Hydric characterisation of rammed earth samples for different lime concentrations

Science.gov (United States)

Soudani, Lucile; Fabbri, Antonin; Woloszyn, Monika; Grillet, Anne-Cécile; Morel, Jean-Claude

2018-04-01

The rehabilitation of ancient rammed earth houses, as well as the use of earthen materials in modern constructions, are a growing matter of concern, especially in area such as Rhône-Alpes, France, where 40% of old constructions are in rammed earth. A current pathology observed for this type of construction is related to the rising damps, for which the water from the ground is absorbed by the wall. This situation leads to a very saturated state. As it has been proven that the compressive strength is altered by the presence of water in the pores, a better understanding on high relative humidity range is necessary to be able to predict the mechanical behavior of buildings and thus ensure a better risk assessment. The present study describes experimental results of the water uptake experiments and moisture storage at high relative humidities.

Contribution to internal pressure and flammable gas concentration in RAM [radioactive material] transport packages

International Nuclear Information System (INIS)

Warrant, M.M.; Brown, N.

1989-01-01

Various facilities in the US generate wastes contaminated with transuranic (TRU) isotopes (such as plutonium and americium) that decay primarily by emission of alpha particles. The waste materials consist of a wide variety of commercially available plastics, paper, cloth, and rubber; concreted or sludge wastes containing water; and metals, glass, and other solid inorganic materials. TRU wastes that have surface dose rates of 200 mrem/hr or less are typically packaged in plastic bags placed inside metal drums or boxes that are vented through high efficiency particulate air (HEPA) filters. These wastes are to be transported from waste generation or storage sites to the Waste Isolation Pilot Plant (WIPP) in the TRUPACT-II, a Type B package. Radiolysis of organic wastes or packaging materials, or wastes containing water generates gas which may be flammable or simply contribute to the internal pressure of the radioactive material (RAM) transport package. This paper discusses the factors that affect the amount and composition of this gas, and summarizes maximum radiolytic G values (number of molecules produced per 100 eV absorbed energy) found in the technical literature for many common materials. These G values can be used to determine the combination of payload materials and decay heats that are safe for transport. G values are established for categories of materials, based on chemical functional groups. It is also shown using transient diffusion and quasi-equilibrium statistical mechanics methods that hydrogen, if generated, will not stratify at the top of the transport package void space. 9 refs., 1 tab

SeaRAM: an evaluation of the safety of RAM transport by sea

International Nuclear Information System (INIS)

McConnell, P.; Sorenson, K.B.; Carter, M.H.; Keane, M.P.; Keith, V.F.; Heid, R.J.

1995-01-01

SeaRAM is a multi-year Department of Energy (DOE) project designed to validate the safety of shipping radioactive materials (RAM) by sea. The project has an ultimate goal of developing and demonstrating analytic tools for performing comprehensive analyses to evaluate the risks to humans and the environment due to sea transport of plutonium, vitrified high-level waste (VHLW), and spent fuel associated with reprocessing and research reactors. To achieve this end, evaluations of maritime databases and structural an thermal analyses of particular severe collision and fire accidents have been and will continue to be conducted. Program management for SeaRAM is based at the DOE's Office of Environmental Restoration. Technical activities for the project are being conducted at Sandia National Laboratories (SNL). Several private organizations are also involved in providing technical support, notably Engineering Computer Optecnomics, Inc. (ECO). The technical work performed for SeaRAM also supports DOE participation in an International Atomic Energy Agency (IAEA) Cooperative Research Program (CRP) entitled Accident Severity at Sea During Transport of Radioactive Material. This paper discusses activities performed during the first year of the project

Characterizing material properties of cement-stabilized rammed earth to construct sustainable insulated walls

Directory of Open Access Journals (Sweden)

Rishi Gupta

2014-01-01

Full Text Available Use of local materials can reduce the hauling of construction materials over long distances, thus reducing the greenhouse gas emissions associated with transporting such materials. Use of locally available soils (earth for construction of walls has been used in many parts of the world. Owing to the thermal mass of these walls and the potential to have insulation embedded in the wall section has brought this construction material/technology at the forefront in recent years. However, the mechanical properties of the rammed earth and the parameters required for design of steel reinforced walls are not fully understood. In this paper, the author presents a case study where full-scale walls were constructed using rammed earth to understand the effect of two different types of shear detailing on the structural performance of the walls. The mechanical properties of the material essential for design such as compressive strength of the material including effect of coring on the strength, pull out strength of different rebar diameters, flexural performance and out-of-plane bending on walls was studied. These results are presented in this case study.

Neutron Absorbing Ability Variation in Neutron Absorbing Material Caused by the Neutron Irradiation in Spent Fuel Storage Facility

Energy Technology Data Exchange (ETDEWEB)

Sohn, Hee Dong; Han, Seul Gi; Lee, Sang Dong; Kim, Ki Hong; Ryu, Eag Hyang; Park, Hwa Gyu [Doosan Heavy Industries and Construction, Changwon (Korea, Republic of)

2014-10-15

In spent fuel storage facility like high density spent fuel storage racks and dry storage casks, spent fuels are stored with neutron absorbing materials installed as a part of those facilities, and they are used for absorbing neutrons emitted from spent fuels. Usually structural material with neutron absorbing material of racks and casks are located around spent fuels, so it is irradiated by neutrons for long time. Neutron absorbing ability could be changed by the variation of nuclide composition in neutron absorbing material caused by the irradiation of neutrons. So, neutron absorbing materials are continuously faced with spent fuels with boric acid solution or inert gas environment. Major nuclides in neutron absorbing material are Al{sup 27}, C{sup 12}, B{sup 11}, B{sup 10} and they are changed to numerous other ones as radioactive decay or neutron absorption reaction. The B{sup 10} content in neutron absorbing material dominates the neutron absorbing ability, so, the variation of nuclide composition including the decrease of B{sup 10} content is the critical factor on neutron absorbing ability. In this study, neutron flux in spent fuel, the activation of neutron absorbing material and the variation of nuclide composition are calculated. And, the minimum neutron flux causing the decrease of B{sup 10} content is calculated in spent fuel storage facility. Finally, the variation of neutron multiplication factor is identified according to the one of B{sup 10} content in neutron absorbing material. The minimum neutron flux to impact the neutron absorbing ability is 10{sup 10} order, however, usual neutron flux from spent fuel is 10{sup 8} order. Therefore, even though neutron absorbing material is irradiated for over 40 years, B{sup 10} content is little decreased, so, initial neutron absorbing ability could be kept continuously.

Absorber materials in CANDU PHWR's

International Nuclear Information System (INIS)

Price, E.G.; Boss, C.R.; Novak, W.Z.; Fong, R.W.L.

1995-03-01

In a CANDU reactor the fuel channels are arranged on a square lattice in a calandria filled with heavy water moderator. This arrangement allows five types of tubular neutron absorber devices to be located in a relatively benign environment of low pressure, low temperature heavy water between neighbouring rows of columns of fuel channels. This paper will describe the roles of the devices and outline the design requirements of the absorber component from a reactor physics viewpoint. Nuclear heating and activation problems associated with the different absorbers will be briefly discussed. The design and manufacture of the devices will be also discussed. The control rod absorbers and shut off materials are cadmium and stainless steel. In the tubular arrangement, the cadmium is sandwiched between stainless steel tubes. This type of device has functioned well, but there is now concern over the availability and expense of cadmium which is used in two types of CANDU control devices. There are also concerns about the toxicity of cadmium during the fabrication of the absorbers. These concerns are prompting AECL to study alternatives. To minimize design changes, pure boron-10 alloyed in stainless steel is a favoured option. Work is underway to confirm the suitability of the boron-loaded steel and identify other encapsulated absorber materials for practical application. Because the reactivity devices or their guide tubes span the calandria vessel, the long slender components must be sufficiently rigid to resist operational vibration and also be seismically stable. Some of these components are made of Zircaloy to minimize neutron absorption. Slow irradiation growth and creep can reduce the spring tension, and periodic adjustments to the springs are required. Experience with the control absorber devices has generally been good. In one instance liquid zone controllers had a problem of vibration induced fretting but a designed back-fit resolved the problem. (author). 3 refs., 1

Rational mapping (RAM) of in-core data

International Nuclear Information System (INIS)

Bonalumi, R.A.; Kherani, N.P.

1985-01-01

A unique processing of in-core flux detector data is described and demonstrated, such that the detailed in-core power distribution can be derived with great accuracy by combining a speciall ''smoothed-out'' set of in-core data with neutron diffusion theory. Rational Mapping (RAM) is designed in such a way that erratic detector signals are recognized very efficiently and can be eliminated from the experimental data set: This is achieved by modal expansion of the difference between theoretical fluxes and experimental fluxes at the detector sites. Sensitivity studies have shown that RAM is quite stable, does not absorb the ''wild'' detector error in the mapping procedure, and results in mapped fluxes with errors about three times smaller than would be obtained by direct interpolation of detector readings. A new method is described to infer corrections to theoretical core parameters based on the difference between the RAM fluxes and the theoretical fluxes

Development of highly effective neutron shields and neutron absorbing materials

International Nuclear Information System (INIS)

Tsuda, K.; Matsuda, F.; Taniuchi, H.; Yuhara, T.; Iida, T.

1993-01-01

A wide range of materials, including polymers and hydrogen-occluded alloys that might be usable as the neutron shielding material were examined. And a wide range of materials, including aluminum alloys that might be usable as the neutron-absorbing material were examined. After screening, the candidate material was determined on the basis of evaluation regarding its adaptabilities as a high-performance neutron-shielding and neutron-absorbing material. This candidate material was manufactured for trial, after which material properties tests, neutron-shielding tests and neutron-absorbing tests were carried out on it. The specifications of this material were thus determined. This research has resulted in materials of good performance; a neutron-shielding material based on ethylene propylene rubber and titanium hydride, and a neutron-absorbing material based on aluminum and titanium hydride. (author)

A high absorbance material for solar collectors' applications

International Nuclear Information System (INIS)

Oliva, A I; Maldonado, R D; Díaz, E A; Montalvo, A I

2013-01-01

In this work, we proposed a low cost material to be used as an excellent absorber for solar collectors, to increase its thermal efficiency by the high capacity to absorb solar radiation. The material, known as 'smoke black' (soot) can be obtained by the incomplete combustion of organic materials, such as the oxygen-acetylene, paraffin, or candles. A comparative analysis between the optical properties (reflectance, absorbance, and emissivity) measured on three covered copper surfaces (without paint, with a commercial matte black paint, and with smoke black) shows amazing optical results for the smoke black. Reflectance values of the smoke black applied over copper surfaces improves 56 times the values obtained from commercial black paints. High values of emissivity (E=0.9988) were measured on the surface covered with smoke black by spectrophotometry in the UV-VIS range, which represents about 7% of increment as compared with the value obtained for commercial black paints (E=0.938). The proposed high absorbance material can be easily applied on any kind of surfaces at low cost.

RAtional Mapping (RAM) of in-core data

International Nuclear Information System (INIS)

Bonalumi, R.A.; Kherani, N.P.

1983-01-01

The paper describes and demonstrates a unique processing of in-core flux detector data, such that the detailed in-core power distribution can be derived with great accuracy by combining a specially 'smoothed-out' set of in-core data with neutron diffusion theory. RAM is designed in such a way that erratic detector signals are recognized very efficiently and can be eliminated from the experimental data set: this is achieved by modal expansion of the difference between theoretical fluxes and experimental fluxes at the detector sites. Sensitivity studies have shown that RAM is quite stable, does not absorb the 'wild' detector errors in the mapping procedure and results in mapped fluxes with errors about three times smaller than would be obtained by direct interpolation of detector readings

Rumenolith formation in a Bapedi ram

Directory of Open Access Journals (Sweden)

Rhoda Leask

2012-04-01

Full Text Available During a routine flock visit, a farmer observed that one of the eight tooth Bapedi rams had been losing body condition despite being separated from the flock and fed supplementary feed. The ram’s body condition score was assessed as 2 out of 5 (one point less than the average of the rest of the rams and the teeth appeared normal with no excessive wear. The rumen was assessed by auscultation, palpation and ballottement where a foreign body (approximately 20 cm × 5 cm – 10 cm was clearly palpated and ballotted. A rumenotomy was performed and a large mass of tightly compacted foreign matter and plant material was removed. The mass consisted of synthetic fibre, plant material and calcium phosphate (50.5%. It appeared to have formed as the result of the ingestion of a synthetic fibre which formed the nidus of a concretion. This was probably the result of deficient nutrition, with the rams eating the synthetic fibre in an attempt to increase feed intake. The ram recovered uneventfully after the rumenotomy was performed and supplementary feeding.

Absorber Materials for Transition-Edge Sensor X-ray Microcalorimeters

Science.gov (United States)

Brown, Ari-David; Bandler, Simon; Brekosky, Regis; Chervenak, James; Figueroa-Feliciano, Enectali; Finkbeiner, Fred; Sadleir, Jack; Iyomoto, Naoko; Kelley, Richard; Kilbourne, Caroline;

A new neutron absorber material for criticality control

International Nuclear Information System (INIS)

Wells, Alan H.

2007-01-01

A new neutron absorber material based on a nickel metal matrix composite has been developed for applications such as the Transport, Aging, and Disposal (TAD) canister for the Yucca Mountain Project. This new material offers superior corrosion resistance to withstand the more demanding geochemical environments found in a 300,000 year to a million year repository. The lifetime of the TAD canister is currently limited to 10,000 years, reflecting the focus of current regulations embodied in 10 CFR 63. The use of DOE-owned nickel stocks from decommissioned enrichment facilities could reduce the cost compared to stainless steel/boron alloy. The metal matrix composite allows the inclusion of more than one neutron absorber compound, so that the exact composition may be adjusted as needed. The new neutron absorber material may also be used for supplementary criticality control of stored or transported PWR spent fuel by forming it into cylindrical pellets that can be inserted into a surrogate control rod. (authors)

Wide band design on the scaled absorbing material filled with flaky CIPs

Science.gov (United States)

Xu, Yonggang; Yuan, Liming; Gao, Wei; Wang, Xiaobing; Liang, Zichang; Liao, Yi

2018-02-01

The scaled target measurement is an important method to get the target characteristic. Radar absorbing materials are widely used in the low detectable target, considering the absorbing material frequency dispersion characteristics, it makes designing and manufacturing scaled radar absorbing materials on the scaled target very difficult. This paper proposed a wide band design method on the scaled absorbing material of the thin absorption coating with added carbonyl iron particles. According to the theoretical radar cross section (RCS) of the plate, the reflection loss determined by the permittivity and permeability was chosen as the main design factor. Then, the parameters of the scaled absorbing materials were designed using the effective medium theory, and the scaled absorbing material was constructed. Finally, the full-size coating plate and scaled coating plates (under three different scale factors) were simulated; the RCSs of the coating plates were numerically calculated and measured at 4 GHz and a scale factor of 2. The results showed that the compensated RCS of the scaled coating plate was close to that of the full-size coating plate, that is, the mean deviation was less than 0.5 dB, and the design method for the scaled material was very effective.

SQL-RAMS

Science.gov (United States)

Alfaro, Victor O.; Casey, Nancy J.

2005-01-01

SQL-RAMS (where "SQL" signifies Structured Query Language and "RAMS" signifies Rocketdyne Automated Management System) is a successor to the legacy version of RAMS -- a computer program used to manage all work, nonconformance, corrective action, and configuration management on rocket engines and ground support equipment at Stennis Space Center. The legacy version resided in the File-Maker Pro software system and was constructed in modules that could act as standalone programs. There was little or no integration among modules. Because of limitations on file-management capabilities in FileMaker Pro, and because of difficulty of integration of FileMaker Pro with other software systems for exchange of data using such industry standards as SQL, the legacy version of RAMS proved to be limited, and working to circumvent its limitations too time-consuming. In contrast, SQL-RAMS is an integrated SQL-server-based program that supports all data-exchange software industry standards. Whereas in the legacy version, it was necessary to access individual modules to gain insight into a particular workstatus document, SQL-RAMS provides access through a single-screen presentation of core modules. In addition, SQL-RAMS enables rapid and efficient filtering of displayed statuses by predefined categories and test numbers. SQL-RAMS is rich in functionality and encompasses significant improvements over the legacy system. It provides users the ability to perform many tasks, which in the past required administrator intervention. Additionally, many of the design limitations have been corrected, allowing for a robust application that is user centric.

Microwave Absorbent Packaging Material from Composites Chitosan-Polyvinyl Alcohol Polymer

Directory of Open Access Journals (Sweden)

Bambang - Riyanto

2014-11-01

Full Text Available Microwave absorbent packaging materials currently tend to biomaterial. Chitosan is a dielectric biomaterial with polycationic properties. The aim of this study was to analyze characteristics of microwave absorbing packaging material made from composite chitosan-polyvinyl alcohol (PVA polymer. The ability of the packaging material to absorb microwave was determined by reflection loss measurement. Formed packaging prototype resembles as a thin transparent yellowish plastic with thickness (0.11-0.22 mm and the tensile strength (106.33±2.82-143.00±2.59 kPa. SEM analysis showed homogenous structure characterized by interaction between chitosan and PVA. Optimum absorption value was obtained from chitosan concentration of 1%, with average value of reflection loss was (-31.9289±4.0094 dB.Keywords: chitosan, material packaging, microwave, reflection loss

Microwave Absorbent Packaging Material from Composites Chitosan-Polyvinyl Alcohol Polymer

Directory of Open Access Journals (Sweden)

Bambang - Riyanto

2015-07-01

Full Text Available Microwave absorbent packaging materials currently tend to biomaterial. Chitosan is a dielectric biomaterial with polycationic properties. The aim of this study was to analyze characteristics of microwave absorbing packaging material made from composite chitosan-polyvinyl alcohol (PVA polymer. The ability of the packaging material to absorb microwave was determined by reflection loss measurement. Formed packaging prototype resembles as a thin transparent yellowish plastic with thickness (0.11-0.22 mm and the tensile strength (106.33±2.82-143.00±2.59 kPa. SEM analysis showed homogenous structure characterized by interaction between chitosan and PVA. Optimum absorption value was obtained from chitosan concentration of 1%, with average value of reflection loss was (-31.9289±4.0094 dB.Keywords: chitosan, material packaging, microwave, reflection loss

RF electromagnetic wave absorbing properties of ferrite polymer composite materials

International Nuclear Information System (INIS)

Dosoudil, Rastislav; Usakova, Marianna; Franek, Jaroslav; Slama, Jozef; Olah, Vladimir

2006-01-01

The frequency dispersion of complex initial (relative) permeability (μ * =μ ' -jμ ' ') and the electromagnetic wave absorbing properties of composite materials based on NiZn sintered ferrite and a polyvinylchloride (PVC) polymer matrix have been studied in frequency range from 1MHz to 1GHz. The complex permeability of the composites was found to increase as the ferrite content increased, and was characterized by frequency dispersion localized above 50MHz. The variation of return loss (RL) of single-layer RF absorbers using the prepared composite materials has been investigated as a function of frequency, ferrite content and the thickness of the absorbers

Design of broadband absorber using 2-D materials for thermo-photovoltaic cell application

Science.gov (United States)

Agarwal, Sajal; Prajapati, Y. K.

2018-04-01

Present study is done to analyze a nano absorber for thermo-photovoltaic cell application. Optical absorbance of two-dimensional materials is exploited to achieve high absorbance. It is found that few alternating layers of graphene/transition metal dichalcogenide provide high absorbance of electromagnetic wave in visible as well as near infrared region. Four transition metal dichalcogenides are considered and found that most of these provide perfect absorbance for almost full considered wavelength range i.e. 200-1000 nm. Demonstrated results confirm the extended operating region and improved absorbance of the proposed absorber in comparison to the existing absorbers made of different materials. Further, absorber performance is improved by using thin layers of gold and chromium. Simple geometry of the proposed absorber also ensures easy fabrication.

First Exploratory Study on the Ageing of Rammed Earth Material

Science.gov (United States)

Bui, Quoc-Bao; Morel, Jean-Claude

2014-01-01

Rammed earth (RE) is attracting renewed interest throughout the world thanks to its “green” characteristics in the context of sustainable building. In this study, the ageing effects on RE material are studied on the walls which have been constructed and exposed for 22 years to natural weathering. First, mechanical characteristics of the “old” walls were determined by two approaches: in-situ dynamic measurements on the walls; laboratory tests on specimens which had been cut from the walls. Then, the walls’ soil was recycled and reused for manufacturing of new specimens which represented the initial state. Comparison between the compressive strength, the Young modulus of the walls after 22 years on site and that of the initial state enables to assess the ageing of the studied walls. PMID:28787920

Review of US accident/incident experience involving the transportation of radioactive material (RAM) 1971-1980

International Nuclear Information System (INIS)

McClure, J.D.; Emerson, E.L.

1980-01-01

This paper analyzes the transportation accidents and incidents which have occurred in the United States in the period 1971-1980 based upon the information in the Radioactive Material Transportation Accident/Incident Data Base developed by the Transportation Technology Center (TTC) at Sandia National Laboratories. The accident/incident data base incorporates the files of the Hazardous Material Incident Report (HMIR) system operated by the Material Transportation Bureau of the US Department of Transportation (DOT) with additional information obtained from the files of the US Nuclear Regulatory Commission (NRC). A principal objective of this paper is to summarize US accident/incident experience for the past ten years, providing a concise statement of radioactive material (RAM) package failure description for the transport modes of truck, rail and air

Effect of different absorbing materials on the performance of basin solar still under Libyan climate conditions

International Nuclear Information System (INIS)

Shuia, Essaied M.; El-Agouz, Elsayed A.

2013-01-01

This experimental study deals with a single-basin solar still using various absorbing materials with and without black painting. Different types of absorbing materials with and without black painting were used to enhance the solar still productivity through improvement in absorptivity. These materials are steel and aluminum with and without black painting and rubber. Two identical solar stills were manufactured using locally available materials. All the results were compared together to reach the best absorbing materials with and without painting that can be used for solar still. it was found that the rubber absorber has the highest water collection during daytime, followed by the black painted steel absorber, then by black painted aluminum absorber and steel without painting absorber. The average enhancement in the daily productivity was about 50% for the rubber absorber compared with the black painted aluminum absorber and about 43% for the rubber absorber compared with the black painted steel absorber.(author)

Characterization of rich in calcium materials using X-ray selective absorbers

International Nuclear Information System (INIS)

Guereca, G.; Ruvalcaba, J.L.

2004-01-01

For Particle Induced X-ray Emission Spectroscopy (PIXE) and X-ray Fluorescence Technique (FRX), the analysis of materials rich in one or two elements may present some difficulties due to high counting rates and saturation effects in X-ray detectors. In this case, it is possible to use selective absorbers in order to reduce the intensity of the major elements with low attenuation for the X-rays of other elements of the material. Using selective absorbers, the detection limits and the sensitivity are increased. For rich Ca materials (shells, bone, teeth and stucco, for instance), the high intensity of Ca X-rays interferes with the detection of lighter and heavier elements. Cl, Ar and Ag compounds are good candidates for Ca selective absorbers, but only Ag and Ar may have a practical absorber thickness. A selective absorber for Ca X-rays using a combination of thin Ag films and a flux of Ar and He was tested at the external beam setup of the Tandem Pelletron Accelerator for PIXE measurements. The improvement on elements detection on bone and colored stucco is shown. (Author) 8 refs., 2 tabs., 8 figs

Strategy on biological evaluation for biodegradable/absorbable materials and medical devices.

Science.gov (United States)

Liu, Chenghu; Luo, Hongyu; Wan, Min; Hou, Li; Wang, Xin; Shi, Yanping

2018-01-01

During the last two decades, biodegradable/absorbable materials which have many benefits over conventional implants are being sought in clinical practices. However, to date, it still remains obscure for us to perform full physic-chemical characterization and biological risk assessment for these materials and related devices due to their complex design and coherent processing. In this review, based on the art of knowledge for biodegradable/absorbable materials and biological risk assessment, we demonstrated some promising strategies to establish and improve the current biological evaluation systems for these biodegradable/absorbable materials and related medical devices.

FPS-RAM: Fast Prefix Search RAM-Based Hardware for Forwarding Engine

Science.gov (United States)

Zaitsu, Kazuya; Yamamoto, Koji; Kuroda, Yasuto; Inoue, Kazunari; Ata, Shingo; Oka, Ikuo

Ternary content addressable memory (TCAM) is becoming very popular for designing high-throughput forwarding engines on routers. However, TCAM has potential problems in terms of hardware and power costs, which limits its ability to deploy large amounts of capacity in IP routers. In this paper, we propose new hardware architecture for fast forwarding engines, called fast prefix search RAM-based hardware (FPS-RAM). We designed FPS-RAM hardware with the intent of maintaining the same search performance and physical user interface as TCAM because our objective is to replace the TCAM in the market. Our RAM-based hardware architecture is completely different from that of TCAM and has dramatically reduced the costs and power consumption to 62% and 52%, respectively. We implemented FPS-RAM on an FPGA to examine its lookup operation.

Atomistic mechanisms of ReRAM cell operation and reliability

Science.gov (United States)

Pandey, Sumeet C.

2018-01-01

We present results from first-principles-based modeling that captures functionally important physical phenomena critical to cell materials selection, operation, and reliability for resistance-switching memory technologies. An atomic-scale description of retention, the low- and high-resistance states (RS), and the sources of intrinsic cell-level variability in ReRAM is discussed. Through the results obtained from density functional theory, non-equilibrium Green’s function, molecular dynamics, and kinetic Monte Carlo simulations; the role of variable-charge vacancy defects and metal impurities in determining the RS, the LRS-stability, and electron-conduction in such RS is reported. Although, the statistical electrical characteristics of the oxygen-vacancy (Ox-ReRAM) and conductive-bridging RAM (M-ReRAM) are notably different, the underlying similar electrochemical phenomena describing retention and formation/dissolution of RS are being discussed.

The effect of BaM/PANI composition with epoxy paint matrix on single and double layers coating with spray coating method for radar absorbing materials applications

Science.gov (United States)

Widyastuti, Fajarin, Rindang; Pratiwi, Vania Mitha; Kholid, Rifki Rachman; Habib, Abdulloh

2018-04-01

In this study, RAM composite has been succesfully synthesized by mixing BaM as magnetic materials and PANI as conductive materials. BaM and PANI materials were prepared separately by solid state method and polymerization method, respectively. To investigated the presence of BaM phase and magnetic property of the as prepared BaM, XRD pert PAN analytical and VSM 250 Dexing Magnet were employed. Inductance Capacitance Resistance technique was carried out to measure electrical conductivity of the synthesized PANI materials. In order to further characterized the structural features of BaM and PANI, SEM-EDX FEI 850 and FTIR characterizations were conducted. RAM composite was prepared by mixing BaM and PANI powders with ultrasonic cleaner. Afterwards, VNA (Vector Network Analyzer) characterization was carried out to determine reflection loss value of RAM by applying mixed RAM composite and epoxy paint on aluminum plate using spray gun. Microscopic characterization was employed to investigated the distribution of RAM particles on the substrate. It was found that reflection loss value as low as -27.153 dB was achieved when applied 15 wt% BaM/PANi composite at 100.6 µm thickness. In addition, the absorption of electromagnetic waves value increase as the addition of RAM composite composition increases.

Optimization on microwave absorbing properties of carbon nanotubes and magnetic oxide composite materials

Science.gov (United States)

Mingdong, Chen; Huangzhong, Yu; Xiaohua, Jie; Yigang, Lu

2018-03-01

Based on the physical principle of interaction between electromagnetic field and the electromagnetic medium, the relationship between microwave absorbing coefficient (MAC) and the electromagnetic parameters of materials was established. With the composite materials of nickel ferrite (NiFe2O4), carbon nanotubes (CNTs) and paraffin as an example, optimization on absorbing properties of CNTs/magnetic oxide composite materials was studied at the frequency range of 2-18 GHz, and a conclusion is drawn that the MAC is the biggest at the same frequency, when the CNTs is 10 wt% in the composite materials. Through study on the relationship between complex permeability and MAC, another interesting conclusion is drawn that MAC is obviously affected by the real part of complex permeability, and increasing real part of complex permeability is beneficial for improving absorbing properties. The conclusion of this paper can provide a useful reference for the optimization research on the microwave absorbing properties of CNTs/ferrite composite materials.

Determining the Absorbance Spectra of Photochromic Materials From Measured Spectrophotometer Data

Science.gov (United States)

Downie, John D.

1998-01-01

If a two-state photochromic material is optically bleached, the absorbance spectrum data measured by a spectrophotometer is in general comprised of components from both the ground state and the upper state. Under general conditions, it may be difficult to extract the actual upper state spectrum from the spectrum of the bleached material. A simple algorithm is presented here for the recovery of the pure absorbance spectra of the upper state of a material such as bacteriorhodopsin, given single wavelength bleaching illumination, steady-state conditions, and accurate knowledge of phototransition rates and thermal decay rates.

Acoustic behavior of a fibrous bulk material. [Kevlar 29 sound absorber

Science.gov (United States)

Hersh, A. S.; Walker, B.

1979-01-01

A semiempirical model is presented describing the acoustic behavior of Kevlar 29, a bulk absorbing material. The model is based on an approximate solution to the one-dimensional equations representing conservation of fluctuating mass, momentum and energy. By treating the material as a momentum sink, theoretical expressions of the material complex propagation constants and characteristic impedance were derived in terms of a single constant. Evaluating the constant at a single frequency for a particular specimen, excellent agreement between prediction and measurement was achieved for a large range of sound frequencies and material porosities and thicknesses. Results show that Kevlar 29 absorbs sound efficiently even at low frequencies. This is explained in terms of a frequency dependent material phase speed.

Moisture buffering capacity of highly absorbing materials

Energy Technology Data Exchange (ETDEWEB)

Cerolini, S.; D' Orazio, M.; Stazi, A. [Department of Architecture, Construction and Structures (DACS), Faculty of Engineering, Polytechnic University of Marche, Via Brecce Bianche, 60100 Ancona (Italy); Di Perna, C. [Department of Energetics, Faculty of Engineering, Polytechnic University of Marche, Via Brecce Bianche, 60100 Ancona (Italy)

2009-02-15

This research investigates the possibility to use highly absorbing materials to dampen indoor RH% variations. The practical MBV of sodium polyacrylate, cellulose-based material, perlite and gypsum is evaluated for a daily cyclic exposure that alternates high (75%) and low (33%) RH% levels for 8 h and 16 h, respectively. The adjustment velocity to RH% variations and the presence of hysteretic phenomena are also presented. The cellulose-based material proves to be the most suitable for moisture buffering applications. Starting from this material's properties, the effect of thickness, vapour resistance factor ({mu}) and mass surface exchange coefficient (Z{sub v}) on sorption capacity is evaluated by the use of a numerical model. (author)

Excellent solar energy absorbing and retaining fabric material. Chikunetsu hoon sen'i sozai

Energy Technology Data Exchange (ETDEWEB)

Furuta, T. (Unitika Ltd., Osaka (Japan). Central Research Lab.)

1993-11-10

Carbides of group IV transition metals such as ZrC, which are used as solar energy selective absorption film for solar energy collectors, has characteristics of absorbing light with a high energy of 0.6eV or more and of converting it to heat when exposed to light, and of not absorbing but reflecting light with a low energy of less than 0.6eV. By using ZrC as fabric materials, therefore, portable and durable heat absorbing and retaining materials can be produced. The authors have developed a solar energy absorbing and retaining fabric material, 'Solar [alpha]' (registered trade mark), which absorbs visible and near infrared rays and converts them to heat, and reflects heat from a human body and confines it. The use of Solar [alpha] has been found in various fields such as clothing as a new material for winter-sportswear, slacks, coats, and swimming suits. In this report, the heat absorbing and retaining mechanisms, basic properties of Solar [alpha], and the results of wearing tests are described. 12 refs., 6 figs., 3 tabs.

A comparative study between different approaches to improve the RCS of a compact double-layer absorber

Science.gov (United States)

El-Hakim, H. A.; Mahmoud, K. R.

2017-10-01

In this paper, straightforward and efficient techniques have been addressed into double-layer structure to enlarge the operating bandwidth to include the X, Ku and K bands, in addition to increase the electromagnetic wave absorption for wide varieties of incident angles and both polarization types. To increase the band-stop resonating frequency up to 26 GHz, an additional layer of meta-surface, circuit analog radar absorber material (CAR), or a thin radar absorber material (RAM) layer is engineered. The synthesized layers are designed based on optimization process with genetic algorithm (GA) through numerical technique (Ansoft design software HFSS) for both transmission line (T.L) and the free space method to get optimal material properties suitable for the design. For different approaches, the designed structures achieved a reflectivity value less than -16 dB on average in the desired bandwidth from 8 to 26 GHz for TE/TM modes with incidence angle up to 50o.

A Field Performance Evaluation Scheme for Microwave-Absorbing Material Coatings

Directory of Open Access Journals (Sweden)

Shaopeng Guan

2017-03-01

Full Text Available Performance evaluation is an important aspect in the study of microwave-absorbing material coatings. The reflectivity of the incident wave is usually taken as the performance indicator. There have been various methods to directly or indirectly measure the reflectivity, but existing methods are mostly cumbersome and require a strict testing environment. What is more, they cannot be applied to field measurement. In this paper, we propose a scheme to achieve field performance evaluation of microwave-absorbing materials, which adopts a small H-plane sectoral horn antenna as the testing probe and a small microwave reflectometer as the indicator. When the size of the H-plane sectoral horn antenna is specially designed, the field distribution at the antenna aperture can be approximated as a plane wave similar to the far field of the microwave emitted by a radar unit. Therefore, the reflectivity can be obtained by a near-field measurement. We conducted experiments on a kind of ferrite-based microwave-absorbing material at X band (8.2–12.4 GHz to validate the scheme. The experimental results show that the reflectivity is in agreement with the reference data measured by the conventional method as a whole.

Progress of ram acceleration with ISL's RAMAC 30

Energy Technology Data Exchange (ETDEWEB)

Seiler, F.; Patz, G.; Smeets, G.; Srulijes, J. [French-German Res. Inst., Saint-Louis (France)

2000-11-01

G. Smeets (1988) published a new concept for a ram accelerator with guiding tube rails for firing rail stabilized projectiles. This concept replaces fin stabilized projectiles accelerated in a cylindrical bore. The rail tube idea offers some advantages, e.g., no sabot is necessary as required for fin guided projectiles, simple projectile geometry, and possibility of varying the inner tube geometry. This principle was tested in 1993 and 1994 in rail tube version I and is now again under investigation since the beginning of 1997 in our RAMAC 30 in version II. In the rail tube concept, circular and finless projectiles are guided in a ram-tube equipped with five inner rails. At the moment we use a ram-section with a length of about 4.8 meters. A conventional powder gun serves as pre-accelerator. In the gun tube with a length of 2.8 meters, projectiles of about 150 grams are accelerated to a muzzle velocity of approximately 1800 m/s which is the initial velocity at the entrance of the ram-section. For successful operating a ram accelerator, the heat release must be limited to avoid ''thermal choking'' followed by an ''unstart''. This choking phenomenon will be investigated in detail in this paper from the gasdynamic point of view in order to predict the right mixture for the given flow conditions around the ram projectile. Moreover, to avoid a firing failure, the material point of view must also be considered. Some recent firings have been done using aluminium, titanium and steel as test materials and its behaviour is discussed herein in detail. The first outcome is for example, for a given projectile geometry and a given gas mixture with a steel cowling no ignition occurs, whereas with aluminium or titanium as combustor surface material the ignition starts well followed by a projectile acceleration. (orig.)

Dielectric microwave absorbing material processed by impregnation of carbon fiber fabric with polyaniline

Directory of Open Access Journals (Sweden)

Luiza de Castro Folgueras

2007-03-01

Full Text Available It is a known fact that the adequate combination of components and experimental conditions may produce materials with specific requirements. This study presents the effect of carbon fiber fabric impregnation with polyaniline conducting polymer aiming at the radar absorbing material processing. The experiments consider the sample preparation with one and two impregnations. The prepared samples were evaluated by reflectivity measurements, in the frequency range of 8-12 GHz and scanning electron microscopy analyses. The correlation of the results shows that the quantity of impregnated material influences the performance of the processed microwave absorber. This study shows that the proposed experimental route provides flexible absorbers with absorption values of the incident radiation close to 87%.

Characterization of shock-absorbing material for packages

International Nuclear Information System (INIS)

Mourao, Rogerio Pimenta

2007-01-01

Since 2001 Brazil has been participating in a regional effort with other Latin American countries which operate research reactors to improve its capability in the management of spent fuel elements from these reactors. One of the options considered is the long-term dry storage of the spent fuel in a dual purpose cask, i.e., a package for the transport and storage of radioactive material. In the scope of an IAEA-sponsored project, a cask was designed and a half-scale model for test was built. The cask consists of a sturdy cylindrical body provided with internal cavity to accommodate a basket holding the spent fuel elements, a double lid system, and external impact limiters. The cask is provided with top and bottom impact limiters, which are structures made of an external stainless steel skin and an energy-absorbing filling material. The filling material chosen was the wood composite denominated Oriented Strand Board (OSB), which is an engineered, mat-formed panel product made of strands, flakes or wafers sliced from small diameter, round wood logs and bonded with a binder under heat and pressure. The characterization of this material was carried in the scope of the cask project at the CDTN's laboratories. The tests conducted were the quasi-static compression, impact, shear-bending and edgewise shear tests. The compression, shear-bending and edgewise shear tests were carried out in a standard compression test machine and the impact test at a drop test tower equipped with a sturdy base and a drop weight. The main parameters of the material, like the Young and shear moduli, as well as the static and dynamic stress-strain curves and the specific energy absorbed, were determined during the test campaign. (author)

Characterization of shock-absorbing material for packages

Energy Technology Data Exchange (ETDEWEB)

Mourao, Rogerio Pimenta [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)]. E-mail: mouraor@cdtn.br

2007-07-01

Since 2001 Brazil has been participating in a regional effort with other Latin American countries which operate research reactors to improve its capability in the management of spent fuel elements from these reactors. One of the options considered is the long-term dry storage of the spent fuel in a dual purpose cask, i.e., a package for the transport and storage of radioactive material. In the scope of an IAEA-sponsored project, a cask was designed and a half-scale model for test was built. The cask consists of a sturdy cylindrical body provided with internal cavity to accommodate a basket holding the spent fuel elements, a double lid system, and external impact limiters. The cask is provided with top and bottom impact limiters, which are structures made of an external stainless steel skin and an energy-absorbing filling material. The filling material chosen was the wood composite denominated Oriented Strand Board (OSB), which is an engineered, mat-formed panel product made of strands, flakes or wafers sliced from small diameter, round wood logs and bonded with a binder under heat and pressure. The characterization of this material was carried in the scope of the cask project at the CDTN's laboratories. The tests conducted were the quasi-static compression, impact, shear-bending and edgewise shear tests. The compression, shear-bending and edgewise shear tests were carried out in a standard compression test machine and the impact test at a drop test tower equipped with a sturdy base and a drop weight. The main parameters of the material, like the Young and shear moduli, as well as the static and dynamic stress-strain curves and the specific energy absorbed, were determined during the test campaign. (author)

Conversion of ionization measurements to radiation absorbed dose in non-water density material

International Nuclear Information System (INIS)

El-Khatib, E.; Connors, S.

1992-01-01

In bone-equivalent materials two different calculations of absorbed dose are possible: the absorbed dose to soft tissue plastic (polystyrene) within bone-equivalent material and the dose to the bone-equivalent material itself. Both can be calculated from ionization measurements in phantoms. These two calculations result in significantly different doses in a heterogeneous phantom composed of polystyrene and aluminium (a bone substitute). The dose to a thin slab of polystyrene in aluminium is much higher than the dose to the aluminium itself at the same depth in the aluminium. Monte Carlo calculations confirm that the calculation of dose to polystyrene in aluminium can be accurately carried out using existing dosimetry protocols. However, the conversion of ionization measurements to absorbed dose to high atomic number materials cannot be accurately carried out with existing protocols and appropriate conversion factors need to be determined. (author)

Nano-Ionic Solid State Resistive Memories (Re-RAM): A Review.

Science.gov (United States)

Sahoo, Satyajeet; Prabaharan, S R S

2017-01-01

Nano-ionic devices based on modest to fast ion conductors as active materials intrigued a revolution in the field of nano solid state resistive memories (the so-called Re-RAM) ever since HP labs unveiled the first solid state memristor device based on titanium dioxide (TiO2). This has brought impetus to the practical implementation of fourth missing element called “Memristor” correlating charge (q) and flux (φ) based on the conceptual thought by Chua in 1971 completing a missing gap between the passive electronic components (R, C and L). It depicts various functional features as memory element in terms of ionic charge transport in solid state by virtue of external electric flux variations. Consequently, a new avenue has been found by manipulating the ionic charge carriers creating a fast switching resistive random access memory (Re-RAM) or the so-called Memristors. The recent research has led to low power, faster switching speed, high endurance and high retention time devices that can be scaled down the order of few nanometers dimension and the 3D stacking is employed that significantly reduces the die area. This review is organized to provide the progress hitherto accomplished in the materials arena to make memristor devices with respect to current research attempts, different stack structures of ReRAM cells using various materials as well as the application of memristive system. Different synthesis approaches to make nano-ionic conducting metal oxides, the fabrication methods for ReRAM cells and its memory performance are reviewed comprehensively.

Super water-absorbing new material from chitosan, EDTA and urea.

Science.gov (United States)

Narayanan, Abathodharanan; Dhamodharan, Raghavachari

2015-12-10

A new, super water-absorbing, material is synthesized by the reaction between chitosan, EDTA and urea and named as CHEDUR. CHEDUR is probably formed through the crosslinking of chitosan molecules (CH) with the EDTA-urea (EDUR) adduct that is formed during the reaction. CHEDUR as well as the other products formed in control reactions are characterized extensively. CHEDUR exhibits a very high water uptake capacity when compared with chitosan, chitosan-EDTA adduct, as well as a commercial diaper material. A systematic study was done to find the optimum composition as well as reaction conditions for maximum water absorbing capacity. CHEDUR can play a vital role in applications that demand the rapid absorption and slow release of water such as agriculture, as a three in one new material for the slow release of urea, water and other metal ions that can be attached through the EDTA component. The other potential advantage of CHEDUR is that it can be expected to degrade in soil based on its chitosan backbone. The new material with rapid and high water uptake could also find potential applications as biodegradable active ingredient of the diaper material. Copyright © 2015 Elsevier Ltd. All rights reserved.

Porphyrin Based Near Infrared-Absorbing Materials for Organic Photovoltaics

Science.gov (United States)

Zhong, Qiwen

The conservation and transformation of energy is essential to the survival of mankind, and thus concerns every modern society. Solar energy, as an everlasting source of energy, holds one of the key solutions to some of the most urgent problems the world now faces, such as global warming and the oil crisis. Advances in technologies utilizing clean, abundant solar energy, could be the steering wheel of our societies. Solar cells, one of the major advances in converting solar energy into electricity, are now capturing people's interest all over the globe. While solar cells have been commercially available for many years, the manufacturing of solar cells is quite expensive, limiting their broad based implementation. The cost of solar cell based electricity is 15-50 cents per kilowatt hour (¢/kwh), depending on the type of solar cell, compared to 0.7 ¢/kwh for fossil fuel based electricity. Clearly, decreasing the cost of electricity from solar cells is critical for their wide spread deployment. This will require a decrease in the cost of light absorbing materials and material processing used in fabricating the cells. Organic photovoltaics (OPVs) utilize organic materials such as polymers and small molecules. These devices have the advantage of being flexible and lower cost than conventional solar cells built from inorganic semiconductors (e.g. silicon). The low cost of OPVs is tied to lower materials and fabrication costs of organic cells. However, the current power conversion efficiencies of OPVs are still below 15%, while convention crystalline Si cells have efficiencies of 20-25%. A key limitation in OPVs today is their inability to utilize the near infrared (NIR) portion of the solar spectrum. This part of the spectrum comprises nearly half of the energy in sunlight that could be used to make electricity. The first and foremost step in conversion solar energy conversion is the absorption of light, which nature has provided us optimal model of, which is

Drop Weight Device Fabrication and Tests for a Dynamic Material Property of Shock-Absorbing Material and Structure in Transportation Package

International Nuclear Information System (INIS)

Choi, Woo Seok; Jeon, Jea Eon; Han, Sang Hyeok; Lee, Sang Hoon; Seo, Ki Seok

2009-01-01

A radioactive material transportation package consists of canister and impact limiters. IAEA Safety Standard Series No. TS-R-1 recommends a drop test to evaluate the structural integrity of a transportation package under a hypothetical accident condition. The free drop test of a transportation package from 9 m height simulates one of accident conditions. The transportation package has a potential energy corresponding to 9 m drop height, and this energy changes to a kinetic energy when it impacts on the target. The energy is absorbed by a deformation of shock-absorbing material so that the minimum energy is transferred to canister. Accordingly, the shock-absorbing material is a very important part in transportation package design. Since the data for shock-absorbing material characteristics is acquired by a static test in general, it is quite different to that of dynamic characteristics. And the dynamic characteristics data is hardly found in literature. In this study, a drop weight facility was designed and fabricated which produces an impact speed like that of free drop of 9 m height. Several materials considered for an impact limiter and impact limiter structures were tested by a drop weight facility to acquire a dynamic material characteristics data

Drop Weight Device Fabrication and Tests for a Dynamic Material Property of Shock-Absorbing Material and Structure in Transportation Package

Energy Technology Data Exchange (ETDEWEB)

Choi, Woo Seok; Jeon, Jea Eon; Han, Sang Hyeok; Lee, Sang Hoon; Seo, Ki Seok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2009-05-15

A radioactive material transportation package consists of canister and impact limiters. IAEA Safety Standard Series No. TS-R-1 recommends a drop test to evaluate the structural integrity of a transportation package under a hypothetical accident condition. The free drop test of a transportation package from 9 m height simulates one of accident conditions. The transportation package has a potential energy corresponding to 9 m drop height, and this energy changes to a kinetic energy when it impacts on the target. The energy is absorbed by a deformation of shock-absorbing material so that the minimum energy is transferred to canister. Accordingly, the shock-absorbing material is a very important part in transportation package design. Since the data for shock-absorbing material characteristics is acquired by a static test in general, it is quite different to that of dynamic characteristics. And the dynamic characteristics data is hardly found in literature. In this study, a drop weight facility was designed and fabricated which produces an impact speed like that of free drop of 9 m height. Several materials considered for an impact limiter and impact limiter structures were tested by a drop weight facility to acquire a dynamic material characteristics data.

Food-processes wastewaters treatment using food solid-waste materials as adsorbents or absorbents

Science.gov (United States)

Rapti, Ilaira; Georgopoulos, Stavros; Antonopoulou, Maria; Konstantinou, Ioannis; Papadaki, Maria

2016-04-01

The wastewaters generated by olive-mills during the production of olive oil, wastewaters from a dairy and a cow-farm unit and wastewaters from a small food factory have been treated by means of selected materials, either by-products of the same units, or other solid waste, as absorbents or adsorbents in order to identify the capacity of those materials to remove organic load and toxicity from the aforementioned wastewaters. The potential of both the materials used as absorbents as well as the treated wastewaters to be further used either as fertilizers or for agricultural irrigation purposes are examined. Dry olive leaves, sheep wool, rice husks, etc. were used either in a fixed-bed or in a stirred batch arrangemen,t employing different initial concentrations of the aforementioned wastewaters. The efficiency of removal was assessed using scpectrophotometric methods and allium test phytotoxicity measurements. In this presentation the response of each material employed is shown as a function of absorbent/adsorbent quantity and kind, treatment time and wastewater kind and initial organic load. Preliminary results on the potential uses of the adsorbents/absorbents and the treated wastewaters are also shown. Keywords: Olive-mill wastewaters, dairy farm wastewaters, olive leaves, zeolite, sheep wool

Neutronic analysis of absorbing materials for the control rod system in reactor ALLEGRO

Energy Technology Data Exchange (ETDEWEB)

Cajko, Frantisek; Secansky, Michal; Chrebet, Tomas; Zajac, Radoslav; Darilek, Petr [VUJE, a.s., Trnava (Slovakia)

2016-09-15

Experimental reactor ALLEGRO is a gas cooled fast reactor in the design stage. The current design of its reactivity control system is based on control rods filled with boron carbide as the absorber. Because of disadvantages connected to high boron enrichment a possibility of using other absorbent materials was explored to lower the boron enrichment and increase the worth of the control rods. The results of neutronic Monte-Carlo analyses in a computational supercell are presented in this paper. Three absorbent materials most suitable for a use in reactor ALLEGRO (B{sub 4}C, EuB{sub 6} and ReB{sub 2}) have been analysed also in a full core model. A possible benefit of a neutron trap concept is explored as well but materials with satisfactory neutronic properties proved to be not suitable for expected high temperatures in the reactor.

Utilizing strongly absorbing materials for low-loss surface-wave nonlinear optics

Science.gov (United States)

Grosse, Nicolai B.; Franz, Philipp; Heckmann, Jan; Pufahl, Karsten; Woggon, Ulrike

2018-04-01

Optical media endowed with large nonlinear susceptibilities are highly prized for their employment in frequency conversion and the generation of nonclassical states of light. Although the presence of an optical resonance can greatly increase the nonlinear response (e.g., in epsilon-near-zero materials), the non-negligible increase in linear absorption often precludes the application of such materials in nonlinear optics. Absorbing materials prepared as thin films, however, can support a low-loss surface wave: the long-range surface exciton polariton (LRSEP). Its propagation lifetime increases with greater intrinsic absorption and reduced film thickness, provided that the film is embedded in a transparent medium (symmetric cladding). We explore LRSEP propagation in a molybdenum film by way of a prism-coupling configuration. Our observations show that excitation of the LRSEP mode leads to a dramatic increase in the yield of second-harmonic generation. This implies that the LRSEP mode is an effective vehicle for utilizing the nonlinear response of absorbing materials.

Preparation of steel slag porous sound-absorbing material using coal powder as pore former.

Science.gov (United States)

Sun, Peng; Guo, Zhancheng

2015-10-01

The aim of the study was to prepare a porous sound-absorbing material using steel slag and fly ash as the main raw material, with coal powder and sodium silicate used as a pore former and binder respectively. The influence of the experimental conditions such as the ratio of fly ash, sintering temperature, sintering time, and porosity regulation on the performance of the porous sound-absorbing material was investigated. The results showed that the specimens prepared by this method had high sound absorption performance and good mechanical properties, and the noise reduction coefficient and compressive strength could reach 0.50 and 6.5MPa, respectively. The compressive strength increased when the dosage of fly ash and sintering temperature were raised. The noise reduction coefficient decreased with increasing ratio of fly ash and reducing pore former, and first increased and then decreased with the increase of sintering temperature and time. The optimum preparation conditions for the porous sound-absorbing material were a proportion of fly ash of 50% (wt.%), percentage of coal powder of 30% (wt.%), sintering temperature of 1130°C, and sintering time of 6.0hr, which were determined by analyzing the properties of the sound-absorbing material. Copyright © 2015. Published by Elsevier B.V.

De las Greguerias: Ah, Ramón, Ramón...

Directory of Open Access Journals (Sweden)

Luis Navarro

1964-11-01

Full Text Available Yo me pregunto qué hará a hora Ramón detrás del biombo irreversible de la muerte. Me lo figuro de espaldas a la pared, con el rostro de simulada contrición y en las manos un blok sobre el que escribe eternamente, renglón tras renglón, las palabras de castigo: "No volveré a hacer burla de las cosas trascendentes". Lope, Quevedo, Goya, Solana y el Marqués de Bradomin, liberados ya de sus respectivos sambenitos en el tiempo metafísico de los muertos, intercederán por el castigado colocando en la terrible Balanza de los Cielos, a favor de Ramón, los libros ejemplares en que este habla de aquellos. Dirán al unísono: todos hablaron de mí, pero ninguno me conoció; solo Ramón.

Ram and Buck Breeding Soundness Examination

Directory of Open Access Journals (Sweden)

Ahmed TIBARY

2018-06-01

Full Text Available Male breeding soundness examination (BSE is an important component of sheep and goat farming. BSE is best performed 2 months before the breeding season and is based on clinical and physical examination as well as sperm abnormalities detection. Rams are classified based on physical examination and semen evaluation finding in one of 4 categories: Unsatisfactory, questionable, satisfactory, and excellent. The satisfactory rams will achieve good reproductive performance if joined to ewes at a ratio of 1:50 for 60 days. However exceptional rams are expected to achieve good reproductive performance at a ratio of 1 ram to 100 ewes. For Buck, scrotal circumference should be at least 25 cm for breeds weighing more than 40 kg. Buck is deemed satisfactory breeder if he passes the physical examination, and has an ejaculate with at least 50% progressively motile spermatozoa and less than 30% total sperm abnormalities. This paper reviews factors affecting fertility, sperm production and quality as well as libido and mating ability in the ram. Details of genital examination and semen evaluation and interpretation of results are discussed. Classification of rams according to their reproductive potential is presented. Specific recommendations, when available for the buck, are highlighted. The main genital diseases are presented. The most frequent culling reason for ram is epididymitis due to Brucella ovis. Systematic culling of rams with epididymitis improves flock lambing rates by 10 to 15%. Overall, the examination of the reproductive capacity in the ram and the buck is an important tool for improvement of flocks/herds fertility and prevention of contagious or hereditary diseases.

Synthesis and microwave absorbing characteristics of functionally graded carbonyl iron/polyurethane composites

Directory of Open Access Journals (Sweden)

R. B. Yang

2016-05-01

Full Text Available Radar absorbing materials (RAMs also known as microwave absorbers, which can absorb and dissipate incident electromagnetic wave, are widely used in the fields of radar-cross section reduction, electromagnetic interference (EMI reduction and human health protection. In this study, the synthesis of functionally graded material (FGM (CI/Polyurethane composites, which is fabricated with semi-sequentially varied composition along the thickness, is implemented with a genetic algorithm (GA to optimize the microwave absorption efficiency and bandwidth of FGM. For impedance matching and broad-band design, the original 8-layered FGM was obtained by the GA method to calculate the thickness of each layer for a sequential stacking of FGM from 20, 30, 40, 50, 60, 65, 70 and 75 wt% of CI fillers. The reflection loss of the original 8-layered FGM below –10 dB can be obtained in the frequency range of 5.12∼18 GHz with a total thickness of 9.66 mm. Further optimization reduces the number of the layers and the stacking sequence of the optimized 4-layered FGM is 20, 30, 65, 75 wt% with thickness of 0.8, 1.6, 0.6 and 1.0 mm, respectively. The synthesis and measurement of the optimized 4-layered FGM with a thickness of 4 mm reveal a minimum reflection loss of –25.2 dB at 6.64 GHz and its bandwidth below – 10 dB is larger than 12.8 GHz.

Corrosion resistant neutron absorbing coatings

Science.gov (United States)

Choi, Jor-Shan [El Cerrito, CA; Farmer, Joseph C [Tracy, CA; Lee, Chuck K [Hayward, CA; Walker, Jeffrey [Gaithersburg, MD; Russell, Paige [Las Vegas, NV; Kirkwood, Jon [Saint Leonard, MD; Yang, Nancy [Lafayette, CA; Champagne, Victor [Oxford, PA

2012-05-29

A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

The behavioral component of the ram effect: the influence of ram sexual behavior on the induction of estrus in anovulatory ewes.

Science.gov (United States)

Perkins, A; Fitzgerald, J A

1994-01-01

The objective of this study was to test whether the sexual behavior of the ram affects the ram effect. Rams exhibiting either high (HP) or low (LP) levels of sexual performance (on the basis of serving capacity tests) were exposed to 89 anestrous ewes for 28 d. Thirty-two anestrous ewes were not exposed to rams. The objective of this study was to compare the efficacy of estrus induction by HP (n = 4) vs LP (n = 4) rams. Plasma progesterone concentration was used as an index of ovarian activity. Groups of ewes were exposed to either an HP or an LP ram in a .32-ha pasture. Courtship behaviors of rams were recorded for 6 h on the initial day of exposure and for 30-min periods on alternate days thereafter. A greater percentage of ewes exposed to HP rams ovulated (95%) compared with ewes exposed to LP rams (78%) (P sexual behavior. These data imply that in addition to a pheromone the sexual behavior of the ram may be important in initiating ovarian cycle activity.

