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0.5 {mu}m E/D AlGaAs/GaAs heterostructure field effect transistor technology with DFET threshold adjust implant

0.5 {mu}m E/D AlGaAs/GaAs heterostructure field effect transistor technology with DFET threshold adjust implant

Date: April 1997
Creator: Baca, A. G.; Sherwin, M. E.; Zolper, J. C.; Shul, R. J.; Briggs, R. D.; Heise, J. A. et al.
Description: A doped-channel heterostructure field effect transistor (H-FET) technology has been developed with self-aligned refractory gate processing and using both enhancement- and depletion-mode transistors. D-HFET devices are obtained with a threshold voltage adjust implant into material designed for E-HFET operation. Both E- and D-HFETs utilize W/WSi bilayer gates, sidewall spacers, and rapid thermal annealing for controlling short channel effects. The 0.5 {mu}m E- HFETs (D-HFETs) have been demonstrated with transconductance of 425 mS/mm (265-310 mS/mm) and f{sub t} of 45-50 GHz. Ring oscillator gate delays of 19 ps with a power of 0.6 mW have been demonstrated using direct coupled FET logic. These results are comparable to previous doped-channel HFET devices and circuits fabricated by selective reactive ion etching rather than ion implantation for threshold voltage adjustment.
Contributing Partner: UNT Libraries Government Documents Department
0.7-eV GaInAs Junction for a GaInP/GaAs/GaInAs(1-eV)/GaInAs(0.7-eV) Four-Junction Solar Cell: Preprint

0.7-eV GaInAs Junction for a GaInP/GaAs/GaInAs(1-eV)/GaInAs(0.7-eV) Four-Junction Solar Cell: Preprint

Date: May 1, 2006
Creator: Friedman, D. J.; Geisz, J. F.; Norman, A. G.; Wanlass, M. W. & Kurtz, S. R.
Description: We discuss recent developments in III-V multijunction solar cells, focusing on adding a fourth junction to the Ga0.5In0.5P/GaAs/Ga0.75In0.25As inverted three-junction cell. This cell, grown inverted on GaAs so that the lattice-mismatched Ga0.75In0.25As third junction is the last one grown, has demonstrated 38% efficiency, and 40% is likely in the near future. To achieve still further gains, a lower-bandgap GaxIn1-xAs fourth junction could be added to the three-junction structure for a four-junction cell whose efficiency could exceed 45% under concentration. Here, we present the initial development of the GaxIn1-xAs fourth junction. Junctions of various bandgaps ranging from 0.88 to 0.73 eV were grown, in order to study the effect of the different amounts of lattice mismatch. At a bandgap of 0.88 eV, junctions were obtained with very encouraging {approx}80% quantum efficiency, 57% fill factor, and 0.36 eV open-circuit voltage. The device performance degrades with decreasing bandgap (i.e., increasing lattice mismatch). We model the four-junction device efficiency vs. fourth junction bandgap to show that an 0.7-eV fourth-junction bandgap, while optimal if it could be achieved in practice, is not necessary; an 0.9-eV bandgap would still permit significant gains in multijunction cell efficiency while being easier to achieve than the lower-bandgap junction.
Contributing Partner: UNT Libraries Government Documents Department
The 0.22 Percent Across-the-Board Cut in FY2001 Appropriations

The 0.22 Percent Across-the-Board Cut in FY2001 Appropriations

Date: May 31, 2001
Creator: Keith, Robert
Description: Report describing changes that affected the government budget for the 2001 fiscal year under the Consolidated Appropriations Act.
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The 0.38 Percent Across-the-Board Cut in FY2000 Appropriations

The 0.38 Percent Across-the-Board Cut in FY2000 Appropriations

Date: February 25, 2000
Creator: Keith, Robert
Description: This report outlines cuts made in the federal budget for FY2000. The 0.38% cut was expected to yield savings of $2.4 billion in budget authority and $1.4 billion in outlays for the fiscal year. Departments with cuts in excess of $100 million included the Departments of Defense, Transportation, Health and Human Services, and Education.
Contributing Partner: UNT Libraries Government Documents Department
0.351 micron Laser Beam propagation in High-temperature Plasmas

