Pour voir les autres types de publications sur ce sujet consultez le lien suivant : Hermetical weld.
Articles de revues sur le sujet « Hermetical weld »
Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres
Consultez les 50 meilleurs articles de revues pour votre recherche sur le sujet « Hermetical weld ».
À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.
Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.
Parcourez les articles de revues sur diverses disciplines et organisez correctement votre bibliographie.
1
Salzer, Thomas E. « A Low-Impedance Projection Welding Device for Large Package Hermetic Sealing ». International Symposium on Microelectronics 2015, no 1 (1 octobre 2015) : 000810–16. http://dx.doi.org/10.4071/isom-2015-thp32.
Texte intégralRésumé :
Electronic packages for medical, communications, defense, and other applications are often hermetically sealed into metal containers using projection welding. However, current projection welding machines may not reliably seal packages with weld perimeters exceeding 7.6 cm (3.0 in), and also may expel metallic particles into the package. This paper describes a novel low-impedance projection welding device that can reliably weld large packages with up to 25.4 cm (10.0 in) weld perimeters with zero weld expulsion and zero weld defects, using half the energy required by traditional machines. The device does not rely on conventional power supplies and transformers, and delivers ≫120kA of weld current while operating from standard electrical outlet (110V, 15A circuits), and requires no external bus bars or cooling system. The system architecture can be easily scaled upward to significantly increase the delivered weld current and hermetically seal packages with weld perimeters greater than 25.4 cm (10.0 in). A commercial version of this device has welded more than 1 million medical, communications, and military electronic packages with zero customer returns. Data is presented showing the weld parameters for a variety of commercial and military hermetic electronic packages.
2
Salzer, Tom. « Advances in Hermetic Projection Weld Sealing ». International Symposium on Microelectronics 2019, no 1 (1 octobre 2019) : 000550–56. http://dx.doi.org/10.4071/2380-4505-2019.1.000550.
Texte intégralRésumé :
Abstract In this article, we describe a novel process for hermetic projection weld sealing of semiconductor devices, considered by many to be an important legacy technology from decades gone bye, but not particularly relevant in today's arsenal of sealing technologies. We will demonstrate that with appropriate modifications to be described, this technology can used to seal various high power devices as well as high reliability semiconductors, crystals, hybrid packages, medical electronics, photonic devices, automotive electronics, etc. Its features primarily stem from the fact that it can be used to quickly and efficiently produce true hermetic seals in components. The welding is so rapid, that it is essentially a room temperature technology and the equipment is small enough that it can be housed in an atmosphere controlled chamber filled with any gas that is not explosive. Air, Nitrogen, Argon, Helium and their mixtures are the most commonly utilized gasses. The process is so adiabatic that it can be used to seal many liquids also. In some applications the technology competes against pulsed laser welding, but unlike laser welding the entire seal takes place in a few milliseconds because it is a single discharge, component-shaped spot/projection weld, which means that the entire seam is made in a single high speed discharge. So, in the same time that it takes a laser welding machine to make one of the many small overlapping spot welds required to make a seal, the projection welder has completed the entire operation. This process results in minimal stress and distortion, and maximum hermetic properties, strength and reliability, without requiring electroplating or preforms. Because the weld involves the localized high speed melting of metals, it among the highest energy density processes. A concern with the earlier resistance welding technologies has been the expulsion of particulates, both out of, and into the seal. This expulsion has been systemic and becomes progressively worse as the package size increases. In the course of this presentation we will demonstrate how this concern has been dealt with and corrected. Internal dew points can be held to −40 degrees, or lower if required. Other common applications for this technology include sealing and welding of nuts and studs for hermetic applications and sealing of devices for medical applications that must endure autoclave sterilization. In the course of this presentation, we will take you back to the roots of the original resistance welding process as taught by the early process developers so that you will understand how things have changed, and the reasons for the changes.
3
Mauri, Luca, Anna Della Porta, Alessio Corazza et Marco Moraja. « Vacuum Packaging Requirements for MEMS and Characterization Techniques ». Proceedings 56, no 1 (15 décembre 2020) : 18. http://dx.doi.org/10.3390/proceedings2020056018.
Texte intégralRésumé :
Getter materials are technically proven and industrially well-implemented solutions for maintaining a vacuum inside electronic devices to assure long lifetimes and proper operating conditions. The pressure requirements of some hermetically packaged microelectromechanical systems (MEMS) devices, such as gyroscopes, accelerometers, infrared (IR) bolometers, and digital mirrors, are very stringent. The internal pressure can be as low as in the 10−3 mbar range. Due to the desorption phenomena of gaseous species from the internal surfaces, the vacuum inside such hermetically sealed electronic devices tends to degrade over time and, in the worst case, can affect the proper operation of the device. The integration of a special nanostructured getter film is an effective way to preserve and guarantee the performance of such devices. In addition to the getter material, there is also the need to develop and customize analytical techniques for post-process vacuum quality control and reliability checks of hermetic bonding, which are extremely important for the assessment of a device’s overall performance, lifetime, and manufacturing process yield.
4
Spruk, S., M. Jenko, L. Koller et D. Railič. « Vacuum tight laser welds for hermetical incapsulation of electronic parts ». Vacuum 44, no 5-7 (mai 1993) : 461–63. http://dx.doi.org/10.1016/0042-207x(93)90073-j.
Texte intégral
5
Vauchy, Romain, Pauline Fouquet-Métivier, Philippe M. Martin, Christophe Maillard, Isabelle Solinhac, Christine Guéneau et Caroline Léorier. « New sample stage for characterizing radioactive materials by X-ray powder diffraction : application on five actinide dioxides ThO2, UO2, NpO2, PuO2 and AmO2 ». Journal of Applied Crystallography 54, no 2 (31 mars 2021) : 636–43. http://dx.doi.org/10.1107/s1600576721002235.
Texte intégralRésumé :
A new sample stage for characterizing radioactive materials by X-ray powder diffraction was developed at the ATALANTE facility (CEA Marcoule, France) using a conventional (non-nuclearized) Bruker D8 goniometer mounted in Bragg–Brentano geometry. The setup consists of a removable, fully hermetic sample stage, with a 200 µm-thick beryllium window, that can be plugged onto a glove-box, allowing the sample to be introduced in an hermetic medium that also encapsulates the glove-box atmosphere throughout the analysis process. The whole setup is thus hermetically unplugged from the glove-box and positioned on the centre of the goniometer. No preliminary decontamination and/or decontainment of the sample is necessary. The device was developed to avoid an expensive and time-consuming nuclearization of the diffractometer while also keeping it easily accessible for maintenance. Ultimately, keeping the diffractometer out of a glove-box also limits the volume of the final nuclear wastes, and thus the removable sample stage is the only `active' part. X-ray diffraction results of two NIST standards LaB6 and α-Al2O3 as well as five actinide dioxides ThO2, UO2, NpO2, PuO2 and AmO2 are presented to show the efficiency of the setup.
6
Paganini, Gianni. « Hobbes's "Mortal God" and Renaissance Hermeticism ». Hobbes Studies 23, no 1 (2010) : 7–28. http://dx.doi.org/10.1163/187502510x496354.
Texte intégralRésumé :
AbstractResearch made by Schuhmann and Bredekamp has pointed up the unsuspected links between Hobbes and one of the ancient traditions best loved by Renaissance philosophy: Hermeticism. Our goal will be to proceed further and to stress the Hermetic significance implicit in the formula "mortal God". If Asclepius can act as a source for the theme of the fabrication of gods, it does not fit in with the antithesis ("mortal god/immortal God") typical of the Leviathan. A proper source for this topic can rather be found in treatise X ("Clavis") of the Corpus Hermeticum, well known to Ficino and to Iustus Lipsius. We must also stress one capital difference: whereas in the Hermetic texts man's apotheosis passes through gnosis and the exercise of the intellect, reserved in practice for a few selected people, in Leviathan on the contrary it is the holder of sovereignty who acquires the features of the "mortal god". Divinisation passes through politics, with the delicate artificial process of "generating the state"; knowledge only provides the tools for the rational technique needed to elaborate sovereignty, through stipulating pacts and the convention of impersonation. The "artificial man" as a mortal God is the apotheosis of the common man who enters into the founding pact with his ordinary intellectual and motivational faculties.
