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Liquid food packages consist of various polymers films, which are bonded together with Aluminum foil (Al-foil) using adhesion or by direct heat. The main aim of this research was to define important material properties such as fracture toughness and some FE-simulation material model parameters such as damage initiation, damage evolution, and the adhesion between Al-foil and low-density polyethylene (LDPE) film. This investigation is based on both physical experiments and FE simulations in ABAQUS with and without initial cracks of different lengths for comparison purposes. The final FE model in ABAQUS was used to compare the numerical input parameters in an extensive study with the ambition to investigate the materials’ parameters in cases with or without adhesion between laminates. Finally, the relation between the theoretical and experimental results for Al-foil using linear elastic fracture mechanics and modified strip yield model were shown, and the fracture toughness was calculated for two different thicknesses of Al-foil. © 2021 by the authors. Licensee MDPI, Basel, Switzerland., open access

Liquid food packages consist of various polymers films, which are bonded together with Aluminum foil (Al-foil) using adhesion or by direct heat. The main aim of this research was to define important material properties such as fracture toughness and some FE-simulation material model parameters such as damage initiation, damage evolution, and the adhesion between Al-foil and low-density polyethylene (LDPE) film. This investigation is based on both physical experiments and FE simulations in ABAQUS with and without initial cracks of different lengths for comparison purposes. The final FE model in ABAQUS was used to compare the numerical input parameters in an extensive study with the ambition to investigate the materials’ parameters in cases with or without adhesion between laminates. Finally, the relation between the theoretical and experimental results for Al-foil using linear elastic fracture mechanics and modified strip yield model were shown, and the fracture toughness was calculated for two different thicknesses of Al-foil. © 2021 by the authors. Licensee MDPI, Basel, Switzerland., open access

Structural carbon fibre composite batteries are a type of multifunctional batteries that combine the energy storage capability of a battery with the load-carrying ability of a structural material. To extract the current from the structural battery cell, current collectors are needed. However, current collectors are expensive, hard to connect to the electrode material and add mass to the system. Further, attaching the current collector to the carbon fibre electrode must not affect the electrochemical properties negatively or requires time-consuming, manual steps. This paper presents a proof-of-concept method for screen-printing of current collectors for structural carbon fibre composite batteries using silver conductive paste. Current collectors are screen-printed directly on spread carbon fibre tows and a polycarbonate carrier film. Experimental results show that the electrochemical performance of carbon fibre vs lithium metal half-cells with the screen-printed collectors is similar to reference half-cells using metal foil and silver adhered metal-foil collectors. The screen-printed current collectors fulfil the requirements for electrical conductivity, adhesion to the fibres and flexible handling of the fibre electrode. The screen-printing process is highly automatable and allows for cost-efficient upscaling to large scale manufacturing of arbitrary and complex current collector shapes. Hence, the screen-printing process shows a promising route to realization of high performing current collectors in structural batteries and potentially in other types of energy storage solutions., QC 20220510

Liquid food packages consist of various polymers films, which are bonded together with Aluminum foil (Al-foil) using adhesion or by direct heat. The main aim of this research was to define important material properties such as fracture toughness and some FE-simulation material model parameters such as damage initiation, damage evolution, and the adhesion between Al-foil and low-density polyethylene (LDPE) film. This investigation is based on both physical experiments and FE simulations in ABAQUS with and without initial cracks of different lengths for comparison purposes. The final FE model in ABAQUS was used to compare the numerical input parameters in an extensive study with the ambition to investigate the materials’ parameters in cases with or without adhesion between laminates. Finally, the relation between the theoretical and experimental results for Al-foil using linear elastic fracture mechanics and modified strip yield model were shown, and the fracture toughness was calculated for two different thicknesses of Al-foil. © 2021 by the authors. Licensee MDPI, Basel, Switzerland., open access

Liquid food packages consist of various polymers films, which are bonded together with Aluminum foil (Al-foil) using adhesion or by direct heat. The main aim of this research was to define important material properties such as fracture toughness and some FE-simulation material model parameters such as damage initiation, damage evolution, and the adhesion between Al-foil and low-density polyethylene (LDPE) film. This investigation is based on both physical experiments and FE simulations in ABAQUS with and without initial cracks of different lengths for comparison purposes. The final FE model in ABAQUS was used to compare the numerical input parameters in an extensive study with the ambition to investigate the materials’ parameters in cases with or without adhesion between laminates. Finally, the relation between the theoretical and experimental results for Al-foil using linear elastic fracture mechanics and modified strip yield model were shown, and the fracture toughness was calculated for two different thicknesses of Al-foil. © 2021 by the authors. Licensee MDPI, Basel, Switzerland., open access

Liquid food packages consist of various polymers films, which are bonded together with Aluminum foil (Al-foil) using adhesion or by direct heat. The main aim of this research was to define important material properties such as fracture toughness and some FE-simulation material model parameters such as damage initiation, damage evolution, and the adhesion between Al-foil and low-density polyethylene (LDPE) film. This investigation is based on both physical experiments and FE simulations in ABAQUS with and without initial cracks of different lengths for comparison purposes. The final FE model in ABAQUS was used to compare the numerical input parameters in an extensive study with the ambition to investigate the materials’ parameters in cases with or without adhesion between laminates. Finally, the relation between the theoretical and experimental results for Al-foil using linear elastic fracture mechanics and modified strip yield model were shown, and the fracture toughness was calculated for two different thicknesses of Al-foil. © 2021 by the authors. Licensee MDPI, Basel, Switzerland., open access