0.351 micron Laser Beam propagation in High-temperature Plasmas

Date: December 10, 2007
Creator: Froula, D.; Divol, L.; Meezan, N.; Ross, J.; Berger, R. L.; Michel, P. et al.
Description: A study of the laser-plasma interaction processes have been performed in plasmas that are created to emulate the plasma conditions in indirect drive inertial confinement fusion targets. The plasma emulator is produced in a gas-filled hohlraum; a blue 351-nm laser beam propagates along the axis of the hohlraum interacting with a high-temperature (T{sub e} = 3.5 keV), dense (n{sub e} = 5 x 10{sup 20}cm{sup -3}), long-scale length (L {approx} 2 mm) plasma. Experiments at these conditions have demonstrated that the interaction beam produces less than 1% total backscatter resulting in transmission greater than 90% for laser intensities less than I < 2 x 10{sup 15} W-cm{sup -2}. The bulk plasma conditions have been independently characterized using Thomson scattering where the peak electron temperatures are shown to scale with the hohlraum heater beam energy in the range from 2 keV to 3.5 keV. This feature has allowed us to determine the thresholds for both backscattering and filamentation instabilities; the former measured with absolutely calibrated full aperture backscatter and near backscatter diagnostics and the latter with a transmitted beam diagnostics. A plasma length scaling is also investigated extending our measurements to 4-mm long high-temperature plasmas. At intensities I < 5 x ...
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0.25mm-thick CCD packaging for the Dark Energy Survey Camera array

0.25mm-thick CCD packaging for the Dark Energy Survey Camera array

Date: June 1, 2006
Creator: Derylo, Greg; Diehl, H.Thomas & Estrada, Juan
Description: The Dark Energy Survey Camera focal plane array will consist of 62 2k x 4k CCDs with a pixel size of 15 microns and a silicon thickness of 250 microns for use at wavelengths between 400 and 1000 nm. Bare CCD die will be received from the Lawrence Berkeley National Laboratory (LBNL). At the Fermi National Accelerator Laboratory, the bare die will be packaged into a custom back-side-illuminated module design. Cold probe data from LBNL will be used to select the CCDs to be packaged. The module design utilizes an aluminum nitride readout board and spacer and an Invar foot. A module flatness of 3 microns over small (1 sqcm) areas and less than 10 microns over neighboring areas on a CCD are required for uniform images over the focal plane. A confocal chromatic inspection system is being developed to precisely measure flatness over a grid up to 300 x 300 mm. This system will be utilized to inspect not only room-temperature modules, but also cold individual modules and partial arrays through flat dewar windows.
Contributing Partner: UNT Libraries Government Documents Department
0.52eV Quaternary InGaAsSb Thermophotovoltaic Diode Technology

0.52eV Quaternary InGaAsSb Thermophotovoltaic Diode Technology

Date: June 9, 2004
Creator: Dashiell, M. W.; Beausang, J. F.; Nichols, G.; Depoy, D. M.; Danielson, L. R.; Ehsani, H. et al.
Description: Thermophotovoltaic (TPV) diodes fabricated from 0.52eV lattice-matched InGaAsSb alloys are grown by Metal Organic Vapor Phase Epitaxy (MOVPE) on GaSb substrates. 4cm{sup 2} multi-chip diode modules with front-surface spectral filters were tested in a vacuum cavity and attained measured efficiency and power density of 19% and 0.58 W/cm{sup 2} respectively at operating at temperatures of T{sub radiator} = 950 C and T{sub diode} = 27 C. Device modeling and minority carrier lifetime measurements of double heterostructure lifetime specimens indicate that diode conversion efficiency is limited predominantly by interface recombination and photon energy loss to the GaSb substrate and back ohmic contact. Recent improvements to the diode include lattice-matched p-type AlGaAsSb passivating layers with interface recombination velocities less than 100 cm/s and new processing techniques enabling thinned substrates and back surface reflectors. Modeling predictions of these improvements to the diode architecture indicate that conversion efficiencies from 27-30% and {approx}0.85 W/cm{sup 2} could be attained under the above operating temperatures.
Contributing Partner: UNT Libraries Government Documents Department
T = 0 AND T = 1 PAIRING IN LIGHT NUCLEI.