7
Kamran, M., I. Afzal, S. M. A. Basra, A. Mahmood et G. Sarwar. « Harvesting and post-harvest management for improving seed quality and subsequent crop yield of cotton ». Crop and Pasture Science 71, no 12 (2020) : 1041. http://dx.doi.org/10.1071/cp20129.
Texte intégralRésumé :
Quality seed is a prerequisite to uniform stand establishment, which contributes to higher crop yield. However, prevalence of poor-quality cottonseed with high moisture content due to suboptimal harvesting and postharvest practices is the primary reason for crop-stand failure in developing countries. The present study evaluated the effects of harvesting environment, drying method and storage conditions on seed quality of transgenic (FH-142) and non-transgenic (FH-942) genotypes of cotton (Gossypium hirsutum L.) cultivated in Pakistan. Both genotypes were picked three times at monthly intervals during the cropping season and subjected to a ginning process. Seed was then dried in the sun or with desiccant zeolite beads, and stored for 5 months in cloth or hermetic bags at room temperature or in paper bags at 10°C. The efficiency of storage systems was evaluated by estimating moisture content and germination potential periodically in the storehouse and later under field conditions. Both genotypes exhibited better seed quality attributes at the first picking, and zeolite beads dried seed to lowest moisture content more quickly than sun-drying. Seeds of both genotypes stored hermetically retained the lowest moisture content, maximum germination potential, and lower fatty acid contents throughout the storage period, as well as performing significantly better in the field by exhibiting early and uniform stand establishment, more fruiting branches and bolls, and higher yield. Thus, use of zeolite beads in post-harvest drying followed by hermetic storage preserves cottonseed quality for longer, and leads to improved crop growth and yield of cotton. These practices will be useful for cotton farmers in developing countries.
8
Schilm, J., A. Goldberg, U. Partsch, W. Dürfeld, D. Arndt, A. Pönicke et A. Michaelis. « Joining technologies for a temperature-stable integration of a LTCC-based pressure sensor ». Journal of Sensors and Sensor Systems 5, no 1 (9 mars 2016) : 73–83. http://dx.doi.org/10.5194/jsss-5-73-2016.
Texte intégralRésumé :
Abstract. Besides the well-known application as circuit boards and housings, multilayer low-temperature co-fired ceramics (LTCC) offer a flexible and temperature-stable platform for the development of complex sensor elements. Commercial LTCC qualities are usually available with a matching set of metallization pastes which allow the integration of various electrical functions. However, for the integration of ceramic sensor elements based on LTCC into standardized steel housings it is necessary to compensate the mismatching thermal expansion behaviour. Therefore balancing elements made of Kovar® (Fe–29 wt% Ni–17 wt% Co) and alumina ceramic (Al2O3) can be used. These components have to be joined hermetically to each other and to the LTCC sensors. In this study, brazing experiments were performed for combinations of Kovar–Al2O3 and Kovar–LTCC with Ag–Cu–Ti- and Ag–Cu–In–Ti-based commercial braze filler metals, Cusil-ABA® and Incusil®-ABA, respectively. For both active braze filler metals, optimized processing parameters were investigated to realize hermetic Kovar–Al2O3 and Kovar–LTCC joints.
9
Likhayo, Paddy, Anani Y. Bruce, Tadele Tefera et Jones Mueke. « Maize Grain Stored in Hermetic Bags : Effect of Moisture and Pest Infestation on Grain Quality ». Journal of Food Quality 2018 (4 novembre 2018) : 1–9. http://dx.doi.org/10.1155/2018/2515698.
Texte intégralRésumé :
Maize (Zea mays) is an important staple food crop produced by the majority of smallholder farmers that provides household food security through direct consumption and income generation. However, postharvest grain losses caused by insect pests during storage pose a major constraint to household food security. Hermetic storage technology is an alternative method that minimises postharvest losses by depleting oxygen and increasing carbon dioxide levels within the storage container through metabolic respiration of the grains, insects, and microorganism. Maize grain was stored for 180 days in hermetic bags or open-weave polypropylene bags to compare quality preservation when subject to initial grain moisture contents of 12, 14, 16, and 18 percent and infestation by Sitophilus zeamais. The moisture content of grain in hermetic bags remained unchanged while in polypropylene bags decreased. Dry grains (12% moisture content) stored well in hermetic bags and suffered 1.2% weight loss while for equivalent grains in polypropylene bags the weight loss was 35.8%. Moist grains (18% moisture content) recorded the lowest insect density (7 adults/kg grain) in hermetic bags while polypropylene bags had the highest (1273 adults/kg grain). Hermetic and polypropylene bags recorded the lowest (0–4 adults/kg grain) and highest (16–41 adults/kg grain) Prostephanus truncatus population, respectively. Discoloured grains were 4, 6, and 12 times more in grains at 14, 16, and 18 than 12 percent moisture content in hermetic bags. Grains at 18% moisture content recorded significantly lower oxygen (10.2%) and higher carbon dioxide (18.9%) levels. Holes made by P. truncatus in the hermetic bags were observed. In conclusion, storage of moist grains (14–18% moisture content) in hermetic bags may pose health risk due to grain discolouration caused by fungal growth that produces mycotoxins if the grains enter the food chain. The study was on only one site which was hot and dry and further investigation under cool, hot, and humid conditions is required.
10
Eickenscheidt, Max, Michael Langenmair, Ahmad Dbouk, Dorit Nötzel, Thomas Hanemann et Thomas Stieglitz. « 3D-Printed Hermetic Alumina Housings ». Materials 14, no 1 (3 janvier 2021) : 200. http://dx.doi.org/10.3390/ma14010200.
Texte intégralRésumé :
Ceramics are repeatedly investigated as packaging materials because of their gas tightness, e.g., as hermetic implantable housing. Recent advances also make it possible to print the established aluminum oxide in a Fused Filament Fabrication process, creating new possibilities for manufacturing personalized devices with complex shapes. This study was able to achieve integration of channels with a diameter of 500 µm (pre-sintered) with a nozzle size of 250 µm (layer thickness 100 µm) and even closed hemispheres were printed without support structures. During sintering, the weight-bearing feedstock shrinks by 16.7%, resulting in a relative material density of 96.6%. The well-known challenges of the technology such as surface roughness (Ra = 15–20 µm) and integrated cavities remain. However, it could be shown that the hollow structures in bulk do not represent a mechanical weak point and that the material can be gas-tight (<10−12 mbar s−1). For verification, a volume-free helium leak test device was developed and validated. Finally, platinum coatings with high adhesion examined the functionalization of the ceramic. All the prerequisites for hermetic housings with integrated metal structures are given, with a new level of complexity of ceramic shapes available.
11
Shaikhiev, I. G., S. V. Sverguzova, Zh A. Sapronova et E. S. Antyufeeva. « USING FOOD WASTE FOR THE GROWING OF HERMETIA ILLUCENS FLY LARVAE (BRIEF REVIEW OF FOREIGN LITERATURE) ». Construction economic and environmental management 77, no 4 (2021) : 17–30. http://dx.doi.org/10.37279/2519-4453-2020-4-17-30.
Texte intégralRésumé :
The information from foreign literature on the use of organic consumption food waste, substandard food products generated at trade objects, as well as their mixtures in the composition of solid municipal waste as substrates for growing larvae and prepupae of the fly Hermetia illucens is briefly summarized. Also shown the possibility of using specific waste as a substrate, such as, in particular, waste from the processing of seafood and mushrooms. It was shown that the larvae and prepupae of Hermetia illucens contribute to the high conversion of the organic substrate into the larvae biomass and waste processing efficiency with a decrease in its mass and volume. Larvae of Hermetia illucens, grown on organic substrates, are characterized in most cases by a high content of saturated and unsaturated fatty acids and proteins. The compost formed after the bioconversion of organic substrates using Hermetia illucens larvae contains a high amount of nutrients and can be used as fertilizer or soil for growing indoor plants and crops. It was revealed that the processing of organic food waste contributes to a significant reduction in greenhouse gas emissions compared to simple composting or anaerobic digestion.
12
Dittman, Timothy. « The True Cost of Hermeticity in Microelectronic Packaging ». International Symposium on Microelectronics 2016, no 1 (1 octobre 2016) : 000644–47. http://dx.doi.org/10.4071/isom-2016-thp45.