HyRAM V1.0 User Guide

Energy Technology Data Exchange (ETDEWEB)

Groth, Katrina M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Zumwalt, Hannah Ruth [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Clark, Andrew Jordan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-03-01

Hydrogen Risk Assessment Models (HyRAM) is a prototype software toolkit that integrates data and methods relevant to assessing the safety of hydrogen fueling and storage infrastructure. The HyRAM toolkit integrates deterministic and probabilistic models for quantifying accident scenarios, predicting physical effects, and characterizing the impact of hydrogen hazards, including thermal effects from jet fires and thermal pressure effects from deflagration. HyRAM version 1.0 incorporates generic probabilities for equipment failures for nine types of components, and probabilistic models for the impact of heat flux on humans and structures, with computationally and experimentally validated models of various aspects of gaseous hydrogen release and flame physics. This document provides an example of how to use HyRAM to conduct analysis of a fueling facility. This document will guide users through the software and how to enter and edit certain inputs that are specific to the user-defined facility. Description of the methodology and models contained in HyRAM is provided in [1]. This User’s Guide is intended to capture the main features of HyRAM version 1.0 (any HyRAM version numbered as 1.0.X.XXX). This user guide was created with HyRAM 1.0.1.798. Due to ongoing software development activities, newer versions of HyRAM may have differences from this guide.

The rapid mode of calcium uptake into heart mitochondria (RaM): comparison to RaM in liver mitochondria.

Science.gov (United States)

Buntinas, L; Gunter, K K; Sparagna, G C; Gunter, T E

2001-04-02

A mechanism of Ca(2+) uptake, capable of sequestering significant amounts of Ca(2+) from cytosolic Ca(2+) pulses, has previously been identified in liver mitochondria. This mechanism, the Rapid Mode of Ca(2+) uptake (RaM), was shown to sequester Ca(2+) very rapidly at the beginning of each pulse in a sequence [Sparagna et al. (1995) J. Biol. Chem. 270, 27510-27515]. The existence and properties of RaM in heart mitochondria, however, are unknown and are the basis for this study. We show that RaM functions in heart mitochondria with some of the characteristics of RaM in liver, but its activation and inhibition are quite different. It is feasible that these differences represent different physiological adaptations in these two tissues. In both tissues, RaM is highly conductive at the beginning of a Ca(2+) pulse, but is inhibited by the rising [Ca(2+)] of the pulse itself. In heart mitochondria, the time required at low [Ca(2+)] to reestablish high Ca(2+) conductivity via RaM i.e. the 'resetting time' of RaM is much longer than in liver. RaM in liver mitochondria is strongly activated by spermine, activated by ATP or GTP and unaffected by ADP and AMP. In heart, RaM is activated much less strongly by spermine and unaffected by ATP or GTP. RaM in heart is strongly inhibited by AMP and has a biphasic response to ADP; it is activated at low concentrations and inhibited at high concentrations. Finally, an hypothesis consistent with the data and characteristics of liver and heart is presented to explain how RaM may function to control the rate of oxidative phosphorylation in each tissue. Under this hypothesis, RaM functions to create a brief, high free Ca(2+) concentration inside mitochondria which may activate intramitochondrial metabolic reactions with relatively small amounts of Ca(2+) uptake. This hypothesis is consistent with the view that intramitochondrial [Ca(2+)] may be used to control the rate of ADP phosphorylation in such a way as to minimize the probability of

Ram-pressure feeding of supermassive black holes.

Science.gov (United States)

Poggianti, Bianca M; Jaffé, Yara L; Moretti, Alessia; Gullieuszik, Marco; Radovich, Mario; Tonnesen, Stephanie; Fritz, Jacopo; Bettoni, Daniela; Vulcani, Benedetta; Fasano, Giovanni; Bellhouse, Callum; Hau, George; Omizzolo, Alessandro

2017-08-16

When a supermassive black hole at the centre of a galaxy accretes matter, it gives rise to a highly energetic phenomenon: an active galactic nucleus. Numerous physical processes have been proposed to account for the funnelling of gas towards the galactic centre to feed the black hole. There are also several physical processes that can remove gas from a galaxy, one of which is ram-pressure stripping by the hot gas that fills the space between galaxies in galaxy clusters. Here we report that six out of a sample of seven 'jellyfish' galaxies-galaxies with long 'tentacles' of material that extend for dozens of kiloparsecs beyond the galactic disks-host an active nucleus, and two of them also have galactic-scale ionization cones. The high incidence of nuclear activity among heavily stripped jellyfish galaxies may be due to ram pressure causing gas to flow towards the centre and triggering the activity, or to an enhancement of the stripping caused by energy injection from the active nucleus, or both. Our analysis of the galactic position and velocity relative to the cluster strongly supports the first hypothesis, and puts forward ram pressure as another possible mechanism for feeding the central supermassive black hole with gas.

RAMS (Risk Analysis - Modular System) methodology

Energy Technology Data Exchange (ETDEWEB)

Stenner, R.D.; Strenge, D.L.; Buck, J.W. [and others

1996-10-01

The Risk Analysis - Modular System (RAMS) was developed to serve as a broad scope risk analysis tool for the Risk Assessment of the Hanford Mission (RAHM) studies. The RAHM element provides risk analysis support for Hanford Strategic Analysis and Mission Planning activities. The RAHM also provides risk analysis support for the Hanford 10-Year Plan development activities. The RAMS tool draws from a collection of specifically designed databases and modular risk analysis methodologies and models. RAMS is a flexible modular system that can be focused on targeted risk analysis needs. It is specifically designed to address risks associated with overall strategy, technical alternative, and `what if` questions regarding the Hanford cleanup mission. RAMS is set up to address both near-term and long-term risk issues. Consistency is very important for any comparative risk analysis, and RAMS is designed to efficiently and consistently compare risks and produce risk reduction estimates. There is a wide range of output information that can be generated by RAMS. These outputs can be detailed by individual contaminants, waste forms, transport pathways, exposure scenarios, individuals, populations, etc. However, they can also be in rolled-up form to support high-level strategy decisions.

Time-bin quantum RAM

Science.gov (United States)

Moiseev, E. S.; Moiseev, S. A.

2016-11-01

We have proposed a compact scheme of quantum random access memory (qRAM) based on the impedance matched multi-qubit photon echo quantum memory incorporated with the control four-level atom in two coupled QED cavities. A set of matching conditions for basic physical parameters of the qRAM scheme that provides an efficient quantum control of the fast single photon storage and readout has been found. In particular, it has been discovered that the efficient qRAM operations are determined by the specific properties of the excited photonic molecule coupling the two QED cavities. Herein, the maximal efficiency of the qRAM is realized when the cooperativity parameter of the photonic molecule equals to unity that can be experimentally achievable. We have also elaborated upon the new quantum address scheme where the multi-time-bin photon state is used for the control of the four-level atom during the readout of the photonic qubits from the quantum memory. The scheme reduces the required number of logical elements to one. Experimental implementation by means of current quantum technologies in the optical and microwave domains is also discussed.

Investigation of advanced propulsion technologies: The RAM accelerator and the flowing gas radiation heater

Science.gov (United States)

Bruckner, A. P.; Knowlen, C.; Mattick, A. T.; Hertzberg, A.

1992-01-01

The two principal areas of advanced propulsion investigated are the ram accelerator and the flowing gas radiation heater. The concept of the ram accelerator is presented as a hypervelocity launcher for large-scale aeroballistic range applications in hypersonics and aerothermodynamics research. The ram accelerator is an in-bore ramjet device in which a projectile shaped like the centerbody of a supersonic ramjet is propelled in a stationary tube filled with a tailored combustible gas mixture. Combustion on and behind the projectile generates thrust which accelerates it to very high velocities. The acceleration can be tailored for the 'soft launch' of instrumented models. The distinctive reacting flow phenomena that have been observed in the ram accelerator are relevant to the aerothermodynamic processes in airbreathing hypersonic propulsion systems and are useful for validating sophisticated CFD codes. The recently demonstrated scalability of the device and the ability to control the rate of acceleration offer unique opportunities for the use of the ram accelerator as a large-scale hypersonic ground test facility. The flowing gas radiation receiver is a novel concept for using solar energy to heat a working fluid for space power or propulsion. Focused solar radiation is absorbed directly in a working gas, rather than by heat transfer through a solid surface. Previous theoretical analysis had demonstrated that radiation trapping reduces energy loss compared to that of blackbody receivers, and enables higher efficiencies and higher peak temperatures. An experiment was carried out to measure the temperature profile of an infrared-active gas and demonstrate the effect of radiation trapping. The success of this effort validates analytical models of heat transfer in this receiver, and confirms the potential of this approach for achieving high efficiency space power and propulsion.

Characterization of weak, fair and strong neutron absorbing materials by means of neutron transmission: Beam hardening effect

Science.gov (United States)

Kharfi, F.; Bastuerk, M.; Boucenna, A.

2006-09-01

The characterization of neutron absorbing materials as well as quantification of neutron attenuation through matter is very essential in various fields, namely in shielding calculation. The objective of this work is to describe an experimental procedure to be used for the determination of neutron transmission through different materials. The proposed method is based on the relation between the gray value measured on neutron radiography image and the corresponding inducing neutron beam. For such a purpose, three kinds of materials (in shape of plate) were investigated using thermal neutrons: (1) boron-alloyed stainless steel as strong absorber; (2) copper and steel as fair absorbers and (3) aluminum as weak absorber. This work is not limited to the determination of neutron transmission through matters; it is also spread out to the measure of the surface density of the neutron absorbing elements (ρs) as a function of thickness of neutron absorbing material such as boron-alloyed stainless steel. The beam hardening effect depending on material thickness was also studied using the neutron transmission measurements. A theoretical approach was used to interpret the experimental results. The neutron transmission measurements were performed at the Neutron Radiography and Tomography facility of the Atomic Institute of the Austrian Universities in Vienna. Finally, a Maxwellian neutron distribution of incident neutron beam was used in the theoretical calculations of neutron energy shift in order to compare with experiments results. The obtained experimental results are in a good agreement with the developed theoretical approach.

Computed phase equilibria for burnable neutron absorbing materials for advanced pressurized heavy water reactors

Energy Technology Data Exchange (ETDEWEB)

Corcoran, E.C. [Department of Chemistry and Chemical Engineering, Royal Military College of Canada, P.O. Box 17000, St. Forces, Kingston, Ont., K7K 7B4 (Canada)], E-mail: emily.corcoran@rmc.ca; Lewis, B.J.; Thompson, W.T. [Department of Chemistry and Chemical Engineering, Royal Military College of Canada, P.O. Box 17000, St. Forces, Kingston, Ont., K7K 7B4 (Canada); Hood, J. [Atomic Energy of Canada Ltd., Sheridan Park, 2251 Speakman Drive, Mississauga, Ont., L5K 1B2 (Canada); Akbari, F.; He, Z. [Atomic Energy of Canada Ltd., Chalk River Laboratories, Chalk River, Ont., K0J 1J0 (Canada); Reid, P. [Atomic Energy of Canada Ltd., Sheridan Park, 2251 Speakman Drive, Mississauga, Ont., L5K 1B2 (Canada)

2009-03-31

Burnable neutron absorbing materials are expected to be an integral part of the new fuel design for the Advanced CANDU [CANDU is as a registered trademark of Atomic Energy of Canada Limited.] Reactor. The neutron absorbing material is composed of gadolinia and dysprosia dissolved in an inert cubic-fluorite yttria-stabilized zirconia matrix. A thermodynamic model based on Gibbs energy minimization has been created to provide estimated phase equilibria as a function of composition and temperature. This work includes some supporting experimental studies involving X-ray diffraction.

A state-of-the-art report on the development of B{sub 4}C materials as neutron absorbers

Energy Technology Data Exchange (ETDEWEB)

Jung, Choong Hwan; Kim, Sun Jae; Park, Jee Yun; Kang, Dae Kab [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1994-01-01

Boron of 10 atomic weight is one of the best neutron absorbing elements. Among the boron compounds, B{sub 4}C and its composites exhibit excellent material properties. Those materials absorb thermal and fast neutrons, are thermally and chemically very stable, and are very strong in mechanical properties. By neutron irradiation B-10 transforms into Li releasing one He atom. This He release causes swelling, cracking and fragmentation of B{sub 4}C bulks and results in degradation of the materials. The essence of technical developments of B{sub 4}C-based neutron absorbers is the minimization of the effects of He release, and this can be realized through microstructural optimizations of grain and porosity distributions. While pure B{sub 4}C is very difficult in sintering, new neutron absorbing materials of B{sub 4}C-cermets are being developed. B{sub 4}C-cermets are composite materials in which B{sub 4}C powders are dispersed in the metal matrix of Al or Cu. Those materials show easiness in sintering, mechanical forming, and B{sub 4}C content controlling. Neutron absorbing and shielding materials play an important role for the safety of reactor operations and environmental protections. Those materials are being used as monolithic pellets for control rods, burnable poison fuel rods, rack materials for spent fuel storages, shielding materials for shipping casks, and especially for shielding plates for liquid metal reactors. 37 figs., 12 tabs., 41 refs. (Author).

Broadband transmission noise reduction of smart panels featuring piezoelectric shunt circuits and sound-absorbing material.

Science.gov (United States)

Kim, Jaehwan; Lee, Joong-Kuen

2002-09-01

The possibility of a broadband noise reduction of piezoelectric smart panels is experimentally studied. A piezoelectric smart panel is basically a plate structure on which piezoelectric patches with electrical shunt circuits are mounted and sound-absorbing material is bonded on the surface of the structure. Sound-absorbing material can absorb the sound transmitted at the midfrequency region effectively while the use of piezoelectric shunt damping can reduce the transmission at resonance frequencies of the panel structure. To be able to reduce the sound transmission at low panel resonance frequencies, piezoelectric damping using the measured electrical impedance model is adopted. A resonant shunt circuit for piezoelectric shunt damping is composed of resistor and inductor in series, and they are determined by maximizing the dissipated energy through the circuit. The transmitted noise-reduction performance of smart panels is tested in an acoustic tunnel. The tunnel is a square cross-sectional tube and a loudspeaker is mounted at one side of the tube as a sound source. Panels are mounted in the middle of the tunnel and the transmitted sound pressure across panels is measured. When an absorbing material is bonded on a single plate, a remarkable transmitted noise reduction in the midfrequency region is observed except for the fundamental resonance frequency of the plate. By enabling the piezoelectric shunt damping, noise reduction is achieved at the resonance frequency as well. Piezoelectric smart panels incorporating passive absorbing material and piezoelectric shunt damping is a promising technology for noise reduction over a broadband of frequencies.

Liver Regeneration After Portal Vein Embolization Using Absorbable and Permanent Embolization Materials in a Rabbit Model

NARCIS (Netherlands)

van den Esschert, Jacomina W.; van Lienden, Krijn P.; Alles, Lindy K.; van Wijk, Albert C.; Heger, Michal; Roelofs, Joris J.; van Gulik, Thomas M.

2012-01-01

Objective: To compare the safety and hypertrophy response after portal vein embolization (PVE) using 2 absorbable and 3 permanent embolization materials. Background: Portal vein embolization is used to increase future remnant liver volume preoperatively. Application of temporary, absorbable

Shock absorber

International Nuclear Information System (INIS)

Housman, J.J.

1978-01-01

A shock absorber is described for use in a hostile environment at the end of a blind passage for absorbing impact loads. The shock absorber includes at least one element which occupies the passage and which is comprised of a porous brittle material which is substantially non-degradable in the hostile environment. A void volume is provided in the element to enable the element to absorb a predetermined level of energy upon being crushed due to impact loading

Neutron absorbers and methods of forming at least a portion of a neutron absorber

Energy Technology Data Exchange (ETDEWEB)

Guillen, Donna P; Porter, Douglas L; Swank, W David; Erickson, Arnold W

2014-12-02

Methods of forming at least a portion of a neutron absorber include combining a first material and a second material to form a compound, reducing the compound into a plurality of particles, mixing the plurality of particles with a third material, and pressing the mixture of the plurality of particles and the third material. One or more components of neutron absorbers may be formed by such methods. Neutron absorbers may include a composite material including an intermetallic compound comprising hafnium aluminide and a matrix material comprising pure aluminum.

Summary of the CERN Workshop on Materials for Collimators and Beam Absorbers

CERN Document Server

Schmidt, R; Bertarelli, A; Ferrari, A; Weterings, W; Mokhov, N V

2008-01-01

The main focus of the workshop was on collimators and beam absorbers for (mainly) High Energy Hadron Accelerators, with the energy stored in the beams far above damage limit. The objective was to better understand the technological limits imposed by mechanisms related to beam impact on materials. The idea to organise this workshop came up during the High Intensity High Brightness Hadron Beams, ICFA-HB2006 in Japan [1]. The workshop was organised 3-5 September 2007 at CERN, with about 60 participants, including 20 from outside CERN. About 30 presentations were given [2]. The event was driven by the LHC challenge, with more than 360 MJoule stored in each proton beam. The entire beam or its fraction will interact with LHC collimators and beam absorbers, and with the LHC beam dump blocks. Collimators and beam absorbers are also of the interest for other labs and accelerators: - CERN: for the CNGS target, for SPS beam absorbers (extraction protection) and collimators for protecting the transfer line between SPS an...

Laser-propelled ram accelerator

Energy Technology Data Exchange (ETDEWEB)

Sasoh, A. [Tohoku Univ., Sendai (Japan). Inst. of Fluid Science

2000-11-01

The concept of 'laser-propelled ram accelerator (L-RAMAC)' is proposed. Theoretically it is capable of achieving a higher launch speed than that by a chemical ram accelerator because a higher specific energy can be input to the propellant gas. The laser beam is supplied through the muzzle, focused as an annulus behind the base of the projectile. The performance of L-RAMAC is analized based on generalized Rankine-Hugoniot relations, suggesting that a superorbital muzzle speed is achievable out of this device. (orig.)

Producing of Impedance Tube for Measurement of Acoustic Absorption Coefficient of Some Sound Absorber Materials

Directory of Open Access Journals (Sweden)

R. Golmohammadi

2008-04-01

Full Text Available Introduction & Objective: Noise is one of the most important harmful agents in work environment. In spit of industrial improvements, exposure with over permissible limit of noise is counted as one of the health complication of workers. In Iran, do not exact information of the absorption coefficient of acoustic materials. Iranian manufacturer have not laboratory for measured of sound absorbance of their products, therefore using of sound absorber is limited for noise control in industrial and non industrial constructions. The goal of this study was to design an impedance tube based on pressure method for measurement of the sound absorption coefficient of acoustic materials.Materials & Methods: In this study designing of measuring system and method of calculation of sound absorption based on a available equipment and relatively easy for measurement of the sound absorption coefficient related to ISO10534-1 was performed. Measuring system consist of heavy asbestos tube, a pure tone sound generator, calibrated sound level meter for measuring of some commonly of sound absorber materials was used. Results: In this study sound absorption coefficient of 23 types of available acoustic material in Iran was tested. Reliability of results by three repeat of measurement was tested. Results showed that the standard deviation of sound absorption coefficient of study materials was smaller than .Conclusion: The present study performed a necessary technology of designing and producing of impedance tube for determining of acoustical materials absorption coefficient in Iran.

Enhancing the Performance of the Microwave Absorbing Materials by Using Dielectric Resonator Arrays

Directory of Open Access Journals (Sweden)

Omar H. Al-Zoubi

2017-01-01

Full Text Available We present a technique for enhancing the performance of microwave absorbing materials in terms of weight, thickness, and bandwidth. The introduced technique is based on fabricating the microwave absorbing (MA material in a structure comprised of an array of circular cylinder dielectric resonators (CDR backed by a perfect electric conductor (PEC ground plane. Numerical electromagnetic methods are employed to study the properties of the proposed MA array structures, where 3D full wave simulation using finite-element method is implemented. The obtained results show that the performance of the MA-CDR arrays significantly outperforms that of a flat layer composed of the same material and having equivalent thickness. A flat layer of MA material with thickness of 5 mm backed by perfect electric conductor (PEC shows as low as -50 dB reflection loss (RL peak and ~3 GHz 10-dB bandwidth, whereas an MA-CDR array, composed of the same MA material, of height of 4 mm can achieve as low as ~−50 dB RL peak and ~12 GHz 10-dB RL bandwidth.

Memoria RAM

DEFF Research Database (Denmark)

Cruz Suárez, Juan Carlos

2013-01-01

The present study intends to open a new theoretical means of analysis within the field of comparative memories. Through the metaphorical designation of RAM memory we will try to observe the continuous circulation of social discourses related to the collective memory of a particular community. Thi...

Incentives for use of inelastic analysis in RAM transport container design

International Nuclear Information System (INIS)

Ammerman, D.J.; Heinstein, M.W.

1992-01-01

The use of inelastic analysis methods instead of the traditional elastic analysis methods in the design of radioactive material (RAM) transport packagings leads to a better understanding of the response ofthe package to mechanical loadings. Thus, better assessment of the containment, thermal protection, and shielding integrity of the package after a structural accident event can be made. A more accurate prediction of the package response can lead to enhanced safety and also allow for a more efficient use of materials, possibly leading to a package with higher capacity and/or lower weight. This paper discusses the incentives for using inelastic analysis in the design of RAM shipping packages. Inelastic analysis provides an improved knowledge of the package behavior. It must be demonstrated that the use of inelastic analysis provides a better design to overcome the difficulties associated with this type of analysis. In this paper, comparisons between elastic and inelastic analyses are made to illustrate the differences in the two analysis techniques for two different types of packages. One is a package to transport a large quantity of RAM by rail with lead gamma shielding,and the other is a package to transport RAM by truck with depleteduranium gamma shielding. Analyses of the center-of-gravity-over-corner impacts will be compared for each package. The comparisons indicate thata package designed to just meet the elastic design criteria will actually undergo some yielding in the locations of highest stress. This results in two consequences in the predicted behavior of the cask. First,the overprediction of the stiffness of these yielded regions by theelastic analysis technique results in an underestimation of the stresses in other portions of the structure. Secondly, in an inelastic analysis, the yielding of a portion of a structure causes the force in thatregion to rise less rapidly than forces in adjacent regions

Architecture of the sperm whale forehead facilitates ramming combat

Directory of Open Access Journals (Sweden)

Olga Panagiotopoulou

2016-04-01

Full Text Available Herman Melville’s novel Moby Dick was inspired by historical instances in which large sperm whales (Physeter macrocephalus L. sank 19th century whaling ships by ramming them with their foreheads. The immense forehead of sperm whales is possibly the largest, and one of the strangest, anatomical structures in the animal kingdom. It contains two large oil-filled compartments, known as the “spermaceti organ” and “junk,” that constitute up to one-quarter of body mass and extend one-third of the total length of the whale. Recognized as playing an important role in echolocation, previous studies have also attributed the complex structural configuration of the spermaceti organ and junk to acoustic sexual selection, acoustic prey debilitation, buoyancy control, and aggressive ramming. Of these additional suggested functions, ramming remains the most controversial, and the potential mechanical roles of the structural components of the spermaceti organ and junk in ramming remain untested. Here we explore the aggressive ramming hypothesis using a novel combination of structural engineering principles and probabilistic simulation to determine if the unique structure of the junk significantly reduces stress in the skull during quasi-static impact. Our analyses indicate that the connective tissue partitions in the junk reduce von Mises stresses across the skull and that the load-redistribution functionality of the former is insensitive to moderate variation in tissue material parameters, the thickness of the partitions, and variations in the location and angle of the applied load. Absence of the connective tissue partitions increases skull stresses, particularly in the rostral aspect of the upper jaw, further hinting of the important role the architecture of the junk may play in ramming events. Our study also found that impact loads on the spermaceti organ generate lower skull stresses than an impact on the junk. Nevertheless, whilst an impact on the

Architecture of the sperm whale forehead facilitates ramming combat.

Science.gov (United States)

Panagiotopoulou, Olga; Spyridis, Panagiotis; Mehari Abraha, Hyab; Carrier, David R; Pataky, Todd C

2016-01-01

Herman Melville's novel Moby Dick was inspired by historical instances in which large sperm whales (Physeter macrocephalus L.) sank 19th century whaling ships by ramming them with their foreheads. The immense forehead of sperm whales is possibly the largest, and one of the strangest, anatomical structures in the animal kingdom. It contains two large oil-filled compartments, known as the "spermaceti organ" and "junk," that constitute up to one-quarter of body mass and extend one-third of the total length of the whale. Recognized as playing an important role in echolocation, previous studies have also attributed the complex structural configuration of the spermaceti organ and junk to acoustic sexual selection, acoustic prey debilitation, buoyancy control, and aggressive ramming. Of these additional suggested functions, ramming remains the most controversial, and the potential mechanical roles of the structural components of the spermaceti organ and junk in ramming remain untested. Here we explore the aggressive ramming hypothesis using a novel combination of structural engineering principles and probabilistic simulation to determine if the unique structure of the junk significantly reduces stress in the skull during quasi-static impact. Our analyses indicate that the connective tissue partitions in the junk reduce von Mises stresses across the skull and that the load-redistribution functionality of the former is insensitive to moderate variation in tissue material parameters, the thickness of the partitions, and variations in the location and angle of the applied load. Absence of the connective tissue partitions increases skull stresses, particularly in the rostral aspect of the upper jaw, further hinting of the important role the architecture of the junk may play in ramming events. Our study also found that impact loads on the spermaceti organ generate lower skull stresses than an impact on the junk. Nevertheless, whilst an impact on the spermaceti organ would

Recognition of a heritage in danger: rammed-earth architecture in Lyon city, France

Science.gov (United States)

Alex, Dorothée

2018-04-01

Historically, man has built with what he had underfoot: if the earthen construction is a tradition of 11 000 years old, the technique of the rammed earth (earth rammed in a formwork) is relatively new since it appeared for the first time in Tunisia in 814 BC. Exported in France, rammed earth is established mainly in Rhône-Alpes Region which has an ideal soil, rich in gravel, sand, silt and clay. Traditionally associated with the rural world, rammed earth heritage is also present in urban centers. The city of Lyon is one of the rare European cities to concentrate a large proportion of rammed earth buildings: the inventories made show that they are present in almost all the districts as well as in the suburban areas. This high density could be explained by the phenomenon of rural exodus experienced by Lyon during the nineteenth century. The agricultural populations, attracted by the prosperity of the city, then settled at the doors of this city, bringing their know-how by building with the cheaper and easier material available: earth. Rammed earth buildings are therefore located on bounder areas between the countryside and the city. They are thus found on lands that were once outside the city walls. With the advent of the industrial era at the end of the 19th century and the appearance of concrete, rammed earth constructions gradually disappeared. The constructions that we see today are therefore prior to 1900. Varied, ranging from detached houses to the 6-storey buildings, they stand as a testimony to a know-how that finds a particular resonance today, while the environmental and economic concerns are at the forefront. Little known, they constitute a heritage in danger that should be rediscovered.

RAMS data collection under Arctic conditions

International Nuclear Information System (INIS)

Barabadi, Abbas; Tobias Gudmestad, Ove; Barabady, Javad

2015-01-01

Reliability, availability, maintainability and supportability analysis is an important step in the design and operation of production processes and technology. Historical data such as time between failures and time to repairs play an important role in such analysis. The data must reflect the conditions that equipment has experienced during its operating time. To have a precise understanding of the conditions experienced, all influence factors on the failure and repair processes of a production facility in Arctic environment need to be identified and collected in the database. However, there is a lack of attention to collect the effect of influence factors in the reliability, availability, maintainability and supportability database. Hence, the aim of this paper is to discuss the challenges of the available methods of data collection and suggest a methodology for data collection considering the effect of environmental conditions. Application of the methodology will make the historical RAMS data of a system more applicable and useful for the design and operation of the system in different types of operational environments. - Highlights: • The challenges related to use of the available RAMS data is discussed. • It is important to collect information about operational condition in RAMS data. • A methodology for RAMS data collection considering environment condition is suggested. • Information about influence factors will make the result of RAMS analysis more applicable

Study of the effects of breed on some innate immunity parameters in rams

Directory of Open Access Journals (Sweden)

Genova Krasimira

2013-09-01

Full Text Available Investigations were carried out on 26 rams from the breeds Karakachan and Copper-Red Shoumen. The non-specific immune parameters, phagocytic activity of leukocytes, bactericidal activity of phagocytes systems (oxygen-dependent and oxygen independent and total plasma protein level were evaluated. Phagocytic response was evaluated against S. aureus 209-P with a certain percentage of active phagocytes (phagocytic index and the number of absorbed particles per one phagocytic cells (phagocyte number. Phagocytosis completion index was defined as the percentage of the microbial cells that have been destroyed by phagocytes after incubation. State of the oxygen-dependent bactericidal systems of phagocytes was assessed in vitro using the NBT test, which reflects the ability of superoxide restore NBT in diphormazane. NBT test was evaluated by the degree of reduction in spontaneous and stimulated reactions, taking into account the intracellular deposits diphormazane. Our studies and results shows that the rams from the two local Bulgarian breeds have a high activity of innate immune parameters and that’s may be useful and important in the breeding programs as an indicator of resistance and highly tolerance to oxidative stress.

The role of absorbent building materials in moderating changes of relative humidity

DEFF Research Database (Denmark)

Padfield, Tim

The problem studied in this work is, how porous, absorbent materials surroundning or placed in a room influence the relative humidity of the room. This is of interest in designing precautions and machinery to monitor the indoor climate in museums and dwelling rooms. - A novel technique for the in...

Recycling ceramic industry wastes in sound absorbing materials

Directory of Open Access Journals (Sweden)

C. Arenas

2016-10-01

Full Text Available The scope of this investigation is to develop a material mainly composed (80% w/w of ceramic wastes that can be applied in the manufacture of road traffic noise reducing devices. The characterization of the product has been carried out attending to its acoustic, physical and mechanical properties, by measuring the sound absorption coefficient at normal incidence, the open void ratio, density and compressive strength. Since the sound absorbing behavior of a porous material is related to the size of the pores and the thickness of the specimen tested, the influence of the particle grain size of the ceramic waste and the thickness of the samples tested on the properties of the final product has been analyzed. The results obtained have been compared to a porous concrete made of crushed granite aggregate as a reference commercial material traditionally used in similar applications. Compositions with coarse particles showed greater sound absorption properties than compositions made with finer particles, besides presenting better sound absorption behavior than the reference porous concrete. Therefore, a ceramic waste-based porous concrete can be potentially recycled in the highway noise barriers field.

Transport of RAM in tanks: how to fit into the IAEA safety philosophy

International Nuclear Information System (INIS)

Schulz-Forberg, B.; Ulrich, A.

1983-01-01

The transport of radioactive materials (RAM) in tanks will become a field of increasing interest. Especially for substances with low radioactive hazard but may be with subsidary risks which can overrule the RAM-philosophy. The IAEA should pay attention to the problem whether to take over a more active part in the non-nuclear field of transport regulations by influencing and using the outcome of RAM transport conditions or to incorporate some or all provisions for tank transport in their own regulations. The necessity to solve the problems of shipments of substances with low radioactive hazards but high chemical hazards is highlighted by the requirements for UF 6 -cylinders. Up to now UF 6 is listed in class 7 only, but the IAEA requirements for large UF 6 cylinders don't come up to the level of requirements needed for the toxic and corrosive nature of UF 6 . 5 references

Decontamination of skin exposed to nanocarriers using an absorbent textile material and PEG-12 dimethicone

International Nuclear Information System (INIS)

Lademann, J; Richter, H; Knorr, F; Baier, G; Landfester, K; Frazier, L; Gefeller, H; Wunderlich, U; Gross, I; Rühl, E

2014-01-01

The removal of noxious particulate contaminants such as pollutants derived from particle-to-gas conversions from exposed skin is essential to avoid the permeation of potentially harmful substances into deeper skin layers via the stratum corneum or the skin appendages and their dispersion throughout the circulatory system. This study is aimed at evaluating the efficacy of using the silicone glycol polymer PEG-12 dimethicone and an absorbent textile material to remove fluorescing hydroxyethyl starch nanocapsules implemented as model contaminants from exposed porcine ear skin. Using laser scanning microscopy, it could be shown that while the application and subsequent removal of the absorbent textile material alone did not result in sufficient decontamination, the combined application with PEG-12 dimethicone almost completely eliminated the nanocapsules from the surface of the skin. By acting as a wetting agent, PEG-12 dimethicone enabled the transfer of the nanocapsules into a liquid phase which was taken up by the absorbent textile material. Only traces of fluorescence remained detectable in several skin furrows and follicular orifices, suggesting that the repeated implementation of the procedure may be necessary to achieve total skin surface decontamination. (letter)

Review of Mid- to High-Temperature Solar Selective Absorber Materials

Energy Technology Data Exchange (ETDEWEB)

Kennedy, C. E.

2002-07-01

This report describes the concentrating solar power (CSP) systems using solar absorbers to convert concentrated sunlight to thermal electric power. It is possible to achieve solar absorber surfaces for efficient photothermal conversion having high solar absorptance (a) for solar radiation and a low thermal emittance (e) at the operational temperature. A low reflectance (?'' 0) at wavelengths (?) 3 mm and a high reflectance (?'' 1) at l 3 mm characterize spectrally selective surfaces. The operational temperature ranges of these materials for solar applications can be categorized as low temperature (T< 100 C), mid-temperature (100 C< T< 400 C), and high-temperature (T> 400 C). High- and mid-temperature applications are needed for CSP applications. For CSP applications, the ideal spectrally selective surface would be low-cost and easy to manufacture, chemically and thermally stable in air at elevated operating temperatures (T= 500 C), and have a solar absorptance= 0.98 and a thermal emittance= 0.05 at 500 C.

Effect of breed and age on sexual behaviour of rams.

Science.gov (United States)

Simitzis, Panagiotis E; Deligeorgis, Stelios G; Bizelis, Joseph A

2006-05-01

The objective of this study was to highlight the problems that arise during the reproduction between thin-tailed rams and fat-tailed ewes. At the same time, particular emphasis laid on the influence of sheep breed, sheep age, time after ram introduction and day of the ewe estrus cycle on ram and ewe sexual behaviour. Rams were subjected to sexual performance tests by being individually exposed to 12 ewes for 3 h daily, 19 consecutive days. The 16 rams of the experiment were separated according to their age (9 and 21 months old) and breed (Chios and Karagouniki), and the 96 ewes of Chios fat-tailed breed, were divided by age (9 and 21 months old). The main characteristics of courtship behaviour, like sniffing, nudging, flehmen response and following were recorded and studied in detail. Mature Chios rams, which were the only one with previous experience of Chios ewes, exhibited higher rates of sexual interest per ewe than the other rams (P nudged more young than mature ewes (P behaviour when they courted with Chios fat-tailed ewes in comparison with Chios rams (P behaviour components decreased (P < 0.001). Finally, the effect of the day of the experiment was only significant in the case of sniffing, which increased during the first 2 days and then declined and stabilized (P < 0.01). As it was demonstrated, ram age and ram breed played a fundamental role in the exhibition of sexual interest elements.

Standard specification for boron-Based neutron absorbing material systems for use in nuclear spent fuel storage racks

CERN Document Server

American Society for Testing and Materials. Philadelphia

2011-01-01

1.1 This specification defines criteria for boron-based neutron absorbing material systems used in racks in a pool environment for storage of nuclear light water reactor (LWR) spent-fuel assemblies or disassembled components to maintain sub-criticality in the storage rack system. 1.2 Boron-based neutron absorbing material systems normally consist of metallic boron or a chemical compound containing boron (for example, boron carbide, B4C) supported by a matrix of aluminum, steel, or other materials. 1.3 In a boron-based absorber, neutron absorption occurs primarily by the boron-10 isotope that is present in natural boron to the extent of 18.3 ± 0.2 % by weight (depending upon the geological origin of the boron). Boron, enriched in boron-10 could also be used. 1.4 The materials systems described herein shall be functional – that is always be capable to maintain a B10 areal density such that subcriticality Keff <0.95 or Keff <0.98 or Keff < 1.0 depending on the design specification for the service...

Membangun Sistem Linux Mandrake Minimal Menggunakan Inisial Disk Ram

OpenAIRE

Wagito, Wagito

2006-01-01

Minimal Linux system is commonly used for special systems like router, gateway, Linux installer and diskless Linux system. Minimal Linux system is a Linux system that use a few facilities of all Linux capabilities. Mandrake Linux, as one of Linux distribution is able to perform minimal Linux system. RAM is a computer resource that especially used as main memory. A part of RAM's function can be changed into disk called RAM disk. This RAM disk can be used to run the Linux system. This ...

The Potential of Coconut Shell Powder (CSP) and Coconut Shell Activated Carbon (CSAC) Composites as Electromagnetic Interference (EMI) Absorbing Material

International Nuclear Information System (INIS)

Siti Nurbazilah Abdul Jabal; Seok, Y.B.; Hoon, W.F.

2016-01-01

Agriculture waste is potentially useful as an alternative material to absorb and attenuate electromagnetic interference (EMI). This research highlights the use of coconut shell powder (CSP) and coconut shell activated carbon (CSAC) as raw materials with epoxy resin and amine hardener composite to absorb microwave signals over frequency of 1 - 8 GHz. In order to investigate the suitability of these raw materials as EMI absorbing material, carbon composition of the raw materials is determined through CHNS Elemental Analysis. The surface morphology of the raw materials in term of porosity is investigated by using TM3000 Scanning Electron Microscope (SEM). The complex permittivity of the composites is determined by using high temperature dielectric probe in conjunction with Network Analyzer. From the result, the Carbon% of CSP and CSAC is 46.70 % and 84.28 % respectively. In term of surface morphology, the surface porosity of CSP and CSAC is in the range of 2 μm and 1 μm respectively. For the dielectric properties, the dielectric constant and the dielectric loss factor for CSP and CSAC is 4.5767 and 64.8307 and 1.2144 and 13.8296 respectively. The materials more potentially useful as substitute materials for electromagnetic interference (EMI) absorbing are discussed. (author)

Perovskite oxides for visible-light-absorbing ferroelectric and photovoltaic materials.

Science.gov (United States)

Grinberg, Ilya; West, D Vincent; Torres, Maria; Gou, Gaoyang; Stein, David M; Wu, Liyan; Chen, Guannan; Gallo, Eric M; Akbashev, Andrew R; Davies, Peter K; Spanier, Jonathan E; Rappe, Andrew M

2013-11-28

Ferroelectrics have recently attracted attention as a candidate class of materials for use in photovoltaic devices, and for the coupling of light absorption with other functional properties. In these materials, the strong inversion symmetry breaking that is due to spontaneous electric polarization promotes the desirable separation of photo-excited carriers and allows voltages higher than the bandgap, which may enable efficiencies beyond the maximum possible in a conventional p-n junction solar cell. Ferroelectric oxides are also stable in a wide range of mechanical, chemical and thermal conditions and can be fabricated using low-cost methods such as sol-gel thin-film deposition and sputtering. Recent work has shown how a decrease in ferroelectric layer thickness and judicious engineering of domain structures and ferroelectric-electrode interfaces can greatly increase the current harvested from ferroelectric absorber materials, increasing the power conversion efficiency from about 10(-4) to about 0.5 per cent. Further improvements in photovoltaic efficiency have been inhibited by the wide bandgaps (2.7-4 electronvolts) of ferroelectric oxides, which allow the use of only 8-20 per cent of the solar spectrum. Here we describe a family of single-phase solid oxide solutions made from low-cost and non-toxic elements using conventional solid-state methods: [KNbO3]1 - x[BaNi1/2Nb1/2O3 - δ]x (KBNNO). These oxides exhibit both ferroelectricity and a wide variation of direct bandgaps in the range 1.1-3.8 electronvolts. In particular, the x = 0.1 composition is polar at room temperature, has a direct bandgap of 1.39 electronvolts and has a photocurrent density approximately 50 times larger than that of the classic ferroelectric (Pb,La)(Zr,Ti)O3 material. The ability of KBNNO to absorb three to six times more solar energy than the current ferroelectric materials suggests a route to viable ferroelectric semiconductor-based cells for solar energy conversion and

PREPARATION OF TEASER RAMS BY LATERAL DEVIATION OF PREPUCE AND PENIS

Directory of Open Access Journals (Sweden)

Rashid Ahmad

2003-07-01

Full Text Available For oestrus detection in sheep while in flocks, limited exposure is given to rams with tied apron in front of their prepucial opening. For better and un-feared use of rams for oestrus detection and for effect of , ram exposure on postpartum reproductive characteristics of ewes, rams before the attainment of puberty and those sexually mature (adult rams were operated for lateral deviation of prepuce and penis. The operations were successful, no post operative complications were recorded and these rams exhibited normal libido and were found efficient for oestrus detection in ewes.

Laser Boost of a Small Interstellar Ram Jet to Obtain Operational Velocity. Implications for the DM Rocket/Ram Jet Model

Science.gov (United States)

Walcott Beckwith, Andrew

2010-05-01

In other conference research papers, Beckwith obtained a maximum DM mass/energy value of up to 5 TeV, as opposed to 400 GeV for DM, which may mean more convertible power for a dark matter ram jet. The consequences are from assuming that axions are CDM, and KK gravitons are for WDM, then ρWarm-Dark-Matter would dominate not only structure formation in early universe formation, but would also influence the viability of the DM ram jet applications for interstellar travel. The increase in convertible DM mass makes the ram jet a conceivable option. This paper in addition to describing the scientific issues leading to that 5 TeV mass for DM also what are necessary and sufficient laser boost systems which would permit a ram net to become operational.

Cold tests of HOM absorber material for the ARIEL eLINAC at TRIUMF

International Nuclear Information System (INIS)

Kolb, P.; Laxdal, R.E.; Zvyagintsev, V.; Chao, Y.C.; Amini, B.

2014-01-01

At TRIUMF development of a 50 MeV electron accelerator is well under way. Five 1.3 GHz, superconducting 9-cell cavities will accelerate 10 mA electrons to a production target to produce rare isotopes. Each cavity will provide 10 MV accelerating voltage. Plans to upgrade the accelerator in the future to a small ring with ERL capabilities requires that the shunt impedance of the dipole higher order modes to be less than 10MΩ . The design of the accelerator incorporates beam line absorbers to reduce the shunt impedance of potentially dangerous dipole modes. The performance of the absorber is dependant on its electrical conductivity at the operational temperature. Measurements of the electrical conductivity in RF fields of a sample of the proposed beam line absorber material at room temperature and at its operational temperature will be presented for frequencies between 1.3 and 2.4 GHz

Cold tests of HOM absorber material for the ARIEL eLINAC at TRIUMF

Energy Technology Data Exchange (ETDEWEB)

Kolb, P., E-mail: kolb@triumf.ca [TRIUMF, Canada' s National Laboratory for Particle and Nuclear Physics, 4004 Wesbrook Mall, Vancouver, B.C., Canada V6T 2A3 (Canada); University of British Columbia, Department of Physics and Astronomy, 6224 Agricultural Road, Vancouver, B.C., Canada V6T 1Z1 (Canada); Laxdal, R.E., E-mail: lax@triumf.ca [TRIUMF, Canada' s National Laboratory for Particle and Nuclear Physics, 4004 Wesbrook Mall, Vancouver, B.C., Canada V6T 2A3 (Canada); Zvyagintsev, V.; Chao, Y.C. [TRIUMF, Canada' s National Laboratory for Particle and Nuclear Physics, 4004 Wesbrook Mall, Vancouver, B.C., Canada V6T 2A3 (Canada); Amini, B. [TRIUMF, Canada' s National Laboratory for Particle and Nuclear Physics, 4004 Wesbrook Mall, Vancouver, B.C., Canada V6T 2A3 (Canada); University of British Columbia, Department of Physics and Astronomy, 6224 Agricultural Road, Vancouver, B.C., Canada V6T 1Z1 (Canada)

2014-01-11

At TRIUMF development of a 50 MeV electron accelerator is well under way. Five 1.3 GHz, superconducting 9-cell cavities will accelerate 10 mA electrons to a production target to produce rare isotopes. Each cavity will provide 10 MV accelerating voltage. Plans to upgrade the accelerator in the future to a small ring with ERL capabilities requires that the shunt impedance of the dipole higher order modes to be less than 10MΩ . The design of the accelerator incorporates beam line absorbers to reduce the shunt impedance of potentially dangerous dipole modes. The performance of the absorber is dependant on its electrical conductivity at the operational temperature. Measurements of the electrical conductivity in RF fields of a sample of the proposed beam line absorber material at room temperature and at its operational temperature will be presented for frequencies between 1.3 and 2.4 GHz.

The Development of Male-Oriented Behavior in Rams

OpenAIRE

Roselli, Charles E.; Reddy, Radhika; Kaufman, Katherine

2011-01-01

The sheep offers a unique mammalian model in which to study paradoxical same-sex sexual partner preferences. Variations in sexual partner preferences occur spontaneously with as many as 8% of rams in a population exhibiting a sexual preference for other rams (male-oriented). The current review presents an overview and update of the male-oriented ram model and discusses several theories that have been invoked to explain same sex preferences in this species. Although our understanding of the bi...

Differential gene expression by RamA in ciprofloxacin-resistant Salmonella Typhimurium.

Directory of Open Access Journals (Sweden)

Jie Zheng

Full Text Available Overexpression of ramA has been implicated in resistance to multiple drugs in several enterobacterial pathogens. In the present study, Salmonella Typhimurium strain LTL with constitutive expression of ramA was compared to its ramA-deletion mutant by employing both DNA microarrays and phenotype microarrays (PM. The mutant strain with the disruption of ramA showed differential expression of at least 33 genes involved in 11 functional groups. The study confirmed at the transcriptional level that the constitutive expression of ramA was directly associated with increased expression of multidrug efflux pump AcrAB-TolC and decreased expression of porin protein OmpF, thereby conferring multiple drug resistance phenotype. Compared to the parent strain constitutively expressing ramA, the ramA mutant had increased susceptibility to over 70 antimicrobials and toxic compounds. The PM analysis also uncovered that the ramA mutant was better in utilization of 10 carbon sources and 5 phosphorus sources. This study suggested that the constitutive expression of ramA locus regulate not only multidrug efflux pump and accessory genes but also genes involved in carbon metabolic pathways.

PREPARATION OF TEASER RAMS BY LATERAL DEVIATION OF PREPUCE AND PENIS

OpenAIRE

Rashid Ahmad

2003-01-01

For oestrus detection in sheep while in flocks, limited exposure is given to rams with tied apron in front of their prepucial opening. For better and un-feared use of rams for oestrus detection and for effect of , ram exposure on postpartum reproductive characteristics of ewes, rams before the attainment of puberty and those sexually mature (adult rams) were operated for lateral deviation of prepuce and penis. The operations were successful, no post operative complications were recorded and t...

A numerical analysis of aspects of absorbed dose in the vicinity of the interface of different materials

Energy Technology Data Exchange (ETDEWEB)

Tada, J [Tsukuba Univ., (Japan); Hirayama, H [National Lab. High Enregy Phys. (Japan); Katoh, K [Ibaraki Pref. Univ. Health Sci., (Japan)

1997-12-31

In the measurement and/or evaluation of the absorbed dose where the charged particle distribution is far from equilibrium, knowledge on the microscopic spatial distribution of the charged particle fluence is important. Spatial distribution of secondary electrons in the vicinity of an interface of materials and the values of the absorbed dose in these regions are investigated with a monte-Carlo simulation code EGS 4. There were experiments on spatial variation of the absorbed dose in the vicinity of an interface of materials. However, the behaviour of secondary electrons were discussed only broadly and qualitatively. In this study, behaviour of the secondary electrons was analysed to clarify contribution of ruling interactions to generate secondary electrons, and influence of the interface on the energy spectra of secondary electrons. 11 figs.

Alpha particle induced soft errors in NMOS RAMs: a review

International Nuclear Information System (INIS)

Carter, P.M.; Wilkins, B.R.

1987-01-01

The paper aims to explain the alpha particle induced soft error phenomenon using the NMOS dynamic random access memory (RAM) as a model. It discusses some of the many techniques experimented with by manufacturers to overcome the problem, and gives a review of the literature covering most aspects of soft errors in dynamic RAMs. Finally, the soft error performance of current dynamic RAM and static RAM products from several manufacturers are compared. (author)

Origin of the OFF state variability in ReRAM cells

International Nuclear Information System (INIS)

Salaoru, Iulia; Khiat, Ali; Li, Qingjiang; Prodromakis, Themistoklis; Berdan, Radu; Papavassiliou, Christos

2014-01-01

This work exploits the switching dynamics of nanoscale resistive random access memory (ReRAM) cells with particular emphasis on the origin of the observed variability when cells are consecutively cycled/programmed at distinct memory states. It is demonstrated that this variance is a common feature of all ReRAM elements and is ascribed to the formation and rupture of conductive filaments that expand across the active core, independently of the material employed as the active switching core, the causal physical switching mechanism, the switching mode (bipolar/unipolar) or even the unit cells' dimensions. Our hypothesis is supported through both experimental and theoretical studies on TiO 2 and In 2 O 3  : SnO 2 (ITO) based ReRAM cells programmed at three distinct resistive states. Our prototypes employed TiO 2 or ITO active cores over 5 × 5 µm 2 and 100 × 100 µm 2 cell areas, with all tested devices demonstrating both unipolar and bipolar switching modalities. In the case of TiO 2 -based cells, the underlying switching mechanism is based on the non-uniform displacement of ionic species that foster the formation of conductive filaments. On the other hand, the resistive switching observed in the ITO-based devices is considered to be due to a phase change mechanism. The selected experimental parameters allowed us to demonstrate that the observed programming variance is a common feature of all ReRAM devices, proving that its origin is dependent upon randomly oriented local disorders within the active core that have a substantial impact on the overall state variance, particularly for high-resistive states. (paper)

Preparation and Properties of Moisture-absorbing Film Impregnated with Polyacrylic Acid Partial Sodium Salt Material

International Nuclear Information System (INIS)

Lee, Youn Suk; Park, Insik; Choi, Hong Yeol

2014-01-01

Moisture is a major factor causing the deteriorative physical change, microbial growth, and chemical reaction of the products. In this study, the moisture absorbing composite films have been prepared with moisture absorbing material of polyacrylic acid partial sodium salt (PAPSS) impregnated on LLDPE polymer for the functional packaging applications. The results showed that PAPSS impregnated film illustrated uniformly dispersed PAPSS particles in the LLDPE polymer matrix. The transparency of the PAPSS impregnated film decreased slightly at higher PAPSS concentrations. An increase in the PAPSS content for moisture-absorbing films showed a similar decrease in tensile strength, percent elongation at break, and tear strength. Their values of films impregnated with PAPSS of 0.5, 1, and 2% showed no significant difference. Meanwhile, 4% PAPSS films significantly decreased the values of mechanical properties compared to the films impregnated with different PAPSS levels. Values of the oxygen permeability and water vapor permeability for PAPSS impregnated films decreased significantly with greater PAPSS. The results indicate that 4% PAPSS impregnated in LLDPE films had high affinity of moisture absorbencies compared to the other films. The mathematical equation that best described the moisture sorption isotherm of each film sample was the GAB equation at 25 .deg. C. The crystallization and melting temperatures of PAPSS films were influenced by the addition of PAPSS material, but showed good thermal stability

Preparation and Properties of Moisture-absorbing Film Impregnated with Polyacrylic Acid Partial Sodium Salt Material

Energy Technology Data Exchange (ETDEWEB)

Lee, Youn Suk; Park, Insik [Yonsei University, Wonju (Korea, Republic of); Choi, Hong Yeol [CJ Cheiljedang, Seoul (Korea, Republic of)

2014-08-15

Moisture is a major factor causing the deteriorative physical change, microbial growth, and chemical reaction of the products. In this study, the moisture absorbing composite films have been prepared with moisture absorbing material of polyacrylic acid partial sodium salt (PAPSS) impregnated on LLDPE polymer for the functional packaging applications. The results showed that PAPSS impregnated film illustrated uniformly dispersed PAPSS particles in the LLDPE polymer matrix. The transparency of the PAPSS impregnated film decreased slightly at higher PAPSS concentrations. An increase in the PAPSS content for moisture-absorbing films showed a similar decrease in tensile strength, percent elongation at break, and tear strength. Their values of films impregnated with PAPSS of 0.5, 1, and 2% showed no significant difference. Meanwhile, 4% PAPSS films significantly decreased the values of mechanical properties compared to the films impregnated with different PAPSS levels. Values of the oxygen permeability and water vapor permeability for PAPSS impregnated films decreased significantly with greater PAPSS. The results indicate that 4% PAPSS impregnated in LLDPE films had high affinity of moisture absorbencies compared to the other films. The mathematical equation that best described the moisture sorption isotherm of each film sample was the GAB equation at 25 .deg. C. The crystallization and melting temperatures of PAPSS films were influenced by the addition of PAPSS material, but showed good thermal stability.

Computerized simulation of the mechanical behavior of wood-filled shock absorbers of radioactive materials transport casks

International Nuclear Information System (INIS)

Neumann, Martin; Wille, Frank

2011-01-01

In Germany the mechanical component inspection of transport containers for radioactive materials is performed by BAM (Bundesanstalt fuer Materialforschung und -pruefung) under consideration of national and international standards and guidelines. Experimental and calculative (analytical and numerical) techniques combined with material and/or component testing are the basis of assessment concepts according the state of the art. The authors describe the experiences of BAM concerning assessment and description of the mechanical behavior of shock absorbing components, including modeling strategies, material models, drop tests and experiment-calculation comparison. Energy absorbing components are used to reduce the impact forces at the container in case of a transport accident. In Germany wood filled thin-walled constructions are used. The deformation behavior of the wood is a main part of the calculative simulation procedures in comparison with experimental tests.

A RAM: Realidade e Utopia

OpenAIRE

Pereira, Carlos Santos

2003-01-01

Evoluções tecnológicas recentes, nomeadamente em matéria de electrónica e de informática, e a busca de conceitos operacionais adaptados às novas tecnologias estão a revolucionar a arte da guerra. O êxito da “Tempestade no Deserto”, em 1991 e das sucessivas intervenções militares dos EUA nos anos seguintes mais reforçaram a ideia de que se estava perante uma verdadeira revolução – É a Revolução nos Assuntos Militares (RAM). Na realidade, a RAM é um fenómeno comple...

Ram Pressure Stripping Made Easy: An Analytical Approach

Science.gov (United States)

Köppen, J.; Jáchym, P.; Taylor, R.; Palouš, J.

2018-06-01

The removal of gas by ram pressure stripping of galaxies is treated by a purely kinematic description. The solution has two asymptotic limits: if the duration of the ram pressure pulse exceeds the period of vertical oscillations perpendicular to the galactic plane, the commonly used quasi-static criterion of Gunn & Gott is obtained which uses the maximum ram pressure that the galaxy has experienced along its orbit. For shorter pulses the outcome depends on the time-integrated ram pressure. This parameter pair fully describes the gas mass fraction that is stripped from a given galaxy. This approach closely reproduces results from SPH simulations. We show that typical galaxies follow a very tight relation in this parameter space corresponding to a pressure pulse length of about 300 Myr. Thus, the Gunn & Gott criterion provides a good description for galaxies in larger clusters. Applying the analytic description to a sample of 232 Virgo galaxies from the GoldMine database, we show that the ICM provides indeed the ram pressures needed to explain the deficiencies. We also can distinguish current and past strippers, including objects whose stripping state was unknown.

Solar radiation absorbing material

Science.gov (United States)

Googin, John M.; Schmitt, Charles R.; Schreyer, James M.; Whitehead, Harlan D.

1977-01-01

Solar energy absorbing means in solar collectors are provided by a solar selective carbon surface. A solar selective carbon surface is a microporous carbon surface having pores within the range of 0.2 to 2 micrometers. Such a surface is provided in a microporous carbon article by controlling the pore size. A thermally conductive substrate is provided with a solar selective surface by adhering an array of carbon particles in a suitable binder to the substrate, a majority of said particles having diameters within the range of about 0.2-10 microns.

Absorbing rods for nuclear fast neutron reactor absorbing assembly

International Nuclear Information System (INIS)

Aji, M.; Ballagny, A.; Haze, R.

1986-01-01

The invention proposes a neutron absorber rod for neutron absorber assembly of a fast neutron reactor. The assembly comprises a bundle of vertical rods, each one comprising a stack of pellets made of a neutron absorber material contained in a long metallic casing with a certain radial play with regard to this casing; this casing includes traps for splinters from the pellets which may appear during reactor operation, at the level of contact between adjacent pellets. The present invention prevents the casing from rupture involved by the disintegration of the pellets producing pieces of boron carbide of high hardness [fr

Thermally tunable broadband omnidirectional and polarization-independent super absorber using phase change material VO2

Directory of Open Access Journals (Sweden)

Zhejun Liu

Full Text Available In this letter, we numerically demonstrate a thermally tunable super absorber by using phase change material VO2 as absorbing layer in metal-insulator-metal structure. An omnidirectional super absorption at λ=2.56μm can be realized by heating the patterned grating VO2 film due to magnetic resonance mechanism. Furthermore, a broadband super absorption higher than 0.8 in the entire 1.6μm–4μm region is achieved when VO2 film is patterned chessboard structure and transformed to metal phase beyond transition temperature. This broadband super absorption can be fulfilled in a wide range of incident angle (0°–70° and under all polarization conditions. Keywords: Phase change material, Metal-insulator-metal, Super absorption, Magnetic resonance

Design and verification of a self-timed RAM

DEFF Research Database (Denmark)

Nielsen, Lars Skovby; Staunstrup, Jørgen

1995-01-01

This paper describes a self-timed static RAM. A single bit RAM is described in the design language SYNCHRONIZED TRANSITIONS and using the verification tools supporting this language, it is shown that the design is speed-independent. Furthermore, a transistor level implementation of the design...