T = 0 AND T = 1 PAIRING IN LIGHT NUCLEI.

Date: January 1, 1969
Creator: Goodman, A. L.
Description: None
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$D^0 \bar{D}^0$ Mixing at BaBar

$D^0 \bar{D}^0$ Mixing at BaBar

Date: October 26, 2011
Creator: Coleman, Jonathon & /SLAC
Description: This article reviews the recent measurement of D{sup 0}-{bar D}{sup 0} mixing with the D{sup 0} {yields} K{pi} decay channel from the BABAR experiment at the PEP-II B-Factory. Averages from the Heavy Flavor Averaging Group between this result and a previous result from BELLE are also presented.
Contributing Partner: UNT Libraries Government Documents Department
D-0 End Calorimeter Warm Tube/TeV Dry Air Purge

D-0 End Calorimeter Warm Tube/TeV Dry Air Purge

Date: August 14, 1991
Creator: Leibfritz, J. R.
Description: This Engineering Note studies the design of the Dry Air Purge that is going to flow through the Warm Tube of the End Calorimeter of the D-O Calorimeter. The Tev tubes through the E.C. can be thought of as a cluster of concentric tubes: The Tev tube, the warm (vacuum vessel) tube, 15 layers of superinsulation, the cold (argon vessel) tube, and the Inner Hadronic center support tube. The Dry Air Purge will involve flowing Dry Air through the annular region between the Warm Tube and the Tev Beam Pipe. This air flow is intended to prevent condensation from forming in this region which could turn to ice under cryogenic temperatures. Any ice formed in this gap, could cause serious problems when these tubes are moved. The Air will flow through a Nylon Tube Fitting -1/4-inch I.D. to 1/8-inch male pipe thread (Cole Palmer YB-06465-15) see Drawing MC-295221 (Appendix A). This fitting will be attached to the Nylon 2-inch Tube-Wiper and Seal Assembly which is clamped to the ends of the Warm Tube (Appendix A). This note includes drawings and calculations that explain the setup of the Dry Air Purge and give the required information on the pressure drops through ...
Contributing Partner: UNT Libraries Government Documents Department
$D^0$ hot topics

$D^0$ hot topics

Date: May 1, 2006
Creator: Buchholz, D.
Description: The authors present recent D0 results based on approximately 1 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV recorded at the Fermilab Tevatron. Preliminary results on a search for the flavor changing neutral current process D{sup +} {yields} {pi}{sup +}{mu}{sup +}{mu}{sup -}, a measurement of the Cp violation parameter in B mixing, {epsilon}{sub B}, and a two sided limit on the B{sub s} oscillation frequency {Delta}m{sub s} are presented. The limits on {epsilon}{sub B} and {Beta}(D{sup +} {yields} {pi}{sup +}{mu}{sup +}{mu}{sup -}) are the world's best limits. The two sided bound on {Delta}m{sub s} is the first direct indication by a single experiment that {Delta}m{sub s} is bounded from above.
Contributing Partner: UNT Libraries Government Documents Department
D-0 North End Cap Calorimeter Cold Test Results

D-0 North End Cap Calorimeter Cold Test Results

Date: August 2, 1990
Creator: Michael, J.
Description: The North endcap calorimeter vessel was recieved on July 1, 1990. A cooldown of the pressure vessel with liquid nitrogen was performed on July 10-11 to check the vessel's integrity. With the pressure vessel cold, the insulating vacuum was monitored for leaks. Through out the testing, the insulating vacuum remained good and the vessel passed the test. The cold test was carried out per the procedures of D-Zero engineering note 3740.220-EN-250. The test was very similar to the cold test performed on the Central Calorimeter in October of 1987. Reference D-Zero engineering notes 3740.210-EN-122, 3740.000-EN107, and 3740.210-EN-110 for information about the CC cold test. The insulating vacuum space was pumped on while equipment was being connected to the pressure vessel. Two hours after starting to pump with the blower the vacuum space pressure was at about 210 microns. Pumping on the vacuum space for the next 15 hours showed no progress and a leak detector was connected to the pumping line. A leak check showed a leak in a thermocouple feedthru on the vacuum space relief plate. After fixing the leak, the pressure dropped to 16 microns in less than one hour. A rate of rise test was performed starting ...
Contributing Partner: UNT Libraries Government Documents Department
D-0 South End Cap Calorimeter Cold Test Results

