Science.gov

Sample records for double wall houses

  1. 97. DAM OPERATING HOUSE WALL SECTION & MISCELLANEOUS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    97. DAM - OPERATING HOUSE - WALL SECTION & MISCELLANEOUS DETAIL (ML-8-41/2-FS) June 1935 - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 8, On Mississippi River near Houston County, MN, Genoa, Vernon County, WI

  2. 75. BUILDING NO. 555, AIR DRY HOUSE FOR DOUBLE BASE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    75. BUILDING NO. 555, AIR DRY HOUSE FOR DOUBLE BASE RIFLE AND CANNON POWDERS, INTERIOR OF DRYING ROOM NO. 2, SHOWING COPPER EXHAUST VENT DUCT IN CORNER, HOT AIR INLET VENT IN CEILING. TWO TYPICAL DRYING RACKS LEANING AGAINST WALL, BOTTOM SIDE SHOWING ON LEFT RACK, TOP SIDE ON RIGHT RACK. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  3. 5. Transmission wheel on southeast wall of Oil House. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Transmission wheel on southeast wall of Oil House. - Delaware, Lackawanna & Western Railroad, Scranton Yards, Oil House, 650 feet Southeast of Cliff & Mechanic Streets, Scranton, Lackawanna County, PA

  4. Detail of west wall of south wing of commandant's house ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of west wall of south wing of commandant's house with scale Fort Simcoe commandant's house & blockhouse - Fort Simcoe, Commandant's House & Blockhouse, Fort Simcoe Road, White Swan, Yakima County, WA

  5. 5. South wall of Gas House showing connection to bridge. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. South wall of Gas House showing connection to bridge. - Delaware, Lackawanna & Western Railroad, Scranton Yards, Gas House, 100 block of South Washington Avenue, west side, Scranton, Lackawanna County, PA

  6. 7. BASEMENT, REAR WALL OF FRONT HOUSE, DETAIL SHOWING MARBLE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. BASEMENT, REAR WALL OF FRONT HOUSE, DETAIL SHOWING MARBLE SILL AND HEADED JAMB OF FORMER BASEMENT WINDOW. Photo by Theodore F. Dillon, August 1960 - Captain James Abercrombie House, 268-270 South Second Street, Philadelphia, Philadelphia County, PA

  7. TENANT HOUSE INTERIOR, LIVING ROOM, SOUTH AND EAST WALLS, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    TENANT HOUSE INTERIOR, LIVING ROOM, SOUTH AND EAST WALLS, LOOKING SOUTHEAST FROM CENTER OF ROOM - Irvine Ranch Agricultural Headquarters, Carillo Tenant House, Southwest of Intersection of San Diego & Santa Ana Freeways, Irvine, Orange County, CA

  8. TENANT HOUSE INTERIOR, KITCHEN, SOUTH AND EAST WALLS, LOOKING SOUTHEAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    TENANT HOUSE INTERIOR, KITCHEN, SOUTH AND EAST WALLS, LOOKING SOUTHEAST FROM CENTER OF ROOM - Irvine Ranch Agricultural Headquarters, Carillo Tenant House, Southwest of Intersection of San Diego & Santa Ana Freeways, Irvine, Orange County, CA

  9. TENANT HOUSE INTERIOR, LIVING ROOM, NORTH AND EAST WALLS, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    TENANT HOUSE INTERIOR, LIVING ROOM, NORTH AND EAST WALLS, LOOKING NORTH FROM CENTER OF ROOM - Irvine Ranch Agricultural Headquarters, Carillo Tenant House, Southwest of Intersection of San Diego & Santa Ana Freeways, Irvine, Orange County, CA

  10. TENANT HOUSE INTERIOR, KITCHEN, NORTH AND EAST WALLS, LOOKING NORTHEAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    TENANT HOUSE INTERIOR, KITCHEN, NORTH AND EAST WALLS, LOOKING NORTHEAST FROM CENTER OF ROOM - Irvine Ranch Agricultural Headquarters, Carillo Tenant House, Southwest of Intersection of San Diego & Santa Ana Freeways, Irvine, Orange County, CA

  11. Detail; Street Car Waiting House window, north wall North ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail; Street Car Waiting House window, north wall - North Philadelphia Station, Street Car Waiting House, 2900 North Broad Street, on northwest corner of Broad Street & Glenwood Avenue, Philadelphia, Philadelphia County, PA

  12. 65. INTERIOR OF 1902 GENERATOR HOUSE. BASEMENT WALL OF 1901 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    65. INTERIOR OF 1902 GENERATOR HOUSE. BASEMENT WALL OF 1901 STEAM ENGINE HOUSE VISIBLE AT REAR. BASEMENT WALL OF 1873 WING AT RIGHT. OPENINGS MADE FOR MECHANICALLY TRANSMITTING POWER FROM STEAM ENGINES TO GENERATORS HAVE BEEN BRICKED UP. - Boston Manufacturing Company, 144-190 Moody Street, Waltham, Middlesex County, MA

  13. Looking east at the west wall of the boiler house, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Looking east at the west wall of the boiler house, boiler water treatment tank, and waste gas stack. Water tower is to the left of the boiler house. - Wheeling-Pittsburgh Steel Corporation, Allenport Works, Boiler House, Route 88 on West bank of Monongahela River, Allenport, Washington County, PA

  14. Double-wall tubing for oil recovery

    NASA Technical Reports Server (NTRS)

    Back, L. H.; Carroll, W. F.; Jaffee, L. D.; Stimpson, L. D.

    1980-01-01

    Insulated double-wall tubing designed for steam injection oil recovery makes process more economical and allows deeper extension of wells. Higher quality wet steam is delivered through tubing to oil deposits with significant reductions in heat loss to surrounding rock allowing greater exploitation of previously unworkable reservoirs.

  15. Double-wall tubing for oil recovery

    NASA Technical Reports Server (NTRS)

    Back, L. H.; Carroll, W. F.; Jaffee, L. D.; Stimpson, L. D.

    1980-01-01

    Insulated double-wall tubing designed for steam injection oil recovery makes process more economical and allows deeper extension of wells. Higher quality wet steam is delivered through tubing to oil deposits with significant reductions in heat loss to surrounding rock allowing greater exploitation of previously unworkable reservoirs.

  16. 9. Dairy barn and milk house yard wall, detail of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Dairy barn and milk house yard wall, detail of construction near southeast corner - A. I. Du Pont Estate, Blue Ball Dairy Barn, Junction of U.S. Route 202 & Rockland Road, Wilmington, New Castle County, DE

  17. 6. TERRACED, STONE RETAINING WALLS BEHIND HOUSE No. 16. VIEW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. TERRACED, STONE RETAINING WALLS BEHIND HOUSE No. 16. VIEW TO WEST. - Rainbow Hydroelectric Facility, On north bank of Missouri River 2 miles Northeast of Great Falls, & end of Rainbow Dam Road, Great Falls, Cascade County, MT

  18. 8. Detail of rebuilt east wall of brick engine house ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Detail of rebuilt east wall of brick engine house spanning raceway; view to southwest. - Champion-International Paper Company, Paper Machine Building, West bank of Spicket River at Canal Street, Lawrence, Essex County, MA

  19. 3. WALL PAPER MILL, POWER HOUSE, AND MERCHANDISE BUILDING IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. WALL PAPER MILL, POWER HOUSE, AND MERCHANDISE BUILDING IN DISTANCE, PRINTING AND ADVERTISING BUILDING, AND ALLSTATE BUILDING, VIEW TO NORTHWEST - Sears Roebuck & Company Mail Order Plant, Bounded by Lexington & Grenshaw Streets, Kedzie Avenue & Independence Boulevard, Chicago, Cook County, IL

  20. 5. View of Julia Steele House, south gable end wall ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. View of Julia Steele House, south gable end wall and front (east) facade, looking to northwest. - Julia Steele House, 5875 Paris Road (US Highway 27/68); 1 1/5 miles north of Bourbon County line, Paris, Bourbon County, KY

  1. 57. Photocopied August 1978. POWER HOUSE MASONRY WALLS, NORTH FRONT, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    57. Photocopied August 1978. POWER HOUSE MASONRY WALLS, NORTH FRONT, JULY 26, 1901. THE COMPLETED TAIL RACE EXITS ARE JUST BELOW THE RISING MASONRY WALL. THE COFFER DAM IS ON THE EXTREME RIGHT HAND PORTION OF THE PHOTOGRAPH. (161) - Michigan Lake Superior Power Company, Portage Street, Sault Ste. Marie, Chippewa County, MI

  2. Monitoring of Double Stud Wall Moisture Conditions in the Northeast

    SciTech Connect

    Ueno, K.

    2015-03-01

    Double-stud walls insulated with cellulose or low-density spray foam can have R-values of 40 or higher. However, double stud walls have a higher risk of interior-sourced condensation moisture damage, when compared with high-R approaches using exterior insulating sheathing.; Moisture conditions in double stud walls were monitored in Zone 5A (Massachusetts); three double stud assemblies were compared.

  3. Method for limiting heat flux in double-wall tubes

    DOEpatents

    Hwang, Jaw-Yeu

    1982-01-01

    A method of limiting the heat flux in a portion of double-wall tubes including heat treating the tubes so that the walls separate when subjected to high heat flux and supplying an inert gas mixture to the gap at the interface of the double-wall tubes.

  4. 13. INTERIOR OF DOUBLE ENGINE BLOWER. IN BLOWER HOUSE, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. INTERIOR OF DOUBLE ENGINE BLOWER. IN BLOWER HOUSE, LOOKING WEST. FANS MADE BY THE BUCKEY BLOWER COMPANY OF COLUMBUS, OHIO. - Jenkins Brick Company, Plant No. 2, Furnace Street, Montgomery, Montgomery County, AL

  5. VIEW SOUTHEAST, ECCENTRIC HOUSE, INTERIOR, NOTE DOUBLE OVER MOUNTED ECCENTRICS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW SOUTHEAST, ECCENTRIC HOUSE, INTERIOR, NOTE DOUBLE OVER MOUNTED ECCENTRICS WITH ATTACHED ROD LINES ON GEAR ASSEMBLY. - South Penn Oil Company, G. M. Mead Lot 492 Lease, Morrison Run Field, Clarendon, Warren County, PA

  6. 73. BUILDING NO. 555, AIR DRY HOUSE FOR DOUBLE BASE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    73. BUILDING NO. 555, AIR DRY HOUSE FOR DOUBLE BASE RIFLE AND CANNON POWDERS, NORTHEAST ELEVATION, EACH COOPER ELBOW VENT ON THE ROOF COMES FROM A DRYING ROOM. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  7. 69. 1911 BOILER HOUSE LOOKING SOUTH SOUTHEAST. EAST WALL AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    69. 1911 BOILER HOUSE LOOKING SOUTH SOUTHEAST. EAST WALL AT LEFT HAS WINDOWS BRICKED UP, PRESUMABLY BECAUSE GLASS WAS TOO VULNERABLE TO VANDALISM ON SIDE ADJACENT TO RAILWAY TRESTLE. - Boston Manufacturing Company, 144-190 Moody Street, Waltham, Middlesex County, MA

  8. 8. South wall and east front of engine house section ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. South wall and east front of engine house section of roundhouse. Top of machine shop section of roundhouse in background at left. View to northwest. - Duluth & Iron Range Rail Road Company Shops, Roundhouse, Southwest of downtown Two Harbors, northwest of Agate Bay, Two Harbors, Lake County, MN

  9. Localization of matter and fermion resonances on double walls

    NASA Astrophysics Data System (ADS)

    Liang, Jun; Duan, Yi-Shi

    2009-10-01

    We investigate the possibility of localizing various matter fields on the double walls. For spin 0 scalar field, massless zero mode can be normalized on the double walls. However, for spin 1 vector field, the zero mode is not localized on the double walls. In the paper [C.A.S. Almeida, M.M. Ferreira Jr., A.R. Gomes, R. Casana, arxiv:arXiv:0901.3543 [hep-th

  10. Double-walled carbon nanotube solar cells.

    PubMed

    Wei, Jinquan; Jia, Yi; Shu, Qinke; Gu, Zhiyi; Wang, Kunlin; Zhuang, Daming; Zhang, Gong; Wang, Zhicheng; Luo, Jianbin; Cao, Anyuan; Wu, Dehai

    2007-08-01

    We directly configured double-walled carbon nanotubes as energy conversion materials to fabricate thin-film solar cells, with nanotubes serving as both photogeneration sites and a charge carriers collecting/transport layer. The solar cells consist of a semitransparent thin film of nanotubes conformally coated on a n-type crystalline silicon substrate to create high-density p-n heterojunctions between nanotubes and n-Si to favor charge separation and extract electrons (through n-Si) and holes (through nanotubes). Initial tests have shown a power conversion efficiency of >1%, proving that DWNTs-on-Si is a potentially suitable configuration for making solar cells. Our devices are distinct from previously reported organic solar cells based on blends of polymers and nanomaterials, where conjugate polymers generate excitons and nanotubes only serve as a transport path.

  11. Technology Solutions Case Study: Monitoring of Double Stud Wall Moisture Conditions in the Northeast, Devens, Massachusetts

    SciTech Connect

    2015-03-01

    Double stud walls have a higher risk of interior-sourced condensation moisture damage when compared with high-R approaches using exterior insulating sheathing. In this project, Building Science Corporation monitored moisture conditions in double-stud walls from 2011 through 2014 at a new production house located in Devens, Massachusetts. The builder, Transformations, Inc., has been using double-stud walls insulated with 12 in. of open cell polyurethane spray foam (ocSPF); however, the company has been considering a change to netted and blown cellulose insulation for cost reasons. Cellulose is a common choice for double-stud walls because of its lower cost (in most markets). However, cellulose is an air-permeable insulation, unlike spray foams, which increases interior moisture risks. The team compared three double-stud assemblies: 12 in. of ocSPF, 12 in. of cellulose, and 5-½ in. of ocSPF at the exterior of a double-stud wall (to approximate conventional 2 × 6 wall construction and insulation levels, acting as a control wall). These assemblies were repeated on the north and south orientations, for a total of six assemblies.

  12. Energetics and electronic structure of double-walled boron nanotubes

    NASA Astrophysics Data System (ADS)

    Tang, Hui; Ismail-Beigi, Sohrab

    2010-03-01

    Single-walled boron nanotubes have been studied extensively since their first successful fabrication in experiments. On the other hand, double-walled or multi-walled boron nanotubes have not yet been discussed in literature. Here, using density functional theory, we present a stable semiconducting two-dimensional double-layered boron sheet, which is 0.14 eV/atom more stable than the most stable single-layered α-sheet [1]. This double-layered sheet is stabilized due to the formation of inter-layer bonds. We show that double-walled boron nanotubes made from this double-layered sheet are all semiconducting. These double-walled nanotubes are more stable than single-walled ones for large nanotubes, but become less energetically favorable when the tube radius is smaller than 20 å due to their large curvature energies. To reduce the large curvature energies, we construct double-walled nanotubes whose inner and outer walls have different number of atoms around their circumference. The resulting nanotubes are more stable than single-walled ones for all radii.[4pt] [1] H. Tang, and S. Ismail-Beigi, PRL 99, 115501 (2007).

  13. Tailoring double-wall carbon nanotubes?

    NASA Astrophysics Data System (ADS)

    Sakurabayashi, Yasunori; Monthioux, Marc; Kishita, Keisuke; Suzuki, Yoshinao; Kondo, Takuya; Le Lay, Mikako

    2003-10-01

    Double-wall carbon nanotubes (DWNTs) are interesting nano-objects derived from single-wall nanotubes (SWNTs) whose potentiality for some applications (such as composite reinforcement) are even more promising than for SWNTs. Depending on the respective chirality of the inner and outer SWNTs involved, electronic properties may also vary, with subsequent possible applications in nanotechnology. Up to now, DWNTs were prepared either from catalytically-enhanced thermal cracking of gaseous hydrocarbons, electric arc, or thermal annealing of C60@SWNTs (peapods). A drawback of the former as opposed to the latter is that DWNTs hardly concern the whole nanotube production as far as they are always mixed with SWNTs and other MWNTs. Whatever, in any DWNT (or MWNT) from the literature so far, the graphene-graphene distance looks about equal to the d002-spacing in turbostratic, polyaromatic carbon, i.e., ˜0.34 nm. For peapod-derived DWNTs prepared from regular 1.35 nm wide SWNTs, for instance, it means that the inner diameter is ˜0.7 nm, i.e. that of the former contained C60 molecules before coalescence. We report here the unexpected experimental observation that the inter-tube distance and/or the inner tube diameter of DWNTs prepared from peapods by combining both electron irradiation and heating may possibly vary. This is likely to interestingly bring variations to the overall electronic properties of DWNTs. On the other hand, it would allow the preparation of SWNTs (the inner tube) with diameters narrower than 0.7 nm, for which no common route exists yet.

  14. Case study of the Mastin double-envelope house

    NASA Astrophysics Data System (ADS)

    Jones, R. F.; Dennehy, G.; Ghaffari, H. T.; Munson, G. E.

    1981-05-01

    An evaluation is made of a double-envelope house of Ekose, a design built by Robert Mastin in Middletown, Rhode Island. The home has two shells with an airspace between through which air can circulate. Performance monitoring of the house in the heating season showed that the requirements for auxiliary heat are very low, about 2.1 Btu per square foot of floor space per degree-day. Design changes are identified which could reduce the heating requirement even further. This ranks the house among the most energy-efficient building designs available today. It is concluded that the low heating needs of the house are due primarily to the excellent insulative value of the double shell.

  15. Elimination Behavior of Shelter Dogs Housed in Double Compartment Kennels

    PubMed Central

    Wagner, Denae; Newbury, Sandra; Kass, Philip; Hurley, Kate

    2014-01-01

    For animals in confinement housing the housing structure has tremendous potential to impact well being. Dogs in animal shelters are often housed in one of two types of confinement housing – single kennels and rooms or double compartment kennels and rooms most often separated by a guillotine door. This study examines the effect of housing on the location of elimination behavior in dogs housed in double compartment kennels were the majority of the dogs were walked daily. One side of the kennel contained the food, water and bed and the other side was empty and available except during cleaning time. Location of urination and defecation was observed daily for 579 dogs housed in indoor double compartment kennels for a total of 4440 days of observation. There were 1856 days (41.9%) when no elimination was noted in the kennel. Feces, urine or both were observed in the kennel on 2584 days (58.1%). When elimination occurred in the kennel the probability of fecal elimination on the opposite side of the bed/food/water was 72.5% (95% CI 69.05% to 75.69%). The probability of urination on the opposite side of the bed/food/water was 77.4% (95% CI 74.33% to 80.07%). This study demonstrates the strong preference of dogs to eliminate away from the area where they eat, drink and sleep. Double compartment housing not only allows this – it allows staff the ability to provide safe, efficient, humane daily care and confers the added benefits of reducing risks for disease transmission for the individual dog as well as the population. PMID:24825357

  16. Elimination behavior of shelter dogs housed in double compartment kennels.

    PubMed

    Wagner, Denae; Newbury, Sandra; Kass, Philip; Hurley, Kate

    2014-01-01

    For animals in confinement housing the housing structure has tremendous potential to impact well being. Dogs in animal shelters are often housed in one of two types of confinement housing - single kennels and rooms or double compartment kennels and rooms most often separated by a guillotine door. This study examines the effect of housing on the location of elimination behavior in dogs housed in double compartment kennels were the majority of the dogs were walked daily. One side of the kennel contained the food, water and bed and the other side was empty and available except during cleaning time. Location of urination and defecation was observed daily for 579 dogs housed in indoor double compartment kennels for a total of 4440 days of observation. There were 1856 days (41.9%) when no elimination was noted in the kennel. Feces, urine or both were observed in the kennel on 2584 days (58.1%). When elimination occurred in the kennel the probability of fecal elimination on the opposite side of the bed/food/water was 72.5% (95% CI 69.05% to 75.69%). The probability of urination on the opposite side of the bed/food/water was 77.4% (95% CI 74.33% to 80.07%). This study demonstrates the strong preference of dogs to eliminate away from the area where they eat, drink and sleep. Double compartment housing not only allows this - it allows staff the ability to provide safe, efficient, humane daily care and confers the added benefits of reducing risks for disease transmission for the individual dog as well as the population.

  17. 70. BUILDING NO. 555, AIR DRY HOUSE FOR DOUBLE BASE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    70. BUILDING NO. 555, AIR DRY HOUSE FOR DOUBLE BASE RIFLE AND CANNON POWDERS, LOOKING NORTH AT SOUTH CORNER. FAN ROOM WITH STEAM HEATER IN FOREGROUND RIGHT. COOPER ELBOW VENTS ON ROOF ARE FROM DRYING ROOMS. STEAM LINE IN FOREGROUND, POWDER WAS DRIED ON RACKS IN DRYING ROOMS VENTILATED WITH HOT AIR. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  18. 71. BUILDING NO. 555, AIR DRY HOUSE FOR DOUBLE BASE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    71. BUILDING NO. 555, AIR DRY HOUSE FOR DOUBLE BASE RIFLE AND CANNON POWDERS, LOOKING SOUTH AT NORTH CORNER, WITH DRAIN BOX FROM BUILDING FLOOR DRAIN IN FOREGROUND. TROUGH IS LEAD-LINED. BOX PRESUMABLY SETTLED OUT ANY NITRO-COTTON OR POWDER FROM WASTE WATER FROM RECOVERY PURPOSES. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  19. 72. BUILDING NO. 555, AIR DRY HOUSE FOR DOUBLE BASE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    72. BUILDING NO. 555, AIR DRY HOUSE FOR DOUBLE BASE RIFLE AND CANNON POWDERS, LOOKING SOUTHWEST AT NORTH CORNER. 3 FT. GUAGE RAILROAD TRACK IN FOREGROUND. WOODEN RAILS SUBSTITUTED FOR STEEL RAILS FOR TRACKS ENTERING BUILDING TO PREVENT SPARKING. EXPLOSION-PROOF LIGHTING MOUNTED ON BUILDING EXTERIOR. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  20. Detail of east wall showing double casement windows set into ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of east wall showing double casement windows set into arched recess, facing west. - Marine Barracks, Panama Canal, Officers' Quarters, 800' West of Bruja Road, Balboa, Former Panama Canal Zone, CZ

  1. Double wall vacuum tubing and method of manufacture

    DOEpatents

    Stahl, Charles R.; Gibson, Michael A.; Knudsen, Christian W.

    1989-01-01

    An evacuated double wall tubing is shown together with a method for the manufacture of such tubing which includes providing a first pipe of predetermined larger diameter and a second pipe having an O.D. substantially smaller than the I.D. of the first pipe. An evacuation opening is then in the first pipe. The second pipe is inserted inside the first pipe with an annular space therebetween. The pipes are welded together at one end. A stretching tool is secured to the other end of the second pipe after welding. The second pipe is then prestressed mechanically with the stretching tool an amount sufficient to prevent substantial buckling of the second pipe under normal operating conditions of the double wall pipe. The other ends of the first pipe and the prestressed second pipe are welded together, preferably by explosion welding, without the introduction of mechanical spacers between the pipes. The annulus between the pipes is evacuated through the evacuation opening, and the evacuation opening is finally sealed. The first pipe is preferably of steel and the second pipe is preferably of titanium. The pipes may be of a size and wall thickness sufficient for the double wall pipe to be structurally load bearing or may be of a size and wall thickness insufficient for the double wall pipe to be structurally load bearing, and the double wall pipe positioned with a sliding fit inside a third pipe of a load-bearing size.

  2. 74. BUILDING NO. 555, AIR DRY HOUSE FOR DOUBLE BASE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    74. BUILDING NO. 555, AIR DRY HOUSE FOR DOUBLE BASE RIFLE AND CANNON POWDERS, DETAIL OF WOODEN DRYING ROOM DOORS WITH WOODEN HINGES AND BOLTS FOR SPARK PREVENTION. RINGS BY DOORS TURN ON HOT AIR FLOW TO DRYING ROOMS. NOTE GROUNDING WIRE FROM RING BRACKETS. RECORDING MACHINES BY DOORS RECORD HUMIDITY IN DRYING ROOMS. DRYING ROOMS ILLUMINATED ONLY BY EXPLOSION-PROOF LIGHTING LOCATED OUTSIDE OF ROOMS. NOTE WOODEN RAILROAD RAILS IN BACKGROUND FOR 3 FT. GUAGE CARS. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  3. Double Mine Building (N) wall showing clerestory slot windows opening ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Double Mine Building (N) wall showing clerestory slot windows opening above level of main roof. Note structure is built on poured concrete foundation partly buried in hillside; view in southeast - Fort McKinley, Double Mine Building, East side of East Side Drive, approximately 125 feet south of Weymouth Way, Great Diamond Island, Portland, Cumberland County, ME

  4. Double Wall Framing Technique An Example of High Performance, Sustainable Building Envelope Technology

    SciTech Connect

    Kosny, Dr. Jan; Asiz, Andi; Shrestha, Som S; Biswas, Kaushik; Nitin, Shukla

    2015-01-01

    Double wall technologies utilizing wood framing have been well-known and used in North American buildings for decades. Most of double wall designs use only natural materials such as wood products, gypsum, and cellulose fiber insulation, being one of few building envelope technologies achieving high thermal performance without use of plastic foams or fiberglass. Today, after several material and structural design modifications, these technologies are considered as highly thermally efficient, sustainable option for new constructions and sometimes, for retrofit projects. Following earlier analysis performed for U.S. Department of Energy by Fraunhofer CSE, this paper discusses different ways to build double walls and to optimize their thermal performance to minimize the space conditioning energy consumption. Description of structural configuration alternatives and thermal performance analysis are presented as well. Laboratory tests to evaluate thermal properties of used insulation and whole wall system thermal performance are also discussed in this paper. Finally, the thermal loads generated in field conditions by double walls are discussed utilizing results from a joined project performed by Zero Energy Building Research Alliance and Oak Ridge National Laboratory (ORNL), which made possible evaluation of the market viability of low-energy homes built in the Tennessee Valley. Experimental data recorded in two of the test houses built during this field study is presented in this work.

  5. Leak location in a double wall tube steam generator. [LMFBR

    SciTech Connect

    Greene, D.A.; McMurtrie, K.R.; Gaubatz, D.C.

    1980-01-01

    An experimental and analytical study was made of an acoustic location system for use with double wall tube steam generators. A conceptual design of an acoustic leak location system was developed. This system has the potential for detecting the third fluid gas escaping from the annulus between the double walled tubes into the sodium. The acoustic system uses an array of accelerometers mounted onto the outside of the steam generator vessel. Electronic circuitry selects a number of accelerometers, forms them into an array which focuses within the vessel. The volume of the vessel is sequentially scanned for anomalous acoustic energy.

  6. Double-walled carbon nanotubes: Challenges and opportunities

    SciTech Connect

    Shen, C; Brozena, Alexandra H.; Wang, YuHuang

    2011-01-01

    Double-walled carbon nanotubes are coaxial nanostructures composed of exactly two single-walled carbon nanotubes, one nested in another. This unique structure offers advantages and opportunities for extending our knowledge and application of the carbon nanomaterials family. This review seeks to comprehensively discuss the synthesis, purification and characterization methods of this novel class of carbon nanomaterials. An emphasis is placed on the double wall physics that contributes to these structures’ complex inter-wall coupling of electronic and optical properties. The debate over the inner-tube photoluminescence provides an interesting illustration of the rich photophysics and challenges associated with the myriad combinations of the inner and outerwall chiralities. Outerwall selective covalent chemistry will be discussed as a potential solution to the unattractive tradeoff between solubility and functionality that has limited some applications of single-walled carbon nanotubes. Finally, we will review the many different uses of double-walled carbon nanotubes and provide an overview of several promising research directions in this new and emerging field.

  7. Double-walled carbon nanotubes: challenges and opportunities.

    PubMed

    Shen, Cai; Brozena, Alexandra H; Wang, YuHuang

    2011-02-01

    Double-walled carbon nanotubes are coaxial nanostructures composed of exactly two single-walled carbon nanotubes, one nested in another. This unique structure offers advantages and opportunities for extending our knowledge and application of the carbon nanomaterials family. This review seeks to comprehensively discuss the synthesis, purification and characterization methods of this novel class of carbon nanomaterials. An emphasis is placed on the double wall physics that contributes to these structures' complex inter-wall coupling of electronic and optical properties. The debate over the inner-tube photoluminescence provides an interesting illustration of the rich photophysics and challenges associated with the myriad combinations of the inner and outerwall chiralities. Outerwall selective covalent chemistry will be discussed as a potential solution to the unattractive tradeoff between solubility and functionality that has limited some applications of single-walled carbon nanotubes. Finally, we will review the many different uses of double-walled carbon nanotubes and provide an overview of several promising research directions in this new and emerging field.

  8. New Whole-House Solutions Case Study: Advanced Extended Plate and Beam Wall System in a Cold-Climate House

    SciTech Connect

    2016-02-10

    A zero energy ready home was recently completed that features an innovative wall system. This highly insulated (high-R) light-frame wall system, called the extended plate and beam, is for use above grade in residential buildings. The Building America research team Home Innovation Research Labs featured this system in a new construction test house.

  9. Ultrasonic probe for inspecting double-wall tube

    DOEpatents

    Cook, Kenneth V.; Cunningham, Jr., Robert A.; Murrin, Horace T.

    1983-01-01

    An ultrasonic probe for inspecting the interface between the walls of a double-wall tube comprises a cylindrical body member having two cavities axially spaced apart thereon. The probe is placed in the tube and ultrasonic energy is transmitted from a transducer in its body member to a reflector in one of its cavities and thence into the inner wall of the tube. A second transducer in the probe body member communicates with the second cavity through a collimation passage in the body member, and the amount of ultrasonic energy reflected from the interface between the walls of the tube to a second reflector through the collimation passage to the second transducer depends upon the characteristics of said interface.

  10. Ultrasonic probe for inspecting double-wall tube. [Patent application

    DOEpatents

    Cook, K.V.; Cunningham, R.A. Jr.; Murrin, H.T.

    1981-05-29

    An ultrasonic probe for inspecting the interface between the walls of a double-wall tube comprises a cylindrical body member having two cavities axially spaced apart thereon. The probe is placed in the tube and ultrasonic energy is transmitted from a transducer in its body member to a reflector in one of its cavities and thence into the inner wall of the tube. A second transducer in the probe body member communicates with the second cavity through a collimation passage in the body member, and the amount of ultrasonic energy reflected from the interface between the walls of the tube to a second reflector through the collimation passage to the second transducer depends upon the characteristics of said interface.

  11. Study of noise reduction characteristics of double-wall panels

    NASA Technical Reports Server (NTRS)

    Navaneethan, R.; Quayle, B.; Stevenson, S.; Graham, M.

    1983-01-01

    The noise reduction characteristics of general aviation type, flat, double-wall structures were investigated. The experimental study was carried out on 20-by-20 inch panels with an exposed area of 18 by 18 inches. A frequency range from 20 to 5000 Hz was covered. The experimental results, in general, follow the expected trends. At low frequencies the double-wall structures are no better than the single-wall structures. However, for depths normally used in the general aviation industry, the double-wall panels are very attractive. The graphite-spoxy skin panels have higher noise reduction at very low frequencies ( 100 Hz) than the Kevlar skin panels. But the aluminum panels have higher noise reduction in the high frequency region, due to their greater mass. Use of fiberglass insulation is not effective in the low frequency region, and at times it is even negative. But the insulation is effective in the high-frequency region. The theoretical model for predicting the transmission loss of these multilayered panels is also discussed.

  12. Behavioral response of Anopheles darlingi to DDT-sprayed house walls in Amazonia.

    PubMed

    Roberts, D R; Alecrim, W D

    1991-01-01

    The behavioral response of Anopheles darlingi females to spraying of house walls with DDT was studied along the Ituxi River in Amazonas, Brazil, using a house sprayed with 2 g DDT per square meter of wall surface and an untreated house serving as a control. It was found that hardly any An. darlingi females entered, exited, or took blood meals inside the treated house after it was sprayed with DDT, and that specimens marked and released inside the house tended to depart immediately. This behavior appears to constitute true repellency rather than contact irritability. Since the typical house in the vicinity of the study site had only two walls, the persistence of malaria in the local area was probably due to home construction practices.

  13. Sustainability of solid wall external insulation in existing UK housing

    NASA Astrophysics Data System (ADS)

    Eleni, Raskou

    2007-12-01

    additional replacement of the glazed areas with high performance double glazing increases the energy and cost savings to a total of 30% by preventing the heat losses through the significant amount of glazing area that part of the building has. However, the 69 years of payback period make the "Wall Reform" installation non viable, unless part of a general refurbishment project, even if it is considered a sustainable solution. Although the increase of the insulant's thickness will give more savings without proportional increase of the capital cost, social view around insulation expects the maximum thermal performance combined with the less visual impact and additional changes of the building's facade. The upgrade of the building envelope using external insulation leads to higher quality of life, achieves thermal comfort to the inside and enhances the external appearance of the building while it improves the social status of the occupants, contributing at the same time to the reduction of greenhouse gases emissions. The only discouraging for its use parameter is its low cost-effectiveness which is, however, the most critical factor for the final selection of an insulation system.

  14. Nanomaterial containing wall paints can increase radon concentration in houses located in radon prone areas.

    PubMed

    Haghani, M; Mortazavi, S M J; Faghihi, R; Mehdizadeh, S; Moradgholi, J; Darvish, L; Fathi-Pour, E; Ansari, L; Ghanbar-Pour, M R

    2013-09-01

    Nowadays, extensive technological advancements have made it possible to use nanopaints which show exciting properties. In IR Iran excessive radon levels (up to 3700 Bq m-3) have been reported in homes located in radon prone areas. Over the past decades, concerns have been raised about the risk posed by residential radon exposure. This study aims at investigating the effect of using nanomaterial containing wall paints on radon concentration in homes. Two wooden model houses were used in this study. Soil samples from Ramsar high background radiation areas were used for simulating the situation of a typical house in radon-prone areas. Conventional water-soluble wall paint was used for painting the walls of the 1st house model; while the 2nd house model was painted with the same wall paint with montmorillonitenanoclay. Three days after sealing the house models, radon level was measured by using a portable radon survey meter. The mean radon level inside the 1st house model (conventional paint) was 515.3 ± 17.8 Bq/m(3) while the mean radon concentration in the 2nd house model (nano-painted house model) was 570.8 ± 18.5 Bq/m(3). The difference between these means was statistically significant (P<0.001). To the best of our knowledge, this study is the first investigation on the effect of nano-material containing wall paints on indoor radon concentrations.  It can be concluded that nano-material-containing wall paints should not be used in houses with wooden walls located in radon prone areas. Although the mechanism of this effect is not clearly known, decreased porosity in nano-paints might be a key factor in increasing the radon concentration in homes.

  15. Nanomaterial Containing Wall Paints Can Increase Radon Concentration in Houses Located in Radon Prone Areas

    PubMed Central

    Haghani, M.; Mortazavi, S. M. J.; Faghihi, R.; Mehdizadeh, S.; Moradgholi, J.; Darvish, L.; Fathi-Pour, E.; Ansari, L.; Ghanbar-pour, M. R.

    2013-01-01

    Background: Nowadays, extensive technological advancements have made it possible to use nanopaints which show exciting properties. In IR Iran excessive radon levels (up to 3700 Bq m–3) have been reported in homes located in radon prone areas. Over the past decades, concerns have been raised about the risk posed by residential radon exposure. Objective: This study aims at investigating the effect of using nanomaterial containing wall paints on radon concentration in homes. Methods: Two wooden model houses were used in this study. Soil samples from Ramsar high background radiation areas were used for simulating the situation of a typical house in radon-prone areas. Conventional water-soluble wall paint was used for painting the walls of the 1st house model; while the 2nd house model was painted with the same wall paint with montmorillonitenanoclay. Results: Three days after sealing the house models, radon level was measured by using a portable radon survey meter. The mean radon level inside the 1st house model (conventional paint) was 515.3 ± 17.8 Bq/m3 while the mean radon concentration in the 2nd house model (nano-painted house model) was 570.8 ± 18.5 Bq/m3. The difference between these means was statistically significant (P<0.001). Conclusion: To the best of our knowledge, this study is the first investigation on the effect of nano-material containing wall paints on indoor radon concentrations.  It can be concluded that nano-material-containing wall paints should not be used in houses with wooden walls located in radon prone areas. Although the mechanism of this effect is not clearly known, decreased porosity in nano-paints might be a key factor in increasing the radon concentration in homes. PMID:25505754

  16. A possible formation mechanism of double-walled and multi-walled carbon nanotube: a molecular dynamics study

    NASA Astrophysics Data System (ADS)

    Han, Dianrong; Luo, Chenglin; Dai, Yafei; Zhu, Xingfeng

    2016-09-01

    Molecular dynamics simulations based on an empirical potential were performed to study the interaction of graphene nanoribbons and the single-walled carbon nanotubes. The results indicated that a piece of graphene nanoribbon can form a tube structure inside or outside single-walled carbon nanotubes spontaneously under certain condition. Based on this kind of spontaneous phenomenon, we proposed a new possible formation mechanism of double walled carbon nanotube and multi-walled carbon nanotube, and suggested the possibility of controlling the structure of double-walled carbon nanotube and/or multi-walled carbon nanotube.

  17. Magnetic domain wall induced ferroelectricity in double perovskites

    NASA Astrophysics Data System (ADS)

    Zhou, Hai Yang; Zhao, Hong Jian; Zhang, Wen Qing; Chen, Xiang Ming

    2015-04-01

    Recently, a magnetically induced ferroelectricity occurring at magnetic domain wall of double perovskite Lu2CoMnO6 has been reported experimentally. However, there exists a conflict whether the electric polarization is along b or c direction. Here, by first-principles calculations, we show that the magnetic domain wall (with ↑↑↓↓ spin configuration) can lead to the ferroelectric displacements of R3+, Ni2+, Mn4+, and O2- ions in double perovskites R2NiMnO6 (R = rare earth ion) via exchange striction. The resulted electric polarization is along b direction with the P21 symmetry. We further reveal the origin of the ferroelectric displacements as that: (1) on a structural point of view, such displacements make the two out-of-plane Ni-O-Mn bond angles as well as Ni-Mn distance unequal, and (2) on an energy point of view, such displacements weaken the out-of-plane Ni-Mn super-exchange interaction obviously. Finally, our calculations show that such a kind of ferroelectric order is general in ferromagnetic double perovskites.

  18. Magnetic domain wall induced ferroelectricity in double perovskites

    SciTech Connect

    Zhou, Hai Yang; Zhao, Hong Jian E-mail: xmchen59@zju.edu.cn; Chen, Xiang Ming E-mail: xmchen59@zju.edu.cn; Zhang, Wen Qing

    2015-04-13

    Recently, a magnetically induced ferroelectricity occurring at magnetic domain wall of double perovskite Lu{sub 2}CoMnO{sub 6} has been reported experimentally. However, there exists a conflict whether the electric polarization is along b or c direction. Here, by first-principles calculations, we show that the magnetic domain wall (with ↑↑↓↓ spin configuration) can lead to the ferroelectric displacements of R{sup 3+}, Ni{sup 2+}, Mn{sup 4+}, and O{sup 2−} ions in double perovskites R{sub 2}NiMnO{sub 6} (R = rare earth ion) via exchange striction. The resulted electric polarization is along b direction with the P2{sub 1} symmetry. We further reveal the origin of the ferroelectric displacements as that: (1) on a structural point of view, such displacements make the two out-of-plane Ni-O-Mn bond angles as well as Ni-Mn distance unequal, and (2) on an energy point of view, such displacements weaken the out-of-plane Ni-Mn super-exchange interaction obviously. Finally, our calculations show that such a kind of ferroelectric order is general in ferromagnetic double perovskites.

  19. Study of noise transmission through double wall aircraft windows

    NASA Technical Reports Server (NTRS)

    Vaicaitis, R.

    1983-01-01

    Analytical and experimental procedures were used to predict the noise transmitted through double wall windows into the cabin of a twin-engine G/A aircraft. The analytical model was applied to optimize cabin noise through parametric variation of the structural and acoustic parameters. The parametric study includes mass addition, increase in plexiglass thickness, decrease in window size, increase in window cavity depth, depressurization of the space between the two window plates, replacement of the air cavity with a transparent viscoelastic material, change in stiffness of the plexiglass material, and different absorptive materials for the interior walls of the cabin. It was found that increasing the exterior plexiglass thickness and/or decreasing the total window size could achieve the proper amount of noise reduction for this aircraft. The total added weight to the aircraft is then about 25 lbs.

  20. Intrinsic phonon properties of double-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Tran, H. N.; Levshov, D. I.; Nguyen, V. C.; Paillet, M.; Arenal, R.; Than, X. T.; Zahab, A. A.; Yuzyuk, Y. I.; Phan, N. M.; Sauvajol, J.-L.; Michel, T.

    2017-03-01

    Double-walled carbon nanotubes (DWNT) are made of two concentric and weakly van der Waals coupled single-walled carbon nanotubes (SWNT). DWNTs are the simplest systems for studying the mechanical and electronic interactions between concentric carbon layers. In this paper we review recent results concerning the intrinsic features of phonons of DWNTs obtained from Raman experiments performed on index-identified DWNTs. The effect of the interlayer distance on the strength of the mechanical and electronic coupling between the layers, and thus on the frequencies of the Raman-active modes, namely the radial breathing-like modes (RBLMs) and G-modes, are evidenced and discussed. Invited talk at 8th International Workshop on Advanced Materials Science and Nanotechnology (IWAMSN2016), 8–12 November 2016, Ha Long City, Vietnam.

  1. Monitoring of Double-Stud Wall Moisture Conditions in the Northeast

    SciTech Connect

    Ueno, K.

    2015-03-01

    Double-stud walls insulated with cellulose or low-density spray foam can have R-values of 40 or higher. However, double-stud walls have a higher risk of interior-sourced condensation moisture damage when compared with high-R approaches using exterior insulating sheathing. Moisture conditions in double-stud walls were monitored in Zone 5A (Massachusetts); three double-stud assemblies were compared.

  2. Stability of Double-Walled Carbon Nanotubes Revisited

    NASA Astrophysics Data System (ADS)

    Semenyuk, N. P.

    2016-01-01

    An approach to the stability analysis of orthotropic two-layer shells with mechanical and electrical properties of carbon nanotubes is proposed. Van der Waals forces act between the layers. The parameters of the continuum between the layers are obtained using the Lennard-Jones potential. The governing system of equations is written for rates of sixteen variables. The loading and boundary conditions are specified for each layer separately. Numerical results are obtained using the discrete orthogonalization method. The stability of single- and double-walled nanotubes is analyzed. Numerical results are summarized in tables and analyzed

  3. Thermodynamics and fluid dynamics of the double shell (envelope) house

    SciTech Connect

    Reno, V.

    1980-01-01

    The concepts of the envelope house are summarized and a systems approach to the house heat energy flows is presented. Some basic principles of physics in the area of thermodynamic conduction are discussed in relation to the envelope concept. (MHR)

  4. Bending instability characteristics of double-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Wang, Quan; Hu, Ting; Chen, Guanhua; Jiang, Qing

    2005-01-01

    The bending instability characteristics of double-walled carbon nanotubes (DWNTs) of various configurations are studied using a hybrid approach in which the deformation-induced increase of the intratube interaction energy is modeled with the bending deformation energy using the elastic theory of beams. The intertube interaction energy is calculated using the van der Waals interatomic potential. This study shows that the bending instability may take place through the formation of a single kink in the midpoint of a DWNT or two kinks, placed symmetrically about the midpoint, depending on both the tube length and diameter. The double-kink mode is more favorable for longer DWNTs with the same diameter, and there exists a threshold length for a fixed diameter, below which the single-kink mode occurs at the onset of the bending instability and above which the double-kink mode prevails. The onset characteristic of bending instability is determined by the effectiveness of the intertube interaction in transferring the load from the outer tube onto the inner tube, and the load-transfer effectiveness increases with the increasing tube length. For a fixed length/diameter ratio, the load-transfer effectiveness is found to decrease with the increasing diameter for smaller tubes while it increases for larger tubes, and, thus, the double-kink mode can prevail for both small DWNTs and large DWNTs.

  5. DOUBLE-WALL COLLIMATOR DESIGN OF THE SNS PROJECT.

    SciTech Connect

    SIMOS,N.; LUDEWIG,H.; CATALAN-LASHERAS,N.; CRIVELLO,S.

    2001-06-18

    The collimator absorber array of the Spallation Neutron Source (SNS) project is responsible for stopping the 1.0 GeV protons that are in the halo of the beam. It is estimated that 0.1% of the 2 MW beam will be intercepted by the adopted collimating scheme implemented at various sections of the beam transport and accumulation. This paper summarizes the conceptual design of the collimator absorber as well as the supporting detailed analysis that were performed and guided the design process. Key requirement in the design process is the need for the collimator beam tube to minimize beam impedance while closely following its beta function. Due to lack of available experimental data, the long-term behavior of irradiated materials in an environment where they interface with coolant flow becomes an issue. Uncertainties in the long-term behavior prompted a special double-wall design that will enable not only beam halo interception but also the efficient transfer of deposited energy both under normal and off-normal conditions to the coolant flow. The thermo-mechanical response of the double wall beam tube and of a particle bed surrounding it are discussed in detail in the paper.

  6. Advanced Extended Plate and Beam Wall System in a Cold-Climate House

    SciTech Connect

    Mallay, Dave; Wiehagen, Joseph; Kochkin, Vladimir

    2016-01-01

    This report presents the design and evaluation of an innovative wall system. This highly insulated (high-R) light-frame wall system for use above grade in residential buildings is referred to as Extended Plate & Beam (EP&B). The EP&B design is the first of its kind to be featured in a new construction test house (NCTH) for the DOE Building America program. The EP&B wall design integrates standard building methods and common building products to construct a high-R wall that minimizes transition risks and costs to builders.

  7. Enhanced ductile behavior of tensile-elongated individual double-walled and triple-walled carbon nanotubes at high temperatures.

    PubMed

    Huang, J Y; Chen, S; Ren, Z F; Wang, Z; Kempa, K; Naughton, M J; Chen, G; Dresselhaus, M S

    2007-05-04

    We report exceptional ductile behavior in individual double-walled and triple-walled carbon nanotubes at temperatures above 2000 degrees C, with tensile elongation of 190% and diameter reduction of 90%, during in situ tensile-loading experiments conducted inside a high-resolution transmission electron microscope. Concurrent atomic-scale microstructure observations reveal that the superelongation is attributed to a high temperature creep deformation mechanism mediated by atom or vacancy diffusion, dislocation climb, and kink motion at high temperatures. The superelongation in double-walled and triple-walled carbon nanotubes, the creep deformation mechanism, and dislocation climb in carbon nanotubes are reported here for the first time.

  8. New Whole-House Solutions Case Study: Evaluating Through-Wall Air Transfer Fans, Pittsburgh, Pennsylvania

    SciTech Connect

    2014-10-01

    In this project, Building America team IBACOS performed field testing in a new construction unoccupied test house in Pittsburgh, Pennsylvania, to evaluate heating, ventilating, and air conditioning (HVAC) distribution systems during heating, cooling, and midseason conditions. The team evaluated a market-available through-wall air transfer fan system that provides air to the bedrooms.The relative ability of this system was considered with respect to relevant Air Conditioning Contractors of America and ASHRAE standards for house temperature uniformity and stability.

  9. Laser Welding Of Contoured Thin-Wall Housings

    NASA Technical Reports Server (NTRS)

    Spiegel, Lyle B.; Oleksiak, Carl E.

    1991-01-01

    Superalloy parts joined with less distortion. Carbon dioxide laser beam directed by optics in numerically controlled robot arm welds shell-type turbopump housings having complicated shapes. 5-kW laser, following single programmed three-dimensional pass, produces high-quality, full-penetration weld pass in age-hardenable nickel superalloy. Operator easily programs robot by using teaching pendant to track weld joint and keeps laser focused on workpiece while following contour of shell. Shells welded in rapid succession, with minimal change in setup for each.

  10. Laser Welding Of Contoured Thin-Wall Housings

    NASA Technical Reports Server (NTRS)

    Spiegel, Lyle B.; Oleksiak, Carl E.

    1991-01-01

    Superalloy parts joined with less distortion. Carbon dioxide laser beam directed by optics in numerically controlled robot arm welds shell-type turbopump housings having complicated shapes. 5-kW laser, following single programmed three-dimensional pass, produces high-quality, full-penetration weld pass in age-hardenable nickel superalloy. Operator easily programs robot by using teaching pendant to track weld joint and keeps laser focused on workpiece while following contour of shell. Shells welded in rapid succession, with minimal change in setup for each.

  11. Superconductivity in bundles of double-wall carbon nanotubes.

    PubMed

    Shi, Wu; Wang, Zhe; Zhang, Qiucen; Zheng, Yuan; Ieong, Chao; He, Mingquan; Lortz, Rolf; Cai, Yuan; Wang, Ning; Zhang, Ting; Zhang, Haijing; Tang, Zikang; Sheng, Ping; Muramatsu, Hiroyuki; Kim, Yoong Ahm; Endo, Morinobu; Araujo, Paulo T; Dresselhaus, Mildred S

    2012-01-01

    We present electrical and thermal specific heat measurements that show superconductivity in double-wall carbon nanotube (DWCNT) bundles. Clear evidence, comprising a resistance drop as a function of temperature, magnetoresistance and differential resistance signature of the supercurrent, suggest an intrinsic superconducting transition below 6.8 K for one particular sample. Additional electrical data not only confirm the existence of superconductivity, but also indicate the T(c) distribution that can arise from the diversity in the diameter and chirality of the DWCNTs. A broad superconducting anomaly is observed in the specific heat of a bulk DWCNT sample, which yields a T(c) distribution that correlates well with the range of the distribution obtained from the electrical data. As quasi one dimensionality of the DWCNTs dictates the existence of electronic density of state peaks, confirmation of superconductivity in this material system opens the exciting possibility of tuning the T(c) through the application of a gate voltage.

  12. Faster motion of double 360° domain walls system induced by spin-polarized current

    SciTech Connect

    Zhang, S. F.; Zhu, Q. Y.; Mu, C. P.; Zheng, Q.; Liu, X. Y.; Liu, Q. F.; Wang, J. B.

    2014-05-07

    By micromagnetic simulation, we investigated a double 360° domain walls system in two parallel nanowires. Two domain walls are coupled to each other via magnetostatic interaction. When a spin-polarized current is applied to only one nanowire or both nanowires with the same direction, the two domain walls propagate along nanowires together. The critical velocity of such system is obviously higher than that of a single 360° domain wall. The interaction between the two domain walls can be modeled as two bodies that connected by a spring, and we analyzed the coupling characteritics of the double 360° domain walls at last.

  13. CONTROL HOUSE, TRA620. MASONS ERECT PUMICE BLOCK WALLS. BUILDING WILL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CONTROL HOUSE, TRA-620. MASONS ERECT PUMICE BLOCK WALLS. BUILDING WILL CONTROL ACCESS TO MTR AND OTHER "HOT" AND CLASSIFIED AREAS. INL NEGATIVE NO. 577. Unknown Photographer, 9/11/1950 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  14. Advanced Extended Plate and Beam Wall System in a Cold-Climate House

    SciTech Connect

    Mallay, Dave; Wiehagen, Joseph; Kochkin, Vladimir

    2016-01-29

    This report presents the design and evaluation of an innovative wall system. This highly insulated (high-R) light-frame wall system for use above grade in residential buildings is referred to as Extended Plate & Beam (EP&B). The EP&B design is the first of its kind to be featured in a new construction test house (NCTH) for the DOE Building America program. The EP&B wall design integrates standard building methods and common building products to construct a high-R wall that minimizes transition risks and costs to builders. The EP&B design combines optimized framing with integrated rigid foam sheathing to increase the wall system's R-value and reduce thermal bridging. The foam sheathing is installed between the wall studs and structural wood sheathing. The exterior wood sheathing is attached directly to a framing extension formed by extended top and bottom plates. The exterior wood sheathing can dry to the exterior and provides bracing, a clear drainage plane and flashing surface for window and door openings, and a nailing surface for siding attachment. With support of the DOE Building America program, Home Innovation Research Labs partnered with Lancaster County Career and Technology Center (LCCTC) to build a NCTH in Lancaster, PA to demonstrate the EP&B wall design in a cold climate (IECC climate zone 5A). The results of the study confirmed the benefits of the systems and the viability of its integration into the house construction process.

  15. Collective π -electronic excitations in BN double-walled nanotubes

    NASA Astrophysics Data System (ADS)

    Margulis, Vl. A.; Muryumin, E. E.; Gaiduk, E. A.

