Structural Responses and Finite Element Modeling of Hakka Tulou Rammed Earth Structures

NASA Astrophysics Data System (ADS)

Sranislawski, Daniel

Hakka Tulous are rammed earth structures that have survived the effects of aging and natural elements upwards of even over a thousand years. These structures have housed the Hakka people of the Fujian Province, China in natural yet modern housing that has provided benefits over newer building materials. The key building material, rammed earth, which is used for the walls of the Hakka Tulou structures, has provided structural stability along with thermal comfort to the respective inhabitants of the Hakka Tulous. Through material testing and analysis this study has examined how the Tulou structures have maintained their structural stability while also providing thermal comfort. Reports of self healing cracks in the rammed earth walls were also analyzed for their validity in this study. The study has found that although the story of the self healing crack cannot be validated, there is reason to believe that with the existence of lime, some type of autogenous healing could occur on a small scale. The study has also found, through the use of nondestructive testing, that both the internal wooden systems (flooring, roof, and column support) and the rammed earth walls, are still structurally sound. Also, rammed earth's high thermal mass along with the use of sufficient shading has allowed for a delay release of heat energy from the walls of the Tulous, thus providing thermal comfort that can be felt during both night and day temperatures. The Hakka Tulou structures have been found to resist destruction from natural disasters such as strong earthquakes even when more modern construction has not. Through finite element modeling, this study has shown that the high volume of rammed earth used in the construction of the Hakka Tulous helps dissipate lateral force energy into much lower stresses for the rammed earth wall. This absorption of lateral force energy allows the rammed earth structures to survive even the strongest of earthquakes experienced in the region. The Hakka Tulou, if rated by the LEED green building certification program, would earn the highest certification as this rammed earth construction has offered efficient living for hundreds of years. As historic as these rammed earth structures are, they present an environmentally friendly option to structures of the future.

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

NASA Technical Reports Server (NTRS)

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.

Resistive Random Access Memory from Materials Development fnd Engineering to Novel Encryption and Neuromorphic Applications

NASA Astrophysics Data System (ADS)

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 layer, and an inert TiN top electrode. Linear sweep and controlled pulse (down to 5 ns) based electrical characterization of 1 transistor 1 ReRAM (1T1R) elements was performed to determine key properties including endurance, reliability, and threshold voltages. We demonstrated endurance values above 1010 cycles with an average on/off ratio of 10, and pulse voltages for set/reset operation of +/-1.5V. The on-chip 1T1R structures show an excellent controllability with respect to the low and high resistive states by manipulating the peak current from 75 up to 350 mu?A resulting in 10 distinct low resistance states (LRS). Our results demonstrate that the set operation (which shifts the ReRAM device from the high to the low resistance state) is only dependent on the voltage of the switching pulse and the peak current limit. The reset operation, however, occurs in an analog fashion and appears to be dependent on the total energy of the applied switching pulse. Pulse energy was modulated by varying the peak voltage resulting in a larger relative change of the ReRAM device resistance. The incremental resistance changes are ideally suited to emulate synaptic weights for future implementation into neuromorphic architectures. Switching results from these devices were also used to develop a model time-delay physical unclonable function (PUF) circuit, which showed excellent performance when compared to a pure CMOS implementation with significant improvements in uniqueness, size and accuracy.

The Evaluation of the Regional Atmospheric Modeling System in the Eastern Range Dispersion Assessment System

NASA Technical Reports Server (NTRS)

Case, Jonathan

2001-01-01

The Applied Meteorology Unit (AMU) evaluated the Regional Atmospheric Modeling System (RAMS) contained within the Eastern Range Dispersion Assessment System (ERDAS). ERDAS provides emergency response guidance for Cape Canaveral Air Force Station and Kennedy Space Center operations in the event of an accidental hazardous material release or aborted vehicle launch. The RAMS prognostic data are available to ERDAS for display and are used to initialize the 45th Space Wing/Range Safety dispersion model. Thus, the accuracy of the dispersion predictions is dependent upon the accuracy of RAMS forecasts. The RAMS evaluation consisted of an objective and subjective component for the 1999 and 2000 Florida warm seasons, and the 1999-2000 cool season. In the objective evaluation, the AMU generated model error statistics at surface and upper-level observational sites, compared RAMS errors to a coarser RAMS grid configuration, and benchmarked RAMS against the nationally-used Eta model. In the subjective evaluation, the AMU compared forecast cold fronts, low-level temperature inversions, and precipitation to observations during the 1999-2000 cool season, verified the development of the RAMS forecast east coast sea breeze during both warm seasons, and examined the RAMS daily thunderstorm initiation and precipitation patterns during the 2000 warm season. This report summarizes the objective and subjective verification for all three seasons.

Investigation of Hafnium oxide/Copper resistive memory for advanced encryption applications

NASA Astrophysics Data System (ADS)

Briggs, Benjamin D.

The Advanced Encryption Standard (AES) is a widely used encryption algorithm to protect data and communications in today's digital age. Modern AES CMOS implementations require large amounts of dedicated logic and must be tuned for either performance or power consumption. A high throughput, low power, and low die area AES implementation is required in the growing mobile sector. An emerging non-volatile memory device known as resistive memory (ReRAM) is a simple metal-insulator-metal capacitor device structure with the ability to switch between two stable resistance states. Currently, ReRAM is targeted as a non-volatile memory replacement technology to eventually replace flash. Its advantages over flash include ease of fabrication, speed, and lower power consumption. In addition to memory, ReRAM can also be used in advanced logic implementations given its purely resistive behavior. The combination of a new non-volatile memory element ReRAM along with high performance, low power CMOS opens new avenues for logic implementations. This dissertation will cover the design and process implementation of a ReRAM-CMOS hybrid circuit, built using IBM's 10LPe process, for the improvement of hardware AES implementations. Further the device characteristics of ReRAM, specifically the HfO2/Cu memory system, and mechanisms for operation are not fully correlated. Of particular interest to this work is the role of material properties such as the stoichiometry, crystallinity, and doping of the HfO2 layer and their effect on the switching characteristics of resistive memory. Material properties were varied by a combination of atomic layer deposition and reactive sputtering of the HfO2 layer. Several studies will be discussed on how the above mentioned material properties influence switching parameters, and change the underlying physics of device operation.

Safe transport of radioactive materials in Egypt

NASA Astrophysics Data System (ADS)

El-Shinawy, Rifaat M. K.

1994-07-01

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 to 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

Atomistic mechanisms of ReRAM cell operation and reliability

NASA Astrophysics Data System (ADS)

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.

Evaluation of the Regional Atmospheric Modeling System in the Eastern Range Dispersion Assessment System

NASA Technical Reports Server (NTRS)

Case, Jonathan

2000-01-01

The Applied Meteorology Unit is conducting an evaluation of the Regional Atmospheric Modeling System (RAMS) contained within the Eastern Range Dispersion Assessment System (ERDAS). ERDAS provides emergency response guidance for operations at the Cape Canaveral Air Force Station and the Kennedy Space Center in the event of an accidental hazardous material release or aborted vehicle launch. The prognostic data from RAMS is available to ERDAS for display and is used to initialize the 45th Range Safety (45 SW/SE) dispersion model. Thus, the accuracy of the 45 SW/SE dispersion model is dependent upon the accuracy of RAMS forecasts. The RAMS evaluation task consists of an objective and subjective component for the Florida warm and cool seasons of 1999-2000. The objective evaluation includes gridded and point error statistics at surface and upper-level observational sites, a comparison of the model errors to a coarser grid configuration of RAMS, and a benchmark of RAMS against the widely accepted Eta model. The warm-season subjective evaluation involves a verification of the onset and movement of the Florida east coast sea breeze and RAMS forecast precipitation. This interim report provides a summary of the RAMS objective and subjective evaluation for the 1999 Florida warm season only.

Metal flow and temperature in direct extrusion of large-size aluminum billets

NASA Astrophysics Data System (ADS)

Valberg, Henry; Costa, André L. M.

2018-05-01

FEM-analysis is used to study thermo-mechanical conditions in aluminum rod extrusion for billets with large size corresponding to that used in industrial production. In the analysis, focus is on how the metal flow and the temperature conditions in the extrusion material is affected by the extrusion velocity in terms of the ram speed used in the extrusion process. In the study, metal flow is characterized by the deformations in extrusion subjected to a perfect grid pattern, consisting of orthogonal crossing lines, added into the longitudinal mid-plane of the initial billet. The analysis shows that metal flow in extrusion conducted at a low ram speed of 1 mms-1, is predicted significantly different from that at a high speed of 5 mms-1, or above. As regards the thermal conditions in the extrusion material, they are also predicted significantly different, at the low and the high ram speed level. A likely explanation why metal flow is different at low and high ram speeds may be that flow is altered because of the concurrent change in the temperature field within the billet.

Body Composition of Lambs and Rams Fed Complete Feed

NASA Astrophysics Data System (ADS)

Rahmawati, F.; Rianto, E.

2018-02-01

This study was aimed to investigate the proportion of body water, protein and fat of lambs and rams. The material used in this study were 6 lambs (weighed of 15.92 kg), and 6 rams (weighed 23.31 kg). The sheep were fed a complete feed. In weeks 1, 5 and 9, the body composition (water, protein and body fat) was measured using the “urea space” method. The results showed that the proportion of water, protein and fat in the body of lambs and sheep differed significantly (P <0.01). The proportion of lambs’ body water in weeks 1, 5 and 9 were 58.71, 58.43 and 58.43%, respectively; while thoset of the rams were 58.40, 58.14% and 58.14%, respectively. The proportion of body protein of lambs in weeks 1, 5 and 9 were 11.84, 11.94 and 11.99%, respectively; while those of rams were 13.01; 13.01 and 13.03%, respectively. The proportion of body fat of lambs in weeks 1, 5 and 9 were 20.51, 20.87 and 20.87%, respectively; while those of rams were 20.9, 21.26 and 21.25%, respectively. Body water of lambs and rams week decreased from week 1 to 9. On the other hand, the proportion of body protein and fat increased. It is concluded that the proportion of body water was higher while the proportions of body protein and fat were lower in lambs as compared with those in rams.

Ball-free mechanochemistry: in situ real-time monitoring of pharmaceutical co-crystal formation by resonant acoustic mixing.

PubMed

Michalchuk, Adam A L; Hope, Karl S; Kennedy, Stuart R; Blanco, Maria V; Boldyreva, Elena V; Pulham, Colin R

2018-04-17

Resonant acoustic mixing (RAM) is a new technology designed for intensive mixing of powders that offers the capability to process powders with minimal damage to particles. This feature is particularly important for mixing impact-sensitive materials such as explosives and propellants. While the RAM technique has been extensively employed for the mixing of powders and viscous polymers, comparatively little is known about its use for mechanosynthesis. We present here the first in situ study of RAM-induced co-crystallisation monitored using synchrotron X-ray powder diffraction. The phase profile of the reaction between nicotinamide and carbamazepine in the presence of a small amount of water was monitored at two different relative accelerations of the mixer. In marked contrast to ball-milling techniques, the lack of milling bodies in the RAM experiment does not hinder co-crystallisation of the two starting materials, which occurred readily and was independent of the frequency of oscillation. The reaction could be optimised by enhancing the number of reactive contacts through mixing and comminution. These observations provide new insight into the role of various experimental parameters in conventional mechanochemistry using liquid-assisted grinding techniques.

Large-scale synthesis and microwave absorption enhancement of actinomorphic tubular ZnO/CoFe2O4 nanocomposites.

PubMed

Cao, Jing; Fu, Wuyou; Yang, Haibin; Yu, Qingjiang; Zhang, Yanyan; Liu, Shikai; Sun, Peng; Zhou, Xiaoming; Leng, Yan; Wang, Shuangming; Liu, Bingbing; Zou, Guangtian

2009-04-09

Actinomorphic tubular ZnO/CoFe(2)O(4) nanocomposites were fabricated in large scale via a simple solution method at low temperature. The phase structures, morphologies, particle size, shell thickness, chemical compositions of the composites have been characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDS), and transmission electron microscopy (TEM). The as-synthesized nanocomposites were uniformly dispersed into the phenolic resin then the mixture was pasted on metal plate with the area of 200 mm x 200 mm as the microwave absorption test plate. The test of microwave absorption was carried out by the radar-absorbing materials (RAM) reflectivity far field radar cross-section (RCS) method. The range of microwave absorption is from 2 to 18 Hz and the best microwave absorption reach to 28.2 dB at 8.5 Hz. The results indicate that the composites are of excellence with respect to microwave absorption.

Preparation and characterization of Ba0.2Sr0.2La0.6MnO3 nanoparticles and investigation of size & shape effect on microwave absorption

NASA Astrophysics Data System (ADS)

Peymanfar, Reza; Javanshir, Shahrzad

2017-06-01

In this paper, the design and characterization of a radar absorbing material (RAM) was investigated at microwave frequency. Ba0.2Sr0.2La0.6MnO3 magnetic nanoparticles was synthesized thru a facile hydrothermal method in the presence of polymethyl methacrylate (PMMA) and the possibility of shape and size-controlled synthesis of nanoparticles (NPs) over the range 15-50 Nm was also explored. Afterward, the effect of shape and size of the synthesized Ba0.2Sr0.2La0.6MnO3 NPs on microwave absorption properties was investigated in KU-band. The crystal structures and morphology of as-synthesized nanoparticles were characterized and confirmed by FESEM, XRD, VSM, FTIR analysis. The RAM samples were prepared by dispersion of magnetic NPs in silicone rubber in an ultrasonic bath. The maximum reflection loss (RL) values NPs were 12.04 dB at 14.82 GHz and a broad absorption band (over 1.22 GHz) with RL values <-10 dB are obtained and the maximum reflection loss (RL) values of decrease and shaped NPs were 22.36 dB at 14.78 GHz and a broad absorption band (over 2.67 GHz) with RL values <-10 dB are obtained. The results indicated that the particle size and shape play a major role on the absorption properties of the composites in the 12.4-18 GHz frequency range. It is observed that microwave absorption properties increased with the decrease in average particle size of NPs.

RECERTIFICATION OF THE MODEL 9977 RADIOACTIVE MATERIAL PACKAGING

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abramczyk, G.; Bellamy, S.; Loftin, B.

2013-06-05

The Model 9977 Packaging was initially issued a Certificate of Compliance (CoC) by the Department of Energy’s Office of Environmental Management (DOE-EM) for the transportation of radioactive material (RAM) in the Fall of 2007. This first CoC was for a single radioactive material and two packing configurations. In the five years since that time, seven Addendums have been written to the Safety Analysis Report for Packaging (SARP) and five Letter Amendments have been written that have authorized either new RAM contents or packing configurations, or both. This paper will discuss the process of updating the 9977 SARP to include allmore » the contents and configurations, including the addition of a new content, and its submittal for recertification.« less

Electromagnetic, morphological and structural characterization of microwave absorbers based on POMA/magnetic filament composites

NASA Astrophysics Data System (ADS)

de Souza Pinto, Simone; Machado, João Paulo Barros; Gomes, Newton A. S.; Rezende, Mirabel Cerqueira

2018-03-01

This study aims to combine dielectric and magnetic properties of different materials in an unique composite. For this, poly(o-methoxyaniline), POMA, was chemically synthesized in situ on magnetic metallic filaments (MF). The obtained composite was inserted into an epoxy resin matrix in the proportions of 40, 50 and 70%, in weight (wt%). The samples were characterized by scanning electron microscopy (SEM), X ray diffraction (XRD) and electromagnetic measurements. On the last case, the measurements considered the reflectivity and the complex parameters of electrical permittivity and magnetic permeability in the frequency range of 8.2-12.4 GHz (X-band). Specimens with different thicknesses were evaluated by reflectivity. XRD results show that the filaments are based on Fe-α steel and SEM analyses show the good incorporation of POMA/MF in the epoxy resin composite. The complex parameters show that the real component of permittivity shows the largest variation with the POMA/MF concentration increasing in epoxy resin and the loss tangent indicates that the magnetic losses are preponderant on dielectric ones. The reflectivity measurements show that the 5 mm-specimen with 50 wt% of POMA/MF presents the best result of attenuation (-21.5 dB, i.e. above 99% of attenuation). Already, the sample containing 70 wt% shows the worst performance (up to -9.0 dB). The increase of POMA/MF concentration in epoxy resin confers maximum attenuation values for less thick specimens. The results show that the combination of dielectric and magnetic materials in a composite contributes for the improvement of microwave absorbing performance, and extends the possibilities of RAM processing with different characteristics.

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

NASA Astrophysics Data System (ADS)

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.

Romanian Experience for Enhancing Safety and Security in Transport of Radioactive Material - 12223

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vieru, Gheorghe

2012-07-01

The transport of Dangerous Goods-Class no.7 Radioactive Material (RAM), is an important part of the Romanian Radioactive Material Management. The overall aim of this activity is for enhancing operational safety and security measures during the transport of the radioactive materials, in order to ensure the protection of the people and the environment. The paper will present an overall of the safety and security measures recommended and implemented during transportation of RAM in Romania. Some aspects on the potential threat environment will be also approached with special referring to the low level radioactive material (waste) and NORM transportation either by roadmore » or by rail. A special attention is given to the assessment and evaluation of the possible radiological consequences due to RAM transportation. The paper is a part of the IAEA's Vienna Scientific Research Contract on the State Management of Nuclear Security Regime (Framework) concluded with the Institute for Nuclear Research, Romania, where the author is the CSI (Chief Scientific Investigator). The transport of RAM in Romania is a very sensible and complex problem taking into consideration the importance and the need of the security and safety for such activities. The Romanian Nuclear Regulatory Body set up strictly regulation and procedures according to the Recommendation of the IAEA Vienna and other international organizations. There were implemented the adequate regulation and procedures in order to keep the environmental impacts and the radiological consequences at the lower possible level and to assure the effectiveness of state nuclear security regime due to possible malicious acts in carrying out these activities including transport and the disposal site at the acceptable international levels. The levels of the estimated doses and risk expectation values for transport and disposal are within the acceptable limits provided by national and international regulations and recommendations but can increase, significantly during potential malicious acts. (authors)« less

Method and apparatus for selectively annealing heterostructures using microwave

NASA Technical Reports Server (NTRS)

Atwater, Harry A. (Inventor); Brain, Ruth A. (Inventor); Barmatz, Martin B. (Inventor)

1998-01-01

The present invention discloses a process for selectively annealing heterostructures using microwaves. A heterostructure, comprised of a material having higher microwave absorption and a material having lower microwave absorption, is exposed to microwaves in the cavity. The higher microwave absorbing material absorbs the microwaves and selectively heats while the lower microwave absorbing material absorbs small amounts of microwaves and minimally heats. The higher microwave absorbing material is thereby annealed onto the less absorbing material which is thermally isolated.

Method and apparatus for selectively annealing heterostructures using microwaves

NASA Technical Reports Server (NTRS)

Atwater, Harry A. (Inventor); Brain, Ruth A. (Inventor); Barmatz, Martin B. (Inventor)

1998-01-01

The present invention discloses a process for selectively annealing heterostructures using microwaves. A heterostructure, comprised of a material having higher microwave absorption and a material having lower microwave absorption, is exposed to microwaves in the cavity. The higher microwave absorbing material absorbs the microwaves and selectively heats while the lower microwave absorbing material absorbs small amounts of microwaves and minimally heats. The higher microwave absorbing material is thereby annealed onto the less absorbing material which is thermally isolated.

Corrosion resistant neutron absorbing coatings

DOEpatents

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.

Corrosion resistant neutron absorbing coatings

DOEpatents

Choi, Jor-Shan; Farmer, Joseph C; Lee, Chuck K; Walker, Jeffrey; Russell, Paige; Kirkwood, Jon; Yang, Nancy; Champagne, Victor

2013-11-12

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.

Protection of Grain Products from Sitophilus oryzae (L.) Contamination by Anti-Insect Pest Repellent Sachet Containing Allyl Mercaptan Microcapsule.

PubMed

Chang, Yoonjee; Lee, Soo-Hyun; Na, Ja Hyun; Chang, Pahn-Shick; Han, Jaejoon

2017-11-01

The purpose of this study was to develop an anti-insect pest repellent sachet to prevent Sitophilus oryzae (L.) (Coleoptera: Curculionidae) contamination in grain packaging. The anti-insect pest activities of essential oils (EOs) from garlic (Allium Sativum), ginger (Zingiber Officinalis), black pepper (Piper nigrum), onion (Allium cepa), and fennel (Foeniculum vulgare) as well as major compounds (allyl disulfide, AD; allyl mercaptan, AM) isolated from of garlic and onion (AD and AM) were measured against S. oryzae. The results revealed that garlic EO, onion EO, AD, and AM showed strong fumigant insecticidal activities. Among these, AM showed the highest acetylcholinesterase (AChE) inhibition rate, indicating that the fumigation insecticidal efficacy of AM is related with its AChE inhibition ability. Subsequently, the microcapsules were produced with a high efficiency (80.02%) by using AM as a core material and rice flour as a wall material. Finally, sachet composed of rice flour microcapsule containing 2% AM (RAM) was produced. Repellent assay was performed to measure anti-insect pest ability of the RAM sachet, showed remarkable repelling effect within 48 h both in the presence or absence of attractant. In a release profile of RAM sachet, it was expected to last over 20 mo during the distribution period of brown rice. Moreover, RAM sachet showed no undesirable changes to the sensory properties of the rice both before and after cooking. Taken together, these results suggest that the newly developed RAM sachet could be used as a packaging material to protect grain products from S. oryzae contamination. The rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae), causes damages to stored products and its contamination in grain products has become a major problem in cereal market. To preserve brown rice, an anti-insect pest repellent sachet containing 2% allyl mercaptan was newly developed and it showed remarkable repellent abilities against S. oryzae. It could be used as an active food packaging system to protect grain products from insect pest contamination. © 2017 Institute of Food Technologists®.

USING A RISK-BASED METHODOLOGY FOR THE TRANSFER OF RADIOACTIVE MATERIAL WITHIN THE SAVANNAH RIVER SITE BOUNDARY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loftin, B; Watkins, R; Loibl, M

2010-06-03

Shipment of radioactive materials (RAM) is discussed in the Code of Federal Regulations in parts of both 49 CFR and 10 CFR. The regulations provide the requirements and rules necessary for the safe shipment of RAM across public highways, railways, waterways, and through the air. These shipments are sometimes referred to as in-commerce shipments. Shipments of RAM entirely within the boundaries of Department of Energy sites, such as the Savannah River Site (SRS), can be made using methodology allowing provisions to maintain equivalent safety while deviating from the regulations for in-commerce shipments. These onsite shipments are known as transfers atmore » the SRS. These transfers must follow the requirements approved in a site-specific Transportation Safety Document (TSD). The TSD defines how the site will transfer materials so that they have equivalence to the regulations. These equivalences are documented in an Onsite Safety Assessment (OSA). The OSA can show how a particular packaging used onsite is equivalent to that which would be used for an in-commerce shipment. This is known as a deterministic approach. However, when a deterministic approach is not viable, the TSD allows for a risk-based OSA to be written. These risk-based assessments show that if a packaging does not provide the necessary safety to ensure that materials are not released (during normal or accident conditions) then the worst-case release of materials does not result in a dose consequence worse than that defined for the SRS. This paper will discuss recent challenges and successes using this methodology at the SRS.« less

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

DOEpatents

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.

Solar energy collector

DOEpatents

Brin, Raymond L.; Pace, Thomas L.

1978-01-01

The invention relates to a solar energy collector comprising solar energy absorbing material within chamber having a transparent wall, solar energy being transmitted through the transparent wall, and efficiently absorbed by the absorbing material, for transfer to a heat transfer fluid. The solar energy absorbing material, of generally foraminous nature, absorbs and transmits the solar energy with improved efficiency.

Analysis of ramming settlement based on dissipative principle

NASA Astrophysics Data System (ADS)

Fu, Hao; Yu, Kaining; Chen, Changli; Li, Changrong; Wang, Xiuli

2018-03-01

The deformation of soil is a kind of dissipative structure under the action of dynamic compaction. The macroscopic performance of soil to steady state evolution is the change of ramming settlement in the process of dynamic compaction. based on the existing solution of dynamic compaction boundary problem, calculated ramming effectiveness (W) and ramming efficiency coefficient( η ). For the same soil, ramming efficiency coefficient is related to ramming factor λ = M/ρr3. By using the dissipative principle to analyze the law between ramming settlements and ramming times under different ramming energy and soil density, come to the conclusion that: Firstly, with the increase of ramming numbers, ramming settlement tends to a stable value, ramming effectiveness coefficient tends to a stable value. Secondly, under the condition of the same single ramming energy, the soil density of before ramming has effect on ramming effectiveness of previous ramming, almost no effect on ramming effectiveness of subsequent ramming. Thirdly, under the condition of the same soil density, different ramming energy correspond to different steady-state, the cumulative ramming settlement and steady-state increase with ramming energy.

Impact of Linearity and Write Noise of Analog Resistive Memory Devices in a Neural Algorithm Accelerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacobs-Gedrim, Robin B.; Agarwal, Sapan; Knisely, Kathrine E.

Resistive memory (ReRAM) shows promise for use as an analog synapse element in energy-efficient neural network algorithm accelerators. A particularly important application is the training of neural networks, as this is the most computationally-intensive procedure in using a neural algorithm. However, training a network with analog ReRAM synapses can significantly reduce the accuracy at the algorithm level. In order to assess this degradation, analog properties of ReRAM devices were measured and hand-written digit recognition accuracy was modeled for the training using backpropagation. Bipolar filamentary devices utilizing three material systems were measured and compared: one oxygen vacancy system, Ta-TaO x, andmore » two conducting metallization systems, Cu-SiO 2, and Ag/chalcogenide. Analog properties and conductance ranges of the devices are optimized by measuring the response to varying voltage pulse characteristics. Key analog device properties which degrade the accuracy are update linearity and write noise. Write noise may improve as a function of device manufacturing maturity, but write nonlinearity appears relatively consistent among the different device material systems and is found to be the most significant factor affecting accuracy. As a result, this suggests that new materials and/or fundamentally different resistive switching mechanisms may be required to improve device linearity and achieve higher algorithm training accuracy.« less

Impact of Linearity and Write Noise of Analog Resistive Memory Devices in a Neural Algorithm Accelerator

DOE PAGES

Jacobs-Gedrim, Robin B.; Agarwal, Sapan; Knisely, Kathrine E.; ...

2017-12-01

Resistive memory (ReRAM) shows promise for use as an analog synapse element in energy-efficient neural network algorithm accelerators. A particularly important application is the training of neural networks, as this is the most computationally-intensive procedure in using a neural algorithm. However, training a network with analog ReRAM synapses can significantly reduce the accuracy at the algorithm level. In order to assess this degradation, analog properties of ReRAM devices were measured and hand-written digit recognition accuracy was modeled for the training using backpropagation. Bipolar filamentary devices utilizing three material systems were measured and compared: one oxygen vacancy system, Ta-TaO x, andmore » two conducting metallization systems, Cu-SiO 2, and Ag/chalcogenide. Analog properties and conductance ranges of the devices are optimized by measuring the response to varying voltage pulse characteristics. Key analog device properties which degrade the accuracy are update linearity and write noise. Write noise may improve as a function of device manufacturing maturity, but write nonlinearity appears relatively consistent among the different device material systems and is found to be the most significant factor affecting accuracy. As a result, this suggests that new materials and/or fundamentally different resistive switching mechanisms may be required to improve device linearity and achieve higher algorithm training accuracy.« less

A Procedure to Measure the in-Situ Hygrothermal Behavior of Earth Walls

PubMed Central

Chabriac, Pierre-Antoine; Fabbri, Antonin; Morel, Jean-Claude; Laurent, Jean-Paul; Blanc-Gonnet, Joachim

2014-01-01

Rammed earth is a sustainable material with low embodied energy. However, its development as a building material requires a better evaluation of its moisture-thermal buffering abilities and its mechanical behavior. Both of these properties are known to strongly depend on the amount of water contained in wall pores and its evolution. Thus the aim of this paper is to present a procedure to measure this key parameter in rammed earth or cob walls by using two types of probes operating on the Time Domain Reflectometry (TDR) principle. A calibration procedure for the probes requiring solely four parameters is described. This calibration procedure is then used to monitor the hygrothermal behavior of a rammed earth wall (1.5 m × 1 m × 0.5 m), instrumented by six probes during its manufacture, and submitted to insulated, natural convection and forced convection conditions. These measurements underline the robustness of the calibration procedure over a large range of water content, even if the wall is submitted to quite important temperature variations. They also emphasize the importance of gravity on water content heterogeneity when the saturation is high, as well as the role of liquid-to-vapor phase change on the thermal behavior. PMID:28788603

COMPOSITE CONTROL ROD

DOEpatents

Rock, H.R.

1963-12-24

A composite control rod for use in controlling a nuclear reactor is described. The control rod is of sandwich construction in which finned dowel pins are utilized to hold together sheets of the neutron absorbing material and nonabsorbing structural material thereby eliminating the need for being dependent on the absorbing material for structural support. The dowel pins perform the function of absorbing the forces due to differential thermal expansion, seating further with the fins into the sheets of material and crushing before damage is done either to the absorbing or non-absorbing material. (AEC)

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

NASA Astrophysics Data System (ADS)

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.

Welding/sealing glass-enclosed space in a vacuum

DOEpatents

Tracy, C.E.; Benson, D.K.

1996-02-06

A method of welding and sealing the edges of two juxtaposed glass sheets together to seal a vacuum space between the sheets comprises the steps of positioning a radiation absorbent material, such as FeO, VO{sub 2}, or NiO, between the radiation transmissive glass sheets adjacent the edges and then irradiating the absorbent material, preferably with a laser beam, through at least one of the glass sheets. Heat produced by the absorbed radiation in the absorbent material melts glass in the portions of both glass sheets that are adjacent the absorbent material, and the melted glass from both sheets flows together to create the weld when the melted glass cools and hardens. The absorbent material can be dissolved and diffused into the melted glass to the extent that it no longer absorbs enough energy to keep the glass melted, thus, with appropriate proportioning of absorbent material to source energy power and welding heat needed, the process can be made self-stopping. 8 figs.

Welding/sealing glass-enclosed space in a vacuum

DOEpatents

Tracy, C. Edwin; Benson, David K.

1996-01-01

A method of welding and sealing the edges of two juxtaposed glass sheets together to seal a vacuum space between the sheets comprises the steps of positioning a radiation absorbant material, such as FeO, VO.sub.2, or NiO, between the radiation transmissive glass sheets adjacent the edges and then irradiating the absorbant material, preferably with a laser beam, through at least one of the glass sheets. Heat produced by the absorbed radiation in the absorbant material melts glass in the portions of both glass sheets that are adjacent the absorbant material, and the melted glass from both sheets flows together to create the weld when the melted glass cools and hardens. The absorbant material can be dissolved and diffused into the melted glass to the extent that it no longer absorbs enough energy to keep the glass melted, thus, with appropriate proportioning of absorbant material to source energy power and welding heat needed, the process can be made self-stopping.

Liftoff process for exfoliation of thin film photovoltaic devices and back contact formation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haight, Richard A.; Hannon, James B.; Oida, Satoshi

A method for forming a back contact on an absorber layer in a photovoltaic device includes forming a two dimensional material on a first substrate. An absorber layer including Cu--Zn--Sn--S(Se) (CZTSSe) is grown over the first substrate on the two dimensional material. A buffer layer is grown on the absorber layer on a side opposite the two dimensional material. The absorber layer is exfoliated from the two dimensional material to remove the first substrate from a backside of the absorber layer opposite the buffer layer. A back contact is deposited on the absorber layer.

First Exploratory Study on the Ageing of Rammed Earth Material

PubMed Central

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

First Exploratory Study on the Ageing of Rammed Earth Material.

PubMed

Bui, Quoc-Bao; Morel, Jean-Claude

2014-12-23

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.

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

NASA Astrophysics Data System (ADS)

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.

Etude par elements finis du comportement thermo-chimiomecanique de la pâte monolithique

NASA Astrophysics Data System (ADS)

Girard, Pierre-Luc

Aluminum industry is in a fierce international competition requiring the constant improvement of the electrolysis cell effectiveness and longevity. The selection of the cell's materials components becomes an important factor to increase the cell's life. The ramming paste, used to seal the cathode lining, is compacted in the joints between the cathode and the side wall of the cell. It is a complex thermo-chemo-reactive material whose proprieties change with the evolution of his baking level. Therefore, the objective of this project is to propose a thermo-chemo-mechanical constitutive law for the ramming paste and implement it in the finite element software ANSYSRTM. A constitutive model was first chosen from the available literature on the subject. It is a pressure dependent model that uses hardening, softening and baking mechanisms in its definition to mimic the behavior of carbon-based materials. Subsequently, the numerical tool was validated using the finite element toolbox FESh++, which contains the most representative carbon-based thermochimio- mechanical material constitutive law at this time. Finally, a validation of the experimental setup BERTA (Banc d'essai de resistance thermomecanique ALCAN) was made in prevision of a larger scale experimental validation of the constitutive law in a near future. However, the analysis of the results shows that BERTA is not suited to adequately measure the mechanical deformation of such kind of material. Following this project, the numerical tool will be used in numerical simulation to introduce the various effects of the baking of the ramming paste during the cell startup. This new tool will help the industrial partner to enhance the understanding of Hall-Heroult cell start-up and optimize this critical step.

Selective molecularly imprinted polymer combined with restricted access material for in-tube SPME/UHPLC-MS/MS of parabens in breast milk samples.

PubMed

Souza, Israel D; Melo, Lidervan P; Jardim, Isabel C S F; Monteiro, Juliana C S; Nakano, Ana Marcia S; Queiroz, Maria Eugênia C

2016-08-17

A new molecularly imprinted polymer modified with restricted access material (a hydrophilic external layer), (MIP-RAM) was synthesized via polymerization in situ in an open fused silica capillary. This stationary phase was used as sorbent for in-tube solid phase microextraction (in-tube SPME) to determine parabens in breast milk samples by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Scanning electron micrographs (SEM) illustrate MIP surface modification after glycerol dimethacrylate (hydrophilic monomer) incorporation. The interaction between parabens and MIP-RAM was investigated by Fourier-transform infrared (FTIR) spectroscopy. The Scatchard plot for MIP-RAM presented two linear parts with different slopes, illustrating binding sites with high- and low-affinity. Endogenous compounds exclusion from the MIP-RAM capillary was demonstrated by in-tube SPME/LC-UV assays carried out with blank milk samples. The in-tube SPME/UHPLC-MS/MS method presented linear range from 10 ng mL(-1) (LLOQ) to 400 ng mL(-1) with coefficients of determination higher than 0.99, inter-assay precision with coefficient of variation (CV) values ranging from 2 to 15%, and inter-assay accuracy with relative standard deviation (RSD) values ranging from -1% to 19%. Analytical validation parameters attested that in-tube SPME/UHPLC-MS/MS is an appropriate method to determine parabens in human milk samples to assess human exposure to these compounds. Analysis of breast milk samples from lactating women demonstrated that the proposed method is effective. Copyright © 2016 Elsevier B.V. All rights reserved.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheen, Yun-Kyeong; Kim, Minjin; Smith, Rory

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 gasmore » 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.« less

Ram-pressure feeding of supermassive black holes.

PubMed

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.

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

NASA Astrophysics Data System (ADS)

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

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.

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

NASA Astrophysics Data System (ADS)

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.

Ram-pressure feeding of supermassive black holes

NASA Astrophysics Data System (ADS)

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

2017-08-01

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.

Integration of SrBi2Ta2O9 thin films for high density ferroelectric random access memory

NASA Astrophysics Data System (ADS)

Wouters, D. J.; Maes, D.; Goux, L.; Lisoni, J. G.; Paraschiv, V.; Johnson, J. A.; Schwitters, M.; Everaert, J.-L.; Boullart, W.; Schaekers, M.; Willegems, M.; Vander Meeren, H.; Haspeslagh, L.; Artoni, C.; Caputa, C.; Casella, P.; Corallo, G.; Russo, G.; Zambrano, R.; Monchoix, H.; Vecchio, G.; Van Autryve, L.

2006-09-01

Ferroelectric random access memory (FeRAM) is an attractive candidate technology for embedded nonvolatile memory, especially in applications where low power and high program speed are important. Market introduction of high-density FeRAM is, however, lagging behind standard complementary metal-oxide semiconductor (CMOS) because of the difficult integration technology. This paper discusses the major integration issues for high-density FeRAM, based on SrBi2Ta2O9 (strontium bismuth tantalate or SBT), in relation to the fabrication of our stacked cell structure. We have worked in the previous years on the development of SBT-FeRAM integration technology, based on a so-called pseudo-three-dimensional (3D) cell, with a capacitor that can be scaled from quasi two-dimensional towards a true three-dimensional capacitor where the sidewalls will importantly contribute to the signal. In the first phase of our integration development, we integrated our FeRAM cell in a 0.35μm CMOS technology. In a second phase, then, possibility of scaling of our cell is demonstrated in 0.18μm technology. The excellent electrical and reliability properties of the small integrated ferroelectric capacitors prove the feasibility of the technology, while the verification of the potential 3D effect confirms the basic scaling potential of our concept beyond that of the single-mask capacitor. The paper outlines the different material and technological challenges, and working solutions are demonstrated. While some issues are specific to our own cell, many are applicable to different stacked FeRAM cell concepts, or will become more general concerns when more developments are moving into 3D structures.

50 CFR 660.15 - Equipment requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... water, slime, mud, debris, or other materials. Scale printouts must show: (A) The vessel name and...; (ii) Random Access Memory (RAM): 256 megabytes (MB) or higher; (iii) Hard disk space: (A) If already...

50 CFR 660.15 - Equipment requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... water, slime, mud, debris, or other materials. Scale printouts must show: (A) The vessel name and...; (ii) Random Access Memory (RAM): 256 megabytes (MB) or higher; (iii) Hard disk space: (A) If already...

50 CFR 660.15 - Equipment requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... water, slime, mud, debris, or other materials. Scale printouts must show: (A) The vessel name and...; (ii) Random Access Memory (RAM): 256 megabytes (MB) or higher; (iii) Hard disk space: (A) If already...

Advanced neutron absorber materials

DOEpatents

Branagan, Daniel J.; Smolik, Galen R.

2000-01-01

A neutron absorbing material and method utilizing rare earth elements such as gadolinium, europium and samarium to form metallic glasses and/or noble base nano/microcrystalline materials, the neutron absorbing material having a combination of superior neutron capture cross sections coupled with enhanced resistance to corrosion, oxidation and leaching.

Research and Applications Modules (RAM), phase B study

NASA Technical Reports Server (NTRS)

1972-01-01

The research and applications modules (RAM) system is discussed. The RAM is a family of payload carrier modules that can be delivered to and retrieved from earth orbit by the space shuttle. The RAM's capability for implementing a wide range of manned and man-tended missions is described. The rams have evolved into three types; (1) pressurized RAMs, (2) unpressurized RAMs, and (3) pressurizable free-flying RAMs. A reference experiment plan for use as a baseline in the derivation and planning of the RAM project is reported. The plan describes the number and frequency of shuttle flights dedicated to RAM missions and the RAM payloads for the identified flights.

77 FR 22504 - Hazardous Materials; Packages Intended for Transport by Aircraft

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-16

... material to absorb the entire contents of the inner packaging, before being placed in its outer package... combination packaging intended for the air transportation of liquid hazardous materials is capable of..., leakproof receptacle or intermediate packaging containing sufficient absorbent material to absorb the entire...

The Influence of Pretreatment Characteristics and Radiotherapy Parameters on Time Interval to Development of Radiation-Associated Meningioma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paulino, Arnold C., E-mail: apaulino@tmhs.or; Ahmed, Irfan M.; Mai, Wei Y.

2009-12-01

Purpose: To identify pretreatment characteristics and radiotherapy parameters which may influence time interval to development of radiation-associated meningioma (RAM). Methods and Materials: A Medline/PUBMED search of articles dealing with RAM yielded 66 studies between 1981 and 2006. Factors analyzed included patient age and gender, type of initial tumor treated, radiotherapy (RT) dose and volume, and time interval from RT to development of RAM. Results: A total of 143 patients with a median age at RT of 12 years form the basis of this report. The most common initial tumors or conditions treated with RT were medulloblastoma (n = 27), pituitarymore » adenoma (n = 20), acute lymphoblastic leukemia (n = 20), low-grade astrocytoma (n = 19), and tinea capitis (n = 14). In the 116 patients whose RT fields were known, 55 (47.4%) had a portion of the brain treated, whereas 32 (27.6%) and 29 (25.0%) had craniospinal and whole-brain fields. The median time from RT to develop a RAM or latent time (LT) was 19 years (range, 1-63 years). Male gender (p = 0.001), initial diagnosis of leukemia (p = 0.001), and use of whole brain or craniospinal field (p <= 0.0001) were associated with a shorter LT, whereas patients who received lower doses of RT had a longer LT (p < 0.0001). Conclusions: The latent time to develop a RAM was related to gender, initial tumor type, radiotherapy volume, and radiotherapy dose.« less

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

NASA Astrophysics Data System (ADS)

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.

Evaluation of suture material characteristics in an in vitro experimental model.

PubMed

Justan, I

2010-01-01

The purpose of our study was to indentify the mechanical characteristics of various suture materials. We created an in-vitro experimental flexor tendon model. Materials were divided into four groups: monofilament polypropylene non-absorbable material (group 1); monofilament long-term absorbable material (group 2); polyester multifilament non-absorbable coated material (group 3) and polyester multifilament non-absorbable uncoated material (group 4). We performed 135 tests. The mean maximal tensile strength was 62.92 N in group 1, 75.20 N in group 2, 36.38 N in group 3 and 72.4 N in group 4. Elasticity in millimetres was adjusted at the 35N level: group 1:2.01 mm, group 2:2.18 mm, group 3:2.14 and group 4:1.51 mm. With regard to its elasticity and favourable SD for tensile strength measurements, polyester multifilament non-absorbable uncoated material was considered to be the most suitable material.

Fracture mechanics based design for radioactive material transport packagings -- Historical review

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, J.A.; Salzbrenner, D.; Sorenson, K.

1998-04-01

The use of a fracture mechanics based design for the radioactive material transport (RAM) packagings has been the subject of extensive research for more than a decade. Sandia National Laboratories (SNL) has played an important role in the research and development of the application of this technology. Ductile iron has been internationally accepted as an exemplary material for the demonstration of a fracture mechanics based method of RAM packaging design and therefore is the subject of a large portion of the research discussed in this report. SNL`s extensive research and development program, funded primarily by the U. S. Department ofmore » Energy`s Office of Transportation, Energy Management and Analytical Services (EM-76) and in an auxiliary capacity, the office of Civilian Radioactive Waste Management, is summarized in this document along with a summary of the research conducted at other institutions throughout the world. In addition to the research and development work, code and standards development and regulatory positions are also discussed.« less

A Wide Band Absorbing Material Design Using Band-Pass Frequency Selective Surface

NASA Astrophysics Data System (ADS)

Xu, Yonggang; Xu, Qiang; Liu, Ting; Zheng, Dianliang; Zhou, Li

2018-03-01

Based on the high frequency advantage characteristics of the Fe based absorbing coating, a method for designing the structure of broadband absorbing structure by using frequency selective surface (FSS) is proposed. According to the transmission and reflection characteristic of the different size FSS structure, the frequency variation characteristic was simulated. Secondly, the genetic algorithm was used to optimize the high frequency broadband absorbing materials, including the single and double magnetic layer material. Finally, the absorbing characteristics in iron layer were analyzed as the band pass FSS structure was embedded, the results showed that the band-pass FSS had the influence on widening the absorbing frequency. As the FSS was set as the bottom layer, it was effective to achieve the good absorbing property in low frequency and the high frequency absorbing performance was not weakened, because the band-pass FSS led the low frequency absorption and the high frequency shielding effect. The results of this paper are of guiding significance for designing and manufacturing the broadband absorbing materials.

Practical Thermal Evaluation Methods For HAC Fire Analysis In Type B Radiaoactive Material (RAM) Packages

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abramczyk, Glenn; Hensel, Stephen J; Gupta, Narendra K.

Title 10 of the United States Code of Federal Regulations Part 71 for the Nuclear Regulatory Commission (10 CFR Part 71.73) requires that Type B radioactive material (RAM) packages satisfy certain Hypothetical Accident Conditions (HAC) thermal design requirements to ensure package safety during accidental fire conditions. Compliance with thermal design requirements can be met by prototype tests, analyses only or a combination of tests and analyses. Normally, it is impractical to meet all the HAC using tests only and the analytical methods are too complex due to the multi-physics non-linear nature of the fire event. Therefore, a combination of testsmore » and thermal analyses methods using commercial heat transfer software are used to meet the necessary design requirements. The authors, along with his other colleagues at Savannah River National Laboratory in Aiken, SC, USA, have successfully used this 'tests and analyses' approach in the design and certification of several United States' DOE/NNSA certified packages, e.g. 9975, 9977, 9978, 9979, H1700, and Bulk Tritium Shipping Package (BTSP). This paper will describe these methods and it is hoped that the RAM Type B package designers and analysts can use them for their applications.« less

Composite neutron absorbing coatings for nuclear criticality control

DOEpatents

Wright, Richard N.; Swank, W. David; Mizia, Ronald E.

2005-07-19

Thermal neutron absorbing composite coating materials and methods of applying such coating materials to spent nuclear fuel storage systems are provided. A composite neutron absorbing coating applied to a substrate surface includes a neutron absorbing layer overlying at least a portion of the substrate surface, and a corrosion resistant top coat layer overlying at least a portion of the neutron absorbing layer. An optional bond coat layer can be formed on the substrate surface prior to forming the neutron absorbing layer. The neutron absorbing layer can include a neutron absorbing material, such as gadolinium oxide or gadolinium phosphate, dispersed in a metal alloy matrix. The coating layers may be formed by a plasma spray process or a high velocity oxygen fuel process.