Liquid food packages consist of various polymers films, which are bonded together with Aluminum foil (Al-foil) using adhesion or by direct heat. The main aim of this research was to define important material properties such as fracture toughness and some FE-simulation material model parameters such as damage initiation, damage evolution, and the adhesion between Al-foil and low-density polyethylene (LDPE) film. This investigation is based on both physical experiments and FE simulations in ABAQUS with and without initial cracks of different lengths for comparison purposes. The final FE model in ABAQUS was used to compare the numerical input parameters in an extensive study with the ambition to investigate the materials’ parameters in cases with or without adhesion between laminates. Finally, the relation between the theoretical and experimental results for Al-foil using linear elastic fracture mechanics and modified strip yield model were shown, and the fracture toughness was calculated for two different thicknesses of Al-foil. © 2021 by the authors. Licensee MDPI, Basel, Switzerland., open access

Hydrogen has become the subject of attention as an environmentally friendly and effective source in recent years. The photocatalysis method with biomass-photocatalyst is an alternative step for hydrogen production via water splitting. In this study, bamboo charcoal (BC) and Fragaria Vesca Powder (FVP) are biomass materials used to develop photocatalysts in hydrogen production. The light source for photocatalysis was a halogen lamp with a wavelength of 560 nm. The hydrogen gas produced is measured using the MQ-8 sensor which is capable of measuring hydrogen gas in 100–10,000 ppm. Hydrogen production is significantly increased with the combination of the BC and FVP photocatalysts. Based on scanning electron microscope (SEM) image analysis by Image J software, BC and FVP have a negative and positive charge, respectively. The aromatic carbon ring in BC has an energy gap of 2.48 eV whereas that in FVP has a lower energy gap, 2.32 eV due to functional groups energizing electron in the FVP aromatic ring. The interaction between positive and negative charges when BC and FVP are combined generates the second lower energy gap in the combined catalyst, 1.66 eV that tends to increase electron density on the catalyst surface. The more dense electrons destabilize more hydrogen and covalent bonds in water increasing hydrogen production by 20 times from that with BC only or by 4 times from that with FVP only. When aluminum foil (AF) was added to the bottom of the reactor tube, the photocatalyst's performance was strengthened. The AF material was an 8011 aluminum alloy with a thickness of 0.02 mm and a diameter of 80 mm. AF has two important roles, that is, accelerates reduction reaction and facilitates the breaking of the hydrogen and covalent bonds in water

Improving environmental conditions in the production of seedlings by expanding the distribution of photosynthetically active radiation in abaxial leaves and protecting the substrate with straw can promote the production of higher quality seedlings.This study aimed to evaluate the reflective materials over the cultivation bench and the use of rice straw over the substrate in the formation of papaya seedlings of the group ‘Formosa’.The joint analysis was performed considering a completely randomized experimental design in a 3 x 2 factorial scheme, with five replications and six seedlings per plot. The use of aluminized screen(Aluminet®) and aluminum foil with an area of 1 m x 1.2 m as reflective material on the cultivation bench and treatment without reflective material were evaluated. Also, the presence and absence of a rice straw layer with 5 cm height, as covering overthe substrate were evaluated. In the benches with aluminum foil and without reflective material, the seedling production without rice straw over the substrate provided papaya seedlings of higher quality than the rice straw over the substrate.The aluminum foil produced high-quality papaya seedlings in thetreatments with rice straw over the substrate.The aluminized screenon the cultivation bench was not favorable for the papaya seedlings production, Mejorar las condiciones ambientales en la producción de plántulas al expandir la distribución de la radiación fotosintéticamente activa en las hojas abaxiales y proteger el sustrato con paja puede promover la producción de plántulas de mayor calidad. Este estudio tuvo como objetivo evaluar los materiales reflectantes sobre el banco de cultivo y el uso de paja de arroz sobre el sustrato en la formación de plántulas de papaya del grupo ‘Formosa’. El análisis conjunto se realizó considerando un diseño experimental completamente al azar en un esquema factorial 3 x 2, con cinco repeticiones y seis plántulas por parcela. Se evaluó el uso de pantalla aluminizada (Aluminet®) y papel de aluminio con un área de 1 m x 1.2 m como material reflectante en el banco de cultivo y el tratamiento sin material reflectante. Además, se evaluó la presencia y ausencia de una capa de paja de arroz con una altura de 5 cm, como cobertura sobre el sustrato. En los bancos con papel de aluminio y sin material reflectante, la producción de plántulas sin paja de arroz sobre el sustrato proporcionó plántulas de papaya de mayor calidad que la paja de arroz sobre el sustrato. El papel de aluminio produjo plántulas de papaya de alta calidad en los tratamientos con paja de arroz sobre el sustrato. La pantalla aluminizada en el banco de cultivo no fue favorable para la producción de plántulas de papaya.