    2008-07-01

    We report a systematic theoretical study of the collective π -electronic excitations in boron nitride double-walled nanotubes (BN-DWNTs). For simplicity, it is assumed that both shells (inner and outer) of such tubes have a zigzag achiral structure. Taking into account intershell Coulomb coupling and neglecting intershell electron tunneling, we introduce the effective dynamic-dielectric-response function of the BN-DWNTs, which depends on frequency ω , wave number q , and angular momentum L . An explicit expression for this function is derived within the random-phase approximation using standard many-body techniques based on the Green’s function method. Numerical results are presented for the wave-number dispersion and damping of the π -plasmon modes with different L ’s, demonstrating a unified picture of the π -plasmon-energy variation with q for the BN-DWNTs of different diameters. According to this picture, the spectrum of the π plasmons, which are shown to be long lived and hence well-defined collective electronic excitations in the BN-DWNTs, consists of a set of nonintersecting upward-dispersed branches, which are well separated in their energies at small values of q , but which tend to merge with increasing q . Each of the branches corresponds to one and only one value of the angular momentum L=0,1,2,… and none of the branches starts from q=0 . The present calculations also show that the π plasmons in the BN-DWNTs can exist even at those q values at which the π -plasmon modes are not supported by either of the nanotube shells alone. It is found that the threshold value of the wavelength, at which the L=0 π -plasmon dispersion curve in the BN-DWNTs makes its start, is redshifted as compared to that in the inner and outer nanotube shells if they are considered separately. The most important features of our calculated results seem to be consistent, more or less reasonable, with those derived from the recent electron

  16. Experimental study of lattice dynamics in individual semiconducting double-walled carbon nanotubes: Tangential G modes

    NASA Astrophysics Data System (ADS)

    Levshov, D. I.; Tran, H. N.; Slabodyan, Yu. S.; Osadchii, A. V.; Roshal', S. B.; Yuzyuk, Yu. I.

    2017-02-01

    The tangential G modes in individual semiconducting double-walled nanotubes have been examined via Raman spectroscopy over a wide laser excitation wavelength range. Individual suspended nanotubes have been synthesized via chemical vapor deposition. The ( n, m) chirality indices are determined via electron diffraction and high-resolution transmission electron microscopy. The pronounced shift in the tangential modes compared to the analogous modes of single-walled nanotubes has been observed in Raman spectra of double-walled nanotubes. The shift value is shown to depend on the interlayer distance and on the van der Waals interaction between the layers in a double-walled tube.

  17. Measure Guideline: Deep Energy Enclosure Retrofit for Double-Stud Walls

    SciTech Connect

    Loomis, H.; Pettit, B.

    2015-06-01

    This Measure Guideline describes a deep energy enclosure retrofit (DEER) solution that provides insulation to the interior of the wall assembly with the use of a double stud wall. The guide describes two approaches to retrofitting the existing the walls: one involving replacement of the existing cladding, and the other that leaves the existing cladding in place. It discusses the design principles related to the use of various insulation types, and provides strategies and procedures for implementing the double stud wall retrofit. It also evaluates important moisture-related and indoor air quality measures that need to be implemented to achieve a durable, high performance wall.

  18. Application of Raman microscopy to biodegradable double-walled microspheres.

    PubMed

    Widjaja, Effendi; Lee, Wei Li; Loo, Say Chye Joachim

    2010-02-15

    Raman mapping measurements were performed on the cross section of the ternary-phase biodegradable double-walled microsphere (DWMS) of poly(D,L-lactide-co-glycolide) (50:50) (PLGA), poly(L-lactide) (PLLA), and poly(epsilon-caprolactone) (PCL), which was fabricated by a one-step solvent evaporation method. The collected Raman spectra were subjected to a band-target entropy minimization (BTEM) algorithm in order to reconstruct the pure component spectra of the species observed in this sample. Seven pure component spectral estimates were recovered, and their spatial distributions within DWMS were determined. The first three spectral estimates were identified as PLLA, PLGA 50:50, and PCL, which were the main components in DWMS. The last four spectral estimates were identified as semicrystalline polyglycolic acid (PGA), dichloromethane (DCM), copper-phthalocyanine blue, and calcite, which were the minor components in DWMS. PGA was the decomposition product of PLGA. DCM was the solvent used in DWMS fabrication. Copper-phthalocyanine blue and calcite were the unexpected contaminants. The current result showed that combined Raman microscopy and BTEM analysis can provide a sensitive characterization tool to DWMS, as it can give more specific information on the chemical species present as well as the spatial distributions. This novel analytical method for microsphere characterization can serve as a complementary tool to other more established analytical techniques, such as scanning electron microscopy and optical microscopy.

  19. Design of double-walled carbon nanotubes for biomedical applications

    NASA Astrophysics Data System (ADS)

    Neves, V.; Heister, E.; Costa, S.; Tîlmaciu, C.; Flahaut, E.; Soula, B.; Coley, H. M.; McFadden, J.; Silva, S. R. P.

    2012-09-01

    Double-walled carbon nanotubes (DWNTs) prepared by catalytic chemical vapour deposition were functionalized in such a way that they were optimally designed as a nano-vector for the delivery of small interfering RNA (siRNA), which is of great interest for biomedical research and drug development. DWNTs were initially oxidized and coated with a polypeptide (Poly(Lys:Phe)), which was then conjugated to thiol-modified siRNA using a heterobifunctional cross-linker. The obtained oxDWNT-siRNA was characterized by Raman spectroscopy inside and outside a biological environment (mammalian cells). Uptake of the custom-designed nanotubes was not associated with detectable biochemical perturbations in cultured cells, but transfection of cells with DWNTs loaded with siRNA targeting the green fluorescent protein (GFP) gene, serving as a model system, as well as with therapeutic siRNA targeting the survivin gene, led to a significant gene silencing effect, and in the latter case a resulting apoptotic effect in cancer cells.

  20. Determinants, reproducibility, and seasonal variation of bacterial cell wall components and viable counts in house dust.

    PubMed

    Leppänen, H K; Täubel, M; Roponen, M; Vepsäläinen, A; Rantakokko, P; Pekkanen, J; Nevalainen, A; von Mutius, E; Hyvärinen, A

    2015-06-01

    The objectives of this study were (i) to assess the determinants that affect concentrations of the bacterial cell wall components 3-hydroxy fatty acids (3-OH FAs) and muramic acid and of total viable bacteria and actinomycetes in house dust; and (ii) to examine the seasonal variation and reproducibility of these bacterial cell wall components in house dust. A number of lifestyle and environmental factors, mostly not consistent for different bacterial measures but commonly including the type of dwelling and farming (number of livestock), explained up to 37% of the variation of the bacterial concentrations in 212 homes in Eastern Finland. The reproducibility of 3-OH FAs and muramic acid measurements in house dust were studied in five urban homes and were found to be generally high (ICC 74-84%). Temporal variation observed in repeated sampling of the same home throughout a year was more pronounced for 3-OH FAs determinations (ICC 22%) than for muramic acid (ICC 55-66%). We conclude that determinants vary largely for different types of bacterial measurements in house dust; the measured parameters represent different aspects of the bacterial content indoors. More than one sample is needed to describe bacterial concentrations in house dust in the home environment due to large temporal variation.

  1. Selective breakdown of metallic pathways in double-walled carbon nanotube networks.

    PubMed

    Ng, Allen L; Sun, Yong; Powell, Lyndsey; Sun, Chuan-Fu; Chen, Chien-Fu; Lee, Cheng S; Wang, YuHuang

    2015-01-07

    Covalently functionalized, semiconducting double-walled carbon nanotubes exhibit remarkable properties and can outperform their single-walled carbon nanotube counterparts. In order to harness their potential for electronic applications, metallic double-walled carbon nanotubes must be separated from the semiconductors. However, the inner wall is inaccessible to current separation techniques which rely on the surface properties. Here, the first approach to address this challenge through electrical breakdown of metallic double-walled carbon nanotubes, both inner and outer walls, within networks of mixed electronic types is described. The intact semiconductors demonstrate a ∼62% retention of the ON-state conductance in thin film transistors in response to covalent functionalization. The selective elimination of the metallic pathways improves the ON/OFF ratio, by more than 360 times, to as high as 40 700, while simultaneously retaining high ON-state conductance.

  2. Thermal analysis of Malaysian double storey housing - low/medium cost unit

    NASA Astrophysics Data System (ADS)

    Normah, M. G.; Lau, K. Y.; Yusoff, S. Mohd.

    2012-06-01

    Almost half of the total energy used today is consumed in buildings. In the tropical climate, air-conditioning a housing unit takes much of the energy bill. Malaysia is no exception. Malaysian double storey terrace housing is popular among developers and buyers. Surveys have shown that housing occupants are much dissatisfied with the thermal comfort and artificial cooling is often sought. The objective of this study is to assess the thermal comfort of the low and medium-cost double storey housing in the area surrounding Universiti Teknologi Malaysia. A simulation program using the Weighting Factor Method calculates the heat transfer interaction, temperature distribution, and PMV level in three types of housing units in relation to the size. Fanger's PMV model based on ISO Standard 7730 is used here because it accounts for all parameters that affect the thermal sensation of a human within its equation. Results showed that both the low and medium-cost housing units studied are out of the comfortable range described by ASHRAE Standard 55 with the units all complied with the local bylaws. In view of the uncertainties in energy supply, future housing units should consider natural ventilation as part of the passive energy management.

  3. First description of a double-wall balloon breach during cryoballoon ablation for atrial fibrillation.

    PubMed

    Suarez, Keith; Banchs, Javier E; Lim, Hae W; Black, James N

    2017-08-01

    To date, this is the first published report of a double-wall breach while using the cryoballoon ablation catheter during the treatment of a patient with atrial fibrillation; however, there have been previous balloon breaches in both the second and third-generation cryoballoon ablation catheter usage. In this report, we describe the case of a double-wall balloon breach and the intraoperative care that was necessary to stabilize the patient. Additionally, we review other known cases of double-wall balloon breaches, and we examine the safety systems of the cryoballoon catheter that mitigate some of the potential patient complications. © 2017 Wiley Periodicals, Inc.

  4. Measure Guideline: Deep Energy Enclosure Retrofit for Double-Stud Walls

    SciTech Connect

    Loomis, H.; Pettit, B.

    2015-06-22

    This Measure Guideline describes a deep energy enclosure retrofit solution that provides insulation to the interior of the wall assembly with the use of a double-stud wall. The guide describes two approaches to retrofitting the existing walls—one that involves replacing the existing cladding and the other that leaves the cladding in place. This guideline also covers the design principles related to the use of various insulation types and provides strategies and procedures for implementing the double-stud wall retrofit. It also includes an evaluation of important moisture-related and indoor air quality measures that need to be implemented to achieve a durable high-performance wall.

  5. The excitonic effects in single and double-walled boron nitride nanotubes

    SciTech Connect

    Wang, Shudong; Li, Yunhai; Wang, Jinlan; Yip, Joanne

    2014-06-28

    The electronic structures and excitonic optical properties of single- and double-walled armchair boron nitride nanotubes (BNNTs) [e.g., (5,5) and (10,10), and (5,5)@(10,10)] are investigated within many-body Green's function and Bethe-Salpeter equation formalism. The first absorption peak of the double-walled nanotube has almost no shift compared with the single-walled (5,5) tube due to the strong optical transition in the double-walled tube that occurs within the inner (5,5) one. Dark and semi-dark excitonic states are detected in the lower energy region, stemming from the charge transfer between inner and outer tubes in the double-walled structure. Most interestingly, the charge transfer makes the electron and the hole reside in different tubes. Moreover, the excited electrons in the double-walled BNNT are able to transfer from the outer tube to the inner one, opposite to that which has been observed in double-walled carbon nanotubes.

  6. The excitonic effects in single and double-walled boron nitride nanotubes.

    PubMed

    Wang, Shudong; Li, Yunhai; Yip, Joanne; Wang, Jinlan

    2014-06-28

    The electronic structures and excitonic optical properties of single- and double-walled armchair boron nitride nanotubes (BNNTs) [e.g., (5,5) and (10,10), and (5,5)@(10,10)] are investigated within many-body Green's function and Bethe-Salpeter equation formalism. The first absorption peak of the double-walled nanotube has almost no shift compared with the single-walled (5,5) tube due to the strong optical transition in the double-walled tube that occurs within the inner (5,5) one. Dark and semi-dark excitonic states are detected in the lower energy region, stemming from the charge transfer between inner and outer tubes in the double-walled structure. Most interestingly, the charge transfer makes the electron and the hole reside in different tubes. Moreover, the excited electrons in the double-walled BNNT are able to transfer from the outer tube to the inner one, opposite to that which has been observed in double-walled carbon nanotubes.

  7. Modelling the nonlinear behaviour of double walled carbon nanotube based resonator with curvature factors

    NASA Astrophysics Data System (ADS)

    Patel, Ajay M.; Joshi, Anand Y.

    2016-10-01

    This paper deals with the nonlinear vibration analysis of a double walled carbon nanotube based mass sensor with curvature factor or waviness, which is doubly clamped at a source and a drain. Nonlinear vibrational behaviour of a double-walled carbon nanotube excited harmonically near its primary resonance is considered. The double walled carbon nanotube is harmonically excited by the addition of an excitation force. The modelling involves stretching of the mid plane and damping as per phenomenon. The equation of motion involves four nonlinear terms for inner and outer tubes of DWCNT due to the curved geometry and the stretching of the central plane due to the boundary conditions. The vibrational behaviour of the double walled carbon nanotube with different surface deviations along its axis is analyzed in the context of the time response, Poincaré maps and Fast Fourier Transformation diagrams. The appearance of instability and chaos in the dynamic response is observed as the curvature factor on double walled carbon nanotube is changed. The phenomenon of Periodic doubling and intermittency are observed as the pathway to chaos. The regions of periodic, sub-harmonic and chaotic behaviour are clearly seen to be dependent on added mass and the curvature factors in the double walled carbon nanotube. Poincaré maps and frequency spectra are used to explicate and to demonstrate the miscellany of the system behaviour. With the increase in the curvature factor system excitations increases and results in an increase of the vibration amplitude with reduction in excitation frequency.

  8. Ground coupling and single-blow thermal storage in a double-envelope house

    NASA Astrophysics Data System (ADS)

    Ghaffari, H. T.; Jones, R. F.

    1981-04-01

    The possibility of ground thermal storage and coupling in a double shell house was investigated. Temperature distribution in the ground, utilization of measured ground temperatures, and the amount of heat retrieval are assessed. One experimental model and several hypothetical models are introduced, and their affects and advantages are compared.

  9. Ground coupling and single-blow thermal storage in a double-envelope house

    SciTech Connect

    Ghaffari, H T; Jones, R F

    1981-01-01

    The possibility of ground thermal storage and coupling in a double-shell house is investigated. Temperature distribution in the ground, utilizing measured ground temperatures, is obtained, and the amount of heat retrieval is assessed. One experimental model and several hypothetical models are introduced; their effects and advantages are compared.

  10. Synthesis and photoeletrochemical performance of AuAg@CdS double-walled nanotubes

    NASA Astrophysics Data System (ADS)

    Guan, Shundong; Fu, Xiuli; Tang, Ying; Peng, Zhijian

    2017-08-01

    Uniform CdS coated AuAg alloyed double-walled nanotubes were successfully fabricated by solvothermal process using Ag nanowires as the template. UV-vis-NIR extinction spectra revealed that the obtained double-walled nanotubes can present an enhanced light absorption ability compared with both pure AuAg alloyed nanotubes and CdS nanowires. Photocurrent and electrochemical impedance spectroscopy measurements indicated that such double-walled structure could significantly extend the lifetime of photo-generated carriers and increase the light-harvesting efficiency of CdS, due to the low charge transfer resistance and a high carrier transfer rate of the double-walled structure. The growth mechanism of such kind of nanotubes was also proposed.

  11. 3-D Flyby of Hurricane Edouard Sees Double Eye-Wall

    NASA Image and Video Library

    On Sept. 17 at 03:39 UTC, the TRMM satellite saw a newer outer eyewall forming around Edouard's original eyewall creating a double eye-wall structure. Red indicates heavy rainfall. Credit: NASA/SSA...

  12. Amino acid functionalization of double-wall carbon nanotubes studied by Raman spectroscopy.

    PubMed

    Marcolongo, Gabriele; Ruaro, Giorgio; Gobbo, Marina; Meneghetti, Moreno

    2007-12-14

    Double-wall carbon nanotubes (DWNT) have been functionalized with lysine after a strong oxidation with MnO4- in acid solution which, as suggested by the Raman spectra, attacked the external nanotube of the DWNT.

  13. Double wall versus single wall incubator for reducing heat loss in very low birth weight infants in incubators.

    PubMed

    Laroia, N; Phelps, D L; Roy, J

    2007-04-18

    Studies have shown improved survival of newborn infants maintained in the thermoneutral range. The concept of an incubator with additional insulation, a double plexiglass wall, is appealing for very low birth weight infants as it may help to provide a thermoneutral environment. To assess the effects of double walled incubator versus a single wall incubator on insensible water loss, rate of oxygen consumption, episodes of hypothermia, time to regain birth weight, duration of hospitalization and infant mortality in premature infants. The standard search strategy of the Cochrane Neonatal Review Group was used. This included searches of electronic databases: Oxford Database of Perinatal Trials, Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2006), MEDLINE (1966 - 2006), EMBASE, previous reviews including cross references, abstracts, conference and symposia proceedings, expert informants in all published languages, and CINAHL (1982 - 2006). Only studies using random or quasi-random methods of allocation were considered for this review. Eligible studies assessed at least one of the outcome variables identified as important to this topic. Independent data extraction and quality assessment of included trials was conducted by the review authors. Data were analyzed using generic inverse variance methodology and weighted mean difference (WMD). Results are presented with 95% confidence intervals. Meta-analysis was undertaken using a fixed effect model. Three studies met the criteria. Four other studies were excluded, as they did not compare double versus single wall incubators (details of the studies are given in the included and excluded studies section). Double wall incubators have the advantage of decreasing heat loss, decreasing heat production and decreasing radiant heat loss when compared to single wall incubators. There is also the advantage of reduced oxygen consumption. A minimal increase in conductive heat loss was noted when

  14. Double-walled microspheres loaded with meglumine antimoniate: preparation, characterization and in vitro release study.

    PubMed

    Navaei, Ali; Rasoolian, Morteza; Momeni, Arash; Emami, Shahriar; Rafienia, Mohammad

    2014-06-01

    The objective of this study was to fabricate double-walled poly(lactide-co-glycolide) (PLGA) microspheres to increase encapsulation efficiency and avoid rapid release of hydrophilic drugs such as meglumine antimoniate. In this study, double-walled and one-layered microspheres of PLGA were prepared using the emulsion solvent evaporation technique to better control the release of a hydrophilic drug, meglumine antimoniate (Glucantime®), which is the first choice treatment of cutaneous leishmaniasis. The effect of hydrophobic coating on microspheres' size, morphology, encapsulation efficiency and drug release characteristics was evaluated. Furthermore, the presence of antimony in meglumine antimoniate made it possible to observe the drug distribution within the microspheres' cross section by means of energy dispersive X-ray spectroscopy. Drug distribution images confirmed accumulation of the drug within the inner core of double-walled microspheres. In addition, these microspheres encapsulated the drug more efficiently up to 87% and demonstrated reduced initial burst and prolonged release compared to one-layered microspheres. These superiorities make double-walled microspheres an optimum candidate for sustained delivery of hydrophilic drugs. Double-walled microspheres provide some advantages over traditional microspheres overcoming most of their limitations. Double-walled microspheres were found to be more efficient than their corresponding one-layered microspheres in terms of encapsulation efficiencies and release characteristics.

  15. Interwall Friction and Sliding Behavior of Centimeters Long Double-Walled Carbon Nanotubes.

    PubMed

    Zhang, Rufan; Ning, Zhiyuan; Xu, Ziwei; Zhang, Yingying; Xie, Huanhuan; Ding, Feng; Chen, Qing; Zhang, Qiang; Qian, Weizhong; Cui, Yi; Wei, Fei

    2016-02-10

    Here, we studied the interwall friction and sliding behaviors of double-walled carbon nanotubes (DWCNTs). The interwall friction shows a linear dependence on the pullout velocity of the inner wall. The axial curvature in DWCNTs causes the significant increase of the interwall friction. The axial curvature also affects the sliding behavior of the inner wall. Compared with the axial curvature, the opening ends of DWCNTs play tiny roles in their interwall friction.

  16. Controlled synthesis of double-wall a-FePO4 nanotubes and their LIB cathode properties.

    PubMed

    Cai, Ren; Liu, Hai; Zhang, Wenyu; Tan, Huiteng; Yang, Dan; Huang, Yizhong; Hng, Huey Hoon; Lim, Tuti Mariana; Yan, Qingyu

    2013-04-08

    Double-wall amorphous FePO4 nanotubes are prepared by an oil-phase chemical route. The inward diffusion of vacancies and outward diffusion of ions through passivation layers result in double-wall nanotubes with thin walls. Such a process can be extended to prepare hollow polydedral nanocrystals and hollow ellipsoids. The double-wall FePO4 nanotubes show interesting cathode performance in Li ion batteries.

  17. Building America Case Study: Monitoring of Double Stud Wall Moisture Conditions in the Northeast, Devens, Massachusetts (Fact Sheet)

    SciTech Connect

    Not Available

    2015-03-01

    Double-stud walls insulated with cellulose or low-density spray foam can have R-values of 40 or higher. However, double stud walls have a higher risk of interior-sourced condensation moisture damage, when compared with high-R approaches using exterior insulating sheathing. Moisture conditions in double stud walls were monitored in Zone 5A (Massachusetts); three double stud assemblies were compared.

  18. Oxygen consumption and temperature control of premature infants in a double-wall incubator.

    PubMed

    Marks, K H; Lee, C A; Bolan, C D; Maisels, M J

    1981-07-01

    The effects of a double wall in a forced convection-heated incubator were studied on ten naked, nondistressed, premature infants by measuring their mean skin temperature, esophageal temperature, and oxygen consumption when they were in thermal steady state, with, and without, the double wall in place. The incubator air temperature was maintained within the recommended thermoneutral zone during the consecutive paired experiments. Ambient room temperature and relative humidity were constant and the infant's activity (quiet sleep) and postprandial state were the same in both conditions. Together with a significant rise in operative temperature (P less than .05) induced by the double wall (accounted for by a 0.9 C mean increased in incubator wall temperature nearest the baby), their mean skin temperature and esophageal temperatures increased (P less than .025), while a decrease in oxygen consumption occurred in nine of the ten infants (P less than .05). These findings suggest that the double wall reduced radiant and total heat loss from the baby by diminishing the temperature gradient between the skin and incubator surfaces and that metabolic heat production (oxygen consumption) was reduced when the double wall was in place.

  19. Sorting of Double-Walled Carbon Nanotubes According to Their Outer Wall Electronic Type via a Gel Permeation Method.

    PubMed

    Moore, Katherine E; Pfohl, Moritz; Tune, Daniel D; Hennrich, Frank; Dehm, Simone; Chakradhanula, Venkata Sai K; Kübel, Christian; Krupke, Ralph; Flavel, Benjamin S

    2015-04-28

    In this work, we demonstrate the application of the gel permeation technique to the sorting of double-walled carbon nanotubes (DWCNTs) according to their outer wall electronic type. Our method uses Sephacryl S-200 gel and yields sorted fractions of DWCNTs with impurities removed and highly enriched in nanotubes with either metallic (M) or semiconducting (S) outer walls. The prepared fractions are fully characterized using optical absorption spectroscopy, transmission electron microscopy, and atomic force microscopy, and the entire procedure is monitored in real time using process Raman analysis. The sorted DWCNTs are then integrated into single nanotube field effect transistors, allowing detailed electronic measurement of the transconductance properties of the four unique inner@outer wall combinations of S@S, S@M, M@S, and M@M.

  20. Technology Solutions Case Study: Stud Walls with Continuous Exterior Insulation for Factory Built Housing

    SciTech Connect

    2014-01-01

    The Advanced Envelope Research effort will provide factory homebuilders with high performance, cost-effective alternative envelope designs. In the near term, these technologies will play a central role in meeting stringent energy code requirements. For manufactured homes, the thermal requirements, last updated by statute in 1994, will move up to the more rigorous IECC 2012 levels in 2013, the requirements of which are consistent with site built and modular housing. This places added urgency on identifying envelope technologies that the industry can implement in the short timeframe. The primary goal of this research is to develop wall designs that meet the thermal requirements based on 2012 IECC standards. Given the affordable nature of manufactured homes, impact on first cost is a major consideration in developing the new envelope technologies. This work is part of a four-phase, multi-year effort. Phase 1 identified seven envelope technologies and provided a preliminary assessment of three selected methods for building high performance wall systems. Phase 2 focused on the development of viable product designs, manufacturing strategies, addressing code and structural issues, and cost analysis of the three selected options. An industry advisory committee helped critique and select the most viable solution to move further in the research — stud walls with continuous exterior insulation. Phase 3, the subject of the current report, focused on the design development of the selected wall concept and explored variations on the use of exterior foam insulation. The scope also included material selection, manufacturing and cost analysis, and prototyping and testing.

  1. Controlled fabrication of porous double-walled TiO2 nanotubes via ultraviolet-assisted anodization

    NASA Astrophysics Data System (ADS)

    Ali, Ghafar; Kim, Hyun Jin; Kim, Jae Joon; Cho, Sung Oh

    2014-03-01

    Double-walled TiO2 nanotubes with porous wall morphologies are fabricated by anodization under ultraviolet (UV) irradiation. TiO2 formed by anodization of Ti is activated to generate electrons and holes by UV and the anodization process is influenced by the photo-generated charges. As a consequence, morphologies of the fabricated TiO2 nanotubes can be adjusted by controlling the UV illumination. Double-walled TiO2 nanotubes or single-walled nanotubes can be selectively formed by switching on/off the UV illumination. The thickness of the inner and outer walls of the double-walled nanotubes can be tailored by changing the UV power. Due to their larger surface areas compared to single-walled nanotubes, the porous double-walled nanotubes exhibit an enhanced photo-degradation rate for methylene blue (MB). The mechanism of the porous double-walled TiO2 nanotubes is proposed based on the photoactive semiconducting property of the as-growing TiO2 nanotubes under UV.Double-walled TiO2 nanotubes with porous wall morphologies are fabricated by anodization under ultraviolet (UV) irradiation. TiO2 formed by anodization of Ti is activated to generate electrons and holes by UV and the anodization process is influenced by the photo-generated charges. As a consequence, morphologies of the fabricated TiO2 nanotubes can be adjusted by controlling the UV illumination. Double-walled TiO2 nanotubes or single-walled nanotubes can be selectively formed by switching on/off the UV illumination. The thickness of the inner and outer walls of the double-walled nanotubes can be tailored by changing the UV power. Due to their larger surface areas compared to single-walled nanotubes, the porous double-walled nanotubes exhibit an enhanced photo-degradation rate for methylene blue (MB). The mechanism of the porous double-walled TiO2 nanotubes is proposed based on the photoactive semiconducting property of the as-growing TiO2 nanotubes under UV. Electronic supplementary information (ESI) available

  2. Numerical Comparison of Active Acoustic and Structural Noise Control in a Stiffened Double Wall Cylinder

    NASA Technical Reports Server (NTRS)

    Grosveld, Ferdinand W.

    1996-01-01

    The active acoustic and structural noise control characteristics of a double wall cylinder with and without ring stiffeners were numerically evaluated. An exterior monopole was assumed to acoustically excite the outside of the double wall cylinder at an acoustic cavity resonance frequency. Structural modal vibration properties of the inner and outer shells were analyzed by post-processing the results from a finite element analysis. A boundary element approach was used to calculate the acoustic cavity response and the coupled structural-acoustic interaction. In the frequency region of interest, below 500 Hz, all structural resonant modes were found to be acoustically slow and the nonresonant modal response to be dominant. Active sound transmission control was achieved by control forces applied to the inner or outer shell, or acoustic control monopoles placed just outside the inner or outer shell. A least mean square technique was used to minimize the interior sound pressures at the nodes of a data recovery mesh. Results showed that single acoustic control monopoles placed just outside the inner or outer shells resulted in better sound transmission control than six distributed point forces applied to either one of the shells. Adding stiffeners to the double wall structure constrained the modal vibrations of the shells, making the double wall stiffer with associated higher modal frequencies. Active noise control obtained for the stiffened double wall configurations was less than for the unstiffened cylinder. In all cases, the acoustic control monopoles controlled the sound transmission into the interior better than the structural control forces.

  3. Exploration of the shapes of double-walled vesicles with a confined inner membrane

    NASA Astrophysics Data System (ADS)

    Guo, Kunkun; Li, Jianfeng

    2011-07-01

    We investigate double-walled vesicles as a simple model system for multi-vesicular structures, where the inner membrane is confined within the outer membrane. Various shapes of double-walled vesicles in two dimensions are obtained by means of our recently-developed discrete space variation method, and the shapes of each layer are found to be interdependent. Confined within the outer membrane, an inner membrane with a larger surface area always shows a cristae shape. As previous simulations and theoretical analyses of a single-walled vesicle have been done before, the geometric properties of double-walled vesicles, including the mean square radius of gyration and volume within the vesicle membrane, are studied in detail as functions of the pressure and surface area. It is found that due to the inter-space restriction of each layer, double-walled vesicles exhibit different behaviors compared with the previously-observed scaling laws of single-walled vesicles. It is straightforward to extend this study to more complicated and realistic biological systems, such as those including electrostatic interactions between membranes and solvent, phase separation, and cooperative interactions between multicomponent membranes.

  4. Technology Solutions Case Study: Hygrothermal Performance of a Double-Stud Cellulose Wall

    SciTech Connect

    2015-06-01

    Moisture problems within the building shell can be caused by a number of factors including excess interior moisture that is transported into the wall through air leakage and vapor drive, bulk water intrusion from leaks and wind-driven rain, capillary action from concrete to wood connections, and through wetted building materials such as siding wetted from rain splash back. With the increasing thickness of walls, moisture issues could increase. Several builders have successfully used “double-wall” systems to more practically achieve higher R-values in thicker framed walls. A double wall typically consists of a load-bearing external frame wall constructed with 2 × 4 framing at 16 in. on center using conventional methods. After the building is enclosed, an additional frame wall is constructed several inches inside the load-bearing wall. Several researchers have used moisture modeling software to conduct extensive analysis of these assemblies; however, little field research has been conducted to validate the results. In this project, the Building America research team Consortium for Advanced Residential Buildings monitored a double-stud assembly in climate zone 5A to determine the accu¬racy of moisture modeling and make recommendations to ensure durable and efficient assemblies.

  5. Interfacial double layer mediated electrochemical growth of thin-walled platinum nanotubes

    NASA Astrophysics Data System (ADS)

    Zhang, Liqiu; Kim, Sang Min; Cho, Sanghyun; Jang, Hee-Jeong; Liu, Lichun; Park, Sungho

    2017-01-01

    This work demonstrates that thin-walled platinum nanotubes can be readily synthesized by controlling the interfacial double layer in alumina nanochannels. The gradient distribution of ions in nanochannels enables the creation of Pt nanotubes with walls as thin as 5 nm at the top end when using a solution containing polyvinylpyrrolidone (PVP) and chloroplatinic acid (H2PtCl6) under the influence of an electric potential in nanochannels. The highly efficient formation of thin-walled Pt nanotubes is a result of the concentration gradient of {{{{PtCl}}}6}2- and a thick double layer, which was caused by the low concentration of Pt precursors and the enhanced surface charge density induced by protonated PVP steric adsorption. This well-controlled synthesis reveals that the interfacial double layer is a useful tool to tailor the structure of nanomaterials in a nanoscale space, and holds promise in the construction of more complex functional nanostructures.

  6. Six Thousand Electrochemical Cycles of Double-Walled Silicon Nanotube Anodes for Lithium Ion Batteries

    SciTech Connect

    Wu, H

    2011-08-18

    Despite remarkable progress, lithium ion batteries still need higher energy density and better cycle life for consumer electronics, electric drive vehicles and large-scale renewable energy storage applications. Silicon has recently been explored as a promising anode material for high energy batteries; however, attaining long cycle life remains a significant challenge due to materials pulverization during cycling and an unstable solid-electrolyte interphase. Here, we report double-walled silicon nanotube electrodes that can cycle over 6000 times while retaining more than 85% of the initial capacity. This excellent performance is due to the unique double-walled structure in which the outer silicon oxide wall confines the inner silicon wall to expand only inward during lithiation, resulting in a stable solid-electrolyte interphase. This structural concept is general and could be extended to other battery materials that undergo large volume changes.

  7. Characteristics of a Sheath with Secondary Electron Emission in the Double Walls of a Hall Thruster

    NASA Astrophysics Data System (ADS)

    Duan, Ping; Li, Xi; Shen, Hongjuan; Chen, Long; E, Peng

    2012-09-01

    In order to investigate the effects of secondary electrons, which are emitted from the wall, on the performance of a thruster, a one-dimensional fluid model of the plasma sheath in double walls is applied to study the characteristics of a magnetized sheath. The effects of secondary electron emission (SEE) coefficients and trapping coefficients, as well as magnetic field, on the structure of the plasma sheath are investigated. The results show that sheath potential and wall potential rise with the increment of SEE coefficient and trapping coefficient which results in a reduced sheath thickness. In addition, magnetic field strength will influence the sheath potential distributions.

  8. The electrostatic properties of Fiber-Reinforced-Plastics double wall underground storage gasoline tanks

    NASA Astrophysics Data System (ADS)

    Li, Yipeng; Liu, Quanzhen; Meng, He; Sun, Lifu; Zhang, Yunpeng

    2013-03-01

    At present Fiber Reinforced Plastics (FRP) double wall underground storage gasoline tanks are wildly used. An FRP product with a resistance of more than 1011 Ω is a static non-conductor, so it is difficult for the static electricity in the FRP product to decay into the earth. In this paper an experimental system was built to simulate an automobile gasoline filling station. Some electrostatic parameters of the gasoline, including volume charge density, were tested when gasoline was unloaded into a FRP double wall underground storage tank. Measurements were taken to make sure the volume charge density in the oil-outlet was similar to the volume charge density in the tank. In most cases the volume charge density of the gasoline was more than 22.7 μC m-3, which is likely to cause electrostatic discharge in FRP double wall underground storage gasoline tanks. On the other hand, it would be hard to ignite the vapor by electrostatic discharge since the vapor pressure in the tanks is over the explosion limit. But when the tank is repaired or re-used, the operators must pay attention to the static electricity and some measurements should be taken to avoid electrostatic accident. Besides the relaxation time of charge in the FRP double wall gasoline storage tanks should be longer.

  9. Optically and biologically active mussel protein-coated double-walled carbon nanotubes.

    PubMed

    Jung, Yong Chae; Muramatsu, Hiroyuki; Fujisawa, Kazunori; Kim, Jin Hee; Hayashi, Takuya; Kim, Yoong Ahm; Endo, Morinobu; Terrones, Mauricio; Dresselhaus, Mildred S

    2011-12-02

    A method of dispersing strongly bundled double-walled carbon nanotubes (DWNTs) via a homogeneous coating of mussel protein in an aqueous solution is presented. Optical activity, mechanical strength, as well as electrical conductivity coming from the nanotubes and the versatile biological activity from the mussel protein make mussel-coated DWNTs promising as a multifunctional scaffold and for anti-fouling materials.

  10. The influence of finite and infinite wall cavities on the sound insulation of double-leaf walls.

    PubMed

    Cambridge, Jason E; Davy, John L; Pearse, John

    2017-01-01

    Theories used to predict the sound insulation of double-leaf cavity wall systems are usually based on the assumption that the wall is of an infinite extent. To account for the effect of the finite extent of the wall, limiting the angle of incidence, a finite radiation efficiency model or the spatial windowing method is used in order to obtain realistic predictions. However, the effects of the finite extent of the cavity are often not included. This paper presents an extension of a finite two-dimensional cavity theory to include limp panels on each side of the cavity. It is shown that the oblique incidence mass-air-mass resonance can only occur for certain frequencies and certain angles of incidence. This is the reason why the infinite extent theories under-predict the sound insulation. The results of the predicted sound insulation agree with measurements when the wall cavity is empty. To obtain agreement when the cavity is full of a porous sound absorbing material, a flow resistivity of about one-fifth of the measured value has to be used. Use of the actual flow resistivity gives sound insulation values that are 10 dB too high.

  11. Building America Case Study: Advanced Extended Plate and Beam Wall System in a Cold-Climate House, Mount Joy, Pennsylvania

    SciTech Connect

    2016-01-01

    This report presents the design and evaluation of a innovative wall system. This highly insulated (high-R) light-frame wall system for use above grade in residential buildings is referred to as Extended Plate & Beam (EP&B). The EP&B design is the first of its kind to be featured in a new construction test house (NCTH) for the DOE Building America program. The EP&B wall design integrates standard building methods and common building products to construct a high-R wall that minimizes transition risks and costs to builders. The EP&B design combines optimized framing with integrated rigid foam sheathing to increase the wall system's R-value and reduce thermal bridging. The foam sheathing is installed between the wall studs and structural wood sheathing. The exterior wood sheathing is attached directly to a framing extension formed by extended top and bottom plates. The exterior wood sheathing can dry to the exterior and provides bracing, a clear drainage plane and flashing surface for window and door openings, and a nailing surface for siding attachment. With support of the DOE Building America program, Home Innovation Research Labs partnered with Lancaster County Career and Technology Center (LCCTC) to build a NCTH in Lancaster, PA to demonstrate the EP&B wall design in a cold climate (IECC climate zone 5A). The results of the study confirmed the benefits of the systems and the viability of its integration into the house construction process.

  12. Exotic domain walls in Bose-Einstein condensates with double-well dispersion

    NASA Astrophysics Data System (ADS)

    Liu, Tongtong; Clark, Logan W.; Chin, Cheng

    2016-12-01

    We study the domain walls which form when Bose condensates acquire a double-well dispersion. Experiments have observed such domain walls in condensates driven across a Z2 symmetry-breaking phase transition in a shaken optical lattice. We derive a generic model to describe the dispersion and to compute the wave functions and energies of the domain walls. We find two distinct regimes which demand different physical pictures. In the weak-coupling regime, where interactions are weak compared to the kinetic-energy barrier, "density-wave domain walls" form that support an extended density wave and a series of phase steps. These features can be understood as the quantum interference between domains with distinct momenta. In the strong-coupling regime where interaction dominates, the system forms "phase domain walls" which have the minimum width allowed by the uncertainty principle and suppressed density modulation. Analytic results for the domain-wall wave functions are obtained in the two regimes. The energy of domain walls behaves similarly to that of topological defects in paradigmatic field theories.

  13. Quantum-coupled radial-breathing oscillations in double-walled carbon nanotubes.

    PubMed

    Liu, Kaihui; Hong, Xiaoping; Wu, Muhong; Xiao, Fajun; Wang, Wenlong; Bai, Xuedong; Ager, Joel W; Aloni, Shaul; Zettl, Alex; Wang, Enge; Wang, Feng

    2013-01-01

    Van der Waals-coupled materials, ranging from multilayers of graphene and MoS(2) to superlattices of nanoparticles, exhibit rich emerging behaviour owing to quantum coupling between individual nanoscale constituents. Double-walled carbon nanotubes provide a model system for studying such quantum coupling mediated by van der Waals interactions, because each constituent single-walled nanotube can have distinctly different physical structures and electronic properties. Here we systematically investigate quantum-coupled radial-breathing mode oscillations in chirality-defined double-walled nanotubes by combining simultaneous structural, electronic and vibrational characterizations on the same individual nanotubes. We show that these radial-breathing oscillations are collective modes characterized by concerted inner- and outer-wall motions, and determine quantitatively the tube-dependent van der Waals potential governing their vibration frequencies. We also observe strong quantum interference between Raman scattering from the inner- and outer-wall excitation pathways, the relative phase of which reveals chirality-dependent excited-state potential energy surface displacement in different nanotubes.

  14. Package of double helical bromine chains inside single-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Yao, Zhen; Liu, Chun Jian; Lv, Hang; Yang, Xi Bao

    2016-10-01

    The helicity of stable double helical bromine chains inside single-walled carbon nanotubes (SWCNTs) was studied through the calculation of systematic interaction energy, using the van der Waals interaction potential. The results presented clear images of stable double helical structures inside SWCNTs. The optimal helical radius and helical angle of chain structure increase and decrease, respectively, with the increase of tube radius. The detailed analysis indicated that some metastable structures in SWCNTs may also co-exist with the optimal structures, but not within the same tubes. In addition, a detailed simulation of X-ray diffraction patterns was performed for the obtained optimal helical structures.

  15. Double-diffusive natural convection in a fluid saturated porous cavity with a freely convecting wall

    SciTech Connect

    Nithiarasu, P.; Sundararajan, T.; Seetharamu, K.N.

    1997-12-01

    Double-diffusive natural convection in fluid saturated porous medium has been investigated using a generalized porous medium model. One of the vertical walls of the porous cavity considered is subjected to convective heat and mass transfer conditions. The results show that the flow, heat and mass transfer become sensitive to applied mass transfer coefficient in both the Darcy and non-Darcy flow regimes. It is also observed that the Sherwood number approaches a constant value as the solutal Biot number increases. Double-diffusive natural convection in fluid saturated porous medium is encountered in applications such as food processing, contaminant transport in ground water, and others.

  16. Mechanical properties and buckling behaviors of condensed double-walled carbon nanotubes.

    PubMed

    Zhang, Yingyan; Wang, Chien Ming; Tan, Vincent Beng Chye

    2009-08-01

    Molecular dynamics (MD) simulations are performed on condensed double-walled carbon nanotubes (CDWCNTs) to investigate the effects of compressed interwall spacings on their mechanical properties, in particular their buckling behavior under axial compression, torsion and bending. In CDWCNTs, the inner and outer nanotubes have diameters that are closer to each other than the nanotubes of conventional double-walled carbon nanotubes (DWCNTs). This leads to a smaller interwall spacing. The mechanical properties of the CDWCNTs, such as Young's modulus, interwall shear modulus, and the buckling strain under axial compression, torsion and bending are found to be greatly enhanced when compared with those of conventional DWCNTs. The enhancement is found to be inversely proportional to the interwall spacing.

  17. Changing and predicting the frequency of double wall carbon nanotubes oscillator

    NASA Astrophysics Data System (ADS)

    Huang, Xing; Xiao, Shao-Rong; Liu, Hong-De; Wang, Tong; Yue, Ju-Qing

    2017-06-01

    Double wall carbon nanotubes have been considered as potential candidate for ultra-high frequency oscillator. However, the exact frequency change versus the nanotubes' shape has not been detailed discussed. In this article, a series of double wall carbon nanotubes oscillators are investigated using molecular dynamics simulation. We find that, by changing the tube length and radius, the oscillation frequency can be easily modified. To better understand the simulation result above, a theoretical model with maximum main force approximation is introduced. Then the tendency for the frequency change can be well interpreted. Moreover, we find the effective force increases linearly with the tube radius. After a careful derivation, a universal formula is given, which can predict the oscillation period with a good accuracy.

  18. Energy transmission in a mechanically-linked double-wall structure coupled to an acoustic enclosure

    NASA Astrophysics Data System (ADS)

    Cheng, L.; Li, Y. Y.; Gao, J. X.

    2005-05-01

    The energy transmission in a mechanically linked double-wall structure into an acoustic enclosure is studied in this paper. Based on a fully coupled vibro-acoustic formulation, focus is put on investigating the effect of the air gap and mechanical links between the two panels on the energy transmission and noise insulation properties of such structures. An approximate formula reflecting the gap effect on the lower-order coupled frequencies of the system is proposed. A criterion, based on the ratio between the aerostatic stiffness of the gap cavity and the stiffness of the link, is proposed to predict the dominant transmitting path, with a view to provide guidelines for the design of appropriate control strategies. Numerical results reveal the existence of three distinct zones, within which energy transmission takes place following different mechanisms and transmitting paths. Corresponding effects on noise insulation properties of the double-wall structure are also investigated. .

  19. Energy transmission in a mechanically-linked double-wall structure coupled to an acoustic enclosure.

    PubMed

    Cheng, L; Li, Y Y; Gao, J X

    2005-05-01

    The energy transmission in a mechanically linked double-wall structure into an acoustic enclosure is studied in this paper. Based on a fully coupled vibro-acoustic formulation, focus is put on investigating the effect of the air gap and mechanical links between the two panels on the energy transmission and noise insulation properties of such structures. An approximate formula reflecting the gap effect on the lower-order coupled frequencies of the system is proposed. A criterion, based on the ratio between the aerostatic stiffness of the gap cavity and the stiffness of the link, is proposed to predict the dominant transmitting path, with a view to provide guidelines for the design of appropriate control strategies. Numerical results reveal the existence of three distinct zones, within which energy transmission takes place following different mechanisms and transmitting paths. Corresponding effects on noise insulation properties of the double-wall structure are also investigated.

  20. DOE ZERH Case Study: KB Home, Double ZeroHouse 3.0, El Dorado Hill, CA

    SciTech Connect

    none,

    2015-09-01

    Case study of a DOE 2015 Housing Innovation Award winning production home in the mixed-dry climate that got a HERS 44 without PV, or HERS -2 with PV, with 2x4 walls 16” on center walls with R-15 cavity plus 1” EPS exterior rigid foam, slab on grade with R-10 slab edge; unvented attic with R-38 blown fiberglass netted to underside of roof deck; 19 SEER heat pump; heat pump water heater; 100% LED.

  1. Controlled fabrication of porous double-walled TiO2 nanotubes via ultraviolet-assisted anodization.

    PubMed

    Ali, Ghafar; Kim, Hyun Jin; Kim, Jae Joon; Cho, Sung Oh

    2014-04-07

    Double-walled TiO2 nanotubes with porous wall morphologies are fabricated by anodization under ultraviolet (UV) irradiation. TiO2 formed by anodization of Ti is activated to generate electrons and holes by UV and the anodization process is influenced by the photo-generated charges. As a consequence, morphologies of the fabricated TiO2 nanotubes can be adjusted by controlling the UV illumination. Double-walled TiO2 nanotubes or single-walled nanotubes can be selectively formed by switching on/off the UV illumination. The thickness of the inner and outer walls of the double-walled nanotubes can be tailored by changing the UV power. Due to their larger surface areas compared to single-walled nanotubes, the porous double-walled nanotubes exhibit an enhanced photo-degradation rate for methylene blue (MB). The mechanism of the porous double-walled TiO2 nanotubes is proposed based on the photoactive semiconducting property of the as-growing TiO2 nanotubes under UV.

  2. Specific features of low-frequency vibrational dynamics and low-temperature heat capacity of double-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Avramenko, M. V.; Roshal, S. B.

    2016-05-01

    A continuous model has been constructed for low-frequency dynamics of a double-walled carbon nanotube. The formation of the low-frequency part of the phonon spectrum of a double-walled nanotube from phonon spectra of its constituent single-walled nanotubes has been considered in the framework of the proposed approach. The influence of the environment on the phonon spectrum of a single double-walled carbon nanotube has been analyzed. A combined method has been proposed for estimating the coefficients of the van der Waals interaction between the walls of the nanotube from the spectroscopic data and the known values of the elastic moduli of graphite. The low-temperature specific heat has been calculated for doublewalled carbon nanotubes, which in the field of applicability of the model ( T < 35 K) is substantially less than the sum of specific heats of two individual single-walled nanotubes forming it.

  3. The Bulging Behavior of Thick-Walled 6063 Aluminum Alloy Tubes Under Double-Sided Pressures

    NASA Astrophysics Data System (ADS)

    Cui, Xiao-Lei; Wang, Xiao-Song; Yuan, Shi-Jian

    2015-05-01

    To make further exploration on the deformation behavior of tube under double-sided pressures, the thick-walled 6063 aluminum alloy tubes with an outer diameter of 65 mm and an average thickness of 7.86 mm have been used to be bulged under the combined action of internal and external pressures. In the experiment, two ends of the thick-walled tubes were fixed using the tooth and groove match. Three levels of external pressure (0 MPa, 40 MPa, and 80 MPa), in conjunction with the internal pressure, were applied on the tube outside and inside simultaneously. The effect of external pressure on the bulging behavior of the thick-walled tubes, such as the limiting expansion ratio, the bulging zone profile, and the thickness distribution, has been investigated. It is shown that the limiting expansion ratio, the bulging zone profile, and the thickness distribution in the homogeneous bulging area are all insensitive to the external pressure. However, the external pressure can make the thick-walled tube achieve a thinner wall at the fracture area. It reveals that the external pressure can only improve the fracture limit of the thick-walled 6063 tubes, but it has very little effect on their homogeneous bulging behavior. It might be because the external pressure can only increase the magnitude of the hydrostatic pressure for the tube but has no effect on the Lode parameter.

  4. Crystal orbital study on the double walls made of nanotubes encapsulated inside zigzag carbon nanotubes

    SciTech Connect

    Zhao, Xin; Qiao, Weiye; Li, Yuliang; Huang, Yuanhe

    2015-01-15

    The structure stabilities and electronic properties are investigated by using ab initio self-consistent-field crystal orbital method based on density functional theory for the one-dimensional (1D) double-wall nanotubes made of n-gon SiO{sub 2} nanotubes encapsulated inside zigzag carbon nanotubes. It is found that formation of the combined systems is energetically favorable when the distance between the two constituents is around the Van der Waals scope. The obtained band structures show that all the combined systems are semiconductors with nonzero energy gaps. The frontier energy bands (the highest occupied band and the lowest unoccupied band) of double-wall nanotubes are mainly derived from the corresponding carbon nanotubes. The mobilities of charge carriers are calculated to be within the range of 10{sup 2}–10{sup 4} cm{sup 2} V{sup −1} s{sup −1} for the hybrid double-wall nanotubes. Young’s moduli are also calculated for the combined systems. For the comparison, geometrical and electronic properties of n-gon SiO{sub 2} nanotubes are also calculated and discussed. - Graphical abstract: Structures and band structures of the optimum 1D Double walls nanotubes. The optimized structures are 3-gon SiO2@(15,0), 5-gon SiO2@(17,0), 6-gon SiO2@(18,0) and 7-gon SiO2@(19,0). - Highlights: • The structure and electronic properties of the 1D n-gon SiO{sub 2}@(m,0)s are studied using SCF-CO method. • The encapsulation of 1D n-gon SiO{sub 2} tubes inside zigzag carbon nanotubes can be energetically favorable. • The 1D n-gon SiO{sub 2}@(m,0)s are all semiconductors. • The mobility of charge carriers and Young’s moduli are calculated.

  5. Stress analysis of a double-wall vacuum vessel for ITER

    SciTech Connect

    Conner, D.L.; Williamson, D.E.; Nelson, B.E.

    1991-01-01

    The preliminary structural analyses performed in support of the design of the vacuum vessel for the International Thermonuclear Experimental Reactor (ITER) are described. A thin, double-wall, all-welded structure is the proposed design concept analyzed. The results of the static stress analysis indicate the adequacy of such a structure. The effects of the proposed high-aspect-ratio design configuration on loading and stresses are also discussed. 4 refs., 6 figs., 1 tab.

  6. On the Acousto-Elastic Behaviour of Double-Wall Panels with a Viscothermal Air Layer

    NASA Astrophysics Data System (ADS)

    BASTEN, T. G. H.; VAN DER HOOGT, P. J. M.; SPIERING, R. M. E. J.; TIJDEMAN, H.

    2001-06-01

    In this paper, an analytical two-dimensional model is presented for the acousto-elastic behaviour of double-wall panels with a thin viscothermal air layer. The model for the air is based on the low reduced frequency solution as introduced by Beltman (1998 Ph.D. Thesis, University of Twente; 1999 Journal of Sound and Vibration227, (Part I), 555-586;227 (Part II), 587-609; Beltman et al., 1997 Journal of Sound and Vibration206 , 217-241; 1998 Journal of Sound and Vibration216, 159-185) [1-5] and includes, apart from inertia and compressibility, the effects of viscosity and thermal conductivity. With the analytical model eigenfrequencies were determined and response and transmission calculations were performed. It is shown that high damping coefficients for double-wall panels can be obtained by using the viscous characteristics of the fluid layer. The model makes it possible to conduct parameter analyses very easily and efficiently, which is important for design studies. Furthermore, the model gives exact results for both the vibrational behaviour and the sound transmission characteristics of double-wall panels which can be used to validate numerical codes.

  7. Suppression mechanism of inter-tube transfer in double-wall carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Uryu, Seiji

    2005-03-01

    Double-wall carbon nanotubes have incommensurate lattice structure and are quasi-periodic[1,2]. Therefore, inter-tube transfer of electrons between incommensurate tubes is the key to understanding of double-wall tubes. Although some theoretical studies reported suppression of inter-tube transfer in multiwall tubes[3], the mechanism has not been well understood. The purpose of this paper is to clarify effects of inter-tube transfer in double-wall tubes. Using a tight-binding model length-dependence of conductance due to inter-tube transfer is calculated. The conductance is negligibly small in comparison to the conductance quantum and oscillates around an average which is approximately independent of the length. It is revealed based on the first-order perturbation theory that the result is attributed to quasi-periodic oscillation of position dependence of small local effective inter-tube coupling. [1] M. Kociak, K. Suenaga, K. Hirahara, Y. Saito, T. Nakahira, and S. Iijima, Phys. Rev. Lett. 89 (2002) 155501. [2] J. M. Zuo, I. Vartanyants, M. Gao, R. Zhang, and L. A. Nagahara, Science 300 (2003) 1419. [3] Y.-G. Yoon, P. Delaney, and S. G. Louie, Phys. Rev. B 66 (2002) 073407.

