstrated. As a result, the maximum responsivity of 593 V/T occurs at 50 kHz of excitation frequency with the second harmonic wave of excitation; however, the minimum magnetic field noise is found to be 0.05 nT/Hz1/2 at 1 Hz under the same excitation. In comparison with other miniature planar fluxgates published to date, the fluxgate magnetic sensor with flip chip configuration offers advances in both device functionality and fabrication simplicity. More importantly, the novel design can be further extended to a silicon-based micro-fluxgate chip manufactured by emerging CMOS-MEMS technologies, thus enriching its potential range of applications in modern engineering and the consumer electronics market.

  4. Characteristics of intermetallics and micromechanical properties during thermal ageing of Sn-Ag-Cu flip-chip solder interconnects

    Energy Technology Data Exchange (ETDEWEB)

    Li Dezhi [Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU (United Kingdom); Liu Changqing [Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU (United Kingdom)]. E-mail: c.liu@lboro.ac.uk; Conway, Paul P. [Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU (United Kingdom)

    2005-01-25

    Sn-3.8 wt.% Ag-0.7 wt.% Cu solder was applied to Al-1 wt.% Cu bond pads with an electroless nickel (Ni-P) interlayer as an under bump metallisation (UBM). The microstructure and micromechanical properties were studied after ageing at 80 deg. C and 150 deg. C. Two types of intermetallic compounds (IMCs) were identified by electron back-scattered diffraction (EBSD), these being a (Cu, Ni){sub 6}Sn{sub 5} formed at the solder-UBM interface and Ag{sub 3}Sn in the bulk solder. The (Cu, Ni){sub 6}Sn{sub 5} layer grew very slowly during the ageing process, with no Kirkendall voids found by scanning electron microscopy (SEM) after ageing at 80 deg. C. Nano-indentation was used to analyse the mechanical properties of different phases in the solder. Both (Cu, Ni){sub 6}Sn{sub 5} and Ag{sub 3}Sn were harder and more brittle than the {beta}-Sn matrix of the Sn-Ag-Cu alloy. The branch-like morphology of the Ag{sub 3}Sn IMC, especially at the solder-UBM interface, could ultimately be detrimental to the mechanical integrity of the solder when assembled in flip-chip joints.

  5. Stresses from flip-chip assembly and underfill; measurements with the ATC4.1 assembly test chip and analysis by finite element method

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, D.W.; Sweet, J.N.; Burchett, S.N.; Hsia, A.

    1996-12-31

    The authors report the first measurements of in-situ flip-chip assembly mechanical stresses using a CMOS piezoresistive test chip repatterned with a fine pitch full area array. A special printed circuit board substrate was designed at Sandia and fabricated by the Hadco Corp. The flip-chip solder attach (FCA) and underfill was performed by a SEMATECH member company. The measured incremental stresses produced by the underfill are reported and discussed for several underfill materials used in this experiment. A FEM of a one-quarter section of the square assembly has been developed to compare with the measured as-assembled and underfill die surface stresses. The initial model utilized linear elastic constitutive models for the Si, solder, underfill, and PC board components. Detailed comparisons between theory and experiment are presented and discussed.

  6. SU-8 cantilever chip interconnection

    DEFF Research Database (Denmark)

    Johansson, Alicia Charlotte; Janting, Jakob; Schultz, Peter;

    2006-01-01

    the electrodes on the SU-8 chip to a printed circuit board. Here, we present two different methods of electrically connecting an SU-8 chip, which contains a microfluidic network and free-hanging mechanical parts. The tested electrical interconnection techniques are flip chip bonding using underfill or flip chip...... bonding using an anisotropic conductive film (ACF). These are both widely used in the Si industry and might also be used for the large scale interconnection of SU-8 chips. The SU-8 chip, to which the interconnections are made, has a microfluidic channel with integrated micrometer-sized cantilevers...... that can be used for label-free biochemical detection. All the bonding tests are compared with results obtained using similar Si chips. It is found that it is significantly more complicated to interconnect SU-8 than Si cantilever chips primarily due to the softness of SU-8....

  7. New Three-Dimensional Integration Technology Using Chip-to-Wafer Bonding to Achieve Ultimate Super-Chip Integration

    Science.gov (United States)

    Fukushima, Takafumi; Yamada, Yusuke; Kikuchi, Hirokazu; Koyanagi, Mitsumasa

    2006-04-01

    A new three-dimensional (3D) integration technology using the chip-to-wafer bonding technique provides the ultimate super-chip integration in which various kinds of chip of different sizes can be vertically stacked and electrically connected through a number of vertical interconnections. We have investigated several key technologies of vertical interconnection formation, chip alignment, chip-to-wafer bonding, adhesive injection, and chip thinning to vertically stack known good dies (KGDs) into 3D LSI chips. By using these key technologies, successful fabrication of 3D LSI test chips with vertical interconnections consisting of In-Au microbumps and buried interconnections filled with polycrystalline silicon (poly-Si) was demonstrated. The test chips was composed of three kinds of very thin chip of 5, 6, and 7 mm2 and ranging in thickness from 30 to 90 μm. Each chip is tightly bonded using a low-viscosity epoxy adhesive as a dielectric material.

  8. Au-SN Flip-Chip Solder Bump for Microelectronic and Optoelectronic Applications

    CERN Document Server

    Yoon, Jeong-Won; Koo, Ja-Myeong; Jung, Seung-Boo

    2007-01-01

    As an alternative to the time-consuming solder pre-forms and pastes currently used, a co-electroplating method of eutectic Au-Sn alloy was used in this study. Using a co-electroplating process, it was possible to plate the Au-Sn solder directly onto a wafer at or near the eutectic composition from a single solution. Two distinct phases, Au5Sn and AuSn, were deposited at a composition of 30at.%Sn. The Au-Sn flip-chip joints were formed at 300 and 400 degrees without using any flux. In the case where the samples were reflowed at 300 degrees, only an (Au,Ni)3Sn2 IMC layer formed at the interface between the Au-Sn solder and Ni UBM. On the other hand, two IMC layers, (Au,Ni)3Sn2 and (Au,Ni)3Sn, were found at the interfaces of the samples reflowed at 400 degrees. As the reflow time increased, the thickness of the (Au,Ni)3Sn2 and (Au,Ni)3Sn IMC layers formed at the interface increased and the eutectic lamellae in the bulk solder coarsened.

  9. LED flip-chip assembly with electroplated AuSn alloy

    Science.gov (United States)

    Maaskant, P. P.; Akhter, M.; Cordero, N.; Casey, D. P.; Rohan, J. F.; Roycroft, B. J.; Corbett, B. M.

    2005-05-01

    InGaN based high brightness (HB)-LED chips have been fabricated and bonded to substrates that were coated with electroplated Au/Sn/Au solder. The assemblies yielded a forward voltage of 5.6 V and an optical output power of 42 mW when tested at 1,000 mA bias. The electroluminescence distribution was mapped with a CCD camera to determine the current spreading into the p-contact region. Computational fluid dynamics (CFD) was used to check the effect of non-uniform current spreading on the thermal resistance of the assemblies. We show that a good knowledge of the non-uniform heat generation is required to obtain accurate modelling results. The bond strength of the AuSn solder joints exceeded the norm, when shear tested according to MIL-STD-883E (method 2019.5).

  10. Comparison of thermomigration behaviors between Pb-free flip chip solder joints and microbumps in three dimensional integrated circuits: Bump height effect

    Science.gov (United States)

    Ouyang, Fan-Yi; Jhu, Wei-Cheng

    2013-01-01

    Packaging technology is currently transition from flip chip technology to three dimensional integrated circuits (3D ICs) to meet the requirements of consumer electronic products. Compared to flip chip technology, the dimension of microbumps in 3D ICs is shrunk by a factor of 10. In this study, the behaviors of thermomigration in Pb-free solders of flip chip and 3D ICs are presented. When the bump height is 100 μm in the flip chip samples, the Sn protrusion was observed at the hot end and voids formation at the cold end. However, when the bump height is reduced to 5.8 μm in the 3D IC samples, no significant microstructural evolution of Sn was found; instead, the dissolution of Ni under-bump metallization at hot end was observed. We propose that discrepancy between flip chip solder joints and 3D IC microbumps is mainly attributed to the effect of back stress and the presence of thicker Ni under-bump metallization in the 3D IC packaging. Moreover, the critical temperature gradient in terms of different bump heights is discussed, showing below which there will be no net effect of thermomigration of Sn.

  11. Photonic Wire Bonds for Terabit/s Chip-to-Chip Interconnects

    CERN Document Server

    Lindenmann, Nicole; Hillerkuss, David; Schmogrow, Rene; Jordan, Meinert; Leuthold, Juerg; Freude, Wolfgang; Koos, Christian

    2011-01-01

    Photonic integration has witnessed tremendous progress over the last years, and chip-scale transceiver systems with Terabit/s data rates have come into reach. However, as on-chip integration density increases, efficient off-chip interfaces are becoming more and more crucial. A technological breakthrough is considered indispensable to cope with the challenges arising from large-scale photonic integration, and this particularly applies to short-distance optical interconnects. In this letter we introduce the concept of photonic wire bonding, where transparent waveguide wire bonds are used to bridge the gap between nanophotonic circuits located on different chips. We demonstrate for the first time the fabrication of three-dimensional freeform photonic wire bonds (PWB), and we confirm their viability in a multi-Terabit/s data transmission experiment. First-generation prototypes allow for efficient broadband coupling with overall losses of only 1.6 dB. Photonic wire bonding will enable flexible optical multi-chip a...

  12. Calculation and Validation of Thermomechanical Stresses in Flip Chip BGA Using the ATC4.2 Test Vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Burchett, S.N.; Mitchell, R.T.; Nguyen, L.; Peterson, D.W.; Sweet, J.N.

    1999-03-09

    We report the first in situ measurements of thermomechanical stresses in a 1000 I/O 250 {micro}m pitch piezoresistive flip chip test chip assembled to a 755 I/O 1.0 mm pitch 35 mm Ball Grid Array (BGA). The BGA substrates employed build-up dielectric layers containing micro-vias over conventional fiberglass laminate cores. Experimental data, which include in situ stress and die bending measurements, were correlated to closed form and Finite Element Method (FEM) calculations. Cracking and delamination were observed in some of the experimental groups undergoing temperature cycling. Through use of bounding conditions in the FEM simulations, these failures were associated with debonding of the underfill fillet from the die edge that caused stresses to shift to weaker areas of the package.

  13. Electromigration Reliability and Morphologies of Cu Pillar Flip-Chip Solder Joints with Cu Substrate Pad Metallization

    Science.gov (United States)

    Lai, Yi-Shao; Chiu, Ying-Ta; Chen, Jiunn

    2008-10-01

    The Cu pillar is a thick underbump metallurgy (UBM) structure developed to alleviate current crowding in a flip-chip solder joint under operating conditions. We present in this work an examination of the electromigration reliability and morphologies of Cu pillar flip-chip solder joints formed by joining Ti/Cu/Ni UBM with largely elongated ˜62 μm Cu onto Cu substrate pad metallization using the Sn-3Ag-0.5Cu solder alloy. Three test conditions that controlled average current densities in solder joints and ambient temperatures were considered: 10 kA/cm2 at 150°C, 10 kA/cm2 at 160°C, and 15 kA/cm2 at 125°C. Electromigration reliability of this particular solder joint turns out to be greatly enhanced compared to a conventional solder joint with a thin-film-stack UBM. Cross-sectional examinations of solder joints upon failure indicate that cracks formed in (Cu,Ni)6Sn5 or Cu6Sn5 intermetallic compounds (IMCs) near the cathode side of the solder joint. Moreover, the ~52- μm-thick Sn-Ag-Cu solder after long-term current stressing has turned into a combination of ~80% Cu-Ni-Sn IMC and ~20% Sn-rich phases, which appeared in the form of large aggregates that in general were distributed on the cathode side of the solder joint.

  14. Silver free III-nitride flip chip light-emitting-diode with wall plug efficiency over 70% utilizing a GaN tunnel junction

    Science.gov (United States)

    Yonkee, B. P.; Young, E. C.; DenBaars, S. P.; Nakamura, S.; Speck, J. S.

    2016-11-01

    A molecular beam epitaxy regrowth technique was demonstrated on standard industrial patterned sapphire substrate light-emitting diode (LED) epitaxial wafers emitting at 455 nm to form a GaN tunnel junction. By using an HF pretreatment on the wafers before regrowth, a voltage of 3.08 V at 20 A/cm2 was achieved on small area devices. A high extraction package was developed for comparison with flip chip devices which utilize an LED floating in silicone over a BaSO4 coated header and produced a peak external quantum efficiency (EQE) of 78%. A high reflectivity mirror was designed using a seven-layer dielectric coating backed by aluminum which has a calculated angular averaged reflectivity over 98% between 400 and 500 nm. This was utilized to fabricate a flip chip LED which had a peak EQE and wall plug efficiency of 76% and 73%, respectively. This flip chip could increase light extraction over a traditional flip chip LED due to the increased reflectivity of the dielectric based mirror.

  15. Electromigration and thermomigration studies in composite high lead and eutectic tin-lead flip chip solder joint

    Science.gov (United States)

    Huang, Annie Tzuyu

    The effect of thermomigration and the combination effect of thermomigration and electromigration have been studied in composite SnPb flip chip solder joints. Because Al line on the silicon chip side is the major heat source exerted on flip chip solder joint, temperature gradient across the joint is induced when a long Al line is stressed with high current density. Under a estimated temperature gradient of 1000°C/cm, Sn-rich and Pb-rich phase separation is found to occur. Experimental results have shown that Sn-rich phase accumulates at the hot side and Pb-rich phase accumulates at the cold side after thermomigration. When solder bumps are current high current density, thermomigration was found to accompany electromigration. Not only Pb-rich phase migrated toward the anode side and Sn-rich phase migrated toward the cathode side due to electromigration, Sn-rich phase was found to migrate along the top of solder joint due to thermomigration. It was found that as void propagates along the top of the solder joint, current crowding region shifts with the tip of the void. This created a local hot spot and thus a lateral temperature gradient was induced for thermomigration to occur. To isolate the thermal effect from the current effect, ac stressing at 60 Hz was also utilized. Interestingly, ac seems to have an effect other than thermal effect due to the difference in microstructure evolution between pure thermomigration and ac case after stressing. Further investigation at different frequency is needed to fully understand the effect of ac. Furthermore, analysis was performed to explain the phenomena of phase separation and phase reversal in the solder joint considering a constraint volume within underfill. Both Kirkendall effect and back stress were considered. Finally, detail morphological change after thermomigration and electromigration were investigated. Grain refinement was found to occur at a certain stressing condition. Production of entropy and morphological

  16. Optical properties of plasmonic light-emitting diodes based on flip-chip III-nitride core-shell nanowires.

    Science.gov (United States)

    Nami, Mohsen; Feezell, Daniel F

    2014-12-01

    In this work, we utilize the finite difference time domain (FDTD) method to investigate the Purcell factor, light extraction efficiency (EXE), and cavity quality parameter (Q), and to predict the modulation response of Ag-clad flip-chip GaN/InGaN core-shell nanowire light-emitting diodes (LEDs) with the potential for electrical injection. We consider the need for a pn-junction, the effects of the substrate, and the limitations of nanoscale fabrication techniques in the evaluation. The investigated core-shell nanowire consists of an n-GaN core, surrounded by nonpolar m-plane quantum wells, p-GaN, and silver cladding layers. The core-shell nanowire geometry exhibits a Purcell factor of 57, resulting in a predicted limit of 30 GHz for the 3dB modulation bandwidth.

  17. Electromigration and solid state aging of flip chip solder joints and analysis of tin whisker on lead-frame

    Science.gov (United States)

    Lee, Taekyeong

    Electromigration and solid state aging in flip chip joint, and whisker on lead frame of Pb-containing (eutectic SnPb) and Pb-free solders (SnAg 3.5, SnAg3.8Cu0.7, and SnCu0.7), have been studied systematically, using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDX), and synchrotron radiation. The high current density in flip chip joint drives the diffusion of atoms of eutectic SnPb and SnAgCu. A marker is used to measure the diffusion flux in a half cross-sectioned solder joint. SnAgCu shows higher resistance against electromigration than eutectic SnPb. In the half cross-sectioned solder joint, void growth is the dominant failure mechanism. However, the whole solder balls in the underfill show that the failure mechanism is a result from the dissolution of electroless Ni under bump metallization (UBM) of about 10 mum thickness. The growth rate between intermetallic compounds in molten and solid solders differed by four orders of magnitude. In liquid solder, the growth rate is about 1 mum/min; the growth rate in solid solder is only about 10 -4 mum/min. The difference is not resulting from factors of thermodynamics, which is the change of Gibbs free energy before and after intermetallic compound formation, but from kinetic factors, which is the rate of change of Gibbs free energy. Even though the difference in growth rate between eutectic SnPb and Pb-free solders during solid state aging was found, the reason behind such difference shown is unclear. The orientation and stress levels of whiskers are measured by white X-ray of synchrotron radiation. The growth direction is nearly parallel to one of the principal axes of tin. The compressive stress level is quite low because the residual stress is relaxed by the whisker growth.

  18. Ultrasonic welding for fast bonding of self-aligned structures in lab-on-a-chip systems

    DEFF Research Database (Denmark)

    Kistrup, Kasper; Poulsen, Carl Esben; Hansen, Mikkel Fougt

    2015-01-01

    Ultrasonic welding is a rapid, promising bonding method for the bonding of polymer chips; yet its use is still limited. We present two lab-on-a-chip applications where ultrasonic welding can be preferably applied: (1) Self-aligned gapless bonding of a two-part chip with a tolerance of 50 um; (2......) bonding of a large area shallow chamber (1.8 cm^2 X 150 um). Using injection moulding combined with ultrasonic welding we achieved a total production and bonding time of 60 s per chip, and a batch of chips could be produced within a day going from design to finished chips. We believe that the technical...

  19. Integração de microssensores a microlaboratórios autônomos através de técnicas de montagem por viragem (Flip-Chip).

    OpenAIRE

    Valtemar Fernandes Cardoso

    2014-01-01

    Neste trabalho é apresentada a análise de técnicas para a integração de ISFETs (Ion Selective Field Effect Transitors), através do método de montagem por viragem (Flip-chip) usando pasta de solda livre de chumbo e epóxi condutivo de prata, com o objetivo de permitir sua aplicação em Microssistemas de Análise Total (µTAS). Para os testes de integração foram construídas estruturas em dois substratos, o FR-4, pelo método de ligação por fios (wire bonding), e o LTCC, que pode ser aplicado na cons...

  20. 倒装芯片互连结构中电流聚集研究%Research on the current crowding in flip chip joint

    Institute of Scientific and Technical Information of China (English)

    刘培生; 杨龙龙; 卢颖; 刘亚鸿

    2015-01-01

    Electro-migration becomes a critical reliability issue for high density solder joints in flip chip technology, especially for current crowding. Electro-migration force and mean time to failure of flip chip were analyzed. This study employed two-dimensional simulation to investigate the distribution of current density and Joule heat in the flip chip joint. And the factors that impact the distribution of current density and Joule heat were studied. The results show that the thicknesses of Al and UBM have great influences on the distribution of current density and Joule heat.%由于电流聚集,在倒装芯片封装技术中,电迁移已经成为一个关键的可靠性问题。分析了电迁移力和电迁移中值失效时间,采用二维模型研究了电流密度和焦耳热在倒装芯片互连结构中的分布以及影响电流密度和焦耳热分布的因素。结果表明铝线(Al)和凸点下金属层(UBM)的厚度对电流密度和焦耳热分布有很大的影响。

  1. Impact of Isothermal Aging and Testing Temperature on Large Flip-Chip BGA Interconnect Mechanical Shock Performance

    Science.gov (United States)

    Lee, Tae-Kyu; Chen, Zhiqiang; Guirguis, Cherif; Akinade, Kola

    2017-10-01

    The stability of solder interconnects in a mechanical shock environment is crucial for large body size flip-chip ball grid array (FCBGA) electronic packages. Additionally, the junction temperature increases with higher electric power condition, which brings the component into an elevated temperature environment, thus introducing another consideration factor for mechanical stability of interconnection joints. Since most of the shock performance data available were produced at room temperature, the effect of elevated temperature is of interest to ensure the reliability of the device in a mechanical shock environment. To achieve a stable␣interconnect in a dynamic shock environment, the interconnections must tolerate mechanical strain, which is induced by the shock wave input and reaches the particular component interconnect joint. In this study, large body size (52.5 × 52.5 mm2) FCBGA components assembled on 2.4-mm-thick boards were tested with various isothermal pre-conditions and testing conditions. With a heating element embedded in the test board, a test temperature range from room temperature to 100°C was established. The effects of elevated temperature on mechanical shock performance were investigated. Failure and degradation mechanisms are identified and discussed based on the microstructure evolution and grain structure transformations.

  2. Impact of Isothermal Aging and Testing Temperature on Large Flip-Chip BGA Interconnect Mechanical Shock Performance

    Science.gov (United States)

    Lee, Tae-Kyu; Chen, Zhiqiang; Guirguis, Cherif; Akinade, Kola

    2017-06-01

    The stability of solder interconnects in a mechanical shock environment is crucial for large body size flip-chip ball grid array (FCBGA) electronic packages. Additionally, the junction temperature increases with higher electric power condition, which brings the component into an elevated temperature environment, thus introducing another consideration factor for mechanical stability of interconnection joints. Since most of the shock performance data available were produced at room temperature, the effect of elevated temperature is of interest to ensure the reliability of the device in a mechanical shock environment. To achieve a stable interconnect in a dynamic shock environment, the interconnections must tolerate mechanical strain, which is induced by the shock wave input and reaches the particular component interconnect joint. In this study, large body size (52.5 × 52.5 mm2) FCBGA components assembled on 2.4-mm-thick boards were tested with various isothermal pre-conditions and testing conditions. With a heating element embedded in the test board, a test temperature range from room temperature to 100°C was established. The effects of elevated temperature on mechanical shock performance were investigated. Failure and degradation mechanisms are identified and discussed based on the microstructure evolution and grain structure transformations.

  3. Inverted tetrahedron-pyramidal micropatterned polymer films for boosting light output power in flip-chip light-emitting diodes.

    Science.gov (United States)

    Leem, Jung Woo; Lee, Soo Hyun; Guan, Xiang-Yu; Yu, Jae Su

    2015-04-20

    We report the improved light output power in gallium nitride-based green flip-chip light-emitting diodes (FCLEDs) employed with inverted tetrahedron-pyramidal micropatterned polydimethylsiloxane (ITPM PDMS) films as an encapsulation and protection layer. The micropatterns are transferred into the surface of PDMS films from the sapphire substrate master molds with two-dimensional periodic hexagonal TPM arrays by a soft imprint lithography method. The ITPM PDMS film laminated on the sapphire dramatically enhances the diffuse transmittance (T(D)) in a wavelength (λ) range of 400-650 nm, exhibiting the larger T(D) value of ~53% at λ = 525 nm, (cf., T(D) ~1% for planar sapphire). By introducing the ITPM PDMS film on the outer surface of sapphire in FCLEDs, the light output power is enhanced, indicating the increment percentage of ~11.1% at 500 mA of injection current compared to the reference FCLED without the ITPM PDMS film, together with better electroluminescence intensity and far-field radiation pattern.

  4. Chip bonding of low-melting eutectic alloys by transmitted laser radiation

    Science.gov (United States)

    Hoff, Christian; Venkatesh, Arjun; Schneider, Friedrich; Hermsdorf, Jörg; Bengsch, Sebastian; Wurz, Marc C.; Kaierle, Stefan; Overmeyer, Ludger

    2017-06-01

    Present-day thermode bond systems for the assembly of radio-frequency identification (RFID) chips are mechanically inflexible, difficult to control, and will not meet future manufacturing challenges sufficiently. Chip bonding, one of the key processes in the production of integrated circuits (ICs), has a high potential for optimization with respect to process duration and process flexibility. For this purpose, the technologies used, so far, are supposed to be replaced by a transmission laser-bonding process using low-melting eutectic alloys. In this study, successful bonding investigations of mock silicon chips and of RFID chips on flexible polymer substrates are presented using the low-melting eutectic alloy, 52In48Sn, and a laser with a wavelength of 2 μm.

  5. Bump bonding of pixel systems

    Energy Technology Data Exchange (ETDEWEB)

    Lozano, M. E-mail: manuel.lozano@cnm.es; Cabruja, E.; Collado, A.; Santander, J.; Ullan, M

    2001-11-01

    A pixel detector consists of an array of radiation sensing elements which is connected to an electronic read-out unit. Many different ways of making this connection between these two different devices are currently being used or considered to be used in the next future. Bonding techniques such as flip chip technology can present real advantages because they allow very fine pitch and a high number of I/Os. This paper presents a review of the different flip chip technologies available and their suitability for manufacturing pixel detectors. The particular problems concerning testing of pixel detectors and thermal issues related to them are pointed out.

  6. Bump bonding of pixel systems

    CERN Document Server

    Lozano, M; Collado, A; Santander, J; Ullán, M

    2001-01-01

    A pixel detector consists of an array of radiation sensing elements which is connected to an electronic read-out unit. Many different ways of making this connection between these two different devices are currently being used or considered to be used in the next future. Bonding techniques such as flip chip technology can present real advantages because they allow very fine pitch and a high number of I/Os. This paper presents a review of the different flip chip technologies available and their suitability for manufacturing pixel detectors. The particular problems concerning testing of pixel detectors and thermal issues related to them are pointed out.

  7. Nanofluidic chip for liquid TEM cell fabricated by parylene and silicon nitride direct bonding

    Science.gov (United States)

    Jang, Heejun; Kang, Il-Suk; Kim, Jihye; Kim, Jonghyun; Cha, Yun Jeong; Yoon, Dong Ki; Lee, Wonhee

    2017-09-01

    Despite the importance of nanofluidic transmission electron microscope (TEM) chips, a simple fabrication method has yet to be developed due to the difficulty of wafer bonding techniques using a nanoscale thick bonding layer. We present a simple and robust wafer scale bonding technique using parylene as a bonding layer. A nanoscale thick parylene layer was deposited on a silicon nitride (SiN) wafer and patterned to construct nanofluidic channels. The patterned parylene layer was directly bonded to another SiN wafer by thermal surface activation and bonding, with a bonding strength of ˜3 MPa. Fourier transform infrared spectroscopy showed that carbon-oxygen bonds were generated by thermal activation. We demonstrated TEM imaging of gold nanoparticles suspended in liquid using the fabricated nanofluidic chip.

  8. High performance low cost interconnections for flip chip attachment with electrically conductive adhesive. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    This final report is a compilation of final reports from each of the groups participating in the program. The main three groups involved in this effort are the Thomas J. Watson Research Center of IBM Corporation in Yorktown Heights, New York, Assembly Process Design of IBM Corporation in Endicott, New York, and SMT Laboratory of Universal Instruments Corporation in Binghamton, New York. The group at the research center focused on the conductive adhesive materials development and characterization. The group in process development focused on processing of the Polymer-Metal-Solvent Paste (PMSP) to form conductive adhesive bumps, formation of the Polymer-Metal Composite (PMC) on semiconductor devices and study of the bonding process to circuitized organic carriers, and the long term durability and reliability of joints formed using the process. The group at Universal Instruments focused on development of an equipment set and bonding parameters for the equipment to produce bond assembly tooling. Reports of each of these individual groups are presented here reviewing their technical efforts and achievements.

  9. Output power enhancement of GaN-based flip-chip light-emitting diodes via conical structures generated by a monolayer of nanospheres

    Science.gov (United States)

    Liu, Mai-Chih; Lin, Chang-Rong; Chan, Chia-Hua

    2016-11-01

    This letter describes the output power enhancement of the GaN-based flip-chip light-emitting diodes (FC LED) featuring conical structures fabricated by etching a self-assembled monolayer SiO2 spheres as the hard mask. By roughening the surface of FC LED components, it increases structural size of the components and elevates the light extraction efficiency of FC LED. At a constant current of 400 mA, the output power of the FC LED with 1200 nm conical structures is 638.1 mW and enhanced by 6.1% compared with the FC LED without surface roughening.

  10. Material development of polymer/metal paste for flip-chip attach interconnection technology. Quarterly report

    Energy Technology Data Exchange (ETDEWEB)

    Saraf, R.F.; Roldan, J.M.; Sambucetti, C.J.

    1997-11-04

    In the last leg of the project the major thrust has been on the assembly process using the conductive adhesive, viz., the optimization of the process conditions and the bonding equipment. The past at this point is deemed optimum in terms of the three basic properties: adhesion, screenability and conductivity. The reliability and wafer level screening is proven reproducibly over several experiment constituting assembly of more than one part. Using the optimum paste the authors have provided an uninterrupted supply of reproducible (optimum) paste. By tweaking the compounding conditions a first-level scale-up was successfully achieved. The initial 30g batch to Endicott is increased to as high as 300 g batches with similar properties. The large batch material is shown to behave similar to the small batch materials. Also, it has been essential to do large wafer level studies: Endicott has scaled up their screening from 5 inch wafer to 8 inch wafer.

  11. Ultrasonic welding for fast bonding of self-aligned structures in lab-on-a-chip systems.

    Science.gov (United States)

    Kistrup, K; Poulsen, C E; Hansen, M F; Wolff, A

    2015-05-07

    Ultrasonic welding is a rapid, promising bonding method for the bonding of polymer chips; yet its use is still limited. We present two lab-on-a-chip applications where ultrasonic welding can be preferably applied: (1) self-aligned gapless bonding of a two-part chip with a tolerance of 50 μm; (2) bonding of a large area shallow chamber (1.8 cm(2) × 150 μm). Using injection moulding combined with ultrasonic welding we achieved a total production and bonding time of 60 s per chip, and a batch of chips could be produced within a day going from design to finished chips. We believe that the technical solutions offered here can significantly help bridge the gap between academia and industry, where the differences in production methods and materials pose a challenge when transferring technology.

  12. Analysis of the light-extraction efficiency of SiC substrate-based flip-chip vertical light-emitting diodes with embedded photonic crystals

    Science.gov (United States)

    Liu, Meng; Li, Kang; Kong, Fan-min; Zhao, Jia; Zhao, Shu-long; Meng, Hao-tian

    2016-11-01

    To improve the light-extraction efficiency (LEE) of flip-chip vertical light-emitting diodes (LEDs) grown on silicon carbide (SiC) substrate, embedded photonic crystals (PhCs) were alternatively introduced into the n-GaN layer of LEDs, since etching of the SiC substrate was very difficult. The finite-difference time-domain (FDTD) method was employed to investigate the combination effects of the micro-cavity and the embedded PhCs. The influences of the PhCs configurations on the LEE of LEDs were also examined to get an optimal structure. With the optimized parameters, about 20% enhancement of LEE was achieved comparing to planar SiC substrate-based flip-chip vertical LEDs. The LEE of conventional surface PhCs LEDs and double layer PhCs LEDs were also investigated for comparison. The results indicated that LEDs with carefully designed embedded PhCs could provide more LEE than surface PhCs LEDs. The structures proposed here offered scopes for the design of high-efficiency, high-power LEDs.

  13. Microstructural Coarsening during Thermomechanical Fatigue and Annealing of Micro Flip-Chip Solder Joints

    Energy Technology Data Exchange (ETDEWEB)

    Barney, Monica Michele [Univ. of California, Berkeley, CA (United States)

    1998-12-01

    Microstructural evolution due to thermal effects was studied in micro solder joints (55 ± 5 μm). The composition of the Sn/Pb solder studied was found to be hypereutectic with a tin content of 65-70 wt%.This was determined by Energy Dispersive X-ray analysis and confirmed with quantitative stereology. The quantitative stereological value of the surface-to-volume ratio was used to characterize and compare the coarsening during thermal cycling from 0-160 C to the coarsening during annealing at 160 C. The initial coarsening of the annealed samples was more rapid than the cycled samples, but tapered off as time to the one-half as expected. Because the substrates to which the solder was bonded have different thermal expansion coefficients, the cycled samples experienced a mechanical strain with thermal cycling. The low-strain cycled samples had a 2.8% strain imposed on the solder and failed by 1,000 cycles, despite undergoing less coarsening than the annealed samples. The high-strain cycled samples experienced a 28% strain and failed between 25 and 250 cycles. No failures were observed in the annealed samples. Failure mechanisms and processing issues unique to small, fine pitch joints are also discussed.

  14. [Paste deposition and chip bonding process development]. IBM, Endicott tenth quarterly report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    The scope of Endicott activity during this quarter includes: paste deposition process development and chip bonding process development. It was discovered that small voids exist in the photobumps. These are typically at the base of the bump and are believed to have always been present. Although the reliability test results have been positive and no failure is attributed to voids, the process development work during the last quarter has focused on understanding how these form and how to reduce them. High feed pressure, slow nozzle speed and lower viscosity reduce void formation. Nozzle design changes have been identified. One change will increase the shearing of the paste during feed, thus reducing the viscosity, a second change will allow higher feed pressures. Chip bonding process development has focused on correlating bonding results between the IBM in-house chip bonder made by Research Devices, Inc. and the Universal development bond tool. Two variables have been identified that correlate with poor bond results. The report describes more detail of the activity during the tenth quarter for paste deposition and chip bonding in each of these areas.

  15. Nanoneedles based on porous silicon for chip bonding with self assembly capability

    Energy Technology Data Exchange (ETDEWEB)

    Jonnalagadda, Prasad; Mescheder, Ulrich; Kovacs, Andras; Nimoe, Antwi [Institute for Applied Research and Faculty Computer and Electrical Engineering, Hochschule Furtwangen University, Robert-Gerwig-Platz 1, 78120 Furtwangen (Germany)

    2011-06-15

    Needle-like surface structures have been fabricated using a self-organized nanostructuring process based on porous silicon. Optimized surfaces have been used for a novel bonding process in Si-MEMS. The realized needle-like surfaces enable Van-der-Waals based bonding at low temperature with self-assembly capability. The bonding forces depend on the surface topology and can be tailored by the nanostructuring process between permanent and detachable bonding. Bond strength for permanent bonding in the range of 1-10 MPa has been achieved. Multiple bonding of the same surface is possible (Velcro {sup registered} -principle). The capability of needle like surfaces for self aligned bonding of Si-chips or small silicon based systems (''smart dust'') on locally nanostructured areas of silicon wafers (Si-motherboard) has been shown. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Thermal Characteristics of InGaN/GaN Flip-Chip Light Emitting Diodes with Diamond-Like Carbon Heat-Spreading Layers

    Directory of Open Access Journals (Sweden)

    Pai-Yang Tsai

    2014-01-01

    Full Text Available The temperature-dependent optical, electrical, and thermal properties of flip-chip light emitting diodes (FCLEDs with diamond-like carbon (DLC heat-spreading layers were investigated. On the basis of the measured results in the 20°C to 100°C temperature range, a significant performance improvement can be achieved for FCLEDs with DLC heat-spreading layers (DLC-FCLED compared with FCLEDs without DLC heat-spreading layers (non-DLC-FCLED. The external quantum efficiency (EQE of the DLC-FCLED improves by 9% at an injection current of 1000 mA and a temperature of 100°C. The forward voltage and spectra variations are smaller than those of non-DLC-FCLEDs. The DLC-FCLED provides high efficiency and high stability performance for high-power and high-temperature applications.

  17. Flipped Learning

    DEFF Research Database (Denmark)

    Holmboe, Peter; Hachmann, Roland

    I FLIPPED LEARNING – FLIP MED VIDEO kan du læse om, hvordan du som underviser kommer godt i gang med at implementere video i undervisning, der har afsæt i tankerne omkring flipped learning. Bogen indeholder fire dele: I Del 1 fokuserer vi på det metarefleksive i at tænke video ind i undervisningen...

  18. Discrete component bonding and thick film materials study. [of capacitor chips bonded with solders and conductive epoxies

    Science.gov (United States)

    Kinser, D. L.

    1976-01-01

    The bonding reliability of discrete capacitor chips bonded with solders and conductive epoxies was examined along with the thick film resistor materials consisting of iron oxide phosphate and vanadium oxide phosphates. It was concluded from the bonding reliability studies that none of the wide range of types of solders examined is capable of resisting failure during thermal cycling while the conductive epoxy gives substantially lower failure rates. The thick film resistor studies proved the feasibility of iron oxide phosphate resistor systems although some environmental sensitivity problems remain. One of these resistor compositions has inadvertently proven to be a candidate for thermistor applications because of the excellent control achieved upon the temperature coefficient of resistance. One new and potentially damaging phenomenon observed was the degradation of thick film conductors during the course of thermal cycling.

  19. New IC package, assembly technique by means of a "blind" alignment "flip-chip" method and assembling facilities

    Institute of Scientific and Technical Information of China (English)

    Vladimir V. Novikov

    2004-01-01

    @@ In spite of a long period of the development ofmicroelectronic components base, the problem of the creation of IC package design, providing minimal area losses in contrast with area of a chip, remains unsolved [1]Area losses can be described by the parameter P,which is equal to the ratio between the package area in plan and the chip area:

  20. Flexible packaging of solid-state integrated circuit chips with elastomeric microfluidics

    OpenAIRE

    Bowei Zhang; Quan Dong; Korman, Can E.; Zhenyu Li; Zaghloul, Mona E.

    2013-01-01

    A flexible technology is proposed to integrate smart electronics and microfluidics all embedded in an elastomer package. The microfluidic channels are used to deliver both liquid samples and liquid metals to the integrated circuits (ICs). The liquid metals are used to realize electrical interconnects to the IC chip. This avoids the traditional IC packaging challenges, such as wire-bonding and flip-chip bonding, which are not compatible with current microfluidic technologies. As a demonstratio...

  1. Two-Step Plasma Process for Cleaning Indium Bonding Bumps

    Science.gov (United States)

    Greer, Harold F.; Vasquez, Richard P.; Jones, Todd J.; Hoenk, Michael E.; Dickie, Matthew R.; Nikzad, Shouleh

    2009-01-01

    A two-step plasma process has been developed as a means of removing surface oxide layers from indium bumps used in flip-chip hybridization (bump bonding) of integrated circuits. The two-step plasma process makes it possible to remove surface indium oxide, without incurring the adverse effects of the acid etching process.

  2. An ultra-small, low-power, all-optical flip-flop memory on a silicon chip

    DEFF Research Database (Denmark)

    Liu, Liu; Kumar, R.; Huybrechts, K.

    2010-01-01

    Ultra-small, low-power, all-optical switching and memory elements, such as all-optical flip-flops, as well as photonic integrated circuits of many such elements, are in great demand for all-optical signal buffering, switching and processing. Silicon-on-insulator is considered to be a promising......-flop working in a continuous-wave regime with an electrical power consumption of a few milliwatts, allowing switching in 60 ps with 1.8 fJ optical energy. The total power consumption and the device size are, to the best of our knowledge, the smallest reported to date at telecom wavelengths. This is also...

  3. Rapid fabrication of a four-layer PMMA-based microfluidic chip using CO2-laser micromachining and thermal bonding

    Science.gov (United States)

    Chen, Xueye; Shen, Jienan; Zhou, Mengde

    2016-10-01

    A smart design method to transform the original two-layer microfluidic chip into a four-layer 3D microfluidic chip is proposed. A novel fabrication method is established to rapidly and effectively produce a four-layer microfluidic chip device made entirely from polymethylmethacrylate (PMMA). Firstly, the CO2-laser cuts the PMMA sheets by melting and blowing away vaporized material from the parent material to obtain high-quality channels of the microfluidic chip. An orthogonal experimental method is used to study its processing stability. In addition, a simple, rapid thermal bonding technique is successfully applied in fabricating the four-layer microfluidic chip, which has a bond strength of 1.3 MPa. A wooden pole is used to improve the accuracy of the alignment. Finally, a mixing experiment with blue ink and water is carried out, which proves that this smart design method and rapid manufacturing technology are successful.

  4. Flipped Learning

    DEFF Research Database (Denmark)

    Hachmann, Roland; Holmboe, Peter

    arbejde med faglige problemstillinger gennem problembaserede og undersøgende didaktiske designs. Flipped Learning er dermed andet og mere end at distribuere digitale materialer til eleverne forud for undervisning. Flipped Learning er i lige så høj grad et syn på, hvordan undervisning med digitale medier...

  5. Decoupling contact and mirror: an effective way to improve the reflector for flip-chip InGaN/GaN-based light-emitting diodes

    Science.gov (United States)

    Zhu, Binbin; Liu, Wei; Lu, Shunpeng; Zhang, Yiping; Hasanov, Namig; Zhang, Xueliang; Ji, Yun; Zhang, Zi-Hui; Tiam Tan, Swee; Liu, Hongfei; Demir, Hilmi Volkan

    2016-07-01

    In the conventional fabrication process of the widely-adopted Ni/Ag/Ti/Au reflector for InGaN/GaN-based flip-chip light-emitting diodes (LEDs), the contact and the mirror are entangled together with contrary processing conditions which set constraints to the device performance severely. Here we first report the concept and its effectiveness of decoupling the contact formation and the mirror construction. The ohmic contact is first formed by depositing and annealing an extremely thin layer of Ni/Ag on top of p-GaN. The mirror construction is then carried out by depositing thick layer of Ag/Ti/Au without any annealing. Compared with the conventional fabrication method of the reflector, by which the whole stack of Ni/Ag/Ti/Au is deposited and annealed together, the optical output power is improved by more than 70% at 350 mA without compromising the electrical performance. The mechanism of decoupling the contact and the mirror is analyzed with the assistance of contactless sheet resistance measurement and secondary ion mass spectrometry (SIMS) depth profile analysis.

  6. Modification of internal quantum efficiency and efficiency droop in GaN-based flip-chip light-emitting diodes via the Purcell effect.

    Science.gov (United States)

    Ryu, Han-Youl

    2015-09-21

    The Purcell effect in GaN-based flip-chip (FC) light-emitting diode (LED) structures is investigated numerically using finite-difference time-domain simulations. Depending on the thickness of the p-GaN layer, the variation of the Purcell factor of FC LEDs is obtained to be as high as 20%, which results in the relative modification of the internal quantum efficiency (IQE) as large as 8% and 2.5% for the unmodified IQE of 0.4 and 0.8, respectively. Since the influence of the Purcell effect becomes more conspicuous as the IQE decreases, the Purcell enhancement can be advantageously used to mitigate the efficiency droop problem to some extent. When the Purcell effect is positively applied to the blue LED with the peak IQE of 0.8 and the droop ratio of 29.1%, the peak IQE and the droop ratio are found to be improved to 0.82 and 26.3%. This small but non-negligible effect on IQE is expected to be importantly adopted for industry development of high efficiency LEDs.

  7. Performance Improvement of GaN-Based Flip-Chip White Light-Emitting Diodes with Diffused Nanorod Reflector and with ZnO Nanorod Antireflection Layer

    Directory of Open Access Journals (Sweden)

    Hsin-Ying Lee

    2014-01-01

    Full Text Available The GaN-based flip-chip white light-emitting diodes (FCWLEDs with diffused ZnO nanorod reflector and with ZnO nanorod antireflection layer were fabricated. The ZnO nanorod array grown using an aqueous solution method was combined with Al metal to form the diffused ZnO nanorod reflector. It could avoid the blue light emitted out from the Mg-doped GaN layer of the FCWLEDs, which caused more blue light emitted out from the sapphire substrate to pump the phosphor. Moreover, the ZnO nanorod array was utilized as the antireflection layer of the FCWLEDs to reduce the total reflection loss. The light output power and the phosphor conversion efficiency of the FCWLEDs with diffused nanorod reflector and 250 nm long ZnO nanorod antireflection layer were improved from 21.15 mW to 23.90 mW and from 77.6% to 80.1% in comparison with the FCWLEDs with diffused nanorod reflector and without ZnO nanorod antireflection layer, respectively.