Texte intégralRésumé :
Abstract Reliability in microelectronic packaging has been, and will continue to be, a major concern that must be taken into account early in the design of a package. Decisions made relative to packaging materials and the methods for achieving environmental protection drive many other aspects of the design, such as component selection and next higher assembly interfaces. A better understanding of current methods for achieving reliability allows the design community to determine the most appropriate packaging solution for use in a given application. Environmental protection in microelectronic packaging may be achieved both with and without hermeticity. Hermetic solutions require a means of sealing the package via laser or seam weld type processes in order to provide environmental protection to the components within the package. These packages are typically in the form of either a metal box assembly or a ceramic substrate with a soldered lead frame. Non-hermetic packaging solutions can be accomplished on a wide variety of material sets but require environmentally protective coatings to prevent damage to the packaged components. Hermetic and non-hermetic packaging solutions, in addition to various types of each, have unique advantages and disadvantages depending upon the application. Characteristics such as electrical performance, producibility, structural integrity and cost must be considered when choosing a packaging solution for an application. This paper will review current microelectronic packaging technology trends and present a trade study on the materials and methods used to achieve environmental protection.
13
Maurer, V., M. Holinger, Z. Amsler, B. Früh, J. Wohlfahrt, A. Stamer et F. Leiber. « Replacement of soybean cake by Hermetia illucens meal in diets for layers ». Journal of Insects as Food and Feed 2, no 2 (10 juin 2016) : 83–90. http://dx.doi.org/10.3920/jiff2015.0071.
Texte intégralRésumé :
Insects will likely play an important role as protein sources for livestock in the future. Many insect species are able to convert materials not suitable for human nutrition – or even waste – into valuable protein with a favourable amino acid composition for poultry and other livestock. A feeding trial with partly de-fatted meal of dried Hermetia illucens larvae (Hermetia meal) reared on vegetarian by-products of the pasta and convenience food industry was carried out in small groups of Lohmann Selected Leghorn laying hens (four rounds, 10 hens/round). Experimental diets H12 and H24 contained 12 and 24 g/100 g Hermetia meal replacing 50 or 100% of soybean cake used in the control feed, respectively. After three weeks of feeding experimental diets, there were no significant differences between feeding groups with regard to performance (egg production, feed intake). There was a tendency (P=0.06) for lower albumen weight in the H24 group; yolk and shell weights did not differ. No mortality and no sign of health disorders occurred. Plumage as well as wound scores remained stable during the feeding period and did not differ between treatments. Dry matter of faeces increased with increasing proportions of Hermetia meal in the diet, with a significant difference between H24 and the control (P=0.03). An increase of black faecal pads was observed in the H12 and H24 groups. Overall, these results suggest Hermetia meal can be a valuable component of layer diets. However, insect meal production still has to become economically more viable through upscaling production and, especially, legislative issues have to be solved.
14
Knapkiewicz, P., et I. Augustyniak. « Sealing of silicon-glass microcavities with polymer filling ». Bulletin of the Polish Academy of Sciences Technical Sciences 64, no 2 (1 juin 2016) : 283–86. http://dx.doi.org/10.1515/bpasts-2016-0032.
Texte intégralRésumé :
Abstract Investigation of hermetic sealing of selected polymers in silicon-glass microcavities has been presented. The anodic bonding method has been adapted for hermetic encapsulation of the polymer in microcavity. According to standard conditions of the anodic bonding process (temperature: 400°C, voltage: 1000 V), the main challenge was the significant reduction of temperature in order to avoid degradation of the polymer. An analysis of the influence of reduced temperature and oxygen-free atmosphere on bond quality has been done. Proper parameters of the anodic bonding process enabling good and hermetic encapsulation of the polymer in the microcavity as well as optimal polymer treatment have been elaborated. Studies have shown that the closure of high density polyethylene in microcavity by anodic bonding process at a temperature reduced to 340°C is possible. This procedure will be used for the fabrication of main elements for a new family of high radiation MEMS sensors.
15
Marinis, Thomas, et Berj Nercessian. « Hermetic Sealing of Stainless Steel Packages by Seam Seal Welding ». International Symposium on Microelectronics 2010, no 1 (1 janvier 2010) : 000720–30. http://dx.doi.org/10.4071/isom-2010-wp5-paper6.
Texte intégralRésumé :
Welded stainless steel packages offer a number of advantages relative to those fabricated from kovar or aluminum metals and braze sealed. They are highly resistant to corrosion, especially in aqueous or elevated temperature environments, are mechanically stronger, dramatically so at temperatures above 100°C, exhibit lower outgassing rates, and have better vibration characteristics. Since welded stainless steel packages do not require over plating to facilitate braze sealing, combined material and fabrication costs are lower than kovar or aluminum packages. Also, unlike kovar, stainless steel is nonmagnetic, which is advantageous in many electronic applications. For sealing stainless steel packages, we elected to use seam sealing rather than laser welding for two reasons. Seam sealing subjects the package contents to lower thermal excursions than laser welding because less material is melted to achieve a weld in seam sealing. Second, seam sealing confines the molten material between the cover and package, where as laser welding produces a surface filet. Consequently, there is more opportunity for molten metal to splatter or react with the atmosphere in laser welding than in seam sealing. We successfully developed a process to weld a 2 millimeter thick cover onto a box with dimensions of 75 mm long by 50 mm wide by 15 mm deep using a seam sealer. The box walls were 1 mm thick and were penetrated by a dozen glass insulated feedthrus on one side. Both cover and box were fabricated from 316L stainless steel. A combination of analytical and finite element modeling were used in conjunction with a designed experiment to optimize the process variables of roller angle, speed and pressure, weld current, pulse shape, duration and spacing, number of weld passes, and sealing atmosphere. Weld quality and seal integrity were evaluated by leak testing before and after environmental stressing, mechanical testing and metallographic cross sectioning. The effects of component dimensions and tolerances on seal integrity were also investigated. Particular attention was paid to cover flatness, flange thickness, and tightness of fit between the cover and box. The process development was concluded by conducting a qualification experiment that used the optimized process parameters with controlled variation about their nominal values. A 100% yield of sealed boxes was obtained. These test articles were then subjected to various environmental screening tests, which were all passed with no failures.
16
Chen, Lei, Jinghua Ding, Junjie Gao, Shuyi Ren, Jingyang Gao et Gang Liu. « Time-Dependent Compressibility of Crude Oil in Gelled State Measured by a New Apparatus ». SPE Journal 25, no 06 (18 juin 2020) : 3200–3216. http://dx.doi.org/10.2118/201211-pa.
Texte intégralRésumé :
Summary Compressibility is a basic property of gelled crude oil, which was always regarded as a constant in the unsteady-pipe-flow process. In this article, the compressibility of gelled crude oil was accurately measured, and some new characteristics were discovered by a new apparatus that was developed using a special sealing method consisting of an elastic film and the Newtonian fluid. There was no leakage in the special hermetical method, and the unexpected seal-ring deformation of the piston in the traditional compression apparatus was also well-avoided. Using the new apparatus, compressibility of the gelled crude oil was tested and it was found that the compressibility of gelled crude oil is strongly time dependent.
17
Steiner, A. M., et P. Ruckenbauer. « Germination of 110-year-old cereal and weed seeds, the Vienna Sample of 1877. Verification of effective ultra-dry storage at ambient temperature ». Seed Science Research 5, no 4 (décembre 1995) : 195–99. http://dx.doi.org/10.1017/s0960258500002853.
Texte intégralRésumé :
AbstractAfter 110 years of hermetic sealed storage at temperatures between 10 and 15°C and at a moisture content of 3.12%, Hordeum vulgare showed 90% germination and Avena sativa 81%. In addition, some seeds of Agrostemma githago, Lolium temulentum, Sinapis alba, Sinapis arvensis, and Vaccaria hispanica were still capable of germinating. This demonstrates that ultra-dry, long-term seed storage under ambient temperature conditions can successfully be achieved with the intention of cutting down risks and costs in germplasm conservation.
18
Winkler, Sebastian, Jan Edelmann, Christine Welsch et Roman Ruff. « Different encapsulation strategies for implanted electronics ». Current Directions in Biomedical Engineering 3, no 2 (7 septembre 2017) : 725–28. http://dx.doi.org/10.1515/cdbme-2017-0153.
Texte intégralRésumé :
AbstractRecent advancements in implant technology include increasing application of electronic systems in the human body. Hermetic encapsulation of electronic components is necessary, specific implant functions and body environments must be considered. Additional functions such as wireless communication systems require specialized technical solutions for the encapsulation.In this paper 3 different implant strategies based on the material groups silicone, ceramics and titanium alloys are evaluated. With the background of a specific application the requirements for the encapsulation are defined and include the implementation of electrical feedthroughs, wireless communication and wireless energy transfer as well as biomedical specifications such as hermetic sealing, mechanical stability and biocompatibility. The encapsulations are manufactured and qualified experimentally.