  8. Crystal orbital study on the double walls made of nanotubes encapsulated inside zigzag carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Zhao, Xin; Qiao, Weiye; Li, Yuliang; Huang, Yuanhe

    2015-01-01

    The structure stabilities and electronic properties are investigated by using ab initio self-consistent-field crystal orbital method based on density functional theory for the one-dimensional (1D) double-wall nanotubes made of n-gon SiO2 nanotubes encapsulated inside zigzag carbon nanotubes. It is found that formation of the combined systems is energetically favorable when the distance between the two constituents is around the Van der Waals scope. The obtained band structures show that all the combined systems are semiconductors with nonzero energy gaps. The frontier energy bands (the highest occupied band and the lowest unoccupied band) of double-wall nanotubes are mainly derived from the corresponding carbon nanotubes. The mobilities of charge carriers are calculated to be within the range of 102-104 cm2 V-1 s-1 for the hybrid double-wall nanotubes. Young's moduli are also calculated for the combined systems. For the comparison, geometrical and electronic properties of n-gon SiO2 nanotubes are also calculated and discussed.

  9. Robust, double-walled microcapsules for self-healing polymeric materials.

    PubMed

    Caruso, Mary M; Blaiszik, Benjamin J; Jin, Henghua; Schelkopf, Stuart R; Stradley, Dylan S; Sottos, Nancy R; White, Scott R; Moore, Jeffrey S

    2010-04-01

    Double-walled polyurethane/poly(urea-formaldehyde) microcapsules (PU/UF) are prepared for use in self-healing materials. This modified encapsulation procedure combines two chemistries to form more robust capsule shell walls in a single operation. Robust capsules are formed by this procedure as long as the aromatic polyisocyanate prepolymer is soluble in the core liquid and the core liquid is compatible with isocyanates. Compared to a standard UF encapsulation, the modified procedure results in capsules with an increase in shell wall thickness from 200 to 675 nm as a function of the amount of PU added to the core liquid. Thermal stability of PU/UF microcapsules prepared with varying amounts of PU is compared to UF microcapsules. Mechanical properties of the PU/UF microcapsules are assessed from single-capsule compression testing.

  10. Quantum interference effects on the intensity of the G modes in double-walled carbon nanotubes

    DOE PAGES

    Tran, Huy Nam; Blancon, Jean-Christophe Robert; Arenal, Raul; ...

    2017-05-08

    The effects of quantum interferences on the excitation dependence of the intensity of G modes have been investigated on single-walled carbon nanotubes [Duque et al., Phys. Rev. Lett.108, 117404 (2012)]. In this work, by combining optical absorption spectroscopy and Raman scattering on individual index identified double-walled carbon nanotubes, we examine the experimental excitation dependence of the intensity of longitudinal optical and transverse optical G modes of the constituent inner and outer single-walled carbon nanotubes. The observed striking dependencies are understood in terms of quantum interference effects. Considering such effects, the excitation dependence of the different components of the G modesmore » permit to unambiguously assign each of them as originating from the longitudinal or transverse G modes of inner and outer tubes.« less

  11. Simulated Solar Heat Tests of M.U.S.T. Air-Inflatable, Double-Wall Hospital Ward Shelters

    DTIC Science & Technology

    1974-05-01

    mm »•’(. oc oc CO c CD l*»r—^ TECHNICAL REPORT TR75-118 AMEL SIMULATED SOLAR HEAT TESTS OF M.U.S.T. AIR-INFLATABLE, DOUBLE-WALL HOSPITAL ...8217^/ 2. OOVT ACCESSION NO SIMULATED^OLAR HEAT TESTS OF M.U.S.T. AIR- INFLATABLE, DOUBLE-WALL HOSPITAL WARD SHELTERS. - .^L . 31 f / AUTHOR 1250...for Building Technology conducted solar heat load tests on five sections of M.U.S.T. air-inflatable, double-wall hospital ward shelters. The purpose

  12. Fabrication Of Double Wall Tube By U-O Press Forming And Pulsed Gas Tungsten Arc-welding

    NASA Astrophysics Data System (ADS)

    Kasuga, Yukio; Kawamori, Shigehiro; Kuroda, Kiyoshi; Okai, Toshihiko

    2011-01-01

    Double walled tubes were trially fabricated by press-forming and arc-welding, as difficulty in fabrication was anticipated in the case of roll-forming. U-O press-formed double walled sheets are TIG arc- welded. For determination of welding conditions, overlapped flat sheets were employed and butt-welded including pulsed arc-welding. Pulse from 1 to 100Hz is effective to obtain penetrated weld bead. With this, the double walled tube could be arc-welded, which could not be achieved by conventional TIG arc-welding.

  13. Average Temperature Model of Double-Row-Pipe Frozen Soil Wall by Equivalent Trapezoid Method

    NASA Astrophysics Data System (ADS)

    Hu, Xiang-dong

    2010-05-01

    Average temperature is pre-requisite in obtaining the mechanical parameters and bearing capacity of frozen soil, and further evaluation of safety of the frozen soil wall could thus be made. This paper introduced Bakholdin's analytical solution for temperature field under double-row-pipe freezing and its correction when counting for the actual freezing temperature of soil. On the base of all these, an analytical model, namely equivalent trapezoid model was developed to calculate the average temperature of frozen soil wall under double-row-pipe freezing. This approach was to, on the base of Bakholdin formula and using equivalent trapezoid method, calculate the average temperature of a certain section which indicated the condition of the whole freezing soil wall. Furthermore, for possible parameter range of freezing tube layout might be applied in actual construction, this paper compared average temperatures of frozen soil wall obtained by the equivalent trapezoid method and by numerical integration of Bakholdin's analytical solution. The result showed that the discrepancy was small enough (<1.32%) to be ignored and the calculation accuracy of equivalent trapezoid method was competent for engineering practice.

  14. Efficient implementation of a van der Waals density functional: application to double-wall carbon nanotubes.

    PubMed

    Román-Pérez, Guillermo; Soler, José M

    2009-08-28

    We present an efficient implementation of the van der Waals density functional of Dion et al. [Phys. Rev. Lett. 92, 246401 (2004)], which expresses the nonlocal correlation energy as a double spatial integral. We factorize the integration kernel and use fast Fourier transforms to evaluate the self-consistent potential, total energy, and atomic forces, in O(NlogN) operations. The resulting overhead, for medium and large systems, is a small fraction of the total computational cost, representing a dramatic speedup over the O(N(2)) evaluation of the double integral. This opens the realm of first-principles simulations to the large systems of interest in soft matter and biomolecular problems. We apply the method to calculate the binding energies and the barriers for relative translation and rotation in double-wall carbon nanotubes.

  15. Vibro-acoustic modelling of aircraft double-walls with structural links using Statistical Energy Analysis

    NASA Astrophysics Data System (ADS)

    Campolina, Bruno L.

    The prediction of aircraft interior noise involves the vibroacoustic modelling of the fuselage with noise control treatments. This structure is composed of a stiffened metallic or composite panel, lined with a thermal and acoustic insulation layer (glass wool), and structurally connected via vibration isolators to a commercial lining panel (trim). The goal of this work aims at tailoring the noise control treatments taking design constraints such as weight and space optimization into account. For this purpose, a representative aircraft double-wall is modelled using the Statistical Energy Analysis (SEA) method. Laboratory excitations such as diffuse acoustic field and point force are addressed and trends are derived for applications under in-flight conditions, considering turbulent boundary layer excitation. The effect of the porous layer compression is firstly addressed. In aeronautical applications, compression can result from the installation of equipment and cables. It is studied analytically and experimentally, using a single panel and a fibrous uniformly compressed over 100% of its surface. When compression increases, a degradation of the transmission loss up to 5 dB for a 50% compression of the porous thickness is observed mainly in the mid-frequency range (around 800 Hz). However, for realistic cases, the effect should be reduced since the compression rate is lower and compression occurs locally. Then the transmission through structural connections between panels is addressed using a four-pole approach that links the force-velocity pair at each side of the connection. The modelling integrates experimental dynamic stiffness of isolators, derived using an adapted test rig. The structural transmission is then experimentally validated and included in the double-wall SEA model as an equivalent coupling loss factor (CLF) between panels. The tested structures being flat, only axial transmission is addressed. Finally, the dominant sound transmission paths are

  16. Reflection and transmission of regular waves from/through single and double perforated thin walls

    NASA Astrophysics Data System (ADS)

    Chioukh, Nadji; Çevik, Esin; Yüksel, Yalçin

    2017-08-01

    In this paper, reflection and transmission coefficients of regular waves from/through perforated thin walls are investigated. Small scale laboratory tests have been performed in a wave flume firstly with single perforated thin Plexiglas plates of various porosities. The plate is placed perpendicular to the flume with the height from the flume bottom to the position above water surface. With this thin wall in the flume wave overtopping is prohibited and incident waves are able to transmit. The porosities of the walls are achieved by perforating the plates with circular holes. Model settings with double perforated walls parallel to each other forming so called chamber system, have been also examined. Several parameters have been used for correlating the laboratory tests' results. Experimental data are also compared with results from the numerical model by applying the multi-domain boundary element method (MDBEM) with linear wave theory. Wave energy dissipation due to the perforations of the thin wall has been represented by a simple yet effective porosity parameter in the model. The numerical model with the MDBEM has been further validated against the previously published data.

  17. Detection of biological objects using dynamic characteristics of double-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Patel, Ajay M.; Joshi, Anand Y.

    2015-08-01

    This study explores double-walled carbon nanotubes as the sensing devices for biological objects including viruses and bacteria. The biological objects studied include alanine with amino terminal residue, deoxyadenosine with free residue, Coronaviridae and Bartonella bacilliformis. An expression has been articulated to identify the mass of biological objects from the shift of frequency. Sensitivity of the sensor has been calculated when subjected to such biological objects. Molecular structural mechanics approach has been used for investigating the vibrational responses of zigzag and armchair double-walled carbon nanotube-based nano biosensors. The elastic properties of beam element are calculated by considering mechanical characteristics of covalent bonds between the carbon atoms in the hexagonal lattice. Spring elements are used to describe the interlayer interactions between the inner and outer tubes caused due to the van der Waals forces. The mass of each beam element is assumed as point mass at nodes coinciding with carbon atoms at inner and outer wall of DWCNT. Based on the sensitivity and the frequency shift it can be concluded that cantilever zigzag DWCNTs are better candidates for detecting the biological objects.

  18. Theoretical Study of α-V2O5 -Based Double-Wall Nanotubes.

    PubMed

    Porsev, Vitaly V; Bandura, Andrei V; Evarestov, Robert A

    2015-10-05

    First-principles calculations of the atomic and electronic structure of double-wall nanotubes (DWNTs) of α-V2 O5 are performed. Relaxation of the DWNT structure leads to the formation of two types of local regions: 1) bulk-type regions and 2) puckering regions. Calculated total density of states (DOS) of DWNTs considerably differ from that of single-wall nanotubes and the single layer, as well as from the DOS of the bulk and double layer. Small shoulders that appear on edges of valence and conduction bands result in a considerable decrease in the band gaps of the DWNTs (up to 1 eV relative to the single-layer gaps). The main reason for this effect is the shift of the inner- and outer-wall DOS in opposite directions on the energetic scale. The electron density corresponding to shoulders at the conduction-band edges is localized on vanadium atoms of the bulk-type regions, whereas the electron density corresponding to shoulders at the valence-band edges belongs to oxygen atoms of both regions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. A molecular dynamics study on the vibration of carbon and boron nitride double-walled hybrid nanotubes

    NASA Astrophysics Data System (ADS)

    Ansari, R.; Ajori, S.

    2015-09-01

    Synthesis of hybrid nanotubes to overcome the drawbacks of individual pure nanotubes in order to apply them in novel nanodevices has attracted great interest of researchers. To this end, pure single- and double-walled boron nitride nanotubes together with carbon and boron nitride double-walled hybrid nanotubes are simulated through molecular dynamics simulations in order to study their vibrational behavior. The natural frequency of nanotubes is computed, and the effects of geometrical parameters and boundary conditions on the natural frequency are investigated. According to the generated results, the natural frequency of boron nitride nanotubes is higher than that of their carbon counterpart and nanotubes with clamped boundary conditions possess the highest natural frequency compared to other types of boundary conditions. Also, the natural frequency of double-walled hybrid nanotubes is found to be between those of pure double-walled boron nitride and carbon nanotubes with small lengths. It is found that the natural frequency of double-walled hybrid nanotubes is less sensitive to length increase compared to pure double-walled carbon and boron nitride ones, leading to higher frequencies at greater lengths. Finally, to study the variation in natural frequency with the length, a rational curve is fitted to each data set and the corresponding constants are computed.

  20. Double-wall TiO2 nanotube arrays: enhanced photocatalytic activity and in situ TEM observations at high temperature.

    PubMed

    Xue, Chaorui; Narushima, Takashi; Ishida, Yohei; Tokunaga, Tomoharu; Yonezawa, Tetsu

    2014-11-26

    By decreasing the water content in an NH4F and glycerol-water electrolyte, the transition from single-wall to double-wall TiO2 nanotube arrays was successfully achieved using an anodization method. The double-wall TiO2 nanotube structures exhibited better photocatalytic activity than the typical single-wall structures. After modification with platinum nanoparticles, the photocatalytic activity of both the single- and double-wall TiO2 nanotubes was improved further. In situ observations at the annealing temperature of the TiO2 nanotubes were performed using a transmission electron microscopy (TEM) system. A slower structural failure of the nanotubes was obtained with the introduction of oxygen gas into the TEM column compared with the structural changes observed under high-vacuum conditions without the introduction of oxygen gas. These behaviors suggest that oxygen injection is an important factor in stabilizing the TiO2 nanotubes during the in situ TEM annealing process. The high-magnification TEM images of the double-wall TiO2 nanotubes revealed that the sintering of the inner wall can draw a clear distinction between the inner and outer walls.

  1. Enhanced catalytic activity of sub-nanometer titania clusters confined inside double-wall carbon nanotubes.

    PubMed

    Zhang, Hongbo; Pan, Xiulian; Liu, Jingyue Jimmy; Qian, Weizhong; Wei, Fei; Huang, Yuying; Bao, Xinhe

    2011-07-18

    Sub-nanometer titania clusters have been homogeneously dispersed within double-wall carbon nantubes (DWNTs) with an inner diameter ranging from 1.0 to 1.5 nm. The confined titania exhibits a much higher activity than the titania particles attached on the outside walls of the DWNTs (the outside titania) in the epoxidation of propylene by H(2)O(2). XPS, XANES and Raman spectroscopy data suggest electron transfer from titanium to the inner surfaces of the DWNTs. In contrast, no electron transfer has been observed for the outside titania. We also found that the extent of this confinement-induced electron transfer is temperature dependent. The enhanced activity of the confined titania clusters is likely attributed to their small sizes and the interaction with the DWNT surface. The synthesis method that we developed here can be readily applied to incorporation of other metal/metal oxide nanoparticles into carbon nanotubes.

  2. Mechanical coupled vibrations in an individual double-walled carbon nanotube

    NASA Astrophysics Data System (ADS)

    Boutahir, Mourad; Rahmani, Abdelhai; Chadli, Hassan; Rahmani, Abdelali

    2016-05-01

    In this paper we calculate the Raman spectra of different double-walled carbon nanotubes (DWCNTs) by using the spectral moments method. Using a convenient Lennard-Jones expression of the van der Waals intermolecular interaction between the inner and outer tubes, the optimized structures of DWCNT are derived. We found that the C-C bond length in DWCNT is depending on the metallic (M) or semiconducting (Sc) character of the inner and outer nanotubes. We show that the radial breathing-like modes (RBLM) of DWCNT are characterized by concerted inner and outer wall motions. Comparison with Raman spectra measurements is given. Contribution to the topical issue "Materials for Energy Harvesting, Conversion and Storage (ICOME 2015) - Elected submissions", edited by Jean-Michel Nunzi, Rachid Bennacer and Mohammed El Ganaoui

  3. Van der Waals-coupled electronic states in incommensurate double-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Liu, Kaihui; Jin, Chenhao; Hong, Xiaoping; Kim, Jihoon; Zettl, Alex; Wang, Enge; Wang, Feng

    2014-10-01

    Non-commensurate two-dimensional materials such as a twisted graphene bilayer or graphene on boron nitride, consisting of components that have no finite common unit cell, exhibit emerging moiré physics such as novel Van Hove singularities, Fermi velocity renormalization, mini Dirac points and Hofstadter butterflies. Here we use double-walled carbon nanotubes as a model system for probing moiré physics in incommensurate one-dimensional systems, by combining structural and optical characterizations. We show that electron wavefunctions between incommensurate inner- and outer-wall nanotubes can hybridize strongly, contrary to the conventional wisdom of negligible electron hybridization due to destructive interference. The chirality-dependent inter-tube electronic coupling is described by one-dimensional zone folding of the electronic structure of twisted-and-stretched graphene bilayers. Our results demonstrate that incommensurate van der Waals interactions can be important for engineering the electronic structure and optical properties of one-dimensional materials.

  4. Low temperature magnetic phase transition and interlayer coupling in double-wall carbon nanotubes

    SciTech Connect

    Diamantopoulou, A.; Glenis, S.; Likodimos, V.; Guskos, N.

    2014-08-28

    The magnetic properties of double wall carbon nanotubes (DWCNTs) were investigated using electron spin resonance (ESR) spectroscopy. An asymmetric resonance line of low intensity was identified and analyzed by the superimposition of a narrow and a broad metallic lineshape, attributed to the distinct contributions of defect spins located on the inner and outer DWCNTs shells. The spin susceptibilities of both ESR components revealed a ferromagnetic phase transition at low temperatures (T < 10 K) with small variation in the corresponding Curie-Weiss temperatures, approaching closely that of metallic single wall carbon nanotubes. Interlayer coupling between the DWCNT layers is suggested to effectively reduce the difference between the transition temperatures for the inner and outer shells and enhance spin-spin interactions between defect spins via the RKKY-type interaction of localized spins with conduction electrons.

  5. Buckling behaviour of composites with double walled nanotubes from carbon and phosphorus.

    PubMed

    Cai, Kun; Wan, Jing; Yang, Likui; Wei, Ning; Shi, Jiao; Qin, Qing-Hua

    2017-04-12

    Due to weak interactions among phosphorus atoms in black phosphorene, a nanotube obtained by curling single-layer black phosphorus is not as stable as a carbon nanotube (CNT) at finite temperature. In the present work, we recommend a new 1D composite material with a double-walled nanotube (DWNT) from a black phosphorus nanotube (BPNT) and a CNT. The dynamic response of the composite DWNTs is simulated using a molecular dynamics approach. Effects of the factors including temperature, slenderness and configurations of DWNTs on dynamic behavior of the composite are discussed. Compared with a single-walled BPNT, the composite DWNTs under uniaxial compression show some unique properties. When a BPNT is embedded in a CNT which will not only isolate the BPNT from the ambient conditions, but also improve the capability of axial deformation of the BPNT, the system will not collapse rapidly even if the BPNT has been buckled.

  6. Low temperature magnetic phase transition and interlayer coupling in double-wall carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Diamantopoulou, A.; Glenis, S.; Likodimos, V.; Guskos, N.

    2014-08-01

    The magnetic properties of double wall carbon nanotubes (DWCNTs) were investigated using electron spin resonance (ESR) spectroscopy. An asymmetric resonance line of low intensity was identified and analyzed by the superimposition of a narrow and a broad metallic lineshape, attributed to the distinct contributions of defect spins located on the inner and outer DWCNTs shells. The spin susceptibilities of both ESR components revealed a ferromagnetic phase transition at low temperatures (T < 10 K) with small variation in the corresponding Curie-Weiss temperatures, approaching closely that of metallic single wall carbon nanotubes. Interlayer coupling between the DWCNT layers is suggested to effectively reduce the difference between the transition temperatures for the inner and outer shells and enhance spin-spin interactions between defect spins via the RKKY-type interaction of localized spins with conduction electrons.

  7. Wave propagation in double walled carbon nanotubes by using doublet mechanics theory

    NASA Astrophysics Data System (ADS)

    Gul, Ufuk; Aydogdu, Metin

    2017-09-01

    Flexural and axial wave propagation in double walled carbon nanotubes embedded in an elastic medium and axial wave propagation in single walled carbon nanotubes are investigated. A length scale dependent theory which is called doublet mechanics is used in the analysis. Governing equations are obtained by using Hamilton principle. Doublet mechanics results are compared with classical elasticity and other size dependent continuum theories such as strain gradient theory, nonlocal theory and lattice dynamics. In addition, experimental wave frequencies of graphite are compared with the doublet mechanics theory. It is obtained that doublet mechanics gives accurate results for flexural and axial wave propagation in nanotubes. Thus, doublet mechanics can be used for the design of electro-mechanical nano-devices such as nanomotors, nanosensors and oscillators.

  8. Testing of and model development for double-walled thermal tubular

    SciTech Connect

    Satchwell, R.M.; Johnson, L.A. Jr.

    1992-08-01

    Insulated tubular products have become essential for use in steam injection projects. In a steam injection project, steam is created at the surface by either steam boilers or generators. During this process, steam travels from a boiler through surface lines to the wellhead, down the wellbore to the sandface, and into the reservoir. For some projects to be an economic success, cost must be reduced and oil recoveries must be increased by reducing heat losses in the wellbore. With reduced heats losses, steam generation costs are lowered and higher quality steam can be injected into the formation. To address this need, work under this project consisted of the design and construction of a thermal flow loop, testing a double-walled tubular product that was manufactured by Inter-Mountain Pipe Company, and the development and verification of a thermal hydraulic numerical simulator for steam injection. Four different experimental configurations of the double-walled pipe were tested. These configurations included: (1) bare pipe case, (2) bare pipe case with an applied annular vacuum, (3) insulated annular pipe case, and (4) insulated annular pipe case with an applied annular vacuum. Both the pipe body and coupling were tested with each configuration. The results of the experimental tests showed that the Inter-Mountain Pipe Company double-walled pipe body achieved a 98 percent reduction in heat loss when insulation was applied to the annular portion of the pipe. The application of insulation to the annular portion of the coupling reduced the heat losses by only 6 percent. In tests that specified the use of a vacuum in the annular portion of the pipe, leaks were detected and the vacuum could not be held.

  9. Conductive nanocomposite films based on functionalized double-walled carbon nanotubes dispersed in PEDOT:PSS

    NASA Astrophysics Data System (ADS)

    De Girolamo Del Mauro, A.; Nenna, G.; Grimaldi, I. A.; Villani, F.; Pandolfi, G.; Minarini, C.

    2012-07-01

    High conductive and transparent nanocomposite films consisting of poly(3,4-ethylenedioxythiphene):poly(4-styrenesulfonate) (PEDOT:PSS) doped with dimethyl sulfoxide (DMSO) and double-walled carbon nanotubes functionalized with carboxylic groups (c-DWCNTs) were spin-coated and their electrical (four-point measurement), optical (UV-Vis spectroscopy), morphological (SEM, AFM) and structural (Raman) properties were investigated. Thin films of c-DWCNT/DMSO-PEDOT:PSS resulted more conductive (950 S/cm) in comparison with the pristine DMSOPEDOT: PSS films (700 S/cm).

  10. Double-walled boron nitride nanotubes grown by floating catalyst chemical vapor deposition.

    PubMed

    Kim, Myung Jong; Chatterjee, Shahana; Kim, Seung Min; Stach, Eric A; Bradley, Mark G; Pender, Mark J; Sneddon, Larry G; Maruyama, Benji

    2008-10-01

    One-dimensional nanostructures exhibit quantum confinement which leads to unique electronic properties, making them attractive as the active elements for nanoscale electronic devices. Boron nitride nanotubes are of particular interest since, unlike carbon nanotubes, all chiralities are semiconducting. Here, we report a synthesis based on the use of low pressures of the molecular precursor borazine in conjunction with a floating nickelocene catalyst that resulted in the formation of double-walled boron nitride nanotubes. As has been shown for carbon nanotube production, the floating catalyst chemical vapor deposition method has the potential for creating high quality boron nitride nanostructures with high production volumes.

  11. Active Control of Vibrations and Noise of Double Wall Cylindrical Shells

    NASA Astrophysics Data System (ADS)

    Wang, C.-Y.; Vaicaitis, R.

    1998-10-01

    Active control of vibrations and noise transmissions of double wall composite cylindrical shells using pairs of spatially discrete piezoelectric actuators is investigated. The velocity feedback and sound pressure rate feedback control procedures are developed. The inner and outer shells which are separated by a soft core are modelled by Love's thin shell theory for laminate composite materials and the inputs are taken as stationary random pressures and/or random point forces. A galerkin-like procedure is used to obtain solutions of the governing structural-acoustic equations. Parametric studies are performed to demonstrate the effect of actuator placement, actuator size, control gains, spillover, structural and acoustic damping characteristics

  12. On the vibration of double-walled carbon nanotubes using molecular structural and cylindrical shell models

    NASA Astrophysics Data System (ADS)

    Ansari, R.; Rouhi, S.; Aryayi, M.

    2016-01-01

    The vibrational behavior of double-walled carbon nanotubes is studied by the use of the molecular structural and cylindrical shell models. The spring elements are employed to model the van der Waals interaction. The effects of different parameters such as geometry, chirality, atomic structure and end constraint on the vibration of nanotubes are investigated. Besides, the results of two aforementioned approaches are compared. It is indicated that by increasing the nanotube side length and radius, the computationally efficient cylindrical shell model gives rational results.

  13. Hybrid heterojunction and photoelectrochemistry solar cell based on silicon nanowires and double-walled carbon nanotubes.

    PubMed

    Shu, Qinke; Wei, Jinquan; Wang, Kunlin; Zhu, Hongwei; Li, Zhen; Jia, Yi; Gui, Xuchun; Guo, Ning; Li, Xinming; Ma, Chaoran; Wu, Dehai

    2009-12-01

    A hybrid solar cell model composed of a heterojunction cell and a photoelectrochemical (PEC) cell has been proposed and characterized. In the hybrid cell, a thin film of double-walled carbon nanotubes forms a heterojunction with the silicon nanowire (SiNW) array and also functions as the transparent counter electrode of the PEC cell. The cell performance can be readily tuned by controlling the SiNW density. Under AM 1.5G illumination, a power conversion efficiency of 1.29%, higher than those reported for SiNW array-based PEC cells, has been obtained.

  14. Prediction of radial breathing-like modes of double-walled carbon nanotubes with arbitrary chirality

    NASA Astrophysics Data System (ADS)

    Ghavanloo, Esmaeal; Fazelzadeh, S. Ahmad

    2014-10-01

    The radial breathing-like modes (RBLMs) of double-walled carbon nanotubes (DWCNTs) with arbitrary chirality are investigated by a simple analytical model. For this purpose, DWCNT is considered as double concentric elastic thin cylindrical shells, which are coupled through van der Waals (vdW) forces between two adjacent tubes. Lennard-Jones potential and a molecular mechanics model are used to calculate the vdW forces and to predict the mechanical properties, respectively. The validity of these theoretical results is confirmed through the comparison of the experimental results. Finally, a new approach is proposed to determine the diameters and the chiral indices of the inner and outer tubes of the DWCNTs with high precision.

  15. The improvement of a simple theoretical model for the prediction of the sound insulation of double leaf walls.

    PubMed

    Davy, John L

    2010-02-01

    This paper presents a revised theory for predicting the sound insulation of double leaf cavity walls that removes an approximation, which is usually made when deriving the sound insulation of a double leaf cavity wall above the critical frequencies of the wall leaves due to the airborne transmission across the wall cavity. This revised theory is also used as a correction below the critical frequencies of the wall leaves instead of a correction due to Sewell [(1970). J. Sound Vib. 12, 21-32]. It is found necessary to include the "stud" borne transmission of the window frames when modeling wide air gap double glazed windows. A minimum value of stud transmission is introduced for use with resilient connections such as steel studs. Empirical equations are derived for predicting the effective sound absorption coefficient of wall cavities without sound absorbing material. The theory is compared with experimental results for double glazed windows and gypsum plasterboard cavity walls with and without sound absorbing material in their cavities. The overall mean, standard deviation, maximum, and minimum of the differences between experiment and theory are -0.6 dB, 3.1 dB, 10.9 dB at 1250 Hz, and -14.9 dB at 160 Hz, respectively.

  16. Investigation of the pulmonary bioactivity of double-walled carbon nanotubes.

    PubMed

    Sager, Tina M; Wolfarth, Michael W; Battelli, Lori A; Leonard, Stephen S; Andrew, Michael; Steinbach, Thomas; Endo, Morinobu; Tsuruoka, Shuji; Porter, Dale W; Castranova, Vincent

    2013-01-01

    Double-walled carbon nanotubes (DWCNT) are a rather new and unexplored variety of carbon nanotubes. Previously conducted studies established that exposure to a variety of carbon nanotubes produced lung inflammation and fibrosis in mice after pharyngeal aspiration. However, the bioactivity of double-walled carbon nanotubes (DWCNT) has not been determined. In this study, the hypothesis that DWCNT would induce pulmonary toxicity was explored by analyzing the pulmonary bioactivity of DWCNT. To test this hypothesis, C57Bl/6 mice were exposed to DWCNT by pharyngeal aspiration. Mice underwent whole-lung lavage (WLL) to assess pulmonary inflammation and injury, and lung tissue was examined histologically for development of pulmonary disease as a function of dose and time. The results showed that DWCNT exposure produced a dose-dependent increase in WLL polymorphonuclear leukocytes (PMN), indicating that DWCNT exposure initiated pulmonary inflammation. DWCNT exposure also produced a dose-dependent rise in lactate dehydrogenase (LDH) activity, as well as albumin levels, in WLL fluid, indicating that DWCNT exposure promoted cytotoxicity as well as decreases in the integrity of the blood-gas barrier in the lung, respectively. In addition, at 7 and 56 d postexposure, the presence of significant alveolitis and fibrosis was noted in mice exposed to 40 μg/mouse DWCNT. In conclusion, this study provides insight into previously uninvestigated pulmonary bioactivity of DWCNT exposure. Data indicate that DWCNT exposure promotes inflammation, injury, and fibrosis in the lung.

  17. Separation of double-wall carbon nanotubes by electronic type and diameter.

    PubMed

    Streit, J K; Lam, S; Piao, Y; Hight Walker, A R; Fagan, J A; Zheng, M

    2017-02-16

    We introduce a new procedure for the efficient isolation and subsequent separation of double-wall carbon nanotubes (DWCNTs). A simplified, rate zonal ultracentrifugation (RZU) process is first applied to obtain samples of highly-enriched DWCNTs from a raw carbon nanotube material that has both single- and double-wall carbon nanotubes. Using this purified DWCNT suspension, we demonstrate for the first time that DWCNTs can be further processed using aqueous two-phase extraction (ATPE) for sequential separation by electronic structure and diameter. Additionally, we introduce analytical ultracentrifugation (AUC) as a new method for DWCNT characterization to assess DWCNT purity in separated samples. Results from AUC analysis are utilized to compare two DWCNT separation schemes. We find that RZU processing followed by sequential bandgap and diameter sorting via ATPE provides samples of highest DWCNT enrichment, whereas single-step redox sorting of the same raw material through ATPE yields SWCNT/DWCNT mixtures of similar diameter and electronic character. The presented methods offer significant advancement in DWCNT processing and separation while also providing a promising alternative for DWCNT sample analysis.

  18. Additional double-wall roof in single-wall, closed, convective incubators: Impact on body heat loss from premature infants and optimal adjustment of the incubator air temperature.

    PubMed

    Delanaud, Stéphane; Decima, Pauline; Pelletier, Amandine; Libert, Jean-Pierre; Stephan-Blanchard, Erwan; Bach, Véronique; Tourneux, Pierre

    2016-09-01

    Radiant heat loss is high in low-birth-weight (LBW) neonates. Double-wall or single-wall incubators with an additional double-wall roof panel that can be removed during phototherapy are used to reduce Radiant heat loss. There are no data on how the incubators should be used when this second roof panel is removed. The aim of the study was to assess the heat exchanges in LBW neonates in a single-wall incubator with and without an additional roof panel. To determine the optimal thermoneutral incubator air temperature. Influence of the additional double-wall roof was assessed by using a thermal mannequin simulating a LBW neonate. Then, we calculated the optimal incubator air temperature from a cohort of human LBW neonate in the absence of the additional roof panel. Twenty-three LBW neonates (birth weight: 750-1800g; gestational age: 28-32 weeks) were included. With the additional roof panel, R was lower but convective and evaporative skin heat losses were greater. This difference can be overcome by increasing the incubator air temperature by 0.15-0.20°C. The benefit of an additional roof panel was cancelled out by greater body heat losses through other routes. Understanding the heat transfers between the neonate and the environment is essential for optimizing incubators.

  19. Retrofit wall system for insulation and lead encasement in older multi-family housing.

    SciTech Connect

    Wendt, R. L.

    1998-08-11

    This paper presents an approach to modernization or rehabilitation of buildings with uninsulated masonry walls that have lead-based paint hazards or deteriorated plaster walls. The approach provides a solution to lead contamination on the walls, increased energy efficiency and comfort improvements associated with better insulated building envelopes. The system sheaths or replaces damaged or contaminated walls with a tight, well-insulated, durable interior surface. The costs of this system are estimated to be less than those of other insulated wall systems. Modeling of the impact of this system shows significant improvement in energy performance. The energy savings over the life of this durable system contribute to significantly offset the often-times sizeable cost of lead hazard remediation.

  20. A density functional theory for association of fluid molecules with a functionalized surface: fluid-wall single and double bonding.

    PubMed

    Haghmoradi, Amin; Wang, Le; Chapman, Walter G

    2017-02-01

    In this manuscript we extend Wertheim's two-density formalism beyond its first order to model a system of fluid molecules with a single association site close to a planar hard wall with association sites on its surface in a density functional theory framework. The association sites of the fluid molecules are small enough that they can form only one bond, while the wall association sites are large enough to bond with more than one fluid molecule. The effects of temperature and of bulk fluid and wall site densities on the fluid density profile, extent of association, and competition between single and double bonding of fluid segments at the wall sites versus distance from the wall are presented. The theory predictions are compared with new Monte Carlo simulation results and they are in good agreement. The theory captures the surface coverage over wide ranges of temperature and bulk density by introducing the effect of steric hindrance in fluid association at a wall site.

  1. Influence of atomic vacancies on the dynamic characteristics of nanoresonators based on double walled carbon nanotube

    NASA Astrophysics Data System (ADS)

    Patel, Ajay M.; Joshi, Anand Y.

    2015-06-01

    The dynamic analysis of double walled carbon nanotubes (DWCNTs) with different boundary conditions has been performed using atomistic finite element method. The double walled carbon nanotube is modeled considering it as a space frame structure similar to a three dimensional beam. The elastic properties of beam element are calculated by considering mechanical characteristics of covalent bonds between the carbon atoms in the hexagonal lattice. Spring elements are used to describe the interlayer interactions between the inner and outer tubes caused due to the van der Waals forces. The mass of each beam element is assumed as point mass at nodes coinciding with carbon atoms at inner and outer wall of DWCNT. It has been reported that atomic vacancies are formed during the manufacturing process in DWCNT which tend to migrate leading to a change in the mechanical characteristics of the same. Simulations have been carried out to visualize the behavior of such defective DWCNTs subjected to different boundary conditions and when used as mass sensing devices. The variation of such atomic vacancies in outer wall of Zigzag and Armchair DWCNT is performed along the length and the change in response is noted. Moreover, as CNTs have been used as mass sensors extensively, the present approach is focused to explore the use of zigzag and armchair DWCNT as sensing device with a mono-atomic vacancy in it. The results clearly state that the dynamic characteristics are greatly influenced by defects like vacancies in it. A higher frequency shift is observed when the vacancy is located away from the fixed end for both Armchair as well as zigzag type of CNTs. A higher frequency shift is reported for armchair CNT for a mass of 10-22 g which remains constant for 10-21 g and then decreases gradually. Comparison with the other experimental and theoretical studies exhibits good association which suggests that defective DWCNTs can further be explored for mass sensing. This investigation is helpful

  2. Double-Wall Carbon Nanotubes for Wide-Band, Ultrafast Pulse Generation

    PubMed Central

    2014-01-01

    We demonstrate wide-band ultrafast optical pulse generation at 1, 1.5, and 2 μm using a single-polymer composite saturable absorber based on double-wall carbon nanotubes (DWNTs). The freestanding optical quality polymer composite is prepared from nanotubes dispersed in water with poly(vinyl alcohol) as the host matrix. The composite is then integrated into ytterbium-, erbium-, and thulium-doped fiber laser cavities. Using this single DWNT–polymer composite, we achieve 4.85 ps, 532 fs, and 1.6 ps mode-locked pulses at 1066, 1559, and 1883 nm, respectively, highlighting the potential of DWNTs for wide-band ultrafast photonics. PMID:24735347

  3. Preparation of large-area double-walled carbon nanotube films and application as film heater

    NASA Astrophysics Data System (ADS)

    Wu, Zi Ping; Wang, Jian Nong

    2009-11-01

    Large-area (larger than 30×30 cm 2) double-walled carbon nanotube (DWCNT) films are prepared and application as a heating element for film heaters is demonstrated. A high heating efficiency is observed. Measurements indicate that the use of the DWCNT film heater would save energy consumption up to 20-30% when compared with a commercial film-like metal-based heater. Morphological analysis reveals that the special surface structure, appropriate electric and high thermal conductivities of the film formed by the network of entangled nanotube bundles may lead to the high heating performance. Considering large-area, shape flexibility, negligible weight and easy manipulation, the film exhibits promising potential applications as a film heater for thermal control in aircrafts, medical equipment, home appliances and other industrial fields at low temperature (below 400 °C).

  4. Nonlinear free vibrations of curved double walled carbon nanotubes using differential quadrature method

    NASA Astrophysics Data System (ADS)

    Cigeroglu, Ender; Samandari, Hamed

    2014-11-01

    Nonlinear free vibration analysis of curved double-walled carbon nanotubes (DWNTs) embedded in an elastic medium is studied in this study. Nonlinearities considered are due to large deflection of carbon nanotubes (geometric nonlinearity) and nonlinear interlayer van der Waals forces between inner and outer tubes. The differential quadrature method (DQM) is utilized to discretize the partial differential equations of motion in spatial domain, which resulted in a nonlinear set of algebraic equations of motion. The effect of nonlinearities, different end conditions, initial curvature, and stiffness of the surrounding elastic medium, and vibrational modes on the nonlinear free vibration of DWCNTs is studied. Results show that it is possible to detect different vibration modes occurring at a single vibration frequency when CNTs vibrate in the out-of-phase vibration mode. Moreover, it is observed that boundary conditions have significant effect on the nonlinear natural frequencies of the DWCNT including multiple solutions.

  5. Conducting, transparent and flexible substrates obtained from interfacial thin films of double-walled carbon nanotubes.

    PubMed

    Souza, Victor H R; Flahaut, Emmanuel; Zarbin, Aldo J G

    2017-09-15

    Conducting and transparent interfacial thin films have been prepared from double-walled carbon nanotubes (DWCNT) and further deposited over glass and plastic (polyethylene terephtalate-PET) substrates. The morphology, vibrational structure as well as the optical and electrical properties have been evaluated. The influence of the DWCNT purifying treatment, the amount of carbon nanotubes used to prepare the thin films, and the annealing of the films at different temperatures has been evaluated to optimize both electrical and optical properties. Values of sheet resistance ranging from 0.53 to 27.8 kΩ □(-1) and transmittance at 550nm from 59 to 90% have been achieved. Similar behavior obtained for films deposited on PET or glass substrates indicate a good reproducibility of the method, besides the high potential for further applications on flexible devices. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Nonlinear Vibration Characteristics of Fluid-Filled Double-Walled Carbon Nanotubes

    NASA Astrophysics Data System (ADS)

    Yan, Y.; Wang, W. Q.; Zhang, L. X.

    Nonlinear vibration behaviors of double-walled carbon nanotubes (DWCNTs) with fluid inside the inner tube are investigated based on Donnell's cylindrical shell model and the more refined van der Waals (vdW) interaction formula. The Galerkin method and harmonic balance method are used to study the issue. The results obtained show that the radial vibrational modes of simply supported DWCNTs have twice the dynamical mode transitions as the frequency increases. The transitions correspond to twice the noncoaxial vibrations which play a critical role in electronic and transport properties of CNTs. Moreover, comparisons of the dynamical behaviors of fluid-filled DWCNTs with different wave numbers, radii and aspect ratios demonstrate that the amplitude-frequency curve topological forms are identical. Meanwhile, it is also concluded that the existence of fluid is significant for the value of amplitude ratio corresponding to noncoaxial vibration whereas it does not change the nonlinear vibrating topological pattern of amplitude-frequency curves.

  7. Fabrication of double-walled section models of the ITER vacuum vessel

    SciTech Connect

    Koizumi, K.; Kanamori, N.; Nakahira, M.; Itoh, Y.; Horie, M.; Tada, E.; Shimamoto, S.

    1995-12-31

    Trial fabrication of double-walled section models has been performed at Japan Atomic Energy Research Institute (JAERI) for the construction of ITER vacuum vessel. By employing TIG (Tungsten-arc Inert Gas) welding and EB (Electron Beam) welding, for each model, two full-scaled section models of 7.5 {degree} toroidal sector in the curved section at the bottom of vacuum vessel have been successfully fabricated with the final dimensional error of within {+-}5 mm to the nominal values. The sufficient technical database on the candidate fabrication procedures, welding distortion and dimensional stability of full-scaled models have been obtained through the fabrications. This paper describes the design and fabrication procedures of both full-scaled section models and the major results obtained through the fabrication.

  8. Atomic nanotube welders: boron interstitials triggering connections in double-walled carbon nanotubes.

    PubMed

    Endo, Morinobu; Muramatsu, Hiroyuki; Hayashi, Takuya; Kim, Yoong-Ahm; Van Lier, Gregory; Charlier, Jean-Christophe; Terrones, Humberto; Terrones, Mauricio; Dresselhaus, Mildred S

    2005-06-01

    Here we demonstrate that the incorporation of boron (B) atoms between double-walled carbon nanotubes (DWNTs) during thermal annealing (1400-1600 degrees C) results in covalent nanotube "Y" junctions, DWNT coalescence, and the formation of flattened multiwalled carbon nanotubes (MWNTs). These processes occur via the merging of adjacent tubes, which is triggered by B interstitial atoms. We observe that B atom interstitials between DWNTs are responsible for the rapid establishment of covalent connections between neighboring tubes (polymerization), thereby resulting in the fast annealing of the carbon cylinders with B atoms embedded in the newly created carbon nanotube network. Once B is in the lattice, tube faceting (polygonization) starts to occur, and the electronic properties are expected to change dramatically. Therefore, B atoms indeed act as atomic nanotube fusers (or welders), and this process could now be used in assembling novel electronic nanotube devices, nanotube networks, carbon nanofoams and heterojunctions exhibiting p-type electronic properties.

  9. Fabrication of flexible transparent conductive films from long double-walled carbon nanotubes

    PubMed Central

    Imazu, Naoki; Fujigaya, Tsuyohiko; Nakashima, Naotoshi

    2014-01-01

    The fabrication of flexible transparent conducting films (TCFs) is important for the development of the next-generation flexible devices. In this study, we used double-walled carbon nanotubes (DWCNTs) as the starting material and described a fabrication method of flexible TCFs. We have determined in a quantitative way that the key factors are the length and the dispersion states of the DWCNTs as well as the weight-ratios of dispersant polymer/DWCNTs. By controlling such factors, we have readily fabricated a flexible highly transparent (94% transmittance) and conductive (surface resistivity = 320 Ω sq−1) DWCNT film without adding any chemical doping that is often used to reduce the surface resistivity. By applying a wet coating, we have succeeded in the fabrication of large-scale conducting transparent DWCNT films based on the role-to-role method. PMID:27877666

  10. Condensation in the annulus of a double-walled cryogenic storage tank

    NASA Astrophysics Data System (ADS)

    Tarakad, R. R.; Durr, C. A.; Crawford, D. B.

    Mechanisms of condensation in the annular space of a double-walled cryogenic storage tank, some situations that can lead to such condensation, criteria for condensation, and methods to prevent condensation are discussed. The discussion emphasizes LNG tanks, but the results can be extended to LPG and NGL tanks. Factors that tend to reduce the rate of condensation or eliminate it include inflow of vapor into the annulus, warming of the tank contents, and decrease in tank pressure. Methods of preventing condensation include continuous purge in LNG tanks and control of the dew point temperature via controlling the vapor composition or by changing pressure in the tank. Condensation in a stratified tank is separately discussed.

  11. Non uniform shrinkages of double-walled carbon nanotube as induced by electron beam irradiation

    SciTech Connect

    Zhu, Xianfang Li, Lunxiong; Gong, Huimin; Yang, Lan; Sun, Chenghua

    2014-09-01

    Electron beam-induced nanoinstabilities of pristine double-walled carbon nanotubes (DWCNTs) of two different configurations, one fixed at both ends and another fixed at only one end, were in-situ investigated in transmission electron microscope at room temperature. It was observed that the DWCNT fixed at both ends shrank in its diameter uniformly. Meanwhile, the DWCNT fixed at only one end intriguingly shrank preferentially from its free cap end along its axial direction whereas its diameter shrinkage was offset. A mechanism of “diffusion” along with “evaporation” at room temperature which is driven by the nanocurvature of the DWCNTs, and the athermal activation induced by the electron beam was proposed to elucidate the observed phenomena. The effect of the interlayer interaction of the DWCNTs was also discussed.

  12. Extremely high thermal conductivity anisotropy of double-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Ma, Zhaoji; Guo, Zhengrong; Zhang, Hongwei; Chang, Tienchong

    2017-06-01

    Based on molecular dynamics simulations, we reveal that double-walled carbon nanotubes can possess an extremely high anisotropy ratio of radial to axial thermal conductivities. The mechanism is basically the same as that for the high thermal conductivity anisotropy of graphene layers - the in-plane strong sp2 bonds lead to a very high intralayer thermal conductivity while the weak van der Waals interactions to a very low interlayer thermal conductivity. However, different from flat graphene layers, the tubular structures of carbon nanotubes result in a diameter dependent thermal conductivity. The smaller the diameter, the larger the axial thermal conductivity but the smaller the radial thermal conductivity. As a result, a DWCNT with a small diameter may have an anisotropy ratio of thermal conductivity significantly higher than that for graphene layers. The extremely high thermal conductivity anisotropy allows DWCNTs to be a promising candidate for thermal management materials.

  13. Insulated Concrete Form Walls Integrated With Mechanical Systems in a Cold Climate Test House

    SciTech Connect

    Mallay, D.; Wiehagen, J.

    2014-09-01

    Transitioning from standard light frame to a thermal mass wall system in a high performance home will require a higher level of design integration with the mechanical systems. The much higher mass in the ICF wall influences heat transfer through the wall and affects how the heating and cooling system responds to changing outdoor conditions. This is even more important for efficient, low-load homes with efficient heat pump systems in colder climates where the heating and cooling peak loads are significantly different from standard construction. This report analyzes a range of design features and component performance estimates in an effort to select practical, cost-effective solutions for high performance homes in a cold climate. Of primary interest is the influence of the ICF walls on developing an effective air sealing strategy and selecting an appropriate heating and cooling equipment type and capacity. The domestic water heating system is analyzed for costs and savings to investigate options for higher efficiency electric water heating. A method to ensure mechanical ventilation air flows is examined. The final solution package includes high-R mass walls, very low infiltration rates, multi-stage heat pump heating, solar thermal domestic hot water system, and energy recovery ventilation. This solution package can be used for homes to exceed 2012 International Energy Conservation Code requirements throughout all climate zones and achieves the DOE Challenge Home certification.

  14. Raman and XPS analyses of pristine and annealed N-doped double-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Shi, Lei; Sauer, Markus; Domanov, Oleg; Rohringer, Philip; Ayala, Paola; Pichler, Thomas

    2015-11-01

    N-doped single/multi-walled carbon nanotubes (CNTs) were studied for long time from synthesis to properties. However, the stability of N in the CNT lattice still needs further developments. In this work, to obtain more stable N-doped CNTs, concentric double-walled (DW) CNTs with more N were synthesized using benzylamine as C and N source. In order to test the stability of N-doped DWCNTs, high-temperature annealing in vacuum was performed. By XPS and Raman spectroscopic measurements, we found that the N-doped DWCNTs are still stable under 1500 $\\,^{\\circ}\\mathrm{C}$: the graphitic N does not change at all, the molecular N is partly removed, and the pyridinic N ratio greatly increases by more than two times. The reason could be that the N atoms from the surrounded N-contained materials combine into the CNT lattice during the annealing. Compared with the undoped DWCNTs, no Raman frequency shift was observed for the RBM, the G-band, and the G'-band of the N-doped DWCNTs.

  15. Strain effects on the performance of zero-Schottky-barrier double-walled carbon nanotube transistors

    NASA Astrophysics Data System (ADS)

    Wahab, Md. Abdul; Khosru, Quazi D. M.

    2010-08-01

    Schrodinger's equation is solved using recursive Green's function algorithm self-consistently with Poisson's equation to study the transport physics of uniaxial and torsional strained double-walled (DW) carbon nanotube (CNT) field-effect transistors (FETs) and to analyze their performance. The characteristics and performance of proposed DW CNTFET are compared with existing single-walled (SW) CNTFET. The strain has great impact on the I-V characteristics of both SW and DW CNT devices. Tensile and torsional strains improve greatly the off-state current and on/off current ratio of both devices. Compressive strain improves on-state current, but this improvement is comparatively small. The effect of strain on off-state current, on-state current, and on/off current ratio is higher in SW CNTFET. The inverse subthreshold slope of DW CNTFET is better than SW CNTFET. But the variation in inverse subthreshold slope with strain is smaller in DW CNTFET. Unlike SW CNTFET the on-state transconductance of DW CNTFET improves with tensile and torsional strains, and degrades with compressive strain. The on-state cut-off frequency of DW CNTFET also shows opposite behavior to SW CNTFET with strain following on-state transconductance. Concrete Physical description is provided to explain all above changes with strain.

  16. First-principles calculations on double-walled inorganic nanotubes with hexagonal chiralities

    NASA Astrophysics Data System (ADS)

    Zhukovskii, Yuri F.; Evarestov, Robert A.; Bandura, Andrei V.; Losev, Maxim V.

    2011-06-01

    The two sets of commensurate double-walled boron nitride and titania hexagonally-structured nanotubes (DW BN and TiO2 NTs) possessing either armchair- or zigzag-type chiralities have been considered, i.e., (n1,n1)@(n2,n2) or (n1,0)@(n2,0), respectively. For symmetry analysis of these nanotubes, the line symmetry groups for one-periodic (1D) nanostructures with rotohelical symmetry have been applied. To analyze the structural and electronic properties of hexagonal DW NTs, a series of large-scale ab initio DFT-LCAO calculations have been performed using the hybrid Hartree-Fock/Kohn-Sham exchange-correlation functional PBE0 (as implemented in CRYSTAL-09 code). To establish the optimal inter-shell distances within DW NTs corresponding to the minima of calculated total energy, the chiral indices n1 and n2 of the constituent single-walled (SW) nanotubes have been successively varied.

  17. Protein encapsulation in and release from monodisperse double-wall polymer microspheres

    PubMed Central

    Xia, Yujie; Xu, Qingxing; Wang, Chi-Hwa; Pack, Daniel W.

    2014-01-01

    Biodegradable polymer double-wall microspheres (DWMS) are promising vehicles for macromolecular therapeutics such as proteins and peptides. Using precision particle fabrication (PPF) technology, uniform DWMS with outer diameter ~55 μm were fabricated comprising poly(lactide-co-glycolide) cores encapsulating bovine serum albumin (BSA) and ~10 μm thick, drug-free, poly(lactic acid) shells of varying PLA molecular weight. Also, monolithic single-wall microspheres (SWMS) were fabricated to mimic the BSA-loaded core. The use of relatively fast extracting ethyl acetate and slowly extracting dichloromethane as shell- and core-phase solvents, respectively, was found to produce DWMS with well-defined core-shell structure, high BSA encapsulation efficiency, and the desired localization of protein in the particle core. Initial protein distribution, particle erosion, and in vitro protein release from DWMS and SWMS were examined. The presence of a BSA-free shell in DWMS decreased the protein release rate and extended the duration of release from ~50 days to 70-80 days, demonstrating the capacity of such DWMS to provide enhanced control of protein delivery rates. PMID:23529836

  18. Controlled protein release from monodisperse biodegradable double-wall microspheres of controllable shell thickness

    PubMed Central

    Xia, Yujie; Ribeiro, Pedro F.; Pack, Daniel W.