Improving environmental conditions in the production of seedlings by expanding the distribution of photosynthetically active radiation in abaxial leaves and protecting the substrate with straw can promote the production of higher quality seedlings.This study aimed to evaluate the reflective materials over the cultivation bench and the use of rice straw over the substrate in the formation of papaya seedlings of the group ‘Formosa’.The joint analysis was performed considering a completely randomized experimental design in a 3 x 2 factorial scheme, with five replications and six seedlings per plot. The use of aluminized screen(Aluminet®) and aluminum foil with an area of 1 m x 1.2 m as reflective material on the cultivation bench and treatment without reflective material were evaluated. Also, the presence and absence of a rice straw layer with 5 cm height, as covering overthe substrate were evaluated. In the benches with aluminum foil and without reflective material, the seedling production without rice straw over the substrate provided papaya seedlings of higher quality than the rice straw over the substrate.The aluminum foil produced high-quality papaya seedlings in thetreatments with rice straw over the substrate.The aluminized screenon the cultivation bench was not favorable for the papaya seedlings production, Mejorar las condiciones ambientales en la producción de plántulas al expandir la distribución de la radiación fotosintéticamente activa en las hojas abaxiales y proteger el sustrato con paja puede promover la producción de plántulas de mayor calidad. Este estudio tuvo como objetivo evaluar los materiales reflectantes sobre el banco de cultivo y el uso de paja de arroz sobre el sustrato en la formación de plántulas de papaya del grupo ‘Formosa’. El análisis conjunto se realizó considerando un diseño experimental completamente al azar en un esquema factorial 3 x 2, con cinco repeticiones y seis plántulas por parcela. Se evaluó el uso de pantalla aluminizada (Aluminet®) y papel de aluminio con un área de 1 m x 1.2 m como material reflectante en el banco de cultivo y el tratamiento sin material reflectante. Además, se evaluó la presencia y ausencia de una capa de paja de arroz con una altura de 5 cm, como cobertura sobre el sustrato. En los bancos con papel de aluminio y sin material reflectante, la producción de plántulas sin paja de arroz sobre el sustrato proporcionó plántulas de papaya de mayor calidad que la paja de arroz sobre el sustrato. El papel de aluminio produjo plántulas de papaya de alta calidad en los tratamientos con paja de arroz sobre el sustrato. La pantalla aluminizada en el banco de cultivo no fue favorable para la producción de plántulas de papaya.

The back end process of passivated emitter and rear cells (PERC) consists of at least one laser process and three screen-printing steps followed by the stringing and tabbing of the cells. To reduce the number of steps we have developed a process that metallizes the rear side including contact formation and simultaneously interconnects the cells. We attach an Al foil to an encapsulant layer. By laser processing we form 'laser-fired and bonding contacts' (LFBC) on the passivated rear side of the solar cells. The Al foil contacting the rear is laser welded to the Ag screen-printed front side metallization of the next cell and thus forms the cell interconnection. The laser contacts on the rear show a surface recombination velocity Scont for the contact regions of cm/s and a contact resistivity of 3.52 m?cm2. We present a first proof-of concept module combining the in-laminate Ag-Al laser welding and the LFBC reaching an efficiency of 18.4%. In accelerated aging test modules show no degradation (< 1% in efficiency) after 100 humidity-free cycles.

Composite materials offer a greater degree of flexibility in design and engineering of specialized space vehicle shielding applications compared to aluminum. A new design for shielding materials has been developed by including specific neutron absorbers and conductive materials into the composite structure. In this research, the neutron shielding capability of two types of custom-designed nanocomposite materials are compared to that of T6061 aluminum., The original document contains color images.

Fracture path of a polymer coated and uncoated aluminium foil (about 6-7 um) is followed in a Scanning Electron Microscope. The crack length and applied load were measured during crack initiation and growth. The specimens’ cross section were then studied using the optical profilometric method to exam the deformed surface. For the uncoated Al-foil, no fracture surface can be observed. Fracture seems to occur through so-called necking. This behaviour was successfully modelled by a modified strip yield model. It leads to a conclusion that the crack tip is preceded a substantial plastic zone as compared with the crack length. The result was then compared to a polymer coated Al-foil. Further more, similar experimental works were performed on a polymer coated and uncoated Polypropylene. The results were discussed and compared to the cases with Al-foil layer.

Fracture path of a polymer coated and uncoated aluminium foil (about 6-7 um) is followed in a Scanning Electron Microscope. The crack length and applied load were measured during crack initiation and growth. The specimens’ cross section were then studied using the optical profilometric method to exam the deformed surface. For the uncoated Al-foil, no fracture surface can be observed. Fracture seems to occur through so-called necking. This behaviour was successfully modelled by a modified strip yield model. It leads to a conclusion that the crack tip is preceded a substantial plastic zone as compared with the crack length. The result was then compared to a polymer coated Al-foil. Further more, similar experimental works were performed on a polymer coated and uncoated Polypropylene. The results were discussed and compared to the cases with Al-foil layer.

Fracture path of a polymer coated and uncoated aluminium foil (about 6-7 um) is followed in a Scanning Electron Microscope. The crack length and applied load were measured during crack initiation and growth. The specimens’ cross section were then studied using the optical profilometric method to exam the deformed surface. For the uncoated Al-foil, no fracture surface can be observed. Fracture seems to occur through so-called necking. This behaviour was successfully modelled by a modified strip yield model. It leads to a conclusion that the crack tip is preceded a substantial plastic zone as compared with the crack length. The result was then compared to a polymer coated Al-foil. Further more, similar experimental works were performed on a polymer coated and uncoated Polypropylene. The results were discussed and compared to the cases with Al-foil layer.