  8. Comparison of Sn-Ag-Cu Solder Alloy Intermetallic Compound Growth Under Different Thermal Excursions for Fine-Pitch Flip-Chip Assemblies

    Science.gov (United States)

    Tian, Ye; Liu, Xi; Chow, Justin; Wu, Yi Ping; Sitaraman, Suresh K.

    2013-08-01

    The intermetallic compound (IMC) evolution in Cu pad/Sn-Ag-Cu solder interface and Sn-Ag-Cu solder/Ni pad interface was investigated using thermal shock experiments with 100- μm-pitch flip-chip assemblies. The experiments show that low standoff height of solder joints and high thermomechanical stress play a great role in the interfacial IMC microstructure evolution under thermal shock, and strong cross-reaction of pad metallurgies is evident in the intermetallic growth. Furthermore, by comparing the IMC growth during thermal aging and thermal shock, it was found that thermal shock accelerates IMC growth and that kinetic models based on thermal aging experiments underpredict IMC growth in thermal shock experiments. Therefore, new diffusion kinetic parameters were determined for the growth of (Cu,Ni)6Sn5 using thermal shock experiments, and the Cu diffusion coefficient through the IMC layer was calculated to be 0.2028 μm2/h under thermal shock. Finite-element models also show that the solder stresses are higher under thermal shock, which could explain why the IMC growth is faster and greater under thermal shock cycling as opposed to thermal aging.

  9. Improvement of Light Extraction Efficiency in Flip-Chip Light Emitting Diodes on SiC Substrate via Transparent Haze Films with Morphology-Controlled Collapsed Alumina Nanorods.

    Science.gov (United States)

    Baek, Seunghwa; Kang, Gumin; Shin, Dongheok; Bae, Kyuyoung; Kim, Yong Hyun; Kim, Kyoungsik

    2016-01-13

    We demonstrate GaN-based flip-chip light emitting diodes (FC-LEDs) on SiC substrate achieving high extraction efficiency by simply attaching the optically transparent haze films consisting of collapsed alumina nanorods. Through controlled etching time of alumina nanorods, we obtain four types of films that have different morphologies with different optical transmittance and haze properties. We show that the light output power of the FC-LEDs with film, which has 95.6% transmittance and 62.7% haze, increases by 20.4% in comparison to the bare LEDs. The angular radiation pattern of the LEDs also follows the Lambertian emission pattern without deteriorating the electrical properties of the device. The improvement of light extraction is mainly attributed to the reduced total internal reflection (TIR) via efficient out-coupling of guided light from SiC substrate to air by collapsed alumina nanorod structures in the film. The high transparency of film and reduced Fresnel reflection via graded refractive index transition between the film and SiC substrate also contribute to the extraction enhancement of the device. We systematically investigate the influence of haze film's geometrical or optical properties on the extraction efficiency of FC-LEDs, and this study will provide a novel approach to enhance the performance of various optoelectronic devices.

  10. Thin film metal sensors in fusion bonded glass chips for high-pressure microfluidics

    Science.gov (United States)

    Andersson, Martin; Ek, Johan; Hedman, Ludvig; Johansson, Fredrik; Sehlstedt, Viktor; Stocklassa, Jesper; Snögren, Pär; Pettersson, Victor; Larsson, Jonas; Vizuete, Olivier; Hjort, Klas; Klintberg, Lena

    2017-01-01

    High-pressure microfluidics offers fast analyses of thermodynamic parameters for compressed process solvents. However, microfluidic platforms handling highly compressible supercritical CO2 are difficult to control, and on-chip sensing would offer added control of the devices. Therefore, there is a need to integrate sensors into highly pressure tolerant glass chips. In this paper, thin film Pt sensors were embedded in shallow etched trenches in a glass wafer that was bonded with another glass wafer having microfluidic channels. The devices having sensors integrated into the flow channels sustained pressures up to 220 bar, typical for the operation of supercritical CO2. No leakage from the devices could be found. Integrated temperature sensors were capable of measuring local decompression cooling effects and integrated calorimetric sensors measured flow velocities over the range 0.5-13.8 mm s-1. By this, a better control of high-pressure microfluidic platforms has been achieved.

  11. Photoelastic Measurement of Strain Induced by Die-Bonding of GaAs Chip on a Copper Heatsink Plate

    Science.gov (United States)

    Chu, Tao; Yamada, Masayoshi

    1999-02-01

    Die-bonding-induced strain in a GaAs chip bonded on a copper heatsink plate has been measured with a reflection type of infrared polariscope.The spatial distributions of bonding-induced strain were seen to vary from sample to sample.The maximum value of the bonding-induced strain was found to be of the order of 10-4, which corresponded to about 1/10 of that estimated from the thermal expansion difference for the unit length between GaAs and copper when it was cooled down from the die-bonding temperature to the room temperature.

  12. Comparison of Ultrasonic Welding and Thermal Bonding for the Integration of Thin Film Metal Electrodes in Injection Molded Polymeric Lab-on-Chip Systems for Electrochemistry

    DEFF Research Database (Denmark)

    Matteucci, Marco; Heiskanen, Arto; Zor, Kinga

    2016-01-01

    We compare ultrasonic welding (UW) and thermal bonding (TB) for the integration of embedded thin-film gold electrodes for electrochemical applications in injection molded (IM) microfluidic chips. The UW bonded chips showed a significantly superior electrochemical performance compared to the ones ...

  13. PMMA to SU-8 bonding for polymer based lab-on-a-chip systems with integrated optics

    DEFF Research Database (Denmark)

    Olsen, Brian Bilenberg; Nielsen, Theodor; Clausen, Bjarne Hans

    2004-01-01

    We present an adhesive bonding technique developed for SU-8 based "lab-on-a-chip"- systems with integrated optical components. Microfluidic channels and optical components (e.g. wave-guides) are defined in SU-8 photoresist on a Pyrex glass substrate. The microfluidic channels are sealed by a second...

  14. PMMA to SU-8 Bonding for Polymer Based Lab-on -a-chip Systems with Integrated Optics

    DEFF Research Database (Denmark)

    Clausen, Bjarne

    2003-01-01

    An adhesive bonding technique for wafer-level sealing of SU-8 based lab-on-a-chip microsystems with integrated optical components is presented. Microfluidic channels and optical components, e.g. waveguides, are fabricated in cross-linked SU-8 and sealed with a Pyrex glass substrate by means...

  15. Flipped Physics

    Science.gov (United States)

    Kettle, Maria

    2013-01-01

    This paper defines flipped learning and then examines its practical implementation in AS and A2 level physics classes, that is, classes for 16-18 year olds. The effect of this teaching style on student learning behaviour and its impact on test results are evaluated. The paper recounts the difficulties of implementing it and evaluates student…

  16. Flipped Physics

    Science.gov (United States)

    Kettle, Maria

    2013-01-01

    This paper defines flipped learning and then examines its practical implementation in AS and A2 level physics classes, that is, classes for 16-18 year olds. The effect of this teaching style on student learning behaviour and its impact on test results are evaluated. The paper recounts the difficulties of implementing it and evaluates student…

  17. Embeded photonic crystal at the interface of p-GaN and Ag reflector to improve light extraction of GaN-based flip-chip light-emitting diode

    Energy Technology Data Exchange (ETDEWEB)

    Zhen, Aigong; Ma, Ping, E-mail: maping@semi.ac.cn; Zhang, Yonghui; Guo, Enqing; Tian, Yingdong; Liu, Boting; Guo, Shikuan; Shan, Liang; Wang, Junxi; Li, Jinmin [Semiconductor Lighting R and D Center, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)

    2014-12-22

    In this experiment, a flip-chip light-emitting diode with photonic crystal was fabricated at the interface of p-GaN and Ag reflector via nanospheres lithography technique. In this structure, photonic crystal could couple with the guide-light efficiently by reason of the little distance between photonic crystal and active region. The light output power of light emitting diode with embedded photonic crystal was 1.42 times larger than that of planar flip-chip light-emitting diode. Moreover, the embedded photonic crystal structure makes the far-field divergence angle decreased by 18° without spectra shift. The three-dimensional finite difference time domain simulation results show that photonic crystal could improve the light extraction, and enhance the light absorption caused by Ag reflector simultaneously, because of the roughed surface. The depth of photonic crystal is the key parameter affecting the light extraction and absorption. Light extraction efficiency increases with the depth photonic crystal structure rapidly, and reaches the maximum at the depth 80 nm, beyond which light extraction decrease drastically.

  18. Marvels of enzyme catalysis at true atomic resolution: distortions, bond elongations, hidden flips, protonation states and atom identities.

    Science.gov (United States)

    Neumann, Piotr; Tittmann, Kai

    2014-12-01

    Although general principles of enzyme catalysis are fairly well understood nowadays, many important details of how exactly the substrate is bound and processed in an enzyme remain often invisible and as such elusive. In fortunate cases, structural analysis of enzymes can be accomplished at true atomic resolution thus making possible to shed light on otherwise concealed fine-structural traits of bound substrates, intermediates, cofactors and protein groups. We highlight recent structural studies of enzymes using ultrahigh-resolution X-ray protein crystallography showcasing its enormous potential as a tool in the elucidation of enzymatic mechanisms and in unveiling fundamental principles of enzyme catalysis. We discuss the observation of seemingly hyper-reactive, physically distorted cofactors and intermediates with elongated scissile substrate bonds, the detection of 'hidden' conformational and chemical equilibria and the analysis of protonation states with surprising findings. In delicate cases, atomic resolution is required to unambiguously disclose the identity of atoms as demonstrated for the metal cluster in nitrogenase. In addition to the pivotal structural findings and the implications for our understanding of enzyme catalysis, we further provide a practical framework for resolution enhancement through optimized data acquisition and processing.

  19. 一种数字微镜器件的倒装封装设计%Design of the Flip-Chip Package for Digital Micromirror Devices

    Institute of Scientific and Technical Information of China (English)

    李中楠; 王淑仙

    2012-01-01

    数字微镜器件是由MEMS工艺制成的数字式光反射开关阵列组成,其I/O管脚工作频率高达800 MHz.针对数字微镜器件的对光电两方面性能的严格要求,设计了一种数字微镜器件的封装结构.首先选择倒装封装技术来减小寄生参数,提高器件响应速度;其次优化了板层结构,采用玻璃基底和遮光层来满足光学要求;最后通过对信号完整性和电源完整性问题的仿真设计,满足了电学性能要求,完善了封装基板设计流程.对制作出的微镜器件封装进行测试,在800 MHz的数据频率下,眼图结果与仿真结果较为吻合,降低了封装对信号完整性的影响,达到封装设计要求的指标.%Digital micromirror device is composed of arrays of fast reflective digital light switches which are made by the MEMS fabrication technology, and the highest frequency of I/O pins can be up to 800 MHz. According to the characteristics of this device, a special package design for the advanced digital micromirror device was proposed. This package used the flip-chip technology for smaller parasitic parameter and higher speed. An optimized package structure which used the glass substrate and light shield was adopted to satisfy the optical requests. An appropriate simulation method for signal integrity and power integrity was adopted to satisfy the electrical requests and improved the substrate design flow. The test for the device which has been produced indicates that the eyediagram tally well with the simulation waveform when the frequency of I/O pins is 800 MHz. It reduces the influence of the package on signal integrity problems and meets the requirement of this design.

  20. Chip-package nano-structured copper and nickel interconnections with metallic and polymeric bonding interfaces

    Science.gov (United States)

    Aggarwal, Ankur

    With the semiconductor industry racing toward a historic transition, nano chips with less than 45 nm features demand I/Os in excess of 20,000 that support computing speed in terabits per second, with multi-core processors aggregately providing highest bandwidth at lowest power. On the other hand, emerging mixed signal systems are driving the need for 3D packaging with embedded active components and ultra-short interconnections. Decreasing I/O pitch together with low cost, high electrical performance and high reliability are the key technological challenges identified by the 2005 International Technology Roadmap for Semiconductors (ITRS). Being able to provide several fold increase in the chip-to-package vertical interconnect density is essential for garnering the true benefits of nanotechnology that will utilize nano-scale devices. Electrical interconnections are multi-functional materials that must also be able to withstand complex, sustained and cyclic thermo-mechanical loads. In addition, the materials must be environmentally-friendly, corrosion resistant, thermally stable over a long time, and resistant to electro-migration. A major challenge is also to develop economic processes that can be integrated into back end of the wafer foundry, i.e. with wafer level packaging. Device-to-system board interconnections are typically accomplished today with either wire bonding or solders. Both of these are incremental and run into either electrical or mechanical barriers as they are extended to higher density of interconnections. Downscaling traditional solder bump interconnect will not satisfy the thermo-mechanical reliability requirements at very fine pitches of the order of 30 microns and less. Alternate interconnection approaches such as compliant interconnects typically require lengthy connections and are therefore limited in terms of electrical properties, although expected to meet the mechanical requirements. A novel chip-package interconnection technology is

  1. Flipping HCI

    Directory of Open Access Journals (Sweden)

    C. Evans

    2016-08-01

    Full Text Available This paper presents the results of two studies involving “flipping the classroom”. Teaching material was delivered via interactive “e-lectures”, allowing face-to-face sessions to focus instead on practice. The e-lectures were designed according to standard usability principles coupled with recent research into the effect of interactivity on learning. The effectiveness of the use of e-lectures was then evaluated using an online survey. The results suggest that students prefer the flexibility offered by e-lectures compared to conventional lectures. The results contribute to our understanding of how this technology fits with face-to-face teaching in the digital age.

  2. Hot embossing and thermal bonding of poly(methyl methacrylate) microfluidic chips using positive temperature coefficient ceramic heater.

    Science.gov (United States)

    Wang, Xia; Zhang, Luyan; Chen, Gang

    2011-11-01

    As a self-regulating heating device, positive temperature coefficient ceramic heater was employed for hot embossing and thermal bonding of poly(methyl methacrylate) microfluidic chip because it supplied constant-temperature heating without electrical control circuits. To emboss a channel plate, a piece of poly(methyl methacrylate) plate was sandwiched between a template and a microscopic glass slide on a positive temperature coefficient ceramic heater. All the assembled components were pressed between two elastic press heads of a spring-driven press while a voltage was applied to the heater for 10 min. Subsequently, the embossed poly(methyl methacrylate) plate bearing negative relief of channel networks was bonded with a piece of poly(methyl methacrylate) cover sheet to obtain a complete microchip using a positive temperature coefficient ceramic heater and a spring-driven press. High quality microfluidic chips fabricated by using the novel embossing/bonding device were successfully applied in the electrophoretic separation of three cations. Positive temperature coefficient ceramic heater indicates great promise for the low-cost production of poly(methyl methacrylate) microchips and should find wide applications in the fabrication of other thermoplastic polymer microfluidic devices.

  3. Self-Assembly of Chip-Size Components with Cavity Structures: High-Precision Alignment and Direct Bonding without Thermal Compression for Hetero Integration

    Directory of Open Access Journals (Sweden)

    Mitsumasa Koyanagi

    2011-02-01

    Full Text Available New surface mounting and packaging technologies, using self-assembly with chips having cavity structures, were investigated for three-dimensional (3D and hetero integration of complementary metal-oxide semiconductors (CMOS and microelectromechanical systems (MEMS. By the surface tension of small droplets of 0.5 wt% hydrogen fluoride (HF aqueous solution, the cavity chips, with a side length of 3 mm, were precisely aligned to hydrophilic bonding regions on the surface of plateaus formed on Si substrates. The plateaus have micro-channels to readily evaporate and fully remove the liquid from the cavities. The average alignment accuracy of the chips with a 1 mm square cavity was found to be 0.4 mm. The alignment accuracy depends, not only on the area of the bonding regions on the substrates and the length of chip periphery without the widths of channels in the plateaus, but also the area wetted by the liquid on the bonding regions. The precisely aligned chips were then directly bonded to the substrates at room temperature without thermal compression, resulting in a high shear bonding strength of more than 10 MPa.

  4. Low-temperature bonding process for the fabrication of hybrid glass-membrane organ-on-a-chip devices

    Science.gov (United States)

    Pocock, Kyall J.; Gao, Xiaofang; Wang, Chenxi; Priest, Craig; Prestidge, Clive A.; Mawatari, Kazuma; Kitamori, Takehiko; Thierry, Benjamin

    2016-10-01

    The integration of microfluidics with living biological systems has paved the way to the exciting concept of "organs-on-a-chip," which aims at the development of advanced in vitro models that replicate the key features of human organs. Glass-based devices have long been utilized in the field of microfluidics but the integration of alternative functional elements within multilayered glass microdevices, such as polymeric membranes, remains a challenge. To this end, we have extended a previously reported approach for the low-temperature bonding of glass devices that enables the integration of a functional polycarbonate porous membrane. The process was initially developed and optimized on specialty low-temperature bonding equipment (μTAS2001, Bondtech, Japan) and subsequently adapted to more widely accessible hot embosser units (EVG520HE Hot Embosser, EVG, Austria). The key aspect of this method is the use of low temperatures compatible with polymeric membranes. Compared to borosilicate glass bonding (650°C) and quartz/fused silica bonding (1050°C) processes, this method maintains the integrity and functionality of the membrane (Tg 150°C for polycarbonate). Leak tests performed showed no damage or loss of integrity of the membrane for up to 150 h, indicating sufficient bond strength for long-term cell culture. A feasibility study confirmed the growth of dense and functional monolayers of Caco-2 cells within 5 days.

  5. In the photograph, one can see the interconnection from one readout chip to the flexible cable realized with ultrasonic wire bonds (25 microns).

    CERN Multimedia

    Saba, A

    2006-01-01

    2 ladders are connected via a multi layer aluminium polyimide flexible cable with a multi chip module containing several custom designed ASICs. The production of the flexible cable was developed and carrier out at CERN. It provides signal and data lines as well as power to the individual readout chipswith a total thickness of only 220 microns. In the photograph, one can see the interconnection from one readout chip to the flexible cable realized with ultrasonic wire bonds (25 microns).

  6. Flexible packaging of solid-state integrated circuit chips with elastomeric microfluidics

    Science.gov (United States)

    Zhang, Bowei; Dong, Quan; Korman, Can E.; Li, Zhenyu; Zaghloul, Mona E.

    2013-01-01

    A flexible technology is proposed to integrate smart electronics and microfluidics all embedded in an elastomer package. The microfluidic channels are used to deliver both liquid samples and liquid metals to the integrated circuits (ICs). The liquid metals are used to realize electrical interconnects to the IC chip. This avoids the traditional IC packaging challenges, such as wire-bonding and flip-chip bonding, which are not compatible with current microfluidic technologies. As a demonstration we integrated a CMOS magnetic sensor chip and associate microfluidic channels on a polydimethylsiloxane (PDMS) substrate that allows precise delivery of small liquid samples to the sensor. Furthermore, the packaged system is fully functional under bending curvature radius of one centimetre and uniaxial strain of 15%. The flexible integration of solid-state ICs with microfluidics enables compact flexible electronic and lab-on-a-chip systems, which hold great potential for wearable health monitoring, point-of-care diagnostics and environmental sensing among many other applications.

  7. Flexible packaging of solid-state integrated circuit chips with elastomeric microfluidics

    Science.gov (United States)

    Zhang, Bowei; Dong, Quan; Korman, Can E.; Li, Zhenyu; Zaghloul, Mona E.

    2013-01-01

    A flexible technology is proposed to integrate smart electronics and microfluidics all embedded in an elastomer package. The microfluidic channels are used to deliver both liquid samples and liquid metals to the integrated circuits (ICs). The liquid metals are used to realize electrical interconnects to the IC chip. This avoids the traditional IC packaging challenges, such as wire-bonding and flip-chip bonding, which are not compatible with current microfluidic technologies. As a demonstration we integrated a CMOS magnetic sensor chip and associate microfluidic channels on a polydimethylsiloxane (PDMS) substrate that allows precise delivery of small liquid samples to the sensor. Furthermore, the packaged system is fully functional under bending curvature radius of one centimetre and uniaxial strain of 15%. The flexible integration of solid-state ICs with microfluidics enables compact flexible electronic and lab-on-a-chip systems, which hold great potential for wearable health monitoring, point-of-care diagnostics and environmental sensing among many other applications.

  8. Comparison of Ultrasonic Welding and Thermal Bonding for the Integration of Thin Film Metal Electrodes in Injection Molded Polymeric Lab-on-Chip Systems for Electrochemistry

    Directory of Open Access Journals (Sweden)

    Marco Matteucci

    2016-10-01

    Full Text Available We compare ultrasonic welding (UW and thermal bonding (TB for the integration of embedded thin-film gold electrodes for electrochemical applications in injection molded (IM microfluidic chips. The UW bonded chips showed a significantly superior electrochemical performance compared to the ones obtained using TB. Parameters such as metal thickness of electrodes, depth of electrode embedding, delivered power, and height of energy directors (for UW, as well as pressure and temperature (for TB, were systematically studied to evaluate the two bonding methods and requirements for optimal electrochemical performance. The presented technology is intended for easy and effective integration of polymeric Lab-on-Chip systems to encourage their use in research, commercialization and education.

  9. Comparison of Ultrasonic Welding and Thermal Bonding for the Integration of Thin Film Metal Electrodes in Injection Molded Polymeric Lab-on-Chip Systems for Electrochemistry.

    Science.gov (United States)

    Matteucci, Marco; Heiskanen, Arto; Zór, Kinga; Emnéus, Jenny; Taboryski, Rafael

    2016-10-27

    We compare ultrasonic welding (UW) and thermal bonding (TB) for the integration of embedded thin-film gold electrodes for electrochemical applications in injection molded (IM) microfluidic chips. The UW bonded chips showed a significantly superior electrochemical performance compared to the ones obtained using TB. Parameters such as metal thickness of electrodes, depth of electrode embedding, delivered power, and height of energy directors (for UW), as well as pressure and temperature (for TB), were systematically studied to evaluate the two bonding methods and requirements for optimal electrochemical performance. The presented technology is intended for easy and effective integration of polymeric Lab-on-Chip systems to encourage their use in research, commercialization and education.

  10. Vertical integration of array-type miniature interferometers at wafer level by using multistack anodic bonding

    Science.gov (United States)

    Wang, Wei-Shan; Wiemer, Maik; Froemel, Joerg; Enderlein, Tom; Gessner, Thomas; Lullin, Justine; Bargiel, Sylwester; Passilly, Nicolas; Albero, Jorge; Gorecki, Christophe

    2016-04-01

    In this work, vertical integration of miniaturized array-type Mirau interferometers at wafer level by using multi-stack anodic bonding is presented. Mirau interferometer is suitable for MEMS metrology and for medical imaging according to its vertical-, lateral- resolutions and working distances. Miniaturized Mirau interferometer can be a promising candidate as a key component of an optical coherence tomography (OCT) system. The miniaturized array-type interferometer consists of a microlens doublet, a Si-based MEMS Z scanner, a spacer for focus-adjustment and a beam splitter. Therefore, bonding technologies which are suitable for heterogeneous substrates are of high interest and necessary for the integration of MEMS/MOEMS devices. Multi-stack anodic bonding, which meets the optical and mechanical requirements of the MOEMS device, is adopted to integrate the array-type interferometers. First, the spacer and the beam splitter are bonded, followed by bonding of the MEMS Z scanner. In the meanwhile, two microlenses, which are composed of Si and glass wafers, are anodically bonded to form a microlens doublet. Then, the microlens doublet is aligned and bonded with the scanner/spacer/beam splitter stack. The bonded array-type interferometer is a 7- wafer stack and the thickness is approximately 5mm. To separate such a thick wafer stack with various substrates, 2-step laser cutting is used to dice the bonded stack into Mirau chips. To simplify fabrication process of each component, electrical connections are created at the last step by mounting a Mirau chip onto a flip chip PCB instead of through wafer vias. Stability of Au/Ti films on the MEMS Z scanner after anodic bonding, laser cutting and flip chip bonding are discussed as well.

  11. Using a non-spin flip model to rationalize the irregular patterns observed in the activation of the C-H and Si-H bonds of small molecules by CpMCO (M = Co, Rh) complexes.

    Science.gov (United States)

    Castro, Guadalupe; Colmenares, Fernando

    2017-09-20

    The activation of the C-H and Si-H bonds of CH(CH3)3 and SiH(CH3)3 molecules by organometallic compounds CpMCO (M = Co, Rh) has been investigated through DFT and CASSCF-MRMP2 calculations. In particular, we have analyzed the pathways joining the lowest-lying triplet and singlet states of the reactants with the products arising from the insertion of the metal atom into the C-H or Si-H bonds of the organic molecules. Channels connecting the reactants with the inserted structure Cp(CO)H-M-C(CH3)3 through the oxidative addition of the C-H bond of the organic molecule to the metal fragment were found only for the reaction CpRhCO + CH(CH3)3. However, inserted structures could also be obtained for the interactions of SiH(CH3)3 with CpCoCO and CpRhCO by two sequential reactions involving the formation and rebounding of the radical fragments Cp(CO)H-M + Si(CH3)3. According to this two-step reaction scheme, the complex CpCoCO is unable to activate the C-H bond of the CH(CH3)3 molecule due to the high energy at which the radical fragments Cp(CO)H-M + C(CH3)3 are located. The picture attained for these interactions is consistent with the available experimental data for this kind of reaction and allows rationalization of the differences in the reactivity patterns determined for them without using spin-flip models, as has been proposed in previous studies.

  12. MICROSTRUCTURE CHARACTERISTICS AT THE BOND INTERFACE

    Institute of Scientific and Technical Information of China (English)

    Li Junhui; Han Lei; Zhong Jue

    2005-01-01

    Lift-off and section characteristics at the interface of thermosonic bond are observed by using scanning electron microscope (KYKY2800) with EDS-test. Results show that the peeling underdeveloped bonds simulate a torus (or doughnut) with an unbonded central region and ridged peripheral region is bonded hardly. Inside roundness at flip chip bonding center are discovered. Bond strength is located between the severely ridged periphery and the non-adhering central area of the bond. For constant force and time, the ridged area of the bond pattern increases when more power is applied. For constant force and power, the ridged location of the bonded region moves closer to the bond center with time. Results of EDS-tests at Au-Al and Au-Ag interfaces show that Kirkendall diffusibility at Au-Ag interface occur and the diffusing speed of Au-atomic is faster than that of Ag,and that intermetallic compounds at Au-A1 interface is generated possibly. And these would be helpful for further research about thermosonic bonding.

  13. Flipped Classroom Approach

    Directory of Open Access Journals (Sweden)

    Fezile Ozdamli

    2016-07-01

    Full Text Available Flipped classroom is an active, student-centered approach that was formed to increase the quality of period within class. Generally this approach whose applications are done mostly in Physical Sciences, also attracts the attention of educators and researchers in different disciplines recently. Flipped classroom learning which wide-spreads rapidly in the world, is not well recognized in our country. That is why the aim of study is to attract attention to its potential in education field and provide to make it recognize more by educators and researchers. With this aim, in the study what flipped classroom approach is, flipped classroom technology models, its advantages and limitations were explained.

  14. Flipping Freshman Mathematics

    Science.gov (United States)

    Zack, Laurie; Fuselier, Jenny; Graham-Squire, Adam; Lamb, Ron; O'Hara, Karen

    2015-01-01

    Our study compared a flipped class with a standard lecture class in four introductory courses: finite mathematics, precalculus, business calculus, and calculus 1. The flipped sections watched video lectures outside of class and spent time in class actively working on problems. The traditional sections had lectures in class and did homework outside…

  15. The flipped classroom

    DEFF Research Database (Denmark)

    Triantafyllou, Evangelia

    2015-01-01

    class time is devoted to clarifications and application of this knowledge. The hypothesis is that there could be deep and creative discussions when teacher and students physically meet. This paper presents design considerations for flipped classrooms, and discusses how Moodle can facilitate...... with a discussion of the opportunities and challenges when implementing the flipped model in a virtual learning environment (VLE) like Moodle....

  16. Flipping Freshman Mathematics

    Science.gov (United States)

    Zack, Laurie; Fuselier, Jenny; Graham-Squire, Adam; Lamb, Ron; O'Hara, Karen

    2015-01-01

    Our study compared a flipped class with a standard lecture class in four introductory courses: finite mathematics, precalculus, business calculus, and calculus 1. The flipped sections watched video lectures outside of class and spent time in class actively working on problems. The traditional sections had lectures in class and did homework outside…

  17. Thermal Stress Assessment for Transient Liquid-Phase Bonded Si Chips in High-Power Modules Using Experimental and Numerical Methods

    Science.gov (United States)

    Lis, Adrian; Kicin, Slavo; Brem, Franziska; Leinenbach, Christian

    2017-02-01

    The potential of transient liquid-phase (TLP) bonding for chip packaging applications has been evaluated, focusing on three interlayer arrangements (Ag-Sn-Ag, Ni-Sn-Ni, and Ag-Sn-Ni). Shear tests on TLP-bonded components provided the interlayer-dependent mechanical strength as well as failure mode and position. Critical local stresses, i.e., failure criteria, within the intermetallic compound (IMC) layer were derived by replicating the shear test conditions with finite-element methods. The missing coefficient of thermal expansion for Ag3Sn IMC was obtained by producing small IMC bulk samples and subjecting them to dilatometric measurements. The experimental results were implemented into a finite-element model of a representative power module architecture to provide first predictions on thermally induced residual stresses that could be classified into fail/safe, as successfully validated by TLP chip bonding experiments. A numerical parameter study then assessed thermal stresses, including failure prediction and design optimization for TLP-bonded Si chips, considering the influence of process temperature, service conditions, TLP interlayer system, and metallization layers within the TLP joint. The presented procedure serves as a guideline to choose an appropriate TLP interlayer system for predefined boundary conditions, or vice versa.

  18. Thermal Stress Assessment for Transient Liquid-Phase Bonded Si Chips in High-Power Modules Using Experimental and Numerical Methods

    Science.gov (United States)

    Lis, Adrian; Kicin, Slavo; Brem, Franziska; Leinenbach, Christian

    2016-11-01

    The potential of transient liquid-phase (TLP) bonding for chip packaging applications has been evaluated, focusing on three interlayer arrangements (Ag-Sn-Ag, Ni-Sn-Ni, and Ag-Sn-Ni). Shear tests on TLP-bonded components provided the interlayer-dependent mechanical strength as well as failure mode and position. Critical local stresses, i.e., failure criteria, within the intermetallic compound (IMC) layer were derived by replicating the shear test conditions with finite-element methods. The missing coefficient of thermal expansion for Ag3Sn IMC was obtained by producing small IMC bulk samples and subjecting them to dilatometric measurements. The experimental results were implemented into a finite-element model of a representative power module architecture to provide first predictions on thermally induced residual stresses that could be classified into fail/safe, as successfully validated by TLP chip bonding experiments. A numerical parameter study then assessed thermal stresses, including failure prediction and design optimization for TLP-bonded Si chips, considering the influence of process temperature, service conditions, TLP interlayer system, and metallization layers within the TLP joint. The presented procedure serves as a guideline to choose an appropriate TLP interlayer system for predefined boundary conditions, or vice versa.

  19. Flipped Learning in the Workplace

    Science.gov (United States)

    Nederveld, Allison; Berge, Zane L.

    2015-01-01

    Purpose: The purpose of this paper is to serve as a summary of resources on flipped learning for workplace learning professionals. A recent buzzword in the training world is "flipped". Flipped learning and the flipped classroom are hot topics that have emerged in K-12 education, made their way to the university and are now being noticed…

  20. The flipped classroom

    DEFF Research Database (Denmark)

    Triantafyllou, Evangelia

    2015-01-01

    One of the novel ideas in teaching that heavily relies on current technology is the “flipped classroom” approach. In a flipped classroom the traditional lecture and homework sessions are inverted. Students are provided with online material in order to gain necessary knowledge before class, while...... class time is devoted to clarifications and application of this knowledge. The hypothesis is that there could be deep and creative discussions when teacher and students physically meet. This paper presents design considerations for flipped classrooms, and discusses how Moodle can facilitate...... communication and information sharing in such classrooms. Furthermore, it provides guidelines for supporting out-of-class instruction in the flipped model by using quizzes and feedback in Moodle, and comments on the potential to follow student use of resources by using Moodle reports. This paper concludes...

  1. Flip Video for Dummies

    CERN Document Server

    Hutsko, Joe

    2010-01-01

    The full-color guide to shooting great video with the Flip Video camera. The inexpensive Flip Video camera is currently one of the hottest must-have gadgets. It's portable and connects easily to any computer to transfer video you shoot onto your PC or Mac. Although the Flip Video camera comes with a quick-start guide, it lacks a how-to manual, and this full-color book fills that void! Packed with full-color screen shots throughout, Flip Video For Dummies shows you how to shoot the best possible footage in a variety of situations. You'll learn how to transfer video to your computer and then edi

  2. Stable 85Rb micro vapour cells: fabrication based on anodic bonding and application in chip-scale atomic clocks

    Science.gov (United States)

    Su, Juan; Deng, Ke; Guo, Deng-Zhu; Wang, Zhong; Chen, Jing; Zhang, Geng-Min; Chen, Xu-Zong

    2010-11-01

    We describe the microfabrication of 85Rb vapour cells using a glass-silicon anodic bonding technique and in situ chemical reaction between rubidium chloride and barium azide to produce Rb. Under controlled conditions, the pure metallic Rb drops and buffer gases were obtained in the cells with a few mm3 internal volumes during the cell sealing process. At an ambient temperature of 90 °C the optical absorption resonance of 85Rb D1 transition with proper broadening and the corresponding coherent population trapping (CPT) resonance, with a signal contrast of 1.5% and linewidth of about 1.7 kHz, have been detected. The sealing quality and the stability of the cells have also been demonstrated experimentally by using the helium leaking detection and the after-9-month optoelectronics measurement which shows a similar CPT signal as its original status. In addition, the physics package of chip-scale atomic clock (CSAC) based on the cell was realized. The measured frequency stability of the physics package can reach to 2.1 × 10-10 at one second when the cell was heated to 100 °C which proved that the cell has the quality to be used in portable and battery-operated devices.

  3. FLIPPED LEARNING: PRACTICAL ASPECTS

    Directory of Open Access Journals (Sweden)

    Olena Kuzminska

    2016-03-01

    Full Text Available The article is devoted to issues of implementation of the flipped learning technology in the practice of higher education institutions. The article defines the principles of technology and a model of the educational process, it notes the need to establish an information support system. The article defines online platforms and resources; it describes recommendations for the design of electronic training courses and organization of the students in the process of implementing the proposed model, as well as tools for assessing its effectiveness. The article provides a description of flipped learning implementation scenario and formulates suggestions regarding the use of this model as a mechanism to improve the efficiency of the learning process in the ICT-rich environment of high school: use of learning management systems (LMS and personal learning environments (PLE of participants in a learning process. The article provides an example of implementation of the flipped learning model as a part of the Information Technologies course in the National University of Life and Environmental Sciences of Ukraine (NULES. The article gives examples of tasks, resources and services, results of students’ research activity, as well as an example of the personal learning network, established in the course of implementation of the flipped learning model and elements of digital student portfolios. It presents the results of the monitoring of learning activities and students’ feedback. The author describes cautions against the mass introduction of the flipped learning model without monitoring of readiness of the participants of the educational process for its implementation

  4. Nursing education: Flipping the classroom.

    Science.gov (United States)

    Hessler, Karen L

    2016-02-18

    This article will introduce the innovative educational concept of the "flipped classroom." How to implement the flipped learning model will be addressed within the framework of The Intentional Instruction Environment Model.

  5. Flipping the Classroom

    Science.gov (United States)

    Riendeau, Diane

    2012-11-01

    A recent trend in education is the ``flipped'' or ``reversed'' classroom. In this educational model, students view videos of the lectures as their homework and class time is used for activities and solving problems that might have been assigned as homework in a traditional classroom. Although far from an expert on flipping the classroom, I can see some merit in the idea. When students watch the videos at home, they can start and restart the lecture as often as they like. The lectures are also available for review before the exam. Class time can be used for higher-order questioning, experiments, and problem solving.

  6. 'Flipping' the Classroom.

    Science.gov (United States)

    Billings, Diane M

    2016-09-01

    This article is one in a series on the roles of adjunct clinical faculty and preceptors, who teach nursing students and new graduates to apply knowledge in clinical settings. This article describes the benefits and challenges of using a "flipped" classroom to promote active engagement among learners and more meaningful interaction between learners and educators.

  7. Flipping the Classroom Revisited

    Science.gov (United States)

    Riendeau, Diane

    2013-02-01

    I received many emails following the first column on flipping the classroom. Many of my local colleagues also approached me at our physics alliance, Physics Northwest. Teachers are very interested in this new pedagogy. As I result, I wanted to share some more videos to inspire you.

  8. All-optical flip-flop based on vertical cavity semiconductor optical amplifiers.

    Science.gov (United States)

    Song, Deqiang; Gauss, Veronica; Zhang, Haijiang; Gross, Matthias; Wen, Pengyue; Esener, Sadik

    2007-10-15

    We report the operation of an all-optical set-reset (SR) flip-flop based on vertical cavity semiconductor optical amplifiers (VCSOAs). This flip-flop is cascadable, has low optical switching power (~10 microW), and has the potential to be integrated on a small footprint (~100 microm(2)). The flip-flop is composed of two cross-coupled electrically pumped VCSOA inverters and uses the principles of cross-gain modulation, polarization gain anisotropy, and highly nonlinear gain characteristics to achieve flip-flop functionality. We believe that, when integrated on chip, this type of all-optical flip-flop opens new prospects for implementing all-optical fast memories and timing regeneration circuits.

  9. Interconnect and bonding techniques for pixelated X-ray and gamma-ray detectors

    Science.gov (United States)

    Schneider, A.; Veale, M. C.; Duarte, D. D.; Bell, S. J.; Wilson, M. D.; Lipp, J. D.; Seller, P.

    2015-02-01

    In the last decade, the Detector Development Group at the Technology Department of the Science and Technology Facilities Council (STFC), U.K., established a variety of fabrication and bonding techniques to build pixelated X-ray and γ-ray detector systems such as the spectroscopic X-ray imaging detector HEXITEC [1]. The fabrication and bonding of such devices comprises a range of processes including material surface preparation, photolithography, stencil printing, flip-chip and wire bonding of detectors to application-specific integrated circuits (ASIC). This paper presents interconnect and bonding techniques used in the fabrication chain for pixelated detectors assembled at STFC. For this purpose, detector dies (~ 20× 20 mm2) of high quality, single crystal semiconductors, such as cadmium zinc telluride (CZT) are cut to the required thickness (up to 5mm). The die surfaces are lapped and polished to a mirror-finish and then individually processed by electroless gold deposition combined with photolithography to form 74× 74 arrays of 200 μ m × 200 μ m pixels with 250 μ m pitch. Owing to a lack of availability of CZT wafers, lithography is commonly carried out on individual detector dies which represents a significant technical challenge as the edge of the pixel array and the surrounding guard band lies close to the physical edge of the crystal. Further, such detector dies are flip-chip bonded to readout ASIC using low-temperature curing silver-loaded epoxy so that the stress between the bonded detector die and the ASIC is minimized. In addition, this reduces crystalline modifications of the detector die that occur at temperature greater than 150\\r{ }C and have adverse effects on the detector performance. To allow smaller pitch detectors to be bonded, STFC has also developed a compression cold-weld indium bump bonding technique utilising bumps formed by a photolithographic lift-off technique.

  10. An analysis of the pull strength behaviors of fine-pitch, flip chip solder interconnections using a Au-Pt-Pd thick film conductor on Low-Temperature, Co-fired Ceramic (LTCC) substrates.

    Energy Technology Data Exchange (ETDEWEB)

    Uribe, Fernando R.; Kilgo, Alice C.; Grazier, John Mark; Vianco, Paul Thomas; Zender, Gary L.; Hlava, Paul Frank; Rejent, Jerome Andrew

    2008-09-01

    inconsistent proportions of metal and glassy phase particles present during the subsequent firing process. The consequences were subtle, intermittent changes to the thick film microstructure that gave rise to the reaction layer and, thus, the low pull strength phenomenon. A mitigation strategy would be the use of physical vapor deposition (PVD) techniques to create thin film bond pads; this is multi-chip module, deposited (MCM-D) technology.

  11. Flipped Classroom, active Learning?

    DEFF Research Database (Denmark)

    Andersen, Thomas Dyreborg; Levinsen, Henrik; Philipps, Morten

    2015-01-01

    Action research is conducted in three physics classes over a period of eighteen weeks with the aim of studying the effect of flipped classroom on the pupils agency and learning processes. The hypothesis is that flipped classroom teaching will potentially allocate more time to work actively...... with the teaching subject compared to more traditional teaching, where introductions and theoretical monologs conducted by the teacher prevail. In addition it is assumed that the pupils learning processes move towards more independency and metacognitive thinking.   During the study period interventions...... didactic workshop with the involved teachers. One of the demands of the didactic design is to include a video embedded in a formative evaluation sheet produced in Google Drive by the teachers themselves. The didactic analysis of the collected audio and video recordings will be presented at the NOFA 5...

  12. Flip the classroom.

    Science.gov (United States)

    Li, Simon

    2015-11-01

    Given the huge expansion in medical knowledge it is both practical and expedient to make better use of students' time with aids for effective learning, rather than by increasing the length of time it takes to earn a medical degree. Embracing a 'flipped classroom' approach is a way to free-up classroom time to promote active learning through opportunities such as case-based and team-based exercises.

  13. Teaching Tip: The Flipped Classroom

    Science.gov (United States)

    Mok, Heng Ngee

    2014-01-01

    The flipped classroom has been gaining popularity in recent years. In theory, flipping the classroom appears sound: passive learning activities such as unidirectional lectures are pushed to outside class hours in the form of videos, and precious class time is spent on active learning activities. Yet the courses for information systems (IS)…

  14. Adventures in Flipping College Algebra

    Science.gov (United States)

    Van Sickle, Jenna

    2015-01-01

    This paper outlines the experience of a university professor who implemented flipped learning in two sections of college algebra courses for two semesters. It details how the courses were flipped, what technology was used, advantages, challenges, and results. It explains what students do outside of class, what they do inside class, and discusses…

  15. Test of electrical multi-chip module for Belle II pixel detector

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Felix [Max-Planck-Institut fuer Physik, Muenchen (Germany); Collaboration: Belle II-Collaboration

    2015-07-01

    DEPFET pixel detectors offer excellent signal to noise ratio, resolution and low power consumption with few material. They will be used at Belle II and are a candidate for an ILC vertex detector. The Electrical Multi-Chip Module (EMCM) has been designed to study the back end of line (BEOL) and the metal layer interconnectivity of the DEPFET matrix production for Belle II. The electrical characterization of the EMCM allows studying the signal and control line routings. Having verified the integrity of the electrical network three different types of ASICs are flip-chipped on the EMCM. The electrical characterization of the assembled module allows the analysis and optimization of the ASICs in terms of data integrity. The EMCM serves also as a mechanical test structure to exercise flip-chip and wire bonding. Finally a small DEPFET prototype matrix is mounted on the module which acts as silicon PCB. Consequently, the full study of the complete readout chain can be done. An overview of the EMCM concept and first characterization results with the latest ASIC generation are presented.