    2013-01-01

    Biodegradable polymer microparticles are promising delivery depots for protein therapeutics due to their relatively simple fabrication and facile administration. Double-wall microspheres (DWMS) comprising a core and shell made of two distinct polymers may provide enhanced control of the drug release profiles. Using precision particle fabrication (PPF) technology, monodisperse DWMS were fabricated with model protein bovine serum albumin (BSA)-loaded poly(lactide-co-glycolide) (PLG) core and drug-free poly(d,l-lactic acid) (PDLL) shell of uniform thickness. Monolithic single-wall microspheres were also fabricated to mimic the BSA-loaded PLG core. Using ethyl acetate and dichloromethane as shell- and core-phase solvents, respectively, BSA was encapsulated selectively in the core region within DWMS with higher loading and encapsulation efficiency compared to using dichloromethane as core and shell solvents. BSA in vitro release rates were retarded by the presence of the drug-free PDLL shell. Moreover, increasing PDLL shell thickness resulted in decreasing BSA release rate. With a 14-µm thick PDLL shell, an extended period of constant-rate release was achieved. PMID:23954731

  19. Experimental evidence of a mechanical coupling between layers in an individual double-walled carbon nanotube.

    PubMed

    Levshov, D; Than, T X; Arenal, R; Popov, V N; Parret, R; Paillet, M; Jourdain, V; Zahab, A A; Michel, T; Yuzyuk, Yu I; Sauvajol, J-L

    2011-11-09

    We perform transmission electron microscopy, electron diffraction, and Raman scattering experiments on an individual suspended double-walled carbon nanotube (DWCNT). The first two techniques allow the unambiguous determination of the DWCNT structure: (12,8)@(16,14). However, the low-frequency features in the Raman spectra cannot be connected to the derived layer diameters d by means of the 1/d power law, widely used for the diameter dependence of the radial-breathing mode of single-walled nanotubes. We discuss this disagreement in terms of mechanical coupling between the layers of the DWCNT, which results in collective vibrational modes. Theoretical predictions for the breathing-like modes of the DWCNT, originating from the radial-breathing modes of the layers, are in a very good agreement with the observed Raman spectra. Moreover, the mechanical coupling qualitatively explains the observation of Raman lines of breathing-like modes, whenever only one of the layers is in resonance with the laser energy.

  20. Insulated Concrete Form Walls Integrated With Mechanical Systems in a Cold Climate Test House

    SciTech Connect

    Mallay, D.; Wiehagen, J.

    2014-09-01

    Transitioning from standard light frame to a thermal mass wall system in a high performance home will require a higher level of design integration with the mechanical systems. The much higher mass in the ICF wall influences heat transfer through the wall and affects how the heating and cooling system responds to changing outdoor conditions. This is even more important for efficient, low-load homes with efficient heat pump systems in colder climates where the heating and cooling peak loads are significantly different from standard construction. This report analyzes a range of design features and component performance estimates in an effort to select practical, cost-effective solutions for high performance homes in a cold climate.

  1. Analysis Of Construction Salt Decomposition Within Walls Of Ceramic Brick In The Midtown Tenement Houses

    NASA Astrophysics Data System (ADS)

    Szostak, Bartosz; Trochonowicz, Maciej

    2015-12-01

    The purpose of this paper is to introduce issues related to the corrosive effects of construction salts. Sequentially, one will discuss issues related to the distribution of salt in the wall, salinity sources and types of masonry material damage. There will also be presented the results of research conducted by the authors, which allowed determining the distribution of salinity in the walls depending on the depth and height of sampling. The paper will present test results of samples taken from several heights and depths within the same piece of wall and summaries from all facilities. Research conducted by the authors were based on chemical analyzes performed using the prepared chemical tests. Assays are made using titration and colorimetric methods.

  2. Mapping strain exerted on blood vessel walls using deuterium double-quantum-filtered MRI

    PubMed Central

    Sharf, Yehuda; Seo, Yoshiteru; Eliav, Uzi; Akselrod, Solang; Navon, Gil

    1998-01-01

    A technique is described for displaying distinct tissue layers of large blood vessel walls as well as measuring their mechanical strain. The technique is based on deuterium double-quantum-filtered (DQF) spectroscopic imaging. The effectiveness of the double-quantum filtration in suppressing the signal of bulk water is demonstrated on a phantom consisting of rat tail tendon fibers. Only intrafibrillar water is displayed, excluding all other signals of water molecules that reorient isotropically. One- and two-dimensional spectroscopic imaging of bovine aorta and coronary arteries show the characteristic DQF spectrum of each of the tissue layers. This property is used to obtain separate images of the outer layer, the tunica adventitia, or the intermediate layer, the tunica media, or both. To visualize the effect of elongation, the average residual quadrupole splitting <Δνq> is calculated for each pixel. Two-dimensional deuterium quadrupolar splitting images are obtained for a fully relaxed and a 55% elongated sample of bovine coronary artery. These images indicate that the strong effect of strain is associated with water molecules in the tunica adventitia whereas the DQF NMR signal of water in the tunica media is apparently strain-insensitive. After appropriate calibration, these average quadrupolar splitting images can be interpreted as strain maps. PMID:9539698

  3. Mapping strain exerted on blood vessel walls using deuterium double-quantum-filtered MRI.

    PubMed

    Sharf, Y; Seo, Y; Eliav, U; Akselrod, S; Navon, G

    1998-04-14

    A technique is described for displaying distinct tissue layers of large blood vessel walls as well as measuring their mechanical strain. The technique is based on deuterium double-quantum-filtered (DQF) spectroscopic imaging. The effectiveness of the double-quantum filtration in suppressing the signal of bulk water is demonstrated on a phantom consisting of rat tail tendon fibers. Only intrafibrillar water is displayed, excluding all other signals of water molecules that reorient isotropically. One- and two-dimensional spectroscopic imaging of bovine aorta and coronary arteries show the characteristic DQF spectrum of each of the tissue layers. This property is used to obtain separate images of the outer layer, the tunica adventitia, or the intermediate layer, the tunica media, or both. To visualize the effect of elongation, the average residual quadrupole splitting is calculated for each pixel. Two-dimensional deuterium quadrupolar splitting images are obtained for a fully relaxed and a 55% elongated sample of bovine coronary artery. These images indicate that the strong effect of strain is associated with water molecules in the tunica adventitia whereas the DQF NMR signal of water in the tunica media is apparently strain-insensitive. After appropriate calibration, these average quadrupolar splitting images can be interpreted as strain maps.

  4. Amines immobilized double-walled silica nanotubes for CO2 capture.

    PubMed

    Ko, Young Gun; Lee, Hyun Jeong; Oh, Hyun Chul; Choi, Ung Su

    2013-04-15

    Novel silica support has been required for high amine loading and good CO2 molecule diffusion into its pores to increase the performance of CO2 adsorbents. Herein, amine groups supported on double-walled silica nanotubes (DWSNTs) have been prepared via the immobilization of various aminosilanes (primary, secondary, tertiary, di-, and tri-aminosilanes) on DWSNT, and found to be a very effective adsorbent for CO2 capture. Amine groups immobilized DWSNTs captured CO2 reversibly in a temperature swing process at various adsorption temperatures (25°C, 50°C, 75°C, and 100°C). The amines on modified DWSNTs showed high CO2 capture capacity in the order of tri-, di-, primary, secondary, and tertiary amines. The CO2 capture capacity of all aminosilanes immobilized DWSNTs decreased linearly with the increase of the adsorption temperature. We expect that DWSNT would be able to inspire researchers to use it not only as a support for CO2 capture but also as a promising candidate for various applications.

  5. Highly transparent and conductive thin films fabricated with nano-silver/double-walled carbon nanotube composites.

    PubMed

    Lee, Shie-Heng; Teng, Chih-Chun; Ma, Chen-Chi M; Wang, Ikai

    2011-12-01

    This study develops a technique for enhancing the electrical conductivity and optical transmittance of transparent double-walled carbon nanotube (DWNT) film. Silver nanoparticles were modified with a NH(2)(CH(2))(2)SH self-assembled monolayer terminated by amino groups and subsequent surface condensation that reacted with functionalized DWNTs. Ag nanoparticles were grafted on the surface of the DWNTs. The low sheet resistance of the resulting thin conductive film on a polyethylene terephthalate (PET) substrate was due to the increased contact areas between DWNTs and work function by grafting Ag nanoparticles on the DWNT surfaces. Increasing the contact area between DWNTs and work function improved the conductivity of the DWNT-Ag thin films. The prepared DWNT-Ag thin films had a sheet resistance of 53.4 Ω/sq with 90.5% optical transmittance at a 550 nm wavelength. After treatment with HNO(3) and annealing at 150 °C for 30 min, a lower sheet resistance of 45.8 Ω/sq and a higher transmittance of 90.4% could be attained. The value of the DC conductivity to optical conductivity (σ(DC)/σ(OP)) ratio is 121.3.

  6. Numerical investigation of sound transmission through double wall cylinders with respect to active noise control

    NASA Technical Reports Server (NTRS)

    Coats, T. J.; Silcox, R. J.; Lester, H. C.

    1993-01-01

    Market pressure for more fuel efficient air travel has led to increased use of turboprop and higher bypass turbofan engines. The low frequency components of propeller, jet and boundary layer noise are difficult to attenuate with conventional passive techniques. Weight and geometric restrictions for sound absorbing meterials limit the amount and type of treatment that may be applied. An active noise control (ANC) method is providing to be an attractive alternative. The approach taken in this paper uses a numerical finite/boundary element method (FEM/BEM) that may be easilty adapted to arbitrary geometries. A double walled cylinder is modeled using commercially available software. The outer shell is modeled as an aluminum cylinder, similar to that of aircraft skins. The inner shell is modeled as a composite material representative of a lightweight, stiff trim panel. Two different inner shell materials are used. The first is representative of current trim structure, the second a much stiffer composite. The primary source is generated by an exterior acoustic monopole. Control fields are generated using normal force inputs to the inner cylindrical shell. A linear least mean square (LMS) algorithm is used to determine amplitudes of control forces that minimize the interior acoustic field. Coupling of acoustic and structural modes and noise reductions are discussed for each of the inner shell materials.

  7. Numerical investigation of sound transmission through double wall cylinders with respect to active noise control

    NASA Astrophysics Data System (ADS)

    Coats, T. J.; Silcox, R. J.; Lester, H. C.

    Market pressure for more fuel efficient air travel has led to increased use of turboprop and higher bypass turbofan engines. The low frequency components of propeller, jet and boundary layer noise are difficult to attenuate with conventional passive techniques. Weight and geometric restrictions for sound absorbing meterials limit the amount and type of treatment that may be applied. An active noise control (ANC) method is providing to be an attractive alternative. The approach taken in this paper uses a numerical finite/boundary element method (FEM/BEM) that may be easilty adapted to arbitrary geometries. A double walled cylinder is modeled using commercially available software. The outer shell is modeled as an aluminum cylinder, similar to that of aircraft skins. The inner shell is modeled as a composite material representative of a lightweight, stiff trim panel. Two different inner shell materials are used. The first is representative of current trim structure, the second a much stiffer composite. The primary source is generated by an exterior acoustic monopole. Control fields are generated using normal force inputs to the inner cylindrical shell. A linear least mean square (LMS) algorithm is used to determine amplitudes of control forces that minimize the interior acoustic field. Coupling of acoustic and structural modes and noise reductions are discussed for each of the inner shell materials.

  8. External mean flow influence on sound transmission through finite clamped double-wall sandwich panels

    NASA Astrophysics Data System (ADS)

    Liu, Yu; Catalan, Jean-Cédric

    2017-09-01

    This paper studies the influence of an external mean flow on the sound transmission through finite clamped double-wall sandwich panels lined with poroelastic materials. Biot's theory is employed to describe wave propagation in poroelastic materials and various configurations of coupling the poroelastic layer to the facing plates are considered. The clamped boundary of finite panels are dealt with by the modal superposition theory and the weighted residual (Garlekin) method, leading to a matrix equation solution for the sound transmission loss (STL) through the structure. The theoretical model is validated against existing theories of infinite sandwich panels with and without an external flow. The numerical results of a single incident wave show that the external mean flow has significant effects on the STL which are coupled with the clamped boundary effect dominating in the low-frequency range. The external mean flow also influences considerably the limiting incidence angle of the panel system and the effect of the incidence angle on the STL. However, the influences of the azimuthal angle and the external flow orientation are negligible.

  9. Heat conduction in double-walled carbon nanotubes with intertube additional carbon atoms.

    PubMed

    Cui, Liu; Feng, Yanhui; Tan, Peng; Zhang, Xinxin

    2015-07-07

    Heat conduction of double-walled carbon nanotubes (DWCNTs) with intertube additional carbon atoms was investigated for the first time using a molecular dynamics method. By analyzing the phonon vibrational density of states (VDOS), we revealed that the intertube additional atoms weak the heat conduction along the tube axis. Moreover, the phonon participation ratio (PR) demonstrates that the heat transfer in DWCNTs is dominated by low frequency modes. The added atoms cause the mode weight factor (MWF) of the outer tube to decrease and that of the inner tube to increase, which implies a lower thermal conductivity. The effects of temperature, tube length, and the number and distribution of added atoms were studied. Furthermore, an orthogonal array testing strategy was designed to identify the most important structural factor. It is indicated that the tendencies of thermal conductivity of DWCNTs with added atoms change with temperature and length are similar to bare ones. In addition, thermal conductivity decreases with the increasing number of added atoms, more evidently for atom addition concentrated at some cross-sections rather than uniform addition along the tube length. Simultaneously, the number of added atoms at each cross-section has a considerably more remarkable impact, compared to the tube length and the density of chosen cross-sections to add atoms.

  10. Investigation of the adsorption of polymer chains on amine-functionalized double-walled carbon nanotubes.

    PubMed

    Ansari, R; Ajori, S; Rouhi, S

    2015-12-01

    Molecular dynamics (MD) simulations were used to study the adsorption of different polymer chains on functionalized double-walled carbon nanotubes (DWCNTs). The nanotubes were functionalized with two different amines: NH2 (a small amine) and CH2-NH2 (a large amine). Considering three different polymer chains, all with the same number of atoms, the effect of polymer type on the polymer-nanotube interaction was studied. In general, it was found that covalent functionalization considerably improved the polymer-DWCNT interaction. By comparing the results obtained with different polymer chains, it was observed that, unlike polyethylene and polyketone, poly(styrene sulfonate) only weakly interacts with the functionalized DWCNTs. Accordingly, the smallest radius of gyration was obtained with adsorbed poly(styrene sulfonate). It was also observed that the DWCNTs functionalized with the large amine presented more stable interactions with polyketone and poly(styrene sulfonate) than with polyethylene, whereas the DWCNTs functionalized with the small amine showed better interfacial noncovalent bonding with polyethylene.

  11. Thermodynamics for the Formation of Double-Stranded DNA-Single-Walled Carbon Nanotube Hybrids.

    PubMed

    Shiraki, Tomohiro; Tsuzuki, Akiko; Toshimitsu, Fumiyuki; Nakashima, Naotoshi

    2016-03-24

    For the first time, the thermodynamics are described for the formation of double-stranded DNA (ds-DNA)-single-walled carbon nanotube (SWNT) hybrids. This treatment is applied to the exchange reaction of sodium cholate (SC) molecules on SWNTs and the ds-DNAs d(A)20 -d(T)20 and nuclear factor (NF)-κB decoy. UV/Vis/near-IR spectroscopy with temperature variations was used for analyzing the exchange reaction on the SWNTs with four different chiralities: (n,m)=(8,3), (6,5), (7,5), and (8,6). Single-stranded DNAs (ss-DNAs), including d(A)20 and d(T)20, are also used for comparison. The d(A)20-d(T)20 shows a drastic change in its thermodynamic parameters around the melting temperature (Tm ) of the DNA oligomer. No such Tm dependency was measured, owing to high Tm in the NF-κB decoy DNA and no Tm in the ss-DNA. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Numerical investigation of sound transmission through double wall cylinders with respect to active noise control

    NASA Technical Reports Server (NTRS)

    Coats, T. J.; Silcox, R. J.; Lester, H. C.

    1993-01-01

    Market pressure for more fuel efficient air travel has led to increased use of turboprop and higher bypass turbofan engines. The low frequency components of propeller, jet and boundary layer noise are difficult to attenuate with conventional passive techniques. Weight and geometric restrictions for sound absorbing meterials limit the amount and type of treatment that may be applied. An active noise control (ANC) method is providing to be an attractive alternative. The approach taken in this paper uses a numerical finite/boundary element method (FEM/BEM) that may be easilty adapted to arbitrary geometries. A double walled cylinder is modeled using commercially available software. The outer shell is modeled as an aluminum cylinder, similar to that of aircraft skins. The inner shell is modeled as a composite material representative of a lightweight, stiff trim panel. Two different inner shell materials are used. The first is representative of current trim structure, the second a much stiffer composite. The primary source is generated by an exterior acoustic monopole. Control fields are generated using normal force inputs to the inner cylindrical shell. A linear least mean square (LMS) algorithm is used to determine amplitudes of control forces that minimize the interior acoustic field. Coupling of acoustic and structural modes and noise reductions are discussed for each of the inner shell materials.

  13. Nonlinear dynamics of bi-layered graphene sheet, double-walled carbon nanotube and nanotube bundle

    NASA Astrophysics Data System (ADS)

    Gajbhiye, Sachin O.; Singh, S. P.

    2016-05-01

    Due to strong van der Waals (vdW) interactions, the graphene sheets and nanotubes stick to each other and form clusters of these corresponding nanostructures, viz. bi-layered graphene sheet (BLGS), double-walled carbon nanotube (DWCNT) and nanotube bundle (NB) or ropes. This research work is concerned with the study of nonlinear dynamics of BLGS, DWCNT and NB due to nonlinear interlayer vdW forces using multiscale atomistic finite element method. The energy between two adjacent carbon atoms is represented by the multibody interatomic Tersoff-Brenner potential, whereas the nonlinear interlayer vdW forces are represented by Lennard-Jones 6-12 potential function. The equivalent nonlinear material model of carbon-carbon bond is used to model it based on its force-deflection relation. Newmark's algorithm is used to solve the nonlinear matrix equation governing the motion of the BLGS, DWCNT and NB. An impulse and harmonic excitations are used to excite these nanostructures under cantilevered, bridged and clamped boundary conditions. The frequency responses of these nanostructures are computed, and the dominant resonant frequencies are identified. Along with the forced vibration of these structures, the eigenvalue extraction problem of armchair and zigzag NB is also considered. The natural frequencies and corresponding mode shapes are extracted for the different length and boundary conditions of the nanotube bundle.

  14. Structure, stability, and motion of dislocations in double-wall carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Zhang, Kai-Wang; Li, Zhong-Qiu; Wu, Jian; Peng, Xiang-Yang; Tan, Xin-Jun; Sun, Li-Zhong; Zhong, Jian-Xin

    2012-10-01

    In this paper, a novel double-wall carbon nanotube (DWCNT) with both edge and screw dislocations is studied by using the molecular dynamics (MD) method. The differences between two adjacent tubule indexes of armchair and zigzag nanotubes are determined to be 5 and 9, respectively, by taking into account the symmetry, integrality, and thermal stability of the composite structures. It is found that melting first occurs near the dislocations, and the melting temperatures of the dislocated armchair and zigzag DWCNTs are around 2600 K—2700 K. At the pre-melting temperatures, the shrink of the dislocation loop, which is comprised of edge and screw dislocations, implies that the composite dislocation in DWCNTs has self-healing ability. The dislocated DWCNTs first fracture at the edge dislocations, which induces the entire break in axial tensile test. The dislocated DWCNTs have a smaller fracture strength compared to the perfect DWCNTs. Our results not only match with the dislocation glide of carbon nanotubes (CNTs) in experiments, but also can free from the electron beam radiation under experimental conditions observed by the high resolution transmission electron microscope (HRTEM), which is deemed to cause the motion of dislocation loop.

  15. Stable cycling of double-walled silicon nanotube battery anodes through solid-electrolyte interphase control.

    PubMed

    Wu, Hui; Chan, Gerentt; Choi, Jang Wook; Ryu, Ill; Yao, Yan; McDowell, Matthew T; Lee, Seok Woo; Jackson, Ariel; Yang, Yuan; Hu, Liangbing; Cui, Yi

    2012-03-25

    Although the performance of lithium ion-batteries continues to improve, their energy density and cycle life remain insufficient for applications in consumer electronics, transport and large-scale renewable energy storage. Silicon has a large charge storage capacity and this makes it an attractive anode material, but pulverization during cycling and an unstable solid-electrolyte interphase has limited the cycle life of silicon anodes to hundreds of cycles. Here, we show that anodes consisting of an active silicon nanotube surrounded by an ion-permeable silicon oxide shell can cycle over 6,000 times in half cells while retaining more than 85% of their initial capacity. The outer surface of the silicon nanotube is prevented from expansion by the oxide shell, and the expanding inner surface is not exposed to the electrolyte, resulting in a stable solid-electrolyte interphase. Batteries containing these double-walled silicon nanotube anodes exhibit charge capacities approximately eight times larger than conventional carbon anodes and charging rates of up to 20C (a rate of 1C corresponds to complete charge or discharge in one hour).

  16. Fast vortex wall motion in wide permalloy strips from double switching of the vortex core

    NASA Astrophysics Data System (ADS)

    Estévez, Virginia; Laurson, Lasse

    2017-08-01

    We study vortex domain wall dynamics in wide permalloy strips driven by applied magnetic fields and spin-polarized electric currents. As recently reported [V. Estévez and L. Laurson, Phys. Rev. B 93, 064403 (2016), 10.1103/PhysRevB.93.064403], for sufficiently wide strips and above a threshold field, periodic dynamics of the vortex core are localized in the vicinity of one of the strip edges, and the velocity drop typically observed for narrow strips is replaced by a high-velocity plateau. Here, we analyze this behavior in more detail by means of micromagnetic simulations. We show that the high-velocity plateau originates from a repeated double switching of the magnetic vortex core, underlying the periodic vortex core dynamics in the vicinity of the strip edge, i.e., the "attraction-repulsion" effect. We also discuss the corresponding dynamics driven by spin-polarized currents, as well as the effect of including quenched random structural disorder to the system.

  17. Superlubricity in centimetres-long double-walled carbon nanotubes under ambient conditions.

    PubMed

    Zhang, Rufan; Ning, Zhiyuan; Zhang, Yingying; Zheng, Quanshui; Chen, Qing; Xie, Huanhuan; Zhang, Qiang; Qian, Weizhong; Wei, Fei

    2013-12-01

    Friction and wear are two main causes of mechanical energy dissipation and component failure, especially in micro/nanomechanical systems with large surface-to-volume ratios. In the past decade there has been an increasing level of research interest regarding superlubricity, a phenomenon, also called structural superlubricity, in which friction almost vanishes between two incommensurate solid surfaces. However, all experimental structural superlubricity has been obtained on the microscale or nanoscale, and predominantly under high vacuum. Here, we show that superlubricity can be realized in centimetres-long double-walled carbon nanotubes (DWCNTs) under ambient conditions. Centimetres-long inner shells can be pulled out continuously from such nanotubes, with an intershell friction lower than 1 nN that is independent of nanotube length. The shear strength of the DWCNTs is only several pascals, four orders of magnitude lower than the lowest reported value in CNTs and graphite. The perfect structure of the ultralong DWCNTs used in our experiments is essential for macroscale superlubricity.

  18. Superlubricity in centimetres-long double-walled carbon nanotubes under ambient conditions

    NASA Astrophysics Data System (ADS)

    Zhang, Rufan; Ning, Zhiyuan; Zhang, Yingying; Zheng, Quanshui; Chen, Qing; Xie, Huanhuan; Zhang, Qiang; Qian, Weizhong; Wei, Fei

    2013-12-01

    Friction and wear are two main causes of mechanical energy dissipation and component failure, especially in micro/nanomechanical systems with large surface-to-volume ratios. In the past decade there has been an increasing level of research interest regarding superlubricity, a phenomenon, also called structural superlubricity, in which friction almost vanishes between two incommensurate solid surfaces. However, all experimental structural superlubricity has been obtained on the microscale or nanoscale, and predominantly under high vacuum. Here, we show that superlubricity can be realized in centimetres-long double-walled carbon nanotubes (DWCNTs) under ambient conditions. Centimetres-long inner shells can be pulled out continuously from such nanotubes, with an intershell friction lower than 1 nN that is independent of nanotube length. The shear strength of the DWCNTs is only several pascals, four orders of magnitude lower than the lowest reported value in CNTs and graphite. The perfect structure of the ultralong DWCNTs used in our experiments is essential for macroscale superlubricity.

  19. Sharp burnout failure observed in high current-carrying double-walled carbon nanotube fibers

    NASA Astrophysics Data System (ADS)

    Song, Li; Toth, Geza; Wei, Jinquan; Liu, Zheng; Gao, Wei; Ci, Lijie; Vajtai, Robert; Endo, Morinobu; Ajayan, Pulickel M.

    2012-01-01

    We report on the current-carrying capability and the high-current-induced thermal burnout failure modes of 5-20 µm diameter double-walled carbon nanotube (DWNT) fibers made by an improved dry-spinning method. It is found that the electrical conductivity and maximum current-carrying capability for these DWNT fibers can reach up to 5.9 × 105 S m - 1 and over 1 × 105 A cm - 2 in air. In comparison, we observed that standard carbon fiber tended to be oxidized and burnt out into cheese-like morphology when the maximum current was reached, while DWNT fiber showed a much slower breakdown behavior due to the gradual burnout in individual nanotubes. The electron microscopy observations further confirmed that the failure process of DWNT fibers occurs at localized positions, and while the individual nanotubes burn they also get aligned due to local high temperature and electrostatic field. In addition a finite element model was constructed to gain better understanding of the failure behavior of DWNT fibers.

  20. Variations of late prehistoric houses in coastal Northwest Alaska: a view from Wales.

    PubMed

    Harritt, Roger K

    2010-01-01

    A review of literature and archival images reveals a distinctive method of double-walled house construction that predominated at the Beach site at Wales, Alaska, minimally from early contact through ca. 1930. Prior studies have suggested that this house construction form was a widespread convention during the contact period; however, this paper demonstrates that this was not the case. The only other occurrence of this house construction form was a kashim at St. Michael observed by Nelson in the late nineteenth century. The double-walled house represents a set of traits that form a fundamental aspect of the ethnic and group identity of the Kiatanamiut occupants of the Beach site. Recent excavations at Kurigitavik Mound have, however, uncovered remains of a house that is consistent with the double walled construction form. Full documentation of this house awaits the completion of an ongoing excavation and the new data will illuminate the relations between the Kashigitagmiut, Kiatanamiut, and Agianamiut in late prehistoric times.

  1. DOE Zero Energy Ready Home Case Study: KB Home — Double ZeroHouse, Lancaster, CA

    SciTech Connect

    none,

    2014-09-01

    The home that won a Production Builder award in the 2014 Housing Innovation Awards serves as a model for this builder, showcasing high-tech features including an electric car charging station; a compressed natural gas (CNG) car fueling station; a greywater recycling system that filters shower, sink, and clothes washer water for yard irrigation; smart appliances; and an electronic energy management system.

  2. Selective and Scalable Chemical Removal of Thin Single-Walled Carbon Nanotubes from their Mixtures with Double-Walled Carbon Nanotubes.

    PubMed

    Komínková, Zuzana; Valeš, Václav; Kalbáč, Martin

    2015-11-02

    Double-walled carbon nanotubes (DWCNTs) are materials in high demand due to their superior properties. However, it is very challenging to prepare DWCNTs samples of high purity. In particular, the removal of single-walled carbon nanotubes (SWCNTs) contaminants is a major problem. Here, a procedure for a selective removal of thin-diameter SWCNTs from their mixtures with DWCNTs by lithium vapor treatment is investigated. The results are evaluated by Raman spectroscopy and in situ Raman spectroelectrochemistry. It is shown that the amount of SWCNTs was reduced by about 35 % after lithium vapor treatment of the studied SWCNTs-DWCNTs mixture. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Site-dependence of van der Waals interaction explains exciton spectra of double-walled tubular J-aggregates

    NASA Astrophysics Data System (ADS)

    Megow, Jörg; Röhr, Merle I. S.; Schmidt am Busch, Marcel; Renger, Thomas; Mitrić, Roland; Kirstein, Stefan; Rabe, Jürgen P.; May, Volkhard

    The simulation of the optical properties of supramolecular aggregates requires the development of methods, which are able to treat a large number of coupled chromophores interacting with the environment. Since it is currently not possible to treat large systems by quantum chemistry, the Frenkel exciton model is a valuable alternative. In this work we show how the Frenkel exciton model can be extended in order to explain the excitonic spectra of a specific double-walled tubular dye aggregate explicitly taking into account dispersive energy shifts of ground and excited states due to van der Waals interaction with all surrounding molecules. The experimentally observed splitting is well explained by the site-dependent energy shift of molecules placed at the inner or outer side of the double-walled tube, respectively. Therefore we can conclude, that inclusion of the site-dependent dispersive effect in the theoretical description of optical properties of nanoscaled dye aggregates is mandatory.

  4. Environmental temperature control in very low birth weight infants (less than 1000 grams) cared for in double-walled incubators.

    PubMed

    Chessex, P; Blouet, S; Vaucher, J

    1988-08-01

    To evaluate the effect of fluctuations in environment and body temperatures on preterm infants, we recorded these variables in very immature newborn infants (birth weight less than 1000 gm) cared for in double-walled incubators (Air-Shields model C-100 and Ohio model IC). Both incubators maintained environmental temperatures corresponding overall to the set point, despite incubator openings. Under skin temperature servocontrol, however, environmental temperature fluctuations were greater than 2 degrees C even in strictly controlled conditions. The pattern of incubator temperature fluctuations depended on the set point rather than on the type of incubator (conventionally heated or heated by warm air blown between the double walls). The long-term clinical significance of the incubator temperature variability remains to be determined; the choice between air and skin servocontrolling should depend in part on the need for environmental stability.

  5. Extraordinary improvement of the graphitic structure of continuous carbon nanofibers templated with double wall carbon nanotubes.

    PubMed

    Papkov, Dimitry; Beese, Allison M; Goponenko, Alexander; Zou, Yan; Naraghi, Mohammad; Espinosa, Horacio D; Saha, Biswajit; Schatz, George C; Moravsky, Alexander; Loutfy, Raouf; Nguyen, Sonbinh T; Dzenis, Yuris

    2013-01-22

    Carbon nanotubes are being widely studied as a reinforcing element in high-performance composites and fibers at high volume fractions. However, problems with nanotube processing, alignment, and non-optimal stress transfer between the nanotubes and surrounding matrix have so far prevented full utilization of their superb mechanical properties in composites. Here, we present an alternative use of carbon nanotubes, at a very small concentration, as a templating agent for the formation of graphitic structure in fibers. Continuous carbon nanofibers (CNF) were manufactured by electrospinning from polyacrylonitrile (PAN) with 1.2% of double wall nanotubes (DWNT). Nanofibers were oxidized and carbonized at temperatures from 600 °C to 1850 °C. Structural analyses revealed significant improvements in graphitic structure and crystal orientation in the templated CNFs, with the largest improvements observed at lower carbonization temperatures. In situ pull-out experiments showed good interfacial bonding between the DWNT bundles and the surrounding templated carbon matrix. Molecular Dynamics (MD) simulations of templated carbonization confirmed oriented graphitic growth and provided insight into mechanisms of carbonization initiation. The obtained results indicate that global templating of the graphitic structure in fine CNFs can be achieved at very small concentrations of well-dispersed DWNTs. The outcomes reveal a simple and inexpensive route to manufacture continuous CNFs with improved structure and properties for a variety of mechanical and functional applications. The demonstrated improvement of graphitic order at low carbonization temperatures in the absence of stretch shows potential as a promising new manufacturing technology for next generation carbon fibers.

  6. Force distribution for double-walled carbon nanotubes and gigahertz oscillators

    NASA Astrophysics Data System (ADS)

    Baowan, Duangkamon; Hill, James M.

    2007-09-01

    Advances in nanotechnology have led to the creation of many nano-scale devices and carbon nanotubes are representative materials to construct these devices. Double-walled carbon nanotubes with the inner tube oscillating can be used as gigahertz oscillators and form the basis of possible nano-electronic devices that might be instrumental in the micro-computer industry which are predominantly based on electron transport phenomena. There are many experiments and molecular dynamical simulations which show that a wave is generated on the outer cylinder as a result of the oscillation of the inner carbon nanotube and that the frequency of this wave is also in the gigahertz range. As a preliminary to analyze and model such devices, it is necessary to estimate accurately the resultant force distribution due to the inter-atomic interactions. Here we determine some new analytical expressions for the van der Waals force using the Lennard Jones potential for general lengths of the inner and outer tubes. These expressions are utilized together with Newton’s second law to determine the motion of an oscillating inner tube, assuming that any frictional effects may be neglected. An idealized and much simplified representation of the Lennard Jones force is used to determine a simple formula for the oscillation frequency resulting from an initial extrusion of the inner tube. This simple formula is entirely consistent with the existing known behavior of the frequency and predicts a maximum oscillation frequency occurring when the extrusion length is (L 2 L 1)/2 where L 1 and L 2 are the respective half-lengths of the inner and outer tubes (L 1 < L 2).

  7. A nano universal joint made from curved double-walled carbon nanotubes

    SciTech Connect

    Cai, Kun; Cai, Haifang; Shi, Jiao; Qin, Qing H.

    2015-06-15

    A nano universal joint is constructed from curved double-wall carbon nanotubes with a short outer tube as stator and a long inner tube as a rotor. When one end of the rotor is driven (by a rotary motor) to rotate, the same rotational speed but with different rotational direction will be induced at the other end of the rotor. This mechanism makes the joint useful for designing a flexible nanodevice with an adjustable output rotational signal. The motion transmission effect of the universal joint is analyzed using a molecular dynamics simulation approach. In particular, the effects of three factors are investigated. The first factor is the curvature of the stator, which produces a different rotational direction of the rotor at the output end. The second is the bonding conditions of carbon atoms on the adjacent tube ends of the motor and the rotor, sp{sup 1} or sp{sup 2} atoms, which create different attraction between the motor and the rotor. The third is the rotational speed of the motor, which can be considered as the input signal of the universal joint. It is noted that the rotor's rotational speed is usually the same as that of the motor when the carbon atoms on the adjacent ends of the motor and the rotor are sp{sup 1} carbon atoms. When they become the new sp{sup 2} atoms, the rotor experiences a jump in rotational speed from a lower value to that of the motor. The mechanism of drops in potential of the motor is revealed. If the carbon atoms on the adjacent ends are sp{sup 2} atoms, the rotor rotates more slowly than the motor, whereas the rotational speed is stable when driven by a higher speed motor.

  8. A density functional theory for association of fluid molecules with a functionalized surface: fluid-wall single and double bonding

    NASA Astrophysics Data System (ADS)

    Haghmoradi, Amin; Wang, Le; Chapman, Walter G.

    2017-02-01

    In this manuscript we extend Wertheim’s two-density formalism beyond its first order to model a system of fluid molecules with a single association site close to a planar hard wall with association sites on its surface in a density functional theory framework. The association sites of the fluid molecules are small enough that they can form only one bond, while the wall association sites are large enough to bond with more than one fluid molecule. The effects of temperature and of bulk fluid and wall site densities on the fluid density profile, extent of association, and competition between single and double bonding of fluid segments at the wall sites versus distance from the wall are presented. The theory predictions are compared with new Monte Carlo simulation results and they are in good agreement. The theory captures the surface coverage over wide ranges of temperature and bulk density by introducing the effect of steric hindrance in fluid association at a wall site.

  9. Double-walled microspheres for the sustained release of a highly water soluble drug: characterization and irradiation studies.

    PubMed

    Lee, Teng Huar; Wang, Jianjun; Wang, Chi-Hwa

    2002-10-30

    Composite double-walled microspheres with biodegradable poly(L-lactic acid) (PLLA) shells and poly(D,L-lactic-co-glycolic acid) (PLGA) cores were fabricated with highly water-soluble etanidazole entrapped within the core as solid crystals. This paper discusses the characterization, in vitro release and the effects of irradiation on this class of microsphere. Through the variation of polymer mass ratios, predictable shell and core dimensions could be fabricated and used to regulate the release rates. A direct and simple method was devised to determine the composition of the shell and core polymer based on the different solubilities of the polymer pair in ethyl acetate. A distribution theory based on solubility parameter explains why highly hydrophilic etanidazole has the tendency to be distributed consistently to the more hydrophilic polymer. Release profiles for normal double-walled samples have about 80% of drug released over 10 days after the initial time lag, while for irradiated double-walled samples, the sustained release lasted for more than 3 weeks. Although sustained release was short of the desired 6-8 weeks required for therapy, a low initial burst of less than 5% and time lags that can be manipulated, allows for administration of these microspheres together with traditional ones to generate pulsatile or new type of releases. The effects of irradiation were also investigated to determine the suitability of these double-walled microspheres as delivery devices to be used in conjunction with radiotherapy. Typical therapeutic dosage of 50 Gy was found to be too mild to have noticeable effects on the polymer and its release profiles, while, sterilization dosages of 25 kGy, lowered the glass transition temperatures and crystalline melting point, indirectly indicating a decrease in molecular weight. This accelerated degradation of the polymer, hence releasing the drug.

  10. Evidence of double-walled Al-Ge imogolite-like nanotubes. a cryo-TEM and SAXS investigation.

    PubMed

    Maillet, Perrine; Levard, Clément; Larquet, Eric; Mariet, Clarisse; Spalla, Olivier; Menguy, Nicolas; Masion, Armand; Doelsch, Emmanuel; Rose, Jérôme; Thill, Antoine

    2010-02-03

    It has been recently discovered that the synthesis of Al-Ge imogolite-like nanotubes is possible at high concentration. Despite this initial success, the structure of these Al-Ge imogolite-like nanotubes remains not completely understood. Using high resolution cryo-TEM and Small Angle X-ray Scattering, we unravel their mesoscale structure in two contrasted situations. On the one hand, Al-Ge imogolite nanotubes synthesized at 0.25 M are double-walled nanotubes of 4.0 +/- 0.1 nm with an inner tube of 2.4 +/- 0.1 nm. Moreover, SAXS data also suggest that the two concentric tubes have an equal length and identical wall structure. On the other hand, at higher concentration (0.5M), both SAXS and cryo-TEM data confirm the formation of single-walled nanotubes of 3.5 +/- 0.15 nm. Infrared spectroscopy confirms the imogolite structure of the tubes. This is the first evidence of any double-walled imogolite or imogolite-like nanotubes likely to renew interest in these materials and associated potential applications.

  11. Effects of walls temperature variation on double diffusive natural convection of Al2O3-water nanofluid in an enclosure

    NASA Astrophysics Data System (ADS)

    Sheikhzadeh, G. A.; Dastmalchi, M.; Khorasanizadeh, H.

    2013-12-01

    The effect of wall temperature variations on double diffusive natural convection of Al2O3-water nanofluid in a differentially heated square enclosure with constant temperature hot and cold vertical walls is studied numerically. Transport mechanisms of nanoparticles including Brownian diffusion and thermophoresis that cause heterogeneity are considered in non-homogeneous model. The hot and cold wall temperatures are varied, but the temperature difference between them is always maintained 5 °C. The thermophysical properties such as thermal conductivity, viscosity and density and thermophoresis diffusion and Brownian motion coefficients are considered variable with temperature and volume fraction of nanoparticles. The governing equations are discretized using the control volume method. The results show that nanoparticle transport mechanisms affect buoyancy force and cause formation of small vortexes near the top and bottom walls of the cavity and reduce the heat transfer. By increasing the temperature of the walls the effect of transport mechanisms decreases and due to enhanced convection the heat transfer rate increases.

  12. S-layer and cytoplasmic membrane - exceptions from the typical archaeal cell wall with a focus on double membranes.

    PubMed

    Klingl, Andreas

    2014-01-01

    The common idea of typical cell wall architecture in archaea consists of a pseudo-crystalline proteinaceous surface layer (S-layer), situated upon the cytoplasmic membrane. This is true for the majority of described archaea, hitherto. Within the crenarchaea, the S-layer often represents the only cell wall component, but there are various exceptions from this wall architecture. Beside (glycosylated) S-layers in (hyper)thermophilic cren- and euryarchaea as well as halophilic archaea, one can find a great variety of other cell wall structures like proteoglycan-like S-layers (Halobacteria), glutaminylglycan (Natronococci), methanochondroitin (Methanosarcina) or double layered cell walls with pseudomurein (Methanothermus and Methanopyrus). The presence of an outermost cellular membrane in the crenarchaeal species Ignicoccus hospitalis already gave indications for an outer membrane similar to Gram-negative bacteria. Although there is just limited data concerning their biochemistry and ultrastructure, recent studies on the euryarchaeal methanogen Methanomassiliicoccus luminyensis, cells of the ARMAN group, and the SM1 euryarchaeon delivered further examples for this exceptional cell envelope type consisting of two membranes.

  13. S-layer and cytoplasmic membrane – exceptions from the typical archaeal cell wall with a focus on double membranes

    PubMed Central

    Klingl, Andreas

    2014-01-01

    The common idea of typical cell wall architecture in archaea consists of a pseudo-crystalline proteinaceous surface layer (S-layer), situated upon the cytoplasmic membrane. This is true for the majority of described archaea, hitherto. Within the crenarchaea, the S-layer often represents the only cell wall component, but there are various exceptions from this wall architecture. Beside (glycosylated) S-layers in (hyper)thermophilic cren- and euryarchaea as well as halophilic archaea, one can find a great variety of other cell wall structures like proteoglycan-like S-layers (Halobacteria), glutaminylglycan (Natronococci), methanochondroitin (Methanosarcina) or double layered cell walls with pseudomurein (Methanothermus and Methanopyrus). The presence of an outermost cellular membrane in the crenarchaeal species Ignicoccus hospitalis already gave indications for an outer membrane similar to Gram-negative bacteria. Although there is just limited data concerning their biochemistry and ultrastructure, recent studies on the euryarchaeal methanogen Methanomassiliicoccus luminyensis, cells of the ARMAN group, and the SM1 euryarchaeon delivered further examples for this exceptional cell envelope type consisting of two membranes. PMID:25505452

  14. SYNTHESIS AND CHARACTERIZATION OF CARBON AEROGEL NANOCOMPOSITES CONTAINING DOUBLE-WALLED CARBON NANOTUBES

    SciTech Connect

    Worsley, M A; Satcher, J H; Baumann, T F

    2008-03-11

    Carbon aerogels (CAs) are novel mesoporous materials with applications such as electrode materials for super capacitors and rechargeable batteries, adsorbents and advanced catalyst supports. To expand the potential application for these unique materials, recent efforts have focused on the design of CA composites with the goal of modifying the structure, conductivity or catalytic activity of the aerogel. Carbon nanotubes (CNTs) possess a number of intrinsic properties that make them promising materials in the design of composite materials. In addition, the large aspect ratios (100-1000) of CNTs means that small additions (less than 1 vol%) of CNTs can produce a composite with novel properties. Therefore, the homogeneous incorporation of CNTs into a CA matrix provides a viable route to new carbon-based composites with enhanced thermal, electrical and mechanical properties. One of the main challenges in preparing CNT composites is achieving a good uniform dispersion of nanotubes throughout the matrix. CAs are typically prepared through the sol-gel polymerization of resorcinol with formaldehyde in aqueous solution to produce organic gels that are supercritically dried and subsequently pyrolyzed in an inert atmosphere. Therefore, a significant issue in fabricating CA-CNT composites is dispersing the CNTs in the aqueous reaction media. Previous work in the design of CACNT composites have addressed this issue by using organic solvents in the sol-gel reaction to facilitate dispersion of the CNTs. To our knowledge, no data has been published involving the preparation of CA composites containing CNTs dispersed in aqueous media. In this report, we describe a new method for the synthesis of monolithic CA-CNT composites that involves the sol-gel polymerization of resorcinol and formaldehyde in an aqueous solution containing a surfactant-stabilized dispersion of double-walled carbon nanotubes (DWNT). One of the advantages of this approach is that it allows one to uniformly

  15. TiS2 and ZrS2 single- and double-wall nanotubes: first-principles study.

    PubMed

    Bandura, Andrei V; Evarestov, Robert A

    2014-02-15

    Hybrid density functional theory has been applied for investigations of the electronic and atomic structure of bulk phases, nanolayers, and nanotubes based on titanium and zirconium disulfides. Calculations have been performed on the basis of the localized atomic functions by means of the CRYSTAL-2009 computer code. The full optimization of all atomic positions in the regarded systems has been made to study the atomic relaxation and to determine the most favorable structures. The different layered and isotropic bulk phases have been considered as the possible precursors of the nanotubes. Calculations on single-walled TiS2 and ZrS2 nanotubes confirmed that the nanotubes obtained by rolling up the hexagonal crystalline layers with octahedral 1T morphology are the most stable. The strain energy of TiS2 and ZrS2 nanotubes is small, does not depend on the tube chirality, and approximately obeys to D(-2) law (D is nanotube diameter) of the classical elasticity theory. It is greater than the strain energy of the similar TiO2 and ZrO2 nanotubes; however, the formation energy of the disulfide nanotubes is considerably less than the formation energy of the dioxide nanotubes. The distance and interaction energy between the single-wall components of the double-wall nanotubes is proved to be close to the distance and interaction energy between layers in the layered crystals. Analysis of the relaxed nanotube shape using radial coordinate of the metal atoms demonstrates a small but noticeable deviation from completely cylindrical cross-section of the external walls in the armchair-like double-wall nanotubes. Copyright © 2013 Wiley Periodicals, Inc.

  16. LNG vapor mitigation by doubling tank-wall integrity. Topical report, September 1987-March 1989

    SciTech Connect

    Atallah, S.; Shah, J.N.

    1990-04-16

    A review of the results of numerous experimental studies on the crack arrest capabilities of 9% nickel-steels and the heat-affected zone has confirmed the excellent historical experience with these materials when used for LNG and other cryogenic liquid storage. In the absence of any actual unzippering tank wall failures involving 9% nickel-steels, the historical data can only suggest that the failure rate of such tanks is much less than 5 x 10(-4) per year. The capability of a second external 9% nickel-steel wall to withstand the asymmetric load and thermal shock resulting from a catastrophic failure of the inner wall was questioned. A concrete wall built around an existing LNG tank, buttressed by an earthen berm is one of several alternative means for reducing the extent of a vapor cloud should the existing tank fail. Guidelines for estimating the initial and annual costs of such a structure are given.

  17. Effects of hydrogen adsorption on the properties of double wall BN and (BN)xCy nanotubes

    NASA Astrophysics Data System (ADS)

    Freitas, A.; Azevedo, S.; Kaschny, J. R.

    2016-01-01

    In the present contribution, we apply first-principles calculations, based on the density functional theory, to study the effects of hydrogen adsorption on the structural and electronic properties of boron nitride and hybrid carbon-boron nitride double wall nanotubes. The results demonstrate that the hydrogen decoration induces significant structural deformation and an appreciable reduction in the gap energy. When the number of hydrogen atoms introduced on the outer wall is increased, desorption of hydrogen pairs are observed. The calculations indicate that each adsorbed hydrogen atom induces a structural deformation with an energetic cost of about 68 meV/atom. It is also found that the introduction of hydrogen atoms can be applied as an efficient tool for tuning the electronic properties of such structures.

  18. Analytical solutions to the free vibration of a double-walled carbon nanotube carrying a bacterium at its tip

    NASA Astrophysics Data System (ADS)

    Storch, Joel A.; Elishakoff, Isaac

    2013-11-01

    We calculate the natural frequencies and mode shapes of a cantilevered double-walled carbon nanotube carrying a rigid body—representative of a bacterium or virus—at the tip of the outer nanotube. By idealizing the nanotubes as Bernoulli-Euler beams, we are able to obtain exact expressions for both the mode shapes and characteristic frequency equation. Separate analyses are performed for the special case of a concentrated tip mass and the more complicated situation where the tip body also exhibits inertia and mass center offset from the beam tip.

  19. Analytical solutions to the free vibration of a double-walled carbon nanotube carrying a bacterium at its tip

    SciTech Connect

    Storch, Joel A.; Elishakoff, Isaac

    2013-11-07

    We calculate the natural frequencies and mode shapes of a cantilevered double-walled carbon nanotube carrying a rigid body—representative of a bacterium or virus—at the tip of the outer nanotube. By idealizing the nanotubes as Bernoulli-Euler beams, we are able to obtain exact expressions for both the mode shapes and characteristic frequency equation. Separate analyses are performed for the special case of a concentrated tip mass and the more complicated situation where the tip body also exhibits inertia and mass center offset from the beam tip.

  20. 48. Interior detail, study, doublehung sash in the south wall. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    48. Interior detail, study, double-hung sash in the south wall. Most of the windows in the John Bartram House were replaced sometime in the first decades of the nineteenth century. This window contains a slightly wider muntin profile than the later sash and is probably representative of the windows used in phase III construction (Mid-1750's-1770). - John Bartram House & Garden, House, 54th Street & Lindbergh Boulevard, Philadelphia, Philadelphia County, PA

  1. Vibroacoustic Response of a Double-Walled Cylindrical FGM Shell with a Porous Sandwiched Layer

    NASA Astrophysics Data System (ADS)

    Ramezani, H.; Talebitooti, R.

    2015-11-01

    The transmission loss of sound through a cylindrical structure whose walls sandwich a layer of porous material is predicted on the basis of the classical shell theory for shells made of functionally graded materials (FGMs). FGM shells composed of metal and ceramic, with three different distributions (power-law, sigmoid, or exponential) of their volume fractions across the wall thickness, are considered. The porous layer is modeled as a fluid with equivalent properties. The transmission loss through the multilayered structure is obtained analytically in a broad frequency band. To validate the results found, they are compared with some known ones. The effects of variation in the volume fractions of materials are also studied.

  2. Optimized removal of antibiotic drugs from aqueous solutions using single, double and multi-walled carbon nanotubes.

    PubMed

    Ncibi, Mohamed Chaker; Sillanpää, Mika

    2015-11-15

    In this study, experiments were carried out to investigate the use of as-synthesized single-walled (SWCNT), double-walled (DWCNT) and multi-walled carbon nanotubes (MWCNT) agglomerates for the removal of two antibiotics, Oxytetracycline (OXY) and Ciprofloxacin (CIP) from aqueous solution. The variations of key operating parameters on the removal process were assessed in order to find out the optimum conditions. It includes exposure time, solution pH, temperature, ultrasound assistance and desorption assays. The experimental results revealed that a moderate increase in adsorption was registered between pH 3 and 7 for both antibiotics. The application of ultrasound helped enhancing the removal capacities of OXY for all tested CNTs. For the case of MWCNTs, 1h of ultrasonication increased the adsorption capacity by 44.6%. As for CIP, the ultrasonic treatment did not enhance the overall adsorption, especially for the case of DWCNTS. The Brouers-Sotolongo equation was the best fitting isotherm model. The highest removal capacities were registered using SWCNTS for both antibiotics (724 mg/g for CIP and 554 mg/g for OXY). In addition, ethanol was the solvent that induced the highest desorption percent for the case of CIP (52% for MWCNTs). However, the desorption of OXY was negligible for all solvents (maximum 3.3% for DWCNTs using ethanol). Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Self-organized double-wall oxide nanotube layers on glass-forming Ti-Zr-Si(-Nb) alloys.

    PubMed

    Sopha, Hanna; Pohl, Darius; Damm, Christine; Hromadko, Ludek; Rellinghaus, Bernd; Gebert, Annett; Macak, Jan M

    2017-01-01

    In this work, we report for the first time on the use of melt spun glass-forming alloys - Ti75Zr10Si15 (TZS) and Ti60Zr10Si15Nb15 (TZSN) - as substrates for the growth of anodic oxide nanotube layers. Upon their anodization in ethylene glycol based electrolytes, highly ordered nanotube layers were achieved. In comparison to TiO2 nanotube layers grown on Ti foils, under the same conditions for reference, smaller diameter nanotubes (~116nm for TZS and ~90nm for TZSN) and shorter nanotubes (~11.5μm and ~6.5μm for TZS and TZSN, respectively) were obtained for both amorphous alloys. Furthermore, TEM and STEM studies, coupled with EDX analysis, revealed a double-wall structure of the as-grown amorphous oxide nanotubes with Ti species being enriched in the inner wall, and Si species in the outer wall, whereby Zr and Nb species were homogeneously distributed. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Optimizing the qusai-static folding and deploying of thin-walled tube flexure hinges with double slots

    NASA Astrophysics Data System (ADS)

    Yang, Hui; Deng, Zongquan; Liu, Rongqiang; Wang, Yan; Guo, Hongwei

    2014-03-01

    The thin-walled tube flexure(TWTF) hinges have important potential application value in the deployment mechanisms of satellite and solar array, but the optimal design of the TWTF hinges haven't been completely solved, which restricts their applications. An optimal design method for the qusai-static folding and deploying of TWTF hinges with double slots is presented based on the response surface theory. Firstly, the full factorial method is employed to design of the experiments. Then, the finite element models of the TWTF hinges with double slots are constructed to simulate the qusai-static folding and deploying non-linear analysis. What's more, the mathematical model of the TWTF flexure hinge quasi-static folding and deploying properties are derived by the response surface method. Considering of small mass and high stability, the peak moment of quasi-static folding and deploying as well as the lightless are set as the objectives to get the optimal performances. The relative errors of the objectives between the optimal design results and the FE analysis results are less than 7%, which demonstrates the precision of the surrogate models. Lastly, the parameter study shows that both the slots length and the slots width both have significant effects to the peak moment of quasi-static folding and deploying of TWTF hinges with double slots. However, the maximum Mises stress of quasi-static folding is more sensitive to the slots length than the slots width. The proposed research can be applied to optimize other thin-walled flexure hinges under quasi-static folding and deploying, which is of great importance to design of flexure hinges with high stability and low stress.