19
Han, Min Fang, Zhong Li Wang et Yu Qian Wang. « On the Sealing Materials for SOFC ». Key Engineering Materials 336-338 (avril 2007) : 452–54. http://dx.doi.org/10.4028/www.scientific.net/kem.336-338.452.
Texte intégralRésumé :
Processing of sealing materials is a key technology in planar SOFC. In this paper, compositions of sealing materials were determined and then mixed and milled for 7~8 h. Glass materials were obtained by melt at 1300 ~ 1600°C and quenched in cold water. The powder materials were made by milling and screening. Properties of thermal expansion of sealing materials were on the same level to both electrolyte and interconnect. Experiments using 7 kinds of materials were carried respectively at 900°C and 1300°C. The most suitable sealing temperatures related to sealing materials were then determined. Thermal cycle experiments were carried and hermetical properties were tested by red-absorption. Microstructure were observed with SEM and it revealed that the prepared sealing materials joins well with YSZ but not so good with metal.
20
Liew, Li-Anne, Ching-Yi Lin et Y. C. Lee. « Polymer-Based Hermetic Packaging for Flexible Micro Devices ». Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2012, DPC (1 janvier 2012) : 001139–62. http://dx.doi.org/10.4071/2012dpc-tp36.
Texte intégralRésumé :
In recent years, polymers have been widely adopted as a low-cost, light-weight and high-flexibility alternative to traditional silicon materials for MEMS. However, the majority of polymers do not provide hermetic protection because of their high moisture- and gas permeation rates. Yet, hermetic packaging is critical for many applications such as medical devices [1], RF MEMS [2] and micro heat pipes [3]. In particular, our group has been developing flexible thermal ground planes based on heat pipe technology [3] for advanced electronics cooling applications. Heat pipes require hermetic sealing, while flexibility requires the structural material to be polymer-based. Hermetic packaging methods for MEMS typically include welding, soldering [4], and various epoxies and polymers [1, 2, 5] to bond the parts in a package together. The bond interface is a major potential source of gas and moisture leakage. Although welds and solder joints offer effective hermetic seals, the bond interface is mechanically rigid. On the other hand, flexible bond materials like epoxies typically possess high moisture absorption rate and bonding strength degradation at high temperature [6] while polymers such as BCB [2] or LCP [7] either provide only semi-hermetic sealing or degrade at high temperature. We report a polymer-based hermetic packaging approach using fluorinated ethylene propylene (FEP), which possesses flexibility, high operating temperature compatibility (204°C), chemical resistance, and low water absorption rate. We report results of hermeticity tests in which FEP, solder, and epoxy were used to bond a copper-clad kapton “lid” onto a water-containing copper vessel which is then kept in an oven at 100 °C. The only path for water loss is through the bond interface. We show that the FEP-bonded test vehicles result in negligible water loss comparable to the solder-bonded containers, and far outperforming the epoxy-bonded containers. References: [1] G. Jiang and D. D. Zhou (Ed.), Implantable Neural Prostheses 2, (2010). [2] A Jourdain, P De Moor, K Baert, I DeWolf and H A C Tilmans, J. Micromech. Microeng.,15 (2005) S89–S96. [3] C.J. Oshman, B. Shi, C. Li, R. Yang, Y.C. Lee, G.P. Peterson, and V.M. Bright, J. Microelectromechanical Systems, 20, 2 (2011), 410–417. [4] T. Rude, J. Subramanian, J. Levin, D. Van Heerden, O. Knio, Proc. IMAPS 2005. [5] G. B. Tepolt, M. J. Meschera, J. J. LeBlanca, R. Lutwakb, M. Varghesec, Proc. of SPIE, Vol. 7592, 2010, 759207. [6] E. M. Petrie, Handbook of Adhesives and Sealants, 1st Ed. (McGraw-Hill, 1999), p. 707. [7] C.-D. Ghiu, S. Dalmia, J. Vickers, L. Carastro, W. Czakon, V. Sundaram, G. White, Proc. 1st European Microwave Integrated Circuits Conference, 2006, pp.545–547.
21
Milanko, Verica, Dusan Gavanski et Mirjana Laban. « Analysis of the effects of storage conditions on the preservation of soybean quality and the prevention of the self-heating process and the occurrence of fires ». Chemical Industry 66, no 4 (2012) : 587–94. http://dx.doi.org/10.2298/hemind110808111m.
Texte intégralRésumé :
After harvest, oilseed raw materials must be stored for a longer or shorter period of time before further processing. The task of storage is the safekeeping of the stored material with a minimal loss in quality. In order to preserve wet grain until processing, it is necessary to provide proper storage conditions. For this purpose, storage in the atmosphere of inert gases as well as storage in hermetically closed storages is applied. Such method is uncommon for oil cultures in domestic practice. Experimental research, analyzed in this paper, with emphasis on the effects of storage conditions on the preservation of soybean grain quality and the prevention of possibilities of the occurrence of the self-heating and self-ignition process, confirms the advantages of application of such method of storage for soybean grain. Soybean with the moisture content of 10.99% and 16.96% is stored in steel semi-industrial silo cells with carbon-dioxide atmosphere, and in hermetically sealed cell. The changes in temperature in the silo cells, changes in moisture content and discoloration of the soybean grains, as well as the amount of oil and protein in the grain were monitored during the experiment. The quality of the oil in grain was determined through the content of free fatty acids. The results of the research showed that, during longer period of time (216 days), the quality of the soybean grain in the sample with higher moisture content (16,96%) was preserved when storage was performed in carbon dioxide atmosphere. The storage of wet grain in a hermetically closed cell, in relation to the grain kept in carbon dioxide atmosphere, did not record significant differences in the examined indicators. Since the storage under controlled conditions did not result in the development of processes that would lead to the spontaneous heating of the soybean mass, the recommendation is to introduce such storage method for oilseed raw materials into domestic practice, with the additional aim of increasing the degree of protection against fire and explosions.
22
Zhang, J. B., J. K. Tomberlin, M. M. Cai, X. P. Xiao, L. Y. Zheng et Z. N. Yu. « Research and industrialisation of Hermetia illucens L. in China ». Journal of Insects as Food and Feed 6, no 1 (6 février 2020) : 5–12. http://dx.doi.org/10.3920/jiff2019.0020.
Texte intégralRésumé :
The larvae of the black soldier fly (BSF), Hermetia illucens L., are commonly associated with decaying organic wastes. Over the past 15 years, investigators in China have conducted extensive research exploring the use of BSF larvae to recycle organic materials as a means to protect the environment, while producing products of value, such as protein and bioenergy. Initial efforts were based on a BSF strain from the USA. However, since then, H. illucens strains from specimens collected in Hubei and Guangdong Provinces have been established and used as models to explore the use of this species in sustainable agriculture. China has played an instrumental role in developing an in-door breeding method using a quartz-iodine lamp rather than depend on natural sunlight. This discovery has allowed the establishment of in-door BSF colonies in regions throughout the world where abiotic conditions (i.e. cold temperatures) are preventative. Researchers in China paved the way for using microbes as a means to enhance BSF production including, enhancing BSF egg-laying as well as waste reduction. Furthermore, bacteria from BSF gut or waste can be cultured and used to promote BSF growth, shorten conversion time, and enhanced conversion efficacy. Recent efforts have demonstrated BSF larvae can degrade antibiotics as well as suppress noxious odours in livestock manure. Due to the efforts of research on BSF in China, numerous companies that recycle organic waste at a large scale (>20 tonnes waste digested/day), have been established. Resulting products include insect powder, and live BSFL that can be used as animal feed ingredients for livestock (e.g. eels and frogs), while protecting the environment. Future work will decipher the mechanisms regulating BSF larval conversion of organic waste so that the system can be optimised. However, efforts are still needed at the government level to establish quality assurance standards if this process is truly to become established as an industry in China.
23
Hunt, Bob, et Andy Tooke. « “Has Microelectronic MCM Technology Matured and is it Capable of Servicing the Widespread Needs of Down Well 225°C Operating Applications in the Oil and Gas Industry?” ». Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2014, HITEC (1 janvier 2014) : 000319–24. http://dx.doi.org/10.4071/hitec-tha17.