  16. Bonding dynamics of compliant microbump during ultrasonic bonding investigated by using Si strain gauge

    Science.gov (United States)

    Iwanabe, Keiichiro; Nakadozono, Kenichi; Senda, Yousuke; Asano, Tanemasa

    2016-06-01

    The bonding dynamics of a cone-shaped microbump during ultrasonic bonding are investigated by in situ measurements of the strain generated in a substrate using a piezoresistance strain sensor. The strain sensor is composed of a pair of p- and n-type piezoresistance gauges to extract strain components in the ultrasonic vibration along the plane parallel to the substrate surface and along the direction perpendicular to the surface. Flip-chip bonding is performed at room-temperature. The time evolution of the strain generated in the substrate according to the load-up of pressing force and application of ultrasonic vibration is clearly detected. The softening of the bump metal during the application of ultrasonic vibration is clearly observed. Results of a comparative study between the bonding of a cone-shaped microbump and that of a flat-top microbump suggest mechanical stress concentration near the top end of the cone-shaped microbump, which results in the transformation of the crystal texture of the bump from grains to fine crystallites.

  17. Effect of electromigration on interfacial reaction in Ni/Sn3.0Ag0.5Cu/Au/Pd/Ni-P flip chip solder joints%电迁移对Ni/Sn3.0Ag0.5Cu/Au/Pd/Ni—P倒装焊点界面反应的影响

    Institute of Scientific and Technical Information of China (English)

    黄明亮; 陈雷达; 周少明; 赵宁

    2012-01-01

    本文研究了150℃,1.0×104A/cm2条件下电迁移对Ni/Sn3.0Ag0.5Cu/Au/Pd/Ni-P倒装焊点界面反应的影响.回流后在solder/Ni和solder/NiP的界面上均形成(Cu,Ni)6Sn5类型金属间化合物.时效过程中两端界面化合物都随时间延长而增厚,且化合物类型都由(Cu,Ni)6Sn5转变为(Ni,Cu)3Sn4.电迁移过程中电子的流动方向对Ni—P层的消耗起着决定性作用.当电子从基板端流向芯片端时,电迁移促进了Ni—P层的消耗,600h后阴极端Ni-P层全部转变为Ni2SnP层.阴极界面处由于Ni2SnP层的存在,使界面Cu-Sn—Ni三元金属间化合物发生电迁移脱落溶解,而且由于Ni2SnP层与Cu焊盘的结合力较差,在Ni2SnP/Cu界面处会形成裂纹.当电子从芯片端流向基板端时,阳极端Ni—P层并没有发生明显的消耗.电流拥挤效应导致了阴极芯片端Ni层和Cu焊盘均发生了局部快速溶解,溶解到钎料中的Cu和Ni原子沿电子运动的方向往阳极运动并在钎料中形成了大量的化合物颗粒.电迁移过程中(Au,Pd,Ni)Sn4的聚集具有方向性,即(Au,Pd,Ni)Sn4因电流作用而在阳极界面处聚集.%The effect of electromigration (EM) on the interracial reaction in the Ni/Sn3.0Ag0.5Cu/Au/Pd/Ni-P flip chip solder joint is investigated under a current density of 1.0 ×104 A/cm2 at 150℃. The (Cu,Ni)6Sn5 intermetallic compounds (IMCs) form at both solder/Ni and solder/Ni-P interfaces in the as-reflowed state. During aging at 150℃, the (Cu,Ni)6Sn5 interfacial IMCs grow thicker and transform into (Ni,Cu)3Sn4 type after 200 h at solder/Ni interface and 600 h at solder/Ni-P interface, respectively. During EM, the current direction plays an important role in Ni-P layer consumption. When electrons flow from Ni-P to Ni, EM enhances the consumption of Ni-P, i.e., the Ni-P s completely consumed and transforms into Ni2SnP after EM for 600 h. There is

  18. Effect of Sintering Temperature on Electrical Properties of Chip on Glass Module with Direct Printing Method

    Science.gov (United States)

    Lee, Young-Chul; Kim, Yongil; Jung, Seung-Boo

    2012-09-01

    In order to apply the direct printing method to the fabrication of chip on glass (COG) modules, we examined that the effect of the sintering temperature on the electrical properties of a COG module with direct printing method. Firstly, we fabricated an Ag conductive circuit on a glass substrate by the screen-printing method. To investigate its the effect on the electrical properties of the circuit, it was sintered at various temperatures, such as 150, 200, 250, and 300 °C for 30 min. Subsequently, we conducted Au electro-plating for the fabrication of a Si dummy chip. Finally, the flip-chip bonding process was conducted using anisotropic conductive film (ACF). The printed Ag circuits were well formed on the quartz substrate without any shorts or remarkable changes compared with the initial design. The electrical properties of the printed Ag circuits improved with increasing sintering temperature. The conductive particles in the ACF were well deformed in between the Au bumps and printed Ag pads after the bonding process. The four-point probe method was employed to measure the connection resistance of the joints constructed with the Au bumps on the Si chip and printed Ag circuit on the quartz substrate. The resistances of the interconnections drastically decreased with increasing sintering temperature, i.e., subsequently converged from 11.8 Ω to 7.36 mΩ.

  19. A flipped 331 model

    CERN Document Server

    Fonseca, Renato M

    2016-01-01

    Models based on the extended $SU(3)_{C}\\times SU(3)_{L}\\times U(1)_{X}$ (331) gauge group usually follow a common pattern: two families of left-handed quarks are placed in anti-triplet representations of the $SU(3)_{L}$ group; the remaining quark family, as well as the left-handed leptons, are assigned to triplets (or vice-versa). In this work we present a flipped 331 model where this scheme is reversed: all three quarks families are in the same representation and it is the lepton families which are discriminated by the gauge symmetry. We discuss fermion masses and mixing, as well as $Z'$ interactions, in a minimal model implementing this idea.

  20. Crystallization by stochastic flips

    Science.gov (United States)

    Bodini, Olivier; Fernique, Thomas; Regnault, Damien

    2010-04-01

    Tilings are often used as a toy model for quasicrystals, with the ground states corresponding to the tilings satisfying some local properties (matching rules). In this context, a challenging problem is to provide a theory for quasicrystals growth. One of the proposed theories is the relaxation process. One assumes that the entropy of a tiling increases with the number of tilings which can be formed with the same tiles, while its energy is proportional to the ratio of satisfied matching rules. Then, by starting from an entropically stabilized tiling at high temperature and by decreasing the temperature, the phason flips which decrease (resp. increase) the energy would become more and more favoured (resp. inhibited). Ideally, the tiling eventually satisfies all the matching rules, and thus shows a quasicrystalline structure. This paper describes a stochastic process inspired by this and discusses its convergence rate.

  1. Practical Quantum Coin Flipping

    CERN Document Server

    Pappa, Anna; Diamanti, Eleni; Kerenidis, Iordanis

    2011-01-01

    In this article we show for the first time that quantum coin flipping with security guarantees that are strictly better than any classical protocol is possible to implement with current technology. Our protocol is tolerant to both loss and noise and takes into account all aspects of an experimental implementation like multi-photon pulses emitted by practical photon sources, channel noise, system loss, detector dark counts and finite quantum efficiency. We calculate the abort probability when both players are honest, as well as the probability of one player forcing his desired outcome. For channel length up to 21 km, we achieve a cheating probability that is better than in any classical protocol. Our protocol is easy to implement using attenuated laser pulses, with no need for entangled photons or any other specific resources.

  2. Transient Liquid Phase Behavior of Sn-Coated Cu Particles and Chip Bonding using Paste Containing the Particles

    National Research Council Canada - National Science Library

    Jun Ho Hwang; Jong-Hyun Lee

    2017-01-01

    .... The thickness of Sn coating was controlled by controlling the number of plating cycles. The Sn-coated Cu particles best suited for TLP bonding were fabricated by Sn plating thrice, and the particles showed a pronounced endothermic peak at 232°C...

  3. Low-cost bump bonding activities at CERN

    Energy Technology Data Exchange (ETDEWEB)

    Vaehaenen, S; Tick, T; Campbell, M, E-mail: Sami.vaehaenen@cern.c [CERN, PH-ESE 1211 Geneva 23 (Switzerland)

    2010-11-15

    Conventional bumping processes used in the fabrication of hybrid pixel detectors for High Energy Physics (HEP) experiments use electroplating for Under Bump Metallization (UBM) and solder bump deposition. This process is laborious, involves time consuming photolithography and can only be performed using whole wafers. Electroplating has been found to be expensive when used for the low volumes which are typical of HEP experiments. In the low-cost bump bonding development work, electroless deposition technology of UBM is studied as an alternative to the electroplating process in the bump size / pitch window beginning from 20 {mu}m / 50 {mu}m. Electroless UBM deposition used in combination with solder transfer techniques has the potential to significantly lower the cost of wafer bumping without requiring increased wafer volumes. A test vehicle design of sensor and readout chip, having daisy chains and Kelvin bump structures, was created to characterize the flip chip process with electroless UBM. Two batches of test vehicle wafers were manufactured with different bump pad metallization. Batch no. 1 had AlSi(1%) metallization, which is similar to the one used on sensor wafers, and Batch no. 2 had AlSi(2%)Cu(1%) metallization, which is very similar to the one used on readout wafers. Electroless UBMs were deposited on both wafer batches. In addition, electroplated Ni UBM and SnPb solder bumps were grown on the test sensor wafers. Test assemblies were made by flip chip bonding the solder-bumped test sensors against the test readout chips with electroless UBMs. Electrical yields and individual joint resistances were measured from assemblies, and the results were compared to a well known reference technique based on electroplated solder bumps structures on both chips. The electroless UBMs deposited on AlSi(2%)Cu(1%) metallization showed excellent electrical yields and small tolerances in individual joint resistance. The results from the UBMs deposited on AlSi(1

  4. Wafer-level packaging and laser bonding as an approach for silicon-into-lab-on-chip integration

    Science.gov (United States)

    Brettschneider, T.; Dorrer, C.; Bründel, M.; Zengerle, R.; Daub, M.

    2013-05-01

    A novel approach for the integration of silicon biosensors into microfluidics is presented. Our approach is based on wafer-level packaging of the silicon die and a laser-bonding process of the resulting mold package into a polymer-multilayer stack. The introduction of a flexible and 40 μm thin hot melt foil as an intermediate layer enables laser bonding between materials with different melting temperatures, where standard laser welding processes cannot be employed. All process steps are suitable for mass production, e.g. the approach does not involve any dispensing steps for glue or underfiller. The integration approach was demonstrated and evaluated regarding process technology by wafer-level redistribution of daisy chain silicon dies representing a generic biosensor. Electrical connection was successfully established and laser-bonding tensile strength of 5.7 N mm-2 and burst pressure of 587 kPa at a temperature of 100 °C were achieved for the new material combination. The feasibility of the complete packaging approach was shown by the fabrication of a microfluidic flow cell with embedded mold package.

  5. Chip, Chip, Hooray!

    Science.gov (United States)

    Kelly, Susan

    2001-01-01

    Presents a science laboratory using different brands of potato chips in which students test their oiliness, size, thickness, saltiness, quality, and cost, then analyze the results to determine the best chip. Gives a brief history of potato chips. (YDS)

  6. Spin flipping a stored polarized proton beam

    Science.gov (United States)

    Caussyn, D. D.; Derbenev, Ya. S.; Ellison, T. J.; Lee, S. Y.; Rinckel, T.; Schwandt, P.; Sperisen, F.; Stephenson, E. J.; von Przewoski, B.; Blinov, B. B.; Chu, C. M.; Courant, E. D.; Crandell, D. A.; Kaufman, W. A.; Krisch, A. D.; Nurushev, T. S.; Phelps, R. A.; Ratner, L. G.; Wong, V. K.; Ohmori, C.

    1994-11-01

    We recently studied the spin flipping of a vertically polarized, stored 139-MeV proton beam. To flip the spin, we induced an rf depolarizing resonance by sweeping our rf solenoid magnet's frequency through the resonance frequency. With multiple spin flips, we found a polarization loss of 0.0000+/-0.0005 per spin flip under the best conditions; this loss increased significantly for small changes in the conditions. Minimizing the depolarization during each spin flip is especially important because frequent spin flipping could significantly reduce the systematic errors in stored polarized-beam experiments.

  7. To Flip or Not to Flip? An Exploratory Study Comparing Student Performance in Calculus I

    Science.gov (United States)

    Schroeder, Larissa B.; McGivney-Burelle, Jean; Xue, Fei

    2015-01-01

    The purpose of this exploratory, mixed-methods study was to compare student performance in flipped and non-flipped sections of Calculus I. The study also examined students' perceptions of the flipping pedagogy. Students in the flipped courses reported spending, on average, an additional 1-2 hours per week outside of class on course content.…

  8. To Flip or Not to Flip? An Exploratory Study Comparing Student Performance in Calculus I

    Science.gov (United States)

    Schroeder, Larissa B.; McGivney-Burelle, Jean; Xue, Fei

    2015-01-01

    The purpose of this exploratory, mixed-methods study was to compare student performance in flipped and non-flipped sections of Calculus I. The study also examined students' perceptions of the flipping pedagogy. Students in the flipped courses reported spending, on average, an additional 1-2 hours per week outside of class on course content.…

  9. Single-transistor-clocked flip-flop

    Science.gov (United States)

    Zhao, Peiyi; Darwish, Tarek; Bayoumi, Magdy

    2005-08-30

    The invention provides a low power, high performance flip-flop. The flip-flop uses only one clocked transistor. The single clocked transistor is shared by the first and second branches of the device. A pulse generator produces a clock pulse to trigger the flip-flop. In one preferred embodiment the device can be made as a static explicit pulsed flip-flop which employs only two clocked transistors.

  10. The Flipped Classroom in Counselor Education

    Science.gov (United States)

    Moran, Kristen; Milsom, Amy

    2015-01-01

    The flipped classroom is proposed as an effective instructional approach in counselor education. An overview of the flipped-classroom approach, including advantages and disadvantages, is provided. A case example illustrates how the flipped classroom can be applied in counselor education. Recommendations for implementing or researching flipped…

  11. A Flipped Classroom Redesign in General Chemistry

    Science.gov (United States)

    Reid, Scott A.

    2016-01-01

    The flipped classroom continues to attract significant attention in higher education. Building upon our recent parallel controlled study of the flipped classroom in a second-term general chemistry course ("J. Chem. Educ.," 2016, 93, 13-23), here we report on a redesign of the flipped course aimed at scaling up total enrollment while…

  12. Flipping a Calculus Class: One Instructor's Experience

    Science.gov (United States)

    Palmer, Katrina

    2015-01-01

    This paper describes one instructor's experiences during a year of flipping four calculus classes. The first exploration attempts to understand student expectations of a math class and their preference towards a flipped classroom. The second examines success of students from a flipped classroom, and the last investigates relationships with student…

  13. A Flipped Classroom Redesign in General Chemistry

    Science.gov (United States)

    Reid, Scott A.

    2016-01-01

    The flipped classroom continues to attract significant attention in higher education. Building upon our recent parallel controlled study of the flipped classroom in a second-term general chemistry course ("J. Chem. Educ.," 2016, 93, 13-23), here we report on a redesign of the flipped course aimed at scaling up total enrollment while…

  14. How To Prepare Effective Flip Charts.

    Science.gov (United States)

    National Audio-Visual Supply, East Rutherford, NJ.

    Designed to help create effective flip chart presentations, this guide contains the basic techniques and helpful hints necessary to produce professional, attention-getting flip charts in a step-by-step procedure format. Five topics are addressed in the guide: (1) eight steps to a successful meeting presentation; (2) advantages of flip chart…

  15. Flip-Flops: Avoid a Flip-Flop Fiasco

    Science.gov (United States)

    ... quality, soft leather. Leather minimizes the potential for blisters and other types of irritation. Do gently bend the flip-flop from end to end, ensuring it bends at the ball of the foot. Shoes of any kind should never fold in half. ...

  16. Using a SPOC to Flip Classroom of Single Chip Computer Tech-nology%基于SPOC的单片机技术翻转课堂教学设计

    Institute of Scientific and Technical Information of China (English)

    丁晨阳; 方小坤

    2016-01-01

    单片机技术是一门实践性要求较高的专业课。为减少课程理论和实践之间的差距,改善学生学习效果,使用SPOC资源对单片机技术课程进行翻转课堂的教学设计,让学生根据自身情况进行学习,并在面对面的课堂中解决实际的单片机控制问题。重新调整后的课程提供给学生一种新的学习探索环境,有利于提高实践能力和创新能力。调查结果表明,大多数学生对这种新的教学方式感到满意。%Single Chip Computer Technology is a practical course. In order to reduce the gap between theory and practice and improve learning eff ect, SPOC is used to fl ip the classroom of Single Chip Computer Technology, so that students are able to study according to their real requirements and solve the actual control problems in a face-to-face classroom. The adjusted course provides students new environment to explore, which is benefi cial to improve their practice and innovation ability. Results show that most of the students are satisfi ed with this teaching mode.

  17. Low temperature co-fired ceramic packaging of CMOS capacitive sensor chip towards cell viability monitoring

    Directory of Open Access Journals (Sweden)

    Niina Halonen

    2016-11-01

    Full Text Available Cell viability monitoring is an important part of biosafety evaluation for the detection of toxic effects on cells caused by nanomaterials, preferably by label-free, noninvasive, fast, and cost effective methods. These requirements can be met by monitoring cell viability with a capacitance-sensing integrated circuit (IC microchip. The capacitance provides a measurement of the surface attachment of adherent cells as an indication of their health status. However, the moist, warm, and corrosive biological environment requires reliable packaging of the sensor chip. In this work, a second generation of low temperature co-fired ceramic (LTCC technology was combined with flip-chip bonding to provide a durable package compatible with cell culture. The LTCC-packaged sensor chip was integrated with a printed circuit board, data acquisition device, and measurement-controlling software. The packaged sensor chip functioned well in the presence of cell medium and cells, with output voltages depending on the medium above the capacitors. Moreover, the manufacturing of microfluidic channels in the LTCC package was demonstrated.

  18. Crack and flip phacoemulsification technique.

    Science.gov (United States)

    Fine, I H; Maloney, W F; Dillman, D M

    1993-11-01

    The crack and flip phacoemulsification technique combines the advantages of circumferential division of the nucleus and nucleofactis techniques. As such, it adds safety and control to the procedure. We describe each of the surgical maneuvers, including machine settings, and explain the rationale for maneuvers and machine settings.

  19. A Local Solubility Activation for Ultrasonic Bonding of Polymer Microfluidic Chips%基于局部溶解性激活的聚合物微流控芯片超声波键合

    Institute of Scientific and Technical Information of China (English)

    张宗波; 罗怡; 王晓东; 王立鼎

    2011-01-01

    Based on localized facial heating of low amplitude ultrasonic bonding on polymer and temperature-dependent solubility of polymethyl methacrylate (PMMA) in isopropanol (IPA ) , a local solubility activated ultrasonic bonding method for rapid and robust bonding of PMMA microfluidic chip was presented in this paper. Theoretical analysis indicates that heat is generated only at the interface when ultrasonic amplitude is below critical amplitude, and the solubility of PMMA in IPA can be well activated at about 70 ℃. PMMA substrates of microfluidic chip with an area-contact style energy director and the micro-channels of 80 μm x 80 μm were fabricated by precision machining method and hot embossing method, respectively. The substrates were successfully bonded under the condition of ultraosonic amplitude 13 (xm, bonding time 8 s and bonding force 300 N. The tensile-strength of bonded chips was 2. 25 Mpa, the microchannels withstood internal pressure of 800 kPa, the dimension loss of microchannel was less than 2% and the bonding time was 8 s without melting of energy director after bonding. The bonding strength and efficiency of this method are much higher than those of traditional bonding method, while its dimension loss is smaller. So the proposed method is potentially the state-of-the-art mass-production process for sealing polymer microfluidic chips.%利用低于临界振幅下的超声波作用在聚合物上仅产生表面热的特点,结合PMMA在异丙醇(IPA)中的温变溶解特性,提出了一种基于局部溶解性激活的超声波聚合物微流控芯片键合方法.理论分析表明当超声振幅小于临界振幅时,只有器件接触表面产生局部表面热,而且在70℃附近IPA对PMMA的溶解性才具有良好的激活作用.在试验研究中,利用精密加工法和热压法制作了带面接触式导能筋结构和80μm×80μm微通道的PMMA微流控芯片基片.在超声振幅为13 μm、键合时间8s、键合压力300N的条件下进

  20. Glass microfabricated nebulizer chip for mass spectrometry.

    Science.gov (United States)

    Saarela, Ville; Haapala, Markus; Kostiainen, Risto; Kotiaho, Tapio; Franssila, Sami

    2007-05-01

    A microfluidic nebulizer chip for mass spectrometry is presented. It is an all-glass device which consists of fusion bonded Pyrex wafers with embedded flow channels and a nozzle at the chip edge. A platinum heater is located on the wafer backside. Fabrication of the chip is detailed, especially glass deep etching, wafer bonding, and metal patterning. Various process combinations of bonding and metallization have been considered (anodic bonding vs. fusion bonding; heater inside/outside channel; metallization before/after bonding; platinum lift-off vs. etching). The chip vaporizes the liquid sample (0.1-10 microL min(-1)) and mixes it with a nebulizer gas (ca. 100 sccm N2). Operating temperatures can go up to 500 degrees C ensuring efficient vaporization. Thermal insulation of the glass ensures low temperatures at the far end of the chip, enabling easy interconnections.

  1. Flipping the Graduate Qualitative Research Methods Classroom: Did It Lead to Flipped Learning?

    Science.gov (United States)

    Earley, Mark

    2016-01-01

    The flipped, or inverted, classroom has gained popularity in a variety of fields and at a variety of educational levels, from K-12 through higher education. This paper describes the author's positive experience flipping a graduate qualitative research methods classroom. After a review of the current literature on flipped classrooms in higher…

  2. How to Flip the Classroom--"Productive Failure or Traditional Flipped Classroom" Pedagogical Design?

    Science.gov (United States)

    Song, Yanjie; Kapur, Manu

    2017-01-01

    The paper reports a quasi-experimental study comparing the "traditional flipped classroom" pedagogical design with the "productive failure" (Kapur, 2016) pedagogical design in the flipped classroom for a 2-week curricular unit on polynomials in a Hong Kong Secondary school. Different from the flipped classroom where students…

  3. C4NP - Lead Free Flip Chip Solder Bumping Manufacturing and Reliability Data%C4NP-无铅倒装晶片焊凸形成生产工艺与可靠性数据

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    high-end logic device packaging using 300 mm wafers bumped with C4NP. This includes initial reliability data for C4NP lead free solder bumped devices attached to organic chip carriers. Mold fill data for CSP type dimensions is included. Solder metrology data and yield information for fine pitch applications is summarized. Relevant process equipment technology and the unique requirements to run a high volume manufacturing C4NP process are reviewed. The paper also summarizes the C4NP manufacturing cost model and elaborates on the cost comparison to alternative bumping techniques. The data in this paper is provided by IBM's packaging operations at the Hudson Valley Research Park in East Fishkill, NY and Bromont, Quebec.

  4. To Flip or Not to Flip? Analysis of a Flipped Classroom Pedagogy in a General Biology Course

    Science.gov (United States)

    Heyborne, William H.; Perrett, Jamis J.

    2016-01-01

    In an attempt to better understand the flipped technique and evaluate its purported superiority in terms of student learning gains, the authors conducted an experiment comparing a flipped classroom to a traditional lecture classroom. Although the outcomes were mixed, regarding the superiority of either pedagogical approach, there does seem to be a…

  5. Process for 3D chip stacking

    Science.gov (United States)

    Malba, V.

    1998-11-10

    A manufacturable process for fabricating electrical interconnects which extend from a top surface of an integrated circuit chip to a sidewall of the chip using laser pantography to pattern three dimensional interconnects. The electrical interconnects may be of an L-connect or L-shaped type. The process implements three dimensional (3D) stacking by moving the conventional bond or interface pads on a chip to the sidewall of the chip. Implementation of the process includes: (1) holding individual chips for batch processing, (2) depositing a dielectric passivation layer on the top and sidewalls of the chips, (3) opening vias in the dielectric, (4) forming the interconnects by laser pantography, and (5) removing the chips from the holding means. The process enables low cost manufacturing of chips with bond pads on the sidewalls, which enables stacking for increased performance, reduced space, and higher functional per unit volume. 3 figs.

  6. Process for 3D chip stacking

    Science.gov (United States)

    Malba, Vincent

    1998-01-01

    A manufacturable process for fabricating electrical interconnects which extend from a top surface of an integrated circuit chip to a sidewall of the chip using laser pantography to pattern three dimensional interconnects. The electrical interconnects may be of an L-connect or L-shaped type. The process implements three dimensional (3D) stacking by moving the conventional bond or interface pads on a chip to the sidewall of the chip. Implementation of the process includes: 1) holding individual chips for batch processing, 2) depositing a dielectric passivation layer on the top and sidewalls of the chips, 3) opening vias in the dielectric, 4) forming the interconnects by laser pantography, and 5) removing the chips from the holding means. The process enables low cost manufacturing of chips with bond pads on the sidewalls, which enables stacking for increased performance, reduced space, and higher functional per unit volume.

  7. The Flipped Classroom: A Twist on Teaching

    Science.gov (United States)

    Schmidt, Stacy M. P.; Ralph, David L.

    2016-01-01

    The traditional classroom has utilized the "I Do", "We Do", "You Do" as a strategy for teaching for years. The flipped classroom truly flips that strategy. The teacher uses "You Do", "We Do", "I Do" instead. Homework, inquiry, and investigation happen in the classroom. At home students…

  8. Flipping Quantitative Classes: A Triple Win

    Science.gov (United States)

    Swart, William; Wuensch, Karl L.

    2016-01-01

    In the "flipped" class, students use online materials to learn what is traditionally learned by attending lectures, and class time is used for interactive group learning. A required quantitative business class was taught as a flipped classroom in an attempt to improve student satisfaction in the course and reduce the "transactional…

  9. Best Practices for Launching a Flipped Classroom

    Science.gov (United States)

    Hall, Ashley A.; DuFrene, Debbie D.

    2016-01-01

    Popularity is growing for flipped classroom instruction, which replaces lectures with out-of-class delivery of streaming video, reading materials, online chats, and other modalities. Face-to-face class time is spent on instructor-student and student-student interaction, including small group problem solving and discussion. Classroom flipping has…

  10. Technology: Differentiating Instruction by Flipping the Classroom

    Science.gov (United States)

    Siegle, Del

    2014-01-01

    Flipping the classroom can be an effective instructional strategy for differentiating instruction for gifted and talented students. The author presents a rationale for using the strategy with gifted students, possible problems educators might encounter, and practical tips for beginning the process of flipping the classroom.

  11. Just in Time to Flip Your Classroom

    Science.gov (United States)

    Lasry, Nathaniel; Dugdale, Michael; Charles, Elizabeth

    2014-01-01

    With advocates like Sal Khan and Bill Gates, flipped classrooms are attracting an increasing amount of media and research attention. We had heard Khan's TED talk and were aware of the concept of inverted pedagogies in general. Yet it really hit home when we accidentally flipped our classroom. Our objective was to better prepare our students…

  12. The Flipped Classroom. IDEA Paper #57

    Science.gov (United States)

    Braseby, Anne M.

    2014-01-01

    Use of the word "flipped" has become the latest buzzword in the educational world. This paper explores the different uses of the term "flipped," examines the research to date, and discusses how and why teachers are starting to use the new model. It offers suggestions for activities both inside and outside of the classroom to…

  13. Conceptualizing "Homework" in Flipped Mathematics Classes

    Science.gov (United States)

    de Araujo, Zandra; Otten, Samuel; Birisci, Salih

    2017-01-01

    Flipped instruction is becoming more common in the United States, particularly in mathematics classes. One of the defining characteristics of this increasingly popular instructional format is the homework teachers assign. In contrast to traditional mathematics classes in which homework consists of problem sets, homework in flipped classes often…

  14. Just in Time to Flip Your Classroom

    Science.gov (United States)

    Lasry, Nathaniel; Dugdale, Michael; Charles, Elizabeth

    2014-01-01

    With advocates like Sal Khan and Bill Gates, flipped classrooms are attracting an increasing amount of media and research attention. We had heard Khan's TED talk and were aware of the concept of inverted pedagogies in general. Yet it really hit home when we accidentally flipped our classroom. Our objective was to better prepare our students…

  15. Diverse Perspectives on a Flipped Biostatistics Classroom

    Science.gov (United States)

    Schwartz, Todd A.; Andridge, Rebecca R.; Sainani, Kirstin L.; Stangle, Dalene K.; Neely, Megan L.

    2016-01-01

    "Flipping" the classroom refers to a pedagogical approach in which students are first exposed to didactic content outside the classroom and then actively use class time to apply their newly attained knowledge. The idea of the flipped classroom is not new, but has grown in popularity in recent years as the necessary technology has…

  16. Just in Time to Flip Your Classroom

    Science.gov (United States)

    Lasry, Nathaniel; Dugdale, Michael; Charles, Elizabeth

    2014-01-01

    With advocates like Sal Khan and Bill Gates, flipped classrooms are attracting an increasing amount of media and research attention.2 We had heard Khan's TED talk and were aware of the concept of inverted pedagogies in general. Yet it really hit home when we accidentally flipped our classroom. Our objective was to better prepare our students for class. We set out to effectively move some of our course content outside of class and decided to tweak the Just-in-Time Teaching approach (JiTT).3 To our surprise, this tweak—which we like to call the flip-JiTT—ended up completely flipping our classroom. What follows is narrative of our experience and a procedure that any teacher can use to extend JiTT to a flipped classroom.

  17. Just in Time to Flip Your Classroom

    CERN Document Server

    Lasry, Nathaniel; Charles, Elizabeth

    2013-01-01

    With advocates like Sal Khan and Bill Gates, flipped classrooms are attracting an increasing amount of media and research attention. We had heard Khan's TED talk and were aware of the concept of inverted pedagogies in general. Yet, it really hit home when we accidentally flipped our classroom. Our objective was to better prepare our students for class. We set out to effectively move some of our course content outside of class and decided to tweak the Just-in-Time-Teaching approach (JiTT). To our surprise, this tweak - which we like to call the flip-JiTT - ended up completely flipping our classroom. What follows is narrative of our experience and a procedure that any teacher can use to extend JiTT to a flipped classroom.

  18. The fabrication of flip-covered plasmonic nanostructure surfaces with enhanced wear resistance

    Science.gov (United States)

    Jung, Joo-Yun; Sung, Sang-Keun; Kim, Kwang-Seop; Cheon, So-Hui; Lee, Jihye; Choi, Jun-Hyuk; Lee, Eungsug

    2017-01-01

    Exposed nanostructure surfaces often suffer from external dynamic wear, particularly when used in human interaction, resulting in surface defects and the degradation of plasmonic resonance properties particularly in terms of transmittance extinction rate and peak-to-valley slope. In this work, a method for the fabrication of flip-covered silver nanostructure-arrayed surfaces is shown to enhance wear resistance. Selectively transferred silver dot and silver webbed-trench exposed reference samples were fabricated by metal nanoimprint, and flip-covered samples were created by flipping and bonding reference samples onto a PET film coated with an adhesive layer. The samples' spectral transmittance was measured before and after a dynamic wear test. Some spectral shift was observed due to the change in refractive index of the surrounding media, but this was not as significant as the effects of the other chosen geometry factors. It was found that dynamic wear had a greater effect on the plasmonic resonance behavior of the exposed samples than in those that had been flip-covered. This suggests that flip-covering may be an effective strategy for the protection of plasmonic resonators against dynamic wear. It is expected that the slight variations in spectral transmittance could be compensated through proper tuning of the sample geometry.

  19. Flipped classroom: a review of recent literature

    Directory of Open Access Journals (Sweden)

    Huseyin Uzunboylu

    2015-07-01

    Full Text Available The use of learning technologies, especially multimedia provide varied facilities for students’ learning that are not possible with other media. Pedagogical literature has proved that individuals have different learning styles. Flipped classroom is a pedagogical approach which means that activities that have traditionally taken place inside the classroom take place outside the classroom and vice versa. Flipped classroom environment ensures that students become more active participants compared with the traditional classroom. The purpose of this paper is to fulfil the needs regarding the review of recent literature on the use of flipped classroom approach in education. The contribution of flipped classroom to education is discussed in relation to the change of students' and instructors' role. Subsequently, flipped classroom applications in various disciplines of education are illustrated. The recommendations made in the literature for design specifications that integrate flipped classrooms with technology are discussed. The paper concludes that a careful consideration of the warnings and recommendations made in the literature can help to produce effective flipped classroom environments and also this paper attempts to inform those who are thinking of using new technologies and approaches to deliver courses.

  20. FLIPS: Friendly Lisp Image Processing System

    Science.gov (United States)

    Gee, Shirley J.

    1991-08-01

    The Friendly Lisp Image Processing System (FLIPS) is the interface to Advanced Target Detection (ATD), a multi-resolutional image analysis system developed by Hughes in conjunction with the Hughes Research Laboratories. Both menu- and graphics-driven, FLIPS enhances system usability by supporting the interactive nature of research and development. Although much progress has been made, fully automated image understanding technology that is both robust and reliable is not a reality. In situations where highly accurate results are required, skilled human analysts must still verify the findings of these systems. Furthermore, the systems often require processing times several orders of magnitude greater than that needed by veteran personnel to analyze the same image. The purpose of FLIPS is to facilitate the ability of an image analyst to take statistical measurements on digital imagery in a timely fashion, a capability critical in research environments where a large percentage of time is expended in algorithm development. In many cases, this entails minor modifications or code tinkering. Without a well-developed man-machine interface, throughput is unduly constricted. FLIPS provides mechanisms which support rapid prototyping for ATD. This paper examines the ATD/FLIPS system. The philosophy of ATD in addressing image understanding problems is described, and the capabilities of FLIPS are discussed, along with a description of the interaction between ATD and FLIPS. Finally, an overview of current plans for the system is outlined.

  1. Comparing the Effectiveness of Blended, Semi-Flipped, and Flipped Formats in an Engineering Numerical Methods Course

    Science.gov (United States)

    Clark, Renee M.; Kaw, Autar; Besterfield-Sacre, Mary

    2016-01-01

    Blended, flipped, and semi-flipped instructional approaches were used in various sections of a numerical methods course for undergraduate mechanical engineers. During the spring of 2014, a blended approach was used; in the summer of 2014, a combination of blended and flipped instruction was used to deliver a semi-flipped course; and in the fall of…

  2. A counting pixel chip and sensor system for X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, P.; Hausmann, J.; Helmich, A.; Lindner, M.; Wermes, N. [Universitaet Bonn (Germany). Physikalisches Institut; Blanquart, L. [CNRS, Marseille (France). Centre de Physique des Particules

    1999-08-01

    Results obtained with a (photon) counting pixel imaging chip connected to a silicon pixel sensor using the bump and flip-chip technology are presented. The performance of the chip electronics is characterized by an average equivalent noise charge (ENC) below 135 e and a threshold spread of less than 35 e after individual threshold adjust, both measured with a sensor attached. First results on the imaging performance are also reported.

  3. Twelve tips for "flipping" the classroom.

    Science.gov (United States)

    Moffett, Jennifer

    2015-04-01

    The flipped classroom is a pedagogical model in which the typical lecture and homework elements of a course are reversed. The following tips outline the steps involved in making a successful transition to a flipped classroom approach. The tips are based on the available literature alongside the author's experience of using the approach in a medical education setting. Flipping a classroom has a number of potential benefits, for example increased educator-student interaction, but must be planned and implemented carefully to support effective learning.

  4. Suggestions for Implementing Flipped Classroom in China

    Institute of Scientific and Technical Information of China (English)

    周婷

    2016-01-01

    Educators in the twenty-first century are constantly adopting new technologies and pedagogies. Flipped Classroom Model is one of the most promising approaches to transforming learning experiences, which has been applied to both K-12 edu-cation and higher education at home and abroad. Influenced by culture and learning styles, the effectiveness and concrete imple-mentation strategies of this teaching model is different in different countries. How to localize the model in China is an important question for educators to think about. The paper makes suggestions for implementing Flipped Classroom in China, aiming at helping teachers to flip their classrooms successfully.

  5. Enhancing student engagement using the flipped classroom.

    Science.gov (United States)

    Gilboy, Mary Beth; Heinerichs, Scott; Pazzaglia, Gina

    2015-01-01

    The flipped classroom is an innovative pedagogical approach that focuses on learner-centered instruction. The purposes of this report were to illustrate how to implement the flipped classroom and to describe students' perceptions of this approach within 2 undergraduate nutrition courses. The template provided enables faculty to design before, during, and after class activities and assessments based on objectives using all levels of Bloom's taxonomy. The majority of the 142 students completing the evaluation preferred the flipped method compared with traditional pedagogical strategies. The process described in the report was successful for both faculty and students.

  6. FLIP the Switch: Regulation of Apoptosis and Necroptosis by cFLIP

    Directory of Open Access Journals (Sweden)

    Yuichi Tsuchiya

    2015-12-01

    Full Text Available cFLIP (cellular FLICE-like inhibitory protein is structurally related to caspase-8 but lacks proteolytic activity due to multiple amino acid substitutions of catalytically important residues. cFLIP protein is evolutionarily conserved and expressed as three functionally different isoforms in humans (cFLIPL, cFLIPS, and cFLIPR. cFLIP controls not only the classical death receptor-mediated extrinsic apoptosis pathway, but also the non-conventional pattern recognition receptor-dependent apoptotic pathway. In addition, cFLIP regulates the formation of the death receptor-independent apoptotic platform named the ripoptosome. Moreover, recent studies have revealed that cFLIP is also involved in a non-apoptotic cell death pathway known as programmed necrosis or necroptosis. These functions of cFLIP are strictly controlled in an isoform-, concentration- and tissue-specific manner, and the ubiquitin-proteasome system plays an important role in regulating the stability of cFLIP. In this review, we summarize the current scientific findings from biochemical analyses, cell biological studies, mathematical modeling, and gene-manipulated mice models to illustrate the critical role of cFLIP as a switch to determine the destiny of cells among survival, apoptosis, and necroptosis.

  7. Base flipping in tn10 transposition: an active flip and capture mechanism.

    Directory of Open Access Journals (Sweden)

    Julien Bischerour

    Full Text Available The bacterial Tn5 and Tn10 transposases have a single active site that cuts both strands of DNA at their respective transposon ends. This is achieved using a hairpin intermediate that requires the DNA to change conformation during the reaction. In Tn5 these changes are controlled in part by a flipped nucleoside that is stacked on a tryptophan residue in a hydrophobic pocket of the transposase. Here we have investigated the base flipping mechanism in Tn10 transposition. As in Tn5 transposition, we find that base flipping takes place after the first nick and is required for efficient hairpin formation and resolution. Experiments with an abasic substrate show that the role of base flipping in hairpin formation is to remove the base from the DNA helix. Specific interactions between the flipped base and the stacking tryptophan residue are required for hairpin resolution later in the reaction. We show that base flipping in Tn10 transposition is not a passive reaction in which a spontaneously flipped base is captured and retained by the protein. Rather, it is driven in part by a methionine probe residue that helps to force the flipped base from the base stack. Overall, it appears that base flipping in Tn10 transposition is similar to that in Tn5 transposition.

  8. Development of vacuum underfill technology for a 3D chip stack

    Science.gov (United States)

    Sakuma, Katsuyuki; Kohara, Sayuri; Sueoka, Kuniaki; Orii, Yasumitsu; Kawakami, Mikio; Asai, Kazuo; Hirayama, Yoshikazu; Knickerbocker, John U.

    2011-03-01

    We developed a vacuum underfill technology for 3D chip stacks and for flip chips in high performance system integration. We fabricated a 3D prototype chip stack using the vacuum underfill technology to apply the adhesive. The underfill was injected into each 6 µm gaps in a 3-layer chip stack and no voids were detected in acoustic microscopy images. Electrical tests and thermal reliability tests were used to measure the resistance of the vertical interconnections and the impact of the underfill. The results showed there was minimal difference in the average interconnection resistance of the chip stack with and without underfill.

  9. Attachment method for stacked integrated circuit (IC) chips

    Energy Technology Data Exchange (ETDEWEB)

    Bernhardt, Anthony F. (Berkeley, CA); Malba, Vincent (Livermore, CA)

    1999-01-01

    An attachment method for stacked integrated circuit (IC) chips. The method involves connecting stacked chips, such as DRAM memory chips, to each other and/or to a circuit board. Pads on the individual chips are rerouted to form pads on the side of the chip, after which the chips are stacked on top of each other whereby desired interconnections to other chips or a circuit board can be accomplished via the side-located pads. The pads on the side of a chip are connected to metal lines on a flexible plastic tape (flex) by anisotropically conductive adhesive (ACA). Metal lines on the flex are likewise connected to other pads on chips and/or to pads on a circuit board. In the case of a stack of DRAM chips, pads to corresponding address lines on the various chips may be connected to the same metal line on the flex to form an address bus. This method has the advantage of reducing the number of connections required to be made to the circuit board due to bussing; the flex can accommodate dimensional variation in the alignment of chips in the stack; bonding of the ACA is accomplished at low temperature and is otherwise simpler and less expensive than solder bonding; chips can be bonded to the ACA all at once if the sides of the chips are substantially coplanar, as in the case for stacks of identical chips, such as DRAM.

  10. Attachment method for stacked integrated circuit (IC) chips

    Energy Technology Data Exchange (ETDEWEB)

    Bernhardt, A.F.; Malba, V.

    1999-08-03

    An attachment method for stacked integrated circuit (IC) chips is disclosed. The method involves connecting stacked chips, such as DRAM memory chips, to each other and/or to a circuit board. Pads on the individual chips are rerouted to form pads on the side of the chip, after which the chips are stacked on top of each other whereby desired interconnections to other chips or a circuit board can be accomplished via the side-located pads. The pads on the side of a chip are connected to metal lines on a flexible plastic tape (flex) by anisotropically conductive adhesive (ACA). Metal lines on the flex are likewise connected to other pads on chips and/or to pads on a circuit board. In the case of a stack of DRAM chips, pads to corresponding address lines on the various chips may be connected to the same metal line on the flex to form an address bus. This method has the advantage of reducing the number of connections required to be made to the circuit board due to bussing; the flex can accommodate dimensional variation in the alignment of chips in the stack; bonding of the ACA is accomplished at low temperature and is otherwise simpler and less expensive than solder bonding; chips can be bonded to the ACA all at once if the sides of the chips are substantially coplanar, as in the case for stacks of identical chips, such as DRAM. 12 figs.

  11. How we flipped the medical classroom.

    Science.gov (United States)

    Sharma, Neel; Lau, C S; Doherty, Iain; Harbutt, Darren

    2015-04-01

    Flipping the classroom centres on the delivery of print, audio or video based material prior to a lecture or class session. The class session is then dedicated to more active learning processes with application of knowledge through problem solving or case based scenarios. The rationale behind this approach is that teachers can spend their face-to-face time supporting students in deeper learning processes. In this paper we provide a background literature review on the flipped classroom along with a three step approach to flipping the classroom comprising implementing, enacting and evaluating this form of pedagogy. Our three step approach is based on actual experience of delivering a flipped classroom at the University of Hong Kong. This initiative was evaluated with positive results. We hope our experience will be transferable to other medical institutions.