Limit analysis, rammed earth material and Casagrande test

NASA Astrophysics Data System (ADS)

El-Nabouch, Ranime; Pastor, Joseph; Bui, Quoc-Bao; Plé, Olivier

2018-02-01

The present paper is concerned with the simulation of the Casagrande test carried out on a rammed earth material for wall-type structures in the framework of Limit Analysis (LA). In a preliminary study, the material is considered as a homogeneous Coulomb material, and existing LA static and kinematic codes are used for the simulation of the test. In each loading case, static and kinematic bounds coincide; the corresponding exact solution is a two-rigid-block mechanism together with a quasi-constant stress vector and a velocity jump also constant along the interface, for the three loading cases. In a second study, to take into account the influence of compressive loadings related to the porosity of the material, an elliptic criterion (denoted Cohesive Cam-Clay, CCC) is defined based on recent homogenization results about the hollow sphere model for porous Coulomb materials. Finally, original finite element formulations of the static and mixed kinematic methods for the CCC material are developed and applied to the Casagrande test. The results are the same than above, except that this time the velocity jump depends on the compressive loading, which is more realistic but not satisfying fully the experimental observations. Therefore, the possible extensions of this work towards non-standard direct methods are analyzed in the conclusion section.

Composition for absorbing hydrogen

DOEpatents

Heung, L.K.; Wicks, G.G.; Enz, G.L.

1995-05-02

A hydrogen absorbing composition is described. The composition comprises a porous glass matrix, made by a sol-gel process, having a hydrogen-absorbing material dispersed throughout the matrix. A sol, made from tetraethyl orthosilicate, is mixed with a hydrogen-absorbing material and solidified to form a porous glass matrix with the hydrogen-absorbing material dispersed uniformly throughout the matrix. The glass matrix has pores large enough to allow gases having hydrogen to pass through the matrix, yet small enough to hold the particles dispersed within the matrix so that the hydrogen-absorbing particles are not released during repeated hydrogen absorption/desorption cycles.

Composition for absorbing hydrogen

DOEpatents

Heung, Leung K.; Wicks, George G.; Enz, Glenn L.

1995-01-01

A hydrogen absorbing composition. The composition comprises a porous glass matrix, made by a sol-gel process, having a hydrogen-absorbing material dispersed throughout the matrix. A sol, made from tetraethyl orthosilicate, is mixed with a hydrogen-absorbing material and solidified to form a porous glass matrix with the hydrogen-absorbing material dispersed uniformly throughout the matrix. The glass matrix has pores large enough to allow gases having hydrogen to pass through the matrix, yet small enough to hold the particles dispersed within the matrix so that the hydrogen-absorbing particles are not released during repeated hydrogen absorption/desorption cycles.

Synthesis of High Symmetry Phase of Hafnium Dioxide Thin Films and Nickel Ferrite's Effect on Microstructure in Composite Heterostructure

NASA Astrophysics Data System (ADS)

Straka, Weston J.

Hafnium dioxide has attracted a great deal of attention recently due to its potential use in two different electronic applications: CMOS and FeRAM. In CMOS, the usefulness of hafnia comes in due to its high dielectric constant and compatibility with current IC processing parameters. For FeRAM, hafnia's recent discovery to exhibit ferroelectricity in an orthorhombic phase makes this material attractive for replacement of the ferroelectric material in FeRAM. This study shows the feasibility of depositing thin films of hafnium oxide via chemical solution deposition for integration into these devices. The processing parameters necessary to produce this phase show how non-equilibrium processing plays a role in its synthesis. The temperature necessary to achieve the high symmetry phase was at 725 °C for 3 minutes on sapphire, silicon, and coated silicon substrates. The thermal conductivity of each was viewed as the property that allowed the hafnia formation. The dielectric constant of the hafnia films were between 30 and 32 with low dissipation factors and up to 47 with a poor dissipation factor all at 1 kHz. The formation of this phase was shown to be thickness independent with the high symmetry phase existing up to 300 nm film thickness. Interfacing the hafnia film with nickel ferrite was also studied to identify the possibility of using this composite for non-destructive reading of FeRAM. The magnetic properties showed an unchanged nickel ferrite film but the interface between the two was poor leading to the conclusion that more work must be done to successfully integrate these two films.

Exploration of perpendicular magnetic anisotropy material system for application in spin transfer torque - Random access memory

NASA Astrophysics Data System (ADS)

Natarajarathinam, Anusha

Perpendicular magnetic anisotropy (PMA) materials have unique advantages when used in magnetic tunnel junctions (MTJ) which are the most critical part of spin-torque transfer random access memory devices (STT-RAMs) that are being researched intensively as future non-volatile memory technology. They have high magnetoresistance which improves their sensitivity. The STT-RAM has several advantages over competing technologies, for instance, low power consumption, non-volatility, ultra-fast read and write speed and high endurance. In personal computers, it can replace SRAM for high-speed applications, Flash for non-volatility, and PSRAM and DRAM for high-speed program execution. The main aim of this research is to identify and optimize the best perpendicular magnetic anisotropy (PMA) material system for application to STT-RAM technology. Preliminary search for perpendicular magnetic anisotropy (PMA) materials for pinned layer for MTJs started with the exploration and optimization of crystalline alloys such as Co50Pd50 alloy, Mn50Al50 and amorphous alloys such as Tb21Fe72Co7 and are first presented in this work. Further optimization includes the study of Co/[Pd/Pt]x multilayers (ML), and the development of perpendicular synthetic antiferromagnets (SAF) utilizing these multilayers. Focused work on capping and seed layers to evaluate interfacial perpendicular anisotropy in free layers for pMTJs is then discussed. Optimization of the full perpendicular magnetic tunnel junction (pMTJ) includes the CoFeB/MgO/CoFeB trilayer coupled to a pinned/pinning layer with perpendicular Co/[Pd/Pt]x SAF and a thin Ta seeded CoFeB free layer. Magnetometry, simulations, annealing studies, transport measurements and TEM analysis on these samples will then be presented.

Hybrid nuclear reactor grey rod to obtain required reactivity worth

DOEpatents

Miller, John V.; Carlson, William R.; Yarbrough, Michael B.

1991-01-01

Hybrid nuclear reactor grey rods are described, wherein geometric combinations of relatively weak neutron absorber materials such as stainless steel, zirconium or INCONEL, and relatively strong neutron absorber materials, such as hafnium, silver-indium cadmium and boron carbide, are used to obtain the reactivity worths required to reach zero boron change load follow. One embodiment includes a grey rod which has combinations of weak and strong neutron absorber pellets in a stainless steel cladding. The respective pellets can be of differing heights. A second embodiment includes a grey rod with a relatively thick stainless steel cladding receiving relatively strong neutron absorber pellets only. A third embodiment includes annular relatively weak netron absorber pellets with a smaller diameter pellet of relatively strong absorber material contained within the aperture of each relatively weak absorber pellet. The fourth embodiment includes pellets made of a homogeneous alloy of hafnium and a relatively weak absorber material, with the percentage of hafnium chosen to obtain the desired reactivity worth.

Remote Asynchronous Message Service Gateway

NASA Technical Reports Server (NTRS)

Wang, Shin-Ywan; Burleigh, Scott C.

2011-01-01

The Remote Asynchronous Message Service (RAMS) gateway is a special-purpose AMS application node that enables exchange of AMS messages between nodes residing in different AMS "continua," notionally in different geographical locations. JPL s implementation of RAMS gateway functionality is integrated with the ION (Interplanetary Overlay Network) implementation of the DTN (Delay-Tolerant Networking) bundle protocol, and with JPL s implementation of AMS itself. RAMS protocol data units are encapsulated in ION bundles and are forwarded to the neighboring RAMS gateways identified in the source gateway s AMS management information base. Each RAMS gateway has interfaces in two communication environments: the AMS message space it serves, and the RAMS network - the grid or tree of mutually aware RAMS gateways - that enables AMS messages produced in one message space to be forwarded to other message spaces of the same venture. Each gateway opens persistent, private RAMS network communication channels to the RAMS gateways of other message spaces for the same venture, in other continua. The interconnected RAMS gateways use these communication channels to forward message petition assertions and cancellations among themselves. Each RAMS gateway subscribes locally to all subjects that are of interest in any of the linked message spaces. On receiving its copy of a message on any of these subjects, the RAMS gateway node uses the RAMS network to forward the message to every other RAMS gateway whose message space contains at least one node that has subscribed to messages on that subject. On receiving a message via the RAMS network from some other RAMS gateway, the RAMS gateway node forwards the message to all subscribers in its own message space.

Automation of GIS-based population data-collection for transportation risk analysis

DOT National Transportation Integrated Search

1999-11-01

Estimation of the potential radiological risks associated with highway transport of radioactive : materials (RAM) requires input data describing population densities adjacent to all portions of : the route to be traveled. Previously, aggregated risks...

Resistive switching characteristics and mechanisms in silicon oxide memory devices

NASA Astrophysics Data System (ADS)

Chang, Yao-Feng; Fowler, Burt; Chen, Ying-Chen; Zhou, Fei; Wu, Xiaohan; Chen, Yen-Ting; Wang, Yanzhen; Xue, Fei; Lee, Jack C.

2016-05-01

Intrinsic unipolar SiOx-based resistance random access memories (ReRAM) characterization, switching mechanisms, and applications have been investigated. Device structures, material compositions, and electrical characteristics are identified that enable ReRAM cells with high ON/OFF ratio, low static power consumption, low switching power, and high readout-margin using complementary metal-oxide semiconductor transistor (CMOS)-compatible SiOx-based materials. These ideas are combined with the use of horizontal and vertical device structure designs, composition optimization, electrical control, and external factors to help understand resistive switching (RS) mechanisms. Measured temperature effects, pulse response, and carrier transport behaviors lead to compact models of RS mechanisms and energy band diagrams in order to aid the development of computer-aided design for ultralarge-v scale integration. This chapter presents a comprehensive investigation of SiOx-based RS characteristics and mechanisms for the post-CMOS device era.

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

NASA Astrophysics Data System (ADS)

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.

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

DTIC Science & Technology

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

Genetic characterization of tigecycline resistance in clinical isolates of Enterobacter cloacae and Enterobacter aerogenes.

PubMed

Veleba, Mark; De Majumdar, Shyamasree; Hornsey, Michael; Woodford, Neil; Schneiders, Thamarai

2013-05-01

The intrinsically encoded ramA gene has been linked to tigecycline resistance through the up-regulation of efflux pump AcrAB in Enterobacter cloacae. The molecular basis for increased ramA expression in E. cloacae and Enterobacter aerogenes, as well as the role of AraC regulator rarA, has not yet been shown. To ascertain the intrinsic molecular mechanism(s) involved in tigecycline resistance in Enterobacter spp., we analysed the expression levels of ramA and rarA and corresponding efflux pump genes acrAB and oqxAB in Enterobacter spp. clinical isolates. The expression levels of ramA, rarA, oqxA and acrA were tested by quantitative real-time RT-PCR. The ramR open reading frames of the ramA-overexpressing strains were sequenced; strains harbouring mutations were transformed with wild-type ramR to study altered ramA expression and tigecycline susceptibility. Tigecycline resistance was mediated primarily by increased ramA expression in E. cloacae and E. aerogenes. Only the ramA-overexpressing E. cloacae isolates showed increased rarA and oqxA expression. Upon complementation with wild-type ramR, all Enterobacter spp. containing ramR mutations exhibited decreased ramA and acrA expression and increased tigecycline susceptibility. Exceptions were one E. cloacae strain and one E. aerogenes strain, where a decrease in ramA levels was not accompanied by lower acrA expression. Increased ramA expression due to ramR deregulation is the primary mediator of tigecycline resistance in clinical isolates of E. cloacae and E. aerogenes. However, some ramA-overexpressing isolates do not show changes in ramR, suggesting alternate pathways of ramA regulation; the rarA regulator and the oqxAB efflux pump may also play a role in tigecycline resistance in E. cloacae.

Origin of the OFF state variability in ReRAM cells

NASA Astrophysics Data System (ADS)

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

2014-04-01

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 TiO2 and In2O3 : SnO2 (ITO) based ReRAM cells programmed at three distinct resistive states. Our prototypes employed TiO2 or ITO active cores over 5 × 5 µm2 and 100 × 100 µm2 cell areas, with all tested devices demonstrating both unipolar and bipolar switching modalities. In the case of TiO2-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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dehoff, Ryan R; Jestings, Lee; Conde, Ricardo

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 andmore » 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.« less

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

PubMed

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 < .02). On the 1st d of exposure, the HP rams exhibited more courtship behavior and spent more time near the ewes (P < .04). The HP rams spent more time within 1 m of ewes during the 28-d exposure. There were no differences in the amount of contact with rams (LP or HP) between rise in progesterone indicate of ovulation tended to occur earlier (P = .06) in ewes penned with HP rams. A greater percentage of ewes exposed to LP rams (P = .03) had early elevations of progesterone with no concurrent 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.

Use of a novel cation-exchange restricted-access material for automated sample clean-up prior to the determination of basic drugs in plasma by liquid chromatography.

PubMed

Chiap, P; Rbeida, O; Christiaens, B; Hubert, Ph; Lubda, D; Boos, K S; Crommen, J

2002-10-25

A new kind of silica-based restricted-access material (RAM) has been tested in pre-columns for the on-line solid-phase extraction (SPE) of basic drugs from directly injected plasma samples before their quantitative analysis by reversed-phase liquid chromatography (LC), using the column switching technique. The outer surface of the porous RAM particlescontains hydrophilic diol groups while sulphonic acid groups are bound to the internal surface, which gives the sorbent the properties of a strong cation exchanger towards low molecular mass compounds. Macromolecules such as proteins have no access to the internal surface of the pre-column due to their exclusion from the pores and are then flushed directly out. The retention capability of this novel packing material has been tested for some hydrophilic basic drugs, such as atropine, fenoterol, ipratropium, procaine, sotalol and terbutaline, used as model compounds. The influence of the composition of the washing liquid on the retention of the analytes in the pre-column has been investigated. The elution profiles of the different compounds and the plasma matrix as well as the time needed for the transfer of the analytes from the pre-column to the analytical column were determined in order to deduce the most suitable conditions for the clean-up step and develop on-line methods for the LC determination of these compounds in plasma. The cationic exchange sorbent was also compared to another RAM, namely RP-18 ADS (alkyl diol silica) sorbent with respect to retention capability towards basic analytes.

MSFC Thermal Protection System Materials on MISSE-6

NASA Technical Reports Server (NTRS)

Finckenor, Miria M.; Valentine, Peter G.; Gubert, Michael K.

2010-01-01

The Lightweight Nonmetallic Thermal Protection Materials Technology (LNTPMT) program studied a number of ceramic matrix composites, ablator materials, and tile materials for durability in simulated space environment. Materials that indicated low atomic oxygen reactivity and negligible change in thermo-optical properties in ground testing were selected to fly on the Materials on International Space Station Experiment (MISSE)-6. These samples were exposed for 17 months to the low Earth orbit environment on both the ram and wake sides of MISSE-6B. Thermo-optical properties are discussed, along with any changes in mass.

Container and method for absorbing and reducing hydrogen concentration

DOEpatents

Wicks, George G.; Lee, Myung W.; Heung, Leung K.

2001-01-01

A method for absorbing hydrogen from an enclosed environment comprising providing a vessel; providing a hydrogen storage composition in communication with a vessel, the hydrogen storage composition further comprising a matrix defining a pore size which permits the passage of hydrogen gas while blocking the passage of gaseous poisons; placing a material within the vessel, the material evolving hydrogen gas; sealing the vessel; and absorbing the hydrogen gas released into the vessel by the hydrogen storage composition. A container for absorbing evolved hydrogen gas comprising: a vessel having an interior and adapted for receiving materials which release hydrogen gas; a hydrogen absorbing composition in communication with the interior, the composition defining a matrix surrounding a hydrogen absorber, the matrix permitting the passage of hydrogen gas while excluding gaseous poisons; wherein, when the vessel is sealed, hydrogen gas, which is released into the vessel interior, is absorbed by the hydrogen absorbing composition.

Boron cage compound materials and composites for shielding and absorbing neutrons

DOEpatents

Bowen, III, Daniel E; Eastwood, Eric A

2014-03-04

Boron cage compound-containing materials for shielding and absorbing neutrons. The materials include BCC-containing composites and compounds. BCC-containing compounds comprise a host polymer and a BCC attached thereto. BCC-containing composites comprise a mixture of a polymer matrix and a BCC filler. The BCC-containing materials can be used to form numerous articles of manufacture for shielding and absorbing neutrons.

Thermal characterization and analysis of phase change random access memory

NASA Astrophysics Data System (ADS)

Giraud, V.; Cluzel, J.; Sousa, V.; Jacquot, A.; Dauscher, A.; Lenoir, B.; Scherrer, H.; Romer, S.

2005-07-01

The cross-plane thermal conductivity of Ge2Sb2Te5, either in its amorphous state or fcc crystallized state, and titanium nitride (TiN) thin films has been measured at room temperature by the 3ω method. These materials are involved in the fabrication of phase change random access memory (PC-RAM), Ge2Sb2Te5 and TiN being the PC and pseudoelectrode materials, respectively. The thermal conductivity of insulating SiO2 and ZnS :SiO2 layers was determined too. Each thermal conductivity measurement was performed by the means of at least two strip widths in order to check both the measurement self-consistency and the measurement accuracy. The performance of PC-RAM cells, i.e., the time needed to reach the melting temperature of the PC material and the cooling speed, has been evaluated as a function of both the measured thermal conductivity of the PC material and the reset current intensity independently of the thermal properties of the pseudoelectrodes by the way of analytical formula. The influence of the thickness and the thermal properties of the pseudoelectrodes on the performances have been determined by numerical simulations.

MULTI-WAVELENGTH STUDIES OF SPECTACULAR RAM PRESSURE STRIPPING OF A GALAXY: DISCOVERY OF AN X-RAY ABSORPTION FEATURE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gu, Liyi; Makishima, Kazuo; Yagi, Masafumi

We report the detection of an X-ray absorption feature near the galaxy M86 in the Virgo cluster. The absorber has a column density of 2-3 × 10{sup 20} cm{sup –2}, and its position coincides with the peak of an intracluster H I cloud which was removed from the galaxy NGC 4388 presumably by ram pressure. These results indicate that the H I cloud is located in front of M86 along the line-of-sight, and suggest that the stripping was primarily created by an interaction between NGC 4388 and the hot plasmas of the Virgo cluster, not the M86 halo. By calculatingmore » an X-ray temperature map, we further detected an X-ray counterpart of the H I cloud up to ≈3' south of M86. It has a temperature of 0.89 keV and a mass of ∼4.5 × 10{sup 8} M {sub ☉}, exceeding the estimated H I gas mass. The high hot-to-cold gas ratio in the cloud indicates a significant evaporation of the H I gas, probably by thermal conduction from the hotter cluster plasma with a sub-Spitzer rate.« less

Basalt fiber reinforced porous aggregates-geopolymer based cellular material

NASA Astrophysics Data System (ADS)

Luo, Xin; Xu, Jin-Yu; Li, Weimin

2015-09-01

Basalt fiber reinforced porous aggregates-geopolymer based cellular material (BFRPGCM) was prepared. The stress-strain curve has been worked out. The ideal energy-absorbing efficiency has been analyzed and the application prospect has been explored. The results show the following: fiber reinforced cellular material has successively sized pore structures; the stress-strain curve has two stages: elastic stage and yielding plateau stage; the greatest value of the ideal energy-absorbing efficiency of BFRPGCM is 89.11%, which suggests BFRPGCM has excellent energy-absorbing property. Thus, it can be seen that BFRPGCM is easy and simple to make, has high plasticity, low density and excellent energy-absorbing features. So, BFRPGCM is a promising energy-absorbing material used especially in civil defense engineering.

Ram locus is a key regulator to trigger multidrug resistance in Enterobacter aerogenes.

PubMed

Molitor, Alexander; James, Chloë E; Fanning, Séamus; Pagès, Jean-Marie; Davin-Regli, Anne

2018-02-01

Several genetic regulators belonging to AraC family are involved in the emergence of MDR isolates of E. aerogenes due to alterations in membrane permeability. Compared with the genetic regulator Mar, RamA may be more relevant towards the emergence of antibiotic resistance. Focusing on the global regulators, Mar and Ram, we compared the amino acid sequences of the Ram repressor in 59 clinical isolates and laboratory strains of E. aerogenes. Sequence types were associated with their corresponding multi-drug resistance phenotypes and membrane protein expression profiles using MIC and immunoblot assays. Quantitative gene expression analysis of the different regulators and their targets (porins and efflux pump components) were performed. In the majority of the MDR isolates tested, ramR and a region upstream of ramA were mutated but marR or marA were unchanged. Expression and cloning experiments highlighted the involvement of the ram locus in the modification of membrane permeability. Overexpression of RamA lead to decreased porin production and increased expression of efflux pump components, whereas overexpression of RamR had the opposite effects. Mutations or deletions in ramR, leading to the overexpression of RamA predominated in clinical MDR E. aerogenes isolates and were associated with a higher-level of expression of efflux pump components. It was hypothesised that mutations in ramR, and the self-regulating region proximal to ramA, probably altered the binding properties of the RamR repressor; thereby producing the MDR phenotype. Consequently, mutability of RamR may play a key role in predisposing E. aerogenes towards the emergence of a MDR phenotype.

Evaluating the reproductive ability of breeding rams in North-Eastern Spain using clinical examination of the body and external genitalia.

PubMed

Mozo, René; Galeote, Ana Isabel; Alabart, José Luis; Fantova, Enrique; Folch, José

2015-11-26

Predicting the ability of rams to detect, mate and fertilise ewes in oestrus accurately is certainly difficult; however, tests based on clinical examinations have been performed to assess the overall potential capacity of rams to serve and impregnate ewes. Clinical examinations for breeding soundness evaluation were carried out in 897 Rasa Aragonesa (RA) rams from 35 flocks in North-Eastern (NE) Spain. Clinical examinations of head, trunk, limbs and genitals were performed in each ram. Blood samples were collected for a serological study of Brucella ovis. The sheep owners were surveyed regarding the characteristics of the flock, rams' health history and the management of rams. The clinical alterations found were classified according to severity (mild or severe). Rams were classified as suitable (without lesions or with only mild lesions) or unsuitable (with severe lesions) for breeding depending on the results of the clinical examinations. The results showed that 60.6 % of rams presented some type of alteration (mild: 43.3 %; severe: 17.3 %) in various body parts (genitalia: 31.6 %; head and trunk: 37.2 %; limbs: 15.5 %), and that 16.7 % of rams were classified as unsuitable breeders. The most common genital alterations were ulcerative posthitis (18.7 %) followed by testicular lesions (5.3 %). The highest prevalence of unsuitable breeders was found in the category of adult and aged rams (13.8 % and 37.4 %, respectively) and in the category of emaciated rams (33.3 %). All rams examined were seronegative to Brucella ovis. The mean percentage of rams in flocks was 2.8 % (min: 1.6 %; max: 4.6 %); nevertheless, this percentage dropped to 2.5 % (min: 1.4 %; max: 3.7 %) and 2.1 % (min: 0.3 %; max: 3.5 %) when only suitable or effective (suitable mature) rams were considered. Thus, it is concluded that there are fewer effective rams in farms than farmers realise. Frequent clinical examination of males is recommended in order to identify potentially infertile rams.

Core-melt source reduction system

DOEpatents

Forsberg, C.W.; Beahm, E.C.; Parker, G.W.

1995-04-25

A core-melt source reduction system for ending the progression of a molten core during a core-melt accident and resulting in a stable solid cool matrix. The system includes alternating layers of a core debris absorbing material and a barrier material. The core debris absorbing material serves to react with and absorb the molten core such that containment overpressurization and/or failure does not occur. The barrier material slows the progression of the molten core debris through the system such that the molten core has sufficient time to react with the core absorbing material. The system includes a provision for cooling the glass/molten core mass after the reaction such that a stable solid cool matrix results. 4 figs.

Core-melt source reduction system

DOEpatents

Forsberg, Charles W.; Beahm, Edward C.; Parker, George W.

1995-01-01

A core-melt source reduction system for ending the progression of a molten core during a core-melt accident and resulting in a stable solid cool matrix. The system includes alternating layers of a core debris absorbing material and a barrier material. The core debris absorbing material serves to react with and absorb the molten core such that containment overpressurization and/or failure does not occur. The barrier material slows the progression of the molten core debris through the system such that the molten core has sufficient time to react with the core absorbing material. The system includes a provision for cooling the glass/molten core mass after the reaction such that a stable solid cool matrix results.

Composite solid-state scintillators for neutron detection

DOEpatents

Dai, Sheng; Im, Hee-Jung; Pawel, Michelle D.

2006-09-12

Applicant's present invention is a composite scintillator for neutron detection comprising a matrix material fabricated from an inorganic sol-gel precursor solution homogeneously doped with a liquid scintillating material and a neutron absorbing material. The neutron absorbing material yields at least one of an electron, a proton, a triton, an alpha particle or a fission fragment when the neutron absorbing material absorbs a neutron. The composite scintillator further comprises a liquid scintillating material in a self-assembled micelle formation homogeneously doped in the matrix material through the formation of surfactant-silica composites. The scintillating material is provided to scintillate when traversed by at least one of an electron, a proton, a triton, an alpha particle or a fission fragment. The scintillating material is configured such that the matrix material surrounds the micelle formation of the scintillating material. The composite scintillator is fabricated and applied as a thin film on substrate surfaces, a coating on optical fibers or as a glass material.

Seasonal influence on sperm parameters, scrotal measurements, and serum testosterone in Ouled Djellal breed rams in Algeria

PubMed Central

Belkadi, S.; Safsaf, B.; Heleili, N.; Tlidjane, M.; Belkacem, L.; Oucheriah, Y.

2017-01-01

Aim: This study was conducted to determine the effect of seasonal variations on testosterone serum concentration, body weight, scrotal circumference, and some sperm parameters in rams living in a semi-arid region of eastern part of Algeria. Materials and Methods: Blood samples were taken monthly from eight Ouled Djellal rams, aged between 3 and 4 years, in the Technical Institute of Breeding “ITELV” located at Ain M’lila City. Sperm were collected by an electro-ejaculator once a month for 1 year (spring, summer, autumn, and winter: 3 times/season). Results: Mean values of volume, mass motility, live sperm, and scrotal circumference were higher during spring (p<0.05) with 1.23±0.26 mL, 3.39±1.07, 79.16±15.82%, and 36.29±1.91 cm, respectively; whereas, the sperm concentration was higher during autumn with 1.19±0.56×109 spz/ml compared to 0.46±0.13×109 spz/mL to spring. The season influenced significantly the percentage of abnormal sperm (p<0.05), especially during winter (6.47±2.12%), but had no influence on the weight of rams. Seasonal hormonal activity was high with 4.89±2.06 ng/mL and 3.09±1.35 ng/mL of testosterone in mating seasons (spring and autumn, respectively), knowing that the sexual season is not marked too much in these latitude. Conclusion: We can conclude that testosterone concentration is strongly correlated with the scrotal circumference and that the season has a significant influence on spermatic parameters, and that despite the large variations in sperm production, the rams can be used throughout the year. PMID:29391691

Plasmonic detection of possible defects in multilayer nanohole array consisting of essential materials in simplified STT-RAM cell

NASA Astrophysics Data System (ADS)

Sadri-Moshkenani, Parinaz; Khan, Mohammad Wahiduzzaman; Zhao, Qiancheng; Krivorotov, Ilya; Nilsson, Mikael; Bagherzadeh, Nader; Boyraz, Ozdal

2017-08-01

Plasmonic nanostructures are highly used for sensing purposes since they support plasmonic modes which make them highly sensitive to the refractive index change of their surrounding medium. Therefore, they can also be used to detect changes in optical properties of ultrathin layer films in a multilayer plasmonic structure. Here, we investigate the changes in optical properties of ultrathin films of macro structures consisting of STT-RAM layers. Among the highest sensitive plasmonic structures, nanohole array has attracted many research interest because of its ease of fabrication, small footprint, and simplified optical alignment. Hence it is more suitable for defect detection in STT-RAM geometries. Moreover, the periodic nanohole pattern in the nanohole array structure makes it possible to couple the light to the surface plasmon polariton (SPP) mode supported by the structure. To assess the radiation damages and defects in STT-RAM cells we have designed a multilayer nanohole array based on the layers used in STT-RAM structure, consisting 4nm- Ta/1.5nm-CoFeB/2nm-MgO/1.5nm-CoFeB/4nm-Ta layers, all on a 300nm silver layer on top of a PEC boundary. The nanoholes go through all the layers and become closed by the PEC boundary on one side. The dimensions of the designed nanoholes are 313nm depth, 350nm diameter, and 700nm period. Here, we consider the normal incidence of light and investigate zeroth-order reflection coefficient to observe the resonance. Our simulation results show that a 10% change in refractive index of the 2nm-thick MgO layer leads to about 122GHz shift in SPP resonance in reflection pattern.

Architecture of the sperm whale forehead facilitates ramming combat.

PubMed

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 reduce skull stresses, it would also cause high compressive stresses on the anterior aspect of the organ and the connective tissue case, possibly making these structures more prone to failure. This outcome, coupled with the facts that the spermaceti organ houses sensitive and essential sonar producing structures and the rostral portion of junk, rather than the spermaceti organ, is frequently a site of significant scarring in mature males suggest that whales avoid impact with the spermaceti organ. Although the unique structure of the junk certainly serves multiple functions, our results are consistent with the hypothesis that the structure also evolved to function as a massive battering ram during male-male competition.

Compact ion chamber based neutron detector

DOEpatents

Derzon, Mark S.; Galambos, Paul C.; Renzi, Ronald F.

2015-10-27

A directional neutron detector has an ion chamber formed in a dielectric material; a signal electrode and a ground electrode formed in the ion chamber; a neutron absorbing material filling the ion chamber; readout circuitry which is electrically coupled to the signal and ground electrodes; and a signal processor electrically coupled to the readout circuitry. The ion chamber has a pair of substantially planar electrode surfaces. The chamber pressure of the neutron absorbing material is selected such that the reaction particle ion trail length for neutrons absorbed by the neutron absorbing material is equal to or less than the distance between the electrode surfaces. The signal processor is adapted to determine a path angle for each absorbed neutron based on the rise time of the corresponding pulse in a time-varying detector signal.

Use of gonadotropin releasing hormone to improve reproductive responses of ewes introduced to rams during seasonal anestrus.

PubMed

Jordan, K M; Inskeep, E K; Knights, M

2009-12-01

Three experiments were conducted on anestrous ewes of Suffolk, Dorset, and Katahdin breeding to examine the potential value of GnRH to improve ovulation and pregnancy in response to introduction of rams. In Experiment 1, treatment with GnRH 2d after treatment with progesterone (P(4); 25mg i.m.) at introduction of rams was compared to treatment with P(4) alone at the time of introduction of rams. Treatment with GnRH did not increase percentages of ewes with a corpus luteum (CL) 14d after introduction of rams, pregnant 32d after treatment with PGF(2)alpha 14d after introduction of rams, or percent of treated ewes lambing to all services. In Experiment 2, treatments with GnRH on day 2, 7, or both after introduction of rams were compared. Treatments did not differ in mean estrous response, percentages of ewes with a detectable CL or number of CL present on day 11, or mean pregnancy and lambing rates. Therefore, neither one nor two injections of GnRH at these times appeared to be effective to induce anestrous ewes to breed. In Experiment 3, treatments compared included GnRH 4d before introduction of rams, GnRH 4d before and 1d after introduction of rams, ram introduction alone, and treatment with P(4) (25mg i.m.) at the time of introduction of rams. Percentages of ewes with concentrations of P(4) greater than 1ng/mL (indicating formation of CL had occurred) 7d after ram introduction tended to be greater (P<0.07) in ewes treated with GnRH or P(4) than in control ewes treated with ram introduction alone. However, there was no difference in P(4) concentrations between groups by day 11 or 12 after introduction of rams. Estrous response rates and percentages of ewes pregnant 95d after PGF(2)alpha was administered (on day 12 after introduction of rams) tended to be greater (P=0.08 and 0.06, respectively) in ewes treated with GnRH or P(4) than in ewes exposed to rams only. There was no difference in response variables between ewes treated with GnRH 4d before introduction of rams and ewes treated with GnRH 4d before and 1d after introduction of rams. In conclusion, treatment with GnRH 4d before ram introduction showed promise as an alternative to treatment with P(4) to improve the ovulatory response and reproductive performance of ewes introduced to rams during seasonal anestrus.

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

NASA Astrophysics Data System (ADS)

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.

Study of sound-absorbing properties of glass-fiber reinforced materials used in engineering

NASA Astrophysics Data System (ADS)

Egorova, V. E.; Habibova, R. R.; Shafigullin, L. N.

2017-09-01

Modern engineering makes high demands to the noise level in the passenger compartment or cabin of KAMAZ. An effective means of dealing with noise is to use sound absorbing materials produced by the automotive industry. To increase sound-absorbing capacity of materials and structures using glass fibre reinforced polyurethane foams (PUF) obtained by the technology Fiber Composite Spraying.

Development of battering ram vibrator system

NASA Astrophysics Data System (ADS)

Sun, F.; Chen, Z.; Lin, J.; Tong, X.

2012-12-01

This paper researched the battering ram vibrator system, by electric machinery we can control oil system of battering ram, we realized exact control of battering ram, after analyzed pseudorandom coding, code "0" and "1" correspond to rest and shake of battering ram, then we can get pseudorandom coding which is the same with battering ram vibrator. After testing , by the reference trace and single shot record, when we using pseudorandom coding mode, the ratio of seismic wavelet to correlation interfere is about 68 dB, while the general mode , the ratio of seismic wavelet to correlation interfere only is 27.9dB, by battering ram vibrator system, we can debase the correlation interfere which come from the single shaking frequency of battering ram, this system advanced the signal-to-noise ratio of seismic data, which can give direction of the application of battering ram vibrator in metal mine exploration and high resolving seismic exploration.

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

DOEpatents

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.

Concentrating light in Cu(In,Ga)Se2 solar cells

NASA Astrophysics Data System (ADS)

Schmid, M.; Yin, G.; Song, M.; Duan, S.; Heidmann, B.; Sancho-Martinez, D.; Kämmer, S.; Köhler, T.; Manley, P.; Lux-Steiner, M. Ch.

2016-09-01

Light concentration has proven beneficial for solar cells, most notably for highly efficient but expensive absorber materials using high concentrations and large scale optics. Here we investigate light concentration for cost efficient thinfilm solar cells which show nano- or microtextured absorbers. Our absorber material of choice is Cu(In,Ga)Se2 (CIGSe) which has a proven stabilized record efficiency of 22.6% and which - despite being a polycrystalline thin-film material - is very tolerant to environmental influences. Taking a nanoscale approach, we concentrate light in the CIGSe absorber layer by integrating photonic nanostructures made from dielectric materials. The dielectric nanostructures give rise to resonant modes and field localization in their vicinity. Thus when inserted inside or adjacent to the absorber layer, absorption and efficiency enhancement are observed. In contrast to this internal absorption enhancement, external enhancement is exploited in the microscale approach: mm-sized lenses can be used to concentrate light onto CIGSe solar cells with lateral dimensions reduced down to the micrometer range. These micro solar cells come with the benefit of improved heat dissipation compared to the large scale concentrators and promise compact high efficiency devices. Both approaches of light concentration allow for reduction in material consumption by restricting the absorber dimension either vertically (ultra-thin absorbers for dielectric nanostructures) or horizontally (micro absorbers for concentrating lenses) and have significant potential for efficiency enhancement.

Fluorinated tin oxide back contact for AZTSSe photovoltaic devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gershon, Talia S.; Gunawan, Oki; Haight, Richard A.

A photovoltaic device includes a substrate, a back contact comprising a stable low-work function material, a photovoltaic absorber material layer comprising Ag.sub.2ZnSn(S,Se).sub.4 (AZTSSe) on a side of the back contact opposite the substrate, wherein the back contact forms an Ohmic contact with the photovoltaic absorber material layer, a buffer layer or Schottky contact layer on a side of the absorber layer opposite the back contact, and a top electrode on a side of the buffer layer opposite the absorber layer.

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

PubMed Central

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

Nanostructured materials for hydrogen storage

DOEpatents

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.

Erosion Data from the MISSE 8 Polymers Experiment After 2 Years of Space Exposure on the International Space Station

NASA Technical Reports Server (NTRS)

de Groh, Kim K.; Banks, Bruce A.; Asmar, Olivia C.; Yi, Grace T.; Mitchell, Gianna G.; Guo, Aobo; Sechkar, Edward A.

2016-01-01

The Polymers Experiment was exposed to the low Earth orbit (LEO) space environment for 2.14 and 2.0 years as part of the Materials International Space Station Experiment 8 (MISSE 8) and the Optical Reflector Materials Experiment-III (ORMatE-III), respectively. The experiment contained 42 samples, which were flown in either ram, wake, or zenith orientations. The primary objective was to determine the effect of solar exposure on the atomic oxygen erosion yield (Ey) of fluoropolymers. This paper provides an overview of the experiment with details on the polymers flown, the characterization techniques used, the atomic oxygen fluence for each exposure orientation, and the LEO Ey results. The Ey values for the fluoropolymers range from 1.45 x 10(exp -25) cm(exp 3)/atom for white Tedlar Registered Trademark? (polyvinyl fluoride with white titanium dioxide pigment) flown in the ram orientation to 6.32 x 10(exp -24) cm(exp 3)/atom for aluminized-Teflon Registered Trademark? fluorinated ethylene propylene (Al-FEP) flown in the zenith orientation. Erosion yield data for FEP flown in ram, wake and zenith orientations are compared, and the Ey was found to be highly dependent on orientation, hence environmental exposure. Teflon FEP had an order of magnitude higher Ey when flown in the zenith direction (6.32 x10(exp -24) cm(exp3)/atom) as compared to the ram direction (2.37 x 10(exp -25) cm(exp 3)/atom). The Ey of FEP was found to increase with a direct correlation to the solar exposure/AO fluence ratio showing the effect of solar radiation and/or heating due to solar exposure on FEP erosion. In addition, back-surface carbon painted FEP (C-FEP) flown in the zenith orientation had a significantly higher Ey than clear FEP or Al-FEP further indicating that heating has a significant impact on the erosion of FEP, particularly in the zenith orientation.

Optimizing Clinical Drug Product Performance: Applying Biopharmaceutics Risk Assessment Roadmap (BioRAM) and the BioRAM Scoring Grid.

PubMed

Dickinson, Paul A; Kesisoglou, Filippos; Flanagan, Talia; Martinez, Marilyn N; Mistry, Hitesh B; Crison, John R; Polli, James E; Cruañes, Maria T; Serajuddin, Abu T M; Müllertz, Anette; Cook, Jack A; Selen, Arzu

2016-11-01

The aim of Biopharmaceutics Risk Assessment Roadmap (BioRAM) and the BioRAM Scoring Grid is to facilitate optimization of clinical performance of drug products. BioRAM strategy relies on therapy-driven drug delivery and follows an integrated systems approach for formulating and addressing critical questions and decision-making (J Pharm Sci. 2014,103(11): 3777-97). In BioRAM, risk is defined as not achieving the intended in vivo drug product performance, and success is assessed by time to decision-making and action. Emphasis on time to decision-making and time to action highlights the value of well-formulated critical questions and well-designed and conducted integrated studies. This commentary describes and illustrates application of the BioRAM Scoring Grid, a companion to the BioRAM strategy, which guides implementation of such an integrated strategy encompassing 12 critical areas and 6 assessment stages. Application of the BioRAM Scoring Grid is illustrated using published literature. Organizational considerations for implementing BioRAM strategy, including the interactions, function, and skillsets of the BioRAM group members, are also reviewed. As a creative and innovative systems approach, we believe that BioRAM is going to have a broad-reaching impact, influencing drug development and leading to unique collaborations influencing how we learn, and leverage and share knowledge. Published by Elsevier Inc.

Mode trap for absorbing transverse modes of an accelerated electron beam

DOEpatents

Chojnacki, Eric P.

1994-01-01

A mode trap to trap and absorb transverse modes formed by a beam in a linear accelerator includes a waveguide having a multiplicity of electrically conductive (preferably copper) irises and rings, each iris and ring including an aperture, and the irises and rings being stacked in a side-by-side, alternating fashion such that the apertures of the irises and rings are concentrically aligned. An absorbing material layer such as a dielectric is embedded in each iris and ring, and this absorbing material layer encircles, but is circumferentially spaced from its respective aperture. Each iris and ring includes a plurality of circumferentially spaced slots around its aperture and extending radially out toward its absorbing material layer.

Potential application of a homogeneous and anisotropic slab as an angle insensitive absorbing material

NASA Astrophysics Data System (ADS)

Wang, Fang; Liu, Chang; Liu, Xiaoning; Niu, Tiaoming; Wang, Jing; Mei, Zhonglei; Qin, Jiayong

2017-06-01

In this paper, a flat and incident angle independence absorbing material is proposed and numerically verified in the optical spectrum. A homogeneous and anisotropic dielectric slab as a non-reflecting layer is first reviewed, and a feasible realization strategy of the slab is then given by using layered isotropic materials. When the loss components of the constitutive materials are not zero, the slab will work as an angle insensitive absorbing layer, and the absorption rate augments with increase of the losses. As the numerical verifications, the field distributions of a metallic cylinder and a triangular metallic object individually covered by the designed absorbing layer are demonstrated. The simulation results show that the designed absorbing layer can efficiently absorb the incident waves with the property of incident angle independence at the operation frequency. This homogeneous slab can be used in one and two dimensional situations for the realization of an invisibility cloak, a carpet cloak and even a skin cloak, if it is used to conformally cover target objects.

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

PubMed

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.

Effect of breed and age on sexual behaviour of rams.

PubMed

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 < 0.05). On the other hand, rams sniffed and nudged more young than mature ewes (P < 0.05), probably due to the fact that young ewes did not express intense symptoms of estrus. Young rams exhibited substandard sexual interest towards mature ewes, when they first came in contact with them (P < 0.05). In general, Karagouniki thin-tailed rams exhibited reduced rates of mating behaviour when they courted with Chios fat-tailed ewes in comparison with Chios rams (P < 0.05). Moreover, as the time after ram introduction passed, the frequency and duration of sexual 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.

Blackcomb: Hardware-Software Co-design for Non-Volatile Memory in Exascale Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schreiber, Robert

Summary of technical results of Blackcomb Memory Devices We explored various different memory technologies (STTRAM, PCRAM, FeRAM, and ReRAM). The progress can be classified into three categories, below. Modeling and Tool Releases Various modeling tools have been developed over the last decade to help in the design of SRAM or DRAM-based memory hierarchies. To explore new design opportunities that NVM technologies can bring to the designers, we have developed similar high-level models for NVM, including PCRAMsim [Dong 2009], NVSim [Dong 2012], and NVMain [Poremba 2012]. NVSim is a circuit-level model for NVM performance, energy, and area estimation, which supports variousmore » NVM technologies, including STT-RAM, PCRAM, ReRAM, and legacy NAND Flash. NVSim is successfully validated against industrial NVM prototypes, and it is expected to help boost architecture-level NVM-related studies. On the other side, NVMain is a cycle accurate main memory simulator designed to simulate emerging nonvolatile memories at the architectural level. We have released these models as open source tools and provided contiguous support to them. We also proposed PS3-RAM, which is a fast, portable and scalable statistical STT-RAM reliability analysis model [Wen 2012]. Design Space Exploration and Optimization With the support of these models, we explore different device/circuit optimization techniques. For example, in [Niu 2012a] we studied the power reduction technique for the application of ECC scheme in ReRAM designs and proposed to use ECC code to relax the BER (Bit Error Rate) requirement of a single memory to improve the write energy consumption and latency for both 1T1R and cross-point ReRAM designs. In [Xu 2011], we proposed a methodology to design STT-RAM for different optimization goals such as read performance, write performance and write energy by leveraging the trade-off between write current and write time of MTJ. We also studied the tradeoffs in building a reliable crosspoint ReRAM array [Niu 2012b]. We have conducted an in depth analysis of the circuit and system level design implications of multi-layer cross-point Resistive RAM (MLCReRAM) from performance, power and reliability perspectives [Xu 2013]. The objective of this study is to understand the design trade-offs of this technology with respect to the MLC Phase Change Memory (MLCPCM).Our MLC ReRAM design at the circuit and system levels indicates that different resistance allocation schemes, programming strategies, peripheral designs, and material selections profoundly affect the area, latency, power, and reliability of MLC ReRAM. Based on this analysis, we conduct two case studies: first we compare MLC ReRAM design against MLC phase-change memory (PCM) and multi-layer cross-point ReRAM design, and point out why multi-level ReRAM is appealing; second we further explore the design space for MLC ReRAM. Architecture and Application We explored hybrid checkpointing using phase-change memory for future exascale systems [Dong 2011] and showed that the use of nonvolatile memory for local checkpointing significantly increases the number of faults covered by local checkpoints and reduces the probability of a global failure in the middle of a global checkpoint to less than 1%. We also proposed a technique called i2WAP to mitigate the write variations in NVM-based last-level cache for the improvement of the NVM lifetime [Wang 2013]. Our wear leveling technique attempts to work around the limitations of write endurance by arranging data access so that write operations can be distributed evenly across all the storage cells. During our intensive research on fault-tolerant NVM design, we found that ECC cannot effectively tolerate hard errors from limited write endurance and process imperfection. Therefore, we devised a novel Point and Discard (PAD) architecture in in [ 2012] as a hard-error-tolerant architecture for ReRAM-based Last Level Caches. PAD improves the lifetime of ReRAM caches by 1.6X-440X under different process variations without performance overhead in the system's early life. We have investigated the applicability of NVM for persistent memory design [Zhao 2013]. New byte addressable NVM enables fast persistent memory that allows in-memory persistent data objects to be updated with much higher throughput. Despite the significant improvement, the performance of these designs is only 50% of the native system with no persistence support, due to the logging or copy-on-write mechanisms used to update the persistent memory. A challenge in this approach is therefore how to efficiently enable atomic, consistent, and durable updates to ensure data persistence that survives application and/or system failures. We have designed a persistent memory system, called Klin, that can provide performance as close as that of the native system. The Klin design adopts a non-volatile cache and a non-volatile main memory for constructing a multi-versioned durable memory system, enabling atomic updates without logging or copy-on-write. Our evaluation shows that the proposed Kiln mechanism can achieve up to 2X of performance improvement to NVRAM-based persistent memory employing write-ahead logging. In addition, our design has numerous practical advantages: a simple and intuitive abstract interface, microarchitecture-level optimizations, fast recovery from failures, and no redundant writes to slow non-volatile storage media. The work was published in MICRO 2013 and received Best Paper Honorable Mentioned Award.« less

ACS Science Data Buffer Check/Self-Tests for CS Buffer RAM and MIE RAM

NASA Astrophysics Data System (ADS)

Balzano, V.