Fracture path of a polymer coated and uncoated aluminium foil (about 6-7 um) is followed in a Scanning Electron Microscope. The crack length and applied load were measured during crack initiation and growth. The specimens’ cross section were then studied using the optical profilometric method to exam the deformed surface. For the uncoated Al-foil, no fracture surface can be observed. Fracture seems to occur through so-called necking. This behaviour was successfully modelled by a modified strip yield model. It leads to a conclusion that the crack tip is preceded a substantial plastic zone as compared with the crack length. The result was then compared to a polymer coated Al-foil. Further more, similar experimental works were performed on a polymer coated and uncoated Polypropylene. The results were discussed and compared to the cases with Al-foil layer.

Fracture path of a polymer coated and uncoated aluminium foil (about 6-7 um) is followed in a Scanning Electron Microscope. The crack length and applied load were measured during crack initiation and growth. The specimens’ cross section were then studied using the optical profilometric method to exam the deformed surface. For the uncoated Al-foil, no fracture surface can be observed. Fracture seems to occur through so-called necking. This behaviour was successfully modelled by a modified strip yield model. It leads to a conclusion that the crack tip is preceded a substantial plastic zone as compared with the crack length. The result was then compared to a polymer coated Al-foil. Further more, similar experimental works were performed on a polymer coated and uncoated Polypropylene. The results were discussed and compared to the cases with Al-foil layer.

Fracture path of a polymer coated and uncoated aluminium foil (about 6-7 um) is followed in a Scanning Electron Microscope. The crack length and applied load were measured during crack initiation and growth. The specimens’ cross section were then studied using the optical profilometric method to exam the deformed surface. For the uncoated Al-foil, no fracture surface can be observed. Fracture seems to occur through so-called necking. This behaviour was successfully modelled by a modified strip yield model. It leads to a conclusion that the crack tip is preceded a substantial plastic zone as compared with the crack length. The result was then compared to a polymer coated Al-foil. Further more, similar experimental works were performed on a polymer coated and uncoated Polypropylene. The results were discussed and compared to the cases with Al-foil layer.

A dual beam focused ion beam-scanning electron microscope (DB FIB-SEM) outfitted with an electron backscatter diffraction (EBSD) system was applied to characterize the internal microstructure and local lattice rotations within multi-crystal micro-scale test samples. The methodology outlined in this paper provides a high-fidelity 3D characterization of the internal grain structure of mechanical test samples in conjunction with knowledge of the external boundary conditions and measurement of the resultant stress-strain behavior, as well as characterization of the internal lattice rotations that have developed., Submitted to Plasticity 2012 Proceedings. Prepared in collaboration with UES Inc., Dayton, OH.

Ultrasonic consolidation is a solid-state bonding process capable of producing metal and metal matrix composite parts. In this work a friction-based heat generation model is proposed to characterize the thermal development of ultrasonically consolidated aluminum foils and continuous fiber alumina reinforced aluminum metal matrix composite tape as a function of process control parameters. The friction coefficient between mating surfaces is determined experimentally, and the credibility of using both a constant friction coefficient and a process dependent friction coefficient is assessed. In most cases a constant friction coefficient is capable of producing results that are within 15% error; while a process dependent friction coefficient achieves an average error of 7%., Published in Journal of Materials Processing Technology, p1-14, 2011.

Under the support of AFOSR grant no. FA9550-07-1-0003, our laboratory at the University of Illinois has pursued the science and applications of microcavity plasmas, both as single devices and in the form of large arrays. Because of its unique properties, microplasma technology has (we believe) profound implications for photonics and electronics, with applications ranging from general lighting to biomedical diagnostics. During the past 3 years, the following milestones have been reached under this AFOSR program: 1. The plasma bipolar junction phototransistor (PBJT) has been discovered. A hybrid plasma/semiconductor device in which a microplasma replaces the collector in an otherwise conventional npn transistor, the PBJT is capable of switching and modulating a plasma with a base-emitter voltage of < 1V. 2. Large arrays of microcavity plasma devices have been fabricated from a single sheet of aluminum foil by a sequence of wet chemical processes in which the electrodes and interconnects are formed automatically while simultaneously being encapsulated in alumina. 3. The ability to reproducibly fabricate microcavities of controllable cross-section in Al or Al2O3 has been demonstrated. Arrays of cavities having a parabolic cross-section and all dimensions specified to within plus or minus 4% can now be fabricated over an area of hundreds of square centimeters. 4. Ellipsoidal microcavities and parabolic cross-section microchannels have been fabricated in glass and crystals (such as CaF2) by a nanopowder blasting technique developed in our laboratory. 5. Microplasma lamps of large area (greater than 100 square centimeters) have been fabricated in Al wire fabric (screen) and characterized. 6. As a direct result of AFOSR funded research, a new company (Eden Park Illumination) was launched in 2007. Today, the company employs eight individuals full time.