  12. En didaktisk model for Flipped Classroom

    DEFF Research Database (Denmark)

    Levinsen, Henrik; Foss, Kristian Kildemoes; Andersen, Thomas Dyreborg

    2016-01-01

    I artiklen præsenterer vi en model over flipped classroom som didaktisk metode udviklet med henblik på at stilladsere både de lærere, som gerne vil prøve kræfter med en flipped classroom-baseret praksis, og dem som allerede har erfaring, men kan have glæde af at bruge modellen til at kvalificere...... deres flipped classroom-undervisning. Modellen kan bidrage til erkendelsen af, at flipped classroom er noget nær et paradigmeskifte i forståelsen af god undervisning. Her tænkes på det skift i fokus metoden indebærer fra, at læreren er mest aktiv, til at eleverne er de mest aktive. Særligt for den...

  13. A scalable multi-chip architecture to realise large-format microshutter arrays for coded aperture applications

    Science.gov (United States)

    McNie, Mark E.; King, David O.; Smith, Gilbert W.; Stone, Steven M.; Brown, Alan G.; Gordon, Neil T.; Slinger, Christopher W.; Cannon, Kevin; Riches, Stephen; Rogers, Stanley

    2009-08-01

    Coded aperture imaging has been used for astronomical applications for several years. Typical implementations used a fixed mask pattern and are designed to operate in the X-Ray or gamma ray bands. Recently applications have emerged in the visible and infra red bands for low cost lens-less imaging systems and system studies have shown that considerable advantages in image resolution may accrue from the use of multiple different images of the same scene - requiring a reconfigurable mask. Previously we reported on the realization of a 2x2cm single chip mask in the mid-IR based on polysilicon micro-opto-electro-mechanical systems (MOEMS) technology and its integration with ASIC drive electronics using conventional wire bonding. The MOEMS architecture employs interference effects to modulate incident light - achieved by tuning a large array of asymmetric Fabry-Perot optical cavities via an applied voltage and uses a hysteretic row/column scheme for addressing. In this paper we present the latest transmission results in the mid-IR band (3-5μm) and report on progress in developing a scalable architecture based on a tiled approach using multiple 2 x 2cm MOEMS chips with associated control ASICs integrated using flip chip technology. Initial work has focused on a 2 x 2 tiled array as a stepping stone towards an 8 x 8 array.

  14. Flip to Regular Triangulation and Convex Hull.

    Science.gov (United States)

    Gao, Mingcen; Cao, Thanh-Tung; Tan, Tiow-Seng

    2017-02-01

    Flip is a simple and local operation to transform one triangulation to another. It makes changes only to some neighboring simplices, without considering any attribute or configuration global in nature to the triangulation. Thanks to this characteristic, several flips can be independently applied to different small, non-overlapping regions of one triangulation. Such operation is favored when designing algorithms for data-parallel, massively multithreaded hardware, such as the GPU. However, most existing flip algorithms are designed to be executed sequentially, and usually need some restrictions on the execution order of flips, making them hard to be adapted to parallel computation. In this paper, we present an in depth study of flip algorithms in low dimensions, with the emphasis on the flexibility of their execution order. In particular, we propose a series of provably correct flip algorithms for regular triangulation and convex hull in 2D and 3D, with implementations for both CPUs and GPUs. Our experiment shows that our GPU implementation for constructing these structures from a given point set achieves up to two orders of magnitude of speedup over other popular single-threaded CPU implementation of existing algorithms.

  15. ConfChem Conference on Flipped Classroom: Flipping at an Open-Enrollment College

    Science.gov (United States)

    Butzler, Kelly B.

    2015-01-01

    The flipped classroom is a blended, constructivist learning environment that reverses where students gain and apply knowledge. Instructors from K-12 to the college level are interested in the prospect of flipping their classes, but are unsure how and with which students to implement this learning environment. There has been little discussion…

  16. Research on Flipping College Algebra: Lessons Learned and Practical Advice for Flipping Multiple Sections

    Science.gov (United States)

    Overmyer, Jerry

    2015-01-01

    This quantitative research compares five sections of College Algebra using flipped classroom methods with six sections using the traditional lecture/homework structure and its effect on student achievement as measured through a common final exam. Common final exam scores were the dependent variables. Instructors of flipped sections who had…

  17. Research on Flipping College Algebra: Lessons Learned and Practical Advice for Flipping Multiple Sections

    Science.gov (United States)

    Overmyer, Jerry

    2015-01-01

    This quantitative research compares five sections of College Algebra using flipped classroom methods with six sections using the traditional lecture/homework structure and its effect on student achievement as measured through a common final exam. Common final exam scores were the dependent variables. Instructors of flipped sections who had…

  18. Characterization of edgeless pixel detectors coupled to Medipix2 readout chip

    Science.gov (United States)

    Kalliopuska, Juha; Tlustos, Lukas; Eränen, Simo; Virolainen, Tuula

    2011-08-01

    VTT has developed a straightforward and fast process to fabricate four-side buttable (edgeless) microstrip and pixel detectors on 6 in. (150 mm) wafers. The process relies on advanced ion implantation to activate the edges of the detector instead of using polysilicon. The article characterizes 150 μm thick n-on-n edgeless pixel detector prototypes with a dead layer at the edge below 1 μm. Electrical and radiation response characterization of 1.4×1.4 cm2 n-on-n edgeless detectors has been done by coupling them to the Medipix2 readout chips. The distance of the detector's physical edge from the pixels was either 20 or 50 μm. The leakage current of flip-chip bonded edgeless Medipix2 detector assembles were measured to be ˜90 nA/cm2 and no breakdown was observed below 110 V. Radiation response characterization includes X-ray tube and radiation source responses. The characterization results show that the detector's response at the pixels close to the physical edge of the detector depend dramatically on the pixel-to-edge distance.

  19. Ion chromatography on-chip.

    Science.gov (United States)

    Murrihy, J P; Breadmore, M C; Tan, A; McEnery, M; Alderman, J; O'Mathuna, C; O'Neill, A P; O'Brien, P; Avdalovic, N; Haddad, P R; Glennon, J D; Advoldvic, N

    2001-07-27

    On-chip separation of inorganic anions by ion-exchange chromatography was realized. Micro separation channels were fabricated on a silicon wafer and sealed with a Pyrex cover plate using standard photolithography, wet and dry chemical etching, and anodic bonding techniques. Quaternary ammonium latex particles were employed for the first time to coat the separation channels on-chip. Owing to the narrow depths of the channels on the chip, 0.5-10 microm, there were more interactions of the analytes with the stationary phase on the chip than in a 50-microm I.D. capillary. With off-chip injection (20 nl) and UV detection, NO2-, NO3-, I-, and thiourea were separated using 1 mM KCl as the eluent. The linear ranges for NO2- and NO3- are from 5 to 1000 microM with the detection limits of 0.5 microM.

  20. Use of Flipped Classroom Technology in Language Learning

    OpenAIRE

    Evseeva, Arina; Solozhenko, Anton

    2015-01-01

    The flipped classroom as a key component of blended learning arouses great interest among researchers and educators nowadays. The technology of flipped classroom implies such organization of the educational process in which classroom activities and homework assignments are reversed. The present paper gives the overview of the flipped classroom technology and explores its potential for both teachers and students. The authors present the results obtained from the experience of the flipped class...

  1. Microfluidic on chip viscometers.

    Science.gov (United States)

    Chevalier, J; Ayela, F

    2008-07-01

    We present the design and the process of fabrication of micromachined capillary on chip rheometers which have performed wall shear stress and shear rate measurements on silicon oil and ethanol-based nanofluids. The originality of these devices comes from the fact that local pressure drop measurements are performed inside the microchannels. Thus, the advantage over existing microviscometers is that they can be used with the fluid under test alone; no reference fluid nor posttreatment of the data are needed. Each on chip viscometer consists of anodically bonded silicon-Pyrex derivative microchannels equipped with local probes. The anodic bonding allows to reach relatively high pressure levels (up to approximately 10 bars) in the channels, and a broad range of shear stress and shear rate values is attainable. Dielectrophoretic and electrorheological effects can be highlighted by employing alternate microstripe electrodes patterned onto the inner side of the Pyrex wall.

  2. Bridging the gap with flipped classroom

    DEFF Research Database (Denmark)

    Selberg, Hanne; Topperzer, Martha

    2016-01-01

    Bridging the gap with flipped classroom Hanne Selberg, Metropolitan University College, Copenhagen, Martha Topperzer, University Hospital Rigshospitalet, Copenhagen, Denmark Background and aims Consistent with the strategy of increasing digitization and learner-centred teaching models...... in the nursing curriculum, we have reversed selected traditional lectures into simulation based teaching activities embedded in a ten week Pediatric Nursing module for third year nursing students. The current pilot study seeks to explore the impact on students’ learning and commitment when flipping the classroom...... using educational technologies such as online preparation contents and simulation based scenarios. Furthermore, the objective is to enhance theory-practice integration in the educational setting. Materials & Methods The flipped classroom model replaces three theoretical lectures addressing disease...

  3. Flipping the statistics classroom in nursing education.

    Science.gov (United States)

    Schwartz, Todd A

    2014-04-01

    Flipped classrooms are so named because they substitute the traditional lecture that commonly encompasses the entire class period with active learning techniques, such as small-group work. The lectures are delivered instead by using an alternative mode--video recordings--that are made available for viewing online outside the class period. Due to this inverted approach, students are engaged with the course material during the class period, rather than participating only passively. This flipped approach is gaining popularity in many areas of education due to its enhancement of student learning and represents an opportunity for utilization by instructors of statistics courses in nursing education. This article presents the author's recent experiences with flipping a statistics course for nursing students in a PhD program, including practical considerations and student outcomes and reaction. This transformative experience deepened the level of student learning in a way that may not have occurred using a traditional format.

  4. Experimental plug and play quantum coin flipping

    Science.gov (United States)

    Pappa, Anna; Jouguet, Paul; Lawson, Thomas; Chailloux, André; Legré, Matthieu; Trinkler, Patrick; Kerenidis, Iordanis; Diamanti, Eleni

    2014-04-01

    Performing complex cryptographic tasks will be an essential element in future quantum communication networks. These tasks are based on a handful of fundamental primitives, such as coin flipping, where two distrustful parties wish to agree on a randomly generated bit. Although it is known that quantum versions of these primitives can offer information-theoretic security advantages with respect to classical protocols, a demonstration of such an advantage in a practical communication scenario has remained elusive. Here we experimentally implement a quantum coin flipping protocol that performs strictly better than classically possible over a distance suitable for communication over metropolitan area optical networks. The implementation is based on a practical plug and play system, developed by significantly enhancing a commercial quantum key distribution device. Moreover, we provide combined quantum coin flipping protocols that are almost perfectly secure against bounded adversaries. Our results offer a useful toolbox for future secure quantum communications.

  5. Stochastic Flips on Two-letter Words

    CERN Document Server

    Bodini, Olivier; Regnault, Damien

    2010-01-01

    This paper introduces a simple Markov process inspired by the problem of quasicrystal growth. It acts over two-letter words by randomly performing \\emph{flips}, a local transformation which exchanges two consecutive different letters. More precisely, only the flips which do not increase the number of pairs of consecutive identical letters are allowed. Fixed-points of such a process thus perfectly alternate different letters. We show that the expected number of flips to converge towards a fixed-point is bounded by $O(n^3)$ in the worst-case and by $O(n^{5/2}\\ln{n})$ in the average-case, where $n$ denotes the length of the initial word.

  6. Coding Education in a Flipped Classroom

    Directory of Open Access Journals (Sweden)

    Vasfi Tugun

    2017-08-01

    Full Text Available The main purpose of this research is to determine the influence of the flipped classroom model on digital game development and student views on the model. 9th grade students attending Bilişim Teknolojiler II at secondary level participated in the study. The research is an experimental research, designed according to the pretest-posttest research model with experimental and control groups. In the experimental group, the lectures were carried out according to the flipped classroom model while the control group was taught with the traditional methods in the laboratory environment. As a result of the research, the success of the digital game development and the opinions of the students were favored by the experimental group students who were educated with the flipped classroom model. The results obtained in the last part of the study and suggestions for the results are discussed.

  7. The flipped classroom: strategies for an undergraduate nursing course.

    Science.gov (United States)

    Schlairet, Maura C; Green, Rebecca; Benton, Melissa J

    2014-01-01

    This article presents the authors' experience with flipping a fundamental concepts of nursing course for students in an undergraduate baccalaureate program. Authors describe implementing a flipped class, practical strategies to transform students' learning experience, and lessons learned. This article serves as a guide to faculty and programs seeking to develop and implement the flipped class model in nursing education.

  8. Impacts of Flipped Classroom in High School Health Education

    Science.gov (United States)

    Chen, Li-Ling

    2016-01-01

    As advanced technology increasingly infiltrated into classroom, the flipped classroom has come to light in secondary educational settings. The flipped classroom is a new instructional approach that intends to flip the traditional teacher-centered classroom into student centered. The purpose of this research is to investigate the impact of the…

  9. Deep Exploration of the Flipped Classroom before Implementing

    Science.gov (United States)

    Logan, Brenda

    2015-01-01

    This paper is a review of the literature that attempts to explain and document the literature on the flipped classroom. It examines 49 studies that explain the flipped approach in the classroom. This paper, particularly, delineates the history, the theory, benefits, criticisms, recommended practices, and what the research on flipping reveals.…

  10. Blended Course with Flipped Classroom Approach

    DEFF Research Database (Denmark)

    Timcenko, Olga; Purwins, Hendrik; Triantafyllou, Evangelia

    2015-01-01

    This paper presents and analyses design decisions and development process of producing teaching materials for a blended course with flipped classroom approach at bachelor level at Aalborg University in Copenhagen, Denmark. Our experiences, as well as students’ reactions and opinions will be descr......This paper presents and analyses design decisions and development process of producing teaching materials for a blended course with flipped classroom approach at bachelor level at Aalborg University in Copenhagen, Denmark. Our experiences, as well as students’ reactions and opinions...

  11. Revisiting fermion helicity flip in Podolsky's Electromagnetism

    CERN Document Server

    Sales, Jorge Henrique; Thibes, Ronaldo

    2016-01-01

    The spin projection of a massive particle onto its direction of motion is called helicity (or "handedness"). It can therefore be positive or negative. When a particle's helicity changes from positive to negative (or vice-versa) due to its interaction with other particles or fields, we say there is a helicity flip. In this work we show that such helicity flip can be seen for an electron of $20 MeV$ of energy interacting with a charged scalar meson through the exchange of a virtual photon. This photon {\\it does not} necessarily need to be Podolsky's proposed photon; in fact, it is independent of it.

  12. Pixel readout chip for the ATLAS experiment

    CERN Document Server

    Ackers, M; Blanquart, L; Bonzom, V; Comes, G; Fischer, P; Keil, M; Kühl, T; Meuser, S; Delpierre, P A; Treis, J; Raith, B A; Wermes, N

    1999-01-01

    Pixel detectors with a high granularity and a very large number of sensitive elements (cells) are a very recent development used for high precision particle detection. At the Large Hadron Collider LHC at CERN (Geneva) a pixel detector with 1.4*10/sup 8/ individual pixel cells is developed for the ATLAS detector. The concept is a hybrid detector. Consisting of a pixel sensor connected to a pixel electronics chip by bump and flip chip technology in one-to-one cell correspondence. The development and prototype results of the pixel front end chip are presented together with the physical and technical requirements to be met at LHC. Lab measurements are reported. (6 refs).

  13. Toggling bistable atoms via mechanical switching of bond angle.

    Science.gov (United States)

    Sweetman, Adam; Jarvis, Sam; Danza, Rosanna; Bamidele, Joseph; Gangopadhyay, Subhashis; Shaw, Gordon A; Kantorovich, Lev; Moriarty, Philip

    2011-04-01

    We reversibly switch the state of a bistable atom by direct mechanical manipulation of bond angle using a dynamic force microscope. Individual buckled dimers at the Si(100) surface are flipped via the formation of a single covalent bond, actuating the smallest conceivable in-plane toggle switch (two atoms) via chemical force alone. The response of a given dimer to a flip event depends critically on both the local and nonlocal environment of the target atom-an important consideration for future atomic scale fabrication strategies.

  14. An automated 55 GHz cryogenic Josephson sampling oscilloscope

    DEFF Research Database (Denmark)

    Bodin, P.; Jacobsen, M. L.; Kyhle, Anders

    1993-01-01

    A computer-automated superconductive 55 GHz sampling oscilloscope based on 4 kA/cm2, Nb/Nb2O5/Pb edge Josephson junctions is presented. The Josephson sampler chip was flip-chip bonded to a carrier chip with a coplanar transmission line by use of a novel flip-chip bonding machine. A 5.6 ps step pu...

  15. CODIMENSION 3 BIFURCATIONS OF HOMOCLINIC ORBITS WITH ORBIT FLIPS AND INCLINATION FLIPS

    Institute of Scientific and Technical Information of China (English)

    SHUI SHULIANG; ZHU DEMING

    2004-01-01

    The homoclinic bifurcations in four dimensional vector fields are investigated by setting up a local coordinates near the homoclinic orbit. This homoclinic orbit is nonprincipal in the meanings that its positive semi-orbit takes orbit flip and its unstable foliation takes inclination flip. The existence, nonexistence, uniqueness and coexistence of the 1-homoclinic orbit and the 1-periodic orbit are studied. The existence of the twofold periodic orbit and three-fold periodic orbit are also obtained.

  16. Performance and Perception in the Flipped Classroom

    Science.gov (United States)

    Blair, Erik; Maharaj, Chris; Primus, Simone

    2016-01-01

    Changes in the conceptualisation of higher education have led to instructional methods that embrace technology as a teaching medium. These changes have led to the flipped classroom phenomenon--where content is delivered outside class, through media such as video and podcast, and engagement with the content, through problem-solving and/or group…

  17. The Flipped Classroom in World History

    Science.gov (United States)

    Gaughan, Judy E.

    2014-01-01

    The flipped Classroom is one in which lectures are presented as homework outside of class in online videos so that class time is reserved for engaging directly with the materials. This technique offers more personalized guidance and interaction with students, instead of lecturing. In this article, Judy Gaughan details her journey through choosing…

  18. Flipped Classrooms for Advanced Science Courses

    Science.gov (United States)

    Tomory, Annette; Watson, Sunnie Lee

    2015-01-01

    This article explains how issues regarding dual credit and Advanced Placement high school science courses could be mitigated via a flipped classroom instructional model. The need for advanced high school courses will be examined initially, followed by an analysis of advanced science courses and the reform they are experiencing. Finally, it will…

  19. Exploring Flipped Classroom Instruction in Calculus III

    Science.gov (United States)

    Wasserman, Nicholas H.; Quint, Christa; Norris, Scott A.; Carr, Thomas

    2017-01-01

    In an undergraduate Calculus III class, we explore the effect of "flipping" the instructional delivery of content on both student performance and student perceptions. Two instructors collaborated to determine daily lecture notes, assigned the same homework problems, and gave identical exams; however, compared to a more traditional…

  20. 6 Expert Tips for Flipping the Classroom

    Science.gov (United States)

    Demski, Jennifer

    2013-01-01

    In a flipped classroom, professors assign pre-class homework consisting of brief, recorded lectures and presentations, digital readings with collaborative annotation capabilities, and discussion board participation. This frees up classroom time to promote active learning through collaborative, project-based activities using simple display and…

  1. Flip-flopping binary black holes.

    Science.gov (United States)

    Lousto, Carlos O; Healy, James

    2015-04-10

    We study binary spinning black holes to display the long term individual spin dynamics. We perform a full numerical simulation starting at an initial proper separation of d≈25M between equal mass holes and evolve them down to merger for nearly 48 orbits, 3 precession cycles, and half of a flip-flop cycle. The simulation lasts for t=20 000M and displays a total change in the orientation of the spin of one of the black holes from an initial alignment with the orbital angular momentum to a complete antialignment after half of a flip-flop cycle. We compare this evolution with an integration of the 3.5 post-Newtonian equations of motion and spin evolution to show that this process continuously flip flops the spin during the lifetime of the binary until merger. We also provide lower order analytic expressions for the maximum flip-flop angle and frequency. We discuss the effects this dynamics may have on spin growth in accreting binaries and on the observational consequences for galactic and supermassive binary black holes.

  2. Exploring Flipped Classroom Instruction in Calculus III

    Science.gov (United States)

    Wasserman, Nicholas H.; Quint, Christa; Norris, Scott A.; Carr, Thomas

    2017-01-01

    In an undergraduate Calculus III class, we explore the effect of "flipping" the instructional delivery of content on both student performance and student perceptions. Two instructors collaborated to determine daily lecture notes, assigned the same homework problems, and gave identical exams; however, compared to a more traditional…

  3. Flip-OFDM for Unipolar Communication Systems

    CERN Document Server

    Fernando, Nirmal; Viterbo, Emanuele

    2011-01-01

    Unipolar communications systems can transmit information using only real and positive signals. This includes a variety of physical channels ranging from optical (fiber or free-space), to RF wireless using amplitude modulation with non-coherent reception, to baseband single wire communications. Unipolar OFDM techniques enable to efficiently compensate frequency selective distortion in the unipolar communication systems. One of the leading examples of unipolar OFDM is asymmetric clipped optical OFDM (ACO-OFDM) originally proposed for optical communications. Flip-OFDM is an alternative approach that was proposed in a patent, but its performance and full potentials have never been investigated in the literature. In this paper, we first compare Flip-OFDM and ACO-OFDM, and show that both techniques have the same performance but different complexities (Flip-OFDM offers 50% saving). We then propose a new detection scheme, which enables to reduce the noise at the Flip-OFDM receiver by almost 3dB. The analytical perfor...

  4. Flipping an Agricultural Education Teaching Methods Course

    Science.gov (United States)

    Conner, Nathan W.; Stripling, Christopher T.; Blythe, Jessica M.; Roberts, T. Grady; Stedman, Nicole L. P.

    2014-01-01

    Flipping or inverting a course is a relatively new approach to structuring a course. Using this method, the lectures traditionally delivered during regularly scheduled class time are converted to a media for delivery online, often in the form of videos. Learners are expected to view the online lectures prior to class. Then in turn, in-class time…

  5. Using lightboard to flip the course

    DEFF Research Database (Denmark)

    Timcenko, Olga; Triantafyllou, Evangelia; Nilsson, Niels Chr.

    , and exercises for in-class work. However, the quality of videos that students have to watch before coming to the class is also important. In this paper, we will describe videos prepared for flipped classroom using light board, an invention from 2014. That allows natural flow of presentation, as it combines...

  6. Spin flips in generic black hole binaries

    CERN Document Server

    Lousto, Carlos O

    2015-01-01

    We study the spin dynamics of individual black holes in a binary system. In particular we focus on the polar precession of spins and the possibility of a complete flip of spins with respect to the orbital plane. We perform a full numerical simulation that displays these characteristics. We evolve equal mass binary spinning black holes for $t=20,000M$ from an initial proper separation of $d=25M$ down to merger after 48.5 orbits. We compute the gravitational radiation from this system and compare it to 3.5 post-Newtonian generated waveforms finding close agreement. We then further use 3.5 post-Newtonian evolutions to show the extension of this spin {flip-flop} phenomenon to unequal mass binaries. We also provide analytic expressions to approximate the maximum {flip-flop} angle and frequency in terms of the binary spins and mass ratio parameters at a given orbital radius. Finally we discuss the effect this spin {flip-flop} would have on accreting matter and other potential observational effects.

  7. Flip-flops of FK Comae Berenices

    DEFF Research Database (Denmark)

    Hackman, T.; Mantere, M.J.; Jetsu, L.

    2013-01-01

    -2010. The observations were carried out with two automated photometric telescopes, Phoenix-10 and Amadeus T7 located in Arizona. Results. We identify complex phase behaviour in 6 of the 15 analysed data segments. We identify five flip-flop events and two cases of phase jumps, where the phase shift is ¿f

  8. Three dimensional, multi-chip module

    Science.gov (United States)

    Bernhardt, Anthony F.; Petersen, Robert W.

    1993-01-01

    A plurality of multi-chip modules are stacked and bonded around the perimeter by sold-bump bonds to adjacent modules on, for instance, three sides of the perimeter. The fourth side can be used for coolant distribution, for more interconnect structures, or other features, depending on particular design considerations of the chip set. The multi-chip modules comprise a circuit board, having a planarized interconnect structure formed on a first major surface, and integrated circuit chips bonded to the planarized interconnect surface. Around the periphery of each circuit board, long, narrow "dummy chips" are bonded to the finished circuit board to form a perimeter wall. The wall is higher than any of the chips on the circuit board, so that the flat back surface of the board above will only touch the perimeter wall. Module-to-module interconnect is laser-patterned o the sides of the boards and over the perimeter wall in the same way and at the same time that chip to board interconnect may be laser-patterned.

  9. All-optical SR flip-flop based on SOA-MZI switches monolithically integrated on a generic InP platform

    Science.gov (United States)

    Pitris, St.; Vagionas, Ch.; Kanellos, G. T.; Kisacik, R.; Tekin, T.; Broeke, R.; Pleros, N.

    2016-03-01

    At the dawning of the exaflop era, High Performance Computers are foreseen to exploit integrated all-optical elements, to overcome the speed limitations imposed by electronic counterparts. Drawing from the well-known Memory Wall limitation, imposing a performance gap between processor and memory speeds, research has focused on developing ultra-fast latching devices and all-optical memory elements capable of delivering buffering and switching functionalities at unprecedented bit-rates. Following the master-slave configuration of electronic Flip-Flops, coupled SOA-MZI based switches have been theoretically investigated to exceed 40 Gb/s operation, provided a short coupling waveguide. However, this flip-flop architecture has been only hybridly integrated with silica-on-silicon integration technology exhibiting a total footprint of 45x12 mm2 and intra-Flip-Flop coupling waveguide of 2.5cm, limited at 5 Gb/s operation. Monolithic integration offers the possibility to fabricate multiple active and passive photonic components on a single chip at a close proximity towards, bearing promises for fast all-optical memories. Here, we present for the first time a monolithically integrated all-optical SR Flip-Flop with coupled master-slave SOA-MZI switches. The photonic chip is integrated on a 6x2 mm2 die as a part of a multi-project wafer run using library based components of a generic InP platform, fiber-pigtailed and fully packaged on a temperature controlled ceramic submount module with electrical contacts. The intra Flip-Flop coupling waveguide is 5 mm long, reducing the total footprint by two orders of magnitude. Successful flip flop functionality is evaluated at 10 Gb/s with clear open eye diagram, achieving error free operation with a power penalty of 4dB.

  10. ChipSeal Inorganic Sealing Technology for Hermetic-Like Integrated Circuits. Volume 1

    Science.gov (United States)

    2000-09-01

    formation (Kerkendall voiding ) and is more susceptible to corrosive attack under adverse conditions. • Degradation of the metallization stack from...processed devices in standard and flip-chip formats, both with and without epoxy encapsulants or underfills . 17 4. Phase I - ChipSeal Process...significant number of bumps exhibited internal voids (Figure 24). A second reflow eliminated the voids open to the surface (Figure 25), but some

  11. Atom chips

    CERN Document Server

    Reichel, Jakob

    2010-01-01

    This book provides a stimulating and multifaceted picture of a rapidly developing field. The first part reviews fundamentals of atom chip research in tutorial style, while subsequent parts focus on the topics of atom-surface interaction, coherence on atom chips, and possible future directions of atom chip research. The articles are written by leading researchers in the field in their characteristic and individual styles.

  12. Using a SPOC to flip the classroom

    OpenAIRE

    Martínez-Muñoz, Gonzalo; Pulido, Estrella

    2015-01-01

    Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. G. Martínez-Muñoz and E. Pulido, "Using a SPOC to flip the classroom," 2015 IEEE Global Engineering Education Conference (EDUC...

  13. 2-bit Flip Mutation Elementary Fitness Landscapes

    OpenAIRE

    Langdon, William

    2010-01-01

    Genetic Programming parity is not elementary. GP parity cannot be represented as the sum of a small number of elementary landscapes. Statistics, including fitness distance correlation, of Parity's fitness landscape are calculated. Using Walsh analysis the eigen values and eigenvectors of the Laplacian of the two bit flip fitness landscape are given and a ruggedness measure for elementary landscapes is proposed. An elementary needle in a haystack (NIH) landscape is g...

  14. Silicon ball grid array chip carrier

    Science.gov (United States)

    Palmer, David W.; Gassman, Richard A.; Chu, Dahwey

    2000-01-01

    A ball-grid-array integrated circuit (IC) chip carrier formed from a silicon substrate is disclosed. The silicon ball-grid-array chip carrier is of particular use with ICs having peripheral bond pads which can be reconfigured to a ball-grid-array. The use of a semiconductor substrate such as silicon for forming the ball-grid-array chip carrier allows the chip carrier to be fabricated on an IC process line with, at least in part, standard IC processes. Additionally, the silicon chip carrier can include components such as transistors, resistors, capacitors, inductors and sensors to form a "smart" chip carrier which can provide added functionality and testability to one or more ICs mounted on the chip carrier. Types of functionality that can be provided on the "smart" chip carrier include boundary-scan cells, built-in test structures, signal conditioning circuitry, power conditioning circuitry, and a reconfiguration capability. The "smart" chip carrier can also be used to form specialized or application-specific ICs (ASICs) from conventional ICs. Types of sensors that can be included on the silicon ball-grid-array chip carrier include temperature sensors, pressure sensors, stress sensors, inertia or acceleration sensors, and/or chemical sensors. These sensors can be fabricated by IC processes and can include microelectromechanical (MEM) devices.

  15. Experimental Test of“Parity-Time Asymmetry”in Electron Spin-Flip Raman Scattering of the N+H…O Hydrogen Bond in Chiral Alanine Crystals%“宇称-时间不对称”的实验探索:手性丙氨酸单晶NH…O氢键的电子自旋翻转相变的不对称拉曼散射

    Institute of Scientific and Technical Information of China (English)

    王文清; 龚; 沈新春; 张玉凤

    2013-01-01

      手性丙氨酸单晶的极性N+H…O氢键在~270 K的自发对称性破缺,可用变温拉曼振动光谱在b(cc)b几何条件下在线测定.由于其对手性的灵敏度,可以测定D-和L-丙氨酸的N+H…O氢键在电子自旋翻转相变时的微小能差.晶体定向能量的正/负,在于电子自旋的上/下转向,取决于原子内在磁场的方向.变温拉曼振动光谱可以观察到:在D-和L-丙氨酸单晶之间,拉曼散射光子的波数位移方向相反,散射光子的不对称度约为1/3.由于自旋是轴矢量,样品必须是单晶,沿轴向测定.多晶粉末不能观察到相变.与次甲基(Cα-H)在260 K的自旋翻转相变,用变温拉曼振动光谱在c(aa)c几何条件下的相对测量结果接近一致.本实验提供了一条证明真实手性和“宇称-时间(PT)不对称”的新线索.%Spontaneous symmetry breaking of the N+H…O bond in chiral alanine crystals around 270 K was detected in situ by Raman vibrational scattering with b(cc)b geometry. An electron spin-flip transition of the N+H…O mode in D-/L-alanine was observed by the scattering of light with left/right orientation and its spin projection antiparal el to the direction of propagation. It is an internal magnetic field originated from the spin-orbit interaction. An obvious Raman wavenumber shift with opposite in sign and roughly one third of the asymmetry (A) of the scattered photon between D-and L-alanine crystals was observed. This shift was not seen in polycrystal ine powder measurements because spin is an axial vector. An electron spin-flip transition of the methyne (Cα-H) mode around 260 K was shown to be approximative coincidence by examining the temperature-dependent relative intensity of asymmetric Raman scattering with c(aa)c geometry. This article provides evidence for the true chirality and parity-time (PT) asymmetry in molecular clusters of D-and L-alanine crystals.

  16. Assessment of learning gains in a flipped biochemistry classroom.

    Science.gov (United States)

    Ojennus, Deanna Dahlke

    2016-01-01

    The flipped classroom has become an increasingly popular pedagogical approach to teaching and learning. In this study, learning gains were assessed in a flipped biochemistry course and compared to gains in a traditional lecture. Although measured learning gains were not significantly different between the two courses, student perception of learning gains did differ and indicates a higher level of satisfaction with the flipped lecture format. © 2015 The International Union of Biochemistry and Molecular Biology.

  17. Student experiences across multiple flipped courses in a single curriculum.

    Science.gov (United States)

    Khanova, Julia; Roth, Mary T; Rodgers, Jo Ellen; McLaughlin, Jacqueline E

    2015-10-01

    The flipped classroom approach has garnered significant attention in health professions education, which has resulted in calls for curriculum-wide implementations of the model. However, research to support the development of evidence-based guidelines for large-scale flipped classroom implementations is lacking. This study was designed to examine how students experience the flipped classroom model of learning in multiple courses within a single curriculum, as well as to identify specific elements of flipped learning that students perceive as beneficial or challenging. A qualitative analysis of students' comments (n = 6010) from mid-course and end-of-course evaluations of 10 flipped courses (in 2012-2014) was conducted. Common and recurring themes were identified through systematic iterative coding and sorting using the constant comparison method. Multiple coders, agreement through consensus and member checking were utilised to ensure the trustworthiness of findings. Several themes emerged from the analysis: (i) the perceived advantages of flipped learning coupled with concerns about implementation; (ii) the benefits of pre-class learning and factors that negatively affect these benefits, such as quality and quantity of learning materials, as well as overall increase in workload, especially in the context of multiple concurrent flipped courses; (iii) the role of the instructor in the flipped learning environment, particularly in engaging students in active learning and ensuring instructional alignment, and (iv) the need for assessments that emphasise the application of knowledge and critical thinking skills. Analysis of data from 10 flipped courses provided insight into common patterns of student learning experiences specific to the flipped learning model within a single curriculum. The study points to the challenges associated with scaling the implementation of the flipped classroom across multiple courses. Several core elements critical to the effective design

  18. Triggering of spin-flipping-modulated exchange bias in FeCo nanoparticles by electronic excitation

    Science.gov (United States)

    Sarker, Debalaya; Bhattacharya, Saswata; Srivastava, Pankaj; Ghosh, Santanu

    2016-12-01

    The exchange coupling between ferromagnetic (FM)-antiferromagnetic (AF) interfaces is a key element of modern spintronic devices. We here introduce a new way of triggering exchange bias (EB) in swift heavy ion (SHI) irradiated FeCo-SiO2 films, which is a manifestation of spin-flipping at high irradiation fluence. The elongation of FeCo nanoparticles (NPs) in SiO2 matrix gives rise to perpendicular magnetic anisotropy at intermediate fluence. However, a clear shift in hysteresis loop is evident at the highest fluence. This reveals the existence of an AF exchange pinning domain in the NPs, which is identified not to be oxide shell from XANES analysis. Thermal spike calculations along with first-principles based simulations under the framework of density functional theory (DFT) demonstrate that spin flipping of 3d valence electrons is responsible for formation of these AF domains inside the FM NPs. EXAFS experiments at Fe and Co K-edges further unravel that spin-flipping in highest fluence irradiated film results in reduced bond lengths. The results highlight the possibility of miniaturization of magnetic storage devices by using irradiated NPs instead of conventionally used FM-AF multilayers.

  19. The flipped classroom: practices and opportunities for health sciences librarians.

    Science.gov (United States)

    Youngkin, C Andrew

    2014-01-01

    The "flipped classroom" instructional model is being introduced into medical and health sciences curricula to provide greater efficiency in curriculum delivery and produce greater opportunity for in-depth class discussion and problem solving among participants. As educators employ the flipped classroom to invert curriculum delivery and enhance learning, health sciences librarians are also starting to explore the flipped classroom model for library instruction. This article discusses how academic and health sciences librarians are using the flipped classroom and suggests opportunities for this model to be further explored for library services.

  20. Characterisation of hybrid integrated all-optical flip-flop

    DEFF Research Database (Denmark)

    Liu, Y.; McDougall, R.; Seoane, Jorge

    2006-01-01

    We present a fully-packaged, hybrid-integrated all-optical flip-flop with separate optical set and reset operation. The flip-flop can control a wavelength converter to route 40 Gb/s data packets all-optically. The experimental results are given.......We present a fully-packaged, hybrid-integrated all-optical flip-flop with separate optical set and reset operation. The flip-flop can control a wavelength converter to route 40 Gb/s data packets all-optically. The experimental results are given....

  1. Immunohistopathological Study of c-FLIP Protein in Mycosis Fungoides

    Science.gov (United States)

    Rezk Hassan, Ghada Fawzy; Marey, Karima

    2017-09-27

    Background: Mycosis fungoides (MF) is the commonest variant of primary cutaneous T cell lymphoma with several clinicopathologic variants. Defective apoptotic mechanism may be important in the pathogenesis and progression of MF. c-FLIP protein is an important anti-apoptotic marker and chemotherapeutic resistant factor. This study aimed to evaluate the c-FLIP expression in MF and its role in the pathogenesis of MF. Methods: Twenty patients of MF and ten normal persons were included in this study. Skin biopsies were obtained from both patients and controls. They were studied and examined immunohistochemically for the expression of CD4 and c-FLIP. Results: c-FLIP expression was significantly increased in patients when compared to controls in both epidermis and dermis. There were positive correlations between c-FLIP expression and CD4+ expression in both epidermal and dermal lesions of patients group. There were statistically significant positive correlations between c-FLIP expression (in both dermal and epidermal lesions) and the age of patients. c-FLIP expression increased with the tumor progression but with no statistical significance. Conclusion: Defective regulation of apoptosis has been considered as a main cause for accumulation of clonal T cells, and it was related to an increased expression of c-FLIP which may have a role in the pathogenesis of MF. Also, c-FLIP may have prognostic information in MF as its level increased with both age of the patients and tumor progression. Creative Commons Attribution License

  2. Flip-invariant SIFT for copy and object detection.

    Science.gov (United States)

    Zhao, Wan-Lei; Ngo, Chong-Wah

    2013-03-01

    Scale-invariant feature transform (SIFT) feature has been widely accepted as an effective local keypoint descriptor for its invariance to rotation, scale, and lighting changes in images. However, it is also well known that SIFT, which is derived from directionally sensitive gradient fields, is not flip invariant. In real-world applications, flip or flip-like transformations are commonly observed in images due to artificial flipping, opposite capturing viewpoint, or symmetric patterns of objects. This paper proposes a new descriptor, named flip-invariant SIFT (or F-SIFT), that preserves the original properties of SIFT while being tolerant to flips. F-SIFT starts by estimating the dominant curl of a local patch and then geometrically normalizes the patch by flipping before the computation of SIFT. We demonstrate the power of F-SIFT on three tasks: large-scale video copy detection, object recognition, and detection. In copy detection, a framework, which smartly indices the flip properties of F-SIFT for rapid filtering and weak geometric checking, is proposed. F-SIFT not only significantly improves the detection accuracy of SIFT, but also leads to a more than 50% savings in computational cost. In object recognition, we demonstrate the superiority of F-SIFT in dealing with flip transformation by comparing it to seven other descriptors. In object detection, we further show the ability of F-SIFT in describing symmetric objects. Consistent improvement across different kinds of keypoint detectors is observed for F-SIFT over the original SIFT.

  3. Mapping of low flip angles in magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Balezeau, Fabien; Saint-Jalmes, Herve [LTSI, INSERM U642, Universite Rennes 1 (France); Eliat, Pierre-Antoine [PRISM, IFR 140, Universite Rennes 1 (France); Cayamo, Alejandro Bordelois, E-mail: fabien.balezeau@gmail.com [Centro De BiofIsika Medica, Universidad de Oriente, Santiago de Cuba (Cuba)

    2011-10-21

    Errors in the flip angle have to be corrected in many magnetic resonance imaging applications, especially for T1 quantification. However, the existing methods of B1 mapping fail to measure lower values of the flip angle despite the fact that these are extensively used in dynamic acquisition and 3D imaging. In this study, the nonlinearity of the radiofrequency (RF) transmit chain, especially for very low flip angles, is investigated and a simple method is proposed to accurately determine both the gain of the RF transmitter and the B1 field map for low flip angles. The method makes use of the spoiled gradient echo sequence with long repetition time (TR), such as applied in the double-angle method. It uses an image acquired with a flip angle of 90{sup 0} as a reference image that is robust to B1 inhomogeneity. The ratio of the image at flip angle alpha to the image at a flip angle of 90{sup 0} enables us to calculate the actual value of alpha. This study was carried out at 1.5 and 4.7 T, showing that the linearity of the RF supply system is highly dependent on the hardware. The method proposed here allows us to measure the flip angle from 1{sup 0} to 60{sup 0} with a maximal uncertainty of 10% and to correct T1 maps based on the variable flip angle method.

  4. Flipped classroom model for learning evidence-based medicine

    National Research Council Canada - National Science Library

    Rucker SY; Ozdogan Z; Al Achkar M

    2017-01-01

    .... A flipped classroom model appears to be an ideal strategy to meet the demands to connect evidence to practice while creating engaged, culturally competent, and technologically literate physicians...

  5. Hybrid polymer waveguide characterization for microoptical tools with integrated laser diode chips for optogenetic applications at 430 nm and 650 nm

    Science.gov (United States)

    Schwaerzle, Michael; Nehlich, Julian; Schwarz, Ulrich T.; Paul, Oliver; Ruther, Patrick

    2016-03-01

    Appropriate micro-optical tools are required to exploit the key advantages of optogenetics in neuroscience, i.e. optical stimulation and inhibition of neural tissue at high spatial as well as temporal resolutions, providing cell specificity and the opportunity to simultaneously record electrophysiological signals. Besides the need for minimally invasive probes mandatory for a reduced tissue damage, highly flexible or wireless interfaces are demanded for experiments with freely behaving animals. Both these technical system requirements are achieved by integrating miniaturized waveguides for light transmission combined with bare laser diode (LD) chips integrated directly into neural probes. This paper describes a system concept using integrated, side emitting LD chips directly coupled to miniaturized waveguides implemented on silicon (Si) substrates. It details the fabrication, assembly, and optical as well as electrical characterization of waveguides (WG) made from the hybrid polymer Ormorcere. The WGs were photolithographically patterned to have a cross-section of 20x15 μm2. Bare LD chips are flip-chip bonded to electroplated gold (Au) pads with +/-5 μm accuracy relative to the WG facets. Transmitted radiant fluxes for blue (430 nm, (Al,In)GaN) and red (650 nm, AlGaInP) LDs are measured to be 150 μW (ID = 35 mA, 5% duty cycle) and 4.35 μW (ID = 225 mA, 0.5% duty cycle), respectively. This corresponds to an efficiency of the coupled and transmitted light of 44% for the red LDs. Long term measurements for 24 h using these systems with red LDs showed a decrease of the radiant flux of about 4% caused by LD aging at stable WG transmission properties. WGs immersed into Ringer's solution showed no significant change of their optical transmission properties after four weeks of exposure to the ionic solution.

  6. The spin-flip extended single excitation configuration interaction method

    Science.gov (United States)

    Casanova, David; Head-Gordon, Martin

    2008-08-01

    An extension of the spin-flip single excitation configuration interaction (SF-CIS) method is introduced. The extension, abbreviated as SF-XCIS, includes all configurations in which no more than one virtual level of the high spin triplet reference becomes occupied and no more than one doubly occupied level becomes vacant. The number of such configurations is quadratic with molecule size, and the method is implemented in a direct algorithm whose cost scales in the same way with molecule size as CIS itself, thus permitting applications to large systems. Starting from a spin restricted triplet determinant, SF-XCIS yields spin-pure singlet, triplet, and quintet states, and treats both half-occupied reference orbitals in a fully balanced way to allow application to strongly correlated problems. Tests on bond dissociation in the HF molecule, the torsional potential of ethylene, and excited states of polyenes show encouraging improvements using SF-XCIS compared to SF-CIS and a previously suggested extension, the spin-complete CIS model.