Electrochemical Corrosion Testing of Neutron Absorber Materials

International Nuclear Information System (INIS)

Tedd Lister; Ron Mizia; Sandra Birk; Brent Matteson; Hongbo Tian

2006-01-01

The Yucca Mountain Project (YMP) has been directed by DOE-RW to develop a new repository waste package design based on the transport, aging, and disposal canister (TAD) system concept. A neutron poison material for fabrication of the internal spent nuclear fuel (SNF) baskets for these canisters needs to be identified. A material that has been used for criticality control in wet and dry storage of spent nuclear fuel is borated stainless steel. These stainless products are available as an ingot metallurgy plate product with a molybdenum addition and a powder metallurgy product that meets the requirements of ASTM A887, Grade A. A new Ni-Cr-Mo-Gd alloy has been developed by the Idaho National Laboratory (INL) with its research partners (Sandia National Laboratory and Lehigh University) with DOE-EM funding provided by the National Spent Nuclear Fuel Program (NSNFP). This neutron absorbing alloy will be used to fabricate the SNF baskets in the DOE standardized canister. The INL has designed the DOE Standardized Spent Nuclear Fuel Canister for the handling, interim storage, transportation, and disposal in the national repository of DOE owned spent nuclear fuel (SNF). A corrosion testing program is required to compare these materials in environmental conditions representative of a breached waste canister. This report will summarize the results of crevice corrosion tests for three alloys in solutions representative of ionic compositions inside the waste package should a breech occur. The three alloys in these tests are Neutronit A978 (ingot metallurgy, hot rolled), Neutrosorb 304B4 Grade A (powder metallurgy, hot rolled), and Ni-Cr-Mo-Gd alloy (ingot metallurgy, hot rolled)

Two-Photon Absorbing Molecules as Potential Materials for 3D Optical Memory

Directory of Open Access Journals (Sweden)

Kazuya Ogawa

2014-01-01

Full Text Available In this review, recent advances in two-photon absorbing photochromic molecules, as potential materials for 3D optical memory, are presented. The investigations introduced in this review indicate that 3D data storage processing at the molecular level is possible. As 3D memory using two-photon absorption allows advantages over existing systems, the use of two-photon absorbing photochromic molecules is preferable. Although there are some photochromic molecules with good properties for memory, in most cases, the two-photon absorption efficiency is not high. Photochromic molecules with high two-photon absorption efficiency are desired. Recently, molecules having much larger two-photon absorption cross sections over 10,000 GM (GM= 10−50 cm4 s molecule−1 photon−1 have been discovered and are expected to open the way to realize two-photon absorption 3D data storage.

Hybrid waste filler filled bio-polymer foam composites for sound absorbent materials

Science.gov (United States)

Rus, Anika Zafiah M.; Azahari, M. Shafiq M.; Kormin, Shaharuddin; Soon, Leong Bong; Zaliran, M. Taufiq; Ahraz Sadrina M. F., L.

2017-09-01

Sound absorption materials are one of the major requirements in many industries with regards to the sound insulation developed should be efficient to reduce sound. This is also important to contribute in economically ways of producing sound absorbing materials which is cheaper and user friendly. Thus, in this research, the sound absorbent properties of bio-polymer foam filled with hybrid fillers of wood dust and waste tire rubber has been investigated. Waste cooking oil from crisp industries was converted into bio-monomer, filled with different proportion ratio of fillers and fabricated into bio-polymer foam composite. Two fabrication methods is applied which is the Close Mold Method (CMM) and Open Mold Method (OMM). A total of four bio-polymer foam composite samples were produce for each method used. The percentage of hybrid fillers; mixture of wood dust and waste tire rubber of 2.5 %, 5.0%, 7.5% and 10% weight to weight ration with bio-monomer. The sound absorption of the bio-polymer foam composites samples were tested by using the impedance tube test according to the ASTM E-1050 and Scanning Electron Microscope to determine the morphology and porosity of the samples. The sound absorption coefficient (α) at different frequency range revealed that the polymer foam of 10.0 % hybrid fillers shows highest α of 0.963. The highest hybrid filler loading contributing to smallest pore sizes but highest interconnected pores. This also revealed that when highly porous material is exposed to incident sound waves, the air molecules at the surface of the material and within the pores of the material are forced to vibrate and loses some of their original energy. This is concluded that the suitability of bio-polymer foam filled with hybrid fillers to be used in acoustic application of automotive components such as dashboards, door panels, cushion and etc.

Development and mastering of production of dysprosium hafnate as absorbing material for control rods of promising thermal neutron reactors

International Nuclear Information System (INIS)

Zakharov, A.V.; Risovany, V.D.; Muraleva, E.M.; Sokolov, V.F.

2011-01-01

The main advantages of dysprosium hafnate as an absorbing material for LWR control rods are the following: -) unlimited radiation resistance; - two absorbing components, Dy and Hf, increasing physical efficiency of the material compared to Dy 2 O 3 -TiO 2 and alloy 80% Ag - 15% In - 5% Cd; -) variability of physical efficiency by changing a composition, but maintaining other performance characteristics of the material; -) high process-ability due to the absence of phase transients and single-phase structure (solid solution); -) production of high density pellets. Lab-scale mastering of dysprosium hafnate pellets production showed a possibility of material synthesis using a solid-phase method, as well as of dysprosium hafnate pellets production by cold pressing and subsequent sintering. Within a whole range of examined compositions (23 mol% - 75 mol% Dy 2 O 3 ), a single-phase material with a highly radiation resistant fluorite-like structure was produced. Experiments on cold pressing and sintering of pellets confirmed a possibility of producing high quality dysprosium hafnate pellets from synthesized powder. A pilot batch of dysprosium hafnate pellets with standard sizes was produced. The standard sizes corresponded to the absorbing elements of the WWER-1000 control rods and met the main requirements to the absorbing element columns. The pilot batch size was approximately 6 kg. Acceptance testing of the pilot batch of dysprosium hafnate pellets was conducted, fulfillment of the requirements of technical conditions was checked and preirradiation properties of the pellets were examined. High quality of the produced pellets was confirmed, thus, demonstrating a real possibility of producing large batches of the dysprosium hafnate pellets. The next step is the production of test absorbing elements and cluster assemblies for the WWER-1000 control rods with their further installation for pilot operation at one of the Russian nuclear power plants

Development of microwave absorbing materials prepared from a polymer binder including Japanese lacquer and epoxy resin

Science.gov (United States)

Iwamaru, T.; Katsumata, H.; Uekusa, S.; Ooyagi, H.; Ishimura, T.; Miyakoshi, T.

Microwave absorption composites were synthesized from a poly urushiol epoxy resin (PUE) mixed with one of microwave absorbing materials; Ni-Zn ferrite, Soot, Black lead, and carbon nano tube (CNT) to investigate their microwave absorption properties. PUE binders were specially made from Japanese lacquer and epoxy resin, where Japanese lacquer has been traditionally used for bond and paint because it has excellent beauty. Japanese lacquer solidifies with oxygen contained in air's moisture, which has difficulty in making composite, but we improved Japanese lacquer's solidification properties by use of epoxy resin. We made 10 mm thickness composite samples and cut them into toroidal shape to measure permittivity, permeability, and reflection loss in frequencies ranging from 50 Hz to 20 GHz. Electric magnetic absorber's composites synthesized from a PUE binders mixed either with Soot or CNT showed significantly higher wave absorption over -27 dB than the others at frequencies around 18 GHz, although Japanese lacquer itself doesn't affect absorption. This means Japanese lacquer can be used as binder materials for microwave absorbers.

Development of FeCoB/Graphene Oxide based microwave absorbing materials for X-Band region

International Nuclear Information System (INIS)

Das, Sukanta; Chandra Nayak, Ganesh; Sahu, S.K.; Oraon, Ramesh

2015-01-01

This work explored the microwave absorption capability of Graphene Oxide and Graphene Oxide coated with FeCoB for stealth technology. Epoxy based microwave absorbing materials were prepared with 30% loading of Graphene Oxide, FeCoB alloy and Graphene Oxide coated with FeCoB. Graphene Oxide and FeCoB were synthesized by Hummer's and Co-precipitation methods, respectively. The filler particles were characterized by FESEM, XRD and Vibrating Sample Magnetometer techniques. Permittivity, permeability and reflection loss values of the composite absorbers were measured with vector network analyzer which showed a reflection loss value of −7.86 dB, at 10.72 GHz, for single layered Graphene Oxide/Epoxy based microwave absorbers which can be correlated to the absorption of about 83.97% of the incident microwave energy. Reflection loss value of FeCoB/Epoxy based microwave absorber showed −13.30 dB at 11.67 GHz, which corresponded to maximum absorption of 93.8%. However, reflection loss values of Graphene Oxide coated with FeCoB/Epoxy based single-layer absorber increased to −22.24 dB at 12.4 GHz which corresponds to an absorption of 99% of the incident microwave energy. - Highlights: • FeCoB coated Graphene Oxide (GO) was synthesized by co-precipitation method. • GO, FeCoB and GO@FeCoB based microwave absorbers were developed with Epoxy matrix. • GO and FeCoB/Epoxy absorbers showed −7.86 & −13.30 dB reflection loss, respectively. • Maximum Reflection loss of −22.24 dB was achieved with GO@FeCoB/Epoxy absorber

Burnable neutron absorbers

International Nuclear Information System (INIS)

Radford, K.C.; Carlson, W.G.

1985-01-01

This patent deals with the fabrication of pellets for neutron absorber rods. Such a pellet includes a matrix of a refractory material which may be aluminum or zirconium oxide, and a burnable poison distributed throughout the matrix. The neutron absorber material may consist of one or more elements or compounds of the metals boron, gadolinium, samarium, cadmium, europium, hafnium, dysprosium and indium. The method of fabricating pellets of these materials outlined in this patent is designed to produce pores or voids in the pellets that can be used to take up the expansion of the burnable poison and to absorb the helium gas generated. In the practice of this invention a slurry of Al 2 O 3 is produced. A hard binder is added and the slurry and binder are spray dried. This powder is mixed with dry B 4 C powder, forming a homogeneous mixture. This mixture is pressed into green tubes which are then sintered. During sintering the binder volatilizes leaving a ceramic with nearly spherical high-density regions of

Design of a 16 kbit superconducting latching/SFQ hybrid RAM

International Nuclear Information System (INIS)

Nagasawa, Shuichi; Hasegawa, Haruhiro; Hashimoto, Tatsunori; Suzuki, Hideo; Miyahara, Kazunori; Enomoto, Youichi

1999-01-01

We have designed a 16 kbit superconducting latching/SFQ hybrid (SLASH) RAM, which enables high-frequency clock operation up to 10 GHz. The 16 kbit SLASH RAM consists of four 4x4 matrix arrays of 256 bit RAM blocks, block decoders, latching block drivers, latching block senses, impedance matched lines and the powering circuits. The 256 bit RAM block is composed of a 16x16 matrix array of vortex transitional memory cells, latching drivers, SFQ NOR decoders and latching sense circuits. We have also designed and implemented an SFQ NOR decoder that is composed of magnetically coupled multi-input OR gates and RSFQ inverters. (author)

Radiation response of two Harris semiconductor radiation hardened 1k CMOS RAMs

International Nuclear Information System (INIS)

Abare, W.E.; Huffman, D.D.; Moffett, G.E.

1982-01-01

This paper describes the testing of two types 1K CMOS static RAMs in various transient and steady state ionizing radiation environments. Type HM 6551R (256x4 bits) and type HM 6508R (1024x1 bit) RAMs were evaluated. The RAMs are radiation hardened versions of Harris' commercial RAMs. A brief description of the radiation hardened process is presented

Sharma, Dr Ram Swaroop

Indian Academy of Sciences (India)

Home; Fellowship. Fellow Profile. Elected: 1989 Section: Earth & Planetary Sciences. Sharma, Dr Ram Swaroop Ph.D. (Basel), FNA. Date of birth: 10 July 1937. Specialization: Metamorphic Petrology, Mineralogy and Precambrian Geology Address: 70/36, Pratapnagar, Sector 7, Sanganer (RHB), Jaipur 302 033, Rajasthan

The Effects of Water-Absorbent Materials on Water Supply for Tree Planting in the Semi-Arid Regions

Directory of Open Access Journals (Sweden)

Gholam Reza Davarpanah Davarpanah

2005-03-01

Full Text Available Numerous studies have so far been focused on increasing irrigation efficiency through such measures as soil moisture retention and soil moisture capacity as well as improving soil physical conditions. In this study, surface runoff reduction, deep penetration of rain water, and use of rain water at irrigation sites with the help of water absorbent chemicals were investigated as measures of supplying for tree water demand and also of reducing drought effects. The absorbent material was purchased from Iran Polymer Research Center. The experimental design included three independent experiments in a completely randomized block design (CRBD with 5 treatments (0, 50, 100, 150 and 200 gr. of the absorbent material and three replications. The tree species used in the experiments were Amygdalus sp., Vitis vinifera, and Pistacia vera. There were 5 experimental units with 4 trees planted 3×3 meters apart. Appropriate amounts of the test material (absorbent were mixed with soil. Three characters of survival including: growth diameter, height, and canopy cover were recorded 4 times a year over two consecutive years. Mstat-c statistical software was used in the statistical analysis (Factor option. Results showed that the tree species had significant differences in their survival due to their genetic and physiological characteristics, so that the species of Vitis vinifera and Pistacia vera recorded the minimum and maximum survival values, respectively. Data collection within the present study is suggested to be continued and similar studies with light and sandy textured soils under greenhouse conditions are needed in order to gain more accurate information on these effects.

Discovery of Ram-pressure Stripped Gas around an Elliptical Galaxy in Abell 2670

International Nuclear Information System (INIS)

Sheen, Yun-Kyeong; Kim, Minjin; Smith, Rory; Yi, Sukyoung K.; Jaffé, Yara; Duc, Pierre-Alain; Nantais, Julie; Candlish, Graeme; Demarco, Ricardo; Treister, Ezequiel

2017-01-01

Studies of cluster galaxies are increasingly finding galaxies with spectacular one-sided tails of gas and young stars, suggestive of intense ram-pressure stripping. These so-called “jellyfish” galaxies typically have late-type morphology. In this paper, we present Multi Unit Spectroscopic Explorer (MUSE) observations of an elliptical galaxy in Abell 2670 with long tails of material visible in the optical spectra, as well as blobs with tadpole-like morphology. The spectra in the central part of the galaxy reveal a stellar component as well as ionized gas. The stellar component does not have significant rotation, while the ionized gas defines a clear star-forming gas disk. We argue, based on deep optical images of the galaxy, that the gas was most likely acquired during a past wet merger. It is possible that the star-forming blobs are also remnants of the merger. In addition, the direction and kinematics of the one-sided ionized tails, combined with the tadpole morphology of the star-forming blobs, strongly suggests that the system is undergoing ram pressure from the intracluster medium. In summary, this paper presents the discovery of a post-merger elliptical galaxy undergoing ram-pressure stripping.

Discovery of Ram-pressure Stripped Gas around an Elliptical Galaxy in Abell 2670

Energy Technology Data Exchange (ETDEWEB)

Sheen, Yun-Kyeong; Kim, Minjin [Korea Astronomy and Space Science Institute, 776, Daedeokdae-ro, Yuseong-gu, Daejeon, 34055 (Korea, Republic of); Smith, Rory; Yi, Sukyoung K. [Department of Astronomy, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722 (Korea, Republic of); Jaffé, Yara [European Southern Observatory, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago de Chile (Chile); Duc, Pierre-Alain [Laboratoire AIM Paris-Saclay, CEA/Irfu/SAp CNRS Universite Paris Diderot, F-91191 Gif-sur-Yvette Cedex (France); Nantais, Julie [Departamento de Ciencias Físicas, Universidad Andres Bello, Fernandez Concha 700, 7591538 Las Condes, Santiago (Chile); Candlish, Graeme [Instituto de Física y Astronomía, Universidad de Valparaíso, Gran Bretaña 1111, Valparaíso (Chile); Demarco, Ricardo [Departamento de Astronomía, Universidad de Concepción, Casilla 160-C, Concepción (Chile); Treister, Ezequiel, E-mail: yksheen@kasi.re.kr [Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago (Chile)

2017-05-01

Studies of cluster galaxies are increasingly finding galaxies with spectacular one-sided tails of gas and young stars, suggestive of intense ram-pressure stripping. These so-called “jellyfish” galaxies typically have late-type morphology. In this paper, we present Multi Unit Spectroscopic Explorer (MUSE) observations of an elliptical galaxy in Abell 2670 with long tails of material visible in the optical spectra, as well as blobs with tadpole-like morphology. The spectra in the central part of the galaxy reveal a stellar component as well as ionized gas. The stellar component does not have significant rotation, while the ionized gas defines a clear star-forming gas disk. We argue, based on deep optical images of the galaxy, that the gas was most likely acquired during a past wet merger. It is possible that the star-forming blobs are also remnants of the merger. In addition, the direction and kinematics of the one-sided ionized tails, combined with the tadpole morphology of the star-forming blobs, strongly suggests that the system is undergoing ram pressure from the intracluster medium. In summary, this paper presents the discovery of a post-merger elliptical galaxy undergoing ram-pressure stripping.

Identification of sexually low-response rams using a libido test and ...

African Journals Online (AJOL)

higher levels of sex-like behaviour with their pen mates. (monosexual groups) during rearing than did normal rams. These workers thus suggested that the poor performance of such rams when exposed to an oestrous ewe was due to their inability to interpret sexual cues correctly. Working with. Karakul rams, Le Roux and ...

A fully operational 1-kb variable threshold Josephson RAM

International Nuclear Information System (INIS)

Kurosawa, I.; Nakagawa, H.; Aoyagi, M.; Kosaks, S.; Takada, S.

1991-01-01

This paper describes the first fully operational Josephson RAM in LSI level integration. The chip was designed as a 4-b x 256-word data RAM unit for a 4-b Josephson computer, The variable threshold memory cell and the relating memory architecture were used. They are so simple in structure that the fabrication is satisfied by the current Josephson junction technology. A directly coupled driver gate for a resistive bit line applies an accurate and stable driving current to the memory cell array. The RAM chip was fabricated with a 3-μm Nb/Al-oxide/Nb junction technology. For obtaining reliable RAM chips, a plasma-enhanced CVD silicon dioxide layer was introduced for insulation between the ground plane and the base electrode. The thermal uniformity of the wafer was improved during the oxidation process for making a tunnel barrier in this work

Proteomics analysis of ram sperm by heavy ion radiation

International Nuclear Information System (INIS)

He Yuxuan; Li Hongyan; Zhang Hong

2013-01-01

The objective of this study was to investigate the proteome changes induced by heavy ion radiation using irradiated ram sperm by a two-dimensional electrophoresis (2-DE) analysis. The 2D gels were stained with Coomassie Brilliant Blue. Differentially expressed proteins were detected by PDQuest 8.0 software and subjected to ion trap mass spectrometer equipped with a surveyor HPLC system, and differential protein spots were identified. Results showed there are five differential protein spots in irradiated sperm gels, four up-regulated protein spots and one spot missed. The differentially expressed protein spots were identified to be two up-regulated proteins including enolase, and enolase 1. It was concluded there was proteome changes induced by heavy ion radiation in ram sperm, which may be useful to clarify the physiology state of ram sperm in heavy ion radiation and provide a theoretical basis for radiation ram breeding. (authors)

A model for acoustic absorbent materials derived from coconut fiber

Directory of Open Access Journals (Sweden)

Ramis, J.

2014-03-01

Full Text Available In the present paper, a methodology is proposed for obtaining empirical equations describing the sound absorption characteristics of an absorbing material obtained from natural fibers, specifically from coconut. The method, which was previously applied to other materials, requires performing measurements of air-flow resistivity and of acoustic impedance for samples of the material under study. The equations that govern the acoustic behavior of the material are then derived by means of a least-squares fit of the acoustic impedance and of the propagation constant. These results can be useful since they allow the empirically obtained analytical equations to be easily incorporated in prediction and simulation models of acoustic systems for noise control that incorporate the studied materials.En este trabajo se describe el proceso seguido para obtener ecuaciones empíricas del comportamiento acústico de un material absorbente obtenido a partir de fibras naturales, concretamente el coco. El procedimiento, que ha sido ensayado con éxito en otros materiales, implica la realización de medidas de impedancia y resistencia al flujo de muestras del material bajo estudio. Las ecuaciones que gobiernan el comportamiento desde el punto de vista acústico del material se obtienen a partir del ajuste de ecuaciones de comportamiento de la impedancia acústica y la constante de propagación del material. Los resultados son útiles ya que, al disponer de ecuaciones analíticas obtenidas empíricamente, facilitan la incorporación de estos materiales en predicciones mediante métodos numéricos del comportamiento cuando son instalados formando parte de dispositivos para el control del ruido.

Low Absorbance Measurements

Science.gov (United States)

Harris, T. D.; Williams, A. M.

1983-10-01

The application of low absorption measurements to dilute solute determination requires specific instrumental characteristics. The use of laser intracavity absorption and thermal lens calorimetry to measure concentration is shown. The specific operating parameters that determine sensitivity are delineated along with the limits different measurement strategies impose. Finally areas of improvement in components that would result in improve sensitivity, accuracy, and reliability are discussed. During the past decade, a large number of methods have been developed for measuring the light absorbed by transparent materials. These include measurements on gases, liquids, and solids. The activity has been prompted by a variety of applications and a similar variety of disciplines. In Table 1 some representative examples of these methods is shown along with their published detection limits.1 It is clear that extraordinarily small absorbances can be measured. Most of the methods can be conveniently divided into two groups. These groups are those that measure the transmission of the sample and those that measure the light absorbed by the sample. The light absorbed methods are calorimetric in character. The advantages and disadvantages of each method varies depending on the principal application for which they were developed. The most prevalent motivation has been to characterize the bulk optical properties of transparent materials. Two examples are the development of extremely transparent glasses for use as fiber optic materials and the development of substrates for high power laser operation.

MEMBANGUN SISTEM LINUX MANDRAKE MINIMAL MENGGUNAKAN INISIAL DISK RAM

OpenAIRE

Wagito, Wagito

2009-01-01

        Minimal Linux system is commonly used for special systems like router, gateway, Linux installer and diskless Linux system. Minimal Linux system is a Linux system that use a few facilities of all Linux capabilities. Mandrake Linux, as one of Linux distribution is able to perform minimal Linux system.         RAM is a computer resource that especially used as main memory. A  part of RAM’s function can be changed into disk called RAM disk. This RAM disk can be used to run the Linux syste...

Quality assurance requirements in the testing of packages to be used for safe transportation of RAM

International Nuclear Information System (INIS)

Vieru, Gheorghe; Nistor, Viorica; Mihaiu, Ramona

2010-01-01

The quality of the Type A, B or C packages used for transport and storage of Radioactive Material (RAM) has to be proved by performing qualification tests in accordance with the Transport Regulations, within the Reliability and Testing Laboratory, Institute for Nuclear Research (INR) Pitesti, where has designed and developed a new Romanian Testing Facility. The qualifications testing are performed under a strict quality assurance programme based on the specific procedures prior approved by the Romanian Nuclear Regulatory Body CNCAN (National Commission for Nuclear Activity Control). This paper describe the quality assurance programme in accordance with the quality management system developed in order to meet the requirements provided by the national regulations as well as to the requirements of the IAEA's safety standard TS-R-1 related to testing of packages to be used for transport of RAM and also provides an overview of the new Romanian Testing Facilities for RAM Packages, developed by the INR's Reliability and Testing Laboratory within an Excellence Scientific Contract. (authors)

Prenatal programming of sexual partner preference: the ram model.

Science.gov (United States)

Roselli, C E; Stormshak, F

2009-03-01

In our laboratory, the domestic ram is used as an experimental model to study the early programming of neural mechanisms underlying same-sex partner preference. This interest developed from the observation that approximately 8% of domestic rams are sexually attracted to other rams (male-oriented) in contrast to the majority of rams that are attracted to oestrous ewes (female-oriented). One prominent feature of sexual differentiation in many species is the presence of a sexually dimorphic nucleus (SDN) in the preoptic/anterior hypothalamus that is larger in males than in females. Lesion studies in rats and ferrets implicate the SDN in the expression of sexual preferences. We discovered an ovine SDN (oSDN) in the preoptic/anterior hypothalamus that is smaller in male- than in female-oriented rams and similar in size to the oSDN of ewes. Neurones of the oSDN show abundant aromatase expression that is also reduced in male-oriented compared to female-oriented rams. This observation suggests that sexual partner preferences are neurologically hard-wired and could be influenced by hormones. Aromatase-containing neurones constitute a nascent oSDN as early as day 60 of gestation, which becomes sexually dimorphic by day 135 of gestation when it is two-fold larger in males than in females. Exposure of fetal female lambs to exogenous testosterone from days 30-90 of gestation resulted in a masculinised oSDN. These data demonstrate that the oSDN develops prenatally and may influence adult sexual preferences. Surprisingly, inhibition of aromatase activity in the brain of ram foetuses during the critical period did not interfere with defeminisation of adult sexual partner preference or oSDN volume. These results fail to support an essential role for neural aromatase in the sexual differentiation of sheep brain and behaviour. Thus, we propose that oSDN morphology and male-typical partner preferences may instead be programmed through an androgen receptor mechanism not involving

Thin and Broadband Two-Layer Microwave Absorber in 4-12 GHz with Developed Flaky Cobalt Material

Science.gov (United States)

Gill, Neeraj; Singh, Jaydeep; Puthucheri, Smitha; Singh, Dharmendra

2018-03-01

Microwave absorbing materials (MAMs) in the frequency range of 2.0-18.0 GHz are essential for the stealth and communication applications. Researchers came up with effective MAMs for the higher frequency regions, i.e., 8.0-18.0 GHz, while absorbers with comparable properties in the lower frequency band are still not in the limelight. Designing a MAM for the lower frequency range is a critical task. It is known that the factors governing the absorption in this frequency predominantly depend on the permeability and conductivity of the material, whereas the shape anisotropy of the particles can initiate different absorption mechanisms like multiple internal reflections, phase cancellations, surface charge polarization and enhanced conductivity that can promote the microwave absorption towards lower frequencies. But the material alone may not serve the purpose of getting broad absorption bandwidth. With the effective use of advanced electromagnetic technique like multi-layering this problem may be solved. Therefore, in this paper, a material with shape anisotropy (cobalt flakes with high shape anisotropy) has been prepared and a two-layer structure is developed which gives the absorption bandwidth in 4.17-12.05 GHz at a coating thickness of 2.66 mm.

Energy-Saving RAM-Power Tap

Science.gov (United States)

Bruner, Alan Roy

1987-01-01

Reverse-flow HEXFET(R) minimizes voltage drop and power dissipation. HEXFET(R) scheme reduces voltage drop by approximately 80 percent. Design for power tap for random-access memory (RAM) has potential application in digital systems.

Semen Characteristics of the West African Dwarf Rams in The ...

African Journals Online (AJOL)

WAD) rams in Makurdi. Semen samples were collected from five rams twice a week by electroejaculation method over a period of two months (September to October). The ejaculate volume, concentration, mass activity, progressive motility, the ...

The effect of reactive ion etch (RIE) process conditions on ReRAM device performance

Science.gov (United States)

Beckmann, K.; Holt, J.; Olin-Ammentorp, W.; Alamgir, Z.; Van Nostrand, J.; Cady, N. C.

2017-09-01

The recent surge of research on resistive random access memory (ReRAM) devices has resulted in a wealth of different materials and fabrication approaches. In this work, we describe the performance implications of utilizing a reactive ion etch (RIE) based process to fabricate HfO2 based ReRAM devices, versus a more unconventional shadow mask fabrication approach. The work is the result of an effort to increase device yield and reduce individual device size. Our results show that choice of RIE etch gas (SF6 versus CF4) is critical for defining the post-etch device profile (cross-section), and for tuning the removal of metal layers used as bottom electrodes in the ReRAM device stack. We have shown that etch conditions leading to a tapered profile for the device stack cause poor electrical performance, likely due to metal re-deposition during etching, and damage to the switching layer. These devices exhibit nonlinear I-V during the low resistive state, but this could be improved to linear behavior once a near-vertical etch profile was achieved. Device stacks with vertical etch profiles also showed an increase in forming voltage, reduced switching variability and increased endurance.

Performance of growing Yankasa rams Fed graded levels of ...

African Journals Online (AJOL)

A feeding trial which lasted eight (8) weeks was carried out to determine the intake and nutrient digestibility by growing Yankasa rams fed graded levels of Tamarindus indica leaves. Twelve Yankasa rams with average liveweight of 17.40kg were randomly allocated to three treatments of four replicates in a Randomized ...

Preference of redear sunfish on zebra mussels and rams-horn snails

Science.gov (United States)

French, John R. P.; Morgan, Michael N.

1995-01-01

We tested prey preferences of adult (200- to 222-mm long) redear sunfish (Lepomis microlophus) on two size classes of zebra mussels (Dreissena polymorpha) and two-ridge rams-horns (Helisoma anceps) in experimental aquaria. We also tested physical limitations on consuming these mollusks and determined prey bioenergetic profitability. Redear sunfish strongly preferred rams-horns over zebra mussels, but they displayed no size preference for either prey. Ingestion was not physically limited since both prey species up to 15-mm long fit within the pharyngeal gapes of redear sunfish. Rams-horns were more bioenergetically profitable than zebra mussels and ingestion of rams-horn shell fragments was about three times less than zebra mussels. Rams-horns were somewhat more resistant to shell-crushing, but all size ranges of both prey species tested were crushable by redear sunfish. These studies suggested that the redear sunfish should not be considered a panacea for biological control of zebra mussels.

Carbon nanotube scaffolds with controlled porosity as electromagnetic absorbing materials in the gigahertz range

Science.gov (United States)

González, M.; Crespo, M.; Baselga, J.; Pozuelo, J.

2016-05-01

Control of the microscopic structure of CNT nanocomposites allows modulation of the electromagnetic shielding in the gigahertz range. The porosity of CNT scaffolds has been controlled by two freezing protocols and a subsequent lyophilization step: fast freezing in liquid nitrogen and slow freezing at -20 °C. Mercury porosimetry shows that slowly frozen specimens present a more open pore size (100-150 μm) with a narrow distribution whereas specimens frozen rapidly show a smaller pore size and a heterogeneous distribution. 3D-scaffolds containing 3, 4, 6 and 7% CNT were infiltrated with epoxy and specimens with 2, 5 and 8 mm thicknesses were characterized in the GHz range. Samples with the highest pore size and porosity presented the lowest reflected power (about 30%) and the highest absorbed power (about 70%), which allows considering them as electromagnetic radiation absorbing materials.Control of the microscopic structure of CNT nanocomposites allows modulation of the electromagnetic shielding in the gigahertz range. The porosity of CNT scaffolds has been controlled by two freezing protocols and a subsequent lyophilization step: fast freezing in liquid nitrogen and slow freezing at -20 °C. Mercury porosimetry shows that slowly frozen specimens present a more open pore size (100-150 μm) with a narrow distribution whereas specimens frozen rapidly show a smaller pore size and a heterogeneous distribution. 3D-scaffolds containing 3, 4, 6 and 7% CNT were infiltrated with epoxy and specimens with 2, 5 and 8 mm thicknesses were characterized in the GHz range. Samples with the highest pore size and porosity presented the lowest reflected power (about 30%) and the highest absorbed power (about 70%), which allows considering them as electromagnetic radiation absorbing materials. Electronic supplementary information (ESI) available: Scheme of hydrogenated derivative of diglycidyl ether of bisphenol-A (HDGEBA) and m-xylylenediamine; X-ray diffractograms of pristine CNT

The Neurobiology of Sexual Partner Preferences in Rams

Science.gov (United States)

Roselli, Charles E.; Stormshak, Fred

2009-01-01

The question of what causes a male animal to seek out and choose a female as opposed to another male mating partner is unresolved and remains an issue of considerable debate. The most developed biologic theory is the perinatal organizational hypothesis, which states that perinatal hormone exposure mediates sexual differentiation of the brain. Numerous animal experiments have assessed the contribution of perinatal testosterone and/or estradiol exposure to the development of a male-typical mate preference, but almost all have used hormonally manipulated animals. In contrast, variations in sexual partner preferences occur spontaneously in domestic rams, with as many as 8% of the population exhibiting a preference for same-sex mating partners (male-oriented rams). Thus, the domestic ram is an excellent experimental model to study possible links between fetal neuroendocrine programming of neural mechanisms and adult sexual partner preferences. In this review, we present an overview of sexual differentiation in relation to sexual partner preferences. We then summarize results that test the relevance of the organizational hypothesis to expression of same-sex sexual partner preferences in rams. Finally, we demonstrate that the sexual differentiation of brain and behavior in sheep do not depend critically on aromatization of testosterone to estradiol. PMID:19446078

The neurobiology of sexual partner preferences in rams.

Science.gov (United States)

Roselli, Charles E; Stormshak, Fred

2009-05-01

The question of what causes a male animal to seek out and choose a female as opposed to another male mating partner is unresolved and remains an issue of considerable debate. The most developed biologic theory is the perinatal organizational hypothesis, which states that perinatal hormone exposure mediates sexual differentiation of the brain. Numerous animal experiments have assessed the contribution of perinatal testosterone and/or estradiol exposure to the development of a male-typical mate preference, but almost all have used hormonally manipulated animals. In contrast, variations in sexual partner preferences occur spontaneously in domestic rams, with as many as 8% of the population exhibiting a preference for same-sex mating partners (male-oriented rams). Thus, the domestic ram is an excellent experimental model to study possible links between fetal neuroendocrine programming of neural mechanisms and adult sexual partner preferences. In this review, we present an overview of sexual differentiation in relation to sexual partner preferences. We then summarize results that test the relevance of the organizational hypothesis to expression of same-sex sexual partner preferences in rams. Finally, we demonstrate that the sexual differentiation of brain and behavior in sheep does not depend critically on aromatization of testosterone to estradiol.

Seasonal variation in semen quality of Dorper rams using different ...

African Journals Online (AJOL)

Seasonal variation in semen quality of Dorper rams using different collection ... libitum throughout the trial, and all rams being fed a 2.5 kg maintenance diet per day. ... quality collected by the AV versus the EE collection method was recorded.

Solar-absorbing metamaterial microencapsulation of phase change materials for thermo-regulating textiles

Directory of Open Access Journals (Sweden)

William Tong

2015-04-01

Full Text Available This paper presents a novel concept for designing solar-absorbing metamaterial microcapsules of phase change materials (PCMs integrated with thermo-regulating smart textiles intended for coats or garments, especially for wear in space or cold weather on earth. The metamaterial is a periodically nanostructured metal-dielectric-metal thin film and can acquire surface plasmons to trap or absorb solar energy at subwavelength scales. This kind of metamaterial microencapsulation is not only able to take advantage of latent heat that can be stored or released from the PCMs over a tunable temperature range, but also has other advantages over conventional polymer microencapsulation of PCMs, such as enhanced thermal conductivity, improved flame-retardant capabilities, and usage as an extra solar power resource. The thermal analysis for this kind of microencapsulation has been done and can be used as a guideline for designing integrated thermo-regulating smart textiles in the future. These metamaterial microcapsules may open up new routes to enhancing thermo-regulating textiles with novel properties and added value.

Alpha-particle-induced soft errors in high speed bipolar RAM

International Nuclear Information System (INIS)

Mitsusada, Kazumichi; Kato, Yukio; Yamaguchi, Kunihiko; Inadachi, Masaaki

1980-01-01

As bipolar RAM (Random Access Memory) has been improved to a fast acting and highly integrated device, the problems negligible in the past have become the ones that can not be ignored. The problem of a-particles emitted from the radioactive substances in semiconductor package materials should be specifically noticed, which cause soft errors. The authors have produced experimentally the special 1 kbit bipolar RAM to investigate its soft errors. The package used was the standard 16 pin dual in-line type, with which the practical system mounting test and a-particle irradiation test have been performed. The results showed the occurrence of soft errors at the average rate of about 1 bit/700 device hour. It is concluded that the cause was due to the a-particles emitted from the package materials, and at the same time, it was found that the rate of soft error occurrence was able to be greatly reduced by shielding a-particles. The error rate significantly increased with the decrease of the stand-by current of memory cells and with the accumulated charge determined by time constant. The mechanism of soft error was also investigated, for which an approximate model to estimate the error rate by means of the effective noise charge due to a-particles and of the amount of reversible charges of memory cells is shown to compare it with the experimental results. (Wakatsuki, Y.)

Electronic bandstructure of the ZnTe absorber material

Energy Technology Data Exchange (ETDEWEB)

Fritsch, Daniel [Leibniz Institute for Solid State and Materials Research IFW Dresden (Germany); Schmidt, Heidemarie [Forschungszentrum Dresden-Rossendorf, Dresden (Germany)

2009-07-01

Due to its large absorption coefficient, zinc telluride proved to be useful for the production of high-efficiency multi-junction solar cells. Nowadays ZnTe with a mixture of zincblende and wurtzite phases is fabricated by thin film growth techniques. The optical properties of both phases have been extensively studied by ab initio density functional methods. Here we focus on the question whether the effective electron and hole mass in ZnTe are small enough to meet the high-efficiency expectation of the ZnTe absorber material in solar cells and present direction dependent effective mass and Luttinger and Luttinger-like parameters of cubic and wurtzite ZnTe, respectively. Making use of the transferability of ionic model potential parameters and the experimentally known transition energies of different II-VI compounds ZnX (X=O,S,Se,Te), we obtained one single set of cationic model parameters for the Zn atom. The calculations have been performed by means of the empirical pseudopotential method using a simple empty core model potential.

Review of radiation effects on ReRAM devices and technology

Science.gov (United States)

Gonzalez-Velo, Yago; Barnaby, Hugh J.; Kozicki, Michael N.

2017-08-01

A review of the ionizing radiation effects on resistive random access memory (ReRAM) technology and devices is presented in this article. The review focuses on vertical devices exhibiting bipolar resistance switching, devices that have already exhibited interesting properties and characteristics for memory applications and, in particular, for non-volatile memory applications. Non-volatile memories are important devices for any type of electronic and embedded system, as they are for space applications. In such applications, specific environmental issues related to the existence of cosmic rays and Van Allen radiation belts around the Earth contribute to specific failure mechanisms related to the energy deposition induced by such ionizing radiation. Such effects are important in non-volatile memory as the current leading technology, i.e. flash-based technology, is sensitive to the total ionizing dose (TID) and single-event effects. New technologies such as ReRAM, if competing with or complementing the existing non-volatile area of memories from the point of view of performance, also have to exhibit great reliability for use in radiation environments such as space. This has driven research on the radiation effects of such ReRAM technology, on both the conductive-bridge RAM as well as the valence-change memories, or OxRAM variants of the technology. Initial characterizations of ReRAM technology showed a high degree of resilience to TID, developing researchers’ interest in characterizing such resilience as well as investigating the cause of such behavior. The state of the art of such research is reviewed in this article.

RAMS - Regional Atmospheric Modelling System for decision support system SWD-WJ/RODOS

International Nuclear Information System (INIS)

Borysiewicz, M.; Potemski, S.; Galkowski, A.; Zelazinska, B.

1999-01-01

Presented is report aimed at implementation of RAMS (Regional Atmospheric Modelling System) to the decision support system SWD-WJ/RODOS. A comprehensive analysis has been made of different meteorological codes, both local and regional. RAMS code, developed at Colorado State University and Aster Division of Mission Research Corporation, has been selected for reasons presented in this report. RAMS has been adjusted to Polish conditions. Necessary data as topography and surface characteristics (roughness, land percentage, see surface temperature, land cover, soil type, etc.) have been obtained from US Geological Survey and NOAA ARL, Washington DC. Numerical tests have been performed on two nested grids, one covering large part of Europe, the other one covering Polish territory. RAMS requires meteorological input from global model and/or from local meteorological stations. Use has been made of data from the Institute of Meteorology and Water Management, Warsaw, and from European Center for Medium Range Forecast (ECMWF, Reading). For the later RAMS acted operationally what means that global data were delivered every 12 h from Reading via Internet to Swierk and subsequently 12 h weather forecast was calculated by RAMS. In a separate experiment RAMS forecast has been benchmarked with a forecast by UMPL code operated routinely at Warsaw University. Results of all of those test are presented in the report. Finally, some suggestions concerning further work has been put forward. (author)

New absorbent acoustic materials from plastic bottle remnants

Directory of Open Access Journals (Sweden)

del Rey, R.

2011-12-01

Full Text Available In the building acoustics field usually fibrous materials are used as sound absorbing materials. Nowadays polyester fiber is one of the most used but the pure chip of polyester has a problem. Polyester is obtained of petroleum and its price was increasing last years. This paper, presents an alternative polyester wool which obtained by PET treatment (recycle of plastic bottle’s. Absorption coefficient values at normal incidence measured in reverberation chamber were compared (new wool obtained by PET method and materials obtained from pure chip of polyester.Furthermore, this paper propound a empiric model that describe the acoustic performance of this new wool. The results have been good. The pure fiber has been replaced by recycle fiber in its manufacture process.

En el ámbito de acústica de la edificación es común el uso de materiales fibrosos como materiales absorbentes acústicos. Uno de estos materiales cada vez más utilizado es la lana de poliéster. Un problema que presenta el chip virgen de poliéster es que se obtiene del petróleo, cuyo precio no hace más que incrementarse en los últimos años. En este trabajo se presenta una lana de poliéster alternativa, obtenida mediante el tratamiento del PET, a través del conveniente ciclo de reciclado de botellas de plástico. Se comparan valores del coeficiente de absorción; en incidencia normal y en cámara reverberante de los materiales elaborados a partir de chip virgen y de las nuevas lanas obtenidas del PET. Además, se propone un modelo empírico de comportamiento acústico de estas nuevas lanas. Los resultados obtenidos han sido favorables, la fibra virgen ya ha sido sustituida por fibra reciclada en su proceso de fabricación.

RAMS - Regional Atmospheric Modelling System for decision support system SWD-WJ/RODOS[34 refs, 26 figs, 4 tabs]; RAMS - numeryczne prognozowanie pogody dla systemu wspomagania decyzji SWD-WJ/RODOS

Energy Technology Data Exchange (ETDEWEB)

Borysiewicz, M; Potemski, S [Inst. of Atomic Energy, Otwock-Swierk (Poland); Galkowski, A [Inst. Fizyki Plazmy i Laserowej Mikrosyntezy, Warsaw (Poland); Zelazinska, B [Inst. of Geophysics, Warsaw University, Warsaw (Poland)

1999-07-01

Presented is report aimed at implementation of RAMS (Regional Atmospheric Modelling System) to the decision support system SWD-WJ/RODOS. A comprehensive analysis has been made of different meteorological codes, both local and regional. RAMS code, developed at Colorado State University and Aster Division of Mission Research Corporation, has been selected for reasons presented in this report. RAMS has been adjusted to Polish conditions. Necessary data as topography and surface characteristics (roughness, land percentage, see surface temperature, land cover, soil type, etc.) have been obtained from US Geological Survey and NOAA ARL, Washington DC. Numerical tests have been performed on two nested grids, one covering large part of Europe, the other one covering Polish territory. RAMS requires meteorological input from global model and/or from local meteorological stations. Use has been made of data from the Institute of Meteorology and Water Management, Warsaw, and from European Center for Medium Range Forecast (ECMWF, Reading). For the later RAMS acted operationally what means that global data were delivered every 12 h from Reading via Internet to Swierk and subsequently 12 h weather forecast was calculated by RAMS. In a separate experiment RAMS forecast has been benchmarked with a forecast by UMPL code operated routinely at Warsaw University. Results of all of those test are presented in the report. Finally, some suggestions concerning further work has been put forward. (author)

Mohan Ram, Prof. Holenarasipur Yoganarasimham

Indian Academy of Sciences (India)

Mohan Ram, Prof. Holenarasipur Yoganarasimham Ph.D. (Delhi), FNA, FNASc, FNAAS Council Service: 1983-88; Vice-President: 1986-88. Date of birth: 24 September 1930. Specialization: Plant Growth & Development and Economic Botany Address: No. 174, SFS DDA Flats, Mukherjee Nagar, Delhi 110 009, U.T.

Recent developments of smart electromagnetic absorbers based polymer-composites at gigahertz frequencies

International Nuclear Information System (INIS)

Idris, Fadzidah Mohd.; Hashim, Mansor; Abbas, Zulkifly; Ismail, Ismayadi; Nazlan, Rodziah; Ibrahim, Idza Riati

2016-01-01

The rapid increase in electromagnetic interference has received a serious attention from researchers who responded by producing a variety of radar absorbing materials especially at high gigahertz frequencies. Ongoing investigation is being carried out in order to find the best absorbing materials which can fulfill the requirements for smart absorbing materials which are lightweight, broad bandwidth absorption, stronger absorption etc. Thus, to improve the absorbing capability, several important parameters need to be taken into consideration such as filler type, loading level, type of polymer matrix, physical thickness, grain sizes, layers and bandwidth. Therefore, this article introduces the electromagnetic wave absorption mechanisms and then reveals and reviews those parameters that enhance the absorption performance. - Highlights: • Development variety of radar absorbing materials especially at high gigahertz frequencies. • Best absorbing materials which can fulfill the requirements for smart absorbing materials which are lightweight, broad bandwidth absorption, stronger absorption etc. • Important parameters need to be taken into consideration to obtain stronger absorption and better performances.

Continuous exposure to sexually active rams extends estrous activity in ewes in spring.

Science.gov (United States)

Abecia, J A; Chemineau, P; Flores, J A; Keller, M; Duarte, G; Forcada, F; Delgadillo, J A

2015-12-01

Sexual activity in sheep is under photoperiodic control, which is the main environmental factor responsible for the seasonality of reproduction. However, other natural environmental factors such as presence of conspecifics can slightly influence the timing of onset and offset of the breeding season. In goats, we have found that the continuous presence of bucks that were rendered sexually active out of season by previous exposure to long days, prevented goats from displaying seasonal anestrus, which suggests that the relative contribution of photoperiod in controlling seasonal anestrus should be reevaluated in small ruminant species. The aim of this study was to assess whether the presence of sexually active rams that had been stimulated by artificial photoperiod and melatonin implants, reduces seasonal anestrus in sheep, by prolonging ovulatory activity in spring. Ewes were assigned to one of two groups (n = 16 and 15), which were housed in two separate barns, and kept in contact, either with the treated or the control rams between March and July. Vasectomized rams were either exposed to 2 months of long days followed by the insertion of three subcutaneous melatonin implants (treated rams, n = 8), or exposed to natural light conditions (control rams, n = 2). Estrus was monitored daily, and weekly plasma progesterone analyses indicated ovulatory activity. Ewes that were exposed to treated rams exhibited a higher proportion of monthly estrus than ewes exposed to the control rams (P ewes (one ewe was not considered because of the presence of persistent CL) exposed to stimulated rams exhibited estrous behavior in a cyclic manner. In contrast, all ewes exposed to control rams stopped estrous activity for a period of time during the study, such that this group exhibited a significantly longer anestrous season (mean ± standard error of the mean 89 ± 9 days) than did the ewes housed with treated rams (26 ± 10 days; P ewes housed with treated rams, 13 of

Ni-Al Alloys as Alternative EUV Mask Absorber

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Vu Luong

2018-03-01

Full Text Available Extreme ultraviolet (EUV lithography is being industrialized as the next candidate printing technique for high-volume manufacturing of scaled down integrated circuits. At mask level, the combination of EUV light at oblique incidence, absorber thickness, and non-uniform mirror reflectance through incidence angle, creates photomask-induced imaging aberrations, known as mask 3D (M3D effects. A possible mitigation for the M3D effects in the EUV binary intensity mask (BIM, is to use mask absorber materials with high extinction coefficient κ and refractive coefficient n close to unity. We propose nickel aluminide alloys as a candidate BIM absorber material, and characterize them versus a set of specifications that a novel EUV mask absorber must meet. The nickel aluminide samples have reduced crystallinity as compared to metallic nickel, and form a passivating surface oxide layer in neutral solutions. Composition and density profile are investigated to estimate the optical constants, which are then validated with EUV reflectometry. An oxidation-induced Al L2 absorption edge shift is observed, which significantly impacts the value of n at 13.5 nm wavelength and moves it closer to unity. The measured optical constants are incorporated in an accurate mask model for rigorous simulations. The M3D imaging impact of the nickel aluminide alloy mask absorbers, which predict significant M3D reduction in comparison to reference absorber materials. In this paper, we present an extensive experimental methodology flow to evaluate candidate mask absorber materials.

Aspects of Toxoplasma Infection on the Reproductive System of Experimentally Infected Rams (Ovis Aries

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Welber Daniel Zanetti Lopes

2009-01-01

Full Text Available Eight reproductive rams with no prior reproductive disease were distributed into three groups of infection with T. gondii: GI, 3 rams, 2.0×105 P strain oocysts; GII, 3 rams, 1.0×106 RH strain tachyzoites; GIII, 2 control rams. Clinical parameters were measured and serological evaluations (IIF were performed. Presence of the parasite in the semen was investigated by PCR and bioassay techniques. The rams presented clinical alterations (hyperthermia and apathy related to toxoplasmosis in both groups infected with Toxoplasma gondii. All the inoculated rams responded to antigenic stimulus, producing antibodies against T. gondii from postinoculation day 5 onwards. In ovine groups I and II, the greatest titers observed were 1 : 4096 and 1 : 8192, respectively. In semen samples collected from these two groups, the presence of T. gondii was detected by bioassay and PCR. This coccidian was isolated (bioassay and PCR in tissue pools (testicles, epididymis, seminal vesicle, and prostrate from two rams infected presenting oocysts and in one presenting tachyzoites.

Denials of Shipments for Radioactive Material - Indian Perspective

International Nuclear Information System (INIS)

Singh, Khaidem Ranjankumar; Hussain, S.A; Panda, G.K.; Singh, T. Dewan; Dinakaran, M.C.

2016-01-01

Radioactive material (RAM) needs to be transported for use in public health and industry and for production of nuclear power. In India, transport of RAM is governed by national and international regulations which are based on the IAEA Regulations for the safe transport of RAM. However, recently there were increasing numbers of instances of denials and delays of shipment of RAM, reported by many countries worldwide including India, despite compliance with regulations. In Indian experience, the reasons for denials of shipment of RAM by the carriers are varied in nature. From the feedback received from the participants (airport operators, airlines, courier and cargo service providers, cargo forwarding agents, port authorities and sea carriers) of awareness programmes on safe transport of RAM conducted from year 2008 onwards by Atomic Energy Regulatory Board (AERB) it became clear that the denials of shipments in India are mainly due to (1) perception of unnecessary fear for transport of RAM (2) lack of confidence and awareness on the procedures for acceptance of shipment of RAM (3) fear of risk during accidents with packages containing RAM (4) policy of the carriers not to accept consignment of dangerous goods (5) poor infrastructure at the major/transit ports (6) problems of transshipments and (7) shippers not having undergone dangerous goods training. In this paper, the Indian experience in dealing with the problems of denial/delay of shipments containing radioactive material and identified possible consequences of such denials including economical impact are discussed in detail. (author)

A Two-Step Absorber Deposition Approach To Overcome Shunt Losses in Thin-Film Solar Cells: Using Tin Sulfide as a Proof-of-Concept Material System

Energy Technology Data Exchange (ETDEWEB)

Steinmann, Vera; Chakraborty, Rupak; Rekemeyer, Paul H.; Hartman, Katy; Brandt, Riley E.; Polizzotti, Alex; Yang, Chuanxi; Moriarty, Tom; Gradečak, Silvija; Gordon, Roy G.; Buonassisi, Tonio

2016-08-31

As novel absorber materials are developed and screened for their photovoltaic (PV) properties, the challenge remains to reproducibly test promising candidates for high-performing PV devices. Many early-stage devices are prone to device shunting due to pinholes in the absorber layer, producing 'false-negative' results. Here, we demonstrate a device engineering solution toward a robust device architecture, using a two-step absorber deposition approach. We use tin sulfide (SnS) as a test absorber material. The SnS bulk is processed at high temperature (400 degrees C) to stimulate grain growth, followed by a much thinner, low-temperature (200 degrees C) absorber deposition. At a lower process temperature, the thin absorber overlayer contains significantly smaller, densely packed grains, which are likely to provide a continuous coating and fill pinholes in the underlying absorber bulk. We compare this two-step approach to the more standard approach of using a semi-insulating buffer layer directly on top of the annealed absorber bulk, and we demonstrate a more than 3.5x superior shunt resistance Rsh with smaller standard error ..sigma..Rsh. Electron-beam-induced current (EBIC) measurements indicate a lower density of pinholes in the SnS absorber bulk when using the two-step absorber deposition approach. We correlate those findings to improvements in the device performance and device performance reproducibility.

Effect of heterologous seminal plasma and semen extenders on motility of frozen-thawed ram spermatozoa

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G.A. Mataveia

2010-05-01

Full Text Available Ram seminal plasma increases the fertility of frozen-thawed ram spermatozoa deposited into the cervix. The aim of the current study was to compare the effect of ram seminal plasma to that of bull seminal plasma, dog prostatic fluid, protein-free TALP, TrilEq (Triladyl with 0.5 mℓ of Equex STM paste added to each 100 mℓ and heat-treated skim milk on longevity and percentages of progressively motile and aberrantly motile frozen-thawed ram spermatozoa. Three ejaculates from each of 6 rams were extended in TrilEq, pooled and frozen in straws as a single batch per ram. One hundred and eight straws (3 straws from each ram for each fluid were thawed in random order. Once thawed, a straw was emptied into a tube with 0.85mℓ of the appropriate fluid at 37 °C and kept at that temperature for 6 h. Motility was assessed at x200 magnification immediately (time zero and 2, 4 and 6 h after thawing. Progressive motility decreased from each time to the next (P < 0.05 and was 39.0% (0 h, 26.0% (2 h, 19.6% (4 h and 12.6% (6 h; SEM 1.24, n=108 for each group. Ram seminal plasma resulted in higher progressive motility than bull seminal plasma, lower than milk, and similar to the other fluids. Ram seminal plasma resulted in lower aberrant motility than protein-free TALP and similar aberrant motility to other fluids. The effect of ram seminal plasma and dog prostatic fluid was very similar. The effect of ram seminal plasma on the fertility of frozen-thawed ram spermatozoa deposited into the cervix is not due an exceptionally beneficial effect on the motility of spermatozoa.

Scanning tunneling spectroscopy on the chalcopyrite solar cell absorber material Cu(In,Ga)Se{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Moenig, Harry; Saez-Araoz, Rodrigo; Lux-Steiner, Martha [Freie Universitaet Berlin (Germany); Sadewasser, Sascha; Ennaoui, Ahmed; Kaufmann, Christian; Kropp, Timo; Lauermann, Iver; Muenchenberg, Tim; Schock, Hans-Werner; Streicher, Ferdinand [Hahn- Meitner-Institut Berlin (Germany)

2007-07-01

Cu(In,Ga)Se{sub 2}-based thin film solar cells have reached efficiencies close to 20%. Nevertheless, little is known about electronic transport and carrier recombination in this material on a microscopic scale. Especially grain boundaries in these polycrystalline materials are considered to play an important role in the performance of these solar cells. We applied scanning tunneling microscopy and spectroscopy to gain more insight in the electronic microstructure of the material. Our results point to lateral electronic inhomogeneities on the absorber surface and to an enhanced density of states at grain boundaries. The influence of charging effects is discussed.

Competitive light absorbers in photoactive dental resin-based materials.

Science.gov (United States)

Hadis, Mohammed A; Shortall, Adrian C; Palin, William M

2012-08-01

The absorbance profile of photoinitiators prior to, during and following polymerization of light curable resin-based materials will have a significant effect on the cure and color properties of the final material. So-called "colorless" photoinitiators are used in some light-activated resin-based composite restorative materials to lessen the yellowing effect of camphoroquinone (CQ) in order to improve the esthetic quality of dental restorations. This work characterizes absorption properties of commonly used photoinitiators, an acylphosphine oxide (TPO) and CQ, and assesses their influence on material discoloration. Dimethacrylate resin formulations contained low (0.0134 mol/dm(3)), intermediate (0.0405 mol/dm(3)) or high (0.0678 mol/dm(3)) concentrations of the photoinitiators and the inhibitor, butylated hydroxytoluene (BHT) at 0, 0.1 or 0.2% by mass. Disc shaped specimens (n = 3) of each resin were polymerized for 60s using a halogen light curing unit. Dynamic measurements of photoinitiator absorption, polymer conversion and reaction temperature were performed. A spectrophotometer was used to measure the color change before and after cure. GLM three-way analysis of variance revealed significant differences (pphotoinitiator type (df = 1; F = 176.12)>% BHT (df = 2, F = 13.17). BHT concentration affected the rate of polymerization and produced lower conversion in some of the CQ-based resins. Significant differences between photoinitiator type and concentrations were seen in color (where TPO resins became yellower and camphoroquinone resins became less yellow upon irradiation). Reaction temperature, kinetics and conversion also differed significantly for both initiators (presins producing a visually perceptible color change upon polymerization, the color change was significantly less than that produced with CQ-based resins. Although some photoinitiators such as TPO may be a more esthetic alternative to CQ, they may actually cause significant color contamination when

Liquid metal reactor absorber technology

International Nuclear Information System (INIS)

Pitner, A.L.

