7,352 research outputs found

    Shuttle car loading system

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    A system is described for loading newly mined material such as coal, into a shuttle car, at a location near the mine face where there is only a limited height available for a loading system. The system includes a storage bin having several telescoping bin sections and a shuttle car having a bottom wall that can move under the bin. With the bin in an extended position and filled with coal the bin sections can be telescoped to allow the coal to drop out of the bin sections and into the shuttle car, to quickly load the car. The bin sections can then be extended, so they can be slowly filled with more while waiting another shuttle car

    Energy absorbing system for mechanical impacts

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    System is described based on use of arrangement of crushable hollow spheres bonded together in layers of progressively different diameter, with largest diameter spheres positioned to receive impact forces initially. System is particularly useful for delivery of payloads by air-drop techniques

    Active hold-down for heat treating

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    The object of the disclosure is to provide a vacuum hold-down for holding thin sheets to a support surface, which permits the thin sheet to change dimensions as it is held down. The hold-down includes numerous holes in the support surface, through which a vacuum is applied from a vacuum source. The holes are arranged in zones. The vacuum is repeatedly interrupted at only one or a few zones, while it continues to be applied to other zones, to allow the workpiece to creep along that interrupted zone. The vacuum to different zones is interrupted at different times, as by a slowly turning valve number, to allow each zone of the workpiece to creep. A positive pressure may be applied from a pressured air source to a zone when the vacuum is interrupted there, to help lift the corresponding workpiece zone off the surface to aid in creeping. The workpiece may undergo dimensional changes because of heating, cooling, drying, or other procedure

    Automated parking garage system model

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    A one-twenty-fifth scale model of the key components of an automated parking garage system is described. The design of the model required transferring a vehicle from an entry level, vertically (+Z, -Z), to a storage location at any one of four storage positions (+X, -X, +Y, +Y, -Y) on the storage levels. There are three primary subsystems: (1) a screw jack to provide the vertical motion of the elevator, (2) a cam-driven track-switching device to provide X to Y motion, and (3) a transfer cart to provide horizontal travel and a small amount to vertical motion for transfer to the storage location. Motive power is provided by dc permanent magnet gear motors, one each for the elevator and track switching device and two for the transfer cart drive system (one driving the cart horizontally and the other providing the vertical transfer). The control system, through the use of a microprocessor, provides complete automation through a feedback system which utilizes sensing devices

    Part I. A Novel Synthesis of Dihydrojasmone. Part II. Polymethyleneketenedimers and Trimers.

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    Part I. A Novel Synthesis of Dihydrojasmone. — 3-Methylcyclopent-2-en-2-ol-l-one, a readily available substance of natural occurrence, was utilized in the synthesis of the well-known dihydrojasmone (2-n-aniyl-3-methylcyclopent-2-en-l-one). This was the first practical synthesis of dihydroJasmone which did not involve a condensation reaction, thus the possibility of obtaining an isomeric mixture of products was eliminated. Acetylation of 3-methylcyclopent-2-en-2-ol-l-one with acetic anhydride gave 2-acetoxy-3-methylcyclopent-2-en-l-one, which was converted by the action of propylene oxide to 2-acetoxy-3-methylcyclopent-2-en-l-one propylene ketal. Saponification of this ketal gave 3- methyl-l,2-cyclopentanedione-l,l-propylene ketal, which served as a precursor to dihydrojasmone. Upon treatment of this compound with n-amylmagnesium chloride, followed by hydrolysis with ammonium chloride solution, 2-n-amyl-3-methylcyclopentan-2-ol-l-one propylene ketal was obtained. Dehydration and deketalization of the latter compound with sulfuric acid solution yielded dihydrojasmone. Part II. Polymethyleneketene Dimers and Trimers. — An excellent method for the preparation of ketoketene dimers involves the dehydrohalogenation of an acyl chloride with triethylamine. The reaction of cyclopropanecarbonyl chloride with triethylamine gave no dimer but instead a solid product, presumably the acyl ammonium chloride, which reacted with aniline to form cyclopropanecarboxanilide. Cyclobutanecarbonyl chloride and triethylamine yielded at temperatures below 25® a similar addition compound which gave cyclobutanecarboxanilide when treated with aniline. When the latter reaction was carried out at a higher temperature, dispiro [3.1.3.1] decane-5,10-dione was obtained. Dispiro [3.1.3.1] decane-5,10-dione, trimethyleneketene dimer, underwent cleavage and decarboxylation in alkali to give dicyclobutyl ketone. The ketone was obtained without acidification of the alkaline solution, which is generally necessary for the decarboxylation of a β-keto acid in the form of its sodium salt. A mechanism was proposed for its formation. Trimethyleneketene dimer reacted with ethanol in the presence of a catalytic amount of base to give ethyl l- (cyclobutanecarbonyl)cyclobutanecarboxylate, and was reduced to the corresponding glycol, dispiro [3.1.3.1] decane-5,10-diol with lithium aluminum hydride. It is known that dimethylketene dimer, tetramethyl-l,3-cyclobutanedione, when treated with a catalytic amount of sodium methoxide, yields the cyclic trimer, hexamethyl-l,3,5-cyclohexanetrione. In the present investigation, this base-catalyzed process was utilized in the synthesis of trimethyleneketene trimer, trispiro [3.1.3.1.3.1] pentadecane-5,10,15-trione, from trimethyleneketene dimer. In this study it was found that the alkaline hydrolysis of dimethylketene trimer with barium hydroxide gave 2,4,4,6-tetramethylheptan-3,5-dione. Trimethyleneketene trimer, upon treatment with the same reagent gave l, l (dicyclobutanecarb6nyl) cyclobutane and dicyclobutyl ketone. Ethanolysis of trimethyleneketene trimer gave ethyl 1-[1-(cyclobutanecarbonyl)cyclobutanecarbonyl] cyclobutanecarboxylate. Reduction of the trimer was accomplished with lithium aluminum hydride to give trispiro [3.1.3.1.3.1] pentadecane-5,10,15- triol. Tetramethyleneketene dimer, dispiro [4.1.4.1] dodecane-6,12-dione, a known compound, was the only product isolated in an attempted synthesis of tetramethyleneketene monomer by dehydrohalogenation of cyclopentanecarbonyl chloride with triethylamine. The dimer underwent cleavage and decarboxylation when treated with alkali to give dicyclopentyl ketone. Only one polymethylene ketene, pentamethyleneketene, has been reported in the literature. It was found that hexamethyleneketene could be synthesized by dehydrohalogenation of cycloheptanecarbonyl chloride with triethylamine. This monomer reacted with aniline to give cycloheptanecarboxanilide, and gave with cyclopentadiene a cycloaddition product, hexamethylenebicyclo [3.2.0] hept-3-en-l-one. Hexamethyleneketene dimerized upon standing to give dispiro- [6.1.6.1] hexadecane-8, l6-dione which underwent reduction with lithium aluminum hydride to give the corresponding glycol, dispiro [6.1.6.1] hexadecane-8,l6- triol