2001-07-01

The ACS Science Buffer RAM is checked for bit flips during SAA passages. This is followed by a Control Section {CS} self-test consisting of writing/reading a specified bit pattern from each memory location in Buffer RAM and a similar test for MIE RAM. The MIE must be placed in BOOT mode for its self-test. The CS Buffer RAM self-test as well as the bit flip tests are all done with the CS in Operate.

COS Side 2 Science Data Buffer Check/Self-Tests for CS Buffer RAM and DIB RAM

NASA Astrophysics Data System (ADS)

Bacinski, John

2013-10-01

The COS Science Buffer RAM is checked for bit flips during SAA passages. This is followed by a Control Section {CS} self-test consisting of writing/reading a specified bit pattern from each memory location in Buffer RAM and a similar test for DIB RAM. The DIB must be placed in BOOT mode for its self-test. The CS Buffer RAM self-test as well as the bit flip tests are all done with the CS in Operate.

ACS Science Data Buffer Check/Self-Tests for CS Buffer RAM and MIE RAM

NASA Astrophysics Data System (ADS)

Welty, Alan

2005-07-01

The ACS Science Buffer RAM is checked for bit flips during SAA passages. Thisis followed by a Control Section {CS} self-test consisting of writing/reading a specified bit pattern from each memory location in Buffer RAM and a similar test for MIE RAM. The MIE must be placed in BOOT mode for its self-test. The CS Buffer RAM self-test as well as the bit flip tests are all done with the CS in Operate.

Short term, repeated exposure to rams during the transition into the breeding season improves the synchrony of mating in the breeding season.

PubMed

Hawken, P A R; Evans, A C O; Beard, A P

2008-07-01

The ram effect is widely used in Mediterranean breeds of sheep but its use in temperate genotypes is restricted by breed seasonality. However, ewes from these highly seasonal genotypes are sensitive to stimulation by rams close to the onset of the natural breeding season. In this study we developed a pre-mating protocol of repeated, short-term exposure to rams (fence-line contact or vasectomised rams) beginning during late anoestrus and continuing into the breeding season. We hypothesised that this pre-mating protocol would synchronise the distribution of mating of North of England Mule ewes during the breeding season above that observed in ewes isolated from rams prior to mating. Ram-exposed ewes were given contact with rams (Experiment 1: fence-line; FR, n=94 and Experiment 2: vasectomised rams; VR; n=103) for 24h on Days 0 (10 September), 17 and 34 of the experiment. Control ewes (Experiment 1; FC, n=98 and Experiment 2; VC; n=106) remained isolated from rams prior to mating. In Experiment 2, a subset of VR (n=35) and VC ewes (n=35) were blood sampled twice weekly to monitor their pre-mating progesterone profiles. At mating, harnessed entire rams were introduced, 17 or 16 days after the last ram exposure (Experiments 1 and 2) and raddle marks were recorded daily. The median time from ram introduction to mating was reduced in ewes given both fence-line and vasectomised ram contact (P<0.001), leading to a more compact distribution of mating and lambing (At least P<0.01). In the blood sampled VR ewes, there was a progressive decline in the number of days from ram exposure to the onset of dioestrus (at least P<0.05). This observation indicates that the cycles in VR ewes became increasingly synchronised over the pre-mating period, a pattern not evident in VC ewes. In conclusion, repeated, short-term exposure of ewes to rams during the transition into the breeding season is an effective method of synchronising the distribution of mating during the breeding season.

Method and apparatus for measuring properties of particle beams using thermo-resistive material properties

DOEpatents

Degtiarenko, Pavel V.; Dotson, Danny Wayne

2007-10-09

A beam position detector for measuring the properties of a charged particle beam, including the beam's position, size, shape, and intensity. One or more absorbers are constructed of thermo-resistive material and positioned to intercept and absorb a portion of the incoming beam power, thereby causing local heating of each absorber. The local temperature increase distribution across the absorber, or the distribution between different absorbers, will depend on the intensity, size, and position of the beam. The absorbers are constructed of a material having a strong dependence of electrical resistivity on temperature. The beam position detector has no moving parts in the vicinity of the beam and is especially suited to beam areas having high ionizing radiation dose rates or poor beam quality, including beams dispersed in the transverse direction and in their time radio frequency structure.

Sound-absorbing slabs and structures based on granular materials (bound and unbound). [energy absorbing efficiency of porous material

NASA Technical Reports Server (NTRS)

Petre-Lazar, S.; Popeea, G.

1974-01-01

Sound absorbing slabs and structures made up of bound or unbound granular materials are considered and how to manufacture these elements at the building site. The raw material is a single grain powder (sand, expanded blast furnace slag, etc.) that imparts to the end products an apparent porosity of 25-45% and an energy dissipation within the structure leading to absorption coefficients that can be compared with those of mineral wool and urethane.

Refractory thermowell for continuous high temperature measurement of molten metal

DOEpatents

Thiesen, Todd J.

1992-01-01

An apparatus for the continuous high temperature measurement of materials in vessels lined with rammed or cast refractory materials. A refractory housing member is integral with the refractory lining of the vessel and contains a plurality of high temperature sensing means, such as thermocouples. A face of the housing is flush with the refractory lining and contacts the high temperature material contained in the vessel. Continuous temperature measurement is achieved by a means which is coupled to the thermocouples for indicating the temperature.

Mode trap for absorbing transverse modes of an accelerated electron beam

DOEpatents

Chojnacki, E.P.

1994-05-31

A mode trap to trap and absorb transverse modes formed by a beam in a linear accelerator includes a waveguide having a multiplicity of electrically conductive (preferably copper) irises and rings, each iris and ring including an aperture, and the irises and rings being stacked in a side-by-side, alternating fashion such that the apertures of the irises and rings are concentrically aligned. An absorbing material layer such as a dielectric is embedded in each iris and ring, and this absorbing material layer encircles, but is circumferentially spaced from its respective aperture. Each iris and ring includes a plurality of circumferentially spaced slots around its aperture and extending radially out toward its absorbing material layer. 9 figs.

COS Science Data Buffer Check/Self-Tests for CS Buffer RAM and DIB RAM

NASA Astrophysics Data System (ADS)

Welty, Alan

2009-07-01

The COS Science Buffer RAM is checked for bit flips during SAA passages. This is followed by a Control Section {CS} self-test consisting of writing/reading a specified bit pattern from each memory location in Buffer RAM and a similar test for DIB RAM. The DIB must be placed in BOOT mode for its self-test. The CS Buffer RAM self-test as well as the bit flip tests are all done with the CS in Operate.Supports Activity COS-03

Acoustic wave propagation in heterogeneous structures including experimental validation

NASA Technical Reports Server (NTRS)

Baumeister, Kenneth J.; Dahl, Milo D.

1989-01-01

A finite element model was developed to solve for the acoustic pressure and energy fields in a heterogeneous suppressor. The derivations from the governing equations assumed that the material properties could vary with position resulting in a heterogeneous variable property two-dimensional wave equation. This eliminated the necessity of finding the boundary conditions between different materials. For a two-media region consisting of part air and part bulk absorber, a model was used to describe the bulk absorber properties in two directions. Complex metallic structures inside the air duct are simulated by simply changing element properties from air to the structural material in a pattern to describe the desired shapes. To verify the numerical theory, experiments were conducted without flow in a rectangular duct with a single folded cavity mounted above the duct and absorbing material mounted inside a cavity. Changes in a nearly plane wave sound field were measured on the wall opposite the absorbing cavity. Fairly good agreement was found in the standing wave pattern upstream of the absorber and in the decay of pressure level opposite the absorber, as a function of distance along the duct. The finite element model provides a convenient method for evaluating the acoustic properties of bulk absorbers.

Microcapsule and methods of making and using microcapsules

DOEpatents

Okawa, David C.; Pastine, Stefan J.; Zettl, Alexander K.; Frechet, Jean M.J.

2014-09-02

An embodiment of a microcapsule includes a shell surrounding a space, a liquid within the shell, and a light absorbing material within the liquid. An embodiment of a method of making microcapsules includes forming a mixture of a light absorbing material and an organic solution. An emulsion of the mixture and an aqueous solution is then formed. A polymerization agent is added to the emulsion, which causes microcapsules to be formed. Each microcapsule includes a shell surrounding a space, a liquid within the shell, and light absorbing material within the liquid. An embodiment of a method of using microcapsules includes providing phototriggerable microcapsules within a bulk material. Each of the phototriggerable microcapsules includes a shell surrounding a space, a chemically reactive material within the shell, and a light absorbing material within the shell. At least some of the phototriggerable microcapsules are exposed to light, which causes the chemically reactive material to release from the shell and to come into contact with bulk material.

Magnetic field effects on microwave absorbing materials

NASA Technical Reports Server (NTRS)

Goldberg, Ira; Hollingsworth, Charles S.; Mckinney, Ted M.

1991-01-01

The objective of this program was to gather information to formulate a microwave absorber that can work in the presence of strong constant direct current (DC) magnetic fields. The program was conducted in four steps. The first step was to investigate the electrical and magnetic properties of magnetic and ferrite microwave absorbers in the presence of strong magnetic fields. This included both experimental measurements and a literature survey of properties that may be applicable to finding an appropriate absorbing material. The second step was to identify those material properties that will produce desirable absorptive properties in the presence of intense magnetic fields and determine the range of magnetic field in which the absorbers remain effective. The third step was to establish ferrite absorber designs that will produce low reflection and adequate absorption in the presence of intense inhomogeneous static magnetic fields. The fourth and final step was to prepare and test samples of such magnetic microwave absorbers if such designs seem practical.

Diesel NO.sub.x reduction by plasma-regenerated absorbend beds

DOEpatents

Wallman, P. Henrik; Vogtlin, George E.

1998-01-01

Reduction of NO.sub.x from diesel engine exhaust by use of plasma-regenerated absorbent beds. 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.degree. C. which is in the area of diesel engine exhaust temperatures.

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

NASA Astrophysics Data System (ADS)

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.

The interbreeding of sheep and goats.

PubMed Central

Kelk, D A; Gartley, C J; Buckrell, B C; King, W A

1997-01-01

To determine the outcome of interbreeding sheep and goats, ewes and does were bred to rams and bucks, and their embryos recovered. Pregnancy was monitored in 2 does bred to a ram. Fertilization rates in ram X does, buck X does, ram X ewes, and buck X ewes were 72%, 96%, 90%, and 0%, respectively. Ram X doe fetuses died at 5 to 10 weeks. PMID:9105723

Epididymitis Caused by Brucella ovis in a Southern Ontario Sheep Flock

PubMed Central

Buckrell, Brian C.; McEwen, Scott A.; Johnson, Walter H.; Savage, Neale C.

1985-01-01

Epididymitis was diagnosed in three rams in a commercial sheep flock in southern Ontario. The affected rams had palpably enlarged epididymides and two rams had semen which contained inflammatory cells and was of poor quality. Serum compliment fixation titers for Brucella ovis were 1:20, 1:80 and 1:90. Five other rams in the flock were clinically normal and without titers. Two of the affected rams had lesions similar to those produced by experimental infection with B. ovis. The infection in the rams had no apparent affect on ewe performance. The source of the infection remains unknown, but the rams were purchased from a flock which had imported ewes from the western U.S.A. ImagesFigure 1.Figure 2. PMID:17422577

Purifying Water by Imbibition

NASA Technical Reports Server (NTRS)

Lawton, E. A.

1986-01-01

Concept for purifying water uses absorbent material to remove organic substances. Entire bulk of material employed, not just surface. Proposed purification process uses inexpensive equipment and low energy. Material is methyl acrylate polymer. Material cheap and regenerated by rinsing with methanol or by allowing absorbed compounds to evaporate from it.

Sexual behaviour of rams: male orientation and its endocrine correlates.

PubMed

Resko, J A; Perkins, A; Roselli, C E; Stellflug, J N; Stormshak, F K

1999-01-01

The components of heterosexual behaviour in rams are reviewed as a basis for understanding partner preference behaviour. A small percentage of rams will not mate with oestrous females and if given a choice will display courtship behaviour towards another ram in preference to a female. Some of the endocrine profiles of these male-oriented rams differ from those of heterosexual controls. These differences include reduced serum concentrations of testosterone, oestradiol and oestrone, reduced capacity to produce testosterone in vitro, and reduced capacity to aromatize androgens in the preoptic-anterior hypothalamus of the brain. Our observation that aromatase activity is significantly lower in the preoptic-anterior hypothalamic area of male-oriented rams than in female-oriented rams may indicate an important neurochemical link to sexual behaviour that should be investigated. The defect in steroid hormone production by the adult testes of the male-oriented ram may represent a defect that can be traced to the fetal testes. If this contention is correct, partner preference behaviour of rams may also be traceable to fetal development and represent a phenomenon of sexual differentiation.

Concentrating light in Cu(In,Ga)Se2 solar cells

NASA Astrophysics Data System (ADS)

Schmid, Martina; Yin, Guanchao; Song, Min; Duan, Shengkai; Heidmann, Berit; Sancho-Martinez, Diego; Kämmer, Steven; Köhler, Tristan; Manley, Phillip; Lux-Steiner, Martha Ch.

2017-01-01

Light concentration has proven beneficial for solar cells, most notably for highly efficient but expensive absorber materials using high concentrations and large scale optics. Here, we investigate the light concentration for cost-efficient thin-film solar cells that show nano- or microtextured absorbers. Our absorber material of choice is Cu(In,Ga)Se2 (CIGSe), which has a proven stabilized record efficiency of 22.6% and which-despite being a polycrystalline thin-film material-is very tolerant to environmental influences. Taking a nanoscale approach, we concentrate light in the CIGSe absorber layer by integrating photonic nanostructures made from dielectric materials. The dielectric nanostructures give rise to resonant modes and field localization in their vicinity. Thus, when inserted inside or adjacent to the absorber layer, absorption and efficiency enhancement are observed. In contrast to this internal absorption enhancement, external enhancement is exploited in the microscaled approach: mm-sized lenses can be used to concentrate light onto CIGSe solar cells with lateral dimensions reduced down to the micrometer range. These micro solar cells come with the benefit of improved heat dissipation compared with the large scale concentrators and promise compact high-efficiency devices. Both approaches of light concentration allow for reduction in material consumption by restricting the absorber dimension either vertically (ultrathin absorbers for dielectric nanostructures) or horizontally (microabsorbers for concentrating lenses) and have significant potential for efficiency enhancement.

Method and apparatus for determining the content and distribution of a thermal neutron absorbing material in an object

DOEpatents

Crane, Thomas W.

1986-01-01

The disclosure is directed to an apparatus and method for determining the content and distribution of a thermal neutron absorbing material within an object. Neutrons having an energy higher than thermal neutrons are generated and thermalized. The thermal neutrons are detected and counted. The object is placed between the neutron generator and the neutron detector. The reduction in the neutron flux corresponds to the amount of thermal neutron absorbing material in the object. The object is advanced past the neutron generator and neutron detector to obtain neutron flux data for each segment of the object. The object may comprise a space reactor heat pipe and the thermal neutron absorbing material may comprise lithium.

Method and apparatus for determining the content and distribution of a thermal neutron absorbing material in an object

DOEpatents

Crane, T.W.

1983-12-21

The disclosure is directed to an apparatus and method for determining the content and distribution of a thermal neutron absorbing material within an object. Neutrons having an energy higher than thermal neutrons are generated and thermalized. The thermal neutrons are detected and counted. The object is placed between the neutron generator and the neutron detector. The reduction in the neutron flux corresponds to the amount of thermal neutron absorbing material in the object. The object is advanced past the neutron generator and neutron detector to obtain neutron flux data for each segment of the object. The object may comprise a space reactor heat pipe and the thermal neutron absorbing material may comprise lithium.

HyRAM V1.0 User Guide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Groth, Katrina M.; Zumwalt, Hannah Ruth; Clark, Andrew Jordan

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 releasemore » 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.« less

50 CFR 660.15 - Equipment requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... perceived weight of water, slime, mud, debris, or other materials. Scale printouts must show: (A) The vessel... with Pentium 75-MHz or higher. Random Access Memory (RAM) must have sufficient megabyte (MB) space to... space of 217 MB or greater. A CD-ROM drive with a Video Graphics Adapter (VGA) or higher resolution...

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

NASA Astrophysics Data System (ADS)

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.

Absorbent product and articles made therefrom

NASA Technical Reports Server (NTRS)

Dawn, F. S.; Correale, J. V. (Inventor)

1982-01-01

A multilayer absorbent product for use in contact with the skin to absorb fluids is described. The product has a water pervious facing layer for contacting the skin, and a first fibrous wicking layer overlaying the water pervious layer. A first container section is defined by inner and outer layers of a water pervious wicking material in between a first absorbent mass and a second container section defined by inner and outer layers of a water pervious wicking material between what is disposed a second absorbent mass, and a liquid impermeable/gas permeable layer overlaying the second fibrous wicking layer.

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

PubMed

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 < 0.05). Glucose, total protein and creatinine were increased as a result of 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 < 0.05). Semen traits were less affected by treatment; WD rams consistently had superior sperm concentrations than C animals; and statistical significances were reached in 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 < 0.001), their frequency of mount attempts decreased [6.8 vs. 5.2 (SEM 0.1); p < 0.001] and their flehmen reaction intensity was negatively affected (p < 0.05). 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.

Characterization of Crude Oil Degrading Bacteria Isolated from Contaminated Soils Surrounding Gas Stations.

PubMed

Abou-Shanab, Reda A I; Eraky, Mohamed; Haddad, Ahmed M; Abdel-Gaffar, Abdel-Rahman B; Salem, Ahmed M

2016-11-01

A total of twenty bacterial cultures were isolated from hydrocarbon contaminated soil. Of the 20 isolates, RAM03, RAM06, RAM13, and RAM17 were specifically chosen based on their relatively higher growth on salt medium amended with 4 % crude oil, emulsion index, surface tension, and degradation percentage. These bacterial cultures had 16S rRNA gene sequences that were most similar to Ochrobactrum cytisi (RAM03), Ochrobactrum anthropi (RAM06 and RAM17), and Sinorhizobium meliloti (RAM13) with 96 %, 100 % and 99 %, and 99 % similarity. The tested strains revealed a promising potential for bioremediation of petroleum oil contamination as they could degrade >93 % and 54 % of total petroleum hydrocarbons (TPHs) in a liquid medium and soil amended with 4 % crude oil, respectively, after 30 day incubation. These bacteria could effectively remove both aliphatic and aromatic petroleum hydrocarbons. In conclusion, these strains could be considered as good prospects for their application in bioremediation of hydrocarbon contaminated environment.

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

PubMed

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 activating the Ca(2+)-induced mitochondrial membrane permeability transition (MPT).

mRNA Cap Methyltransferase, RNMT-RAM, Promotes RNA Pol II-Dependent Transcription.

PubMed

Varshney, Dhaval; Lombardi, Olivia; Schweikert, Gabriele; Dunn, Sianadh; Suska, Olga; Cowling, Victoria H

2018-05-01

mRNA cap addition occurs early during RNA Pol II-dependent transcription, facilitating pre-mRNA processing and translation. We report that the mammalian mRNA cap methyltransferase, RNMT-RAM, promotes RNA Pol II transcription independent of mRNA capping and translation. In cells, sublethal suppression of RNMT-RAM reduces RNA Pol II occupancy, net mRNA synthesis, and pre-mRNA levels. Conversely, expression of RNMT-RAM increases transcription independent of cap methyltransferase activity. In isolated nuclei, recombinant RNMT-RAM stimulates transcriptional output; this requires the RAM RNA binding domain. RNMT-RAM interacts with nascent transcripts along their entire length and with transcription-associated factors including the RNA Pol II subunits SPT4, SPT6, and PAFc. Suppression of RNMT-RAM inhibits transcriptional markers including histone H2BK120 ubiquitination, H3K4 and H3K36 methylation, RNA Pol II CTD S5 and S2 phosphorylation, and PAFc recruitment. These findings suggest that multiple interactions among RNMT-RAM, RNA Pol II factors, and RNA along the transcription unit stimulate transcription. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Harnessing structural darkness in the visible and infrared wavelengths for a new source of light.

PubMed

Huang, Jianfeng; Liu, Changxu; Zhu, Yihan; Masala, Silvia; Alarousu, Erkki; Han, Yu; Fratalocchi, Andrea

2016-01-01

Engineering broadband light absorbers is crucial to many applications, including energy-harvesting devices and optical interconnects. The performances of an ideal absorber are that of a black body, a dark material that absorbs radiation at all angles and polarizations. Despite advances in micrometre-thick films, the absorbers available to date are still far from an ideal black body. Here, we describe a disordered nanostructured material that shows an almost ideal black-body absorption of 98-99% between 400 and 1,400 nm that is insensitive to the angle and polarization of the incident light. The material comprises nanoparticles composed of a nanorod with a nanosphere of 30 nm diameter attached. When diluted into liquids, a small concentration of nanoparticles absorbs on average 26% more than carbon nanotubes, the darkest material available to date. By pumping a dye optical amplifier with nanosecond pulses of ∼100 mW power, we harness the structural darkness of the material and create a new type of light source, which generates monochromatic emission (∼5 nm wide) without the need for any resonance. This is achieved through the dynamics of light condensation in which all absorbed electromagnetic energy spontaneously generates single-colour energy pulses.

Design on the wide band absorber with low density based on the particle distribution

NASA Astrophysics Data System (ADS)

Zheng, Dianliang; Liu, Ting; Liu, Longbin; Xu, Yonggang

2018-04-01

In order to widen the absorbing band, an equivalent gradient structure absorber was designed based on the particle distribution. Firstly, the electromagnetic parameter of the absorbent with uniform dispersion was tested using the vector network analyzer in 8-18 GHz. Three different equivalent materials of the spherical, square and hexagon empty shape were designed. The scattering parameters and the monostatic reflection loss (RL) of the periodic structural materials were simulated in the commercial software. Then the effective permittivity and the permeability was derived by the Nicolson-Ross-Weir algorithm and fitted by Maxwell-Garnett mixing rule. The results showed that the simulated reflectance and transmission parameters of equivalent composites with the different shapes were very close. The derived effective permittivity and permeability of the composite with different absorbent content was also close, and the average deviation was about 0.52 + j0.15 and 0.15 + j0.01 respectively. Finally, the wide band absorbing material was designed using the genetic algorithm. The optimized RL result showed that the absorbing composites with thickness 3 mm had an excellent absorbing property (RL <-10 dB) in 8-18 GHz, the equivalent absorber density could be decreased 30.7% compared with the uniform structure.

Realtime photoacoustic microscopy in vivo with a 30-MHz ultrasound array transducer.

PubMed

Zemp, Roger J; Song, Liang; Bitton, Rachel; Shung, K Kirk; Wang, Lihong V

2008-05-26

We present a novel high-frequency photoacoustic microscopy system capable of imaging the microvasculature of living subjects in realtime to depths of a few mm. The system consists of a high-repetition-rate Q-switched pump laser, a tunable dye laser, a 30-MHz linear ultrasound array transducer, a multichannel high-frequency data acquisition system, and a shared-RAM multi-core-processor computer. Data acquisition, beamforming, scan conversion, and display are implemented in realtime at 50 frames per second. Clearly resolvable images of 6-microm-diameter carbon fibers are experimentally demonstrated at 80 microm separation distances. Realtime imaging performance is demonstrated on phantoms and in vivo with absorbing structures identified to depths of 2.5-3 mm. This work represents the first high-frequency realtime photoacoustic imaging system to our knowledge.

Perpendicular STT_RAM cell in 8 nm technology node using Co1/Ni3(1 1 1)||Gr2||Co1/Ni3(1 1 1) structure as magnetic tunnel junction

NASA Astrophysics Data System (ADS)

Varghani, Ali; Peiravi, Ali; Moradi, Farshad

2018-04-01

The perpendicular anisotropy Spin-Transfer Torque Random Access Memory (P-STT-RAM) is considered to be a promising candidate for high-density memories. Many distinct advantages of Perpendicular Magnetic Tunnel Junction (P-MTJ) compared to the conventional in-plane MTJ (I-MTJ) such as lower switching current, circular cell shape that facilitates manufacturability in smaller technology nodes, large thermal stability, smaller cell size, and lower dipole field interaction between adjacent cells make it a promising candidate as a universal memory. However, for small MTJ cell sizes, the perpendicular technology requires new materials with high polarization and low damping factor as well as low resistance area product of a P-MTJ in order to avoid a high write voltage as technology is scaled down. A new graphene-based STT-RAM cell for 8 nm technology node that uses high perpendicular magnetic anisotropy cobalt/nickel (Co/Ni) multilayer as magnetic layers is proposed in this paper. The proposed junction benefits from enough Tunneling Magnetoresistance Ratio (TMR), low resistance area product, low write voltage, and low power consumption that make it suitable for 8 nm technology node.

Absorber Materials for Transition-Edge Sensor X-ray Microcalorimeters

NASA Technical Reports Server (NTRS)

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

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

PubMed Central

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 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. PMID:26816631

Ram seminal plasma improves pregnancy rates in ewes cervically inseminated with ram semen stored at 5 °C for 24 hours.

PubMed

López-Pérez, A; Pérez-Clariget, R

2012-01-15

In this study, we compared pregnancy rates obtained using ram semen stored at 5 °C for 24 h, with ram or bull seminal plasma (SP) added to TRIS-egg yolk extender. During the breeding period, 670 adult Corriedale ewes were cervically inseminated with semen (2 × 10(8) sperm in a volume of 0.2 mL) from eight adult Corriedale rams. Ejaculates, obtained using an artificial vagina, were split into three aliquots and diluted with the following: TRIS-egg yolk based extender (T), T + 30% ram SP (R), or T + 30% bull SP (B). Samples were refrigerated and stored at 5 °C for 24 h until used for AI. Pregnancy was assessed by ultrasonography 35 to 40 d after AI. Pregnancy rate was not affected by ram (P = 0.77) or breeding period (P = 0.43), and there were no interactions between extender and ram (P = 0.94), or extender and breeding period (P = 0.24). However, there was an effect of extender (P = 0.0009) on pregnancy rates; ram SP, but not bull SP, increased pregnancy rates compared with extender without SP (49.7, 38.1, and 31.1%, for R, B, and T respectively). In conclusion, ram SP added to TRIS-egg yolk extender had a beneficial effect on the pregnancy rate of ram sperm stored at 5 °C for 24 h and used for cervical insemination of ewes. Copyright © 2012 Elsevier Inc. All rights reserved.

Lanthanum hexaboride for solar energy applications.

PubMed

Sani, Elisa; Mercatelli, Luca; Meucci, Marco; Zoli, Luca; Sciti, Diletta

2017-04-06

We investigate the optical properties of LaB 6 - based materials, as possible candidates for solid absorbers in Concentrating Solar Power (CSP) systems. Bulk LaB 6 materials were thermally consolidated by hot pressing starting from commercial powders. To assess the solar absorbance and spectral selectivity properties, room-temperature hemispherical reflectance spectra were measured from the ultraviolet to the mid-infrared, considering different compositions, porosities and surface roughnesses. Thermal emittance at around 1100 K has been measured. Experimental results showed that LaB 6 can have a solar absorbance comparable to that of the most advanced solar absorber material in actual plants such as Silicon Carbide, with a higher spectral selectivity. Moreover, LaB 6 has also the appealing characteristics to be a thermionic material, so that it could act at the same time both as direct high-temperature solar absorber and as electron source, significantly reducing system complexity in future concentrating solar thermionic systems and bringing a real innovation in this field.

Plasma-assisted microwave processing of materials

NASA Technical Reports Server (NTRS)

Barmatz, Martin (Inventor); Jackson, Henry (Inventor); Ylin, Tzu-yuan (Inventor)

1998-01-01

A microwave plasma assisted method and system for heating and joining materials. The invention uses a microwave induced plasma to controllably preheat workpiece materials that are poorly microwave absorbing. The plasma preheats the workpiece to a temperature that improves the materials' ability to absorb microwave energy. The plasma is extinguished and microwave energy is able to volumetrically heat the workpiece. Localized heating of good microwave absorbing materials is done by shielding certain parts of the workpiece and igniting the plasma in the areas not shielded. Microwave induced plasma is also used to induce self-propagating high temperature synthesis (SHS) process for the joining of materials. Preferably, a microwave induced plasma preheats the material and then microwave energy ignites the center of the material, thereby causing a high temperature spherical wave front from the center outward.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steinmann, Vera; Chakraborty, Rupak; Rekemeyer, Paul H.

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 lowermore » 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.« less

Determining the Absorbance Spectra of Photochromic Materials From Measured Spectrophotometer Data

NASA Technical Reports Server (NTRS)

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.

Research and Applications Modules (RAM). Phase B study: Executive summary

NASA Technical Reports Server (NTRS)

1972-01-01

The design, development, and characteristics of the Research and Applications Module (RAM) system is discussed. The RAM system is a family of payload carriers that can be delivered to and retrieved from low earth orbit by the space shuttle. The RAM payload carriers are used to support diverse technological and scientific investigations. The NASA study objectives, the relationship of the RAM payload carriers to other systems in the orbital space program, and recommendations for additional effort are presented.

A Review: Characteristics of Noise Absorption Material

NASA Astrophysics Data System (ADS)

Amares, S.; Sujatmika, E.; Hong, T. W.; Durairaj, R.; Hamid, H. S. H. B.

2017-10-01

Noise is always treated as a nuisance to human and even noise pollution appears in the environmental causing discomfort. This also concerns the engineering design that tends to cultivate this noise propagation. Solution such as using material to absorb the sound have been widely used. The fundamental of the sound absorbing propagation, sound absorbing characteristics and its factors are minimally debated. Furthermore, the method in order to pertain sound absorbing related to the sound absorption coefficient is also limited, as many studies only contributes in result basis and very little in literature aspect. This paper revolves in providing better insight on the importance of sound absorption and the materials factors in obtaining the sound absorption coefficient.

Freeze-Dried Carbon Nanotube Aerogels for High-Frequency Absorber Applications.

PubMed

Anoshkin, Ilya V; Campion, James; Lioubtchenko, Dmitri V; Oberhammer, Joachim

2018-06-13

A novel technique for millimeter wave absorber material embedded in a metal waveguide is proposed. The absorber material is a highly porous carbon nanotube (CNT) aerogel prepared by a freeze-drying technique. CNT aerogel structures are shown to be good absorbers with a low reflection coefficient, less than -12 dB at 95 GHz. The reflection coefficient of the novel absorber is 3-4 times lower than that of commercial absorbers with identical geometry. Samples prepared by freeze-drying at -25 °C demonstrate resonance behavior, while those prepared at liquid nitrogen temperature (-196 °C) exhibit a significant decrease in reflection coefficient, with no resonant behavior. CNT absorbers of identical volume based on wet-phase drying preparation show significantly worse performance than the CNT aerogel absorbers prepared by freeze-drying. Treatment of the freeze-dried CNT aerogel with n- and p-dopants (monoethanolamine and iodine vapors, respectively) shows remarkable improvement in the performance of the waveguide embedded absorbers, reducing the reflection coefficient by 2 dB across the band.

Metamaterial Absorber for Electromagnetic Waves in Periodic Water Droplets

PubMed Central

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

2015-01-01

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. PMID:26354891

Metamaterial Absorber for Electromagnetic Waves in Periodic Water Droplets

NASA Astrophysics Data System (ADS)

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

2015-09-01

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.

Metamaterial Absorber for Electromagnetic Waves in Periodic Water Droplets.

PubMed

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.

Remote Attitude Measurement Sensor (RAMS)

NASA Technical Reports Server (NTRS)

Davis, H. W.

1989-01-01

Remote attitude measurement sensor (RAMS) offers a low-cost, low-risk, proven design concept that is based on mature, demonstrated space sensor technology. The electronic design concepts and interpolation algorithms were tested and proven in space hardware like th Retroreflector Field Tracker and various star trackers. The RAMS concept is versatile and has broad applicability to both ground testing and spacecraft needs. It is ideal for use as a precision laboratory sensor for structural dynamics testing. It requires very little set-up or preparation time and the output data is immediately usable without integration or extensive analysis efforts. For on-orbit use, RAMS rivals any other type of dynamic structural sensor (accelerometer, lidar, photogrammetric techniques, etc.) for overall performance, reliability, suitability, and cost. Widespread acceptance and extensive usage of RAMS will occur only after some interested agency, such as OAST, adopts the RAMS concept and provides the funding support necessary for further development and implementation of RAMS for a specific program.

Evaluation of a nutritional strategy to increase ovulation rate in merino ewes mated in late spring-early summer.

PubMed

Nottle, M B; Kleemann, D O; Grosser, T I; Seamark, R F

1997-07-01

A nutritional strategy for increasing ovulation rate in Merino ewes mated in late spring-early summer was evaluated on two commercial farms. The strategy used the 'ram effect' to induce oestrus in seasonally anoestrus ewes and supplementary feeding of lupin grain six days prior to oestrus to increase ovulation rate. Ewes that had been isolated from rams for 6 weeks were exposed to vasectomised rams for 2 weeks and then mated to fertile rams for 6 weeks. Feeding 500 g lupins/head/day for 14 days commencing 12 days after the introduction of vasectomised rams, increased the number of ovulations from 126 to 146 per 100 ewes exposed to rams (P < 0.05). This increase was reflected in an improvement in fecundity (lambs born per ewe lambing; P < 0.05) but not fertility (ewes lambing per ewe mated to rams). Net reproductive performance (the product of fertility, fecundity and lamb survival) was increased by 11 lambs weaned per 100 ewes exposed to rams due to lupin supplementation at mating.

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

NASA Technical Reports Server (NTRS)

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.

Effects of Long-Term Flutamide Treatment during Development on Sexual Behavior and Hormone Responsiveness in Rams

PubMed Central

Roselli, Charles E.; Meaker, Mary; Stormshak, Fred; Estill, Charles T.

2016-01-01

Testosterone (T) exposure during midgestation differentiates neural circuits controlling sex-specific behaviors and patterns of gonadotropin secretion in male sheep. T acts through androgen receptors (AR) and/or after aromatization to estradiol and binding to estrogen receptors. The current study assessed the role of AR activation in male sexual differentiation. We compared rams that were exposed to the AR antagonist flutamide (Flu) throughout the critical period (i.e. day 30 – 90 of gestation) to control rams and ewes that received no prenatal treatments. The external genitalia of all Flu rams were phenotypically female. Testes were positioned subcutaneously in the inguinal region of the abdomen, exhibited seasonally impaired androgen secretion and were azospermic. Flu rams displayed male-typical precopulatory and mounting behaviors, but could not intromit or ejaculate because they lacked a penis. Flu rams exhibited greater mounting behavior than control rams, and like controls, showed sexual partner preferences for estrous ewes. Neither control nor Flu rams responded to estradiol treatments with displays of female-typical receptive behavior or LH surge responses; whereas all control ewes responded as expected. The ovine sexually dimorphic nucleus in Flu rams was intermediate in volume between control rams and ewes and significantly different from both. . These results indicate that prenatal antiandrogen exposure is not able to block male sexual differentiation in sheep and suggest that compensatory mechanisms intervene to maintain sufficient androgen stimulation during development. PMID:27005749

Effect of Ram and Zenith Exposure on the Optical Properties of Polymers in Space

NASA Technical Reports Server (NTRS)

Li, Yuachun; de Groh, Kim K.; Banks, Bruce A.; Leneghan, Halle; Asmar, Olivia

2017-01-01

The temperature of spacecraft is influenced by the solar absorptance and thermal emittance of the external spacecraft materials. Optical and thermal properties can degrade over time in the harsh low Earth orbital (LEO) space environment where spacecraft external materials are exposed to various forms of radiation, thermal cycling, and atomic oxygen. Therefore, it is important to test the durability of spacecraft materials in the space environment. One objective of the Polymers and Zenith Polymers Experiments was to determine the effect of LEO space exposure on the optical properties of various spacecraft polymers. These experiments were flown as part of the Materials International Space Station Experiment 7 (MISSE 7) mission on the exterior of the International Space Station (ISS) for 1.5 years. Samples were flown in ram, wake or zenith directions, receiving varying amounts of atomic oxygen and solar radiation exposure. Total and diffuse reflectance and transmittance of flight and corresponding control samples were obtained post-flight using a Cary 5000 UV-Vis-NIR Spectrophotometer. Integrated air mass zero solar absorptance (s) of the flight and control samples were computed from the total transmittance and reflectance, and compared. The optical data are compared with similar polymers exposed to space for four years as part of MISSE 2, and with atomic oxygen erosion data, to help understand the degradation of these polymers in the space environment. Results show that prolonged space exposure increases the solar absorptance of some materials. Knowing which polymers remain stable will benefit future spacecraft design.

Multilayer composite material and method for evaporative cooling

NASA Technical Reports Server (NTRS)

Buckley, Theresa M. (Inventor)

2002-01-01

A multilayer composite material and method for evaporative cooling of a person employs an evaporative cooling liquid that changes phase from a liquid to a gaseous state to absorb thermal energy. The evaporative cooling liquid is absorbed into a superabsorbent material enclosed within the multilayer composite material. The multilayer composite material has a high percentage of the evaporative cooling liquid in the matrix. The cooling effect can be sustained for an extended period of time because of the high percentage of phase change liquid that can be absorbed into the superabsorbent. Such a composite can be used for cooling febrile patients by evaporative cooling as the evaporative cooling liquid in the matrix changes from a liquid to a gaseous state to absorb thermal energy. The composite can be made with a perforated barrier material around the outside to regulate the evaporation rate of the phase change liquid. Alternatively, the composite can be made with an imperveous barrier material or semipermeable membrane on one side to prevent the liquid from contacting the person's skin. The evaporative cooling liquid in the matrix can be recharged by soaking the material in the liquid. The multilayer composite material can be fashioned into blankets, garments and other articles.

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

PubMed

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 (P<0.05) neurons were positive for tyrosine hydroxylase in the VTA. Sexually inactive rams had fewer (P<0.05) FRA and tyrosine hydroxylase positive neurons in the VTA than sexually 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.

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

PubMed

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.

X-ray filter for x-ray powder diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sinsheimer, John Jay; Conley, Raymond P.; Bouet, Nathalie C. D.

Technologies are described for apparatus, methods and systems effective for filtering. The filters may comprise a first plate. The first plate may include an x-ray absorbing material and walls defining first slits. The first slits may include arc shaped openings through the first plate. The walls of the first plate may be configured to absorb at least some of first x-rays when the first x-rays are incident on the x-ray absorbing material, and to output second x-rays. The filters may comprise a second plate spaced from the first plate. The second plate may include the x-ray absorbing material and wallsmore » defining second slits. The second slits may include arc shaped openings through the second plate. The walls of the second plate may be configured to absorb at least some of second x-rays and to output third x-rays.« less

Erosion Results of the MISSE 7 Polymers Experiment and Zenith Polymers Experiment After 1.5 Years of Space Exposure

NASA Technical Reports Server (NTRS)

De Groh, Kim K.; Banks, Bruce A.; Yi, Grace T.; Haloua, Athena; Imka, Emily C.; Mitchell, Gianna G.; Asmar, Olivia C.; Leneghan, Halle A.; Sechkar, Edward A.

2016-01-01

Polymers and other oxidizable materials on the exterior of spacecraft in the low Earth orbit (LEO) space environment can be eroded due to reaction with atomic oxygen (AO). Therefore, in order to design durable spacecraft it is important to know the LEO AO erosion yield (E(sub y), volume loss per incident oxygen atom) of materials susceptible to AO reaction. Two spaceflight experiments, the Polymers Experiment and the Zenith Polymers Experiment, were developed to determine the AO E(sub y) of various polymers flown in ram, wake or zenith orientations in LEO. These experiments were flown as part of the Materials International Space Station Experiment 7 (MISSE 7) mission for 1.5 years on the exterior of the International Space Station (ISS). The experiments included Kapton H(TradeMark) witness samples for AO fluence determination in ram and zenith orientations. The Polymers Experiment also included samples to determine whether AO erosion of high and low ash containing polymers is dependent on fluence. This paper provides an overview of the MISSE 7 mission, a description of the flight experiments with details on the polymers flown, the characterization techniques used, the AO fluence for each exposure orientation, and the LEO E(sub y) results. The E(sub y) values ranged from 7.99x10(exp -28)cu cm/atom for TiO2/Al2O3 coated Teflon(TradeMark) fluorinated ethylene propylene (FEP) flown in the ram orientation to 1.22x10(exp -23cu cm/atom for polyvinyl alcohol (PVOH) flown in the zenith orientation. The E(sub y) of similar samples flown in different orientations has been compared to help determine solar exposure and associated heating effects on AO erosion. The E(sub y) data from these ISS spaceflight experiments provides valuable information for LEO spacecraft design purposes.

Innovative Anti Crash Absorber for a Crashworthy Landing Gear

NASA Astrophysics Data System (ADS)

Guida, Michele; Marulo, Francesco; Montesarchio, Bruno; Bruno, Massimiliano

2014-06-01

This paper defines an innovative concept to anti-crash absorber in composite material to be integrated on the landing gear as an energy-absorbing device in crash conditions to absorb the impact energy. A composite cylinder tube in carbon fiber material is installed coaxially to the shock absorber cylinder and, in an emergency landing gear condition, collapses in order to enhance the energy absorption performance of the landing system. This mechanism has been developed as an alternative solution to a high-pressure chamber installed on the Agusta A129 CBT helicopter, which can be considered dangerous when the helicopter operates in hard and/or crash landing. The characteristics of the anti-crash device are presented and the structural layout of a crashworthy landing gear adopting the developed additional energy absorbing stage is outlined. Experimental and numerical results relevant to the material characterization and the force peaks evaluation of the system development are reported. The anti-crash prototype was designed, analysed, optimized, made and finally the potential performances of a landing gear with the additional anti-crash absorber system are tested by drop test and then correlated with a similar test without the anti-crash system, showing that appreciable energy absorbing capabilities and efficiencies can be obtained in crash conditions.

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

NASA Astrophysics Data System (ADS)

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

Enhancement mechanism of the additional absorbent on the absorption of the absorbing composite using a type-based mixing rule

NASA Astrophysics Data System (ADS)

Xu, Yonggang; Yuan, Liming; Zhang, Deyuan

2016-04-01

A silicone rubber composite filled with carbonyl iron particles and four different carbonous materials (carbon black, graphite, carbon fiber or multi-walled carbon nanotubes) was prepared using a two-roller mixture. The complex permittivity and permeability were measured using a vector network analyzer at the frequency of 2-18 GHz. Then a type-based mixing rule based on the dielectric absorbent and magnetic absorbent was proposed to reveal the enhancing mechanism on the permittivity and permeability. The enforcement effect lies in the decreased percolation threshold and the changing pending parameter as the carbonous materials were added. The reflection loss (RL) result showed the added carbonous materials enhanced the absorption in the lower frequency range, the RL decrement value being about 2 dB at 4-5 GHz with a thickness of 1 mm. All the added carbonous materials reinforced the shielding effectiveness (SE) of the composites. The maximum increment value of the SE was about 3.23 dB at 0.5 mm and 4.65 dB at 1 mm, respectively. The added carbonous materials could be effective additives for enforcing the absorption and shielding property of the absorbers.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 formore » 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.« less

Stability of an arch type shock absorber made of a rubber-like material

NASA Astrophysics Data System (ADS)

Kabrits, Sergey A.; Kolpak, Eugeny P.

2018-05-01

The paper considers the stability problem of an arch shock absorber made of a rubber-like material. As a model, the nonlinear theory of thin shells from elastomers K.F. Chernykh is used. The case of symmetrical and asymmetrical deformation of an arch shock absorber under symmetrical compression is investigated. The possibility of asymmetric bifurcation is evaluated depending on the boundary conditions.

21 CFR 74.3106 - D&C Blue No. 6.

Code of Federal Regulations, 2010 CFR

2010-04-01

... material for coloring plain or chromic collagen absorbable sutures for general surgical use; (iii) Not to exceed 0.5 percent by weight of the suture material for coloring plain or chromic collagen absorbable...

21 CFR 74.3106 - D&C Blue No. 6.

Code of Federal Regulations, 2014 CFR

2014-04-01

... material for coloring plain or chromic collagen absorbable sutures for general surgical use; (iii) Not to exceed 0.5 percent by weight of the suture material for coloring plain or chromic collagen absorbable...

21 CFR 74.3106 - D&C Blue No. 6.

Code of Federal Regulations, 2012 CFR

2012-04-01

... material for coloring plain or chromic collagen absorbable sutures for general surgical use; (iii) Not to exceed 0.5 percent by weight of the suture material for coloring plain or chromic collagen absorbable...

21 CFR 74.3106 - D&C Blue No. 6.

Code of Federal Regulations, 2011 CFR

2011-04-01

... material for coloring plain or chromic collagen absorbable sutures for general surgical use; (iii) Not to exceed 0.5 percent by weight of the suture material for coloring plain or chromic collagen absorbable...

21 CFR 74.3106 - D&C Blue No. 6.

Code of Federal Regulations, 2013 CFR

2013-04-01

... material for coloring plain or chromic collagen absorbable sutures for general surgical use; (iii) Not to exceed 0.5 percent by weight of the suture material for coloring plain or chromic collagen absorbable...

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perry, Robert James; Soloveichik, Grigorii Lev; Rubinsztajn, Malgorzata Iwona

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 2 or have a high-affinity for CO 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 2. The absorbent may be utilized in methods to reduce carbon dioxide in an exhaust gas, and finds particular utility in power plants.

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

DOEpatents

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.

