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Corn-Harvesting Machinery

Description: Report discussing the use of different machines for harvesting corn. Machines discussed include sled harvesters, binders, shockers, pickers, huskers, and shredders.
Date: 1907
Creator: Zintheo, C. J.
Partner: UNT Libraries Government Documents Department

Smart Surfaces: New Coatings & Paints with Radiation Detection Functionality

Description: Paints are being developed and tested that might ultimately be able to detect radiological agents in the environment by incorporating special pigments into an organic polymeric binder that can be applied as a paint or coatings. These paints detect radioactive sources and contaminants with inorganic or organic scintillation or thermo-luminescent pigments, which are selected based upon the radiation ({alpha}, {beta}, {gamma} or n) to be detected, and are shown in Figure 1.
Date: March 12, 2007
Creator: Farmer, J & Choi, J
Partner: UNT Libraries Government Documents Department

A Cell-Based Approach for the Biosynthesis/Screening of Cyclic Peptide Libraries against Bacterial Toxins

Description: Available methods for developing and screening small drug-like molecules able to knockout toxins or pathogenic microorganisms have some limitations. In order to be useful, these new methods must provide high-throughput analysis and identify specific binders in a short period of time. To meet this need, we are developing an approach that uses living cells to generate libraries of small biomolecules, which are then screened inside the cell for activity. Our group is using this new, combined approach to find highly specific ligands capable of disabling anthrax Lethal Factor (LF) as proof of principle. Key to our approach is the development of a method for the biosynthesis of libraries of cyclic peptides, and an efficient screening process that can be carried out inside the cell.
Date: October 24, 2007
Creator: Camarero, J. A.; Kimura, R.; Woo, Y.; Cantor, J. & Steenblock, E.
Partner: UNT Libraries Government Documents Department

Processing Variables of Alumina Slips and Their Effects on the Density and Grain Size of the Sintered Sample

Description: High densities and small grain size of alumina ceramic bodies provide high strength and better mechanical properties than lower density and larger grain size bodies. The final sintered density and grain size of slip-cast, alumina samples depends greatly on the processing of the slip and the alumina powder, as well as the sintering schedule. There were many different variables explored that include initial powder particle size, slurry solids percent, amount and type of dispersant used, amount and type of binder used, and sintering schedule. Although the experimentation is not complete, to this point the sample with the highest density and smallest grain size has been a SM8/Nano mixture with Darvan C as the dispersant and Polyvinyl Alcohol (PVA) as the binder, with a solids loading of 70 wt% and a 1500 C for 2 hours sintering schedule. The resultant density was 98.81% of theoretical and the average grain size was approximately 2.5 {micro}m.
Date: January 1, 2002
Creator: Rowley, R. & Chu, H.
Partner: UNT Libraries Government Documents Department

Optimization of Acetylene Black Conductive Additive andPolyvinylidene Difluoride Composition for High Power RechargeableLithium-Ion Cells

Description: Fundamental electrochemical methods were applied to study the effect of the acetylene black (AB) and the polyvinylidene difluoride (PVDF) polymer binder on the performance of high-power designed rechargeable lithium ion cells. A systematic study of the AB/PVDF long-range electronic conductivity at different weight ratios is performed using four-probe direct current tests and the results reported. There is a wide range of AB/PVDF ratios that satisfy the long-range electronic conductivity requirement of the lithium-ion cathode electrode; however, a significant cell power performance improvement is observed at small AB/PVDF composition ratios that are far from the long-range conductivity optimum of 1 to 1.25. Electrochemical impedance spectroscopy (EIS) tests indicate that the interfacial impedance decreases significantly with increase in binder content. The hybrid power pulse characterization results agree with the EIS tests and also show improvement for cells with a high PVDF content. The AB to PVDF composition plays a significant role in the interfacial resistance. We believe the higher binder contents lead to a more cohesive conductive carbon particle network that results in better overall all local electronic conductivity on the active material surface and hence reduced charge transfer impedance.
Date: July 1, 2007
Creator: Liu, G.; Zheng, H.; Battaglia, V.S.; Simens, A.S.; Minor, A.M. & Song, X.
Partner: UNT Libraries Government Documents Department