Texte intégralRésumé :
This paper reviews development and qualification work performed on 225°C operating temperature modules based on ceramic thick film multi-layer substrates supporting embedded thick film resistors, assembled passive and active components with ‘chip and wire’ connections and sealing in hermetic metal and ceramic cavity packages. It considers aspects of development and importantly investigates product qualification which includes shock and vibration at elevated temperatures as well as thermal shock and temperature cycling. In conclusion there is an attempt to answer the question “Has microelectronic MCM technology matured and is it capable of servicing the widespread needs of down well 225 °C operating applications in the Oil and Gas industry?”
24
Balluch, Bruno, Ibrahim Atassi, Michael Weilguni, Goran Radosavljevic et Arsim Myrtezani. « Realisation of Hermetically Tight Joints for Microfluidic Applications in LTCC - Technology ». Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2012, CICMT (1 septembre 2012) : 000423–27. http://dx.doi.org/10.4071/cicmt-2012-wa414.
Texte intégralRésumé :
Channel clogging by particles inside microfluidic LTCC devices for biochemical analytics may lead to critical system pressures especially affecting joints, seals or areas of material transition. Biological contamination by device leaks could become a crucial factor regarding operational safety. Therefore, this hereby presented work deals with technological aspects concerning cavity sealing of microfluidic LTCC- devices. Aluminum oxide cover elements as well as sapphire glasses acting as optical windows for spectroscopic investigations are bonded to microfluidic test modules by different glass solders. Different material combinations are discussed by means of compressive strength experiments. CeramTec GC test samples consisting of four layers with a fired thickness of 1mm and a test area of 33mm2 withstand pressures up to 90bar.
25
Godwin, Joscelyn. « Astral Ascent in the Occult Revival ». Culture and Cosmos 19, no 1 and 2 (octobre 2015) : 189–206. http://dx.doi.org/10.46472/cc.01219.0221.
Texte intégralRésumé :
The occult revival of the later 19th century inherited Neoplatonic and Hermetic ideas of astral ascent and commerce with the planetary spirits, but felt obliged to square these with contemporary discoveries in astronomy. In the 1850s, Andrew Jackson Davis adapted Swedenborgian ideas into a semi-scientific cosmology that served as the norm for spiritualists. In the 1870s, occultism separated from spiritualism and made its own pact with science, with results visible in the works of Emma Hardinge Britten, H. P. Blavatsky, and the Hermetic Brotherhood of Luxor. Outside these well-known movements, Cyrus Teed, known as Koresh, taught that the earth is a concave sphere with the heavenly bodies at the center. His system revived the themes of astral immortality through ascesis and an alchemical relation of humans to a closed cosmos. It was the basis for one of America's more successful utopian communities, which outlasted Teed for more than 50 years.
26
Ciężak, Patryk, et Adam Rdzanek. « Corrosion Monitoring of Aircraft Based on the Corrosion Prognostic Health Management (CPHM) System ». Journal of KONBiN 50, no 4 (1 décembre 2020) : 205–16. http://dx.doi.org/10.2478/jok-2020-0082.
Texte intégralRésumé :
Abstract The article presents methods to monitor the actual state of aircraft’s airframe, in particular, the onset of corrosion. The greatest emphasis is put on the “Corrosion Prognostic Health Management” CPHM system. Authors discuss corrosion detection using NDT methods as well as the possibilities of forecasting methods for estimating the onset of corrosion basing on the data gathered by means corrosion sensors. Based on the results of the previous research and analyses, authors focus on monitoring the internal microclimate and the factors causing corrosion in the aspect of damage tolerance operation of the aircraft. The results of the preliminary studies giving credibility to the concepts of predicting corrosion onset in the aircraft structure are presented. Preliminary results of tests carried out in supervised flights are also presented. The final part of the article presents the concept of modernizing the corrosion field site in order to use it in hermetic and non-hermetic tests of aircraft spaces.
27
Passmore, B. S., J. Stabach, S. Storkov, D. Martin, G. Falling, R. Shaw et T. McNutt. « A High Temperature (> ; 250 °C) SiC Schottky Diode Bridge Rectifier for Extreme Environment Applications ». Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2014, HITEC (1 janvier 2014) : 000018–21. http://dx.doi.org/10.4071/hitec-ta15.
Texte intégralRésumé :
A high temperature, 1200 V / 5 A SiC Schottky diode bridge rectifier packaged in a 4 pin TO-254 hermetically sealed package is presented. The package consists of high temperature (> 250 °C) assembly processes and materials, including the seals, baseplate, power substrate, die attach, and passivation. The forward voltage as well as the reverse leakage characteristics as a function of temperature is presented. In addition, rectification in a 275 °C environment is demonstrated using the bridge TO-254 style package.
28
Vinokurov, V. V. « Prototype Hermetic Teachings : Hermes Trismegistus and Three Hermes ». Concept : philosophy, religion, culture 5, no 1 (1 avril 2021) : 60–72. http://dx.doi.org/10.24833/2541-8831-2021-1-17-60-72.
Texte intégralRésumé :
The paper treats the topic of hermeticism — an esoteric tradition of teachings — with the view to its origins and varying interpretations. In setting research objectives, the text aims at identifying the common structural foundations of myths and ideas of the hermetic genesis and to establish the main vectors of the formation and transformation of esoteric teachings presented in the spiritual domain and reflected in the material culture of Western Europe from the 4th century BC to the present. For the needs of such a comparative study that embraces philosophical, religious and historical phenomena of culture, the following methods are used. As it is mostly the texts that are analyzed, the methodological framework consists of the interpretation of texts and artifacts – all along the line of presentation of historical sequences, of their recursion, of structural and functional aspects. The sources included not only texts, mathematical operations and chemical formulas of previously known alchemic artifacts are also introduced into the comprehensive analysis. The examination of cultural phenomena leads to the systematization of religious origins, historical and philosophical traditions and scientific achievements that underlie the formation of hermeticism. This structuralisation is possible due to the tools for the analysis of the hermetic body developed in this text. The mapping of the historical development of hermeticism is proposed in a three-level paradigm model based on the image of the Thrice-Great Hermes. It is concluded that the basis of the image of Hermes is the invariant of the historical three-level model of cognition of esoteric teachings, for descriptions of which the terms of ABC — paradigm are introduced. Each of the Hermea has own disciplinary paradigm. The first level of Hermes I, the author of cosmogonic visions, A — paradigm, is represented by inner visions (revelations of the cosmic mind or daimonic visions), thus forming the cultural level of mythology, theology. The level of Hermes II, the founder of writing and counting, lies in the realm of concepts of visions ‒ e.g. the Platonic philosophy, geometry, mathematics (B — paradigm). The third level (C — paradigm) is represented by texts and alchemical artifacts (Alexandrian crystal) of Hermes III, the founder of the art of healing and chemistry, that further embodied in empirical sciences, chemistry and astronomy, as well as ancient technological knowledge of the production of metals, glass and dyes. In general, all hermetic disciplines and practices emerge on the basis of this three-level paradigm.
29
Svetashov, V. N., S. A. Frolov et D. D. Vodorezov. « ON APPLICATION OF REUSABLE INFLATABLE PACKERS ». Oil and Gas Studies, no 1 (1 mars 2017) : 83–87. http://dx.doi.org/10.31660/0445-0108-2017-1-83-87.
Texte intégralRésumé :
The paper discusses the technology of application of inflatable packers, also companies, which are developing the design for this type of packers, as well as the main directions of their development. Currently, the authors developed an inflatable packer, creating a hermetic separation of cased borehole cavities at a wide range of temperatures and pressures, with the possibility of multiple quick installation and removal in a single or series of downhole operations.
30
Ohme, Bruce W., et Mark R. Larson. « High Temperature Analog-to-Digital Converter Reliability Testing ». Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2012, HITEC (1 janvier 2012) : 000245–52. http://dx.doi.org/10.4071/hitec-wp17.
Texte intégralRésumé :
Initial test results have been previously reported for a high-temperature (225°C) 12-bit analog-to-digital converter (HTADC12) fabricated using a production high-temperature silicon-on-insulator (SOI) CMOS process and assembled in hermetically sealed ceramic packages (ref. 1). Reliability test results for the HTADC12 are presented including parametric and functional test results from 1500 hours of dynamic life test at 250°C as well 1000 temperature cycles from −65°C to 200°C. Results of post-stress wirebond, and die bond testing are also provided.