    Diamond Jenness (1886-1969)

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    Canada's most distinguished anthropologist, Dr. Diamond Jenness, formerly Chief of the Division of Anthropology, National Museums of Canada, and Honorary Associate of the Arctic Institute of North America, died peacefully at his home in the Gatineau Hills near Ottawa on 29 November, 1969. He was one of that rapidly-vanishing, virtually extinct kind - the all round anthropologist, who, working seriously, turned out first-class publications in all four major branches of the discipline: ethnology, linguistics, archaeology, and physical anthropology. One must also add a fifth: applied anthropology, a fitting designation for the series of monographs on Eskimo administration in Alaska, Canada, and Greenland which he wrote after his retirement and which were published by the Arctic Institute of North America. ... [In response to an invitation to join Stefansson Arctic Expedition and study Eskimos for three years, Jenness found himself a member of the Southern Party with an assignment to study the Copper Eskimos around Coronation Gulf. These plans were interrupted due to the presence of sea ice.] On 30 September, Stefansson, with his secretary Burt McConnell, Jenness, two Eskimos, and the expedition's photographer G.H. Wilkins (later Sir Hubert Wilkins), left the Karluk near the mouth of the Colville River to hunt caribou and lay in a supply of fresh meat when it had become apparent that the ship, immobilized in the ice, could proceed no further. With two sleds, twelve dogs and food for twelve days the party set out for the mainland, but they never saw the Karluk again, for a week or so later the unfortunate vessel began her final drift westward. This was the inauspicious beginning of Jenness' arctic career. Few young anthropologists have faced such difficulties in beginning field-work in a new and unfamiliar area; yet none, surely, has emerged from the test with a more brilliant record of work accomplished. ... Jenness' first winter's field-work on the Arctic coast of Alaska led to [an] impressive list of publications ... conducted under conditions that many an ethnographer would have found intolerable. ... Scarcely a hint of these personal experiences of his first winter in the Arctic will be found in Jenness' anthropological writings. They were reserved for his retrospective volume Dawn in Arctic Alaska (1957) which he wrote while on a Gugenheim scholarship in 1954, some years after his retirement. ... Jenness' first year in the Arctic ended in July 1914 when the Expedition's schooners left Camden Bay and sailed eastward to Dolphin and Union Strait where he was to meet with another though very different, Eskimo people named by Stefansson the Copper Eskimos, most of whom, before Stefansson worked among them in 1910-1911, had never seen a white man. ... To obtain a faithful picture of the life of the Copper Eskimos Jenness chose an approach that in those days was not often employed by ethnologists. He entered into their life directly, as one of them. He attached himself to an Eskimo family and became the adopted son of Ikpukhuak, one of the foremost hunters and respected leaders of the Puivlik tribe of southwest Victoria Island, and his wife Higilak (Ice House), who was not only proficient in the ordinary and burdensome duties of an Eskimo wife but was also a shaman in her own right, a talent that saved Jenness from a local murder charge. Jenness lived with these people in their snow houses in winter and skin tents in summer, observing and recording the vastly different modes of life according to season. ... Jenness' researches extended far beyond Coronation Gulf and the arctic coast westward. ... Jenness always disclaimed being an archaeologist, yet he made two discoveries that are fundamental to an understanding of Eskimo prehistory - discovery of the Dorset culture in the eastern Arctic, and of the Old Bering Sea, earliest stage of the maritime pattern of Eskimo culture that later spread from northern Alaska to Canada and Greenland to form the principal basis for modern Eskimo culture. ... And so much more. In 1926, Jenness succeeded Edward Sapir as Chief Anthropologist of the National Museum of Canada. ... He developed the Antiquities Legislation that has been so important for the protection of archaeological resources in the Northwest Territories. ... Between 1962 and 1968 the Arctic Institute of North America published his admirable five volumes on Eskimo administration in Alaska, Canada, and Greenland. These monographs reflect his durable and compassionate concern for Canadian Indians and Eskimos and in them one can find much of the advice that he, for so many decades, provided the Canadian Government. ... [Jenness' accomplishments extend beyond the realm of anthropology and his reputation was both national and international. For his services in the field of anthropology, particularly in connection with the Indian and Eskimo population of Canada, he was appointed a Companion of the Order of Canada.