Thermal tuning of infrared resonant absorbers based on hybrid gold-VO{sub 2} nanostructures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kocer, Hasan; Department of Electrical Engineering, Turkish Military Academy, 06654 Ankara; Butun, Serkan

2015-04-20

Resonant absorbers based on plasmonic materials, metamaterials, and thin films enable spectrally selective absorption filters, where absorption is maximized at the resonance wavelength. By controlling the geometrical parameters of nano/microstructures and materials' refractive indices, resonant absorbers are designed to operate at wide range of wavelengths for applications including absorption filters, thermal emitters, thermophotovoltaic devices, and sensors. However, once resonant absorbers are fabricated, it is rather challenging to control and tune the spectral absorption response. Here, we propose and demonstrate thermally tunable infrared resonant absorbers using hybrid gold-vanadium dioxide (VO{sub 2}) nanostructure arrays. Absorption intensity is tuned from 90% to 20%more » and 96% to 32% using hybrid gold-VO{sub 2} nanowire and nanodisc arrays, respectively, by heating up the absorbers above the phase transition temperature of VO{sub 2} (68 °C). Phase change materials such as VO{sub 2} deliver useful means of altering optical properties as a function of temperature. Absorbers with tunable spectral response can find applications in sensor and detector applications, in which external stimulus such as heat, electrical signal, or light results in a change in the absorption spectrum and intensity.« less

Absorber for microwave investigation in the open space

NASA Astrophysics Data System (ADS)

Kubacki, Roman; Smólski, Bogusław; Głuszewski, Wojciech; Przesmycki, Rafał; Rudyk, Karol

2017-04-01

In some circumstances there is a need to realize the Electromagnetic Compatibility (EMC) investigation not in the specialized anechoic chamber but in the open space. Typical absorbers used in anechoic chamber to reduce the reflected rays from walls and floor, such as ferrite plates and graphite cones, are not suitable in the open space. In the work the investigation of the flexible absorbing material intended to the liquidation of the radiation reflected from the ground has been presented. As an absorbing material the metallic-glass with graphite was elaborated. This material was additionally exposed to the ionizing radiation in the dose of 100 kGy in the radioactive gamma source. The permittivity, permeability as well as the shielding properties have been analyzed.

The ovine sexually dimorphic nucleus, aromatase, and sexual partner preferences in sheep.

PubMed

Roselli, C E; Stormshak, F

2010-02-28

We are using the domestic ram as an experimental model to examine the role of aromatase in the development of sexual partner preferences. This interest has arisen because of the observation that as many as 8% of domestic rams are sexually attracted to other rams (male-oriented) in contrast to the majority of rams that are attracted to estrous ewes (female-oriented). Our findings demonstrate that aromatase expression is enriched in a cluster of neurons in the medial preoptic nucleus called the ovine sexually dimorphic nucleus (oSDN). The size of the oSDN is associated with a ram's sexual partner preference, such that the nucleus is 2-3 times larger in rams that are attracted to females (female-oriented) than in rams that are attracted to other rams (male-oriented). Moreover, the volume of the oSDN in male-oriented rams is similar to the volume in ewes. These volume differences are not influenced by adult concentrations of serum testosterone. Instead, we found that the oSDN is already present in late gestation lamb fetuses (approximately day 135 of gestation) when it is approximately 2-fold greater in males than in females. Exposure of genetic female fetuses to exogenous testosterone during the critical period for sexual differentiation masculinizes oSDN volume and aromatase expression when examined subsequently on day 135. The demonstration that the oSDN is organized prenatally by testosterone exposure suggests that the brain of the male-oriented ram may be under-androgenized during development. Copyright 2009 Elsevier Ltd. All rights reserved.

In Vitro Selection of ramR and soxR Mutants Overexpressing Efflux Systems by Fluoroquinolones as Well as Cefoxitin in Klebsiella pneumoniae▿

PubMed Central

Bialek-Davenet, Suzanne; Marcon, Estelle; Leflon-Guibout, Véronique; Lavigne, Jean-Philippe; Bert, Frédéric; Moreau, Richard; Nicolas-Chanoine, Marie-Hélène

2011-01-01

The relationship between efflux system overexpression and cross-resistance to cefoxitin, quinolones, and chloramphenicol has recently been reported in Klebsiella pneumoniae. In 3 previously published clinical isolates and 17 in vitro mutants selected with cefoxitin or fluoroquinolones, mutations in the potential regulator genes of the AcrAB efflux pump (acrR, ramR, ramA, marR, marA, soxR, soxS, and rob) were searched, and their impacts on efflux-related antibiotic cross-resistance were assessed. All mutants but 1, and 2 clinical isolates, overexpressed acrB. No mutation was detected in the regulator genes studied among the clinical isolates and 8 of the mutants. For the 9 remaining mutants, a mutation was found in the ramR gene in 8 of them and in the soxR gene in the last one, resulting in overexpression of ramA and soxS, respectively. Transformation of the ramR mutants and the soxR mutant with the wild-type ramR and soxR genes, respectively, abolished overexpression of acrB and ramA in the ramR mutants and of soxS in the soxR mutant, as well as antibiotic cross-resistance. Resistance due to efflux system overexpression was demonstrated for 4 new antibiotics: cefuroxime, cefotaxime, ceftazidime, and ertapenem. This study shows that the ramR and soxR genes control the expression of efflux systems in K. pneumoniae and suggests the existence of efflux pumps other than AcrAB and of other loci involved in the regulation of AcrAB expression. PMID:21464248

Objective assessment of sperm motion characteristics of Malpura ram lambs raised under intensive management system in semiarid tropical environment.

PubMed

Kumar, Davendra; Joshi, Anil; Naqvi, S M K

2010-04-01

A study was conducted to evaluate the semen production and sperm motion characteristics of ram lambs by computer-aided semen analysis technique. Eight Malpura rams were raised under intensive management system and were trained for semen collection at a weekly interval from the age of 6 months. Rams were scheduled for semen collection at a weekly interval up to 1 year of age to assess their potential for semen production and objective evaluation of semen quality. The average age of ram lambs at the time of first ejaculation was 219 days ranging from 186 to 245 days. The age of ram lambs significantly (p < 0.05) influenced sperm concentration, sperm velocities, and beat frequency of spermatozoa, which were higher in 9-12-month-old compared to 6-9-month-old ram lambs. However, the effect of age was not significant on semen volume, percent motility, percent rapid, medium or slow motile spermatozoa, percent linearity, percent straightness, amplitude of lateral head displacement, percent elongation, and area of sperm head. The body weight of ram lambs was significantly (p < 0.01) and positively correlated (r = 0.46) with age. The results indicate that Malpura ram lambs of 9-12 months of age raised under the intensive management system in a semiarid tropical environment can produce good quality of semen.

X-ray wind tomography of IGR J17252-3616

NASA Astrophysics Data System (ADS)

Manousakis, Antonios; Walter, Roland

IGR J17252-3616 is an heavily absorbed and eclipsing High Mass X-ray Binary with an ab-sorbing hydrogen column density >1023 cm-2 . We have observed it with XMM-Newton to understand the geometry of the absorbing material. Observations were scheduled in order to cover as many orbital phases as possible. Timing analysis is constraining the orbital solution and the physical parameters of the system. Spectral analysis reveals remarkable variations of the absorbing column density and of the Iron Kα fluorescence line around the eclipse. These variations allow to map the geometry of the absorbing and reflection material. Very large accretion structures could be imaged for the first time.

Structures Flight Test Handbook

DTIC Science & Technology

1990-11-01

landing gear and must absorb most of the shock of the landing impact (hydraulically or pneumatically) as well as provide a means of stopping the plane...amount of energy a material car. absorb elastically in a unit volume of the material. Strength - ability to withstand external loads without failure...Toughness - total energy absorbed before failure occurs. NOMENCLATURE A cross-sectional area DLL design limit load E Young’s Modulus e strain FEM

Novel Ultraviolet Light Absorbing Polymers For Optical Applications

NASA Astrophysics Data System (ADS)

Doddi, Namassivaya; Yamada, Akira; Dunks, Gary B.

1988-07-01

Ultraviolet light absorbing monomers have been developed that can be copolymerized with acrylates. The composition of the resultant stable copolymers can be adjusted to totally block the transmission of light below about 430 nm. Fabrication of lenses from the materials is accomplished by lathe cutting and injection molding procedures. These ultraviolet light absorbing materials are non-mutagenic and non-toxic and are currently being used in intraocular lenses.

Electronic Materials Based on Co0.5Zn0.5Fe2O4/Pb(Zr0.52Ti0.48)O3 Nanocomposites

NASA Astrophysics Data System (ADS)

Mandal, Avinandan; Das, Chapal Kumar

2013-01-01

The reduction of the radar cross-sectional area achieved in stealth technology has been a major challenge since the Second World War, being accomplished by covering the metallic surfaces of aircraft, ships, tanks, etc. with radar-absorbing materials. Nowadays, the development of lightweight microwave-absorbing materials with reduced thickness has a greater impact due to their excellent microwave-absorbing properties. In this study, the microwave-absorbing properties of nanocomposites based on Zn-substituted cobalt ferrite and lead zirconium titanate have been investigated in the X-band (8.2 GHz to 12.4 GHz) region. Zn-substituted cobalt ferrite (CZF) and lead zirconium titanate (PZT) nanoparticles were prepared by the coprecipitation and homogeneous precipitation method, respectively. Nanocomposites were developed by dispersing these nanoparticles with different compositions into an epoxy resin matrix. All the composite materials showed more than 90% microwave absorption in the X-band region. The nanocomposite containing CZF/PZT (3:1) with 2 mm thickness displayed maximum return loss of -47.87 dB at 12.23 GHz. The microwave absorbers based on epoxy resin polymeric matrix exhibited better absorbing properties when the dielectric contribution matched the magnetic contribution, and the loss mechanisms were mainly due to the dielectric loss.

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

PubMed

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 < 0.05). Thirteen of 15 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 < 0.0001). Among 15 ewes housed with treated rams, 13 of them exhibited continuous ovulatory activity between March and July, whereas one stopped in June and two in July. All ewes kept with control rams stopped ovulating for some time; consequently, those ewes had a longer anovulation period than did the group exposed to treated rams (3 ± 3 vs. 18 ± 7 days, respectively; P < 0.05). In conclusion, continuous exposure to sexually activated rams induced by artificial photoperiod and melatonin implants in spring extended the ovarian activity of ewes in spring, which results in an increase in estrous expression. Copyright © 2015 Elsevier Inc. All rights reserved.

Method and apparatus for powering an electrodeless lamp with reduced radio frequency interference

DOEpatents

Simpson, James E.

1999-01-01

An electrodeless lamp waveguide structure includes tuned absorbers for spurious RF signals. A lamp waveguide with an integral frequency selective attenuation includes resonant absorbers positioned within the waveguide to absorb spurious out-of-band RF energy. The absorbers have a negligible effect on energy at the selected frequency used to excite plasma in the lamp. In a first embodiment, one or more thin slabs of lossy magnetic material are affixed to the sidewalls of the waveguide at approximately one quarter wavelength of the spurious signal from an end wall of the waveguide. The positioning of the lossy material optimizes absorption of power from the spurious signal. In a second embodiment, one or more thin slabs of lossy magnetic material are used in conjunction with band rejection waveguide filter elements. In a third embodiment, one or more microstrip filter elements are tuned to the frequency of the spurious signal and positioned within the waveguide to couple and absorb the spurious signal's energy. All three embodiments absorb negligible energy at the selected frequency and so do not significantly diminish the energy efficiency of the lamp.

Method and apparatus for powering an electrodeless lamp with reduced radio frequency interference

DOEpatents

Simpson, J.E.

1999-06-08

An electrodeless lamp waveguide structure includes tuned absorbers for spurious RF signals. A lamp waveguide with an integral frequency selective attenuation includes resonant absorbers positioned within the waveguide to absorb spurious out-of-band RF energy. The absorbers have a negligible effect on energy at the selected frequency used to excite plasma in the lamp. In a first embodiment, one or more thin slabs of lossy magnetic material are affixed to the sidewalls of the waveguide at approximately one quarter wavelength of the spurious signal from an end wall of the waveguide. The positioning of the lossy material optimizes absorption of power from the spurious signal. In a second embodiment, one or more thin slabs of lossy magnetic material are used in conjunction with band rejection waveguide filter elements. In a third embodiment, one or more microstrip filter elements are tuned to the frequency of the spurious signal and positioned within the waveguide to couple and absorb the spurious signal's energy. All three embodiments absorb negligible energy at the selected frequency and so do not significantly diminish the energy efficiency of the lamp. 18 figs.

Discrete Huygens’ modeling for the characterization of a sound absorbing medium

NASA Astrophysics Data System (ADS)

Chai, L.; Kagawa, Y.

2007-07-01

Based on the equivalence between the wave propagation in the electrical transmission-lines and acoustic tubes, the authors proposed the use of the transmission-line matrix modeling (TLM) for time-domain solution method of the sound field. TLM is known in electromagnetic engineering community, which is equivalent to the discrete Huygens' modeling. The wave propagation is simulated by tracing the sequences of the transmission and scattering of impulses. The theory and the demonstrated examples are presented in the references, in which a sound absorbing field was preliminarily considered to be a medium with simple acoustic resistance independent of frequency and the angle of incidence for the absorbing layer placed on the room wall surface. The present work is concerned with the time-domain response for the characterization of the sound absorbing materials. A lossy component with variable propagation velocity is introduced for sound absorbing materials to facilitate the energy consumption. The frequency characteristics of the absorption coefficient are also considered for the normal, oblique and random incidence. Some numerical demonstrations show that the present modeling provide a reasonable modeling of the homogeneous sound absorbing materials in time domain.

Prevalence in the USA of rilpivirine resistance-associated mutations in clinical samples and effects on phenotypic susceptibility to rilpivirine and etravirine.

PubMed

Picchio, Gaston R; Rimsky, Laurence T; Van Eygen, Veerle; Haddad, Mojgan; Napolitano, Laura A; Vingerhoets, Johan

2014-01-01

The prevalence of rilpivirine resistance-associated mutations (RAMs) in the USA, and their effect on phenotypic susceptibility to rilpivirine and etravirine, was evaluated in clinical samples from HIV-1-infected patients. In total, 15,991 samples submitted to Monogram Biosciences (South San Francisco, CA, USA) for routine resistance testing between January 2010 and June 2011 were assessed for the presence of known rilpivirine RAMs K101E/P, E138A/G/K/Q/R, V179L, Y181C/I/V, Y188L, H221Y, F227C and M230I/L; non-nucleoside reverse transcriptase inhibitor (NNRTI) RAMs K103N, L100I and L100I+K103N; and the nucleoside reverse transcriptase inhibitor (NRTI) RAMs M184I/V and their combinations with rilpivirine RAMs. Phenotypic susceptibility (PhenoSenseGT(®) assay; Monogram Biosciences) was evaluated, with reduced susceptibility defined as fold change (FC) in 50% inhibitory concentration (IC50)>2.0 for rilpivirine and FC>2.9 for etravirine. Of the 15,991 samples, 17% harboured ≥1 rilpivirine RAMs. The prevalence of most rilpivirine RAMs and combinations of NNRTI RAMs of interest was low (≤3%), except for Y181C (7%). Rilpivirine RAMs were often associated with reduced rilpivirine phenotypic susceptibility. Median FC values >2.0 were observed for clinical isolates with rilpivirine RAMs K101P, E138Q/R, Y181C/I/V, Y188L or M230L, and for the combination of E138K with M184I/V, and K101E with M184I. Most rilpivirine FC values >2.0 were associated with etravirine FC values >2.9 for individual rilpivirine RAMs and those combined with M184I/V. There was no relationship between the presence of K103N and rilpivirine FC. However, the L100I+K103N combination (without rilpivirine RAMs), at <2% prevalence, was associated with a rilpivirine FC>2.0. Based on 15,991 US clinical samples from HIV-1-infected patients, the frequency of most known rilpivirine RAMs apart from Y181C was low.

Prevalence of etravirine-associated mutations in clinical samples with resistance to nevirapine and efavirenz.

PubMed

Llibre, J M; Santos, J R; Puig, T; Moltó, J; Ruiz, L; Paredes, R; Clotet, B

2008-11-01

To evaluate the expected activity of etravirine in clinical samples, according to mutational patterns associated with decreased virological response (VR). We identified 1586 routine clinical samples with resistance-associated mutations (RAMs) to nevirapine and efavirenz (K103N 60%, Y181C 37%, G190A 27%, V108I 13%). Concerning in vitro identified etravirine mutations, samples with F227C, Y181I, M230L or L100I plus K103N plus Y181C were considered highly resistant. Samples with two RAMs plus Y181C or V179D or K101E or Y188L were considered intermediate. The prevalence of 13 RAMs recently associated with decreased VR to etravirine in the DUET clinical trials was also investigated. Most samples (69%) harboured more than one IAS-USA RAM to first-generation non-nucleoside reverse transcriptase inhibitors (NNRTIs): 42% harboured two RAMs, 21% three RAMs and 6% four or more RAMs. The prevalence of 13 specific etravirine RAMs was V179F 0.12%, G190S 3.9%, Y181V 0.1%, V106I 2.6%, V179D 1.6%, K101P 2.0%, K101E 10.1%, Y181C 36.9%, A98G 5.9%, V90I 6.9%, Y181I 3.6%, G190A 27% and L100I 9.1%. The five RAMs with the most impact on VR (V179F/D, G190S, Y181V and V106I) occurred less often. Overall, 8.2% of the samples had three or more etravirine RAMs and only 1.1% had four or more. In addition, patterns of RAMs previously associated with intermediate etravirine resistance were present in 26.2% of the samples, whereas 4.85% displayed patterns of high-degree resistance. For RAMs associated with decreased VR, etravirine resistance in routine clinical samples was lower than previously reported. High-degree resistance was uncommon, even in patients with resistance to first-generation NNRTIs, whereas low-to-intermediate etravirine resistance was more common.

Advanced Design and Optimization of High Performance Combatant Craft: Material Testing and Computational Tools

DTIC Science & Technology

2012-05-31

inherently shock-absorbent, and more durable than conventional materials. Despite these initial demonstration successes, there are still barriers that need...to deliver boats that are stronger, lighter, inherently shock‐absorbent, and more durable than those manufactured with conventional materials...and more durable than conventional materials (e.g. aluminum). Further, prior research by the University of Maine, Virginia Tech, and others has

Realtime photoacoustic microscopy in vivo with a 30-MHz ultrasound array transducer

PubMed Central

Zemp, Roger J.; Song, Liang; Bitton, Rachel; Shung, K. Kirk; Wang, Lihong V.

2009-01-01

We present a novel high-frequency photoacoustic microscopy system capable of imaging the microvasculature of living subjects in realtime to depths of a few mm. The system consists of a high-repetition-rate Q-switched pump laser, a tunable dye laser, a 30-MHz linear ultrasound array transducer, a multichannel high-frequency data acquisition system, and a shared-RAM multi-core-processor computer. Data acquisition, beamforming, scan conversion, and display are implemented in realtime at 50 frames per second. Clearly resolvable images of 6-µm-diameter carbon fibers are experimentally demonstrated at 80 µm separation distances. Realtime imaging performance is demonstrated on phantoms and in vivo with absorbing structures identified to depths of 2.5–3 mm. This work represents the first high-frequency realtime photoacoustic imaging system to our knowledge. PMID:18545502

Deep sequencing analysis of HIV-1 reverse transcriptase at baseline and time of failure in patients receiving rilpivirine in the phase III studies ECHO and THRIVE.

PubMed

Van Eygen, Veerle; Thys, Kim; Van Hove, Carl; Rimsky, Laurence T; De Meyer, Sandra; Aerssens, Jeroen; Picchio, Gaston; Vingerhoets, Johan

2016-05-01

Minority variants (1.0-25.0%) were evaluated by deep sequencing (DS) at baseline and virological failure (VF) in a selection of antiretroviral treatment-naïve, HIV-1-infected patients from the rilpivirine ECHO/THRIVE phase III studies. Linkage between frequently emerging resistance-associated mutations (RAMs) was determined. DS (llIumina®) and population sequencing (PS) results were available at baseline for 47 VFs and time of failure for 48 VFs; and at baseline for 49 responders matched for baseline characteristics. Minority mutations were accurately detected at frequencies down to 1.2% of the HIV-1 quasispecies. No baseline minority rilpivirine RAMs were detected in VFs; one responder carried 1.9% F227C. Baseline minority mutations associated with resistance to other non-nucleoside reverse transcriptase inhibitors (NNRTIs) were detected in 8/47 VFs (17.0%) and 7/49 responders (14.3%). Baseline minority nucleoside/nucleotide reverse transcriptase inhibitor (NRTI) RAMs M184V and L210W were each detected in one VF (none in responders). At failure, two patients without NNRTI RAMs by PS carried minority rilpivirine RAMs K101E and/or E138K; and five additional patients carried other minority NNRTI RAMs V90I, V106I, V179I, V189I, and Y188H. Overall at failure, minority NNRTI RAMs and NRTI RAMs were found in 29/48 (60.4%) and 16/48 VFs (33.3%), respectively. Linkage analysis showed that E138K and K101E were usually not observed on the same viral genome. In conclusion, baseline minority rilpivirine RAMs and other NNRTI/NRTI RAMs were uncommon in the rilpivirine arm of the ECHO and THRIVE studies. DS at failure showed emerging NNRTI resistant minority variants in seven rilpivirine VFs who had no detectable NNRTI RAMs by PS. © 2015 Wiley Periodicals, Inc.

Fattening ability and carcass value of Dhamari and Tehami ram lambs, F₁ crossbreds of Dhamari × Tehami in Yemen.

PubMed

Al Khewani, Talal; Momani Shaker, Mohamed; Al-Olofi, Samer

2014-12-01

A fattening experiment was carried out to analyze and evaluate the effect of ram lamb genotype on the growth, feed conversion (FC), and carcass value of Dhamari ram lambs, F1 crossbreds of Dhamari × Tehami (F1 DhT), and Tehami ram lambs. Genotype of the ram lambs including the experiment (n = 30) had high significant effect on total weight gain (TWG), average daily gain (ADG), and FC (P < 0.01-0.001). Genotype of the lamb had significant effect on hot and cold dressing percentage (P < 0.001). Also, genotype of the lamb had significant effect on the highest leg percentage (P < 0.001). Furthermore, genotype of the ram lambs had significant effect on musculus longissimus dorsi (MLD) area (P < 0.001). Genotype of the ram lamb had significant effect on TWG, ADG, and FC (P < 0.001). The results of moisture percentage, crude protein percentage, and ash percentage of muscle samples were significantly influenced by ram lamb's genotype (P < 0.001). Fasting live weight and other carcass measurements (hot carcass weight, leg weight, loin weight, shoulder weight, first quality cuts weight) have a positive and highest correlations (P < 0.001). The positive and the highest correlations were found between fasting live weight and hot carcass weight, first quality parts weight. In addition, the positive and the highest correlations were found between hot carcass weight and first quality cuts weight. In general, the results of this study documented that F1 DhT was better than Tehami ram lambs in ADG, TWG, and FC. Additionally, the results show that the feed conversion was in F1 DhT crossbreds ram lambs better than pure Dhamari and Tehami ram lambs, mainly in the carcass indicators.

The Model 9977 Radioactive Material Packaging Primer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abramczyk, G.

2015-10-09

The Model 9977 Packaging is a single containment drum style radioactive material (RAM) shipping container designed, tested and analyzed to meet the performance requirements of Title 10 the Code of Federal Regulations Part 71. A radioactive material shipping package, in combination with its contents, must perform three functions (please note that the performance criteria specified in the Code of Federal Regulations have alternate limits for normal operations and after accident conditions): Containment, the package must “contain” the radioactive material within it; Shielding, the packaging must limit its users and the public to radiation doses within specified limits; and Subcriticality, themore » package must maintain its radioactive material as subcritical« less

Design and Manufacture of Energy Absorbing Materials

ScienceCinema

Duoss, Eric

2018-01-16

Learn about an ordered cellular material that has been designed and manufactured using direct ink writing (DIW), a 3-D printing technology being developed at LLNL. The new material is a patterned cellular material that can absorb mechanical energy-a cushion-while also providing protection against sheering. This material is expected to find utility in application spaces that currently use unordered foams, such as sporting and consumer goods as well as defense and aerospace.

Thermally switchable meta-material absorber involving vanadium dioxide semiconductor-metal transition for thermo photovoltaic conversion

NASA Astrophysics Data System (ADS)

Bendelala, Fathi; Cheknane, Ali; Hilal, Hikmat S.

2018-01-01

A new switchable absorber design using meta-materials for thermo photovoltaic applications is proposed here. Conventional absorbents are normally non-adjustable with narrow band-widths and polarization-dependence. The present study describes an alternative infrared absorber structure with tunable characteristics. The absorber is based on VO2 which exhibits transition from semiconductor to metallic conductor by thermal effect. With this design, the results show that wide-band absorption can be achieved. The absorption bandwidth can be improved from 15.94 to 36.75 THz. With 40.42% relative shift in the peak frequency, a maximum absorption efficiency of 99% can be achieved. This structure design is polarization-independent of normal incident radiations, and may accommodate radiations from wide oblique angles. These new features make the new thermally adjustable absorber potentially useful in thermo-photovoltaic conversion devices.

Influence of grazing management on the seasonal change in testicular morphology in Corriedale rams.

PubMed

Bielli, A; Pedrana, G; Gastel, M T; Castrillejo, A; Moraña, A; Lundeheim, N; Forsberg, M; Rodriguez-Martinez, H

1999-06-28

The present study was conducted: (a) to determine the degree of seasonal variation in testis stereology in Corriedale rams between autumn and winter; (b) to test the hypothesis that testis stereology of Corriedale rams grazing native pastures during autumn and winter would differ from those of Corriedale rams grazing sown pastures and supplemented with grain during the same period; and (c) to determine whether Sertoli cell numbers differ in adult rams between the breeding season (autumn) and the following non-breeding season (winter). Twenty experimental animals were studied. Six rams (autumn control group, C-A) that had been grazing on native pasture (stocking rate = 2-3 animals ha(-1)) were castrated at the beginning of the experiment (March, early autumn). Seven rams (winter control group, C-W) continued to graze on native pasture at the same stocking rate until the end of the experiment (August, late winter). Another seven rams (treated group, T) grazed on improved pasture (stocking rate = 1-2 animals ha(-1)) and were supplemented with 1 kg grain ram(-1) day(-1) until the end of the experiment. Live weight, scrotal circumference, serum testosterone concentration and selected testicular stereological parameters were measured. The treatment did not impede the winter reduction in testicular activity and reduced its magnitude slightly (group T) compared with controls (group C-W). Sertoli cell numbers were higher in autumn (group C-A) than in winter, both on native (group C-W) and sown pastures (group T). Diminishing Sertoli cell numbers between autumn and the following winter suggest the occurrence of that Sertoli cell death during this period. The results indicate that, although the reproductive activity of Corriedale rams is moderately seasonal, a restricted change in grazing and grain supplementation can only modify it to a limited extent.

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

PubMed

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 < 0.05). By contrast, no differences in HR were observed between rams that interacted with estrous versus nonestrous 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 ( < 0.05) during mating. In summary, 1) rams that mated estrous 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.

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

PubMed Central

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

Influence of trophy hunting and horn size on mating behavior and survivorship of mountain sheep

USGS Publications Warehouse

Singer, F.J.; Zeigenfuss, L.C.

2002-01-01

We conducted a study of the effects of horn sizes and trophy hunting on mating behavior and survival of rams in hunted and unhunted populations of Dall sheep (Ovis dalli), Rocky Mountain bighorn (O. canadensis canadensis), and desert bighorn (O. c. nelsoni) sheep. Mating success was positively correlated with horn size in Dall sheep (P = 0.03) and Rocky Mountain bighorns (P = 0.05), but not in the desert bighorn (P > 0.05) taxa. Group sizes, rams per rut group, and competition between rams were lowest in desert bighorn sheep. There were indications of greater harassment of ewes by young rams in trophy-hunted populations. In hunted populations, compared with unhunted, ewes ran away more often from approaching rams, ewes moved farther away from courting young rams (P = 0.003), younger rams performed fewer courtship displays (P = 0.042) and more aggressive displays to ewes, and sheep interacted 27% more of the time. Ram-to-ewe interaction times per individual ewe did not differ for any of the taxa (P > 0.05), and, apparently as a consequence of this, we found no discernable effects of trophy hunting on survivorship of ewes, ewe fecundity, or recruitment of young (P > 0.05). There were greater energy expenditures by young rams in the heavily hunted Dall sheep population versus the paired Dall sheep unhunted population, but not in the lightly hunted Rocky Mountain and desert bighorn populations when compared with unhunted populations. This was consistent with evidence for depressed survivorship of rams too young or too small to be hunted (approximately ages 4–6) in the heavily hunted Dall sheep population (P = 0.0001), but not in the bighorn sheep populations (P > 0.05).

Reliability and Validity of a Brief Questionnaire to Assess Calcium Intake in Female Collegiate Athletes

PubMed Central

Ward, Kenneth D.; Hunt, Kami Mays; Berg, Melanie Burstyne; Slawson, Deborah A.; Vukadinovich, Christopher M.; McClanahan, Barbara S.; Clemens, Linda H.

2016-01-01

Calcium intake often is inadequate in female collegiate athletes, increasing the risk for training injuries and future osteoporosis. Thus, a brief and accurate assessment tool to quickly measure calcium intake in athletes is needed. We evaluated the reliability and validity, compared to 6 days of diet records (DRs), of the Rapid Assessment Method (RAM), a self-administered calcium checklist (14). Seventy-six female collegiate athletes (mean age = 18.8 yrs, range = 17–21; 97% Caucasian) were recruited from basketball, cross-country, field hockey, soccer, and volleyball teams. Athletes completed a RAM at the start of the training season to assess calcium intake during the past week. Two weeks later, a second RAM was completed to assess reliability, and athletes began 6 days of diet records (DRs) collection. At completion of DRs, athletes completed a final RAM, corresponding to the same time period as DRs, to assess agreement between the 2 instruments. The RAM demonstrated adequate test-retest reliability over 2 weeks (n = 56; Intraclass correlation [ICC] = .54, p < .0001) and adequate agreement with DRs (n = 34; ICC = .41, p = .0067). Calcium intake was below recommended levels, and mean estimates did not differ significantly on the RAM (823 ± 387 mg/d) and DRs (822 ± 330 mg/d; p = .988). Adequacy of calcium intake from both DRs and the RAM was classified as “inadequate” (<1000 mg/d) and “adequate” (≥1000 mg/d). Agreement between the RAM and DRs for adequacy classification was fair (ICC = .30, p = .042), with the RAM identifying 84% of athletes judged to have inadequate calcium intake based on DRs. The RAM briefly and accurately estimates calcium intake in female collegiate athletes compared to DRs. PMID:15118194

Space Station

NASA Image and Video Library

1971-01-01

This is an artist's concept of the Research and Applications Modules (RAM). Evolutionary growth was an important consideration in space station plarning, and another project was undertaken in 1971 to facilitate such growth. The RAM study, conducted through a Marshall Space Flight Center contract with General Dynamics Convair Aerospace, resulted in the conceptualization of a series of RAM payload carrier-sortie laboratories, pallets, free-flyers, and payload and support modules. The study considered two basic manned systems. The first would use RAM hardware for sortie mission, where laboratories were carried into space and remained attached to the Shuttle for operational periods up to 7 days. The second envisioned a modular space station capability that could be evolved by mating RAM modules to the space station core configuration. The RAM hardware was to be built by Europeans, thus fostering international participation in the space program.

Reliability evaluation of CMOS RAMs

NASA Astrophysics Data System (ADS)

Salvo, C. J.; Sasaki, A. T.

The results of an evaluation of the reliability of a 1K x 1 bit CMOS RAM and a 4K x 1 bit CMOS RAM for the USAF are reported. The tests consisted of temperature cycling, thermal shock, electrical overstress-static discharge and accelerated life test cells. The study indicates that the devices have high reliability potential for military applications. Use-temperature failure rates at 100 C were 0.54 x 10 to the -5th failures/hour for the 1K RAM and 0.21 x 10 to the -5th failures/hour for the 4K RAM. Only minimal electrostatic discharge damage was noted in the devices when they were subjected to multiple pulses at 1000 Vdc, and redesign of the 7 Vdc quiescent parameter of the 4K RAM is expected to raise its field threshold voltage.

HVOF repair of steering rams for the USS Saipan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dwyer, A.L.; Jones, S.A.; Wykle, R.J.

1995-12-31

The steering rams aboard the USS Saipan (LHA-2) were badly corroded after 18 years of service. These rams are hydraulically operated and change the angle of the ship`s rudder. This corrosion allowed excessive leaking of hydraulic fluid into the machinery space. Permanent repairs were required as the ship has more than 20 years of service life remaining. Two methods of repair were considered, chrome plating and a HVOF applied coating. The size, 13 in. diameter and 15 ft in length, posed a significant problem for either process. The cost of the repair was similar but the time for completion wasmore » better with the HVOF process since chrome plating would have to be accomplished off yard. The HVOF process was not available within the shipyard at the time and the process and material to be used had not been approved. Extensive testing was required to get approval to proceed, a facility to accomplish the work had to be built, and the operators and HVOF procedure had to be qualified. After completion of spraying, single point machining and honing was used to obtain the required surface finish. This was the largest single HVOF coating applied by the Navy and great interest to all concerned.« less

SQL-RAMS

NASA Technical Reports Server (NTRS)

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.

SQL-RAMS

NASA Technical Reports Server (NTRS)

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 FileMaker Pro software system and was constructed in modules that could act as stand-alone 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 to a particular work-status documents, SQL-RAMS provides access through a single-screen presentation of core modules. In addition, SQL-RAMS enable 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.

Characterization and preparation of p(U-MMA-An) interpenetrating polymer network damping and absorbing material.

PubMed

Liu, Jun; Li, Qingshan; Zhuo, Yuguo; Hong, Wei; Lv, Wenfeng; Xing, Guangzhong

2014-06-01

P(U-MMA-ANI) interpenetrating polymer network (IPN) damping and absorbing material is successfully synthesized by PANI particles served as an absorbing agent with the microemulsion polymerization and P(U-MMA) foam IPN network structure for substrate materials with foaming way. P(U-MMA-ANI) IPN is characterized by the compression mechanical performance testing, TG-DSC, and DSC. The results verify that the P(U-MMA) IPN foam damping material has a good compressive strength and compaction cycle property, and the optimum content of PMMA was 40% (mass) with which the SEM graphs do not present the phase separation on the macro level between PMMA and PU, while the phase separation was observed on the micro level. The DTG curve indicates that because of the formation of P(U-MMA) IPN, the decomposition temperature of PMMA and the carbamate in PU increases, while that of the polyol segment in PU has almost no change. P(U-MMA-ANI) IPN foam damping and absorbing material is obtained by PANI particles served as absorbing agent in the form of filler, and PMMA in the form of micro area in substrate material. When the content of PANI was up to 2.0% (mass), the dissipation factor of composites increased, and with the increasing of frequency the dissipation factor increased in a straight line.

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

NASA Technical Reports Server (NTRS)

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.

Pressure Characteristics of a Diffuser in a Ram RDE Propulsive Device

DTIC Science & Technology

2017-07-21

Continuous detonation Rotating-detonation- engine Ethylene-air Diffuser Pressure feedback Modeling and simulation Office of Naval Research 875 N. Randolph...RDE PROPULSIVE DEVICE INTRODUCTION This report focuses on the diffuser of a ram Rotating Detonation Engine (RDE) device. A ram RDE is a ramjet with...the constant pressure combustion chamber replaced with a Rotating Detonation Engine combustor to accomplish pressure gain combustion. A ram engine

Activity of the hypothalamo-pituitary axis and testicular development in prepubertal ram lambs with induced hypothyroidism or hyperthyroidism.

PubMed

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

1985-10-01

Prepubertal (16 weeks old) ram lambs were used to investigate the effects of hyperthyroidism and hypothyroidism on development of reproductive endocrine function. Over a period of 8 weeks, ram lambs were made hypothyroid (serum T4 less than or equal to 3 ng/ml compared with controls congruent to 30 ng/ml) by daily oral administration of methyl thiouracil or hyperthyroid (serum T4 congruent to 135 ng/ml) by daily sc injection of T4. Hyperthyroidism was associated with decreases in LH pulse frequency (2.25 +/- 0.75/12 h compared with controls 5.75 +/- 0.48/12 h), basal LH, and mean LH concentrations, together with arrested testicular growth and aspermatogenesis. Hypothyroid rams showed normal pubertal development. After iv injection of LHRH, hyperthyroid ram lambs showed similar LH responses to control and hypothyroid rams. Basal testosterone production (5.6 +/- 1.0 ng/min) and plasma testosterone concentrations after human CG (2.0 +/- 0.7 ng/ml) in hyperthyroid rams were significantly lower than in controls (67.5 +/- 24.0 ng/min and 5.2 +/- 1.0 ng/ml, respectively). It is concluded that retarded testicular development in hyperthyroid ram lambs results from changes in hypothalamo-pituitary activity manifested in a decreased LH pulse frequency.

Integrated optical tamper sensor with planar waveguide

DOEpatents

Carson, Richard F.; Casalnuovo, Stephen A.

1993-01-01

A monolithic optical tamper sensor, comprising an optical emitter and detector, connected by an optical waveguide and placed into the critical entry plane of an enclosed sensitive region, the tamper sensor having a myriad of scraps of a material optically absorbent at the wavelength of interest, such that when the absorbent material is in place on the waveguide, an unique optical signature can be recorded, but when entry is attempted into the enclosed sensitive region, the scraps of absorbent material will be displaced and the optical/electrical signature of the tamper sensor will change and that change can be recorded.

Integrated optical tamper sensor with planar waveguide

DOEpatents

Carson, R.F.; Casalnuovo, S.A.

1993-01-05

A monolithic optical tamper sensor, comprising an optical emitter and detector, connected by an optical waveguide and placed into the critical entry plane of an enclosed sensitive region, the tamper sensor having a myriad of scraps of a material optically absorbent at the wavelength of interest, such that when the absorbent material is in place on the waveguide, an unique optical signature can be recorded, but when entry is attempted into the enclosed sensitive region, the scraps of absorbent material will be displaced and the optical/electrical signature of the tamper sensor will change and that change can be recorded.

Different CO2 absorbents-modified SBA-15 sorbent for highly selective CO2 capture

NASA Astrophysics Data System (ADS)

Liu, Xiuwu; Zhai, Xinru; Liu, Dongyang; Sun, Yan

2017-05-01

Different CO2 absorbents-modified SBA-15 materials are used as CO2 sorbent to improve the selectivity of CH4/CO2 separation. The SBA-15 sorbents modified by physical CO2 absorbents are very limited to increasing CO2 adsorption and present poor selectivity. However, the SBA-15 sorbents modified by chemical CO2 absorbents increase CO2 adsorption capacity obviously. The separation coefficients of CO2/CH4 increase in this case. The adsorption and regeneration properties of the SBA-15 sorbents modified by TEA, MDEA and DIPA have been compared. The SBA-15 modified by triethanolamine (TEA) presents better CO2/CH4 separation performance than the materials modified by other CO2 absorbents.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hammer, F.; Yang, Y. B.; Flores, H.

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 theirmore » 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.« less

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

NASA Astrophysics Data System (ADS)

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.

3. Light tower, view northwest, south side Ram Island ...

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

3. Light tower, view northwest, south side - Ram Island Light Station, Ram Island, south of Ocean Point & just north of Fisherman Island, marking south side of Fisherman Island Passage, Ocean Point, Lincoln County, ME

Gambling and the Reasoned Action Model: Predicting Past Behavior, Intentions, and Future Behavior.

PubMed

Dahl, Ethan; Tagler, Michael J; Hohman, Zachary P

2018-03-01

Gambling is a serious concern for society because it is highly addictive and is associated with a myriad of negative outcomes. The current study applied the Reasoned Action Model (RAM) to understand and predict gambling intentions and behavior. Although prior studies have taken a reasoned action approach to understand gambling, no prior study has fully applied the RAM or used the RAM to predict future gambling. Across two studies the RAM was used to predict intentions to gamble, past gambling behavior, and future gambling behavior. In study 1 the model significantly predicted intentions and past behavior in both a college student and Amazon Mechanical Turk sample. In study 2 the model predicted future gambling behavior, measured 2 weeks after initial measurement of the RAM constructs. This study stands as the first to show the utility of the RAM in predicting future gambling behavior. Across both studies, attitudes and perceived normative pressure were the strongest predictors of intentions to gamble. These findings provide increased understanding of gambling and inform the development of gambling interventions based on the RAM.

Ontogenic and nutritional changes in circulating insulin-like growth factor (IGF)-I, IGF-II and IGF-binding proteins in growing ewe and ram lambs.

PubMed

Gatford, K L; Quinn, K J; Walton, P E; Grant, P A; Hosking, B J; Egan, A R; Owens, P C

1997-10-01

The ontogeny of the IGF endocrine system was investigated in 15 young lambs before and after weaning at 62 days of age. Before weaning, plasma IGF-I concentrations were higher in rams than ewes, and plasma concentrations of IGF-II and IGF-binding protein-3 (IGFBP-3) also tended to be higher in rams than in ewes. Feed intake of ewes and rams was restricted after weaning to remove sex differences in feed intake. Plasma concentrations of IGF-I and IGFBP-3 did not differ between rams and ewes at 100 days of age, but plasma IGF-II was higher in rams than in ewes at this time. Since circulating concentrations of GH were higher in rams than in ewes at 100 days of age, this implies that the restricted feed intake blocked the IGF-I and IGFBP-3 responses to GH. We conclude that sex differences in circulating IGF-I and IGFBP-3 concentrations in the growing lamb alter with age, and are not present when nutrition is restricted.

Determination of fatty acid profile in ram spermatozoa and seminal plasma.

PubMed

Díaz, R; Torres, M A; Bravo, S; Sanchez, R; Sepúlveda, N

2016-08-01

Fatty acids are important in male reproductive function because they are associated with membrane fluidity, acrosome reaction, sperm motility and viability, but limited information exists about the fatty acid profile of ram semen. Our aim was to determine the fatty acid composition in ram spermatozoa and seminal plasma. Sixty ejaculates were obtained from three ram (20 ejaculates/ram) using artificial vagina. Ram spermatozoa (RS) and seminal plasma (SP) were separated using centrifugation, and the fatty acids were analysed by gas chromatography. Total lipids obtained in ram spermatozoa were 1.8% and 1.6% in seminal plasma. Saturated fatty acid (SFA) was proportionally major in SP (66.6%) that RS (49.9%). The highest proportions of SFA corresponded to C4:0 (RS = 16.3% and SP = 28.8%) and C16:0 (RS = 16.3% and PS = 20%). The most important unsaturated fatty acid (UFA) was docosahexaenoic acid (DHA), 44.9% in RS and 31.5% in SP. The profile of fatty acid and their proportions showed differences between spermatozoa and seminal plasma. © 2015 Blackwell Verlag GmbH.

Vibration Damping Analysis of Lightweight Structures in Machine Tools

PubMed Central

Aggogeri, Francesco; Borboni, Alberto; Merlo, Angelo; Pellegrini, Nicola; Ricatto, Raffaele

2017-01-01

The dynamic behaviour of a machine tool (MT) directly influences the machining performance. The adoption of lightweight structures may reduce the effects of undesired vibrations and increase the workpiece quality. This paper aims to present and compare a set of hybrid materials that may be excellent candidates to fabricate the MT moving parts. The selected materials have high dynamic characteristics and capacity to dampen mechanical vibrations. In this way, starting from the kinematic model of a milling machine, this study evaluates a number of prototypes made of Al foam sandwiches (AFS), Al corrugated sandwiches (ACS) and composite materials reinforced by carbon fibres (CFRP). These prototypes represented the Z-axis ram of a commercial milling machine. The static and dynamical properties have been analysed by using both finite element (FE) simulations and experimental tests. The obtained results show that the proposed structures may be a valid alternative to the conventional materials of MT moving parts, increasing machining performance. In particular, the AFS prototype highlighted a damping ratio that is 20 times greater than a conventional ram (e.g., steel). Its application is particularly suitable to minimize unwanted oscillations during high-speed finishing operations. The results also show that the CFRP structure guarantees high stiffness with a weight reduced by 48.5%, suggesting effective applications in roughing operations, saving MT energy consumption. The ACS structure has a good trade-off between stiffness and damping and may represent a further alternative, if correctly evaluated. PMID:28772653

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

NASA Astrophysics Data System (ADS)

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.

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

USGS Publications Warehouse

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.

Ultrathin and lightweight microwave absorbers made of mu-near-zero metamaterials

PubMed Central

Zhong, Shuomin; He, Sailing

2013-01-01

We present a theory of perfect absorption in a bilayer model composed of a mu-near-zero (MNZ) metamaterial (MM) absorbing layer on a metallic substrate. Our analytical solutions reveal that a MM layer with a large purely imaginary permeability and a moderate permittivity backed by a metallic plane has a zero reflection at normal incidence when the thickness is ultrathin. The impedance-mismatched metamaterial absorber (MA) can be 77.3% thinner than conventional impedance-matched MAs with the same material loss in order to get the same absorption. A microwave absorber using double-layered spiral MMs with a thickness of only about one percent of the operating wavelength is designed and realized. An absorption efficiency above 93% at 1.74 GHz is demonstrated experimentally at illumination angles up to 60 degrees. Our absorber is 98% lighter than traditional microwave absorbers made of natural materials working at the same frequencies. PMID:23803861

The design and performance of the nano-carbon based double layers flexible coating for tunable and high-efficiency microwave absorption

NASA Astrophysics Data System (ADS)

Zhang, Danfeng; Hao, Zhifeng; Qian, Yannan; Zeng, Bi; Zhu, Haiping; Wu, Qibai; Yan, Chengjie; Chen, Muyu

2018-05-01

Nanocarbon-based materials are outstanding microwave absorbers with good dielectric properties. In this study, double-layer silicone resin flexible absorbing coatings, composed of carbon-coated nickel nanoparticles (Ni@C) and carbon nanotubes (CNTs), with low loading and a total thickness of 2 mm, were prepared. The reflection loss (RL) of the double-layer absorbing coatings has measured for frequencies between 2 and 18 GHz using the Arch reflecting testing method. The effects of the thickness and electromagnetic parameters of each layer and of the layer sequence on the absorbing properties were investigated. It is found that the measured bandwidth (RL ≤ - 10 dB) of the optimum double-layer structure in our experiment range achieves 3.70 GHz. The results indicated that the double coating structure composed of different materials has greater synergistic absorption effect on impedance matching than that of same materials with different loading. The maximum RL of S1 (5 wt% CNTs)/S3 (60 wt% Ni@C) double-layer absorbing coating composed of different materials (S1 and S3) was larger than the one achieved using either S1 or S3 alone with the same thickness. This was because double-layer coating provided a suitable matching layer and improve the interfacial impedance. It was also shown that absorbing peak value and frequency position can be adjusted by double-layer coating structure.