Scintillator panels of the same type as those used in portal detector units, made of polyvinyl toluene and measuring 12 x 15 x 2 in were purchased from three vendors. Each vendor supplied two scintillators, one wrapped by the vendor with aluminum foil coated mylar, and two unwrapped. The scintillators where exposed to a ~8 microCurie source collimated 137Cs source which decays with a 662 keV gamma-ray 85% of the time. A Hamamatsu R329-02 photomultiplier tube was optically mated to the 12 x 2 in surface of the scintillator. The pulse-height spectrum was recorded with the source placed at different positions across the surface of the scintillator. Analysis of the pulse-height spectrum determined efficiency and resolution differences across the surface of the scintillation panels. The resolution ranged from 23% at the corner furthest from the PMT to 33% an inch away from the PMT. The absolute efficiency ranged from 0.02 to 0.027 . The location and height of the Compton edge had trends, with the greatest height at the center and dropping off on the sides, but the peak location having a maximum in the corner along the axis of the PMT

United Ammunition Container (UAC) in Milan, Tennessee is the current contractor that produces mortar ammunition inner packing fiber containers for the U.S. Army. UAC has not been able to secure any manufacturer that will agree to produce the needed aluminum foil. Apparently, it is not within the commercial standard manufacturing range, which is projected today due to its thickness, temper, and slit width. Not just any material can be used. The U.S. Army Armament Research, Development and Engineering Center's Packaging Division had suggested an alternative commercially available foil, but his is not possible due the nature of the winding process and the pressures involved. As a result, it was decided that water-vapor permeability study be conducted to compare the moisture protection performance of polyethylene laminated ammunition fiber containers with and without aluminum foil.

We describe a high-power solid-state laser built in our laboratory and its applications to defense missions. We discuss selected target interaction experiments recently performed with this laser. These involve the irradiation of painted aluminum foils at a power of about 25 kW, in the presence of high-speed airflow. The spot sizes were large, covering the range 9-16 cm. Penetration was achieved within a few seconds, depending on the spot size. We present a numerical model which successfully describes the main experimental results., See also ADM002075. Presented at the Army Science Conference (25th) held in Orlando, Florida on 27-30 November 2006. The original document contains color images.

A contractor is currently fabricating flat panels of high-modulus fiber K13CU/siloxane-modified polycyanurate matrix resin composites. Mechanical testing at a commercial lab showed that the interlaminar shear strengths and the flat-wise tensile properties were below that expected. We evaluated the degree of consolidation and cure to verify that incorporated foil layers were not causing premature failure. A number of composite panels were analyzed using dynamic mechanical analysis and optical microscopy. The measured glass-transition temperatures (Tg's) of the samples all suggested that they were properly cured. A solvent exposure test developed in our laboratory also corroborated these results. Optical micrographs of cross-sections for the different composites indicated good consolidation and no observable foil debonds. All of the samples exhibited similar failure modes from our testing. The focus of the lower-than-expected strengths was then placed on the sample preparation procedure for mechanical testing. Sample preparation of the test specimens at the testing laboratory was identified as the cause for the lower-than-expected strengths. Subsequent tests on articles with proper sample preparation yielded acceptable mechanical strengths.

Early work (1974) by the Navy, which involved studies of the front portion of the detonation products from overdriven explosive cylinders of PETN, suggested two anomalous mechanisms of energy transfer in the forward direction. These included a "prompt" (optical) mechanism and a "detached plasma" mechanism. An independent study in 1983 by the present author indicated that the prompt mechanism could not be confirmed from the existing Navy data; neither could the single Navy experiment, which displayed the detached plasma phenomenon, be repeated. However, persistent "hot" (bright) plasma regions, located at the front end of the detonation products, were shown to be present m virtually all cases. This present follow-on study, which was carried out in 1985 with the experimental assistance of Mr. George Hauver of the U.S. Army Ballistic Research Laboratory (BRL), clearly showed that the prompt (optical) energy-transport mechanism was not present However, time-resolved optical measurements of material removal from a thin, aluminum foil target on a transparent plastic substrate, located at a long distance forward of the charge, yielded extremely high, mass-removal rates and very high, deduced- energy-deposition rates, very early in the interaction between the hot front end of the detonation products and the aluminum target foil. More work remains to be done to explain these residual phenomena.

Control of acoustic cavitation (sound-induced bubble activity) is the subject of this dissertation. Application is to clinical lithotripsy where cavitation contributes to kidney stone comminution and tissue damage. An electrical spark at the near focus of an underwater ellipsoidal reflector was the acoustical source, as in the Dornier HM3 lithotripter. Experiments were done with rigid reflectors, pressure-release reflectors, and pairs of reflectors sharing a common focus and a controlled delay between sparks. Since a bubble hit by a single shock pulse can grow profoundly and then collapse violently, our hypothesis was that a second pulse timed to arrive during the collapse phase would intensify the ultimate collapse. Experiments and numerical calculations confirmed the hypothesis. Pitted by bubble collapses, aluminum foil placed along the reflector axis recorded the spatial cavitation field. Tempered collapse was also discovered; a sufficiently short delay between two pulses or a change in order of the positive and negative phases of a single pulse stifled bubble growth. Early collapse was detected acoustically. Computations of bubble radius and collapse pressure reinforced the observations.

The ability to retain volatile organic compounds (VOCs) while collecting and transferring intact soils for in-vial analysis was evaluated with field and laboratory samples. Experiments were designed to assess if VOC concentrations are maintained in an intact soil sample when (1) held for under an hour in a metal core liner, (2) held for days in a metal core liner sealed with TFE-flourocarbon sheets or aluminum foil (ASTM D4547-91), (3) held for less than 2 minutes in a plastic bag after extruding from a sampling device, and (4) immediately transferred to an empty vial to which a solvent was added later. Results indicate that these procedures are all highly susceptible to volatilization losses. To maintain site-representative VOC concentrations, collection of soil samples for in-vial analysis should occur within minutes of exposing a fresh surface by using a device that limits soil structure disruption and exposure.