  5. Preparation, characterization and in vitro release study of BSA-loaded double-walled glucose-poly(lactide-co-glycolide) microspheres.

    PubMed

    Ansary, Rezaul H; Rahman, Mokhlesur M; Awang, Mohamed B; Katas, Haliza; Hadi, Hazrina; Mohamed, Farahidah; Doolaanea, Abd Almonem; Kamaruzzaman, Yunus B

    2016-09-01

    The aim of this study was to prepare a model protein, bovine serum albumin (BSA) loaded double-walled microspheres using a fast degrading glucose core, hydroxyl-terminated poly(lactide-co-glycolide) (Glu-PLGA) and a moderate-degrading carboxyl-terminated PLGA polymers to reduce the initial burst release and to eliminate the lag phase from the release profile of PLGA microspheres. The double-walled microspheres were prepared using a modified water-in-oil-in-oil-in-water (w/o/o/w) method and single-polymer microspheres were prepared using a conventional water-in-oil-in-water (w/o/w) emulsion solvent evaporation method. The particle size, morphology, encapsulation efficiency, thermal properties, in vitro drug release and structural integrity of BSA were evaluated in this study. Double-walled microspheres prepared with Glu-PLGA and PLGA polymers with a mass ratio of 1:1 were non-porous, smooth-surfaced, and spherical in shape. A significant reduction of initial burst release was achieved for the double-walled microspheres compared to single-polymer microspheres. In addition, microspheres prepared using Glu-PLGA and PLGA polymers in a mass ratio of 1:1 exhibited continuous BSA release after the small initial burst without any lag phase. It can be concluded that the double-walled microspheres made of Glu-PLGA and PLGA polymers in a mass ratio of 1:1 can be a potential delivery system for pharmaceutical proteins.

  6. Riser Difference Evaluation from Ultrasonic Wall Thickness Inspection of Thirteen Double-Shell Tanks

    SciTech Connect

    Weier, Dennis R.; Pardini, Allan F.

    2010-03-15

    PNNL has performed an analysis of ultrasonic thickness measurements taken on Hanford's double-shell tanks (DSTs) approximately eight years apart. The analysis was performed to determine whether significant differences exist between ultrasonic thickness measurements made in two opposite risers in Hanford DSTs that have been examined twice.

  7. Double radiooptical resonance in 87Rb atomic vapor in cells with antirelaxation wall coating

    NASA Astrophysics Data System (ADS)

    Litvinov, A. N.; Kazakov, G. A.; Matisov, B. G.; Mazets, I. E.

    2009-02-01

    The object of investigation is double radiooptic resonance in 87Rb atomic vapor contained in a cell covered by an antirelaxation coating. The Dicke narrowing is studied in terms of the quantum-kinetic approach. It is found that optical pumping using a laser with a “wide” radiation spectrum makes it possible to improve the short-term stability of the frequency standard by an order of magnitude compared with a narrow-spectrum laser.

  8. Modelling of side-wall angle for optical proximity correction for self-aligned double patterning

    NASA Astrophysics Data System (ADS)

    Moulis, Sylvain; Farys, Vincent; Belledent, Jérôme; Foucher, Johann

    2012-03-01

    The pursuit of even smaller transistors has pushed some technological innovations in the field of lithography. In order to continue following the path of Moore's law, several solutions were proposed: EUV, e-beam and double patterning lithography. As EUV and e-beam lithography are still not ready for mass production for 20nm and 14nm nodes, double patterning lithography will play an important role for these nodes. In this work, we had focused on Self- Aligned Double-Patterning processes which consist in depositing a spacer material on each side of a mandrel exposed during a first lithography stepmaking the pitch to be divided by two after transfer into the substrate, the cutting of unwanted patterns being addressed through a second lithography exposure. In the specific case where spacers are deposited directly on the flanks of the resist, it is crucial to control its profiles as it could induce final CD errors or even spacer collapse. In this work, we will first study with a simple model the influence of the resist profile on the post-etch spacer CD. Then we will show that the placement of Sub-Resolution Assist Features (SRAF) can influence the resist profile and finally, we will see how much control of the spacer and inter-spacer CD we can achieve by tuning SRAF placement.

  9. Six Basic Plan Concepts Used for California School Housing. A Sequential Development from 1900 to Today.

    ERIC Educational Resources Information Center

    California State Dept. of Education, Sacramento. Bureau of School Planning.

    A floor plan accompanies each of six chronologically arranged schemes for housing educational programs. Scheme A represents the in-line corridor plan whose main characteristics are--(1) double loaded corridors with fixed bearing walls, (2) single window walls providing minimal light and ventilation, and (3) small classrooms with fixed desks and…

  10. The surface chemical properties of multi-walled carbon nanotubes modified by thermal fluorination for electric double-layer capacitor

    NASA Astrophysics Data System (ADS)

    Jung, Min-Jung; Jeong, Euigyung; Lee, Young-Seak

    2015-08-01

    The surfaces of multi-walled carbon nanotubes (MWCNTs) were thermally fluorinated at various temperatures to enhance the electrochemical properties of the MWCNTs for use as electric double-layer capacitor (EDLC) electrodes. The fluorine functional groups were added to the surfaces of the MWCNTs via thermal fluorination. The thermal fluorination exposed the Fe catalyst on MWCNTs, and the specific surface area increased due to etching during the fluorination. The specific capacitances of the thermally fluorinated at 100 °C, MWCNT based electrode increased from 57 to 94 F/g at current densities of 0.2 A/g, respectively. This enhancement in capacitance can be attributed to increased polarization of the thermally fluorinated MWCNT surface, which increased the affinity between the electrode surface and the electrolyte ions.

  11. Passively Q-switched erbium doped fiber laser based on double walled carbon nanotubes-polyvinyl alcohol saturable absorber

    NASA Astrophysics Data System (ADS)

    Mohammed, D. Z.; Al-Janabi, A. H.

    2016-11-01

    A passively Q-switched Er-doped fiber laser with a ring cavity operating at 1568.6 nm is demonstrated using a saturable absorber based on a double walled carbon nanotubes film, which is prepared using polyvinyl alcohol as a host polymer. The Q-switching operation is achieved at a low pump threshold of 40 mW. The proposed fiber laser produces stable pulses train of repetition rate ranging from 14.7 KHz to 47 KHz as the pump power increases from threshold to 203 mW. The minimum recorded pulse width was 4.6 µs at 203 mW, while the highest energy obtained was 102.1 nJ.

  12. Single-step electrochemical functionalization of double-walled carbon nanotube (DWCNT) membranes and the demonstration of ionic rectification

    PubMed Central

    2013-01-01

    Carbon nanotube (CNT) membranes allow the mimicking of natural ion channels for applications in drug delivery and chemical separation. Double-walled carbon nanotube membranes were simply functionalized with dye in a single step instead of the previous two-step functionalization. Non-faradic electrochemical impedance spectra indicated that the functionalized gatekeeper by single-step modification can be actuated to mimic the protein channel under bias. This functional chemistry was proven by a highly efficient ion rectification, wherein the highest experimental rectification factor of ferricyanide was up to 14.4. One-step functionalization by electrooxidation of amine provides a simple and promising functionalization chemistry for the application of CNT membranes. PMID:23758999

  13. The growth model and electronic properties of single- and double-walled zigzag silicon nanotubes: Depending on the structures

    NASA Astrophysics Data System (ADS)

    Lin, Xiang; Lu, Junzhe; Liu, Jing; Tang, Yuchao; Zhu, Hengjiang

    2017-02-01

    The growth model and electronic properties of the capped zigzag single- and double-walled silicon nanotubes (SWSiNTs and DWSiNTs) are studied with the Density Functional Theory (DFT) method. Particularly, the morphologies of the silicon nanotubes (SiNTs) and the layer-by-layer growth process are explored. Capping of SiNTs is explained well in terms of pentagons. It seems that pentagons or heptagons play apivotal role during the SiNTs growth. Moreover, the structures of the finite SWSiNTs and DWSiNTs are studied. Finally, the infinite SWSiNTs and DWSiNTs can be set up with the repeat unit cells based on the periodic trait of the corresponding finite SiNTs. All of the zigzag SWSiNTs and DWSiNTs have a narrow band gap.

  14. Highly Sensitive Hot-Wire Anemometry Based on Macro-Sized Double-Walled Carbon Nanotube Strands

    PubMed Central

    Wang, Dingqu; Xiong, Wei; Zhou, Zhaoying; Zhu, Rong; Yang, Xing; Li, Weihua; Jiang, Yueyuan; Zhang, Yajun

    2017-01-01

    This paper presents a highly sensitive flow-rate sensor with carbon nanotubes (CNTs) as sensing elements. The sensor uses micro-size centimeters long double-walled CNT (DWCNT) strands as hot-wires to sense fluid velocity. In the theoretical analysis, the sensitivity of the sensor is demonstrated to be positively related to the ratio of its surface. We assemble the flow sensor by suspending the DWCNT strand directly on two tungsten prongs and dripping a small amount of silver glue onto each contact between the DWCNT and the prongs. The DWCNT exhibits a positive TCR of 1980 ppm/K. The self-heating effect on the DWCNT was observed while constant current was applied between the two prongs. This sensor can evidently respond to flow rate, and requires only several milliwatts to operate. We have, thus far, demonstrated that the CNT-based flow sensor has better sensitivity than the Pt-coated DWCNT sensor. PMID:28762998

  15. Effects of reducing temperatures on the hydrogen storage capacity of double-walled carbon nanotubes with Pd loading.

    PubMed

    Sheng, Qu; Wu, Huimin; Wexler, David; Liu, Huakun

    2014-06-01

    The effects of different temperatures on the hydrogen sorption characteristics of double-walled carbon nanotubes (DWCNTs) with palladium loading have been investigated. When we use different temperatures, the particle sizes and specific surface areas of the samples are different, which affects the hydrogen storage capacity of the DWCNTs. In this work, the amount of hydrogen storage capacity was determined (by AMC Gas Reactor Controller) to be 1.70, 1.85, 2.00, and 1.93 wt% for pristine DWCNTS and for 2%Pd/DWCNTs-300 degrees C, 2%Pd/DWCNTs-400 degrees C, and 2%Pd/DWCNTs-500 degrees C, respectively. We found that the hydrogen storage capacity can be enhanced by loading with 2% Pd nanoparticles and selecting a suitable temperature. Furthermore, the sorption can be attributed to the chemical reaction between atomic hydrogen and the dangling bonds of the DWCNTs.

  16. A nonlocal shell theory model for evaluation of thermoelastic damping in the vibration of a double-walled carbon nanotube

    NASA Astrophysics Data System (ADS)

    Hoseinzadeh, M. S.; Khadem, S. E.

    2014-03-01

    Thermoelastic damping (TED) is a major factor of dissipating energy in the vibration control of nanodevices. On the other hand, application of classic theory in the study of nanostructures is not reasonable. In this paper, a model based on nonlocal shell theory, accounting for the small-scale effects, is used to investigate thermoelastic vibration behavior and damping of double-walled carbon nanotubes (DWCNTs) with simply supported boundary conditions. The inner and outer carbon nanotubes are considered as two individual thin shells. The set of general thermoelastic coupled equations are numerically solved. The results show that the small-scale effects decrease natural frequencies and increase thermoelastic damping compared to the local model, especially for the coaxial frequency and large circumferential wave numbers. The numerical results also show that when the radius of nanotubes rises, the influence of small-size effect on natural frequencies and thermoelastic damping drops dramatically.

  17. Integrated ternary artificial nacre via synergistic toughening of reduced graphene oxide/double-walled carbon nanotubes/poly(vinyl alcohol)

    NASA Astrophysics Data System (ADS)

    Gong, Shanshan; Wu, Mengxi; Jiang, Lei; Cheng, Qunfeng

    2016-07-01

    The synergistic toughening effect of building blocks and interface interaction exists in natural materials, such as nacre. Herein, inspired by one-dimensional (1D) nanofibrillar chitin and two-dimensional (2D) calcium carbonate platelets of natural nacre, we have fabricated integrated strong and tough ternary bio-inspired nanocomposites (artificial nacre) successfully via the synergistic effect of 2D reduced graphene oxide (rGO) nanosheets and 1D double-walled carbon nanotubes (DWNTs) and hydrogen bonding cross-linking with polyvinyl alcohol (PVA) matrix. Moreover, the crack mechanics model with crack deflection by 2D rGO nanosheets and crack bridging by 1D DWNTs and PVA chains induces resultant artificial nacre exhibiting excellent fatigue-resistance performance. These outstanding characteristics enable the ternary bioinspired nanocomposites have many promising potential applications, for instance, aerospace, flexible electronics devices and so forth. This synergistic toughening strategy also provides an effective way to assemble robust graphene-based nanocomposites.

  18. Double-walled cryogenic storage tanks - effect of perlite/fiberglass insulation on dynamic loads in case of inner tank failure

    SciTech Connect

    Adorjan, A.S.; Crawford, D.B.; Handman, S.E.

    1983-01-01

    In double-wall LNG storage tanks, the dynamic load on the wall of the outer tank upon sudden failure of the inner tank can be considerably higher than hydrostatic pressure. However, a simplified analytical model has shown that insulation and gas containment in the annular space between the two tanks will dampen this load. Factors influencing this dampening effect are the dimensions of the insulation space, perlite stiffness, and fiberglass elasticity.

  19. Stud Walls With Continuous Exterior Insulation for Factory Built Housing: New York, New York (Fact Sheet), NREL (National Renewable Energy Laboratory)

    SciTech Connect

    None, None

    2014-01-01

    The Advanced Envelope Research effort will provide factory homebuilders with high performance, cost-effective alternative envelope designs. In the near term, these technologies will play a central role in meeting stringent energy code requirements. For manufactured homes, the thermal requirements, last updated by statute in 1994, will move up to the more rigorous IECC 2012 levels in 2013, the requirements of which are consistent with site built and modular housing. This places added urgency on identifying envelope technologies that the industry can implement in the short timeframe. The primary goal of this research is to develop wall designs that meet the thermal requirements based on 2012 IECC standards. Given the affordable nature of manufactured homes, impact on first cost is a major consideration in developing the new envelope technologies. This work is part of a four-phase, multi-year effort. Phase 1 identified seven envelope technologies and provided a preliminary assessment of three selected methods for building high performance wall systems. Phase 2 focused on the development of viable product designs, manufacturing strategies, addressing code and structural issues, and cost analysis of the three selected options. An industry advisory committee helped critique and select the most viable solution to move further in the research - stud walls with continuous exterior insulation. Phase 3, the subject of the current report, focused on the design development of the selected wall concept and explored variations on the use of exterior foam insulation. The scope also included material selection, manufacturing and cost analysis, and prototyping and testing.

  20. Isochronal annealing study of X-ray induced defects in single- and double-walled carbon nanotubes

    SciTech Connect

    Murakami, Toshiya; Yamamoto, Yuki; Itoh, Chihiro; Kisoda, Kenji

    2013-09-21

    X-ray induced defects in single-walled (SWCNTs) and double-walled carbon nanotubes (DWCNTs) were characterized by Raman scattering spectroscopy. Frenkel defects, interstitial-vacancy pairs, were revealed to form in both SWCNTs and DWCNTs after X-ray irradiation because these defects were entirely healed by thermal annealing. In order to clarify the structure of the X-ray induced defect in SWCNT and DWCNT, isochronal-annealing experiments were performed on the irradiated samples and the activation energy for defect healing was estimated. The intensity of D band (defect induced band) on Raman spectra was used as a measure of the density of X-ray induced defects. The experimental results were in good agreement with the simulated values using second order reaction model, which indicated that the defect healing was determined by the migration energy of interstitials on the carbon layer. We also found that the activation energy for defect healing of SWCNT and DWCNT were around 0.5 eV and 0.32 eV, respectively. The X-ray induced defects in SWCNTs were more stable than those in DWCNTs. Compared these estimated activation energies to previous theoretical reports, we concluded that bridge and/or dumbbell interstitials are formed in both SWCNT and DWCNT by X-ray irradiation.

  1. Size-dependent vibration of fluid-conveying double-walled carbon nanotubes using couple stress shell theory

    NASA Astrophysics Data System (ADS)

    Zeighampour, Hamid; Tadi Beni, Y.

    2014-07-01

    This work investigated vibrations and instability of double-walled carbon nanotube (DWCNT) conveying fluid by a modified couple stress theory. For this purpose, Donnell's shell model was developed and, using the modified couple stress theory, the equations of motion and corresponding classical and non-classical boundary conditions of DWCNT were obtained through Hamilton's principle. Then, DWCNT with simple-simple and clamped-clamped supports were investigated. The effect of the van der Waals (vdW) forces was considered between the two walls, and the DWCNT surroundings were modeled as a visco-Pasternak foundation. The governing equations of motion and corresponding boundary conditions were discretized through differential quadrature method (DQM), and the vibration problem was solved by using the boundary conditions. The results show that the effects of fluid velocity, stiffness and damping of the visco-Pasternak foundation, nanotube length, and size parameter in the modified couple stress theory are stronger than in the classical theory. Finally, the effect of vdW forces and presence of fluid in the DWCNT examined on the natural frequencies of DWCNT.

  2. Cell wall biogenesis in a double chitin synthase mutant (chsG-/chsE-) of Aspergillus fumigatus.

    PubMed

    Mellado, E; Dubreucq, G; Mol, P; Sarfati, J; Paris, S; Diaquin, M; Holden, D W; Rodriguez-Tudela, J L; Latgé, J P

    2003-02-01

    Previous studies (Aufauvre-Brown et al., 1997; Mellado et al., 1996a,b ) have shown that only two genes of the Aspergillus fumigatus chitin synthase family, chsG and chsE, play a role in the morphogenesis of this fungal species. An A. fumigatus strain lacking both chsG (class III CHS) and chsE (class V CHS) genes was constructed by gene replacement of the chsE gene with a copy that has its conserved coding region interrupted by the hph resistance cassette in an A. fumigatus chsG- genetic background. Unexpectedly the double disruption was not lethal. The double mutant AfchsG-/chsE- strain (i) has reduced chitin synthase activity with or without trypsin stimulation, (ii) has a reduced colony radial growth rate, (iii) produces highly branched hyphae, (iv) exhibits aberrant features, such as periodic swellings along the length of the hyphae and a block in conidiation that can be partially restored by an osmotic stabilizer (v) shows alterations in the shape and germination capacity of the conidia, and (vi) has a cell wall that contains half the chitin of the parental strain and is, unexpectedly, highly enriched in alpha-(1-3) glucan.

  3. MODELNG RADON ENTRY INTO FLORIDA HOUSES WITH CONCRETE SLABS AND CONCRETE-BLOCK STEM WALLS, FLORIDA RADON RESEARCH PROGRAM

    EPA Science Inventory

    The report discusses results of modeling radon entry into a typical Florida house whose interior is slightly depressurized. he model predicts that the total radon entry rate is relatively low unless the soil or backfill permeability or radium content is high. ost of the factors c...

  4. MODELNG RADON ENTRY INTO FLORIDA HOUSES WITH CONCRETE SLABS AND CONCRETE-BLOCK STEM WALLS, FLORIDA RADON RESEARCH PROGRAM

    EPA Science Inventory

    The report discusses results of modeling radon entry into a typical Florida house whose interior is slightly depressurized. he model predicts that the total radon entry rate is relatively low unless the soil or backfill permeability or radium content is high. ost of the factors c...

  5. 5. EXTERIOR OF SOUTH END OF HOUSE SHOWING OPEN DOOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. EXTERIOR OF SOUTH END OF HOUSE SHOWING OPEN DOOR TO BASEMENT BELOW KITCHEN, ORIGINAL PAIRED WOODFRAMED SLIDING-GLASS WINDOWS ON KITCHEN WALL AND 1LIGHT OVER 1-LIGHT DOUBLE-HUNG WINDOW ON STORM PORCH ADDITION. VIEW TO WEST. - Rush Creek Hydroelectric System, Clubhouse Cottage, Rush Creek, June Lake, Mono County, CA

  6. Compact 4.7 W, 18.3% wall-plug efficiency green laser based on an electrically pumped VECSEL using intracavity frequency doubling.

    PubMed

    Zhao, Pu; Xu, Bing; van Leeuwen, Robert; Chen, Tong; Watkins, Laurence; Zhou, Delai; Gao, Peng; Xu, Guoyang; Wang, Qing; Ghosh, Chuni

    2014-08-15

    We have demonstrated a compact, 4.7 W green laser based on an electrically pumped vertical external-cavity surface emitting laser through intracavity frequency doubling. The overall wall-plug efficiency (electrical to green) was 18.3%. The power fluctuations were measured to be ±1.4% over a 2 h time period.

  7. Vibration characteristics of walls and a plate glass window representative of those of a wood-frame house

    NASA Technical Reports Server (NTRS)

    Carden, H. D.

    1979-01-01

    Mechanical excitation was used, and measurements of acceleration response, natural frequencies, and nodal patterns were performed. Results indicate that the wall sections and the complete wall did not act as a unit in responding to sinusoidal vibration inputs. Calculated frequencies of the components that account for this independent behavior of the studs and face sheets agreed resonably well with experimental frequencies. Experimental vibrations of the plate glass window agreed with the calculated behavior, and responses of the window exposed to airplane flyover noise were readily correlated with the test results.

  8. Field Study on Moisture Problems in Exterior Walls of Family Housing Units at Naval Air Station Pensacola, Florida.

    DTIC Science & Technology

    1984-02-01

    exterior exposed concrete block walls with 2 inch (nominal) furring, 1 inch cellular board ( expanded polystyrene ) insulation, and gypsum board finish, as...furring strips, and new expanded polystyrene board thermal insu- lation and new gypsum board were installed. The purpose of the coating on the concrete

  9. Development of a 3D finite element acoustic model to predict the sound reduction index of stud based double-leaf walls

    NASA Astrophysics Data System (ADS)

    Arjunan, A.; Wang, C. J.; Yahiaoui, K.; Mynors, D. J.; Morgan, T.; Nguyen, V. B.; English, M.

    2014-11-01

    Building standards incorporating quantitative acoustical criteria to ensure adequate sound insulation are now being implemented. Engineers are making great efforts to design acoustically efficient double-wall structures. Accordingly, efficient simulation models to predict the acoustic insulation of double-leaf wall structures are needed. This paper presents the development of a numerical tool that can predict the frequency dependent sound reduction index R of stud based double-leaf walls at one-third-octave band frequency range. A fully vibro-acoustic 3D model consisting of two rooms partitioned using a double-leaf wall, considering the structure and acoustic fluid coupling incorporating the existing fluid and structural solvers are presented. The validity of the finite element (FE) model is assessed by comparison with experimental test results carried out in a certified laboratory. Accurate representation of the structural damping matrix to effectively predict the R values are studied. The possibilities of minimising the simulation time using a frequency dependent mesh model was also investigated. The FEA model presented in this work is capable of predicting the weighted sound reduction index Rw along with A-weighted pink noise C and A-weighted urban noise Ctr within an error of 1 dB. The model developed can also be used to analyse the acoustically induced frequency dependent geometrical behaviour of the double-leaf wall components to optimise them for best acoustic performance. The FE modelling procedure reported in this paper can be extended to other building components undergoing fluid-structure interaction (FSI) to evaluate their acoustic insulation.

  10. Airway wall thickness of allergic asthma caused by weed pollen or house dust mite assessed by computed tomography.

    PubMed

    Liu, Liping; Li, Guangrun; Sun, Yuemei; Li, Jian; Tang, Ningbo; Dong, Liang

    2015-03-01

    Little was known about Airway wall thickness of asthma patients with different allergen allergy. So we explored the possible difference of Airway wall thickness of asthma patients mono-sensitized to weed pollen or HDM using high-resolution computed tomography. 85 severe asthma patients were divided into weed pollen group and HDM group according to relevant allergen. 20 healthy donors served as controls. Airway wall area, percentage wall area and luminal area at the trunk of the apical bronchus of the right upper lobe were quantified using HRCT and compared. The values of pulmonary function were assessed as well. There were differences between HDM group and weed pollen group in WA/BSA,WA% and FEF25-75% pred, and no significant difference in FEV1%pred, FEV1/FVC and LA/BSA. In weed pollen group, WA/BSA was observed to correlate with the duration of rhinitis, whereas in HDM group, WA/BSA and LA/BSA was observed to correlate with the duration of asthma. In weed pollen group, FEV1/FVC showed a weak but significant negative correlation with WA%, but in HDM group FEV1/FVC showed a significant positive correlation with WA% and a statistical negative correlation with LA/BSA. FEV1/FVC and FEF25-75% pred were higher and WA/BSA and LA/BSA were lower in healthy control group than asthma group. FEV1%pred and WA% was no significant difference between asthma patients and healthy subjects. There are differences between HDM mono-sensitized subjects and weed pollen mono-sensitized subjects, not only in airway wall thickness, but also small airway obstruction. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Boltless Seal for Electronic Housings

    NASA Technical Reports Server (NTRS)

    Dawe, R. H.; Evans, J. T.

    1982-01-01

    Spring clips seal housings for electronic circuitry, preventing electromagnetic interference from entering or leaving housings. Clips also keep dust out of housing. Since no bolts are used, housing can be opened quickly; unlike bolts, clips can be used on thin-walled housing. Seal was developed for an X-band array amplifier.

  12. Double-Wall Nanotubes and Graphene Nanoplatelets for Hybrid Conductive Adhesives with Enhanced Thermal and Electrical Conductivity.

    PubMed

    Messina, Elena; Leone, Nancy; Foti, Antonino; Di Marco, Gaetano; Riccucci, Cristina; Di Carlo, Gabriella; Di Maggio, Francesco; Cassata, Antonio; Gargano, Leonardo; D'Andrea, Cristiano; Fazio, Barbara; Maragò, Onofrio Maria; Robba, Benedetto; Vasi, Cirino; Ingo, Gabriel Maria; Gucciardi, Pietro Giuseppe

    2016-09-07

    Improving the electrical and thermal properties of conductive adhesives is essential for the fabrication of compact microelectronic and optoelectronic power devices. Here we report on the addition of a commercially available conductive resin with double-wall carbon nanotubes and graphene nanoplatelets that yields simultaneously improved thermal and electrical conductivity. Using isopropanol as a common solvent for the debundling of nanotubes, exfoliation of graphene, and dispersion of the carbon nanostructures in the epoxy resin, we obtain a nanostructured conducting adhesive with thermal conductivity of ∼12 W/mK and resistivity down to 30 μΩ cm at very small loadings (1% w/w for nanotubes and 0.01% w/w for graphene). The low filler content allows one to keep almost unchanged the glass-transition temperature, the viscosity, and the curing parameters. Die shear measurements show that the nanostructured resins fulfill the MIL-STD-883 requirements when bonding gold-metalized SMD components, even after repeated thermal cycling. The same procedure has been validated on a high-conductivity resin characterized by a higher viscosity, on which we have doubled the thermal conductivity and quadrupled the electrical conductivity. Graphene yields better performances with respect to nanotubes in terms of conductivity and filler quantity needed to improve the resin. We have finally applied the nanostructured resins to bond GaN-based high-electron-mobility transistors in power-amplifier circuits. We observe a decrease of the GaN peak and average temperatures of, respectively, ∼30 °C and ∼10 °C, with respect to the pristine resin. The obtained results are important for the fabrication of advanced packaging materials in power electronic and microwave applications and fit the technological roadmap for CNTs, graphene, and hybrid systems.

  13. Catalytic growth of single-, double-, and multi-walled carbon nanotubes and studies of their potential applications

    NASA Astrophysics Data System (ADS)

    Kayastha, Vijaya Kumar

    Catalytic growth of carbon nanotubes (CNTs) by thermal chemical vapor deposition (CVD) was investigated, and role of various growth parameters on the CNT growth rate, density and structures was identified. A unified growth model was proposed which involves dissociative adsorption of acetylene on catalyst particles, and vapor-liquid-solid mechanism. According to it, balance between decomposition of C2H2 molecules on the catalyst surface, and diffusion of released carbon atoms into the catalyst particles is the key step towards the continuous growth of CNTs. Guided by our growth model, we demonstrated the growth of ultra-high dense vertically aligned multi-walled as well as rarely reported vertically aligned single-walled and double-walled CNTs. Post-growth manipulation and purification of CNTs by using AC electric field (dielectrophoresis) were investigated. Deeper understanding on the roles of the applied field strength and AC frequency was achieved. Increasing the electric field enhances the density of aligned nanotubes while increasing frequency enhances the dispersion, and hence the degree of alignment of CNTs, but reduces the nanotube density. CNTs were placed across a pair of electrodes with control of density and degree of alignment. Individual CNTs were successfully placed on an AFM tip. We investigated electron field emission from various types of CNT films and found that graphitic order of the CNTs is a major intrinsic factor which affects the emission current stability. Due to superior structural order, MWCNTs grown by thermal CVD have better emission stability than those grown by plasma enhanced CVD. These findings were explained by introducing a concept of emission current-induced dislocation and electron trapping effects, in which the dislocations induced in CNTs, and thus the electron transport along the CNTs prior to electron tunneling through them depend on the graphitic order of the CNTs. MWCNTs were successfully integrated into 2D and 3D carbon

  14. Clinicopathological characteristics of 10 patients with rupture of both ventricular free wall and septum (double rupture) after acute myocardial infarction.

    PubMed

    Tanaka, Keiji; Sato, Naoki; Yasutake, Masahiro; Takeda, Shinhiro; Takano, Teruo; Ochi, Masami; Tanaka, Shigeo; Tamura, Koichi

    2003-02-01

    Cardiac ruptures after myocardial infarction are classified as ventricular free wall ruptures (FWR), ventricular septal ruptures (VSR), and papillary muscle ruptures (PMR). A combination of any two types of rupture is called "ventricular double rupture;" (VDR) and shows a specific clinical course. 3,284 patients with acute myocardial infarction (AMI) were admitted to the CCU of our hospital between April, 1973 and December, 2001, and 10 patients (8 males and 2 female, aged 54 through 82 years) with VDR were clinicopathologically evaluated. All were diagnosed as VDR consisting of FWR and VSR. VDR was observed in 0.30% of all patients with AMI, in 3.0% of those with FWR, and in 16.1% of those with VSR. The infarct site was anteroseptal in 3 patients, anterolateral in 3, inferior in 3, and posterolateral in 1. Two patients with inferior infarction complicated RV infarction and a patient with posterolateral infarction had healed inferior infarction. The risk factors related to VDR were age, a history of hypertension, increased sympathetic tone to improve hemodynamic aggravation after perforation, cardiotonic agents, thrombolytic agents, delayed reperfusion, right ventricular volume overload by shunt and re-infarction. However, these factors might have played only a subsidiary role. The most important factor in VDR was the pathological findings. The site of septal perforation was the apex close to the septum-free wall junction in 9 patients and the site of rupture was also apical in 8 patients. Four patients already had VSR on admission to our CCU. FWR developed soon after VSR was demonstrated in 4 patients. FWR and VSR occurred simultaneously in one patient. These results suggest that VSR in the apical region is a precursor of VDR and requires the earliest surgical treatment. Surgical treatment was carried out in the operating room in 5 patients and 3 (60.0%) of them survived for 4 months or more. Two patients with rupture incidentally detected during operation for VSR

  15. 1. SOUTHEAST REAR WALL AND NORTHEAST SIDE WALL OF CABINS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. SOUTHEAST REAR WALL AND NORTHEAST SIDE WALL OF CABINS FORGEMAN'S HOUSE NO. 1 AT RIGHT - Mount Etna Iron Works, Forgeman's House No. 1, Legislative Route 07020 between junctions of T.R. 461 & 463, Williamsburg, Blair County, PA

  16. Flow and Temperature Distribution Evaluation on Sodium Heated Large-sized Straight Double-wall-tube Steam Generator

    SciTech Connect

    Kisohara, Naoyuki; Moribe, Takeshi; Sakai, Takaaki

    2006-07-01

    The sodium heated steam generator (SG) being designed in the feasibility study on commercialized fast reactor cycle systems is a straight double-wall-tube type. The SG is large sized to reduce its manufacturing cost by economics of scale. This paper addresses the temperature and flow multi-dimensional distributions at steady state to obtain the prospect of the SG. Large-sized heat exchanger components are prone to have non-uniform flow and temperature distributions. These phenomena might lead to tube buckling or tube to tube-sheet junction failure in straight tube type SGs, owing to tubes thermal expansion difference. The flow adjustment devices installed in the SG are optimized to prevent these issues, and the temperature distribution properties are uncovered by analysis methods. The analysis model of the SG consists of two parts, a sodium inlet distribution plenum (the plenum) and a heat transfer tubes bundle region (the bundle). The flow and temperature distributions in the plenum and the bundle are evaluated by the three-dimensional code 'FLUENT' and the two dimensional thermal-hydraulic code 'MSG', respectively. The MSG code is particularly developed for sodium heated SGs in JAEA. These codes have revealed that the sodium flow is distributed uniformly by the flow adjustment devices, and that the lateral tube temperature distributions remain within the allowable temperature range for the structural integrity of the tubes and the tube to tube-sheet junctions. (authors)

  17. Effect of the fluorination technique on the surface-fluorination patterning of double-walled carbon nanotubes

    PubMed Central

    Fedoseeva, Yuliya V; Flahaut, Emmanuel; Rio, Jérémy; Ewels, Christopher P; Koroteev, Victor O; Van Lier, Gregory; Vyalikh, Denis V; Okotrub, Alexander V

    2017-01-01

    Double-walled carbon nanotubes (DWCNTs) are fluorinated using (1) fluorine F2 at 200 °C, (2) gaseous BrF3 at room temperature, and (3) CF4 radio-frequency plasma functionalization. These have been comparatively studied using transmission electron microscopy and infrared, Raman, X-ray photoelectron, and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. A formation of covalent C–F bonds and a considerable reduction in the intensity of radial breathing modes from the outer shells of DWCNTs are observed for all samples. Differences in the electronic state of fluorine and the C–F vibrations for three kinds of the fluorinated DWCNTs are attributed to distinct local surroundings of the attached fluorine atoms. Possible fluorine patterns realized through a certain fluorination technique are revealed from comparison of experimental NEXAFS F K-edge spectra with quantum-chemical calculations of various models. It is proposed that fluorination with F2 and BrF3 produces small fully fluorinated areas and short fluorinated chains, respectively, while the treatment with CF4 plasma results in various attached species, including single or paired fluorine atoms and –CF3 groups. The results demonstrate a possibility of different patterning of carbon surfaces through choosing the fluorination method. PMID:28875106

  18. Wave propagation in double-walled carbon nanotubes on a novel analytically nonlocal Timoshenko-beam model

    NASA Astrophysics Data System (ADS)

    Yang, Yang; Zhang, Lixiang; Lim, C. W.

    2011-04-01

    This paper is concerned with the characteristics of wave propagation in double-walled carbon nanotubes (DWCNTs). The DWCNTs is simulated with a Timoshenko beam model based on the nonlocal continuum elasticity theory, referred to as an analytically nonlocal Timoshenko-beam (ANT) model. The governing equations of the DWCNTs beam consist of a set of four equations that are derived from the variational principle of the beam with high-order boundary conditions at the both ends, in which the effects of the nano-scale nonlocality and the van der Waals interaction between inner and outer tubes are inclusive. The characteristics of the wave propagation in the DWCNTs beam were analyzed with the new ANT model proposed and the comparisons with the partially nonlocal Timoshenko-beam (PNT) models in publication were made in details. The results show that the nonlocal effects of the ANT model proposed in the present study on the wave propagations are more significant because it is in stronger stiffness enhancement to the DWCNTs beam.

  19. High-speed nano-bearings constructed from double-walled carbon nanotubes: Effect of flexile deformation

    NASA Astrophysics Data System (ADS)

    Zhu, Chunzhang; Zhao, Yang

    2013-11-01

    Double-walled carbon nanotubes (DWCNTs) have been proposed to be the leading candidates for high-speed nanobearings owing to superlubric characteristics between adjacent nanotubes. Performance of the DWCNT bearings is closely related to intertube friction, which is influenced by many factors, and in this work, we focus on the issue of flexibility of the nanotubes. Using molecular dynamics simulation, it has been found that considerable deformation of the nanotubes can emerge in the (5, 5)/(18, 0) DWCNT bearing with a length of ˜80 Å if the angular speed of the shaft reaches 1.3 rev/ps. Such flexile deformation results in two distinct states with differing frictional characteristics. One of the two states, the slippery rotation, represents an interim period characterized by in-phase distortions of the inner and outer tubes, while the other state, the resistant rotation, is a steady state with the inner-tube curving lags behind that of the outer tube. Such a lag leads to a considerable increase of circular deflection of the outer tube and a sharp decrease of the minimal distance between tubes, therefore preventing the inner tube from slippery rotation.

  20. Integrated Ternary Bioinspired Nanocomposites via Synergistic Toughening of Reduced Graphene Oxide and Double-Walled Carbon Nanotubes.

    PubMed

    Gong, Shanshan; Cui, Wei; Zhang, Qi; Cao, Anyuan; Jiang, Lei; Cheng, Qunfeng

    2015-12-22

    With its synergistic toughening effect and hierarchical micro/nanoscale structure, natural nacre sets a "gold standard" for nacre-inspired materials with integrated high strength and toughness. We demonstrated strong and tough ternary bioinspired nanocomposites through synergistic toughening of reduced graphene oxide and double-walled carbon nanotube (DWNT) and covalent bonding. The tensile strength and toughness of this kind of ternary bioinspired nanocomposites reaches 374.1 ± 22.8 MPa and 9.2 ± 0.8 MJ/m(3), which is 2.6 and 3.3 times that of pure reduced graphene oxide film, respectively. Furthermore, this ternary bioinspired nanocomposite has a high conductivity of 394.0 ± 6.8 S/cm and also shows excellent fatigue-resistant properties, which may enable this material to be used in aerospace, flexible energy devices, and artificial muscle. The synergistic building blocks with covalent bonding for constructing ternary bioinspired nanocomposites can serve as the basis of a strategy for the construction of integrated, high-performance, reduced graphene oxide (rGO)-based nanocomposites in the future.

  1. Advanced catalytic performance of Au-Pt double-walled nanotubes and their fabrication through galvanic replacement reaction.

    PubMed

    Chen, Lu; Kuai, Long; Yu, Xue; Li, Wenzheng; Geng, Baoyou

    2013-08-26

    Bimetallic tubular nanostructures have been the focus of intensive research as they have very interesting potential applications in various fields including catalysis and electronics. In this paper, we demonstrate a facile method for the fabrication of Au-Pt double-walled nanotubes (Au-Pt DWNTs). The DWNTs are fabricated through the galvanic displacement reaction between Ag nanowires and various metal ions, and the Au-Pt DWNT catalysts exhibit high active catalytic performances toward both methanol electro-oxidation and 4-nitrophenol (4-NP) reduction. First, they have a high electrochemically active surface area of 61.66 m(2)  g(-1), which is close to the value of commercial Pt/C catalysts (64.76 m(2) g(-1)), and the peak current density of Au-Pt DWNTs in methanol oxidation is recorded as 138.25 mA mg(-1), whereas those of Pt nanotubes, Au/Pt nanotubes (simple mixture), and commercial Pt/C are 24.12, 40.95, and 120.65 mA mg(-1), respectively. The Au-Pt DWNTs show a markedly enhanced electrocatalytic activity for methanol oxidation compared with the other three catalysts. They also show an excellent catalytic performance in comparison with common Au nanotubes for 4-nitrophenol (4-NP) reduction. The attractive performance exhibited by these prepared Au-Pt DWNTs can be attributed to their unique structures, which make them promising candidates as high-performance catalysts.

  2. Carbon nanotube ecotoxicity in amphibians: assessment of multiwalled carbon nanotubes and comparison with double-walled carbon nanotubes.

    PubMed

    Mouchet, Florence; Landois, Perine; Puech, Pascal; Pinelli, Eric; Flahaut, Emmanuel; Gauthier, Laury

    2010-08-01

    The potential impact of industrial multiwalled carbon nanotubes (MWNTs) was investigated under normalized laboratory conditions according to the International Standard micronucleus assay ISO 21427-1 for 12 days of half-static exposure to 0.1, 1, 10 and 50 mg/l of MWNTs in water. Three different end points were carried out for 12 days of exposure: mortality, growth inhibition and micronuclei induction in erythrocytes of the circulating blood of larvae. Raman spectroscopy analysis was used to study the presence of carbon nanotubes in the biological samples. Considering the high diversity of carbon nanotubes according to their different characteristics, MWNTs were analyzed in Xenopus larvae, comparatively to double-walled carbon nanotubes used in a previous study in similar conditions. Growth inhibition in larvae exposed to 50 mg/l of MWNTs was evidenced; however, no genetoxicity (micronucleus assay) was noticed, at any concentration. Carbon nanotube localization in the larvae leads to different possible hypothesis of mechanisms explaining toxicity in Xenopus.

  3. Optimization of a Composite Double-Walled Cylindrical Shell Lined with Porous Materials for Higher Sound Transmission Loss by using a Genetic Algorithm

    NASA Astrophysics Data System (ADS)

    Ramezani, H.; Saghafi, A.

    2014-03-01

    A study on the optimization of sound transmission loss (TL) across a double-walled cylindrical laminated composite shell whose walls sandwich a layer of porous material is investigated using a genetic algorithm. First, an exact relation is presented by considering the effective wave component in the porous layer within the framework of the classic theory for laminated composite shells. The TL of the structure is estimated in a broadband frequency. Then, an acoustic optimization is considered for the sandwich structure with respect to the constraints of geometric properties.

  4. Fabrication of double-walled carbon nanotube film/Cu2O nanoparticle film/TiO2 nanotube array heterojunctions for photosensors

    NASA Astrophysics Data System (ADS)

    Yang, Mingjie; Xu, Jia; Wei, Jinquan; Sun, Jia-Lin; Liu, Wei; Zhu, Jia-Lin

    2012-06-01

    A structure for visible photosensors based on double-walled carbon nanotube (DWCNT) film/Cu2O nanoparticle (NP) film/TiO2 nanotube array (TNA) heterojunctions has been fabricated. Cu2O nanoparticles reduce dark current and enhance photoresponse of the heterojunctions. Consequently, the optoelectric performance is significantly enhanced compared to that of the heterojunctions without Cu2O nanoparticles. The photocurrent-to-dark current ratio reaches ˜1 × 104 under illumination at 405 nm and ˜3 × 104 under illumination at 532 nm, which is two orders of magnitude higher than the results of double-walled carbon nanotube film/TiO2 nanotube array heterojunctions under the same illumination density. Moreover, the response speed of the heterojunctions is greatly improved.

  5. In situ Raman study on single- and double-walled carbon nanotubes as a function of lithium insertion.

    PubMed

    Kim, Yoong Ahm; Kojima, Masahito; Muramatsu, Hiroyuki; Umemoto, Souichiro; Watanabe, Takaaki; Yoshida, Kazuto; Sato, Keigo; Ikeda, Takuya; Hayashi, Takuya; Endo, Morinobu; Terrones, Mauricio; Dresselhaus, Mildred S

    2006-05-01

    We investigated the electrochemical lithium ion (Li(+)) insertion/desertion behavior on highly pure and bundled single- and double-walled carbon nanotubes (SWNTs and DWNTs) using an in situ Raman technique. In general, two storage sites could host Li(+) in SWNT and DWNT bundles when varying an external potential: a) the outer surface sites, and b) the interstitial spaces within the bundles. The most sensitive changes in the tangential mode (TM) of the Raman spectra upon doping with Li(+) can be divided into two regions. The first region was found from 2.8 to 1.0 V (the coverage of Li(+) on the outer surface of a bundled nanotube) and was characterized by the loss of resonant conditions via partial charge transfer, where the G(+) line of the SWNT and the TM of the outer tube of DWNTs experienced a highly depressed intensity, but remained almost constant in frequency. The appearance of a Breit-Wigner-Fano (BWF) profile provided strong evidence of metallic inner tubes within DWNTs. The second region was observed when the applied potentials ranged from 0.9 to 0 V and was characterized by Li(+) diffusion into the interstitial sites of the bundled nanotube material. This phenomenon invoked a large downshift of the G(-) band in SWNTs, and a small downshift of the TM of the inner tube of DWNTs caused by expansion of the C--C bonds due to the charge transferred to the nanotubes, and the disappearance of the BWF profile through the screening effect of the interstitial Li(+) layers.

  6. Extremal states of energy of a double-layered thick-walled tube - application to residually stressed arteries.

    PubMed

    Waffenschmidt, Tobias; Menzel, Andreas

    2014-01-01

    Various biological tissues are designed to optimally support external loads for complex geometries and mechanobiological structures. This results in complex microstructures of such materials. The design of, for instance, (healthy) arteries, which are in the focus of this work, is characterised by a residually stressed fibre-reinforced multi-layered composite with highly non-linear elastic response. The complex interaction of material properties with the geometry and residual stress effects enables the optimal support under different blood pressures, respectively blood flow, within the vessel. The fibres reinforcing the arterial wall, as well as residual stresses present in the vessel, strongly influence its overall behaviour and performance. Turn-over and remodelling processes of the collagenous fibres occurring in the respective layers - either resulting from natural growth phenomena or from artificially induced changes in loading condition such as stent deployment - support the optimisation of the multi-layered composite structure of arteries for the particular loading conditions present in the artery. Within this contribution, the overall energetic properties of an artery are discussed by means of the inflation, bending and extension of a double-layered cylindrical tube. Different states of residual stresses and different fibre orientations are considered so that, for instance, representative fibre angles that result in extremal states of the total potential energy can be identified. In view of turn-over and remodelling processes, these orientations are considered to constitute preferred directions of fibre alignment. In summary, the main goal of this work is to calculate optimal material, structural and loading parameters by concepts of energy-minimisation. Several numerical studies show that the obtained values - such as the fibre orientations, the residual axial stretch and the opening angle - are in good agreement with respective physiological parameters

  7. Simultaneous interfacial rheology and microstructure measurement of densely aggregated particle laden interfaces using a modified double wall ring interfacial rheometer.

    PubMed

    Barman, Sourav; Christopher, Gordon F

    2014-08-19

    The study of particle laden interfaces has increased significantly due to the increasing industrial use of particle stabilized foams and Pickering emulsions, whose bulk rheology and stability are highly dependent on particle laden interface's interfacial rheology, which is a function of interfacial microstructure. To understand the physical mechanisms that dictate interfacial rheology of particle laden interfaces requires correlating rheology to microstructure. To achieve this goal, a double wall ring interfacial rheometer has been modified to allow real time, simultaneous interfacial visualization and shear rheology measurements. The development of this tool is outlined, and its ability to provide novel and unique measurements is demonstrated on a sample system. This tool has been used to examine the role of microstructure on the steady shear rheology of densely packed, aggregated particle laden interfaces at three surface concentrations. Through examination of the rheology and analysis of interfacial microstructure response to shear, a transition from shear thinning due to aggregated cluster breakup to yielding at a slip plane within the interface has been identified. Interestingly, it is found that aggregated interfaces transition to yielding well before they reached a jammed state. Furthermore, these systems undergo significant shear induced order when densely packed. These results indicate that the mechanics of these interfaces are not simply jammed or unjammed and that the interfacial rheology relationship with microstructure can give us significant insight into understanding how to engineer particle laden interfaces in the future. By examining both rheology and microstructure, the mechanisms that dictate observed rheology are now understood and can be used to predict and control the rheology of the interface.

  8. Double-deck structure of the boundary layer in the problem of flow in an axially symmetric pipe with small irregularities on the wall for large Reynolds numbers

    NASA Astrophysics Data System (ADS)

    Danilov, V. G.; Gaydukov, R. K.

    2017-01-01

    The problem of flow of a viscous incompressible fluid in an axially symmetric pipe with small irregularities on the wall is considered. An asymptotic solution of the problem with the double-deck structure of the boundary layer and the unperturbed flow in the environment (the "core flow") is obtained. The results of flow numerical simulation in the thin and "thick" boundary layers are given.

  9. On the vibrational behavior of single- and double-walled carbon nanotubes under the physical adsorption of biomolecules in the aqueous environment: a molecular dynamics study.

    PubMed

    Ajori, S; Ansari, R; Darvizeh, M

    2016-03-01

    The adsorption of biomolecules on the walls of carbon nanotubes (CNTs) in an aqueous environment is of great importance in the field of nanobiotechnology. In this study, molecular dynamics (MD) simulations were performed to understand the mechanical vibrational behavior of single- and double-walled carbon nanotubes (SWCNTs and DWCNTs) under the physical adsorption of four important biomolecules (L-alanine, guanine, thymine, and uracil) in vacuum and an aqueous environment. It was observed that the natural frequencies of these CNTs in vacuum reduce under the physical adsorption of biomolecules. In the aqueous environment, the natural frequency of each pure CNT decreased as compared to its natural frequency in vacuum. It was also found that the frequency shift for functionalized CNTs as compared to pure CNTs in the aqueous environment was dependent on the radius and the number of walls of the CNT, and could be positive or negative.

  10. Effects of hydrogen adsorption on the properties of double wall BN and (BN){sub x}C{sub y} nanotubes

    SciTech Connect

    Freitas, A.; Azevedo, S.; Kaschny, J.R.

    2016-01-15

    In the present contribution, we apply first-principles calculations, based on the density functional theory, to study the effects of hydrogen adsorption on the structural and electronic properties of boron nitride and hybrid carbon–boron nitride double wall nanotubes. The results demonstrate that the hydrogen decoration induces significant structural deformation and an appreciable reduction in the gap energy. When the number of hydrogen atoms introduced on the outer wall is increased, desorption of hydrogen pairs are observed. The calculations indicate that each adsorbed hydrogen atom induces a structural deformation with an energetic cost of about 68 meV/atom. It is also found that the introduction of hydrogen atoms can be applied as an efficient tool for tuning the electronic properties of such structures. - Graphical abstract: Localized density of states of a hydrogenated double wall boron nitride nanotube. Some hydrogen pairs are desorbed, forming H{sub 2} molecules. - Highlights: • Hydrogenation induces structural deformation and reduction in the gap energy. • Each H atom induces a deformation with an energetic cost of about 68 meV/atom. • In some cases, desorption of H pairs from the outer wall is observed.

  11. Randomized double-blind placebo-controlled trial of sublingual immunotherapy in children with house dust mite allergy in primary care: study design and recruitment

    PubMed Central

    de Bot, Cindy MA; Moed, Heleen; Berger, Marjolein Y; Röder, Esther; de Groot, Hans; de Jongste, Johan C; van Wijk, Roy Gerth; Wouden, Johannes C van der

    2008-01-01

    Background For respiratory allergic disorders in children, sublingual immunotherapy has been developed as an alternative to subcutaneous immunotherapy. Sublingual immunotherapy is more convenient, has a good safety profile and might be an attractive option for use in primary care. A randomized double-blind placebo-controlled study was designed to establish the efficacy of sublingual immunotherapy with house dust mite allergen compared to placebo treatment in 6 to18-year-old children with allergic rhinitis and a proven house dust mite allergy in primary care. Described here are the methodology, recruitment phases, and main characteristics of the recruited children. Methods Recruitment took place in September to December of 2005 and 2006. General practitioners (in south-west Netherlands) selected children who had ever been diagnosed with allergic rhinitis. Children and parents could respond to a postal invitation. Children who responded positively were screened by telephone using a nasal symptom score. After this screening, an inclusion visit took place during which a blood sample was taken for the RAST test. Results A total of 226 general practitioners invited almost 6000 children: of these, 51% was male and 40% <12 years of age. The target sample size was 256 children; 251 patients were finally included. The most frequent reasons given for not participating were: absence or mildness of symptoms, absence of house dust mite allergy, and being allergic to grass pollen or tree pollen only. Asthma symptoms were reported by 37% of the children. Of the enrolled children, 71% was sensitized to both house dust mite and grass pollen. Roughly similar proportions of children were diagnosed as being sensitized to one, two, three or four common inhalant allergens. Conclusion Our study was designed in accordance with recent recommendations for research on establishing the efficacy of sublingual immunotherapy; 98% of the target sample size was achieved. This study is expected to

  12. Use of ultramolecular potencies of allergen to treat asthmatic people allergic to house dust mite: double blind randomised controlled clinical trial

    PubMed Central

    Lewith, G T; Watkins, A D; Hyland, M E; Shaw, S; Broomfield, J A; Dolan, G; Holgate, S T

    2002-01-01

    Objective To evaluate the efficacy of homoeopathic immunotherapy on lung function and respiratory symptoms in asthmatic people allergic to house dust mite. Design Double blind randomised controlled trial. Setting 38 general practices in Hampshire and Dorset. Participants 242 people with asthma and positive results to skin prick test for house dust mite; 202 completed clinic based assessments, and 186 completed diary based assessments. Intervention After a four week baseline assessment, participants were randomised to receive oral homoeopathic immunotherapy or placebo and then assessed over 16 weeks with three clinic visits and diary assessments every other week. Outcome measure Clinic based assessments: forced expiratory volume in one second (FEV1), quality of life, and mood. Diary based assessments: morning and evening peak expiratory flow, visual analogue scale of severity of asthma, quality of life, and daily mood. Results There was no difference in most outcomes between placebo and homoeopathic immunotherapy. There was a different pattern of change over the trial for three of the diary assessments: morning peak expiratory flow (P=0.025), visual analogue scale (P=0.017), and mood (P=0.035). At week three there was significant deterioration for visual analogue scale (P=0.047) and mood (P=0.013) in the homoeopathic immunotherapy group compared with the placebo group. Any improvement in participants' asthma was independent of belief in complementary medicine. Conclusion Homoeopathic immunotherapy is not effective in the treatment of patients with asthma. The different patterns of change between homoeopathic immunotherapy and placebo over the course of the study are unexplained. What is already known on this topicHomoeopathic remedies probably have an effect that is greater than placeboSome of the better quality homoeopathic studies involve homoeopathic doses of allergens used to treat allergic diseaseWhat this study addsIn this study homoeopathic remedies were no

  13. Multiple intra-tube junctions in the inner tube of peapod-derived double walled carbon nanotubes: theoretical study and experimental evidence.