  7. Flip or Flop? Students' Perspectives of a Flipped Lecture in Mathematics

    Science.gov (United States)

    Novak, Julia; Kensington-Miller, Barbara; Evans, Tanya

    2017-01-01

    This paper describes students' perspectives of a one-off flipped lecture in a large undergraduate mathematics service course. The focus was on calculating matrix determinants and was designed specifically to introduce debate and argumentation into a mathematics lecture. The intention was to promote a deeper learning and understanding through…

  8. Students, Parents Give Thumbs-Up to Flipped Classroom

    Science.gov (United States)

    Pearson, George

    2012-01-01

    The Flipped Classroom isn't for everyone, but it's been well received by Math and Biology students and their parents at Okanagan Mission Secondary School (OKM) in Kelowna, B.C., and was strongly supported by the OKM principal, Scott Mclean. As teacher Graham Johnson noted in his personal account of his first year using the Flipped Classroom…

  9. Case Study: Case Studies and the Flipped Classroom

    Science.gov (United States)

    Herreid, Clyde Freeman; Schiller, Nancy A.

    2013-01-01

    This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue discusses the positive and negative aspects of the "flipped classroom." In the flipped classroom model, what is normally done in class and what is normally done as…

  10. Flipped Classroom Research and Trends from Different Fields of Study

    Science.gov (United States)

    Zainuddin, Zamzami; Halili, Siti Hajar

    2016-01-01

    This paper aims to analyse the trends and contents of flipped classroom research based on 20 articles that report on flipped learning classroom initiatives from 2013-2015. The content analysis was used as a methodology to investigate methodologies, area of studies, technology tools or online platforms, the most frequently used keywords and works…

  11. Flipped Classrooms and Student Learning: Not Just Surface Gains

    Science.gov (United States)

    McLean, Sarah; Attardi, Stefanie M.; Faden, Lisa; Goldszmidt, Mark

    2016-01-01

    The flipped classroom is a relatively new approach to undergraduate teaching in science. This approach repurposes class time to focus on application and discussion; the acquisition of basic concepts and principles is done on the students' own time before class. While current flipped classroom research has focused on student preferences and…

  12. Malaysian Students' Perceptions of Flipped Classroom: A Case Study

    Science.gov (United States)

    Zainuddin, Zamzami; Attaran, Mohammad

    2016-01-01

    The purpose of this study was to evaluate a class in University of Malaya where flipped learning was applied, and to examine students' perceptions and feedback towards flipped classroom. Data were collected using both quantitative and qualitative methods, i.e. survey, focus group and individual interviews. The results indicated that most students…

  13. Case Study: Guidelines for Producing Videos to Accompany Flipped Cases

    Science.gov (United States)

    Prud'homme-Généreux, Annie; Schiller, Nancy A.; Wild, John H.; Herreid, Clyde Freeman

    2017-01-01

    Three years ago, the "National Center for Case Study Teaching in Science" (NCCSTS) was inspired to merge the case study and flipped classroom approaches. The resulting project aimed to create the materials required to teach a flipped course in introductory biology by assigning videos as homework and case studies in the classroom. Three…

  14. Flipping College Algebra: Effects on Student Engagement and Achievement

    Science.gov (United States)

    Ichinose, Cherie; Clinkenbeard, Jennifer

    2016-01-01

    This study compared student engagement and achievement levels between students enrolled in a traditional college algebra lecture course and students enrolled in a "flipped" course. Results showed that students in the flipped class had consistently higher levels of achievement throughout the course than did students in the traditional…

  15. Student Perceptions of the Flipped Classroom in College Algebra

    Science.gov (United States)

    Ogden, Lori

    2015-01-01

    The flipped classroom approach was implemented across three semesters of a College Algebra course. This paper is part of a larger design and development research study and focuses on student perceptions of the flipped classroom teaching approach. Qualitative methodology was used to describe how students perceived the instruction of their College…

  16. Model studies of lipid flip-flop in membranes

    DEFF Research Database (Denmark)

    Parisio, Giulia; Ferrarini, Alberta; Sperotto, Maria Maddalena

    2016-01-01

    for the molecular-level understanding of flip-flop. In this review we present a summary of the state of the art of computational studies of spontaneous flip-flop of phospholipids, sterols and fatty acids. Also, we highlight critical issues and strategies that have been developed to solve them, and what remains...

  17. Flipping the Calculus Classroom: A Cost-Effective Approach

    Science.gov (United States)

    Young, Andrea

    2015-01-01

    This article discusses a cost-effective approach to flipping the calculus classroom. In particular, the emphasis is on low-cost choices, both monetarily and with regards to faculty time, that make the daunting task of flipping a course manageable for a single instructor. Student feedback and overall impressions are also presented.

  18. Flipping a College Calculus Course: A Case Study

    Science.gov (United States)

    Sahin, Alpaslan; Cavlazoglu, Baki; Zeytuncu, Yunus E.

    2015-01-01

    As online videos have become more easily available and more attractive to the new generation of students, and as new student-learning approaches tend to have more technology integration, the flipped classroom model has become very popular. The purpose of this study was to understand college students' views on flipped courses and investigate how…

  19. Flipping the Calculus Classroom: A Cost-Effective Approach

    Science.gov (United States)

    Young, Andrea

    2015-01-01

    This article discusses a cost-effective approach to flipping the calculus classroom. In particular, the emphasis is on low-cost choices, both monetarily and with regards to faculty time, that make the daunting task of flipping a course manageable for a single instructor. Student feedback and overall impressions are also presented.

  20. On Flipping First-Semester Calculus: A Case Study

    Science.gov (United States)

    Petrillo, Joseph

    2016-01-01

    High failure rates in calculus have plagued students, teachers, and administrators for decades, while science, technology, engineering, and mathematics programmes continue to suffer from low enrollments and high attrition. In an effort to affect this reality, some educators are "flipping" (or inverting) their classrooms. By flipping, we…

  1. On Flipping First-Semester Calculus: A Case Study

    Science.gov (United States)

    Petrillo, Joseph

    2016-01-01

    High failure rates in calculus have plagued students, teachers, and administrators for decades, while science, technology, engineering, and mathematics programmes continue to suffer from low enrollments and high attrition. In an effort to affect this reality, some educators are "flipping" (or inverting) their classrooms. By flipping, we…

  2. A Flipped Spoon and Chin Prompt to Increase Mouth Clean

    Science.gov (United States)

    Dempsey, Jack; Piazza, Cathleen C.; Groff, Rebecca A.; Kozisek, Jennifer M.

    2011-01-01

    We treated the liquid refusal of a 15-month-old girl using 2 antecedent manipulations: flipped spoon and chin prompt. Use of the chin prompt in the absence of the flipped spoon failed to produce increases in mouth clean (a product measure of swallowing). By contrast, modest increases in mouth clean resulted from the implementation of the flipped…

  3. Flipping to Teach the Conceptual Foundations of Successful Workplace Writing

    Science.gov (United States)

    Campbell, Kim Sydow

    2016-01-01

    Flipping originated in science, technology, engineering, and mathematics fields, where didactic transmission of conceptual knowledge has been the standard pedagogy. Flipping has resulted in additional focus on procedural knowledge within class meetings. This article argues that business and professional writing pedagogy, which already focuses…

  4. Application of Flipped Classroom to Vocational College English Teaching

    Institute of Scientific and Technical Information of China (English)

    宋薇

    2014-01-01

    Unlike traditional teaching method,flipped classroom is a form of blended learning in which students learn content online by watching video lecture,usually at home,and students and teachers discuss and solve questions by more personalized guidance and interaction in class,instead of lecturing.Flipped classroom is very useful to vocational college English teaching.

  5. The Perceived Effects of Flipped Teaching on Knowledge Acquisition

    Science.gov (United States)

    Newman, Galen; Kim, Jun-Hyun; Lee, Ryun Jung; Brown, Brandy A.; Huston, Sharon

    2016-01-01

    Increased demands for technological integration in higher education have resulted in new forms of course instruction. Under a flipped approach, students learn course materials outside the classroom while active learning methods are employed inside. This study focuses on the perceived effects of flipped instruction on knowledge acquisition in…

  6. The Implementation of a Flipped Classroom in Foreign Language Teaching

    Science.gov (United States)

    Basal, Ahmet

    2015-01-01

    Alongside the rise of educational technology, many teachers have been taking gradual but innovative steps to redesign their teaching methods. For example, in flipped learning or a flipped classroom, students watch instructional videos outside the classroom and do assignments or engage in activities inside the classroom. Language teachers are one…

  7. Examining Student Perceptions of Flipping an Agricultural Teaching Methods Course

    Science.gov (United States)

    Conner, Nathan W.; Rubenstein, Eric D.; DiBenedetto, Cathy A.; Stripling, Christopher T.; Roberts, T. Grady; Stedman, Nicole L. P.

    2014-01-01

    To meet the needs of the 21st century student, college instructors have been challenged to transform their classrooms from passive to active, "minds-on" learning environments. This qualitative study examined an active learning approach known as a flipped classroom and sought to explore student perceptions of flipping a teaching methods…

  8. Assessment of Learning Gains in a Flipped Biochemistry Classroom

    Science.gov (United States)

    Ojennus, Deanna Dahlke

    2016-01-01

    The flipped classroom has become an increasingly popular pedagogical approach to teaching and learning. In this study, learning gains were assessed in a flipped biochemistry course and compared to gains in a traditional lecture. Although measured learning gains were not significantly different between the two courses, student perception of…

  9. Gradient Descent Bit Flipping Algorithms for Decoding LDPC Codes

    OpenAIRE

    Wadayama, Tadashi; Nakamura, Keisuke; Yagita, Masayuki; Funahashi, Yuuki; Usami, Shogo; Takumi, Ichi

    2007-01-01

    A novel class of bit-flipping (BF) algorithms for decoding low-density parity-check (LDPC) codes is presented. The proposed algorithms, which are called gradient descent bit flipping (GDBF) algorithms, can be regarded as simplified gradient descent algorithms. Based on gradient descent formulation, the proposed algorithms are naturally derived from a simple non-linear objective function.

  10. Flipping College Algebra: Effects on Student Engagement and Achievement

    Science.gov (United States)

    Ichinose, Cherie; Clinkenbeard, Jennifer

    2016-01-01

    This study compared student engagement and achievement levels between students enrolled in a traditional college algebra lecture course and students enrolled in a "flipped" course. Results showed that students in the flipped class had consistently higher levels of achievement throughout the course than did students in the traditional…

  11. Curriculum Design of a Flipped Classroom to Enhance Haematology Learning

    Science.gov (United States)

    Porcaro, Pauline A.; Jackson, Denise E.; McLaughlin, Patricia M.; O'Malley, Cindy J.

    2016-01-01

    A common trend in higher education is the "flipped" classroom, which facilitates active learning during class. The flipped approach to teaching was instituted in a haematology "major" class and the students' attitudes and preferences for the teaching materials were surveyed. The curriculum design was explicit and involved four…

  12. Assessing the Flipped Classroom in Operations Management: A Pilot Study

    Science.gov (United States)

    Prashar, Anupama

    2015-01-01

    The author delved into the results of a flipped classroom pilot conducted for an operations management course module. It assessed students' perception of a flipped learning environment after making them experience it in real time. The classroom environment was construed using a case research approach and students' perceptions were studied using…

  13. The Flipped Class: Experience in a University Business Communication Course

    Science.gov (United States)

    Sherrow, Tammy; Lang, Brenda; Corbett, Rod

    2016-01-01

    Business, like many other programs in higher education, continues to rely largely on traditional classroom environments. In this article, another approach to teaching and learning, the flipped classroom, is explored. After a review of relevant literature, the authors present their experience with the flipped classroom approach to teaching and…

  14. Using Presentation Software to Flip an Undergraduate Analytical Chemistry Course

    Science.gov (United States)

    Fitzgerald, Neil; Li, Luisa

    2015-01-01

    An undergraduate analytical chemistry course has been adapted to a flipped course format. Course content was provided by video clips, text, graphics, audio, and simple animations organized as concept maps using the cloud-based presentation platform, Prezi. The advantages of using Prezi to present course content in a flipped course format are…

  15. Exploring Flipped Classroom Effects on Second Language Learners' Cognitive Processing

    Science.gov (United States)

    Kim, Jeong-eun; Park, Hyunjin; Jang, Mijung; Nam, Hosung

    2017-01-01

    This study investigated the cognitive effects of the flipped classroom approach in a content-based instructional context by comparing second language learners' discourse in flipped vs. traditional classrooms in terms of (1) participation rate, (2) content of comments, (3) reasoning skills, and (4) interactional patterns. Learners in two intact…

  16. Partially Flipped Linear Algebra: A Team-Based Approach

    Science.gov (United States)

    Carney, Debra; Ormes, Nicholas; Swanson, Rebecca

    2015-01-01

    In this article we describe a partially flipped Introductory Linear Algebra course developed by three faculty members at two different universities. We give motivation for our partially flipped design and describe our implementation in detail. Two main features of our course design are team-developed preview videos and related in-class activities.…

  17. Application of Flipped Classroom to Vocational College English Teaching

    Institute of Scientific and Technical Information of China (English)

    宋薇

    2014-01-01

    Unlike traditional teaching method,flipped classroom is a form of blended learning in which students learn content online by watching video lecture,usually at home,and students and teachers discuss and solve questions by more personalized guidance and interaction in class,instead of lecturing. Flipped classroom is very useful to vocational college English teaching.

  18. The Flipped Class: Experience in a University Business Communication Course

    Science.gov (United States)

    Sherrow, Tammy; Lang, Brenda; Corbett, Rod

    2016-01-01

    Business, like many other programs in higher education, continues to rely largely on traditional classroom environments. In this article, another approach to teaching and learning, the flipped classroom, is explored. After a review of relevant literature, the authors present their experience with the flipped classroom approach to teaching and…

  19. Flipping photons backward: reversed Cherenkov radiation

    Directory of Open Access Journals (Sweden)

    Hongsheng Chen

    2011-01-01

    Full Text Available Charged particles moving faster than light in a medium produce Cherenkov radiation. In traditional, positive index-of-refraction materials this radiation travels forward. Metamaterials, with negative indices of refraction, flip the radiation backward. This readily separates it from the particles, providing higher flexibility in photon manipulation and is useful for particle identification and counting. Here we review recent advances in reversed Cherenkov radiation research, including the first demonstration of backward emission. We also discuss the potential for developing new types of devices, such as ones that pierce invisibility cloaks.

  20. uFlip: Understanding Flash IO Patterns

    DEFF Research Database (Denmark)

    Bouganim, Luc; Jonsson, Bjørn; Bonnet, Philippe

    2009-01-01

    want to establish what kind of IOs should be favored (or avoided) when designing algorithms and architectures for flash-based systems. In this paper, we focus on flash IO patterns, that capture relevant distribution of IOs in time and space, and our goal is to quantify their performance. We define u......FLIP, a benchmark for measuring the response time of flash IO patterns. We also present a benchmarking methodology which takes into account the particular characteristics of flash devices. Finally, we present the results obtained by measuring eleven flash devices, and derive a set of design hints that should drive...

  1. Pass transistor Based Negative Edge Trigged D Flip Flop (PTDFF

    Directory of Open Access Journals (Sweden)

    S. P. Nagamani Bai

    2014-04-01

    Full Text Available In this paper a new technique is proposed based on the comparison between Conventional Transistorized Flipflopand Data transition Look ahead D flip flop here we are checking the working of DLDFF and the conventional D Flip-flop after that we are analyzing the characteristic comparison using power & area constraints after that we are proposing a Negative Edge triggered flip-flop named as Passtransistor based negative edge trigged D Flip Flop(PTDFF with reduced number of transistors which will reduce the overall power area as well as delay. The simulations are done using Microwind& DSCH analysis software tools and the result between all those types are listed below. Our proposed system simulations are done under 50nm technology and the results are tabulated below. In that our proposed system is showing better output than the other flip-flops compared here.

  2. Pixelized M-pi-n CdTe detector coupled to Medipix2 readout chip

    CERN Document Server

    Kalliopuska, J; Penttila, R; Andersson, H; Nenonen, S; Gadda, A; Pohjonen, H; Vanttajac, I; Laaksoc, P; Likonen, J

    2011-01-01

    We have realized a simple method for patterning an M-pi-n CdTe diode with a deeply diffused pn-junction, such as indium anode on CdTe. The method relies on removing the semiconductor material on the anode-side of the diode until the physical junction has been reached. The pixelization of the p-type CdTe diode with an indium anode has been demonstrated by patterning perpendicular trenches with a high precision diamond blade and pulsed laser. Pixelization or microstrip pattering can be done on both sides of the diode, also on the cathode-side to realize double sided detector configuration. The article compares the patterning quality of the diamond blade process, pulsed pico-second and femto-second lasers processes. Leakage currents and inter-strip resistance have been measured and are used as the basis of the comparison. Secondary ion mass spectrometry (SIMS) characterization has been done for a diode to define the pn-junction depth and to see the effect of the thermal loads of the flip-chip bonding process. Th...

  3. A Quasi Experiment to Determine the Effectiveness of a "Partially Flipped" versus "Fully Flipped" Undergraduate Class in Genetics and Evolution

    Science.gov (United States)

    Adams, Alison E. M.; Garcia, Jocelyn; Traustadóttir, Tinna

    2016-01-01

    Two sections of Genetics and Evolution were taught by one instructor. One group (the fully flipped section) had the entire class period devoted to active learning (with background material that had to be watched before class), and the other group (the partially flipped section) had just a portion of class time spent on active learning (with the…

  4. Application of Flipped Classroom in English Majors' Grammar Teaching%Application of Flipped Classroom in English Majors'Grammar Teaching

    Institute of Scientific and Technical Information of China (English)

    滕丽梅

    2016-01-01

    This paper analyzed how flipped classroom facilitated grammar teaching for English majors by indicating the principle status of students in class, shaping good classroom atmosphere of grammar learning and expanding English grammar teaching. Meanwhile, it raised strategies of flipped classroom applied in English majors' grammar teaching such as preparations before class and abundant teaching methods.

  5. Single Chip Sensing of Multiple Gas Flows

    CERN Document Server

    Bruschi, P; Piotto, M

    2008-01-01

    The fabrication and experimental characterization of a thermal flow meter, capable of detecting and measuring two independent gas flows with a single chip, is described. The device is based on a 4 x 4 mm2 silicon chip, where a series of differential micro-anemometers have been integrated together with standard electronic components by means of postprocessing techniques. The innovative aspect of the sensor is the use of a plastic adapter, thermally bonded to the chip, to convey the gas flow only to the areas where the sensors are located. The use of this inexpensive packaging procedure to include different sensing structures in distinct flow channels is demonstrated.

  6. Observations of Langmuir Circulation From FLIP

    Science.gov (United States)

    Smith, J. A.

    2002-12-01

    Langmuir circulation has significance across the marine disciplines. Enhanced deepening and inhibited re-stratification can alter the surface temperature and hence net air-sea exchanges. Organization of bubbles into windrows introduces dramatic sound speed variability and also affects air/sea gas fluxes. Organization of seaweed and plankton affects marine life, including pelagic fisheries. Finally, dispersal by Langmuir circulation is a major component in models for oil-spill tracking and for search-and-rescue operations. To get an adequate picture of the forcing and response of Langmuir circulation (and the wind-mixed layer in general), the observations needed include windstress, directional waves, wave breaking, heat and moisture fluxes, stratification (temperature and salinity profiles), velocity profiles across the mixed layer and thermocline, spacing and orientation of windrows, and a measure of the strength of the circulation (e.g., surface rms velocities). These measurements span both the air/sea interface and the thermocline, and must be maintained continuously for many days to span storms and daily, tidal, and inertial cycles. In addition, the total power requirements exceed that comfortably supplied by batteries or local generation by wind or solar energy. It appears that FLIP is uniquely qualified as a platform from which the required range of measurements may all be made. Findings concerning the evolution and dynamics of Langmuir circulation that were facilitated by FLIP are reviewed and summarized, with emphasis on observations from 1990, 1995, and 2002.

  7. Flipped models in Trinification: A Comprehensive Approach

    CERN Document Server

    Rodríguez, Oscar; Ponce, William A; Rojas, Eduardo

    2016-01-01

    By considering the 3-3-1 and the left-right symmetric models as low energy effective theories of the trinification group, alternative versions of these models are found. The new neutral gauge bosons in the universal 3-3-1 model and its flipped versions are considered; also, the left-right symmetric model and the two flipped variants of it are also studied. For these models, the couplings of the $Z'$ bosons to the standard model fermions are reported. The explicit form of the null space of the vector boson mass matrix for an arbitrary Higgs tensor and gauge group is also presented. In the general framework of the trinification gauge group, and by using the LHC experimental results and EW precision data, limits on the $Z'$ mass and the mixing angle between $Z$ and the new gauge bosons $Z'$ are imposed. The general results call for very small mixing angles in the range $10^{-3}$ radians and $M_{Z'}$ > 2.5 TeV.

  8. Perceptions of Senior-Year ELT Students for Flipped Classroom: A Materials Development Course

    Science.gov (United States)

    Adnan, Müge

    2017-01-01

    This paper describes a structured attempt to integrate the flipped classroom model into a senior-level course at the higher education level. This study's purpose is to examine and compare the impact of flipped classrooms versus non-flipped as a means to contribute to the growing line of research on flipped teaching through an evaluation of both…

  9. Chips 2020

    CERN Document Server

    2016-01-01

    The release of this second volume of CHIPS 2020 coincides with the 50th anniversary of Moore’s Law, a critical year marked by the end of the nanometer roadmap and by a significantly reduced annual rise in chip performance. At the same time, we are witnessing a data explosion in the Internet, which is consuming 40% more electrical power every year, leading to fears of a major blackout of the Internet by 2020. The messages of the first CHIPS 2020, published in 2012, concerned the realization of quantum steps for improving the energy efficiency of all chip functions. With this second volume, we review these messages and amplify upon the most promising directions: ultra-low-voltage electronics, nanoscale monolithic 3D integration, relevant-data, brain- and human-vision-inspired processing, and energy harvesting for chip autonomy. The team of authors, enlarged by more world leaders in low-power, monolithic 3D, video, and Silicon brains, presents new vistas in nanoelectronics, promising  Moore-like exponential g...

  10. Base flip in DNA studied by molecular dynamics simulationsof differently-oxidized forms of methyl-Cytosine.

    Science.gov (United States)

    Helabad, Mahdi Bagherpoor; Kanaan, Natalia; Imhof, Petra

    2014-07-03

    Distortions in the DNA sequence, such as damage or mispairs, are specifically recognized and processed by DNA repair enzymes. Many repair proteins and, in particular, glycosylases flip the target base out of the DNA helix into the enzyme's active site. Our molecular dynamics simulations of DNA with intact and damaged (oxidized) methyl-cytosine show that the probability of being flipped is similar for damaged and intact methyl-cytosine. However, the accessibility of the different 5-methyl groups allows direct discrimination of the oxidized forms. Hydrogen-bonded patterns that vary between methyl-cytosine forms carrying a carbonyl oxygen atom are likely to be detected by the repair enzymes and may thus help target site recognition.

  11. Base Flip in DNA Studied by Molecular Dynamics Simulationsof Differently-Oxidized Forms of Methyl-Cytosine

    Directory of Open Access Journals (Sweden)

    Mahdi Bagherpoor Helabad

    2014-07-01

    Full Text Available Distortions in the DNA sequence, such as damage or mispairs, are specifically recognized and processed by DNA repair enzymes. Many repair proteins and, in particular, glycosylases flip the target base out of the DNA helix into the enzyme’s active site. Our molecular dynamics simulations of DNA with intact and damaged (oxidized methyl-cytosine show that the probability of being flipped is similar for damaged and intact methyl-cytosine. However, the accessibility of the different 5-methyl groups allows direct discrimination of the oxidized forms. Hydrogen-bonded patterns that vary between methyl-cytosine forms carrying a carbonyl oxygen atom are likely to be detected by the repair enzymes and may thus help target site recognition.

  12. Bond Issues.

    Science.gov (United States)

    Pollack, Rachel H.

    2000-01-01

    Notes trends toward increased borrowing by colleges and universities and offers guidelines for institutions that are considering issuing bonds to raise money for capital projects. Discussion covers advantages of using bond financing, how use of bonds impacts on traditional fund raising, other cautions and concerns, and some troubling aspects of…

  13. Studenters erfaringer med Flipped Classroom i en helsefagutdanning

    Directory of Open Access Journals (Sweden)

    Christine Tørris

    2015-12-01

    Full Text Available Background: The flipped classroom approach has gained increased attention in educational research literature. The purpose of this study was to investigate how students experience a flipped classroom approach in health education, compared to ordinary lectures. Method: Bachelor students (n=25 who watched the video-based material in the flipped classrooms pre-session, answered a questionnaire to evaluate their flipped classroom experience. The questionnaire consisted of both closed and open questions. Results: Ninety six per cent (24/25 of respondents found the video-based material in the pre-session useful. Seventy six per cent (19/25 of respondents found that the flipped classroom approach resulted in the highest learning outcome, over the traditional approach (16%, 4/25. Barriers to the flipped classroom approach was technical problems with the video-based material, such as screen view. Conclusion: The flipped classroom approach is promising as an acceptable approach for teaching in health science curricular in higher education.

  14. Magnetic flipping - Reconnection in three dimensions without null points

    Science.gov (United States)

    Priest, E. R.; Forbes, T. G.

    1992-01-01

    In three dimensions, magnetic reconnection may take place in a sheared magnetic field at any singular field line, where the nearby field has X-type topology in planes perpendicular to the field line and where an electric field is present parallel to the field line. In the ideal region around the singular line there will, in general, be singularities in the plasma flow and electric field, both at the singular line and at 'magnetic flipping layers', which are remnants of local magnetic separatrices. In the absence of a three-dimensional magnetic neutral point or null point, reconnection of field lines can still occur by a process of magnetic flipping, in which the plasma crosses the flipping layers but the field lines rapidly flip along them by magnetic diffusion. Depending on the boundary conditions, there may be two or four flipping layers which converge on the singular line. A boundary layer analysis of a flipping layer is given, in which the magnetic field parallel to the layer decreases as one crosses it while the plasma pressure (or magnetic pressure associated with the field along the singular line) increases. The width of the flipping layer decreases with distance from the singular line.

  15. Magnetic flipping: Reconnection in three-dimensions without null points

    Energy Technology Data Exchange (ETDEWEB)

    Priest, E.R.; Forbes, T.G. (Univ. of New Hampshire, Durham (United States))

    1992-02-01

    In three dimensions, magnetic reconnection may take place in a sheared magnetic field at any singular field line, where the nearby field has X-type topology in planes perpendicular to the field line and where an electric field is present parallel to the field line. In the ideal region around the singular line there will, in general, be singularities in the plasma flow and electric field, both at the singular line and at magnetic flipping layers, which are remnants of local magnetic separatrices. In the absence of a three-dimensional magnetic point or null point, reconnection of field lines can still occur by a process of magnetic flipping, in which the plasma crosses the flipping layers but the field lines rapidly flip along them by magnetic diffusion. Depending on the boundary conditions, there may be two or four flipping layers which converge on the singular line. A boundary layer analysis of a flipping layer is given, in which the magnetic field parallel to the layer decreases as one crosses it while the plasma pressure (or magnetic pressure associated with the field along the singular line) increases. The width of the flipping layer decreases with distance from the singular line.

  16. Studenters erfaringer med Flipped Classroom i en helsefagutdanning

    Directory of Open Access Journals (Sweden)

    Christine Tørris

    2015-12-01

    Full Text Available Background: The flipped classroom approach has gained increased attention in educational research literature. The purpose of this study was to investigate how students experience a flipped classroom approach in health education, compared to ordinary lectures. Method: Bachelor students (n=25 who watched the video-based material in the flipped classrooms pre-session, answered a questionnaire to evaluate their flipped classroom experience. The questionnaire consisted of both closed and open questions. Results: Ninety six per cent (24/25 of respondents found the video-based material in the pre-session useful. Seventy six per cent (19/25 of respondents found that the flipped classroom approach resulted in the highest learning outcome, over the traditional approach (16%, 4/25. Barriers to the flipped classroom approach was technical problems with the video-based material, such as screen view. Conclusion: The flipped classroom approach is promising as an acceptable approach for teaching in health science curricular in higher education.

  17. The Phenomenology of Flipped SU(5)

    Science.gov (United States)

    Abel, S. A.

    1990-01-01

    Available from UMI in association with The British Library. In this thesis, I examine the phenomenology of the supersymmetric flipped SU(5) model. Such a model has been derived as a low energy approximation to heterotic string theory, probably with a 'no-scale' supersymmetry breaking mechanism. It is found that a large region of the flipped SU(5) parameter space predicts a satisfactory breaking down to the standard model on renormalization down to low energies. In particular it contains a number of phenomenological advantages over other GUT schemes, such as a natural Higg's doublet-triplet mass splitting, and a neutrino see-saw mechanism. Analysis of the neutrino sector shows that this model may allow rapid decays of the heavy neutrinos into lighter electron-neutrinos. This is due to new flavour changing couplings in the superpotential, which are included in the neutrino mass matrix. Such fast decays may be able to evade certain cosmological bounds, based on the standard inflationary scenarios and the observation of the 3K background radiation. Thus it is possible that neutrinos could form a substantial proportion of the dark matter in the Universe. Rare processes may be significantly enhanced in the flipped SU(5) scenario, due to new couplings whose off diagonal Kobayashi-Maskawa matrix elements need not be small. In particular, the gaugino-fermion-sfermion coupling may give important new flavour changing diagrams, since, after supersymmetry is broken, the fermions and sfermions are no longer simultaneously diagonalizable. This leads to the possibility of decays such as Z to bs and muto egamma being detected in the near future. In addition to this there are significant new contributions to the electric dipole moment of the neutron which may be as high as the present day limit of | d_ n| < 10^{-25}ecm. Support for this model may come from neutralino contributions to the number of 'neutrino species' measured in Z decays. Finally, the anomalous magnetic moment of the

  18. Research, Perspectives, and Recommendations on Implementing the Flipped Classroom.

    Science.gov (United States)

    Rotellar, Cristina; Cain, Jeff

    2016-03-25

    Flipped or inverted classrooms have become increasingly popular, and sometimes controversial, within higher education. Many educators have touted the potential benefits of this model and initial research regarding implementation has been primarily positive. The rationale behind the flipped classroom methodology is to increase student engagement with content, increase and improve faculty contact time with students, and enhance learning. This paper presents a summary of primary literature regarding flipped classrooms, discusses concerns and unanswered questions from both a student and faculty member perspective, and offers recommendations regarding implementation.

  19. Integral Optimization of Systematic Parameters of Flip-Flow Screens

    Institute of Scientific and Technical Information of China (English)

    翟宏新

    2004-01-01

    The synthetic index Ks for evaluating flip-flow screens is proposed and systematically optimized in view of the whole system. A series of optimized values of relevant parameters are found and then compared with those of the current industrial specifications. The results show that the optimized value Ks approaches the one of those famous flip-flow screens in the world. Some new findings on geometric and kinematics parameters are useful for improving the flip-flow screens with a low Ks value, which is helpful in developing clean coal technology.

  20. Polarizing a stored proton beam by spin flip?

    CERN Document Server

    Oellers, D; Barsov, S; Bechstedt, U; Benati, P; Bertelli, S; Chiladze, D; Ciullo, G; Contalbrigo, M; Dalpiaz, P F; Dietrich, J; Dolfus, N; Dymov, S; Engels, R; Erven, W; Garishvili, A; Gebel, R; Goslawski, P; Grigoryev, K; Hadamek, H; Kacharava, A; Khoukaz, A; Kulikov, A; Langenberg, G; Lehrach, A; Lenisa, P; Lomidze, N; Lorentz, B; Macharashvili, G; Maier, R; Martin, S; Merzliakov, S; Meshkov, I N; Meyer, H O; Mielke, M; Mikirtychiants, M; Mikirtychiants, S; Nass, A; Nekipelov, M; Nikolaev, N N; Nioradze, M; d'Orsaneo, G; Papenbrock, M; Prasuhn, D; Rathmann, F; Sarkadi, J; Schleichert, R; Smirnov, A; Seyfarth, H; Sowinski, J; Spoelgen, D; Stancari, G; Stancari, M; Statera, M; Steffens, E; Stein, H J; Stockhorst, H; Straatmann, H; Ströher, H; Tabidze, M; Tagliente, G; Engblom, P Thoerngren; Trusov, S; Vasilyev, A; Weidemann, Chr; Welsch, D; Wieder, P; Wüstner, P; Zupranski, P

    2009-01-01

    We discuss polarizing a proton beam in a storage ring, either by selective removal or by spin flip of the stored ions. Prompted by recent, conflicting calculations, we have carried out a measurement of the spin flip cross section in low-energy electron-proton scattering. The experiment uses the cooling electron beam at COSY as an electron target. The measured cross sections are too small for making spin flip a viable tool in polarizing a stored beam. This invalidates a recent proposal to use co-moving polarized positrons to polarize a stored antiproton beam.

  1. Introducing a Flipped Classroom for a Statistics Course

    DEFF Research Database (Denmark)

    Triantafyllou, Eva; Timcenko, Olga

    2014-01-01

    One of the novel ideas in teaching that heavily relies on current technology is the “flipped classroom” approach, or “inverse teaching”. In a flipped classroom the traditional lecture and homework sessions are inverted. Students are provided with online material in order to gain necessary knowledge...... students in a Bachelor program in Media Technology. The results of the experiment revealed some strengths and weaknesses of this instructional model. We conclude that the flipped classroom can be beneficial for students, provided that it is based on a careful design....

  2. Assisted crack tip flipping under Mode I thin sheet tearing

    DEFF Research Database (Denmark)

    Felter, Christian Lotz; Nielsen, Kim Lau

    2017-01-01

    such as slanting, cup-cone (rooftop), or cup-cup (bathtub) the flipping crack never settles in a steady-state as the near tip stress/strain field continuously change when the flip successively initiates and develops shear-lips. A recent experimental investigation has revealed new insight by exploiting 3D X...... type loading) on the tip of a slant Mode I crack can provoke it to flip to the opposite side. Both experiments and micro-mechanics based modeling support this hypothesis....

  3. Operation and Maintenance of the Research Platform FLIP

    Science.gov (United States)

    2015-07-01

    operate safety in sup^urt uf uNk fcSedieh. \\ uiiJin^ ficts also cuveieJ the cust uf a ruutlnc dry docking of FLIP in 2013. Dry dockings occur at 3...support of ONR research. ONR funding has also covered the cost of an 18 June to 18 July 2013 routine dry docking , of FLIP. Dry dockings occur at a 3-year...18 July 2013, FLIP underwent a routine dry dockings in the navy floating dry dock USS ARCO ARDM 5 at the Naval Base Point Loma, San Diego. Routine

  4. [Flipped classroom in basic medical education].

    Science.gov (United States)

    Merenmies, Jussi; Niemi-Murola, Leila; Pyörälä, Eeva

    2015-01-01

    Medical education is facing changes in order to improve young doctors' competency to respond better to current needs of the patients and the society. Both curriculum content and teaching methods are revised. In addition to vibrant research in academic medical education, teachers are supported by the improved web-based learning environments and novel technical tools. Flipped classroom, a new paradigm that benefits from technical development, provides many opportunities for medical education. This teaching method always consists of two mutually complementary parts. The first part of the learning action takes place independently off classroom with video lectures or other stimuli for learning. The second part takes place in conjunction with the teacher and other students, and requires student group interactions.

  5. Front propagation and rejuvenation in flipping processes

    Energy Technology Data Exchange (ETDEWEB)

    Ben-naim, Eli [Los Alamos National Laboratory; Krapivsky, P I [BOSTON UNIV; Antal, T [HARVARD UNIV; Ben - Avrahm, D [HARVARD UNIV

    2008-01-01

    We study a directed flipping process that underlies the performance of the random edge simplex algorithm. In this stochastic process, which takes place on a one-dimensional lattice whose sites may be either occupied or vacant, occupied sites become vacant at a constant rate and simultaneously cause all sites to the right to change their state. This random process exhibits rich phenomenology. First, there is a front, defined by the position of the leftmost occupied site, that propagates at a nontrivial velocity. Second, the front involves a depletion zone with an excess of vacant sites. The total excess {Delta}{sub k} increases logarithmically, {Delta}{sub k} {approx_equal}ln k, with the distance k from the front. Third, the front exhibits ageing -- young fronts are vigorous but old fronts are sluggish. We investigate these phenomena using a quasi-static approximation, direct solutions of small systems and numerical simulations.

  6. Bridging the gap with flipped classroom

    DEFF Research Database (Denmark)

    Selberg, Hanne; Topperzer, Martha

    2016-01-01

    using educational technologies such as online preparation contents and simulation based scenarios. Furthermore, the objective is to enhance theory-practice integration in the educational setting. Materials & Methods The flipped classroom model replaces three theoretical lectures addressing disease...... are designed according to Dieckmann´s model (2009) consisting of a pre-briefing with the possibility to reflect on and clarify uncertainties relating to theory and physiology relating to the simulation themes, which are then followed by setting intro, simulator briefing, scenarios and debriefing...... • Challenges the students´ performance • Facilitates an enhanced level of reflection and engagement in debriefing • The concept allows theoretical knowledge to be translated into practical application • The theory-practice integration enhances the learning outcome and helps memorize the content • Applying...

  7. Flipping the classroom to improve student performance and satisfaction.

    Science.gov (United States)

    Missildine, Kathy; Fountain, Rebecca; Summers, Lynn; Gosselin, Kevin

    2013-10-01

    This study aimed to determine the effects of a flipped classroom (i.e., reversal of time allotment for lecture and homework) and innovative learning activities on academic success and the satisfaction of nursing students. A quasi-experimental design was used to compare three approaches to learning: traditional lecture only (LO), lecture and lecture capture back-up (LLC), and the flipped classroom approach of lecture capture with innovative classroom activities (LCI). Examination scores were higher for the flipped classroom LCI group (M = 81.89, SD = 5.02) than for both the LLC group (M = 80.70, SD = 4.25), p = 0.003, and the LO group (M = 79.79, SD = 4.51), p flipped classroom method than with either of the other methods (p classroom activities can result in improved learning but not necessarily improved student satisfaction.

  8. Evaluation of a Flipped Drug Literature Evaluation Course.

    Science.gov (United States)

    Giuliano, Christopher Alan; Moser, Lynette R

    2016-05-25

    Objective. To evaluate a flipped drug literature evaluation course for first-year pharmacy students. Design. A drug literature evaluation course was flipped during the 2014 winter semester. Homework from 2013 was transformed into activities and lectures were transformed into multiple short YouTube videos. Assessment. Average examination scores increased from 75.6% to 86.1%. Eighty-two of 94 students completed the postcourse survey in 2014. Compared to traditional lecture, 59.8% of students indicated they preferred the flipped course. Additionally, students felt the course was important, the in-class activities were helpful, and some of the YouTube videos could be improved. We found length of the video to be significantly correlated with the percentage of videos viewed. Conclusion. The flipped model should be considered in drug literature evaluation courses that seek to increase the amount of active learning in the classroom.

  9. What millennial medical students say about flipped learning.

    Science.gov (United States)

    Pettit, Robin K; McCoy, Lise; Kinney, Marjorie

    2017-01-01

    Flipped instruction is gaining popularity in medical schools, but there are unanswered questions such as the optimum amount of the curriculum to flip and whether flipped sessions should be mandatory. We were in a unique position to evaluate feedback from first-year medical students who had experienced both flipped and lecture-based courses during their first semester of medical school. A key finding was that the students preferred a variety of different learning formats over an "all or nothing" learning format. Learning format preferences did not necessarily align with perceptions of which format led to better course exam performance. Nearly 70% of respondents wanted to make their own decisions regarding attendance. Candid responses to open-ended survey prompts reflected millennial preferences for choice, flexibility, efficiency, and the ability to control the pace of their learning, providing insight to guide curricular improvements.

  10. Online Learning Room for ”Flipped Classroom”

    DEFF Research Database (Denmark)

    Bugge, Ellen Margrethe; Nielsen, Linda Susanna Hauschildt

    2014-01-01

    working actively and innovatively to create a didactic design in our online learning rooms in our LMS that satisfy the demands for flipped learning and at the same time adapted to the special needs of each learning module at the nursing education programme. Keywords: Online learning, flipped classroom......Abstract The “flipped classroom” learning concept is an alternative way of teaching & learning. The fundamental idea of the "flipped classroom" is to change the way students prepare for classes and the work that takes place when the students are together in the classroom. This integrates online...... learning with learning in the classroom. The learning room must support the students’ unassisted learning, their preparation for class and their preparation for supervision in both a motivating and clear way. At the Nursing Education Programme at University College Lillebaelt in Denmark, we have been...

  11. Flipped classroom model for learning evidence-based medicine.

    Science.gov (United States)

    Rucker, Sydney Y; Ozdogan, Zulfukar; Al Achkar, Morhaf

    2017-01-01

    Journal club (JC), as a pedagogical strategy, has long been used in graduate medical education (GME). As evidence-based medicine (EBM) becomes a mainstay in GME, traditional models of JC present a number of insufficiencies and call for novel models of instruction. A flipped classroom model appears to be an ideal strategy to meet the demands to connect evidence to practice while creating engaged, culturally competent, and technologically literate physicians. In this article, we describe a novel model of flipped classroom in JC. We present the flow of learning activities during the online and face-to-face instruction, and then we highlight specific considerations for implementing a flipped classroom model. We show that implementing a flipped classroom model to teach EBM in a residency program not only is possible but also may constitute improved learning opportunity for residents. Follow-up work is needed to evaluate the effectiveness of this model on both learning and clinical practice.

  12. What millennial medical students say about flipped learning

    Science.gov (United States)

    Pettit, Robin K; McCoy, Lise; Kinney, Marjorie

    2017-01-01

    Flipped instruction is gaining popularity in medical schools, but there are unanswered questions such as the optimum amount of the curriculum to flip and whether flipped sessions should be mandatory. We were in a unique position to evaluate feedback from first-year medical students who had experienced both flipped and lecture-based courses during their first semester of medical school. A key finding was that the students preferred a variety of different learning formats over an “all or nothing” learning format. Learning format preferences did not necessarily align with perceptions of which format led to better course exam performance. Nearly 70% of respondents wanted to make their own decisions regarding attendance. Candid responses to open-ended survey prompts reflected millennial preferences for choice, flexibility, efficiency, and the ability to control the pace of their learning, providing insight to guide curricular improvements. PMID:28769600

  13. Flipped classroom model for learning evidence-based medicine

    Science.gov (United States)

    Rucker, Sydney Y; Ozdogan, Zulfukar; Al Achkar, Morhaf

    2017-01-01

    Journal club (JC), as a pedagogical strategy, has long been used in graduate medical education (GME). As evidence-based medicine (EBM) becomes a mainstay in GME, traditional models of JC present a number of insufficiencies and call for novel models of instruction. A flipped classroom model appears to be an ideal strategy to meet the demands to connect evidence to practice while creating engaged, culturally competent, and technologically literate physicians. In this article, we describe a novel model of flipped classroom in JC. We present the flow of learning activities during the online and face-to-face instruction, and then we highlight specific considerations for implementing a flipped classroom model. We show that implementing a flipped classroom model to teach EBM in a residency program not only is possible but also may constitute improved learning opportunity for residents. Follow-up work is needed to evaluate the effectiveness of this model on both learning and clinical practice. PMID:28919831

  14. Step to improve neural cryptography against flipping attacks.

    Science.gov (United States)

    Zhou, Jiantao; Xu, Qinzhen; Pei, Wenjiang; He, Zhenya; Szu, Harold

    2004-12-01

    Synchronization of neural networks by mutual learning has been demonstrated to be possible for constructing key exchange protocol over public channel. However, the neural cryptography schemes presented so far are not the securest under regular flipping attack (RFA) and are completely insecure under majority flipping attack (MFA). We propose a scheme by splitting the mutual information and the training process to improve the security of neural cryptosystem against flipping attacks. Both analytical and simulation results show that the success probability of RFA on the proposed scheme can be decreased to the level of brute force attack (BFA) and the success probability of MFA still decays exponentially with the weights' level L. The synchronization time of the parties also remains polynomial with L. Moreover, we analyze the security under an advanced flipping attack.