To satisfy requirements for productivity, versatility and flexibility, the horizontal form/fill/seal machine was specified and developed (based on the Tiromat 3000) to provide MRE pouch packaging rates of 100 per minute and for integration into the Combat Ration Advanced Manufacturing Technology Demonstration. Over 45,000 pouches have been produced during the test runs (including debugging) at rates up to 102 per minute demonstrated with residual gas levels below 10cc and meeting the other MIL specifications. Performance of the F/F/S machine was enhanced by Rutgers developing a unique method of measurement and analysis of interrelated operations. The method uses a computer based data acquisition system and the existing Tiromat sensors. Cycle (production) rates, quality of packages and control of product slosh were improved. This technique is useful during equipment installation, measuring equipment performance and monitoring package quality. A new version of laminated film was developed by Reynolds Metal that can be formed, sealed to specification and does not delaminate after retorting. Earlier performance will be verified by acceptance testing and NRDEC approval of this alternate pouch production method.

Microwave energy is used to join high dielectric loss Si-SiC to Si-SiC with Al foil as an interlayer. Rapid heating with moderate applied pressure has led to excellent bond strength in a short time. The joining was successfully achieved in about 5 minutes at 1250 deg C and 1.2 MPa axial pressure in a single mode microwave cavity without damaging the samples. The joined specimen interfaces were examined using optical microscopy and scanning electron microscopy. The diffusion paths of Al were also detected with electron microprobe image mapping. Average fracture strength of the joined specimen was shown to be comparable to the original material strength using the four point bending fracture test. Comparison of Weibull plots for original and joined Si-SiC has also verified the high strength at the Si-SiC/Al/Si-SiC interface., This article is from 'Ceramic Transactions. Volume 21. Proceedings of the Symposium on Microwave Theory and Application in Materials Processing Annual Meeting of the American Ceramic Society (23rd) Held in Cincinnati, Ohio on April 29 - May 3, 1991,' AD-A253 631, p507-514.

This research effort successfully implemented an automatic, optically based image segmentation scheme for locating potential targets in a cluttered FLIR image. Such a design is critical to achieve real-time segmentation and classification for machine vision applications. The segmentation scheme used in this research was based on texture discrimination and employs orientation specific, bandpass spatial filters as its main component. The orientation specific, bandpass spatial filters designed during this research include symmetrically located circular apertures implemented on heavy, black aluminum foil; cosine and sine Gabor filters implemented with detour-phase computer generated holography photoreduced onto glass slides; and symmetrically located circular apertures implemented on a liquid crystal television (LCTV) for real- time filter selection. The most successful design was the circular aperture pairs implemented on the aluminum foil. Segmentation was illustrated for simple and complex texture slides, glass template slides, and static and real-time FLIR imagery displayed on an LCTV.

Recent development of new microwave systems with very high-peak-power microwave pulses and other unique characteristics has increased concern for the safety of personnel working in and around such equipment. The objective of this experiment was to determine the effects of high-peak-power microwaves produced by a virtual cathode oscillator (VIRCATOR) on the performance of rhesus monkeys (Macaca mulatta). The monkeys were repeatedly exposed to high-peak-power, short- duration microwave pulses (50-80 ns) delivered concurrently with auditory signals to which the monkeys were trained to respond. In addition, sham exposures were conducted by shielding the monkeys from the microwave pulses using an aluminum foil barrier. Compared to sham-exposure sessions. the microwave pulses did not produce statistically significant effects on behavioral performance. This experiment demonstrated that exposure to short high-peak-power microwave pulses with very large peak SARs (365-827 kW/kg) but low whole-body average SARs (less than 0.1 W/kg) did not significantly alter a well-trained behavior. Therefore, the whole-body SAR limit of 0.4 W/kg and the part-body SAR limit of 8 W/kg for human exposure to microwave energy remains justified.

Thirty-two operational guides are given for the procurement, issuing of ingredients, and preparation of frozen foods in the Air Force missile site feeding system. Each item's guide presents formulations for specific batch sizes and ingredients are listed in units used for procurement. Procedures for preparation incorporate methods and equipment used at the F.E. Warren Foil Pack Preparation Facility. Operational and Ingredient Room Notes cover information on alternate preparations and ingredients as well as special interest notes on problems typically encountered for that formula. An ingredient source guide provides information on stock available in the Federal Supply System.

Metallic coating systems for graphite/epoxy laminated aircraft structures were developed to provide protection against moisture penetration, electromagnetic interference (EMI), paint strippers and lightning strikes. Foil coatings and pressed powder coatings were evaluated to assess their resistance to these hostile environments. The foil coatings provided a significant reduction in the moisture penetration and the associated strength loss of the laminate after exposure to humidity and humidity-thermal spiking. Techniques were developed for the application of foil coatings to graphite/epoxy laminates. Solid and perforated aluminum foil were applied to cured laminates in a secondary bonding operation. Sulfur dioxide/salt spray testing performed on foil-coated laminates did not indicate a severe corrosion problem.