    PubMed

    Xu, Ziwei; Li, Hui; Fujisawa, Kazunori; Kim, Yoong Ahm; Endo, Morinobu; Ding, Feng

    2012-01-07

    The coalescence process of fullerenes in the hollow core of single walled carbon nanotubes is systematically explored by the kinetic Monte Carlo method. Two elongation (or growth) modes via the coalescence (i) between an inner tube and fullerenes and (ii) between neighboring inner tubes are identified. It is found that the coalescence of two inner tubes mostly creates a very stable intra-tube junction which is composed of multiple pentagon-heptagon pairs. As a consequence, the study predicts that the inner tube of peapod derived double walled carbon nanotubes (DWNTs) must contain many intra-tube junctions. Careful high resolution transmission electron microscopy observation on peapod-grown DWNT sample provides experimental evidence of the presence of the junctions.

  14. CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES: Operation Mechanism of Double-Walled Carbon Nanotubes Transistors Investigated By ab initio Calculations

    NASA Astrophysics Data System (ADS)

    Lan, Hai-Ping; Zhang, Shuang

    2009-11-01

    Recently, a new switching characteristic of double-walled carbon nanotubes (DWNTs) transistors is found in during experiments. We carry out a series of ab intio calculations on DWNTs' electronic properities, together with verification on the electronic response under the electric field. Our results reveal that the peculiar energy states relation in DWNTs and related contact modes should account for the distinct switching behavior of DWNT transistors. We believe these results have important implications in the fabrication and understanding of electronic devices with DWNTs.

  15. DOE Zero Energy Ready Home Case Study: Transformations, Inc., Production House, Devens, Massachusetts

    SciTech Connect

    none,

    2013-09-01

    A collaboration with Building America team Building Science Corporation helped this builder win a 2013 Housing Innovation Award in 2013—a 2,508-ft2 home built on speculation in the Devens, MA, subdivision. For the above-grade walls, the super-insulated building shell starts with 12 inch thick double walls composed of two 2x4 16-inch on-center walls spaced 5 inches apart. The space between the walls is filled with low-density (open-cell) spray foam for an insulation value of R-45.

  16. [Effect of vacuum cleaning of room floors and bed clothes of patients on house dust mites counts and clinical scores of atopic dermatitis. A double blind control trial].

    PubMed

    Endo, K; Fukuzumi, T; Adachi, J; Kojima, M; Aoki, T; Yoshida, M; Morita, K; Nari, T; Tsujino, M

    1997-10-01

    By a randomized double blind control trial we studied the effect of vacuum cleaning of room floors, mattresses and quilts for twelve months on clinical symptoms and laboratory data of atopic dermatitis patients. All patients used the identical new vacuum cleaners. Thirty patients (3-12 years of age) with relatively stable skin conditions were randomly allocated to either of the following two groups. In the monitor group we visited patient's home every three weeks and mite specialists cleaned drastically the room floors, mattresses and quilts and the patient continued to clean in the same way in-between. In the control group we visited similarly but the cleaning was made insufficiently which was also followed by the patient. But, at 2 occasions (the first and the last visits), cleaning was made drastically also in the control group. Thus the mite numbers were counted precisely at the start and the end of the experiment both in the monitor and control groups. Each patient was seen every six weeks by the same doctor and estimated of his symptoms using our unique scoring system (Fig. 1). At the start and the end of the study, total IgE and specific IgE antibodies to house dust mites in the serum were evaluated. The monitor group showed a tendency to count smaller number of mites than the control group after a year, when there was a significant difference only in quilts. However, a statistically significant decrease in the mite counts was observed only in room floors and not in mattresses and quilts both in the monitor and control groups (Fig. 2). Clinical scores after a year significantly improved only in the monitor group and not in the control group (Fig. 3). Serum IgE value and specific antibody titer to house dust mites were not changed significantly after the trial in both groups. As a conclusion, vacuum cleaning of the patient's room improved the clinical symptoms of atopic dermatitis but this could not be related to the reduction of house dust mite number.

  17. Synthesis of nanoparticles-deposited double-walled TiO₂-B nanotubes with enhanced performance for lithium-ion batteries.

    PubMed

    Qu, Jie; Cloud, Jacqueline E; Yang, Yongan; Ding, Jianning; Yuan, Ningyi

    2014-12-24

    A one-step hydrothermal method, followed by calcination at 300 °C in an argon atmosphere, has been developed to synthesize TiO2-B nanoparticles/double-walled nanotubes (NP/DWNT) and TiO2-B nanoparticles/multiple-walled nanotubes (NP/MWNT). To the best of our knowledge, this is the first synthesis of TiO2-B NP/NT hierarchical structures. Both NP/DWNT and NP/MWNT show high performance as anode materials for lithium-ion batteries, superior to their counterparts of DWNT and MWNT, respectively. Among all the four materials studied herein, NP/DWNT demonstrates the highest discharge-charge capacity, rate capability, and cycling stability. The enhancement due to the NP loading results from the increased surface areas, the improved kinetics, and the decreased transport distance for both electrons and Li ions. The charge capacity at high rates lies in the intercalation pseudocapacitance originating from fast Li-ion transport through the infinite channels in TiO2-B. The superiority of DWNT materials versus MWNT materials is ascribed to the thinner walls, which provide a shorter distance for Li-ion transport through the radial direction.

  18. The effect on the transmission loss of a double wall panel of using helium gas in the gap

    NASA Technical Reports Server (NTRS)

    Atwal, M. S.; Crocker, M. J.

    1985-01-01

    The possibility of increasing the sound-power transmission loss of a double panel by using helium gas in the gap is investigated. The transmission loss of a panel is defined as ten times the common logarithm of the ratio of the sound power incident on the panel to the sound power transmitted to the space on the other side of the panel. The work is associated with extensive research being done to develop new techniques for predicting the interior noise levels on board high-speed advanced turboprop aircraft and reducing the noise levels with a minimum weight penalty. Helium gas was chosen for its inert properties and its low impedance compared with air. With helium in the gap, the impedance mismatch experienced by the sound wave will be greater than that with air in the gap. It is seen that helium gas in the gap increases the transmission loss of the double panel over a wide range of frequencies.

  19. EAST WALL OF CRYSTALLIZER WING TO THE LEFT, END WALL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EAST WALL OF CRYSTALLIZER WING TO THE LEFT, END WALL OF CRUSHING MILL IN CENTER. GABLE END OF BOILING HOUSE IN LEFT BACKGROUND. VIEW FROM THE SOUTH - Kekaha Sugar Company, Sugar Mill Building, 8315 Kekaha Road, Kekaha, Kauai County, HI

  20. Through the wall solar cooker

    SciTech Connect

    Kerr, B.P.

    1987-04-07

    This patent describes a solar appliance for extending from the interior of a kitchen through an exterior wall of the building and beyond a predetermined distance in a cantilever manner to receive and concentrate in the appliance outside of the building, solar radiation rays for cooking purposes comprising: a housing, the housing being mounted to extend from a kitchen through an external wall of a building and beyond in a cantilever manner and forming a closed oven, the oven comprising a bottom, glass top, a pair of sides and a first end positioned with access from within the kitchen and comprising an oven door, a first reflective panel member mounted above, juxtapositioned to one edge of the glass top for positioning against the outer surface of the external wall and extending laterally therefrom for receiving and directing solar rays impinging thereon through the glass top and into the oven, and a second double-sided reflective panel mounted above and juxtapositioned to the glass top and extending substantially perpendicular to the first reflective panel for receiving solar rays impinging on either side thereof, and directing the solar rays into the oven.

  1. Structure and electronic properties of the double-wall nanotubes constructed from SiO2 nanotubes encapsulated inside zigzag carbon nanotubes.

    PubMed

    Qiao, Weiye; Bai, Hongcun; Zhu, Ying; Huang, Yuanhe

    2012-05-09

    This paper presents ab initio self-consistent field crystal orbital calculations on the structures, stabilities, elastic and electronic properties of the double-wall nanotubes made of SiO(2) nanotubes encapsulated inside zigzag carbon nanotubes based on density functional theory. It is found that formation of the combined systems is energetically favorable when the nearest distance between the two constituents is in the area of the van der Waals effect. The obtained band structures show that all the combined systems are semiconductors with nonzero energy gaps. Based on the deformation potential theory and effective mass approximation, the mobilities of charge carriers are calculated to be in the range of 10(2)-10(4) cm(2) V(-1) s(-1), the same order of magnitude as those of the corresponding zigzag carbon nanotubes. The Young's moduli are also calculated for the combined systems.

  2. Duality of two pairs of double-walled nanotubes consisting of S=1 and S=3/2 spins probed by means of a quantum simulation approach

    NASA Astrophysics Data System (ADS)

    Liu, Zhaosen; Ian, Hou

    2017-01-01

    Using a quantum simulation approach, we investigate in the present work the spontaneous magnetic properties of two pairs of double-walled cylindrical nanotubes consisting of different spins. Our simulated magnetic and thermodynamic properties for each pair of them are precisely identical, exhibiting a fascinating property of the nature world and demonstrating the correctness of our simulation approach. The second pair of nanotubes are frustrated, two magnetic phases of distinct spin configurations appear in the low temperature region, but only the inner layer consisting of small spins is frustrated evidently, its magnetization is considerably suppressed in the high temperature phase. Moreover, the nanosystems exhibit typical Ising-like behavior due to the uniaxial anisotropy along the z-direction, and evident finite-size effects as well.

  3. On sound transmission through double-walled cylindrical shells lined with poroelastic material: Comparison with Zhou's results and further effect of external mean flow

    NASA Astrophysics Data System (ADS)

    Liu, Yu; He, Chuanbo

    2015-12-01

    In this discussion, the corrections to the errors found in the derivations and the numerical code of a recent analytical study (Zhou et al. Journal of Sound and Vibration 333 (7) (2014) 1972-1990) on sound transmission through double-walled cylindrical shells lined with poroelastic material are presented and discussed, as well as the further effect of the external mean flow on the transmission loss. After applying the corrections, the locations of the characteristic frequencies of thin shells remain unchanged, as well as the TL results above the ring frequency where BU and UU remain the best configurations in sound insulation performance. In the low-frequency region below the ring frequency, however, the corrections attenuate the TL amplitude significantly for BU and UU, and hence the BB configuration exhibits the best performance which is consistent with previous observations for flat sandwich panels.

  4. Double-Walled Microparticles-Embedded Self-Cross-Linked, Injectable, and Antibacterial Hydrogel for Controlled and Sustained Release of Chemotherapeutic Agents.

    PubMed

    Davoodi, Pooya; Ng, Wei Cheng; Yan, Wei Cheng; Srinivasan, Madapusi P; Wang, Chi-Hwa

    2016-09-07

    First-line cancer chemotherapy has been prescribed for patients suffered from cancers for many years. However, conventional chemotherapy provides a high parenteral dosage of anticancer drugs over a short period, which may cause serious toxicities and detrimental side effects in healthy tissues. This study aims to develop a new drug delivery system (DDS) composed of double-walled microparticles and an injectable hydrogel for localized dual-agent drug delivery to tumors. The uniform double-walled microparticles loaded with cisplatin (Cis-DDP) and paclitaxel (PTX) were fabricated via coaxial electrohydrodynamic atomization (CEHDA) technique and subsequently were embedded into injectable alginate-branched polyethylenimine. The findings show the uniqueness of CEHDA technique for simply swapping the place of drugs to achieve a parallel or a sequential release profile. This study also presents the simulation of CEHDA technique using computational fluid dynamics (CFD) that will help in the optimization of CEHDA's operating conditions prior to large-scale production of microparticles. The new synthetic hydrogel provides an additional diffusion barrier against Cis-DDP and confines premature release of drugs. In addition, the hydrogel can provide a versatile tool for retaining particles in the tumor resected cavity during the injection after debulking surgery and preventing surgical site infection due to its inherent antibacterial properties. Three-dimensional MDA-MB-231 (breast cancer) spheroid studies demonstrate a superior efficacy and a greater reduction in spheroid growth for drugs released from the proposed composite formulation over a prolonged period, as compared with free drug treatment. Overall, the new core-shell microparticles embedded into injectable hydrogel can serve as a flexible controlled release platform for modulating the release profiles of anticancer drugs and subsequently providing a superior anticancer response.

  5. Enlightening the ultrahigh electrical conductivities of doped double-wall carbon nanotube fibers by Raman spectroscopy and first-principles calculations.

    PubMed

    Tristant, Damien; Zubair, Ahmed; Puech, Pascal; Neumayer, Frédéric; Moyano, Sébastien; Headrick, Robert J; Tsentalovich, Dmitri E; Young, Colin C; Gerber, Iann C; Pasquali, Matteo; Kono, Junichiro; Leotin, Jean

    2016-12-01

    Highly aligned, packed, and doped carbon nanotube (CNT) fibers with electrical conductivities approaching that of copper have recently become available. These fibers are promising for high-power electrical applications that require light-weight, high current-carrying capacity cables. However, a microscopic understanding of how doping affects the electrical conductance of such CNT fibers in a quantitative manner has been lacking. Here, we performed Raman spectroscopy measurements combined with first-principles calculations to determine the position of the average Fermi energy and to obtain the temperature of chlorosulfonic-acid-doped double-wall CNT fibers under high current. Due to the unique way in which double-wall CNT Raman spectra depend on doping, it is possible to use Raman data to determine the doping level quantitatively. The correspondence between the Fermi level shift and the carbon charge transfer is derived from a tight-binding model and validated by several calculations. For the doped fiber, we were able to associate an average Fermi energy shift of ∼-0.7 eV with a conductance increase by a factor of ∼5. Furthermore, since current induces heating, local temperature determination is possible. Through the Stokes-to-anti-Stokes intensity ratio of the G-band peaks, we estimated a temperature rise at the fiber surface of ∼135 K at a current density of 2.27 × 10(8) A m(-2) identical to that from the G-band shift, suggesting that thermalization between CNTs is well achieved.

  6. Single- and double-walled carbon nanotubes enhance atherosclerogenesis by promoting monocyte adhesion to endothelial cells and endothelial progenitor cell dysfunction.

    PubMed

    Suzuki, Yuka; Tada-Oikawa, Saeko; Hayashi, Yasuhiko; Izuoka, Kiyora; Kataoka, Misa; Ichikawa, Shunsuke; Wu, Wenting; Zong, Cai; Ichihara, Gaku; Ichihara, Sahoko

    2016-10-13

    The use of carbon nanotubes has increased lately. However, the cardiovascular effect of exposure to carbon nanotubes remains elusive. The present study investigated the effects of pulmonary exposure to single-walled carbon nanotubes (SWCNTs) and double-walled carbon nanotubes (DWCNTs) on atherosclerogenesis using normal human aortic endothelial cells (HAECs) and apolipoprotein E-deficient (ApoE(-/-)) mice, a model of human atherosclerosis. HAECs were cultured and exposed to SWCNTs or DWCNTs for 16 h. ApoE(-/-) mice were exposed to SWCNTs or DWCNTs (10 or 40 μg/mouse) once every other week for 10 weeks by pharyngeal aspiration. Exposure to CNTs increased the expression level of adhesion molecule (ICAM-1) and enhanced THP-1 monocyte adhesion to HAECs. ApoE(-/-) mice exposed to CNTs showed increased plaque area in the aorta by oil red O staining and up-regulation of ICAM-1 expression in the aorta, compared with vehicle-treated ApoE(-/-) mice. Endothelial progenitor cells (EPCs) are mobilized from the bone marrow into the circulation and subsequently migrate to the site of endothelial damage and repair. Exposure of ApoE(-/-) mice to high-dose SWCNTs or DWCNTs reduced the colony-forming units of EPCs in the bone marrow and diminished their migration function. The results suggested that SWCNTs and DWCNTs enhanced atherosclerogenesis by promoting monocyte adhesion to endothelial cells and inducing EPC dysfunction.

  7. Study of collective radial breathing-like modes in double-walled carbon nanotubes: combination of continuous two-dimensional membrane theory and Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Levshov, Dmitry I.; Avramenko, Marina V.; Than, Xuan-Tinh; Michel, Thierry; Arenal, Raul; Paillet, Matthieu; Rybkovskiy, Dmitry V.; Osadchy, Alexander V.; Rochal, Sergei B.; Yuzyuk, Yuri I.; Sauvajol, Jean-Louis

    2016-01-01

    Radial breathing modes (RBMs) are widely used for the atomic structure characterization and index assignment of single-walled carbon nanotubes (SWNTs) from resonant Raman spectroscopy. However, for double-walled carbon nanotubes (DWNTs), the use of conventional ωRBM(d) formulas is complicated due to the van der Waals interaction between the layers, which strongly affects the frequencies of radial modes and leads to new collective vibrations. This paper presents an alternative way to theoretically study the collective radial breathing-like modes (RBLMs) of DWNTs and to account for interlayer interaction, namely the continuous two-dimensional membrane theory. We obtain an analytical ωRBLM(do,di) relation, being the equivalent of the conventional ωRBM(d) expressions, established for SWNTs. We compare our theoretical predictions with Raman data, measured on individual index-identified suspended DWNTs, and find a good agreement between experiment and theory. Moreover, we show that the interlayer coupling in individual DWNTs strongly depends on the interlayer distance, which is manifested in the frequency shifts of the RBLMs with respect to the RBMs of the individual inner and outer tubes. In terms of characterization, this means that the combination of Raman spectroscopy data and predictions of continuous membrane theory may give additional criteria for the index identification of DWNTs, namely the interlayer distance.

  8. A randomized, double-blind, placebo-controlled study of ten-cha (Rubus suavissimus) on house dust mite allergic rhinitis.

    PubMed

    Yonekura, Syuji; Okamoto, Yoshitaka; Yamasaki, Kazuki; Horiguchi, Shigetoshi; Hanazawa, Toyoyuki; Matsune, Shoji; Kurono, Yuichi; Yamada, Takechiyo; Fujieda, Shigeharu; Okano, Mitsuhiro; Okubo, Kimihiro

    2011-10-01

    Self-care with ten-cha is the most common complementary alternative medicine for allergic rhinitis in Japan, but evidence for an actual therapeutic effect is lacking. The purpose of the study was to investigate the effect of ten-cha (Rubus suavissimus) on house dust mite allergic rhinitis. The study was performed in the otolaryngology departments of 5 facilities (Chiba University, Kagoshima University, Fukui University, Okayama University, and Nippon Medical School) from July to December 2009. A randomized double-blind study was performed with central enrollment and allocation. The subjects ingested 400mg of ten-cha extract or placebo (3 capsules/day) daily for 4 weeks as a food intervention. The number of subjects was chosen with anticipation of an effect equivalent to that of mast cell-stabilizing drugs. A nasal allergy diary-based symptom score and a QOL score were used for evaluation. The ten-cha and placebo groups included 47 and 42 subjects, respectively. The improvement rates for sneeze, nasal discharge, nasal obstruction, and symptom scores were greater in the ten-cha group than in the placebo group throughout the intervention period, and the effect tended to increase with time in the ten-cha group. However, the differences between the groups were not significant. QOL was not significantly improved in either group. Ingestion of ten-cha had an effect on allergic rhinitis, but the effect of Ten-Cha was limited and did not differ significantly from placebo. These results suggest that ten-cha does not exhibit an effect equivalent to mast cell-stabilizing drugs at the dose used in this study. Crown Copyright © 2010. Published by Elsevier Ireland Ltd. All rights reserved.

  9. Construction Guidelines for High R-Value Walls without Exterior Rigid Insulation

    SciTech Connect

    Arena, Lois B.

    2016-07-13

    High-R wall assemblies (R-40 and above) are gaining popularity in the market due to programs like the DOE's Zero Energy Ready Home program, Passive House (PH), Net Zero Energy Home (NZEH) challenges in several states, and highly incentivized retrofit programs. In response to this demand, several builders have successfully used 'double wall' systems to more practically achieve higher R-values in thicker, framed walls. To builders of conventional stick-framed homes, often one of the most appealing features of double wall systems is that there are very few new exterior details. Exterior sheathing, structural bracing, house wrap or building paper, window and door flashing, and siding attachment are usually identical to good details in conventional framed wall systems. The information presented in this guide is intended to reduce the risk of failure in these types of assemblies, increase durability, and result in a reduction of material brought to landfills due to failures and resulting decay. While this document focuses on double wall framing techniques, the majority of the information on how to properly construct and finish high R-value assemblies is applicable to all wall assemblies that do not have foam insulation installed on the exterior of the structural sheathing. The techniques presented have been shown through field studies to reduce the likelihood of mold growth and moisture related damage and are intended for builders, framing contractors, architects, and consultants involved in designing and building super insulated homes.

  10. Prevention of blood cell adhesion in porous inner wall of double-layered tube by saline perfusion.

    PubMed

    Kim, S S; Park, J B

    1993-01-01

    A double-layered tube consisting of a porous inner tube and a solid outer tube was used to perfuse isotonic saline solution into blood to prevent blood cell adhesion. Polystyrene/poly(styrene-co-butadiene) (PS-SBR) porous tubes were made using a dipping method. Citrated canine blood was circulated for 30 min with the flow rate of 100 ml/min using an in vitro blood circulation setup which makes nonpulsatile blood flow. Blood cell adhesion in the PS/SBR porous tubes decreased with increased saline perfusion rate regardless of changes in variables such as tube porosities, tube materials, and perfusion materials. The relationship between blood cell adhesion and perfusion rate was semi-logarithmic. Blood cell adhesion was relatively high in the more porous tube (65% sugar tube), compared to the less porous tube (55% sugar tube) for an identical saline perfusion rate. The blood cell adhesion in the sulfonated PS/SBR porous tube was less than that in the nonsulfonated (control) PS/SBR porous tube. The blood cell adhesion was also decreased by citrate perfusion. The results of this study indicates that the saline perfusion method can be used to prevent blood cell adhesion in the blood lines of extracorporeal circulation systems (such as hemodialysis and heart-lung machines) if certain technical problems involving the surface roughness can be resolved.

  11. Advanced houses guide

    SciTech Connect

    1995-12-31

    Section 1 of this report describes the R-2000 and Advanced Houses programs, and reviews the technical requirements of Advanced Houses with regard to purchased energy, environmental features, and indoor comfort/health. Subsequent sections describe design considerations, construction issues, existing installations, and alternate approaches used in the following components of Advanced Houses: Foundation systems, wall systems, windows and exterior doors, interior finishes and indoor air quality, environmental materials, mechanical systems, home automation, lights and appliances, renewable energy and heat recovery systems, and environmental management.

  12. Double-Wall Carbon Nanotube Hybrid Mode-Locker in Tm-doped Fibre Laser: A Novel Mechanism for Robust Bound-State Solitons Generation

    PubMed Central

    Chernysheva, Maria; Bednyakova, Anastasia; Al Araimi, Mohammed; Howe, Richard C. T.; Hu, Guohua; Hasan, Tawfique; Gambetta, Alessio; Galzerano, Gianluca; Rümmeli, Mark; Rozhin, Aleksey

    2017-01-01

    The complex nonlinear dynamics of mode-locked fibre lasers, including a broad variety of dissipative structures and self-organization effects, have drawn significant research interest. Around the 2 μm band, conventional saturable absorbers (SAs) possess small modulation depth and slow relaxation time and, therefore, are incapable of ensuring complex inter-pulse dynamics and bound-state soliton generation. We present observation of multi-soliton complex generation in mode-locked thulium (Tm)-doped fibre laser, using double-wall carbon nanotubes (DWNT-SA) and nonlinear polarisation evolution (NPE). The rigid structure of DWNTs ensures high modulation depth (64%), fast relaxation (1.25 ps) and high thermal damage threshold. This enables formation of 560-fs soliton pulses; two-soliton bound-state with 560 fs pulse duration and 1.37 ps separation; and singlet+doublet soliton structures with 1.8 ps duration and 6 ps separation. Numerical simulations based on the vectorial nonlinear Schr¨odinger equation demonstrate a transition from single-pulse to two-soliton bound-states generation. The results imply that DWNTs are an excellent SA for the formation of steady single- and multi-soliton structures around 2 μm region, which could not be supported by single-wall carbon nanotubes (SWNTs). The combination of the potential bandwidth resource around 2 μm with the soliton molecule concept for encoding two bits of data per clock period opens exciting opportunities for data-carrying capacity enhancement. PMID:28287159

  13. Double-Wall Carbon Nanotube Hybrid Mode-Locker in Tm-doped Fibre Laser: A Novel Mechanism for Robust Bound-State Solitons Generation

    NASA Astrophysics Data System (ADS)

    Chernysheva, Maria; Bednyakova, Anastasia; Al Araimi, Mohammed; Howe, Richard C. T.; Hu, Guohua; Hasan, Tawfique; Gambetta, Alessio; Galzerano, Gianluca; Rümmeli, Mark; Rozhin, Aleksey

    2017-03-01

    The complex nonlinear dynamics of mode-locked fibre lasers, including a broad variety of dissipative structures and self-organization effects, have drawn significant research interest. Around the 2 μm band, conventional saturable absorbers (SAs) possess small modulation depth and slow relaxation time and, therefore, are incapable of ensuring complex inter-pulse dynamics and bound-state soliton generation. We present observation of multi-soliton complex generation in mode-locked thulium (Tm)-doped fibre laser, using double-wall carbon nanotubes (DWNT-SA) and nonlinear polarisation evolution (NPE). The rigid structure of DWNTs ensures high modulation depth (64%), fast relaxation (1.25 ps) and high thermal damage threshold. This enables formation of 560-fs soliton pulses; two-soliton bound-state with 560 fs pulse duration and 1.37 ps separation; and singlet+doublet soliton structures with 1.8 ps duration and 6 ps separation. Numerical simulations based on the vectorial nonlinear Schr¨odinger equation demonstrate a transition from single-pulse to two-soliton bound-states generation. The results imply that DWNTs are an excellent SA for the formation of steady single- and multi-soliton structures around 2 μm region, which could not be supported by single-wall carbon nanotubes (SWNTs). The combination of the potential bandwidth resource around 2 μm with the soliton molecule concept for encoding two bits of data per clock period opens exciting opportunities for data-carrying capacity enhancement.

  14. Double-Wall Carbon Nanotube Hybrid Mode-Locker in Tm-doped Fibre Laser: A Novel Mechanism for Robust Bound-State Solitons Generation.

    PubMed

    Chernysheva, Maria; Bednyakova, Anastasia; Al Araimi, Mohammed; Howe, Richard C T; Hu, Guohua; Hasan, Tawfique; Gambetta, Alessio; Galzerano, Gianluca; Rümmeli, Mark; Rozhin, Aleksey

    2017-03-13

    The complex nonlinear dynamics of mode-locked fibre lasers, including a broad variety of dissipative structures and self-organization effects, have drawn significant research interest. Around the 2 μm band, conventional saturable absorbers (SAs) possess small modulation depth and slow relaxation time and, therefore, are incapable of ensuring complex inter-pulse dynamics and bound-state soliton generation. We present observation of multi-soliton complex generation in mode-locked thulium (Tm)-doped fibre laser, using double-wall carbon nanotubes (DWNT-SA) and nonlinear polarisation evolution (NPE). The rigid structure of DWNTs ensures high modulation depth (64%), fast relaxation (1.25 ps) and high thermal damage threshold. This enables formation of 560-fs soliton pulses; two-soliton bound-state with 560 fs pulse duration and 1.37 ps separation; and singlet+doublet soliton structures with 1.8 ps duration and 6 ps separation. Numerical simulations based on the vectorial nonlinear Schr¨odinger equation demonstrate a transition from single-pulse to two-soliton bound-states generation. The results imply that DWNTs are an excellent SA for the formation of steady single- and multi-soliton structures around 2 μm region, which could not be supported by single-wall carbon nanotubes (SWNTs). The combination of the potential bandwidth resource around 2 μm with the soliton molecule concept for encoding two bits of data per clock period opens exciting opportunities for data-carrying capacity enhancement.

  15. Use of in situ and confocal Raman spectroscopy to study the nature and distribution of carotenoids in brown patinas from a deteriorated wall painting in Marcus Lucretius House (Pompeii).

    PubMed

    Maguregui, M; Knuutinen, U; Trebolazabala, J; Morillas, H; Castro, K; Martinez-Arkarazo, I; Madariaga, J M

    2012-02-01

    Colonisation of wall paintings by microorganisms and other organisms is a well-known problematic phenomenon. Besides taxonomic identification of the biodeteriogen, it is essential to evaluate the consequences of the colonisation, e.g., unsightly coloured patinas. This work proposes new methodology for characterisation of the nature of the main carotenoids and their distribution in brown stains or patinas of a deteriorated wall painting on the north wall of the atrium of Marcus Lucretius House (Pompeii, Italy). Characterisation of the brown patinas and surrounding areas (plaster and polychromy) from the wall painting started with in situ screening using, mainly, a portable Raman instrument with a handheld FTIR (DRIFTS sampling interface) in order to select the sampling areas suitable for further analysis in the laboratory. Two wall painting fragments were then analysed in the laboratory in two steps. First, microscopic observations (SEM and phase-contrast microscopy) were used to determine whether biodeteriogens were present in the samples. In a second step, confocal Raman microscopy (785 and 514 nm excitation lasers) was used to characterise the main biogenic compounds of the brown stains. Because of the resonance Raman effect (514 nm excitation laser), it was possible to obtain reliable Raman features to assign not only the nature of the main biogenic pigments (carotenoids) present in the stains, but also their spatial conformation. Moreover, Raman confocal applications, for example, Raman imaging and depth profiling were also used in a first attempt to determine the distribution of biosynthesised carotenoids in the stains, and to determine the thickness of the brown patinas.

  16. Oxygen and light sensitive field-effect transistors based on ZnO nanoparticles attached to individual double-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Chanaewa, Alina; Juárez, Beatriz H.; Weller, Horst; Klinke, Christian

    2011-12-01

    The attachment of semiconducting nanoparticles to carbon nanotubes is one of the most challenging subjects in nanotechnology. Successful high coverage attachment and control over the charge transfer mechanism and photo-current generation open a wide field of new applications such as highly effective solar cells and fibre-enhanced polymers. In this work we study the charge transfer in individual double-walled carbon nanotubes highly covered with uniform ZnO nanoparticles. The synthetic colloidal procedure was chosen to avoid long-chained ligands at the nanoparticle-nanotube interface. The resulting composite material was used as conductive channel in a field-effect transistor device and the electrical photo-response was analysed under various conditions. By means of the transfer characteristics we could elucidate the mechanism of charge transfer from non-covalently attached semiconducting nanoparticles to carbon nanotubes. The role of positive charges remaining on the nanoparticles is discussed in terms of a gating effect.The attachment of semiconducting nanoparticles to carbon nanotubes is one of the most challenging subjects in nanotechnology. Successful high coverage attachment and control over the charge transfer mechanism and photo-current generation open a wide field of new applications such as highly effective solar cells and fibre-enhanced polymers. In this work we study the charge transfer in individual double-walled carbon nanotubes highly covered with uniform ZnO nanoparticles. The synthetic colloidal procedure was chosen to avoid long-chained ligands at the nanoparticle-nanotube interface. The resulting composite material was used as conductive channel in a field-effect transistor device and the electrical photo-response was analysed under various conditions. By means of the transfer characteristics we could elucidate the mechanism of charge transfer from non-covalently attached semiconducting nanoparticles to carbon nanotubes. The role of positive

  17. Fabrication of Au nanoparticle/double-walled carbon nanotube film/TiO2 nanotube array/Ti heterojunctions with low resistance state for broadband photodetectors

    NASA Astrophysics Data System (ADS)

    Chen, Yan; Zhang, Guowei; Dong, Zhanmin; Wei, Jinquan; Zhu, Jia-Lin; Sun, Jia-Lin

    2017-03-01

    A broadband photodetector based on Au nanoparticle/double-walled carbon nanotube film/TiO2 nanotube array /Ti multilayer heterojunction structures has been fabricated. A pre-electroforming process at a voltage bias of 35 V was used to switch the photodetector from a high resistance state to a low resistance state. At a voltage bias of 1 V under 532-nm laser illumination in air, the photoresponsivity of the device reached 15.41 mA W-1, which is enhanced by approximately 1.91 times when compared with that of device before deposition of Au nanoparticles. In addition, in a vacuum under a voltage bias of 1 V, the photoresponsivity of the device reached 23.29 mA W-1 and 6.85 mA W-1 at 532 nm and 1064 nm, respectively. The surface plasmon polaritons of the Au nanoparticles allowed extension of the sensitivity of the photosensitive regions into the mid-infrared range. The experimental results show that the device photoresponsivity reached 2.26 mA W-1 at a voltage bias of 1 V under 10.6-μm laser illumination in air.

  18. Controllable Synthesis of TiO2@Fe2O3 Core-Shell Nanotube Arrays with Double-Wall Coating as Superb Lithium-Ion Battery Anodes

    NASA Astrophysics Data System (ADS)

    Zhong, Yan; Ma, Yifan; Guo, Qiubo; Liu, Jiaqi; Wang, Yadong; Yang, Mei; Xia, Hui

    2017-01-01

    Highlighted by the safe operation and stable performances, titanium oxides (TiO2) are deemed as promising candidates for next generation lithium-ion batteries (LIBs). However, the pervasively low capacity is casting shadow on desirable electrochemical behaviors and obscuring their practical applications. In this work, we reported a unique template-assisted and two-step atomic layer deposition (ALD) method to achieve TiO2@Fe2O3 core-shell nanotube arrays with hollow interior and double-wall coating. The as-prepared architecture combines both merits of the high specific capacity of Fe2O3 and structural stability of TiO2 backbone. Owing to the nanotubular structural advantages integrating facile strain relaxation as well as rapid ion and electron transport, the TiO2@Fe2O3 nanotube arrays with a high mass loading of Fe2O3 attained desirable capacity of ~520 mA h g-1, exhibiting both good rate capability under uprated current density of 10 A g-1 and especially enhanced cycle stability (~450 mA h g-1 after 600 cycles), outclassing most reported TiO2@metal oxide composites. The results not only provide a new avenue for hybrid core-shell nanotube formation, but also offer an insight for rational design of advanced electrode materials for LIBs.

  19. Laccase electrodes based on the combination of single-walled carbon nanotubes and redox layered double hydroxides: Towards the development of biocathode for biofuel cells

    NASA Astrophysics Data System (ADS)

    Ding, Shou-Nian; Holzinger, Michael; Mousty, Christine; Cosnier, Serge

    Single-walled carbon nanotubes (SWCNT) were combined with layered double hydroxides (LDH) intercalated with 2,2‧-azino-bis(3-ethylbenzothiazoline-6-sulfonate) diammonium salt [ZnCr-ABTS] to entrap and electrically connect laccase enzyme. The resulting laccase electrodes exhibited an electro-enzymatic activity for O 2 reduction. To improve this electrocatalytic activity, varying SWCNT quantities and loading methods were tested to optimize the configuration of the laccase electrodes. Furthermore, the resulting bioelectrode was successfully used as a biocathode for the elaboration of a membrane-less glucose/air biofuel cell. In 0.1 M phosphate buffer (PBS) of pH 6.0, containing glucose (5 mM) under ambient conditions, the assembled biofuel cell yielded a maximum power density of 18 μW cm -2 at a cell voltage of 0.3 V whereas this power decreased to 8.3 μW cm -2 for a biofuel cell based on the identical biocathode setup without SWCNT.

  20. Utilizing Electrical Characteristics of Individual Nanotube Devices to Study the Charge Transfer between CdSe Quantum Dots and Double-Walled Nanotubes

    DOE PAGES

    Zhu, Yuqi; Zhou, Ruiping; Wang, Lei; ...

    2017-03-02

    To study the charge transfer between cadmium selenide (CdSe) quantum dots (QDs) and double-walled nanotubes (DWNTs), various sizes of CdSe-ligand-DWNT structures are synthesized, and field-effect transistors (FETs) from individual functionalized DWNTs rather than networks of the same are fabricated. From the electrical measurements, two distinct electron transfer mechanisms from the QD system to the nanotube are identified. By the formation of the CdSe-ligand-DWNT heterostructure, an effectively n-doped nanotube is created due to the smaller work function of CdSe as compared with the nanotube. In addition, once the QD-DWNT system is exposed to laser light, further electron transfer from the QDmore » through the ligand, i.e. 4-mercaptophenol (MTH), to the nanotube occurs and a clear QD-size dependent tunneling process is observed. Furthermore, the detailed analysis of a large set of devices and the particular methodology employed here for the first time allowed for extracting a wavelength and quantum dot size dependent charge transfer efficiency – a quantity that is evaluated for the first time through electrical measurement.« less

  1. Dynamic stability experimental/analytical program results on a multiple tube sodium heated steam generator model employing double wall tubes. [LMFBR

    SciTech Connect

    Efferding, L.E.

    1983-01-01

    Experimental results are described of a test program which induced water/steam dynamic instability in the multiple tube circuits of a sodium heated, double-wall tube, steam generator model whose water/steam side is designed to operate under once-through conditions with exit superheat (457/sup 0/C/855/sup 0/F; 15.8 MPa/2290 psia). The instability thresholds were determined experimentally with off-nominal operation in order to establish the stability margin that exists with and without the damping orifice configuration employed at the inlet of each tube circuit. Two classes of experiments were performed; one with low magnitudes of water/steam mass velocity resulting in high exit superheat (Benson Cycle), and the other with high magnitudes of mass velocity and no bulk exit steam superheat (Sulzer Cycle). Analytical prediction of the instability inception conditions were compared with experiment and are included along with an evaluation of the applicability of the analysis method to plant scale stability evaluations.

  2. Buckling analysis of defective cross-linked functionalized single- and double-walled carbon nanotubes with polyethylene chains using molecular dynamics simulations.

    PubMed

    Ajori, S; Ansari, R; Parsapour, H

    2016-12-01

    Functionalized carbon nanotubes (CNTs) can be used for improving the mechanical properties and load transfer in nanocomposites. In this research, the buckling behavior of perfect and defective cross-linked functionalized CNTs with polyethylene (PE) chains is studied employing molecular dynamics (MD) simulations. Two different configurations with the consideration of vacancy defects, namely mapped and wrapped, are selected. According to the results, critical buckling force of cross-linked functionalized CNTs with PE chains increases as compared to pure CNTs, especially in the case of double-walled carbon nanotubes (DWCNTs). By contrast, it is demonstrated that critical strain of cross-linked functionalized CNTs decreases as compared to that of pristine CNTs. Also, it is observed that increasing the weight percentage leads to the higher increase and the decrease in critical buckling force and strain of cross-linked functionalized CNTs, respectively. Moreover, the presence of defect considerably reduces both critical buckling force and strain of cross-linked functionalized CNTs. Finally, it is shown that the critical buckling strain is more sensitive to the presence of defects as compared to critical buckling force.

  3. Controllable Synthesis of TiO2@Fe2O3 Core-Shell Nanotube Arrays with Double-Wall Coating as Superb Lithium-Ion Battery Anodes.

    PubMed

    Zhong, Yan; Ma, Yifan; Guo, Qiubo; Liu, Jiaqi; Wang, Yadong; Yang, Mei; Xia, Hui

    2017-01-18

    Highlighted by the safe operation and stable performances, titanium oxides (TiO2) are deemed as promising candidates for next generation lithium-ion batteries (LIBs). However, the pervasively low capacity is casting shadow on desirable electrochemical behaviors and obscuring their practical applications. In this work, we reported a unique template-assisted and two-step atomic layer deposition (ALD) method to achieve TiO2@Fe2O3 core-shell nanotube arrays with hollow interior and double-wall coating. The as-prepared architecture combines both merits of the high specific capacity of Fe2O3 and structural stability of TiO2 backbone. Owing to the nanotubular structural advantages integrating facile strain relaxation as well as rapid ion and electron transport, the TiO2@Fe2O3 nanotube arrays with a high mass loading of Fe2O3 attained desirable capacity of ~520 mA h g(-1), exhibiting both good rate capability under uprated current density of 10 A g(-1) and especially enhanced cycle stability (~450 mA h g(-1) after 600 cycles), outclassing most reported TiO2@metal oxide composites. The results not only provide a new avenue for hybrid core-shell nanotube formation, but also offer an insight for rational design of advanced electrode materials for LIBs.

  4. A case of penetration of the intestinal wall by a soft-shelled turtle bone successfully removed with double-balloon endoscopy.

    PubMed

    Sawada, Mizuho; Sekigawa, Kenichiro; Mitsui, Hiroshi; Kobayashi, Katsuya; Okubo, Masao; Yamaguchi, Hajime; Hashimoto, Naoaki

    2015-10-01

    A 62-year-old male was admitted to our hospital due to left lower abdominal pain. Three days before admission, he ate seafood in a Japanese restaurant. Two days before admission, he suffered from intermittent left lower abdominal pain. One day before admission, he developed a high fever and subsequently visited our hospital the following day. Localized tenderness and rebound pain were observed in the left lower abdomen, and C-reactive protein was elevated. Computed tomography revealed a linear high-density object in the distal portion of the small intestine accompanied by edema of the wall, suggesting penetration by something like a fishbone. On the ninth hospital day, double-balloon endoscopy was performed via the transanal route. Yellow foreign material was found in the ileum and was then successfully removed with biopsy forceps. The removed material measured 3 mm in width, 3 cm in length and was slightly curved. It proved to be a bone of the forefoot of a soft-shelled turtle, which had been included on the menu of the restaurant. The patient was completely cured and discharged on the 14th hospital day.

  5. Controllable Synthesis of TiO2@Fe2O3 Core-Shell Nanotube Arrays with Double-Wall Coating as Superb Lithium-Ion Battery Anodes

    PubMed Central

    Zhong, Yan; Ma, Yifan; Guo, Qiubo; Liu, Jiaqi; Wang, Yadong; Yang, Mei; Xia, Hui

    2017-01-01

    Highlighted by the safe operation and stable performances, titanium oxides (TiO2) are deemed as promising candidates for next generation lithium-ion batteries (LIBs). However, the pervasively low capacity is casting shadow on desirable electrochemical behaviors and obscuring their practical applications. In this work, we reported a unique template-assisted and two-step atomic layer deposition (ALD) method to achieve TiO2@Fe2O3 core-shell nanotube arrays with hollow interior and double-wall coating. The as-prepared architecture combines both merits of the high specific capacity of Fe2O3 and structural stability of TiO2 backbone. Owing to the nanotubular structural advantages integrating facile strain relaxation as well as rapid ion and electron transport, the TiO2@Fe2O3 nanotube arrays with a high mass loading of Fe2O3 attained desirable capacity of ~520 mA h g−1, exhibiting both good rate capability under uprated current density of 10 A g−1 and especially enhanced cycle stability (~450 mA h g−1 after 600 cycles), outclassing most reported TiO2@metal oxide composites. The results not only provide a new avenue for hybrid core-shell nanotube formation, but also offer an insight for rational design of advanced electrode materials for LIBs. PMID:28098237

  6. Purification, separation and extraction of inner tubes from double-walled carbon nanotubes by tailoring density gradient ultracentrifugation using optical probes

    PubMed Central

    Rohringer, Philip; Shi, Lei; Liu, Xianjie; Yanagi, Kazuhiro; Pichler, Thomas

    2014-01-01

    We studied the effect of varying sonication and centrifugation parameters on double-walled carbon nanotubes (DWCNT) by measuring optical absorption and photoluminescence (PL) of the samples. We found that by using a low sonication intensity before applying density gradient ultracentrifugation (DGU), only inner tube species with a diameter ⩽0.8 nm can be identified in absorption measurements. This is in stark contrast to the result after sonicating at higher intensities, where also bigger inner tubes can be found. Furthermore, by comparing PL properties of samples centrifugated either with or without a gradient medium, we found that applying DGU greatly enhances the PL intensity, whereas centrifugation at even higher speeds but without a gradient medium results in lower intensities. This can be explained by extraction of inner tubes from their host outer tubes in a two-stage process: the different shearing forces from the sonication treatments result in some DWCNT to be opened, whereas others stay uncut. A subsequent application of DGU leads to the extraction of the inner tubes or not if the host nanotube stayed uncut or no gradient medium was used. This work shows a pathway to avoid this phenomenon to unravel the intrinsic PL from inner tubes of DWCNT. PMID:25843961

  7. Numerical analysis of non-Newtonian blood flow and wall shear stress in realistic single, double and triple aorto-coronary bypasses.

    PubMed

    Vimmr, J; Jonášová, A; Bublík, O

    2013-10-01

    Considering the fact that hemodynamics plays an important role in the patency and overall performance of implanted bypass grafts, this work presents a numerical investigation of pulsatile non-Newtonian blood flow in three different patient-specific aorto-coronary bypasses. The three bypass models are distinguished from each other by the number of distal side-to-side and end-to-side anastomoses and denoted as single, double and triple bypasses. The mathematical model in the form of time-dependent nonlinear system of incompressible Navier-Stokes equations is coupled with the Carreau-Yasuda model describing the shear-thinning property of human blood and numerically solved using the principle of the SIMPLE algorithm and cell-centred finite volume method formulated for hybrid unstructured tetrahedral grids. The numerical results computed for non-Newtonian and Newtonian blood flow in the three aorto-coronary bypasses are compared and analysed with emphasis placed on the distribution of cycle-averaged wall shear stress and oscillatory shear index. As shown in this study, the non-Newtonian blood flow in all of the considered bypass models does not significantly differ from the Newtonian one. Our observations further suggest that, especially in the case of sequential grafts, the resulting flow field and shear stimulation are strongly influenced by the diameter of the vessels involved in the bypassing. Copyright © 2013 John Wiley & Sons, Ltd.

  8. DOE Zero Energy Ready Home Case Study: Transformations, Inc., Custom House, Devens, Massachusetts

    SciTech Connect

    none,

    2013-09-01

    This single-family home features a superinsulated shell with 12-inch double walls filled with open cell spray foam, as well as R-5 triple-pane windows. The 18.33 kW photovoltaic system can produce all the electricity the home can use in a year with enough left over to power an electric car for 30,000 miles.These features helped the builder to win a 2013 Housing Innovation Award in the custom home category.

  9. 1. Oil house, keeper's house, Southern Light Tower and Northern ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Oil house, keeper's house, Southern Light Tower and Northern Light Tower, view northwest, south and east sides - Kennebec River Light Station, South side of Doubling Point Road, off State Highway 127, 1.8 miles south of U.S. Route 1, Arrowsic, Sagadahoc County, ME

  10. Building America Case Study: Construction Guidelines for High R-Value Walls without Exterior Rigid Insulation, Cold Climate Region

    SciTech Connect

    2017-01-01

    High-R wall assemblies (R-40 and above) are gaining popularity in the market due to programs like the DOE's Zero Energy Ready Home program, Passive House (PH), Net Zero Energy Home (NZEH) challenges in several states, and highly incentivized retrofit programs. In response to this demand, several builders have successfully used 'double wall' systems to more practically achieve higher R-values in thicker, framed walls. To builders of conventional stick-framed homes, often one of the most appealing features of double wall systems is that there are very few new exterior details. Exterior sheathing, structural bracing, house wrap or building paper, window and door flashing, and siding attachment are usually identical to good details in conventional framed wall systems. The information presented in this guide is intended to reduce the risk of failure in these types of assemblies, increase durability, and result in a reduction of material brought to landfills due to failures and resulting decay. While this document focuses on double wall framing techniques, the majority of the information on how to properly construct and finish high R-value assemblies is applicable to all wall assemblies that do not have foam insulation installed on the exterior of the structural sheathing. The techniques presented have been shown through field studies to reduce the likelihood of mold growth and moisture related damage and are intended for builders, framing contractors, architects, and consultants involved in designing and building super insulated homes.

  11. Double-walled hollow polymeric microspheres with independent pH and temperature dual-responsive and magnetic-targeting function from onion-shaped core-shell structures.

    PubMed

    Du, Pengcheng; Wang, Tingmei; Liu, Peng

    2013-02-01

    The magnetic-targeting stimuli-responsive hollow polymeric microspheres show unique performance as the intelligent carriers for the site specific controlled delivery of drugs or genes. In the work, the well-defied dual-responsive double-walled hollow microspheres with movable magnetic cores were prepared from the penta-layer onion-shaped core-shell microspheres. Their double-walled shells were independent, with the pH-responsive crosslinked poly(methacrylic acid) (PMAA) layer as the inner shell and the temperature responsive crosslinked poly(N-isopropylacrylamide) (PNIPAM) layer as the outer shell. The combination of the pH and temperature dual-responsive and the magnetic-targeting function make the hollow microspheres to be the most promising intelligent carriers in the biomedical fields. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. A compact multi-wavelength optoacoustic system based on high-power diode lasers for characterization of double-walled carbon nanotubes (DWCNTs) for biomedical applications

    NASA Astrophysics Data System (ADS)

    Leggio, Luca; de Varona, Omar; Escudero, Pedro; Carpintero del Barrio, Guillermo; Osiński, Marek; Lamela Rivera, Horacio

    2015-06-01

    During the last decade, Optoacoustic Imaging (OAI), or Optoacoustic Tomography (OAT), has evolved as a novel imaging technique based on the generation of ultrasound waves with laser light. OAI may become a valid alternative to techniques currently used for the detection of diseases at their early stages. It has been shown that OAI combines the high contrast of optical imaging techniques with high spatial resolution of ultrasound systems in deep tissues. In this way, the use of nontoxic biodegradable contrast agents that mark the presence of diseases in near-infrared (NIR) wavelengths range (0.75-1.4 um) has been considered. The presence of carcinomas and harmful microorganisms can be revealed by means of the fluorescence effect exhibited by biopolymer nanoparticles. A different approach is to use carbon nanotubes (CNTs) which are a contrast agent in NIR range due to their absorption characteristics in the range between 800 to 1200 nm. We report a multi-wavelength (870 and 905 nm) laser diode-based optoacoustic (OA) system generating ultrasound signals from a double-walled carbon nanotubes (DWCNTs) solution arranged inside a tissue-like phantom, mimicking the scattering of a biological soft tissue. Optoacoustic signals obtained with DWCNTs inclusions within a tissue-like phantom are compared with the case of ink-filled inclusions, with the aim to assess their absorption. These measurements are done at both 870 and 905 nm, by using high power laser diodes as light sources. The results show that the absorption is relatively high when the inclusion is filled with ink and appreciable with DWCNTs.

  13. The effects of stage absorption on reverberation times in opera house seating areas.

    PubMed

    Jeon, Jin Yong; Kim, Jae Ho; Ryu, Jong Kwan

    2015-03-01

    The effects of stage absorption on reverberation times in opera houses were investigated using computer simulations and scale model measurements. The reverberation time (RT) was measured in stalls seating with and without variable stage elements (e.g., fly curtains, side curtains, cycloramas, and stage sets). The absorption coefficients of the walls and ceiling of the stage houses were varied accordingly. It was found that variable stage elements have a significant influence on reverberation times in seating areas, particularly for a reverberant stage house, due to the low absorption of the walls and ceiling in the stage house. It was also found that the absorption coefficients of the walls and ceiling should be over 0.5 to avoid RT decreases of over 10% due to the absorption of the variable stage elements. In addition, coupled room effects were investigated both with and without variable stage elements and the results show that double slope was not found in the opera houses investigated in this study.

  14. House calls.

    PubMed

    Unwin, Brian K; Tatum, Paul E

    2011-04-15

    House calls provide a unique perspective on patients' environment and health problems. The demand for house calls is expected to increase considerably in future decades as the U.S. population ages. Although study results have been inconsistent, house calls involving multidisciplinary teams may reduce hospital readmissions and long-term care facility stays. Common indications for house calls are management of acute or chronic illnesses, and palliative care. Medicare beneficiaries must meet specific criteria to be eligible for home health services. The INHOMESSS mnemonic provides a checklist for components of a comprehensive house call. In addition to performing a clinical assessment, house calls may involve observing the patient performing daily activities, reconciling medication discrepancies, and evaluating home safety. House calls can be integrated into practice with careful planning, including clustering house calls by geographic location and coordinating visits with other health care professionals and agencies.