1990-10-01

The selection of boron carbide as the reference liquid metal reactor absorber material is supported by results presented for irradiation performance, reactivity worth compatibility, and benign failure consequences. Scram response requirements are met easily with current control rod configurations. The trend in absorber design development is toward larger sized pins with fewer pins per bundle, providing economic savings and improved hydraulic characteristics. Very long-life absorber designs appear to be attainable with the application of vented pin and sodium-bonded concepts. 3 refs., 3 figs

GASP. IX. Jellyfish galaxies in phase-space: an orbital study of intense ram-pressure stripping in clusters

Science.gov (United States)

Jaffé, Yara L.; Poggianti, Bianca M.; Moretti, Alessia; Gullieuszik, Marco; Smith, Rory; Vulcani, Benedetta; Fasano, Giovanni; Fritz, Jacopo; Tonnesen, Stephanie; Bettoni, Daniela; Hau, George; Biviano, Andrea; Bellhouse, Callum; McGee, Sean

2018-06-01

It is well known that galaxies falling into clusters can experience gas stripping due to ram pressure by the intra-cluster medium. The most spectacular examples are galaxies with extended tails of optically bright stripped material known as `jellyfish'. We use the first large homogeneous compilation of jellyfish galaxies in clusters from the WINGS and OmegaWINGS surveys, and follow-up MUSE observations from the GASP MUSE programme to investigate the orbital histories of jellyfish galaxies in clusters and reconstruct their stripping history through position versus velocity phase-space diagrams. We construct analytic models to define the regions in phase-space where ram-pressure stripping is at play. We then study the distribution of cluster galaxies in phase-space and find that jellyfish galaxies have on average higher peculiar velocities (and higher cluster velocity dispersion) than the overall population of cluster galaxies at all cluster-centric radii, which is indicative of recent infall into the cluster and radial orbits. In particular, the jellyfish galaxies with the longest gas tails reside very near the cluster cores (in projection) and are moving at very high speeds, which coincides with the conditions of the most intense ram pressure. We conclude that many of the jellyfish galaxies seen in clusters likely formed via fast (˜1-2 Gyr), incremental, outside-in ram-pressure stripping during first infall into the cluster in highly radial orbits.

Proposed Model for Integrating RAMS Method in the Design Process in Construction

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Saad Al-Jibouri

2010-05-01

Full Text Available There is a growing trend in the Netherlands for outsourcing public construction activities to the private sector through the use of integrated contracts. There is also an increasing emphasis from public clients on the use of RAMS and life cycle costing (LCC in the design process of infrastructural projects to improve the performance of designed systems and optimize the project cost. RAMS is an acronym for `reliability, availability, maintainability and safety' and represents a collection of techniques to provide predictions of the performance targets of the required system. Increasingly, RAMS targets are being specified in invitation to tender or contract documents and the parties responsible for the design are required to provide evidence of its application in their design. Recent evidence from practice, complemented with a literature study, has shown that the knowledge and application of RAMS in infrastructural designs are in their infancy compared with other industrial sectors and many designers in construction do not have the necessary knowledge and experience to apply it. This paper describes a proposed model for the integration of RAMS and LCC into the design process in construction. A variation of the model for the application of RAMS in `design, build, finance and maintain' (DBFM contracts that include maintenance requirements is also proposed. The two models involve providing guidelines to simplify the application of RAMs by the designers. The model has been validated for its practicality and usefulness during a workshop by experienced designers. DOI: 10.3763/aedm.2008.0100 Published in the Journal AEDM - Volume 5, Number 4, 2009 , pp. 179-192(14

Diesel NO{sub x} reduction by plasma-regenerated absorbent beds

Science.gov (United States)

Wallman, P.H.; Vogtlin, G.E.

1998-02-10

Reduction of NO{sub x} from diesel engine exhaust by use of plasma-regenerated absorbent beds is described. This involves a process for the reduction of NO{sub x} and particulates from diesel engines by first absorbing NO{sub x} onto a solid absorbent bed that simultaneously acts as a physical trap for the particulate matter, and second regenerating said solid absorbent by pulsed plasma decomposition of absorbed NO{sub x} followed by air oxidation of trapped particulate matter. The absorbent bed may utilize all metal oxides, but the capacity and the kinetics of absorption and desorption vary between different materials, and thus the composition of the absorbent bed is preferably a material which enables the combination of NO{sub x} absorption capability with catalytic activity for oxidation of hydrocarbons. Thus, naturally occurring or synthetically prepared materials may be utilized, particularly those having NO{sub x} absorption properties up to temperatures around 400 C which is in the area of diesel engine exhaust temperatures. 1 fig.

The TN-RAM - a new cask for shipping high activity irradiated hardware

International Nuclear Information System (INIS)

Neider, T.; Hanson, A.S.

1993-01-01

Transnuclear, Inc. has developed a Type B(U) radioactive material transport packaging designed specifically for the transport of dry, irradiated, non-fuel bearing components (NFBC). The TN-RAM is a transport cask in the configuration of a right circular cylinder, fabricated from lead and stainless steel, with wood-filled impact limiters attached at both ends. The lead and stainless steel construction of the lid, walls, and bottom provides a shielding effectiveness of approximately 7.1 inches (18 cm) lead equivalent. (J.P.N.)

Evaluation of absorbent materials for use as ad hoc dry decontaminants during mass casualty incidents as part of the UK's Initial Operational Response (IOR.

Directory of Open Access Journals (Sweden)

Nick Kassouf

Full Text Available The UK's Initial Operational Response (IOR is a revised process for the medical management of mass casualties potentially contaminated with hazardous materials. A critical element of the IOR is the introduction of immediate, on-scene disrobing and decontamination of casualties to limit the adverse health effects of exposure. Ad hoc cleansing of the skin with dry absorbent materials has previously been identified as a potential means of facilitating emergency decontamination. The purpose of this study was to evaluate the in vitro oil and water absorbency of a range of materials commonly found in the domestic and clinical environments and to determine the effectiveness of a small, but representative selection of such materials in skin decontamination, using an established ex vivo model. Five contaminants were used in the study: methyl salicylate, parathion, diethyl malonate, phorate and potassium cyanide. In vitro measurements of water and oil absorbency did not correlate with ex vivo measurements of skin decontamination. When measured ex vivo, dry decontamination was consistently more effective than a standard wet decontamination method ("rinse-wipe-rinse" for removing liquid contaminants. However, dry decontamination was ineffective against particulate contamination. Collectively, these data confirm that absorbent materials such as wound dressings and tissue paper provide an effective, generic capability for emergency removal of liquid contaminants from the skin surface, but that wet decontamination should be used for non-liquid contaminants.

Radiation Level Changes at RAM Package Surfaces

Energy Technology Data Exchange (ETDEWEB)

Opperman, Erich [Washington Savannah River Company; Hawk, Mark B [ORNL; Kapoor, Ashok [U.S. Department of Energy, Office of Packaging and Transportation; Natali, Ronald [R. B. Natali Consulting, Inc.

2010-01-01

This paper will explore design considerations required to meet the regulations that limit radiation level variations at external surfaces of radioactive material (RAM) packages. The radiation level requirements at package surfaces (e.g. TS-R-1 paragraphs 531 and 646) invoke not only maximum radiation levels, but also strict limits on the allowable increase in the radiation level during transport. This paper will explore the regulatory requirements by quantifying the amount of near surface movement and/or payload shifting that results in a 20% increase in the radiation level at the package surface. Typical IP-2, IP-3, Type A and Type B packaging and source geometries will be illustrated. Variations in surface radiation levels are typically the result of changes in the geometry of the surface due to an impact, puncture or crush event, or shifting and settling of radioactive contents.

Development of a Continuum Damage Mechanics Material Model of a Graphite-Kevlar(Registered Trademark) Hybrid Fabric for Simulating the Impact Response of Energy Absorbing Kevlar(Registered Trademark) Hybrid Fabric for Simulating the Impact Response of Energy Absorbing

Science.gov (United States)

Jackson, Karen E.; Fasanella, Edwin L.; Littell, Justin D.

2017-01-01

This paper describes the development of input properties for a continuum damage mechanics based material model, Mat 58, within LS-DYNA(Registered Trademark) to simulate the response of a graphite-Kevlar(Registered Trademark) hybrid plain weave fabric. A limited set of material characterization tests were performed on the hybrid graphite-Kevlar(Registered Trademark) fabric. Simple finite element models were executed in LS-DYNA(Registered Trademark) to simulate the material characterization tests and to verify the Mat 58 material model. Once verified, the Mat 58 model was used in finite element models of two composite energy absorbers: a conical-shaped design, designated the "conusoid," fabricated of four layers of hybrid graphite-Kevlar(Registered Trademark) fabric; and, a sinusoidal-shaped foam sandwich design, designated the "sinusoid," fabricated of the same hybrid fabric face sheets with a foam core. Dynamic crush tests were performed on components of the two energy absorbers, which were designed to limit average vertical accelerations to 25- to 40-g, to minimize peak crush loads, and to generate relatively long crush stroke values under dynamic loading conditions. Finite element models of the two energy absorbers utilized the Mat 58 model that had been verified through material characterization testing. Excellent predictions of the dynamic crushing response were obtained.

Neutron absorbers, and the production method

International Nuclear Information System (INIS)

Kayano, Hideo; Yajima, Seishi; Oono, Hironori.

1979-01-01

Purpose: To integrally sinter a metal powder and a metal network material thereby to obtain a material having a high neutron absorbing function, an excellent corrosion resistance and an excellent oxidation resistance. Method: An element having a high neutron absorbing function, such as Gd, or a compound thereof and a powder of a metal having excellent corrosion resistance, oxidation resistance and ductility, such as Fe, Cr or the like are uniformly mixed with each other. In a case where a substance having a neutron absorbing function is a hydroxide an organic complex or the like, it is formed into a gel-like substance and mixed uniformly with the metal powder, the gel-like substance being pasted, and covered on the surface of the metal powder and dried. Then, the mixture or the dry coated material is extended and the metal network material having excellent corrosion resistance, oxidation resistance and ductility is covered or interposed or between at least one layer of upper, intermediate or lower layers of said laminated material, and thereafter is subjected to cold or hot rolling, and then sintered and furthermore rolled, if necessary, the thus treated material being burned in vacuum or a non-oxidizing atmosphere. (Kamimura, M.)

Digital Alloy Absorber for Photodetectors

Science.gov (United States)

Hill, Cory J. (Inventor); Ting, David Z. (Inventor); Gunapala, Sarath D. (Inventor)

2016-01-01

In order to increase the spectral response range and improve the mobility of the photo-generated carriers (e.g. in an nBn photodetector), a digital alloy absorber may be employed by embedding one (or fraction thereof) to several monolayers of a semiconductor material (insert layers) periodically into a different host semiconductor material of the absorber layer. The semiconductor material of the insert layer and the host semiconductor materials may have lattice constants that are substantially mismatched. For example, this may performed by periodically embedding monolayers of InSb into an InAsSb host as the absorption region to extend the cutoff wavelength of InAsSb photodetectors, such as InAsSb based nBn devices. The described technique allows for simultaneous control of alloy composition and net strain, which are both key parameters for the photodetector operation.

Additive manufacturing of RF absorbers

Science.gov (United States)

Mills, Matthew S.

The ability of additive manufacturing techniques to fabricate integrated electromagnetic absorbers tuned for specific radio frequency bands within structural composites allows for unique combinations of mechanical and electromagnetic properties. These composites and films can be used for RF shielding of sensitive electromagnetic components through in-plane and out-of-plane RF absorption. Structural composites are a common building block of many commercial platforms. These platforms may be placed in situations in which there is a need for embedded RF absorbing properties along with structural properties. Instead of adding radar absorbing treatments to the external surface of existing structures, which adds increased size, weight and cost; it could prove to be advantageous to integrate the microwave absorbing properties directly into the composite during the fabrication process. In this thesis, a method based on additive manufacturing techniques of composites structures with prescribed electromagnetic loss, within the frequency range 1 to 26GHz, is presented. This method utilizes screen printing and nScrypt micro dispensing to pattern a carbon based ink onto low loss substrates. The materials chosen for this study will be presented, and the fabrication technique that these materials went through to create RF absorbing structures will be described. The calibration methods used, the modeling of the RF structures, and the applications in which this technology can be utilized will also be presented.

Design and analysis of hydraulic ram water pumping system

Science.gov (United States)

Hussin, N. S. M.; Gamil, S. A.; Amin, N. A. M.; Safar, M. J. A.; Majid, M. S. A.; Kazim, M. N. F. M.; Nasir, N. F. M.

2017-10-01

The current pumping system (DC water pump) for agriculture is powered by household electricity, therefore, the cost of electricity will be increased due to the higher electricity consumption. In addition, the water needs to be supplied at different height of trees and different places that are far from the water source. The existing DC water pump can pump the water to 1.5 m height but it cost money for electrical source. The hydraulic ram is a mechanical water pump that suitable used for agriculture purpose. It can be a good substitute for DC water pump in agriculture use. The hydraulic ram water pumping system has ability to pump water using gravitational energy or the kinetic energy through flowing source of water. This project aims to analyze and develop the water ram pump in order to meet the desired delivery head up to 3 meter height with less operation cost. The hydraulic ram is designed using CATIA software. Simulation work has been done using ANSYS CFX software to validate the working concept. There are three design were tested in the experiment study. The best design reached target head of 3 m with 15% efficiency and flow rate of 11.82l/min. The results from this study show that the less diameter of pressure chamber and higher supply head will create higher pressure.

The Influence Of Loam Type And Cement Content On The Compressive Strength Of Rammed Earth

Directory of Open Access Journals (Sweden)

Narloch P. L.

2015-03-01

Full Text Available Currently, a worldwide dynamic rise of interest in using soil as a construction material can be observed. This trend is evident in the rapid rise of the amount of standards that deal with soil techniques. In 2012 the number of standards was larger by one third than five years prior. To create a full standardization of the rammed earth technique it is necessary to take into account the diversity of used soil and stabilizing additives. The proportion of the components, the process of element production and the research methods must also be made uniform. The article describes the results of research on the compressive strength of rammed earth samples that differed from each other with regards to the type of loam used for the mixture and the amount of the stabilizer. The stabilizer used was Portland cement CEM I 42.5R. The research and the analysis of the results were based on foreign publications, the New Zealand standard NZS 4298:1998, the American Standard NMAC14.7.4 and archival Polish Standards from the 1960’s that dealt with earth material.

La Palabra de Ramón Frediani: Las Retenciones

Directory of Open Access Journals (Sweden)

Marcelo Coser

2008-04-01

Full Text Available En el marco del programa "Prisma Económico" del Instituto de Economía y Finanzas (IEF, Marcelo Coser, su conductor, consulta al Profesor Ramón Osvaldo Frediani, docente de la asignatura “Economía Regional y Urbana” e investigadordel Instituto. Durante la nota, Ramón Frediani nos da sus conceptos sobre las debatidas retenciones y los propósitos que éstas persiguen, brindando su visión respecto al accionar del Gobierno Nacional.

Thin absorbers for large-area soft X-ray microcalorimeters

Energy Technology Data Exchange (ETDEWEB)

Rocks, L. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States)]. E-mail: rocks@wisp.physics.wisc.edu; Anderson, M.B. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Bilgri, N. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Brekosky, R. [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Gwynne Crowder, S. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Figueroa-Feliciano, E. [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Kelley, R. [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Kilbourne, C.A. [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Lai, T. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Lindeman, M.A. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Man, J. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); McCammon, D. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Nelms, K.L. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Porter, F.S. [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Sivananthan, S. [University of Illinois at Chicago, Chicago, IL 60607 (United States); Vidugiris, G. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Zhao, J. [University of Illinois at Chicago, Chicago, IL 60607 (United States)

2006-04-15

The X-ray Quantum Calorimeter (XQC) sounding rocket experiment utilizes a microcalorimeter array for observing the diffuse soft X-ray background. Observations of such low surface-brightness targets require a large-area detector. We will be using an array of large absorbers. Good absorbers must rapidly and completely thermalize photons, have small heat capacity for high stopping efficiency and have good lateral thermal transport. For observing the soft X-ray background (energies <1 keV), the volume and heat capacity of absorber material can be kept to a minimum by making the absorbers only as thick as needed for high quantum efficiency at these low energies. These thin, large-area absorbers are not self-supporting and have poor lateral heat transport. Depositing the absorber material on a Si substrate provides support and improves lateral thermal conduction. We present heat capacity results for thin HgTe and thin Bi, each on Si substrates. We also describe the HgTe absorber fabrication.

Radar absorbing properties of carbon nanotubes/polymer ...

Indian Academy of Sciences (India)

This research is devoted to the study of radar absorbing properties of the composites, based on the epoxy binder and ... Radar absorbing materials; carbon nanotubes; nanocomposites; reflection loss. 1. ..... So, for example, the papers of [3–5 ...

Absorbed Energy in Ship Collisions and Grounding

DEFF Research Database (Denmark)

Pedersen, Preben Terndrup; Zhang, Shengming

1998-01-01

is that the absorbed energy does not depend on the arrangement of the structure, the material properties, and the damage mode.The purpose of the present paper is to establish a new simple relation between the absorbed energy and the destroyed material volume, which can be used as a design tool for analysis of ship...... collisions and grounding. The developed expressions reflect the structural arrangement, the material properties and different damage patterns.The present method is validated against a large number of existing experimental results and detailed numerical simulation results. Applications to full-sale ship...

PERFORMANCE OF FAT-TAILED RAMS FED COMPLETE FEED BASED OIL PALM FRONDS

Directory of Open Access Journals (Sweden)

A. Hamidah

2014-10-01

Full Text Available The aim of this experiment was to evaluate the performance of fat-tailed rams fed complete feedbased oil palm fronds (OPF. This experiment was arranged in Completely Randomized Design (CRDwith 5 treatments and 4 replications i.e. 0, 25, 50, 75 and 100% of OPF substituting fields grass incomplete feed for A, B, C, D and E treatments, respectively. Twenty fat-tailed rams were fed twice at08.00 and 14.00 with pellet of complete feed for 4 months. The result of this experiment showed thatOPF significantly influenced nutrient consumption, average daily gain (ADG and feed efficiency ratio(FER. Oil palm fronds significantly affected (P<0.05 fat-tailed rams’s dry matter intake (DMI, organicmatter intake (OMI, crude protein intake (CPI, ADG and FER. The highest DMI, OMI, CPI, ADG, andFER of fat-tailed rams was in C treatment and significantly different from the others. It was concludedthat C treatment was the best treatment which can give the best fat-tailed rams performance. The OPFcan be used to replace the field grass as feed up to 75% proportion in complete feed and could increasethe performance and productivity of fat-tailed rams.

State-Transition-Aware Spilling Heuristic for MLC STT-RAM-Based Registers

Directory of Open Access Journals (Sweden)

Yuanhui Ni

2017-01-01

Full Text Available Multilevel Cell Spin-Transfer Torque Random Access Memory (MLC STT-RAM is a promising nonvolatile memory technology to build registers for its natural immunity to electromagnetic radiation in rad-hard space environment. Unlike traditional SRAM-based registers, MLC STT-RAM exhibits unbalanced write state transitions due to the fact that the magnetization directions of hard and soft domains cannot be flipped independently. This feature leads to nonuniform costs of write states in terms of latency and energy. However, current SRAM-targeting register allocations do not have a clear understanding of the impact of the different write state-transition costs. As a result, those approaches heuristically select variables to be spilled without considering the spilling priority imposed by MLC STT-RAM. Aiming to address this limitation, this paper proposes a state-transition-aware spilling cost minimization (SSCM policy, to save power when MLC STT-RAM is employed in register design. Specifically, the spilling cost model is first constructed according to the linear combination of different state-transition frequencies. Directed by the proposed cost model, the compiler picks up spilling candidates to achieve lower power and higher performance. Experimental results show that the proposed SSCM technique can save energy by 19.4% and improve the lifetime by 23.2% of MLC STT-RAM-based register design.

Effect of the bio-absorbent on the microwave absorption property of the flaky CIPs/rubber absorbers

Energy Technology Data Exchange (ETDEWEB)

Cheng, Yang; Xu, Yonggang, E-mail: xuyonggang221@163.com; Cai, Jun; Yuan, Liming; Zhang, Deyuan

2015-09-01

Microwave absorbing composites filled with flaky carbonyl iron particles (CIPs) and the bio-absorbent were prepared by using a two-roll mixer and a vulcanizing machine. The electromagnetic (EM) parameters were measured by a vector network analyzer and the reflection loss (RL) was measured by the arch method in the frequency range of 1–4 GHz. The uniform dispersion of the absorbents was verified by comparing the calculated RL with the measured one. The results confirm that as the bio-absorbent was added, the permittivity was increased due to the volume content of absorbents, and the permeability was enlarged owing to the volume content of CIPs and interactions between the two absorbents. The composite filled with bio-absorbents achieved an excellent absorption property at a thickness of 1 mm (minimum RL reaches −7.8 dB), and as the RL was less than −10 dB the absorption band was widest (2.1–3.8 GHz) at a thickness of 2 mm. Therefore, the bio-absorbent is a promising additive candidate on fabricating microwave absorbing composites with a thinner thickness and wider absorption band. - Graphical abstract: Morphology of composites filled with flaky CIPs and the bio-absorbent. The enhancement of bio-absorbent on the electromagnetic absorption property of composites filled with flaky carbonyl iron particles (CIPs) is attributed to the interaction of the two absorbents. The volume content of the FCMPs with the larger shape CIPs play an important role in this effects, the composites filled with irons and bio-absorbents can achieve wider-band and thinner-thickness absorbing materials. - Highlights: • Absorbers filled with bio-absorbents and CIPs was fabricated. • Bio-absorbents enhanced the permittivity and permeability of the composites. • The absorbent interactions play a key role in the enhancement mechanism. • Bio-absorbents enhanced the composite RL in 1–4 GHz.

A Ramón Valdés, In Memoriam.

Directory of Open Access Journals (Sweden)

Joan Prat

2012-06-01

Full Text Available I. Cuando Verena Stolcke y poco después Aurelio Díaz me invitaron a participar en este acto de homenaje y memoria a Ramón Valdés del Toro pensé, en primer lugar,que prepararía algo sobre el papel de Ramón en los inicios de la Antropología española.Comencé a escribirlo pero resultaba un texto demasiado erudito, aburrido y difícil de digerir. En esta situación de stand by agradecí un correo electrónico de Verena en el que se nos instaba a “intervenir a vuestro aire en torno a vuestros recuerdos personales del magisterio y de la obra de Ramón”. Respiré aliviado ya que esto me resultaba mucho más cómodo y gratificante. En las líneas que siguen no he dedicado mucho esfuerzo a disimular el tono coloquial que tuvo la intervención oral.

A wideband absorber for television studios

Science.gov (United States)

Baird, M. D. M.

The acoustic treatment in BBC television has taken various forms to date, all of which have been relatively expensive, some of which provide inadequate absorption. An investigation has been conducted into the possibilities of producing a new type of wideband absorber which would be more economic, also taking installation time into account, than earlier designs. This Report describes the absorption coefficient measurements made on various combinations of materials, from which a wideband sound absorber has been developed. The absorber works efficiently between 50 Hz and 10 kHz, is simple and easy to construct using readily available materials, and is fire resistant. The design lends itself, if necessary, to on-site fine tuning, and savings in the region of 50 percent can be achieved in terms of cost and space with respect to previous designs.

Metamaterial Absorber for Electromagnetic Waves in Periodic Water Droplets.

Science.gov (United States)

Yoo, Young Joon; Ju, Sanghyun; Park, Sang Yoon; Ju Kim, Young; Bong, Jihye; Lim, Taekyung; Kim, Ki Won; Rhee, Joo Yull; Lee, YoungPak

2015-09-10

Perfect metamaterial absorber (PMA) can intercept electromagnetic wave harmful for body in Wi-Fi, cell phones and home appliances that we are daily using and provide stealth function that military fighter, tank and warship can avoid radar detection. We reported new concept of water droplet-based PMA absorbing perfectly electromagnetic wave with water, an eco-friendly material which is very plentiful on the earth. If arranging water droplets with particular height and diameter on material surface through the wettability of material surface, meta-properties absorbing electromagnetic wave perfectly in GHz wide-band were shown. It was possible to control absorption ratio and absorption wavelength band of electromagnetic wave according to the shape of water droplet-height and diameter- and apply to various flexible and/or transparent substrates such as plastic, glass and paper. In addition, this research examined how electromagnetic wave can be well absorbed in water droplets with low electrical conductivity unlike metal-based metamaterials inquiring highly electrical conductivity. Those results are judged to lead broad applications to variously civilian and military products in the future by providing perfect absorber of broadband in all products including transparent and bendable materials.

Investigating EMIC Wave Dynamics with RAM-SCB-E

Science.gov (United States)

Jordanova, V. K.; Fu, X.; Henderson, M. G.; Morley, S.; Welling, D. T.; Yu, Y.

2017-12-01

The distribution of ring current ions and electrons in the inner magnetosphere depends strongly on their transport in realistic electric (E) and magnetic (B) fields and concurrent energization or loss. To investigate the high variability of energetic particle (H+, He+, O+, and electron) fluxes during storms selected by the GEM Surface Charging Challenge, we use our kinetic ring current model (RAM) two-way coupled with a 3-D magnetic field code (SCB). This model was just extended to include electric field calculations, making it a unique, fully self-consistent, anisotropic ring current-atmosphere interactions model, RAM-SCB-E. Recently we investigated electromagnetic ion cyclotron (EMIC) instability in a local plasma using both linear theory and nonlinear hybrid simulations and derived a scaling formula that relates the saturation EMIC wave amplitude to initial plasma conditions. Global dynamic EMIC wave maps obtained with our RAM-SCB-E model using this scaling will be presented and compared with statistical models. These plasma waves can affect significantly both ion and electron precipitation into the atmosphere and the subsequent patterns of ionospheric conductance, as well as the global ring current dynamics.

RANGE RAM: a long-term planning method for managing grazing lands

Science.gov (United States)

Henricus C. Jansen

1976-01-01

Range RAM (Resource Allocation Method) is a computerized planning method designed to assist range managers in developing and selecting alternatives in spatial and temporal allocation of resources. The technique is applicable at the frest or district management levels, or their equivalents. Range RAM can help formulate plans that maximize the production of range outputs...

A Simplified Model of an Offset Ram Press for Sunflower Oil ...

African Journals Online (AJOL)

This paper presents the theoretical analysis of a simplified model of a ram press. The design of the ram press is based on the classical slider-crank mechanism. A force analysis of the press was performed for several successive positions of the driving lever (handle) and for a range of values of certain dimensionless ...

Comparison of sexual performance and testicular characteristics of melatonin treated Kivircik and Charollais rams during the non-breeding season

Directory of Open Access Journals (Sweden)

M. Cevik

Full Text Available ABSTRACT This study was conducted to investigate the effects of melatonin implantation on basic testicular characteristics and reproductive performance of Kivircik and Charollais rams and ewes during the non-breeding season. In this study, 8 Kivircik and 6 Charollais rams were used. Rams were implanted with 54 mg melatonin according to the manufacturer's instructions. At melatonin implantation and at ram introduction the reproductive performance and testicular characteristics were evaluated. Throughout the experimental period, rams were permanently kept outdoors under conditions of natural day length and at ambient temperature. The effects of exogenous melatonin treatments on the reproductive performances of rams and ewes, estrus response, pregnancy rate, litter size and twinning rate of ewes were evaluated in all groups. Libido values were significantly higher in Charollais rams compared to Kivircik rams (P<0.001. Testicular volume (TV was increased in both ram breeds. Scrotal length (SL was also increased in both Kivircik and Charollais rams (P<0.01. In conclusion, we showed that the treatment of rams with slow release melatonin implants increased scrotal diameters and testicular volumes in both Kivircik and Charollais rams. Furthermore, melatonin implantation improved the reproductive performances of ewes naturally mated with these melatonin implanted rams during non-breeding season.

A study of environmental radon levels in rammed earth dwellings in the south west of Western Australia

International Nuclear Information System (INIS)

Walsh, M.; Jennings, P.

2002-01-01

Indoor radon and thoron progeny Equilibrium Equivalent Concentrations (EEC) were measured with a portable 'Radon Sniffer' in 10 rammed earth dwellings and 10 conventional dwellings in Margaret River in the South West of Western Australia. Natural background gamma radiation was also measured within the dwellings. The results of this study show that the mean indoor radon progeny concentrations in rammed earth and non-rammed earth dwellings was 24 Bq m -3 EEC and 9.3 Bq m -3 EEC respectively. The mean indoor thoron progeny concentrations in rammed earth and non-rammed earth dwellings was 3.9 Bq m -3 EEC and 0.8 Bq m -3 EEC respectively. The ranges of combined indoor radon and thoron progeny concentrations in rammed earth and non-rammed earth dwellings were between 2.1 and 76 Bq m -3 EEC and 2.0 and 27 Bq m -3 EEC respectively. The mean annual effective radiation dose equivalents from combined indoor radon and thoron progeny concentrations EEC using UNSCEAR's (1982) conversion factors in rammed earth and non-rammed earth dwellings were 4.1 mSv y -1 and 2.2 mSv y -1 respectively. Copyright (2002) Australasian Radiation Protection Society Inc

Expression of basal cell marker revealed by RAM11 antibody during epithelial regeneration in rabbits.

Directory of Open Access Journals (Sweden)

Tadeusz Cichocki

2010-06-01

Full Text Available RAM11 is a mouse monoclonal anti-rabbit macrophage antibody recognizing connective tissue and vascular macrophages. Our previous report showed that RAM11 reacted with basal cells of stratified squamous epithelia of rabbit skin, oral mucosa and esophagus. The aim of the present study was to follow the appearance of RAM11 immunoreactivity in basal cells of regenerating oral epithelium in rabbits. No RAM11 immunostaining was observed in the regenerating epithelium examined on days 1 and 3 of wound healing. A weak immunofluorescence first appeared on day 7 in single basal cells and 32% of RAM11- positive basal cells were observed on day 14. These findings indicate that expression of the antigen recognized by RAM11 antibody is a transient event in the differentiation of oral keratinocytes which not always occurs during epithelial repair, although it is a constant feature of epithelial turnover in mature epithelium. Therefore this antigen can be regarded as basal cell marker only in mature stratified squamous epithelia.

Using Oblivious RAM in Genomic Studies

NARCIS (Netherlands)

Karvelas, Nikolaos P.; Peter, Andreas; Katzenbeisser, Stefan; Garcia-Alfaro, Joaquin; Navarro-Aribas, Guillermo; Hartenstein, Hannes; Herrera-Joancomarti, Jordi

2017-01-01

Since the development of tree-based Oblivious RAMs by Shi et al. it has become apparent that privacy preserving outsourced storage can be practical. Although most current constructions follow a client-server model, in many applications, such as Genome Wide Association Studies (GWAS), it is desirable

Nanostructured composites based on carbon nanotubes and epoxy resin for use as radar absorbing materials

Energy Technology Data Exchange (ETDEWEB)

Silva, Valdirene Aparecida [Instituto Tecnologico de Aeronautica (ITA), Sao Jose dos Campos, SP (Brazil); Folgueras, Luiza de Castro; Candido, Geraldo Mauricio; Paula, Adriano Luiz de; Rezende, Mirabel Cerqueira, E-mail: mirabelmcr@iae.cta.br [Instituto de Aeronautica e Espaco (IAE), Sao Jose dos Campos, SP (Brazil). Div. de Materiais; Costa, Michelle Leali [Universidade Estadual Paulista Julio de Mesquita Filho (DMT/UNESP), Guaratingueta, SP (Brazil). Dept. de Materiais e Tecnologia

2013-07-01

Nanostructured polymer composites have opened up new perspectives for multifunctional materials. In particular, carbon nanotubes (CNTs) present potential applications in order to improve mechanical and electrical performance in composites with aerospace application. The combination of epoxy resin with multi walled carbon nanotubes results in a new functional material with enhanced electromagnetic properties. The objective of this work was the processing of radar absorbing materials based on formulations containing different quantities of carbon nanotubes in an epoxy resin matrix. To reach this objective the adequate concentration of CNTs in the resin matrix was determined. The processed structures were characterized by scanning electron microscopy, rheology, thermal and reflectivity in the frequency range of 8.2 to 12.4 GHz analyses. The microwave attenuation was up to 99.7%, using only 0.5% (w/w) of CNT, showing that these materials present advantages in performance associated with low additive concentrations (author)

Fire effects in Pinus uncinata Ram plantations

Directory of Open Access Journals (Sweden)

Adrián Cardil Forradellas

2016-04-01

Full Text Available Aim of study: Understanding fire ecology of main forest species is essential for a sound, scientifically based on managing of wildlands and also to assess likely implications due to changes in fire regime under a global change scenario. Few references can be found about fire ecology of Pinus uncinata Ram. (PU. PU species grows in the Central Pyrenees where large, severe wildland fires did not occur frequently in the past. However, several fires with extreme fire behavior have affected PU stands in last years and they might disturb other PU forest in the future.Area of study: Cabdella fire (February 2012, in Lleida province, is one of the several wildland fires occurred in 2012 (winter season in the Central Pyrenees. Fire affected a large PU plantation (102 ha located at 1.800-2,100 meters above the sea.Material and methods: We have analyzed first order fire effects in three fireline intensity thresholds along three years in terms of mortality ratio, scorched height, percentage of scorched crown volume and bark char height.Main results: PU seems to be a very tolerant species to low and medium fire line intensity but fire effects were very significant when fire line intensity was high. In medium fireline intensity sites, probability of mortality ranged from 15 to 30% and the dead trees had the highest values on scorched height and percentage of scorched crown volume.Research highlights: Results from this work supports that prescribed burning might be used to efficiently decrease fuel load and fuel vertical continuity while avoiding considerable PU mortality. It also displayed that when fuel management has been implemented, PU mortality might be limited even under extreme fire behavior.Abbreviations used: PU: Pinus uncinata Ram.

PERFORMANCE OF FAT-TAILED RAMS FED COMPLETE FEED BASED OIL PALM FRONDS

Directory of Open Access Journals (Sweden)

A. Hamidah

2011-09-01

Full Text Available The aim of this experiment was to evaluate the performance of fat-tailed rams fed complete feed based oil palm fronds (OPF. This experiment was arranged in Completely Randomized Design (CRD with 5 treatments and 4 replications i.e. 0, 25, 50, 75 and 100% of OPF substituting fields grass in complete feed for A, B, C, D and E treatments, respectively. Twenty fat-tailed rams were fed twice at 08.00 and 14.00 with pellet of complete feed for 4 months. The result of this experiment showed that OPF significantly influenced nutrient consumption, average daily gain (ADG and feed efficiency ratio (FER. Oil palm fronds significantly affected (P<0.05 fat-tailed rams’s dry matter intake (DMI, organic matter intake (OMI, crude protein intake (CPI, ADG and FER. The highest DMI, OMI, CPI, ADG, and FER of fat-tailed rams was in C treatment and significantly different from the others. It was concluded that C treatment was the best treatment which can give the best fat-tailed rams performance. The OPF can be used to replace the field grass as feed up to 75% proportion in complete feed and could increase the performance and productivity of fat-tailed rams.

Methodology for assessing the safety of Hydrogen Systems: HyRAM 1.1 technical reference manual

Energy Technology Data Exchange (ETDEWEB)

Groth, Katrina; Hecht, Ethan; Reynolds, John Thomas; Blaylock, Myra L.; Erin E. Carrier

2017-03-01

The HyRAM software toolkit provides a basis for conducting quantitative risk assessment and consequence modeling for hydrogen infrastructure and transportation systems. HyRAM is designed to facilitate the use of state-of-the-art science and engineering models to conduct robust, repeatable assessments of hydrogen safety, hazards, and risk. HyRAM is envisioned as a unifying platform combining validated, analytical models of hydrogen behavior, a stan- dardized, transparent QRA approach, and engineering models and generic data for hydrogen installations. HyRAM is being developed at Sandia National Laboratories for the U. S. De- partment of Energy to increase access to technical data about hydrogen safety and to enable the use of that data to support development and revision of national and international codes and standards. This document provides a description of the methodology and models contained in the HyRAM version 1.1. HyRAM 1.1 includes generic probabilities for hydrogen equipment fail- ures, probabilistic models for the impact of heat flux on humans and structures, and computa- tionally and experimentally validated analytical and first order models of hydrogen release and flame physics. HyRAM 1.1 integrates deterministic and probabilistic models for quantifying accident scenarios, predicting physical effects, and characterizing hydrogen hazards (thermal effects from jet fires, overpressure effects from deflagrations), and assessing impact on people and structures. HyRAM is a prototype software in active development and thus the models and data may change. This report will be updated at appropriate developmental intervals.

Energy Absorbing Effectiveness – Different Approaches

Directory of Open Access Journals (Sweden)

Kotełko Maria

2018-03-01

Full Text Available In the paper the study of different crashworthiness indicators used to evaluate energy absorbing effectiveness of thin-walled energy absorbers is presented. Several different indicators are used to assess an effectiveness of two types of absorbing structures, namely thin-walled prismatic column with flaws and thin-walled prismatic frustum (hollow or foam filled in both cases subjected to axial compressive impact load. The indicators are calculated for different materials and different geometrical parameters. The problem of selection of the most appropriate and general indicators is discussed.

Proposal concerning the absorbed dose conversion factor

Energy Technology Data Exchange (ETDEWEB)

Shiragai, A [National Inst. of Radiological Sciences, Chiba (Japan)

1978-03-01

New definitions of the absorbed dose conversion factors Csub(lambda) and Csub(E) are proposed. The absorbed dose in water is given by the product of absorbed dose conversion factor, exposure calibration factor, ionisation chamber reading, cap displacement correction factor and perturbation correction factor. At exposure calibration the material of the build-up cap must be the same as that of the chamber wall. An ionisation chamber of which the wall material is water-equivalent or air-equivalent may be used. In the latter case the wall must be thin. For these two cases absorbed dose conversion factors are introduced and it is recommended that either of the two sets should be adopted. Furthermore, if the chamber wall is neither water- nor air-equivalent, the factor by which these currently defined values should be multiplied is also given: again the wall must be thin. The ICRU definitions of Csub(lambda) and Csub(E) are inconsistent, as recently pointed out, while the definitions presented here are consistent.

the effect of freezing method on the survival of ram spermatozoa

African Journals Online (AJOL)

Sci.2l, 351. SALAIIiON, S., 1970. The survival of ram spermatozoa following pellet freezing below-79oC. Aust- .1. hiol..n'r. 13. 459. SALAMON, S. & BRANDON, M.R., l97l . Effect of compcition of thawing solution on sunrival of ram spernntozoa iroznn by the pellet method. Aust. J. biol. Sci. 24,355. SALAMON, S. & VISSER, D., ...

The New S-RAM Air Variable Compressor/Expander for Heat Pump and Waste Heat to Power Application

Energy Technology Data Exchange (ETDEWEB)

Dehoff, Ryan R [ORNL; Jestings, Lee [S-RAM Dynamics; Conde, Ricardo [S-RAM Dynamics

2016-05-23

S-RAM Dynamics (S-RAM) has designed an innovative heat pump system targeted for commercial and industrial applications. This new heat pump system is more efficient than anything currently on the market and utilizes air as the refrigerant instead of hydrofluorocarbon (HFC) refrigerants, leading to lower operating costs, minimal environmental costs or concerns, and lower maintenance costs. The heat pumps will be manufactured in the United States. This project was aimed at determining the feasibility of utilizing additive manufacturing to make the heat exchanger device for the new heat pump system. ORNL and S-RAM Dynamics collaborated on determining the prototype performance and subsequently printing of the prototype using additive manufacturing. Complex heat exchanger designs were fabricated using the Arcam electron beam melting (EBM) powder bed technology using Ti-6Al-4V material. An ultrasonic welding system was utilized in order to remove the powder from the small openings of the heat exchanger. The majority of powder in the small chambers was removed, however, the amount of powder remaining in the heat exchanger was a function of geometry. Therefore, only certain geometries of heat exchangers could be fabricated. SRAM Dynamics evaluated a preliminary heat exchanger design. Although the results of the additive manufacturing of the heat exchanger were not optimum, a less complex geometry was demonstrated. A sleeve valve was used as a demonstration piece, as engine designs from S-RAM Dynamics require the engine to have a very high density. Preliminary designs of this geometry were successfully fabricated using the EBM technology.

C-RAM: breaking mobile device memory barriers using the cloud

OpenAIRE

Pamboris, A; Pietzuch, P

2015-01-01

?Mobile applications are constrained by the available memory of mobile devices. We present C-RAM, a system that uses cloud-based memory to extend the memory of mobile devices. It splits application state and its associated computation between a mobile device and a cloud node to allow applications to consume more memory, while minimising the performance impact. C-RAM thus enables developers to realise new applications or port legacy desktop applications with a large memory footprint to mobile ...

Aluminum alloy excellent in neutron absorbing performance

International Nuclear Information System (INIS)

Iida, Tetsuya; Tamamura, Tadao; Morimoto, Hiroyuki; Ouchi, Ken-ichiro.

1987-01-01

Purpose: To obtain structural materials made of aluminum alloys having favorable neutron absorbing performance and excellent in the performance as structural materials such as processability and strength. Constitution: Powder of Gd 2 O 3 as a gadolinium compound or metal gadolinium is uniformly mixed with the powder of aluminum or aluminum alloy. The amount of the gadolinium compound added is set to 0.1 - 30 % by weight. No sufficient neutron absorbing performance can be obtained if it is less than 0.1 % by weight, whereas the processability and mechanical property of the alloy are degraded if it exceeds 30 % by weight. Further, the grain size is set to less about 50 μm. Further, since the neutron absorbing performance varies greatly if the aluminum powder size exceeds 100 μm, the diameter is set to less than about 100 μm. These mixtures are molded in a hot press. This enables to obtain aimed structural materials. (Takahashi, M.)

Nb multilayer planarization technology for a subnanosecond Josephson 1K-bit RAM

International Nuclear Information System (INIS)

Nagasawa, S.; Wada, Y.; Tsuge, H.; Hidaka, M.; Ishida, I.; Tahara, S.

1989-01-01

Nb multilayer planarization technology has been developed. This planarization technology consists of an etch-back technique using 2000-molecular weight polystyrene and SiO/sub 2/ for the junction layer and wiring layers, and a tapered edge etching technique for contact between individual wiring layers. A Josephson 1K-bit random access memory (RAM) has been fabricated using this planarization technology. Excellent planarity, wherein level differences in all step areas are reduced to less than 1/20th of their original value, was achieved in the multilayer structure of the RAM. Moreover, appropriate RAM operations, with 570ps minimum access time and 13mW power dissipation, were confirmed

Synthesis of Novel UV Absorbers Bisindolylmethanes and Investigation of Their Applications on Cotton-Based Textile Materials

Directory of Open Access Journals (Sweden)

Hikmet Nil Ergindemir

2016-06-01

Full Text Available Nowadays modified textiles, especially UV-protective, antibacterial and antimicrobial ones, have become the focus of great interest. In this study, several new UV absorbers, bis(indolylmethane derivatives, were synthesized and grafted onto polyvinyl alcohol polymer (PVA. Their application properties on cotton-based textile materials were determined; the UV protection factor values of the modified fabrics were measured (UPF; and the antibacterial features of the fabrics were tested.

Energy deposition studies for the LBNE beam absorber

International Nuclear Information System (INIS)

Rakhno, Igor L.; Mokhov, Nikolai V.; Tropin, Igor S.

2015-01-01

Results of detailed Monte Carlo energy deposition studies performed for the LBNE absorber core and the surrounding shielding with the MARS15 code are described. The model of the entire facility that includes a pion-production target, focusing horns, target chase, decay channel, hadron absorber system - all with corresponding radiation shielding - was developed using the recently implemented ROOT-based geometry option in the MARS15 code. This option provides substantial flexibility and automation when developing complex geometry models. Both normal operation and accidental conditions were studied. Various design options were considered, in particular the following: (i) filling the decay pipe with air or helium; (ii) the absorber mask material and shape; (iii) the beam spoiler material and size. Results of detailed thermal calculations with the ANSYS code helped to select the most viable absorber design options. (authors)

RAM R-200 - A Portable Ruggedized Radiation Monitoring System

International Nuclear Information System (INIS)

Wengrowicz, U.; Mazor, T.; Assido, H.; Kadmon, Y.; Tirosh, D.; Shani, G.

1999-01-01

RAM R-200, a new generation of ruggedized portable radiation-monitoring systems, is presented. The system which is a result of interdisciplinary research, was developed at the NRCN in collaboration with Ben-Gurion University. It consists of RAM R-200 - a portable radiation meter, and a variety of external probes for wide range gamma radiation fields and beta-gamma contamination detection and measurement. The meter or each one of the external probes can be used as a portable system or a stand-alone radiation measurement station. All the system's components were specially designed to meet severe environmental conditions

Sea transport of radioactive materials in Egypt (invited paper)

International Nuclear Information System (INIS)

El-Shinawy, R.M.K.; Gomaa, M.A.

1998-01-01

In Egypt the national regulations for safe transport of radioactive materials (RAM) are based on the International Atomic Energy Agency (IAEA) regulations. In addition, regulations for the safe transport of these materials through the Suez Canal (SC) were laid down by the Egyptian Atomic Energy Authority (EAEA) and the Suez Canal Authority (SCA). They are continuously updated to meet the increased knowledge and the experience gained. The technical and protective measures taken during transport of RAM through SC are mentioned. Assessment of the impact of transporting radioactive materials through the Suez Canal using the INTERTRAN computer code was carried out in cooperation with IAEA. The transported activities and empty containers, the number of vessels carrying RAM through the Canal from 1963 to 1996 and their nationalities are also discussed. The protective measures are mentioned. (author)

Array-level stability enhancement of 50 nm AlxOy ReRAM

Science.gov (United States)

Iwasaki, Tomoko Ogura; Ning, Sheyang; Yamazawa, Hiroki; Takeuchi, Ken

2015-12-01

ReRAM's low voltage and low current programmability are attractive features to solve the scaling issues of conventional floating gate Flash. However, read instability in ReRAM is a critical issue, due to random telegraph noise (RTN), sensitivity to disturb and retention. In this work, the array-level characteristics of read stability in 50 nm AlxOy ReRAM are investigated and a circuit technique to improve stability is proposed and evaluated. First, in order to quantitatively assess memory cell stability, a method of stability characterization is defined. Next, based on this methodology, a proposal to improve read stability, called ;stability check loop; is evaluated. The stability check loop is a stability verification procedure, by which, instability improvement of 7×, and read error rate improvement of 40% are obtained.

A black body absorber from vertically aligned single-walled carbon nanotubes

Science.gov (United States)

Mizuno, Kohei; Ishii, Juntaro; Kishida, Hideo; Hayamizu, Yuhei; Yasuda, Satoshi; Futaba, Don N.; Yumura, Motoo; Hata, Kenji

2009-01-01

Among all known materials, we found that a forest of vertically aligned single-walled carbon nanotubes behaves most similarly to a black body, a theoretical material that absorbs all incident light. A requirement for an object to behave as a black body is to perfectly absorb light of all wavelengths. This important feature has not been observed for real materials because materials intrinsically have specific absorption bands because of their structure and composition. We found a material that can absorb light almost perfectly across a very wide spectral range (0.2–200 μm). We attribute this black body behavior to stem from the sparseness and imperfect alignment of the vertical single-walled carbon nanotubes. PMID:19339498

Regulations of safe transport of radioactive material

International Nuclear Information System (INIS)

Patel, R.J.; Sumathi, E.

2017-01-01

BARC is a multi-disciplinary nuclear research organisation with facilities located at various parts of the country. The nuclear and radiological facilities in BARC include fuel fabrication facilities, nuclear research reactors, radiological laboratories, nuclear recycle facilities, waste management facilities and other associated facilities. RAdioactive Material (RAM) such as fresh nuclear fuel, irradiated fuel, radioactive sources, vitrified high level wastes, special nuclear material etc., are transported between these facilities either within the controlled premises or in public domain. In BARC the regulatory approval for the packages used for transport of RAM is issued by BARC Safety Council (BSC). Competent Authority for issuing the design approval for the BARC packages in public domain is Director, BARC. In this aspect BSC is assisted by Safety Review Committee-Transport of Radioactive Material (SRC-TRM) constituted by BSC entrusted with the mandate to ensure the packages are designed, manufactured and transported in accordance with the current regulations. This article summarizes the regulatory requirements for transport of RAM and experience in BARC facilities

Graphene and Graphene Metamaterials for Terahertz Absorbers

DEFF Research Database (Denmark)

Andryieuski, Andrei; Pizzocchero, Filippo; Booth, Tim

2013-01-01

Graphene, due to the possibility to tune its conductivity, is the promising material for a range of the terahertz (THz) applications, such as tunable reflectors, absorbers, modulators, filters and polarization converters. Subwavelength structuring of graphene in order to form metamaterials allows...... for even more control over the THz waves. In this poster presentation I will show an elegant way to describe the graphene metamaterials and the design of graphene based absorbers. I will also present our recent experimental results on the graphene absorbers characterization....

A Study of the Failure of Joints in Composite Material Fuel Cells Due to Hydraulic Ram Loading

Science.gov (United States)

1976-06-01

H co PSw Z QW <H W CO 33 PS4 o CO O CM \\ Q> 00 vO m CO CM N ra Figure VI.B.l THICKNESS MODEL 55 it acts upon on the membrane, gives the force to be...ability of the joint to carry the loads created by hydraulic ram loading. It would also make the manufacturing procedure easier, less time consuming , and...70 less expensive. Cutting holes and channels in a composite plate not only alters the behavior and load carrying capa- bility of the plate, but it is

Maintenance modeling and optimization integrating human and material resources

International Nuclear Information System (INIS)

Martorell, S.; Villamizar, M.; Carlos, S.; Sanchez, A.

2010-01-01

Maintenance planning is a subject of concern to many industrial sectors as plant safety and business depend on it. Traditionally, the maintenance planning is formulated in terms of a multi-objective optimization (MOP) problem where reliability, availability, maintainability and cost (RAM+C) act as decision criteria and maintenance strategies (i.e. maintenance tasks intervals) act as the only decision variables. However the appropriate development of each maintenance strategy depends not only on the maintenance intervals but also on the resources (human and material) available to implement such strategies. Thus, the effect of the necessary resources on RAM+C needs to be modeled and accounted for in formulating the MOP affecting the set of objectives and constraints. In this paper RAM+C models to explicitly address the effect of human resources and material resources (spare parts) on RAM+C criteria are proposed. This extended model allows accounting for explicitly how the above decision criteria depends on the basic model parameters representing the type of strategies, maintenance intervals, durations, human resources and material resources. Finally, an application case is performed to optimize the maintenance plan of a motor-driven pump equipment considering as decision variables maintenance and test intervals and human and material resources.

Maintenance modeling and optimization integrating human and material resources

Energy Technology Data Exchange (ETDEWEB)

Martorell, S., E-mail: smartore@iqn.upv.e [Dpto. Ingenieria Quimica y Nuclear, Universidad Politecnica Valencia (Spain); Villamizar, M.; Carlos, S. [Dpto. Ingenieria Quimica y Nuclear, Universidad Politecnica Valencia (Spain); Sanchez, A. [Dpto. Estadistica e Investigacion Operativa Aplicadas y Calidad, Universidad Politecnica Valencia (Spain)

2010-12-15

Maintenance planning is a subject of concern to many industrial sectors as plant safety and business depend on it. Traditionally, the maintenance planning is formulated in terms of a multi-objective optimization (MOP) problem where reliability, availability, maintainability and cost (RAM+C) act as decision criteria and maintenance strategies (i.e. maintenance tasks intervals) act as the only decision variables. However the appropriate development of each maintenance strategy depends not only on the maintenance intervals but also on the resources (human and material) available to implement such strategies. Thus, the effect of the necessary resources on RAM+C needs to be modeled and accounted for in formulating the MOP affecting the set of objectives and constraints. In this paper RAM+C models to explicitly address the effect of human resources and material resources (spare parts) on RAM+C criteria are proposed. This extended model allows accounting for explicitly how the above decision criteria depends on the basic model parameters representing the type of strategies, maintenance intervals, durations, human resources and material resources. Finally, an application case is performed to optimize the maintenance plan of a motor-driven pump equipment considering as decision variables maintenance and test intervals and human and material resources.

Performance evaluation of METAMIC neutron absorber in spent fuel storage rack

Directory of Open Access Journals (Sweden)

Kiyoung Kim

2018-06-01

Full Text Available High-density spent fuel (SF storage racks have been installed to increase SF pool capacity. In these SF racks, neutron absorber materials were placed between fuel assemblies allowing the storage of fuel assemblies in close proximity to one another. The purpose of the neutron absorber materials is to preclude neutronic coupling between adjacent fuel assemblies and to maintain the fuel in a subcritical storage condition. METAMIC neutron absorber has been used in high-density storage racks. But, neutron absorber materials can be subject to severe conditions including long-term exposure to gamma radiation and neutron radiation. Recently, some of them have experienced degradation, such as white spots on the surface. Under these conditions, the material must continue to serve its intended function of absorbing neutrons. For the first time in Korea, this article uses a neutron attenuation test to examine the performance of METAMIC surveillance coupons. Also, scanning electron microscope analysis was carried out to verify the white spots that were detected on the surface of METAMIC. In the neutron attenuation test, there was no significant sign of boron loss in most of the METAMIC coupons, but the coupon with white spots had relatively less B-10 content than the others. In the scanning electron microscope analysis, corrosion material was detected in all METAMIC coupons. Especially, it was confirmed that the coupon with white spots contains much more corrosion material than the others. Keywords: Blister, Criticality, METAMIC, Neutron Absorber, Neutron Attenuation Test, Scanning Electron Microscope

The Literary Criticism and Memoirs of Juan Ramón Jiménez

Directory of Open Access Journals (Sweden)

Allen W. Phillips

1983-01-01

Full Text Available Equally as demanding of others as he was of himself, Juan Ramón Jiménez conceived of literary criticism as a serious and exacting task. The critic and the poet, standing side by side, are devoted to complementary activities of mutual enrichment. However fragmentary and partial the critical opinions of Juan Ramón may be (also outspoken and polemical in nature, they are invaluable as a personal historical and aesthetic guide to about fifty or sixty years of Hispanic literary development (1900-1960. Not to take them into account is to fail to recognize a highly important aspect of his total artistic personality. These varied critical texts are a product of a first rate intelligence and the sensibility of a writer of consummate discrimination who was endowed not only with an excellent memory but also a very special talent for appreciating the authentic. Juan Ramón as a critic is quick to praise (San Juan, Bécquer, Dario, Unamuno and Machado and at the same time strong in his censure of certain contemporaries. Several recently collected volumes of miscellaneous critical materials have resolved the bibliographical muddle for the initial study of this fundamental aspect of the poet, but still particularly important are the expressionistic portraits of Españoles de tres mundos , longer tributes to Valle, Ortega and Villaespesa as well as the extensive lectures delivered in his latter years. Examination of these pages gives us an historical and creative overview of the period in which he lived and worked in addition to original considerations about the evolution of Hispanic poetry. Of course, one of the constant focal points of his literary criticism was the modernist epoch of his early days, a movement or attitude which he considered to be a modern twentieth century renaissance. Together with detailed study of these two areas of historical and aesthetic nature, in the ensuing pages some conclusions are pointed out as to the essence of poetry

Sb2Te3 crystal a potential absorber material for broadband photodetector: A first-principles study

Directory of Open Access Journals (Sweden)

Abdullahi Lawal

Full Text Available Antimony telluride (Sb2Te3, a layered semiconductor material, is considered a promising absorbing material for a high-performance optoelectronic device within broadband wavelengths because of remarkable features like strong optical absorbance and the narrow direct band gap. In this work, based on the first-principles approach, we investigate in detail the structural, electronic and optical properties of the hexagonal Sb2Te3 compound. The structural and electronic properties were computed using the first-principles approach, treating exchange–correlation potential with generalized gradient approximation (GGA within density functional theory (DFT. Furthermore, for accurate prediction of the band gap, we go beyond DFT and calculated band structure using GW correction. The optical properties, namely, imaginary and real parts of complex dielectric function, absorption coefficient, refractive index, reflectivity, extinction coefficient, electron energy loss function and optical conductivity are performed by quasi-particle many-body perturbation theory (MBPT via Bethe-Salpeter equation (BSE. The computed structural parameters are in good agreement with available experimental data. The obtained quasi-particle (GW correction band structure show the semiconducting character of Sb2Te3 material with a direct band gap Eg of 0.221 eV, in agreement with previously reported value (Eg = 0.210 eV while the projected density of states indicates (PDOS that the p-orbital of Sb and Te atoms are responsible for material properties near the Fermi level. To our knowledge, our first reported calculations of optical properties, with the inclusion of electron-hole effects are consistent with available experimental measurements. Consistencies of our findings with experimental data validate the effectiveness of electron-hole interaction for theoretical investigation of optical properties. Keywords: DFT, Quasi-particle many-body perturbation theory, Bethe

High-volume use of self-cementing spray dry absorber material for structural applications

Science.gov (United States)

Riley, Charles E.