In order to evaluate the effects of processing method and heating procedure on nutrient content, four different meat entrees were formulated and produced at the U.S. Army Natick, Research, Development and Engineering Center, then packaged and processed frozen, in a Tray Pack and in a no. 10 can. The objective of this study was to determine (1) the impact of the three packaging and processing variables on the nutrient content, (2) the nutrient losses which may have occurred when all entrees were heated for service, and (3) the differences between forced convection oven and water-bath heating on the nutrients available for consumption in the Tray Pack entrees. The thiamin and pyridoxine retention in the Tray Pack entrees when heated were 52 and 73 percent of the corresponding precooked frozen entrees, while the retentions in cylindrical no. 10 can entrees were 26 and 56 percent, respectively. Moisture retention was maximized in the Tray Pack entrees in comparison to both the precooked frozen and no. 10 can products. The forced-convection oven and water- bath methods of heat treatment were equally effective in minimizing pyridoxine losses., See also Part 1, ADA167187.

The contract involves the production of individual servings of food packaged in microwavable polymeric trays and thermostabilized. These products were all packed in microwavable barrier polymeric trays for further study for their possible inclusion in military feeding programs. The items that were actually produced were as follows: Fruit Mix, Sliced Peaches, Sliced Pears, Chocolate Pudding, Potatoes au Gratin, Rice in Butter Sauce, Beef Stew, Beef Strips with Green Peppers and Gravy, Chicken a la King, Spaghetti with Meat Sauce. The material used for the barrier trays was manufactured from a five-layer coextrusion of polypropylene, an adhesive layer, the barrier layer which is ethylene vinyl-alcohol (EVOH), an adhesive layer, and a final layer of polypropylene. The lid material was a three-ply laminate consisting of polyolefin film, aluminum foil, and polyester. The report shows the complete procedure for each product. This includes the Quality Control procedures and heat penetration and process determination. Keywords: Food processing; Food service; Food packaging; Military rationing.

The purpose of this task is to analytically determine the trinitrotoluene, dinitrotoleune and cyclotrimethylene trinitramine content of lagoon sediment from four Installations. To assess any safety problems in the treatment of explosive contaminated sediment, lagoon sediment samples were collected from four Army installations. Atlantic Research Corporation analyzed the sediments for percent moisture, TNT, RDX, 2,4-DNT and 2,6-DNT. The sediment samples were then sent to the Large Caliber Weapon Systems Laboratory for sensitivity analysis. USATHAMA will (U.S. Army Hazardous and Toxic Materials Agency) will then correlate the sediment sensitivity vs. explosive levels in the sediment. Five to six samples of wet contaminated lagoon sediment were received from four installations: Alabama Army Ammunition Plant (AAAP), Louisiana Army Ammunitions Plant (LAAP), Umatilla Army Depot (UAD), and Savannah Army Depot (SAD) at various times during the month of July. As instructed by USATHAMA, each individual sample was well mixed and a 4 - 6 gram sample was taken to determine the precent moisture. The percent moisture samples were put in an oven at 110C for 24 hours. The samples were then cooled in a desiccator and reweighed to a constant weight. A twenty gram sample was also taken from each sediment sample to determine explosive content. These samples were air dried overnight on the dull side of a sheet of aluminum foil.

X-band radiation has been observed which occurs when an electron beam travelling in air traverses an aluminum plate. The radiation pattern is more complicated than can be explained with a simplified model of Cerenkov radiation from air and transition radiation from the aluminum-air interface. The empirical observation is that the peak angle decreases with energy until about 70 MeV, then increases with energy. The angular width of the peak distribution shows a similar behavior with energy. The observed peak angle decreases as the distance from the horn antenna to the aluminum foil is increased. The explanation of the radiation distribution observed is not yet satisfactory. A major improvement in the data accumulation process has been introduced by measuring radiation at a fixed angle as data is taken with a movable horn. This procedure allows us to compensate for the fluctuating electron beam intensity. The data can now be digitized and stored in a computer for analysis. Previous experiments allowed only for analog measurements. Further work, both theoretical and experimental, will be required to understand fully the radiation signature of the electron beam. Keywords: Cerenkov radiation; Transition radiation; Normalization. Theses.

The Army is studying methods of protecting sensitive electronic equipment against electromagnetic pulse (EMP) and radiofrequency interference (RFI) events. Part of this work focuses on metal arc-spray techniques as a potentially low-cost alternative to traditional EMP/RFI protection. Arc-sprayed metal coatings have been used for several years in different applications; however, little is known about the physical and electrical properties of these coatings. A better understanding of these properties would allow spraying parameters to be optimized, ensuring the most effective coatings at the lowest cost. In this study, aluminum, aluminum bronze, copper, low-carbon steel, 13 percent chrome steel, nickel, nickel chrome, tin, and zinc were sprayed onto paper and aluminum foil substrates using the two-wire arc-spray process to determine the physical and electrical characteristics of these materials when sprayed on ordinary rooms composed of common construction materials. Keywords: Arc spraying; Electromagnetic pulses; Radiation shields; Coatings.