D-0 South End Cap Calorimeter Cold Test Results

Date: November 26, 1990
Creator: Rucinski, R.
Description: The South endcap calorimeter vessel was moved into Lab A on Sept. 18, 1990. A cooldown of the pressure vessel with liquid nitrogen was performed on Sept. 26 to check the vessel's integrity. With the pressure vessel cold, the insulating vacuum was monitored for leaks. Through out the testing, the insulating vacuum remained good and the vessel passed the test. The cold test was carried out per the procedures of D-Zero engineering note 3740.220-EN-250. The test was very similar to the cold test performed on the Central Calorimeter in October of 1987. The test of the ECS was performed in the same manner using the same equipment as the ECN cold test. Reference D-Zero engineering notes 3740.210-EN-122, 3740.000-EN-I07, and 3740.210-EN-II0 for information about the CC cold test. Reference EN-260 for the results of the ECN cold test. The insulating vacuum space was pumped on while equipment was being connected to the pressure vessel. Two hours after starting to pump with the blower the vacuum space pressure was at about 40 microns. The pumping continued overnight (another 16 hours). In the morning the pressure was 11.5 microns. A rate of rise test was performed. With the pump valved off, the pressure ...
Contributing Partner: UNT Libraries Government Documents Department
1.1-meter bore, 8-Tesla test facility

1.1-meter bore, 8-Tesla test facility

Date: November 19, 1975
Creator: Nelson, R.; Cornish, D.; Zbasnik, J.; Sackett, S. & Taylor, C.
Description: The design and fabrication of a 1.1-m bore superconducting coil for an 8- T facility at Lawrence Livermore Laboratory are discussed. This facility will provide the backing field required for testing large multifilamentary Nb$sub 3$Sn coils as part of the superconductor development program at Livermore. The magnet measures 1.85 m o.d., is 1.5 m in length, and is solenoid wound in four separate modules. Total cold weight of the assembly is 18,000 Kg. A NbTi superconductor is used throughout with a gradation of current density within the magnet to provide complete cryostatic stability. The preliminary design of a large 3500-A multifilamentary Nb$sub 3$Sn insert magnet is also included. Together, the backing coil and insert magnets are designed to produce a 12-T central field in a 0.4m bore. The ''equal area'' theory of cryostatic stability is applied in the design of both magnet systems and is discussed in detail. A large open-mouth cryostat is used and measures 2 m in diameter and 3.7 m in length. Details of Dewar design and the refrigeration requirements are included. (auth)
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1.1 Simulations of a Free-Electron Laser Oscillator at Jefferson Lab Lasing in the Vacuum Ultraviolet

1.1 Simulations of a Free-Electron Laser Oscillator at Jefferson Lab Lasing in the Vacuum Ultraviolet

Date: April 1, 2013
Creator: Shinn, Michelle D. & Benson, Stephen V.
Description: The UVFEL at Jefferson Lab has provided a 10 eV photon beam for users by outcoupling the coherent third harmonic of the UVFEL operated at 372 nm. This can provide up to tens of milliwatts of power in the VUV. Operation of the FEL at the fundamental might enhance this power by up to a factor of 1000. With minor upgrades to the accelerator now underway and a new undulator proposed by Calabazas Creek Research, Inc. we show that we can lase in the fundamental at 124 nm. The predicted output is higher by four orders of magnitude on an average power basis and six orders of magnitude on a peak fluence basis than the Advanced Light Source at Lawrence Berkeley National Laboratory.
Contributing Partner: UNT Libraries Government Documents Department
1/2 CREEP FRACTURE IN CERAMIC POLYCRYSTALS I. CREEP CAVITATION EFFECTS IN POLYCRYSTALLINE ALUMINA