Spray dry absorber (SDA) material, or spray dryer ash, is a byproduct of energy generation by coal combustion and sulfur emissions controls. Like any resource, it ought to be used to its fullest potential offsetting as many of the negative environmental impacts of coal combustion as possible throughout its lifecycle. Its cementitious and pozzolanic properties suggest it be used to augment or replace another energy and emissions intensive product: Portland cement. There is excellent potential for spray dryer ash to be used beneficially in structural applications, which will offset CO2 emissions due to Portland cement production, divert landfill waste by further utilizing a plentiful coal combustion by-product, and create more durable and sustainable structures. The research into beneficial use applications for SDA material is relatively undeveloped and the material is highly underutilized. This dissertation explored a specific self-cementing spray dryer ash for use as a binder in structural materials. Strength and stiffness properties of hydrated spray dryer ash mortars were improved by chemical activation with Portland cement and reinforcement with polymer fibers from automobile tire recycling. Portland cement at additions of five percent of the cementitious material was found to function effectively as an activating agent for spray dryer ash and had a significant impact on the hardened properties. The recycled polymer fibers improved the ductility and toughness of the material in all cases and increased the compressive strength of weak matrix materials like the pure hydrated ash. The resulting hardened materials exhibited useful properties that were sufficient to suggest that they be used in structural applications such as concrete, masonry block, or as a hydraulic cement binder. While the long-term performance characteristics remain to be investigated, from an embodied-energy and carbon emissions standpoint the material investigated here is far superior to

Tyrosine hydroxylase in the ventral tegmental area of rams with high or low libido-A role for dopamine.

Science.gov (United States)

Kramer, A C; Mirto, A J; Austin, K J; Roselli, C E; Alexander, B M

2017-12-01

Dopamine synthesis in the ventral tegmental area (VTA) is necessary for the reinforcement of sexual behavior. The objective of this study determined if sexual stimuli initiates reward, and whether reward is attenuated in sexually inactive rams. Sexually active rams were exposed to urine from estrous (n=4) or ovariectomized (n=3) ewes with inactive rams (n=3) exposed to urine from estrous ewes. Following exposure, rams were exsanguinated and brains perfused. Alternating sections of the VTA were stained for Fos related antigens (FRA), tyrosine hydroxylase, and dopamine beta-hydroxylase activity. Forebrain tissue, mid-sagittal ventral to the anterior corpus callosum, was stained for dopamine D 2 receptors. Concentrations of cortisol was determined prior to and following exposure. Exposure to ovariectomized-ewe urine in sexually active rams did not influence (P=0.6) FRA expression, but fewer (PSexually inactive rams had fewer (Psexually active rams following exposure to estrous ewe urine. VTA neurons staining positive for dopamine beta-hydroxylase did not differ by sexual activity (P=0.44) or urine exposure (P=0.07). Exposure to stimulus did not influence (P=0.46) numbers of forebrain neurons staining positive for dopamine D2 receptors in sexually active rams, but fewer (P=0.04) neurons stain positive in inactive rams. Serum concentrations of cortisol did not differ (P≥0.52) among rams prior to or following stimulus. In conclusion sexual inactivity is unlikely due to stress, but may be partially a result of decreased tyrosine hydroxylase and/or the response to dopamine. Copyright © 2017 Elsevier B.V. All rights reserved.

Graphene Based Terahertz Absorber Designed With Effective Surface Conductivity Approach

DEFF Research Database (Denmark)

Andryieuski, Andrei; Pizzocchero, Filippo; Booth, Tim

Young field of terahertz (THz) science and technology demands new materials and devices, such as filters, modulators, polarization converters and absorbers. Graphene, a recently discovered single-atom-thick material, provides exciting properties for functional terahertz applications. Graphene...... conductivity and how to use it in optical design. We demonstrate a tunable THz perfect absorber, which consists of continuous graphene various structured graphene metamaterials above a metal mirror. Changing the Fermi level from 0 eV to 0.5 eV allows for drastic changes in absorbance from less than 0.1 to 1...

Consideraciones sobre Infortunios de Alonso Ramírez

Directory of Open Access Journals (Sweden)

Leonor Taiano

2010-12-01

Full Text Available This article attempts to provide new perspectives for approaching the study of Infortunios de Alonso Ramírez. Several researches about the text have given to Sigüenza y Góngora a character of strangeness to it, which would reduce him to the role of mere amanuensis, indicating that the discursive elaboration belongs to Ramirez. In view of that, I have performed a textual analysis, supported on the book's title and the final passage of the account, that I consider important elements that can offer a new perception on this issue. I base my research, additionally, on the study of its context of publication under the patronage of the New Spain viceroy, as well as the similarities of Infortunios de Alonso Ramírez with other contemporary texts.

Heart rate patterns during courtship and mating in rams and in estrous and nonestrous ewes ().

Science.gov (United States)

Orihuela, A; Omaña, J C; Ungerfeld, R

2016-02-01

The aim of this study was to compare the heart rate (HR) patterns in rams mated with estrous or nonestrous ewes and in mated estrous and nonestrous ewes () during courtship and mating. For this purpose, HR and behavior were recorded using a radio telemetry recording system and a closed-circuit television system with video recording, respectively. Rams were joined with either an estrous ( = 10) or a nonestrous ( = 10) ewe that was restrained in a stanchion by the neck. Data were continuously recorded until each ram performed 3 ejaculations. Eight days later, the HR of the 10 estrous and 10 nonestrous ewes was recorded during mating. Although the time between entrance into the yard and the first ejaculation was similar across rams, rams that mounted estrous ewes were faster at attaining their second (3min5s ± 17 s vs. 5min28s ± 18 s) and third (7min58s ± 45 s vs. 12 min ± 1min14s) ejaculations (all ewes. In all cases, HR reached maximum values immediately after each ejaculation and the HR pattern was similar across ejaculations (first, second, and third). Although HR was similar between estrous and nonestrous ewes before mating, nonestrous ewes had higher HR ( ewes displayed shorter interejaculation periods but HR did not differ between groups of rams during any ejaculation (first, second, or third), 2) HR for both groups of rams peaked shortly after each ejaculation, and 3) HR increased more in nonestrous than in estrous ewes while mating.

Effect of semen extender and storage temperature on ram sperm motility over time

Science.gov (United States)

Storage of ram semen for long period of time depends on a number of factors, including type of extender and storage temperature. A study compared the effect of semen extender and storage temperature on motility of ram semen stored for 72 h. Semen collected via electroejaculator from 5 mature Katahd...

Thin films of copper antimony sulfide: A photovoltaic absorber material

Energy Technology Data Exchange (ETDEWEB)

Ornelas-Acosta, R.E. [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66450 (Mexico); Shaji, S. [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66450 (Mexico); Universidad Autónoma de Nuevo León-CIIDIT, Apodaca, Nuevo León (Mexico); Avellaneda, D.; Castillo, G.A.; Das Roy, T.K. [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66450 (Mexico); Krishnan, B., E-mail: kbindu_k@yahoo.com [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66450 (Mexico); Universidad Autónoma de Nuevo León-CIIDIT, Apodaca, Nuevo León (Mexico)

2015-01-15

Highlights: • CuSbS{sub 2} thin films were prepared by heating Sb{sub 2}S{sub 3}/Cu layers. • Analyzed the structure, composition, optical, and electrical properties. • PV structures: glass/SnO{sub 2}:F/n-CdS/p-CuSbS{sub 2}/C/Ag were formed at different conditions. • The PV parameters (J{sub sc}, V{sub oc}, and FF) were evaluated from the J–V characteristics. • J{sub sc}: 0.52–3.20 mA/cm{sup 2}, V{sub oc}:187–323 mV, FF: 0.27–0.48 were obtained. - Abstract: In this work, we report preparation and characterization of CuSbS{sub 2} thin films by heating glass/Sb{sub 2}S{sub 3}/Cu layers and their use as absorber material in photovoltaic structures: glass/SnO{sub 2}:F/n-CdS/p-CuSbS{sub 2}/C/Ag. The Sb{sub 2}S{sub 3} thin films of 600 nm were prepared by chemical bath deposition on which copper thin films of 50 nm were thermally evaporated, and the glass/Sb{sub 2}S{sub 3}/Cu multilayers were heated in vacuum at different temperatures. X-ray diffraction analysis showed the formation of orthorhombic CuSbS{sub 2} after heating the precursor layers. Studies on identification and chemical state of the elements were done using X-ray photoelectron spectroscopy. The optical band gap of the CuSbS{sub 2} thin films was 1.55 eV and the thin films were photoconductive. The photovoltaic parameters of the devices using CuSbS{sub 2} as absorber and CdS as window layer were evaluated from the J–V curves, yielding J{sub sc}, V{sub oc}, and FF values in the range of 0.52–3.20 mA/cm{sup 2}, 187–323 mV, and 0.27–0.48, respectively, under illumination of AM1.5 radiation.

Filtration: Novel Absorber Evaluation Club aims at standardized testing

International Nuclear Information System (INIS)

Anon.

1990-01-01

In the past few years a number of novel absorber materials, both organic and inorganic, have appeared on the market - some claiming to achieve very large decontamination factors for metal ions, including those having radioactive isotopes. Several of these materials have been tested by individual companies in the nuclear industry and some have shown promise as decontaminants for radioactive waste streams. Unfortunately, the results obtained for the treatment of a particular waste stream cannot be applied directly to the many and diverse waste streams generated throughout the nuclear industry. A unified and standardized testing programme making use of available expertise is necessary to provide a fair and meaningful comparison. In November 1988, representatives of the United Kingdom nuclear industry agreed to form the Novel Absorber Evaluation Club to assess absorber materials and to undertake the necessary work to identify the extent and rate of adsorption of radionuclides by such materials from a set of typical reference waste streams. (author)

Device for absorbing seismic effects on buildings

International Nuclear Information System (INIS)

Xercavins, Pierre; Pompei, Michel.

1979-01-01

Device for absorbing seismic effects. The construction or structure to be protected rests on its foundations through at least one footing formed of a stack of metal plates interlinked by layers of adhesive material, over at least a part of their extent, this material being an elastomer that can distort, characterized in that at least part of the area of some metal plates works in association with components which are able to absorb at least some of the energy resulting from friction during the relative movements of the metal plates against the distortion of the elastomer [fr

Perfectly Secure Oblivious RAM without Random Oracles

DEFF Research Database (Denmark)

Damgård, Ivan Bjerre; Meldgaard, Sigurd Torkel; Nielsen, Jesper Buus

2011-01-01

We present an algorithm for implementing a secure oblivious RAM where the access pattern is perfectly hidden in the information theoretic sense, without assuming that the CPU has access to a random oracle. In addition we prove a lower bound on the amount of randomness needed for implementing...

Growth performance and hematology of Djallonké rams fed haulms of four varieties of groundnut (Arachis hypogaea L.

Directory of Open Access Journals (Sweden)

Terry Ansah

2017-12-01

Full Text Available The study was conducted to assess the chemical composition of the haulms of 4 dual-purpose groundnut (Arachis hypogaea L. varieties and their effects on the growth and hematology of Djallonké rams. The groundnut varieties were ICGV 97049 (Obolo, ICGX SM 87057 (Yenyawoso, RMP 12 (Azivivi and Manipinta. Rams (live weight 15.0 ± 3.0 kg were randomly assigned to 4 sole groundnut haulm meal (GHM treatments, with 4 rams each in an individual pen per treatment (total n = 16 rams. Samples of the groundnut haulms were milled and analyzed for crude protein (CP, neutral detergent fiber (NDF and acid detergent fiber (ADF. The CP concentration was higher (P  0.05 when the Djallonké rams were fed the haulms. However, significant differences were observed in final live weight and average daily live weight gain. Rams fed the Yenyawoso variety had higher (P < 0.05 final live weight and average daily live weight gain compared with those fed Obolo and Azivivi varieties. Consumption of any of the 4 varieties of groundnut haulms by Djallonké rams did not have any harmful effect on their red and white blood cell numbers and hemoglobin concentration. The study revealed that the different varieties of groundnut haulms differ in nutrient composition and also affect the growth performance of the rams. The Yenyawoso variety may be used as a sole diet for fattening Djallonké rams.

Absorbable magnesium-based stent: physiological factors to consider for in vitro degradation assessments

OpenAIRE

Wang, Juan; Smith, Christopher E.; Sankar, Jagannathan; Yun, Yeoheung; Huang, Nan

2015-01-01

Absorbable metals have been widely tested in various in vitro settings using cells to evaluate their possible suitability as an implant material. However, there exists a gap between in vivo and in vitro test results for absorbable materials. A lot of traditional in vitro assessments for permanent materials are no longer applicable to absorbable metallic implants. A key step is to identify and test the relevant microenvironment and parameters in test systems, which should be adapted according ...

Purification of beta-acetylglucosaminase and beta-galactosidase from ram testis.

Science.gov (United States)

Caygill, J C; Roston, C P; Jevons, F R

1966-02-01

1. The presence of beta-galactosidase (EC 3.2.1.23) in an acetic acid extract of ram testis is reported. Some properties of the crude enzyme preparation were studied. 2. The purification of beta-acetylglucosaminase (EC 3.2.1.30) and of beta-galactosidase from the ram-testis extract by ammonium sulphate precipitation and chromatography on a CM-cellulose column is described. 3. The final purifications of the separated enzymes achieved were for the beta-acetylglucosaminase 35 times and for the beta-galactosidase 99 times. 4. The possibility of using DEAE-cellulose and Sephadex G-200 to purify the enzymes was investigated.

Kinematics of ram filter feeding and beat-glide swimming in the northern anchovy Engraulis mordax.

Science.gov (United States)

Carey, Nicholas; Goldbogen, Jeremy A

2017-08-01

In the dense aquatic environment, the most adept swimmers are streamlined to reduce drag and increase the efficiency of locomotion. However, because they open their mouth to wide gape angles to deploy their filtering apparatus, ram filter feeders apparently switch between diametrically opposite swimming modes: highly efficient, streamlined 'beat-glide' swimming, and ram filter feeding, which has been hypothesized to be a high-cost feeding mode because of presumed increased drag. Ram filter-feeding forage fish are thought to play an important role in the flux of nutrients and energy in upwelling ecosystems; however, the biomechanics and energetics of this feeding mechanism remain poorly understood. We quantified the kinematics of an iconic forage fish, the northern anchovy, Engraulis mordax , during ram filter feeding and non-feeding, mouth-closed beat-glide swimming. Although many kinematic parameters between the two swimming modes were similar, we found that swimming speeds and tailbeat frequencies were significantly lower during ram feeding. Rather than maintain speed with the school, a speed which closely matches theoretical optimum filter-feeding speeds was consistently observed. Beat-glide swimming was characterized by high variability in all kinematic parameters, but variance in kinematic parameters was much lower during ram filter feeding. Under this mode, body kinematics are substantially modified, and E. mordax swims more slowly and with decreased lateral movement along the entire body, but most noticeably in the anterior. Our results suggest that hydrodynamic effects that come with deployment of the filtering anatomy may limit behavioral options during foraging and result in slower swimming speeds during ram filtration. © 2017. Published by The Company of Biologists Ltd.

Radiation immune RAM semiconductor technology for the 80's. [Random Access Memory

Science.gov (United States)

Hanna, W. A.; Panagos, P.

1983-01-01

This paper presents current and short term future characteristics of RAM semiconductor technologies which were obtained by literature survey and discussions with cognizant Government and industry personnel. In particular, total ionizing dose tolerance and high energy particle susceptibility of the technologies are addressed. Technologies judged compatible with spacecraft applications are ranked to determine the best current and future technology for fast access (less than 60 ns), radiation tolerant RAM.

The use of silicon devices (diodes, RAMs, etc.) for alpha particle detection

International Nuclear Information System (INIS)

Agosteo, S.; Foglio Para, A.

1993-01-01

Silicon electronic devices (diodes, random access memories (RAMs), etc.) can be employed in alpha particle detection and spectroscopy with a good energy resolution. The detection mechanisms are first discussed; the performances of these devices operating in the pulse and in the current mode are then described starting from the pioneering works of the last decade. Some peculiar applications of RAMs are finally reported. (author). 7 refs, 5 figs, 1 tab

Safe transport of radioactive materials in Egypt

International Nuclear Information System (INIS)

El-Shinawy, R.M.K.

1994-01-01

In Egypt the national regulations for safe transport of radioactive materials (RAM) are based on the International Atomic Energy Agency (IAEA) regulations. In addition, regulations for the safe transport of these materials through the Suez Canal (SC) were laid down by the Egyptian Atomic Energy Authority (EAEA) and the Suez Canal Authority (SCA). They are continuously updated to meet the increased knowledge and the gained experience. The technical and protective measures taken during transport of RAM through SC are mentioned. Assessment of the impact of transporting radioactive materials through the Suez Canal using the INTERTRAN computer code was carried out in cooperation with IAEA. The transported activities and empty containers, the number of vessels carrying RAM through the canal from 1963 and 1991 and their nationalities are also discussed. The protective measures are mentioned. A review of the present situation of the radioactive wastes storage facilities at the Atomic Energy site at Inshas is given along with the regulation for safe transportation and disposal of radioactive wastes. (Author)

A simple parameterization of aerosol emissions in RAMS

Science.gov (United States)

Letcher, Theodore

Throughout the past decade, a high degree of attention has been focused on determining the microphysical impact of anthropogenically enhanced concentrations of Cloud Condensation Nuclei (CCN) on orographic snowfall in the mountains of the western United States. This area has garnered a lot of attention due to the implications this effect may have on local water resource distribution within the Region. Recent advances in computing power and the development of highly advanced microphysical schemes within numerical models have provided an estimation of the sensitivity that orographic snowfall has to changes in atmospheric CCN concentrations. However, what is still lacking is a coupling between these advanced microphysical schemes and a real-world representation of CCN sources. Previously, an attempt to representation the heterogeneous evolution of aerosol was made by coupling three-dimensional aerosol output from the WRF Chemistry model to the Colorado State University (CSU) Regional Atmospheric Modeling System (RAMS) (Ward et al. 2011). The biggest problem associated with this scheme was the computational expense. In fact, the computational expense associated with this scheme was so high, that it was prohibitive for simulations with fine enough resolution to accurately represent microphysical processes. To improve upon this method, a new parameterization for aerosol emission was developed in such a way that it was fully contained within RAMS. Several assumptions went into generating a computationally efficient aerosol emissions parameterization in RAMS. The most notable assumption was the decision to neglect the chemical processes in formed in the formation of Secondary Aerosol (SA), and instead treat SA as primary aerosol via short-term WRF-CHEM simulations. While, SA makes up a substantial portion of the total aerosol burden (much of which is made up of organic material), the representation of this process is highly complex and highly expensive within a numerical

Fractal Model for Acoustic Absorbing of Porous Fibrous Metal Materials

Directory of Open Access Journals (Sweden)

Weihua Chen

2016-01-01

Full Text Available To investigate the changing rules between sound absorbing performance and geometrical parameters of porous fibrous metal materials (PFMMs, this paper presents a fractal acoustic model by incorporating the static flow resistivity based on Biot-Allard model. Static flow resistivity is essential for an accurate assessment of the acoustic performance of the PFMM. However, it is quite difficult to evaluate the static flow resistivity from the microstructure of the PFMM because of a large number of disordered pores. In order to overcome this difficulty, we firstly established a static flow resistivity formula for the PFMM based on fractal theory. Secondly, a fractal acoustic model was derived on the basis of the static flow resistivity formula. The sound absorption coefficients calculated by the presented acoustic model were validated by the values of Biot-Allard model and experimental data. Finally, the variation of the surface acoustic impedance, the complex wave number, and the sound absorption coefficient with the fractal dimensions were discussed. The research results can reveal the relationship between sound absorption and geometrical parameters and provide a basis for improving the sound absorption capability of the PFMMs.

HyRAM Testing Script.

Energy Technology Data Exchange (ETDEWEB)

Parkins, Owen

2014-12-01

The testing script is to provide a method of inspections to HyRAM (v1.0.0.244 Alpha) application features. This document will lead participants through the use of the application to make sure the application performs as designed. If a feature of the application becomes non-working, this script will relay useful information back to the designers of the application so that the feature can be fixed. This is essential to keep the application updated and performing as designed so that the users of this program can be satisfied. There will be frequent updates of this document to ensure proper testing of future application versions.

Optical RAM row access using WDM-enabled all-passive row/column decoders

Science.gov (United States)

Papaioannou, Sotirios; Alexoudi, Theoni; Kanellos, George T.; Miliou, Amalia; Pleros, Nikos

2014-03-01

Towards achieving a functional RAM organization that reaps the advantages offered by optical technology, a complete set of optical peripheral modules, namely the Row (RD) and Column Decoder (CD) units, is required. In this perspective, we demonstrate an all-passive 2×4 optical RAM RD with row access operation and subsequent all-passive column decoding to control the access of WDM-formatted words in optical RAM rows. The 2×4 RD exploits a WDM-formatted 2-bit-long memory WordLine address along with its complementary value, all of them encoded on four different wavelengths and broadcasted to all RAM rows. The RD relies on an all-passive wavelength-selective filtering matrix (λ-matrix) that ensures a logical `0' output only at the selected RAM row. Subsequently, the RD output of each row drives the respective SOA-MZI-based Row Access Gate (AG) to grant/block the entry of the incoming data words to the whole memory row. In case of a selected row, the data word exits the row AG and enters the respective CD that relies on an allpassive wavelength-selective Arrayed Waveguide Grating (AWG) for decoding the word bits into their individual columns. Both RD and CD procedures are carried out without requiring any active devices, assuming that the memory address and data word bits as well as their inverted values will be available in their optical form by the CPU interface. Proof-of-concept experimental verification exploiting cascaded pairs of AWGs as the λ-matrix is demonstrated at 10Gb/s, providing error-free operation with a peak power penalty lower than 0.2dB for all optical word channels.

Role of the GRAS transcription factor ATA/RAM1 in the transcriptional reprogramming of arbuscular mycorrhiza in Petunia hybrida.

Science.gov (United States)

Rich, Mélanie K; Courty, Pierre-Emmanuel; Roux, Christophe; Reinhardt, Didier

2017-08-08

Development of arbuscular mycorrhiza (AM) requires a fundamental reprogramming of root cells for symbiosis. This involves the induction of hundreds of genes in the host. A recently identified GRAS-type transcription factor in Petunia hybrida, ATA/RAM1, is required for the induction of host genes during AM, and for morphogenesis of the fungal endosymbiont. To better understand the role of RAM1 in symbiosis, we set out to identify all genes that depend on activation by RAM1 in mycorrhizal roots. We have carried out a transcript profiling experiment by RNAseq of mycorrhizal plants vs. non-mycorrhizal controls in wild type and ram1 mutants. The results show that the expression of early genes required for AM, such as the strigolactone biosynthetic genes and the common symbiosis signalling genes, is independent of RAM1. In contrast, genes that are involved at later stages of symbiosis, for example for nutrient exchange in cortex cells, require RAM1 for induction. RAM1 itself is highly induced in mycorrhizal roots together with many other transcription factors, in particular GRAS proteins. Since RAM1 has previously been shown to be directly activated by the common symbiosis signalling pathway through CYCLOPS, we conclude that it acts as an early transcriptional switch that induces many AM-related genes, among them genes that are essential for the development of arbuscules, such as STR, STR2, RAM2, and PT4, besides hundreds of additional RAM1-dependent genes the role of which in symbiosis remains to be explored. Taken together, these results indicate that the defect in the morphogenesis of the fungal arbuscules in ram1 mutants may be an indirect consequence of functional defects in the host, which interfere with nutrient exchange and possibly other functions on which the fungus depends.

RAM-efficient external memory sorting

DEFF Research Database (Denmark)

Arge, Lars; Thorup, Mikkel

2013-01-01

In recent years a large number of problems have been considered in external memory models of computation, where the complexity measure is the number of blocks of data that are moved between slow external memory and fast internal memory (also called I/Os). In practice, however, internal memory time...... often dominates the total running time once I/O-efficiency has been obtained. In this paper we study algorithms for fundamental problems that are simultaneously I/O-efficient and internal memory efficient in the RAM model of computation....

Radioactive material package seal tests

International Nuclear Information System (INIS)

Madsen, M.M.; Humphreys, D.L.; Edwards, K.R.

1990-01-01

General design or test performance requirements for radioactive materials (RAM) packages are specified in Title 10 of the US Code of Federal Regulations Part 71 (US Nuclear Regulatory Commission, 1983). The requirements for Type B packages provide a broad range of environments under which the system must contain the RAM without posing a threat to health or property. Seals that provide the containment system interface between the packaging body and the closure must function in both high- and low-temperature environments under dynamic and static conditions. A seal technology program, jointly funded by the US Department of Energy Office of Environmental Restoration and Waste Management (EM) and the Office of Civilian Radioactive Waste Management (OCRWM), was initiated at Sandia National Laboratories. Experiments were performed in this program to characterize the behavior of several static seal materials at low temperatures. Helium leak tests on face seals were used to compare the materials. Materials tested include butyl, neoprene, ethylene propylene, fluorosilicone, silicone, Eypel, Kalrez, Teflon, fluorocarbon, and Teflon/silicone composites. Because most elastomer O-ring applications are for hydraulic systems, manufacturer low-temperature ratings are based on methods that simulate this use. The seal materials tested in this program with a fixture similar to a RAM cask closure, with the exception of silicone S613-60, are not leak tight (1.0 x 10 -7 std cm 3 /s) at manufacturer low-temperature ratings. 8 refs., 3 figs., 1 tab

Nuclear reactor core having nuclear fuel and composite burnable absorber arranged for power peaking and moderator temperature coefficient control

International Nuclear Information System (INIS)

Kapil, S.K.

1991-01-01

This patent describes a nuclear reactor core. It comprises a first group of fuel rods containing fissionable material and being free of burnable absorber material; and a second group of fuel rods containing fissionable material and first and second burnable absorber material; the first burnable absorber material being a boron-bearing material which does not contain erbium and the second burnable absorber material being an erbium material; the first and second burnable absorber materials being in the form of an outer coating on the fissionable material, the outer coating being composed of an inner layer of one of the boron-bearing material which does not contain erbium and the erbium material and an outer layer of the other of the boron-bearing material which does not contain erbium and the erbium material

APPLICATION OF POLYURETHANE FOAM FOR IMPACT ABSORPTION AND THERMAL INSULATION FOR RADIOACTIVE MATERIALS PACKAGINGS

International Nuclear Information System (INIS)

Smith, A; Glenn Abramczyk, G; Paul Blanton, P; Steve Bellamy, S; William Daugherty, W; Sharon Williamson, S

2007-01-01

Polyurethane foam has been widely used as an impact absorbing and thermal insulating material for large radioactive materials packages, since the 1980's. With the adoption of the regulatory crush test requirement, for smaller packages, polyurethane foam has been adopted as a replacement for cane fiberboard, because of its ability to withstand the crush test. Polyurethane foam is an engineered material whose composition is much more closely controlled than that of cane fiberboard. In addition, the properties of the foam can be controlled by controlling the density of the foam. The conditions under which the foam is formed, whether confined or unconfined have an affect on foam properties. The study reported here reviewed the application of polyurethane foam in RAM packagings and compared property values reported in the literature with published property values and test results for foam specimens taken from a prototype 9977 packaging. The study confirmed that, polyurethane foam behaves in a predictable and consistent manner and fully satisfies the functional requirements for impact absorption and thermal insulation

A comparison of RAM importance measures

International Nuclear Information System (INIS)

Atwood, C.L.; Wolford, A.J.; Wright, R.E.

1989-01-01

In this paper measures of importance of components and cut sets of a system are reviewed. The measures considered are based on reliability, availability, and maintainability, the three elements of the acronym RAM. They follow the approaches of Fussell and Vesely and of Birnbaum. A new Birnbaum-type unmaintainability importance measure is proposed. The measures are compared in a simple example, and the appropriate use of unmaintainability importance is discussed

COMPARISON OF ABSORBABLE EXTRA LONG TERM POLY HYDROXY BUTYRATE SUTURE VS NON ABSORBABLE (POLYPROPYLENE SUTURE FOR ABDOMINAL WALL CLOSURE

Directory of Open Access Journals (Sweden)

Mallikarjun

2015-07-01

Full Text Available PURPOSE: The aim of study is to compare Continuous technique with non - absorbable sutures, Interrupted technique with non - absorbable sutures and Continuous technique with slowly absorbable sutures Focusing mainly on incidence of incisional hernias, burst abdomen, wound infections, chronic wound pain, suture sinus, stitch granuloma, time for rectus closure. METHODOLOGY : Study was conducted for a period of one year on 271 randomized patients with primary elective midline laparotomy in our hospital . patients are divided into group I includes 102 patients with continuous technique using non absorbable polypropylene, group II includes 91 patients with interrupted technique using non absorbable polypropylene and group III includes 78 patients with continuous slowly absorbable polyhydroxybutyrate. RESULTS: No significant difference observed in incidence of wound infections and burst abdomen in all the 3 groups but relatively higher incidence of wound infections in noted our hospital. Incidence of stich granuloma suture sinus and chronic wound pain is more with interrupted technique than continuous technique and are more with non - absor bable suture material. CONCLUSION: Incidence of incisional hernias, suture complications like suture sinus, stitch granuloma can be more effectively reduced with slowly absorbable continuous sutures.

Purification of β-acetylglucosaminase and β-galactosidase from ram testis

Science.gov (United States)

Caygill, J. C.; Roston, Christine P. J.; Jevons, F. R.

1966-01-01

1. The presence of β-galactosidase (EC 3.2.1.23) in an acetic acid extract of ram testis is reported. Some properties of the crude enzyme preparation were studied. 2. The purification of β-acetylglucosaminase (EC 3.2.1.30) and of β-galactosidase from the ram-testis extract by ammonium sulphate precipitation and chromatography on a CM-cellulose column is described. 3. The final purifications of the separated enzymes achieved were for the β-acetylglucosaminase 35 times and for the β-galactosidase 99 times. 4. The possibility of using DEAE-cellulose and Sephadex G-200 to purify the enzymes was investigated. PMID:5949569

Eggshell and Bacterial Cellulose Composite Membrane as Absorbent Material in Active Packaging

Directory of Open Access Journals (Sweden)

S. Ummartyotin

2016-01-01

Full Text Available Bacterial cellulose and eggshell composite was successfully developed. Eggshell was mixed with bacterial cellulose suspension and it was casted as a composite film. CaCO3 derived from eggshell was compared with its commercial availability. It can be noted that good dispersion of eggshell particle was prepared. Eggshell particle was irregular in shape with a variation in size. It existed in bacterial cellulose network. Characterization on composite was focused on thermal and mechanical properties. It showed that flexibility and thermal stability of composite were enhanced. No significant effect of mechanical properties was therefore observed. The thermal stability of composite was stable up to 300°C. The adsorption experiment on water and vegetable oil capacity was performed. The enhancement on adsorption was due to the existence of eggshell in bacterial cellulose composite. It exhibited the potential to be a good candidate for absorbent material in active packaging.

Effect of suction on the mechanical characteristics of uniformly compacted rammed earth

Science.gov (United States)

El Hajjar, A.; Chauhan, P.; Prime, N.; Plé, O.

2018-04-01

Rammed earth, in the current environmental situation, is an alternative construction technique which can help in reducing energy and raw material consumption owing to its “sustainable” characteristics. To fully understand its behavior and properties, recent scientific investigations consider it as a compacted unsaturated material with suction as its one of the main sources of strength. Eathern constructions face, over their lifetime, variations in the suction state which have a significant impact on their mechanical characteristics. In the present contribution, unconfined compression tests are performed, with and without unload-reload cycles, on homogeneously compacted samples subjected to various suction conditions. This study shows that both the unconfined compressive strength and Young modulus reduce with the reduction of suction states. Suction also seems to influence the amount of plastic strains and damage phenomenon. Indeed, the soils analyzed are slightly active and shows both plasticity behavior and damage phenomenon.

GTL Based Internet of Things Enable Processor Specific RAM Design on 65nm FPGA

DEFF Research Database (Denmark)

Moudgil, Aditi; Garg, Kanika; Pandey, Bishwajeet

2015-01-01

In this work, we are making Energy Efficient Internet of Things (IoTs) Enable RAM. In order to make it energy efficient, we are using Gunning Transceiver Logic (GTL) IO Standard and Gunning Transceiver Logic Plus (GTLP). We are using the 4 different members of GTL and GTLP IO standards family...... and searching the most energy efficient among them. We observed that when we use 3.6 GHz operating frequency, there is 90.2% reduction in I/O power when we used GTL instead of GTLP_DCI. We are inserting 128-bit IP address in RAM to make internet of things enable RAM. Finally, we are operating our IOTs Enable...

National RAM transport regulations implementation in Russia

International Nuclear Information System (INIS)

Gubanov, V.A.

1995-01-01

A brief review is given of the main provisions of the state regulation and safety assurance of RAM transport in Russia. This appears to be useful to various persons and organisations abroad, concerned with such transport in Russia. Two aspects of the system are presented - regulatory documents (normative-technical documentation) and regulatory and control activities of state organisations. (Author)

Radiation-hardened nonvolatile MNOS RAM

International Nuclear Information System (INIS)

Wrobel, T.F.; Dodson, W.H.; Hash, G.L.; Jones, R.V.; Nasby, R.D.; Olson, R.J.

1983-01-01

A radiation hardened nonvolatile MNOS RAM is being developed at Sandia National Laboratories. The memory organization is 128 x 8 bits and utilizes two p-channel MNOS transistors per memory cell. The peripheral circuitry is constructed with CMOS metal gate and is processed with standard Sandia rad-hard processing techniques. The devices have memory retention after a dose-rate exposure of 1E12 rad(Si)/s, are functional after total dose exposure of 1E6 rad(Si), and are dose-rate upset resistant to levels of 7E8 rad(Si)/s

Semen characteristics of pubertal Yankasa rams fed Zingiber ...

African Journals Online (AJOL)

Ginger (Zingiber officinale) is consumed by humans and has been reported to possess medicinal uses. It possesses androgenic property with significant increase on male reproductive parameters. This study assessed the reproductive performance of Yankasa rams fed diets supplemented with different levels of ginger ...

Effects of breed and ram exposure on Spring estrous behavior and Summer fertility in domestic ewes

OpenAIRE

Nugent, Russell A., III

1987-01-01

The present studies were conducted to check the effects of acute ram introduction into a flock of anestrus ewes in Virginia. Ewes were bled via jugular venipuncture twice weekly and serum samples were radioimmunoassayed for progesterone (P4) content as an indicator of estrous activity. All rams were fitted with crayon equipped marking harnesses for use as an indicator of mating behavior in ewes. The first study tested the effects of introduction of vasectomized rams in...

Selective solar absorber emittance measurement at elevated temperature

Science.gov (United States)

Giraud, Philémon; Braillon, Julien; Raccurt, Olivier

2017-06-01

Durability of solar components for CSP (Concentrated Solar Power Plant) technologies is a key point to lower cost and ensure their large deployment. These technologies concentrated the solar radiation by means of mirrors on a receiver tube where it is collected as thermal energy. The absorbers are submitted to strong environmental constraints and the degradation of their optical properties (emittance and solar absorbance) have a direct impact on performance. The characterization of a material in such condition is complicated and requires advanced apparatuses, and different measurement methods exist for the determination of the two quantities of relevance regarding an absorber, which are its emittance and its solar absorbance. The objective is to develop new optical equipment for measure the emittance of this solar absorber at elevated temperature. In this paper, we present an optical bench developed for emittance measurement on absorbers is conditions of use. Results will be shown, with a discussion of some factors of influence over this measurement and how to control them.

OrbusNeich fully absorbable coronary stent platform incorporating dual partitioned coatings.

Science.gov (United States)

Cottone, Robert J; Thatcher, G Lawrence; Parker, Sherry P; Hanks, Laurence; Kujawa, David A; Rowland, Stephen M; Costa, Marco; Schwartz, Robert S; Onuma, Yoshinobu

2009-12-15

The field of stent based tissue engineering continues to revolutionise modern medicine by designing novel materials to restore vascular tissue function. Accordingly, the following discussion examines a novel, absorbable, polymeric scaffold engineered in combination with dual therapeutic coating, enabling locally administered temporary scaffolding in the coronary arteries for long term vascular patency and repair. This coronary stent platform consists of an absorbable polymeric material stent structure that incorporates a dual partitioned coating, by means of pro-healing EPC (endothelial progenitor cell) capture technology allowing for rapid endothelial coverage, and an absorbable polymer matrix with sustained elution of sirolimus, a drug controlling neointimal proliferation. This paper provides a brief overview of the various innovations developed by OrbusNeich to create this fully absorbable coronary device platform.

Molecular characterization with random amplified microsatellites (RAMs of Inchi (Caryodendron orinocense K.

Directory of Open Access Journals (Sweden)

Ana Cruz Morillo Coronado

2015-01-01

Full Text Available The Inchi or Cacay (Caryodendron orinocense Karsten is one of the most promising species of the Amazon and Orinoco Colombian. The main product of Cacay are its almonds, from extracted oil cosmetic, phytotherapeutic and food applications, also has a high content of antioxidants such as Omega 3, 6 and 9 and vitamins like A and E. There are no studies on the molecular characterization of this plant genetic resource; therefore the objective of this research was to characterize the genetic diversity using Random Amplified Microsatellite markers (RAMs. The similarity analysis to 0.50 formed four groups according to geographical location, being materials from Putumayo, Cacayal 19, Pauna and Castilla lowest similarity. Estimated heterozygosity values were 0.16 and 0.28 for the primers CGA and GT, respectively. The percentage of polymorphic loci ranged from 55% for the primer CGA and 90% for the GT. The average Fst value for the 27 materials studied was 0.35, showing the space-temporal dynamics of materials Caryodendron tend toward genetic differentiation, due to their own evolutionary processes and domestication incidence.

Rice straw-wood particle composite for sound absorbing wooden construction materials.

Science.gov (United States)

Yang, Han-Seung; Kim, Dae-Jun; Kim, Hyun-Joong

2003-01-01

In this study, rice straw-wood particle composite boards were manufactured as insulation boards using the method used in the wood-based panel industry. The raw material, rice straw, was chosen because of its availability. The manufacturing parameters were: a specific gravity of 0.4, 0.6, and 0.8, and a rice straw content (10/90, 20/80, and 30/70 weight of rice straw/wood particle) of 10, 20, and 30 wt.%. A commercial urea-formaldehyde adhesive was used as the composite binder, to achieve 140-290 psi of bending modulus of rupture (MOR) with 0.4 specific gravity, 700-900 psi of bending MOR with 0.6 specific gravity, and 1400-2900 psi of bending MOR with a 0.8 specific gravity. All of the composite boards were superior to insulation board in strength. Width and length of the rice straw particle did not affect the bending MOR. The composite boards made from a random cutting of rice straw and wood particles were the best and recommended for manufacturing processes. Sound absorption coefficients of the 0.4 and 0.6 specific gravity boards were higher than the other wood-based materials. The recommended properties of the rice straw-wood particle composite boards are described, to absorb noises, preserve the temperature of indoor living spaces, and to be able to partially or completely substitute for wood particleboard and insulation board in wooden constructions.

Plasmonic materials based on ZnO films and their potential for developing broadband middle-infrared absorbers

Energy Technology Data Exchange (ETDEWEB)

Kesim, Yunus E., E-mail: yunus.kesim@bilkent.edu.tr; Battal, Enes [Department of Electrical and Electronics Engineering, Bilkent University, Ankara, 06800 (Turkey); UNAM-National Nanotechnology Research Center, Bilkent University, Ankara, 06800 (Turkey); Okyay, Ali K. [Department of Electrical and Electronics Engineering, Bilkent University, Ankara, 06800 (Turkey); UNAM-National Nanotechnology Research Center, Bilkent University, Ankara, 06800 (Turkey); Institute of Materials Science and Nanotechnology, Bilkent University, Ankara, 06800 (Turkey)

2014-07-15

Noble metals such as gold and silver have been extensively used for plasmonic applications due to their ability to support plasmons, yet they suffer from high intrinsic losses. Alternative plasmonic materials that offer low loss and tunability are desired for a new generation of efficient and agile devices. In this paper, atomic layer deposition (ALD) grown ZnO is investigated as a candidate material for plasmonic applications. Optical constants of ZnO are investigated along with figures of merit pertaining to plasmonic waveguides. We show that ZnO can alleviate the trade-off between propagation length and mode confinement width owing to tunable dielectric properties. In order to demonstrate plasmonic resonances, we simulate a grating structure and computationally demonstrate an ultra-wide-band (4–15 μm) infrared absorber.

Absorbable magnesium-based stent: physiological factors to consider for in vitro degradation assessments.

Science.gov (United States)

Wang, Juan; Smith, Christopher E; Sankar, Jagannathan; Yun, Yeoheung; Huang, Nan

2015-03-01

Absorbable metals have been widely tested in various in vitro settings using cells to evaluate their possible suitability as an implant material. However, there exists a gap between in vivo and in vitro test results for absorbable materials. A lot of traditional in vitro assessments for permanent materials are no longer applicable to absorbable metallic implants. A key step is to identify and test the relevant microenvironment and parameters in test systems, which should be adapted according to the specific application. New test methods are necessary to reduce the difference between in vivo and in vitro test results and provide more accurate information to better understand absorbable metallic implants. In this investigative review, we strive to summarize the latest test methods for characterizing absorbable magnesium-based stent for bioabsorption/biodegradation behavior in the mimicking vascular environments. Also, this article comprehensively discusses the direction of test standardization for absorbable stents to paint a more accurate picture of the in vivo condition around implants to determine the most important parameters and their dynamic interactions.

Truly Absorbed Microbial Protein Synthesis, Rumen Bypass Protein, Endogenous Protein, and Total Metabolizable Protein from Starchy and Protein-Rich Raw Materials

NARCIS (Netherlands)

Parand, Ehsan; Vakili, Alireza; Mesgaran, Mohsen Danesh; Duinkerken, Van Gert; Yu, Peiqiang

2015-01-01

This study was carried out to measure truly absorbed microbial protein synthesis, rumen bypass protein, and endogenous protein loss, as well as total metabolizable protein, from starchy and protein-rich raw feed materials with model comparisons. Predictions by the DVE2010 system as a more

Inkjet Printing and Ebeam Sintering Approach to Fabrication of GHz Meta material Absorber

International Nuclear Information System (INIS)

Park, J. W.; Kim, Y. J.; Lee, Y. P.; Park, I. S.; Kang, J. H.; Lim, Jongwoo; Kim, Jonghee; Kim, Hyotae

2013-01-01

Metamaterial absorber structure of GHz range is fabricated by inkjet printing and e-beam sintering. The inkjet printing is of interest, which give the easier and quicker way to fabricate large scale metamaterials than the approaches by the lithographic process, Furthermore it is more suitable to make flexible electronics, which has yet been great technologic trend. Usual post process of inkjet printing is the sintering to ensure solvent-free from the printed pattern and to its better conductivity comparable to the ordinary vacuum deposition process. E-beam irradiation sintering of the pattern is promising because it is inherently local and low temperature process. The main procedure of metamaterials fabrication is printing a resonator structure with lossy metal such as Ag or Au. We designed two types of Ag based multiband absorber which are double and quadruple bands. Those adsorber patterns are printed on polyimide substrate with commercially available Ag ink (DGP 40LT-15C, 25C). The absorbance performance of fabricated metamaterials is characterized by Hewlett-Packard E836B network analyzer in microwave anechoic chamber. The conductivity enhancement after e-beam or other sintering process is checked by measuring sheet resistance. The absorbance of the fabricated metamaterial is measured around 60% for the types designed. The absorbance is not high enough to practical use, which is attributed to low conductivity of the printed pattern. The spectrum shows, however, quite interesting large broadness, which come in the interval between each pack absorbance, witch needs further study. Though the extent of its effectiveness of inkjet printing in metamaterials needs more experimental studies, the demonstrated capability of quick and large area fabrication to flexible substrate is excellent

Structural investigation and microwave characteristics of (Ba{sub 0.2}La{sub 0.8})Fe{sub 0.2}Mn{sub 0.4}Ti{sub 0.4}O{sub 3} absorbing materials

Energy Technology Data Exchange (ETDEWEB)

Manaf, Azwar [Dept. of Physics, Faculty of Mathematics and Natural Sciences, Indonesia of University (Indonesia); Adi, Wisnu Ari, E-mail: dwisnuaa@batan.go.id [Center for Technology of Nuclear Industry Material, National Nuclear Energy Agency (Indonesia)

2014-03-24

Synthesis and characterization of (Ba{sub 0.2}La{sub 0.8})Fe{sub 0.2}Mn{sub 0.4}Ti{sub 0.4}O{sub 3} absorbing material by mechanical alloying process has been performed. The absorbing material was prepared by oxide materials, namely BaCO{sub 3}, La{sub 2}O{sub 3}, TiO{sub 2}, Fe{sub 2}O{sub 3}, and MnCO{sub 3}. The mixture was milled for 10 h and then sintered at a temperature of 1000 ° C for 10 h. The refinement results of x-ray diffraction pattern of lanthanum manganite substituted with barium showed that the sample consisted of two phases, namely, La{sub 0.9125}MnO{sub 3} phase which has a structure monoclinic (I12/a1) with lattice parameters a = 5.527(1) Å, b = 5.572(1) Å and c = 7.810(1) Å, α = γ = 90° and β = 89.88(5)°, the unit cell volume of V = 240.57(8) Å{sup 3}, and the atomic density of ρ = 6.238 gr.cm{sup −3}. The microstructure analyses showed that the particle shapes was polygonal with the varied particle sizes of 1 ∼ 3 μm distributed homogeneously on the surface of the samples. The results of the electromagnetic wave absorption curve analysis by using a vector network analyzer (VNA) showed that the sample can absorb microwaves in the frequency range of 8-15 GHz with a very wide absorption bandwidth. It indicates that the as prepared absorber presents potential absorbing property in X and Ku-band. We concluded that the (Ba{sub 0.2}La{sub 0.8})Fe{sub 0.2}Mn{sub 0.4}Ti{sub 0.4}O{sub 3} material can be applied as a candidate absorber material of microwaves or electromagnetic wave.

Review of Plasmonic Nanocomposite Metamaterial Absorber

Directory of Open Access Journals (Sweden)

Mehdi Keshavarz Hedayati

2014-02-01

Full Text Available Plasmonic metamaterials are artificial materials typically composed of noble metals in which the features of photonics and electronics are linked by coupling photons to conduction electrons of metal (known as surface plasmon. These rationally designed structures have spurred interest noticeably since they demonstrate some fascinating properties which are unattainable with naturally occurring materials. Complete absorption of light is one of the recent exotic properties of plasmonic metamaterials which has broadened its application area considerably. This is realized by designing a medium whose impedance matches that of free space while being opaque. If such a medium is filled with some lossy medium, the resulting structure can absorb light totally in a sharp or broad frequency range. Although several types of metamaterials perfect absorber have been demonstrated so far, in the current paper we overview (and focus on perfect absorbers based on nanocomposites where the total thickness is a few tens of nanometer and the absorption band is broad, tunable and insensitive to the angle of incidence. The nanocomposites consist of metal nanoparticles embedded in a dielectric matrix with a high filling factor close to the percolation threshold. The filling factor can be tailored by the vapor phase co-deposition of the metallic and dielectric components. In addition, novel wet chemical approaches are discussed which are bio-inspired or involve synthesis within levitating Leidenfrost drops, for instance. Moreover, theoretical considerations, optical properties, and potential application of perfect absorbers will be presented.

Characterization of load dependent creep behavior in medically relevant absorbable polymers.

Science.gov (United States)

Dreher, Maureen L; Nagaraja, Srinidhi; Bui, Hieu; Hong, Danny

2014-01-01

While synthetic absorbable polymers have a substantial history of use in medical devices, their use is expanding and becoming more prevalent for devices where long term loading and structural support is required. In addition, there is evidence that current absorbable medical devices may experience permanent deformations, warping (out of plane twisting), and geometric changes in vivo. For clinical indications with long term loading or structural support requirements, understanding the material's viscoelastic properties becomes increasingly important whereas these properties have not been used historically as preclinical indications of performance or design considerations. In this study we measured the static creep, creep recovery and cyclic creep responses of common medically relevant absorbable materials (i.e., poly(l-lactide, PLLA) and poly(l-co-glycolide, PLGA) over a range of physiologically relevant loading magnitudes. The results indicate that both PLLA and PLGA exhibit creep behavior and failure at loads significantly less than the yield or ultimate properties of the material and that significant material specific responses to loading exist. In addition, we identified a strong correlation between the extent of creep in the material and its crystallinity. Results of the study provide new information on the creep behavior of PLLA and PLGA and support the use of viscoelastic properties of absorbable polymers as part of the material selection process. © 2013 Published by Elsevier Ltd.

A chiral microwave absorbing absorbent of Fe–CoNiP coated on spirulina

Energy Technology Data Exchange (ETDEWEB)

Xu, Yonggang, E-mail: xuyonggang221@163.com [Science and Technology on Electromagnetic Scattering Laboratory, Shanghai, 200438 (China); Yuan, Liming [Science and Technology on Electromagnetic Scattering Laboratory, Shanghai, 200438 (China); Zhang, Deyuan [School of Mechanical Engineering and Automation, Beihang University, Beijing, 100191 (China)

2015-11-15

A chiral bio-absorbent of Fe–CoNiP coated on the spirulina was fabricated by the electroless and chemical vapor decomposition. The scanning electron microscopy (SEM) was used to evaluate the spirulina cells particle morphology. X-ray diffraction (XRD) patterns were done to analyze the particle crystal grain structure. The permittivity and permeability was measured by a vector network analyzer in frequency 8–18 GHz, and the reflection loss (RL) was calculated. The results showed the carbonyl iron particles (CIPs) and CoNiP were bonded to the spirulina surface, the permittivity and permeability could be enlarged as Fe films coated on the particles compared with the CoNiP spirulina, it was attributed to the excellent electromagnetic property of CIPs. The chiral Fe–CoNiP composites had a better absorbing property at 8–18 GHz than the CoNiP spirulina composite, the RL was −16.26 dB at 10.48 GHz, the absorbing band was 9.5–11.5 GHz of RL less than −10 dB, which indicated the Fe–CoNiP spirulina could be an effective absorbent used in 8–18 GHz. - Highlights: • Absorbers filled with Fe–CoNiP coating on the spirulina were fabricated. • The permittivity and permeability increased as CIPs coated. • The Fe material enhanced the electromagnetic property. • The spirulina coated Fe–CoNiP was effective in 8–18 GHz.

Recurrent 3-day cycles of water deprivation for over a month depress mating behaviour but not semen characteristics of adult rams.

Science.gov (United States)

Khnissi, S; Lassoued, N; Rekik, M; Ben Salem, H

2016-02-01

This study aimed to investigate the effect of water deprivation (WD) on reproductive traits of rams. Ten mature rams were used and allocated to two groups balanced for body weight. Control (C) rams had free access to drinking water, while water-restricted rams (WD) were deprived from water for 3 consecutive days and early on the morning of day 4, they had ad libitum access to water for 24 h, similar to C animals. The experiment lasted 32 days, that is eight 4-day cycles of water deprivation and subsequent watering. Feed and water intake were significantly affected by water deprivation; in comparison with C rams, WD rams reduced their feed intake by 18%. During the watering day of the deprivation cycle, WD rams consumed more water than C rams on the same day (11.8 (SD = 3.37) and 8.4 (SD = 1.92) l respectively; p water deprivation. However, testosterone levels were lowered as a result of water deprivation and average values were 10.9 and 6.2 (SEM 1.23) ng/ml for C and WD rams respectively (p cycles 5 and 8 of water deprivation. Several mating behaviour traits were modified as a result of water deprivation. When compared to controls, WD rams had a more prolonged time to first mount attempt (p Water deprivation may have practical implications reducing the libido and therefore the serving capacity of rams under field conditions. Journal of Animal Physiology and Animal Nutrition © 2015 Blackwell Verlag GmbH.

Absorbing device for stationary arrangement in the lattice of a boiling water reactor

International Nuclear Information System (INIS)

Fredin, B.; Nylund, O.

1980-01-01

The invention refers to an absorbing device for stationary arrangement in the lattice of a BWR in a gap between two bundles of vertical fuel rods. It consists of at least one absorbing plate containing burnable absorbing material. Both lateral surfaces of this plate are directed to one surface each of the bundles mentioned above. According to the invention the absorbing material is contained in channels formed by welding together two adjacent sheet elements, at least one of which being corrugated. The welds will be made at the points where to tops of the waves touch the other sheet element. (orig.) [de

Generalized pin factor methodology for LWR reload cores with discrete burnable absorbers

International Nuclear Information System (INIS)

Hah, C.J.; Hideki Matsumoto; Toshikazu Ida; Lee, C.; Chao, Y.A.

2005-01-01

Discrete burnable absorbers are used to suppress excess reactivity as well as peak pin power in an assembly. After the burn-out of absorption material, discrete burnable absorbers are usually removed from assembly guide tubes for the next cycle. For that case, the pin factors with discrete burnable absorbers cannot be used since the assembly configuration is physically changed. The pin factors without discrete burnable absorbers also have noticeable deviation from the actual case because they do not take into account the history effect due to the residence of discrete burnable absorbers for the previous cycle. In this paper, the generalized pin factor (GPF) method is developed to accurately predict pin powers by considering the history effect. The method uses a second-order polynomial function to approximate the history effect which builds up during the residence of burnable absorber material and employs a linear approximation to simulate the decay of the history effect after discrete burnable absorbers are removed. The verification results from Westinghouse Vantage- 5H assemblies with WABAs showed that pin power errors were significantly reduced by using the GPF. (authors)

On the definition of absorbed dose

International Nuclear Information System (INIS)

Grusell, Erik

2015-01-01

Purpose: The quantity absorbed dose is used extensively in all areas concerning the interaction of ionizing radiation with biological organisms, as well as with matter in general. The most recent and authoritative definition of absorbed dose is given by the International Commission on Radiation Units and Measurements (ICRU) in ICRU Report 85. However, that definition is incomplete. The purpose of the present work is to give a rigorous definition of absorbed dose. Methods: Absorbed dose is defined in terms of the random variable specific energy imparted. A random variable is a mathematical function, and it cannot be defined without specifying its domain of definition which is a probability space. This is not done in report 85 by the ICRU, mentioned above. Results: In the present work a definition of a suitable probability space is given, so that a rigorous definition of absorbed dose is possible. This necessarily includes the specification of the experiment which the probability space describes. In this case this is an irradiation, which is specified by the initial particles released and by the material objects which can interact with the radiation. Some consequences are discussed. Specific energy imparted is defined for a volume, and the definition of absorbed dose as a point function involves the specific energy imparted for a small mass contained in a volume surrounding the point. A possible more precise definition of this volume is suggested and discussed. Conclusions: The importance of absorbed dose motivates a proper definition, and one is given in the present work. No rigorous definition has been presented before. - Highlights: • A stringent definition of absorbed dose is given. • This requires the definition of an irradiation and a suitable probability space. • A stringent definition is important for an understanding of the concept absorbed dose

Prevalence of gastrointestinal parasites of rams brought into ...

African Journals Online (AJOL)

In an effort to gain a better understanding into the role played by food animals in the epidemiology of gastrointestinal parasites, we assessed the prevalence of gastrointestinal parasites in different breeds of rams brought into Abeokuta during a festive season by ... The only protozoan parasite identified was Eimeria spp.

Detecting danger labels with RAM-based neural networks

DEFF Research Database (Denmark)

Jørgensen, T.M.; Christensen, S.S.; Andersen, A.W.