Nickel Nanoparticle Encapsulated in Few-Layer Nitrogen-Doped Graphene Supported by Nitrogen-Doped Graphite Sheets as a High-Performance Electromagnetic Wave Absorbing Material.

PubMed

Yuan, Haoran; Yan, Feng; Li, Chunyan; Zhu, Chunling; Zhang, Xitian; Chen, Yujin

2018-01-10

Herein we develop a facile strategy for fabricating nickel particle encapsulated in few-layer nitrogen-doped graphene supported by graphite carbon sheets as a high-performance electromagnetic wave (EMW) absorbing material. The obtained material exhibits sheetlike morphology with a lateral length ranging from a hundred nanometers to 2 μm and a thickness of about 23 nm. Nickel nanoparticles with a diameter of approximately 20 nm were encapsulated in about six layers of nitrogen-doped graphene. As applied for electromagnetic absorbing material, the heteronanostructures exhibit excellent electromagnetic wave absorption property, comparable to most EMW absorbing materials previously reported. Typically, the effective absorption bandwidth (the frequency region falls within the reflection loss below -10 dB) is up to 8.5 GHz at the thicknesses of 3.0 mm for the heteronanostructures with the optimized Ni content. Furthermore, two processes, carbonization at a high temperature and subsequent treatment in hot acid solution, were involved in the preparation of the heteronanostructures, and thus, mass production was achieved easily, facilitating their practical applications.

Characterization of Two Distinct Glycosyl Hydrolase Family 78 α-l-Rhamnosidases from Pediococcus acidilactici▿†

PubMed Central

Michlmayr, Herbert; Brandes, Walter; Eder, Reinhard; Schümann, Christina; del Hierro, Andrés M.; Kulbe, Klaus D.

2011-01-01

α-l-Rhamnosidases play an important role in the hydrolysis of glycosylated aroma compounds (especially terpenes) from wine. Although several authors have demonstrated the enological importance of fungal rhamnosidases, the information on bacterial enzymes in this context is still limited. In order to fill this important gap, two putative rhamnosidase genes (ram and ram2) from Pediococcus acidilactici DSM 20284 were heterologously expressed, and the respective gene products were characterized. In combination with a bacterial β-glucosidase, both enzymes released the monoterpenes linalool and cis-linalool oxide from a muscat wine extract under ideal conditions. Additionally, Ram could release significant amounts of geraniol and citronellol/nerol. Nevertheless, the potential enological value of these enzymes is limited by the strong negative effects of acidity and ethanol on the activities of Ram and Ram2. Therefore, a direct application in winemaking seems unlikely. Although both enzymes are members of the same glycosyl hydrolase family (GH 78), our results clearly suggest the distinct functionalities of Ram and Ram2, probably representing two subclasses within GH 78: Ram could efficiently hydrolyze only the synthetic substrate p-nitrophenyl-α-l-rhamnopyranoside (Vmax = 243 U mg−1). In contrast, Ram2 displayed considerable specificity toward hesperidin (Vmax = 34 U mg−1) and, especially, rutinose (Vmax = 1,200 U mg−1), a disaccharide composed of glucose and rhamnose. Both enzymes were unable to hydrolyze the flavanone glycoside naringin. Interestingly, both enzymes displayed indications of positive substrate cooperativity. This study presents detailed kinetic data on two novel rhamnosidases, which could be relevant for the further study of bacterial glycosidases. PMID:21784921

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Groth, Katrina; Hecht, Ethan; Reynolds, John Thomas

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 andmore » 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.« less

Realizing thin electromagnetic absorbers for wide incidence angles from commercially available planar circuit materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glover, Brian B; Whites, Kieth W; Radway, Matthew J

2009-01-01

In this study, recent work on engineering R-card surface resistivity with printed metallic patterns is extended to the design of thin electromagnetic absorbers. Thin electromagnetic absorbers for wide incidence angles and both polarizations have recently been computationally verified by Luukkonen et al.. These absorbers are analytically modeled high-impedance surfaces with capacitive arrays of square patches implemented with relatively high dielectric constant and high loss substrate. However, the advantages provided by the accurate analytical model are largely negated by the need to obtain high dielectric constant material with accurately engineered loss. Fig. I(c) illustrates full-wave computational results for an absorber withoutmore » vias engineered as proposed by Luukkonen et al.. Unique values for the dielectric loss are required for different center frequencies. Parameters for the capacitive grid are D=5.0 mm and w=O.l mm for a center frequency of 3.36 GHz. The relative permittivity and thickness is 9.20(1-j0.234) and 1=3.048 mm. Consider a center frequency of5.81 GHz and again 1=3.048 mm, the required parameters for the capacitive grid are D=2.0 mm and w=0.2 mm where the required relative permittivity is now 9.20(1-j0.371) Admittedly, engineered dielectrics are themselves a historically interesting and fruitful research area which benefits today from advances in monolithic fabrication using direct-write of dielectrics with nanometer scale inclusions. However, our objective in the present study is to realize the advantages of the absorber proposed by Luukkonen et al. without resort to engineered lossy dielectrics. Specifically we are restricted to commercially available planer circuit materials without use of in-house direct-write technology or materials engineering capability. The materials considered here are TMM 10 laminate with (35 {mu}lm copper cladding with a complex permittivity 9.20-j0.0022) and Ohmegaply resistor conductor material (maximum 250 {Omega}/sq.). A thin electromagnetic absorber for incidence angles greater than 30deg. but less than 60deg. and both polarizations is computationally demonstrated. This absorber utilizes high-permittivity, low-loss microwave substrate in conjunction with an engineered lossy sheet impedance. The lossy sheet impedance is easily engineered with simple analytical approximations and can be manufactured from commercially available laminate materials on microwave substrate.« less

78 FR 29772 - Information Collection Activities: Decommissioning Activities, Proposed Collection; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-21

... and view all related materials. We will post all comments. Email [email protected] . Mail or hand... operations. For example, section 109(c)(2) and (d)(1), 30 U.S.C. 1719(c)(2) and (d)(1), impose substantial.... Notify District Manager at least 72 hours prior to shearing ram tests. 1706(a) Request approval of well...

Experimental and Numerical Study on the Strength of Aluminum Extrusion Welding.

PubMed

Bingöl, Sedat; Bozacı, Atilla

2015-07-17

The quality of extrusion welding in the extruded hollow shapes is influenced significantly by the pressure and effective stress under which the material is being joined inside the welding chamber. However, extrusion welding was not accounted for in the past by the developers of finite element software packages. In this study, the strength of hollow extrusion profile with seam weld produced at different ram speeds was investigated experimentally and numerically. The experiments were performed on an extruded hollow aluminum profile which was suitable to obtain the tensile tests specimens from its seam weld's region at both parallel to extrusion direction and perpendicular to extrusion direction. A new numerical modeling approach, which was recently proposed in literature, was used for numerical analyses of the study. The simulation results performed at different ram speeds were compared with the experimental results, and a good agreement was obtained.

Space ultra-vacuum facility and method of operation

NASA Technical Reports Server (NTRS)

Naumann, Robert J. (Inventor)

1988-01-01

A wake shield space processing facility (10) for maintaining ultra-high levels of vacuum is described. The wake shield (12) is a truncated hemispherical section having a convex side (14) and a concave side (24). Material samples (68) to be processed are located on the convex side of the shield, which faces in the wake direction in operation in orbit. Necessary processing fixtures (20) and (22) are also located on the convex side. Support equipment including power supplies (40, 42), CMG package (46) and electronic control package (44) are located on the convex side (24) of the shield facing the ram direction. Prior to operation in orbit the wake shield is oriented in reverse with the convex side facing the ram direction to provide cleaning by exposure to ambient atomic oxygen. The shield is then baked-out by being pointed directed at the sun to obtain heating for a suitable period.

Fluorescence enhancement and nonreciprocal transmission of light waves by nanomaterial interfaces

NASA Astrophysics Data System (ADS)

Nyman, M.; Shevchenko, A.; Kaivola, M.

2017-11-01

In an optically absorbing or amplifying linear medium, the energy flow density of interfering optical waves is in general periodically modulated in space. This makes the wave transmission through a material boundary, as described by the Fresnel transmission coefficients, nonreciprocal and apparently violating the energy conservation law. The modulation has been previously described in connection to ordinary homogeneous nonmagnetic materials. In this work, we extend the description to nanomaterials with designed structural units that can be magnetic at optical frequencies. We find that in such a "metamaterial" the modulation in energy flow can be used to enhance optical far-field emission in spite of the fact that the material is highly absorbing. We also demonstrate a nanomaterial design that absorbs light, but simultaneously eliminates the power flow modulation and returns the reciprocity, which is impossible to achieve with a nonmagnetic material. We anticipate that these unusual optical effects can be used to increase the efficiency of nanostructured light emitters and absorbers, such as light-emitting diodes and solar cells.

RAM Technology Study.

DTIC Science & Technology

1980-01-03

characteristics. 4 2 Example of MOS scaling. 18 3 RAM chip area comparison. 31 4 Summary of RAM switching response. 34 5 Summary of RAM power dissipation...array to retain the data after power is removed (volatility). The level of chip complexity is that of the most complex arrays in current production and is...4) ..4 L) . C U ~~~~ -- -- t 0 -, 4 4 . . Data in the Read-Only-Memory is defined by the metallization pattern during chip fabrication. The stored

High throughput light absorber discovery, Part 2: Establishing structure–band gap energy relationships

DOE PAGES

Suram, Santosh K.; Newhouse, Paul F.; Zhou, Lan; ...

2016-09-23

Combinatorial materials science strategies have accelerated materials development in a variety of fields, and we extend these strategies to enable structure-property mapping for light absorber materials, particularly in high order composition spaces. High throughput optical spectroscopy and synchrotron X-ray diffraction are combined to identify the optical properties of Bi-V-Fe oxides, leading to the identification of Bi 4V 1.5Fe 0.5O 10.5 as a light absorber with direct band gap near 2.7 eV. Here, the strategic combination of experimental and data analysis techniques includes automated Tauc analysis to estimate band gap energies from the high throughput spectroscopy data, providing an automated platformmore » for identifying new optical materials.« less

High throughput light absorber discovery, Part 2: Establishing structure–band gap energy relationships

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suram, Santosh K.; Newhouse, Paul F.; Zhou, Lan

Combinatorial materials science strategies have accelerated materials development in a variety of fields, and we extend these strategies to enable structure-property mapping for light absorber materials, particularly in high order composition spaces. High throughput optical spectroscopy and synchrotron X-ray diffraction are combined to identify the optical properties of Bi-V-Fe oxides, leading to the identification of Bi 4V 1.5Fe 0.5O 10.5 as a light absorber with direct band gap near 2.7 eV. Here, the strategic combination of experimental and data analysis techniques includes automated Tauc analysis to estimate band gap energies from the high throughput spectroscopy data, providing an automated platformmore » for identifying new optical materials.« less

High Throughput Light Absorber Discovery, Part 2: Establishing Structure-Band Gap Energy Relationships.

PubMed

Suram, Santosh K; Newhouse, Paul F; Zhou, Lan; Van Campen, Douglas G; Mehta, Apurva; Gregoire, John M

2016-11-14

Combinatorial materials science strategies have accelerated materials development in a variety of fields, and we extend these strategies to enable structure-property mapping for light absorber materials, particularly in high order composition spaces. High throughput optical spectroscopy and synchrotron X-ray diffraction are combined to identify the optical properties of Bi-V-Fe oxides, leading to the identification of Bi 4 V 1.5 Fe 0.5 O 10.5 as a light absorber with direct band gap near 2.7 eV. The strategic combination of experimental and data analysis techniques includes automated Tauc analysis to estimate band gap energies from the high throughput spectroscopy data, providing an automated platform for identifying new optical materials.

Single-Event Effect Response of a Commercial ReRAM

NASA Technical Reports Server (NTRS)

Chen, Dakai; Label, Kenneth A.; Kim, Hak; Phan, Anthony; Wilcox, Edward; Buchner, Stephen; Khachatrian, Ani; Roche, Nicolas

2014-01-01

We show heavy ion test results of a commercial production-level ReRAM. The memory array is robust to bit upsets. However the ReRAM system is vulnerable to SEFIs due to upsets in peripheral circuits, including the sense amplifier.

Uniform Self-rectifying Resistive Switching Behavior via Preformed Conducting Paths in a Vertical-type Ta2O5/HfO2-x Structure with a Sub-μm(2) Cell Area.

PubMed

Yoon, Jung Ho; Yoo, Sijung; Song, Seul Ji; Yoon, Kyung Jean; Kwon, Dae Eun; Kwon, Young Jae; Park, Tae Hyung; Kim, Hye Jin; Shao, Xing Long; Kim, Yumin; Hwang, Cheol Seong

2016-07-20

To replace or succeed the present NAND flash memory, resistive switching random access memory (ReRAM) should be implemented in the vertical-type crossbar array configuration. The ReRAM cell must have a highly reproducible resistive switching (RS) performance and an electroforming-free, self-rectifying, low-power-consumption, multilevel-switching, and easy fabrication process with a deep sub-μm(2) cell area. In this work, a Pt/Ta2O5/HfO2-x/TiN RS memory cell fabricated in the form of a vertical-type structure was presented as a feasible contender to meet the above requirements. While the fundamental RS characteristics of this material based on the electron trapping/detrapping mechanisms have been reported elsewhere, the influence of the cell scaling size to 0.34 μm(2) on the RS performance by adopting the vertical integration scheme was carefully examined in this work. The smaller cell area provided much better switching uniformity while all the other benefits of this specific material system were preserved. Using the overstressing technique, the nature of RS through the localized conducting path was further examined, which elucidated the fundamental difference between the present material system and the general ionic-motion-related bipolar RS mechanism.

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)

PubMed Central

Kassouf, Nick; Syed, Sara; Larner, Joanne; Amlôt, Richard

2017-01-01

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. PMID:28152053

Apparatus and method for measuring the Seebeck coefficient and resistivity of materials

NASA Technical Reports Server (NTRS)

Hadek, V. (Inventor)

1973-01-01

An apparatus for measuring the thermoelectric properties of materials under high pressure is described that includes a pair of force transmitting assemblies constructed of thermally and electrically conductive material positioned between the ram and anvil of a press. Each force transmitting assembly has a small diameter pressing portion for contacting a face of the sample so that the sample can be squeezed between them. Each assembly also includes a heat exchanger to maintain the sample face at a controlled temperature, and an electrical conductor to carry current generated by the sample. A sleeve of thermally and electrically insulative material closely surrounds the pressing portions of the two assemblies.

The “Ram Effect”: A “Non-Classical” Mechanism for Inducing LH Surges in Sheep

PubMed Central

Fabre-Nys, Claude; Chanvallon, Audrey; Dupont, Joëlle; Lardic, Lionel; Lomet, Didier; Martinet, Stéphanie; Scaramuzzi, Rex J.

2016-01-01

During spring sheep do not normally ovulate but exposure to a ram can induce ovulation. In some ewes an LH surge is induced immediately after exposure to a ram thus raising questions about the control of this precocious LH surge. Our first aim was to determine the plasma concentrations of oestradiol (E2) E2 in anoestrous ewes before and after the “ram effect” in ewes that had a “precocious” LH surge (starting within 6 hours), a “normal” surge (between 6 and 28h) and “late» surge (not detected by 56h). In another experiment we tested if a small increase in circulating E2 could induce an LH surge in anoestrus ewes. The concentration of E2 significantly was not different at the time of ram introduction among ewes with the three types of LH surge. “Precocious” LH surges were not preceded by a large increase in E2 unlike “normal” surges and small elevations of circulating E2 alone were unable to induce LH surges. These results show that the “precocious” LH surge was not the result of E2 positive feedback. Our second aim was to test if noradrenaline (NA) is involved in the LH response to the “ram effect”. Using double labelling for Fos and tyrosine hydroxylase (TH) we showed that exposure of anoestrous ewes to a ram induced a higher density of cells positive for both in the A1 nucleus and the Locus Coeruleus complex compared to unstimulated controls. Finally, the administration by retrodialysis into the preoptic area, of NA increased the proportion of ewes with an LH response to ram odor whereas treatment with the α1 antagonist Prazosin decreased the LH pulse frequency and amplitude induced by a sexually active ram. Collectively these results suggest that in anoestrous ewes NA is involved in ram-induced LH secretion as observed in other induced ovulators. PMID:27384667

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

PubMed

Ansah, Terry; Yaccub, Zanabongo I; Rahman, Nurudeen A

2017-12-01

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) in Azivivi, Manipinta and Yenyawoso than in Obolo. The highest ( P  < 0.05) NDF and ADF fractions were obtained in Obolo. Whilst no significant difference was reported in total and daily dry matter (DM) intake among the varieties, CP, NDF and ADF intake all differed between Obolo and other varieties. The apparent nutrient digestibility did not differ ( 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.

Superabsorbents in Personal Care Industry

NASA Astrophysics Data System (ADS)

Li, Yong

1997-10-01

Water swellable hydrogels, often called Superabsorbent Polymers, are used as a major component in many absorbent products such as baby diapers. The superabsorbents used in personal care industry are typically lightly crosslinked sodium polyacrylate polymers. The current annual worldwide production of the material is close to one million metric tons. These hydrogels can absorb water more than 100 times of their own weight. The absorbed liquid is tightly held inside the superabsorbent materials even against pressure. The balance of many different properties will be discussed.

Failure mechanisms in energy-absorbing composite structures

NASA Astrophysics Data System (ADS)

Johnson, Alastair F.; David, Matthew

2010-11-01

Quasi-static tests are described for determination of the energy-absorption properties of composite crash energy-absorbing segment elements under axial loads. Detailed computer tomography scans of failed specimens were used to identify local compression crush failure mechanisms at the crush front. These mechanisms are important for selecting composite materials for energy-absorbing structures, such as helicopter and aircraft sub-floors. Finite element models of the failure processes are described that could be the basis for materials selection and future design procedures for crashworthy structures.

Material Activation Benchmark Experiments at the NuMI Hadron Absorber Hall in Fermilab

NASA Astrophysics Data System (ADS)

Matsumura, H.; Matsuda, N.; Kasugai, Y.; Toyoda, A.; Yashima, H.; Sekimoto, S.; Iwase, H.; Oishi, K.; Sakamoto, Y.; Nakashima, H.; Leveling, A.; Boehnlein, D.; Lauten, G.; Mokhov, N.; Vaziri, K.

2014-06-01

In our previous study, double and mirror symmetric activation peaks found for Al and Au arranged spatially on the back of the Hadron absorber of the NuMI beamline in Fermilab were considerably higher than those expected purely from muon-induced reactions. From material activation bench-mark experiments, we conclude that this activation is due to hadrons with energy greater than 3 GeV that had passed downstream through small gaps in the hadron absorber.

Analytical Versus Numerical Estimates of Water-Level Declines Caused by Pumping, and a Case Study of the Iao Aquifer, Maui, Hawaii

USGS Publications Warehouse

Oki, Delwyn S.; Meyer, William

2001-01-01

Comparisons were made between model-calculated water levels from a one-dimensional analytical model referred to as RAM (Robust Analytical Model) and those from numerical ground-water flow models using a sharp-interface model code. RAM incorporates the horizontal-flow assumption and the Ghyben-Herzberg relation to represent flow in a one-dimensional unconfined aquifer that contains a body of freshwater floating on denser saltwater. RAM does not account for the presence of a low-permeability coastal confining unit (caprock), which impedes the discharge of fresh ground water from the aquifer to the ocean, nor for the spatial distribution of ground-water withdrawals from wells, which is significant because water-level declines are greatest in the vicinity of withdrawal wells. Numerical ground-water flow models can readily account for discharge through a coastal confining unit and for the spatial distribution of ground-water withdrawals from wells. For a given aquifer hydraulic-conductivity value, recharge rate, and withdrawal rate, model-calculated steady-state water-level declines from RAM can be significantly less than those from numerical ground-water flow models. The differences between model-calculated water-level declines from RAM and those from numerical models are partly dependent on the hydraulic properties of the aquifer system and the spatial distribution of ground-water withdrawals from wells. RAM invariably predicts the greatest water-level declines at the inland extent of the aquifer where the freshwater body is thickest and the potential for saltwater intrusion is lowest. For cases in which a low-permeability confining unit overlies the aquifer near the coast, however, water-level declines calculated from numerical models may exceed those from RAM even at the inland extent of the aquifer. Since 1990, RAM has been used by the State of Hawaii Commission on Water Resource Management for establishing sustainable-yield values for the State?s aquifers. Data from the Iao aquifer, which lies on the northeastern flank of the West Maui Volcano and which is confined near the coast by caprock, are now available to evaluate the predictive capability of RAM for this system. In 1995 and 1996, withdrawal from the Iao aquifer reached the 20 million gallon per day sustainable-yield value derived using RAM. However, even before 1996, water levels in the aquifer had declined significantly below those predicted by RAM, and continued to decline in 1997. To halt the decline of water levels and to preclude the intrusion of salt-water into the four major well fields in the aquifer, it was necessary to reduce withdrawal from the aquifer system below the sustainable-yield value derived using RAM. In the Iao aquifer, the decline of measured water levels below those predicted by RAM is consistent with the results of the numerical model analysis. Relative to model-calculated water-level declines from numerical ground-water flow models, (1) RAM underestimates water-level declines in areas where a low-permeability confining unit exists, and (2) RAM underestimates water-level declines in the vicinity of withdrawal wells.

Comparison of Postoperative Respiratory Monitoring by Acoustic and Transthoracic Impedance Technologies in Pediatric Patients at Risk of Respiratory Depression.

PubMed

Patino, Mario; Kalin, Megan; Griffin, Allison; Minhajuddin, Abu; Ding, Lili; Williams, Timothy; Ishman, Stacey; Mahmoud, Mohamed; Kurth, C Dean; Szmuk, Peter

2017-06-01

In children, postoperative respiratory rate (RR) monitoring by transthoracic impedance (TI), capnography, and manual counting has limitations. The rainbow acoustic monitor (RAM) measures continuous RR noninvasively by a different methodology. Our primary aim was to compare the degree of agreement and accuracy of RR measurements as determined by RAM and TI to that of manual counting. Secondary aims include tolerance and analysis of alarm events. Sixty-two children (2-16 years old) were admitted after tonsillectomy or receiving postoperative patient/parental-controlled analgesia. RR was measured at regular intervals by RAM, TI, and manual count. Each TI or RAM alarm resulted in a clinical evaluation to categorize as a true or false alarm. To assess accuracy and degree of agreement of RR measured by RAM or TI compared with manual counting, a Bland-Altman analysis was utilized showing the average difference and the limits of agreement. Sensitivity and specificity of RR alarms by TI and RAM are presented. Fifty-eight posttonsillectomy children and 4 patient/parental-controlled analgesia users aged 6.5 ± 3.4 years and weighting 35.3 ± 22.7 kg (body mass index percentile 76.6 ± 30.8) were included. The average monitoring time per patient was 15.9 ± 4.8 hours. RAM was tolerated 87% of the total monitoring time. The manual RR count was significantly different from TI (P = .007) with an average difference ± SD of 1.39 ± 10.6 but were not significantly different from RAM (P = .81) with an average difference ± SD of 0.17 ± 6.8. The proportion of time when RR measurements differed by ≥4 breaths was 22% by TI and was 11% by RAM. Overall, 276 alarms were detected (mean alarms/patient = 4.5). The mean number of alarms per patient were 1.58 ± 2.49 and 2.87 ± 4.32 for RAM and TI, respectively. The mean number of false alarms was 0.18 ± 0.71 for RAM and 1.00 ± 2.78 for TI. The RAM was found to have 46.6% sensitivity (95% confidence interval [CI], 0.29-0.64), 95.9% specificity (95% CI, 0.90-1.00), 88.9% positive predictive value (95% CI, 0.73-1.00), and 72.1% negative predictive value (95% CI, 0.61-0.84), whereas the TI monitor had 68.5% sensitivity (95% CI, 0.53-0.84), 72.0% specificity (95% CI, 0.60-0.84), 59.0% positive (95% CI, 0.44-0.74), and 79.5% negative predictive value (95% CI, 0.69-0.90). In children at risk of postoperative respiratory depression, RR assessment by RAM was not different to manual counting. RAM was well tolerated, had a lower incidence of false alarms, and had better specificity and positive predictive value than TI. Rigorous evaluation of the negative predictive value is essential to determine the role of postoperative respiratory monitoring with RAM.

Progress on the Ram Wing Concept with Emphasis on Lateral Dynamics

DOT National Transportation Integrated Search

1971-01-01

Theoretical and experimental efforts conducted at the Transportation Systems Center in the ram wing program are described. Glide Tests were performed using a simple ram wing model operating in an open rectangular trough 50 ft long. Lift drag ratios o...

SEM Analysis Techniques for LSI Microcircuits. Volume 2

DTIC Science & Technology

1980-08-01

4~, 1 v’ ’ RADC-TR80-250, Vol 11 (of two), Final Technical -Report, Augut1980 SEM, ANALYSIS TECHNIQUES, FOR LSI MICROCIRCUITS: ’Martin...Bit Static ’RAM.. Volume II - 1024 Bit Stat’i RAM, 4096 Bit Dynamic RAM (SiGATE WOS,)., 4096 Bit -Dynamic RAM ( 1 2 L Bipolar)., ,Summary. RADC-TR-80-250...States, ithout.irst obtani an export nse, is a violation t Internatio 1 Tr ffic in A . eguiations. Such violation is subject o penalty of to 2 years impr

Absorbent properties of carboxymethylated fiber, hydroentangled nonwoven and regenerated cellulose: a comparative study

USDA-ARS?s Scientific Manuscript database

Commercially-available, bleached cotton fibers, rayon, and their hydroentangled counterparts were carboxymethylated to produce cellulosic products with increased absorbency. These cellulose materials were tested for absorbance, spectroscopic properties, degree of substitution and carding ability. Ca...

Reference intervals for serum reactive oxygen metabolites, biological antioxidant potential, and oxidative stress index in adult rams.

PubMed

Oikonomidis, Ioannis L; Kiosis, Evangelos A; Brozos, Christos N; Kritsepi-Konstantinou, Maria G

2017-03-01

OBJECTIVE To establish reference intervals for serum reactive oxygen metabolites (ROMs), biological antioxidant potential (BAP), and oxidative stress index (OSi) in adult rams by use of controlled preanalytic and analytic procedures. ANIMALS 123 healthy 1- to 4-year-old rams of 2 Greek breeds (Chios [n = 62] and Florina [61]). PROCEDURES 4 hours after rams were fed, a blood sample was obtained from each ram, and serum was harvested. Concentrations of ROMs and BAP were measured colorimetrically on a spectrophotometric analyzer. The OSi was calculated as ROMs concentration divided by BAP concentration. Combined and breed-specific reference intervals were calculated by use of nonparametric and robust methods, respectively. Reference intervals were defined as the 2.5th to 97.5th percentiles. RESULTS Reference intervals for ROMs, BAP, and OSi for all rams combined were 65 to 109 Carratelli units, 2,364 to 4,491 μmol/L, and 18.2 to 43.0 Carratelli units/(mmol/L), respectively. Reference intervals of Chios rams for ROMs, BAP, and OSi were 56 to 113 Carratelli units, 2,234 to 4,290 μmol/L, and 12.9 to 38.4 Carratelli units/(mmol/L), respectively. Reference intervals of Florina rams for ROMs, BAP, and OSi were 68 to 111 Carratelli units, 2,337 to 4,363 μmol/L, and 14.1 to 38.1 Carratelli units/(mmol/L), respectively. CONCLUSIONS AND CLINICAL RELEVANCE Reference intervals calculated in this study can be used as a guide for the interpretation of ROMs, BAP, and OSi results in rams and, under appropriate conditions, can be adopted for use by veterinary laboratories.

Multi-wavelength access gate for WDM-formatted words in optical RAM row architectures

NASA Astrophysics Data System (ADS)

Fitsios, D.; Alexoudi, T.; Vagionas, C.; Miliou, A.; Kanellos, G. T.; Pleros, N.

2013-03-01

Optical RAM has emerged as a promising solution for overcoming the "Memory Wall" of electronics, indicating the use of light in RAM architectures as the approach towards enabling ps-regime memory access times. Taking a step further towards exploiting the unique wavelength properties of optical signals, we reveal new architectural perspectives in optical RAM structures by introducing WDM principles in the storage area. To this end, we demonstrate a novel SOAbased multi-wavelength Access Gate for utilization in a 4x4 WDM optical RAM bank architecture. The proposed multiwavelength Access Gate can simultaneously control random access to a 4-bit optical word, exploiting Cross-Gain-Modulation (XGM) to process 8 Bit and Bit channels encoded in 8 different wavelengths. It also suggests simpler optical RAM row architectures, allowing for the effective sharing of one multi-wavelength Access Gate for each row, substituting the eight AGs in the case of conventional optical RAM architectures. The scheme is shown to support 10Gbit/s operation for the incoming 4-bit data streams, with a power consumption of 15mW/Gbit/s. All 8 wavelength channels demonstrate error-free operation with a power penalty lower than 3 dB for all channels, compared to Back-to-Back measurements. The proposed optical RAM architecture reveals that exploiting the WDM capabilities of optical components can lead to RAM bank implementations with smarter column/row encoders/decoders, increased circuit simplicity, reduced number of active elements and associated power consumption. Moreover, exploitation of the wavelength entity can release significant potential towards reconfigurable optical cache mapping schemes when using the wavelength dimension for memory addressing.

Feeding of the megamouth shark (Pisces: Lamniformes: Megachasmidae) predicted by its hyoid arch: a biomechanical approach.

PubMed

Tomita, Taketeru; Sato, Keiichi; Suda, Kenta; Kawauchi, Junro; Nakaya, Kazuhiro

2011-05-01

Studies of the megamouth shark, one of three planktivorous sharks, can provide information about their evolutionary history. Megamouth shark feeding has never been observed in life animals, but two alternative hypotheses on biomechanics suggest either feeding, i.e., ram feeding or suction feeding. In this study, the second moment of area of the ceratohyal cartilages, which is an indicator of the flexural stiffness of the cartilages, is calculated for 21 species of ram- and suction-feeding sharks using computed tomography. The results indicate that suction-feeding sharks have ceratohyal cartilages with a larger second moment of area than ram-feeding sharks. The result also indicates that the ram-suction index, which is an indicator of relative contribution of ram and suction behavior, is also correlated with the second moment of area of the ceratohyal. Considering that large bending stresses are expected to be applied to the ceratohyal cartilage during suction, the larger second moment of area of the ceratohyal of suction-feeding sharks can be interpreted as an adaptation for suction feeding. Based on the small second moment of area of the ceratohyal cartilage of the megamouth shark, the feeding mode of the megamouth shark is considered to be ram feeding, similar to the planktivorous basking shark. From these results, an evolutionary scenario of feeding mechanics of three species of planktivorous sharks can be suggested. In this scenario, the planktivorous whale shark evolved ram feeding from a benthic suction-feeding ancestor. Ram feeding in the planktivorous megamouth shark and the basking shark evolved from ram feeding swimming-type ancestors and that both developed their unique filtering system to capture small-sized prey. Copyright © 2011 Wiley-Liss, Inc.

Tech Transfer Webinar: Energy Absorbing Materials

ScienceCinema

Duoss, Eric

2018-01-16

A new material has been designed and manufactured at LLNL that can absorb mechanical energy--a cushion--while also providing protection against sheering. This ordered cellular material is 3D printed using direct ink writing techniques under development at LLNL. It is expected to find utility in application spaces that currently use unordered foams, such as sporting and consumer goods as well as defense and aerospace.

Improving impact resistance of ceramic materials by energy absorbing surface layers

NASA Technical Reports Server (NTRS)

Kirchner, H. P.; Seretsky, J.

1974-01-01

Energy absorbing surface layers were used to improve the impact resistance of silicon nitride and silicon carbide ceramics. Low elastic modulus materials were used. In some cases, the low elastic modulus was achieved using materials that form localized microcracks as a result of thermal expansion anisotropy, thermal expansion differences between phases, or phase transformations. In other cases, semi-vitreous or vitreous materials were used. Substantial improvements in impact resistance were observed at room and elevated temperatures.

Study on preparation and microwave absorption property of the core-nanoshell composite materials doped with La.

PubMed

Wei, Liqiu; Che, Ruxin; Jiang, Yijun; Yu, Bing

2013-12-01

Microwave absorbing material plays a great role in electromagnetic pollution controlling, electromagnetic interference shielding and stealth technology, etc. The core-nanoshell composite materials doped with La were prepared by a solid-state reaction method, which is applied to the electromagnetic wave absorption. The core is magnetic fly-ash hollow cenosphere, and the shell is the nanosized ferrite doped with La. The thermal decomposition process of the sample was investigated by thermogravimetry and differential thermal analysis. The morphology and components of the composite materials were investigated by the X-ray diffraction analysis, the microstructure was observed by scanning electron microscope and transmission electron microscope. The results of vibrating sample magnetometer analysis indicated that the exchange-coupling interaction happens between ferrite of magnetic fly-ash hollow cenosphere and nanosized ferrite coating, which caused outstanding magnetic properties. The microwave absorbing property of the sample was measured by reflectivity far field radar cross section of radar microwave absorbing material with vector network analyzer. The results indicated that the exchange-coupling interaction enhanced magnetic loss of composite materials. Therefore, in the frequency of 5 GHz, the reflection coefficient can achieve -24 dB. It is better than single material and is consistent with requirements of the microwave absorbing material at the low-frequency absorption. Copyright © 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

PADDLEFISH BUCCAL FLOW VELOCITY DURING RAM SUSPENSION FEEDING AND RAM VENTILATION

PubMed

Cech; Cheer

1994-01-01

A micro-thermistor probe was inserted into the buccal cavity of freely swimming paddlefish to measure flow velocity during ram ventilation, ram suspension feeding and prey processing. Swimming speed was measured from videotapes recorded simultaneously with the buccal flow velocity measurements. Both swimming velocity and buccal flow velocity were significantly higher during suspension feeding than during ram ventilation. As the paddlefish shifted from ventilation to feeding, buccal flow velocity increased to approximately 60 % of the swimming velocity. During prey processing, buccal flow velocity was significantly higher than the swimming velocity, indicating that prey processing involves the generation of suction. The Reynolds number (Re) for flow at the level of the paddlefish gill rakers during feeding is about 30, an order of magnitude lower than the Re calculated previously for pump suspension-feeding blackfish. These data, combined with data available from the literature, indicate that the gill rakers of ram suspension-feeding teleost fishes may operate at a substantially lower Re than the rakers of pump suspension feeders.

Pelamis: experience from concept to connection.

PubMed

Yemm, Richard; Pizer, David; Retzler, Chris; Henderson, Ross

2012-01-28

The development of the Pelamis wave energy converter from its conceptual origins to its commercial deployment is reviewed. The early emphasis on designing for survivability and favourable power absorption characteristics focused attention towards a self-referenced articulated line-absorber in an attenuator orientation. A novel joint and control system allow the machine to be actively tuned to provide a resonant response power amplification in small and moderate seas. In severe seas, the machine is left in its default or natural condition, which is benign and non-resonant. Hydraulic rams at the joints provide the primary power take-off with medium-term storage in high-pressure accumulators yielding smooth electricity generation. Land-based modular construction requiring minimal weather windows for rapid offshore installation is an essential engineering feature necessary for viable commercialization. The second-generation Pelamis designs built for E.ON and ScottishPower Renewables are presented, and the scope for further cost reduction and performance enhancements are explained.

Signal-to-noise optimization and evaluation of a home-made visible diode-array spectrophotometer

PubMed Central

Raimundo, Jr., Ivo M.; Pasquini, Celio

1993-01-01

This paper describes a simple low-cost multichannel visible spectrophotometer built with an RL512G EGG-Reticon photodiode array. A symmetric Czerny-Turner optical design was employed; instrument control was via a single-board microcomputer based on the 8085 Intel microprocessor. Spectral intensity data are stored in the single-board's RAM and then transferred to an IBM-AT 3865X compatible microcomputer through a RS-232C interface. This external microcomputer processes the data to recover transmittance, absorbance or relative intensity of the spectra. The signal-to-noise ratio and dynamic range were improved by using variable integration times, which increase during the same scan; and by the use of either weighted or unweighted sliding average of consecutive diodes. The instrument is suitable for automatic methods requiring quasi-simultaneous multiwavelength detections, such as multivariative calibration and flow-injection gradient scan techniques. PMID:18924979

Morphological and electrical properties of epoxy-based composites reinforced with exfoliated graphite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lamberti, Patrizia; Spinelli, Giovanni, E-mail: gspinelli@unisa.it; Tucci, Vincenzo

An experimental study has been carried out to prepare and characterize epoxy/amine-based composites filled with different percentages of partially exfoliated graphite (i.e. pEG) particles having an exfoliation degree of 56% in order to analyze the effect of the filler amounts on the electrical properties of the resulting nanocomposites. Moreover, in order to fully investigate the direct relationship between the physical properties of the employed filler and the results of the electrical characterization, a structural and morphological characterization of the pEG samples is carried out by means of various type of analysis such as X-ray diffraction patterns, micro-Raman and Scanning Electronmore » Microscopy (SEM) images. The DC electrical characterization reveals a percolation thresholds (EPT) that falls in the range [2–3] wt% and an electrical conductivity of about 0.66 S/m at the highest filler loading (6.5 wt%). From the analysis of the percolative curve it is possible to derive the percolation law parameters and in particular the critical exponent t, whose value (i.e. 1.2) reflects an effective 2D organization of the percolating structure consistent with the type of filler used (2-dimensional). Finally, an extensive analysis concerning the electrical properties in the frequency domain has been carried out in order to evaluate the effectiveness of pEG-loaded composites in terms of electromagnetic interference compatibility (EMC) and their applicability as radar absorbers materials (RAMs).« less

Microwave impregnation of porous materials with thermal energy storage materials

DOEpatents

Benson, David K.; Burrows, Richard W.

1993-01-01

A method for impregnating a porous, non-metallic construction material with a solid phase-change material is described. The phase-change material in finely divided form is spread onto the surface of the porous material, after which the porous material is exposed to microwave energy for a time sufficient to melt the phase-change material. The melted material is spontaneously absorbed into the pores of the porous material. A sealing chemical may also be included with the phase-change material (or applied subsequent to the phase-change material) to seal the surface of the porous material. Fire retardant chemicals may also be included with the phase-change materials. The treated construction materials are better able to absorb thermal energy and exhibit increased heat storage capacity.

Microwave impregnation of porous materials with thermal energy storage materials

DOEpatents

Benson, D.K.; Burrows, R.W.

1993-04-13

A method for impregnating a porous, non-metallic construction material with a solid phase-change material is described. The phase-change material in finely divided form is spread onto the surface of the porous material, after which the porous material is exposed to microwave energy for a time sufficient to melt the phase-change material. The melted material is spontaneously absorbed into the pores of the porous material. A sealing chemical may also be included with the phase-change material (or applied subsequent to the phase-change material) to seal the surface of the porous material. Fire retardant chemicals may also be included with the phase-change materials. The treated construction materials are better able to absorb thermal energy and exhibit increased heat storage capacity.

Effect of ram semen extenders and supplements on computer assisted sperm analysis parameters

USDA-ARS?s Scientific Manuscript database

A study evaluated the effects of ram semen extender and extender supplementation on computer assisted sperm analysis (CASA) parameters positively correlated with progressive motility. Semen collected from 5 rams was distributed across treatment combinations consisting of either TRIS citrate (T) or ...

Study on the characteristics of magneto-sensitive electromagnetic wave-absorbing properties of magnetorheological elastomers

NASA Astrophysics Data System (ADS)

Yu, Miao; Yang, Pingan; Fu, Jie; Liu, Shuzhi; Qi, Song

2016-08-01

Magnetorheological (MR) materials are a class of materials whose mechanical and electrical properties can be reversible controlled by the magnetic field. In this study, we pioneered research on the effect of a uniform magnetic field with different strengths and directions on the microwave-absorbing properties of magnetorheological elastomers (MREs), in which the ferromagnetic particles are flower-like carbonyl iron powders (CIPs) prepared by an in situ reduction method. The electromagnetic (EM) absorbing properties of the composites have been analyzed by vector network analysis with the coaxial reflection/transmission technique. Under the magnetic field, the columnar or chainlike structures were formed, which allows EM waves to penetrate. Meanwhile, stronger Debye dipolar relaxation and attenuation constant have been obtained when changing the direction of the applied magnetic field. Compared with untreated MREs, not only have the minimum reflection loss (RL) and the effective absorption bandwidth (below -20 dB) greatly increased, the frequencies of the absorbing peaks shift about 15%. This suggests that MREs are a magnetic-field-sensitive electromagnetic wave-absorbing material and have great potential in applications such as in anti-radar camouflage, due to the fact that radar can continuously conduct detection at many electromagnetic frequencies, while the MR materials can adjust the microwave-absorption peak according to the radar frequency.

Numerical analysis of radiation propagation in innovative volumetric receivers based on selective laser melting techniques

NASA Astrophysics Data System (ADS)

Alberti, Fabrizio; Santiago, Sergio; Roccabruna, Mattia; Luque, Salvador; Gonzalez-Aguilar, Jose; Crema, Luigi; Romero, Manuel

2016-05-01

Volumetric absorbers constitute one of the key elements in order to achieve high thermal conversion efficiencies in concentrating solar power plants. Regardless of the working fluid or thermodynamic cycle employed, design trends towards higher absorber output temperatures are widespread, which lead to the general need of components of high solar absorptance, high conduction within the receiver material, high internal convection, low radiative and convective heat losses and high mechanical durability. In this context, the use of advanced manufacturing techniques, such as selective laser melting, has allowed for the fabrication of intricate geometries that are capable of fulfilling the previous requirements. This paper presents a parametric design and analysis of the optical performance of volumetric absorbers of variable porosity conducted by means of detailed numerical ray tracing simulations. Sections of variable macroscopic porosity along the absorber depth were constructed by the fractal growth of single-cell structures. Measures of performance analyzed include optical reflection losses from the absorber front and rear faces, penetration of radiation inside the absorber volume, and radiation absorption as a function of absorber depth. The effects of engineering design parameters such as absorber length and wall thickness, material reflectance and porosity distribution on the optical performance of absorbers are discussed, and general design guidelines are given.

Erosion Results of the MISSE 8 Polymers Experiment After 2 Years of Space Exposure on the International Space Station

NASA Technical Reports Server (NTRS)

de Groh, Kim K.; Banks, Bruce A.; Asmar, Olivia C.; Yi, Grace T.; Mitchell, Gianna G.; Guo, Aobo; Sechkar, Edward A.

2017-01-01

Polymers and other oxidizable materials on the exterior of spacecraft in the low Earth orbit (LEO) space environment can be eroded due to reaction with atomic oxygen (AO). Therefore, in order to design durable spacecraft, it is important to know the LEO AO erosion yield (E(sub y), volume loss per incident oxygen atom) of materials susceptible to AO reaction. A spaceflight experiment, called the Polymers Experiment, which contained 42 samples, was developed to determine the effect of solar exposure on the AO E(sub y) of fluoropolymers flown in ram, wake, or zenith orientations. The Polymers Experiment was exposed to the LEO space environment on the exterior of the International Space Station (ISS) as part of the Materials International Space Station Experiment 8 (MISSE 8) mission. The MISSE 8 mission included samples flown in a zenith/nadir orientation for 2.14 years in the MISSE 8 Passive Experiment Container (PEC), and samples flown in a ram/wake orientation for 2.0 years in the Optical Reflector Materials Experiment-III (ORMatEIII) tray. The experiment included Kapton H (Registered Trademark) witness samples for AO fluence determination in each orientation. This paper provides an overview of the MISSE 8 mission, a description of the flight experiment with details on the polymers flown, the characterization techniques used, the AO fluence for each exposure orientation, and the LEO E(sub y) results. The E(sub y) of Teflon fluorinated ethylene propylene (FEP) samples flown in ram, wake, and zenith orientations have been compared, and the E(sub y) was found to be highly dependent on orientation and therefore environmental exposure. The FEP E(sub y) was found to directly correlate with the solar exposure/AO fluence ratio showing the effect of solar radiation and/or heating due to solar exposure on FEP erosion. In addition, back-surface carbon painted FEP (C-FEP) flown in the zenith orientation had a significantly higher E(sub y) than clear FEP or Al-FEP further indicating that heating has a significant impact on the erosion of FEP. This experiment provides valuable LEO flight data on the erosion of Teflon FEP, a commonly used spacecraft thermal insulation.

Type B drum packages

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCoy, J.C.

1994-08-01

The Type B drum packages (TBD) are conceptualized as a family of containers in which a single 208 L or 114 L (55 gal or 30 gal) drum containing Type B quantities of radioactive material (RAM) can be packaged for shipment. The TBD containers are being developed to fill a void in the packaging and transportation capabilities of the U.S. Department of Energy as no container packaging single drums of Type B RAM exists offering double containment. Several multiple-drum containers currently exist, as well as a number of shielded casks, but the size and weight of these containers present manymore » operational challenges for single-drum shipments. As an alternative, the TBD containers will offer up to three shielded versions (light, medium, and heavy) and one unshielded version, each offering single or optional double containment for a single drum. To reduce operational complexity, all versions will share similar design and operational features where possible. The primary users of the TBD containers are envisioned to be any organization desiring to ship single drums of Type B RAM, such as laboratories, waste retrieval activities, emergency response teams, etc. Currently, the TBD conceptual design is being developed with the final design and analysis to be completed in 1995 to 1996. Testing and certification of the unshielded version are planned to be completed in 1996 to 1997 with production to begin in 1997 to 1998.« less

The ram accelerator - A chemically driven mass launcher

NASA Technical Reports Server (NTRS)

Kaloupis, P.; Bruckner, A. P.