  15. House dust fungal communities' characterization: a double take on the six by sixty by six (6 × 60 × 6) project

    NASA Astrophysics Data System (ADS)

    Amaro, Raquel; Coelho, Sónia D.; Pastorinho, M. Ramiro; Taborda-Barata, Luís; Vaz-Patto, Maria A.; Monteiro, Marisa; Nepomuceno, Miguel C. S.; Lanzinha, Joăo C. G.; Teixeira, Joăo P.; Pereira, Cristiana C.; Sousa, Ana C. A.

    2016-11-01

    Fungi are a group of microbes that are found with particular incidence in the indoor environment. Their direct toxicity or capability of generating toxic compounds has been associated with a large number of adverse health effects, such as infectious diseases and allergies. Given that in modern society people spend a large part of their time indoors; fungal communities' characterization of this environmental compartment assumes paramount importance in the comprehension of health effects. House dust is an easy to obtain, time-integrative matrix, being its use in epidemiological studies on human exposure to environmental contaminants highly recommended. Furthermore, dust can carry a great variety of fungal content that undergoes a large number of processes that modulate and further complexify human exposure. Our study aims to identify and quantify the fungal community on house dust samples collected using two different methodologies (an approach not often seen in the literature): active (vacuum cleaner bags) and passive sampling (dust settled in petri dishes). Sampling was performed as part of the ongoing 6 × 60 × 6 Project in which six houses from Covilhă (Portugal), with building dates representative of six decades, were studied for a period of sixty days.

  16. Historic Houses.

    ERIC Educational Resources Information Center

    Curtis, Nancy

    1997-01-01

    Reviews some of the efforts of the Society for the Preservation of New England Antiquities (SPNEA) to preserve, conserve, and interpret historic houses to the public. Examines the history and some of the specific preservation problems concerning the Beauport Cottage, the Sayward-Wheeler House, and the Gropius House. (MJP)

  17. Historic Houses.

    ERIC Educational Resources Information Center

    Curtis, Nancy

    1997-01-01

    Reviews some of the efforts of the Society for the Preservation of New England Antiquities (SPNEA) to preserve, conserve, and interpret historic houses to the public. Examines the history and some of the specific preservation problems concerning the Beauport Cottage, the Sayward-Wheeler House, and the Gropius House. (MJP)

  18. Substandard Housing.

    ERIC Educational Resources Information Center

    Milkove, Daniel L., Comp.

    1986-01-01

    Defines substandard housing and summarizes newly derived data from the 1980 Census showing that 7.5% of all rural occupied housing in the Nation was substandard. Points out regional and rural-urban differences. Notes effects on rural housing of poverty rates, percentage of nonwhite households, average household size, growth in county population,…

  19. 14. INTERIOR VIEW OF FIREPLACE AND SURROUNDING WALL IN FIRST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. INTERIOR VIEW OF FIREPLACE AND SURROUNDING WALL IN FIRST FLOOR, NORTHWEST PARLOR, NORTH WALL, WITH SCALE (NOTE WALL STENCILING) - George W. Eckhart House, 810 Main Street, Wheeling, Ohio County, WV

  20. A one piece wall box for space electronics

    SciTech Connect

    Greenwood, W.H.

    1995-05-01

    In extraterrestrial applications, satellite payloads have printed circuit modules that are housed in boxes or chassis. The box may be a one piece wall or a segmented wall. These two wall options are compared for function and cost.

  1. Why housing?

    PubMed

    Aidala, Angela A; Sumartojo, Esther

    2007-11-01

    Housing/lack of housing and HIV are powerfully linked. Housing occupies an important place in the causal chains linking poverty and inequality, and HIV risk and outcomes of infection. The articles in this Special Supplement of AIDS and Behavior confirm the impact of homelessness, and poor or unstable housing, on HIV/AIDS, and challenge scientists to test and policy makers to implement the promise of housing as an innovative response to the epidemic. In order to influence the development of policies on housing to benefit at-risk or HIV-infected persons, however, proponents must justify why this association exists, and how housing can help end the epidemic as well as improve the care and health of persons living with HIV/AIDS. We introduce this supplement with a discussion of the "why" question.

  2. Innovative Composite Wall System for Sheathing Masonry Walls

    SciTech Connect

    Wendt, Robert L.; Cavallo, James

    1997-09-25

    Existing Housing - Much of the older multifamily housing stock in the United States includes units in structures with uninsulated masonry walls. Included in this stock are two- and three-story walk-up apartments, larger apartment complexes, and public housing (both high- rise and townhouse). This older multifamily housing has seen years of heavy use that may have left the plaster wall marred or damaged. Long- term building settlement or movement may have cracked the plaster, sometimes severely. Moisture from invented kitchens and baths may have caused condensation on uninsulated exterior walls. At best this condensation has left stains on the paint or wallpaper. At worst it has supported mold and mildew growth, fouling the air and creating unhealthy living conditions. Deteriorating plaster and flaking paint also result from wet walls. The presence of flaking, lead-based paint in older (pre-1978) housing is a major public health concern. Children can suffer permanent mental handicaps and psychological disorders if they are subjected to elevated levels of lead, while adults can suffer hypertension and other maladies. Studies have found that, in some urban communities with older housing stocks, over 35% of children tested have elevated blood lead levels (Hastings, et al.: 1997). Nationally, nearly 22% of black, non-hispanic children living in pre-1946 housing were found to have elevated levels of lead in their blood (MWWR Article: February 21,1997). The deterioration of many of these walls is to the point that lead can freely enter the living space.

  3. 4. EXTERIOR VIEW OF HILLMAN FAN HOUSE LOOKING NORTHEAST This ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. EXTERIOR VIEW OF HILLMAN FAN HOUSE LOOKING NORTHEAST This view shows the concrete roof covering the airways and the engine room. The reinforced concrete roof is supported by metal beams. Note how the airshaft, in the foreground, widens to create an airway on either side for the double inlet fan. The brick fan housing is capped by a curved sheet metal roof whose segments are bolted together. The brick updraft chimney, capped with concrete, is to the rear (northeast). Also evident on the wall is the cover over the air velocity indicator. The Hollenback Cemetery, which adjoins the Dorrance Colliery property is in the background. - Dorrance Colliery Fan Complex, South side of Susquehanna River at Route 115 & Riechard Street, Wilkes-Barre, Luzerne County, PA

  4. 15. INTERIOR VIEW OF HILLMAN FAN HOUSE LOOKING WEST The ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. INTERIOR VIEW OF HILLMAN FAN HOUSE LOOKING WEST The No. 2 (Hillman) shaft is on the other side of the rail barrier. In the background are the ventilating doors leading to the airway from the No. 4 (Baltimore) shaft. The brick wall on the left is pointed; it splits the air directing it to both sides of the double inlet Guibal centrifugal fan. The concrete rail support also is pointed to reduce air resistance. The rails are recycled light guage mine railroad tracks. The alterations to the fan house are evident in the left background, where a sloping joint between the concrete and brick suggests an earlier roof pitched the other way. - Dorrance Colliery Fan Complex, South side of Susquehanna River at Route 115 & Riechard Street, Wilkes-Barre, Luzerne County, PA

  5. View of Northwest corner of the Merry Generator House showing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of Northwest corner of the Merry Generator House showing floor boards and cross beams. Shifting of structure evident in staggered wall board profile. - Arthur Holmes Merry Generator House, Signal Lake North of Range Road, Fort Gordon, Richmond County, GA

  6. View of West wing of the Merry Generator House, looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of West wing of the Merry Generator House, looking south. Shifting of structure evident in staggered wall board profile. - Arthur Holmes Merry Generator House, Signal Lake North of Range Road, Fort Gordon, Richmond County, GA

  7. INTERIOR VIEW OF THE SHELTER HOUSE LOCATED ON THE EAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW OF THE SHELTER HOUSE LOCATED ON THE EAST END OF BIG DALTON DAM SHOWING THE NORTHEAST AND NORTHWEST WALLS - Big Dalton Dam, Shelter House, 2600 Big Dalton Canyon Road, Glendora, Los Angeles County, CA

  8. House, south side, west railing on stoop (note: east railing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    House, south side, west railing on stoop (note: east railing the same, CA. 1935, made from iron fencing that was removed and replaced by a brick wall - Colonel John Stuart House, 106 Tradd Street, Charleston, Charleston County, SC

  9. Assessment of penetration potential of pH responsive double walled biodegradable nanogels coated with eucalyptus oil for the controlled delivery of 5-fluorouracil: In vitro and ex vivo studies.

    PubMed

    Sahu, Prashant; Kashaw, Sushil K; Jain, Sanyog; Sau, Samaresh; Iyer, Arun K

    2017-05-10

    Penetration enhancers coated biodegradable polymeric nanogels loaded with cytotoxic drugs applied via the topical route, can be a promising strategy for improving the chemotherapeutic efficiency of skin cancers. The major objective of proposed research was to investigate the in vitro and ex vivo chemotherapeutic potential of double walled PLGA-chitosan biodegradable nanogel entrapped with 5-fluororuacil (5-FU) coated with eucalyptus oil, topically applied onto the skin. 5-FU was first entrapped in PLGA core by solvent evaporation technique followed by coating with cationic chitosan for ionic interaction with anionic skin cancer cell membrane. A surface coating of eucalyptus oil (1%) was employed to improve the penetration efficacy of the nanogel into stratum corneum. The surface modified biodegradable double walled nanogel was characterized for particle size, charge and thermal properties followed by pH dependent in vitro analysis. Human keratinocyte (HaCaT) cell line was employed for the bio- and cyto-compatibility testing prior to the hemolysis assay and coagulation assessment. A porcine skin ex vivo screening was performed for assessing the penetration potential of the nanogels. DLS and TEM revealed a particle size about 170nm for the double walled nanogels. The nanogels also exhibited high thermal stability as analyzed by thermogravimetry (TG) and differential thermal analysis (DTA). The drug entrapment efficacy was about ~40%. The drug release showed sustained release pattern noted up to 24h. The low hemolysis of 2.39% with short prothrombin time (PT) and activated partial thromboplastin time (APTT) of 14.2 and 35.5s respectively, revealed high biocompatibility of the nanogels. The cellular uptake and localization was assessed by confocal microscopy. The cytotoxicity (MTT assay) on HaCaT cell line demonstrated high cytocompatibilty of the nanogels. An ex vivo evaluation using porcine skin displayed efficient and steady state flux of 5-FU from the biodegradable

  10. MHTool User's Guide - Software for Manufactured Housing Structural Design

    SciTech Connect

    W. D. Richins

    2005-07-01

    Since the late 1990s, the Department of Energy's Idaho National Laboratory (INL) has worked with the US Department of Housing and Urban Development (HUD), the Manufactured Housing Institute (MHI), the National Institute of Standards and Technology (NIST), the National Science Foundation (NSF), and an industry committee to measure the response of manufactured housing to both artificial and natural wind loads and to develop a computational desktop tool to optimize the structural performance of manufactured housing to HUD Code loads. MHTool is the result of an 8-year intensive testing and verification effort using single and double section homes. MHTool is the first fully integrated structural analysis software package specifically designed for manufactured housing. To use MHTool, industry design engineers will enter information (geometries, materials, connection types, etc.) describing the structure of a manufactured home, creating a base model. Windows, doors, and interior walls can be added to the initial design. Engineers will input the loads required by the HUD Code (wind, snow loads, interior live loads, etc.) and run an embedded finite element solver to find walls or connections where stresses are either excessive or very low. The designer could, for example, substitute a less expensive and easier to install connection in areas with very low stress, then re-run the analysis for verification. If forces and stresses are still within HUD Code requirements, construction costs would be saved without sacrificing quality. Manufacturers can easily change geometries or component properties to optimize designs of various floor plans then submit MHTool input and output in place of calculations for DAPIA review. No change in the regulatory process is anticipated. MHTool, while not yet complete, is now ready for demonstration. The pre-BETA version (Build-16) was displayed at the 2005 National Congress & Expo for Manufactured & Modular Housing. Additional base models and an

  11. Turbocharger with turbine backplate and center housing oil shield

    SciTech Connect

    Gutknecht, D.A.; Ho, I.C.

    1991-06-25

    This paper describes a turbocharger. It comprises: a center housing, a compressor housing, and a turbine housing, means for securing the turbine housing and the compressor housing to the center housing, the center housing including a circumferentially extending wall defining a cavity therewithin, means carried by the center housing for rotatably supporting a shaft in the cavity, the shaft including portions extending into the compressor housing and into the turbine housing, a turbine wheel mounted on the portion of the shaft in the turbine housing, a compressor wheel mounted on the portion of the shaft in the compressor housing, the cavity having opposite ends facing the turbine and compressor housings respectively, the end facing the turbine housing being an open end, and an annular backplate member separate from the center housing and from the turbine housing, the annular backplate member circumscribing the shaft for closing the open end of the center housing, the securing means including fastening means extending between the center housing and the turbine housing, the backplate member including a portion clamped between the center housing and the turbine housing by compressive forces generated by the fastening means and transmitted from the turbine housing to the compressor housing through the portion of the backplate member, and a circumferentially extending shroud between the annular backplate member and the turbine wheel.

  12. Social Support of Homeless and Housed Mothers: A Comparison of Temporary and Permanent Housing Arrangements.

    ERIC Educational Resources Information Center

    Letiecq, Bethany L.; Anderson, Elaine A.; Koblinsky, Sally A.

    1998-01-01

    Compares the social support of 115 low-income housed mothers and 92 homeless mothers residing in emergency shelters, transitional housing, and doubled-up arrangements. Results reveal that homeless mothers in emergency shelters and transitional housing had significantly less contact with friends and relatives. Implications for policy development…

  13. Rental Housing.

    ERIC Educational Resources Information Center

    American Association of Retired Persons, Washington, DC. Consumer Housing Information Service for Seniors.

    This is one of a series of booklets prepared as a resource for trained Housing Information Volunteers to provide impartial information to older people who have questions of concern about how to find safe, comfortable, affordable housing; how to cut household expenses or use their homes to earn extra income; home maintenance and home improvement;…

  14. Clay Houses

    ERIC Educational Resources Information Center

    Pedro, Cathy

    2011-01-01

    In this article, the author describes a project designed for fourth-graders that involves making clay relief sculptures of houses. Knowing the clay houses will become a family heirloom makes this lesson even more worth the time. It takes three classes to plan and form the clay, and another two to underglaze and glaze the final products.

  15. Clay Houses

    ERIC Educational Resources Information Center

    Pedro, Cathy

    2011-01-01

    In this article, the author describes a project designed for fourth-graders that involves making clay relief sculptures of houses. Knowing the clay houses will become a family heirloom makes this lesson even more worth the time. It takes three classes to plan and form the clay, and another two to underglaze and glaze the final products.

  16. House Hearing

    NASA Image and Video Library

    2012-03-28

    Cristina Chaplain, director, Acquisition and Sourcing Management, U.S. Government Accountability Office testifies during a hearing before the House Committee on Science, Space, and Technology regarding access to and sustainability of the International Space Station, Wednesday, March 28, 2012 at the Rayburn House Office Building in Washington. Photo Credit: (NASA/Carla Cioffi)

  17. House Hearing

    NASA Image and Video Library

    2012-03-28

    Retired astronaut Lt. Gen. Thomas Stafford, right, and Cristina Chaplain, director, Acquisition and Sourcing Management, U.S. Government Accountability Office listen during a hearing before the House Committee on Science, Space, and Technology regarding access to and sustainability of the International Space Station, Wednesday, March 28, 2012 at the Rayburn House Office Building in Washington. Photo Credit: (NASA/Carla Cioffi)

  18. House Hearing

    NASA Image and Video Library

    2012-03-28

    Retired astronaut Lt. Gen. Thomas Stafford testifies during a hearing before the House Committee on Science, Space, and Technology regarding access to and sustainability of the International Space Station, Wednesday, March 28, 2012 at the Rayburn House Office Building in Washington. Photo Credit: (NASA/Carla Cioffi)

  19. House Hearing

    NASA Image and Video Library

    2012-03-28

    William Gerstenmaier, Associate Administrator, Human Exploration and Operations Mission Directorate, NASA Headquarters, testifies during a hearing before the House Committee on Science, Space, and Technology regarding access to and sustainability of the International Space Station, Wednesday, March 28, 2012 at the Rayburn House Office Building in Washington. Photo Credit: (NASA/Carla Cioffi)

  20. House Hearing

    NASA Image and Video Library

    2012-03-28

    U.S. Congressman Steven Palazzo (R-MS) asks a question during a hearing before the House Committee on Science, Space, and Technology regarding access to and sustainability of the International Space Station, Wednesday, March 28, 2012 at the Rayburn House Office Building in Washington. Photo Credit: (NASA/Carla Cioffi)

  1. House Hearing

    NASA Image and Video Library

    2012-03-28

    U.S. Congresswoman Eddie Bernice Johnson (D-TX) listens to testimony during a hearing before the House Committee on Science, Space, and Technology regarding access to and sustainability of the International Space Station, Wednesday, March 28, 2012 at the Rayburn House Office Building in Washington. Photo Credit: (NASA/Carla Cioffi)

  2. Housing Deprivation

    ERIC Educational Resources Information Center

    Atkinson, Reilly

    1975-01-01

    This testimony, before a public hearing of the New York City Commission on Human Rights in May 1974, summarizes the implications of a study done at the Joint Center for Urban Studies of the number and characteristics of families that will buy a house, and what kind of housing problems they have, for the relative status of blacks or whites or other…

  3. Transformations, Inc.. Partnering To Build Net-Zero Energy Houses in Massachusetts

    SciTech Connect

    Ueno, K.; Bergey, D.; Wytrykowska, H.

    2013-09-01

    Transformations, Inc. is a residential development and building company that has partnered with Building Science Corporation to build new construction net-zero energy houses in Massachusetts under the Building America program. There are three communities that will be constructed through this partnership: Devens Sustainable Housing ("Devens"), The Homes at Easthampton Meadow ("Easthampton") and Phase II of the Coppersmith Way Development ("Townsend"). This report intends to cover all of the single-family new construction homes that have been completed to date. The houses built in these developments are net zero energy homes built in a cold climate. They will contribute to finding answers to specific research questions for homes with high R double stud walls and high efficiency ductless air source heat pump systems ("mini-splits"); allow to explore topics related to the financing of photovoltaic systems and basements vs. slab-on-grade construction; and provide feedback related to the performance of ductless mini-split air source heat pumps.

  4. Transformations, Inc.: Partnering to Build Net-Zero Energy Houses in Massachusetts

    SciTech Connect

    Ueno, K.; Bergey, D.; Wytrykowska, H.

    2013-09-01

    Transformations, Inc. is a residential development and building company that has partnered with Building Science Corporation to build new construction net-zero energy houses in Massachusetts under the Building America program. There are three communities that will be constructed through this partnership: Devens Sustainable Housing ('Devens'), The Homes at Easthampton Meadow ('Easthampton') andPhase II of the Coppersmith Way Development ('Townsend'). This report intends to cover all of the single-family new construction homes that have been completed to date. The houses built in these developments are net zero energy homes built in a cold climate. They will contribute to finding answers to specific research questions for homes with high R double stud walls and high efficiency ductlessair source heat pump systems ('mini-splits'); allow to explore topics related to the financing of photovoltaic systems and basements vs. slab-on-grade construction; and provide feedback related to the performance of ductless mini-split air source heat pumps.

  5. Tech House

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The members of the Swain family- Dr. Charles "Bill" Swain, wife Elaine, daughter Carol, 17, son "Chuck", 12, and dog Susie have an interesting assignment. They are active participants in an important NASA research program involving the application of space-age technology to home construction. b' Transplanted Floridians, the Swains now reside in NASA's Tech House, loatedat Langley Research Center, Hampton, Virginia. Their job is to use and help evaluate the variety of advanced technology systems in Tech House. A contemporary three-bedroom home, Tech House incorporates NASA technology, the latest commercial building techniques and other innovations, all designed to reduce energy and water consumption and to provide new levels of comfort, convenience, security and fire safety. Tech House equipment performed well in initial tests, but a house is not a home until it has people. That's where the Swains come in. NASA wants to see how the various systems work under actual living conditions, to confirm the effectiveness of the innovations or to determine necessary modifications for improvement. The Swains are occupying the house for a year, during which NASA engineers are computer monitoring the equipment and assembling a record of day-to-day performance. . Tech House is a laboratory rather than a mass production prototype, but its many benefits may influence home design and construction. In a period of sharply rising utility costs, widespread adoption of Tech House features could provide large-scale savings to homeowners and potentially enormous national benefit in resources conservation. Most innovations are aerospace spinoffs: Some of the equipment is now commercially available; other systems are expected to be in production within a few years. Around 1980, a Tech House-type of home could be built for $45-50,000 (1 976 dollars). It is estimated that the homeowner would save well over $20,000 (again 1976 dollars) in utility costs over the average mortgage span of 20 years.

  6. House Rules.

    ERIC Educational Resources Information Center

    Hammel, Bette

    2001-01-01

    Discusses the "house" concept architectural design at Albert Lea High School (Minnesota) and how the design addresses the community's 21st Century educational goals. Photos and a floor plan are included. (GR)

  7. House Rules.

    ERIC Educational Resources Information Center

    Hammel, Bette

    2001-01-01

    Discusses the "house" concept architectural design at Albert Lea High School (Minnesota) and how the design addresses the community's 21st Century educational goals. Photos and a floor plan are included. (GR)

  8. House Hearing

    NASA Image and Video Library

    2012-03-07

    Rep. Eddie Bernice Johnson, D-TX, asks a question of NASA Administrator Charles Bolden during a House Science, Space and Technology Committee hearing on Wednesday, March 7, 2012 in Washington. Photo Credit: (NASA/Bill Ingalls)

  9. Double-diffusive natural convection of Cu-water nanofluid in a window shaped cavity containing multiple obstacles with a heater on bottom wall

    NASA Astrophysics Data System (ADS)

    Chowdhury, Raju; Parvin, Salma; Khan, Md. Abdul Hakim

    2017-06-01

    In the present study, natural convective heat and mass transfer and fluid flow inside a window shaped cavity filled with Cu-water nanofluid and containing multiple obstacles with a finite size heater placed in its horizontal wall is numerically investigated. Sinusoidal temperature distribution is maintained by the heater. The left and right inclined walls of the cavity are maintained at a relatively low temperature while the vertical walls are insulated. The governing equations are transformed to the dimensionless form and solved numerically using Galerkin weighted residual technique of finite element method. The influence of pertinent parameters such as thermal Rayleigh number, location of the heater and solid volume fraction of nanoparticles on the heat and mass transfer and fluid flow is studied. The results are obtained in terms of streamlines, isotherms, isoconcentrations, average Sherwood number and average Nueeslt number for the considered parameters and it is observed that the flow pattern, temperature and concentration fields are affected by the variation of the mentioned parameters.

  10. 9. Boat house, detail of boat winch, looking northwest ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Boat house, detail of boat winch, looking northwest - Doubling Point Light Station, End of Doubling Point Road, off State Highway 127, 1.8 miles south of U.S. Route 1, Arrowsic, Sagadahoc County, ME

  11. 4. Electric motor and transmission wheel on southeast wall of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Electric motor and transmission wheel on southeast wall of Oil House. - Delaware, Lackawanna & Western Railroad, Scranton Yards, Oil House, 650 feet Southeast of Cliff & Mechanic Streets, Scranton, Lackawanna County, PA

  12. View of the garden wall and passage with wrought iron ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of the garden wall and passage with wrought iron gate to the northwest of the house (duplicate of HABS No. SC-115-14) - William Washington House, 8 South Battery Street, Charleston, Charleston County, SC

  13. View of original brick wall on the western face of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of original brick wall on the western face of the boiler house (center right) and electrical department (far right). - Johnson Steel Street Rail Company, Electrical Department & Boiler House, 525 Central Avenue, Johnstown, Cambria County, PA

  14. 12. Detail view, north wall of porch containing the exterior ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Detail view, north wall of porch containing the exterior pantry door (note the lintel stone with the abstracted wave motif). - John Bartram House & Garden, House, 54th Street & Lindbergh Boulevard, Philadelphia, Philadelphia County, PA

  15. 8. Historic American Buildings Survey February, 1953 WEST WALL OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Historic American Buildings Survey February, 1953 WEST WALL OF THE JONATHAN HAGER HOUSE IN ITS RELATION TO THE UNCOVERED FOUNDATION OF A SECOND STRUCTURE WHICH WAS LAID ON SHALE - Jonathan Hager House (Foundation), Hagerstown, Washington County, MD

  16. Texas Ranch House: Interactive Programming from Thirteen/WNET

    ERIC Educational Resources Information Center

    Donlevy, Jim

    2006-01-01

    Texas Ranch House, produced by Thirteen/WNET and Wall to Wall Television, is a dynamic look at life in Texas in the 1860s, before the development of modem conveniences. In addition to the video program series, Texas Ranch House boasts an extensive interactive website (www.pbs.org/wnetlranchhouse) that will be of interest to teachers and students.…

  17. NORTHWEST SIDE OF THE HOUSE WHERE A HOLE HAS BEEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    NORTHWEST SIDE OF THE HOUSE WHERE A HOLE HAS BEEN CUT INTO THE WALL TO ALLOW FOR THROUGH WALL AIR CONDITIONERS - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Two-Bedroom Single-Family Type 6, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

  18. Texas Ranch House: Interactive Programming from Thirteen/WNET

    ERIC Educational Resources Information Center

    Donlevy, Jim

    2006-01-01

    Texas Ranch House, produced by Thirteen/WNET and Wall to Wall Television, is a dynamic look at life in Texas in the 1860s, before the development of modem conveniences. In addition to the video program series, Texas Ranch House boasts an extensive interactive website (www.pbs.org/wnetlranchhouse) that will be of interest to teachers and students.…

  19. The House that NASA Built

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Tech House, located at NASA's Langley Research Center, Hampton, Virginia, is a demonstration project in which aerospace and commercial building technology are combined to produce an energy-efficient home. Advanced technology offers savings to the family in utility costs and energy conservation. Solar panels on the roof of tech house provide the principal energy saving. They capture the sun's rays to heat water in pipes that run through the solar collectors. The heated water is then stored in a large, well insulated underground tank. A heat exchanger extracts beat from the water and blows it through ducts to warm the house. Tech House is well insulated for energy savings. The principal insulation is fireproof Tripolymer foam which is sprayed onto walls and ceilings in thicknesses up to six inches.

  20. New methods for isolation of keratolytic bacteria inducing intractable hoof wall cavity (Gidoh) in a horse; double screening procedures of the horn powder agar-translucency test and horn zymography

    PubMed Central

    KUWANO, Atsutoshi; NIWA, Hidekazu; ARAI, Katsuhiko

    2017-01-01

    ABSTRACT To establish a new system to isolate keratolytic bacteria from the hoof wall cavity (Gidoh) of a racehorse, we invented the horn powder agar-translucency (HoPAT) test and horn zymography (HZ). Using routine bacteriological techniques and these methods, we isolated five strains of keratolytic soil bacteria, which were then identified by means of 16S ribosomal RNA (rRNA) gene sequencing analysis. The findings from the study on the horse suggested that Brevibacterium luteolum played the main role in the local fragility of the hoof, eventually forming a Gidoh in coordination with four other strains of keratolytic bacteria. The double screening procedures of the HoPAT test and HZ were useful and easy techniques for isolating the keratolytic bacteria from the horn lesions. PMID:28400703

  1. A multi-domain boundary element method to analyze the reflection and transmission of oblique waves from double porous thin walls

    NASA Astrophysics Data System (ADS)

    Bakhti, Yamina; Chioukh, Nadji; Hamoudi, Benameur; Boukhari, Mohamed

    2017-09-01

    In the present paper, we examine the performance of an efficient type of wave-absorbing porous marine structure under the attack of regular oblique waves by using a Multi-Domain Boundary Element Method (MDBEM). The structure consists of two perforated vertical thin barriers creating what can be called a wave absorbing chamber system. The barriers are surface piercing, thereby eliminating wave overtopping. The problem of the interaction of obliquely incident linear waves upon a pair of perforated barriers is first formulated in the context of linear diffraction theory. The resulting boundary integral equation, which is matched with far-field solutions presented in terms of analytical series with unknown coefficients, as well as the appropriate boundary conditions at the free surface, seabed, and barriers, is then solved numerically using MDBEM. Dissipation of the wave energy due to the presence of the perforated barriers is represented by a simple yet effective relation in terms of the porosity parameter appropriate for thin perforated walls. The results are presented in terms of reflection and transmission coefficients. The effects of the incident wave angles, relative water depths, porosities, depths of the walls, and other major parameters of interest are explored.

  2. Construction Guidelines for High R-Value Walls without Exterior Rigid Insulation

    SciTech Connect

    Arena, Lois B.

    2016-07-13

    High R-value wall assemblies (R-40 and above) are gaining popularity in the market due to programs such as the U.S. Department of Energy Zero Energy Ready Home program, Passive House, Net Zero Energy Home challenges in several states, and highly incentivized retrofit programs. In response to this demand, several builders have successfully used double-wall systems to achieve higher R-values in thicker, framed walls. To builders of conventional stick-framed homes, often one of the most appealing features of double-wall systems is that there are very few new exterior details. Exterior sheathings, structural bracings, house wraps or building paper, window and door flashings, and siding attachments are usually identical to good details in conventional framed-wall systems. However, although the details in double-wall systems are very similar to those in conventional stick framing, there is sometimes less room for error. Several studies have confirmed colder temperatures of exterior sheathing in high R-value wall assemblies that do not have exterior rigid foam insulation. These colder temperatures can lead to increased chances for condensation from air exfiltration, and they have the potential to result in moisture-related problems (Straube and Smegal 2009, Arena 2014, Ueno 2015). The information presented in this guide is intended to reduce the risk of failure in these types of assemblies, increase durability, and reduce material brought to landfills due to failures and resulting decay. Although this document focuses on double-wall framing techniques, the majority of the information about how to properly construct and finish high R-value assemblies is applicable to all wall assemblies that do not have foam insulation installed on the exterior of the structural sheathing. The techniques presented have been shown through field studies to reduce the likelihood of mold growth and moisture-related damage and are intended for builders, framing contractors, architects, and

  3. 6. INTERIOR, NORTH WING, VIEW THROUGH DOORWAY IN EAST WALL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. INTERIOR, NORTH WING, VIEW THROUGH DOORWAY IN EAST WALL OF SOUTHEAST ROOM, SHOWING RUINOUS FIRST AND SECOND FLOOR (EAST) WALL OF NORTHWEST ROOM IN CENTRAL BLOCK - Bulows Minde Estate House, Bulows Minde, Bulows Minde, St. Croix, VI

  4. 8. INTERIOR, NORTH WING, VIEW THROUGH DOORWAY IN NORTH WALL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. INTERIOR, NORTH WING, VIEW THROUGH DOORWAY IN NORTH WALL OF SOUTHEAST ROOM, SHOWING FENESTRATED NORTH WALL (BASEMENT THROUGH SECOND LEVELS) OF NORTH-CENTRAL ROOM - Bulows Minde Estate House, Bulows Minde, Bulows Minde, St. Croix, VI

  5. Interior, view of pump looking to north wall and east ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior, view of pump looking to north wall and east wall with door, view to the northeast - Ellsworth Air Force Base, Rushmore Air Force Station, Well House, Menoher Road, Blackhawk, Meade County, SD

  6. Housing Projects.

    ERIC Educational Resources Information Center

    Schmalz, Georgann

    1985-01-01

    Building specifications for birdhouses (nesting boxes) are given for 11 species (chickadee, titmouse, nuthatch, Carolina wren, house wren, downy woodpecker, hairy woodpecker, flicker, bluebird, screech owl, and wood duck) including length, width, depth, entrance diameter, and height above the ground. Pointers for construction, materials, and…

  7. Housing Projects.

    ERIC Educational Resources Information Center

    Schmalz, Georgann

    1985-01-01

    Building specifications for birdhouses (nesting boxes) are given for 11 species (chickadee, titmouse, nuthatch, Carolina wren, house wren, downy woodpecker, hairy woodpecker, flicker, bluebird, screech owl, and wood duck) including length, width, depth, entrance diameter, and height above the ground. Pointers for construction, materials, and…

  8. House Hearing

    NASA Image and Video Library

    2012-03-07

    Chairman of the U.S. House Science, Space and Technology Committee Rep. Ralph Hall, R-TX, asks a question of NASA Administrator Charles Bolden during a hearing on Wednesday, March 7, 2012 in Washington. Photo Credit: (NASA/Bill Ingalls)

  9. 5. View of Clovelley Farm tenant house from driveway area ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. View of Clovelley Farm tenant house from driveway area on north side of house, looking northwest to back gable addition (left) and north side wall of main block. - Clovelley Farm Tenant House, 4958 Paris Road (east side), Paris, Bourbon County, KY

  10. 4. View of Clovelley Farm tenant house, back side (east) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. View of Clovelley Farm tenant house, back side (east) area of two room addition. Note dark metal heating oil tank against rear wall and silver maple trees to shade house from south and east. - Clovelley Farm Tenant House, 4958 Paris Road (east side), Paris, Bourbon County, KY

  11. Contextual view to northwest of Burton Park Club House and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Contextual view to northwest of Burton Park Club House and Amphitheater. Gable-roofed building at right is barn housing maintenance equipment for the park. Adobe wall with pilasters forms backdrop for amphitheater stage (135mm lens). - Burton Park, Club House & Amphitheater, Adjacent ot south end of Chestnut Avenue, San Carlos, San Mateo County, CA

  12. DOE ZERH Case Study: Mutual Housing California, Mutual Housing at Spring Lake, Woodland, CA

    SciTech Connect

    none,

    2015-09-01

    Case study of a DOE 2015 Housing Innovation Award winning multifamily project of 62 affordable-housing apartment home in the hot-dry climate that exceeded CA Title 24-2008 by 35%, with 2x4 16” on center walls with R-21 fiberglass bass walls, uninsulated salb on grade foundation; vented attic with R-44 blown fiberglass; air to water heat pumps.

  13. 1. EXTERIOR VIEW OF NEW FAN HOUSE AND HILLMAN FAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. EXTERIOR VIEW OF NEW FAN HOUSE AND HILLMAN FAN HOUSE LOOKING NORTHWEST The building on the left, the New Fan House, houses a Corliss steam engine which powered a Buffalo Forge Company single inlet Duplex Conoidal centrifugal exhausted fan through a metal updraft chimney. Part of the brick airway leading to the Baltimore shaft is visible to its right rear. The Hillman Fan House, on the right, houses the 1883 double inlet Guibal fan. The south entry, the curve of the fan housing, and brick updraft chimney are visible in this view. - Dorrance Colliery Fan Complex, South side of Susquehanna River at Route 115 & Riechard Street, Wilkes-Barre, Luzerne County, PA

  14. 10. EXTERIOR VIEW OF STONE RETAINING WALL, AIRWAY, BALTIMORE FAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. EXTERIOR VIEW OF STONE RETAINING WALL, AIRWAY, BALTIMORE FAN HOUSE AND HILLMAN FAN HOUSE LOOKING EAST The stone retaining wall encloses a pit which may have been the original site of the Hillman Fan House steam engine. The concrete foundations in the left foreground are more recent (c. 1930) additions which may be supports for a porch or stairway. The sloping airshaft, in the middle ground, connected the Baltimore shaft to the New Fan House (not shown) and Hillman Fan House in the background. The Hillman engine house is on the left. - Dorrance Colliery Fan Complex, South side of Susquehanna River at Route 115 & Riechard Street, Wilkes-Barre, Luzerne County, PA

  15. 17. DETAIL OF INTERIOR AND EXTERIOR WALL CONSTRUCTION, VIEW TOWARD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. DETAIL OF INTERIOR AND EXTERIOR WALL CONSTRUCTION, VIEW TOWARD NORTHEAST CORNER, THIRD BAY Showing insulated exterior wall at right; asphalt felt on interior separation wall at left; sill beam, stud, and concrete foundation detailing of interior wall. - U.S. Military Academy, Ice House, Mills Road at Howze Place, West Point, Orange County, NY

  16. Wall turbulence without walls

    NASA Astrophysics Data System (ADS)

    Mizuno, Yoshinori; Jimenez, Javier

    2008-11-01

    Direct numerical simulations are presented of isolated logarithmic layers without an underlying buffer zone. They are implemented by enforcing artificial boundary conditions within the logarithmic layer which are synthesized from values from the interior of the flow. As an example, simulations of a half-channel employing this technique are discussed. The results exhibit logarithmic mean velocity profiles, and velocity fluctuation intensities that are similar to those obtained by the full DNS of half or full channels. Those results strongly suggest that the formation of a logarithmic layer is not overly dependent on the presence of a near-wall region, and that such a flow can exist by itself. The technique enables us to perform conceptual experiments to clarify what is essential to the logarithmic layer. For example, preliminary results show that the logarithmic layer cannot be created only by a non-uniform shear, and requires a spatial gradient of the scales of the fluctuations. Somewhat surprisingly, some simulations result in Kármán constants fairly different from κ=0.4, providing clues to what determines κ in real wall turbulence.

  17. Smart Houses

    NASA Technical Reports Server (NTRS)

    1987-01-01

    GWS takes plans for a new home and subjects them to intensive computerized analysis that does 10,000 calculations relative to expected heat loss and heat gain, then provides specifications designed specifically for each structure as to heating, cooling, ventilation and insulation. As construction progresses, GWS inspects the work of the electrical, plumbing and insulation contractors and installs its own Smart House Radiant Barrier. On completion of the home, GWS technicians use a machine that creates a vacuum in the house and enables computer calculation of the air exchanged, a measure of energy efficiency. Key factor is the radiant barrier, borrowed from the Apollo program. This is an adaptation of a highly effective aluminized heat shield as a radiation barrier holding in or keeping out heat, cold air and water vapor.

  18. Energy budgets and masonry houses: A preliminary analysis of the comparative energy performance of masonry and wood-frame houses

    NASA Astrophysics Data System (ADS)

    Goldstein, D. B.; Levine, M. D.; Mass, J.

    1980-09-01

    Procedures for evaluating energy performance in terms of heat storage were reviewed. The cost effectiveness for masonry houses to conform to optimum energy budgets was determined. The insulation levels and costs were also determined. Life cycle costs for masonry houses were calculated and compared to values for wood frame houses. To conform with the optimal energy budgets, masonry houses must be insulated to almost as large an R-value as frame walls.

  19. Unofficial policy: access to housing, housing information and social services among homeless drug users in Hartford, Connecticut.

    PubMed

    Dickson-Gomez, Julia; Convey, Mark; Hilario, Helena; Corbett, A Michelle; Weeks, Margaret

    2007-03-07

    Much research has shown that the homeless have higher rates of substance abuse problems than housed populations and that substance abuse increases individuals' vulnerability to homelessness. However, the effects of housing policies on drug users' access to housing have been understudied to date. This paper will look at the "unofficial" housing policies that affect drug users' access to housing. Qualitative interviews were conducted with 65 active users of heroin and cocaine at baseline, 3 and 6 months. Participants were purposively sampled to reflect a variety of housing statuses including homeless on the streets, in shelters, "doubled-up" with family or friends, or permanently housed in subsidized, unsubsidized or supportive housing. Key informant interviews and two focus group interviews were conducted with 15 housing caseworkers. Data were analyzed to explore the processes by which drug users receive information about different housing subsidies and welfare benefits, and their experiences in applying for these. A number of unofficial policy mechanisms limit drug users' access to housing, information and services, including limited outreach to non-shelter using homeless regarding housing programs, service provider priorities, and service provider discretion in processing applications and providing services. Unofficial policy, i.e. the mechanisms used by caseworkers to ration scarce housing resources, is as important as official housing policies in limiting drug users' access to housing. Drug users' descriptions of their experiences working with caseworkers to obtain permanent, affordable housing, provide insights as to how access to supportive and subsidized housing can be improved for this population.

  20. Improvement of signal-to-noise ratio of optoacoustic signals from double-walled carbon nanotubes by using an array of dual-wavelength high-power diode lasers

    NASA Astrophysics Data System (ADS)

    Leggio, Luca; de Varona, Omar E.; Escudero, Pedro; Carpintero del Barrio, Guillermo; Osiński, Marek; Lamela Rivera, Horacio

    2015-07-01

    Optoacoustic (OA) imaging is a rising biomedical technique that has attracted much interest over the last 15 years. This technique permits to visualize the internal soft tissues in depth by using short laser pulses, able to generate ultrasonic signals in a large frequency range. It combines the high contrast of optical imaging with the high resolution of ultrasound systems. The OA signals detected from the whole surface of the body serve to reconstruct in detail the image of the internal tissues, where the absorbed optical energy distribution outlines the regions of interest. In fact, the use of contrast agents could improve the detection of growing anomalies in soft tissues, such as carcinomas. This work proposes the use of double-walled carbon nanotubes (DWCNTs) as a potential nontoxic biodegradable contrast agent applicable in OA to reveal the presence of malignant in-depth tissues in near infrared (NIR) wavelength range (0.75-1.4 μm), where the biological tissues are fairly transparent to optical radiation. A dual-wavelength (870 and 905 nm) OA system is presented, based on arrays of high power diode lasers (HPDLs) that generate ultrasound signals from a DWCNT solution embedded within a biological phantom. The OA signals generated by DWCNTs are compared with those obtained using black ink, considered to be a very good absorber at these wavelengths. The experiments prove that DWCNTs are a potential contrast agent for optoacoustic spectroscopy (OAS).

  1. Grafted-double walled carbon nanotubes as electrochemical platforms for immobilization of antibodies using a metallic-complex chelating polymer: Application to the determination of adiponectin cytokine in serum.

    PubMed

    Ojeda, Irene; Barrejón, Myriam; Arellano, Luis M; González-Cortés, Araceli; Yáñez-Sedeño, Paloma; Langa, Fernando; Pingarrón, José M

    2015-12-15

    An electrochemical immunosensor for adiponectin (APN) using screen printed carbon electrodes (SPCEs) modified with functionalized double-walled carbon nanotubes (DWCNTs) as platforms for immobilization of the specific antibodies is reported. DWCNTs were functionalized by treatment with 4-aminobenzoic acid (HOOC-Phe) in the presence of isoamylnitrite resulting in the formation of 4-carboxyphenyl-DWCNTs. The oriented binding of specific antibodies toward adiponectin was accomplished by using the metallic-complex chelating polymer Mix&Go™. The HOOC-Phe-DWCNTs-modified SPCEs were characterized by cyclic voltammetry and compared with HOOC-Phe-SWCNTs/SPCE. The different variables affecting the performance of the developed immunosensor were optimized. Under the selected conditions, a calibration plot for APN was constructed showing a range of linearity extending between 0.05 and 10.0 μg/mL which is adequate for the determination of the cytokine in real samples. A detection limit of 14.5 ng/mL was achieved. The so prepared immunosensor exhibited a good reproducibility for the APN measurements, excellent storage stability and selectivity, and a much shorter assay time than the available ELISA kits. The usefulness of the immunosensor for the analysis of real samples was demonstrated by analyzing human serum from female or male healthy patients.

  2. Fair Housing and Latinos.

    ERIC Educational Resources Information Center

    Cubillos, Herminia L.

    Latinos need the protection of the proposed Fair Housing Amendments of 1987 and the active support of the Department of Housing and Urban Development (HUD) to overcome housing discrimination. Latinos are both disproportionately poor and inadequately housed, but low income alone cannot fully explain the poor housing conditions under which many…

  3. Faculty Housing Assistance.

    ERIC Educational Resources Information Center

    Fink, Ira

    1982-01-01

    Some of the creative financing programs currently used to provide faculty housing assistance in California and elsewhere in the United States are described. Generally, the programs fall into one of four categories: rental housing, owner housing, mortgage assistance, and housing stipends. Institutions with a comprehensive housing program often have…

  4. United States housing, 2013

    Treesearch

    Delton Alderman

    2016-01-01

    This publication provides an overview of the 2013 U.S. housing market, including updated information and data, and is part of an ongoing series of quarterly and annual housing reports that provide historical information on housing permits, starts, houses under construction, and completions. In addition, short briefs present information regarding house sales,...

  5. [Housing and health].

    PubMed

    Fiedler, K

    1998-11-01

    Most of our lifetime we stay indoors. Both the home environment and housing behaviour may promote health complaints and disease. The term "sick building syndrome (SBS)" is used to describe a complex of unspecific symptoms attributed to staying in an indoor environment. In contrast, "building-related illness" (BRI) designates specific diseases attributed to special factors of indoor environment. A number of factors is known to influence health in the indoor environment, such as indoor emissions, ambient air, indoor climate (temperature, air flow, humidity) optical influences, water supply and sewage disposal, sound waves (noise, vibrations), non-ionising radiation, construction and characteristic design features of a home (e.g. floor area, functionality) and also psychological factors. Epidemiological studies have revealed that dark and noisy homes, rooms with insufficiently insulated external walls, single glazing, heating by gas heaters fitted to external walls and too low humidity of indoor air will increase morbidity. A checklist based on medical considerations is presented permitting assessment of the health relevance of important areas/factors of the home environment by means of a scoring system.

  6. Wonderful Walls

    ERIC Educational Resources Information Center

    Greenman, Jim

    2006-01-01

    In this article, the author emphasizes the importance of "working" walls in children's programs. Children's programs need "working" walls (and ceilings and floors) which can be put to use for communication, display, storage, and activity space. The furnishings also work, or don't work, for the program in another sense: in aggregate, they serve as…

  7. United States housing, 2012

    Treesearch

    Delton Alderman

    2013-01-01

    Provides current and historical information on housing market in the United States. Information includes trends for housing permits and starts, housing completions for single and multifamily units, and sales and construction. This report will be updated annually.

  8. New Whole-House Solutions Case Study: Quadrant Homes

    SciTech Connect

    none,

    2013-02-01

    Quadrant moved ducts and high efficiency furnace inside conditioned space on nearly all 300 customizable house plans. The builder uses dry, true factory-assembled walls, extensive air sealing, and just in time delivery for pre-sold homes.

  9. 7. INTERIOR VIEW OF BREW HOUSE, AMMONIA COMPRESSOR READS: THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. INTERIOR VIEW OF BREW HOUSE, AMMONIA COMPRESSOR- READS: THE FRED WOLF CO. 139 REES STREET, CHICAGO; CLOSER RANGE (NOTE GAUGES ON FAR WALL) - August Schell Brewing Company, Twentieth Street South, New Ulm, Brown County, MN

  10. 106. Photocopied August 1978. EXTENSION OF TAIL PIT WALLS, APRIL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    106. Photocopied August 1978. EXTENSION OF TAIL PIT WALLS, APRIL 28, 1917. THE TIMBERWORK IN THE FOREGROUND WAS USED AS A COMBINATION COFFER DAM AND FORM FOR POURING THE CONCRETE TAIL RACE WALL EXTENSION. IN THE BACKGROUND ALONG THE POWER HOUSE SEVERAL COMPLETED WALL EXTENSIONS CAN BE SEEN DIMLY. (787) - Michigan Lake Superior Power Company, Portage Street, Sault Ste. Marie, Chippewa County, MI

  11. Detail, north end wall, Burton Park Amphitheater, view to southwest ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail, north end wall, Burton Park Amphitheater, view to southwest (90mm lens). Also visible are pilasters along back wall, east wing of stage area (within doorway), and east steps. Walls are adobe brick, with concrete coping. - Burton Park, Club House & Amphitheater, Adjacent ot south end of Chestnut Avenue, San Carlos, San Mateo County, CA

  12. Operative correction of abdominal rectus diastasis (ARD) reduces pain and improves abdominal wall muscle strength: A randomized, prospective trial comparing retromuscular mesh repair to double-row, self-retaining sutures.

    PubMed

    Emanuelsson, Peter; Gunnarsson, Ulf; Dahlstrand, Ursula; Strigård, Karin; Stark, Birgit

    2016-11-01

    The primary aim of this prospective, randomized, clinical, 2-armed trial was to evaluate the risk for recurrence using 2 different operative techniques for repair of abdominal rectus diastasis. Secondary aims were comparison of pain, abdominal muscle strength, and quality of life and to compare those outcomes to a control group receiving physical training only. Eighty-six patients were enrolled. Twenty-nine patients were allocated to retromuscular polypropylene mesh and 27 to double-row plication with Quill technology. Thirty-two patients participated in a 3-month training program. Diastasis was evaluated with computed tomography scan and clinically. Pain was assessed using the ventral hernia pain questionnaire, a quality-of-life survey, SF-36, and abdominal muscle strength using the Biodex System-4. One early recurrence occurred in the Quill group, 2 encapsulated seromas in the mesh group, and 3 in the suture group. Significant improvements in perceived pain, the ventral hernia pain questionnaire, and quality of life appeared at the 1-year follow-up with no difference between the 2 operative groups. Significant muscular improvement was obtained in all groups (Biodex System-4). Patient perceived gain in muscle strength assessed with a visual analog scale improved similarly in both operative groups. This improvement was significantly greater than that seen in the training group. Patients in the training group still experienced bodily pain at follow-up. There was no difference between the Quill technique and retromuscular mesh in the effect on abdominal wall stability, with a similar complication rate 1 year after operation. An operation improves functional ability and quality of life. Training strengthens the abdominal muscles, but patients still experience discomfort and pain. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Electrochemical immunosensor for simultaneous determination of interleukin-1 beta and tumor necrosis factor alpha in serum and saliva using dual screen printed electrodes modified with functionalized double-walled carbon nanotubes.

    PubMed

    Sánchez-Tirado, E; Salvo, C; González-Cortés, A; Yáñez-Sedeño, P; Langa, F; Pingarrón, J M

    2017-03-22

    Dual screen-printed carbon electrodes modified with 4-carboxyphenyl-functionalized double-walled carbon nanotubes (HOOC-Phe-DWCNTs/SPCEs) have been used as scaffolds for the preparation of electrochemical immunosensors for the simultaneous determination of the cytokines Interleukin-1β (IL-1β) and factor necrosis tumor α (TNF-α). IL-1β. Capture antibodies were immobilized onto HOOC-Phe-DWCNTs/SPCEs in an oriented form making using the commercial polymeric coating Mix&Go™. Sandwich type immunoassays with amperometric signal amplification through the use of poly-HRP-streptavidin conjugates and H2O2 as HRP substrate and hydroquinone as redox mediator were implemented. Upon optimization of the experimental variables affecting the immunosensor performance, the dual immunosensor allows ranges of linearity extending between 0.5 and 100 pg/mL and from 1 to 200 pg/mL for IL-1β and TNF-α, respectively, these ranges being adequate for the determination of the cytokines in clinical samples. The achieved limits of detection were 0.38 pg/mL (IL-1β) and 0.85 pg/mL (TNF-α). In addition, the dual immunosensor exhibits excellent reproducibility of the measurements, storage stability of the anti-IL-Phe-DWCNTs/SPCE and anti-TNF-Phe-DWCNTs/SPCE conjugates, and selectivity as well as negligible cross-talking. The dual immunosensor was applied to the simultaneous determination of IL-1β and TNF-α in human serum spiked at clinically relevant concentration levels and in real saliva samples.

  14. Simultaneous speciation of inorganic arsenic and antimony in water samples by hydride generation-double channel atomic fluorescence spectrometry with on-line solid-phase extraction using single-walled carbon nanotubes micro-column

    NASA Astrophysics Data System (ADS)

    Wu, Hong; Wang, Xuecui; Liu, Bing; Liu, Yueling; Li, Shanshan; Lu, Jusheng; Tian, Jiuying; Zhao, Wenfeng; Yang, Zonghui

    2011-01-01

    A new method was developed for the simultaneous speciation of inorganic arsenic and antimony in water by on-line solid-phase extraction coupled with hydride generation-double channel atomic fluorescence spectrometry (HG-DC-AFS). The speciation scheme involved the on-line formation and retention of the ammonium pyrrolidine dithiocarbamate complexes of As(III) and Sb(III) on a single-walled carbon nanotubes packed micro-column, followed by on-line elution and simultaneous detection of As(III) and Sb(III) by HG-DC-AFS; the total As and total Sb were determined by the same protocol after As(V) and Sb(V) were reduced by thiourea, with As(V) and Sb(V) concentrations obtained by subtraction. Various experimental parameters affecting the on-line solid-phase extraction and determination of the analytes species have been investigated in detail. With 180 s preconcentration time, the enrichment factors were found to be 25.4 for As(III) and 24.6 for Sb(III), with the limits of detection (LODs) of 3.8 ng L - 1 for As(III) and 2.1 ng L - 1 for Sb(III). The precisions (RSD) for five replicate measurements of 0.5 μg L -1 of As(III) and 0.2 μg L -1 of Sb(III) were 4.2 and 4.8%, respectively. The developed method was validated by the analysis of standard reference materials (NIST SRM 1640a), and was applied to the speciation of inorganic As and Sb in natural water samples.