31
Huo, Ping, Jian Ping Wang et Rui Xiang Gao. « Experimental Study on Hermetically-Sealed Construction and Ether-Resistance Materials in DME Engines ». Advanced Materials Research 199-200 (février 2011) : 784–89. http://dx.doi.org/10.4028/www.scientific.net/amr.199-200.784.
Texte intégralRésumé :
Considering the characteristics of Dimethyl ether(DME), such as low viscosity, strong dissolvability, swelling and ageing for usual rubber blankets, as well as mechanical property variation, some gum elastic parts could be corroded and lose their sealability. In order to avoid leak out of fuel feeding line and oil reserve tank, the taper face Hermetically-sealed construction was designed as the tube joint and the ether-resistance materials FM-1 was chosen as the sealant. And a gas impermeability experiment of joint was conducted to assess the tightness.
32
Williams, Jennifer, et Johnson Matthey. « High Temperature Protection against Unwanted Species within Hermetic Packaging ». Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2015, HiTEN (1 janvier 2015) : 000116–22. http://dx.doi.org/10.4071/hiten-session3b-paper3b_3.
Texte intégralRésumé :
The need for electronic applications to be able to withstand high temperatures has become more prevalent in recent years. With drilling in the oil and gas industry getting deeper, the operating temperatures are getting higher, with typical geothermal gradients of 25 °C/km. Temperatures up to 250 °C are often seen by drilling operations, which is putting a greater strain on the electronics and associated packaging. Standard methods of cooling are not viable for these harsh environments, so new technology is required to negate the effects of the extreme temperatures. As well as the use of high temperature stable electronic components, High Temperature Getters are required to remove gaseous contaminants from electronic housings to negate the associated deleterious effect on performance. The contaminating species to be removed are commonly H2O, CO2, and H2, and sometimes short chain organic molecules. Conventional getter materials can remove damaging species at temperatures up to about 80 °C. New technology is however required to eliminate these species at temperatures up to 250 °C, where existing getter formulations would certainly fail. Johnson Matthey has developed a range of getters that can remove multiple contaminants at both ambient and elevated temperatures. The first product in the series, HTA 1 can remove water and carbon dioxide. Addition of a metal oxide component in HTA 2 facilitates hydrogen removal at elevated temperatures, with capacities in excess of 70 cm3/g achieved. HTA 3 can adsorb unwanted organic contaminants in addition to removing water and carbon dioxide. HTA 4 is a combined getter capable of eliminating all of the aforementioned contaminant species. These products, combined with the unique, precision engineered Hi-Rel encapsulation (Figure 1) allow getters to be supplied pre-activated, without the end user needing to apply a thermal treatment prior to use. The product can be fitted into any hermetic device to extend the lifetime, thus decreasing the number of failures within electronic assemblies, improving system reliability and preventing operations being shut down as frequently.
33
Shaikhiev, Ildar, svetlana Sverguzova, Jeanne Sapronova, Anastasia Vladimirovna Svyatchenko et Nina Aleksandrovna Ushakova. « USING INSECT BIOMASS FOR RAINBOW TROUT CULTIVATION IN AQUACULTURE (FOREIGN LITERATURE REVIEW) ». Vestnik of Astrakhan State Technical University. Series : Fishing industry 2021, no 1 (17 mars 2021) : 69–81. http://dx.doi.org/10.24143/2073-5529-2021-1-69-81.
Texte intégralRésumé :
The article focuses on the data from foreign literature on growing rainbow trout or mykiss (Oncorhynchus mykiss) with the inclusion of dried and / or fat-free insect biomass in diets. The following seven types of insects could be recommended for inclusion in the diet of rainbow trout and other fish species: larvae and / or pupae of diptera fly (Hermetia illucens), housefly (Musca domestica), flour worm larva (Tenebrio molitor), locusts and grasshoppers (Acrididae), crickets (Gryllidae) and cathidids (Tettigoniidae), silkworm pupae (Bombyx mori). The brief data on physiology and life cycle of these insects are given, as well as the data on proteins and fatty acids concentration in fresh and dry larvae of insects. It has been shown that the flour from dried insect biomass contains a large amount of amino acids and fatty acids. There has been given the data on the influence of flour from insect larvae on the mass increase of rainbow trout juveniles and adults, digestibility of feed dry matter, organoleptic characteristics of fish fillets, amino acid and fatty acid composition, and other indicators. It has been found out that in most cases the survival rate is significantly higher in the experimental groups of Oncorhynchus mykiss juveniles fed a diet containing insect flour. It has been inferred that including flour from insect biomass in certain proportions has a positive effect on the growth and life of Oncorhynchus mykiss species. The most promising is adding Hermetia illucens larvae flour in the diet of rainbow trout in aquaculture, because Hermetia illucens larvae have the highest biomass yield per unit time compared to other insects.
34
Zhang, Jingfei, Wangyu Ren, Yunyun Zhou, Pei Li, Lin Xu, Dongmei Sun, Ping Wu, Yiming Zhou et Yawen Tang. « Hermetically Coated and Well-Separated Co3O4Nanophase within Porous Graphitic Carbon Nanosheets : Synthesis, Confinement Effect, and Improved Lithium-Storage Capacity and Durability ». Chemistry - A European Journal 22, no 28 (1 juin 2016) : 9599–606. http://dx.doi.org/10.1002/chem.201600573.
Texte intégral
35
Beebout, Charlie, et Erick M. Spory. « Environmentally Hardening IC Die Previously Assembled in Plastic Packages through Die Removal, Bond Pad Replating and Reassembly into Hermetic Packages ». Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2018, HiTEC (1 mai 2018) : 000039–44. http://dx.doi.org/10.4071/2380-4491-2018-hiten-000039.
Texte intégralRésumé :
ABSTRACT Many integrated circuits (ICs) will operate well above their maximum rated temperature of +70°C or +125°C, but are often not packaged appropriately to reliably endure temperatures above +150C. Specifically, the original gold or copper bonds on the aluminum die bond pads are prone to Kirkendall or Horsting voiding, particularly at temperatures greater than +150°C. Also the mold compounds used in plastic packaging for IC assembly can degrade at these elevated temperatures. In some cases, commercial demand for higher temperature reliability can justify a separate offering of ICs assembled in hermetic, ceramic packages from the original component manufacturer (OCM). However, in most cases, the market demand is deemed insufficient. Global Circuit Innovations (GCI) has developed a high-yielding process, which can remove a semiconductor die (i.e., computer chip) from a plastic package, remove the original bond wires and/or ball bonds, plate the aluminum die bond pads with Electroless Nickel, Electroless Palladium, and Immersion Gold (ENEPIG), and then reassemble the now improved semiconductor die into a hermetic, ceramic package. Device Extraction, ENEPIG die bond pad plating and Repackaging (DEER) provides an improved die bond pad surface such that works well with either gold or aluminum bond wires in applications up to +250°C without mechanical or electrical connectivity degradation. GCI routinely exposes sample devices to +250°C bakes with 100% post bake yields so as to continuously ensure that any device processed with the DEER technology will reliably perform in high-temperature environments. Although the oil and gas industry has already expressed significant interest in the DEER process, with excellent lifetest and production application results demonstrating dramatically increased component lifetimes at elevated temperatures, this technology can also be leveraged for any application exposing ICs to harsh environments. Not only is the high-temperature reliability dramatically increased, but also the new hermetic, ceramic package protects the IC from a variety of elements and environments (i.e., corrosives and moisture).
36
Almeida, Igor Marcel Gomes, Cleiton Rubens Formiga Barbosa et Francisco de Assis Oliveira Fontes. « METHODS OF WEAR TESTS FOR HERMETIC RECIPROCATING COMPRESSORS : AN OVERVIEW ». HOLOS 4 (9 septembre 2016) : 86. http://dx.doi.org/10.15628/holos.2016.2078.
Texte intégralRésumé :
The refrigerants being used in vapor compression processes have specific thermodynamic properties, which are decisive for the performance of the compressor of the system. The Montreal and the Kyoto protocols initiated a discussion of alternative refrigerants, which lead to new requirements of the compressor. The reliability of reciprocal compressors has become a leading field for compressor research. One of the main tools in the reliability field is accelerated degradation/life testing (ADT or ALT). These tests are designed to provide life estimates or to define lower bounds of product/parts reliability at shortened periods of time. The objective of this paper is to discuss the literature on accelerated life testing of reciprocating hermetic compressors, focusing on the wear of mechanical components. Several test methodologies are discussed as well as the procedures used to wear quantification. It is noted that there are numerous test methodologies. This fact can be attributed to the lack of standardization updated. Most authors have been focused the tests development to assess the scuffing occurrence in components. The evaluation of wear (qualitative and quantitative) is carried through optical microscopy techniques, scanning electron microscopy, surface roughness, physical-chemical analysis of the oil and electric power consumption. Test methodologies are presented based on critical analysis of the existing literature and the current scenario of refrigerants and lubricants development.