Purpose of the study was to evaluate nine main meal foods over a 36- month period of storage. Three processing/packaging combinations of each food were included: (1) precooked frozen, packed in half-size steamtable aluminum foil trays; (2) heat-processed in cylindrical No. 10 cans; and (3) heat- processed in rectangular tray cans. Frozen products were stored at a constant - 18C; heat-processed products at 21 and 38C. Products were evaluated initially and following 6, 12, 18, 24 and 36 months storage. Two sensory panels were used concurrently for product evaluations: (1) a panel of food technologists using a quality evaluation scale, and (2) a Natick RD&E Center employee panel using an hedonic scale. In addition to the sensory evaluations, interior surfaces of the containers were examined for corrosion after selected periods of storage. Prior to initial and six-month evaluations, all products were bacteriologically cleared for consumption. Sensory tests generally indicated that expected storage life of Tray Packs exceeded that of cylindrical cans at both storage temperatures. Precooked frozen products were generally highest rated, and No. 10 heat-processed products were lowest. Thus, of the heat-processed products, the Tray Pack foods were rated 'preferred'. The interior enamel food contact coating of the tin-free steel container was the most resistant to attack over the 36- month period of the study. Precooked frozen foods had aerobic plate counts that were well below Military standards and contained no fecal coliforms.

A numerical simulation of the ablation of a planar, aluminum foil target by a neodymium laser in the presence of a 2.5 Torr nitrogen background gas is presented. The simulation includes inverse bremsstrahlung absorption during the laser pulse, the cold isotherm in the equation of state for solid aluminum, non-equilibrium chemistry for both the target material and the background gas, radiation transport of the continuum, ion and electron energy equations, and blast wave formation in the background gas. The simulation is followed out to 50 nsec from the peak of the laser pulse. Although the Lagrangian code is 1-D, the divergence of the ablated target material expanding toward the laser (forward) as well as the rearward acceleration of the remaining target is accounted for by using an oblate spheroidal coordinate system. The primary results of the simulations are as follows: (i), by about 50 nsec a cavity with T sub e about 60 ev and ne about 2 times 10 to the 17th power 1cc has formed behind the denser and cooler forward moving blast wave; (ii), this cavity is not in chemical equilibrium but highly overionized for its temperature with predominantly Al(+9),Al(+10),Al(+11),N(+5) and N(+6); and (iii), the conditions for a deceleration driven Rayleigh Taylor instability are satisfied at the rear blast wave near one equal mass radius. This last feature may account for the experimentally observed floculli on the rearward side. Keywords: Laser plasmas; Blast wave; Numerical simulation; and Raleigh Taylor instability.

Charcoal, charcoal residue, potting soil, aluminum foil, bismuth germanate, and petroleum samples have been investigated using instrumental photon activation analysis (i.e., no radiochemistry). The major and minor elements routinely observed by this nondestructive method were: C, C1, Ca, Fe, Mg, Si, and K. A compreshensive review of the principles of IPAA was also included in the study. The principles were applied to a theroetical analysis of an oil sample in which the trace element concentrations were known. It was concluded that IPAA is a highly sensitive technique which could be used to fingerprint oils. (Author)

A four-stage Anderson cascade impactor, fitted onto a standard high volume air sampler was used to collect 24-hour suspended particulate samples at four sites in the Dayton, Ohio, metropolitan area. The particulate was impacted on tared perforated aluminum foil disks and two sheets of Whatman 41 cellulose paper were used as backup filters. The suspended particulate was thus fractionated into five aero-dynamic size ranges, each of which can be related to a specific area of deposition within the human respiratory tract. Some of the particles were removed from the collection media and mounted on slides with Aroclor 5662 for microscopic examination. The foil impaction disks were cut into eight sections each and the particles thereon dry ashed in a low temperature asher for 30 minutes to remove any organic materials. After ashing, each foil section was placed in 10 N nitric acid and the sample removed with a polyethylene scraper. The scraper and foil were rinsed with distilled water, and the total solution was slowly evaporated on a hot plate to approximately 15 milliliters, then diluted in a 25 milliliter volumetric flask with distilled water. One-half of each backup filter was cut into narrow strips, placed in an aluminum foil boat and ashed for 16 hours.

This report presents the results of a technology program directed towards the development of a long-life, high-energy density capacitor for application in spacecraft. The capacitor has low inductance (approximately 20 nH) and an energy density up to 40 J/lb. Voltage vs. life curves are shown which indicate this capacitor will withstand over 10 to the 7th power discharges when operated at rated voltage of 2.2 kV. Materials were employed in this capacitor which should render it resistant to damage from radiation. To attain radiation resistance and high-energy density, kraft tissue was successfully excluded from the winding which is composed principally of K-F polymer and aluminum foil. Various impregnants were tested and the most successful was silicone oil. (Author)

A joint USAF/Canadian government development program conducted to evaluate the fuel tank ullage explosion suppression performance and to qualify the airborne military use of EXPLOSAFE void filler material, is reported. The material was subjected to laboratory testing to characterize its performance with regard to the manufacturing variables and subsequently exposed to typical ballistic threats up to 23mm HEI-T. The material properties are extensively defined together with the operational penalties associated with its use. Operational and environmental tests are described which determined the tolerance of the material to static loading, fuel slosh vibration, and exposure to fuel, fuel + additives, and corrosive fuel contaminants. Further tests demonstrate that the material does not affect fuel system operation with regard to flow, free motion of fuel during aircraft inversion and fuel tank venting. Installation studies were conducted on fuel tanks of varying complexity to demonstrate feasibility of assembly using existing apertures.