1/2 CREEP FRACTURE IN CERAMIC POLYCRYSTALS I. CREEP CAVITATION EFFECTS IN POLYCRYSTALLINE ALUMINA

Date: September 1980
Creator: Porter, J. R.; Blumenthal, W. & Evans, A. G.
Description: Fine grained polycrystalline alumina has been deformed in creep at high temperatures, to examine the evolution of cavities at grain boundaries. Cavities with equilibrium and crack-like morphologies have been observed, distributed non-uniformly throughout the material. The role of cavities during creep has been described. A transition from equilibrium to crack-like morphology has been observed and correlated with a model based on the influence of the surface to boundary diffusivity ratio and the local tensile stress. The contribution of cavitation to the creep rate and total creep strain has been analyzed and excluded as the principal cause of the observed non-linear creep rate,
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1,2-HOIQO--A highly versatile 1,2-HOPO analog

1,2-HOIQO--A highly versatile 1,2-HOPO analog

Date: August 7, 2006
Creator: Seitz, Michael; Pluth, Michael D. & Raymond, Kenneth N.
Description: A cyclic, bidentate hydroxamic acid binding unit based on an isoquinoline scaffold has been utilized for the synthesis of a hexadentate tripodal ligand based on the TREN backbone. This prototype for a new class of multidentate chelators forms mononuclear iron(III) complexes and one-dimensional coordination polymers with lanthanide(III) cations. The latter has been determined by single crystal X-ray analysis of the cerium species. The solid state structure in the monoclinic space group P2{sub 1}/c (C{sub 36}H{sub 34}CeN{sub 7}O{sub 11}, a = 12.341(2){angstrom}, b = 26.649(4){angstrom}, c = 10.621(2){angstrom}, {alpha} = {gamma} = 90{sup o}, {beta} = 96.753(3){sup o}, V = 3468.6(9) {angstrom}{sup 3}, Z = 4) exhibits a trigonal-dodecahedral environment around the cerium cation. The proof of concept for the versatility of the new scaffold has been shown by the modification of the crucial precursor 3-carboxyiso-coumarin through electrophilic aromatic substitutions to yield the corresponding chlorosulfonated and nitrated analogs.
Contributing Partner: UNT Libraries Government Documents Department
1,2-Hydroxypyridonates as Contrast Agents for Magnetic ResonanceImaging: TREN-1,2-HOPO

1,2-Hydroxypyridonates as Contrast Agents for Magnetic ResonanceImaging: TREN-1,2-HOPO

Date: May 8, 2007
Creator: Jocher, Christoph J.; Moore, Evan G.; Xu, Jide; Avedano, Stefano; Botta, Mauro; Aime, Silvio et al.
Description: 1,2-Hydroxypyridinones (1,2-HOPO) form very stable lanthanide complexes that may be useful as contrast agents for Magnetic Resonance Imaging (MRI). X-ray diffraction of single crystals established that the solid state structures of the Eu(III) and the previously reported [Inorg. Chem. 2004, 43, 5452] Gd(III) complex are identical. The recently discovered sensitizing properties of 1,2-HOPO chelates for Eu(III) luminescence allow direct measurement of the number if water molecules in the metal complex. Fluorescence measurements of the Eu(III) complex corroborate that in solution two water molecules coordinate the lanthanide (q = 2) as proposed from the analysis of NMRD profiles. In addition, fluorescence measurements have verified the anion binding interactions of lanthanide TREN-1,2-HOPO complexes in solution, studied by relaxivity, revealing only very weak oxalate binding (K{sub A} = 82.7 {+-} 6.5 M{sup -1}). Solution thermodynamic studies of the metal complex and free ligand have been carried out using potentiometry, spectrophotometry and fluorescence spectroscopy. The metal ion selectivity of TREN-1,2-HOPO supports the feasibility of using 1,2-HOPO ligands for selective lanthanide binding [pGd = 19.3 (2); pZn = 15.2 (2), pCa = 8.8 (3)].
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1.2 MW klystron for Asymmetric Storage Ring B Factory

1.2 MW klystron for Asymmetric Storage Ring B Factory

Date: March 1995
Creator: Fowkes, W. R.; Caryotakis, G. & Doyle, E.
Description: A cw klystron operating at 476 MHz has been developed jointly by SLAC and Varian Associates. The unique set of characteristics of this tube were strongly guided by requirements of the fast feedback necessary to prevent oscillations of the storage ring beams caused by the detuned accelerating cavity. This requires a combination of bandwidth and short group delay within the klystron. The RF feedback stabilization scheme also requires amplitude modulation making it necessary to operate the klystron about 10% below saturation. Performance specifications and initial operating results are presented.
Contributing Partner: UNT Libraries Government Documents Department
1/2 SINTERING OF MULLITE-CONTAINING MATERIALS: I. EFFECT OF COMPOSITION