  15. PENGARUH FLIPPED MASTERY CLASSROM TERHADAP PEROLEHAN HASIL BELAJAR KOGNITIF MAHASISWA

    Directory of Open Access Journals (Sweden)

    Muhammad Ridha

    2016-04-01

    Tujuan dari penelitian ini adalah untuk mengetahui pengaruh penerapan strategi flipped mastery classroom terhadap perolehan hasil belajar kognitif mahasiswa pada matakuliah psikologi pendidikan. Subjek dalam penelitian ini adalah mahasiswa Jurusan Teknologi Pendidikan Universitas Negeri Malang semester genap tahun ajaran 2015/2016 pada kelas utuh. Kelas eksperimen dibelajarkan dengan strategi flipped-mastery classroom dan kelas kontrol dibelajarkan dengan strategi tradisional.  Penelitian ini menggunakan rancangan kuasi eksperimen Non Equivalent Control Group Design. Hasil penelitian menunjukkan bahwa penerapan strategi flipped mastery classroom memberikan pengaruh positif terhadap perolehan hasil belajar kognitif mahasiswa. Perolehan hasil belajar kognitif mahasiswa yang dibelajarkan dengan strategi flipped-mastery lebih tinggi secara signifikan dari pada perolehan hasil belajar mahasiswa yang dibelajarkan dengan strategi tradisional.

  16. Implementing the Flipped Classroom in Teacher Education: Evidence from Turkey

    National Research Council Canada - National Science Library

    Gökçe Kurt

    2017-01-01

    The flipped classroom, a form of blended learning, is an emerging instructional strategy reversing a traditional lecture-based teaching model to improve the quality and efficiency of the teaching and learning process...

  17. Using the flipped classroom in graduate nursing education.

    Science.gov (United States)

    Critz, Catharine M; Knight, Diane

    2013-01-01

    A flipped classroom is a pedagogical model that involves having students view online lectures, read current evidence-based articles, and complete text readings prior to class. Students then come to class ready to actively engage in collaborative learning through case scenarios, small group discussion, or other meaningful, interactive activities. The flipped classroom model described here was an overwhelming success for both students and faculty.

  18. The Implementation of A Flipped Classroom in Foreign Language Teaching

    Directory of Open Access Journals (Sweden)

    Ahmet BASAL

    2015-10-01

    Full Text Available Alongside the rise of educational technology, many teachers have been taking gradual but innovative steps to redesign their teaching methods. For example, in flipped learning or a flipped classroom, students watch instructional videos outside the classroom and do assignments or engage in activities inside the classroom. Language teachers are one group of educators exploring the flipped classroom. In foreign language classes, such an approach may offer great benefits for both the teachers and students since classroom time can be applied to more interactive tasks. By extending classroom hours in this way, language teachers can focus on successfully addressing all subjects in the curriculum. The aim of this study is (a to gain insights into the perceptions of prospective English language teachers at a state university in Turkey on flipped classrooms and (b to introduce the implementation of a flipped classroom into an English language class. A total of 47 prospective English teachers participated in the study. Qualitative research design was used and data were collected via an open-ended question. Findings of the study indicated that pre-service English teachers had positive perceptions towards the use of the flipped classroom as an integral part of face-to-face courses. It can be concluded that flipped classroom was beneficial in terms of 4 categories based on the content analysis of the responses: learning at one’s own pace, advance student preparation, overcoming the limitations of class time, increasing the participation in the classroom. The study also provides recommendations towards LMS integration into courses in other English language teaching departments and for implementing flipped classrooms in language teaching.

  19. Spin-flip noise in a multiterminal spin valve

    OpenAIRE

    Belzig, Wolfgang; Zareyan, Malek

    2004-01-01

    We study shot noise and cross-correlations in a four terminal spin-valve geometry using a Boltzmann-Langevin approach. The Fano factor (shot noise to current ratio) depends on the magnetic configuration of the leads and the spin-flip processes in the normal metal. In a four-terminal geometry, spin-flip processes are particularly prominent in the cross-correlations between terminals with opposite magnetization.

  20. Biocompatible "click" wafer bonding for microfluidic devices

    OpenAIRE

    Saharil, Farizah; Carlborg, Carl Fredrik; Haraldsson, Tommy; van der Wijngaart, Wouter

    2012-01-01

    We introduce a novel dry wafer bonding concept designed for permanent attachment of micromolded polymer structures to surface functionalized silicon substrates. The method, designed for simultaneous fabrication of many lab-on-chip devices, utilizes a chemically reactive polymer microfluidic structure, which rapidly bonds to a functionalized substrate via "click" chemistry reactions. The microfluidic structure consists of an off-stoichiometry thiol-ene (OSTE) polymer with a very high density o...

  1. Comparison of the copper and gold wire bonding processes for LED packaging*

    Institute of Scientific and Technical Information of China (English)

    Chen Zhaohui; Liu Yong; Liu Sheng

    2011-01-01

    Wire bonding is one of the main processes of the LED packaging which provides electrical interconnection between the LED chip and lead frame The gold wire bonding process has been widely used in LED packaging industry currently. However, due to the high cost of gold wire, copper wire bonding is a good substitute for the gold wire bonding which can lead to significant cost saving. In this paper, the copper and gold wire bonding processes on the high power LED chip are compared and analyzed with finite element simulation. This modeling work may provide guidelines for the parameter optimization of coppor wire bonding process on the high power LED packaging.

  2. Parental Bonding

    Directory of Open Access Journals (Sweden)

    T. Paul de Cock

    2014-08-01

    Full Text Available Estimating the early parent–child bonding relationship can be valuable in research and practice. Retrospective dimensional measures of parental bonding provide a means for assessing the experience of the early parent–child relationship. However, combinations of dimensional scores may provide information that is not readily captured with a dimensional approach. This study was designed to assess the presence of homogeneous groups in the population with similar profiles on parental bonding dimensions. Using a short version of the Parental Bonding Instrument (PBI, three parental bonding dimensions (care, authoritarianism, and overprotection were used to assess the presence of unobserved groups in the population using latent profile analysis. The class solutions were regressed on 23 covariates (demographics, parental psychopathology, loss events, and childhood contextual factors to assess the validity of the class solution. The results indicated four distinct profiles of parental bonding for fathers as well as mothers. Parental bonding profiles were significantly associated with a broad range of covariates. This person-centered approach to parental bonding has broad utility in future research which takes into account the effect of parent–child bonding, especially with regard to “affectionless control” style parenting.

  3. IC chip stress during plastic package molding

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, D.W.; Benson, D.A.; Peterson, D.W.; Sweet, J.N.

    1998-02-01

    Approximately 95% of the world`s integrated chips are packaged using a hot, high pressure transfer molding process. The stress created by the flow of silica powder loaded epoxy can displace the fine bonding wires and can even distort the metalization patterns under the protective chip passivation layer. In this study the authors developed a technique to measure the mechanical stress over the surface of an integrated circuit during the molding process. A CMOS test chip with 25 diffused resistor stress sensors was applied to a commercial lead frame. Both compression and shear stresses were measured at all 25 locations on the surface of the chip every 50 milliseconds during molding. These measurements have a fine time and stress resolution which should allow comparison with computer simulation of the molding process, thus allowing optimization of both the manufacturing process and mold geometry.

  4. Ge0.975Sn0.025 320  ×  256 imager chip for 1.6-1.9  μm infrared vision.

    Science.gov (United States)

    Chang, Chiao; Li, Hui; Ku, Chien-Te; Yang, Shih-Guo; Cheng, Hung Hsiang; Hendrickson, Joshua; Soref, Richard A; Sun, Greg

    2016-12-20

    We report the experimental fabrication and testing of a GeSn-based 320×256 image sensor focal plane array operating at -15°C in the 1.6-1.9 μm spectral range. For image readout, the 2D pixel array of Ge/GeSn/Ge p-i-n heterophotodiodes was flip-chip bonded to a customized silicon CMOS readout integrated circuit. The resulting camera chip was operated using back-side illumination. Successful imaging of a tungsten-filament light bulb was attained with observation of gray-scale "hot spot" infrared features not seen using a visible-light camera. The Ge wafer used in the present imaging array will be replaced in future tests by a germanium-on-silicon wafer offering thin-film Ge upon Si or on SiO2/Si. This is expected to increase the infrared responsivity obtained in back-side illumination, and it will allow an imager in a Si-based foundry to be manufactured. Our experiments are a significant step toward the realization of group IV near-mid-infrared imaging systems, such as those for night vision.

  5. The SRA domain of UHRF1 flips 5-methylcytosine out of the DNA helix

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, H.; Horton, J.R.; Zhang, X.; Bostick, M.; Jacobsen, S.; Cheng, X. (Emory-MED); (UCLA)

    2008-11-13

    Maintenance methylation of hemimethylated CpG dinucleotides at DNA replication forks is the key to faithful mitotic inheritance of genomic methylation patterns. UHRF1 (ubiquitin-like, containing PHD and RING finger domains 1) is required for maintenance methylation by interacting with DNA nucleotide methyltransferase 1 (DNMT1), the maintenance methyltransferase, and with hemimethylated CpG, the substrate for DNMT1 (refs 1 and 2). Here we present the crystal structure of the SET and RING-associated (SRA) domain of mouse UHRF1 in complex with DNA containing a hemimethylated CpG site. The DNA is contacted in both the major and minor grooves by two loops that penetrate into the middle of the DNA helix. The 5-methylcytosine has flipped completely out of the DNA helix and is positioned in a binding pocket with planar stacking contacts, Watson-Crick polar hydrogen bonds and van der Waals interactions specific for 5-methylcytosine. Hence, UHRF1 contains a previously unknown DNA-binding module and is the first example of a non-enzymatic, sequence-specific DNA-binding protein domain to use the base flipping mechanism to interact with DNA.

  6. Multi-layer microfluidic glass chips for microanalytical applications

    NARCIS (Netherlands)

    Daridon, Antoine; Fascio, Valia; Lichtenberg, Jan; Wütrich, Rolf; Langen, Hans; Verpoorte, Elisabeth; De Rooij, Nico F.

    2001-01-01

    A new, versatile architecture is presented for microfluidic devices made entirely from glass, for use with reagents which would prove highly corrosive for silicon. Chips consist of three layers of glass wafers bonded together by fusion bonding. On the inside wafer faces a network of microfluidic cha

  7. 比热和直流磁化率证明N+H…O-氢键的电子自旋翻转在D-和L-丙氨酸单晶中的不对称相变%Heat Capacity and DC-Magnetic Susceptibility Evidence for the Asymmetry of Electron Spin-Flip Phase Transition of N+H…O- Bond in Chiral Alanine Crystal

    Institute of Scientific and Technical Information of China (English)

    王文清; 沈新春; 吴季兰; 龚; 申国华; 赵洪凯

    2012-01-01

    With a view to understanding the argument of phase-transition mechanisms of D- and L-alanine at around 270 K,the temperature dependence of heat capacity measurements was investigated,for single crystals,ground powders,and polycrystalline products,using differential scanning calorimetry (DSC).The Cp (heat capacity under constant pressure) values of D- and L-alanine were calibrated with standard sapphire by the triple-curve method; these values coincide with the standard Cp values in the literature.Endothermic transition peaks were observed at Tc=272.02 K,ΔH=1.87 J· mol-1 and Tc=271.85 K,ΔH=1.46 J·mol-1 for D- and L- alanine,respectively,and Tc=273.59 K,ΔH=1.75 J·mol-1 and Tc=273.76 K,ΔH=1.57 J·mol-1 for the reference crystals D- and L-valine,respectively.The energy differences of 0.41 J· mol-1 for D-and L-alanine and 0.18 J · mol-1 for D- and L-valine,which were observed from pre-aligned molecules in the single crystals and vanished in the ground powders and polycrystalline products,show that the phase transition is related to the crystal lattice.Neutron diffraction results exclude the possibility of a D→L configuration change,and show that the hydrogen bonds run antiparallel to the c-axis in the D- and L-crystals.Polarized Raman vibrational spectroscopy shows that the transition mechanism may be related to the electronic orbital angular momentum and magnetic dipole moments of N+H … O- in the crystals.External magnetic fields,H=+1,-1 T,were applied parallel to the c(z)-axis of the D- and L-alanine crystalline lattices,respectively.The DC-magnetic susceptibilities show electron spin-flip transitions at around 270 K in D- and L-alanine.The spin is “up” or “down” relative to the direction of N+H… O- bond along the c(z)-axis.Based on spin rigidity and magnetic anisotropy,the results help to explain the discrepancies among heat capacity and magnetic susceptibility data for single crystals and polycrystalline powders of D- and L-alanine.%为了

  8. The flipped classroom: now or never?

    Science.gov (United States)

    Hawks, Sharon J

    2014-08-01

    Pedagogical changes and new models of delivering educational content should be considered in the effort to address the recommendations of the 2007 Institute of Medicine report and Benner's recommendations on the radical transformation of nursing. Transition to the nurse anesthesia practice doctorate addresses the importance of these recommendations, but educational models and specific strategies on how to implement changes in educational models and systems are still emerging. The flipped classroom (FC) is generating a considerable amount of buzz in academic circles. The FC is a pedagogical model that employs asynchronous video lectures, reading assignments, practice problems, and other digital, technology-based resources outside the classroom, and interactive, group-based, problem-solving activities in the classroom. This FC represents a unique combination of constructivist ideology and behaviorist principles, which can be used to address the gap between didactic education and clinical practice performance. This article reviews recent evidence supporting use of the FC in health profession education and suggests ways to implement the FC in nurse anesthesia educational programs.

  9. Flipping organic chemistry course: Possibilities and challenges

    Science.gov (United States)

    Cha, J.; Kim, H. B.

    2016-06-01

    The flipped classroom approach was applied to an introductory organic chemistry course. A total of 76 video clips (15 hours of running time) were developed and delivered to 41 sophomores (21 females and 20 males) through Youtube in addition to the university's learning management system. The students were asked to preview the lecture contents before each class by watching a pre-class video. For in-class activities, exercise problems were presented to groups of 3-5 students. An instructor and a teaching assistant guided each group to solve problems cooperatively, monitored the students’ group activity and answered their questions. At the end of every chapter, the students were asked to evaluate their group work and personal preparedness for the class and also to write a short reflective journal. The muddiest point of each chapter, i.e., the topic posing the most difficulty to students’ understanding, was surveyed through Google Forms®. The students liked watching the videos before each class and performing student-centered, in-class group activities but a few limitations were also found and reported.

  10. Flipped classroom or an active lecture?

    Science.gov (United States)

    Pickering, James D; Roberts, David J H

    2017-08-31

    Recent changes in anatomy education have seen the introduction of flipped classrooms as a replacement to the traditional didactic lecture. This approach utilizes the increasing availability of digital technology to create learning resources that can be accessed prior to attending class, with face-to-face sessions then becoming more student-centered via discussion, collaborative learning, and problem-solving activities. Although this approach may appear intuitive, this viewpoint commentary presents a counter opinion and highlights a simple alternative that utilizes evidence-based active learning approaches as part of the traditional lecture. The active lecture takes the traditional lecture, and (1) ensures the lecture content is relevant and has clear objectives, (2) contains lecture material that is designed according to the latest evidence-base, (3) complements it with additional supplementary material, (4) creates space to check prior understanding and knowledge levels, and (5) utilizes suitable technology to facilitate continual engagement and interaction. Clin. Anat., 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  11. Thermal bonding of polyimide to form sealed microchannels

    Science.gov (United States)

    Mekaru, Harutaka

    2017-06-01

    Polyimide has high stability, so it is attractive for use in disposable microfluidic chips. Also, it has high resistance to soft X-ray irradiation. However, its high stability makes processing polyimide difficult. In particular, sealed microchannels are difficult to fabricate; additives are usually required. Here, a technique for sealing microchannels by thermal bonding using ordinary polyimide without any special functionalities is developed. First, as a guide to form sealed microchannels in polyimide microfluidic chips, optimum bonding conditions are determined by measuring bonding strength through tensile testing. Trench structures are formed by laser ablation on the surface of a polyimide substrate, and then the polyimide substrate is bonded thermally with a polyimide film under optimal bonding conditions. The water-tightness of the resulting chip is checked by feeding a liquid into the sealed microchannels. The bonding conditions obtained in the tensile test form sealed microchannels on the polyimide microfluidic chip. Using our technique for fabricating a polyimide chip, it will be possible to easily observe microstructures in a cell containing water in a soft X-ray microscope.

  12. Use of single chip microcomputer in hydraulic digital adaptive control system

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Presents a one-grade adaptive controller with one reference model which is built according to δ MRACS adaptive control theorv and used to control an actual high-order hydraulic system, and the whole hard ware system used, which includes a AT89C51 single chip microcomputer, 74Ls373 flip-latch, 6116 store, eight-bit ADC0809, and so on, and the satisfactory results obtained in study on hydraulic control system.

  13. 电迁移对Ni/Sn3.0Ag0.5Cu/Cu焊点界面反应的影响%EFFECT OF ELECTROMIGRATION ON INTERFACIAL REACTION IN Ni/Sn3.0Ag0.5Cu/Cu FLIP CHIP SOLDER JOINTS

    Institute of Scientific and Technical Information of China (English)

    黄明亮; 陈雷达; 周少明

    2012-01-01

    The effect of electromigration (EM) on the interfacial reaction in Ni/Sn3.0Ag0.5Cu/Cu solder joints was investigated under a current density of 5.0 ×l03 A/cm2 at 150 ℃ All solder joints were aged at 150 ℃ for comparison purpose. It has been found that the (Cu,Ni)6Sn5 intermetallic compounds (IMCs) form at both soIder/Ni and solder/Cu interfaces in the as-reflowed state. During aging at 150 ℃, the thickness of interfacial IMC increases with increasing aging time, and no interfacial IMC transformation occurs even after aging for 800 h. The flowing direction of electrons plays an important role in Cu consumption. When electrons flow from printed circuit board (PCB) to chip, the current crowding effect induces a rapid and localized dissolution of Cu pad on PCB and a formation of microcrack at the Sn3.0Ag0.5Cu/(Cu, Ni)6Sn5 interface. The dissolved Cu atoms are driven towards anode by EM, and a large amount of Cu6Sn5 IMC particles form in solder matrix along the flowing direction of electrons. When electrons flow from chip to PCB, no obvious consumption of Ni underbump metallogy (UBM) has been observed and few Cu6Sn5 IMC particles form in solder matrix near the anode interface. There is no evidence of failure induced by EM in solder joints even after EM for 800 h. To sum up, EM enhances the growth of interfacial (Cu, Ni)6Sn5 at anode side, no matter how the direction of electrons is. The interfacial IMC at anode side is thicker than that at cathode side. The Ni/Sn3.0Ag0.5Cu/Cu solder joint is prone to fail when electrons flowing from Cu to Ni.%研究了温度为150℃,电流密度为5.0×103 A/cm2的条件下电迁移对Ni/Sn3.0Ag0.5Cu/Cu焊点界面反应的影响.回流焊后在Sn3.0Ag0.5Cu/Ni和Sn3.0Ag0.5Cu/Cu的界面上均形成了(Cu,Ni)6Sn5型化合物.时效过程中界面化合物随时效时间增加而增厚,时效800 h后两端的化合物并没有发生转变,仍为(Cu,Ni)6Sn5型.电流方向对Cu基板的消耗起着决定作用.当电子从基板

  14. On flipping first-semester calculus: a case study

    Science.gov (United States)

    Petrillo, Joseph

    2016-05-01

    High failure rates in calculus have plagued students, teachers, and administrators for decades, while science, technology, engineering, and mathematics programmes continue to suffer from low enrollments and high attrition. In an effort to affect this reality, some educators are 'flipping' (or inverting) their classrooms. By flipping, we mean administering course content outside of the classroom and replacing the traditional in-class lectures with discussion, practice, group work, and other elements of active learning. This paper presents the major results from a three-year study of a flipped, first-semester calculus course at a small, comprehensive, American university with a well-known engineering programme. The data we have collected help quantify the positive and substantial effects of our flipped calculus course on failure rates, scores on the common final exam, student opinion of calculus, teacher impact on measurable outcomes, and success in second-semester calculus. While flipping may not be suitable for every teacher, every student, and in every situation, this report provides some evidence that it may be a viable option for those seeking an alternative to the traditional lecture model.

  15. Active Longitudes and Flip-Flops in Binary Stars

    Science.gov (United States)

    Korhonen, Heidi; Järvinen, Silva P.

    2007-08-01

    In many active stars the spots concentrate on two permanent active longitudes which are 180 degrees apart. In some of these stars the dominant part of the spot activity changes the longitude every few years. This so-called flip-flop phenomenon was first reported in the early 1990's in the single, late type giant FK Com. Since then flip-flops have been reported also on binary stars, young solar type stars and the Sun itself. Even though this phenomenon has been detected on many different kinds of active stars, still less than ten stars are known to exhibit this effect. Therefore no statistically significant correlation between the stellar parameters and the flip-flop phenomenon can be carried out. Here we present results from investigation where we have studied the long-term photometry of several magnetically active RS CVn binaries to see whether or not they show permanent active longitudes and the flip-flop phenomenon. We find that it is very common for the active regions to occur on permanent active longitudes, and some of these stars also show clear flip-flop phenomenon.

  16. [Flipped classroom as a strategy to enhance active learning].

    Science.gov (United States)

    Wakabayashi, Noriyuki

    2015-03-01

    This paper reviews the introduction of a flipped class for fourth grade dentistry students, and analyzes the characteristics of the learning method. In fiscal 2013 and 2014, a series of ten three-hour units for removable partial prosthodontics were completed with the flipped class method; a lecture video of approximately 60 minutes was made by the teacher (author) and uploaded to the university's e-learning website one week before each class. Students were instructed to prepare for the class by watching the streaming video on their PC, tablet, or smartphone. In the flipped class, students were not given a lecture, but were asked to solve short questions displayed on screen, to make a short presentation about a part of the video lecture, and to discuss a critical question related to the main subject of the day. An additional team-based learning (TBL) session with individual and group answers was implemented. The average individual scores were considerably higher in the last two years, when the flipped method was implemented, than in the three previous years when conventional lectures were used. The following learning concepts were discussed: the role of the flipped method as an active learning strategy, the efficacy of lecture videos and short questions, students' participation in the class discussion, present-day value of the method, cooperation with TBL, the significance of active learning in relation with the students' learning ability, and the potential increase in the preparation time and workload for students.

  17. Flipped classroom model for learning evidence-based medicine

    Directory of Open Access Journals (Sweden)

    Rucker SY

    2017-08-01

    Full Text Available Sydney Y Rucker,1 Zulfukar Ozdogan,1 Morhaf Al Achkar2 1School of Education, Indiana University, Bloomington, IN, 2Department of Family Medicine, School of Medicine, University of Washington, Seattle, WA, USA Abstract: Journal club (JC, as a pedagogical strategy, has long been used in graduate medical education (GME. As evidence-based medicine (EBM becomes a mainstay in GME, traditional models of JC present a number of insufficiencies and call for novel models of instruction. A flipped classroom model appears to be an ideal strategy to meet the demands to connect evidence to practice while creating engaged, culturally competent, and technologically literate physicians. In this article, we describe a novel model of flipped classroom in JC. We present the flow of learning activities during the online and face-to-face instruction, and then we highlight specific considerations for implementing a flipped classroom model. We show that implementing a flipped classroom model to teach EBM in a residency program not only is possible but also may constitute improved learning opportunity for residents. Follow-up work is needed to evaluate the effectiveness of this model on both learning and clinical practice. Keywords: evidence-based medicine, flipped classroom, residency education

  18. What millennial medical students say about flipped learning

    Directory of Open Access Journals (Sweden)

    Pettit RK

    2017-07-01

    Full Text Available Robin K Pettit, Lise McCoy, Marjorie Kinney School of Osteopathic Medicine in Arizona, A. T. Still University, Mesa, AZ, USA Abstract: Flipped instruction is gaining popularity in medical schools, but there are unanswered questions such as the optimum amount of the curriculum to flip and whether flipped sessions should be mandatory. We were in a unique position to evaluate feedback from first-year medical students who had experienced both flipped and lecture-based courses during their first semester of medical school. A key finding was that the students preferred a variety of different learning formats over an “all or nothing” learning format. Learning format preferences did not necessarily align with perceptions of which format led to better course exam performance. Nearly 70% of respondents wanted to make their own decisions regarding attendance. Candid responses to open-ended survey prompts reflected millennial preferences for choice, flexibility, efficiency, and the ability to control the pace of their learning, providing insight to guide ­curricular improvements. Keywords: flipped classroom, mandatory attendance, medical education, lecture-based, variety

  19. An Experiential Learning Perspective on Students’ Satisfaction Model in a Flipped Classroom Context

    National Research Council Canada - National Science Library

    Xuesong Zhai; Jibao Gu; Hefu Liu; Jyh-Chong Liang; Chin-Chung Tsai

    2017-01-01

    ...’ perceptions of flipped settings. In order to fill this gap, in this study, a students’ satisfaction model for the flipped classroom was constructed based on the experiential learning theory...

  20. Bond Boom

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The Ministry of Finance recently kick-started a pilot program allowing local governments of Shanghai and Shenzhen,and Zhejiang and Guangdong provinces to issue bonds for the first time.How will the new policy affect fiscal capacities of local governments and the broader economy? What else should the country do to build a healthy bond market? Economists and experts discussed these issues in an interview with the Shanghai Securities Journal.Edited excerpts follow.

  1. Bond Boom

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The Ministry of Finance recently kick-started a pilot program allowing local governments of Shanghai and Shenzhen, and Zhejiang and Guangdong provinces to issue bonds for the first time. How will the new policy affect fiscal capacities of local governments and the broader economy? What else should the country do to build a healthy bond market? Economists and experts discussed these issues in an interview with the ShanghaiSecuritiesJournal. Edited excerpts follow:

  2. Using 3DClass To Flip Biochemistry Classroom

    Directory of Open Access Journals (Sweden)

    T. Silva

    2014-08-01

    Full Text Available The flipped classroom inverts traditional teaching methods, in order to have studentsprepared for topics and techniques covered in the following meeting. This approach wasadopted in a biochemistry course taught to biology freshmen students at the University ofCampinas, using a Virtual Learning Environment called 3DClass. Before each classroomsession, a quiz was delivered covering the following topic and students were allowed totake quizzes as many times as they wanted. This approach was utilized in order to betterprepare students in classes and to perform lab experiments. Every student attempt wasrecorded in a database. Before each classroom session, the instructors were provided witha summary of the class answers, highlighting questions where students had more difficultyand the ones that scored higher. This kind of information was helpful to design activities tocover the topics where students had more difficulties. Based on the 3DClass records thestudents behaviors were mapped, such as students taking the quizzes seriously, studentsguessing, students answering a quiz until scoring 100%, students that continue answeringafter scoring 100% in order to increase their grades, students that never score 100%.However, the most relevant information 3DClass brought us was the possibility to identifystudent’s confidence in their answers, which could be observed by the analysis of theirattempts for each question. If they had made different choices each try, it would haveindicated a low confidence level, while always providing the same answer indicated ahigher confidence level, even whilst picking incorrect answers. This experiment haverevealed that students coming to the classroom better prepared reflected positively on thedeveloped activities, but the number of students taking the quizzes seriously were not asgreat as we had expected, indicating that more actions should be taken to improvestudents engagement with these activities.

  3. Rapid bonding of Pyrex glass microchips.

    Science.gov (United States)

    Akiyama, Yoshitake; Morishima, Keisuke; Kogi, Atsuna; Kikutani, Yoshikuni; Tokeshi, Manabu; Kitamori, Takehiko

    2007-03-01

    A newly developed vacuum hot press system has been specially designed for the thermal bonding of glass substrates in the fabrication process of Pyrex glass microchemical chips. This system includes a vacuum chamber equipped with a high-pressure piston cylinder and carbon plate heaters. A temperature of up to 900 degrees C and a force of as much as 9800 N could be applied to the substrates in a vacuum atmosphere. The Pyrex substrates bonded with this system under different temperatures, pressures, and heating times were evaluated by tensile strength tests, by measurements of thickness, and by observations of the cross-sectional shapes of the microchannels. The optimal bonding conditions of the Pyrex glass substrates were 570 degrees C for 10 min under 4.7 N/mm(2) of applied pressure. Whereas more than 16 h is required for thermal bonding with a conventional furnace, the new system could complete the whole bonding processes within just 79 min, including heating and cooling periods. Such improvements should considerably enhance the production rate of Pyrex glass microchemical chips. Whereas flat and dust-free surfaces are required for conventional thermal bonding, especially without long and repeated heating periods, our hot press system could press a fine dust into glass substrates so that even the areas around the dust were bonded. Using this capability, we were able to successfully integrate Pt/Ti thin film electrodes into a Pyrex glass microchip.

  4. Flipped Instruction in a High School Science Classroom

    Science.gov (United States)

    Leo, Jonathan; Puzio, Kelly

    2016-10-01

    This paper reports on a quasi-experimental study examining the effectiveness of flipped instruction in a 9th grade biology classroom. This study included four sections of freshmen-level biology taught by the first author at a private secondary school in the Pacific Northwest. Using a block randomized design, two sections were flipped and two remained traditional. The quiz and posttest data were adjusted for pretest differences using ANCOVA. The results suggest that flipped instruction had a positive effect student achievement, with effect sizes ranging from +0.16 to +0.44. In addition, some students reported that they preferred watching video lectures outside of class and appreciated more active approaches to learning.

  5. Out of Classroom Instruction in the Flipped Classroom

    DEFF Research Database (Denmark)

    Triantafyllou, Evangelia; Timcenko, Olga

    2015-01-01

    This article presents experiences and student perceptions on the introduction of the flipped classroom model in two consecutive semesters at Media Technology department of Aalborg University, Copenhagen, Denmark. We introduced the flipped instruction model to a statistics course and a mathematics...... workshop. We collected data by two online survey studies, which show support for student perceptions that out-of-classroom instruction with online resources enhances learning, by providing visual and in depth explanations, and can engage the learner. However, students stated that they miss just......-in-time explanations when learning with online resources and they questioned the quality and validity of some of them. Based on these findings and our own experience, we discuss requirements for resources and activities in flipped classrooms in order for the student to engage and learn. Finally, we present a framework...

  6. Graphene Layer Growth Chemistry: Five-Six-Ring Flip Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Whitesides, R.; Domin, D.; Salomon-Ferrer, R.; Lester Jr., W.A.; Frenklach, M.

    2007-12-01

    Reaction pathways are presented for hydrogen-mediated isomerization of a five and six member carbon ring complex on the zigzag edge of a graphene layer. A new reaction sequence that reverses orientation of the ring complex, or 'flips' it, was identified. Competition between the flip reaction and 'ring separation' was examined. Ring separation is the reverse of the five and six member ring complex formation reaction, previously reported as 'ring collision'. The elementary steps of the pathways were analyzed using density-functional theory (DFT). Rate coefficients were obtained by solution of the energy master equation and classical transition state theory utilizing the DFT energies, frequencies, and geometries. The results indicate that the flip reaction pathway dominates the separation reaction and should be competitive with other pathways important to the graphene zigzag edge growth in high temperature environments.

  7. Spin flip of multiqubit states in discrete phase space

    Science.gov (United States)

    Srinivasan, K.; Raghavan, G.

    2017-02-01

    Time reversal and spin flip are discrete symmetry operations of substantial importance to quantum information and quantum computation. Spin flip arises in the context of separability, quantification of entanglement and the construction of universal NOT gates. The present work investigates the relationship between the quantum state of a multiqubit system represented by the discrete Wigner function (DWFs) and its spin-flipped counterpart. The two are shown to be related through a Hadamard matrix that is independent of the choice of the quantum net used for the tomographic reconstruction of the DWF. These results are of interest to cases involving the direct tomographic reconstruction of the DWF from experimental data, and in the analysis of entanglement related properties purely in terms of the DWF.

  8. Fully simulatable quantum-secure coin-flipping and applications

    DEFF Research Database (Denmark)

    Lunemann, Carolin; Nielsen, Jesper Buus

    2011-01-01

    We propose a coin-flip protocol which yields a string of strong, random coins and is fully simulatable against poly-sized quantum adversaries on both sides. It can be implemented with quantum-computational security without any set-up assumptions, since our construction only assumes mixed commitment...... schemes which we show how to construct in the given setting. We then show that the interactive generation of random coins at the beginning or during outer protocols allows for quantum-secure realizations of classical schemes, again without any set-up assumptions. As example applications we discuss quantum...... zero-knowledge proofs of knowledge and quantum-secure two-party function evaluation. Both applications assume only fully simulatable coin-flipping and mixed commitments. Since our framework allows to construct fully simulatable coin-flipping from mixed commitments, this in particular shows that mixed...

  9. Two-Bit Bit Flipping Decoding of LDPC Codes

    CERN Document Server

    Nguyen, Dung Viet; Marcellin, Michael W

    2011-01-01

    In this paper, we propose a new class of bit flipping algorithms for low-density parity-check (LDPC) codes over the binary symmetric channel (BSC). Compared to the regular (parallel or serial) bit flipping algorithms, the proposed algorithms employ one additional bit at a variable node to represent its "strength." The introduction of this additional bit increases the guaranteed error correction capability by a factor of at least 2. An additional bit can also be employed at a check node to capture information which is beneficial to decoding. A framework for failure analysis of the proposed algorithms is described. These algorithms outperform the Gallager A/B algorithm and the min-sum algorithm at much lower complexity. Concatenation of two-bit bit flipping algorithms show a potential to approach the performance of belief propagation (BP) decoding in the error floor region, also at lower complexity.

  10. The flipped classroom for professional development: part I. Benefits and strategies.

    Science.gov (United States)

    McDonald, Katie; Smith, Charlene M

    2013-10-01

    Individualizing the educational encounter is supported by flipping the classroom experience. This column offers an overview and describes the benefits of flipping the classroom. Part II will explore the practicalities and pedagogy of lecture capture using podcasts and videos, a technology strategy used in flipping the classroom.

  11. [Evaluation of flipped classroom teaching model in undergraduates education of oral and maxillofacial surgery].

    Science.gov (United States)

    Cai, Ming; Cao, Xia; Fang, Xiao; Wang, Xu-dong; Zhang, Li-li; Zheng, Jia-wei; Shen, Guo-fang

    2015-12-01

    Flipped classroom is a new teaching model which is different from the traditional teaching method. The history and characteristics of flipped classroom teaching model were introduced in this paper. A discussion on how to establish flipped classroom teaching protocol in oral and maxillofacial surgery education was carried out. Curriculum transformation, construction of education model and possible challenges were analyzed and discussed.

  12. Scaffolded Semi-Flipped General Chemistry Designed to Support Rural Students' Learning

    Science.gov (United States)

    Lenczewski, Mary S.

    2016-01-01

    Students who lack academic maturity can sometimes feel overwhelmed in a fully flipped classroom. Here an alternative, the Semi-Flipped method, is discussed. Rural students, who face unique challenges in transitioning from high school learning to college-level learning, can particularly profit from the use of the Semi-Flipped method in the General…

  13. K-12 Teacher Perceptions Regarding the Flipped Classroom Model for Teaching and Learning

    Science.gov (United States)

    Gough, Evan; DeJong, David; Grundmeyer, Trent; Baron, Mark

    2017-01-01

    A great deal of evidence can be cited from higher education literature on the effectiveness of the flipped classroom; however, very little research was discovered on the flipped classroom at the K-12 level. This study examined K-12 teachers' perceptions regarding the flipped classroom and differences in teachers' perceptions based on grade level…

  14. Present Research on the Flipped Classroom and Potential Tools for the EFL Classroom

    Science.gov (United States)

    Mehring, Jeff

    2016-01-01

    The flipped classroom can support the implementation of a communicative, student-centered learning environment in the English as a foreign language classroom. Unfortunately, there is little research which supports the incorporation of flipped learning in the English as a foreign language classroom. Numerous studies have focused on flipped learning…

  15. Student learning and perceptions in a flipped linear algebra course

    Science.gov (United States)

    Love, Betty; Hodge, Angie; Grandgenett, Neal; Swift, Andrew W.

    2014-04-01

    The traditional lecture style of teaching has long been the norm in college science, technology, engineering, and mathematics (STEM) courses, but an innovative teaching model, facilitated by recent advances in technology, is gaining popularity across college campuses. This new model inverts or 'flips' the usual classroom paradigm, in that students learn initial course concepts outside of the classroom, while class time is reserved for more active problem-based learning and practice activities. While the flipped classroom model shows promise for improving STEM learning and increasing student interest in STEM fields, discussions to date of the model and its impact are more anecdotal than data driven - very little research has been undertaken to rigorously assess the potential effects on student learning that can result from the flipped classroom environment. This study involved 55 students in 2 sections of an applied linear algebra course, using the traditional lecture format in one section and the flipped classroom model in another. In the latter, students were expected to prepare for the class in some way, such as watching screencasts prepared by the instructor, or reading the textbook or the instructor's notes. Student content understanding and course perceptions were examined. Content understanding was measured by the performance on course exams, and students in the flipped classroom environment had a more significant increase between the sequential exams compared to the students in the traditional lecture section, while performing similarly in the final exam. Course perceptions were represented by an end-of-semester survey that indicated that the flipped classroom students were very positive about their experience in the course, and particularly appreciated the student collaboration and instructional video components.

  16. All-optical flip-flop and control methods thereof

    Science.gov (United States)

    Maywar, Drew; Agrawal, Govind P.

    2010-03-23

    Embodiments of the invention pertain to remote optical control of holding beam-type, optical flip-flop devices, as well as to the devices themselves. All-optical SET and RE-SET control signals operate on a cw holding beam in a remote manner to vary the power of the holding beam between threshold switching values to enable flip-flop operation. Cross-gain modulation and cross-polarization modulation processes can be used to change the power of the holding beam.

  17. Flipped version of the supersymmetric strongly coupled preon model

    Science.gov (United States)

    Fajfer, S.; Mileković, M.; Tadić, D.

    1989-12-01

    In the supersymmetric SU(5) [SUSY SU(5)] composite model (which was described in an earlier paper) the fermion mass terms can be easily constructed. The SUSY SU(5)⊗U(1), i.e., flipped, composite model possesses a completely analogous composite-particle spectrum. However, in that model one cannot construct a renormalizable superpotential which would generate fermion mass terms. This contrasts with the standard noncomposite grand unified theories (GUT's) in which both the Georgi-Glashow electrical charge embedding and its flipped counterpart lead to the renormalizable theories.

  18. A non-volatile flip-flop based on diode-selected PCM for ultra-low power systems

    Science.gov (United States)

    Ye, Yong; Du, Yuan; Gao, Dan; Kang, Yong; Song, Zhitang; Chen, Bomy

    2016-10-01

    As the process technology is continuously shrinking, low power consumption is a major issue in VLSI Systems-on-Chip (SoCs), especially for standby-power-critical applications. Recently, the emerging CMOS-compatible non-volatile memories (NVMs), such as Phase Change Memory (PCM), have been used as on-chip storage elements, which can obtain non-volatile processing, nearly-zero standby power and instant-on capability. PCM has been considered as the best candidate for the next generation of NVMs for its low cost, high density and high resistance transformation ratio. In this paper, for the first time, we present a diode-selected PCM based non-volatile flip-flop (NVFF) which is optimized for better power consumption and process variation tolerance. With dual trench isolation process, the diode-selected PCM realizes ultra small area, which is very suitable for multi-context configuration and large scale flip-flops matrix. Since the MOS-selected PCM is hard to shrink further due to large amount of PCM write current, the proposed NVFF achieves higher power efficiency without loss of current driving capability. Using the 40nm manufacturing process, the area of the cell (1D1R) is as small as 0.016 μm2. Simulation results show that the energy consumption during the recall operation is 62 fJ with 1.1 standard supply voltage, which is reduced by 54.9% compared to the previous 2T2R based NVFF. When the supply voltage reduces to 0.7 V, the recall energy is as low as 17 fJ. With the great advantages in cell size and energy, the proposed diode-selected NVFF is very applicable and cost-effective for ULP systems.

  19. On-chip optical detection of laser cooled atoms.

    Science.gov (United States)

    Quinto-Su, P; Tscherneck, M; Holmes, M; Bigelow, N

    2004-10-18

    We have used an optical fiber based system to implement optical detection of atoms trapped on a reflective "atom-chip". A fiber pair forms an emitter-detector setup that is bonded to the atom-chip surface to optically detect and probe laser cooled atoms trapped in a surface magneto-optical trap. We demonstrate the utility of this scheme by measuring the linewidth of the Cs D2 line at different laser intensities.

  20. Flipping the Science Classroom: Exploring Merits, Issues and Pedagogy

    Science.gov (United States)

    Ng, Wan

    2014-01-01

    Educators are continually being challenged to think about how best to integrate digital technologies meaningfully and effectively in their classrooms. A current trend in educational technology which has the potential to enable this in a pragmatic manner is the flipped classroom concept. This paper aims to explore the idea in Science teaching and…

  1. Case Study: Student-Produced Videos for the Flipped Classroom

    Science.gov (United States)

    Prud'homme-Genereux, Annie

    2016-01-01

    This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue describes a way of building a library of student-produced videos to use in the flipped classroom.

  2. Adult Students' Experiences of a Flipped Mathematics Classroom

    Science.gov (United States)

    Larsen, Judy

    2015-01-01

    The flipped classroom is a flexible blended learning model that is growing in popularity due to the emergent accessibility to online content delivery technology. By delivering content outside of class time asynchronously, teachers are able to dedicate their face to face class time for student-centred teaching approaches. The flexibility in…

  3. Implementation and Critical Assessment of the Flipped Classroom Experience

    Science.gov (United States)

    Scheg, Abigail G., Ed.

    2015-01-01

    In the past decade, traditional classroom teaching models have been transformed in order to better promote active learning and learner engagement. "Implementation and Critical Assessment of the Flipped Classroom Experience" seeks to capture the momentum of non-traditional teaching methods and provide a necessary resource for individuals…

  4. Successful EFL Teaching Using Mobile Technologies in a Flipped Classroom

    Science.gov (United States)

    Obari, Hiroyuki; Lambacher, Stephen

    2015-01-01

    Two case studies evaluating the effectiveness of a flipped classroom compared to a traditional classroom were performed. The studies were conducted from April 2014 to January 2015 at a private university in Tokyo, targeting 60 first-year and 25 third-year undergraduates, respectively. In the first study, an assessment of pre- and post-treatment…

  5. On flipping the classroom in large first year calculus courses

    Science.gov (United States)

    Jungić, Veselin; Kaur, Harpreet; Mulholland, Jamie; Xin, Cindy

    2015-05-01

    Over the course of two years, 2012--2014, we have implemented a 'flipping' the classroom approach in three of our large enrolment first year calculus courses: differential and integral calculus for scientists and engineers. In this article we describe the details of our particular approach and share with the reader some experiences of both instructors and students.