Novel Binders and Methods for Agglomeration of Ore

Description: Heap leaching is one of the methods being used to recover metal from low grade ore deposits. The main problem faced during heap leaching is the migration of fine grained particles through the heap, forming impermeable beds which result in poor solution flow. The poor solution flow leads to less contact between the leach solution and the ore, resulting in low recovery rates. Agglomeration of ore into coarse, porous masses prevents fine particles from migrating and clogging the spaces and channels between the larger ore particles. Currently, there is one facility in the United States which uses agglomeration. This operation agglomerates their ore using leach solution (raffinate), but is still experiencing undesirable metal recovery from the heaps due to agglomerate breakdown. The use of a binder, in addition to the leach solution, during agglomeration would help to produce stronger agglomerates that did not break down during processing. However, there are no known binders that will work satisfactorily in the acidic environment of a heap, at a reasonable cost. As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. Increasing copper recovery in heap leaching by the use of binders and agglomeration would result in a significant decrease in the amount of energy consumed. Assuming that 70% of all the leaching heaps would convert to using agglomeration technology, as much as 1.64*10{sup 12} BTU per year would be able to be saved if a 25% increase in copper recovery was experienced, which is equivalent to saving approximately 18% of the energy currently being used in leaching heaps. For every week a leach cycle was decreased, a savings of as much as 1.23*10{sup 11} BTU per week would result. This project has identified several acid-resistant binders and agglomeration procedures. ...
Date: September 30, 2006
Creator: Kawatra, S. K.; Eisele, T. C.; Lewandowski, K. A. & Gurtler, J. A.
Partner: UNT Libraries Government Documents Department

Final Technical Report

Description: The Center for Advanced Biobased was created with funding supplied by the Department of Energy to study biobased alternatives to petroleum based materials used in the manufacture of foundry sand binders. The project was successful in developing two new biobased polymers that are based on renewable agricultural materials or abundant naturally occurring organic materials. The technology has the potential of replacing large amounts of chemicals produced from oil with environmentally friendly alternatives.
Date: September 30, 2009
Creator: Thiel, Jerry; Giese, Scott R; Beckermann, Christoph; Combi, Joan; Yavorsky, James & Cannon, Fred
Partner: UNT Libraries Government Documents Department

Method to prepare Semtex

Description: This procedure requires the binder and uncoated RDX be prepared in separate steps, see Figure 1: (1) The binder and dye are mixed by agitation with a water-insoluble organic solvent (e.g., toluene), I; (2) The RDX/PETN is agitated thoroughly with water, II; (3) The binder solution I is added to the RDX/water mixture at II with thorough mixing to form a slurry III; (4) In the next step the solvent is distilled off at IV leaving resulting granules; (5) The next step is followed by filtration at V, which may be done by vacuum; (6) The composition is then dried at VI to a dough-like consistency.
Date: November 26, 2006
Creator: Alcaraz, A & Dougan, A
Partner: UNT Libraries Government Documents Department

A parametric pressing study using a plastic-bonded explosive

Description: Pressed plastic-bonded explosives, PBXs, are commonly used by defense and private industry. PBX 9501 is composed of HMX crystals held together with a plastic binder 'softened' with plasticizers. The detonation behavior of any explosive is very dependent upon its density, with the desire to have a uniform, high density throughout the explosive component. A parametric study has been performed pressing PBX 9501 hydrostatically and uniaxially. The effects of several pressing parameters on the bulk density and density profile, as well as mechanical properties, have been measured. The parameters investigated include pressure, temperature, number of cycles, dwell time, rest time, sack thickness, and particle distribution and size. Density distributions within the pressed explosives were also compared.
Date: January 1, 2002
Creator: Hayden, D. J. (David J.); Maez, L. R. (Leland R.); Olinger, B. W. (Barton W.) & Powell, S. J. (Sandra J.)
Partner: UNT Libraries Government Documents Department