1988-01-01

The ram accelerator, a chemically propelled mass driver, is presented as a viable new approach for directly launching acceleration-insensitive payloads into low earth orbit. The propulsion principle is similar to that of a conventional air-breathing ramjet. The cargo vehicle resembles the center-body of a ramjet and travels through a tube filled with a pre-mixed fuel and oxidizer mixture. The launch tube acts as the outer cowling of the ramjet and the combustion process travels with the vehicle. Two drive modes of the ram accelerator propulsion system are described, which when used in sequence are capable of accelerating the vehicle to as high as 10 km/sec. The requirements are examined for placing a 2000 kg vehicle into a 500 km orbit with a minimum of on-board rocket propellant for circularization maneuvers. It is shown that aerodynamic heating during atmospheric transit results in very little ablation of the nose. An indirect orbital insertion scenario is selected, utilizing a three step maneuver consisting of two burns and aerobraking. An on-board propulsion system using storable liquid propellants is chosen in order to minimize propellant mass requirements, and the use of a parking orbit below the desired final orbit is suggested as a means to increase the flexibility of the mass launch concept. A vehicle design using composite materials is proposed that will best meet the structural requirements, and a preliminary launch tube design is presented.

Axial collapse characteristics of CFRP composites with stacking conditions under the hygrothermal

NASA Astrophysics Data System (ADS)

Yang, Yongjun; Choi, Juho; Hwang, Woochae; Son, Jaekyung; Kook, Hyun; Im, Kwanghee; Sim, Jaeki; Yang, Inyoung

2012-04-01

CFRP composite material has superior specific strength and rigidity compared to metallic material, and is widely adopted in the various fields. Exceptional corrosion resistance enables the acceptance in maritime structural members such as ship and oildrilling machineries. However, CFRP composite material has the weakness in hygrothermal environment and crash environment. Especially, moisture ingress into composite material under hygrothermal environment can change molecule arrangement and chemical properties. In addition, interface characteristics and component material properties can be degraded. An experimental investigation was carried out to study the crash evaluations of CFRP composites to dynamic crushing by impact loading. We have made a collapse experiment to research into the difference of absorbed energy and deformation mode between moisture absorbed specimen and non-moisture absorbed specimen. As a result, the effect of moisture absorption and impact loads of approximately 30~50% reduction in strength are shown.

Axial collapse characteristics of CFRP composites with stacking conditions under the hygrothermal

NASA Astrophysics Data System (ADS)

Yang, Yongjun; Choi, Juho; Hwang, Woochae; Son, Jaekyung; Kook, Hyun; Im, Kwanghee; Sim, Jaeki; Yang, Inyoung

2011-11-01

CFRP composite material has superior specific strength and rigidity compared to metallic material, and is widely adopted in the various fields. Exceptional corrosion resistance enables the acceptance in maritime structural members such as ship and oildrilling machineries. However, CFRP composite material has the weakness in hygrothermal environment and crash environment. Especially, moisture ingress into composite material under hygrothermal environment can change molecule arrangement and chemical properties. In addition, interface characteristics and component material properties can be degraded. An experimental investigation was carried out to study the crash evaluations of CFRP composites to dynamic crushing by impact loading. We have made a collapse experiment to research into the difference of absorbed energy and deformation mode between moisture absorbed specimen and non-moisture absorbed specimen. As a result, the effect of moisture absorption and impact loads of approximately 30~50% reduction in strength are shown.

Unglazed transpired solar collector having a low thermal-conductance absorber

DOEpatents

Christensen, Craig B.; Kutscher, Charles F.; Gawlik, Keith M.

1997-01-01

An unglazed transpired solar collector using solar radiation to heat incoming air for distribution, comprising an unglazed absorber formed of low thermal-conductance material having a front surface for receiving the solar radiation and openings in the unglazed absorber for passage of the incoming air such that the incoming air is heated as it passes towards the front surface of the absorber and the heated air passes through the openings in the absorber for distribution.

Unglazed transpired solar collector having a low thermal-conductance absorber

DOEpatents

Christensen, C.B.; Kutscher, C.F.; Gawlik, K.M.

1997-12-02

An unglazed transpired solar collector using solar radiation to heat incoming air for distribution, comprises an unglazed absorber formed of low thermal-conductance material having a front surface for receiving the solar radiation and openings in the unglazed absorber for passage of the incoming air such that the incoming air is heated as it passes towards the front surface of the absorber and the heated air passes through the openings in the absorber for distribution. 3 figs.

Enhanced microwave absorption properties of epoxy composites containing graphite nanosheets@Fe3O4 decorated comb-like MnO2 nanoparticles

NASA Astrophysics Data System (ADS)

Su, Xiaogang; Wang, Jun; Zhang, Bin; Chen, Wei; Wu, Qilei; Dai, Wei; Zou, Yi

2018-05-01

Recently, owing to the radiation and interference from electromagnetic wave (EMW), the requirements of EMW absorbing materials have been increasing. Herein, a novel absorber composed of graphite nanosheets@Fe3O4 composites decorated comb-like MnO2 (GNFM) has been successfully synthesized via a facile two steps, characterized using x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), x-ray photoelectron spectroscopy (XPS), Raman spectroscopy, vibrating sample magnetometry (VSM) and vector network analyzer (VNA). The ternary composites with enhanced microwave absorption performance are due to the complementary effects of electroconductive material (graphite nanosheets), dielectric materials (MnO2) and magnetic material (Fe3O4 nanospheres). Hence, the maximum reflection loss of GNFM/epoxy composites is up to ‑31.7 dB at 5.85 GHz with absorbing thickness of 4.5 mm, and the efficient frequency bandwidth below ‑10 dB can reach up to 4.47 GHz (11.87–16.34 GHz) at matching thickness of 2 mm. The results demonstrate that GNFM could be regarded as a novel type of microwave absorbing material.

Bamboo fiberboards and attapulgite : does it lead to an improvement of humidity control in buildings?

NASA Astrophysics Data System (ADS)

Nguyen, D. M.; Grillet, A. C.; Goldin, T.; Hanh Diep, T. M.; Woloszyn, M.

2018-04-01

In order to save energy used to heat or cool buildings and to improve the inhabitants comfort, control of humidity inside buildings must be improved. This can be done by using buffering materials able to absorb and release moisture when necessary. Natural fibers and mineral absorbent are good candidates to manufacture such materials. The aim of this research is to mix bamboo fibers with attapulgite to evaluate the influence of this mineral absorbent on the hygric behavior of the fiberboards. The hygric properties are slightly improved by the attapulgite and thus bamboo fiberboards can be used as building insulation materials able to participate to the indoor moisture control.

REACTOR VIEWING APPARATUS

DOEpatents

Monk, G.S.

1959-01-13

An optical system is presented that is suitable for viewing objects in a region of relatively high radioactivity, or high neutron activity, such as a neutronic reactor. This optical system will absorb neutrons and gamma rays thereby protecting personnel fronm the harmful biological effects of such penetrating radiations. The optical system is comprised of a viewing tube having a lens at one end, a transparent solid member at the other end and a transparent aqueous liquid completely filling the tube between the ends. The lens is made of a polymerized organic material and the transparent solid member is made of a radiation absorbent material. A shield surrounds the tube betwcen the flanges and is made of a gamma ray absorbing material.

Magnetic latch trigger for inherent shutdown assembly

DOEpatents

Sowa, Edmund S.

1976-01-01

An inherent shutdown assembly for a nuclear reactor is provided. A neutron absorber is held ready to be inserted into the reactor core by a magnetic latch. The latch includes a magnet whose lines of force are linked by a yoke of material whose Curie point is at the critical temperature of the reactor at which the neutron absorber is to be inserted into the reactor core. The yoke is in contact with the core coolant or fissionable material so that when the coolant or the fissionable material increase in temperature above the Curie point the yoke loses its magnetic susceptibility and the magnetic link is broken, thereby causing the absorber to be released into the reactor core.

Lightweight flywheel containment

DOEpatents

Smith, James R.

2001-01-01

A lightweight flywheel containment composed of a combination of layers of various material which absorb the energy of a flywheel structural failure. The various layers of material act as a vacuum barrier, momentum spreader, energy absorber, and reaction plate. The flywheel containment structure has been experimentally demonstrated to contain carbon fiber fragments with a velocity of 1,000 m/s and has an aerial density of less than 6.5 g/square centimeters. The flywheel containment, may for example, be composed of an inner high toughness structural layer, and energy absorbing layer, and an outer support layer. Optionally, a layer of impedance matching material may be utilized intermediate the flywheel rotor and the inner high toughness layer.

Lightweight flywheel containment

DOEpatents

Smith, James R.

2004-06-29

A lightweight flywheel containment composed of a combination of layers of various material which absorb the energy of a flywheel structural failure. The various layers of material act as a vacuum barrier, momentum spreader, energy absorber, and reaction plate. The flywheel containment structure has been experimentally demonstrated to contain carbon fiber fragments with a velocity of 1,000 m/s and has an aerial density of less than 6.5 g/square centimeters. The flywheel containment, may for example, be composed of an inner high toughness structural layer, and energy absorbing layer, and an outer support layer. Optionally, a layer of impedance matching material may be utilized intermediate the flywheel rotor and the inner high toughness layer.

Analytical Studies of the Lift and Roll Stability of a Ram Air Cushion Vehicle

DOT National Transportation Integrated Search

1972-12-01

A ram air cushion vehicle (a type of ram wing) is described schematically and compared with a conventional air cushion vehicle design. The nonlinear equations for the flow in the cushion region are derived. A review is made of the most recent literat...

Reliable Acquisition of RAM Dumps from Intel-Based Apple Mac Computers over FireWire

NASA Astrophysics Data System (ADS)

Gladyshev, Pavel; Almansoori, Afrah

RAM content acquisition is an important step in live forensic analysis of computer systems. FireWire offers an attractive way to acquire RAM content of Apple Mac computers equipped with a FireWire connection. However, the existing techniques for doing so require substantial knowledge of the target computer configuration and cannot be used reliably on a previously unknown computer in a crime scene. This paper proposes a novel method for acquiring RAM content of Apple Mac computers over FireWire, which automatically discovers necessary information about the target computer and can be used in the crime scene setting. As an application of the developed method, the techniques for recovery of AOL Instant Messenger (AIM) conversation fragments from RAM dumps are also discussed in this paper.

Molecular gas mass and star formation of 12 Virgo spiral galaxies along the ram pressure time sequence

NASA Astrophysics Data System (ADS)

Chung, Eun Jung; Kim, S.

2014-01-01

The ram pressure stripping is known as one of the most efficient mechanisms to deplete the ISM of a galaxy in the clusters of galaxies. As being affected continuously by ICM pressure, a galaxy may lose their gas that is the fuel of star formation, and consequently star formation rate would be changed. We select twelve Virgo spiral galaxies according to their stage of the ram pressure stripping event to probe possible consequences of star formation of spiral galaxies in the ram pressure and thus the evolution of galaxies in the Virgo cluster. We investigate the molecular gas properties, star formation activity, and gas depletion time along the time from the ram pressure peak. We also discussed the evolution of galaxies in the cluster.

DESTINY

DOE Office of Scientific and Technical Information (OSTI.GOV)

2015-03-10

DESTINY is a comprehensive tool for modeling 3D and 2D cache designs using SRAM,embedded DRAM (eDRAM), spin transfer torque RAM (STT-RAM), resistive RAM (ReRAM), and phase change RAM (PCN). In its purpose, it is similar to CACTI, CACTI-3DD or NVSim. DESTINY is very useful for performing design-space exploration across several dimensions, such as optimizing for a target (e.g. latency, area or energy-delay product) for agiven memory technology, choosing the suitable memory technology or fabrication method (i.e. 2D v/s 3D) for a given optimization target, etc. DESTINY has been validated against several cache prototypes. DESTINY is expected to boost studies ofmore » next-generation memory architectures used in systems ranging from mobile devices to extreme-scale supercomputers.« less

A Study of Pattern Prediction in the Monitoring Data of Earthen Ruins with the Internet of Things.

PubMed

Xiao, Yun; Wang, Xin; Eshragh, Faezeh; Wang, Xuanhong; Chen, Xiaojiang; Fang, Dingyi

2017-05-11

An understanding of the changes of the rammed earth temperature of earthen ruins is important for protection of such ruins. To predict the rammed earth temperature pattern using the air temperature pattern of the monitoring data of earthen ruins, a pattern prediction method based on interesting pattern mining and correlation, called PPER, is proposed in this paper. PPER first finds the interesting patterns in the air temperature sequence and the rammed earth temperature sequence. To reduce the processing time, two pruning rules and a new data structure based on an R-tree are also proposed. Correlation rules between the air temperature patterns and the rammed earth temperature patterns are then mined. The correlation rules are merged into predictive rules for the rammed earth temperature pattern. Experiments were conducted to show the accuracy of the presented method and the power of the pruning rules. Moreover, the Ming Dynasty Great Wall dataset was used to examine the algorithm, and six predictive rules from the air temperature to rammed earth temperature based on the interesting patterns were obtained, with the average hit rate reaching 89.8%. The PPER and predictive rules will be useful for rammed earth temperature prediction in protection of earthen ruins.

The X-ray and ultraviolet absorbing outflow in 3C 351

NASA Astrophysics Data System (ADS)

Mathur, Smita; Wilkes, Belinda; Elvis, Martin; Fiore, Fabrizio

1994-10-01

3C 351 (z = 0.371), and X-ray-'quiet' quasar, is one of the few quasars showing signs of a 'warm absorber' in its X-ray spectrum; i.e., partially ionized absorbing material in the line of sight whose opacity depends on its ionization structure. The main feature in the X-ray spectrum is a K-edge due to O VII or O VIII. 3C 351 also shows unusually strong, blueshifted, associated, absorption lines in the ultraviolet (Bahcall et al. 1993) including O VI (lambda lambda 1031, 1037). This high ionization state strongly suggests an identification with the X-ray absorber and a site within the active nucleus. In this paper we demonstrate that the X-ray and UV absorption is due to the same material. This is the first confirmed UV/X-ray absorber. Physical conditions of the absorber are determined through the combination of constraints derived from both the X-ray and UV analysis. This highly ionized, outflowing, low-density, high-column density absorber situated outside the broad emission line region (BELR) is a previously unknown component of nuclear material. We rule out the identification of the absorber with a BELR cloud as the physical conditions in the two regions are inconsistent with one another. The effect of the X-ray quietness and IR upturn in the 3C 351 continuum on the BELR is also investigated. The strengths of the high-ionization lines of C IV lambda-1549 and O VI lambda-1034 with respect to Lyman-alpha are systematically lower (up to a factor of 10) in the material ionized by the 3C 351 continuum as compared to those produced by the 'standard' quasar continuum, the strongest effect being on the strength of O VI lambda-1034. We find that for a 3C 351-like continuum, C III) lambda-1909 ceases to be a density indicator.

On-Board Hydrogen Gas Production System For Stirling Engines

DOEpatents

Johansson, Lennart N.

2004-06-29

A hydrogen production system for use in connection with Stirling engines. The production system generates hydrogen working gas and periodically supplies it to the Stirling engine as its working fluid in instances where loss of such working fluid occurs through usage through operation of the associated Stirling engine. The hydrogen gas may be generated by various techniques including electrolysis and stored by various means including the use of a metal hydride absorbing material. By controlling the temperature of the absorbing material, the stored hydrogen gas may be provided to the Stirling engine as needed. A hydrogen production system for use in connection with Stirling engines. The production system generates hydrogen working gas and periodically supplies it to the Stirling engine as its working fluid in instances where loss of such working fluid occurs through usage through operation of the associated Stirling engine. The hydrogen gas may be generated by various techniques including electrolysis and stored by various means including the use of a metal hydride absorbing material. By controlling the temperature of the absorbing material, the stored hydrogen gas may be provided to the Stirling engine as needed.

An antibacterial and absorbable silk-based fixation material with impressive mechanical properties and biocompatibility

NASA Astrophysics Data System (ADS)

Shi, Chenglong; Pu, Xiaobing; Zheng, Guan; Feng, Xinglong; Yang, Xuan; Zhang, Baoliang; Zhang, Yu; Yin, Qingshui; Xia, Hong

2016-11-01

Implant-associated infections and non-absorbing materials are two important reasons for a second surgical procedure to remove internal fixation devices after an orthopedic internal fixation surgery. The objective of this study was to produce an antibacterial and absorbable fixation screw by adding gentamicin to silk-based materials. The antibacterial activity was assessed against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) in vitro by plate cultivation and scanning electron microscopy (SEM). We also investigated the properties, such as the mechanical features, swelling properties, biocompatibility and degradation, of gentamicin-loaded silk-based screws (GSS) in vitro. The GSS showed significant bactericidal effects against S. aureus and E. coli. The antibacterial activity remained high even after 4 weeks of immersion in protease solution. In addition, the GSS maintained the remarkable mechanical properties and excellent biocompatibility of pure silk-based screws (PSS). Interestingly, after gentamicin incorporation, the degradation rate and water-absorbing capacity increased and decreased, respectively. These GSS provide both impressive material properties and antibacterial activity and have great potential for use in orthopedic implants to reduce the incidence of second surgeries.

Analyzing Spatial and Temporal Variation in Precipitation Estimates in a Coupled Model

NASA Astrophysics Data System (ADS)

Tomkins, C. D.; Springer, E. P.; Costigan, K. R.

2001-12-01

Integrated modeling efforts at the Los Alamos National Laboratory aim to simulate the hydrologic cycle and study the impacts of climate variability and land use changes on water resources and ecosystem function at the regional scale. The integrated model couples three existing models independently responsible for addressing the atmospheric, land surface, and ground water components: the Regional Atmospheric Model System (RAMS), the Los Alamos Distributed Hydrologic System (LADHS), and the Finite Element and Heat Mass (FEHM). The upper Rio Grande Basin, extending 92,000 km2 over northern New Mexico and southern Colorado, serves as the test site for this model. RAMS uses nested grids to simulate meteorological variables, with the smallest grid over the Rio Grande having 5-km horizontal grid spacing. As LADHS grid spacing is 100 m, a downscaling approach is needed to estimate meteorological variables from the 5km RAMS grid for input into LADHS. This study presents daily and cumulative precipitation predictions, in the month of October for water year 1993, and an approach to compare LADHS downscaled precipitation to RAMS-simulated precipitation. The downscaling algorithm is based on kriging, using topography as a covariate to distribute the precipitation and thereby incorporating the topographical resolution achieved at the 100m-grid resolution in LADHS. The results of the downscaling are analyzed in terms of the level of variance introduced into the model, mean simulated precipitation, and the correlation between the LADHS and RAMS estimates. Previous work presented a comparison of RAMS-simulated and observed precipitation recorded at COOP and SNOTEL sites. The effects of downscaling the RAMS precipitation were evaluated using Spearman and linear correlations and by examining the variance of both populations. The study focuses on determining how the downscaling changes the distribution of precipitation compared to the RAMS estimates. Spearman correlations computed for the LADHS and RAMS cumulative precipitation reveal a disassociation over time, with R equal to 0.74 at day eight and R equal to 0.52 at day 31. Linear correlation coefficients (Pearson) returned a stronger initial correlation of 0.97, decreasing to 0.68. The standard deviations for the 2500 LADHS cells underlying each 5km RAMS cell range from 8 mm to 695 mm in the Sangre de Cristo Mountains and 2 mm to 112 mm in the San Luis Valley. Comparatively, the standard deviations of the RAMS estimates in these regions are 247 mm and 30 mm respectively. The LADHS standard deviations provide a measure of the variability introduced through the downscaling routine, which exceeds RAMS regional variability by a factor of 2 to 4. The coefficient of variation for the average LADHS grid cell values and the RAMS cell values in the Sangre de Cristo Mountains are 0.66 and 0.27, respectively, and 0.79 and 0.75 in the San Luis Valley. The coefficients of variation evidence the uniformity of the higher precipitation estimates in the mountains, especially for RAMS, and also the lower means and variability found in the valley. Additionally, Kolmogorov-Smirnov tests indicate clear spatial and temporal differences in mean simulated precipitation across the grid.

Modeling of behavioral responses for successful selection of easy-to-train rams for semen collection with an artificial vagina.

PubMed

Ambrosi, Claudia Pamela; Rubio, Natalia; Giménez, Gustavo; Venturino, Andrés; Aisen, Eduardo Gabriel; López Armengol, María Fernanda

2018-06-01

The aim of this study was to analyze the reproductive behavioral responses in Australian Merino rams, to identify those related to a faster training for semen collection with an artificial vagina. Eight Australian Merino rams, aged 1.5 years and with no prior sexual experience, were randomly selected from an extensively grazed flock. One immobilized ewe with no hormone stimulation was used for rams to sexually interact and mount. The frequencies of approaching, sniffing, flehmen, pushing, pawing with chin resting, and tongue flicking were recorded during eight training and three post-training assessments periods. In addition, the duration of sniffing and flehmen responses, as well as the time from when the ram started to approach the ewe until the mount with ejaculation (completed mount) were recorded. Descriptive, correlation, and modeling analyses were performed. Amongst the rams, four mounted the ewe and ejaculated for the first time during the training phase, and three mounted and ejaculated for the first time after the training phase. The remaining ram mounted the ewe and ejaculated for the first time during the post-training evaluation in the following year. A great variability in the behavior repertoire was observed among rams. The correlation analysis indicated that the completed mount was associated with the behaviors during the approaching response. The expression of the sniffing response decreased between the training phase and post-training evaluation, while the responses of pushing the ewe and tongue flicking ceased to occur. Pawing the side of the ewe with the chin resting on the back of the ewe and flehmen responses, however, continued between the training and post-training phases. This led to a decrease in the time from when the ram started to approach the ewe until the completed mount. It is concluded that the responses of approaching the ewe, pawing the side of the ewe with chin resting on the ewe, and sniffing of the ewe (the latter occurring only during the training phase) are behavioral indicators that could be used for selection of easy-to-train rams for purposes of semen collection with an artificial vagina. Copyright © 2018 Elsevier B.V. All rights reserved.

Photoluminescence and Photoconductivity to Assess Maximum Open-Circuit Voltage and Carrier Transport in Hybrid Perovskites and Other Photovoltaic Materials.

PubMed

Braly, Ian L; Stoddard, Ryan J; Rajagopal, Adharsh; Jen, Alex K-Y; Hillhouse, Hugh W

2018-06-06

Photovoltaic (PV) device development is much more expensive and time consuming than the development of the absorber layer alone. This perspective focuses on two methods that can be used to rapidly assess and develop PV absorber materials independent of device development. The absorber material properties of quasi-Fermi level splitting and carrier diffusion length under steady effective one-Sun illumination are indicators of a material's ability to achieve high VOC and JSC. These two material properties can be rapidly and simultaneously assessed with steady-state absolute intensity photoluminescence and photoconductivity measurements. As a result, these methods are extremely useful for predicting the quality and stability of PV materials prior to PV device development. Here, we summarize the methods, discuss their strengths and weaknesses, and compare photoluminescence and photoconductivity results with device performance for four hybrid perovskite compositions of various bandgaps (1.35 to 1.82 eV), CISe, CIGSe, and CZTSe.

Length and activity of the root apical meristem revealed in vivo by infrared imaging.

PubMed

Bizet, François; Hummel, Irène; Bogeat-Triboulot, Marie-Béatrice

2015-03-01

Understanding how cell division and cell elongation influence organ growth and development is a long-standing issue in plant biology. In plant roots, most of the cell divisions occur in a short and specialized region, the root apical meristem (RAM). Although RAM activity has been suggested to be of high importance to understand how roots grow and how the cell cycle is regulated, few experimental and numeric data are currently available. The characterization of the RAM is difficult and essentially based upon cell length measurements through destructive and time-consuming microscopy approaches. Here, a new non-invasive method is described that couples infrared light imaging and kinematic analyses and that allows in vivo measurements of the RAM length. This study provides a detailed description of the RAM activity, especially in terms of cell flux and cell division rate. We focused on roots of hydroponic grown poplars and confirmed our method on maize roots. How the RAM affects root growth rate is studied by taking advantage of the high inter-individual variability of poplar root growth. An osmotic stress was applied and did not significantly affect the RAM length, highlighting its homeostasis in short to middle-term responses. The methodology described here simplifies a lot experimental procedures, allows an increase in the number of individuals that can be taken into account in experiments, and means new experiments can be formulated that allow temporal monitoring of the RAM length. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

The Implementation and Evaluation of the Emergency Response Dose Assessment System (ERDAS) at Cape Canaveral Air Station/Kennedy Space Center

NASA Technical Reports Server (NTRS)

Evans, Randolph J.; Tremback, Craig J.; Lyons, Walter A.

1996-01-01

The Emergency Response Dose Assessment System (ERDAS) is a system which combines the mesoscale meteorological prediction model RAMS with the diffusion models REEDM and HYPACT. Operators use a graphical user interface to run the models for emergency response and toxic hazard planning at CCAS/KCS. The Applied Meteorology Unit has been evaluating the ERDAS meteorological and diffusion models and obtained the following results: (1) RAMS adequately predicts the occurrence of the daily sea breeze during non-cloudy conditions for several cases. (2) RAMS shows a tendency to predict the sea breeze to occur slightly earlier and to move it further inland than observed. The sea breeze predictions could most likely be improved by better parameterizing the soil moisture and/or sea surface temperatures. (3) The HYPACT/REEDM/RAMS models accurately predict launch plume locations when RAMS winds are accurate and when the correct plume layer is modeled. (4) HYPACT does not adequately handle plume buoyancy for heated plumes since all plumes are presently treated as passive tracers. Enhancements should be incorporated into the ERDAS as it moves toward being a fully operational system and as computer workstations continue to increase in power and decrease in cost. These enhancements include the following: activate RAMS moisture physics; use finer RAMS grid resolution; add RAMS input parameters (e.g. soil moisture, radar, and/or satellite data); automate data quality control; implement four-dimensional data assimilation; modify HYPACT plume rise and deposition physics; and add cumulative dosage calculations in HYPACT.

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

NASA Astrophysics Data System (ADS)

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.

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

NASA Astrophysics Data System (ADS)

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.

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

DOE PAGES

Divan, Ralu; Gades, Lisa M.; Kenesei, Peter; ...

2017-11-08

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,more » and gold/electroplated bismuth absorbers, fabricated on the same die with identical thermal coupling. Lastly, we show that the bismuth morphology is linked to the spectral response of X-ray TES microcalorimeters.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Divan, Ralu; Gades, Lisa M.; Kenesei, Peter

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,more » and gold/electroplated bismuth absorbers, fabricated on the same die with identical thermal coupling. Lastly, we show that the bismuth morphology is linked to the spectral response of X-ray TES microcalorimeters.« less

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

USDA-ARS?s Scientific Manuscript database

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...

Integrated semiconductor-magnetic random access memory system

NASA Technical Reports Server (NTRS)

Katti, Romney R. (Inventor); Blaes, Brent R. (Inventor)

2001-01-01

The present disclosure describes a non-volatile magnetic random access memory (RAM) system having a semiconductor control circuit and a magnetic array element. The integrated magnetic RAM system uses CMOS control circuit to read and write data magnetoresistively. The system provides a fast access, non-volatile, radiation hard, high density RAM for high speed computing.

The psychological health of remote area medics in Iraq.

PubMed

Whittaker-Howe, S; Brown, G; Williamson, V; Greenberg, N

2017-12-30

Remote area medics (RAMs) may be at increased risk of mental health difficulties. To explore the occupational experiences of RAMs to identify stressors and the mental health impact. Semi-structured interviews were conducted with six RAMs working in Iraq to gather data, which was explored using interpretative phenomenological analysis. Three key themes emerged from the data (i) the experience of being remote, (ii) cultural shock and (iii) social support. A number of key stressors were identified, including loneliness and boredom, associated with being remote, and the loss of professional identity due to the occupational role. Three out of the six participants reported substantial depressive symptoms. A number of positive coping strategies were identified, particularly relationships with other RAMs, via instant messaging forums. RAMs experience a number of particular stressors that could put them at risk of depression. Adaptive coping strategies were identified; in particular, virtual social support. These findings should be of interest to companies which employ RAMs. © The Author 2017. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Ram Pressure Stripping Made Easy: An Analytical Approach

NASA Astrophysics Data System (ADS)

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.

Single-cell full-length total RNA sequencing uncovers dynamics of recursive splicing and enhancer RNAs.

PubMed

Hayashi, Tetsutaro; Ozaki, Haruka; Sasagawa, Yohei; Umeda, Mana; Danno, Hiroki; Nikaido, Itoshi

2018-02-12

Total RNA sequencing has been used to reveal poly(A) and non-poly(A) RNA expression, RNA processing and enhancer activity. To date, no method for full-length total RNA sequencing of single cells has been developed despite the potential of this technology for single-cell biology. Here we describe random displacement amplification sequencing (RamDA-seq), the first full-length total RNA-sequencing method for single cells. Compared with other methods, RamDA-seq shows high sensitivity to non-poly(A) RNA and near-complete full-length transcript coverage. Using RamDA-seq with differentiation time course samples of mouse embryonic stem cells, we reveal hundreds of dynamically regulated non-poly(A) transcripts, including histone transcripts and long noncoding RNA Neat1. Moreover, RamDA-seq profiles recursive splicing in >300-kb introns. RamDA-seq also detects enhancer RNAs and their cell type-specific activity in single cells. Taken together, we demonstrate that RamDA-seq could help investigate the dynamics of gene expression, RNA-processing events and transcriptional regulation in single cells.

Digital Alloy Absorber for Photodetectors

NASA Technical Reports Server (NTRS)

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.

Translatory shock absorber for attitude sensors

NASA Technical Reports Server (NTRS)

Vonpragenau, G. L.; Morgan, I. T., Jr.; Kirby, C. A. (Inventor)

1976-01-01

A translatory shock absorber is provided for mounting an attitude sensor thereon for isolating a sensor from translatory vibrations. The translatory shock absorber includes a hollow block structure formed as one piece to form a parallelogram. The absorber block structure includes a movable top plate for supporting the attitude sensor and a fixed base plate with opposed side plates interposed between. At the junctions of the side plates, and the base and top plates, there are provided grooves which act as flexible hinges for attenuating translatory vibrations. A damping material is supported on a pedestal which is carried on the base plate between the side plates thereof. The top of the damping material rests against the bottom surface of the top plate for eliminating the resonant peaks of vibration.

Rechargeable alkaline manganese dioxide cells. A test report

NASA Astrophysics Data System (ADS)

Farrington, Michael D.

The rechargeable alkaline MnO 2 (RAM) system has now been commercially available for several years. The Canadian Department of National Defence is interested in determining if the low cost RAM system is technically capable of replacing existing cells and batteries now in use. A preliminary study identified sufficient candidate batteries in use within the Department whose performance requirements compared favourably with RAM manufacturers' claims. Further study was warranted. Replacement cost savings could be significant. A study is now in progress that is aimed at determining how well the RAM technology actually performs. This paper presents test results that illustrate how RAM cells compare to primary alkaline cells and nickel/cadmium. The majority of the work is focused on the 'AA' size products from Rayovac and Pure Energy: tests were also conducted on Rayovac 'D' cells.

Resistance profile of darunavir: combined 24-week results from the POWER trials.

PubMed

de Meyer, Sandra; Vangeneugden, Tony; van Baelen, Ben; de Paepe, Els; van Marck, Herwig; Picchio, Gaston; Lefebvre, Eric; de Béthune, Marie-Pierre

2008-03-01

The resistance profile of darunavir (TMC114) in treatment-experienced patients was explored using pooled week 24 data from POWER 1, 2, and 3 at the recommended dose of darunavir with low-dose ritonavir (darunavir/r, 600/100 mg bid, N = 458). Baseline darunavir fold change in EC(50) was a strong predictor of virological response at week 24. Preliminary phenotypic clinical cut-offs of 10 and 40 were established. Virological response to darunavir/r was maintained in the presence at baseline of a high number of IAS-USA PI resistance-associated mutations (IAS-USA PI RAMS); a diminished response occurred with >or=14. Eleven protease mutations associated with diminished darunavir/r virological response were identified (V11I, V32I, L33F, I47V, I50V, I54L/M, G73S, L76V, I84V, and L89V). These darunavir resistance-associated mutations (DRV RAMS) occurred in the presence of a high number of IAS-USA PI RAMS. Virological response was diminished with three or more DRV RAMS in the background of a high number of IAS-USA PI RAMS. Incremental numbers of DRV RAMS were more predictive of outcome than were IAS-USA PI RAMS. Mutations developing during darunavir/r virological failure (V32I, L33F, I47V, I54L, and L89V) were also featured in the DRV RAMS list. Site-directed mutants carrying these five mutations, or any one of these mutations either alone or together with one or two IAS-USA PI RAMS, showed no reduced darunavir susceptibility, suggesting that a high number of additional background mutations is required for darunavir resistance. In this population of treatment-experienced patients, darunavir/r demonstrated significantly greater efficacy than investigator-selected control PIs of trials POWER 1 and 2, regardless of baseline viral genotype or phenotype, while exhibiting a high genetic barrier to the development of resistance.

Rare emergence of drug resistance in HIV-1 treatment-naïve patients after 48 weeks of treatment with elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide.

PubMed

Margot, Nicolas A; Kitrinos, Kathryn M; Fordyce, Marshall; McCallister, Scott; Miller, Michael D; Callebaut, Christian

2016-03-01

Tenofovir alafenamide (TAF), a novel prodrug of the NtRTI tenofovir (TFV), delivers TFV-diphosphate (TFV-DP) to target cells more efficiently than the current prodrug, tenofovir disoproxil fumarate (TDF), with a 90% reduction in TFV plasma exposure. TAF, within the fixed dose combination of elvitegravir /cobicistat / emtricitabine (FTC)/TAF (E/C/F/TAF), has been evaluated in one Phase 2 and two Phase 3 randomized, double-blinded studies in HIV-infected treatment-naive patients, comparing E/C/F/TAF to E/C/F/TDF. In these studies, the TAF-containing group demonstrated non-inferior efficacy to the TDF-containing comparator group with 91.9% of E/C/F/TAF patients having <50 copies/mL of HIV-1 RNA at week 48. An integrated resistance analysis across these three studies was conducted, including HIV-1 genotypic analysis at screening, and genotypic/phenotypic analysis for patients with HIV-1 RNA>400 copies/mL at virologic failure. Pre-existing primary resistance-associated mutations (RAMs) were observed at screening among the 1903 randomized and treated patients: 7.5% had NRTI-RAMs, 18.2% had NNRTI-RAMs, and 3.4% had primary PI-RAMs. Pre-treatment RAMs did not influence treatment response at Week 48. In the E/C/F/TAF group, resistance development was rare; seven patients (0.7%, 7/978) developed NRTI-RAMs, five of whom (0.5%, 5/978) also developed primary INSTI-RAMs. In the E/C/F/TDF group, resistance development was also rare; seven patients (0.8%, 7/925) developed NRTI-RAMs, four of whom (0.4%, 4/925) also developed primary INSTI-RAMs. An additional analysis by deep sequencing in virologic failures revealed minimal differences compared to population sequencing. Overall, resistance development was rare in E/C/F/TAF-treated patients, and the pattern of emergent mutations was similar to E/C/F/TDF.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barr, Jonathan L.; Taira, Randal Y.; Orr, Heather M.

The purpose of this document is to describe the operating concepts, capabilities, and benefits of RAMS including descriptions of how the system implementations can improve emergency response, damage assessment, task prioritization, and situation awareness. This CONOPS provides general information on operational processes and procedures required to utilize RAMS, and expected performance benefits of the system. The primary audiences for this document are the end users of RAMS (including flight operators and incident commanders) and the RAMS management team. Other audiences include interested offices within the Department of Homeland Security (DHS), and officials from other state and local jurisdictions who wantmore » to implement similar systems.« less

Preliminary survey of propulsion using chemical energy stored in the upper atmosphere

NASA Technical Reports Server (NTRS)

Baldwin, Lionel V; Blackshear, Perry L

1958-01-01

Ram-jet cycles that use the chemical energy of dissociated oxygen for propulsion in the ionosphere are presented. After a review of the properties and compositions of the upper atmosphere, the external drag, recombination kinetics, and aerodynamic-heating problems of an orbiting ram jet are analyzed. The study indicates that the recombination ram jet might be useful for sustaining a satellite at an altitude of about 60 miles. Atmospheric composition and recombination-rate coefficients were too uncertain for more definite conclusions. The ram jet is a marginal device even in the optimistic view.

A self-testing dynamic RAM chip

NASA Astrophysics Data System (ADS)

You, Y.; Hayes, J. P.

1985-02-01

A novel approach to making very large dynamic RAM chips self-testing is presented. It is based on two main concepts: on-chip generation of regular test sequences with very high fault coverage, and concurrent testing of storage-cell arrays to reduce overall testing time. The failure modes of a typical 64 K RAM employing one-transistor cells are analyzed to identify their test requirements. A comprehensive test generation algorithm that can be implemented with minimal modification to a standard cell layout is derived. The self-checking peripheral circuits necessary to implement this testing algorithm are described, and the self-testing RAM is briefly evaluated.

Fabrication of High-Resolution Gamma-Ray Metallic Magnetic Calorimeters with Ag:Er Sensor and Thick Electroplated Absorbers

NASA Astrophysics Data System (ADS)

Hummatov, Ruslan; Hall, John A.; Kim, Geon-Bo; Friedrich, Stephan; Cantor, Robin; Boyd, S. T. P.

2018-05-01

We are developing metallic magnetic calorimeters for high-resolution gamma-ray spectroscopy for non-destructive assay of nuclear materials. Absorbers for these higher-energy photons can require substantial thickness to achieve adequate stopping power. We developed a new absorber fabrication process using dry-film photoresists to electroform cantilevered, thick absorbers. Gamma detectors with these absorbers have an energy resolution of 38 eV FWHM at 60 keV. In this report, we summarize modifications to STARCryo's "Delta 1000" process for our devices and describe the new absorber fabrication process.

eRAM: encyclopedia of rare disease annotations for precision medicine.

PubMed

Jia, Jinmeng; An, Zhongxin; Ming, Yue; Guo, Yongli; Li, Wei; Liang, Yunxiang; Guo, Dongming; Li, Xin; Tai, Jun; Chen, Geng; Jin, Yaqiong; Liu, Zhimei; Ni, Xin; Shi, Tieliu

2018-01-04

Rare diseases affect over a hundred million people worldwide, most of these patients are not accurately diagnosed and effectively treated. The limited knowledge of rare diseases forms the biggest obstacle for improving their treatment. Detailed clinical phenotyping is considered as a keystone of deciphering genes and realizing the precision medicine for rare diseases. Here, we preset a standardized system for various types of rare diseases, called encyclopedia of Rare disease Annotations for Precision Medicine (eRAM). eRAM was built by text-mining nearly 10 million scientific publications and electronic medical records, and integrating various data in existing recognized databases (such as Unified Medical Language System (UMLS), Human Phenotype Ontology, Orphanet, OMIM, GWAS). eRAM systematically incorporates currently available data on clinical manifestations and molecular mechanisms of rare diseases and uncovers many novel associations among diseases. eRAM provides enriched annotations for 15 942 rare diseases, yielding 6147 human disease related phenotype terms, 31 661 mammalians phenotype terms, 10,202 symptoms from UMLS, 18 815 genes and 92 580 genotypes. eRAM can not only provide information about rare disease mechanism but also facilitate clinicians to make accurate diagnostic and therapeutic decisions towards rare diseases. eRAM can be freely accessed at http://www.unimd.org/eram/. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Overview of the response of anoestrous ewes to the ram effect.

PubMed

Ungerfeld, R; Forsberg, M; Rubianes, E

2004-01-01

The present review summarises knowledge of the reproductive response of anoestrous ewes to the introduction of rams - in other words, the ram effect. The ovarian and endocrine response, the factors that determine whether ewes will respond or not (associated with both the stimulus and the receptivity of the ewes) and some aspects of practical management are discussed. Information on the use of the ram effect to stimulate post-partum, prepubertal and cyclic ewes is also given. New insights are provided on ovarian response patterns, including recently collected information on luteal responses. The existence of delayed ovulation (5-7 days after the introduction of the rams) followed by luteal phases of normal or short length, luteal cysts and luteinised follicles is reported after scanning the ovaries with ultrasound. Endocrine parameters for depth of anoestrus, such as LH pulsatility and FSH concentrations, and how the concentrations of these hormones should be considered are discussed. Particular attention is paid to the observation of spontaneous, higher LH pulsatility and higher FSH concentrations in anoestrous ewes that respond to rams with luteal phases than in those that fail to respond. The use of progestogen priming and single progestogen administration and the possible advantages for synchronisation of oestrus are also discussed. Other factors that should be considered before the ram effect is applied, such as the strength of the stimulus and some practical considerations, are also included.

Binder of Sperm Proteins 1 and 5 have contrasting effects on the capacitation of ram spermatozoa.

PubMed

Pini, Taylor; de Graaf, Simon P; Druart, Xavier; Tsikis, Guillaume; Labas, Valerie; Teixeira-Gomes, Ana Paula; Gadella, Barend M; Leahy, Tamara

2018-06-01

Binder of Sperm Proteins (BSPs) are the most abundant seminal plasma protein family in the ram and bull. They have been extensively studied in the bull but less is known about their function in ovine seminal plasma and current knowledge suggests that BSPs may have different effects in these two species. In the bull, they facilitate capacitation and destabilize the sperm membrane during in vitro handling, whereas in the ram, they appear to stabilize the sperm membrane and prevent cryopreservation-induced capacitation-like changes. Further investigation into the effects of BSPs on ram spermatozoa under capacitating conditions is required to further clarify their physiological roles in the ram. We investigated the effects of Binder of Sperm Proteins 1 and 5 on epididymal ram spermatozoa in conditions of low, moderate, and high cAMP. BSPs had minimal effects on sperm function in low-cAMP conditions, but caused significant changes under cAMP upregulation. BSP1 stabilized the membrane and qualitatively reduced protein tyrosine phosphorylation, but significantly increased cholesterol efflux and induced spontaneous acrosome reactions. BSP5 slightly increased spontaneous acrosome reactions and caused sperm necrosis. However, BSP5 had minimal effects on membrane lipid order and cholesterol efflux and did not inhibit protein tyrosine phosphorylation. These findings demonstrate that under maximal cAMP upregulation, BSP1 affected ram spermatozoa in a manner comparable to bull spermatozoa, while BSP5 did not.

Radiation Sensitivity of Soluble Polysilane Derivatives: Science and Applications

DTIC Science & Technology

1988-08-01

sigma bonded, all substituted silane polymers absorb strongly in the UV-visible region. Their absorption spectra depend to some extent on the nature...of the substituents. In this regard alkyl substituted, atatic, amphorous materials absorb from 300-325 nm with sterically bulky groups producing a...cases, the polysilane is the primary absorber of the incident radiation. Interestingly, when 3, which absorbs at -400 inm, was incorporated into a film

Investigations on Absorber Materials at Cryogenic Temperatures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marhauser, Frank; Elliott, Thomas; Rimmer, Robert

2009-05-01

In the framework of the 12 GeV upgrade project for the Continuous Electron Beam Accelerator Facility (CEBAF) improvements are being made to refurbish cryomodules housing Thomas Jefferson National Accelerator Facility's (JLab) original 5-cell cavities. Recently we have started to look into a possible simplification of the existing Higher Order Mode (HOM) absorber design combined with the aim to find alternative material candidates. The absorbers are implemented in two HOM-waveguides immersed in the helium bath and operate at 2 K temperature. We have built a cryogenic setup to perform measurements on sample load materials to investigate their lossy characteristics and variationsmore » from room temperature down to 2 K. Initial results are presented in this paper.« less

Atomic Oxygen Effects on POSS Polyimides

DTIC Science & Technology

2011-07-25

resistance to UV damage, and excellent thermal properties.1 Despite the desirable properties of Kapton, this polyimide and all organic polymeric materials...stability, insulation properties, IR transparency, low solar absorptance, resistance to UV damage, and excellent thermal properties.1 Despite the...8 × 1021 atoms cm-2. Free standing films of MC-POSS polyimide were sewn to a Kapton blanket and exposed to a sweeping ram in LEO on MISSE-5

Viscoelastic Damping of Turbine and Compressor Blade Vibrations.

DTIC Science & Technology

1982-03-01

and Materials Conference, Atlanta, GA: 6 April 1981. 6. Balfour, A. and D.H. Marwick. Pro-ramming in Standard FORTRAN 77. New York: North- Holand Inc...EIGENVALUE PROBLEM RESULTING FROM THE EQUATION OF C MOTION IN THE ANALYTICAL SECTION REAL Gl,G2,C,T,L,M,K,J, F1 ,F2,F3,F4,X1,X2 COMPLEX Z,Z1,B,D,F,W COMMON

Timber RAM. . .a long-range planning method for commercial timber lands under multiple-use management

Treesearch

Daniel I. Navon

1971-01-01

Timber RAM (Resource Allocation Method) is a long-range planning method for commercial timber lands under multiple-use management. Timber RAM can produce cutting and reforestation schedules and related harvest and economic reports. Each schedule optimizes an index of performance, subject to periodic constraints on revenues, costs, and, harvest levels. Periodic...

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

Treesearch

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...

The production of glow precursors by oxidative erosion of spacecraft surfaces

NASA Technical Reports Server (NTRS)

Gregory, J. C.; Peters, P. N.

1985-01-01

Erosion rates of organic materials are measured during a recent flight of the shuttle (STS-8). Several forms of carbon and a variety of thermosetting and thermoplastic polymers are exposed to the ram beam of atomic oxygen. Arrhenius energies of about 1000 to 2000 cal/mole were measured from the rate dependencies on temperature. If some simple assumptions are made about the chemical nature of the desorbed species, the data can be used to estimate production rates at surfaces in orbit under different conditions of temperature, oxygen atom flux, and material surface conditions.

Production of a recombinant phospholipase A2 in Escherichia coli using resonant acoustic mixing that improves oxygen transfer in shake flasks.