1996-01-01

An image processing system for the automatic location of danger labels on the back of containers is presented. The system uses RAM-based neural networks to locate and classify labels after a pre-processing step involving specially designed non-linear edge filters and RGB-to-HSV conversion. Result...

Performance and carcass characteristics of Yankasa ram fed with ...

African Journals Online (AJOL)

Remember me ... and 50% maize and wheat offal mixture, were better when compared to the control (B0) and other test diet in terms of performance and carcass characteristics. ... Key words: Performance, carcass, biscuit waste, Yankasa ram.

The effect of cargo on the crush loading of RAM transportation packages in ship collisions

International Nuclear Information System (INIS)

Radloff, H.D.; Ammerman, D.J.

1998-03-01

Recent intercontinental radioactive material shipping campaigns have focused public and regulatory attention on the safety of transport of this material by ocean-going vessels. One major concern is the response of the vessel and onboard radioactive material (RAM) packages during a severe ship-to-ship collision. These collisions occur at velocities less than the velocity obtained in the Type B package regulatory impact event and the bow of the striking ship is less rigid than the unyielding target used in those tests (Ammerman and Daidola, 1996). This implies that ship impact is not a credible scenario for damaging the radioactive material packages during ship collisions. It is possible, however, for these collisions to generate significant amounts of crush force by the bow of the impacting ship overrunning the package. It is the aim of this paper to determine an upper bound on the magnitude of this crush force taking into account the strength of the radioactive material carrying vessel and any other cargo that may be stowed in the same hold as the radioactive material

Long-term effects of neutron absorber and fuel matrix corrosion on criticality

International Nuclear Information System (INIS)

Culbreth, W.G.; Zielinski, P.R.

1994-01-01

Proposed waste package designs will require the addition of neutron absorbing material to prevent the possibility of a sustained chain reaction occurring in the fuel in the event of water intrusion. Due to the low corrosion rates of the fuel matrix and the Zircaloy cladding, there is a possibility that the neutron absorbing material will corrode and leak from the waste container long before the subsequent release of fuel matrix material. An analysis of the release of fuel matrix and neutron absorber material based on a probabilistic model was conducted and the results were used to prepare input to KENO-V, an neutron criticality code. The results demonstrate that, in the presence of water, the computed values of k eff exceeded the maximum of 0.95 for an extended period of time

Microwave absorbing property of a hybrid absorbent with carbonyl irons coating on the graphite

Energy Technology Data Exchange (ETDEWEB)

Xu, Yonggang, E-mail: xuyonggang221@163.com [Science and Technology on Electromagnetic Scattering Laboratory, Shanghai, 200438 (China); Yan, Zhenqiang; Zhang, Deyuan [Bionic and Micro/Nano/Bio Manufacturing Technology Research Center, School of Mechanical Engineering and Automation, Beihang University, Beijing 100191 (China)

2015-11-30

Graphical abstract: The absorbing property could be enhanced as the CIPs coated on the graphite. - Highlights: • Absorbers filled with CIPs coating on the graphite was fabricated. • The permittivity and permeability increased as CIPs coated. • The CIP materials enhanced the electromagnetic property. • The graphite coated CIPs were effective in 2–18 GHz. - Abstract: The hybrid absorbent filled with carbonyl iron particles (CIPs) coating on the graphite was prepared using a chemical vapor decomposition (CVD) process. X-ray diffraction (XRD) patterns were done to analyze the particle crystal grain structure. The complex permittivity and permeability were measured using a vector network analyzer in the frequency range of 2–18 GHz. The results showed that α-Fe appeared in the super-lattice diffraction peaks in XRD graph. The composites added CIPs coating on the graphite had a higher permittivity and imaginary permeability due to the superior microwave dielectric loss and magnetic loss of the CIPs. The reflection loss (RL) result showed that composites filled with 5 vol% Fe-graphite had an excellent absorbing property in the 2–18 GHz, the minimum RL was −25.14 dB at 6 mm and −26.52 dB at 8 mm, respectively.

Thermal Shielding Effects of a Damaged Shock Absorber and an Intact Shock Absorber

Energy Technology Data Exchange (ETDEWEB)

Bang, K. S.; Lee, J. C.; Kim, K. Y.; Seo, C. S.; Seo, K. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2011-05-15

In order to safely transport the radioactive waste arising from the hot test of an ACP(Advanced Spent Fuel Conditioning Process) a shipping package is required. Therefore, KAERI is developing a shipping package to transport the radioactive waste arising from the ACPF during a hot test. The regulatory requirements for a Type B package are specified in the Korea Most Act 2009-37, IAEA Safety Standard Series No. TS-R-1, and US 10 CFR Part. These regulatory guidelines classify the hot cell cask as a Type B package, and state that the Type B package for transporting radioactive materials should be able to withstand a test sequence consisting of a 9 m drop onto an unyielding surface, a 1 m drop onto a puncture bar, and a 30 minute fully engulfing fire. Greiner et al. investigated the thermal protection provided by shock absorbers by using the CAFE computer code. To evaluate the thermal shielding effect of the shock absorber, the thermal test was performed by using a 1/2 scale model with a shock absorber which was damaged by both a 9 m drop test and a 1 m puncture test. For the purpose of comparison, the thermal test was also carried out by using a 1/2 scale model with the intact shock absorber

Integrated approach for combining sustainability and safety into a RAM analysis, RAM2S (Reliability, Availability, Maintainability, Sustainability and Safety) towards greenhouse gases emission targets

Energy Technology Data Exchange (ETDEWEB)

Alvarenga, Tobias V. [Det Norske Veritas (DNV), Hovik, Oslo (Norway)

2009-07-01

This paper aims to present an approach to integrate sustainability and safety concerns on top of a typical RAM Analysis to support new enterprises to find alternatives to align themselves to the greenhouse gases emission targets, measured as CO{sub 2} (carbon dioxide) equivalent. This approach can be used to measure the impact of the potential CO{sub 2} equivalent emission levels mainly related to new enterprises with high CO{sub 2} content towards environment and production, as per example, the extraction of oil and gas from the Brazilian Pre-salt layers. In this sense, this integrated approach, combining Sustainability and Safety into a RAM analysis, RAM2S (Reliability, Availability, Maintainability, Sustainability and Safety), can be used to assess the impact of CO{sub 2} 'production' along the entire enterprise life-cycle, including the impact of possible facility shutdown due to emission restrictions limits, as well as due to the occurrence of additional failures modes related to CO{sub 2} corrosion capabilities. Thus, at the end, this integrated approach would allow companies to find out a more cost-effective alternative to adapt their business into the global warming reality, overcoming the inherent threats of greenhouse gases. (author)

Design of data transportation based on dual-port RAM in IMS system

International Nuclear Information System (INIS)

Zhang Guohui; Li Yongping

2010-01-01

Ion mobility spectroscopy (IMS) is a rugged, portable, sensitive, low cost, field instrumental technique capable of trace organic detection and monitoring for environmental pollutants, pesticides, explosives, narcotics, and other analytes, hence it is of great significance to social security and stability. High rate data transmission mechanism between DSP processor and ARM core is required in the electronic system of IMS. After careful comparison of UART and dual port RAM, a new design based on dual port RAM that can be applied to other similar systems. (authors)

Performance modeling in critical engineering systems using RAM analysis

International Nuclear Information System (INIS)

Sharma, Rajiv Kumar; Kumar, Sunand

2008-01-01

Reliability, availability and maintainability (RAM) analysis of system is helpful in carrying out design modifications, if any, required to achieve minimum failures or to increase mean time between failures (MTBF) and thus to plan maintainability requirements, optimize reliability and maximize equipment availability. To this effect, the paper presents the application of RAM analysis in a process industry. Markovian approach is used to model the system behavior. For carrying out analysis, transition diagrams for various subsystems are drawn and differential equations associated with them are formulated. After obtaining the steady state solution the corresponding values of reliability and maintainability are estimated at different mission times. The computed results are presented to plant personnel for their active consideration. The results proved helpful to them for analyzing the system behavior and thereby to improve the system performance considerably by adopting and practicing suitable maintenance policies/strategies

Uudised : Hortus Musicus Moskvas. TPÜ naiskoor koorikonkursil. RAM samal laval Mark Knopfleriga. "Tuuleveskid. Kerkokell" / Joosep Sang

Index Scriptorium Estoniae

Sang, Joosep

2000-01-01

Hortus Musicus esines 23. ja 24. nov. Moskvas. TPÜnaiskoor võitis II preemia XVII rahvusvahelisel F.Schuberti nim. koorikonkursil Austrias. RAM esineb 8. dets. Helsingis Hartwall Areenas heategevuskontserdil. RAM esineb 6. dets. Estonia kontserdisaalis kavaga "Tuuleveskid. Kerkokell"

Geographic resolution issues in RAM transportation risk analysis

International Nuclear Information System (INIS)

Mills G, Scott; Neuhauser, Sieglinde

2000-01-01

Over the years that radioactive material (RAM) transportation risk estimates have been calculated using the RADTRAN code, demand for improved geographic resolution of route characteristics, especially density of population neighboring route segments, has led to code improvements that provide more specific route definition. With the advent of geographic information systems (GISs), the achievable resolution of route characteristics is theoretically very high. The authors have compiled population-density data in 1-kilometer increments for routes extending over hundreds of kilometers without impractical expenditures of time. Achievable resolution of analysis is limited, however, by the resolution of available data. U.S. Census data typically have 1-km or better resolution within densely-populated portions of metropolitan areas but census blocks are much larger in rural areas. Geographic resolution of accident-rate data, especially for heavy/combination trucks, are typically tabulated on a statewide basis. These practical realities cause one to ask what level(s) of resolution may be necessary for meaningful risk analysis of transportation actions on a state or interstate scale

Combining linear polarization spectroscopy and the Representative Layer Theory to measure the Beer-Lambert law absorbance of highly scattering materials.

Science.gov (United States)

Gobrecht, Alexia; Bendoula, Ryad; Roger, Jean-Michel; Bellon-Maurel, Véronique

2015-01-01

Visible and Near Infrared (Vis-NIR) Spectroscopy is a powerful non destructive analytical method used to analyze major compounds in bulk materials and products and requiring no sample preparation. It is widely used in routine analysis and also in-line in industries, in-vivo with biomedical applications or in-field for agricultural and environmental applications. However, highly scattering samples subvert Beer-Lambert law's linear relationship between spectral absorbance and the concentrations. Instead of spectral pre-processing, which is commonly used by Vis-NIR spectroscopists to mitigate the scattering effect, we put forward an optical method, based on Polarized Light Spectroscopy to improve the absorbance signal measurement on highly scattering samples. This method selects part of the signal which is less impacted by scattering. The resulted signal is combined in the Absorption/Remission function defined in Dahm's Representative Layer Theory to compute an absorbance signal fulfilling Beer-Lambert's law, i.e. being linearly related to concentration of the chemicals composing the sample. The underpinning theories have been experimentally evaluated on scattering samples in liquid form and in powdered form. The method produced more accurate spectra and the Pearson's coefficient assessing the linearity between the absorbance spectra and the concentration of the added dye improved from 0.94 to 0.99 for liquid samples and 0.84-0.97 for powdered samples. Copyright © 2014 Elsevier B.V. All rights reserved.

Hydraulic ram analysis = Analyse du bélier hydraulique

NARCIS (Netherlands)

Verspuy, C.; Tijsseling, A.S.

1993-01-01

A simple mathematical model describing the operation of a hydraulic ram is presented. Predictions of the model are compared with measurements done in an earlier stage of the project. The model is used to perform a parameter variation study.

Quantitative neutron radiography using neutron absorbing honeycomb

International Nuclear Information System (INIS)

Tamaki, Masayoshi; Oda, Masahiro; Takahashi, Kenji; Ohkubo, Kohei; Tasaka, Kanji; Tsuruno, Akira; Matsubayashi, Masahito.

1993-01-01

This investigation concerns quantitative neutron radiography and computed tomography by using a neutron absorbing honeycomb collimator. By setting the neutron absorbing honeycomb collimator between object and imaging system, neutrons scattered in the object were absorbed by the honeycomb material and eliminated before coming to the imaging system, but the neutrons which were transmitted the object without interaction could reach the imaging system. The image by purely transmitted neutrons gives the quantitative information. Two honeycombs were prepared with coating of boron nitride and gadolinium oxide and evaluated for the quantitative application. The relation between the neutron total cross section and the attenuation coefficient confirmed that they were in a fairly good agreement. Application to quantitative computed tomography was also successfully conducted. The new neutron radiography method using the neutron-absorbing honeycomb collimator for the elimination of the scattered neutrons improved remarkably the quantitativeness of the neutron radiography and computed tomography. (author)

Design of absorber assemblies with intentional pellet-cladding mechanical interaction

International Nuclear Information System (INIS)

Hollenberg, G.W.; Birney, K.R.; Pitner, A.L.; Basmajian, J.A.

1980-04-01

A number of improvements in absorber assembly performance characteristics can be achieved through implementation of absorber cladding mechanical interaction (ACMI). Benefits include lower operating temperatures, less potential for material relocation, longer lifetime, and increased reactivity worth. Analyses indicate that substantial cladding strains may be attainable without significant risk of breach. However, actual in-reactor testing of ACMI in absorber elements will be required before design criteria can be revised to accept ACMI

Design and testing of a shock absorber for a type I container

International Nuclear Information System (INIS)

Sappok, M.; Beine, B.; Rittscher, D.; Jais, M.

1994-01-01

A simple method of designing a shock absorber to protect a type B cast-iron container is developed. The results of deformation tests of the structural material (steel pipes) used for the shock absorber are presented. The accelerations and strains measured during the 9m drop tests of the container with the shock absorber are compared with the theoretical results of the calculations for the shock absorber design. ((orig.))

Un discurso de Ramón y Cajal sobre El Quijote

Directory of Open Access Journals (Sweden)

González Quirós, José Luis

2006-04-01

Full Text Available The article is a brief study to a lecture by Santiago Ramon y Cajal, entitled Psichology of Don Quixote and Quixotism. It is a rather unknown text, as well as one of the main works regarding the topic produced at the time of the 3rd centennary of Don Quixote. The lecture was commissioned by the Medical College of San Carlos, and was read on May 9th, 1905. The existing editions contain quite a few printing errors. Our analysis sets out Cajal’s ideas regarding the situation of Spanish science and the necessary measures that need to be taken. We also put these ideas in comparison with those of Unamuno and Ortega, the two main Spanish authors to write about the same topic in the same years. We emphasize the agreement between Unamuno and Cajal, as well as the radical difference we can find between Ortega’s and Cajal’s approaches to the subject of science.El artículo es un breve análisis del discurso de Santiago Ramón y Cajal titulado Psicología de Don Quijote y el quijotismo, un texto poco conocido que fue una de las piezas principales producida en torno al tema con motivo del III centenario del Quijote. El discurso de Ramón y Cajal le fue encargado por el Colegio Médico de San Carlos, y se pronunció en Madrid el día 9 de Mayo de 1905. Las ediciones existentes contienen algunas erratas e inexactitudes. Nuestro análisis expone las ideas de Ramón y Cajal en relación con la situación de la ciencia española y con los remedios que es necesario poner en práctica y con el espíritu que debe animarlos para poner luego en relación las ideas de Ramón y Cajal con las de Unamuno y Ortega, los dos principales autores españoles que escribieron sobre el tema en aquellos mismos años, subrayando la coincidencia entre Unamuno y Ramón y Cajal y la llamativa distancia de Ortega con las ideas de nuestro histólogo en relación con la ciencia.

Camouflage, Concealment, and Decoys

Science.gov (United States)

2010-11-26

otherwise dull Note. Use canned milk or powdered eggs to increase the binding properties of field-expedient paints. RADAR-ABSORBING MATERIAL 3-72. RAM... falsification of evidence, inducing him to react in a manner prejudicial to his interests. decoy An imitation in any sense of a person, an object

Software for dimensioning of hydraulic ram; Software para dimensionamento de carneiro hidraulico

Energy Technology Data Exchange (ETDEWEB)

Borges Neto, Manuel Rangel [Centro Federal de Educacao Tecnologica de Petrolina, CE (Brazil); Borges, Grace Anne Pontes [Faculdade de Tecnologia de Sao Paulo (FATEC), Sao Paulo, SP (Brazil). Dept. de Processamento de Dados; Borges, Everton Pontes [Centro Federal de Educacao Tecnologica do Rio Grande do Norte, Natal, RN (Brazil). Curso Tecnologia em Automacao Industrial

2004-07-01

The search for new renewable energy sources sometimes takes us always from existing solutions applications. The hydraulic ram is equipment developed in 1796, used to water pumping, without using electricity energy and can be used for small rural producer in places where the conventional electricity grid access is limited. The objective of this work is Software introducing, developed to help a commercial hydraulic ram dimensioning, which isn't necessary previous hydraulic knowledge, and can also be used as a didactic resource at technicians and technologists courses in subjects as hydraulics or irrigation. (author)

Dose calculation for atmospheric releases from a nuclear accident using RAMS/HYPACT

International Nuclear Information System (INIS)

Tamura, Junji; Tomita, Kenichi; Homma, Toshimitsu

2004-01-01

This paper describes the investigation of uncertainties in the structure of the atmospheric dispersion/deposition model used in the probabilistic accident consequence assessment code, OSCAAR. To investigate these uncertainties, we have introduced the more sophisticated computer codes, RAMS and HYPACT, which were widely used in the research field of atmospheric phenomena. In this work, the capabilities of the HYPACT model were extended for use in accident consequence assessments. The preliminary comparison between the predictions by OSCAAR and those by RAMS/HYPACT were conducted for both individual and collective consequences in terms of probabilistic results. (author)

Minsk ja RAM 7 / Evelyn Müürsepp

Index Scriptorium Estoniae

Müürsepp, Evelyn

2005-01-01

Minskis toimunud RAM 7-st (Reapproaching New Media. Models of Collaboration / Ümberhinnates uut meediat. Koostöömudelid". Korraldajad Tatjana Dushina ja Denis Romanovski üritavad luua uue meedia keskust Valgevene kunstiakadeemiasse. Eestit esindasid Evelin Müürsepp ja John Grzinich (modereeris vabade ülikoolide kursust). Osalemisest fotomängus "FotoOhota"

Comparing interfertility data with random amplified microsatellites DNA (RAMS) studies in Ganoderma Karst. Taxonomy.

Science.gov (United States)

Nudin, Nur Fatihah Hasan; S, Siddiquee

2012-03-01

The taxonomy of the causal pathogen of basal stem rot of oil palms, Ganoderma is somewhat problematic at present. In order to determine the genetic distance relationship between G. boninense isolates and non-boninense isolates, a random amplified microsatellites DNA (RAMS) technique was carried out. The result was then compared with interfertility data of G. boninense that had been determined in previous mating studies to confirm the species of G. boninense. Dendrogram from cluster analysis based on UPGMA of RAMS data showed that two major clusters, I and II which separated at a genetic distance of 0.7935 were generated. Cluster I consisted of all the biological species G. boninense isolates namely CNLB, GSDK 3, PER 71, WD 814, GBL 3, GBL 6, OC, GH 02, 170 SL and 348781 while all non-boninense isolates namely G. ASAM, WRR, TFRI 129, G. RES, GJ, and CNLM were grouped together in cluster II. Although the RAMS markers showed polymorphisms in all the isolates tested, the results obtained were in agreement with the interfertility data. Therefore, the RAMS data could support the interfertility data for the identification of Ganoderma isolates.

Species-specific nested PCR as a diagnostic tool for Brucella ovis infection in rams

Directory of Open Access Journals (Sweden)

L.F. Costa

2013-02-01

Full Text Available The aim of the present study was to evaluate a species-specific nested PCR based on a previously described species-specific PCR for detection of B. ovis in semen and urine samples of experimentally infected rams. The performance of the species-specific nested PCR was compared with the results of a genus-specific PCR. Fourteen rams were experimentally infected with the Brucella ovis REO 198 strain and samples of semen and urine were collected every week up to 180 days post infection. Out of 83 semen samples collected, 42 (50.6% were positive for the species-specific nested PCR, and 23 (27.7% were positive for the genus-specific PCR. Out of 75 urine samples, 49 (65.3% were positive for the species-specific nested PCR, whereas 11 (14.6% were genus-specific PCR positive. Species-specific nested PCR was significantly more sensitive (P<0.001 than the genus-specific PCR in semen and urine from experimentally infected rams. In conclusion, the species-specific nested PCR developed in this study may be used as a diagnostic tool for the detection of B. ovis in semen and urine samples from suspected rams.

Shock absorber in combination with a nuclear reactor core structure

International Nuclear Information System (INIS)

Housman, J.J.

1976-01-01

This invention relates to the provision of shock absorbers for use in blind control rod passages of a nuclear reactor core structure which are not subject to degradation. The shock absorber elements are made of a porous brittle carbonaceous material, a porous brittle ceramic material, or a porous brittle refractory oxide and have a void volume of between 30% and 70% of the total volume of the element for energy absorption by fracturing due to impact loading by a control rod. (UK)

Measurement of absorbed doses near metal and dental material interfaces irradiated by x- and gamma-ray therapy beams

International Nuclear Information System (INIS)

Farahani, M.; Eichmiller, F.C.; McLaughlin, W.L.

1990-01-01

Soft-tissue damage adjacent to dental restorations is a deleterious side effect of radiation therapy associated with low-energy electron scatter from dental materials of high electron density. This study was designed to investigate the enhancement of dose to soft tissue (or water) close to high electron-density materials and to measure the detailed lateral and depth-dose profiles in soft-tissue-simulating polymer adjacent to planar interfaces of several higher atomic-number materials: 18-carat gold dental casting alloy; Ag-Hg dental amalgam alloy; Ni-Cr dental casting alloy; and natural human tooth structure. Results indicate that the dose-enhancement in 'tissue' is as great as a factor of 2 on the backscatter side adjacent to gold and a factor of 1.2 adjacent to tooth tissue, but is insignificant on the forward-scatter side because of the predominant effect of attenuation by the high-density, high atomic-number absorbing material. (author)

Absorber rod driving into a gas-cooled nuclear reactor

International Nuclear Information System (INIS)

Elter, C.; Schmitt, H.; Schoening, J.

1987-01-01

The absorber rod consists of a hollow cylinder which has a layer of absorber material applied on its inside circumferential surface. The absorber rod is held via a guide sleeve, which is supported centrally in a hole in the side reflector. The guidance within the sleeve is provided by flanges on the hollow cylinder. The movement of the hollow cylinder is carried out hydraulically or pneumatically. A flow of cooling gas is used for cooling, which is passed through the inner central areas of the hollow cylinder and the guide sleeve. (DG) [de

Development and realization of the new state system of account and control of RAM and RAW

International Nuclear Information System (INIS)

Gubanov, V.; Shilko, V.; Syssoev, M.; Ershov, V.; Yanovskaya, N.

1998-01-01

In the article the principles of organization, organizational structure and main functions of the automated system of the state account and control of radioactive material (RAM) and waste (RAW), which is developed now in Russia, are presented. On the base of analysis the existing ( >) system the acute necessity in automation of processes of an account and control DA and DAI, based on use of modern information technologies is shown. There are presented a structure and content of normative - legal, program and information parts of the system and milestones of designing it. (author)

Low-power non-volatile spintronic memory: STT-RAM and beyond

International Nuclear Information System (INIS)

Wang, K L; Alzate, J G; Khalili Amiri, P

2013-01-01

The quest for novel low-dissipation devices is one of the most critical for the future of semiconductor technology and nano-systems. The development of a low-power, universal memory will enable a new paradigm of non-volatile computation. Here we consider STT-RAM as one of the emerging candidates for low-power non-volatile memory. We show different configurations for STT memory and demonstrate strategies to optimize key performance parameters such as switching current and energy. The energy and scaling limits of STT-RAM are discussed, leading us to argue that alternative writing mechanisms may be required to achieve ultralow power dissipation, a necessary condition for direct integration with CMOS at the gate level for non-volatile logic purposes. As an example, we discuss the use of the giant spin Hall effect as a possible alternative to induce magnetization reversal in magnetic tunnel junctions using pure spin currents. Further, we concentrate on magnetoelectric effects, where electric fields are used instead of spin-polarized currents to manipulate the nanomagnets, as another candidate solution to address the challenges of energy efficiency and density. The possibility of an electric-field-controlled magnetoelectric RAM as a promising candidate for ultralow-power non-volatile memory is discussed in the light of experimental data demonstrating voltage-induced switching of the magnetization and reorientation of the magnetic easy axis by electric fields in nanomagnets. (paper)

RackSaver neutron absorbing device development and testing

International Nuclear Information System (INIS)

Lambert, R.; O'Leary, P.; Roberts, P.

1996-01-01

Siemens Power Corporation (SPC), in cooperation with the Electric Power Research Institute (EPRI), has developed the RackSaver neutron absorbing insert. The RackSaver insert can be installed onto spent nuclear fuel assemblies to replace deteriorating Boraflex neutron absorbing material installed in some spent-fuel storage racks. This paper describes results of a development and in-pool demonstration program performed to support potential utilization of the RackSaver neutron absorbing insert by affected utilities. The program objective was to advance the RackSaver concept into a field-demonstrated product. This objective was accomplished through three phases: design, licensing and criticality evaluations, and demonstration testing

Report on investigations and studies on development of materials for hydrogen absorbing alloys; Suiso kyuzo gokin no zairyo no kaihatsu ni kansuru chosa kenkyu hokokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1984-03-01

This paper describes investigations and studies on hydrogen absorbing alloy materials and the technologies to utilize them. In the investigations and studies, literatures were collected and put into order, questionnaire surveys were performed and analyzed, lecture meetings and panel discussions were held, and the discussion results were summarized. In the present status of developing hydrogen absorbing alloys, the current status of and problems in developing such hydrogen absorbing alloys as Ti-based, Mg-based, and rare earth-based alloys were put into order. Discussions were given on prospects of possibilities of developing new alloys, making them amorphous, and putting them into mass production. In the current status of developing the utilizing technologies, such technologies as hydrogen storage systems and heat pumps were put into order and discussed. With regard to problems in hydrogen absorbing alloys, discussions were given on alloy weight, pulverization, activation, heat conductivity, and alloy costs. In discussing the safety, discussions were given on the safety and compliance with related laws and regulations relative to hydrogen transportation using a great amount of hydrogen absorbing alloys, their storage, and heat storage systems. In addition, questionnaire surveys were carried out with an objective to identify the status of developing hydrogen absorbing alloys and needs from the industries. (NEDO)

A graphite based STT-RAM cell with reduction in switching current

International Nuclear Information System (INIS)

Varghani, Ali; Peiravi, Ali

2015-01-01

Spin Transfer Torque Random Access Memory (STT-RAM) is a serious candidate for “universal memory” because of its non-volatility, fast access time, high density, good scalability, high endurance and relatively low power dissipation. However, problems with low write speed and large write current are important existing challenges in STT-RAM design and there is a tradeoff between them and data retention time. In this study, a novel STT-RAM cell structure which uses perfect graphite based Magnetic Tunnel Junction (MTJ) is proposed. First, the cross-section of the structure is selected to be an ellipse of 45 nm and 180 nm dimensions and a six-layer graphite is used as tunnel barrier. By passing a lateral current with a short pulse width (before applying STT current and independent of it) through four middle graphene layers of the tunnel barrier, a 27% reduction in the amplitude of the switching current (for fast switching time of 2 ns) or a 58% reduction in its pulse width is achieved without any reduction in data retention time. Finally, the effect of downscaling of technology on the proposed structure is evaluated. A reduction of 31.6% and 9% in switching current is achieved for 90 and 22 nm cell width respectively by passing sufficient current (100 µA with 0.1 ns pulse width) through the tunnel barrier. Simulations are done using Object Oriented Micro Magnetic Framework (OOMMF). - Highlights: • A new STT-RAM cell structure which uses perfect graphite based MTJ is proposed. • The amplitude of the switching current or its pulsewidth can be reduced without any sacrifice of data retention time. • The proposed design is down-scalable from 90 nm to 22 nm. • Micromagnetic simulations are done with OOMMF

Reproductive performance of postpartum ewes treated with insulin or progesterone hormones in association with ram effect.

Science.gov (United States)

Ferreira-Silva, J C; Basto, Srl; Tenório Filho, F; Moura, M T; Silva Filho, M L; Oliveira, Mal

2017-08-01

The reproductive performance of postpartum Santa Inês (SI) and Morada Nova (MN) ewes treated with insulin or progesterone hormones in association with ram effect was evaluated. Ewes from SI (n = 69) and MN (n = 69) breeds were randomly allocated to three groups of each breed (T1-ram effect only; T2-ram effect + insulin; T3-ram effect + progesterone). Progesterone concentrations (ηg/ml; mean ± SD) before and after introduction of rams (n = 6) were 0.51 ± 0.22 and 3.78 ± 0.68 (T1), 0.65 ± 0.21 and 3.77 ± 0.78 (T2) and 0.52 ± 0.21 and 3.84 ± 0.84 (T3) in SI ewes and 0.74 ± 0.19 and 3.71 ± 0.56 (T1), 0.70 ± 0.21 and 3.79 ± 0.75 (T2) and 0.81 ± 0.14 and 3.87 ± 0.80 (T3) in MN ewes, respectively. Thus, lower progesterone concentrations were found before the introduction of rams (p ewes and at 64 (T1), 40 (T2) and 44 (T3) hr in MN ewes. The mean number of ovulations was similar between groups (p > .05), was 1.3 ± 0.51 (T1), 1.5 ± 0.54 (T2) and 1.6 ± 0.51 (T3) in SI ewes and 1.3 ± 0.51 (T1), 1.6 ± 0.51 (T2) and 1.6 ± 0.51 (T3) in MN ewes. In conclusion, the ram effect alone is effective at inducing and synchronizing oestrus in sheep under postpartum anoestrus, irrespective of hormone treatments. © 2017 Blackwell Verlag GmbH.

Effects of Agricultural Byproducts in Ration on Productive and Reproductive Performance of Saidi Rams

Directory of Open Access Journals (Sweden)

G. A. Megahed

2006-01-01

Full Text Available The influence of selected agricultural byproducts supplementation to feed rations on the ram's body gain, reproductive performance, and subsequent fertility were investigated. Forty Saidi rams were divided into 4 groups (n = 10. Group 1 (control was fed 500 g/head/day concentrate feed mixtures (CFM plus wheat straw ad libitum. Groups 2, 3 and 4 were fed 500 g/head/day CFM plus corn cobs or sugar cane tops or sugar cane bagasse (these roughages were treated with 1% urea, respectively. Serum testosterone, glucose and total cholesterol levels were determined and semen evaluations were carried out every 15 days. Testicular size, scrotal circumference and body weight were recorded each month. At the end of the experiment, 12 rams were allowed to mount 114 healthy ewes to evaluate the pregnancy rate for each group. The results have shown that the body weight, daily body gain, testicular size and scrotal circumference increased (p p p < 0.01 as compared with group 1 (1.76 ± 0.09 ng/ml. Moreover, supplementation of treated agricultural byproducts had a significant improving effects on the semen quality. The semen volume increased, along with individual motility and live sperm percentages. Pregnancy rate in this study indicated that rams of groups 2, 3 and 4 yielded a higher pregnancy rate (83.33%, 86.67% and 81.48%, respectively than group 1 (74.07%. Agricultural byproducts such as corn cobs, sugar cane tops and sugar cane bagasse treated with 1% urea had a beneficial effect on the daily body gain and improved the reproductive performance and subsequent fertility of Saidi rams, compared to wheat straw.

An energy and cost efficient majority-based RAM cell in quantum-dot cellular automata

Directory of Open Access Journals (Sweden)

Milad Bagherian Khosroshahy

Full Text Available Nanotechnologies, notably quantum-dot cellular automata, have achieved major attentions for their prominent features as compared to the conventional CMOS circuitry. Quantum-dot cellular automata, particularly owning to its considerable reduction in size, high switching speed and ultra-low energy consumption, is considered as a potential alternative for the CMOS technology. As the memory unit is one of the most essential components in a digital system, designing a well-optimized QCA random access memory (RAM cell is an important area of research. In this paper, a new five-input majority gate is presented which is suitable for implementing efficient single-layer QCA circuits. In addition, a new RAM cell with set and reset capabilities is designed based on the proposed majority gate, which has an efficient and low-energy structure. The functionality, performance and energy consumption of the proposed designs are evaluated based on the QCADesigner and QCAPro tools. According to the simulation results, the proposed RAM design leads to on average 38% lower total energy dissipation, 25% smaller area, 20% lower cell count, 28% lower delay and 60% lower QCA cost as compared to its previous counterparts. Keywords: Quantum-dot cellular automata (QCA, Majority gate, Random access memory (RAM, Energy efficiency

Liquid carbon dioxide absorbents, methods of using the same, and related system

Science.gov (United States)

Perry, Robert James; Soloveichik, Grigorii Lev; Rubinsztajn, Malgorzata Iwona; O'Brien, Michael Joseph; Lewis, Larry Neil; Lam, Tunchiao Hubert; Kniajanski, Sergei; Hancu, Dan

2018-05-01

A carbon dioxide absorbent composition is described, including (i) a liquid, nonaqueous silicon-based material, functionalized with one or more groups that either reversibly react with CO2 or have a high-affinity for CO2, and (ii) a hydroxy-containing solvent that is capable of dissolving both the silicon-based material and a reaction product of the silicon-based material and CO2. The absorbent may be utilized in methods to reduce carbon dioxide in an exhaust gas, and finds particular utility in power plants.

Performance analysis of STT-RAM with cross shaped free layer using Heusler alloys

Science.gov (United States)

Bharat Kumary, Tangudu; Ghosh, Bahniman; Awadhiya, Bhaskar; Verma, Ankit Kumar

2016-01-01

We have investigated the performance of a spin transfer torque random access memory (STT-RAM) cell with a cross shaped Heusler compound based free layer using micromagnetic simulations. We have designed a free layer using a Cobalt based Heusler compound. Simulation results clearly show that the switching time from one state to the other state has been reduced, also it has been found that the critical switching current density (to switch the magnetization of the free layer of the STT RAM cell) is reduced.

Role of the calcaneal heel pad and polymeric shock absorbers in attenuation of heel strike impact.

Science.gov (United States)

Noe, D A; Voto, S J; Hoffmann, M S; Askew, M J; Gradisar, I A

1993-01-01

The capacity of the calcaneal heel pad, with and without augmentation by a polymeric shock absorbing material (Sorbothane 0050), to attenuate heel strike impulses has been studied using five fresh human cadaveric lower leg specimens. The specimens, instrumented with an accelerometer, were suspended and impacted with a hammer; a steel rod was similarly suspended and impacted. The calcaneal heel pad attenuated the peak accelerations by 80%. Attenuations of up to 93% were achieved by the shock absorbing material when tested against the steel rod; however, when tested in series with the calcaneal heel pad, the reduction in peak acceleration due to the shock absorbing material dropped to 18%. Any evaluation of the effectiveness of shock absorbing shoe materials must take into account their mechanical interaction with the body.

Study of diluting and absorber materials to control the reactivity during a postulated core meltdown accident in generation IV reactors

International Nuclear Information System (INIS)

Plevacova, Kamila

2010-01-01

In order to limit the consequences of a hypothetical core meltdown accident in Generation IV Sodium Fast Reactors, absorber materials in or near the core, such as boron carbide B 4 C, and diluting materials in the core catcher will be used to prevent recriticality within the mixture of molten oxide fuel and molten structures called corium. The aim of the PhD thesis was to select materials of both types and to understand their behaviour during their interaction with corium, from chemical and thermodynamic points of view. Concerning B 4 C, thermodynamic calculations and experiments agree with the formation of two immiscible phases at high temperature in the B 4 C - UO 2 system: one oxide and one boride. This separation of phases can reduce the efficiency of the neutrons absorption inside the molten fuel contained in the oxide phase. Moreover, volatilization of a part of the boron element can occur. According to these results, the necessary quantity of B 4 C to be introduced should be reconsidered for postulated severe accident sequence. Other solution could be the use of Eu 2 O 3 or HfO 2 as absorber material. These oxides form a solid solution with the oxide fuel. Concerning the diluting materials, mixed oxides Al 2 O 3 - HfO 2 and Al 2 O 3 - Eu 2 O 3 were preselected. These systems being completely unknown to date at high temperature in association with UO 2 , first points on the corresponding ternary phase diagrams were researched. Contrary to Al 2 O 3 - Eu 2 O 3 - UO 2 system, the Al 2 O 3 - HfO 2 - UO 2 mixture presents only one eutectic and thus only one solidification path which makes easier forecasting the behaviour of corium in the core catcher. (author)

Study of diluting and absorber materials to control reactivity during a postulated core melt down accident in Generation IV reactors

International Nuclear Information System (INIS)

Plevacova, K.

2010-01-01

In order to limit the consequences of a hypothetical core meltdown accident in Generation IV Sodium Fast Reactors, absorber materials in or near the core, such as boron carbide B 4 C, and diluting materials in the core catcher will be used to prevent recriticality within the mixture of molten oxide fuel and molten structures called corium. The aim of the PhD thesis was to select materials of both types and to understand their behaviour during their interaction with corium, from chemical and thermodynamic point of view. Concerning B 4 C, thermodynamic calculations and experiments agree with the formation of two immiscible phases at high temperature in the B 4 C - UO 2 system: one oxide and one boride. This separation of phases can reduce the efficiency of the neutrons absorption inside the molten fuel contained in the oxide phase. Moreover, a volatilization of a part of the boron element can occur. According to these results, the necessary quantity of B 4 C to be introduced should be reconsidered for postulated severe accident sequence. Other solution could be the use of Eu 2 O 3 or HfO 2 as absorber material. These oxides form a solid solution with the oxide fuel. Concerning the diluting materials, mixed oxides Al 2 O 3 - HfO 2 and Al 2 O 3 - Eu 2 O 3 were preselected. These systems being completely unknown to date at high temperature in association with UO 2 , first points on the corresponding ternary phase diagrams were researched. Contrary to Al 2 O 3 - Eu 2 O 3 - UO 2 system, the Al 2 O 3 - HfO 2 - UO 2 mixture presents only one eutectic and thus only one solidification path which makes easier forecasting the behaviour of corium in the core catcher. (author) [fr

Performance and carcass characteristics of Yankasa ram fed with ...

African Journals Online (AJOL)

Administrator

2011-05-30

May 30, 2011 ... were randomly assign to the 5 dietary treatment with four rams per treatment. ... estimate dry matter intake (g/d /W 0.7 kg), daily mean life weight gain ... 1.78%) and rib eye area (6.06 and 8.29) which were obtained from the ...

Shock absorbing structure

International Nuclear Information System (INIS)

Kojima, Naoki; Matsushita, Kazuo.

1992-01-01

Small pieces of shock absorbers are filled in a space of a shock absorbing vessel which is divided into a plurality of sections by partitioning members. These sections function to prevent excess deformation or replacement of the fillers upon occurrence of falling accident. Since the shock absorbing small pieces in the shock absorbing vessel are filled irregularly, shock absorbing characteristics such as compression strength is not varied depending on the direction, but they exhibit excellent shock absorbing performance. They surely absorb shocks exerted on a transportation vessel upon falling or the like. If existing artificial fillers such as pole rings made of metal or ceramic and cut pieces such as alumium extrusion molding products are used as the shock absorbing pieces, they have excellent fire-proofness and cold resistance since the small pieces are inflammable and do not contain water. (T.M.)

A one bath chemo-enzymatic process for preparation of absorbent cotton

Directory of Open Access Journals (Sweden)

A.S.M. Raja

2016-09-01

Full Text Available Cotton is the raw material for preparation of absorbent cotton. Raw cotton has to be subjected to scouring and bleaching processes for making it absorbent by removing the naturally present wax, protein and minerals in the fibre. The scouring is done at 115 °C using alkali followed by bleaching at boiling condition using alkaline hydrogen peroxide solution. The effluent coming out of such processes contains high COD and BOD values. Due to the stringent environmental regulation and great awareness among the public about environment, worldwide attempts have been made to develop green and sustainable chemical processing of materials. Based on the above, in the present study efforts have been made to develop an eco-friendly one bath preparatory process for the production of absorbent cotton using chemo-enzymatic formulation. The result indicated that absorbent cotton produced using the developed process fulfilled the required performance properties as per pharmacopoeia in comparable with the conventional process made one.

Integration of RAMS in LCC analysis for linear transport infrastructures. A case study for railways.

Science.gov (United States)

Calle-Cordón, Álvaro; Jiménez-Redondo, Noemi; Morales-Gámiz, F. J.; García-Villena, F. A.; Garmabaki, Amir H. S.; Odelius, Johan

2017-09-01

Life-cycle cost (LCC) analysis is an economic technique used to assess the total costs associated with the lifetime of a system in order to support decision making in long term strategic planning. For complex systems, such as railway and road infrastructures, the cost of maintenance plays an important role in the LCC analysis. Costs associated with maintenance interventions can be more reliably estimated by integrating the probabilistic nature of the failures associated to these interventions in the LCC models. Reliability, Maintainability, Availability and Safety (RAMS) parameters describe the maintenance needs of an asset in a quantitative way by using probabilistic information extracted from registered maintenance activities. Therefore, the integration of RAMS in the LCC analysis allows obtaining reliable predictions of system maintenance costs and the dependencies of these costs with specific cost drivers through sensitivity analyses. This paper presents an innovative approach for a combined RAMS & LCC methodology for railway and road transport infrastructures being developed under the on-going H2020 project INFRALERT. Such RAMS & LCC analysis provides relevant probabilistic information to be used for condition and risk-based planning of maintenance activities as well as for decision support in long term strategic investment planning.

Microstructure Analysis of Bismuth Absorbers for Transition-Edge Sensor X-ray Microcalorimeters

Science.gov (United States)

Yan, Daikang; Divan, Ralu; Gades, Lisa M.; Kenesei, Peter; Madden, Timothy J.; Miceli, Antonino; Park, Jun-Sang; Patel, Umeshkumar M.; Quaranta, Orlando; Sharma, Hemant; Bennett, Douglas A.; Doriese, William B.; Fowler, Joseph W.; Gard, Johnathon D.; Hays-Wehle, James P.; Morgan, Kelsey M.; Schmidt, Daniel R.; Swetz, Daniel S.; Ullom, Joel N.

2018-03-01

Given its large X-ray stopping power and low specific heat capacity, bismuth (Bi) is a promising absorber material for X-ray microcalorimeters and has been used with transition-edge sensors (TESs) in the past. However, distinct X-ray spectral features have been observed in TESs with Bi absorbers deposited with different techniques. Evaporated Bi absorbers are widely reported to have non-Gaussian low-energy tails, while electroplated ones do not show this feature. In this study, we fabricated Bi absorbers with these two methods and performed microstructure analysis using scanning electron microscopy and X-ray diffraction microscopy. The two types of material showed the same crystallographic structure, but the grain size of the electroplated Bi was about 40 times larger than that of the evaporated Bi. This distinction in grain size is likely to be the cause of their different spectral responses.

Truck transport of RAM: Risk effects of avoiding metropolitan areas

International Nuclear Information System (INIS)

Mills, G.S.; Neuhauser, K.S.

1997-11-01

In the transport of radioactive material (RAM), e.g., spent nuclear fuel (SNF), stakeholders are generally most concerned about risks in high population density areas along transportation routes because of the perceived high consequences of potential accidents. The most significant portions of a transcontinental route and an alternative examined previously were evaluated again using population density data derived from US Census Block data. This method of characterizing population that adjoins route segments offers improved resolution of population density variations, especially in high population density areas along typical transport routes. Calculated incident free doses and accident dose risks for these routes, and the rural, suburban and urban segments are presented for comparison of their relative magnitudes. The results indicate that modification of this route to avoid major metropolitan areas through use of non-Interstate highways increases total risk yet does not eliminate a relatively small urban component of the accident dose risk. This conclusion is not altered by improved resolution of route segments adjoining high density populations

Caracterización de las Reacciones Adversas a Medicamentos (RAMs observadas en una institución asistencial de III nivel de complejidad

Directory of Open Access Journals (Sweden)

D Arroyo Monterrosa

2015-07-01

Full Text Available Resumen – Las Reacciones Adversas a Medicamentos (RAMs constituyen un problema de salud pública, acerca del cual han tomado intervención los organismos de Farmacovigilancia de cada país, no solo mediante su notificación sino también por su prevención y educación en el uso de los medicamentos. Objetivo: Documentar retrospectivamente los reportes de RAMs generados en una Clínica de IV nivel en Barranquilla (Atl., Col. Metodología: Se incluyeron todas los reportes de RAMs identificadas por el personal clínico teniendo en cuenta que el proceso en tiempo real al momento de producirse el informe y el actuar del Químico Farmacéutico. Resultado: En un lapso de 15 meses se reportaron 94 RAMs, con un promedio 6,27±4,35 RAMs por cada mes El género femenino fue quien más presentó RAMs (55,32 %, el grupo etario con mayor reporte fue el de 18-44 años (42,55 %. Las RAM de mayor reporte fueron en cuanto a Gravedad, las Moderadas (58,51%, causalidad las Probadas 37,23% y Evitabilidad las Prevenibles 57,45%. Los fármacos con mayor número de RAM fueron los Anti-infecciosos Vía General 31,9%. El personal de Salud que más reportó RAM fueron las Enfermeras (35,11%. Conclusiones: El alto número de RAM referentes a los antiinfecciosos es posiblemente como una consecuencia a sus amplias indicaciones y alto uso, generando un gran espacio de oportunidad de aprendizaje para el Comité de Infecciones para promover su uso seguro.

Positive effects of melatonin treatment on the reproductive performance of young border leicester rams mated to merino ewes in spring: preliminary observations.

Science.gov (United States)

Kleemann, D O; Kelly, J M; Arney, L J; Farley, I L; Tilbrook, A J; Walker, S K

2014-12-01

Poor reproductive performance of Merino ewe flocks when mated to Border Leicester rams during spring may be due to seasonality of the Border Leicester breed. Two approaches were taken to test this assumption. Six young (12 months old) or six mixed-age (12, 24 and ≥36 months old) Border Leicester rams were either treated or not treated with melatonin implants (2 × 2 design) 6 weeks before the four groups of rams were each put with approximately 300 Merino ewes for an 8-week mating period. Implants were inserted in early September (experiment 1). The second approach was to yard or not yard ewes and mixed-age rams on several occasions during the first 3 weeks of the mating period (experiment 2). Pregnancy rate and twinning percentage were assessed by ultrasonography. In experiment 1, melatonin treatment in young rams increased (p pregnancy rate from 5.0% to 92.6%, but mixed-age rams did not respond (90.7% vs 89.5% for melatonin and non-melatonin treatments, respectively). Twinning rate was similar (p > 0.05) for ewes mated to either melatonin or non-melatonin-treated young rams (36.8% vs 40.0%, respectively), whereas melatonin significantly improved (p melatonin treatment, scrotal circumference was greater (p pregnancy rate compared with non-yarded counterparts (89.5% vs 65.5%). Twinning rate was not affected (37.7% vs 36.1%, respectively). In summary, melatonin treatment of Border Leicester rams significantly improved flock reproductive performance in spring due to improved pregnancy rates with young rams and improved litter size with mixed-age rams. © 2014 Commonwealth of Australia.

Testicular Damage following Testicular Sperm Retrieval: A Ram Model Study

Directory of Open Access Journals (Sweden)

Jens Fedder

2017-01-01

Full Text Available The aim of this study was to evaluate the possible development of histological abnormalities such as fibrosis and microcalcifications after sperm retrieval in a ram model. Fourteen testicles in nine rams were exposed to open biopsy, multiple TESAs, or TESE, and the remaining four testicles were left unoperated on as controls. Three months after sperm retrieval, the testicles were removed, fixed, and cut into 1/2 cm thick slices and systematically put onto a glass plate exposing macroscopic abnormalities. Tissue from abnormal areas was cut into 3 μm sections and stained for histological evaluation. Pathological abnormalities were observed in testicles exposed to sperm retrieval (≥11 of 14 compared to 0 of 4 control testicles. Testicular damage was found independently of the kind of intervention used. Therefore, cryopreservation of excess sperm should be considered while retrieving sperm.

Liquid carbon dioxide absorbents, methods of using the same, and related systems

Energy Technology Data Exchange (ETDEWEB)

O' Brien, Michael Joseph; Perry, Robert James; Lam, Tunchiao Hubert; Soloveichik, Grigorii Lev; Kniajanski, Sergei; Lewis, Larry Neil; Rubinsztajn, Malgorzata Iwona; Hancu, Dan

2016-09-13

A carbon dioxide absorbent composition is described, including (i) a liquid, nonaqueous silicon-based material, functionalized with one or more groups that either reversibly react with CO.sub.2 or have a high-affinity for CO.sub.2; and (ii) a hydroxy-containing solvent that is capable of dissolving both the silicon-based material and a reaction product of the silicon-based material and CO.sub.2. The absorbent may be utilized in methods to reduce carbon dioxide in an exhaust gas, and finds particular utility in power plants.

Geographic Resolution Issues in RAM Transport Risk Analysis

International Nuclear Information System (INIS)

Mills, G.S.; Neuhauser, K.S.

2000-01-01

Transport risk analyses based on the RADTRAN code have been met with continual demands for increased spatial resolution of variations in population densities and other parameters employed in the calculation of risk estimates for transport of radioactive material (RAM). With the advent of geographic information systems (GISs) large quantities of data required to describe transport routes, which may extend to hundreds of kilometers, with high resolution (e.g. 1 km segments) can be handled without inordinate expense. This capability has raised a question concerning the maximum resolution of available input data and compatibility with RADTRAN computational models. Quantitative examinations are presented of spatial resolution issues in the calculation of incident-free doses and accident dose risks. For incident-free calculations, the effect of decreasing route-segment length on accuracy, in view of the model employed, is examined, and means of reducing total data input to the RADTRAN calculations, without loss of meaningful resolution of population concentrations, are presented. In the case of accident-risk calculations, the ability to detail population density under very large dispersal plumes permits comparison of plume modelling to actual data. In both types of calculations, meaningful limits to geographic extent are suggested. (author)

Study of seasonal sexual activity variations in Algerian rams: Sexual ...

African Journals Online (AJOL)

benia

2013-10-09

Oct 9, 2013 ... testosterone in sheep, even for Rembi rams, in our .... Blood samples were then transported to the laboratory, centrifuged at 3000 rpm/min for 20 min. ... homogeneity of the data was assessed and conformed to the model.

Externally Verifiable Oblivious RAM

Directory of Open Access Journals (Sweden)

Gancher Joshua

2017-04-01

Full Text Available We present the idea of externally verifiable oblivious RAM (ORAM. Our goal is to allow a client and server carrying out an ORAM protocol to have disputes adjudicated by a third party, allowing for the enforcement of penalties against an unreliable or malicious server. We give a security definition that guarantees protection not only against a malicious server but also against a client making false accusations. We then give modifications of the Path ORAM [15] and Ring ORAM [9] protocols that meet this security definition. These protocols both have the same asymptotic runtimes as the semi-honest original versions and require the external verifier to be involved only when the client or server deviates from the protocol. Finally, we implement externally verified ORAM, along with an automated cryptocurrency contract to use as the external verifier.

Reproductive indices of Merino rams fed sun-cured Leucaena ...

African Journals Online (AJOL)

Reproductive indices of Merino rams fed sun-cured Leucaena leucocephala forage. I.V. Nsahlai, B.K. Byebwa, M.L.K. Bonsi. Abstract. (South African J of Animal Science, 2000, 30, Supplement 1: 111-112). Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

Delayed puberty caused by hyperthyroidism in ram lambs is not a result of suppression in body growth.

Science.gov (United States)

Chandrasekhar, Y; D'Occhio, M J; Setchell, B P

1986-03-01

Over a period of 8 weeks ram lambs (16 weeks old) were made hyperthyroidal (serum thyroxine approximately equal to 150 ng/ml, compared with control approximately equal to 48 ng/ml) by daily subcutaneous injections of thyroxine or maintained at a constant body weight by restriction of the feed intake. Hyperthyroidal and restricted-intake lambs remained at a constant body weight during the period of treatment whilst control rams gained body weight. Testicular growth was normal in restricted-intake lambs but was suppressed in hyperthyroidal animals. Hyperthyroidism, but not feed restriction, was also associated with decrease in LH pulse frequency (1.3 +/- 0.3/12 h compared with controls 4.8 +/- 0.9/12 h. Hyperthyroidal lambs showed normal LH responses to exogenous LHRH. After cessation of treatment testicular growth continued to be suppressed for up to 16 weeks in previously hyperthyroidic rams; thereafter testes began to increase in size but at 30 weeks after treatment were still smaller than those of control rams. It is concluded that elevated thyroxine concentrations directly influence sexual maturation in ram lambs through actions at hypothalamic and/or higher brain centres which control LH secretion. Transient hyperthyroidism during sexual maturation may cause permanent impairment of sexual development.

Reliability and Maintainability model (RAM) user and maintenance manual. Part 2

Science.gov (United States)

Ebeling, Charles E.

1995-01-01

This report documents the procedures for utilizing and maintaining the Reliability and Maintainability Model (RAM) developed by the University of Dayton for the NASA Langley Research Center (LaRC). The RAM model predicts reliability and maintainability (R&M) parameters for conceptual space vehicles using parametric relationships between vehicle design and performance characteristics and subsystem mean time between maintenance actions (MTBM) and manhours per maintenance action (MH/MA). These parametric relationships were developed using aircraft R&M data from over thirty different military aircraft of all types. This report describes the general methodology used within the model, the execution and computational sequence, the input screens and data, the output displays and reports, and study analyses and procedures. A source listing is provided.

An overview of the development, testing, and application of composite absorbers

International Nuclear Information System (INIS)

Sebesta, F.; John, J.

1995-02-01

Although inorganic exchangers offer many advantages for removing selected elements from radioactive waste streams, few of these materials are suitable for use in packed-bed columns. We review various adaptations of inorganic exchangers for use in columns, which include granular forms of the intrinsic absorbers, absorber compounds supported on other materials, and composite absorbers that use organic or inorganic binders. An organic binding polymer of polyacrylonitrile (PAN), developed at the Czech Technical University, has been demonstrated to offer advantages. We describe general methods for preparing inorganic exchange materials, which then are incorporated into PAN-based composites. Such PAN composites have been used to remove selected radionuclides from a variety of liquid waste streams. Sixteen different PAN composites were prepared for testing at Los Alamos National Laboratory (LANL) as part of an evaluation of potential partitioning agents for remediating the liquid waste in underground storage tanks at the Hanford site near Richland, Washington. Our collaboration with LANL is expected to continue for another 2 years

An overview of the development, testing, and application of composite absorbers

Energy Technology Data Exchange (ETDEWEB)

Sebesta, F. [Czech Technical Univ., Brehova (Czech Republic); John, J. [Los Alamos National Lab., NM (United States)

1995-02-01

Although inorganic exchangers offer many advantages for removing selected elements from radioactive waste streams, few of these materials are suitable for use in packed-bed columns. We review various adaptations of inorganic exchangers for use in columns, which include granular forms of the intrinsic absorbers, absorber compounds supported on other materials, and composite absorbers that use organic or inorganic binders. An organic binding polymer of polyacrylonitrile (PAN), developed at the Czech Technical University, has been demonstrated to offer advantages. We describe general methods for preparing inorganic exchange materials, which then are incorporated into PAN-based composites. Such PAN composites have been used to remove selected radionuclides from a variety of liquid waste streams. Sixteen different PAN composites were prepared for testing at Los Alamos National Laboratory (LANL) as part of an evaluation of potential partitioning agents for remediating the liquid waste in underground storage tanks at the Hanford site near Richland, Washington. Our collaboration with LANL is expected to continue for another 2 years.

New Technology in Hydrogen Absorbers for Muon Cooling Channels

CERN Document Server

Cummings, M A C

2005-01-01

Ionization cooling is the only technique fast enough to cool and focus muons for neutrino factories and muon colliders, and hydrogen is the optimal material for maximum cooling and minimal multiple scattering. Liquid hydrogen absorber R&D for the Muon Collaboration has proceeded on parallel and complementary fronts. The continuing LH2 absorber engineering and technical developments by the MuCool group conducted by ICAR* institutions (NIU, IIT and UIUC), the University of Mississippi and Oxford University, in cooperation with Fermilab, will be summarized, including results from the first hydrogen absorber tests at the newly constructed FNAL Mucool Test Area (MTA). The program includes designs for the high-powered test of an absorber prototype (external heat exchange) at the MTA which are nearing completion to be installed by summer 2005, an alternative absorber design (internal heat exchange) being finalized for the approved cooling experiment (MICE) at Rutherford-Appleton Laboratory, and a novel idea for ...

Neutron physics calculation for WWER-1000 absorber element lifetime determination

International Nuclear Information System (INIS)

Kurakin, K.Yu.; Kushmanov, S.A.