MESOSCALE MODELLING OF SHOCK INITIATION IN HMX-BASED EXPLOSIVES

Description: Hydrocode calculations we used to simulate initiation in single- and double-shock experiments on several HMX-based explosives. Variations in the reactive behavior of theee materials reflects the differences between binders in the material, providing information regarding the sensitivity of the explosive to the mechanical properties of the constituents. Materials considered are EDC-37, with a soft binder, PBX-9601, with a relatively malleable binder, and PIBX-9404, with a stiff binder. Bulk reactive behavior of these materials is dominated by the HMX component and should be comparable, while the mechanical response varies. The reactive flow model is temperature-dependent, based on a modified Arrhenius rate. Some unreacted material is allowed to react at a rate given by the state of the hotspot rather than the bulk state of the unreacted explosive, according to a length scale reflecting the hotspot size, and a time scale for thermal equilibration. The Arrhenius rate for HMX is wsumed to be the same for all compositions. The initiation data for different HMX-bwd explosives axe modelled by choosing plausible parameters to describe the reactive and dissipative properties of the binder, and hence the behavior of the hotspots in each formulation.
Date: January 1, 2001
Creator: Mulford, R. N. R. (Robert N. R.) & Swift, D. C. (Damian C.)
Partner: UNT Libraries Government Documents Department

The Effects of Various Conductive Additive and Polymeric Binder Contents on the Performance of a Lithium-ion Composite

Description: Fundamental electrochemical methods, cell performance tests, and physical characterization tests such as electron microscopy were used to study the effects of levels of the inert materials (acetylene black (AB), a nano-conductive additive, and polyvinylidene difluoride (PVDF), a polymer binder) on the power performance of lithium-ion composite cathodes. The electronic conductivity of the AB/PVDF composites at different compositions was measured with a four-point probe direct current method. The electronic conductivity was found to increase rapidly and plateau at a AB:PVDF ratio 0.2:1 (by weight), with 0.8:1 being the highest conductivity composition. AB:PVDF compositions along the plateau of 0.2:1, 0.4:1, 0.6:1 and 0.8:1 were investigated. Electrodes of each of those compositions were fabricated with different fractions of AB/PVDF to active material. It was found that at the 0.8:1 AB:PVDF, the rate performance improved with increases in the AB/PVDF loading, whereas at the 0.2:1 AB:PVDF, the rate performance improved with decreases in the AB/PVDF loading. The impedance of electrodes made with 0.6:1 AB:PVDF was low and relatively invariant.
Date: August 7, 2008
Creator: Stevenson, Cynthia; Liu, G.; Zheng, H.; Kim, S.; Deng, Y.; Minor, A.M. et al.
Partner: UNT Libraries Government Documents Department

Irreversible volume growth in polymer-bonded powder systems: effects of crystalline anisotropy, particle size distribution, and binder strength

Description: Pressed-powdered crystallites of intrinsically anisotropic materials have been shown to undergo irreversible volume expansion when subjected to repeated cycles of heating and cooling. We develop a coarse-grained (micron-scale) interaction Hamiltonian for this system and perform molecular dynamics simulations, which quantitatively reproduce the experimentally observed irreversible growth. The functional form and values of the interaction parameters at the coarse-grained level are motivated by our knowledge at the atomic/molecular scale, and allows a simple way to incorporate the effect of polymeric binder. We demonstrate that irreversible growth happens only in the presence of intrinsic crystalline anisotropy of the powder material, is mediated by particles much smaller than the average crystallite size, and can be significantly reduced in the presence of high-strength polymeric binder with elevated glass transition temperatures.
Date: August 22, 2007
Creator: Maiti, A; Gee, R H; Hoffman, D & Fried, L E
Partner: UNT Libraries Government Documents Department

Aging and PBX 9502

Description: Components made from PBX 9502, an insensitive high explosive formulated with triaminotrinitrobenzene (TATB) and Kel-F 800 binder, have been in service for nearly two decades. Since that time, samples have been destructively evaluated to determine if potential changes that might affect safety, reliability, or performance have occurred in the high explosive with time. Data from routine, historical testing is reported elsewhere. This paper focuses on specific tests conducted to evaluate the effects of natural aging on handling sensitivity (through the small-scale tests of Human Electrostatic Discharge, friction, and Drop Weight Impact), compressive strength, and thermal ignition. Also reported are the effects of a radiation environment on TATB. Small-scale sensitivity tests show no differences between aged and unaged material. Observed differences in compressive strength behavior are attributed to conditions of original material rather than aging effects. Thermal ignition by flame and laser methods showed no changes between aged and unaged material. Extreme levels of radiation are shown to have only minimal effects in explosive response tests. PBX 9502 is concluded, once again, to be a very stable material, aging gracefully.
Date: December 31, 1998
Creator: Skidmore, C.B.; Idar, D.J.; Buntain, G.A.; Son, S.F. & Sander, R.K.
Partner: UNT Libraries Government Documents Department