PubMed

Valdez-Cruz, Norma A; Reynoso-Cereceda, Greta I; Pérez-Rodriguez, Saumel; Restrepo-Pineda, Sara; González-Santana, Jesus; Olvera, Alejandro; Zavala, Guadalupe; Alagón, Alejandro; Trujillo-Roldán, Mauricio A

2017-07-25

Shake flasks are widely used during the development of bioprocesses for recombinant proteins. Cultures of recombinant Escherichia coli with orbital mixing (OM) have an oxygen limitation negatively affecting biomass growth and recombinant-protein production. With the aim to improve mixing and aeration in shake flask cultures, we analyzed cultures subjected to OM and the novel resonant acoustic mixing (RAM) by applying acoustic energy to E. coli BL21-Gold (DE3): a producer of recombinant phospholipase A2 (rPLA2) from Micrurus laticollaris snake venom. Comparing OM with RAM (200 rpm vs. 7.5g) at the same initial volumetric oxygen transfer coefficient (k L a ≈ 80 h -1 ) ~69% less biomass was obtained with OM compared with RAM. We analyzed two more conditions increasing agitation until maximal speed (12.5 and 20g), and ~1.6- and ~1.4-fold greater biomass was obtained as compared with cultures at 7.5g. Moreover, the specific growth rate was statistically similar in all cultures carried out in RAM, but ~1.5-fold higher than that in cultures carried out under OM. Almost half of the glucose was consumed in OM, whereas between 80 and 100% of the glucose was consumed in RAM cultures, doubling biomass per glucose yields. Differential organic acid production was observed, but acetate production was prevented at the maximal RAM (20g). The amount of rPLA2 in both, OM and RAM cultures, represented 38 ± 5% of the insoluble protein. A smaller proportion of α-helices and β-sheet of purified inclusion bodies (IBs) were appreciated by ATR-FTIR from cultures carried out under OM, than those from RAM. At maximal agitation by RAM, internal E. coli localization patterns of protein aggregation changed, as well as, IBs proteolytic degradation, in conjunction with the formation of small external vesicles, although these changes did not significantly affect the cell survival response. In moderate-cell-density recombinant E. coli BL21-Gold (DE3) cultures, the agitation increases in RAM (up to the maximum) was not enough to avoid the classical oxygen limitation that happens in OM shake flasks. However, RAM presents a decrease of oxygen limitation, resulting in a favorable effect on biomass growth and volumetric rPLA2 production. While under OM a higher recombinant protein yield was obtained.

Energy absorption of composite material and structure

NASA Technical Reports Server (NTRS)

Farley, Gary L.

1987-01-01

Results are presented from a joint research program on helicopter crashworthiness conducted by the U.S. Army Aerostructures Directorate and NASA Langley. Through the ongoing research program an in-depth understanding has been developed on the cause/effect relationships between material and architectural variables and the energy-absorption capability of composite material and structure. Composite materials were found to be efficient energy absorbers. Graphite/epoxy subfloor structures were more efficient energy absorbers than comparable structures fabricated from Kevlar or aluminum. An accurate method of predicting the energy-absorption capability of beams was developed.

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

PubMed

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.

RamA, a Protein Required for Reductive Activation of Corrinoid-dependent Methylamine Methyltransferase Reactions in Methanogenic Archaea*S⃞

PubMed Central

Ferguson, Tsuneo; Soares, Jitesh A.; Lienard, Tanja; Gottschalk, Gerhard; Krzycki, Joseph A.

2009-01-01

Archaeal methane formation from methylamines is initiated by distinct methyltransferases with specificity for monomethylamine, dimethylamine, or trimethylamine. Each methylamine methyltransferase methylates a cognate corrinoid protein, which is subsequently demethylated by a second methyltransferase to form methyl-coenzyme M, the direct methane precursor. Methylation of the corrinoid protein requires reduction of the central cobalt to the highly reducing and nucleophilic Co(I) state. RamA, a 60-kDa monomeric iron-sulfur protein, was isolated from Methanosarcina barkeri and is required for in vitro ATP-dependent reductive activation of methylamine:CoM methyl transfer from all three methylamines. In the absence of the methyltransferases, highly purified RamA was shown to mediate the ATP-dependent reductive activation of Co(II) corrinoid to the Co(I) state for the monomethylamine corrinoid protein, MtmC. The ramA gene is located near a cluster of genes required for monomethylamine methyltransferase activity, including MtbA, the methylamine-specific CoM methylase and the pyl operon required for co-translational insertion of pyrrolysine into the active site of methylamine methyltransferases. RamA possesses a C-terminal ferredoxin-like domain capable of binding two tetranuclear iron-sulfur proteins. Mutliple ramA homologs were identified in genomes of methanogenic Archaea, often encoded near methyltrophic methyltransferase genes. RamA homologs are also encoded in a diverse selection of bacterial genomes, often located near genes for corrinoid-dependent methyltransferases. These results suggest that RamA mediates reductive activation of corrinoid proteins and that it is the first functional archetype of COG3894, a family of redox proteins of unknown function. PMID:19043046

Hubble space telescope imaging of decoupled dust clouds in the ram pressure stripped Virgo spirals NGC 4402 and NGC 4522

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abramson, Anne; Kenney, Jeffrey D. P., E-mail: anne.abramson@yale.edu, E-mail: jeff.kenney@yale.edu

We present the highest-resolution study to date of the interstellar medium (ISM) in galaxies undergoing ram pressure stripping, using Hubble Space Telescope BVI imaging of NGC 4522 and NGC 4402, Virgo Cluster spirals that are well known to be experiencing intracluster medium (ICM) ram pressure. We find that throughout most of both galaxies, the main dust lane has a fairly well-defined edge, with a population of giant molecular cloud (GMC) sized (tens- to hundreds-of-pc scale), isolated, highly extincting dust clouds located up to ∼1.5 kpc radially beyond it. Outside of these dense clouds, the area has little or no diffusemore » dust extinction, indicating that the clouds have decoupled from the lower-density ISM material that has already been stripped. Several of the dust clouds have elongated morphologies that indicate active ram pressure, including two large (kpc scale) filaments in NGC 4402 that are elongated in the projected ICM wind direction. We calculate a lower limit on the H I + H{sub 2} masses of these clouds based on their dust extinctions and find that a correction factor of ∼10 gives cloud masses consistent with those measured in CO for clouds of similar diameters, probably due to the complicating factors of foreground light, cloud substructure, and resolution limitations. Assuming that the clouds' actual masses are consistent with those of GMCs of similar diameters (∼10{sup 4}-10{sup 5} M {sub ☉}), we estimate that only a small fraction (∼1%-10%) of the original H I + H{sub 2} remains in the parts of the disks with decoupled clouds. Based on Hα images, a similar fraction of star formation persists in these regions, 2%-3% of the estimated pre-stripping star formation rate. We find that the decoupled cloud lifetimes may be up to 150-200 Myr.« less

RAM simulation model for SPH/RSV systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schryver, J.C.; Primm, A.H.; Nelson, S.C.

1995-12-31

The US Army`s Project Manager, Crusader is sponsoring the development of technologies that apply to the Self-Propelled Howitzer (SPH), formerly the Advanced Field Artillery System (AFAS), and Resupply Vehicle (RSV), formerly the Future Armored Resupply Vehicle (FARV), weapon system. Oak Ridge National Laboratory (ORNL) is currently performing developmental work in support of the SPH/PSV Crusader system. Supportive analyses of reliability, availability, and maintainability (RAM) aspects were also performed for the SPH/RSV effort. During FY 1994 and FY 1995 OPNL conducted a feasibility study to demonstrate the application of simulation modeling for RAM analysis of the Crusader system. Following completion ofmore » the feasibility study, a full-scale RAM simulation model of the Crusader system was developed for both the SPH and PSV. This report provides documentation for the simulation model as well as instructions in the proper execution and utilization of the model for the conduct of RAM analyses.« less

FDDI network test adaptor error injection circuit

NASA Technical Reports Server (NTRS)

Eckenrode, Thomas (Inventor); Stauffer, David R. (Inventor); Stempski, Rebecca (Inventor)

1994-01-01

An apparatus for injecting errors into a FDDI token ring network is disclosed. The error injection scheme operates by fooling a FORMAC into thinking it sent a real frame of data. This is done by using two RAM buffers. The RAM buffer normally accessed by the RBC/DPC becomes a SHADOW RAM during error injection operation. A dummy frame is loaded into the shadow RAM in order to fool the FORMAC. This data is just like the data that would be used if sending a normal frame, with the restriction that it must be shorter than the error injection data. The other buffer, the error injection RAM, contains the error injection frame. The error injection data is sent out to the media by switching a multiplexor. When the FORMAC is done transmitting the data, the multiplexor is switched back to the normal mode. Thus, the FORMAC is unaware of what happened and the token ring remains operational.

Basic and applied studies of the ram accelerator as a hypervelocity projectile launcher

NASA Astrophysics Data System (ADS)

Bruckner, Adam P.; Knowlen, Carl

1993-12-01

The potential of using ram accelerator technology for an impulsive launcher of autonomously guided interceptors, such as the LEAP, has been studied during this contract period. In addition, fundamental investigations on some of the engineering issues which must be addressed for enabling ram accelerator propulsive modes to operate at 4 km/sec have been undertaken. An experimental investigation of the gas dynamic limits of ram accelerator operation has demonstrated the existence of two distinct limiting mechanisms that must be accounted for when designing projectiles for these launchers. Other experiments were conducted to make detailed pressure measurements of the flow fields at the tube walls to study the effects of projectile canting. Results from this LEAP launcher study and the experimental investigations indicate that the ram accelerator technology is well suited for applications as a transportable launcher capable of meeting the needs of theater ballistic missile defense missions.

Quantification of Material Fluorescence and Light Scattering Cross Sections Using Ratiometric Bandwidth-Varied Polarized Resonance Synchronous Spectroscopy.

PubMed

Xu, Joanna Xiuzhu; Hu, Juan; Zhang, Dongmao

2018-05-25

Presented herein is the ratiometric bandwidth-varied polarized resonance synchronous spectroscopy (BVPRS2) method for quantification of material optical activity spectra. These include the sample light absorption and scattering cross-section spectrum, the scattering depolarization spectrum, and the fluorescence emission cross-section and depolarization spectrum in the wavelength region where the sample both absorbs and emits. This ratiometric BVPRS2 spectroscopic method is a self-contained technique capable of quantitatively decoupling material fluorescence and light scattering signal contribution to its ratiometric BVPRS2 spectra through the linear curve-fitting of the ratiometric BVPRS2 signal as a function of the wavelength bandwidth used in the PRS2 measurements. Example applications of this new spectroscopic method are demonstrated with materials that can be approximated as pure scatterers, simultaneous photon absorbers/emitters, simultaneous photon absorbers/scatterers, and finally simultaneous photon absorbers/scatterers/emitters. Because the only instruments needed for this ratiometric BVPRS2 technique are the conventional UV-vis spectrophotometer and spectrofluorometer, this work should open doors for routine decomposition of material UV-vis extinction spectrum into its absorption and scattering component spectra. The methodology and insights provided in this work should be of broad significance to all chemical research that involves photon/matter interactions.

Highly efficient special sound absorbing solutions

NASA Technical Reports Server (NTRS)

Ionescu, M.; Petre-Lazar, S.

1974-01-01

Highly efficient special sound absorbing structures with the following criteria are considered: (1) A distribution surface of the sound absorbing material greater than that of the building element on which the structure is placed; (2) The highest possible absorption coefficient in the widest possible frequency band; and (3) adaptability to different construction and aesthetic conditions.

A Novel Ni/WOX/W Resistive Random Access Memory with Excellent Retention and Low Switching Current

NASA Astrophysics Data System (ADS)

Chien, Wei-Chih; Chen, Yi-Chou; Lee, Feng-Ming; Lin, Yu-Yu; Lai, Erh-Kun; Yao, Yeong-Der; Gong, Jeng; Horng, Sheng-Fu; Yeh, Chiao-Wen; Tsai, Shih-Chang; Lee, Ching-Hsiung; Huang, Yu-Kai; Chen, Chun-Fu; Kao, Hsiao-Feng; Shih, Yen-Hao; Hsieh, Kuang-Yeu; Lu, Chih-Yuan

2011-04-01

The behavior of WOX resistive random access memory (ReRAM) is a strong function of the top electrode material, which controls the conduction mechanism and the forming process. When using a top electrode with low work function, the current conduction is limited by space charges. On the other hand, the mechanism becomes thermionic emission for devices with a high work function top electrode. These (thermionic) devices are also found to have higher initial resistance, reduced forming current, and larger resistance window. Based on these insights and considering the compatibility to complementary metal-oxide-semiconductor (CMOS) process, we proposed to use Ni as the top electrode for high performance WOX ReRAM devices. The new Ni/WOX/W device can be switched at a low current density less than 8×105 A/cm2, with RESET/SET resistance ratio greater than 100, and extremely good data retention of more than 300 years at 85 °C.

Nuclear reactor shutdown system

DOEpatents

Bhate, Suresh K.; Cooper, Martin H.; Riffe, Delmar R.; Kinney, Calvin L.

1981-01-01

An inherent shutdown system for a nuclear reactor having neutron absorbing rods affixed to an armature which is held in an upper position by a magnetic flux flowing through a Curie temperature material. The Curie temperature material is fixedly positioned about the exterior of an inner duct in an annular region through which reactor coolant flows. Elongated fuel rods extending from within the core upwardly toward the Curie temperature material are preferably disposed within the annular region. Upon abnormal conditions which result in high neutron flux and coolant temperature, the Curie material loses its magnetic permeability, breaking the magnetic flux path and allowing the armature and absorber rods to drop into the core, thus shutting down the fissioning reaction. The armature and absorber rods are retrieved by lowering the housing for the electromagnet forming coils which create a magnetic flux path which includes the inner duct wall. The coil housing then is raised, resetting the armature.

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

NASA Astrophysics Data System (ADS)

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 Light Modulator for THz Applications," Advanced Optical Materials, vol. 2, pp. 275-279, 2014. [7] H. Tao, N. I. Landy, C. M. Bingham, X. Zhang, R. D. Averitt, and W. J. Padilla, "A metamaterial absorber for the terahertz regime: Design, fabrication and characterization," Optics Express, vol. 16, pp. 7181-7188, May 12 2008. [8] J. Hao, J. Wang, X. Liu, W. J. Padilla, L. Zhou, and M. Qiu, "High performance optical absorber based on a plasmonic metamaterial," Applied Physics Letters, vol. 96, p. 251104, 2010. [9] X. Liu, T. Tyler, T. Starr, A. F. Starr, N. M. Jokerst, and W. J. Padilla, "Taming the Blackbody with Infrared Metamaterials as Selective Thermal Emitters," Physical Review Letters, vol. 107, p. 045901, 07/18/ 2011. [10] T. Maier and H. Brückl, "Wavelength-tunable microbolometers with metamaterial absorbers," Optics Letters, vol. 34, pp. 3012-3014, 2009/10/01 2009. [11] A. Tittl, P. Mai, R. Taubert, D. Dregely, N. Liu, and H. Giessen, "Palladium-Based Plasmonic Perfect Absorber in the Visible Wavelength Range and Its Application to Hydrogen Sensing," Nano Letters, vol. 11, pp. 4366-4369, 2011/10/12 2011. [12] N. Liu, M. Mesch, T. Weiss, M. Hentschel, and H. Giessen, "Infrared Perfect Absorber and Its Application As Plasmonic Sensor," Nano Letters, vol. 10, pp. 2342-2348, Jul 2010. [13] G. H. Li, X. S. Chen, O. P. Li, C. X. Shao, Y. Jiang, L. J. Huang, et al., "A novel plasmonic resonance sensor based on an infrared perfect absorber," Journal of Physics D-Applied Physics, vol. 45, p. 205102, May 23 2012.

Novel quad-band terahertz metamaterial absorber based on single pattern U-shaped resonator

NASA Astrophysics Data System (ADS)

Wang, Ben-Xin; Wang, Gui-Zhen

2017-03-01

A novel quad-band terahertz metamaterial absorber using four different modes of single pattern resonator is demonstrated. Four obvious frequencies with near-perfect absorption are realized. Near-field distributions of the four modes are provided to reveal the physical picture of the multiple-band absorption. Unlike most previous quad-band absorbers that typically require four or more patterns, the designed absorber has only one resonant structure, which is simpler than previous works. The presented quad-band absorber has potential applications in biological sensing, medical imaging, and material detection.

Preparation and microwave absorption properties of honeycomb core structures coated with composite absorber

NASA Astrophysics Data System (ADS)

Luo, Hui; Chen, Fu; Wang, Fang; Wang, Xian; Dai, Weiyong; Hu, Sheng; Gong, Rongzhou

2018-05-01

Honeycomb structure coated with paraffin filled with composite of graphene and flaky carbonyl iron powder (FCIP) as lossy filler have been studied. The composite of graphene/FCIP with different weight ratio were synthesized via mechanical milling, the electromagnetic properties of the samples were measured by transmission/reflection method in the frequency range of 8-12 GHz. The microwave absorbing properties of the microwave absorbing honeycomb structure (MAHS) and microwave absorbing honeycomb sandwich structure (MAHSS) were studied based on the Finite Element Method with periodical boundary conditions. The matching layer on the top of the honeycomb sandwich structure can enhanced the microwave absorption properties. It was shown that a light weight and broadband MAHSS could be implemented with the use of the magnetic material and dielectric material.

Experimental study on the cool storage performance of super absorbent polymers for cool storage clothes

NASA Astrophysics Data System (ADS)

Li, Shidong; Mo, Caisong; Wang, Junze; Zheng, Jingfu; Tian, Ruhong

2017-11-01

In this paper, a kind of cool storage clothes which can cool the human body in high temperature condition is put forward. super absorbent polymers was selected as a cold storage material, through at the normal and extreme environment simulation, the cold storage materials were prepared with different composition, and their performance was tested. Test results show that:under normal temperature conditions, the 1:50 concentration of super absorbent polymers continued to release the longest cooling time, compared with pure water, cooling time extended 43 minutes by about 30%; under the condition of 37°C, the 1:100 concentration of super absorbent polymers continued to release the longest cooling time, compared with pure water, cooling time extended 105 minutes by about 50%.

Lightweight armor system

DOEpatents

Chu, Henry S; Langhorst, Benjamin R; Bakas, Michael P; Thinnes, Gary L

2013-02-26

The disclosure provides a shock absorbing layer comprised of one or more shock absorbing cells, where a shock absorbing cell is comprised of a cell interior volume containing a plurality of hydrogel particles and a free volume, and where the cell interior volume is surrounded by a containing layer. The containing layer has a permeability such that the hydrogel particles when swollen remain at least partially within the cell interior volume when subjected to a design shock pressure wave, allowing for force relaxation through hydrogel compression response. Additionally, the permeability allows for the flow of exuded free water, further dissipating wave energy. In an embodiment, a plurality of shock absorbing cells is combined with a penetration resistant material to mitigate the transmitted shock wave generated by an elastic precursor wave in the penetration resistant material.

A wideband absorber for television studios

NASA Astrophysics Data System (ADS)

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.

Low temperature selective absorber research

NASA Astrophysics Data System (ADS)

Herzenberg, S. A.; Silberglitt, R.

1982-04-01

Research carried out since 1979 on selective absorbers is surveyed, with particular attention given to the low-temperature coatings seen as promising for flat plate and evacuated tube applications. The most thoroughly investigated absorber is black chrome, which is highly selective and is the most durable low-temperature absorber. It is believed that other materials, because of their low cost and lower content of strategic materials, may eventually supplant black chrome. Among these candidates are chemically converted black nickel; anodically oxidized nickel, zinc, and copper composites; and nickel or other low-cost multilayer coatings. In reviewing medium and high-temperature research, black chrome, multilayer coatings and black cobalt are seen as best medium-temperature candidates. For high temperatures, an Al2O3/Pt-Al203 multilayer composite or the zirconium diboride coating is preferred.

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

NASA Astrophysics Data System (ADS)

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.

Inspection of Stryker Engines Evaluated Using SCPL in a 20K Mile RAM-D Test

DTIC Science & Technology

2014-02-01

Availability, Maintainability, and Durability (RAM-D) test. The Caterpillar 3126 engine as tested was removed from the IAV Stryker, an 18 ton 8-wheeled...The objective of this work was to complete a tear down and inspection of two CAT 3126 engines as used in the IAV Stryker. A 20k mile RAM-D test was

Lessons Learned from Application of System and Software Level RAMS Analysis to a Space Control System

NASA Astrophysics Data System (ADS)

Silva, N.; Esper, A.

2012-01-01

The work presented in this article represents the results of applying RAMS analysis to a critical space control system, both at system and software levels. The system level RAMS analysis allowed the assignment of criticalities to the high level components, which was further refined by a tailored software level RAMS analysis. The importance of the software level RAMS analysis in the identification of new failure modes and its impact on the system level RAMS analysis is discussed. Recommendations of changes in the software architecture have also been proposed in order to reduce the criticality of the SW components to an acceptable minimum. The dependability analysis was performed in accordance to ECSS-Q-ST-80, which had to be tailored and complemented in some aspects. This tailoring will also be detailed in the article and lessons learned from the application of this tailoring will be shared, stating the importance to space systems safety evaluations. The paper presents the applied techniques, the relevant results obtained, the effort required for performing the tasks and the planned strategy for ROI estimation, as well as the soft skills required and acquired during these activities.

[Reaction of the fibrose eyeball covering upon the suture material synthetic and absorbable "Dexon". (Experimental study) (author's transl)].

PubMed

Olah, Z

1979-11-01

The present paper deals with the results of 20 eyes of experimentally operated laboratory animals, whose perforating wounds (of cornea and those of sclerocorneal region) have been suturated with a new type of absorbable synthetic suture material "Dexon" thickness being 6-0. The synthetic absorbable suture material "Dexon" is made of polyglycol acid, and it has been introduced to market by the firm Davis and Geck (U.S.A.). The inflammatory tissue reaction to the presence of the suture material "Dexon" is prominent and can by compared to the reaction to chromic resorbable suture materials (catgut or collagen). The suture material "Dexon" start to resorb in the course of the 2nd-3rd weeks after operation. The suture material "Dexon" can be used at an advantage in the operation where it is possible to cover the knots by a conjuctival lobe (in sclerocorneal region or in strabismus surgery) in this way the tendency to overgrowing of epithelial cells along the suture channels can be prevented. The "Dexon" material is sufficiently flexible and firm and has no antigenic properties, therefore it appears very prospective for ophthalmosurgery.

Review of radiation effects on ReRAM devices and technology

NASA Astrophysics Data System (ADS)

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.

The relationship between post-thaw sperm DNA integrity and non-return rate among Norwegian cross-bred rams.

PubMed

Nordstoga, A B; Krogenæs, A; Nødtvedt, A; Farstad, W; Waterhouse, K

2013-04-01

With the aim of investigating the relationship between sperm DNA integrity and non-return rate (NRR) among Norwegian cross-bred rams, semen from 15 individuals was examined by flow cytometry. Sperm Chromatin Structure Assay (SCSA) quantifies the proportion of spermatozoa with denatured DNA after in situ acid treatment, and the four parameters % DFI, % HDS, MEAN DFI and SD DFI are all different measures of DNA denaturation and maturation. Field fertility, reported as NRR 25 days after insemination was based on all inseminations from a large-scale breeding programme and supplied by the Norwegian Association of Sheep and Goat Farmers. From each ram, four straws from four different weeks of the breeding season were analysed, and the associations between 25-day NRR and the mean of the four SCSA parameters were tested using a logistic regression model. The results revealed no association between fertility and % DFI or % HDS, while SD DFI and MEAN DFI showed a significant negative association with NRR. Further, the SCSA values varied significantly between ejaculates within ram among some of the rams in the study. However, no significant association was seen between these intra-individual differences in sperm DNA integrity and NRR. In conclusion, this study suggests an association between sperm DNA integrity and NRR for rams. However, further research must be conducted to confirm these findings and determine whether sperm DNA assessments can be applied to predict ram fertility. © 2012 Blackwell Verlag GmbH.

Helicopter crashworthiness research program

NASA Technical Reports Server (NTRS)

Farley, Gary L.; Boitnott, Richard L.; Carden, Huey D.

1988-01-01

Results are presented from the U.S. Army-Aerostructures Directorate/NASA-Langley Research Center joint research program on helicopter crashworthiness. Through the on-going research program an in-depth understanding was developed on the cause/effect relationships between material and architectural variables and the energy-absorption capability of composite material and structure. Composite materials were found to be efficient energy absorbers. Graphite/epoxy subfloor structures were more efficient energy absorbers than comparable structures fabricated from Kevlar or aluminum. An accurate method predicting the energy-absorption capability of beams was developed.

Metallic dielectric photonic crystals and methods of fabrication

DOEpatents

Chou, Jeffrey Brian; Kim, Sang-Gook

2017-12-05

A metallic-dielectric photonic crystal is formed with a periodic structure defining a plurality of resonant cavities to selectively absorb incident radiation. A metal layer is deposited on the inner surfaces of the resonant cavities and a dielectric material fills inside the resonant cavities. This photonic crystal can be used to selectively absorb broadband solar radiation and then reemit absorbed radiation in a wavelength band that matches the absorption band of a photovoltaic cell. The photonic crystal can be fabricated by patterning a sacrificial layer with a plurality of holes, into which is deposited a supporting material. Removing the rest of the sacrificial layer creates a supporting structure, on which a layer of metal is deposited to define resonant cavities. A dielectric material then fills the cavities to form the photonic crystal.

(C6H13N)2BiI5: A One-Dimensional Lead-Free Perovskite-Derivative Photoconductive Light Absorber.

PubMed

Zhang, Weichuan; Tao, Kewen; Ji, Chengmin; Sun, Zhihua; Han, Shiguo; Zhang, Jing; Wu, Zhenyue; Luo, Junhua

2018-04-16

Lead-free organic-inorganic hybrid perovskites have recently attracted intense interest as environmentally friendly, low-cost, chemically stable light absorbers. Here, we reported a new one-dimensional (1D) zigzag chainlike light-absorbing hybrid material of (C 6 H 13 N) 2 BiI 5 , in which the corner-sharing octahedral bismuth halide chains are surrounded by organic cations of tetramethylpiperidinium. This unique zigzag 1D hybrid perovskite-derivative material shows a narrow direct band gap of 2.02 eV and long-lived photoluminescence, which is encouraging for optoelectronic applications. Importantly, it behaves as a typical semiconducting material and displays obvious photoresponse in the visible-light range. This work opens a potential pathway for the further application of 1D lead-free hybrids.

Metallic dielectric photonic crystals and methods of fabrication

DOEpatents

Chou, Jeffrey Brian; Kim, Sang-Gook

2016-12-20

A metallic-dielectric photonic crystal is formed with a periodic structure defining a plurality of resonant cavities to selectively absorb incident radiation. A metal layer is deposited on the inner surfaces of the resonant cavities and a dielectric material fills inside the resonant cavities. This photonic crystal can be used to selectively absorb broadband solar radiation and then reemit absorbed radiation in a wavelength band that matches the absorption band of a photovoltaic cell. The photonic crystal can be fabricated by patterning a sacrificial layer with a plurality of holes, into which is deposited a supporting material. Removing the rest of the sacrificial layer creates a supporting structure, on which a layer of metal is deposited to define resonant cavities. A dielectric material then fills the cavities to form the photonic crystal.

Thermal and chemical remediation of mixed wastes

DOEpatents

Nelson, Paul A.; Swift, William M.

1997-01-01

A process for treating organic waste materials without venting gaseous emissions to the atmosphere which includes oxidizing the organic waste materials at an elevated temperature not less than about 500.degree. C. with a gas having an oxygen content in the range of from about 20% to about 70% to produce an oxidation product containing CO.sub.2 gas. The gas is then filtered to remove particulates, and then contacted with an aqueous absorbent solution of alkali metal carbonates or alkanolamines to absorb a portion of the CO.sub.2 gas from the particulate-free oxidation product. The CO.sub.2 absorbent is thereafter separated for further processing. A process and system are also disclosed in which the waste materials are contacted with a reactive medium such as lime and product treatment as described.

Method and apparatus for component separation using microwave energy

DOEpatents

Morrow, Marvin S.; Schechter, Donald E.; Calhoun, Jr., Clyde L.

2001-04-03

A method for separating and recovering components includes the steps of providing at least a first component bonded to a second component by a microwave absorbent adhesive bonding material at a bonding area to form an assembly, the bonding material disposed between the components. Microwave energy is directly and selectively applied to the assembly so that substantially only the bonding material absorbs the microwave energy until the bonding material is at a debonding state. A separation force is applied while the bonding material is at the debonding state to permit disengaging and recovering the components. In addition, an apparatus for practicing the method includes holders for the components.

PET Imaging of VEGFR-2 Expression in Lung Cancer with 64Cu-Labeled Ramucirumab.

PubMed

Luo, Haiming; England, Christopher G; Graves, Stephen A; Sun, Haiyan; Liu, Glenn; Nickles, Robert J; Cai, Weibo

2016-02-01

Lung cancer accounts for 17% of cancer-related deaths worldwide, and most patients present with locally advanced or metastatic disease. Novel PET imaging agents for assessing vascular endothelial growth factor receptor-2 (VEGFR-2) expression can be used for detecting VEGFR-2-positive malignancies and subsequent monitoring of therapeutic response to VEGFR-2-targeted therapies. Here, we report the synthesis and characterization of an antibody-based imaging agent for PET imaging of VEGFR-2 expression in vivo. Ramucirumab (named RamAb), a fully humanized IgG1 monoclonal antibody, was conjugated to 2-S-(4-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid (p-SCN-Bn-NOTA) and labeled with (64)Cu. Flow cytometry analysis and microscopy studies were performed to compare the VEGFR-2 binding affinity of RamAb and NOTA-RamAb. PET imaging and biodistribution studies were performed in nude mice bearing HCC4006 and A549 xenograft tumors. Ex vivo histopathology was performed to elucidate the expression patterns of VEGFR-2 in different tissues and organs to validate in vivo results. Flow cytometry examination revealed the specific binding capacity of fluorescein isothiocyanate-RamAb to VEGFR-2, and no difference in VEGFR-2 binding affinity was seen between RamAb and NOTA-RamAb. After being labeled with (64)Cu, PET imaging revealed specific and prominent uptake of (64)Cu-NOTA-RamAb in VEGFR-2-positive HCC4006 tumors (9.4 ± 0.5 percentage injected dose per gram at 48 h after injection; n = 4) and significantly lower uptake in VEGFR-2-negative A549 tumors (4.3 ± 0.2 percentage injected dose per gram at 48 h after injection; n = 3). Blocking experiments revealed significantly lower uptake in HCC4006 tumors, along with histology analysis, further confirming the VEGFR-2 specificity of (64)Cu-NOTA-RamAb. This study provides initial evidence that (64)Cu-NOTA-RamAb can function as a PET imaging agent for visualizing VEGFR-2 expression in vivo, which may also find potential applications in monitoring the treatment response of VEGFR-2-targeted cancer therapy. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Light-emitting device with organic electroluminescent material and photoluminescent materials

DOEpatents

McNulty, Thomas Francis; Duggal, Anil Raj; Turner, Larry Gene; Shiang, Joseph John

2005-06-07

A light-emitting device comprises a light-emitting member, which comprises two electrodes and an organic electroluminescent material disposed between the electrodes, and at least one organic photoluminescent ("PL") material. The light-emitting member emits light having a first spectrum in response to a voltage applied across the two electrodes. The organic PL material absorbs a portion of the light emitted by the light-emitting member and emits light having second spectrum different than the first spectrum. The light-emitting device can include an inorganic PL material that absorbs another portion of the light emitted from the light-emitting member and emits light having a third spectrum different than both the first and the second spectra.

Confirmation Tests of Hot and Cold Artillery Shell Drawing Operations

DTIC Science & Technology

1979-05-01

internally, to increase the production rate. The flow stress of the deforming materials under hot drawing con - ditions is a function of strain rate...of the press, and its cable was hooked to the slider of the press ram. The amplified output of the displacement transducer was con - cected to the...present investigation, tests were conducted with both con - ventional conical and streamlined die designs to evaluate the mathematical models of the

VARIABLE-THROW CAM

DOEpatents

Godsil, E.C.; Robinson, E.Y.

1963-07-16

A variable-throw cam comprising inner and outer eccentric sleeves which are adjustably locked together is described. The cam throw is varied by unlocking the inner and outer sleeves, rotating the outer sleeve relative to the inner one until the desired throw is obtained, and locking the sleeves together again. The cam is useful in applications wherein a continuously-variable throw is required, e.g., ram-and-die pressing operations, cyclic fatigue testing of materials, etc. (AEC)

Freedom and Information. Assessing Publicly Available Data Regarding U.S. Transportation Infrastructure Security

DTIC Science & Technology

2007-01-01

Scenario 6: Suicide Boat Rams a Docked Cruise Ship at the Port of Los Angeles . . . . . . . . . . . . . . . . . . . . . . 31 Validation...with nuclear material from a foreign port through the Port of Los Angeles /Long Beach (LA/LB). The terrorist would want to find an overseas port where... the Sea Infrastructure Scenario 3: Shipping a nuclear device in a cargo container (Port of Los Angeles /Long Beach [LA/LB]) (RFID Journal, 2003; see

Estimated Environmental Exposures for MISSE-7B

NASA Technical Reports Server (NTRS)

Finckenor, Miria M.; Moore, Chip; Norwood, Joseph K.; Henrie, Ben; DeGroh, Kim

2012-01-01

This paper details the 18-month environmental exposure for Materials International Space Station Experiment 7B (MISSE-7B) ram and wake sides. This includes atomic oxygen, ultraviolet radiation, particulate radiation, thermal cycling, meteoroid/space debris impacts, and observed contamination. Atomic oxygen fluence was determined by measured mass and thickness loss of polymers of known reactivity. Diodes sensitive to ultraviolet light actively measured solar radiation incident on the experiment. Comparisons to earlier MISSE flights are discussed.

Investigation into the energy-absorbing properties of multilayered circular thin-walled tube

NASA Astrophysics Data System (ADS)

Qi, Aidong; Liu, Chuanhua; Hu, Gongli; Gu, Hongjun

2002-05-01

With the rise in collision accident and the increase in requirement for resistance of blastproof structures in recent years, people attach much importance to the research and application of energy-absorbing device. In this paper the author calculates the specific strength, the specific hardness and ultimate internal force of a circular thin-walled tube by theoretic calculations, discusses the feasibility of using circular thin-walled tube as an energy-absorbing element, analyzes the energy-absorbing properties and the energy-absorbing mechanism through the energy-absorbing experiments using various materials and forms of arrangement, reaches the conclusion that the load-bearing capacity and energy-absorbing properties of multilayered tubes are superior to that of single tube, and puts forward the concept of 'grading tube'.

A Triaxial Applicator for the Measurement of the Electromagnetic Properties of Materials

PubMed Central

2018-01-01

The design, analysis, and fabrication of a prototype triaxial applicator is described. The applicator provides both reflected and transmitted signals that can be used to characterize the electromagnetic properties of materials in situ. A method for calibrating the probe is outlined and validated using simulated data. Fabrication of the probe is discussed, and measured data for typical absorbing materials and for the probe situated in air are presented. The simulations and measurements suggest that the probe should be useful for measuring the properties of common radar absorbing materials under usual in situ conditions. PMID:29382122

Solar-collector materials exposure to the IPH site environment. Task 5.0

NASA Astrophysics Data System (ADS)

Morris, V. L.

1982-07-01

An environmental exposure test was conducted at a site which utilizes solar energy for enhanced oil recovery procedures. Two types of reflector materials were evaluated for survivability in this environment: second surface silvered glass and aluminized acrylic (FEK-244) on an aluminum substrate. Black chrome absorber material and low iron float glass were evaluated for thermal, photochemical and environmental degradation. The reflector specimens were monitored for decreases in specular and hemispherical reflectance due to soil buildup. The absorber material is evaluated for changes in solar absorptivity and emissivity and the glass cover plates is evaluated for changes in transmissivity.

Digital MOS integrated circuits

NASA Astrophysics Data System (ADS)

Elmasry, M. I.

MOS in digital circuit design is considered along with aspects of digital VLSI, taking into account a comparison of MOSFET logic circuits, 1-micrometer MOSFET VLSI technology, a generalized guide for MOSFET miniaturization, processing technologies, novel circuit structures for VLSI, and questions of circuit and system design for VLSI. MOS memory cells and circuits are discussed, giving attention to a survey of high-density dynamic RAM cell concepts, one-device cells for dynamic random-access memories, variable resistance polysilicon for high density CMOS Ram, high performance MOS EPROMs using a stacked-gate cell, and the optimization of the latching pulse for dynamic flip-flop sensors. Programmable logic arrays are considered along with digital signal processors, microprocessors, static RAMs, and dynamic RAMs.

Nutrient Digestibility, Rumen Microbial Protein Synthesis, and Growth Performance in Sheep Consuming Rations Containing Sea Buckthorn Pomace.

PubMed

Hao, X Y; Diao, X G; Yu, S C; Ding, N; Mu, C T; Zhao, J X; Zhang, J X

2018-05-12

This experiment was conducted to investigate nutrient digestibility, rumen microbial protein synthesis, and growth performance when different proportions of sea buckthorn pomace (SBP) were included in the diet of sheep. A total of forty1/2 Dorper × 1/2 thin-tailed Han ram lambs (BW= 22.2 ± 0.92 kg, Age =120 ± 11 d; mean ± SD) were selected and divided into four groups in a randomized design, and were randomly allocated to 1 of 4 treatment diets. Diets were formulated isonitrogenously and contained different levels of SBP: 1) 0% SBP (control); 2) 7.8% of DM SBP (8SBP); 3)16.0% of DM SBP (16SBP); and 4) 23.5% of DM SBP (24SBP). A portion of corn and forages were replaced with SBP. Dry matter intake and average daily gain increased linearly (P=0.001), but feed efficiency was not affected (P≥0.460) by increasing SBP inclusion rate. As the SBP inclusion increased, organic matter, neutral detergent fiber, and acid detergent fiber digestibility decreased linearly (P≤0.005) and that crude protein increased linearly (P=0.012). Response to inclusion level of SBP was quadratic (P=0.003) for the estimated microbial crude protein yield with the greatest at intermediate SBP levels. For intestinally absorbable dietary protein, a quadratic (P=0.029) effects was observed among treatments. The metabolizable protein supplies was linearly (P<0.0001) improved with increasing SBP inclusion rate. The results indicated that sea buckthorn pomace can be incorporated in the ration of ram lambs and improve metabolizable protein supply and average daily gain. However, high content of it in the diet was adverse for nutrient digestibility. The optimal proportion was 16.0% under the condition of this experiment.

Superabsorbent Multilayer Fabric

NASA Technical Reports Server (NTRS)

Coreale, J. V.; Dawn, F. S.

1982-01-01

Material contains gel-forming polymer and copolymer that absorb from 70 to 200 times their weight of liquid. Superabsorbent Polymer and Copolymer form gels to bind and retain liquid in multiply fabric. Until reaction between liquid and absorbent masses forms gel, backing layer retains liquids within fabric; also allows material to "breathe." Possible applications include baby diapers, female hygiene napkins, and hospital bedpads. Might also have uses in improvement of dry soil.

Sweat collection capsule

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Delaplaine, R. W. (Inventor)

1980-01-01

A sweat collection capsule permitting quantitative collection of sweat is described. The device consists of a frame held immobile on the skin, a closure secured to the frame and absorbent material located next to the skin in a cavity formed by the frame and the closure. The absorbent material may be removed from the device by removing the closure from the frame while the frame is held immobile on the skin.

Can plant-based natural flax replace mineral-based basalt and synthetic E-glass for fibre reinforced polymer tubular energy absorbers? A comparative study on quasi-static axial crushing

NASA Astrophysics Data System (ADS)

Yan, Libo; Wang, Bo; Kasal, Bohumil

2017-12-01

Using plant-based natural fibres to substitute glass fibres as reinforcement of composite materials is of particular interest due to their economic, technical and environmental significance. One potential application of plant-based natural fibre reinforced polymer (FRP) composites is in automotive engineering as crushable energy absorbers. Current study experimentally investigated and compared the energy absorption efficiency of plant-based natural flax, mineral-based basalt and glass FRP composite tubular energy absorbers subjected to quasi-static axial crushing. The effects of number of flax fabric layer, the use of foam-filler and the type of fibre materials on the crashworthiness characteristics and energy absorption capacities were discussed. In addition, the failure mechanisms of the hollow and foam-filled flax, basalt and glass FRP tubes in quasi-static axial crushing were analysed and compared. The test results showed that the energy absorption capabilities of both hollow and foam-filled energy absorbers made of flax were superior to the corresponding energy absorbers made of basalt and were close to energy absorbers made of glass. This study therefore indicated that flax fibre has the great potential to be suitable replacement of basalt and glass fibres for crushable energy absorber application.

Omnidirectional, broadband light absorption using large-area, ultrathin lossy metallic film coatings

NASA Astrophysics Data System (ADS)

Li, Zhongyang; Palacios, Edgar; Butun, Serkan; Kocer, Hasan; Aydin, Koray

2015-10-01

Resonant absorbers based on nanostructured materials are promising for variety of applications including optical filters, thermophotovoltaics, thermal emitters, and hot-electron collection. One of the significant challenges for such micro/nanoscale featured medium or surface, however, is costly lithographic processes for structural patterning which restricted from industrial production of complex designs. Here, we demonstrate lithography-free, broadband, polarization-independent optical absorbers based on a three-layer ultrathin film composed of subwavelength chromium (Cr) and oxide film coatings. We have measured almost perfect absorption as high as 99.5% across the entire visible regime and beyond (400-800 nm). In addition to near-ideal absorption, our absorbers exhibit omnidirectional independence for incidence angle over ±60 degrees. Broadband absorbers introduced in this study perform better than nanostructured plasmonic absorber counterparts in terms of bandwidth, polarization and angle independence. Improvements of such “blackbody” samples based on uniform thin-film coatings is attributed to extremely low quality factor of asymmetric highly-lossy Fabry-Perot cavities. Such broadband absorber designs are ultrathin compared to carbon nanotube based black materials, and does not require lithographic processes. This demonstration redirects the broadband super absorber design to extreme simplicity, higher performance and cost effective manufacturing convenience for practical industrial production.

Preparation of new diatomite-chitosan composite materials and their adsorption properties and mechanism of Hg(II).

PubMed

Fu, Yong; Xu, Xiaoxu; Huang, Yue; Hu, Jianshe; Chen, Qifan; Wu, Yaoqing

2017-12-01

A new composite absorbent with multifunctional and environmental-friendly structures was prepared using chitosan, diatomite and polyvinyl alcohol as the raw materials, and glutaraldehyde as a cross-linking agent. The structure and morphology of the composite absorbent, and its adsorption properties of Hg(II) in water were characterized with Fourier transform infrared (FT-IR) spectra, scanning electron microscope (SEM), X-ray diffraction (XRD), Brunauer Emmett Teller (BET) measurements and ultraviolet-visible (UV-Vis) spectra. The effect of the pH value and contact time on the removal rate and absorbance of Hg(II) was discussed. The adsorption kinetic model and static adsorption isotherm and regeneration of the obtained composite absorbent were investigated. The results indicated that the removal of Hg(II) on the composite absorbent followed a rapid adsorption for 50 min, and was close to the adsorption saturation after 1 h, which is in accord with the Langmuir adsorption isotherm model and the pseudo-second-order kinetic model. When the pH value, contact time and the mass of the composite absorbent was 3, 1 h and 100 mg, respectively, the removal rate of Hg(II) on the composite absorbent reached 77%, and the maximum adsorption capacity of Hg(II) reached 195.7 mg g -1 .

Preparation of new diatomite–chitosan composite materials and their adsorption properties and mechanism of Hg(II)

PubMed Central

Fu, Yong; Xu, Xiaoxu; Huang, Yue; Hu, Jianshe; Chen, Qifan; Wu, Yaoqing

2017-01-01

A new composite absorbent with multifunctional and environmental-friendly structures was prepared using chitosan, diatomite and polyvinyl alcohol as the raw materials, and glutaraldehyde as a cross-linking agent. The structure and morphology of the composite absorbent, and its adsorption properties of Hg(II) in water were characterized with Fourier transform infrared (FT-IR) spectra, scanning electron microscope (SEM), X-ray diffraction (XRD), Brunauer Emmett Teller (BET) measurements and ultraviolet–visible (UV–Vis) spectra. The effect of the pH value and contact time on the removal rate and absorbance of Hg(II) was discussed. The adsorption kinetic model and static adsorption isotherm and regeneration of the obtained composite absorbent were investigated. The results indicated that the removal of Hg(II) on the composite absorbent followed a rapid adsorption for 50 min, and was close to the adsorption saturation after 1 h, which is in accord with the Langmuir adsorption isotherm model and the pseudo-second-order kinetic model. When the pH value, contact time and the mass of the composite absorbent was 3, 1 h and 100 mg, respectively, the removal rate of Hg(II) on the composite absorbent reached 77%, and the maximum adsorption capacity of Hg(II) reached 195.7 mg g−1. PMID:29308226

Neutron reflectometry on highly absorbing films and its application to 10B4C-based neutron detectors

PubMed Central

Piscitelli, F.; Khaplanov, A.; Devishvili, A.; Schmidt, S.; Höglund, C.; Birch, J.; Dennison, A. J. C.; Gutfreund, P.; Hall-Wilton, R.; Van Esch, P.

2016-01-01

Neutron reflectometry is a powerful tool used for studies of surfaces and interfaces. The absorption in the typical studied materials is neglected and this technique is limited only to the reflectivity measurement. For strongly absorbing nuclei, the absorption can be directly measured by using the neutron-induced fluorescence technique which exploits the prompt particle emission of absorbing isotopes. This technique is emerging from soft matter and biology where highly absorbing nuclei, in very small quantities, are used as a label for buried layers. Nowadays, the importance of absorbing layers is rapidly increasing, partially because of their application in neutron detection; a field that has become more active also due to the 3He-shortage. We extend the neutron-induced fluorescence technique to the study of layers of highly absorbing materials, in particular 10B4C. The theory of neutron reflectometry is a commonly studied topic; however, when a strong absorption is present the subtle relationship between the reflection and the absorption of neutrons is not widely known. The theory for a general stack of absorbing layers has been developed and compared to measurements. We also report on the requirements that a 10B4C layer must fulfil in order to be employed as a converter in neutron detection. PMID:26997902

Microstructures of superhydrophobic plant leaves - inspiration for efficient oil spill cleanup materials.