    Electrostatically Tunable Meta-Atoms Integrated With In Situ Fabricated MEMS Cantilever Beam Arrays

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    Two concentric split ring resonators (SRRs) or meta-atoms designed to have a resonant frequency of 14 GHz are integrated with microelectromechanical systems cantilever arrays to enable electrostatic tuning of the resonant frequency. The entire structure was fabricated monolithically to improve scalability and minimize losses from externally wire-bonded components. A cantilever array was fabricated in the gap of both the inner and outer SRRs and consisted of five evenly spaced beams with lengths ranging from 300 to 400 ÎĽm. The cantilevers pulled in between 15 and 24 V depending on the beam geometry. Each pulled-in beam increased the SRR gap capacitance resulting in an overall 1-GHz shift of the measured meta-atom resonant frequency

    SRRs Embedded with MEMS Cantilevers to Enable Electrostatic Tuning of the Resonant Frequency

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    A microelectromechanical systems (MEMS) cantilever array was monolithically fabricated in the gap region of a split ring resonator (SRR) to enable electrostatic tuning of the resonant frequency. The design consisted of two concentric SRRs each with a set of cantilevers extending across the split region. The cantilever array consisted of five beams that varied in length from 300 to 400 μm, with each beam adding about 2 pF to the capacitance as it actuated. The entire structure was fabricated monolithically to reduce its size and minimize losses from externally wire bonded components. The beams actuate one at a time, longest to shortest with an applied voltage ranging from 30–60 V. The MEMS embedded SRRs displayed dual resonant frequencies at 7.3 and 14.2 GHz or 8.4 and 13.5 GHz depending on the design details. As the beams on the inner SRR actuated the 14.2 GHz resonance displayed tuning, while the cantilevers on the outer SRR tuned the 8.4 GHz resonance. The 14.2 GHz resonant frequency shifts 1.6 GHz to 12.6 GHz as all the cantilevers pulled-in. Only the first two beams on the outer cantilever array pulled-in, tuning the resonant frequency 0.4 GHz from 8.4 to 8.0 GHz

    Effect of non-nicotinic moist snuff replacement and lobeline on withdrawal symptoms during 48-h smokeless tobacco deprivation

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    The present study investigated the effects of two herbal components (BACCOFFTM and DIPSTOP ™) of a commercially available smokeless tobacco treatment program for reducing subjective withdrawal symptoms during deprivation. One component, BACCOFF™, is a non-nicotinic chew. The second component, DIPSTOP™, is a liquid containing the alkaloid lobeline, which to some extent mimics peripheral nicotinic effects. All participants (N = 22 males) were placed in four conditions: BACCOFF™ + DIPSTOP™, BACCOFF™ + placebo control, DIPSTOP™ only, and placebo control only. The conditions involved 48 h of deprivation, and subjects were exposed to one condition per week for 4 weeks. Withdrawal measures were taken at baseline, 24 h, and 48 h of deprivation. Individuals were randomly assigned, and conditions were counterbalanced. Results showed that BACCOFF™, as compared with DIPSTOP™, significantly reduced withdrawal symptoms but not craving. These data suggest that behavioral/sensory substitutes’ influence on withdrawal might be routed through the product’s ability to approximate the preferred moist snuff
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