  6. Microlectures in a Flipped Classroom: Application, Creation and Resources

    Science.gov (United States)

    Sweet, Dawn

    2014-01-01

    Using microlectures in a flipped classroom is a growing trend. In this media review, the benefits of microlectures for such classrooms are discussed, including how they can be used to help students become more responsible for their learning, as well as how they can be used by teachers to provide differentiated instruction. A list of resources for…

  7. Reflections on a Flipped Classroom in First Year Higher Education

    Science.gov (United States)

    McCarthy, Josh

    2016-01-01

    This paper explores the efficacy of a flipped classroom model for teaching first year students three-dimensional (3D) animation, and analyses the advantages and disadvantages when compared to traditional teaching mechanisms. In 2015, within the course "Introduction to CGI" at the University of South Australia, two different tutorial…

  8. Using Digital Learning Platforms to Extend the Flipped Classroom

    Science.gov (United States)

    Balzotti, Jonathan M.; McCool, Lynn B.

    2016-01-01

    Although digital environments already play a vital role in the flipped classroom model, this research project shows that in university writing classrooms, innovative content design and delivery systems can extend the walls of the classroom to areas beyond, in which students transfer and connect course content with the professional world. In this…

  9. Inquiry-Based Learning and the Flipped Classroom Model

    Science.gov (United States)

    Love, Betty; Hodge, Angie; Corritore, Cynthia; Ernst, Dana C.

    2015-01-01

    The flipped classroom model of teaching can be an ideal venue for turning a traditional classroom into an engaging, inquiry-based learning (IBL) environment. In this paper, we discuss how two instructors at different universities made their classrooms come to life by moving the acquisition of basic course concepts outside the classroom and using…

  10. Flipping & Clicking Your Way to Higher-Order Learning

    Science.gov (United States)

    Garver, Michael S.; Roberts, Brian A.

    2013-01-01

    This innovative system of teaching and learning includes the implementation of two effective learning technologies: podcasting ("flipping") and classroom response systems ("clicking"). Students watch lectures in podcast format before coming to class, which allows the "entire" class period to be devoted to active…

  11. Using Flip Camcorders for Active Classroom Metacognitive Reflection

    Science.gov (United States)

    Hargis, Jace; Marotta, Sebastian M.

    2011-01-01

    A Center for Teaching and Learning provided Flip camcorders to a group of 10 new faculty members, who were asked to use this teaching tool in their classroom instruction. The classes included mathematics, political science, computer engineering, psychology, business, music and dance. The qualitative results indicate that all faculty members and…

  12. University and Flipped Learning TIC & DIL Project: Framework and Design

    Science.gov (United States)

    Pinnelli, Stefania; Fiorucci, Andrea

    2015-01-01

    The flipped classroom approach (FC) is for the educational world a chance of recovery and improvement of pedagogical student-centered model and collaborative teaching methods aimed at optimizing the time resource and to promote personalization and self-learning in a perspective of autonomy. The paper moving from a pedagogical reflection on…

  13. Fermion helicity flip in higher-derivative electromagnetism

    Energy Technology Data Exchange (ETDEWEB)

    Accioly, A.J. [Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil); Mukai, H. [Universidade Estadual de Maringa, PR (Brazil). Dept. de Fisica

    1996-10-01

    It is shown that massive fermions have their helicity flipped on account of their interaction with an electromagnetic field described by Podolsky`s generalized electrodynamics. Massless fermions, in turn, seem to be unaffected by the electromagnetic field as far as their helicity is concerned. (author).

  14. On Flipping the Classroom in Large First Year Calculus Courses

    Science.gov (United States)

    Jungic, Veselin; Kaur, Harpreet; Mulholland, Jamie; Xin, Cindy

    2015-01-01

    Over the course of two years, 2012-2014, we have implemented a "flipping" the classroom approach in three of our large enrolment first year calculus courses: differential and integral calculus for scientists and engineers. In this article we describe the details of our particular approach and share with the reader some experiences of…

  15. The Effectiveness of a Technology-Enhanced Flipped Science Classroom

    Science.gov (United States)

    Sezer, Baris

    2017-01-01

    This study examined the effect on the learning and motivation of students of a flipped classroom environment enriched with technology. A mixed research design using a pretest or posttest experimental model, combined with qualitative data, was conducted in a public middle school in Turkey for 2 weeks (three class hours) within a science course.…

  16. On Flipping the Classroom in Large First Year Calculus Courses

    Science.gov (United States)

    Jungic, Veselin; Kaur, Harpreet; Mulholland, Jamie; Xin, Cindy

    2015-01-01

    Over the course of two years, 2012-2014, we have implemented a "flipping" the classroom approach in three of our large enrolment first year calculus courses: differential and integral calculus for scientists and engineers. In this article we describe the details of our particular approach and share with the reader some experiences of…

  17. Can Flipping the Classroom Work? Evidence from Undergraduate Chemistry

    Science.gov (United States)

    Casasola, Timothy; Nguyen, Tutrang; Warschauer, Mark; Schenke, Katerina

    2017-01-01

    Our study describes student outcomes from an undergraduate chemistry course that implemented a flipped format: a pedagogical model that consists of students watching recorded video lectures outside of the classroom and engaging in problem solving activities during class. We investigated whether (1) interest, study skills, and attendance as…

  18. Preparing Students for Flipped or Team-Based Learning Methods

    Science.gov (United States)

    Balan, Peter; Clark, Michele; Restall, Gregory

    2015-01-01

    Purpose: Teaching methods such as Flipped Learning and Team-Based Learning require students to pre-learn course materials before a teaching session, because classroom exercises rely on students using self-gained knowledge. This is the reverse to "traditional" teaching when course materials are presented during a lecture, and students are…

  19. Periodicals Price Survey 2002: Doing the Digital Flip.

    Science.gov (United States)

    Van Orsdel, Lee; Born, Kathleen

    2002-01-01

    Presents the annual periodicals price study. Highlights include average prices; cost histories; cost projections for future budgeting; electronic journal issues; flip pricing, defined as online access at the core of pricing negotiations; various pricing models; purchasing print at deeply discounted prices; and current trends in pricing and in the…

  20. The Flipped Classroom Model: When Technology Enhances Professional Skills

    Science.gov (United States)

    Baytiyeh, Hoda

    2017-01-01

    Purpose: The purpose of this paper is to investigate the effectiveness of the flipped classroom model in teaching and learning as well as the skills that can be acquired by students after being exposed to this learning style. Design/methodology/approach: This paper uses a qualitative case study design. In total, 20 students, from various majors,…

  1. Student Learning and Perceptions in a Flipped Linear Algebra Course

    Science.gov (United States)

    Love, Betty; Hodge, Angie; Grandgenett, Neal; Swift, Andrew W.

    2014-01-01

    The traditional lecture style of teaching has long been the norm in college science, technology, engineering, and mathematics (STEM) courses, but an innovative teaching model, facilitated by recent advances in technology, is gaining popularity across college campuses. This new model inverts or "flips" the usual classroom paradigm, in…

  2. Using Flip Camcorders for Active Classroom Metacognitive Reflection

    Science.gov (United States)

    Hargis, Jace; Marotta, Sebastian M.

    2011-01-01

    A Center for Teaching and Learning provided Flip camcorders to a group of 10 new faculty members, who were asked to use this teaching tool in their classroom instruction. The classes included mathematics, political science, computer engineering, psychology, business, music and dance. The qualitative results indicate that all faculty members and…

  3. The Flipped Classroom Model: When Technology Enhances Professional Skills

    Science.gov (United States)

    Baytiyeh, Hoda

    2017-01-01

    Purpose: The purpose of this paper is to investigate the effectiveness of the flipped classroom model in teaching and learning as well as the skills that can be acquired by students after being exposed to this learning style. Design/methodology/approach: This paper uses a qualitative case study design. In total, 20 students, from various majors,…

  4. Homoclinic Bifurcation of Orbit Flip with Resonant Principal Eigenvalues

    Institute of Scientific and Technical Information of China (English)

    Tian Si ZHANG; De Ming ZHU

    2006-01-01

    Codimension-3 bifurcations of an orbit-flip homoclinic orbit with resonant principal eigenvalues are studied for a four-dimensional system. The existence, number, co-existence and non-coexistence of 1-homoclinic orbit, 1-periodic orbit, 2n-homoclinic orbit and 2n-periodic orbit are obtained. The bifurcation surfaces and existence regions are also given.

  5. Degenerate Orbit Flip Homoclinic Bifurcations with Higher Dimensions

    Institute of Scientific and Technical Information of China (English)

    Ran Chao WU; Jian Hua SUN

    2006-01-01

    Bifurcations of a degenerate homoclinic orbit with orbit flip in high dimensional system are existence and uniqueness of 1-homoclinic orbit and 1-periodic orbit are given. Also considered is the existence of 2-homoclinic orbit and 2-periodic orbit. In additon, the corresponding bifurcation surfaces are given.

  6. Student and Instructor Perceptions of a Flipped College Algebra Classroom

    Science.gov (United States)

    Jaster, Robert W.

    2017-01-01

    Each year about half a million students fail to make planned academic progress due to college algebra, hence the need for researchers to find ways of improving the quality of instruction in the course. Recent research suggests that flipping college algebra to allow time for active learning in the classroom may improve student performance. Also,…

  7. How do medical students prepare for flipped classrooms?

    NARCIS (Netherlands)

    Bouwmeester, RAM; de Kleijn, R.A.M.; ten Cate, TJ; van Rijen, HVM; Westerveld, HE

    A flipped classroom, an approach abandoning traditional lectures and having students come together to apply acquired knowledge, requires students to come to class well prepared. The nature of this preparation is currently being debated. Watching web lectures as a preparation has typically been

  8. Flipped Top-Down is Systematic Bottom-Up

    NARCIS (Netherlands)

    Zaytsev, V.; Sturm, A.; Clark, T.

    2016-01-01

    The paper presents an experience report in course design for a versatile group of computer science students where their needs were surfaced and met by the combination of strict top-down exposure to course material and the flipped classroom model of lecturing.

  9. Adapting algebraic diagrammatic construction schemes for the polarization propagator to problems with multi-reference electronic ground states exploiting the spin-flip ansatz

    Science.gov (United States)

    Lefrancois, Daniel; Wormit, Michael; Dreuw, Andreas

    2015-09-01

    For the investigation of molecular systems with electronic ground states exhibiting multi-reference character, a spin-flip (SF) version of the algebraic diagrammatic construction (ADC) scheme for the polarization propagator up to third order perturbation theory (SF-ADC(3)) is derived via the intermediate state representation and implemented into our existing ADC computer program adcman. The accuracy of these new SF-ADC(n) approaches is tested on typical situations, in which the ground state acquires multi-reference character, like bond breaking of H2 and HF, the torsional motion of ethylene, and the excited states of rectangular and square-planar cyclobutadiene. Overall, the results of SF-ADC(n) reveal an accurate description of these systems in comparison with standard multi-reference methods. Thus, the spin-flip versions of ADC are easy-to-use methods for the calculation of "few-reference" systems, which possess a stable single-reference triplet ground state.

  10. Applying a learning design methodology in the flipped classroom approach – empowering teachers to reflect

    DEFF Research Database (Denmark)

    Triantafyllou, Evangelia; Kofoed, Lise; Purwins, Hendrik

    2016-01-01

    One of the recent developments in teaching that heavily relies on current technology is the “flipped classroom” approach. In a flipped classroom the traditional lecture and homework sessions are inverted. Students are provided with online material in order to gain necessary knowledge before class...... through flipped classroom designs. In order to discuss the opportunities arising by this approach, the different components of the Learning Design – Conceptual Map (LD-CM) are presented and examined in the context of the flipped classroom. It is shown that viewing the flipped classroom through the lens......, tools and resources used in specific flipped classroom models, and it can make educators more aware of the decisions that have to be taken and people who have to be involved when designing a flipped classroom. By using the LD-CM, this paper also draws attention to the importance of characteristics...

  11. The Ins and Outs of Lipid Flip-Flop.

    Science.gov (United States)

    Allhusen, John S; Conboy, John C

    2017-01-17

    Our current view of cellular membranes centers on the fluid-mosaic model, which envisions the cellular membrane as a "liquidlike" bilayer of lipids, cholesterol, and proteins that freely diffuse in two dimensions. In stark contrast, the exchange of materials between the leaflets of a bilayer was presumed to be prohibited by the large enthalpic barrier associated with translocating hydrophilic materials, such as a charged lipid headgroup, through the hydrophobic membrane core. This static picture with regard to lipid translocation (or "flip-flop" as it is affectionately known) has been a long-held belief in the study of membrane dynamics. The current accepted membrane model invokes specific protein flippase (inward moving), floppase (outward moving), and scramblase (bidirectional) enzymes that assist in the movement of lipids between the leaflets of cellular membranes. The low rate of protein-free lipid flip-flop has also been a cornerstone of our understanding of the bilateral organization of cellular membrane components, specifically the asymmetric distribution of lipid species found in the luminal and extracellular leaflets of the plasma membrane of eukaryotic cells. Much of the previous work contributing to our current understanding of lipid flip-flop has utilized fluorescent- or spin-labeled lipids. However, there is growing evidence that these lipid probes do not accurately convey the dynamics and thermodynamics of native (unlabeled) lipid motion. This Account summarizes our research efforts directed toward developing a deep physical and chemical understanding of protein-free lipid flip-flop in phospholipid membrane models using sum-frequency vibrational spectroscopy (SFVS). Our use of SFVS enables the direct measurement of native lipid flip-flop in model membranes. In particular, we have explored the kinetic rates and activation thermodynamics of lipid translocation as a means of deciphering the underlying chemical and physical directors governing this

  12. Module comprising IC memory stack dedicated to and structurally combined with an IC microprocessor chip

    Science.gov (United States)

    Carson, John C. (Inventor); Indin, Ronald J. (Inventor); Shanken, Stuart N. (Inventor)

    1994-01-01

    A computer module is disclosed in which a stack of glued together IC memory chips is structurally integrated with a microprocessor chip. The memory provided by the stack is dedicated to the microprocessor chip. The microprocessor and its memory stack may be connected either by glue and/or by solder bumps. The solder bumps can perform three functions--electrical interconnection, mechanical connection, and heat transfer. The electrical connections in some versions are provided by wire bonding.

  13. Polarizing a stored proton beam by spin-flip?

    Energy Technology Data Exchange (ETDEWEB)

    Oellers, Dieter Gerd Christian

    2010-04-15

    The present thesis discusses the extraction of the electron-proton spin-flip cross-section. The experimental setup, the data analysis and the results are pictured in detail. The proton is described by a QCD-based parton model. In leading twist three functions are needed. The quark distribution, the helicity distribution and the transversity distribution. While the first two are well-known, the transversity distribution is largely unknown. A self-sufficient measurement of the transversity is possible in double polarized proton-antiproton scattering. This rises the need of a polarized antiproton beam. So far spin filtering is the only tested method to produce a polarized proton beam, which may be capable to hold also for antiprotons. In-situ polarization build-up of a stored beam either by selective removal or by spin-flip of a spin-(1)/(2) beam is mathematically described. A high spin-flip cross-section would create an effective method to produce a polarized antiproton beam by polarized positrons. Prompted by conflicting calculations, a measurement of the spin-flip cross-section in low-energy electron-proton scattering was carried out. This experiment uses the electron beam of the electron cooler at COSY as an electron target. The depolarization of the stored proton beam is detected. An overview of the experiment is followed by detailed descriptions of the cycle setup, of the electron target and the ANKE silicon tracking telescopes acting as a beam polarimeter. Elastic protondeuteron scattering is the analyzing reaction. The event selection is depicted and the beam polarization is calculated. Upper limits of the two electron-proton spin-flip cross-sections {sigma} {sub parallel} and {sigma} {sub perpendicular} {sub to} are deduced using the likelihood method. (orig.)

  14. Flipping the Learning: An Investigation into the Use of the Flipped Classroom Model in an Introductory Teaching Course

    Science.gov (United States)

    Vaughan, Michelle

    2014-01-01

    With a classroom full of millennial learners, it is essential that teacher educators adjust their pedagogy to meet their students' needs. This study explores the use of a flipped classroom model to engage preservice teachers in an Introduction to the Teaching Profession course. In addition, it explores the need for teacher education…

  15. Element nodes of sports equipment double back flip factions and double back flip hunched performed gymnast in floor exercise

    Directory of Open Access Journals (Sweden)

    Potop V.A.

    2014-04-01

    Full Text Available Purpose: to identify the node elements of sports equipment double back somersault tuck and double back flip bent. To compare the two types of nodes for double somersault. Material : the study involved eight gymnasts (age 12 - 14 years. All finalists in the competition floor exercise - reserve team Romania. The method of video - computer research and method of postural orientation movements. Results : identified nodal elements of sports equipment double back somersault tuck and double back flip bent. In the preparatory phase of motor actions - launcher body posture for reaching is repulsive to flip. In the phase of basic motor action - animation body postures (double back somersault tuck and bent (bent double back flip. Exercises are performed on the ascending and descending parts of the flight path of the demonstration of individual maximum lift height common center of mass. In the final phase of motor actions - final body posture - steady landing. Conclusions : indicators of key elements of sports equipment acrobatic exercises contain new scientific facts kinematic and dynamic structures of motor actions. They are necessary for the development of modern training programs acrobatic exercises in step specialized base preparation.

  16. Reservoir-on-a-Chip (ROC): A new paradigm in reservoir engineering

    NARCIS (Netherlands)

    Kumar Gunda, N.S.; Bera, B.; Karadimitriou, N.K.; Mitra, S.K.; Hassanizadeh, S.M.

    2011-01-01

    In this study, we design a microfluidic chip, which represents the pore structure of a naturally occurring oil-bearing reservoir rock. The pore-network has been etched in a silicon substrate and bonded with a glass covering layer to make a complete microfluidic chip, which is termed as

  17. Pixel detector readout chip

    CERN Multimedia

    1991-01-01

    Close-up of a pixel detector readout chip. The photograph shows an aera of 1 mm x 2 mm containing 12 separate readout channels. The entire chip contains 1000 readout channels (around 80 000 transistors) covering a sensitive area of 8 mm x 5 mm. The chip has been mounted on a silicon detector to detect high energy particles.

  18. Targeting the Anti-Apoptotic Protein c-FLIP for Cancer Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Safa, Ahmad R., E-mail: asafa@iupui.edu [Department of Pharmacology and Toxicology, Indiana University School of Medicine, 980 W. Walnut Street, R3-C524, Indianapolis, IN 46202 (United States); Indiana University Simon Cancer Center, Indiana University School of Medicine, 980 W. Walnut Street, R3-C524, Indianapolis, IN 46202 (United States); Pollok, Karen E. [Department of Pharmacology and Toxicology, Indiana University School of Medicine, 980 W. Walnut Street, R3-C524, Indianapolis, IN 46202 (United States); Indiana University Simon Cancer Center, Indiana University School of Medicine, 980 W. Walnut Street, R3-C524, Indianapolis, IN 46202 (United States); Herman B. Wells Center for Pediatric Research, 980 W. Walnut Street, R3-C524, Indianapolis, IN 46202 (United States)

    2011-03-29

    Cellular FLICE (FADD-like IL-1beta-converting enzyme)-inhibitory protein (c-FLIP) is a major resistance factor and critical anti-apoptotic regulator that inhibits tumor necrosis factor-alpha (TNF-alpha), Fas-L, and TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis as well as chemotherapy-triggered apoptosis in malignant cells. c-FLIP is expressed as long (c-FLIP{sub L}), short (c-FLIP{sub S}), and c-FLIP{sub R} splice variants in human cells. c-FLIP binds to FADD and/or caspase-8 or -10 in a ligand-dependent and-independent fashion, which in turn prevents death-inducing signaling complex (DISC) formation and subsequent activation of the caspase cascade. Moreover, c-FLIP{sub L} and c-FLIP{sub S} are known to have multifunctional roles in various signaling pathways, as well as activating and/or upregulating several cytoprotective signaling molecules. Upregulation of c-FLIP has been found in various tumor types, and its downregulation has been shown to restore apoptosis triggered by cytokines and various chemotherapeutic agents. Hence, c-FLIP is an important target for cancer therapy. For example, small interfering RNAs (siRNAs) that specifically knockdown the expression of c-FLIP{sub L} in diverse human cancer cell lines augmented TRAIL-induced DISC recruitment and increased the efficacy of chemotherapeutic agents, thereby enhancing effector caspase stimulation and apoptosis. Moreover, small molecules causing degradation of c-FLIP as well as decreasing mRNA and protein levels of c-FLIP{sub L} and c-FLIP{sub S} splice variants have been found, and efforts are underway to develop other c-FLIP-targeted cancer therapies. This review focuses on (1) the functional role of c-FLIP splice variants in preventing apoptosis and inducing cytokine and drug resistance; (2) the molecular mechanisms that regulate c-FLIP expression; and (3) strategies to inhibit c-FLIP expression and function.

  19. A novel role of c-FLIP protein in regulation of ER stress response.

    Science.gov (United States)

    Conti, Silvia; Petrungaro, Simonetta; Marini, Elettra Sara; Masciarelli, Silvia; Tomaipitinca, Luana; Filippini, Antonio; Giampietri, Claudia; Ziparo, Elio

    2016-09-01

    Cellular-Flice-like inhibitory protein (c-FLIP) is an apoptosis modulator known to inhibit the extrinsic apoptotic pathway thus blocking Caspase-8 processing in the Death Inducing Signalling Complex (DISC). We previously demonstrated that c-FLIP localizes at the endoplasmic reticulum (ER) and that c-FLIP-deficient mouse embryonic fibroblasts (MEFs) display an enlarged ER morphology. In the present study, we have addressed the consequences of c-FLIP ablation in the ER stress response by investigating the effects of pharmacologically-induced ER stress in Wild Type (WT) and c-FLIP-/- MEFs. Surprisingly, c-FLIP-/- MEFs were found to be strikingly more resistant than WT MEFs to ER stress-mediated apoptosis. Analysis of Unfolded Protein Response (UPR) pathways revealed that Pancreatic ER Kinase (PERK) and Inositol-Requiring Enzyme 1 (IRE1) branch signalling is compromised in c-FLIP-/- cells when compared with WT cells. We found that c-FLIP modulates the PERK pathway by interfering with the activity of the serine threonine kinase AKT. Indeed, c-FLIP-/- MEFs display higher levels of active AKT than WT MEFs upon ER stress, while treatment with a specific AKT inhibitor of c-FLIP-/- MEFs subjected to ER stress restores the PERK but not the IRE1 pathway. Importantly, the AKT inhibitor or dominant negative AKT transfection sensitizes c-FLIP-/- cells to ER stress-induced cell death while the expression of a constitutively active AKT reduces WT cells sensitivity to ER stress-induced death. Thus, our results demonstrate that c-FLIP modulation of AKT activity is crucial in controlling PERK signalling and sensitivity to ER stress, and highlight c-FLIP as a novel molecular player in PERK and IRE1-mediated ER stress response.

  20. Biocompatible "click" wafer bonding for microfluidic devices.

    Science.gov (United States)

    Saharil, Farizah; Carlborg, Carl Fredrik; Haraldsson, Tommy; van der Wijngaart, Wouter

    2012-09-07

    We introduce a novel dry wafer bonding concept designed for permanent attachment of micromolded polymer structures to surface functionalized silicon substrates. The method, designed for simultaneous fabrication of many lab-on-chip devices, utilizes a chemically reactive polymer microfluidic structure, which rapidly bonds to a functionalized substrate via"click" chemistry reactions. The microfluidic structure consists of an off-stoichiometry thiol-ene (OSTE) polymer with a very high density of surface bound thiol groups and the substrate is a silicon wafer that has been functionalized with common bio-linker molecules. We demonstrate here void free, and low temperature (silane functionalized silicon wafer.

  1. Information Literacy and the Flipped Classroom: Examining the Impact of a One-Shot Flipped Class on Student Learning and Perceptions

    Science.gov (United States)

    Brooks, Andrea Wilcox

    2014-01-01

    This article examines the flipped classroom approach in higher education and its use in one -shot information literacy instruction sessions. The author presents findings from a pilot study of student learning and student perceptions pertaining to flipped model IL instruction. Students from two sections of the same course participated in this…

  2. Flip-Chip GaN-Based Light-Emitting Diodes with Mesh-Contact Electrodes

    Institute of Scientific and Technical Information of China (English)

    ZHU Yan-Xu; XU Chen; HAN Jun; SHEN Guang-Di

    2007-01-01

    @@ GaN-based light-emitting diodes (LEDs) with mesh-contact electrodes have been developed. The p-type ohmic contact layer is composed of oxidized Ni/Au mesh and NiO overlay (20 (A)). An Ag (3000 (A)) omni-directional reflector covers the p-type contact. The n-type contact is a Ti/Al planar film with a 10-μm-width Ti/Al stripe.The Ti/Al stripe surrounds the centre of LED mesa. With a 20-mA current injection, the light output power of GaN-based LEDs with mesh-contact electrodes is 23% higher than that of the conventional LEDs.

  3. Observations of microstructural coarsening in micro flip-chip solder joints

    Science.gov (United States)

    Barney, Monica M.; Morris, J. W.

    2001-09-01

    Coarsening of solder microstructures dramatically affects fatigue lifetimes. This paper presents a study of microstructural evolution due to thermal cycling and aging of small solder joints. The lead-tin solder joints in this study have a height of 55 5 m and a tin content of 65 70 wt.%, with a degenerate eutectic microstructure. The joint microstructure coarsens more rapidly during aging at 160°C than cycling from 0 160°C. No coarsened bands are observed. The cycling data scales with standard coarsening equations, while the aging data fits to an enhanced trend. The joints experiencing 2.8% strain during cycling fail by 1000 cycles.

  4. Electrodeposition and characterisation of Sn-Ag-Cu solder alloys for flip-chip interconnection

    Energy Technology Data Exchange (ETDEWEB)

    Qin Yi [Department of Materials, Loughborough University, Leicestershire, LE11 3TU (United Kingdom); Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Leicestershire, LE11 3TU (United Kingdom); Wilcox, G.D., E-mail: G.D.Wilcox@lboro.ac.u [Department of Materials, Loughborough University, Leicestershire, LE11 3TU (United Kingdom); Liu Changqing [Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Leicestershire, LE11 3TU (United Kingdom)

    2010-12-15

    A pyrophosphate and iodide based bath was investigated for the electrodeposition of near-eutectic Sn-Ag-Cu alloys, which are promising lead-free solder candidates for electronics interconnection. Near-eutectic Sn-Ag-Cu electrodeposits (2.5-4.2 wt.% Ag and 0.7-1.5 wt.% Cu) were achieved from the system as measured by wavelength dispersive X-ray spectroscopy (WDS). Electroplating such near-eutectic ternary alloys at higher deposition rates was possible with the application of electrolyte agitation. Different morphologies of deposited Sn-Ag-Cu films were analysed using scanning electron microscopy (SEM). X-ray diffraction (XRD) data indicated that Sn, Ag{sub 3}Sn and Cu{sub 6}Sn{sub 5} were present in the 'as-electrodeposited' Sn-Ag-Cu film. The microstructure of the deposits and the morphology of Ag{sub 3}Sn and Cu{sub 6}Sn{sub 5} intermetallics were characterised from cross-sectional images produced from a focused ion beam scanning electron microscopy and then imaged from transmission electron microscopy (TEM) micrographs. The proposed bath proved capable of producing fine pitch near-eutectic Sn-Ag-Cu solder bumps as demonstrated on a glass test wafer.

  5. Information Literacy and the Flipped Classroom: Examining the Impact of a One-Shot Flipped Class on Student Learning and Perceptions

    Directory of Open Access Journals (Sweden)

    Andrea Wilcox Brooks

    2014-12-01

    Full Text Available This article examines the flipped classroom approach in higher education and its use in one-shot information literacy instruction sessions. The author presents findings from a pilot study of student learning and student perceptions pertaining to flipped model IL instruction. Students from two sections of the same course participated in this study. One section received one-shot information literacy instruction using a flipped approach, while the other section received traditional one-shot instruction. No difference was found between the two groups on a pre- and post-test analysis; however, an analysis of students’ final papers from the flipped section showed more bibliography citations to scholarly journal articles. In addition, a survey was conducted showing the majority of students preferred the flipped approach.

  6. Fundamental study of microelectronic chip response under laser ultrasonic-interferometric inspection using C-scan method

    Science.gov (United States)

    Yang, Lei; Gong, Jie; Ume, I. Charles

    2014-02-01

    In modern surface mount packaging technologies, such as flip chips, chip scale packages, and ball grid arrays(BGA), chips are attached to the substrates/printed wiring board (PWB) using solder bump interconnections. The quality of solder bumps between the chips and the substrate/board is difficult to inspect. Laser ultrasonic-interferometric technique was proved to be a promising approach for solder bump inspection because of its noncontact and nondestructive characteristics. Different indicators extracted from received signals have been used to predict the potential defects, such as correlation coefficient, error ratio, frequency shifting, etc. However, the fundamental understanding of the chip behavior under laser ultrasonic inspection is still missing. Specifically, it is not sure whether the laser interferometer detected out-of-plane displacements were due to wave propagation or structural vibration when the chip was excited by pulsed laser. Plus, it is found that the received signals are chip dependent. Both challenges impede the interpretation of acquired signals. In this paper, a C-scan method was proposed to study the underlying phenomenon during laser ultrasonic inspection. The full chip was inspected. The response of the chip under laser excitation was visualized in a movie resulted from acquired signals. Specifically, a BGA chip was investigated to demonstrate the effectiveness of this method. By characterizing signals using discrete wavelet transform(DWT), both ultrasonic wave propagation and vibration were observed. Separation of them was successfully achieved using ideal band-pass filter and visualized in resultant movies, too. The observed ultrasonic waves were characterized and their respective speeds were measured by applying 2-D FFT. The C-scan method, combined with different digital signal processing techniques, was proved to be an very effective methodology to learn the behavior of chips under laser excitation. This general procedure can be

  7. Flipping the classroom to teach population health: Increasing the relevance.

    Science.gov (United States)

    Simpson, Vicki; Richards, Elizabeth

    2015-05-01

    In recent years, there have been multiple calls to enhance the population health and health promotion aspects of nursing programs. Further impetus has been provided by passage of the Affordable Care Act in 2010 with its focus on prevention. The need to develop students who can critically think and apply knowledge learned is crucial to the development of nurses who can integrate and apply the concepts of population-focused practice in society and a healthcare system undergoing transformation. This coupled with the ever changing needs of learners requires a different approach to content delivery and presentation. Flipped classroom courses, with an online component, offer the flexibility and technology desired by current undergraduate students. The use of a flipped classroom approach to re-design a population health course in a Midwestern nursing program resulted in stronger course evaluations from students and reflected better student understanding of the relevance of such content in a nursing curriculum.

  8. Pharmacists correcting schedule II prescriptions: DEA flip-flops continue.

    Science.gov (United States)

    Abood, Richard R

    2010-12-01

    The Drug Enforcement Administration (DEA) has in recent years engaged in flip-flopping over important policy decisions. The most recent example involved whether a pharmacist can correct a written schedule II prescription upon verification with the prescriber. For several years the DEA's policy permitted this practice. Then the DEA issued a conflicting policy statement in 2007 in the preamble to the multiple schedule II prescription regulation, causing a series of subsequent contradictory statements ending with the policy that pharmacists should follow state law or policy until the Agency issues a regulation. It is doubtful that the DEA's opinion in the preamble would in itself constitute legal authority, or that the Agency would try to enforce the opinion. Nonetheless, these flip-flop opinions have confused pharmacists, caused some pharmacies to have claims rejected by third party payors, and most likely have inconvenienced patients.

  9. The ideal flip-through impact: experimental and numerical investigation

    DEFF Research Database (Denmark)

    Bredmose, Henrik; Hunt-Raby, A.; Jayaratne, R.

    2010-01-01

    , with the focus location adjusted to produce a near-breaking wave impact with no discernible air entrainment or entrapment. Details of the resultant impact are presented in the form of high-speed video, pressure transducer and wave gauge records. Numerical reproduction of the wave transformation and impact...... is achieved by application of a linear wave-analysis model and a fully nonlinear potential-flow solver. Although more advanced models exist, use of the latter model type is interesting as (1) it was applied by Cooker and Peregrine (Proceedings of the 22nd International Conference on Coastal Engineering, 164......-176, 1990) in their original numerical discovery of the flip-through impact and (2) the assumptions behind the potential-flow model remain reasonably valid, until the flip-through jet begins to break into droplets. In the present study, the potential-flow model has been extended with the Schwarz...

  10. Neutron spin-flip scattering of nanocrystalline cobalt

    Energy Technology Data Exchange (ETDEWEB)

    Honecker, D; Doebrich, F; Michels, A [Laboratory for the Physics of Advanced Materials, University of Luxembourg, 162A Avenue de la Faiencerie, L-1511 Luxembourg (Luxembourg); Dewhurst, C D; Wiedenmann, A, E-mail: andreas.michels@uni.l [Institut Laue-Langevin, 6 Rue Jules Horowitz, BP 156, F-38042 Grenoble Cedex 9 (France)

    2011-01-12

    We report results of longitudinal (one-dimensional) neutron polarization analysis on polycrystalline bulk Co with an average crystallite size of D = 10 nm. The spin-flip small-angle neutron scattering (SANS) data are analyzed in the approach-to-saturation regime within the framework of micromagnetic theory. In particular, we provide a closed-form expression for the spin-flip SANS cross section d{Sigma}{sup {+-}-+}/d{Omega}. From the data analysis, we find a room-temperature value of A = (2.6 {+-} 0.1) x 10{sup -11} J m{sup -1} for the exchange-stiffness constant, which agrees well with earlier data.

  11. Comments on Flipped SU(5) (and F-theory)

    CERN Document Server

    Kuflik, Eric

    2010-01-01

    We study the impact of nonrenormalizable operators in flipped SU(5) that can generate a large mu term, R-parity violation, and rapid proton decay. While our motivation is to determine whether F-theory can naturally realize flipped SU(5), this analysis is general and leads to a characterization of symmetries capable of controlling such operators and should be independent of F-theory. We then discuss some specific implications for F-theory model building, where a significant mu problem is unavoidable. Finally, we mention previously noted difficulties associated to engineering GUT-Higgs fields in F-theory, suggest a direct engineering of SU(5) \\times U(1)_{\\chi} as an alternative, and present a sample construction of this type.

  12. Empowering Pre-Service Teachers to Produce Ubiquitous Flipped Classes

    Directory of Open Access Journals (Sweden)

    Soraya García-Sánchez

    2017-01-01

    Full Text Available This work focuses on technological and educational outcomes that resulted from the production of foreign language educational videos by 90 pre-service instructors enrolled in an official Master’s Degree in Secondary Education programme. This teaching practice, conducted during two consecutive years, was set in a ubiquitous learning environment with the intention of effectively linking digital technology with pedagogy by means of producing flipped classroom units. The findings reveal that these pre-service teachers successfully combined instructional dynamics with digital skills to produce flipped classes adapted to the young generation’s needs. The classroom becomes, therefore, a more participatory learner-centred scenario with a variety of interactive and collaborative activities performed by foreign language students.

  13. Nonlinear self-flipping of polarization states in asymmetric waveguides

    CERN Document Server

    Zhang, Wen Qi; Monro, Tanya M; Afshar, V Shahraam

    2012-01-01

    Waveguides of subwavelength dimensions with asymmetric geometries, such as rib waveguides, can display nonlinear polarization effects in which the nonlinear phase difference dominates the linear contribution, provided the birefringence is sufficiently small. We demonstrate that self-flipping polarization states can appear in such rib waveguides at low (mW) power levels. We describe an optical power limiting device with optimized rib waveguide parameters that can operate at low powers with switching properties.

  14. On Teacher's Teaching Behavior Based on the Flipped Classroom

    Institute of Scientific and Technical Information of China (English)

    Yang Haili; Huang Yumei

    2016-01-01

    Teacher’s teaching behavior refers to dominant behavior and invisible behaviors conducted by teachers during the process of teaching. The teaching process includes teaching preparation, lead-in, presentation and surveillance.Teacher’s teaching behavior has a vital effect on classroom teaching and students’ English learning. Therefore, the thesis analyzes and discusses the teacher’s behavior on the base of the flipped classroom and aims to make the teacher’s behavior have positive impact on students’ English learning.

  15. Surgical Outcome of Acetabular Fracture Using Trochanteric Flip Osteotomy

    Directory of Open Access Journals (Sweden)

    Espandar R

    2012-01-01

    Full Text Available Background: One of the difficulties in acetabulum surgery is appropriate exposure of the site of surgery. Trochanteric flip osteotomy is one of the surgical methods for superoposterior and posterior acetabulum exposure. However, due to possible complications some surgeons prefer to avoid this procedure. This study was undertaken to determine the outcome of surgical treatment of acetabular fracture using trochanteric flip osteotomy. Methods : In this prospective cohort study, 14 patients with acetabular fracture who had been admitted in Imam Khomeini Hospital in Tehran, Iran, during 2003-2006 underwent trochanteric flip osteotomy. The patients were followed for at least one year post-surgically. Demographics, radiologic findings, intensity of pain using visual analogue scale (VAS, Harris hip score (HHS, force of hip abductors and complications were noted. Data analysis was performed using SPSS ver. 13.Results : The mean HHS was 82.5 (55-95. Heterotopic ossification was observed in three patients. There were no cases of postoperative infection or nonunion. Only two patients showed displacement of osteotomized fragments. Reduction was anatomic in 10 patients. In one patient, the force of hip abductors was three-fifth. The mean hip pain was 3.4 based on VAS. There were no cases of femoral head osteonecrosis. With respect to HHS, the final hip status was excellent and good in four and six patients, respectively. Three patients had fair and only one patient had poor condition.Conclusion: It seems that trochanteric flip osteotomy has much fewer complications in comparison to other methods justifying its use in such cases.

  16. Spin flips and quantum information for anti-parallel spins

    CERN Document Server

    Gisin, Nicolas

    1999-01-01

    We consider two different ways to encode quantum information, by parallel or anti-parallel pairs of spins. We find that there is more information in the anti-parallel ones. This purely quantum mechanical effect is due to entanglement, not of the states but occuring in the course of the measuring process. We also introduce a range of quantum information processing machines, such as spin-flip and anti-cloning.

  17. Nonparaxial propagation of phase-flipped Gaussian beams

    Institute of Scientific and Technical Information of China (English)

    Gao Zeng-Hui; Lü Bai-Da

    2008-01-01

    This paper derives the closed-form expressions for nonparaxial phase flipped Gaussian (PFG) beams propagating in free space, through a knife edge and an aperture, which enable us to study nonparaxial propagation properties of PFG beams and to compare nonparaxial results with paraxial ones. It is found that the f parameter, offsetting distance of the knife edge and truncation parameter affect the nonparaxial beam propagation properties. Only under certain conditions the paraxial approximation is applicable. The results are illustrated by numerical examples.

  18. The worldline approach to helicity flip in plane waves

    CERN Document Server

    Ilderton, Anton

    2016-01-01

    We apply worldline methods to the study of vacuum polarisation effects in plane wave backgrounds, in both scalar and spinor QED. We calculate helicity-flip probabilities to one loop order and treated exactly in the background field, and provide a toolkit of methods for use in investigations of higher-order processes. We also discuss the connections between the worldline, S-matrix, and lightfront approaches to vacuum polarisation effects.

  19. Multi-layer microfluidic glass chips for microanalytical applications

    OpenAIRE

    Daridon, Antoine; Fascio, Valia; Lichtenberg, Jan; Wütrich, Rolf; Langen, Hans; Verpoorte, Elisabeth; De Rooij, Nicolaas F

    2010-01-01

    A new, versatile architecture is presented for microfluidic devices made entirely from glass, for use with reagents which would prove highly corrosive for silicon. Chips consist of three layers of glass wafers bonded together by fusion bonding. On the inside wafer faces a network of microfluidic channels is created by photolithography and wet chemical etching. Low dead-volume fluidic connections between the layers are fabricated by spark-assisted etching (SAE), a computer numerical controlled...

  20. Experimental study of surface crystallization on integrated circuit chips

    Institute of Scientific and Technical Information of China (English)

    Zhang Xin; Liu Meng-Xin; Gao Yong; Wang Cai-Lin; Wang Zhi-Wei; Zhang Xian

    2006-01-01

    A surface crystallization phenomenon on bonding pads and wires of integrated circuit chip is reported in this paper. Through a lot of experiments, an unknown failure effect caused by mixed crystalline matter is revealed, whereas non-plasma fluorine contamination cannot cause the failure of bonding pads. By experiments combined with infrared spectroscopy analysis, the surface crystallization effect is studied. The conclusion of the study can provide the guidance for IC fabrication, modelling and analysis.

  1. A New Pixels Flipping Method for Huge Watermarking Capacity of the Invoice Font Image

    Directory of Open Access Journals (Sweden)

    Li Li

    2014-01-01

    Full Text Available Invoice printing just has two-color printing, so invoice font image can be seen as binary image. To embed watermarks into invoice image, the pixels need to be flipped. The more huge the watermark is, the more the pixels need to be flipped. We proposed a new pixels flipping method in invoice image for huge watermarking capacity. The pixels flipping method includes one novel interpolation method for binary image, one flippable pixels evaluation mechanism, and one denoising method based on gravity center and chaos degree. The proposed interpolation method ensures that the invoice image keeps features well after scaling. The flippable pixels evaluation mechanism ensures that the pixels keep better connectivity and smoothness and the pattern has highest structural similarity after flipping. The proposed denoising method makes invoice font image smoother and fiter for human vision. Experiments show that the proposed flipping method not only keeps the invoice font structure well but also improves watermarking capacity.

  2. Comparison of Pharmaceutical Calculations Learning Outcomes Achieved Within a Traditional Lecture or Flipped Classroom Andragogy.

    Science.gov (United States)

    Anderson, H Glenn; Frazier, Lisa; Anderson, Stephanie L; Stanton, Robert; Gillette, Chris; Broedel-Zaugg, Kim; Yingling, Kevin

    2017-05-01

    Objective. To compare learning outcomes achieved from a pharmaceutical calculations course taught in a traditional lecture (lecture model) and a flipped classroom (flipped model). Methods. Students were randomly assigned to the lecture model and the flipped model. Course instructors, content, assessments, and instructional time for both models were equivalent. Overall group performance and pass rates on a standardized assessment (Pcalc OSCE) were compared at six weeks and at six months post-course completion. Results. Student mean exam scores in the flipped model were higher than those in the lecture model at six weeks and six months later. Significantly more students passed the OSCE the first time in the flipped model at six weeks; however, this effect was not maintained at six months. Conclusion. Within a 6 week course of study, use of a flipped classroom improves student pharmacy calculation skill achievement relative to a traditional lecture andragogy. Further study is needed to determine if the effect is maintained over time.