37
Mercy, T. D., Rahul Sharma, V. F. Kaladharan et K. P. Kamalakaran. « Laser Beam Welding of Aluminium : Process Optimisation to Achieve Hermetic Sealing for Electrochemical Energy System Containers ». Materials Science Forum 710 (janvier 2012) : 632–37. http://dx.doi.org/10.4028/www.scientific.net/msf.710.632.
Texte intégralRésumé :
Hermetic sealing is essential for long cycle life and calendar life of Lithium ion cells. Ingress of moisture and leaking of electrolyte in Lithium ion cells deteriorates the electrochemical performance. Nickel coated mild steel, Stainless steel, Aluminium and its alloys are generally used as case material. Pure Aluminium and Aluminium alloys are used to improve energy density of Lithium ion cells. High heat input is required for aluminium to obtain a sound weld because of the high thermal conductivity of the Aluminium. High heat input results in increased heat affected zone (HAZ) and transfer of heat into internal components during welding. Laser Beam Welding (LBW) results in very narrow heat affected zone (HAZ) and it is possible to have dissimilar metal welding. In the present work, experimental studies conducted to optimise the laser beam welding parameters for welding of Li-ion AA3003 cell case to lid without defects viz porosity and required weld strength. Hermeticity and strength of the weld bead were analysed in detail to ensure the adequacy of the process. It has been demonstrated that laser beam welding is a viable process for joining of cell case to its cover.
38
Leong, Siew Yoong, Soo Shin Chong et Kah Seng Chin. « Biodiesel Derive Bio-oil of Hermetia illucens Pre-pupae Catalysed by Sulphonated Biochar ». E3S Web of Conferences 34 (2018) : 02004. http://dx.doi.org/10.1051/e3sconf/20183402004.
Texte intégralRésumé :
This study investigates the development of biochar catalyst from bamboo applied for biodiesel synthesis. A non-conventional biodiesel feedstock was used in the in-situ transesterification reaction. This non-conventional feedstock is obtained from an insect’s fly, the Hermetia illucens fly. Biochar derived from bamboo has been investigated as a promising catalyst for biodiesel synthesis. The biochar acid catalysts were prepared by sulphonation via impregnation with concentrated sulphuric acid. The prepared catalysts were investigated for their performance to catalyse in-situ transesterification via ultra-sonication of Hermetia illucens bio-oil. The effects of carbonisation time (1 hour and 2 hour) and temperature (400°C, 500°C and 600°C) as well as catalyst loading (5-20 wt% on oil basis) on the transesterification yield were studied. Result showed that the highest yield of FAME obtained was 95.6% with catalyst loading of 15 wt% carbonized at 500°C for 2 hours. Sharp band of methyl ester functional groups were observed in the FTIR spectra at 1735-1750cm-1. The composition of this methyl ester was further deduced using gas chromatography and the fatty acid was predominantly lauric acid.
39
Zhen, Zhao Hui, et Zheng Shun Wang. « Pressure Sensitive Essence Microcapsules with MF-UF Resin as Double Wall ». Advanced Materials Research 746 (août 2013) : 106–9. http://dx.doi.org/10.4028/www.scientific.net/amr.746.106.
Texte intégralRésumé :
The paper studied the preparation and micro-encapsulation of pressure sensitive essence microcapsules with MF resin and UF resin as double wall by using the in situ polymerization method, and the optimal preparation conditions were also studied. The microcapsules were characterized on structure, morphologies, thermal properties, mean particle size and size distribution. The experiment illustrated that the wall of microcapsule consisted of the MF resin and the UF resin had been synthesized in the process of preparation, the essence oil was encapsulated into the microcapsules, the mean particle size and size distribution was well-proportioned and narrowed respectively, the particle morphologies were single core and global, the wall was hermetically sealed.
40
Goyal, Shashank, Denise Ott, Jens Liebscher, Dennis Höfling, Ariane Müller, Jens Dautz, Herwig O. Gutzeit, Dirk Schmidt et Rosmarie Reuss. « Sustainability Analysis of Fish Feed Derived from Aquatic Plant and Insect ». Sustainability 13, no 13 (1 juillet 2021) : 7371. http://dx.doi.org/10.3390/su13137371.
Texte intégralRésumé :
Fish and meat production and processing will grow drastically in the coming decades. In aquacultural systems, insects are gaining interest as feed to provide a sustainable alternative to the fishmeal paradox, whose production leads to high consumption of resources and negative environmental impacts. Within the scope of this study, the production of fish feed from Hermetia illucens larvae and Lemna minor in an inline recirculating aquaponics model for urban sites was developed and optimized, which efficiently combines waste and environmental service concepts in one production system. At the same time, the value chain produces high-quality, market-accessible raw materials for the fish feed industry. All investigations were accompanied by a comparative Life Cycle Assessment (LCA) to measure and compare ecological effects to finally result in sustainable alternatives. The results achieved in this research show that fish feed based on Hermetia illucens and Lemna minor can have the potential to be ecologically competitive or more sustainable than standard feed. It should be noted that the comparison here represents the results of the project on a pilot scale. Various optimization potentials were shown, which are essential for the large-scale implementation of the breeding of both species as well as their processing up to the fish feed pellets.
41
Ogashiwa, Toshinori, Kentaro Totsu, Mitsutomo Nishizawa, Hiroyuki Ishida, Yuya Sasaki, Masayuki Miyairi, Hiroshi Murai, Yukio Kanehira, Shuji Tanaka et Masayoshi Esashi. « Hermetic Seal Bonding at Low-temperature with Sub-micron Gold Particles for Wafer Level Packaging ». International Symposium on Microelectronics 2015, no 1 (1 octobre 2015) : 000073–78. http://dx.doi.org/10.4071/isom-2015-tp32.
Texte intégralRésumé :
Au/Au hermetic sealing was successfully done using a rim structure covered with sub-micron-size Au particles by low-temperature thermo-compression bonding. The easy deformability of sintered Au particles is advantageous in terms of the compliance with surface irregularity as well as the insensitivity of surface flatness. From the deflection of Si diaphragms over the sealed cavity, an inside pressure of 100 Pa and the maximum leak rate in a range of 10−14 Pa·m3/s (He) were estimated, which is sufficient for many MEMS applications.
42
Guzzon, Filippo, Pedro Bello, Kent J. Bradford, María de los Angeles Mérida Guzman et Denise E. Costich. « Enhancing seed conservation in rural communities of Guatemala by implementing the dry chain concept ». Biodiversity and Conservation 29, no 14 (13 octobre 2020) : 3997–4017. http://dx.doi.org/10.1007/s10531-020-02059-6.
Texte intégralRésumé :
Abstract Seed conservation in rural communities of low- and middle-income countries located in tropical areas is particularly problematic, due to high relative humidity that promotes insect and fungal infestations and leads to rapid losses in seed viability. Seed conservation in those areas is affected by unreliable power supplies that do not allow the use of dehumidifying and refrigeration systems recommended for the long-term storage of seeds. We tested the dry chain, i.e., initial seed drying with a reusable desiccant in the form of zeolite beads followed by seed conservation in hermetic containers, in rural communities of Guatemala (Huehuetenango Department). In this region, a network of community seed reserves (CSRs) has been established to provide a safety backup for seed and to conserve local agrobiodiversity. Using a local maize variety in three communities, we compared the dry chain with the seed conservation methodology employed in the CSRs (i.e., undried seeds in hermetic flasks) as well as with seed conservation in open storage, both in the local CSR and in a farmer’s granary. Seed conserved using the dry chain treatment maintained very high seed viability (> 80%) throughout the whole experiment (6 months) and reduced fungal and insect infestations (< 3%). In the other treatments, the viability declined significantly to an average of 52% non-viable and 19% infested seeds after 6 months of storage. The dry chain was demonstrated to be an excellent solution for enhancing seed conservation in biodiversity hotspots of tropical areas as well as for improving seed security for farmers.