Stabilizers in PBX 9501

Description: An analysis of the analytical data from initial acceptance of PBX 9501 at Pantex and the current analysis of the library samples of the same lots show that the amount of Irganox has reduced linearly with time in the library samples. Data from the cycle reports show no negative trend in a sealed inert atmosphere. We also found that the stockpile return samples show very little change, both by thermal analysis with the ARC and chemical analysis by NMR, and can be said to be aging gracefully.
Date: December 1, 1997
Creator: Campbell, M.S.
Partner: UNT Libraries Government Documents Department

Extrudable explosives. Quarterly report, October--December, 1971

Description: Several extrudable HE formulations using, principally, HNAB as the explosive component were examined in efforts to develop an extrudable composition more temperature-resistant than Extex. It is shown that extrudability is dependent upon particle character, wetting of the binder compound, roll-milling technique and the addition of fine metallic oxides to improve flow properties, while detonability is dependent upon explosive concentration, a hard cure, and the shock parameters of the confining media.
Date: December 31, 1972
Creator: Warren, T.W. & Irion, C.E.
Partner: UNT Libraries Government Documents Department

Demonstration of enhanced warhead performance with more powerful explosives

Description: Enhanced warhead performance has been demonstrated for several warhead configurations loaded with more powerful explosives. This paper presents experimental results from several warheads loaded with one of the new more powerful explosives, LX-19. The LX-19 formulation is a volume analog to LX-14 (HMX/Estane) that consists of 95.8 wt.% epsilon CL-20 formulated with 4.2 wt.% Estane binder. The LX-19 formulation, characterization, and evaluation efforts presseted in this paper are the result of several studies that have been ongoing since 1991. The warhead configurations that have been tested include a trumpet lined shaped charge, a hemispherical lined shaped cahrge, an EFP charge, and a fragmentation warhead, Performation improvements have been demonstrated with all configurations that were tested.
Date: December 1, 1997
Creator: Murphy, M.J.; Baum, D.; Simpson, R.L.; Monoto, J.; Montesi, L.; Newman, K. et al.
Partner: UNT Libraries Government Documents Department

Recent developments in freeform fabrication of dense ceramics from slurry deposition

Description: A freeform fabrication technique for dense ceramics and composites has been developed. The technique requires less than 2 volume percent of organic additives and relies on the principle of layerwise deposition of highly loaded colloidal slurries. Components can be manufactured into complex geometries with thick solid sections as well as with thin-walled sections with high aspect ratios. Process feasibility and quality is dependent on the processing parameters of solids loading, slurry rheology, deposition rate, and drying rate. These interrelated parameters must be controlled so that sintering defects are prevented and shape tolerance is maintained. A review of this freeform fabrication technique, called robocasting, will be discussed for fabrication of aluminum oxide parts. Recent developments for a finite element analysis technique for modeling the drying process will also be presented.
Date: November 1, 1997
Creator: Cesarano, J. III; Baer, T.A. & Calvert, P.
Partner: UNT Libraries Government Documents Department

Progress report - bonding of DATB - progress report

Description: DATB (diaminotrinitrobenzine) pressings were made in an effort to find the most suitable binder. After successfully pressing ball milled DATB at 110 C,it was found that normal DATB (fine powder) could also be hot pressed at this temperature and 20,000 psi. Bulk density might vary from batch to batch.
Date: August 1, 1958
Creator: Archibald, P.
Partner: UNT Libraries Government Documents Department

Activation and Micropore Structure Determination of Activated Carbon-Fiber Composites

Description: Previous work focused on the production of carbon fiber composites and subsequently activating them to induce adsorbent properties. One problem related to this approach is the difficulty of uniformly activating large composites. In order to overcome this problem, composites have been made from pre-activated fibers. The loss of surface area upon forming the composites after activation of the fibers was investigated. The electrical resistivity and strength of these composites were compared to those made by activation after forming. It was found that the surface area is reduced by about 35% by forming the composite from pre-activated fibers. However, the properties of the activated sample are very uniform: the variation in surface area is less than {+-}0.5%. So, although the surface area is somewhat reduced, it is believed that making composites from pre-activated fibers could be useful in applications where the BET surface area is not required to be very high. The strength of the composites produced from pre-activated fibers is lower than for composites activated after forming when the carbon burnoff is below 45%. For higher burnoffs, the strength of composites made with pre-activated fibers is as good or better. In both cases, there is a dramatic decrease in strength when the fiber:binder ratio is reduced below 4:1. The electrical resistivity is slightly higher for composites made from pre-activated fibers than for composites that are activated after forming, other parameters being constant (P-200 fibers, similar carbon burnoffs). For both types of composite the resistivity was also found to increase with carbon burnoff. This is attributed to breakage of the fiber causing shorter conductive paths. The electrical resistivity also increases when the binder content is lowered, which suggests that there are fewer solid contact points between the fibers.
Date: April 23, 1999
Creator: Jagtoyen, M. & Derbyshire, F.
Partner: UNT Libraries Government Documents Department