1/2 SINTERING OF MULLITE-CONTAINING MATERIALS: I. EFFECT OF COMPOSITION

Date: December 1, 1981
Creator: Sacks, Michael D. & Pask, Joseph A.
Description: Sintering behavior of mullite-containing powders was studied over a range of chemical compositions (Al{sub 2}O{sub 3}/SiO{sub 2} ratio). Densification measurements were made for both liquid phase-containing and solid state systems. Small amounts of liquid phase were observed to have a significant effect on densification rate. A linear relationship was obtained between the percent of theoretical density and the logarithm of time for compositions in the range 73-75 wt% Al{sub 2}O{sub 3}. Currently available models for intermediate stage sintering kinetics were considered to be inadequate for these systems. Grain boundary transport 0r diffusion appeared to be the primary mechanism of densification.
Contributing Partner: UNT Libraries Government Documents Department
1.3 GHz superconducting RF cavity program at Fermilab

1.3 GHz superconducting RF cavity program at Fermilab

Date: March 1, 2011
Creator: Ginsburg, C. M.; Arkan, T.; Barbanotti, S.; Carter, H.; Champion, M.; Cooley, L. et al.
Description: At Fermilab, 9-cell 1.3 GHz superconducting RF (SRF) cavities are prepared, qualified, and assembled into cryomodules (CMs) for Project X, an International Linear Collider (ILC), or other future projects. The 1.3 GHz SRF cavity program includes targeted R&D on 1-cell 1.3 GHz cavities for cavity performance improvement. Production cavity qualification includes cavity inspection, surface processing, clean assembly, and one or more cryogenic low-power CW qualification tests which typically include performance diagnostics. Qualified cavities are welded into helium vessels and are cryogenically tested with pulsed high-power. Well performing cavities are assembled into cryomodules for pulsed high-power testing in a cryomodule test facility, and possible installation into a beamline. The overall goals of the 1.3 GHz SRF cavity program, supporting facilities, and accomplishments are described.
Contributing Partner: UNT Libraries Government Documents Department
1,3-Propanediol Made From Fermentation-Derived Malonic Acid: Office of Industrial Technologies (OIT) Agriculture Project Fact Sheet

1,3-Propanediol Made From Fermentation-Derived Malonic Acid: Office of Industrial Technologies (OIT) Agriculture Project Fact Sheet

Date: September 12, 2001
Creator: Carde, T.
Description: 1,3-Propanediol is one of two ingredients used in producing polytrimethylene terephthalate (PTT), a polymer which can be used in polyester and nylon applications. Researchers are developing a process to ferment biomass feedstock to malonic acid using filamentous fungi and then catalytically convert malonic acid to 1,3-propanediol.
Contributing Partner: UNT Libraries Government Documents Department
A 1.5 GeV compact light source with superconducting bending magnets

A 1.5 GeV compact light source with superconducting bending magnets

Date: May 1995
Creator: Garren, A. A.; Cline, D. B.; Kolonko, J. J.; Green, M. A.; Johnson, D. E.; Leung, E. M. et al.
Description: This paper describes the design of a compact electron synchrotron light source for producing X-rays for medical imaging, protein crystallography, nano-machining and other uses up to 35 keV. The source will provide synchrotron light from six 6.9 tesla superconducting 60{degree} bending magnet stations. In addition the ring, contains conventional quadrupoles and sextupoles. The light source has a circumference of 26 meters, which permits it to be located in a variety of industrial and medical facilities.
Contributing Partner: UNT Libraries Government Documents Department
1.5-GeV FFAG Accelerator for the AGS Facility

1.5-GeV FFAG Accelerator for the AGS Facility

Date: February 1, 2004
Creator: Ruggiero, A. G.; Blaskiewicz, M.; Courant, E.; Trbojevic, D.; Tsoupas, N. & Zhang, W.
Description: N/A
Contributing Partner: UNT Libraries Government Documents Department
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