  15. HVI Ballistic Performance Characterization of Non-Parallel Walls

    NASA Technical Reports Server (NTRS)

    Bohl, William; Miller, Joshua; Christiansen, Eric

    2012-01-01

    The Double-Wall, "Whipple" Shield [1] has been the subject of many hypervelocity impact studies and has proven to be an effective shield system for Micro-Meteoroid and Orbital Debris (MMOD) impacts for spacecraft. The US modules of the International Space Station (ISS), with their "bumper shields" offset from their pressure holding rear walls provide good examples of effective on-orbit use of the double wall shield. The concentric cylinder shield configuration with its large radius of curvature relative to separation distance is easily and effectively represented for testing and analysis as a system of two parallel plates. The parallel plate double wall configuration has been heavily tested and characterized for shield performance for normal and oblique impacts for the ISS and other programs. The double wall shield and principally similar Stuffed Whipple Shield are very common shield types for MMOD protection. However, in some locations with many spacecraft designs, the rear wall cannot be modeled as being parallel or concentric with the outer bumper wall. As represented in Figure 1, there is an included angle between the two walls. And, with a cylindrical outer wall, the effective included angle constantly changes. This complicates assessment of critical spacecraft components located within outer spacecraft walls when using software tools such as NASA's BumperII. In addition, the validity of the risk assessment comes into question when using the standard double wall shield equations, especially since verification testing of every set of double wall included angles is impossible.

  16. `Mice In Space': evaluation of a new housing system

    NASA Astrophysics Data System (ADS)

    Silva, Mitchell; Liu, Yi; Serradj, Nadjet; Salanova, Michele; Touma, Chadi; Poursaberi, Ahmad; Jamon, Marc; Blottner, Dieter; Cancedda, Ranieri; Giuliani, Alessandra; Rustichelli, Franco; Aerts, Jean-Marie; Vico, Lawrence; D'Hooge, Rudi; Falcetti, Giancarlo; Berckmans, Daniel

    In this project a cage design is being proposed in which mice can be housed in a microgravity environment. The objective of this paper is to describe and evaluate the proposed cage design, by investigating the micro-environment within such a MIS cage, and to quantify the difference in activity between single and double housed mice by using integrated cameras in the top covers of the cages and quantifying the differences in stress levels by fecal hormone extraction. By assessing the gradients in air circulation in the cage, it can be visualized that high air flow gradients exist within the MIS cage. Measuring the 3D temperature distribution showed small temperature gradients, being maximum 0.1 C. Single housed MIS mice showed significant different body weight compared to double housed MIS mice and controls (p¡0.05). The effect of individual or double housing on activity was quantified with images recorded during 25 day trials. There was a significantly difference observed as single housed show significant more activity compared to double housed mice (p¡0.05). No significant difference was found in stress levels between MIS housed mice and control mice. The technical description in this paper should allow researchers to be informed about the possibilities that will come available to do mice experimentations in space. Keywords: mouse, spaceflight, animal housing, cage design, micro environment

  17. 62. 1901 STEAM ENGINE HOUSE LOOKING SOUTH THROUH TO 1902 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    62. 1901 STEAM ENGINE HOUSE LOOKING SOUTH THROUH TO 1902 STEAM TURBINE ROOM COLUMNS SUPPORT TRUE EXTERIOR WEST WALL OF THE BUILDING. PORTION TO RIGHT OF COLUMNS IS A LOWER CONNECTOR BETWEEN THE ENGINE HOUSE AND THE 1873 WING. - Boston Manufacturing Company, 144-190 Moody Street, Waltham, Middlesex County, MA

  18. 67. CANAL TENDER'S HOUSE AT LOCK 2 EAST. DUE TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    67. CANAL TENDER'S HOUSE AT LOCK 2 EAST. DUE TO DETERIORATION OF THE BUILDINGS WALLS AND FOUNDATION, CABLES FROM AN INCLINED PLANE WERE WRAPPED AROUND THE HOUSE AND FASTENED TO PLANE RAILS PLACED ON OPPOSITE ENDS OF THE STRUCTURE. - Morris Canal, Phillipsburg, Warren County, NJ

  19. SOUTHEAST VIEW OF THE SHELTER HOUSE LOCATED ON THE EAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    SOUTHEAST VIEW OF THE SHELTER HOUSE LOCATED ON THE EAST END OF BIG DALTON DAM SHOWING THE NORTHWEST SIDE OF THE BUILDING. THE PARAPET WALL IS SHOWN IN THE FOREGROUND - Big Dalton Dam, Shelter House, 2600 Big Dalton Canyon Road, Glendora, Los Angeles County, CA

  20. Interior, main room, Burton Park Club House, view to north ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior, main room, Burton Park Club House, view to north (90mm lens). Fireplace at left, kitchen and restroom are through open doorway visible at right side of opposite end wall. - Burton Park, Club House & Amphitheater, Adjacent ot south end of Chestnut Avenue, San Carlos, San Mateo County, CA

  1. 2. PEAVEY GLOVE ELEVATOR, WORKHOUSE (NO. 1 HOUSE) WOOD FRAME ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. PEAVEY GLOVE ELEVATOR, WORKHOUSE (NO. 1 HOUSE) WOOD FRAME CONSTRUCTION, SHIPLOADER SIDE. WEST WALL. MARINE LEG ADDED SOME TIME BETWEEN 1907-1919. METAL PASSENGER ELEVATOR SHAFT ADDED IN EARLY 1970S. - Peavey Globe Elevator, No. 1 House, West Gate Basin & Howard's Bay, east side of slip, Superior, Douglas County, WI

  2. 8. Julia Steele House, interior view detail of oak mantle ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Julia Steele House, interior view detail of oak mantle in front left (south) parlor, with north wall pocket door to left of view. - Julia Steele House, 5875 Paris Road (US Highway 27/68); 1 1/5 miles north of Bourbon County line, Paris, Bourbon County, KY

  3. Distant view from downstream of lock with southeast machinery house, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Distant view from downstream of lock with southeast machinery house, SF 109, and timber guide wall on left, exterior view of closed lower lock gates and hydro-electric power house and dam in background, view towards west - St. Lucie Canal, St. Lucie Lock No. 1, St. Lucie, Cross State Canal, Okeechobee Intracoastal Waterway, Stuart, Martin County, FL

  4. 67. 1911 BOILER HOUSE LOOKING SOUTH. AREA FRAMED BY HIGH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    67. 1911 BOILER HOUSE LOOKING SOUTH. AREA FRAMED BY HIGH WINDOWS ON RIGHT IS FORMER EAST EXTERIOR WALL OF 1901 STEAM ENGINE HOUSE. BELOW RIGHT IS A TANK FOR HEATING OIL ENCLOSED IN CEMENT BLOCK CA. 1945. - Boston Manufacturing Company, 144-190 Moody Street, Waltham, Middlesex County, MA

  5. Wall Turbulence.

    ERIC Educational Resources Information Center

    Hanratty, Thomas J.

    1980-01-01

    This paper gives an account of research on the structure of turbulence close to a solid boundary. Included is a method to study the flow close to the wall of a pipe without interferring with it. (Author/JN)

  6. Housing, Design, and Furnishings.

    ERIC Educational Resources Information Center

    Texas Tech Univ., Lubbock. Home Economics Curriculum Center.

    This document contains teacher's materials for a six-unit secondary education vocational home economics course on housing, design, and furnishings. The units cover: (1) the societal aspects of housing (including the relationship between housing and the economy, population trends, and culture-related housing characteristics); (2) family housing…

  7. 78 FR 66670 - Housing Counseling Program: New Certification Requirements; Extension of Public Comment Period

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-06

    ... Housing Counseling Program regulations for the purpose of implementing the Dodd-Frank Wall Street Reform... proposed rule in the Federal Register that would implement changes made by the Dodd-Frank Wall Street..., Department of Housing and Urban Development, 451 7th Street SW., Room 10276, Washington, DC...

  8. The Insulation of Houses against Noise from Aircraft in Flight.

    ERIC Educational Resources Information Center

    Scholes, W. E.; Parkin, P. H.

    Three groups of traditional houses were insulated against aircraft noise by double glazing and installing sound attenuating ventilator units. For upper floor rooms of two story houses, overall insulations of 35-40 dB were obtainable, providing transmission through the roofs and down flues were also reduced. The noise levels caused by ventilator…

  9. Low-cost sustainable wall construction system

    SciTech Connect

    Vohra, A.; Rosenfeld, A.H.

    1998-07-01

    Houses with no wall cavities, such as those made of adobe, stone, brick, or block, have poor thermal properties but are rarely insulated because of the cost and difficulty of providing wall insulation. A simple, low-cost technique using loose-fill indigenous materials has been demonstrated for the construction of highly insulated walls or the retrofit of existing walls in such buildings. Locally available pumice, in sandbags stacked along the exterior wall of an adobe house in New Mexico, added a thermal resistance (R) of 16 F{sm{underscore}bullet}ft{sup 2}{sm{underscore}bullet}h/Btu (2.8 m{sup 2}{sm{underscore}bullet}K/W). The total cost of the sandbag insulation wall retrofit was $3.76 per square foot ($40.50/m{sup 2}). Computer simulations of the adobe house using DOE 2.1E show savings of $275 per year, corresponding to 50% reduction in heating energy consumption. The savings-to-investment ratio ranges from 1.1 to 3.2, so the cost of conserved energy is lower than the price of propane, natural gas and electric heat, making the system cost-effective. Prototype stand-alone walls were also constructed using fly ash and sawdust blown into continuous polypropylene tubing, which was folded between corner posts as it was filled to form the shape of the wall. Other materials could also be used. The inexpensive technique solves the problem of insulating solid-wall hours and constructing new houses without specialized equipment and skills, thereby saving energy, reducing greenhouse gas emissions, and improving comfort for people in many countries. The US Department of Energy (DOE) has filed patent applications on this technology, which is part of a DOE initiative on sustainable building envelope materials and systems.

  10. Definition of squatter housing.

    PubMed

    Gedik, A

    1993-01-01

    One of the most critical urban problems of developing countries is squatter housing. Squatter housing was defined as housing illegally established and roughly constructed. The initial structure was small in size, made of low-quality materials, and built with nominal labor costs on squatter land with a nominal rent. The basic housing unit may be expanded over time. Squatter housing arises out of a variety of circumstances, including an inadequate supply of old depleted formal housing near the central business district. Squatter housing is attractive to migrants and others in low-income and insecure employment. Improvements in squatter housing locations are possible when spatial location problems are not a concern. Policies concerning squatter housing have changed over time. Most government policies accept the inevitability of squatter housing and seek to improve and upgrade housing and public service conditions. The literature on squatter housing spans a variety of forms of housing. The variety of forms was due to the variety of levels of development within countries, changes over time, and changes toward a more permanent population in the labor force rather then temporary migrants. The forms of housing were identified as legal-formal residential housing which excluded slums, residential slums, squatter housing, and other residential housing. Set theory was used to clarify, with explicitness and a minimum of redundancies, 14 different sets. The 14 sets revolved around socioeconomic levels, housing and environmental conditions, construction process, land ownership, zoning regulations, subdivision regulations, and building construction regulations. Legal-formal housing meant legal land ownership and conformity to legal zoning, subdivision, and building construction regulations. Usually housing was of higher quality and construction was according to a time schedule. Slum housing also conformed to legal status and a regular time span for construction, but the

  11. 'Stucco' Walls

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This projected mosaic image, taken by the microscopic imager, an instrument located on the Mars Exploration Rover Opportunity 's instrument deployment device, or 'arm,' shows the partial clotting or cement-like properties of the sand-sized grains within the trench wall. The area in this image measures approximately 3 centimeters (1.2 inches) wide and 5 centimeters (2 inches) tall.(This image also appears as an inset on a separate image from the rover's navigation camera, showing the location of this particular spot within the trench wall.)

  12. 'Stucco' Walls

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This projected mosaic image, taken by the microscopic imager, an instrument located on the Mars Exploration Rover Opportunity 's instrument deployment device, or 'arm,' shows the partial clotting or cement-like properties of the sand-sized grains within the trench wall. The area in this image measures approximately 3 centimeters (1.2 inches) wide and 5 centimeters (2 inches) tall.(This image also appears as an inset on a separate image from the rover's navigation camera, showing the location of this particular spot within the trench wall.)

  13. 24 CFR 982.618 - Shared housing: Housing quality standards.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false Shared housing: Housing quality standards. 982.618 Section 982.618 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN HOUSING, DEPARTMENT OF HOUSING...

  14. 24 CFR 982.618 - Shared housing: Housing quality standards.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 4 2014-04-01 2014-04-01 false Shared housing: Housing quality standards. 982.618 Section 982.618 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN HOUSING, DEPARTMENT OF HOUSING...

  15. 24 CFR 982.618 - Shared housing: Housing quality standards.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 4 2012-04-01 2012-04-01 false Shared housing: Housing quality standards. 982.618 Section 982.618 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN HOUSING, DEPARTMENT OF HOUSING...

  16. 24 CFR 982.618 - Shared housing: Housing quality standards.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 4 2013-04-01 2013-04-01 false Shared housing: Housing quality standards. 982.618 Section 982.618 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN HOUSING, DEPARTMENT OF HOUSING...

  17. Housing of the Rural Elderly. Rural Development Research Report Number 42.

    ERIC Educational Resources Information Center

    Arnold, Gail D.

    Based on the 1979 Annual Housing Survey, the elderly--especially the rural elderly--are more likely than other groups to live in inadequate housing. Housing was defined as inadequate if it had one or more of the following flaws: incomplete plumbing facilities, incomplete kitchen facilities, leaking roof, holes in walls or ceilings, and exposed…

  18. Wall Art

    ERIC Educational Resources Information Center

    McGinley, Connie Q.

    2004-01-01

    The author of this article, an art teacher at Monarch High School in Louisville, Colorado, describes how her experience teaching in a new school presented an exciting visual challenge for an art teacher--monotonous brick walls just waiting for decoration. This school experienced only minimal instances of graffiti, but as an art teacher, she did…

  19. Wall Art

    ERIC Educational Resources Information Center

    McGinley, Connie Q.

    2004-01-01

    The author of this article, an art teacher at Monarch High School in Louisville, Colorado, describes how her experience teaching in a new school presented an exciting visual challenge for an art teacher--monotonous brick walls just waiting for decoration. This school experienced only minimal instances of graffiti, but as an art teacher, she did…

  20. Wall Covering

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The attractive wall covering shown below is one of 132 styles in the Mirror Magic II line offered by The General Tire & Rubber Company, Akron, Ohio. The material is metallized plastic fabric, a spinoff from space programs. Wall coverings are one of many consumer applications of aluminized plastic film technology developed for NASA by a firm later bought by King-Seeley Thermos Company, Winchester, Massachusetts, which now produces the material. The original NASA use was in the Echo 1 passive communications satellite, a "space baloon" made of aluminized mylar; the high reflectivity of the metallized coating enabled relay of communications signals from one Earth station to another by "bouncing" them off the satellite. The reflectivity feature also made the material an extremely efficient insulator and it was subsequently widely used in the Apollo program for such purposes as temperature control of spacecraft components and insulation of tanks for fuels that must be maintained at very low temperatures. I Used as a wall covering, the aluminized material offers extra insulation, reflects light and I resists cracking. In addition to General Tire, King-Seeley also supplies wall covering material to Columbus Coated Fabrics Division of Borden, Incorporated, Columbus, Ohio, among others.

  1. Perspective: Double Jeopardy--Another Look.

    ERIC Educational Resources Information Center

    Bolduan, Linda M.; Dailey, Dianne K.

    1997-01-01

    Explores how a defendant can face a civil action and criminal prosecution for the same act without violating the principle of double jeopardy. For instance, burning down a house can engender criminal prosecution charges and a civil suit from the insurance company. Double jeopardy only applies to criminal actions. (MJP)

  2. 7 CFR 3560.460 - Double damages.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Double damages. 3560.460 Section 3560.460 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, DEPARTMENT OF AGRICULTURE... Actions § 3560.460 Double damages. (a) Action to recover assets or income. (1) The Agency may request to...

  3. 2. Historic American Buildings Survey R. J. Wall, Photographer August ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Historic American Buildings Survey R. J. Wall, Photographer August 8th, 1935. HALL OF RECORDS, ADJOINING COURT HOUSE, NORTH AND WEST ELEVATIONS - Hall of Records, Main Street, Knoxville, Knox County, IL

  4. 19. View looking N at mill wall ruins with open ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. View looking N at mill wall ruins with open end of purging house in background. - Hacienda Azucarera La Esperanza, Mill (Ruins), 2.65 miles North of PR Route 2 Bridge Over Manati River, Manati, Manati Municipio, PR

  5. SUGAR BIN WITH EAST WALL OF CRUSHING MILL TO ITS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    SUGAR BIN WITH EAST WALL OF CRUSHING MILL TO ITS RIGHT. CONVEYOR FROM BOILING HOUSE ABOVE. VIEW FROM THE NORTHEAST - Kekaha Sugar Company, Sugar Mill Building, 8315 Kekaha Road, Kekaha, Kauai County, HI

  6. 4. LARGE MEETING ROOM, SOUTH WALL, FIREPLACE AND PAINTING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. LARGE MEETING ROOM, SOUTH WALL, FIREPLACE AND PAINTING - Penn School Historic District, Frissell Community House, SC Route 37, 1 mile South of Frogmore, St. Helena Island, Frogmore, Beaufort County, SC

  7. 72. INTERIOR VIEW OF THE WESTERN WALL OF THE BLOWERS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    72. INTERIOR VIEW OF THE WESTERN WALL OF THE BLOWERS CONTROL HOUSE FOR DOROTHY SIX BLAST FURNACE. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  8. 70. INTERIOR, FIRST FLOOR, MAHOGANY GUEST ROOM, EAST WALL, DETAIL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    70. INTERIOR, FIRST FLOOR, MAHOGANY GUEST ROOM, EAST WALL, DETAIL OF SPEAKING TUBE MOUTHPIECE (TUBE TO KITCHEN) - Mark Twain House, 351 Farmington Avenue (corrected from original address of 531 Farmington Avenue), Hartford, Hartford County, CT

  9. VIEW OF RETAINING WALL BEHIND FACILITY 532. VIEW FACING EAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF RETAINING WALL BEHIND FACILITY 532. VIEW FACING EAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  10. FIRST FLOOR, Looking west at doors along the south wall ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FIRST FLOOR, Looking west at doors along the south wall of Room 111 and the doorway at the far end to Room 112 - Department of Energy, Mound Facility, Hydrolysis House Building (HH Building), One Mound Road, Miamisburg, Montgomery County, OH

  11. 6. VIEW OF INTERIOR WALL OF SARATOGA GAS LIGHT COMPANY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW OF INTERIOR WALL OF SARATOGA GAS LIGHT COMPANY GASHOLDER NO. 2 HOUSE, LOOKING NORTH. - Saratoga Gas Light Company, Gasholder No. 2, Niagara Mohawk Power Corporation Substation Facility, intersection of Excelsior & East Avenues, Saratoga Springs, NY

  12. 8. VIEW OF INTERIOR WALL OF SARATOGA GAS LIGHT COMPANY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW OF INTERIOR WALL OF SARATOGA GAS LIGHT COMPANY GASHOLDER NO. 2. HOUSE, LOOKING EAST. - Saratoga Gas Light Company, Gasholder No. 2, Niagara Mohawk Power Corporation Substation Facility, intersection of Excelsior & East Avenues, Saratoga Springs, NY

  13. 7. VIEW OF INTERIOR WALL OF SARATOGA GAS LIGHT COMPANY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. VIEW OF INTERIOR WALL OF SARATOGA GAS LIGHT COMPANY GASHOLDER NO. 2. HOUSE, LOOKING NORTHEAST. - Saratoga Gas Light Company, Gasholder No. 2, Niagara Mohawk Power Corporation Substation Facility, intersection of Excelsior & East Avenues, Saratoga Springs, NY

  14. 88. 451 MADISON AVENUE, LIBRARY, SOUTH WALL, WEST CENTRAL SECTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    88. 451 MADISON AVENUE, LIBRARY, SOUTH WALL, WEST CENTRAL SECTION SHOWING WINDOW AND RADIATOR (Pair with NY-5635-89) - Villard Houses, 451-457 Madison Avenue & 24 East Fifty-first Street, New York County, NY

  15. Interior view showing south wall and windows of living room ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior view showing south wall and windows of living room and dining room. Entrance to kitchen is at extreme right center. - Clara E. Stoltz House, 817-823 North Hunter Street, Stockton, San Joaquin County, CA

  16. STREET FRONT AND LAVA ROCK RETAINING WALL WITH ENTRY AWNING. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    STREET FRONT AND LAVA ROCK RETAINING WALL WITH ENTRY AWNING. VIEW FACING NORTH-NORTHEAST. - U.S. Naval Base, Pearl Harbor, Naval Housing Area Makalapa, Senior Officers' Quarters Type A, 37 Makalapa Drive, Pearl City, Honolulu County, HI

  17. North & south wall elevation of the east entrance loggia; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    North & south wall elevation of the east entrance loggia; detail of pilaster base and capital - National Zoological Park, Elephant House, 3001 Connecticut Avenue NW, Washington, District of Columbia, DC

  18. Detail view of basrelief sculpture in tympanum at south wall ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail view of bas-relief sculpture in tympanum at south wall of east entrance loggia, with scale stick - National Zoological Park, Elephant House, 3001 Connecticut Avenue NW, Washington, District of Columbia, DC

  19. Detail view of basrelief sculpture in tympanum at south wall ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail view of bas-relief sculpture in tympanum at south wall of west entrance loggia, with scale stick - National Zoological Park, Elephant House, 3001 Connecticut Avenue NW, Washington, District of Columbia, DC

  20. 72. View of reservoir adjacent to south wall of blowing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    72. View of reservoir adjacent to south wall of blowing engine house where water from furnaces was allowed to cool. - Sloss-Sheffield Steel & Iron, First Avenue North Viaduct at Thirty-second Street, Birmingham, Jefferson County, AL

  1. 4. NORTH ROOM, WEST WALL, THIRD FLOOR. NOTE PLAIN MANTLEPIECE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. NORTH ROOM, WEST WALL, THIRD FLOOR. NOTE PLAIN MANTLEPIECE AND ORIGINAL WINDOW. See also PA-1345 C-5 - Marshall's Court Area Study, David Simpson House, 411 Marshall's Court, Philadelphia, Philadelphia County, PA

  2. 3. VIEW OF PARK FROM SOUTHWEST SHOWING BRICK WALLS OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VIEW OF PARK FROM SOUTHWEST SHOWING BRICK WALLS OF BUS RAMP, GANNET HOUSE IN REAR LEFT, AUSTIN HALL IN CENTER, LITTAUER HALL TO RIGHT - Flagstaff Park, Massachusetts Avenue & Kirkland Street, Cambridge, Middlesex County, MA

  3. 11. Second floor, northwest chamber, south wall. Former passage to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Second floor, northwest chamber, south wall. Former passage to southwest chamber (door blocked off on far side) on left; closet on right. - Conner Homestead, House, Epping Road (State Route 101), Exeter, Rockingham County, NH

  4. 16. HISTORIC VIEW FROM NORTH OF PRISON WALL AND FRONT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. HISTORIC VIEW FROM NORTH OF PRISON WALL AND FRONT HOUSE, CIRCA 1900 Photographer unknown. By courtesy of the Free Public Library of Trenton, New Jersey. - New Jersey State Prison, Second & Federal Streets, Trenton, Mercer County, NJ

  5. 25. May 1985. DETAIL OF CELLAR STEPS AND EARTH WALL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. May 1985. DETAIL OF CELLAR STEPS AND EARTH WALL OF CELLAR IN CENTRAL BLOCK - Borough House, West Side State Route 261, about .1 mile south side of junction with old Garners Ferry Road, Stateburg, Sumter County, SC

  6. 13. FRIST FLOOR, SOUTHEAST ROOM, SOUTHWEST WALL, HEARTH WITH KETTLES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. FRIST FLOOR, SOUTHEAST ROOM, SOUTHWEST WALL, HEARTH WITH KETTLES USED FOR RENDERING LARD (LEFT) AND MAKING APPLE BUTTER (RIGHT) WITH SCALE - Open Gate Farm, House, Ridge Road, 1 mile East of Elephant Road, Perkasie, Bucks County, PA

  7. 12. FRIST FLOOR, SOUTHEAST ROOM, SOUTHWEST WALL, HEARTH WITH KETTLES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. FRIST FLOOR, SOUTHEAST ROOM, SOUTHWEST WALL, HEARTH WITH KETTLES USED FOR RENDERING LARD (LEFT) AND MAKING APPLE BUTTER (RIGHT) - Open Gate Farm, House, Ridge Road, 1 mile East of Elephant Road, Perkasie, Bucks County, PA

  8. 20. Living room, view to east wall and pocket doors ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. Living room, view to east wall and pocket doors to front parlor; view to east; 65mm lens with electronic flash illumination. - Warner Hutton House, 13495 Sousa Lane, Saratoga, Santa Clara County, CA

  9. 31. SECOND FLOOR, NORTHWEST ROOM, SOUTH WALL. Three raisedpanel doors ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    31. SECOND FLOOR, NORTHWEST ROOM, SOUTH WALL. Three raised-panel doors with bolection panel molds, all probably original with house. - Mulberry, Cooper River, West Branch, Moncks Corner, Berkeley County, SC

  10. 7. Row of pumps against first floor interior west wall. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Row of pumps against first floor interior west wall. - Delaware, Lackawanna & Western Railroad, Scranton Yards, Oil House, 650 feet Southeast of Cliff & Mechanic Streets, Scranton, Lackawanna County, PA

  11. 62. INTERIOR, FIRST FLOOR, LIBRARY, EAST WALL WITH FIREPLACE AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    62. INTERIOR, FIRST FLOOR, LIBRARY, EAST WALL WITH FIREPLACE AND MANTLE, WITH SCALE - Mark Twain House, 351 Farmington Avenue (corrected from original address of 531 Farmington Avenue), Hartford, Hartford County, CT

  12. 63. INTERIOR, FIRST FLOOR, LIBRARY, EAST WALL WITH FIREPLACE AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    63. INTERIOR, FIRST FLOOR, LIBRARY, EAST WALL WITH FIREPLACE AND MANTLE, WITHOUT SCALE - Mark Twain House, 351 Farmington Avenue (corrected from original address of 531 Farmington Avenue), Hartford, Hartford County, CT

  13. 64. INTERIOR, FIRST FLOOR, LIBRARY, EAST WALL, DETAIL VIEW OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    64. INTERIOR, FIRST FLOOR, LIBRARY, EAST WALL, DETAIL VIEW OF FIREPLACE AND MANTLE, WITH SCALE - Mark Twain House, 351 Farmington Avenue (corrected from original address of 531 Farmington Avenue), Hartford, Hartford County, CT

  14. 65. INTERIOR, FIRST FLOOR, LIBRARY, EAST WALL, DETAIL VIEW OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    65. INTERIOR, FIRST FLOOR, LIBRARY, EAST WALL, DETAIL VIEW OF FIREPLACE AND MANTLE, WITHOUT SCALE - Mark Twain House, 351 Farmington Avenue (corrected from original address of 531 Farmington Avenue), Hartford, Hartford County, CT

  15. 66. INTERIOR, FIRST FLOOR, LIBRARY, SIDE VIEW OF WEST WALL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    66. INTERIOR, FIRST FLOOR, LIBRARY, SIDE VIEW OF WEST WALL FIREPLACE AND MANTLE FROM THE SOUTH - Mark Twain House, 351 Farmington Avenue (corrected from original address of 531 Farmington Avenue), Hartford, Hartford County, CT

  16. 90. INTERIOR, THIRD FLOOR, BILLIARD ROOM, SOUTH WALL, DETAIL OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    90. INTERIOR, THIRD FLOOR, BILLIARD ROOM, SOUTH WALL, DETAIL OF TRANSLUCENT CARVED MARBLE WINDOW ON THE EAST SIDE - Mark Twain House, 351 Farmington Avenue (corrected from original address of 531 Farmington Avenue), Hartford, Hartford County, CT

  17. 91. INTERIOR, THIRD FLOOR, BILLIARD ROOM, SOUTH WALL, DETAIL OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    91. INTERIOR, THIRD FLOOR, BILLIARD ROOM, SOUTH WALL, DETAIL OF TRANSLUCENT CARVED MARBLE WINDOW ON THE WEST SIDE - Mark Twain House, 351 Farmington Avenue (corrected from original address of 531 Farmington Avenue), Hartford, Hartford County, CT

  18. 60. 451 MADISON AVENUE, DRAWING ROOM, NORTH WALL, WEST MURAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    60. 451 MADISON AVENUE, DRAWING ROOM, NORTH WALL, WEST MURAL PAINTING SHOWING A WOMAN (See NY-5635-54 for original location) - Villard Houses, 451-457 Madison Avenue & 24 East Fifty-first Street, New York County, NY

  19. 13. Greenhouse, east elevation. The boardandbatten wall covers an opening ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. Greenhouse, east elevation. The board-and-batten wall covers an opening that was originally fitted with windows which allowed sunlight into the greenhouse. - John Bartram House & Garden, Greenhouse, 54th Street & LIndbergh Boulevard, Philadelphia, Philadelphia County, PA

  20. 5. Log calving barn. Detail of wall corner showing half ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Log calving barn. Detail of wall corner showing half dovetail notching on hand-hewn logs. - William & Lucina Bowe Ranch, Log Calving Barn, 230 feet south-southwest of House, Melrose, Silver Bow County, MT

  1. 35. SECOND FLOOR, SOUTHEAST ROOM, NORTH WALL: BLACK MARBLE MANTLE. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    35. SECOND FLOOR, SOUTHEAST ROOM, NORTH WALL: BLACK MARBLE MANTLE. Grape clusters above columns repeat in upper part of cornice and probably in destroyed ceiling centerpiece - Governor Thomas Bennett House, 1 Lucas Street, Charleston, Charleston County, SC

  2. Analysis on design and performance of a solar rotary house

    NASA Astrophysics Data System (ADS)

    Fan, Xuhong; Zhang, Zhaochang; Yang, Fan; Cao, Lilin; Xu, Jing; Yuan, Mingyang

    2017-04-01

    A solar rotary house is designed, composed of rotating main structure, fixed cylinder, rotating drive system, solar photovoltaic system and so on, to achieve 360° rotation. Thus it can change the dark and humid situation of the traditional fixed house shade. Its bearing capacity, driving force and safety are analyzed. Rotary driving force and living energy are provided by solar photovoltaic system on roofs and walls. The Phonenics, Ecotect simulation analysis conclude that the rotating house indoor has better natural ventilation effect, more uniform lighting, better the sunshine time compared with traditional houses, becoming a green, energy-saving, comfortable building model.

  3. Sonoma House. Monitoring of the First U.S. Passive House Retrofit

    SciTech Connect

    German, A.; Weitzel, B.; Backman, C.; Hoeschele, M.; Dakin, B.

    2012-12-01

    The Sonoma Deep Retrofit is a single-story deep retrofit project in the marine climate of Sonoma, California. The design was guided by Passive House principles that promote the use of very high levels of wall, ceiling, and floor insulation along with tight envelope construction to maintain a comfortable indoor environment with little or no need for conventional heating or cooling.

  4. Sonoma House: Monitoring of the First U.S. Passive House Retrofit

    SciTech Connect

    German, A.; Weitzel, B.; Backman, C.; Hoeschele, M.; Dakin, B.

    2012-12-01

    The Sonoma Deep Retrofit is a single-story deep retrofit project in the marine climate of Sonoma, California. The design was guided by Passive House principles which promote the use of very high levels of wall, ceiling, and floor insulation along with tight envelope construction to maintain a comfortable indoor environment with little or no need for conventional heating or cooling.

  5. How to Teach Housing

    ERIC Educational Resources Information Center

    Wysocki, Joseph L.

    1977-01-01

    A list of topics and related field experiences accompany this description of an introductory undergraduate course on housing and society. Topics and community experiences are also outlined for a graduate course in advanced housing and interior design. (TA)

  6. Student-Initiated Housing

    ERIC Educational Resources Information Center

    Feild, Robert M.

    1973-01-01

    Summarizes a report that describes housing where student groups lease, purchase, or even develop their own living quarters. Considers the birth of the movement, federal student housing programs, and a view to future programs. (Author/DN)

  7. Insulator for laser housing

    DOEpatents

    Duncan, David B.

    1992-01-01

    The present invention provides a heat-resistant electrical insulator adapted for joining laser housing portions, which insulator comprises: an annulus; a channel in the annulus traversing the circumference and length of the housing; at least two ports, each communicating with the channel and an outer surface of the housing; and an attachment for securely attaching each end of the annulus to a laser housing member.

  8. Insulator for laser housing

    DOEpatents

    Duncan, D.B.

    1992-12-29

    The present invention provides a heat-resistant electrical insulator adapted for joining laser housing portions, which insulator comprises: an annulus; a channel in the annulus traversing the circumference and length of the housing; at least two ports, each communicating with the channel and an outer surface of the housing; and an attachment for securely attaching each end of the annulus to a laser housing member. 3 figs.

  9. New Whole-House Case Study: Transformations, Inc. Net Zero Energy Communities, Devens, Easthampton, Townsend, Massachusetts

    SciTech Connect

    2013-11-01

    In 2009, Transformations, Inc. partnered with Building America team Building Science Corporation (BSC) to build new net zero energy houses in three developments in Massachusetts. The company has been developing strategies for cost-effective super-insulated homes in the New England market since 2006. After years of using various construction techniques, it has developed a specific set of assemblies and specifications that achieve a 44.9% reduction in energy use compared with a home built to the 2009 International Residential Code, qualifying the houses for the DOE’s Challenge Home. The super-insulated houses provide data for several research topics in a cold climate. BSC studied the moisture risks in double stud walls insulated with open cell spray foam and cellulose. The mini-split air source heat pump (ASHP) research focused on the range of temperatures experienced in bedrooms as well as the homeowners’ perceptions of equipment performance. BSC also examined the developer’s financing options for the photovoltaic (PV) systems, which take advantage of Solar Renewable Energy Certificates, local incentives, and state and federal tax credits.

  10. Solar Heating Retrofit of Military Family Housing

    DTIC Science & Technology

    1976-09-01

    6.12 Remote House Controlier (Solar Control 6-13: ’ House) 6.13 Status Display Console 6-14 *6.14 Teletype 6-15 (. 15 Pyranometer 6-20 6.16 AN/TMQ-15...The meteorological monitoring system includes a spectral pyranometer mounted atop the roof array for measuring solar insolation, and two Air Force...cement was used without additives. No course aggregate was used jecause of the narrow control dimensions of the wall thickness . The aggregate thus used

  11. Unofficial policy: access to housing, housing information and social services among homeless drug users in Hartford, Connecticut

    PubMed Central

    Dickson-Gomez, Julia; Convey, Mark; Hilario, Helena; Corbett, A Michelle; Weeks, Margaret

    2007-01-01

    Background Much research has shown that the homeless have higher rates of substance abuse problems than housed populations and that substance abuse increases individuals' vulnerability to homelessness. However, the effects of housing policies on drug users' access to housing have been understudied to date. This paper will look at the "unofficial" housing policies that affect drug users' access to housing. Methods Qualitative interviews were conducted with 65 active users of heroin and cocaine at baseline, 3 and 6 months. Participants were purposively sampled to reflect a variety of housing statuses including homeless on the streets, in shelters, "doubled-up" with family or friends, or permanently housed in subsidized, unsubsidized or supportive housing. Key informant interviews and two focus group interviews were conducted with 15 housing caseworkers. Data were analyzed to explore the processes by which drug users receive information about different housing subsidies and welfare benefits, and their experiences in applying for these. Results A number of unofficial policy mechanisms limit drug users' access to housing, information and services, including limited outreach to non-shelter using homeless regarding housing programs, service provider priorities, and service provider discretion in processing applications and providing services. Conclusion Unofficial policy, i.e. the mechanisms used by caseworkers to ration scarce housing resources, is as important as official housing policies in limiting drug users' access to housing. Drug users' descriptions of their experiences working with caseworkers to obtain permanent, affordable housing, provide insights as to how access to supportive and subsidized housing can be improved for this population. PMID:17343735

  12. Housing: Topic Paper F.

    ERIC Educational Resources Information Center

    National Council on the Handicapped, Washington, DC.

    This paper, one of a series of topic papers assessing federal laws and programs affecting persons with disabilities, addresses the issue of housing. Major federal responsibilities are to develop additional housing opportunities for persons with disabilities and to assure that currently available housing is equally open to individuals with…

  13. [Accessible Rural Housing.

    ERIC Educational Resources Information Center

    Baker, Nick, Ed.

    1995-01-01

    This issue of the quarterly newsletter "Rural Exchange" provides information and resources on accessible rural housing for the disabled. "Accessible Manufactured Housing Could Increase Rural Home Supply" (Nick Baker) suggests that incorporation of access features such as lever door handles and no-step entries into manufactured housing could help…

  14. White House Science Fair

    NASA Image and Video Library

    2014-05-27

    President Barack Obama spoke at the White House Science Fair Tuesday, May 27, 2014 at the White House. NASA Administrator Charles Bolden attended and was recognized by the President at the fourth White House Science Fair, which included 100 students from more than 30 different states who competed in science, technology, engineering, and math (STEM) competitions. (Photo Credit: NASA/Aubrey Gemignani)

  15. The Hispanic Housing Crisis.

    ERIC Educational Resources Information Center

    Dolbeare, Cushing N.; Canales, Judith A.

    This report examines the housing characteristics and needs of Hispanic households in the United States, drawing on information from the 1980 Census and the 1983 Annual Housing Survey. Among the conclusions are the following: (1) housing quality is a major problem for more than one in six Hispanic families; (2) among Hispanic subgroups, Puerto…

  16. Wall Turbulence

    DTIC Science & Technology

    1992-04-01

    Doppler velocimeter, computer experiments, and pulsed-laser velocimetry. External influences to be studied are imposed flow oscillations , wavy walls...imposed flow oscillations Studies of the effect of imposed small amplitude flow oscillations have shown no effect on the time mean flow. Work was...undertaken to see if imposed large amplitude oscillations can affect drag. The system used was water flow through a two inch pipe. The flow oscillations

  17. Wall mounted combined radiactive-convective electric space heater

    SciTech Connect

    Meiser, R.; Burkert, J.; Bendel, R.

    1987-07-21

    A space heating apparatus is described for mounting on a wall surface of a room to be heated, the apparatus comprising: a housing including a substantially flat rear wall adapted for mounting to the wall surface. A front wall adjacent the rear wall, the front wall and the real wall conjointly defining a space between through which the air passes. The front wall has a lower portion extending upwardly from the bottom of the housing a solid uninterrupted mid portion devoid of any openings and a portion extending upwardly; an inlet means at the lower end of the housing admits and directs the air into the space; air outlet means at the upper end of the housing where heated air leaves the space and passes from the housing: a solid, uninterrupted metal plate having a first flat side and a second flat side; an electrically insulating plastic layer formed only on the first flat side of the metal plate; the metal plate being mounted in the space so as to partition the space into two convecting channels and having an upper portion extending above the mid portion of the front wall; the plastic layer and the rear wall conjointly defining one of the convecting channels for communicating with a portion of the air outlet means and for conducting a portion of the incoming air admitted to the space; the second flat side and the front wall with the solid uninterrupted mid portion conjointly defining the other one of the convecting channels; resistance heating means embedded in and throughout the plastic layer for heating the air rising in both of the convecting channels and for radiating heat from the second flat side of the plate; and the remainder of the outlet means being formed in the upper portion of the front wall so as to be disposed laterally of the upper portion of the metal plate.

  18. Detail, steps and walls, east corner, Burton Park Amphitheater, view ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail, steps and walls, east corner, Burton Park Amphitheater, view to west (90mm lens). Open doorway to left of steps leads to stage wing area; steps lead to Club House grade level. - Burton Park, Club House & Amphitheater, Adjacent ot south end of Chestnut Avenue, San Carlos, San Mateo County, CA

  19. 30. SECOND FLOOR, NORTHEAST ROOM, SOUTH WALL. Bolection mold fireplace ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. SECOND FLOOR, NORTHEAST ROOM, SOUTH WALL. Bolection mold fireplace surround probably original with house and only remaining one thus. Note bolection panel molds on raised-panel door, also probably original with house. - Mulberry, Cooper River, West Branch, Moncks Corner, Berkeley County, SC

  20. 66. Interior view, "new" cellar, south wall. Located under the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    66. Interior view, "new" cellar, south wall. Located under the study, this room was the only cellar constructed during phase III. The floor was laid with stone and stone stairs-visible on the right-rose up to a bulkhead door on the south side of the house. This door was closed-off when the conservatory was constructed early in the nineteenth century. - John Bartram House & Garden, House, 54th Street & Lindbergh Boulevard, Philadelphia, Philadelphia County, PA

  1. DOE Zero Energy Ready Home Case Study: Ithaca Neighborhood Housing Services, Ithaca, New York

    SciTech Connect

    none,

    2013-10-01

    Eleven new townhomes comply with EPA's airPLUS criteria and use EPA WaterSense-qualifying features. Foundation walls are insulated on the exterior with XPS insulation. Non-shared walls use wall panels that were produced offsite. This builder was awarded a 2013 Housing Innovation Award in the affordable home category.

  2. 18. DETAIL OF EXTERIOR WALL CONSTRUCTION, VIEW TOWARD EAST, THIRD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. DETAIL OF EXTERIOR WALL CONSTRUCTION, VIEW TOWARD EAST, THIRD BAY Showing furring strips, kraft faced cellulose fiber insulation, and asphalt felt applied to interior of exterior wall studs. - U.S. Military Academy, Ice House, Mills Road at Howze Place, West Point, Orange County, NY

  3. 19. DETAIL OF INTERIOR WALL CONSTRUCTION, VIEW TOWARD SOUTH, THIRD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. DETAIL OF INTERIOR WALL CONSTRUCTION, VIEW TOWARD SOUTH, THIRD BAY Showing asphalt felt applied to both sides of interior wall studs beneath wood cladding. Back-nailing of felt indicates sequence of felt and cladding installation. - U.S. Military Academy, Ice House, Mills Road at Howze Place, West Point, Orange County, NY

  4. DETAIL VIEW, CENTER FIRSTFLOOR WINDOW IN WEST WALL. ORIGINALLY, THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW, CENTER FIRST-FLOOR WINDOW IN WEST WALL. ORIGINALLY, THE EXTERIOR OF THE HOUSE WAS, AT THE VERY LEAST, LIMED, AND POSSIBLY STUCCOED. THUS, THE CONTRAST BETWEEN THE NEATLY CRAFTED BRICK WINDOW SURROUNDS AND THE STONE WALL WOULD HAVE BEEN REDUCED - The Woodlands, 4000 Woodlands Avenue, Philadelphia, Philadelphia County, PA

  5. 17. Interior view, greenhouse, north wall taken from the ground. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. Interior view, greenhouse, north wall taken from the ground. Stucco-painted white-covered the interior walls in order to seal-off any drafts and to reflect the sunlight entering through the east-facing windows. - John Bartram House & Garden, Greenhouse, 54th Street & LIndbergh Boulevard, Philadelphia, Philadelphia County, PA

  6. 18. Detail view, greenhouse, north wall (Note the type of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. Detail view, greenhouse, north wall (Note the type of stone used in the wall construction, the degradation of the interior stucco, and one of the pockets for a former floor joist). - John Bartram House & Garden, Greenhouse, 54th Street & LIndbergh Boulevard, Philadelphia, Philadelphia County, PA

  7. Cooling wall

    SciTech Connect

    Nosenko, V.I.

    1995-07-01

    Protecting the shells of blast furnaces is being resolved by installing cast iron cooling plates. The cooling plates become non-operational in three to five years. The problem is that defects occur in manufacturing the cooling plates. With increased volume and intensity of work placed on blast furnaces, heat on the cast iron cooling plates reduces their reliability that limits the interim repair period of blast furnaces. Scientists and engineers from the Ukraine studied this problem for several years, developing a new method of cooling the blast furnace shaft called the cooling wall. Traditional cast iron plates were replaced by a screen of steel tubes, with the area between the tubes filled with fireproof concrete. Before placing the newly developed furnace shaft into operation, considerable work was completed such as theoretical calculations, design, research of temperature fields and tension. Continual testing over many years confirms the value of this research in operating blast furnaces. The cooling wall works with water cooling as well as vapor cooling and is operating in 14 blast furnaces in the Ukraine and two in Russia, and has operated for as long as 14 years.

  8. 75 FR 4100 - Affirmative Fair Housing, Marketing (AFHM) Plan-Multifamily Housing, Affirmative Fair Housing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-26

    ... URBAN DEVELOPMENT Affirmative Fair Housing, Marketing (AFHM) Plan-Multifamily Housing, Affirmative Fair Housing Marketing (AFHM) Plan-Single Family Housing and Affirmative Fair Housing Marketing (AFHM) Plan... forms to describe their intent for marketing to ensure that they meet the Fair Housing guidelines...

  9. Improved poultry house

    SciTech Connect

    1983-01-01

    The relationship of energy and poultry production was explored in three areas: methane production from litter, broiler house insulation, and broiler house HVAC systems. The findings show that while a methane plant would not be popular with individual American poultry producers; the pay back in fuel and fertilizer, if the plant was located in close proximinity to the processing plant, would be favorable. Broiler house insulation has been dramatically improved since the outset of this study. Presently, all new installations in the survey area are the Environmental houses which are fully insulated. HVAC systems have had to keep pace with the introduction of better insulation. The new Environmental houses HVAC systems are fully automated and operating on a positive atmosphere principal. Ammonia and other problems have been kept in check while reducing air changes per house from a high of 7 per hour to as little as 3 per hour.

  10. Hierarchy in a double braneworld

    SciTech Connect

    Guerrero, Rommel; Rodriguez, R. Omar; Melfo, Alejandra; Pantoja, Nelson

    2006-10-15

    We show that the hierarchy between the Planck and the weak scales can follow from the tendency of gravitons and fermions to localize at different edges of a thick double wall embedded in an AdS{sub 5} spacetime without reflection symmetry. This double wall is a stable BPS thick-wall solution with two subwalls located at its edges; fermions are coupled to the scalar field through Yukawa interactions, but the lack of reflection symmetry forces them to be localized in one of the subwalls. We show that the graviton zero-mode wave function is suppressed in the fermion edge by an exponential function of the distance between the subwalls, and that the massive modes decouple so that Newtonian gravity is recuperated.

  11. Wall thickness measuring method and apparatus

    DOEpatents

    Salzer, Leander J.; Bergren, Donald A.

    1989-01-01

    An apparatus for measuring the wall thickness of a nonmagnetic article having a housing supporting a magnet and a contiguous supporting surface. The tubular article and the housing are releasably secured to the supporting surface and a support member of an optical comparator, respectively. To determine the wall thickness of the article at a selected point, a magnetically responsive ball is positioned within the tubular article over said point and retained therein by means of a magnetic field produced by the magnet. Thereafter, an optical comparator is employed to project a magnified image of the ball on a screen and the wall thickness at the selected point is calculated by using a ball surface measurement taken with the comparator in conjunction with a previously determined base line measurement.

  12. NASA Tech House

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The NASA Technology Utilization House, called Tech House, was designed and constructed at NASA's Langley Research Center in Hampton, Virginia, to demonstrate new technology that is available or will be available in the next several years and how the application of aerospace technology could help advance the homebuilding industry. Solar energy use, energy and water conservation, safety, security, and cost were major considerations in adapting the aerospace technology to the construction of Tech House.

  13. House Resolutions of Inquiry

    DTIC Science & Technology

    2003-05-12

    14 Two years later, the House made another change to its rules governing resolutions of inquiry, requiring not merely a day’s delay but also...of Government “does not necessarily belong to the province of legislation. It does not profess to be asked for that object.”42 Second, if the House ...recognized that the power of impeachment gives the House “the right to investigate the conduct of all public officers under the Government . This is

  14. White House Science Fair

    NASA Image and Video Library

    2014-05-27

    Bobak Ferdowsi, a system's engineer at NASA's Jet Propulsion Laboratory who became widely known for his mohawk hairstyle during the broadcast of the Curiosity landing on Mars, is seen here discussing a project with a participant in the White House Science Fair. The fourth White House Science Fair was held at the White House and included 100 students from more than 30 different states who competed in science, technology, engineering, and math (STEM) competitions. (Photo Credit: NASA/Aubrey Gemignani)

  15. Earthquake resistant structural walls: Test of walls with and without openings

    NASA Astrophysics Data System (ADS)

    Shiu, K. N.; Daniel, J. I.; Aristizabal-Ochoa, J. D.; Fiorato, A. E.; Corley, W. G.

    1981-07-01

    Two one-third scale, six-story wal specimens were subjected to inelastic load reversals representing severe earthquake forces exerted by double acting hydraulic rams, located on both sides of the wall specimens, and applied to the top of each wall. The specimens were designed of earthquake resistant reinforced concrete wall elements in coupled wall systems based on the 1976 Uniform Building Code. The loading was calculated using a modified DRAIN two-dimensional computer program with two actual earthquake records used as input ground motion data. One specimen was a solid wall and the other included six openings simulating windows. When data was normalized by yield capacities, the resonse of the two walls to the inelastic loading was similar. The presence of window openings had little effect on the deformation characteristics of the sample walls in response to the cyclic loads.

  16. Strategy Guideline: Modeling Enclosure Design in Above-Grade Walls

    SciTech Connect

    Lstiburek, J.; Ueno, K.; Musunuru, S.

    2016-02-24

    The Strategy Guideline describes how to model and interpret results of models for above grade walls. The Measure Guideline analyzes the failure thresholds and criteria for above grade walls. A library of above-grade walls with historically successful performance was used to calibrate WUFI (Warme Und Feuchte Instationar) software models. The information is generalized for application to a broad population of houses within the limits of existing experience.

  17. Wall to Wall Optimal Transport

    NASA Astrophysics Data System (ADS)

    Chini, Gregory P.; Hassanzadeh, Pedram; Doering, Charles R.

    2013-11-01

    How much heat can be transported between impermeable fixed-temperature walls by incompressible flows with a given amount of kinetic energy or enstrophy? What do the optimal velocity fields look like? We employ variational calculus to address these questions in the context of steady 2D flows. The resulting nonlinear Euler-Lagrange equations are solved numerically, and in some cases analytically, to find the maximum possible Nusselt number Nu as a function of the Péclect number Pe , a measure of the flow's energy or enstrophy. We find that in the fixed-energy problem Nu ~ Pe , while in the fixed-enstrophy problem Nu ~ Pe 10 / 17 . In both cases, the optimal flow consists of an array of convection cells with aspect ratio Γ (Pe) . Interpreting our results in terms of the Rayleigh number Ra for relevant buoyancy-driven problems, we find Nu <= 1 + 0 . 035 Ra and Γ ~ Ra - 1 / 2 for porous medium convection (which occurs with fixed energy), and Nu <= 1 + 0 . 115 Ra 5 / 12 and Γ ~ Ra - 1 / 4 for Rayleigh-Bénard convection (which occurs with fixed enstrophy and for free-slip walls). This work was supported by NSF awards PHY-0855335, DMS-0927587, and PHY-1205219 (CRD) and DMS-0928098 (GPC). Much of this work was completed at the 2012 Geophysical Fluid Dynamics (GFD) Program at Woods Hole Oceanographic Institution.

  18. The Effects of Housing Status, Stability and the Social Contexts of Housing on Drug and Sexual Risk Behaviors.

    PubMed

    Dickson-Gomez, Julia; McAuliffe, Timothy; Quinn, Katherine

    2017-07-01

    Research on the relationship between housing instability and HIV risk has often focused on two different conceptions of stability. In one conceptualization, housing stability is defined according to physical location with homeless or unstably housed individuals defined as those who reside in places not meant for human habitation or in emergency shelters. The other conceptualization has defined housing stability as individuals' degree of transience, often operationalized as the number of moves or evictions a person has had within a specified amount of time. Less studied has been the social context of living situation, e.g. living with other drug users, conflict over living expenses, or having to have sex in order to stay. This paper uses data from 392 low-income residents in Hartford, CT to explore how people in different housing situations-including those who are housed and homeless-experience housing stability, feelings of security in their homes, and the social context of their housing. We then explore how these varied measures of housing context affect drug use frequency and sexual risk. Results show that participants who are homeless feel more overall housing instability in terms of number of moves and negative reasons for moving. Those who were doubled up with family or friends were more likely to experience conflict over household expenses and more likely to live with drug users. Among homeless and housed, hard drug use was associated with experiencing violence in the place where they lived, perceiving greater housing stability, having moved for a positive reason, doubling up, and longer periods of homelessness, while number of moves and longer prison sentence predicted sexual risk. Among the housed, living with other drug users was associated with more hard drug use, while contributing money toward household expenses was associated with less hard drug use. Two significant interactions were associated with sexual risk among the housed. Those with longer

  19. 16. RW Meyer Sugar Mill: 18761889. Boiling House Interior, 1878. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. RW Meyer Sugar Mill: 1876-1889. Boiling House Interior, 1878. View: Looking from west to east through boiling house. The sorghum pan is on the right. The beams; joists, and trusses are of northwest pine; side boards are of redwood. A foundation line of a loading dock and smokestack are in the foreground. Both end walls have deteriorated completely. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

  20. 7. Julia Steele House, interior view detail of oak mantel ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Julia Steele House, interior view detail of oak mantel in front left (south) parlor. Note Corinthian column supporting over mantle. Beveled mirror and capital of column below. To left of mantle is pocket door in north wall of parlor. - Julia Steele House, 5875 Paris Road (US Highway 27/68); 1 1/5 miles north of Bourbon County line, Paris, Bourbon County, KY