Factor analysis of GPC-FTIR data in PBX9501 binder degradation studies

Description: The GPC/FTIR data consist of sets of 120 FTIR spectra corresponding to 120 GPC fractions. The GPC fractions can be further categorized by their polystyrene equivalent molecular weight and retention time, The FTIR data to be compared is in three sets of 120 spectra corresponding to the control, thermally aged, and radiolytically aged binder material. Figure 1 shows the extracted spectra (or factors) and corresponding concentration profiles (or scores) for the control data set. The four extracted spectra correspond to spectra for the background/baseline, Estane, Irganox, and NP. The extracted spectra match the spectra of pure components with the exception of Irganox. The Irganox spectrum has some spectral features corresponding to Irganox, but others are due to the poor signal-to-noise in the spectra of these GPC fractions. The low concentration for Irganox results in a widely varying concentration profile and the poor extracted spectrum. The factors and scores for the thermally aged data set demonstrate the same components that are evident in the control data set. The concentration profile shows an asymmetric distribution for Estane with a tail on the low molecular weight side. Less NP is associated with Estane in this region compared to the control data. The major NP concentration is near fraction 80, but is considerably less in magnitude (relative to Estane) when compared to the control. For the radiolytically aged sample set a five-factor solution provides a better fit for the data. The primary difference is the presence of additional bands near 1050,1320, and 1560 cm{sup {minus}1} for factor 5. Factor 5 shows concentration primarily in the same region as Estane.
Date: November 1, 2000
Creator: Schoonover, J. & Bridgewater, J.
Partner: UNT Libraries Government Documents Department

Low Temperature Sorbents for removal of Sulfur Compounds from fluid feed Streams

Description: A sorbent material is provided comprising a material reactive with sulfur, a binder unreactive with sulfur and an inert material, wherein the sorbent absorbs the sulfur at temperatures between 30 and 200 C. Sulfur absorption capacity as high as 22 weight percent has been observed with these materials.
Date: September 30, 1999
Creator: Siriwardane, Ranjan
Partner: UNT Libraries Government Documents Department

Processing of Mo-Si-B intermetallics by extrusion and oxidation properties of the extruded Tl-MoSi{sub 2}-MoB System

Description: An extrusion process was developed that is able to consistently produce large quantities of Mo-Si-B rods without the presence of defects. Binder removal from the extruded rods was studied in detail and it was determined that heating rates on the order of 0.02{degree}/minute (1.2{degree}/hour) are necessary to remove the binder without the formation of defects. This low heating rate resulted in debinding times in excess of 70 hours (approximately 3 days). Wicking was investigated as a means to decrease the time necessary for binder removal. Using 0.05{micro}m alumina powder as a wicking agent, binder removal times were reduced to 10 hours with heating rates up to 1{degree}/minute employed without defect formation. Once the extrusion process was complete the oxidation properties of the Tl-MoSi{sub 2}-MoB extruded phase assemblage was investigated. It was determined that this composition exhibits catastrophic oxidation or pesting in the temperature range of 660--760 C, resulting in the material turning to dust. Outside of this temperature range the composition is oxidatively stable. Continuous mass measurements were taken at 1,300, 1,450, and 1,600 C to determine the oxidation rate constants of this material. Parabolic rate constants of 6.9 x 10{sup {minus}3}, 1.3 x 10{sup {minus}3}, and 9.1 x 10{sup {minus}3} mg{sup 2}/cm{sup 4}/hr were determined for 1,300, 1,450, and 1,600 C respectively.
Date: November 8, 1999
Creator: Summers, Eric
Partner: UNT Libraries Government Documents Department