  3. Spin flipping a stored vertically polarized proton beam with an RF solenoid

    Science.gov (United States)

    Phelps, R. A.; Blinov, B. B.; Chu, C. M.; Courant, E. D.; Crandell, D. A.; Kaufman, W. A.; Krisch, A. D.; Nurushev, T. S.; Ratner, L. G.; Wong, V. K.; Caussyn, D. D.; Derbenev, Ya. S.; Ellison, T. J. P.; Lee, S. Y.; Rinckel, T.; Schwandt, P.; Sperisen, F.; Stephenson, E. J.; Przewoski, B. von; Ohmori, C.

    1995-09-01

    A recent experiment in the IUCF cooler ring studied the spin flip of a stored vertically polarized 139 MeV proton beam. This spin flip was accomplished by using an RF solenoid to induce an artificial depolarizing resonance in the ring, and then varying the solenoid's frequency through this resonance value to induce spin flip. We found a polarization loss after multiple spin flips of about 0.00±0.05% per flip and also losses for very long flip times. This device will be useful for reducing systematic errors in polarized beam-internal target scattering asymmetry experiments by enabling experimenters to perform frequent beam polarization reversals in the course of the experiment.

  4. A new pixels flipping method for huge watermarking capacity of the invoice font image.

    Science.gov (United States)

    Li, Li; Hou, Qingzheng; Lu, Jianfeng; Xu, Qishuai; Dai, Junping; Mao, Xiaoyang; Chang, Chin-Chen

    2014-01-01

    Invoice printing just has two-color printing, so invoice font image can be seen as binary image. To embed watermarks into invoice image, the pixels need to be flipped. The more huge the watermark is, the more the pixels need to be flipped. We proposed a new pixels flipping method in invoice image for huge watermarking capacity. The pixels flipping method includes one novel interpolation method for binary image, one flippable pixels evaluation mechanism, and one denoising method based on gravity center and chaos degree. The proposed interpolation method ensures that the invoice image keeps features well after scaling. The flippable pixels evaluation mechanism ensures that the pixels keep better connectivity and smoothness and the pattern has highest structural similarity after flipping. The proposed denoising method makes invoice font image smoother and fiter for human vision. Experiments show that the proposed flipping method not only keeps the invoice font structure well but also improves watermarking capacity.

  5. Curriculum Design of a Flipped Classroom to Enhance Haematology Learning

    Science.gov (United States)

    Porcaro, Pauline A.; Jackson, Denise E.; McLaughlin, Patricia M.; O'Malley, Cindy J.

    2016-06-01

    A common trend in higher education is the "flipped" classroom, which facilitates active learning during class. The flipped approach to teaching was instituted in a haematology `major' class and the students' attitudes and preferences for the teaching materials were surveyed. The curriculum design was explicit and involved four major components (1) the preparation of the students; (2) the weekly pre-class work; (3) the in-class active learning strategies and (4) closing the learning loop using formative quizzes. Each of these components is discussed in detail and was informed by sound pedagogical strategies. Several different sources of information and several freely available software tools to engage the students are discussed. Two iterations are reported here, with improved pass rate for the final examination from 47 to 48 % in the traditional class to 56-65 % in the flipped classroom approach. The majority of students (93 and 89 %) came to the class prepared, after viewing the screencasts and engaged fully with the activities within the face-to-face time. The students perceived that solving case studies (93 %) was the most beneficial activity for their learning and this was closely followed by the production of essay plans (71 %). The majority of students recommended that this approach be repeated the following year (69 and 75 %).

  6. Classification of flipped SU(5) heterotic-string vacua

    Science.gov (United States)

    Faraggi, Alon E.; Rizos, John; Sonmez, Hasan

    2014-09-01

    We extend the classification of free fermionic heterotic-string vacua to models in which the SO(10) GUT symmetry is reduced at the string level to the flipped SU(5) subgroup. In our classification method the set of boundary condition basis vectors is fixed and the enumeration of string vacua is obtained in terms of the Generalised GSO (GGSO) projection coefficients entering the one-loop partition function. We derive algebraic expressions for the GGSO projections for all the physical states appearing in the sectors generated by the set of basis vectors. This enables the programming of the entire spectrum analysis in a computer code. For that purpose we developed two independent codes, based on FORTRAN95 and JAVA, and all results presented are confirmed by the two independent routines. We perform a statistical sampling in the space of 244∼1013 flipped SU(5) vacua, and scan up to 1012 GGSO configurations. Contrary to the corresponding Pati-Salam classification results, we do not find exophobic flipped SU(5) vacua with an odd number of generations. We study the structure of exotic states appearing in the three generation models, that additionally contain a viable Higgs spectrum, and demonstrate the existence of models in which all the exotic states are confined by a hidden sector non-Abelian gauge symmetry, as well as models that may admit the racetrack mechanism.

  7. "Flipping" educational technology professional development for K-12 educators

    Science.gov (United States)

    Spencer, Daniel

    As the demand for more effective professional development increases in K-12 schools, trainers must adjust their training methods to meet the needs of their teacher learners. Just as lecture-heavy, teacher-centered instruction only meet the learning needs of a small minority of students, "sit and get" professional development rarely results in the teachers gaining the skills and confidence necessary to use technology effectively in their instruction. To resolve the frustrations of teachers related to ineffective professional development, a "Flipped PD" training model was developed based on the learning needs of adult learners, the integration of technological, pedagogical, and content knowledge (TPACK), learning activities, and the Flipped Classroom concept. Under this model, training shifts from a passive, trainer-centered format, to an active, learner-centered format where teachers learn to use technology in their classrooms by first focusing on pedagogical issues, then choosing the options that work best for addressing those issues in their unique situation, and completing "learn-by-doing" projects. Those who participate in "Flipped PD" style trainings tend to have more confidence upon completion that they can use the tools they were trained on in their teaching, as well as believe that the PD was engaging and a good use of their time.

  8. Perforin rapidly induces plasma membrane phospholipid flip-flop.

    Directory of Open Access Journals (Sweden)

    Sunil S Metkar

    Full Text Available The cytotoxic cell granule secretory pathway is essential for host defense. This pathway is fundamentally a form of intracellular protein delivery where granule proteases (granzymes from cytotoxic lymphocytes are thought to diffuse through barrel stave pores generated in the plasma membrane of the target cell by the pore forming protein perforin (PFN and mediate apoptotic as well as additional biological effects. While recent electron microscopy and structural analyses indicate that recombinant PFN oligomerizes to form pores containing 20 monomers (20 nm when applied to liposomal membranes, these pores are not observed by propidium iodide uptake in target cells. Instead, concentrations of human PFN that encourage granzyme-mediated apoptosis are associated with pore structures that unexpectedly favor phosphatidylserine flip-flop measured by Annexin-V and Lactadherin. Efforts that reduce PFN mediated Ca influx in targets did not reduce Annexin-V reactivity. Antigen specific mouse CD8 cells initiate a similar rapid flip-flop in target cells. A lipid that augments plasma membrane curvature as well as cholesterol depletion in target cells enhance flip-flop. Annexin-V staining highly correlated with apoptosis after Granzyme B (GzmB treatment. We propose the structures that PFN oligomers form in the membrane bilayer may include arcs previously observed by electron microscopy and that these unusual structures represent an incomplete mixture of plasma membrane lipid and PFN oligomers that may act as a flexible gateway for GzmB to translocate across the bilayer to the cytosolic leaflet of target cells.

  9. Classification of flipped SU(5 heterotic-string vacua

    Directory of Open Access Journals (Sweden)

    Alon E. Faraggi

    2014-09-01

    Full Text Available We extend the classification of free fermionic heterotic-string vacua to models in which the SO(10 GUT symmetry is reduced at the string level to the flipped SU(5 subgroup. In our classification method the set of boundary condition basis vectors is fixed and the enumeration of string vacua is obtained in terms of the Generalised GSO (GGSO projection coefficients entering the one-loop partition function. We derive algebraic expressions for the GGSO projections for all the physical states appearing in the sectors generated by the set of basis vectors. This enables the programming of the entire spectrum analysis in a computer code. For that purpose we developed two independent codes, based on FORTRAN95 and JAVA, and all results presented are confirmed by the two independent routines. We perform a statistical sampling in the space of 244∼1013 flipped SU(5 vacua, and scan up to 1012 GGSO configurations. Contrary to the corresponding Pati–Salam classification results, we do not find exophobic flipped SU(5 vacua with an odd number of generations. We study the structure of exotic states appearing in the three generation models, that additionally contain a viable Higgs spectrum, and demonstrate the existence of models in which all the exotic states are confined by a hidden sector non-Abelian gauge symmetry, as well as models that may admit the racetrack mechanism.

  10. Classification of flipped SU(5) heterotic-string vacua

    Energy Technology Data Exchange (ETDEWEB)

    Faraggi, Alon E., E-mail: alon.faraggi@liv.ac.uk [Department of Mathematical Sciences, University of Liverpool, Liverpool L69 7ZL (United Kingdom); Rizos, John, E-mail: irizos@uoi.gr [Department of Physics, University of Ioannina, GR45110 Ioannina (Greece); Sonmez, Hasan, E-mail: Hasan.Sonmez@liv.ac.uk [Department of Mathematical Sciences, University of Liverpool, Liverpool L69 7ZL (United Kingdom)

    2014-09-15

    We extend the classification of free fermionic heterotic-string vacua to models in which the SO(10) GUT symmetry is reduced at the string level to the flipped SU(5) subgroup. In our classification method the set of boundary condition basis vectors is fixed and the enumeration of string vacua is obtained in terms of the Generalised GSO (GGSO) projection coefficients entering the one-loop partition function. We derive algebraic expressions for the GGSO projections for all the physical states appearing in the sectors generated by the set of basis vectors. This enables the programming of the entire spectrum analysis in a computer code. For that purpose we developed two independent codes, based on FORTRAN95 and JAVA, and all results presented are confirmed by the two independent routines. We perform a statistical sampling in the space of 2{sup 44}∼10{sup 13} flipped SU(5) vacua, and scan up to 10{sup 12} GGSO configurations. Contrary to the corresponding Pati–Salam classification results, we do not find exophobic flipped SU(5) vacua with an odd number of generations. We study the structure of exotic states appearing in the three generation models, that additionally contain a viable Higgs spectrum, and demonstrate the existence of models in which all the exotic states are confined by a hidden sector non-Abelian gauge symmetry, as well as models that may admit the racetrack mechanism.

  11. Base Flipping in Open Complex Formation at Bacterial Promoters

    Directory of Open Access Journals (Sweden)

    Mary E. Karpen

    2015-04-01

    Full Text Available In the process of transcription initiation, the bacterial RNA polymerase binds double-stranded (ds promoter DNA and subsequently effects strand separation of 12 to 14 base pairs (bp, including the start site of transcription, to form the so-called “open complex” (also referred to as RPo. This complex is competent to initiate RNA synthesis. Here we will review the role of σ70 and its homologs in the strand separation process, and evidence that strand separation is initiated at the −11A (the A of the non-template strand that is 11 bp upstream from the transcription start site of the promoter. By using the fluorescent adenine analog, 2-aminopurine, it was demonstrated that the −11A on the non-template strand flips out of the DNA helix and into a hydrophobic pocket where it stacks with tyrosine 430 of σ70. Open complexes are remarkably stable, even though in vivo, and under most experimental conditions in vitro, dsDNA is much more stable than its strand-separated form. Subsequent structural studies of other researchers have confirmed that in the open complex the −11A has flipped into a hydrophobic pocket of σ70. It was also revealed that RPo was stabilized by three additional bases of the non-template strand being flipped out of the helix and into hydrophobic pockets, further preventing re-annealing of the two complementary DNA strands.

  12. Digital Storytelling in a Flipped Classroom for Effective Learning

    Directory of Open Access Journals (Sweden)

    Clemens Bechter

    2017-06-01

    Full Text Available Conclusive empirical evidence on whether virtual classrooms result in higher performance, satisfaction, or an improvement in problem solving skills when compared with traditional face-to-face lecturing does not exist. Various studies point in different directions. However, blended learning outperforms the traditional classroom in student performance and satisfaction. A flipped classroom is one type of blended learning. For more than 20 years, this approach has been used at a European executive MBA (EMBA program delivering online content combined with six residential weeks where students collaborate and reflect upon their online learning. Our research examined the overall setup of this program, and assessed one course in depth. As part of the course—International Management—an intercultural negotiation project was chosen to highlight the integration of online and offline activities. The flipped classroom is a demonstration of the reform-based teaching approach. The power of reform-based learning in executive education is the engaging combination of practice and theory, which improves the performance of executives. The participants considered the flipped approach exciting, dynamic, and insightful. The emphasis on a negotiation process involving classmates from around the world increased their global understanding. Beginning with a negotiation experience in the digital story project gave them a better appreciation of the relevant theories, techniques, and applications. Focusing on the practice of international negotiation and a cross-cultural analysis with reflection on cultural intelligence improved the competencies of the participants both during the course and after it.

  13. Supermassive black hole spin-flip during the inspiral

    Energy Technology Data Exchange (ETDEWEB)

    Gergely, Laszlo A [Department of Theoretical Physics, University of Szeged (Hungary); Biermann, Peter L [MPI for Radioastronomy, Bonn (Germany); Caramete, Laurentiu I, E-mail: gergely@physx.u-szeged.h, E-mail: plbiermann@mpifr-bonn.mpg.d, E-mail: lcaramete@gmail.co [Institute for Space Sciences, Bucharest (Romania)

    2010-10-07

    During post-Newtonian evolution of a compact binary, a mass ratio {nu} different from 1 provides a second small parameter, which can lead to unexpected results. We present a statistics of supermassive black hole candidates, which enables us first to derive their mass distribution, and then to establish a logarithmically even probability in {nu} of the mass ratios at their encounter. In the mass ratio range {nu} in (1/30, 1/3) of supermassive black hole mergers representing 40% of all possible cases, the combined effect of spin-orbit precession and gravitational radiation leads to a spin-flip of the dominant spin during the inspiral phase of the merger. This provides a mechanism for explaining a large set of observations on X-shaped radio galaxies. In another 40% with mass ratios {nu} in (1/30, 1/1000) a spin-flip never occurs, while in the remaining 20% of mergers with mass ratios {nu} in (1/3, 1) it may occur during the plunge. We analyze the magnitude of the spin-flip angle occurring during the inspiral as a function of the mass ratio and original relative orientation of the spin and orbital angular momentum. We also derive a formula for the final spin at the end of the inspiral in this mass ratio range.

  14. Supermassive black hole spin-flip during the inspiral

    CERN Document Server

    Gergely, László Á; Caramete, Laurenţiu I

    2010-01-01

    During post-Newtonian evolution of a compact binary, a mass ratio different from one provides a second small parameter, which can lead to unexpected results. We present a statistics of supermassive black hole candidates, which enables us first to derive their mass distribution, then to establish a logarithmically even probability of the mass ratios at their encounter. In the mass ratio range (1/30,1/3) of supermassive black hole mergers representing 40% of all possible cases, the combined effect of spin-orbit precession and gravitational radiation leads to a spin-flip of the dominant spin during the inspiral phase of the merger. This provides a mechanism for explaining a large set of observations on X-shaped radio galaxies. In another 40%, with mass ratios (1/30,1/1000) a spin-flip never happens, while in the remaining 20% of mergers with mass ratios (1/3,1) it may occur during the plunge. We analyze the magnitude of the spin-flip angle occurring during the inspiral as function of the mass ratio and original ...

  15. Comparative analysis of learning gains and students attitudes in a flipped precalculus classroom

    OpenAIRE

    Voigt, Matthew

    2016-01-01

    International audience; Flipped classrooms are becoming increasingly prevalent at the undergraduate level as institutions seek cost-saving measures while also desiring to implement technological innovations to attract 21st century learners. This study examined undergraduate pre-calculus students' (N=427) experiences, attitudes and mathematical knowledge in a flipped classroom format compared to students in a traditional lecture format. Our initial results indicate students in the flipped form...

  16. The Flipped Classroom Teaching Model and Its Use for Information Literacy Instruction

    Directory of Open Access Journals (Sweden)

    Sara Arnold-Garza

    2014-07-01

    Full Text Available The “flipped classroom” teaching model has emerged in a variety of educational settings. It provides many advantages for students and exploits the affordances of modern technology. This article describes some of the pedagogical and logistical characteristics of the flipped teaching model. It situates the flipped classroom in higher education and library instruction, and make the case that there are characteristics of information literacy instruction that fit well with the flipped teaching model, in addition to providing some unique challenges.

  17. EXPRESSION OF FLIP IN HUMAN COLON CARCINOMAS:A NEW MECHANISM OF IMMUNE EVASION

    Institute of Scientific and Technical Information of China (English)

    XING Bao-cai; S. Wimmenauer; EH. Farthmann

    2005-01-01

    Objective: It has been proposed that Fas ligand (FasL) may play an important role in immune escape of tumors and FLIP is an important mediator of Fas/FasL pathway. In this study, the expression of FLIP was determined in human colon carcinoma cell lines and tissue to investigate the new mechanism of immune evasion of human colon carcinomas. Methods:RT-PCR and immunohistochemistry (IHC) were performed to investigate the expression of FLIP in human colon carcinoma cell lines SW480, LS174 and twenty human primary colon carcinoma specimens. Results: It was shown that SW480 cells,LS174 cells and primary colon carcinoma specimen constitutively expressed FLIP at the mRNA and protein level. The expression of FLIP was not found in the epithelial cells of normal colon mucosa. Conclusion: FLIP was expressed in human primary colon carcinoma specimens but not in the normal counterpart. It suggested that the expression of FLIP may occur during the malignant transformation from normal colon epithelial cells to colon carcinoma cells. Tumor cells might obtain the ability to resist the Fas-mediated apoptosis by expressing FLIP. The expression of FLIP might contribute to the formation of colon carcinomas.

  18. Effect of transgenic overexpression of FLIP on lymphocytes on development and resolution of experimental autoimmune thyroiditis.

    Science.gov (United States)

    Fang, Yujiang; Sharp, Gordon C; Braley-Mullen, Helen

    2011-09-01

    In our previous studies, resolution of granulomatous experimental autoimmune thyroiditis (G-EAT) was promoted when thyroid epithelial cells were protected from Fas-mediated apoptosis due to transgenic overexpression of FLIP. We hypothesized that if FLIP were overexpressed on lymphocytes, CD4(+) effector cells would be protected from Fas-mediated apoptosis, and resolution would be delayed. To test this hypothesis, we generated transgenic (Tg) mice overexpressing FLIP under the CD2 promoter. Transgenic FLIP was expressed on CD4(+) and CD8(+) T cells and B cells. Transgenic overexpression of FLIP protected cultured splenocytes from Fas-mediated, but not irradiation-induced, apoptosis in vitro. Unexpectedly, Tg(+) donor cells transferred minimal G-EAT, which was partially overcome by depleting donor CD8(+) T cells. When Tg(+) and Tg(-) donors transferred equivalent disease, G-EAT resolution was delayed in FLIP transgenic mice. However, CD2-FLIP Tg(+) donors often transferred less severe G-EAT, even after depletion of CD8(+) T cells. This influenced the rate of G-EAT resolution, resulting in little difference in G-EAT resolution between groups. Tg(+) mice always had reduced anti-mouse thyroglobulin autoantibody responses, compared with Tg(-) littermates, presumably because of FLIP overexpression on B cells. These results suggest that effects of transgenic FLIP on a particular autoimmune disease vary, depending on what cells express the transgene and whether those cells are effector cells or if they function to modulate disease.

  19. CHIP Reporting in the CPS

    Data.gov (United States)

    U.S. Department of Health & Human Services — CHIP reporting in the CPS is unreliable. Only 10 to 30 percent of those with CHIP (but not Medicaid) report this type of coverage in the CPS. Many with CHIP report...

  20. Fabrication method for chip-scale-vacuum-packages based on a chip-to-wafer-process

    Science.gov (United States)

    Bauer, J.; Weiler, D.; Ruß, M.; Heß, J.; Yang, P.; Voß, J.; Arnold, N.,; Vogt, H.

    2010-10-01

    This paper introduces a simple vacuum packaging method which is based on a Chip-to-Wafer process. The MEMS-device is provided with an electroplated solder frame. A Si-lid with the same solder frame is mounted on each die of the wafer using a flip chip process. The same materials for lid and substrate are used in order to reduce the mechanical stress due to the same thermal coefficients of expansion. The resulting cavity between die and lid can be evacuated and hermetically sealed with an eutectic soldering process. The feasibility of the method is demonstrated with an infrared focal plane array (IR-FPA). In this case, the Si-lid acts as an optical window and contains an anti reflective layer for the 8-14 μm wavelength area on both sides. The long-term vacuum stability is supported by a getter film inside the package. This method simplifies the sawing process and has the additional cost benefit that it is possible to package only known good dies.

  1. PACE3 - front-end chip for the CMS Preshower

    CERN Multimedia

    Aspel, Paul

    2003-01-01

    This is PACE3 which is the front-end chip for the CMS Preshower. In fact PACE3 is the combination of two ASICs called Delta3 and PACEAM3. Delta3 is on the left and PACEAM3 is on the right. The two ASICs are bonded together and then packaged within a single 196 pin fpBGA package.

  2. Chip Multithreaded Consistency Model

    Institute of Scientific and Technical Information of China (English)

    Zu-Song Li; Dan-Dan Huan; Wei-Wu Hu; Zhi-Min Tang

    2008-01-01

    Multithreaded technique is the developing trend of high performance processor. Memory consistency model is essential to the correctness, performance and complexity of multithreaded processor. The chip multithreaded consistency model adapting to multithreaded processor is proposed in this paper. The restriction imposed on memory event ordering by chip multithreaded consistency is presented and formalized. With the idea of critical cycle built by Wei-Wu Hu, we prove that the proposed chip multithreaded consistency model satisfies the criterion of correct execution of sequential consistency model. Chip multithreaded consistency model provides a way of achieving high performance compared with sequential consistency model and ensures the compatibility of software that the execution result in multithreaded processor is the same as the execution result in uniprocessor. The implementation strategy of chip multithreaded consistency model in Godson-2 SMT processor is also proposed. Godson-2 SMT processor supports chip multithreaded consistency model correctly by exception scheme based on the sequential memory access queue of each thread.

  3. UW VLSI chip tester

    Science.gov (United States)

    McKenzie, Neil

    1989-12-01

    We present a design for a low-cost, functional VLSI chip tester. It is based on the Apple MacIntosh II personal computer. It tests chips that have up to 128 pins. All pin drivers of the tester are bidirectional; each pin is programmed independently as an input or an output. The tester can test both static and dynamic chips. Rudimentary speed testing is provided. Chips are tested by executing C programs written by the user. A software library is provided for program development. Tests run under both the Mac Operating System and A/UX. The design is implemented using Xilinx Logic Cell Arrays. Price/performance tradeoffs are discussed.

  4. Bond-updating mechanism in cluster Monte Carlo calculations

    Science.gov (United States)

    Heringa, J. R.; Blöte, H. W. J.

    1994-03-01

    We study a cluster Monte Carlo method with an adjustable parameter: the number of energy levels of a demon mediating the exchange of bond energy with the heat bath. The efficiency of the algorithm in the case of the three-dimensional Ising model is studied as a function of the number of such levels. The optimum is found in the limit of an infinite number of levels, where the method reproduces the Wolff or the Swendsen-Wang algorithm. In this limit the size distribution of flipped clusters approximates a power law more closely than that for a finite number of energy levels.

  5. Body of Knowledge (BOK) for Copper Wire Bonds

    Science.gov (United States)

    Rutkowski, E.; Sampson, M. J.

    2015-01-01

    Copper wire bonds have replaced gold wire bonds in the majority of commercial semiconductor devices for the latest technology nodes. Although economics has been the driving mechanism to lower semiconductor packaging costs for a savings of about 20% by replacing gold wire bonds with copper, copper also has materials property advantages over gold. When compared to gold, copper has approximately: 25% lower electrical resistivity, 30% higher thermal conductivity, 75% higher tensile strength and 45% higher modulus of elasticity. Copper wire bonds on aluminum bond pads are also more mechanically robust over time and elevated temperature due to the slower intermetallic formation rate - approximately 1/100th that of the gold to aluminum intermetallic formation rate. However, there are significant tradeoffs with copper wire bonding - copper has twice the hardness of gold which results in a narrower bonding manufacturing process window and requires that the semiconductor companies design more mechanically rigid bonding pads to prevent cratering to both the bond pad and underlying chip structure. Furthermore, copper is significantly more prone to corrosion issues. The semiconductor packaging industry has responded to this corrosion concern by creating a palladium coated copper bonding wire, which is more corrosion resistant than pure copper bonding wire. Also, the selection of the device molding compound is critical because use of environmentally friendly green compounds can result in internal CTE (Coefficient of Thermal Expansion) mismatches with the copper wire bonds that can eventually lead to device failures during thermal cycling. Despite the difficult problems associated with the changeover to copper bonding wire, there are billions of copper wire bonded devices delivered annually to customers. It is noteworthy that Texas Instruments announced in October of 2014 that they are shipping microcircuits containing copper wire bonds for safety critical automotive applications

  6. Hybrid photonic chip interferometer for embedded metrology

    Science.gov (United States)

    Kumar, P.; Martin, H.; Maxwell, G.; Jiang, X.

    2014-03-01

    Embedded metrology is the provision of metrology on the manufacturing platform, enabling measurement without the removal of the work piece. Providing closer integration of metrology upon the manufacturing platform can lead to the better control and increased throughput. In this work we present the development of a high precision hybrid optical chip interferometer metrology device. The complete metrology sensor system is structured into two parts; optical chip and optical probe. The hybrid optical chip interferometer is based on a silica-on-silicon etched integrated-optic motherboard containing waveguide structures and evanescent couplers. Upon the motherboard, electro-optic components such as photodiodes and a semiconductor gain block are mounted and bonded to provide the required functionality. The key structure in the device is a tunable laser module based upon an external-cavity diode laser (ECDL). Within the cavity is a multi-layer thin film filter which is rotated to select the longitudinal mode at which the laser operates. An optical probe, which uses a blazed diffracting grating and collimating objective lens, focuses light of different wavelengths laterally over the measurand. Incident laser light is then tuned in wavelength time to effectively sweep an `optical stylus' over the surface. Wavelength scanning and rapid phase shifting can then retrieve the path length change and thus the surface height. We give an overview of the overall design of the final hybrid photonic chip interferometer, constituent components, device integration and packaging as well as experimental test results from the current version now under evaluation.

  7. Understanding Bonds - Denmark

    DEFF Research Database (Denmark)

    Rimmer, Nina Røhr

    2016-01-01

    a specified rate of interest during the life of the bond and to repay the face value of the bond (the principal) when it “matures,” or comes due. Among the types of bonds you can choose from are: Government securities, municipal bonds, corporate bonds, mortgage and asset-backed securities, federal agency...

  8. Investigation of ball bond integrity for 0.8 mil (20 microns) diameter gold bonding wire on low k die in wire bonding technology

    Science.gov (United States)

    Kudtarkar, Santosh Anil

    Microelectronics technology has been undergoing continuous scaling to accommodate customer driven demand for smaller, faster and cheaper products. This demand has been satisfied by using novel materials, design techniques and processes. This results in challenges for the chip connection technology and also the package technology. The focus of this research endeavor was restricted to wire bond interconnect technology using gold bonding wires. Wire bond technology is often regarded as a simple first level interconnection technique. In reality, however, this is a complex process that requires a thorough understanding of the interactions between the design, material and process variables, and their impact on the reliability of the bond formed during this process. This research endeavor primarily focused on low diameter, 0.8 mil thick (20 mum) diameter gold bonding wire. Within the scope of this research, the integrity of the ball bond formed by 1.0 mil (25 mum) and 0.8 mil (20 mum) diameter wires was compared. This was followed by the evaluation of bonds formed on bond pads having doped SiO2 (low k) as underlying structures. In addition, the effect of varying the percentage of the wire dopant, palladium and bonding process parameters (bonding force, bond time, ultrasonic energy) for 0.8 mil (20 mum) bonding wire was also evaluated. Finally, a degradation empirical model was developed to understand the decrease in the wire strength. This research effort helped to develop a fundamental understanding of the various factors affecting the reliability of a ball bond from a design (low diameter bonding wire), material (low k and bonding wire dopants), and process (wire bonding process parameters) perspective for a first level interconnection technique, namely wire bonding. The significance of this research endeavor was the systematic investigation of the ball bonds formed using 0.8 mil (20 microm) gold bonding wire within the wire bonding arena. This research addressed low k

  9. Turning the Classroom Upside Down: Experimenting with the Flipped Classroom in American Government

    Science.gov (United States)

    Whitman Cobb, Wendy N.

    2016-01-01

    With the concept of the flipped classroom taking the teaching world by storm, research into its effectiveness, particularly in higher education, has been lacking. This research aims to rectify this by detailing the results of an experiment comparing student success in American Federal Government in a flipped classroom, a traditional, lecture-based…

  10. Content Planning and Delivery in a Flipped Classroom: A Qualitative Examination

    Science.gov (United States)

    Oyola, Michelle

    2016-01-01

    The problem this qualitative case study addressed is the lack of a clear model for flipping all content planning and delivery in elementary classrooms. The purpose of this study was to create a model of how to flip all aspects of content planning and delivery in an elementary classroom. A total of 11 teachers were recruited to participate. All…

  11. A Quantitative Evaluation of the Flipped Classroom in a Large Lecture Principles of Economics Course

    Science.gov (United States)

    Balaban, Rita A.; Gilleskie, Donna B.; Tran, Uyen

    2016-01-01

    This research provides evidence that the flipped classroom instructional format increases student final exam performance, relative to the traditional instructional format, in a large lecture principles of economics course. The authors find that the flipped classroom directly improves performance by 0.2 to 0.7 standardized deviations, depending on…

  12. Motivation and Cognitive Load in the Flipped Classroom: Definition, Rationale and a Call for Research

    Science.gov (United States)

    Abeysekera, Lakmal; Dawson, Phillip

    2015-01-01

    Flipped classroom approaches remove the traditional transmissive lecture and replace it with active in-class tasks and pre-/post-class work. Despite the popularity of these approaches in the media, Google search, and casual hallway chats, there is very little evidence of effectiveness or consistency in understanding what a flipped classroom…

  13. The Flipped Classroom and Cooperative Learning: Evidence from a Randomised Experiment

    Science.gov (United States)

    Foldnes, Njål

    2016-01-01

    This article describes a study which compares the effectiveness of the flipped classroom relative to the traditional lecture-based classroom. We investigated two implementations of the flipped classroom. The first implementation did not actively encourage cooperative learning, with students progressing through the course at their own pace. With…

  14. Biology Teacher's Flipped Classroom: "A Simple Thing, But It's so Powerful"

    Science.gov (United States)

    Pearson, George

    2012-01-01

    Carolyn Durley is a veteran Biology teacher who adopted the Flipped Classroom in the 2011-2012 school year, the same year as Graham Johnson adopted it for Math. They both teach in Okanagan Mission Secondary School in Kelowna , B.C. This paper offers Durley's observations regarding her adoption of Flipped Classroom. She narrates her teaching…

  15. Improvements from a Flipped Classroom May Simply Be the Fruits of Active Learning

    Science.gov (United States)

    Jensen, Jamie L.; Kummer, Tyler A.; Godoy, Patricia D. d. M.

    2015-01-01

    The "flipped classroom" is a learning model in which content attainment is shifted forward to outside of class, then followed by instructor-facilitated concept application activities in class. Current studies on the flipped model are limited. Our goal was to provide quantitative and controlled data about the effectiveness of this model.…

  16. Using Flipped Classroom Components in Blended Courses to Maximize Student Learning

    Science.gov (United States)

    Heinerichs, Scott; Pazzaglia, Gina; Gilboy, Mary Beth

    2016-01-01

    Context: The flipped classroom is an educational approach that has become popular in higher education because it is student centered. Objective: To provide a rationale for a specific way of approaching the flipped classroom using a blended course design and resources necessary to help instructors be successful. Main Outcome Measure(s): Three class…

  17. Comparative Case Study on Designing and Applying Flipped Classroom at Universities

    Science.gov (United States)

    Lim, Cheolil; Kim, Sunyoung; Lee, Jihyun; Kim, Hyeonsu; Han, Hyeongjong

    2014-01-01

    There have been many reports on cases where flipped classroom was applied which put greater emphasis on conducting various learning activities during class. However, there is a limitation in redesigning existing university lectures as flipped classrooms merely based on reports that describe the learning activities of and their effects on…

  18. Search Strategy Development in a Flipped Library Classroom: A Student-Focused Assessment

    Science.gov (United States)

    Goates, Michael C.; Nelson, Gregory M.; Frost, Megan

    2017-01-01

    Librarians at Brigham Young University compared search statement development between traditional lecture and flipped instruction sessions. Students in lecture sessions scored significantly higher on developing search statements than those in flipped sessions. However, student evaluations show a strong preference for pedagogies that incorporate…

  19. A Controlled Study of the Flipped Classroom with Numerical Methods for Engineers

    Science.gov (United States)

    Bishop, Jacob L.

    2013-01-01

    Recent advances in technology and ideology have unlocked entirely new directions for education research. Mounting pressure from increasing tuition costs and free, online course offerings are opening discussion and catalyzing change in the physical classroom. The flipped classroom is at the center of this discussion. The flipped classroom is a new…

  20. Implementing Flipped Classroom in Blended Learning Environments: A Proposal Based on the Cognitive Flexibility Theory

    Science.gov (United States)

    Andrade, Mariel; Coutinho, Clara

    2017-01-01

    Flipped Classroom is an issue that gains increased attention in Blended Learning models. Generally, in the traditional classroom, the teacher uses the time in the classroom to explain the theoretical and conceptual body content and leaves the practices and exercises as extracurricular activities. In the Flipped Classroom, students study at home…

  1. Flipped Classrooms: A Review of Key Ideas and Recommendations for Practice

    Science.gov (United States)

    DeLozier, Sarah J.; Rhodes, Matthew G.

    2017-01-01

    Flipped classrooms refer to the practice of assigning lectures outside of class and devoting class time to a variety of learning activities. In this review, we discuss the range of approaches to the flipped classroom and focus on activities frequently used in these settings. Amongst these, we examine both out-of-class activities (e.g., video…

  2. Academic Achievements and Satisfaction of the Clicker-Aided Flipped Business English Writing Class

    Science.gov (United States)

    Zhonggen, Yu; Guifang, Wang

    2016-01-01

    The flipped classroom has been achieving a great success in teaching innovation. This study, aiming to determine the effectiveness of the flipped model in business English writing course, combined the quantitative with the qualitative research methods. Participants were randomly selected from undergraduate students majoring in business English.…

  3. Flipping a Math Content Course for Pre-Service Elementary School Teachers

    Science.gov (United States)

    Ford, Pari

    2015-01-01

    In this paper I will share my experience with flipping a math content course for pre-service elementary teachers. The flipped class format involves students receiving instruction outside the classroom through readings and/or video lectures and working on "homework" inside the classroom. I will share strategies for creating lessons for my…

  4. The Flipped Classroom Teaching Model and Its Use for Information Literacy Instruction

    Science.gov (United States)

    Arnold-Garza, Sara

    2014-01-01

    The flipped classroom, a teaching method that delivers lecture content to students at home through electronic means and uses class time for practical application activities, may be useful for information literacy instruction. This article describes many of the characteristics of the flipped classroom teaching model, illustrated with examples from…

  5. Flipping the Classroom for English Language Learners to Foster Active Learning

    Science.gov (United States)

    Hung, Hsiu-Ting

    2015-01-01

    This paper describes a structured attempt to integrate flip teaching into language classrooms using a WebQuest active learning strategy. The purpose of this study is to examine the possible impacts of flipping the classroom on English language learners' academic performance, learning attitudes, and participation levels. Adopting a…

  6. Coordinated Implementation and Evaluation of Flipped Classes and Peer-Led Team Learning in General Chemistry

    Science.gov (United States)

    Robert, Jenay; Lewis, Scott E.; Oueini, Razanne; Mapugay, Andrea

    2016-01-01

    The research-based pedagogical strategy of flipped classes has been shown to be effective for increasing student achievement and retention in postsecondary chemistry classes. The purpose of flipped classes is to move content delivery (e.g., lecture) outside of the classroom, freeing more face-to-face time for active learning strategies. The…

  7. Flipping the Composing Process: Collaborative Drafting and Résumé Writing

    Science.gov (United States)

    Anders, Abram

    2016-01-01

    This article argues for a flipped learning approach to business and professional communication composing processes. Flipped learning sequences can scaffold more robust engagement with prewriting activities and support opportunities for in-class collaborative and facilitated drafting exercises. These types of learning experiences offer numerous…

  8. The Flipped Classroom Impact in Grammar Class on EFL Saudi Secondary School Students' Performances and Attitudes

    Science.gov (United States)

    Al-Harbi, Sarah S.; Alshumaimeri, Yousif A.

    2016-01-01

    The aim of this study was to apply the flipped classroom strategy in teaching English grammar to examine its impact on secondary school students' performances, perceptions, and attitudes toward learning English independently. The researcher implemented the flipped classroom strategy by selecting videos based on the students' textbook and uploading…

  9. Flipped Classrooms: An Agenda for Innovative Marketing Education in the Digital Era

    Science.gov (United States)

    Green, Teegan

    2015-01-01

    Flipped classrooms reverse traditional lecturing because students learn content before class through readings and prerecorded videos, freeing lectures for hands-on activities and discussion. However, there is a dearth of literature in marketing education addressing flipped classrooms. This article fills this void using grounded theory to develop a…

  10. Using Flipped Classroom Approach to Explore Deep Learning in Large Classrooms

    Science.gov (United States)

    Danker, Brenda

    2015-01-01

    This project used two Flipped Classroom approaches to stimulate deep learning in large classrooms during the teaching of a film module as part of a Diploma in Performing Arts course at Sunway University, Malaysia. The flipped classes utilized either a blended learning approach where students first watched online lectures as homework, and then…

  11. Flipped Classrooms: An Agenda for Innovative Marketing Education in the Digital Era

    Science.gov (United States)

    Green, Teegan

    2015-01-01

    Flipped classrooms reverse traditional lecturing because students learn content before class through readings and prerecorded videos, freeing lectures for hands-on activities and discussion. However, there is a dearth of literature in marketing education addressing flipped classrooms. This article fills this void using grounded theory to develop a…

  12. CK2 controls TRAIL and Fas sensitivity by regulating FLIP levels in endometrial carcinoma cells.

    Science.gov (United States)

    Llobet, D; Eritja, N; Encinas, M; Llecha, N; Yeramian, A; Pallares, J; Sorolla, A; Gonzalez-Tallada, F J; Matias-Guiu, X; Dolcet, X

    2008-04-17

    Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has emerged as a promising antineoplastic agent because of its ability to selectively kill tumoral cells. However, some cancer cells are resistant to TRAIL-induced apoptosis. We have previously demonstrated that in endometrial carcinoma cells such resistance is caused by elevated FLICE-inhibitory protein (FLIP) levels. The present study focuses on the mechanisms by which FLIP could be modulated to sensitize endometrial carcinoma cells to TRAIL-induced apoptosis. We find that inhibition of casein kinase (CK2) sensitizes endometrial carcinoma cells to TRAIL- and Fas-induced apoptosis. CK2 inhibition correlates with a reduction of FLIP protein, suggesting that CK2 regulates resistance to TRAIL and Fas by controlling FLIP levels. FLIP downregulation correlates with a reduction of mRNA and is prevented by addition of the MG-132, suggesting that CK2 inhibition results in a proteasome-mediated degradation of FLIP. Consistently, forced expression of FLIP restores resistance to TRAIL and Fas. Moreover, knockdown of either FADD or caspase-8 abrogates apoptosis triggered by inhibition of CK2, indicating that CK2 sensitization requires formation of functional DISC. Finally, because of the possible role of both TRAIL and CK2 in cancer therapy, we demonstrate that CK2 inhibition sensitizes primary endometrial carcinoma explants to TRAIL apoptosis. In conclusion, we demonstrate that CK2 regulates endometrial carcinoma cell sensitivity to TRAIL and Fas by regulating FLIP levels.

  13. The Effect of Flipped Learning (Revised Learning) on Iranian Students' Learning Outcomes

    Science.gov (United States)

    Yousefzadeh, Malahat; Salimi, Asghar

    2015-01-01

    The purpose of this study was to investigate whether the flipped (revised) learning had effect on student learning outcome. Lage et al (2000) describes the flipped classroom as " Inverting the classroom means that events that have traditionally take place inside the classroom now take place outside the class and vice versa" (p.32). The…

  14. A Half-Flipped Classroom or an Alternative Approach?: Primary Sources and Blended Learning

    Science.gov (United States)

    Westermann, Edward B.

    2014-01-01

    This paper examines an alternate approach to the "flipped" classroom paradigm for an upper level history class using a blended on-line and in-class format. The concept of the flipped classroom has received increasing emphasis based on its potential to create a student-centered learning environment that incorporates practical instruction…

  15. Academic Achievements and Satisfaction of the Clicker-Aided Flipped Business English Writing Class

    Science.gov (United States)

    Zhonggen, Yu; Guifang, Wang

    2016-01-01

    The flipped classroom has been achieving a great success in teaching innovation. This study, aiming to determine the effectiveness of the flipped model in business English writing course, combined the quantitative with the qualitative research methods. Participants were randomly selected from undergraduate students majoring in business English.…

  16. Flipping the Classroom: A Case Study of a Mathematics Methods Class

    Science.gov (United States)

    Muir, Tracey; Chick, Helen

    2014-01-01

    The "flipped classroom" is gaining popularity in a number of settings, including secondary schools, reflecting a belief that the approach is more engaging and effective for students. This paper reports on a senior secondary mathematics class's experience with adopting a flipped classroom approach. The findings indicate that the teacher…

  17. An Application of Flipped Classroom Method in the Instructional Technologies and Material Development Course

    Science.gov (United States)

    Özpinar, Ilknur; Yenmez, Arzu Aydogan; Gökçe, Semirhan

    2016-01-01

    A natural outcome of change in technology, new approaches towards teaching and learning have emerged and the applicability of the flipped classroom method, a new educational strategy, in the field of education has started to be discussed. It was aimed with the study to examine the effect of using flipped classroom method in academic achievements…

  18. The Effect of Flipped Model of Instruction on EFL Learners' Reading Comprehension: Learners' Attitudes in Focus

    Science.gov (United States)

    Karimi, Mehrnoosh; Hamzavi, Raouf

    2017-01-01

    The present study aimed at investigating the effect of flipped model of instruction on EFL learners' reading comprehension ability. Moreover, this study aimed at identifying EFL students' attitudes toward flipped model of instruction. To this end, 60 EFL learners studying at an accredited private language institute in Isfahan were first…

  19. How A Flipped Learning Environment Affects Learning In A Course On Theoretical Computer Science

    DEFF Research Database (Denmark)

    Gnaur, Dorina; Hüttel, Hans

    2014-01-01

    This paper reports initial experiences with flipping the classroom in an undergraduate computer science course as part of an overall attempt to enhance the pedagogical support for student learning. Our findings indicate that, just as the flipped classroom implies, a shift of focus in the learning...

  20. Wikis, Workshops and Writing: Strategies for Flipping a College Community Engagement Course

    Science.gov (United States)

    Maloy, Robert W.; Edwards, Sharon A.; Evans, Allison

    2014-01-01

    This paper describes utilizing wiki technology, small group workshops, and reflective writing assignments to "flip" a community engagement/service-learning course for college undergraduates who are tutoring culturally and linguistically diverse students in K-12 schools. Flipped classrooms are gaining popularity in the teaching of…