2009-01-01

Absorber element with compound absorber has been operating in WWER-1000 power units since 1995. AE design meets operating organizations requirements for reliability, service life (to 10 years) and safety functions. Extension of AE service life up to 20 - 30 years by the complex of calculation and experimental work is an important problem of WWER new designs development. The paper deals with the issues related to calculation determination of main factors that influence AE service life limitation - neutron flux and fluence onto absorbing and structural materials during extended service life. (Authors)

Preparation and characterization of super absorbent polymer from sugarcane bagasse

International Nuclear Information System (INIS)

Wiwien Andriyanti; Suyanti; Ngasifudin

2012-01-01

Sugarcane bagasse is a source of biomass which large enough numbers and has not been fully exploited. At this time has developed a super absorbent polymer material of sugarcane bagasse that can absorb water up to several times of its own weight and keep this water. Super absorbent polymers can be used as a soil conditioner that can be used as an absorber and storage of ground water, the giver of nutrients for plants, and can improve soil properties. The purpose of this study is to make and characterization of super absorbent polymer (PCS) from sugarcane bagasse. Preparation of super absorbent polymers (PCS) has been done by grafting method using ionizing radiation from Electron Beam Engineering (MBE) 350 mA keV/10. Irradiation process carried out with a dose variation of 20, 35, and 50 kGy. Increasing doses of radiation will increase the percentage fraction of transplantation (grafting) and the fraction of water absorption ability (swelling ratio). (author)

High Conduction Neutron Absorber to Simulate Fast Reactor Environment in an Existing Test Reactor

Energy Technology Data Exchange (ETDEWEB)

Guillen, Donna; Greenwood, Lawrence R.; Parry, James

2014-06-22

A need was determined for a thermal neutron absorbing material that could be cooled in a gas reactor environment without using large amounts of a coolant that would thermalize the neutron flux. A new neutron absorbing material was developed that provided high conduction so a small amount of water would be sufficient for cooling thereby thermalizing the flux as little as possible. An irradiation experiment was performed to assess the effects of radiation and the performance of a new neutron absorbing material. Neutron fluence monitors were placed inside specially fabricated holders within a set of drop-in capsules and irradiated for up to four cycles in the Advanced Test Reactor. Following irradiation, the neutron fluence monitor wires were analyzed by gamma and x-ray spectrometry to determine the activities of the activation products. The adjusted neutron fluences were calculated and grouped into three bins – thermal, epithermal and fast to evaluate the spectral shift created by the new material. Fluence monitors were evaluated after four different irradiation periods to evaluate the effects of burn-up in the absorbing material. Additionally, activities of the three highest activity isotopes present in the specimens are given.

Nuclear reactor core having nuclear fuel and composite burnable absorber arranged for power peaking and moderator temperature coefficient control

International Nuclear Information System (INIS)

Kapil, S.K.

1992-01-01

This patent describes a burnable absorber coated nuclear fuel. It comprises a nuclear fuel substrate containing a fissionable material; and an outer burnable absorber coating applied on an outer surface of the substrate; the outer absorber coating being composed of an inner layer of a boron-bearing material except for erbium boride and an outer layer of an erbium material

Identification of the arabidopsis RAM/MOR signalling network: adding new regulatory players in plant stem cell maintenance and cell polarization

Science.gov (United States)

Zermiani, Monica; Begheldo, Maura; Nonis, Alessandro; Palme, Klaus; Mizzi, Luca; Morandini, Piero; Nonis, Alberto; Ruperti, Benedetto

2015-01-01

Background and Aims The RAM/MOR signalling network of eukaryotes is a conserved regulatory module involved in co-ordination of stem cell maintenance, cell differentiation and polarity establishment. To date, no such signalling network has been identified in plants. Methods Genes encoding the bona fide core components of the RAM/MOR pathway were identified in Arabidopsis thaliana (arabidopsis) by sequence similarity searches conducted with the known components from other species. The transcriptional network(s) of the arabidopsis RAM/MOR signalling pathway were identified by running in-depth in silico analyses for genes co-regulated with the core components. In situ hybridization was used to confirm tissue-specific expression of selected RAM/MOR genes. Key Results Co-expression data suggested that the arabidopsis RAM/MOR pathway may include genes involved in floral transition, by co-operating with chromatin remodelling and mRNA processing/post-transcriptional gene silencing factors, and genes involved in the regulation of pollen tube polar growth. The RAM/MOR pathway may act upstream of the ROP1 machinery, affecting pollen tube polar growth, based on the co-expression of its components with ROP-GEFs. In silico tissue-specific co-expression data and in situ hybridization experiments suggest that different components of the arabidopsis RAM/MOR are expressed in the shoot apical meristem and inflorescence meristem and may be involved in the fine-tuning of stem cell maintenance and cell differentiation. Conclusions The arabidopsis RAM/MOR pathway may be part of the signalling cascade that converges in pollen tube polarized growth and in fine-tuning stem cell maintenance, differentiation and organ polarity. PMID:26078466

Electromagnetic and microwave absorbing properties of hollow ...

Indian Academy of Sciences (India)

bandwidth below −10 dB and minimum RL decrease with increasing thickness of HCNSs/paraffin composites. Keywords. Nanomaterials; nanospheres; CVD; electric; magnetic; microwave absorption properties. 1. Introduction. In recent years, microwave absorbing materials have attracted considerable attention because it ...

An absorbent for an application to a package for a liquid radioactive isotope for medical usage

International Nuclear Information System (INIS)

Bang, K.S.; Lim, S.P.; Lee, J.C.; Seo, K.S.; Han, H.S.

2004-01-01

A radioactive isotope has to be safely transport from the producing center to the consuming center. The shipping package to safely transport the radioactive isotope should be able to withstand the prescribed conditions by law. In the field of nuclear medicine, the radioactive isotope is used in a liquid or capsule form. A Type A package, which is to transport liquid radioactive materials, shall be provided with a containment system composed of primary inner and secondary outer containment components or shall be provided with sufficient absorbent material to absorb twice the volume of the liquid contents. Hospitals prefer to use not only convenient but also re-usable packages. To apply an absorbent material to the Type A package, that is to transport liquid radioactive isotope, the free absorbency of the absorbents was estimated. In the case of a liquid with NaOH 0.4%, the free absorbency of the melanine form was the most superior at 91 g/g. In the case of a liquid with Na 0.9%, the free absorbency of the melanine form was the most excellent at 88 g/g also

Tribology Aspect of Rubber Shock Absorbers Development

Directory of Open Access Journals (Sweden)

M. Banić

2013-09-01

Full Text Available Rubber is a very flexible material with many desirable properties Which enable its broad use in engineering practice. Rubber or rubber-metal springs are widely used as anti-vibration or anti-shock components in technical systems. Rubber-metal springs are usually realized as a bonded assembly, however especially in shock absorbers, it is possible to realize free contacts between rubber and metal parts. In previous research it authors was observed that friction between rubber and metal in such case have a significant influence on the damping characteristics of shock absorber. This paper analyzes the development process of rubber or rubber-metal shock absorbers realized free contacts between the constitutive parts, starting from the design, construction, testing and operation, with special emphasis on the development of rubber-metal springs for the buffing and draw gear of railway vehicles.

A 1K shadow RAM for circumvention applications

International Nuclear Information System (INIS)

Murray, J.R.

1991-01-01

This paper reports that circumvention applications require a memory that retains data through radiation (total dose and transient) and loss of power. Various memory technologies have been reviewed and none, as yet, can meet, these requirements. However, if complementary metal oxide silicon (CMOS) and silicon nitride oxide silicon (SNOS) memories are combined in a shadow RAM (random access memory) configuration, the requirements can be fulfilled

Neutron absorber qualification and acceptance testing from the designer's perspective

International Nuclear Information System (INIS)

Bracey, W.; Chiocca, R.

2004-01-01

Starting in the mid 1990's, the USNRC began to require less than 100% credit for the 10B present in fixed neutron absorbers spent fuel transport packages. The current practice in the US is to use only 75% of the specified 10B in criticality safety calculations unless extensive acceptance testing demonstrates both the presence of the 10B and uniformity of its distribution. In practice, the NRC has accepted no more than 90% credit for 10B in recent years, while other national competent authorities continue to accept 100%. More recently, with the introduction of new neutron absorber materials, particularly aluminum / boron carbide metal matrix composites, the NRC has also expressed expectations for qualification testing, based in large part on Transnuclear's successful application to use a new composite material in the TN-68 storage / transport cask. The difficulty is that adding more boron than is really necessary to a metal has some negative effects on the material, reducing the ductility and the thermal conductivity, and increasing the cost. Excessive testing requirements can have the undesired effect of keeping superior materials out of spent fuel package designs, without a corresponding justification based on public safety. In European countries and especially in France, 100% credit has been accepted up to now with materials controls specified in the Safety Analysis Report (SAR): Manufacturing process approved by qualification testing Materials manufacturing controlled under a Quality Assurance system. During fabrication, acceptance testing directly on products or on representative samples. Acceptance criteria taking into account a statistical uncertainty corresponding to 3σ. The original and current bases for the reduced 10 B credit, the design requirements for neutron absorber materials, and the experience of Transnuclear and Cogema Logistics with neutron absorber testing are examined. Guidelines for qualification and acceptance testing and process controls

Timber management planning with timber ram and goal programming

Science.gov (United States)

Richard C. Field

1978-01-01

By using goal programming to enhance the linear programming of Timber RAM, multiple decision criteria were incorporated in the timber management planning of a National Forest in the southeastern United States. Combining linear and goal programming capitalizes on the advantages of the two techniques and produces operationally feasible solutions. This enhancement may...

A reflective-backing-free metamaterial absorber with broadband response

Directory of Open Access Journals (Sweden)

Cuilian Xu

2017-06-01

Full Text Available In this paper, we propose a polarization-independent and broadband perfect infrared (IR metamaterial absorber (MA without reflective backing. The proposed absorber is a periodic meta-atom array consisting of metal-dielectric-multilayer truncated cones which can absorb 80% EM wave from 50.70 to 81.87THz, while transmit 80% EM wave from 0 to 37.71THz. With the decreasing of frequency, the transmissivity increases, which is close to 100% from 0 to 5THz. We can broaden the absorption bandwidth of the MA by cascading multi-layers truncated cones. Furthermore, the proposed IR MA promises to be one desirable stealth material for radar-IR compatibility.

Fos Expression in the Olfactory Pathway of High- and Low-Sexually Performing Rams Exposed to Urine from Estrous or Ovariectomized Ewes

Science.gov (United States)

Mirto, AJ; Austin, KJ; Uthlaut, VA; Roselli, CE; Alexander, BM

2015-01-01

Exposure to estrous ewe urine stimulates investigation and mounting activity in sexually active but not sexually inactive rams. It was hypothesized sexual indifference may result from an inability to detect olfactory cues or an interruption of the pathway from detection of the olfactory stimulus to the motor response. Sexually active (n=4) and inactive (n=3) rams were exposed to urine from estrous ewes. An additional group of sexually active rams (n=3) were exposed to urine from ovariectomized ewes. Rams were exsanguinated following 1 h of exposure to stimulus. Neural activity was determined in tissues of interest by the presence of fos and fos-related proteins detected by immunohistochemistry procedures. Sexually active rams exposed to urine from ovariectomized ewes had more (P ≤ 0.05) fos-positive cells in the olfactory bulb, but fewer (P = 0.03) fos-positive cells in the cortical amygdala compared to sexually active rams exposed to urine from estrous ewes. Sexually inactive rams had similar (P ≥ 0.13) numbers of fos positive neurons in the olfactory bulb and medial amygdala but fewer (P ≤ 0.04) in the central amygdala, bed nucleus of the stria terminalis and the medial preoptic area compared to sexually active rams exposed to urine from estrous ewes. Sexual inactivity was not associated with decreased hypothalamic function since fos activity was similar (P ≥ 0.14) among groups in the suprachiasmatic and ventral medial nucleus. Sexual inactivity is not likely due to an impaired ability to detect or process olfactory stimuli by the main olfactory bulb and medial-cortical amygdala. Sexually inactive rams may have reduced attentiveness to sexual stimuli and/or decreased responsiveness of regions in the brain which regulate reproductive behaviors. PMID:28348447

Reflection and Refraction of Light in Absorbing Media

Science.gov (United States)

Katsumata, Koichi; Sasaki, Shosuke

2018-05-01

The results of a rigorous calculation of optical phenomena in absorbing media based on Maxwell's equations are reported. In the case of an absorbing dielectric, we assume a complex dielectric constant. We find an expression for the angle of refraction as a function of the incident angle and the real and imaginary parts of the complex dielectric constant, all of which are real. The amplitudes of the reflected and transmitted waves are calculated on the same footing. These amplitudes are shown to be complex, from which we deduce the magnitude and phase change of the reflection and transmission coefficients. The same argument applies to an absorbing magnetic material if we replace the complex dielectric constant by a complex magnetic permeability.

Perpetual pavement – absorbing stress and functional maintenance

Directory of Open Access Journals (Sweden)

Rong Gao

2017-03-01

Full Text Available Perpetual Pavement combines the well documented smoothness and safety advantages of asphalt with an advanced, multi-layer paving design process, that with routine maintenance, extends the useful life of a roadway. Perpetual provides long lasting road and smoothness for the construction purposes. This study has the design key points of perpetual pavement based on the idea of life cycle, which has a new direction for the new highway construction, reconstruction and expansion. First, the structure of long life pavement design is studied to analyze the effect of stress absorbing layer. Second, researches on stress absorbing layer from the aspects of raw materials, mix proportion are implemented. Third, the design index of stress absorbing layer is determined by the shear strength test. The results show that the design idea of composite perpetual pavement can be realized by reasonable design of the stress absorbing layer and carrying out the surface functional maintenance can ensure the pavement to avoid structural damage in the operation stage.

Shock absorber system for nuclear reactor ice condenser compartment

International Nuclear Information System (INIS)

Meier, J.F.; Rudd, G.E.; Pradhan, A.V.; George, J.A.; Lippincott, H.W.; Sutherland, J.D.

1979-01-01

A shock absorber system was designed to absorb the energy imparted to doors in a nuclear reactor ice condenser compartment as they swing rapidly to an open position. Each shock absorber which is installed on a wall adjacent to each door is large and must absorb up to about 40,000 foot pounds of energy. The basic shock absorber component comprises foam enclosed in a synthetic fabric bag having a volume about twice the foam volume. A stainless steel knitted mesh bag of the same volume as the fabric bag, contains the fabric bag and its enclosed foam. To protect the foam and bags during construction activities at the reactor site and from the shearing action of the doors, a protective sheet metal cover is installed over the shock absorber ends and the surface to be contacted by the moving door. With the above shock absorber mounted on a wall behind each door, as the door is forcibly opened by steam pressure and air resulting from a pipe break in the reactor compartment, it swings at a high velocity into contact with the shock absorber, crushes the foam and forces it into the fabric bag excess material thus containing the foam fragmented particles, and minimizes build-up of pressure in the bag as a result of the applied compressive force

CEPRAM: Compression for Endurance in PCM RAM

OpenAIRE

González Alberquilla, Rodrigo; Castro Rodríguez, Fernando; Piñuel Moreno, Luis; Tirado Fernández, Francisco

2017-01-01

We deal with the endurance problem of Phase Change Memories (PCM) by proposing Compression for Endurance in PCM RAM (CEPRAM), a technique to elongate the lifespan of PCM-based main memory through compression. We introduce a total of three compression schemes based on already existent schemes, but targeting compression for PCM-based systems. We do a two-level evaluation. First, we quantify the performance of the compression, in terms of compressed size, bit-flips and how they are affected by e...

A THz plasmonics perfect absorber and Fabry-Perot cavity mechanism (Conference Presentation)

Science.gov (United States)

Zhou, Jiangfeng; Bhattarai, Khagendra; Silva, Sinhara; Jeon, Jiyeon; Kim, Junoh; Lee, Sang Jun; Ku, Zahyun

2016-10-01

The plasmonic metamaterial perfect absorber (MPA) is a recently developed branch of metamaterial which exhibits nearly unity absorption within certain frequency range.[1-6] The optically thin MPA possesses characteristic features of angular-independence, high Q-factor and strong field localization that have inspired a wide range of applications including electromagnetic wave absorption,[3, 7, 8] spatial[6] and spectral[5] modulation of light,[9] selective thermal emission,[9] thermal detecting[10] and refractive index sensing for gas[11] and liquid[12, 13] targets. In this work, we demonstrate a MPA working at terahertz (THz) regime and characterize it using an ultrafast THz time-domain spectroscopy (THz-TDS). Our study reveal an ultra-thin Fabry-Perot cavity mechanism compared to the impedance matching mechanism widely adopted in previous study [1-6]. Our results also shows higher-order resonances when the cavities length increases. These higher order modes exhibits much larger Q-factor that can benefit potential sensing and imaging applications. [1] C. M. Watts, X. L. Liu, and W. J. Padilla, "Metamaterial Electromagnetic Wave Absorbers," Advanced Materials, vol. 24, pp. 98-120, Jun 19 2012. [2] M. Hedayati, F. Faupel, and M. Elbahri, "Review of Plasmonic Nanocomposite Metamaterial Absorber," Materials, vol. 7, pp. 1221-1248, 2014. [3] N. I. Landy, S. Sajuyigbe, J. J. Mock, D. R. Smith, and W. J. Padilla, "Perfect metamaterial absorber," Physical Review Letters, vol. 100, p. 207402, May 23 2008. [4] H. R. Seren, G. R. Keiser, L. Cao, J. Zhang, A. C. Strikwerda, K. Fan, et al., "Optically Modulated Multiband Terahertz Perfect Absorber," Advanced Optical Materials, vol. 2, pp. 1221-1226, 2014. [5] D. Shrekenhamer, J. Montoya, S. Krishna, and W. J. Padilla, "Four-Color Metamaterial Absorber THz Spatial Light Modulator," Advanced Optical Materials, vol. 1, pp. 905-909, 2013. [6] S. Savo, D. Shrekenhamer, and W. J. Padilla, "Liquid Crystal Metamaterial Absorber Spatial

Fabrication of high efficacy selective solar absorbers

CSIR Research Space (South Africa)

Tile, N

2012-03-01

Full Text Available High efficiency tandem selective solar absorber materials of carbon in nickel oxide (C-NiO) composite were fabricated on an aluminium substrate using a simple and cost effective sol-gel process. The process involved preparation of carbon and nickel...

Waste Feed Delivery System Phase 1 Preliminary RAM Analysis

International Nuclear Information System (INIS)

DYKES, A.A.

2000-01-01

This report presents the updated results of the preliminary reliability, availability, and maintainability (RAM) analysis of selected waste feed delivery (WFD) operations to be performed by the Tank Farm Contractor (TFC) during Phase I activities in support of the Waste Treatment and Immobilization Plant (WTP). For planning purposes, waste feed tanks are being divided into five classes in accordance with the type of waste in each tank and the activities required to retrieve, qualify, and transfer waste feed. This report reflects the baseline design and operating concept, as of the beginning of Fiscal Year 2000, for the delivery of feed from three of these classes, represented by source tanks 241-AN-102, 241-AZ-101 and 241-AN-105. The preliminary RAM analysis quantifies the potential schedule delay associated with operations and maintenance (OBM) field activities needed to accomplish these operations. The RAM analysis is preliminary because the system design, process definition, and activity planning are in a state of evolution. The results are being used to support the continuing development of an O and M Concept tailored to the unique requirements of the WFD Program, which is being documented in various volumes of the Waste Feed Delivery Technical Basis (Carlson. 1999, Rasmussen 1999, and Orme 2000). The waste feed provided to the WTP must: (1) meet limits for chemical and radioactive constituents based on pre-established compositional envelopes (i.e., feed quality); (2) be in acceptable quantities within a prescribed sequence to meet feed quantities; and (3) meet schedule requirements (i.e., feed timing). In the absence of new criteria related to acceptable schedule performance due to the termination of the TWRS Privatization Contract, the original criteria from the Tank Waste Remediation System (77443s) Privatization Contract (DOE 1998) will continue to be used for this analysis

Identification of Spanish isolates of Rhizoctonia solani from potato by anastomosis grouping, ITS-RFLP and RAMS-fingerprinting

Directory of Open Access Journals (Sweden)

A.M. Elbakali

2003-08-01

Full Text Available Anastomosis grouping, restriction fragment length polymorphism (RFLP of the ITS regions including the 5.85 rDNA, and random amplified microsatellites (RAMS were used to characterize isolates of Rhizoctonia solani collected from Spain and Finland. There was a high similarity between the results obtained with the three techniques. RAMS markers revealed more genetic variation among isolates of R. solani than RFLP. The anastomosis group (AG–3 isolates were clearly separated from isolates belonging to other AGs by RAMS, RFLPs and anastomosis grouping. Almost all the isolates sampled from potato belonged to AG–3. No differences were observed between Spanish and Finnish AG–3 isolates.

Absorbing Property of Multi-layered Short Carbon Fiber Absorbing Coating

OpenAIRE

Liu, Zhaohui; Tao, Rui; Ban, Guodong; Luo, Ping

2018-01-01

The radar absorbing coating was prepared with short carbon fiber asabsorbent and waterborne polyurethane (WPU) as matrix resin. The coating’s absorbing property was tested with vectornetwork analyzer, using aramid honeycomb as air layer which was matched withcarbon fiber coating. The results demonstrate that the single-layered carbonfiber absorbing coating presented relatively poor absorbing property when thelayer was thin, and the performance was slightly improved after the matched airlayer ...

Development Radar Absorber Material using Rice Husk Carbon for Anechoic Chamber Application

Science.gov (United States)

Zulpadrianto, Z.; Yohandri, Y.; Putra, A.

2018-04-01

The developments of radar technology in Indonesia are very strategic due to the vast territory and had a high-level cloud cover more than 55% of the time. The objective of this research is to develop radar technology facility in Indonesia using local natural resources. The target of this research is to present a low cost and satisfy quality of anechoic chambers. Anechoic chamber is a space designed to avoid reflection of EM waves from outside or from within the room. The reflection coefficient of the EM wave is influenced by the medium imposed by the EM wave. In laboratory experimental research has been done the development of material radar absorber using rice husk. The rice husk is activated using HCl and KOH by stirring using a magnetic stirrer for 1 Hours. The results of rice husk activation were measured using a Vector Network Analyzer by varying the thickness of the ingredients and the concentration of the activation agent. The VNA measurement is obtained reflection coefficient of -12dB and. -6.22dB for 1M HCL and KOH at thickness 10mm, respectively.

Integrating RAMS engineering and management with the safety life cycle of IEC 61508

International Nuclear Information System (INIS)

Lundteigen, Mary Ann; Rausand, Marvin; Utne, Ingrid Bouwer

2009-01-01

This article outlines a new approach to reliability, availability, maintainability, and safety (RAMS) engineering and management. The new approach covers all phases of the new product development process and is aimed at producers of complex products like safety instrumented systems (SIS). The article discusses main RAMS requirements to a SIS and presents these requirements in a holistic perspective. The approach is based on a new life cycle model for product development and integrates this model into the safety life cycle of IEC 61508. A high integrity pressure protection system (HIPPS) for an offshore oil and gas application is used to illustrate the approach.

Role of the GRAS transcription factor ATA/RAM1 in the transcriptional reprogramming of arbuscular mycorrhiza in Petunia hybrida

OpenAIRE

Rich, Melanie K.; Courty, Pierre-Emmanuel; Roux, Christophe; Reinhardt, Didier

2017-01-01

Background Development of arbuscular mycorrhiza (AM) requires a fundamental reprogramming of root cells for symbiosis. This involves the induction of hundreds of genes in the host. A recently identified GRAS-type transcription factor in Petunia hybrida, ATA/RAM1, is required for the induction of host genes during AM, and for morphogenesis of the fungal endosymbiont. To better understand the role of RAM1 in symbiosis, we set out to identify all genes that depend on activation by RAM1 in mycorr...

Seasonal variations of melatonin in ram seminal plasma are correlated to those of testosterone and antioxidant enzymes

Directory of Open Access Journals (Sweden)

Muiño-Blanco Teresa

2010-06-01

Full Text Available Abstract Background Some breeds of sheep are highly seasonal in terms of reproductive capability, and these changes are regulated by photoperiod and melatonin secretion. These changes affect the reproductive performance of rams, impairing semen quality and modifying hormonal profiles. Also, the antioxidant defence systems seem to be modulated by melatonin secretion, and shows seasonal variations. The aim of this study was to investigate the presence of melatonin and testosterone in ram seminal plasma and their variations between the breeding and non-breeding seasons. In addition, we analyzed the possible correlations between these hormones and the antioxidant enzyme defence system activity. Methods Seminal plasma from nine Rasa Aragonesa rams were collected for one year, and their levels of melatonin, testosterone, superoxide dismutase (SOD, glutathione reductase (GRD, glutathione peroxidase (GPX and catalase (CAT were measured. Results All samples presented measurable quantities of hormones and antioxidant enzymes. Both hormones showed monthly variations, with a decrease after the winter solstice and a rise after the summer solstice that reached the maximum levels in October-November, and a marked seasonal variation (P Conclusions These results show the presence of melatonin and testosterone in ram seminal plasma, and that both hormones have seasonal variations, and support the idea that seasonal variations of fertility in the ram involve interplay between melatonin and the antioxidant defence system.

Santiago Ramón y Cajal and the Spanish school of neurology.

Science.gov (United States)

Andres-Barquin, Pedro J

2002-11-01

Advances in neurology are now possible thanks to the endeavours of a few scientists who in the past laid firm foundations for the study of the nervous system. Santiago Ramón y Cajal (1852-1934) was one such pioneer of brain exploration and is acknowledged as the founder of modern neuroscience. He described the structure and organisation of virtually all parts of the nervous system and developed theories, including the neuron doctrine and the law of functional polarisation, that are the cornerstones of neuroscience. In addition to devoting his life to research, Ramón y Cajal was a dedicated teacher and mentor and created a school that greatly contributed to the flourishing of neurology.

Investigation on MCU Clustering Methodologies for Cross-Section Estimation of RAMs

CERN Document Server

Bosser, A; Tsiligiannis, G; Javanainen, A; Kettunen, H; Puchner, H; Saigne, F; Virtanen, A; Wrobel, F; Dilillo, L

2015-01-01

During irradiation testing of RAMs, various failure scenarios may occur which may generate different characteristic Multiple Cell Upset (MCU) error patterns. This work proposes a method based on spatial and temporal criteria to identify them.

Computerized simulation of the mechanical behavior of wood-filled shock absorbers of radioactive materials transport casks; Rechnerische Simulation des mechanischen Verhaltens von holzgefuellten Stossdaempfern von Transportbehaeltern fuer radioaktive Stoffe

Energy Technology Data Exchange (ETDEWEB)

Neumann, Martin; Wille, Frank [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany)

2011-07-01

In Germany the mechanical component inspection of transport containers for radioactive materials is performed by BAM (Bundesanstalt fuer Materialforschung und -pruefung) under consideration of national and international standards and guidelines. Experimental and calculative (analytical and numerical) techniques combined with material and/or component testing are the basis of assessment concepts according the state of the art. The authors describe the experiences of BAM concerning assessment and description of the mechanical behavior of shock absorbing components, including modeling strategies, material models, drop tests and experiment-calculation comparison. Energy absorbing components are used to reduce the impact forces at the container in case of a transport accident. In Germany wood filled thin-walled constructions are used. The deformation behavior of the wood is a main part of the calculative simulation procedures in comparison with experimental tests.

Apparatus and method for the measurement of neutron moderating or absorbing properties of objects

International Nuclear Information System (INIS)

Untermyer, S.I.

1981-01-01

An apparatus and method for measuring the neutron moderating or absorbing properties of objects or materials is disclosed in which a fast neutron source cooperates with a neutron absorbing material which reduces the energy of the fast neutrons by inelastic scattering so that they can be readily thermalized by a moderator. A thermal neutron detector is disposed adjacent the material and serves to detect thermal neutrons emitted by a moderator placed to receive and thermalize the reduced energy neutrons. A material whose absorption is to be measured is placed between a moderator and the detector

System Verification Through Reliability, Availability, Maintainability (RAM) Analysis & Technology Readiness Levels (TRLs)

Energy Technology Data Exchange (ETDEWEB)

Emmanuel Ohene Opare, Jr.; Charles V. Park

2011-06-01

The Next Generation Nuclear Plant (NGNP) Project, managed by the Idaho National Laboratory (INL), is authored by the Energy Policy Act of 2005, to research, develop, design, construct, and operate a prototype fourth generation nuclear reactor to meet the needs of the 21st Century. A section in this document proposes that the NGNP will provide heat for process heat applications. As with all large projects developing and deploying new technologies, the NGNP is expected to meet high performance and availability targets relative to current state of the art systems and technology. One requirement for the NGNP is to provide heat for the generation of hydrogen for large scale productions and this process heat application is required to be at least 90% or more available relative to other technologies currently on the market. To reach this goal, a RAM Roadmap was developed highlighting the actions to be taken to ensure that various milestones in system development and maturation concurrently meet required availability requirements. Integral to the RAM Roadmap was the use of a RAM analytical/simulation tool which was used to estimate the availability of the system when deployed based on current design configuration and the maturation level of the system.

The containment and an absorbent evaluation for a package for a liquid radioactive isotope

Energy Technology Data Exchange (ETDEWEB)

Bang, K. S.; Lee, J. C.; Kim, D. H.; Hwang, C. S.; Kim, H. J.; Seo, K. S

2005-03-01

Radioactive isotopes must be safely transported from the production centre to the point of use. The shipping package to safely transport radioactive isotopes should be able to withstand the conditions prescribed by law. A type a package, which is used to transport liquid radioactive materials, should have a containment system comprising a primary inner and a secondary outer containment or it should be provided with a sufficiently absorbent material to absorb twice the volume of the liquid contents. Accordingly, an absorbent material for use in a Type A package to transport a liquid radioactive isotope was estimated. To estimate the integrity of containment, the leakage tests for a containment system for a Type A package for domestic and abroad expert were conducted.

The Magellanic Stream System. I. Ram-Pressure Tails and the Relics of the Collision Between the Magellanic Clouds

Science.gov (United States)

Hammer, F.; Yang, Y. B.; Flores, H.; Puech, M.; Fouquet, S.

2015-11-01

We have analyzed the Magellanic Stream (MS) using the deepest and the most resolved H i survey of the Southern Hemisphere (the Galactic All-Sky Survey). The overall Stream is structured into two filaments, suggesting two ram-pressure tails lagging behind the Magellanic Clouds (MCs), and resembling two close, transonic, von Karman vortex streets. The past motions of the Clouds appear imprinted in them, implying almost parallel initial orbits, and then a radical change after their passage near the N(H i) peak of the MS. This is consistent with a recent collision between the MCs, 200-300 Myr ago, which has stripped their gas further into small clouds, spreading them out along a gigantic bow shock, perpendicular to the MS. The Stream is formed by the interplay between stellar feedback and the ram pressure exerted by hot gas in the Milky Way (MW) halo with n h = 10-4 cm-3 at 50-70 kpc, a value necessary to explain the MS multiphase high-velocity clouds. The corresponding hydrodynamic modeling provides the currently most accurate reproduction of the whole H i Stream morphology, of its velocity, and column density profiles along L MS. The “ram pressure plus collision” scenario requires tidal dwarf galaxies, which are assumed to be the Cloud and dSph progenitors, to have left imprints in the MS and the Leading Arm, respectively. The simulated LMC and SMC have baryonic mass, kinematics, and proper motions consistent with observations. This supports a novel paradigm for the MS System, which could have its origin in material expelled toward the MW by the ancient gas-rich merger that formed M31.

The radioactive materials packaging handbook: Design, operations, and maintenance

International Nuclear Information System (INIS)

Shappert, L.B.; Bowman, S.M.; Arnold, E.D.

1998-01-01

As part of its required activities in 1994, the US Department of Energy (DOE) made over 500,000 shipments. Of these shipments, approximately 4% were hazardous, and of these, slightly over 1% (over 6,400 shipments) were radioactive. Because of DOE's cleanup activities, the total quantities and percentages of radioactive material (RAM) that must be moved from one site to another is expected to increase in the coming years, and these materials are likely to be different than those shipped in the past. Irradiated fuel will certainly be part of the mix as will RAM samples and waste. However, in many cases these materials will be of different shape and size and require a transport packaging having different shielding, thermal, and criticality avoidance characteristics than are currently available. This Handbook provides guidance on the design, testing, certification, and operation of packages for these materials

The radioactive materials packaging handbook: Design, operations, and maintenance

Energy Technology Data Exchange (ETDEWEB)

Shappert, L.B.; Bowman, S.M. [Oak Ridge National Lab., TN (United States); Arnold, E.D. [Lockheed Martin Energy Systems, Oak Ridge, TN (United States)] [and others

1998-08-01

As part of its required activities in 1994, the US Department of Energy (DOE) made over 500,000 shipments. Of these shipments, approximately 4% were hazardous, and of these, slightly over 1% (over 6,400 shipments) were radioactive. Because of DOE`s cleanup activities, the total quantities and percentages of radioactive material (RAM) that must be moved from one site to another is expected to increase in the coming years, and these materials are likely to be different than those shipped in the past. Irradiated fuel will certainly be part of the mix as will RAM samples and waste. However, in many cases these materials will be of different shape and size and require a transport packaging having different shielding, thermal, and criticality avoidance characteristics than are currently available. This Handbook provides guidance on the design, testing, certification, and operation of packages for these materials.

Recommended method for measurement of absorbency of superabsorbent polymers in cement-based materials

DEFF Research Database (Denmark)

Esteves, Luis Pedro

2015-01-01

—laser diffraction particle size analysis, and it allows an easy and reliable measurement of the absorbency of superabsorbent polymers. It is shown in detail how both the definition of the exposure liquid and the definition of the system of SAP particles can be selected so that absorbency can be experimentally...... so that the properties of concrete with superabsorbent polymers can be better controlled in practice. In this paper, a technique that can be potentially used as a standard method is developed. The method is based on a measurement technique validated through an international standard procedure...

Thermal Evaluation of Storage Rack with an Advanced Neutron Absorber during Normal Operation

Energy Technology Data Exchange (ETDEWEB)

Lee, Hee-Jae; Kim, Mi-Jin; Sohn, Dong-Seong [UNIST, Ulsan (Korea, Republic of)

2016-10-15

The storage capacity of the domestic wet storage site is expected to reach saturation from Hanbit in 2024 to Sin-wolseong in 2038 and accordingly management alternatives are urgently taken. Since installation of the dense rack is considered in the short term, it is necessary to urgently develop an advanced neutron absorber which can be applied to a spent nuclear fuel storage facility. Neutron absorber is the material for controlling the reactivity. A material which has excellent thermal neutron absorption ability, high strength and corrosion resistance must be selected as the neutron absorber. Existing neutron absorbers are made of boron which has a good thermal absorption ability such as BORAL and METAMIC. However, possible problems have been reported in using the boron-based neutron absorber for wet storage facility. Gadolinium is known to have higher neutron absorption cross-section than that of boron. And the strength of duplex stainless steel is about 1.5 times higher than stainless steel 304 which has been frequently used as a structural material. Therefore, duplex stainless steel which contains gadolinium is in consideration as an advanced neutron absorber. Temperature distribution is shown in figure 4. In pool bottom region near the inlet shows a relatively low tendency and heat generated from the fuel assemblies is transmitted to the pool upper region by the vertical flow. Also, temperature gradient appear in rack structures for the axial direction and temperature is uniformly distributed in the pool upper region. Table 1 presents the calculated results. The maximum temperature is 306.63K and does not exceed the 333.15K (60℃). The maximum temperature of the neutron absorber is 306.48K.

Selective solar absorber coating research at the CSIR (South Africa)

CSIR Research Space (South Africa)

Roro, Kittessa T

2011-05-01

Full Text Available A sol-gel technique has been established at a laboratory scale for low cost production of high efficient selective solar absorbers comprising a composite material of nano-structured carbon in a nickel oxide matrix. In order for these materials...

The Two Populations of Kisspeptin Neurons Are Involved in the Ram-Induced LH Pulsatile Secretion and LH Surge in Anestrous Ewes.

Science.gov (United States)

Fabre-Nys, Claude; Cognié, Juliette; Dufourny, Laurence; Ghenim, Meriem; Martinet, Stephanie; Lasserre, Olivier; Lomet, Didier; Millar, Robert P; Ohkura, Satoshi; Suetomi, Yuta

2017-11-01

Exposure to a ram during spring stimulates luteinizing hormone (LH) secretion and can induce ovulation in sexually quiescent ewes ("ram effect"). Kisspeptin (Kiss) present in the arcuate nucleus (ARC) and the preoptic area (POA) is a potent stimulators of LH secretion. Our aim was to investigate whether Kiss neurons mediate the increase in LH secretion during the ram effect. With double immunofluorescent detection, we identified Kiss neurons (Kiss IR) activated (Fos IR) by exposure to a ram for 2 hours (M2) or 12 hours (M12) or to ewes for 2 hours (C). The density of cells Kiss + Fos IR and the proportion of Kiss IR cells that were also Fos IR cells were higher in M2 and M12 than in C in ARC (P populations of Kiss neurons are involved in the ram-induced pulsatile LH secretion and in the LH surge. Copyright © 2017 Endocrine Society.

A graphite based STT-RAM cell with reduction in switching current

Science.gov (United States)

Varghani, Ali; Peiravi, Ali

2015-10-01

Spin Transfer Torque Random Access Memory (STT-RAM) is a serious candidate for "universal memory" because of its non-volatility, fast access time, high density, good scalability, high endurance and relatively low power dissipation. However, problems with low write speed and large write current are important existing challenges in STT-RAM design and there is a tradeoff between them and data retention time. In this study, a novel STT-RAM cell structure which uses perfect graphite based Magnetic Tunnel Junction (MTJ) is proposed. First, the cross-section of the structure is selected to be an ellipse of 45 nm and 180 nm dimensions and a six-layer graphite is used as tunnel barrier. By passing a lateral current with a short pulse width (before applying STT current and independent of it) through four middle graphene layers of the tunnel barrier, a 27% reduction in the amplitude of the switching current (for fast switching time of 2 ns) or a 58% reduction in its pulse width is achieved without any reduction in data retention time. Finally, the effect of downscaling of technology on the proposed structure is evaluated. A reduction of 31.6% and 9% in switching current is achieved for 90 and 22 nm cell width respectively by passing sufficient current (100 μA with 0.1 ns pulse width) through the tunnel barrier. Simulations are done using Object Oriented Micro Magnetic Framework (OOMMF).

The influence of exercising rams on the lambing performance of a ...

African Journals Online (AJOL)

obtained in body mass between the exercised and non-exercised rams. ... Several aspects of male fertility, viz. testis size, mating behaviour, libido ... no differences in the feeding status existed due to a possible difference in .... output in cattle.

Acoustic Properties of Absorbent Asphalts

Science.gov (United States)

Trematerra, Amelia; Lombardi, Ilaria

2017-08-01

Road traffic is one of the greater cause of noise pollution in urban centers; a prolonged exposure to this source of noise disturbs populations subjected to it. In this paper is reported a study on the absorbent coefficients of asphalt. The acoustic measurements are carried out with a impedance tube (tube of Kundt). The sample are measured in three conditions: with dry material (traditional), “wet” asphalt and “dirty” asphalt.

Method of absorbing UF6 from gaseous mixtures in alkamine absorbents

International Nuclear Information System (INIS)

Lafferty, R.H.; Smiley, S.H.; Radimer, K.J.

1976-01-01

A method is described for recovering UF 6 from gaseous mixtures by absorption in a liquid. The liquid absorbent must have a relatively low viscosity and at least one component of the absorbent is an alkamine having less than 3 carbon atoms bonded to the amino nitrogen, less than 2 of the carbon atoms other than those bonded to the amino nitrogen are free of the hydroxy radical and precipitate the absorbed uranium from the absorbent. At least one component of the absorbent is chosen from the group consisting of ethanolamine, diethanolamine, and 3-methyl-3-amino-propane-diol-1,2

Effects of increased collagen-matrix density on the mechanical properties and in vivo absorbability of hydroxyapatite-collagen composites as artificial bone materials

Energy Technology Data Exchange (ETDEWEB)

Yunoki, Shunji [Life Science Group, Tokyo Metropolitan Industrial Technology Research Institute, 2-11-1 Fukasawa, Setagaya-ku, Tokyo 158-0081 (Japan); Sugiura, Hiroaki; Kondo, Eiji; Yasuda, Kazunori [Department of Sports Medicine and Joint Surgery, Graduate School of Medicine, Hokkaido University, Kita-15 Nishi-7, Sapporo, Hokkaido 060-8638 Japan (Japan); Ikoma, Toshiyuki; Tanaka, Junzo, E-mail: yunoki.shunji@iri-tokyo.jp [Department of Metallurgy and Ceramics Science, 2-12-1-S7-1, Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)

2011-02-15

The aim of this study was to evaluate the effects of increased collagen-matrix density on the mechanical properties and in vivo absorbability of porous hydroxyapatite (HAp)-collagen composites as artificial bone materials. Seven types of porous HAp-collagen composites were prepared from HAp nanocrystals and dense collagen fibrils. Their densities and HAp/collagen weight ratios ranged from 122 to 331 mg cm{sup -3} and from 20/80 to 80/20, respectively. The flexural modulus and strength increased with an increase in density, reaching 2.46 {+-} 0.48 and 0.651 {+-} 0.103 MPa, respectively. The porous composites with a higher collagen-matrix density exhibited much higher mechanical properties at the same densities, suggesting that increasing the collagen-matrix density is an effective way of improving the mechanical properties. It was also suggested that other structural factors in addition to collagen-matrix density are required to achieve bone-like mechanical properties. The in vivo absorbability of the composites was investigated in bone defects of rabbit femurs, demonstrating that the absorption rate decreased with increases in the composite density. An exhaustive increase in density is probably limited by decreases in absorbability as artificial bones.

Effects of increased collagen-matrix density on the mechanical properties and in vivo absorbability of hydroxyapatite-collagen composites as artificial bone materials

International Nuclear Information System (INIS)

Yunoki, Shunji; Sugiura, Hiroaki; Kondo, Eiji; Yasuda, Kazunori; Ikoma, Toshiyuki; Tanaka, Junzo

2011-01-01

The aim of this study was to evaluate the effects of increased collagen-matrix density on the mechanical properties and in vivo absorbability of porous hydroxyapatite (HAp)-collagen composites as artificial bone materials. Seven types of porous HAp-collagen composites were prepared from HAp nanocrystals and dense collagen fibrils. Their densities and HAp/collagen weight ratios ranged from 122 to 331 mg cm -3 and from 20/80 to 80/20, respectively. The flexural modulus and strength increased with an increase in density, reaching 2.46 ± 0.48 and 0.651 ± 0.103 MPa, respectively. The porous composites with a higher collagen-matrix density exhibited much higher mechanical properties at the same densities, suggesting that increasing the collagen-matrix density is an effective way of improving the mechanical properties. It was also suggested that other structural factors in addition to collagen-matrix density are required to achieve bone-like mechanical properties. The in vivo absorbability of the composites was investigated in bone defects of rabbit femurs, demonstrating that the absorption rate decreased with increases in the composite density. An exhaustive increase in density is probably limited by decreases in absorbability as artificial bones.

Beta irradiation as a method of the static MOS RAM memories processing and circuit design verification

International Nuclear Information System (INIS)

Wislowski, J.; Jagusztyn, M.

1985-01-01

1K NMOS RAM's in plastic packages were investigated after beta irradiation up to 100 Gy (Si) total dose. The memory samples differed as regards processing details and circuit design. Radioisotope beta sources were used for irradiation as the most safe and least expensive. A new version of the model of radiation-induced functional degradation of MOS RAM's has been proposed. 19 refs., 8 figs., 5 tabs. (author)

Design of a five-band terahertz perfect metamaterial absorber using two resonators

Science.gov (United States)

Meng, Tianhua; Hu, Dan; Zhu, Qiaofen

2018-05-01

We present a polarization-insensitive five-band terahertz perfect metamaterial absorber composed of two metallic circular rings and a metallic ground film separated by a dielectric layer. The calculated results show that the absorber has five distinctive absorption bands whose peaks are greater than 99% on average. The physical origin of the absorber originates from the combination of dipolar, hexapolar, and surface plasmon resonance of the patterned metallic structure, which is different from the work mechanism of previously reported absorbers. In addition, the influence of the structural parameters on the absorption spectra is analyzed to further confirm the origin of the five-band absorption peaks. The proposed absorber has potential applications in terahertz imaging, refractive index sensing, and material detecting.

Nanostructured materials for hydrogen storage

Science.gov (United States)

Williamson, Andrew J.; Reboredo, Fernando A.

2007-12-04

A system for hydrogen storage comprising a porous nano-structured material with hydrogen absorbed on the surfaces of the porous nano-structured material. The system of hydrogen storage comprises absorbing hydrogen on the surfaces of a porous nano-structured semiconductor material.

The sexual cycle of the Impala ram Aepyceros melampus Lichtenstein

African Journals Online (AJOL)

The sexual cycle of the Impala ram Aepyceros melampus Lichtenstein. J.D. Skinner. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors ...

Characterization of Time-Dependent Behavior of Ramming Paste Used in an Aluminum Electrolysis Cell

Science.gov (United States)

Orangi, Sakineh; Picard, Donald; Alamdari, Houshang; Ziegler, Donald; Fafard, Mario

2015-12-01

A new methodology was proposed for the characterization of time-dependent behavior of materials in order to develop a constitutive model. The material used for the characterization was ramming paste, a porous material used in an aluminum electrolysis cell, which is baked in place under varying loads induced by the thermal expansion of other components of the cell. In order to develop a constitutive model representing the paste mechanical behavior, it was necessary to get some insight into its behavior using samples which had been baked at different temperatures ranging from 200 to 1000 °C. Creep stages, effect of testing temperature on the creep, creep-recovery, as well as nonlinear creep were observed for designing a constitutive law. Uniaxial creep-recovery tests were carried out at two temperatures on the baked paste: ambient and higher. Results showed that the shape of creep curves was similar to a typical creep; recovery happened and the creep was shown to be nonlinear. Those experimental observations and the identification of nonlinear parameters of developed constitutive model demonstrated that the baked paste experiences nonlinear viscoelastic-viscoplastic behavior at different temperatures.

Effect of low-Z absorber's thickness on gamma-ray shielding parameters

Energy Technology Data Exchange (ETDEWEB)

Mann, Kulwinder Singh, E-mail: ksmann6268@gmail.com [Department of Applied Sciences, Punjab Technical University, Kapurthala 144601 (India); Department of Physics, D.A.V. College, Bathinda 151001, Punjab (India); Heer, Manmohan Singh [Department of Physics, Kanya Maha Vidyalaya, Jalandhar 144001 (India); Rani, Asha [Department of Applied Sciences, Ferozpur College of Engineering and Technology, Ferozshah, Ferozpur 142052 (India)

2015-10-11

Gamma ray shielding behaviour of any material can be studied by various interaction parameters such as total mass attenuation coefficient (μ{sub m}); half value layer (HVL); tenth value layer (TVL); effective atomic number (Z{sub eff}), electron density (N{sub el}), effective atomic weight (A{sub eff}) and buildup factor. For gamma rays, the accurate measurements of μ{sub m} (cm{sup 2} g{sup −1}) theoretically require perfect narrow beam irradiation geometry. However, the practical geometries used for the experimental investigations deviate from perfect-narrowness thereby the multiple scattered photons cause systematic errors in the measured values of μ{sub m}. Present investigation is an attempt to find the optimum value of absorber thickness (low-Z) for which these errors are insignificant and acceptable. Both experimental and theoretical calculations have been performed to investigate the effect of absorber's thickness on μ{sub m} of six low-Z (10materials (cement-black; cement-white; clay; red-mud; lime-stone and plaster of paris) at gamma-ray energies 661.66 keV, 1173.24 keV and 1332.50 keV. A computer program (GRIC2-toolkit) was designed for theoretical evaluation of shielding parameters of any material. Good agreement of theoretical and measured values of μ{sub m} was observed for all absorbers with thickness ≤0.5 mean free paths, thus considered it as optimum thickness for low-Z materials in the selected energy range. White cement was found to possess maximum shielding effectiveness for the selected gamma rays. - Highlights: • Optimum thickness value is 0.5 mfp for low-Z absorbers in energy range 662–1332 keV. • For accurate measurement of μ{sub m} absorber's thickness should be ≤optimum thickness. • GRIC2-toolkit is useful for γ-ray shielding analysis of composite materials.

Serum testosterone level and affecting factors in Syrian Awassi ram lambs

International Nuclear Information System (INIS)

Zarkawi, M.

2004-01-01

Results showed that testosterone exists in the blood of ram lams as early as the first month of age with no significant difference between single and twin births. This level, however, increased gradually with advancing age of ram lambs, indicating that the gonads (testes) of these growing lambs were active in secreting testosterone hormone after birth, but the rate of secretion differed with age of the lambs. A sharp increase in testosterone level was recorded at age of 8 months in twin births (5.32 ± 20.99 nmol/l) and in single births (7.26 ± 3.29 nmol/l). Throughout the study period, mean testosterone serum level was 3.29 ± 2.73 and 2.54 ± 2.15 nmol/l for single and twin births, respectively, as compared with an overall mean of 3.00 ± 2.49 nmol/l. However, the monthly difference in testosterone level between single and twin births was not significant (P>0.05) throughout the study period (10 months). Results also indicated an increase in live weight of lambs with advancing age, and live weight in single births was higher, but not significantly, than in twin births throughout the study period. Results of the study showed a sharp increase in the mean live weight of single births at age of 8 months (48.5 ± 10.8 kg) as compared with an overall live weight of the lambs (35.8 ± 15.2 and 32.7 ± 15.4 kg for single and twin births, respectively). A positive and significant correlation (r= 0.95, P>0.0001) was found between serum testosterone level and lamb live weight during the first 10 months of their age. Finally and for the first time, normal serum testosterone levels in Syrian Awassi ram lambs were determined during early stages. It was concluded, based on both, testosterone level and lamb live weight, that puberty in Awassi ram lambs could be reached at 8 months of age with a mean live weight of around 47 kg. Type of birth, lamb birth weight or weaning weight had no significant effect on testosterone level. (author)

Applied acoustics concepts, absorbers, and silencers for acoustical comfort and noise control alternative solutions, innovative tools, practical examples

CERN Document Server

Fuchs, Helmut V

2013-01-01

The author gives a comprehensive overview of materials and components for noise control and acoustical comfort. Sound absorbers must meet acoustical and architectural requirements, which fibrous or porous material alone can meet. Basics and applications are demonstrated, with representative examples for spatial acoustics, free-field test facilities and canal linings. Acoustic engineers and construction professionals will find some new basic concepts and tools for developments in order to improve acoustical comfort. Interference absorbers, active resonators and micro-perforated absorbers of different materials and designs complete the list of applications.

Eliminating the non-Gaussian spectral response of X-ray absorbers for transition-edge sensors

Science.gov (United States)

Yan, Daikang; Divan, Ralu; Gades, Lisa M.; Kenesei, Peter; Madden, Timothy J.; Miceli, Antonino; Park, Jun-Sang; Patel, Umeshkumar M.; Quaranta, Orlando; Sharma, Hemant; Bennett, Douglas A.; Doriese, William B.; Fowler, Joseph W.; Gard, Johnathon D.; Hays-Wehle, James P.; Morgan, Kelsey M.; Schmidt, Daniel R.; Swetz, Daniel S.; Ullom, Joel N.

2017-11-01

Transition-edge sensors (TESs) as microcalorimeters for high-energy-resolution X-ray spectroscopy are often fabricated with an absorber made of materials with high Z (for X-ray stopping power) and low heat capacity (for high resolving power). Bismuth represents one of the most compelling options. TESs with evaporated bismuth absorbers have shown spectra with undesirable and unexplained low-energy tails. We have developed TESs with electroplated bismuth absorbers over a gold layer that are not afflicted by this problem and that retain the other positive aspects of this material. To better understand these phenomena, we have studied a series of TESs with gold, gold/evaporated bismuth, and gold/electroplated bismuth absorbers, fabricated on the same die with identical thermal coupling. We show that the bismuth morphology is linked to the spectral response of X-ray TES microcalorimeters.

Distributions of 15 elements on 58 absorbers from simulated Hanford Double-Shell Slurry Feed (DSSF)

International Nuclear Information System (INIS)

Marsh, S.F.; Svitra, Z.V.; Bowen, S.M.

1994-11-01

As part of the Hanford Tank Waste Remediation System program at Los Alamos, we evaluated 58 commercially available or experimental absorber materials for their ability to remove hazardous components from high-level waste. These absorbers included cation and anion exchange resins, inorganic exchangers, composite absorbers, pillared layered materials, and a series of liquid extractants sorbed on porous support-beads. We tested these absorbers with a solution that simulates Hanford double-shell slurry feed (DSSF) (pH 14.0). To this simulant solution we added the appropriate radionuclides and used gamma spectrometry to measure fission products (Ce, Cs, Sr, Tc, and Y), actinides (U and Am), and matrix elements (Cr, Co, Fe, Mn, Ni, V, Zn, and Zr). For each of 870 element/absorber combinations, we measured distribution coefficients for dynamic contact periods of 30 min, 2 h, and 6 h to obtain information about sorption kinetics. On the basis of these 2610 measured distribution coefficients, we determined that many of the tested absorbers may be suitable for processing DSSF solutions

Optical RAM-enabled cache memory and optical routing for chip multiprocessors: technologies and architectures

Science.gov (United States)

Pleros, Nikos; Maniotis, Pavlos; Alexoudi, Theonitsa; Fitsios, Dimitris; Vagionas, Christos; Papaioannou, Sotiris; Vyrsokinos, K.; Kanellos, George T.

2014-03-01

The processor-memory performance gap, commonly referred to as "Memory Wall" problem, owes to the speed mismatch between processor and electronic RAM clock frequencies, forcing current Chip Multiprocessor (CMP) configurations to consume more than 50% of the chip real-estate for caching purposes. In this article, we present our recent work spanning from Si-based integrated optical RAM cell architectures up to complete optical cache memory architectures for Chip Multiprocessor configurations. Moreover, we discuss on e/o router subsystems with up to Tb/s routing capacity for cache interconnection purposes within CMP configurations, currently pursued within the FP7 PhoxTrot project.

Error analysis and prevention of cosmic ion-induced soft errors in static CMOS RAMS

International Nuclear Information System (INIS)

Diehl, S.E.; Ochoa, A. Jr.; Dressendorfer, P.V.; Koga, R.; Kolasinski, W.A.

1982-06-01

Cosmic ray interactions with memory cells are known to cause temporary, random, bit errors in some designs. The sensitivity of polysilicon gate CMOS static RAM designs to logic upset by impinging ions has been studied using computer simulations and experimental heavy ion bombardment. Results of the simulations are confirmed by experimental upset cross-section data. Analytical models have been extended to determine and evaluate design modifications which reduce memory cell sensitivity to cosmic ions. A simple design modification, the addition of decoupling resistance in the feedback path, is shown to produce static RAMs immune to cosmic ray-induced bit errors

Sodium antimony sulfide (NaSbS2: Turning an unexpected impurity into a promising, environmentally friendly novel solar absorber material

Directory of Open Access Journals (Sweden)

Siti Utari Rahayu

2016-11-01

Full Text Available We present a novel absorber material—NaSbS2—for solar cells. NaSbS2 is formed as an unexpected byproduct in the chemical synthesis of Sb2S3. However, NaSbS2 has many attractive features for a solar material. Here single phase NaSbS2 nanoparticles were synthesized through solution processing. NaSbS2 semiconductor-sensitized solar cells were demonstrated for the first time. The best cell yielded Jsc = 10.76 mA/cm2, Voc = 0.44 V, FF = 48.6%, and efficiency η = 2.30% under 1 sun. At the reduced 0.1 sun, the η increased to 3.18%—a respectable η for a new solar material.

Measurement and analysis of the water hammer in ram pump

Indian Academy of Sciences (India)

This paper presents the results of experimental research of the phenomena occurring in water ram during a single cycle of its operation. Apart from a brief introduction and description of the test stand and data recording system, the work includes a broad interpretation of the obtained results. Based on the pressure ...

A realization of the RAM digital filter. [Random Access Memory

Science.gov (United States)

Zohar, S.

1976-01-01

The digital filtering algorithm of W. D. Little, which employs a large RAM to obtain high speed, is implemented in a simple hardware configuration. The nonrecursive version of this filter is compared to the counting digital filter and found to be competitive for low-order filters up to order 7 (8 coefficients).