43
Stadtlander, T., A. Stamer, A. Buser, J. Wohlfahrt, F. Leiber et C. Sandrock. « Hermetia illucens meal as fish meal replacement for rainbow trout on farm ». Journal of Insects as Food and Feed 3, no 3 (septembre 2017) : 165–75. http://dx.doi.org/10.3920/jiff2016.0056.
Texte intégralRésumé :
In a 7-week on-farm feeding trial rainbow trout (Oncorhynchus mykiss) were provided with a diet containing 28% mechanically de-fatted insect meal prepared from larvae of the black soldier fly, Hermetia illucens (HIM) and compared to a control that received a certified organic and fishmeal based diet. In the test diet insect meal replaced almost 50% of the fishmeal. The whole experiment was conducted under practical conditions on an organically certified rainbow trout farm in Switzerland. Fish of initially 66.5±2.3 g body weight were grown to 125±4.5 g and assessed for their growth performance, as well as analysed for their proximate composition, feed conversion ratio, fatty acid contents and organoleptic properties. Improved lipid utilisation and decreased protein utilisation were observed in fish fed the HIM diet. Furthermore, in a controlled degustation no differences except a slightly darker coloration of fish fed HIM were observed. The experiment demonstrated that substantial replacement of fishmeal by insect meal is possible without compromising growth, feed conversion and product quality. However, the decreased protein utilisation efficiency in HIM fed fish might lower production efficiency when applied over a whole production cycle and not only over 7 weeks.
44
SCHMIEDEN, HARTMUT. « THE BGO-OPENDIPOLE SETUP AT ELSA ». International Journal of Modern Physics E 19, no 05n06 (juin 2010) : 1043–54. http://dx.doi.org/10.1142/s0218301310015485.
Texte intégralRésumé :
At the electron accelerator facility ELSA of the University of Bonn presently the new BGO-OpenDipole experiment is being setup. It is optimized for meson photoproduction final states of mixed charges. The detector combines hermetic coverage for photon detection through the BGO ball of the former GRAAL experiment with high resolution detection of forward going charged particles in the Open Dipole spectrometer. This setup is well suited for many different channels, including pseudoscalar, vectormeson and associated strangeness photoproduction. This contribution highlights the strangeness channels associated with the Λ and Σ ground states and the Λ(1405) excited state.
45
Janssen, Niek. « A Gemstone of Many Complexions ». Mnemosyne 68, no 6 (4 décembre 2015) : 956–74. http://dx.doi.org/10.1163/1568525x-12341763.
Texte intégralRésumé :
The Orphic Lithica is often considered an incoherent hodge-podge of teachings on magical stones. This paper, however, argues that the polyphony of voices (human, semi-divine, and divine), as well as the amalgam of various subtypes of the hexametric super-genre (didactic epic, narrative epic, bucolic, hymn, oracle), contribute to the ultimate goal of the Lithica: to overwhelm the reader with authorities for the hermetic truth that the poem preaches. The poem further accomplishes this by appealing to the poetic tradition, so as to make the subject matter more recognizable and enjoyable to the audience.
46
Sevekar, Shrirang, Poonam Shingare, Vivek Jogani, Mihir Jha et Sonal D. Patil. « Pediatric Obturating Materials And Techniques ». Journal of Contemporary Dentistry 1, no 2 (2011) : 27–32. http://dx.doi.org/10.5005/jcd-1-2-27.
Texte intégralRésumé :
Abstract Pulp therapy helps in preserving a pulpally involved primary tooth by eliminating bacteria and their products and ensures hermetic seal of the root canals so that the primary tooth can complete its function without harming the successor or affecting the health of the patient. A thorough understanding of the pulp morphology and root formation and resorption in primary teeth as well as different materials and techniques used is imperative for a successful pulp therapy. One of the major areas of continued research is in the area of finding obturating materials to suit the specific properties of these teeth. This article seeks to present a review of the major obturating materials and techniques with their modifications as well as their advantages and disadvantages.
47
Maniglia, Anthony J., Wen H. Ko, Mary Rosenbaum, Wei-Lin Zhu, John Werning, Robert Belser, Paul Drago, Ted Falk et William Frenz. « A Contactless Electromagnetic Implantable Middle Ear Device for Sensorineural Hearing Loss ». Ear, Nose & ; Throat Journal 73, no 2 (février 1994) : 78–90. http://dx.doi.org/10.1177/014556139407300206.
Texte intégralRésumé :
Following basic science experiments, improvement of precision micromechanics and electronics design, and development of different prototypes, a contactless electromagnetic hearing device has been successfully implanted in cats (acute experiments). Chronic animal experiments using the cat as well as the rabbit are ongoing to test the components of the device. A highly efficient air core coil is used to vibrate a neodymium-iron-boron magnet cemented to the body of the incus. The parts of the system, including implanted electronics (hybrid circuit, solid state), are laser welded and hermetically sealed. The system allows for the generation of enough force which vibrates the magnet implanted on the incus. It would be suitable for the treatment of moderate to severe sensorineural hearing loss.
48
Jensen, R. A., et A. M. Agnone. « A New Method to Leak Test Piping Joints ». Journal of Manufacturing Science and Engineering 118, no 4 (1 novembre 1996) : 604–9. http://dx.doi.org/10.1115/1.2831073.
Texte intégralRésumé :
A new device to leak test piping joints is described. The test is done external to the unpressurized pipe while the joints are easily accessible. Typically it would be done before burial of the pipe and completion of the entire system. It is adaptable to metal or plastic piping systems and a variety of joint types. The device was tested on butt fusion welds in polyethylene piping, a type of pipe commonly used in the distribution systems of natural gas utilities. Test results show that the device is as reliable as a standard soap bubble test, or a pressure test, both of which require the system to be hermetically sealed and pressurized. A trained mechanic can do this test in the field in about 20 minutes.
49
Keefer, Michael H. « Agrippa's Dilemma : Hermetic “Rebirth” and the Ambivalences of De vanitate and De occulta philosophia* ». Renaissance Quarterly 41, no 4 (1988) : 614–53. http://dx.doi.org/10.2307/2861884.
Texte intégralRésumé :
When in 1625 Gabriel Naudé wished to clear the name of Cornelius Agrippa (1486-1535) from the pious slanders of the demonologists of the intervening century, he argued that this learned man, “who was not only a new Trismegistus in the three higher faculties of Theology, Law, and Medicine, but who desired to travel in body through every part of Europe, and to exercise his mind on all sciences and disciplines,” deserved better than to be abused with stories “which would be much more appropriate in the magical tales of Merlin, Maugis, and of Doctor Faust, than in writings which are (or rather should be) serious and well-examined… . “ Naudé's words provide an accurate anticipation of the three principal reasons for the interest of modern scholars in the writings of this enigmatic humanist and magician.
50
Mahmood, Saleha, Christian Zurbrügg, Amtul Bari Tabinda, Azhar Ali et Adil Ashraf. « Sustainable Waste Management at Household Level with Black Soldier Fly Larvae (Hermetia illucens) ». Sustainability 13, no 17 (30 août 2021) : 9722. http://dx.doi.org/10.3390/su13179722.
Texte intégralRésumé :
Waste management service is inefficient in peri-urban and rural areas where biowaste is a major component of the household waste produced. Biowaste recycling using black soldier fly larvae (BSFL) at source can reduce the burden on the authorities and add economic value to a yet underutilized resource. This study evaluated the practicability of BSFL bin use at the household level to handle kitchen biowaste by placing three bins per house after 15 days interval of larval feeding. It was found that 50% of the households contacted cooperated well to continue the experiment. A set of instructions for handling BSFL bins based on reasons of agreement and disagreement was developed and shared. Key parameters to evaluate waste treatment performance and larval development were waste dry matter weight reduction (89.66%, SD 6.77%), volumetric reduction (81.3%, SD 4.8), final prepupal dry weight (69 mg/larvae, SD 7.1), biomass conversion rate (12.9%, SD 1.7), metabolism (77.3%, SD 6.0) and residue (10.4%, SD 6.8). On average, 87.7% (SD 9.1) of waste was actually digested, with 16.6% (SD 2.2) efficiently converted into biomass. Initial moisture content of waste was found to be more significant for achieving greater waste dry weight reduction as compared with the feeding rate. Source separation of biowaste and cooperation between households and authorities may lead to successful implementation of BSFL-assisted biowaste bins.