Design of a nonlinear torsional vibration absorber

Science.gov (United States)

Tahir, Ammaar Bin

larger than that in the latter. A nonlinear absorber design has been proposed comprising of thin beams as elastic elements. The geometric configuration of the proposed design has been shown to provide cubic stiffness nonlinearity in torsion. The values of design variables, namely the strength of nonlinearity alpha and torsional stiffness kalpha, were obtained by optimizing dimensions and material properties of the beams for a maximum vibration energy dissipation in the nonlinear absorber. A parametric study has also been conducted to analyze the effect of the magnitude of excitation provided to the system on the performance of a nonlinear absorber. It has been shown that the nonlinear absorber turns out to be more effective in terms of energy dissipation as compared to a linear absorber with an increase in the excitation level applied to the system.

Automatic track counting with an optic RAM-based instrument

International Nuclear Information System (INIS)

Staderini, E.M.; Castellano, Alfredo

1986-01-01

A new image sensor, the optic RAM, is now used in a microprocessor controlled instrument to read and digitize images from CR39 solid state nuclear track detectors. The system performs image analysis, filtering, tracks counting and evaluation in a fully automatic way, not requiring an optic microscope, nor photographic or television devices. The proposed system is a very compact and low power device. (author)

THE MAGELLANIC STREAM SYSTEM. I. RAM-PRESSURE TAILS AND THE RELICS OF THE COLLISION BETWEEN THE MAGELLANIC CLOUDS

Energy Technology Data Exchange (ETDEWEB)

Hammer, F.; Yang, Y. B.; Flores, H.; Puech, M.; Fouquet, S., E-mail: francois.hammer@obspm.fr [GEPI, Observatoire de Paris, CNRS, 5 Place Jules Janssen, Meudon F-92195 (France)

2015-11-10

We have analyzed the Magellanic Stream (MS) using the deepest and the most resolved H i survey of the Southern Hemisphere (the Galactic All-Sky Survey). The overall Stream is structured into two filaments, suggesting two ram-pressure tails lagging behind the Magellanic Clouds (MCs), and resembling two close, transonic, von Karman vortex streets. The past motions of the Clouds appear imprinted in them, implying almost parallel initial orbits, and then a radical change after their passage near the N(H i) peak of the MS. This is consistent with a recent collision between the MCs, 200–300 Myr ago, which has stripped their gas further into small clouds, spreading them out along a gigantic bow shock, perpendicular to the MS. The Stream is formed by the interplay between stellar feedback and the ram pressure exerted by hot gas in the Milky Way (MW) halo with n{sub h} = 10{sup −4} cm{sup −3} at 50–70 kpc, a value necessary to explain the MS multiphase high-velocity clouds. The corresponding hydrodynamic modeling provides the currently most accurate reproduction of the whole H i Stream morphology, of its velocity, and column density profiles along L{sub MS}. The “ram pressure plus collision” scenario requires tidal dwarf galaxies, which are assumed to be the Cloud and dSph progenitors, to have left imprints in the MS and the Leading Arm, respectively. The simulated LMC and SMC have baryonic mass, kinematics, and proper motions consistent with observations. This supports a novel paradigm for the MS System, which could have its origin in material expelled toward the MW by the ancient gas-rich merger that formed M31.

A Study of the Anechoic Performance of Rice Husk-Based, Geometrically Tapered, Hollow Absorbers

Directory of Open Access Journals (Sweden)

Muhammad Nadeem Iqbal

2014-01-01

Full Text Available Although solid, geometrically tapered microwave absorbers are preferred due to their better performance, they are bulky and must have a thickness on the order of λ or more. The goal of this study was to design lightweight absorbers that can reduce the electromagnetic reflections to less than −10 dB. We used a very simple approach; two waste materials, that is, rice husks and tire dust in powder form, were used to fabricate two independent samples. We measured and used their dielectric properties to determine and compare the propagation constants and quarter-wave thickness. The quarter-wave thickness for the tire dust was 3 mm less than that of the rice husk material, but we preferred the rice-husk material. This preference was based on the fact that our goal was to achieve minimum backward reflections, and the rice-husk material, with its low dielectric constant, high loss factor, large attenuation per unit length, and ease of fabrication, provided a better opportunity to achieve that goal. The performance of the absorbers was found to be better (lower than −20 dB, and comparison of the results proved that the hollow design with 58% less weight was a good alternative to the use of solid absorbers.

Development of an innovative solar absorber

Science.gov (United States)

Goodchild, Gavin

Solar thermal systems have great potential to replace or reduce the dependence of conventional fossil fuel based heating technologies required for space and water heating. Specifically solar domestic hot water systems can contribute 50-75% of the annual thermal load. To date residential users have been slow to purchase and install systems, primarily due to the large monetary investment required to purchase and install a system. Recent innovations in materials design and manufacturing techniques, offer opportunities for the development of absorber plate designs that have the potential to reduce cost, increase efficiency and reduce payback periods. Consequently, this design study was conducted in conjunction with industrial partners to develop an improved absorber based on roll bond manufacturing that can be produced at reduced cost with comparable or greater thermal efficiency.

High-speed nonvolatile CMOS/MNOS RAM

International Nuclear Information System (INIS)

Derbenwick, G.F.; Dodson, W.D.; Sokel, R.J.

1979-01-01

A bulk silicon technology for a high-speed static CMOS/MNOS RAM has been developed. Radiation-hardened, high voltage CMOS circuits have been fabricated for the memory array driving circuits and the enhancement-mode p-channel MNOS memory transistors have been fabricated using a native tunneling oxide with a 45 nm CVD Si 3 N 4 insulator deposited at 750 0 C. Read cycle times less than 350 ns and write cycle times of 1 μs are projected for the final 1Kx1 design. The CMOS circuits provide adequate speed for the write and read cycles and minimize the standby power dissipation. Retention times well in excess of 30 min are projected

Consignor's part and multimodality of the packages of RAM

International Nuclear Information System (INIS)

Grenier, M.

1993-01-01

One of the essential principles of Safety in transport of RAM as it was carried on, until the present days, is that the safety comes firstly from the packaging, and not from a special consideration of the mode of transport or anything else. A natural consequence was that the packaging remains the same, whatever is the used mode of transport, another that the transport mode does not take part, otherly than by its normal safety in the carriage itself in the protection against the radioactive hazard. Some recent actions, nevertheless, could be considered as putting some doubt on the implementation of this principles in the regulations and sometimes on these principles themselves. However, these latter come from the fact that the safety of the transport lays essentially in the hands of the consignor. He is indeed the only one who knows well enough the material and who is able to assess the adequation of the packaging and to warrant it to the Competent Authority when necessary. Besides, the packaging is the only direct grasp he has on the shipment, outside the special case of exclusive use. This situation is not completely incompatible with a new possible graduation of the packaging according to the transport mode, under the condition that this graduation be unidimensional which means the same in every field of testing. The consignor must, then, select the packaging corresponding to the most demanding of the possible modes. It is certainly much more difficult to adapt the mode of transport to the shipped materials themselves. All the transport has then to be in the hands of the consignor. That perhaps, can be relevant to industrial nuclear transport (eg: irradiated fuels, wastes), but not to the carriage of radioactive materials in general, which is the scope of IAEA regulations. (author)

Single port-assisted fully laparoscopic abdominoperineal resection (APR) with immediate V-RAM flap reconstruction of the perineal defect.

LENUS (Irish Health Repository)

Ali, Sayid

2012-09-01

Abdominoperineal resection (APR) of anorectal cancers after neoadjuvant chemoradiotherapy may incur significant perineal morbidity. While vertical rectus abdominis muscle (V-RAM) flaps can fill the pelvic resection space with health tissue, their use has previously been described predominantly in association with laparotomy. Here, we describe a means of combination laparoscopic APR with V-RAM flap reconstruction that allows structural preservation of the entire abdominal wall throughout the oncological resection and of the deep parietal layers after V-RAM donation. Furthermore, a single port access device used at the end colostomy site allows a second senior surgeon assist with an additional two working instruments for the purpose of improved pelvic tissue retraction, especially useful in obese patients.

The ram effect: New insights into neural modulation of the gonadotropic axis by male odors and socio-sexual interactions.

Directory of Open Access Journals (Sweden)

CLAUDE eFABRE NYS

2015-04-01

Full Text Available Reproduction in mammals is controlled by the hypothalamo-pituitary-gonadal (HPG axis under the influence of external and internal factors such as photoperiod, stress, nutrition, and social interactions. Sheep are seasonal breeders and stop mating when day length is increasing (anestrus. However, interactions with a sexually active ram during this period can override the steroid negative feedback responsible for the anoestrus state, stimulate LH secretion and eventually reinstate cyclicity. This is known as the ram effect and research into the mechanisms underlying it is shedding new light on HPG axis regulation. The first step in the ram effect is increased LH pulsatile secretion in anestrus ewes exposed to a sexually active male or only to its fleece, the latter finding indicating a pheromone-like effect. Estradiol secretion increases in all ewes and this eventually induces a LH surge and ovulation, just as during the breeding season. An exception is a minority of ewes that exhibit a precocious LH surge (within 4h with no prior increase in estradiol. The main olfactory system and the cortical nucleus of the amygdala are critical brain structures in mediating the ram effect since it is blocked by their inactivation. Sexual experience is also important since activation (increased c-fos expression in these and other regions is greatly reduced in sexually naïve ewes. In adult ewes kisspeptin neurons in both arcuate and preoptic regions and some preoptic GnRH neurons are activated 2h after exposure to a ram. Exposure to rams also activates noradrenergic neurons in the locus coeruleus and A1 nucleus and increased noradrenalin release occurs in the posterior preoptic area. Pharmacological modulation of this system modifies LH secretion in response to the male or his odor. Together these results show that the ram effect can be a fruitful model to promote both a better understanding of the neural and hormonal regulation of the HPG axis in general and

Experimental and numerical investigation of ram extrusion of bread dough

Science.gov (United States)

Mohammed, M. A. P.; Wanigasooriya, L.; Charalambides, M. N.

2016-10-01

An experimental and numerical study on ram extrusion of bread dough was conducted. A laboratory ram extrusion rig was designed and manufactured, where dies with different angles and exit radii were employed. Rate dependent behaviour was observed from tests conducted at different extrusion speeds, and higher extrusion pressure was reported for dies with decreasing exit radius. A finite element simulation of extrusion was performed using the adaptive meshing technique in Abaqus. Simulations using a frictionless contact between the billet and die wall showed that the model underestimates the response at high entry angles. On the other hand, when the coefficient of friction value was set to 0.09 as measured from friction experiments, the dough response was overestimated, i.e. the model extrusion pressure was much higher than the experimentally measured values. When a critical shear stress limit, τmax, was used, the accuracy of the model predictions improved. The results showed that higher die angles require higher τmax values for the model and the experiments to agree.

Design and testing of a shock absorber for a type 1 container

International Nuclear Information System (INIS)

Sappok, M.; Beine, B.; Rittscher, D.

1993-01-01

A shock-absorber will be required for a rad. waste 'Konrad' type 1 container made of ductile cast iron whenever it will be used as a type B container according to the IAEA-Regulations for the Safe Transport of Radioactive materials. The shock-absorber has to protect the type B container during shipping such as to withstand the accident scenarios that are covered by the IAEA-Regulation tests without substantial loss of its shielding and tightness functions. The designation as type 1 container originates from German regulations for the intermediate storage site Gorleben and the final depository Konrad-mine. These regulations call for the limits on outside dimensions of 1700 mm in length, 1600 mm in width and 1450 mm in height as well as for a limit of 20 Mg on total weight without shock-absorber. The relatively simple design method for the shock-absorber has been validated by the test results. It can be extended to other materials and designs for shock-absorbers if reliable force-displacement-diagrams are available for the structural elements from which the absorbed energy and the displacements can be calculated by integration. In order to account for the dynamic effects, the better approximation of the true duration of the impact would be helpful. The present limit of 0.5 R p0,2 on the nominal stresses should be discussed because the large number of tests on containers made of ductile cast iron that have been performed up to now have shown a substantial level of conservatism on this respect. The sharply tapered pipes on edge Kl of the shock-absorbers should be replaced by pipe bends. This will result in smaller accelerations and in an even higher level of protection of the container than effected by the tested shock-absorber

Comparison of iron and tungsten absorber structures for an analog hadron calorimeter

International Nuclear Information System (INIS)

Guenter, Clemens

2015-05-01

Future electron-positron-collider experiments will require unprecedented jet-energy resolution to complete their physics programs. This can only be achieved with novel approaches to calorimetry. One of these novel approaches is the Particle Flow Algorithm, which uses the best suited sub-detector to measure the energy of the particles produced by the electronpositron collision. The CALICE Collaboration evaluates different read-out technologies for Particle Flow Calorimeters. This thesis describes the comparison of two different absorber materials, iron and tungsten, for the CALICE Analog Hadron Calorimeter. It is described how test-beam data, that have been recorded in the range from 2 GeV to 10 GeV with the Analog Hadron Calorimeter are calibrated, and how samples are selected containing showers from just one particle type. The data are then compared to simulations, and the remaining disagreement between data and simulation is discussed. The validated simulations are then used to decompose the showers into different fractions. These fractions are compared for the two absorber materials to understand the impact of the absorber material choice on the calorimeter performance.

An experimental study of an energy absorbing restrainer for piping systems

International Nuclear Information System (INIS)

Sone, A.; Suzuki, K.

1989-01-01

Recently, in the seismic design methodology of the piping systems in nuclear power plants, new and improved design criteria and calculation techniques which will lead to more reliable and cost saving design products have been investigated. For instance, problems for reducing the snubbers in nuclear power plants which provide high costs for their inspections and maintenances and related flexible design problems for the dynamic piping systems have been investigated. Thus, in order to replace snubbers, various types of alternative supporting devices such as dynamic absorbers, gapped support and energy absorbing support devices have been proposed. A number of energy absorbing restrainers have been designed in Japan and United-States by allowing yield to occur during strong earthquakes. Advantages and disadvantages of these restrainers were examined analytically and experimentally. In order to overcome the disadvantages, the authors introduced new absorbing material LSPZ (laminated super plastic zinc) in which SPZ is expected to have reliable ductility and also efficient energy absorbability still under the normal temperature condition. This paper is devoted to an experimental works for this updated absorbing restrainer

Comparison of HuRAM+ and HERA for Development of Data Worksheet for Simulator based HERA Databank

International Nuclear Information System (INIS)

Choi, Sunyoung; Jung, Wondea

2013-01-01

We also compared the existing HERA methods and HERA database to select essential data fields. We performed a preliminary study to see the possibility to induce the operator's emergency operating procedure (EOP) noncompliance behaviors under a simulated emergency. The purpose of this paper is to compare the HuRAM + and HERA to obtain an insight into the construction of a data worksheet for a qualitative HERA. In this paper, we performed a case study for applying simulator training data to HuRAM + and HERA. With this insight, as well as the results of the researches mentioned above, we have a plan to develop a systematic and qualitative HERA and a data worksheet for the work. In this paper, we compared HuRAM + and HERA to obtain an insight into the construction of a data worksheet for a qualitative HERA and performed a case study. HERA requires a burden to analyze and input an event data due to too many data fields even though it is well designed to estimate Heaps. It is somewhat more convenient to input data into the HuRAM + ; however, it is difficult to analyze the organization and safety culture factors. We are now trying to develop the framework of a data worksheet for a qualitative HERA based on simulator training data. The purpose of our data worksheet is to provide key information for HEP estimation and to enhance the understanding of an operators' behavior under an off-normal plant status. We aim less encumbered means of obtaining the needed data for HERA by changing the existing data worksheet framework of HuRAM + and HERA and by reducing data fields that require reading the between the lines

Design considerations for application of metallic honeycomb as an energy absorber

International Nuclear Information System (INIS)

Lee, W.H.; Roemer, R.E.

1980-01-01

Design for postulated accidents in nuclear power plants often requires mitigation of impact to safety-related structures. Plastically designed, energy absorbing mechanisms are often used in the design of such mitigating structures. Metallic honeycomb is the most efficient, practical, energy-absorbing material currently in use. Recent tests indicate that its use in this application, however, presents some unique design and fabrication problems. The paper presents the results of static and dynamic crush tests concerned with the effect of impact velocity, material properties, cell density, loading configuration, and overall pad geometry. Specific design recommendations are made in each area, and suggestions are provided to improve fabrication techniques and minimize subsequent problems

Random incidence absorption coefficients of porous absorbers based on local and extended reaction models

DEFF Research Database (Denmark)

Jeong, Cheol-Ho

2011-01-01

resistivity and the absorber thickness on the difference between the two surface reaction models are examined and discussed. For a porous absorber backed by a rigid surface, the local reaction models give errors of less than 10% if the thickness exceeds 120 mm for a flow resistivity of 5000 Nm-4s. As the flow...... incidence acoustical characteristics of typical building elements made of porous materials assuming extended and local reaction. For each surface reaction, five well-established wave propagation models, the Delany-Bazley, Miki, Beranek, Allard-Champoux, and Biot model, are employed. Effects of the flow...... resistivity doubles, a decrease in the required thickness by 25 mm is observed to achieve the same amount of error. For an absorber backed by an air gap, the thickness ratio between the material and air cavity is important. If the absorber thickness is approximately 40% of the cavity depth, the local reaction...

The collaborative effect of ram pressure and merging on star formation and stripping fraction

Science.gov (United States)

Bischko, J. C.; Steinhauser, D.; Schindler, S.

2015-04-01

Aims: We investigate the effect of ram pressure stripping (RPS) on several simulations of merging pairs of gas-rich spiral galaxies. We are concerned with the changes in stripping efficiency and the time evolution of the star formation rate. Our goal is to provide an estimate of the combined effect of merging and RPS compared to the influence of the individual processes. Methods: We make use of the combined N-body/hydrodynamic code GADGET-2. The code features a threshold-based statistical recipe for star formation, as well as radiative cooling and modeling of galactic winds. In our simulations, we vary mass ratios between 1:4 and 1:8 in a binary merger. We sample different geometric configurations of the merging systems (edge-on and face-on mergers, different impact parameters). Furthermore, we vary the properties of the intracluster medium (ICM) in rough steps: the speed of the merging system relative to the ICM between 500 and 1000 km s-1, the ICM density between 10-29 and 10-27 g cm-3, and the ICM direction relative to the mergers' orbital plane. Ram pressure is kept constant within a simulation time period, as is the ICM temperature of 107 K. Each simulation in the ICM is compared to simulations of the merger in vacuum and the non-merging galaxies with acting ram pressure. Results: Averaged over the simulation time (1 Gyr) the merging pairs show a negligible 5% enhancement in SFR, when compared to single galaxies under the same environmental conditions. The SFRs peak at the time of the galaxies first fly-through. There, our simulations show SFRs of up to 20 M⊙ yr-1 (compared to 3 M⊙ yr-1 of the non-merging galaxies in vacuum). In the most extreme case, this constitutes a short-term (<50 Myr) SFR increase of 50 % over the non-merging galaxies experiencing ram pressure. The wake of merging galaxies in the ICM typically has a third to half the star mass seen in the non-merging galaxies and 5% to 10% less gas mass. The joint effect of RPS and merging, according

Romanian experience in a assessment of the risk and environmental consequences due to radioactive materials transportation

International Nuclear Information System (INIS)

Vieru, Gheorghe

2006-01-01

Full text: The transport of radioactive materials (RAM) is a very important problem taking into consideration its potential risks over the environment and the radiological consequences of this activity. Romania as a Member State of the International Atomic Energy Agency has implemented national regulations for a safe transport of RAM in complying with the Agency's recommendations as well as other international specialized organizations. The paper will present the main sources of radioactive materials in Romania, and their transportation routes with a particular focus on the radioactive wastes (very low level and mixed low-level radioactive materials), radioactive isotopes and sources, and natural uranium ore. Starting from the fact that the safety in the transport of radioactive materials is dependent on packaging appropriate for the contents being shipped, rather than operational and/or administrative actions required for the package, the paper presents, very briefly, the qualification tests for the main packages used for transport and storage of RAM in Romania. There are presented also specific problems related to the identification and evaluation of the environmental risks and impacts as well as the potential radiological consequences associated with the transport of radioactive materials, for all those three possible situations: routine transport (without incidents), normal transport (with minor incidents) and during potential accidents. As a conclusion, it is stated that the evaluated annual collective dose for the population due to RAM transport is less than those received by natural radiation sources. At the same time it is concluded that Romanian made packages are safe and prevent loss of its radioactive contents into environment. (author)

RAM, an RGDS analog, exerts potent anti-melanoma effects in vitro and in vivo.

Directory of Open Access Journals (Sweden)

Maria Simona Aguzzi

Full Text Available Peptides containing the RGD sequence are under continuous investigation given their ability to control cell adhesion and apoptosis. Since small peptides are quickly metabolized and degraded in vivo, developing analogs resistant to serum-induced degradation is a challenging task. RGD analogs developed so far are known as molecules mostly inhibiting cell adhesion; this feature may reduce cell proliferation and tumor development but may not induce regression of tumors or metastases already formed. In the current study, carried out in melanoma in vitro and in vivo models, we show that RAM, an RGD-non-peptide Analog-Molecule, strongly inhibits cells adhesion onto plastic, vitronectin, fibronectin, laminin and von Willebrand Factor while it does not inhibit cell adhesion onto collagen IV, similarly to the RGDS template peptide. It also strongly inhibits in vitro cell proliferation, migration and DNA-synthesis, increases melanoma cells apoptosis and reduces survivin expression. All such effects were observed in collagen IV seeded cells, therefore are most likely independent from the anti adhesive properties. Further, RAM is more stable than the template RGDS; in fact it maintains its anti-proliferation and anti-adhesion effects after long serum exposure while RGDS almost completely loses its effects upon serum exposure. In a mouse metastatic melanoma in vivo model, increasing doses of RAM significantly reduce up to about 80% lung metastases development, while comparable doses of RGDS are less potent. In conclusion these data show that RAM is a potent inhibitor of melanoma growth in vitro, strongly reduces melanoma metastases development in vivo and represents a novel candidate for further in vivo investigations in the cancer treatment field.

CMOS/SOS RAM transient radiation upset and ''inversion'' effect investigation

International Nuclear Information System (INIS)

Nikiforov, A.Y.; Poljakov, I.V.

1996-01-01

The Complementary Metal-Oxide-Semiconductor/Silicon-on-Sapphire Random Access Memory (CMOS/SOS RAM) transient upset and inversion effect were investigated with pulsed laser, pulsed voltage generator and low-intensity light simulators. It was found that the inversion of information occurs due to memory cell photocurrents simultaneously with the power supply voltage drop transfer to memory cells outputs

A new procedure for static RAM evaluation under x-ray pulses

International Nuclear Information System (INIS)

Marec, R.; Gaillard, R.; Mary, P.; Fairbank, X.; Ferrant, R.; Palau, J.M.; Gasiot, J.

1994-01-01

An original method, to identify the initial patterns that are the most favorable to obtain upsets under X-ray pulses, has been developed on Static RAMs in the standby mode. The results obtained with these initial patterns are interesting in order to analyze the radiation induced failures

An energy and cost efficient majority-based RAM cell in quantum-dot cellular automata

Science.gov (United States)

Khosroshahy, Milad Bagherian; Moaiyeri, Mohammad Hossein; Navi, Keivan; Bagherzadeh, Nader

Nanotechnologies, notably quantum-dot cellular automata, have achieved major attentions for their prominent features as compared to the conventional CMOS circuitry. Quantum-dot cellular automata, particularly owning to its considerable reduction in size, high switching speed and ultra-low energy consumption, is considered as a potential alternative for the CMOS technology. As the memory unit is one of the most essential components in a digital system, designing a well-optimized QCA random access memory (RAM) cell is an important area of research. In this paper, a new five-input majority gate is presented which is suitable for implementing efficient single-layer QCA circuits. In addition, a new RAM cell with set and reset capabilities is designed based on the proposed majority gate, which has an efficient and low-energy structure. The functionality, performance and energy consumption of the proposed designs are evaluated based on the QCADesigner and QCAPro tools. According to the simulation results, the proposed RAM design leads to on average 38% lower total energy dissipation, 25% smaller area, 20% lower cell count, 28% lower delay and 60% lower QCA cost as compared to its previous counterparts.

Elastic, Frictional, Strength and Dynamic Characteristics of the Bell Shape Shock Absorbers Made of MR Wire Material

Science.gov (United States)

Lazutkin, G. V.; Davydov, D. P.; Boyarov, K. V.; Volkova, T. V.

2018-01-01

The results of the mechanical characteristic experimental studies are presented for the shock absorbers of DKU type with the elastic elements of the bell shape made of MR material and obtained by the cold pressing of mutually crossing wire spirals with their inclusion in the array of reinforcing wire harnesses. The design analysis and the technology of MR production based on the methods of similarity theory and dimensional analysis revealed the dimensionless determined and determining parameters of elastic frictional, dynamic and strength characteristics under the static and dynamic loading of vibration isolators. The main similarity criteria of mechanical characteristics for vibration isolators and their graphical and analytical representation are determined, taking into account the coefficients of these (affine) transformations of the hysteresis loop family field.

Resistive Random Access Memory from Materials Development fnd Engineering to Novel Encryption and Neuromorphic Applications

Science.gov (United States)

Beckmann, Karsten

Resistive random access memory (ReRAM or RRAM) is a novel form of non-volatile memory that is expected to play a major role in future computing and memory solutions. It has been shown that the resistance state of ReRAM devices can be precisely tuned by modulating switching voltages, by limiting peak current, and by adjusting the switching pulse properties. This enables the realization of novel applications such as memristive neuromorphic computing and neural network computing. I have developed two processes based on 100 and 300mm wafer platforms to demonstrate functional HfO2 based ReRAM devices. The first process is designed for a rapid materials engineering and device characterization, while the second is an advanced hybrid ReRAM/CMOS combination based on the IBM 65nm 10LPe process technology. The 100mm wafer efforts were used to show impacts of etch processes on ReRAM switching performance and the need for a rigorous structural evaluation of ReRAM devices before starting materials development. After an etch development, a bottom electrode comparison between the inert materials Pt, Ru and W was performed where Ru showed superior results with respect to yield and resilience against environmental impacts such as humidity over a 2-month period. A comparison of amorphous and crystalline devices showed no statistical difference in the performance with respect to random telegraph noise. This demonstrates, that the forming process fundamentally alters the crystallographic structure within and around the filament. The 300mm wafer development efforts were aimed towards implementing ReRAM in the FEOL, combined with CMOS, to yield a seamless process flow of 1 transistor 1 ReRAM structures (1T1R). This technology was customized with custom-developed tungsten metal 1 (M1) and dual tungsten/copper via 1 (V1) structures, within which the ReRAM stack is embedded. The ReRAM itself consists of an inert W bottom electrode, HfO2 based active switching layer, a Ti oxygen scavenger

Aperiodic-metamaterial-based absorber

Directory of Open Access Journals (Sweden)

Quanlong Yang

2017-09-01

Full Text Available The periodic-metamaterial-based perfect absorber has been studied broadly. Conversely, if the unit cell in the metamaterial-based absorber is arranged aperiodically (aperiodic-metamaterial-based absorber, how does it perform? Inspired by this, here we present a systematic study of the aperiodic-metamaterial-based absorber. By investigating the response of metamaterial absorbers based on periodic, Fibonacci, Thue-Morse, and quasicrystal lattices, we found that aperiodic-metamaterial-based absorbers could display similar absorption behaviors as the periodic one in one hand. However, their absorption behaviors show different tendency depending on the thicknesses of the spacer. Further studies on the angle and polarization dependence of the absorption behavior are also presented.

Doctor Ramón Luis Miranda Torres, su relación con las neurociencias

OpenAIRE

Hodelín Tablada,Ricardo

2005-01-01

Objetivo: en el presente trabajo se reseña la relación del doctor Ramón Luis Miranda con las neurociencias, dirigido a destacar su inclinación por estas disciplinas. Desarrollo: conocido en la historiografía médica como el médico de José Martí el apóstol cubano el doctor Ramón Luis Miranda Torres, se destacó en otros aspectos poco divulgados, por lo que opinamos que no se le ha otorgado su verdadera dimensión. Nacido en la ciudad de Matanzas, Cuba, estudió medicina en Francia y desde sus años...

Reliability and Maintainability Model (RAM): User and Maintenance Manual. Part 2; Improved Supportability Analysis

Science.gov (United States)

Ebeling, Charles E.

1996-01-01

This report documents the procedures for utilizing and maintaining the Reliability & Maintainability Model (RAM) developed by the University of Dayton for the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC). The purpose of the grant is to provide support to NASA in establishing operational and support parameters and costs of proposed space systems. As part of this research objective, the model described here was developed. This Manual updates and supersedes the 1995 RAM User and Maintenance Manual. Changes and enhancements from the 1995 version of the model are primarily a result of the addition of more recent aircraft and shuttle R&M data.

Neutron absorber qualification and acceptance testing from the designer's perspective

Energy Technology Data Exchange (ETDEWEB)

Bracey, W. [Transnuclear, Inc, Hawthorne, NY (United States); Chiocca, R. [Cogema Logistics, St. Quentin en Yvelines (France)

2004-07-01

Starting in the mid 1990's, the USNRC began to require less than 100% credit for the 10B present in fixed neutron absorbers spent fuel transport packages. The current practice in the US is to use only 75% of the specified 10B in criticality safety calculations unless extensive acceptance testing demonstrates both the presence of the 10B and uniformity of its distribution. In practice, the NRC has accepted no more than 90% credit for 10B in recent years, while other national competent authorities continue to accept 100%. More recently, with the introduction of new neutron absorber materials, particularly aluminum / boron carbide metal matrix composites, the NRC has also expressed expectations for qualification testing, based in large part on Transnuclear's successful application to use a new composite material in the TN-68 storage / transport cask. The difficulty is that adding more boron than is really necessary to a metal has some negative effects on the material, reducing the ductility and the thermal conductivity, and increasing the cost. Excessive testing requirements can have the undesired effect of keeping superior materials out of spent fuel package designs, without a corresponding justification based on public safety. In European countries and especially in France, 100% credit has been accepted up to now with materials controls specified in the Safety Analysis Report (SAR): Manufacturing process approved by qualification testing Materials manufacturing controlled under a Quality Assurance system. During fabrication, acceptance testing directly on products or on representative samples. Acceptance criteria taking into account a statistical uncertainty corresponding to 3{sigma}. The original and current bases for the reduced {sup 10}B credit, the design requirements for neutron absorber materials, and the experience of Transnuclear and Cogema Logistics with neutron absorber testing are examined. Guidelines for qualification and acceptance testing and

Self-shielding and burn-out effects in the irradiation of strongly-neutron-absorbing material

International Nuclear Information System (INIS)

Sekine, T.; Baba, H.

1978-01-01

Self-shielding and burn-out effects are discussed in the evaluation of radioisotopes formed by neutron irradiation of a strongly-neutron-absorbing material. A method of the evaluation of such effects is developed both for thermal and epithermal neutrons. Gadolinium oxide uniformly mixed with graphite powder was irradiated by reactor-neutrons together with pieces of a Co-Al alloy wire (the content of Co being 0.475%) as the neutron flux monitor. The configuration of the samples and flux monitors in each of two irradiations is illustrated. The yields of activities produced in the irradiated samples were determined by the γ-spectrometry with a Ge(Li) detector of a relative detection efficiency of 8%. Activities at the end of irradiation were estimated by corrections due to pile-up, self-absorption, detection efficiency, branching ratio, and decay of the activity. Results of the calculation are discussed in comparison with the observed yields of 153 Gd, 160 Tb, and 161 Tb for the case of neutron irradiation of disc-shaped targets of gadolinium oxide. (T.G.)

Dispersion-Type Absorbing Materials for the Control Organs of Thermal Reactors; Absorbants du Type a Dispersion pour les Organes de Commande des Reacteurs a Neutrons Thermiques; Pogloshchayushchie materialy dispersionnogo tipa dlya organov regulirovaniya teplovykh reaktorov; Absorbentes de Tipo Dispersion para los Organos de Mando de los Reactores Termicos

Energy Technology Data Exchange (ETDEWEB)

Nosov, V. I.; Ponomarjov-Stepnoj, H. H.; Portnoj, K. I.; Savel' ev, E. G.

1964-06-15

The paper gives the results of a study of the physical characteristics of NIMONIC-type absorbing alloys with oxides of rare-earth elements dispersed in them (gadolinium, samarium, europium etc. ). The paper discusses changes in absorbing capacity in relation to the composition of the material, describes the mechanical and thermophysical properties of the absorbing materials as a function of the concentration of absorber introduced into the alloy and, finally, gives the results of a study of the effect of radiation on the properties of the materials. It is shown that absorbing alloys with oxides of rare-earth elements dispersed in the metallic matrix possess considerable absorbing capacity for relatively small amounts of absorber in the alloy (5 to 10%). When oxides of rare-earth elements are added, NIMONIC-type alloys have relatively high resistance and thermophysical characteristics (o{sub B}, E, {lambda}) at high temperatures for absorber concentrations up to about 10%. Dispersion materials of this type have satisfactory radiation stability in a radiation field of about 3 x 10{sup 20}n/cm{sup 2} at high temperature. (author) [French] Les auteurs exposent les resultats de recherches sur les caracteristiques physiques des alliages absorbants du type nimonik, contenant des terres rares dispersees dans leur masse (gadolinium, samarium, europium, etc.). Ils examinent les variations de la capacite d'absorption selon la composition du materiau; on donne des indications sur les caracteristiques mecaniques et thermophysiques des absorbants en fonction de la concentration de Tabsorbeur incorpore dans l 'alliage ainsi que les resultats d 'une etude relative a l 'influence de l'irradiation sur ces caracteristiques. Ils montrent que les alliages absorbants contenant des oxydes de terres rares disperses dans une matrice metallique ont une capacite d'absorption importante pour une teneur de l'alliage relativement faible en'matieres absorbantes (environ 5 a 10%). Les alliages du

Synthesis of hemicellulose-acrylic acid graft copolymer super water absorbent resin by ultrasonic irradiation technology

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Fangfang LIU

2015-12-01

Full Text Available The hemicellulose super water absorbent resin is prepared by using ultrasonic irradiation technology, with the waste liquid produced during the preparation of viscose fiber which contains a large amount of hemicellulose as raw material, acrylic acid as graft monomer, N,N’-methylene bis acrylamide (NMBA as cross linking agent, and (NH42S2O8-NaHSO3 as the redox initiation system. The synthesis conditions, structure and water absorption ability of resin are discussed. The results indicate that water absorbency of the resin is 311 g/g, the tap water absorbency is 102 g/g, the normal saline absorbency is 55 g/g, and the artificial urine absorbency is 31 g/g under the optimal synthesis conditions, so the resin has great water absorption rate and water retaining capacity. The FT-IR and SEM analysis shows that the resin with honeycomb network structure is prepared. The successfully synthesized of the resin means that the hemicellulose waste liquid can be highly effectively recycled, and it provides a kind of new raw material for the synthesis of super water absorbent resin.

Transport of radioactive material in Romania -the assessment of the radiological consequences and the environmental impacts

International Nuclear Information System (INIS)

Vieru, Gheorghe

2008-01-01

The transport of radioactive materials (RAM) is a very important problem considering the potential risks and radiological consequences in carrying-out this activity. Romania as a Member State of the International Atomic Energy Agency has implemented national regulations for a safe transport of RAM in accordance with the Agency's recommendations as well as other international specialized organizations. Based on the IAEA's Safety Standard-TS-R-1 (ST-1), Romanian National Nuclear Regulatory Body - CNCAN adopted and implemented, by Act no. 357/December 21, 2005, the safety regulations for the transport of radioactive materials in Romania under the title: 'Regulations for the Transport of Radioactive Materials'. The paper will present the main sources of radioactive materials in Romania their transportation routes with a particular interest paid to the radioactive wastes (low level radioactive materials), isotopes and radioactive sources, uranium ore. Starting from the fact that the safety in the transport of radioactive materials is dependent on appropriate packaging for the contents being shipped, rather than operational and/or administrative actions required for the package, the paper presents, briefly the main packages used for transport and storage of such RAM in Romania. There are presented hypothetical scenarios for specific problems related to the identification and evaluation of the risks and potential radiological consequences associated with the transport of radioactive materials in Romania, for all these three situations: routine transport (without incidents), normal transport (with minor incidents) and during possible accidents. As a conclusion, it is ascertained that the evaluated annual collective dose for the population due to RAM transport is less than that received by natural radiation sources. At the same time it is concluded that Romanian made packages are safe and prevent loss of their radioactive contents into the environment. (author)

Parametric study on the performance of automotive MR shock absorbers

Science.gov (United States)

Gołdasz, J.; Dzierżek, S.

2016-09-01

The paper contains the results of a parametric study to explore the influence of various quantities on the performance range of semi-active automotive shock absorbers using the magnetorheological (MR) fluid under steady-state and transient excitations. The analysis was performed with simulated data and using a standard single-tube shock absorber configuration with a single-gap MR valve. Additionally, the impact of material variables and valves geometry was examined as the parameters were varied and its dynamic range studied.

Methods for absorbing neutrons

Science.gov (United States)

Guillen, Donna P [Idaho Falls, ID; Longhurst, Glen R [Idaho Falls, ID; Porter, Douglas L [Idaho Falls, ID; Parry, James R [Idaho Falls, ID

2012-07-24

A conduction cooled neutron absorber may include a metal matrix composite that comprises a metal having a thermal neutron cross-section of at least about 50 barns and a metal having a thermal conductivity of at least about 1 W/cmK. Apparatus for providing a neutron flux having a high fast-to-thermal neutron ratio may include a source of neutrons that produces fast neutrons and thermal neutrons. A neutron absorber positioned adjacent the neutron source absorbs at least some of the thermal neutrons so that a region adjacent the neutron absorber has a fast-to-thermal neutron ratio of at least about 15. A coolant in thermal contact with the neutron absorber removes heat from the neutron absorber.

Neutron absorbing article and method for manufacture of such article

International Nuclear Information System (INIS)

Hortman, M.T.; Mcmurtry, C.H.; Naum, R.G.; Owens, D.P.

1980-01-01

A neutron absorbing article, preferably in long, thin, flat form , suitable for but not necessarily limited to use in storage racks for spent nuclear fuel at locations between volumes of such stored fuel, to absorb neutrons from said spent fuel and prevent uncontrolled nuclear reaction of the spent fuel material, is composed of finely divided boron carbide particles and a solid, irreversibly cured phenolic polymer, forming a continuous matrix about the boron carbide particles, in such proportions that at least 6% of b10 from the boron carbide content is present therein. The described articles withstand thermal cycling from repeated spent fuel insertions and removals, withstand radiation from said spent nuclear fuel over long periods of time without losing desirable neutron absorbing and physical properties, are sufficiently chemically inert to water so as to retain neutron absorbing properties if brought into contact with it, are not galvanically corrodible and are sufficiently flexible so as to withstand operational basis earthquake and safe shutdown earthquake seismic events, without loss of neutron absorbing capability and other desirable properties, when installed in storage racks for spent nuclear fuel. The disclosure also relates to a plurality of such neutron absorbing articles in a storage rack for spent nuclear fuel and to a method for the manufacture of the articles

Ramón Cote Baraibar

Directory of Open Access Journals (Sweden)

Juan Gustavo Cobo Borda

2005-05-01

Full Text Available Hijo de poeta, como María Mercedes Carranza y Santiago Mutis, Ramón Cote nació en Cúcuta el 19 de mayo de 1963- Su primer libro fue publicado en 1984 por ediciones Arnao, de Madrid, donde se graduó en historia del arte en la Universidad Complutense. Al instalarse en Colombia, se dedicó a la publicidad. Ha publicado ensayos sobre poesía colombiana en revistas como ínsula, y en 1992, con el título de  |Diez de ultramar publicó una muestra de joven poesía latinoamericana que abarcaba nombres como José Luis Rivas, Coral Bracho, Raúl Zurita, Fabio Morabito, Yolanda Pantin y Eduardo Chirinos. Entre la nueva poesía colombiana, su voz es una de las más reconocibles. Vale la pena, entonces, repasar la totalidad de su trayectoria.

Variations of motility and survival with storage time at 4°C of epididymal spermatozoa Ouled-Djellal breed rams in Eastern Algeria

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B. Safsaf

2015-03-01

Full Text Available Aim: The aim of this study was to evaluate some reproduction performances in Ouled-Djellal rams. Materials and Methods: This study involved genital organs removed after slaughter from 54 rams at the municipal slaughterhouse of Batna (East Algeria. Results: The measurements of survival and mobility of epididymal sperm followed at 0, 24, 48 and 72 h after collection, revealed significant (p0.001 according to time. Thus, concerning the sperm motility the values were 91.00±2.40%, 89.20±2.40%, 77.00±6.20% and 62.60±1.20% at 0, 24, 48 and 72 h, respectively. Indeed, in live sperm, the viability rates were 82.15±1.48%, 77.67±1.74%, 66.56±1.95% and 52.30±1.46 at 0, 24, 48 and 72 h, respectively. Conclusion: This study revealed that epididymal spermatozoa stored at 04°C for 72 h kept their mobility and vitality at nearly a half of their the original parameters.

Effect of Three Days Storage of Coated Spermatozoa at Cooling and Adding Seminal Plasma on Ram Fertility

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Alireza Vaferi

2016-08-01

Full Text Available Introduction Artificial insemination (AI has only been used as a supplement to natural mating. AI, when used in conjunction with accurate progeny testing schemes, can substantially increase the rate of genetic progress compared with that of natural service. Moreover, the use of AI causes the limitation of the transmitted diseases. Cervical insemination with frozen-thawed ram semen has not been widely adopted, probably because of the relative poor fertility obtained. Thus using fresh and diluted semen is only approach for performing AI. AI is currently limited by the poor fertility achieved after cervical insemination with the storage of liquid semen at sub-ambient temperature. The success of this procedure in sheep is restricted by the short length of time that ram sperm can be stored in a liquid state. Moreover, the effect of cooling on sperm differs depending on species. It is also well known that ram spermatozoa are more sensitive to cold-shock stress than those of other species. Seminal plasma, as physiological secretion, is a complex mixture of secretions originating from testis, epididymis and accessory sex glands which is mixed with epididymal sperm at ejaculation; it serves as the carrier of sperm to the female genital tract. This mixture contains numerous factors such as organic and nonorganic material which play an important role in the final maturation of the spermatozoa through hormonal, enzymatic and surface-modifying events. During natural mating, a mechanism may be activated to separate spermatozoa from seminal plasma. After being ejaculated into the vagina, sperm swim through cervical mucus and enter the uterus within minutes (>30 min; cervical mucus acts as a barrier for seminal plasma. In the artificial insemination industry, seminal plasma with all the useful and harmful components is not removed from semen and is in contact with sperm throughout cooling, freezing and storage. On the other hand, it was demonstrated that the

Radiation and shielding around beam absorbers

International Nuclear Information System (INIS)

Hurkmans, A.; Maas, R.

1978-12-01

During operational conditions it is anticipated that a fair amount of the total available beam power is dumped in either the slit system on one of the beam dumps. Thses beam absorbers therefore become strong radioactive sources. The radiation level due to the absorption of a 100 kW electron beam is estimated and the problem of residual activity is treated. Proposed shielding materials are discussed. (C.F.)

PLC based control system for RAM assembly test facility

International Nuclear Information System (INIS)

Kulkarni, S.S.; Kumar, Vinaya; Chandra, Umesh

1994-01-01

The flexibility, expandability, ease of programming and diagnostic features makes the programmable logic controller (PLC) suitable for a variety of control applications in engineering system test facilities. A PLC based control system for RAM assembly test facility (RATF) and for testing the related hydraulic components is being developed and installed at BARC. This paper describes the approach taken for meeting the control requirements and illustrates the PLC software that has been developed. (author). 1 fig

Heterogeneous neutron absorbers development

International Nuclear Information System (INIS)

Boccaccini, Aldo; Agueda, Horacio; Russo, Diego; Perez, Edmundo

1987-01-01

The use of solid burnable absorber materials in power light water reactors has increased in the last years, specially due to improvements attained in costs of generated electricity. The present work summarizes the basic studies made on an alumina-gadolinia system, where alumina is the inert matrix and gadolinia acts as burnable poison, and describes the fabrication method of pellets with that material. High density compacts were obtained in the range of concentrations used by cold pressing and sintering at 1600 deg C in inert (Ar) atmosphere. Finally, the results of the irradiation experiences made at RA-6 reactor, located at the Bariloche Atomic Center, are given where variations on negative reactivity caused by introduction of burnable poison rods were measured. The results obtained from these experiences are in good agreement with those coming from calculation codes. (Author)

Effect of Freezing on Spermatozoa from Tigaie Rams Belonging to the Mountain Ecotype

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Vasile Miclea

2011-05-01

Full Text Available Our aim was to study the influence of freezing on the viability and frequency of abnormalities in frozen ram spermatozoa. Sperm was collected form 20 rams belonging to the mountain ecotype of the Tigaie breed using the artificial vagina technique and volume and motility were assessed. Afterward it was diluted with Tryladil (1:4 supplemented with 20% egg yolk and heated at 37°C. Subsequently the temperature decreased at a rate of 0.2°C/minute until reaching 4°C and an equilibration time of 2 hours followed. During this time the diluted sperm was packaged in 0.25 ml straws. After sealing these were kept 6 cm above liquid nitrogen level for 13 minutes (- 120°C and then plunged into nitrogen. Volume, motility and concentration were assessed before freezing. After thawing sperm morphology was assessed using Hancock’s method and at the same time the endurance (at 10, 30 and 60 minutes and HOST tests were performed. The highest motility (0.40 was graded at 30 minutes. It could be correlated with the increased percentage of HOST positive spermatozoa, 27.78%. The percentage of abnormal spermatozoa was also high (47.89%, 38.44% of them having acrosome flaws. Cryopreservation has a negative effect on the characteristics of sperm cells from Tigaie rams belonging to the mountain ecotype.

A study of the switching mechanism and electrode material of fully CMOS compatible tungsten oxide ReRAM

Science.gov (United States)

Chien, W. C.; Chen, Y. C.; Lai, E. K.; Lee, F. M.; Lin, Y. Y.; Chuang, Alfred T. H.; Chang, K. P.; Yao, Y. D.; Chou, T. H.; Lin, H. M.; Lee, M. H.; Shih, Y. H.; Hsieh, K. Y.; Lu, Chih-Yuan

2011-03-01

Tungsten oxide (WO X ) resistive memory (ReRAM), a two-terminal CMOS compatible nonvolatile memory, has shown promise to surpass the existing flash memory in terms of scalability, switching speed, and potential for 3D stacking. The memory layer, WO X , can be easily fabricated by down-stream plasma oxidation (DSPO) or rapid thermal oxidation (RTO) of W plugs universally used in CMOS circuits. Results of conductive AFM (C-AFM) experiment suggest the switching mechanism is dominated by the REDOX (Reduction-oxidation) reaction—the creation of conducting filaments leads to a low resistance state and the rupturing of the filaments results in a high resistance state. Our experimental results show that the reactions happen at the TE/WO X interface. With this understanding in mind, we proposed two approaches to boost the memory performance: (i) using DSPO to treat the RTO WO X surface and (ii) using Pt TE, which forms a Schottky barrier with WO X . Both approaches, especially the latter, significantly reduce the forming current and enlarge the memory window.

Laser Beam Melting of Alumina: Effect of Absorber Additions

Science.gov (United States)

Moniz, Liliana; Colin, Christophe; Bartout, Jean-Dominique; Terki, Karim; Berger, Marie-Hélène

2018-03-01

Ceramic laser beam melting offers new manufacturing possibilities for complex refractory structures. Poor absorptivity in near infra-red wavelengths of oxide ceramics is overcome with absorber addition to ceramic powders. Absorbers affect powder bed densities and geometrical stability of melted tracks. Optimum absorber content is defined for Al2O3 by minimizing powder bed porosity, maximizing melting pool geometrical stability and limiting shrinkage. Widest stability fields are obtained with addition of 0.1 wt.% C and 0.5 wt.% β-SiC. Absorption coefficient values of Beer-Lambert law follow stability trends: they increase with C additions, whereas with β-SiC, a maximum is reached for 0.5 wt.%. Powder particle ejections are also identified. Compared to metallic materials, this ejection phenomenon can no longer be neglected when establishing a three-dimensional manufacturing strategy.

Performance of fast-absorbable suture and histo-glue in closing incisions in Brown trout

DEFF Research Database (Denmark)

Jepsen, Niels; Larsen, Martin Hage; Aarestrup, Kim

2017-01-01

, growth, tag expulsion rate and incision healing was compared among three groups of dummy transmitter-tagged wild brown trout Salmo trutta where incisions were closed with two types of suture material (absorbable vs. fast absorbable) and Histo-glue. The tagged fish were kept in semi-natural ponds for 20...

Experimental Results and Issues on Equalization for Nonlinear Memory Channel: Pre-Cursor Enhanced Ram-DFE Canceler

Science.gov (United States)

Yuan, Lu; LeBlanc, James

1998-01-01

This thesis investigates the effects of the High Power Amplifier (HPA) and the filters over a satellite or telemetry channel. The Volterra series expression is presented for the nonlinear channel with memory, and the algorithm is based on the finite-state machine model. A RAM-based algorithm operating on the receiver side, Pre-cursor Enhanced RAM-FSE Canceler (PERC) is developed. A high order modulation scheme , 16-QAM is used for simulation, the results show that PERC provides an efficient and reliable method to transmit data on the bandlimited nonlinear channel. The contribution of PERC algorithm is that it includes both pre-cursors and post-cursors as the RAM address lines, and suggests a new way to make decision on the pre-addresses. Compared with the RAM-DFE structure that only includes post- addresses, the BER versus Eb/NO performance of PERC is substantially enhanced. Experiments are performed for PERC algorithms with different parameters on AWGN channels, and the results are compared and analyzed. The investigation of this thesis includes software simulation and hardware verification. Hardware is setup to collect actual TWT data. Simulation on both the software-generated data and the real-world data are performed. Practical limitations are considered for the hardware collected data. Simulation results verified the reliability of the PERC algorithm. This work was conducted at NMSU in the Center for Space Telemetering and Telecommunications Systems in the Klipsch School of Electrical and Computer Engineering Department.

Is prnt a pseudogene? Identification of ram Prt in testis and ejaculated spermatozoa.

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Jorge Pimenta

Full Text Available A hallmark of prion diseases or transmissible spongiform encephalopaties is the conversion of the cellular prion protein (PrP(C, expressed by the prion gene (prnp, into an abnormally folded isoform (PrP(Sc with amyloid-like features that causes scrapie in sheep among other diseases. prnp together with prnd (which encodes a prion-like protein designated as Doppel, and prnt (that encodes the prion protein testis specific--Prt with sprn (shadow of prion protein gene, that encodes Shadoo or Sho genes, constitute the "prion gene complex". Whereas a role for prnd in the proper functioning of male reproductive system has been confirmed, the function of prnt, a recently discovered prion family gene, comprises a conundrum leading to the assumption that ruminant prnt is a pseudogene with no protein expression. The main objective of the present study was to identify Prt localization in the ram reproductive system and simultaneously to elucidate if ovine prnt gene is transcribed into protein-coding RNA. Moreover, as Prt is a prnp-related protein, the amyloid propensity was also tested for ovine and caprine Prt. Recombinant Prt was used to immunize BALB/c mice, and the anti-Prt polyclonal antibody (APPA immune response was evaluated by ELISA and Western Blot. When tested by indirect immunofluorescence, APPA showed high avidity to the ram sperm head apical ridge subdomain, before and after induced capacitation, but did not show the same behavior against goat spermatozoa, suggesting high antibody specificity against ovine-Prt. Prt was also found in the testis when assayed by immunohistochemistry during ram spermatogenesis, where spermatogonia, spermatocytes, spermatids and spermatozoa, stained positive. These observations strongly suggest ovine prnt to be a translated protein-coding gene, pointing to a role for Prt protein in the ram reproductive physiology. Besides, caprine Prt appears to exhibit a higher amyloid propensity than ovine Prt, mostly associated

Lightweight aluminum shock absorbers; Leichtbau-Stossdaempfer aus Aluminium

Energy Technology Data Exchange (ETDEWEB)

Kusche, R. [Serienentwicklung, ThyssenKrupp Bilstein GmbH, Ennepetal (Germany)

2004-12-01

One way in which the automotive industry is striving to reduce costs and environmental impact is by continuously lowering the fuel consumption of vehicles. To achieve this objective, lightweight materials are increasingly being used in automotive design. Increasing demands are also being made on shock absorber suppliers to reduce weight. (orig.)

The modification and application of RAMS computer code. Final report

International Nuclear Information System (INIS)

McKee, T.B.

1995-01-01

The Regional Atmospheric Modeling System (RAMS) has been utilized in its most updated form, version 3a, to simulate a case night from the Atmospheric Studies in COmplex Terrain (ASCOT) experimental program. ASCOT held a wintertime observational campaign during February, 1991 to observe the often strong drainage flows which form on the Great Plains and in the canyons embedded within the slope from the Continental Divide to the Great Plains. A high resolution (500 m grid spacing) simulation of the 4-5 February 1991 case night using the more advanced turbulence closure now available in RAMS 3a allowed greater analysis of the physical processes governing the drainage flows. It is found that shear interaction above and within the drainage flow are important, and are overpredicted with the new scheme at small grid spacing (< ∼1000 m). The implication is that contaminants trapped in nighttime stable flows such as these, will be mixed too strongly in the vertical reducing predicted ground concentrations. The HYPACT code has been added to the capability at LANL, although due to the reduced scope of work, no simulations with HYPACT were performed

Endocrine and Ovarian Changes in Response to the Ram Effect in Medroxyprogesterone Acetate-primed Corriedale Ewes During the Breeding and Nonbreeding Season

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Rubianes E

2005-03-01

Full Text Available Two experiments were performed to determine the endocrine and ovarian changes in medroxyprogesterone acetate (MAP-primed ewes after ram introduction. Experiment 1 was performed during the mid-breeding season with 71 ewes primed with an intravaginal MAP sponge for 12 days. While the control (C ewes (n = 35 were in permanent contact with rams, the ram effect (RE ewes (n = 36 were isolated for 34 days prior to contact with rams. At sponge withdrawal, all ewes were joined with eight sexually experienced marking Corriedale rams and estrus was recorded over the next 4 days. The ovaries were observed by laparoscopy 4–6 days after estrus. Four weeks later, pregnancy was determined by transrectal ultrasonography. In eight ewes from each group, ovaries were ultrasonographically scanned; FSH, LH, and estradiol-17β were measured every 12 hours until ovulation or 96 hours after estrus. The response to the rams was not affected by the fact that ewes had been kept or not in close contact with males before teasing. No differences were found in FSH, LH, estradiol-17β concentrations, growth of the ovulatory follicle, onset of estrus, ovulation rate, or pregnancy rate. Experiment 2 was performed with 14 ewes during the nonbreeding season. Ewes were isolated from rams for 1 month, and received a 6-day MAP priming. Ovaries were ultrasonographically scanned every 12 hours, and FSH, LH, estradiol-17β, and progesterone were measured. Ewes that ovulated and came into estrus had higher FSH and estradiol-17β levels before introduction of the rams than did ewes that had a silent ovulation. The endocrine pattern of the induced follicular phase of ewes that came into estrus was more similar to a normal follicular phase, than in ewes that had a silent ovulation. The follicle that finally ovulated tended to emerge earlier and in a more synchronized fashion in those ewes that did come into estrus. All ewes that ovulated had an LH surge and reached higher maximum FSH

Growth and Carcass Physical Components of Thin Tail Rams Fed on Different Levels of Rice Bran

OpenAIRE

Rianto, E; Lindasari, E; Purbowati, E

2006-01-01

This experiment was aimed to investigate the effect of rice bran supplementation on live weight gain (LWG), the proportion of carcass meat, bone and fat of Thin Tail Rams. Twelve thin tail rams, aged about 12 months, weighed 20.95 ± 1.52 kg (CV = 7.26%) were allocated into a Randomized Block Design with 2 blocks and 3 treatments. The treatments applied were levels of rice bran supplementation, i.e. Napier grass ad libitum without rice bran (T1), Napier grass ad libitum and 200 g rice bran (T2...

Recent developments in the applications of the Regional Atmospheric Modeling System (RAMS) for emergency response planning and operational forecasting at the Kennedy Space Center

International Nuclear Information System (INIS)

Lyons, W.A.; Tremback, C.J.

1996-01-01

The authors will summarize ten years of developing and applying the Regional Atmospheric Modeling System (RAMS) to emergency response and operational dispersion forecasting at the Kennedy Space Center (KSC). RAMS forms the core of two workstation-based operational systems, ERDAS (the Emergency Response Dose Assessment System) and PROWESS (Parallelized RAMS Operational Weather Simulation System) which are undergoing extensive operational testing prior to potential deployment as part of the range forecasting system at KSC. RAMS has been interfaced with HYPACT (the Hybrid Particle and Concentration Transport Model) to produce detailed 3-D dispersion forecasts from a variety of sources including cold spills, routine launch operations, and explosive conflagrations of launch vehicles