PubMed

Zeiger, Claudia; Rodrigues da Silva, Isabelle C; Mail, Matthias; Kavalenka, Maryna N; Barthlott, Wilhelm; Hölscher, Hendrik

2016-08-16

The cleanup of accidental oil spills in water is an enormous challenge; conventional oil sorbents absorb large amounts of water in addition to oil and other cleanup methods can cause secondary pollution. In contrast, fresh leaves of the aquatic ferns Salvinia are superhydrophobic and superoleophilic, and can selectively absorb oil while repelling water. These selective wetting properties are optimal for natural oil absorbent applications and bioinspired oil sorbent materials. In this paper we quantify the oil absorption capacity of four Salvinia species with different surface structures, water lettuce (Pistia stratiotes) and Lotus leaves (Nelumbo nucifera), and compare their absorption capacity to artificial oil sorbents. Interestingly, the oil absorption capacities of Salvinia molesta and Pistia stratiotes leaves are comparable to artificial oil sorbents. Therefore, these pantropical invasive plants, often considered pests, qualify as environmentally friendly materials for oil spill cleanup. Furthermore, we investigated the influence of oil density and viscosity on the oil absorption, and examine how the presence and morphology of trichomes affect the amount of oil absorbed by their surfaces. Specifically, the influence of hair length and shape is analyzed by comparing different hair types ranging from single trichomes of Salvinia cucullata to complex eggbeater-shaped trichomes of Salvinia molesta to establish a basis for improving artificial bioinspired oil absorbents.

Lyophilization closures for protein based drugs.

PubMed

DeGrazio, F; Flynn, K

1992-01-01

Rubber stopper formulations which are currently used as lyophilization stoppers vary widely in their capacities to absorb and release moisture. Release of moisture from the stopper over the shelf life of the product may result in drug degradation for extremely low cake weight products. The degree to which rubber formulations absorb water is dependent upon the components of these formulations. Independently, polymers and fillers absorb water during autoclave cycles to varying levels depending upon such factors as the solubility, structure, possibility of chemical reactions and impurity levels of these materials. Once combined into a stopper formulation, the raw materials can react to form species which further promote absorption. Data is presented comparing the absorption characteristics of low versus high absorbent rubber formulations. The release of moisture from these formulas when stoppered on vials containing dry product is also discussed.

NEUTRON SHIELDING STRUCTURE

DOEpatents

Mattingly, J.T.

1962-09-25

A lightweight neutron shielding structure comprises a honeycomb core which is filled with a neutron absorbing powder. The honeycomb core is faced with parallel planar facing sheets to form a lightweight rigid unit. Suitable absorber powders are selected from among the following: B, B/sub 4/C, B/sub 2/O/ sub 3/, CaB/sub 6/, Li/sub 2/CO3, LiOH, LiBO/sub 2/, Li/s ub 2/O. The facing sheets are constructed of a neutron moderating material, so that fast neutrons will be moderated while traversing the facing sheets, and ultimately be absorbed by the absorber powder in the honeycomb. Beryllium is a preferred moderator material for use in the facing sheets. The advantage of the structure is that it combines the rigidity and light weight of a honeycomb construction with the neutron absorption properties of boron and lithium. (AEC)

Absorption-induced scattering and surface plasmon out-coupling from absorber-coated plasmonic metasurfaces

PubMed Central

Petoukhoff, Christopher E.; O'Carroll, Deirdre M.

2015-01-01

Interactions between absorbers and plasmonic metasurfaces can give rise to unique optical properties not present for either of the individual materials and can influence the performance of a host of optical sensing and thin-film optoelectronic applications. Here we identify three distinct mode types of absorber-coated plasmonic metasurfaces: localized and propagating surface plasmons and a previously unidentified optical mode type called absorption-induced scattering. The extinction of the latter mode type can be tuned by controlling the morphology of the absorber coating and the spectral overlap of the absorber with the plasmonic modes. Furthermore, we show that surface plasmons are backscattered when the crystallinity of the absorber is low but are absorbed for more crystalline absorber coatings. This work furthers our understanding of light–matter interactions between absorbers and surface plasmons to enable practical optoelectronic applications of metasurfaces. PMID:26271900

P-Compensated and P-Doped Superlattice Infrared Detectors

NASA Technical Reports Server (NTRS)

Khoshakhlagh, Arezou (Inventor); Ting, David Z. (Inventor); Gunapala, Sarath D. (Inventor)

2017-01-01

Barrier infrared detectors configured to operate in the long-wave (LW) infrared regime are provided. The barrier infrared detector systems may be configured as pin, pbp, barrier and double heterostructrure infrared detectors incorporating optimized p-doped absorbers capable of taking advantage of high mobility (electron) minority carriers. The absorber may be a p-doped Ga-free InAs/InAsSb material. The p-doping may be accomplished by optimizing the Be doping levels used in the absorber material. The barrier infrared detectors may incorporate individual superlattice layers having narrower periodicity and optimization of Sb composition to achieve cutoff wavelengths of.about.10.mu.m.

Absorbing Boundary Conditions For Optical Pulses In Dispersive, Nonlinear Materials

NASA Technical Reports Server (NTRS)

Goorjian, Peter M.; Kwak, Dochan (Technical Monitor)

1995-01-01

This paper will present results in computational nonlinear optics. An algorithm will be described that provides absorbing boundary conditions for optical pulses in dispersive, nonlinear materials. A new numerical absorber at the boundaries has been developed that is responsive to the spectral content of the pulse. Also, results will be shown of calculations of 2-D electromagnetic nonlinear waves computed by directly integrating in time the nonlinear vector Maxwell's equations. The results will include simulations of "light bullet" like pulses. Here diffraction and dispersion will be counteracted by nonlinear effects. Comparisons will be shown of calculations that use the standard boundary conditions and the new ones.

Nanocrystal powered nanomotor

DOEpatents

Regan, Brian C [Los Angeles, CA; Zettl, Alexander K [Kensington, CA; Aloni, Shaul [Albany, CA

2011-01-04

A nanoscale nanocrystal which may be used as a reciprocating motor is provided, comprising a substrate having an energy differential across it, e.g. an electrical connection to a voltage source at a proximal end; an atom reservoir on the substrate distal to the electrical connection; a nanoparticle ram on the substrate distal to the atom reservoir; a nanolever contacting the nanoparticle ram and having an electrical connection to a voltage source, whereby a voltage applied between the electrical connections on the substrate and the nanolever causes movement of atoms between the reservoir and the ram. Movement of the ram causes movement of the nanolever relative to the substrate. The substrate and nanolever preferably comprise multiwalled carbon nanotubes (MWNTs) and the atom reservoir and nanoparticle ram are preferably metal (e.g. indium) deposited as small particles on the MWNTs. The substrate may comprise a silicon chip that has been fabricated to provide the necessary electrodes and other electromechanical structures, and further supports an atomic track, which may comprise an MWNT.

Santiago Ramón y Cajal and Harvey Cushing: two forefathers of neuroscience and neurosurgery.

PubMed

Zamora-Berridi, Grettel J; Pendleton, Courtney; Ruiz, Gabriel; Cohen-Gadol, Aaron A; Quiñones-Hinojosa, Alfredo

2011-11-01

To summarize the extraordinary accomplishments, and the commonalities, between Santiago Ramon y Cajal and Harvey Williams Cushing. Existing literature describing the lives and achievements of Ramón y Cajal and Cushing, as well as personal communication, and the surgical records of the Johns Hopkins Hospital, from 1896 to 1912, were reviewed. Both Ramón y Cajal and Cushing were men of unusually broad interests and talents, and these shared characteristics undoubtedly influenced the career paths and scientific investigations they pursued. Although Santiago Ramón y Cajal and Harvey Williams Cushing never directly interacted, the links between them can be traced through some of their disciples, including Pío del Río Hortega, Wilder Penfield, and Percival Bailey. Ramón y Cajal and Cushing are widely considered the forefathers of neuroscience and neurosurgery, respectively, and their discoveries have made lasting impressions on both the scientific and medical communities. Copyright © 2011 Elsevier Inc. All rights reserved.

A robust activity marking system for exploring active neuronal ensembles

PubMed Central

Sørensen, Andreas T; Cooper, Yonatan A; Baratta, Michael V; Weng, Feng-Ju; Zhang, Yuxiang; Ramamoorthi, Kartik; Fropf, Robin; LaVerriere, Emily; Xue, Jian; Young, Andrew; Schneider, Colleen; Gøtzsche, Casper René; Hemberg, Martin; Yin, Jerry CP; Maier, Steven F; Lin, Yingxi

2016-01-01

Understanding how the brain captures transient experience and converts it into long lasting changes in neural circuits requires the identification and investigation of the specific ensembles of neurons that are responsible for the encoding of each experience. We have developed a Robust Activity Marking (RAM) system that allows for the identification and interrogation of ensembles of neurons. The RAM system provides unprecedented high sensitivity and selectivity through the use of an optimized synthetic activity-regulated promoter that is strongly induced by neuronal activity and a modified Tet-Off system that achieves improved temporal control. Due to its compact design, RAM can be packaged into a single adeno-associated virus (AAV), providing great versatility and ease of use, including application to mice, rats, flies, and potentially many other species. Cre-dependent RAM, CRAM, allows for the study of active ensembles of a specific cell type and anatomical connectivity, further expanding the RAM system’s versatility. DOI: http://dx.doi.org/10.7554/eLife.13918.001 PMID:27661450

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

PubMed

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.

Advanced Cu chemical displacement technique for SiO2-based electrochemical metallization ReRAM application.

PubMed

Chin, Fun-Tat; Lin, Yu-Hsien; You, Hsin-Chiang; Yang, Wen-Luh; Lin, Li-Min; Hsiao, Yu-Ping; Ko, Chum-Min; Chao, Tien-Sheng

2014-01-01

This study investigates an advanced copper (Cu) chemical displacement technique (CDT) with varying the chemical displacement time for fabricating Cu/SiO2-stacked resistive random-access memory (ReRAM). Compared with other Cu deposition methods, this CDT easily controls the interface of the Cu-insulator, the switching layer thickness, and the immunity of the Cu etching process, assisting the 1-transistor-1-ReRAM (1T-1R) structure and system-on-chip integration. The modulated shape of the Cu-SiO2 interface and the thickness of the SiO2 layer obtained by CDT-based Cu deposition on SiO2 were confirmed by scanning electron microscopy and atomic force microscopy. The CDT-fabricated Cu/SiO2-stacked ReRAM exhibited lower operation voltages and more stable data retention characteristics than the control Cu/SiO2-stacked sample. As the Cu CDT processing time increased, the forming and set voltages of the CDT-fabricated Cu/SiO2-stacked ReRAM decreased. Conversely, decreasing the processing time reduced the on-state current and reset voltage while increasing the endurance switching cycle time. Therefore, the switching characteristics were easily modulated by Cu CDT, yielding a high performance electrochemical metallization (ECM)-type ReRAM.

Numerical study for identification of influence of energy absorption and frontal crush for vehicle crashworthiness

NASA Astrophysics Data System (ADS)

Suman, Shwetabh; Shah, Haard; Susarla, Vaibhav; Ravi, K.

2017-11-01

According to the statistics it has been seen that everyday nearly 400 people are killed due to road accidents. Due to this it has become an important concern to concentrate on the safety of the passengers which can be done by improving the crashworthiness of the vehicle. During the impact, a large amount of energy is released which if not absorbed, will be transmitted to the passenger compartment. For the safety of the passenger this energy has to be absorbed. Front rail is one of the main energy absorbing components in the vehicle front structure. When it comes to the structure and material of the part or component of the vehicle that is to be designed for crash, it is done based on three parameters: Specific Energy of Absorption, Mass of the front rail and maximum crush force. In this work, we are considering different internal geometries with different materials to increase the energy absorbing capacity of the front rail. Based on the extensive analysis carried aluminium seizes to be the opt material for frontal crash.

Multi-domain boundary element method for axi-symmetric layered linear acoustic systems

NASA Astrophysics Data System (ADS)

Reiter, Paul; Ziegelwanger, Harald

2017-12-01

Homogeneous porous materials like rock wool or synthetic foam are the main tool for acoustic absorption. The conventional absorbing structure for sound-proofing consists of one or multiple absorbers placed in front of a rigid wall, with or without air-gaps in between. Various models exist to describe these so called multi-layered acoustic systems mathematically for incoming plane waves. However, there is no efficient method to calculate the sound field in a half space above a multi layered acoustic system for an incoming spherical wave. In this work, an axi-symmetric multi-domain boundary element method (BEM) for absorbing multi layered acoustic systems and incoming spherical waves is introduced. In the proposed BEM formulation, a complex wave number is used to model absorbing materials as a fluid and a coordinate transformation is introduced which simplifies singular integrals of the conventional BEM to non-singular radial and angular integrals. The radial and angular part are integrated analytically and numerically, respectively. The output of the method can be interpreted as a numerical half space Green's function for grounds consisting of layered materials.

Experimental investigations of the performance of a solar air collector with latent heat thermal storage integrated with the solar absorber

NASA Astrophysics Data System (ADS)

Charvat, P.; Pech, O.; Hejcik, J.

2013-04-01

The paper deals with experimental investigations of the performance of a solar air collector with latent heat thermal storage integrated with the solarabsorber. The main purpose of heat storage in solar thermal systems is to store heat when the supply of solar heat exceeds demand and release it when otherwise. A number of heat storage materials can be used for this purpose; the phase change materials among them. Short-term latent heat thermal storage integrated with the solar absorber can stabilize the air temperature at the outlet of the collector on cloudy days when solar radiation intensity incident on a solar collector fluctuates significantly. Two experimental front-and-back pass solar air collectors of the same dimensions have been built for the experimental investigations. One collector had a "conventional" solar absorber made of a metal sheet while the solar absorber of the other collector consisted of containers filled with organic phase change material. The experimental collectors were positioned side by side during the investigations to ensure the same operating conditions (incident solar radiation, outdoor temperature).

Qualitative analysis of Pb liquid sample using laser-induced breakdown spectroscopy (LIBS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suyanto, Hery; Rupiasih, Ni Nyoman; Winardi, T. B.

2013-09-03

Qualitative analysis of liquid sample containing 1,000 ppm of Pb was performed by using LIBS technique. In order to avoid splashing off of the liquid sample during laser irradiation, a sample pretreatment was done, namely the liquid sample was absorbed by using commercial available stomach medicine. Two kinds of absorbent materials were chosen in this experiment, first containing 125 mg activated carbon and second 600 mg activated attapulgite. These absorbent materials were used since carbon sample gives better absorption of infrared laser irradiation used in this experiment. In order to characterize the absorption process, three treatments were conducted in thismore » experiment; first, without heating the sample but varying the absorption time before laser irradiation; second by varying the heating temperature after certain time of absorption process and third by varying the temperature only. The maximum emission intensity of Pb I 405.7 nm was found in the second treatment of heating the sample till 85°C after 30 minutes absorption of the liquid sample in both absorbent materials.« less

Absorbent product to absorb fluids. [for collection of human wastes

NASA Technical Reports Server (NTRS)

Dawn, F. S.; Correale, J. V. (Inventor)

1982-01-01

A multi-layer absorbent product for use in contact with the skin to absorb fluids is discussed. The product utilizes a water pervious facing layer for contacting the skin, overlayed by a first fibrous wicking layer, the wicking layer preferably being of the one-way variety in which fluid or liquid is moved away from the facing layer. The product further includes a first container section defined by inner and outer layer of a water pervious wicking material between which is disposed a first absorbent mass. A second container section defined by inner and outer layers between which is disposed a second absorbent mass and a liquid impermeable/gas permeable layer. Spacesuit applications are discussed.

Advanced gray rod control assembly

DOE Office of Scientific and Technical Information (OSTI.GOV)

Drudy, Keith J; Carlson, William R; Conner, Michael E

An advanced gray rod control assembly (GRCA) for a nuclear reactor. The GRCA provides controlled insertion of gray rod assemblies into the reactor, thereby controlling the rate of power produced by the reactor and providing reactivity control at full power. Each gray rod assembly includes an elongated tubular member, a primary neutron-absorber disposed within the tubular member said neutron-absorber comprising an absorber material, preferably tungsten, having a 2200 m/s neutron absorption microscopic capture cross-section of from 10 to 30 barns. An internal support tube can be positioned between the primary absorber and the tubular member as a secondary absorber tomore » enhance neutron absorption, absorber depletion, assembly weight, and assembly heat transfer characteristics.« less

Effectiveness of Synthetic Polyurethane Foam as a Nasal Packing Material in Endoscopic Endonasal Dacryocystorhinostomy.

PubMed

Lee, Joonsik; Lee, Hwa; Lee, Hyun Kyu; Chang, Minwook; Park, Minsoo; Baek, Sehyun

2015-10-01

To compare the effects of 2 nasal packing materials, synthetic polyurethane foam (absorbable) and expandable polyvinyl acetate (nonabsorbable), on the surgical success rate and postoperative complications after endoscopic endonasal dacryocystorhinostomy (EDCR). A retrospective medical review of 459 patients (580 eyes) who underwent EDCR for primary acquired nasolacrimal duct obstruction at Korea University Guro Hospitals from January 2009 to February 2014. Surgical success rate (anatomical, functional), postoperative complications (granuloma, synechia, bleeding, and infection) were compared between the 2 groups, absorbable (318 eyes) and nonabsorbable (262 eyes). The absorbable group showed better results in surgical success rate regarding anatomical (90.5% versus 76.3%, P = 0.00) and functional (89.3% versus 75.9%, P = 0.00). Granulomas developed less frequently in the absorbable group (24.5% versus 38.9%, P = 0.00). Also, bleeding and crust were less frequent in the absorbable group (P = 0.00). Infections were less frequent in the nonabsorbable group (1.52%) compared with the absorbable group (7.86%, P = 0.00). The rate of revision surgery was lower in the absorbable group (7.86% versus 20.9%, P = 0.00). As for the influence of secondary outcomes to the surgical success by multiple logistic regression, granulomas had the largest effect on surgical success either anatomical or functional (odds ratio = 82.393 to anatomical and 44.058 to functional). Synechia had the second largest effect on surgical success (odds ratio = 11.897 to anatomical and 9.605 to functional). The authors suggest that using a synthetic polyurethane foam as a nasal packing material is not only a surgical option, but also a crucial and essential procedure in EDCR.

Experiment evaluation of impact attenuator for a racing car under static load

NASA Astrophysics Data System (ADS)

Imanullah, Fahmi; Ubaidillah, Prasojo, Arfi Singgih; Wirawan, Adhe Aji

2018-02-01

The automotive world is a world where one of the factors that must be considered carefully is the safety aspect. In the formula student car one of the safety factor in the form of impact attenuator. Impact attenuator is used as anchoring when a collision occurs in front of the vehicle. In the rule of formula society of automotive engineer (FSAE) student, impact attenuator is required to absorb the energy must meet or exceed 7350 Joules with a slowdown in speed not exceeding 20 g average and peak of 40 g. The student formula participants are challenged to pass the boundaries so that in designing and making the impact attenuator must pay attention to the strength and use of the minimum material so that it can minimize the expenditure. In this work, an impact attenuator was fabricated and tested using static compression. The primary goal was evaluating the actual capability of the impact attenuator for impact energy absorption. The prototype was made of aluminum alloy in a prismatic shape, and the inside wall was filled with rooftop plastic slices and polyurethane hard foam. The compression test has successfully carried out, and the load versus displacement data could be used in calculating energy absorption capability. The result of the absorbent energy of the selected impact attenuator material. Impact attenuator full polyurethane absorbed energy reach 6380 Joule. For impact attenuator with aluminum polyurethane with a slashed rooftop material as section absorbed energy reach 6600 Joule. Impact attenuator with Aluminum Polyurethane with aluminum orange peel partitions absorbed energy reach 8800 Joule. From standard student formula, energy absorbed in this event must meet or exceed 7350 Joules that meet aluminum polyurethane with aluminum orange peel partitions with the ability to absorb 8800 Joule.

Response of anestrous ewes to the ram effect after follicular wave synchronization with a single dose of estradiol-17beta.

PubMed

Ungerfeld, Rodolfo; Dago, Ana L; Rubianes, Edgardo; Forsberg, Mats

2004-01-01

Anestrous ewes respond to the introduction of rams with either an ovulation within 2-3 days that may be followed by luteal phases of normal or short length, with delayed ovulations (5-6 days later), or with the luteinization of follicles. The aim of this work was to study the relationship between the growth status of the largest follicle present when rams are introduced and the type of ovarian response in non-treated ewes and in ewes treated with estradiol-17beta before ram introduction. Thirteen anestrous Corriedale ewes were divided into 2 groups: E2 (n = 7) and C (n = 6). The E2 ewes received a single dose of 50 microg estradiol-17beta 5 days before the introduction of the rams to synchronize the onset of their follicle waves, while C ewes remained untreated. When the rams were introduced, all E2 ewes had the largest follicle in a growing stage in contrast with the C ewes (3 out of 6; P < 0.05). Five C and 4 E2 ewes ovulated after the introduction of the rams (Day 3.4 +/- 0.4 for C vs. 4.8 +/- 0.3 for E2 ewes, respectively, P < 0.05). Only one ewe from each group developed a normal luteal phase: 4 C and 3 E2 ewes had short luteal phases. One C ewe and 2 E2 ewes had short luteal phases originating from follicles that did not ovulate. After the first luteal phase, all ewes returned to anesirus without a second ovulation or luteal phase. The remaining E2 ewe did not ovulate or show any changes in progesterone serum concentrations. We conclude that the growth status of the largest follicle alone does not determine the ovarian responding pattern of anestrous ewes to the ram effect.

Exposure to Photoperiod-Melatonin-Induced, Sexually-Activated Rams after Weaning Advances the Resumption of Sexual Activity in Post-Partum Mediterranean Ewes Lambing in January.

PubMed

Abecia, José A; Chemineau, Philippe; Gómez, Andrea; Palacios, Carlos; Keller, Matthieu; Delgadillo, José A

2017-01-21

This study was aimed to determine whether the presence of sexually stimulated rams by photoperiodic and melatonin treatments can advance the resumption of post-partum sexual activity in Mediterranean ewes lambing in January and weaned at the end of the breeding season at 41°N, in March. Rams were exposed to two months of long days (16 h light/day) and given three melatonin implants at the end of the long days (sexually-activated rams; SAR). Control rams (CR) were exposed to the natural photoperiod. Thirty-six ewes weaned on 25 February were assigned to one of two groups. From 1 March to 30 June, one group was housed with four SAR males (SAR-treated; n = 18), and the other group (CR-treated; n = 18) was housed with four unstimulated rams. Ovulation was assessed once per week based on plasma progesterone concentrations. Estrus was monitored daily by marks left on ewes by rams' harnesses. SAR-treated ewes had a shorter ( p < 0.01) weaning-first estrus interval than CR-treated ewes (61 ± 17 days vs. 102 ± 47 days; mean date of first estrus after weaning on April 26 and June 6, respectively). The proportion of the ewes ovulating in April or May was higher ( p < 0.05) in the SAR-treated group than in the CR-treated group. SAR-treated ewes resumed estrous activity sooner than CR-treated ewes such that, in April, May, and June, the proportion of females that exhibited estrus was higher ( p < 0.01) in the SAR-treated group (72%, 89%, and 100%, respectively) than in the CR-treated group (17%, 44%, and 61%, respectively). In conclusion, the introduction at weaning of sexually activated rams advanced the resumption of estrous activity in ewes in spring. The practical implications of this work could be important in ewes adapted for intensive production and accelerated lambing systems.

Prenatal programming of sexual partner preference: the ram model.

PubMed

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 aromatisation.

Appetitive and Consummatory Sexual Behaviors of Rams Treated with Exogenous Testosterone and Exposed to Anestrus Dorper Ewes: Efficacy of the Male Effect.

PubMed

Tejada, Luz M; Meza-Herrera, Cesar A; Rivas-Muñoz, Raymundo; Rodríguez-Martínez, Rafael; Carrillo, Evaristo; Mellado, Miguel; Véliz-Deras, Francisco G

2017-04-01

We determine whether Dorper rams treated with testosterone in the sexual resting season trigger both appetitive and consummatory sexual behaviors and sexual and reproductive outcomes in anestrous ewes at 26° North during March-April. Dorper rams (n = 12, 2.5 years) were randomly divided prior to mating in two groups: GT (treated group; n = 6), treated with testosterone propionate (25 mg i.m. every 3 days × 3 weeks) and GC (control group; n = 6), treated with saline. Thereafter, adult anovulatory Dorper ewes (n = 61) were exposed to the GT-rams while the other group (n = 60) was exposed to the GC-rams. Ram's appetitive sexual behavior was similar (50 %) in both groups, yet the GT-rams exerted 100 % of the consummatory sexual behavior. Sexual and reproductive outcomes of the anestrus females exposed to both male groups considered two phases: 0-15 and 16-25 days from exposure to males. Involved variables were: ewes in estrus, ewes ovulating, duration of estrus, pregnant ewes, and lambed ewes. All the average variables favored those ewes exposed to GT-males: ewes in estrus: 85 versus 40 %; ewes ovulating: 80 versus 53 %; duration of estrus: 37 versus 25 h; pregnant ewes: 60 versus 31 %, and lambed ewes: 57 versus 31 %. Results confirm that adult Dorper rams treated with exogenous testosterone had improved consummatory sexual behavior and induced increased ovulation and pregnancy rates when exposed to anestrus ewes. This feasible and inexpensive testosterone-based protocol through the male effect also enhanced both sexual and reproductive outcomes in previously anestrous Dorper ewes during the natural out-of-season. Results are important to speed up reproductive performance of sheep during the natural anestrous season at this latitude, while also they embrace interesting outcomes from a comparative sexual behavior stand point.

Growing without a mother results in poorer sexual behaviour in adult rams.

PubMed

Damián, J P; Beracochea, F; Machado, S; Hötzel, M J; Banchero, G; Ungerfeld, R

2018-01-01

The aim of this study was to determine if the absence of the mother during rearing has long-term effects on sexual behaviour and physiological reproductive parameters of adult rams. Two groups of rams were: (1) artificially reared, separated from their dams 24 to 36 h after birth (Week 0) and fed using sheep milk until 10 weeks of age (group AR, n=14); and (2) reared by their dams until 10 weeks of age (group DR, n=13). Sexual behaviour (tests of 20 min) and physiological reproductive parameters were analysed separately for the non-breeding (Weeks 42 to 64) and the breeding (Weeks 66 to 90) seasons. Body weight, scrotal circumference, gonado-somatic index, testosterone concentrations or sperm parameters were similar in both rearing conditions (AR v. DR) in both seasons. During the non-breeding season AR rams displayed fewer ano-genital sniffings (AR: 4.2±0.4 v. DR: 5.3±0.4, P=0.04) and matings (AR: 1.2±0.2 v. DR: 1.8±0.2, P=0.002) than DR rams. During the breeding season AR rams displayed fewer ano-genital sniffings (AR: 4.3±0.5 v. DR: 5.7±0.5, P=0.005), flehmen (AR: 0.7±0.2 v. DR: 1.1±0.2, P=0.03), mount attempts (AR: 1.4±0.2 v. DR: 2.1±0.2, P=0.04), and tended to mount less frequently (AR: 6.6±0.9 v. DR: 8.8±0.9, P=0.08) than DR rams. In conclusion, the absence of the mother during the rearing period negatively affected display of sexual behaviour towards oestrous ewes during a rams adult life in both breeding and non-breeding seasons. However, it did not affect testis size, testosterone secretion or sperm variables.

Developmental programming in sheep: administration of testosterone during 60-90 days of pregnancy reduces breeding success and pregnancy outcome.

PubMed

Steckler, T L; Roberts, E K; Doop, D D; Lee, T M; Padmanabhan, V

2007-02-01

Evidence suggests that exposure to excess steroids during critical periods of fetal development leads to reproductive disorders. Exposure of female lambs to excess testosterone (T) from Days 60 to 90 of gestation (T60-90; term, 147 days) delayed onset of the LH surge and resulted in to male-typical reproductive behavior. The objectives of this study were to test the ability of T60-90 ewes to mate, conceive and lamb during the first three breeding seasons (Years 1, 2 and 3). Pregnant Suffolk ewes were injected with T propionate in cottonseed oil (100mg, im twice weekly) or vehicle (control; C) from Days 60 to 90 of gestation. In Year 1, ewes (C=12, T60-90=12) were kept with a vasectomized ram for 3 months and markings/visual observation of copulations were recorded. Rams had paint applied to their chest to facilitate detection of estrus and mating. All C but only three T60-90 ewes were marked (P<0.001). All ewes were then estrus-synchronized with two injections of prostaglandin F2alpha (20mg, im) given 11 days apart and allowed to mate with a painted, fertile ram. Nine of 12 C and 4 of 12 T60-90 ewes (P=0.1) were mated. Based on estrus and long-term monitoring of progesterone, more C than T60-90 became pregnant (82 and 18%, respectively; P<0.01). In Year 2, to maximize ram exposure, two C and two T60-90 estrus-synchronized ewes were placed with a painted, fertile ram at a time and mated ewes were removed to a nearby pen to force mating with others. Twenty-four hour video monitoring revealed the rams mated more C than T60-90 ewes (83 and 25%, respectively; P=0.01). In both Years 1 and 2, the rams preferred C over T60-90 ewes; therefore in Year 3 rams were given access only to T60-90 ewes. Only four T60-90 estrus-synchronized ewes were placed with a painted ram at a time. Not given an option, 91% of the T60-90 ewes were marked resulting in 4 of 11 (36%; first-service pregnancy rate in the breeding herd was 91%) ewes becoming pregnant to the synchronized estrus. Collectively these studies showed that fertility in T60-90 females was severely compromised, even after overcoming ram preference for controls.

Precision Controlled Carbon Materials for Next-Generation Optoelectronic and Photonic Devices

DTIC Science & Technology

2018-01-08

absorbers. Semiconducting nanotubes are strong, dye-like absorbers with bandgaps tunable to the ideal for single-junction solar PV ~1.3 eV or deeper...semiconducting carbon nanotube-based photovoltaic solar cells and photodetectors; (2) high-performance carbon nanotube electronics; (3) stretchable...photovoltaic solar cells and photodetectors Semiconducting carbon nanotubes are attractive absorbers for photovoltaic and photodetector devices. The

Effect of Zn doping on the microwave absorption of BFO multiferroic materials

NASA Astrophysics Data System (ADS)

Bi, S.; Li, J.; Mei, B.; Su, X. J.; Ying, C. Z.; Li, P. H.

2018-01-01

The microwave absorbing materials were firstly used in the Second World War. And the BiFeO3 (BFO) based microwave absorbers have been widely applied into the microwave absorbing area due to its possession of excellent electromagnetic properties. Various methods have been conducted to improve the microwave absorption performance of the BFO based materials. In the work, the sol-gel method were used to prepare the BFO, and the Zn were doped into the BFO to prepare the Bi1-xZnxFeO3 nanoparticles. The X-ray diffraction, scanning electron microscope, and vector network analysis (VNA) were conducted to characterize the microstructure and electromagnetic properties of the as-prepared samples. The results indicate that the Bi1-xZnxFeO3 nanoparticles were successfully gained and the as-prepared samples possess excellent microwave absorption properties.

Solar energy panel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hyman, M.

1980-03-04

A light-weight, low-cost and high efficiency solar panel includes a light-weight rectangular wood frame which surrounds and houses a copper absorber plate. A pair of spaced glazings, formed from plastic film materials, are disposed above the absorber to define a pair of enclosed air spaces. The lower glazing is capable of withstanding high temperatures and the upper glazing material is capable of providing good weather resistance. The material of the upper glazing extends fully about the frame to protect the entire frame from weathering. Insulation is provided beneath the absorber plate. The frame rests on top of a bottom sheetmore » of insulative foam plastic which is wrapped in a plastic envelope. The surrounding film of the outer glazing is bonded securely to the envelope to encase the entire panel within a protective sealed envelope of weather-resistant plastic film.« less

Thermal and chemical remediation of mixed wastes

DOEpatents

Nelson, P.A.; Swift, W.M.

1997-12-16

A process is described for treating organic waste materials without venting gaseous emissions to the atmosphere which includes oxidizing the organic waste materials at an elevated temperature not less than about 500 C with a gas having an oxygen content in the range of from about 20% to about 70% to produce an oxidation product containing CO{sub 2} gas. The gas is then filtered to remove particulates, and then contacted with an aqueous absorbent solution of alkali metal carbonates or alkanolamines to absorb a portion of the CO{sub 2} gas from the particulate-free oxidation product. The CO{sub 2} absorbent is thereafter separated for further processing. A process and system are also disclosed in which the waste materials are contacted with a reactive medium such as lime and product treatment as described. 8 figs.

Ferroelectric tunneling element and memory applications which utilize the tunneling element

DOEpatents

Kalinin, Sergei V [Knoxville, TN; Christen, Hans M [Knoxville, TN; Baddorf, Arthur P [Knoxville, TN; Meunier, Vincent [Knoxville, TN; Lee, Ho Nyung [Oak Ridge, TN

2010-07-20

A tunneling element includes a thin film layer of ferroelectric material and a pair of dissimilar electrically-conductive layers disposed on opposite sides of the ferroelectric layer. Because of the dissimilarity in composition or construction between the electrically-conductive layers, the electron transport behavior of the electrically-conductive layers is polarization dependent when the tunneling element is below the Curie temperature of the layer of ferroelectric material. The element can be used as a basis of compact 1R type non-volatile random access memory (RAM). The advantages include extremely simple architecture, ultimate scalability and fast access times generic for all ferroelectric memories.

Hierarchical structure and compressive deformation mechanisms of bighorn sheep (Ovis canadensis) horn.

PubMed

Huang, Wei; Zaheri, Alireza; Jung, Jae-Young; Espinosa, Horacio D; Mckittrick, Joanna

2017-12-01

Bighorn sheep (Ovis canadensis) rams hurl themselves at each other at speeds of ∼9 m/s (20 mph) to fight for dominance and mating rights. This necessitates impact resistance and energy absorption mechanisms, which stem from material-structure components in horns. In this study, the material hierarchical structure as well as correlations between the structure and mechanical properties are investigated. The major microstructural elements of horns are found as tubules and cell lamellae, which are oriented with (∼30⁰) angle with respect to each other. The cell lamellae contain keratin cells, in the shape of pancakes, possessing an average thickness of ∼2 µm and diameter of ∼20-30 µm. The morphology of keratin cells reveals the presence of keratin fibers and intermediate filaments with diameter of ∼200 nm and ∼12 nm, respectively, parallel to the cell surface. Quasi-static and high strain rate impact experiments, in different loading directions and hydration states, revealed a strong strain rate dependency for both dried and hydrated conditions. A strong anisotropy behavior was observed under impact for the dried state. The results show that the radial direction is the most preferable impact orientation because of its superior energy absorption. Detailed failure mechanisms under the aforementioned conditions are examined by bar impact recovery experiments. Shear banding, buckling of cell lamellae, and delamination in longitudinal and transverse direction were identified as the cause for strain softening under high strain rate impact. While collapse of tubules occurs in both quasi-static and impact tests, in radial and transverse directions, the former leads to more energy absorption and impact resistance. Bighorn sheep (Ovis canadensis) horns show remarkable impact resistance and energy absorption when undergoing high speed impact during the intraspecific fights. The present work illustrates the hierarchical structure of bighorn sheep horn at different length scales and investigates the energy dissipation mechanisms under different strain rates, loading orientations and hydration states. These results demonstrate how horn dissipates large amounts of energy, thus provide a new path to fabricate energy absorbent and crashworthiness engineering materials. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Intrascleral outflow after deep sclerectomy with absorbable and non-absorbable implants in the rabbit eye.

PubMed

Kałużny, Jakub J; Grzanka, Dariusz; Wiśniewska, Halina; Niewińska, Alicja; Kałużny, Bartłomiej J; Grzanka, Alina

2012-10-01

The purpose of the study is an analysis of intrascleral drainage vessels formed in rabbits' eyes after non-penetrating deep sclerectomy (NPDS) with absorbable and non-absorbable implants, and comparison to eyes in which surgery was performed without implanted material. NPDS was carried out in 12 rabbits, with implantation of non-absorbable methacrylic hydrogel (N=10 eyes) or absorbable cross-linked sodium hyaluronate (N=6 eyes), or without any implant (N=8 eyes). All the animals were euthanized 1 year after surgery. Twenty-one eyeballs were prepared for light microscopy and 3 were prepared for transmission electron microscope (TEM) analysis. Aqueous humour pathways were stained with ferritin in 6 eyeballs. By light microscopy, small vessels adjacent to the areas of scarring were the most common abnormality. Vessel density was significantly higher in operated sclera compared to normal, healthy tissue, regardless of the type of implant used. The average vessel densities were 2.18±1.48 vessels/mm2 in non-implanted sclera, 2.34±1.69 vessels/mm2 in eyes with absorbable implants, and 3.64±1.78 vessels/mm2 in eyes with non-absorbable implants. Analysis of iron distribution in ferritin-injected eyes showed a positive reaction inside new aqueous draining vessels in all groups. TEM analysis showed that the ultrastructure of new vessels matched the features of the small veins. Aqueous outflow after NPDS can be achieved through the newly formed network of small intrascleral veins. Use of non-absorbable implants significantly increases vessel density in the sclera adjacent to implanted material compared to eyes in which absorbable implants or no implants were used.

In-vivo assessment of barbed suturing thread with regard to tissue reaction and material absorption in a rat model.

PubMed

Petrut, Bogdan; Hogea, Maximiliam; Fetica, Bogdan; Kozan, Andrei; Feflea, Dragos; Sererman, Gabriel; Goezen, Ali Serdar; Rassweiler, Jens

2013-01-01

The laparoscopic approach in urological surgery demands a high degree of skill in intracorporeal suturing and knot tying. In an effort to reduce the amount of time required to perform a suture, new materials have been developed that through selfanchorage distribute tension more evenly across the suture and also eliminate the need of knot tying. The goal of this study was to assess the in vivo tissue response to a novel material (V-Loc tm; Covidien) in comparison to established materials (Vicryl, PDS II), in the case of bladder suturing, in a rat model. The study included 48 male Wistar rats. All underwent a median abdominal incision, with a 1cm cystotomy, followed by a running suture. The suture material used was either V-Loc absorbable self anchoring thread, Vicryl threaded absorbable suture or monofilament absorbable suture. The abdominal cavity and the bladder suture were macroscopically evaluated at the rats' scheduled death at 3 and 6 weeks. The bladder wall was microscopically assessed by a pathologist, with regard to tissue reaction and suture material degradation. All rats survived the procedure, with the abdominal scar fully healed at week 2. There were no signs of infection or lithiasis during the observation. Macroscopically, at 3 weeks, the suture material was recognizable and visible in all cases, with special mention that the V-Loc thread was considerably more rigid, retaining its shape almost entirely, and provoked more adhesion of the surrounding tissue. At 6 weeks, the suture was indistinguishable in the bladder wall in the case of monofilament absorbable material, barely visible in the case of Vicryl, while the aspect of the V-Loc suture resembled the one at 3 weeks, with the material still clearly visible in the bladder wall, shape almost entirely maintained, and surrounding tissue adherence. Microscopically, at 3 weeks and 6 weeks, all bladder walls examined had regained their structure. At 3 weeks, the monofilament absorbable suture showed intense tissue reaction, with the material already in phagocytosis; at 6 weeks, no clear evidence of leftover material was observed. At 3 weeks, the Vicryl material showed moderate tissue reaction, with phagocytosis initiated between the strands of the material; at 6 weeks, the material was almost entirely absorbed, but with a clear leftover tissue reaction. In the case of the V-Loc suture, due to the hardness of the thread, the material itself could not be cut for analysis with the bladder wall, and the examination could only involve the bladder wall and marks of the thread. Thus, the tissue reaction was minimal, as was the presence of phagocytes at the suture site. The material showed little, if any, signs of absorption after 6 weeks. The materials tested all proved equally effective in suturing the bladder wall in a rat model. However, the novel barbed thread proved a consistently low in-vivo absorption rate, while maintaining its rigidity over time. More research is needed to assess the possible clinical implications of these findings.

In-vivo assessment of barbed suturing thread with regard to tissue reaction and material absorption in a rat model

PubMed Central

PETRUT, BOGDAN; HOGEA, MAXIMILIAM; FETICA, BOGDAN; KOZAN, ANDREI; FEFLEA, DRAGOS; SERERMAN, GABRIEL; GOEZEN, ALI SERDAR; RASSWEILER, JENS

2013-01-01

Aim The laparoscopic approach in urological surgery demands a high degree of skill in intracorporeal suturing and knot tying. In an effort to reduce the amount of time required to perform a suture, new materials have been developed that through selfanchorage distribute tension more evenly across the suture and also eliminate the need of knot tying. The goal of this study was to assess the in vivo tissue response to a novel material (V-Loc tm; Covidien) in comparison to established materials (Vicryl, PDS II), in the case of bladder suturing, in a rat model. Methods The study included 48 male Wistar rats. All underwent a median abdominal incision, with a 1cm cystotomy, followed by a running suture. The suture material used was either V-Loc absorbable self anchoring thread, Vicryl threaded absorbable suture or monofilament absorbable suture. The abdominal cavity and the bladder suture were macroscopically evaluated at the rats’ scheduled death at 3 and 6 weeks. The bladder wall was microscopically assessed by a pathologist, with regard to tissue reaction and suture material degradation. Results All rats survived the procedure, with the abdominal scar fully healed at week 2. There were no signs of infection or lithiasis during the observation. Macroscopically, at 3 weeks, the suture material was recognizable and visible in all cases, with special mention that the V-Loc thread was considerably more rigid, retaining its shape almost entirely, and provoked more adhesion of the surrounding tissue. At 6 weeks, the suture was indistinguishable in the bladder wall in the case of monofilament absorbable material, barely visible in the case of Vicryl, while the aspect of the V-Loc suture resembled the one at 3 weeks, with the material still clearly visible in the bladder wall, shape almost entirely maintained, and surrounding tissue adherence. Microscopically, at 3 weeks and 6 weeks, all bladder walls examined had regained their structure. At 3 weeks, the monofilament absorbable suture showed intense tissue reaction, with the material already in phagocytosis; at 6 weeks, no clear evidence of leftover material was observed. At 3 weeks, the Vicryl material showed moderate tissue reaction, with phagocytosis initiated between the strands of the material; at 6 weeks, the material was almost entirely absorbed, but with a clear leftover tissue reaction. In the case of the V-Loc suture, due to the hardness of the thread, the material itself could not be cut for analysis with the bladder wall, and the examination could only involve the bladder wall and marks of the thread. Thus, the tissue reaction was minimal, as was the presence of phagocytes at the suture site. The material showed little, if any, signs of absorption after 6 weeks. Conclusion The materials tested all proved equally effective in suturing the bladder wall in a rat model. However, the novel barbed thread proved a consistently low in-vivo absorption rate, while maintaining its rigidity over time. More research is needed to assess the possible clinical implications of these findings. PMID:26527981

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

NASA Technical Reports Server (NTRS)

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.

Hybrid vapor phase-solution phase growth techniques for improved CZT(S,Se) photovoltaic device performance

DOEpatents

Chang, Liang-Yi; Gershon, Talia S.; Haight, Richard A.; Lee, Yun Seog

2016-12-27

A hybrid vapor phase-solution phase CZT(S,Se) growth technique is provided. In one aspect, a method of forming a kesterite absorber material on a substrate includes the steps of: depositing a layer of a first kesterite material on the substrate using a vapor phase deposition process, wherein the first kesterite material includes Cu, Zn, Sn, and at least one of S and Se; annealing the first kesterite material to crystallize the first kesterite material; and depositing a layer of a second kesterite material on a side of the first kesterite material opposite the substrate using a solution phase deposition process, wherein the second kesterite material includes Cu, Zn, Sn, and at least one of S and Se, wherein the first kesterite material and the second kesterite material form a multi-layer stack of the absorber material on the substrate. A photovoltaic device and method of formation thereof are also provided.

Long-range parametric amplification of THz wave with absorption loss exceeding parametric gain.

PubMed

Wang, Tsong-Dong; Huang, Yen-Chieh; Chuang, Ming-Yun; Lin, Yen-Hou; Lee, Ching-Han; Lin, Yen-Yin; Lin, Fan-Yi; Kitaeva, Galiya Kh

2013-01-28

Optical parametric mixing is a popular scheme to generate an idler wave at THz frequencies, although the THz wave is often absorbing in the nonlinear optical material. It is widely suggested that the useful material length for co-directional parametric mixing with strong THz-wave absorption is comparable to the THz-wave absorption length in the material. Here we show that, even in the limit of the absorption loss exceeding parametric gain, the THz idler wave can grows monotonically from optical parametric amplification over a much longer distance in a nonlinear optical material until pump depletion. The coherent production of the non-absorbing signal wave can assist the growth of the highly absorbing idler wave. We also show that, for the case of an equal input pump and signal in difference frequency generation, the quick saturation of the THz idler wave predicted from a much simplified and yet popular plane-wave model fails when fast diffraction of the THz wave from the co-propagating optical mixing waves is considered.

Instrumentation for Airwake Measurements on the Flight Deck of a FFG-7

DTIC Science & Technology

1991-11-01

volatile RAM to the computer hard disk with a unique file name based on time and date. At an opportune time the data file(s) are manually transferred...1967 6 Royal Air Force Manual (Volume D) AP3456D Al-i APPENDIX 1 GENERAL SPECIFICATION FOR VADAR VADAR was developed by the Instrumentation and Trials...TTCP HTP -6) N. Matheson N. Pollock DJ. Sherman Materials Research Laboratory Director/Library Defence Science & Technology Organisation Salisbury

Development of Fracture Mechanics Maps for Composite Materials. Volume 1.

DTIC Science & Technology

1985-12-01

A________________________ N 4. PERFORMING ORGANIZATION REPORT NUMBER (S) 5. MONITORING ORGANIZATION REPORT NUMBER (S) None AFWAL-TR-85-4150, Vol 1 6. NAME OF ... OF FUNDING/SPONSORING Sb. OFFICE SYMBOL 9. PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER ORGANIZATION if appplicable) European Space Technology Comm...ttee N/A ESTEC/ Contract No 4825/81/ML/AK(SC) B:. ADDRESS (City. State a=d ZIP Codel 10. SOURCE OF FUNDING NOS. ROG RAM’ PR OJE CT TASK WORK UNIT

LOADING MACHINE FOR REACTORS

DOEpatents

Simon, S.L.

1959-07-01

An apparatus is described for loading or charging slugs of fissionable material into a nuclear reactor. The apparatus of the invention is a "muzzle loading" type comprising a delivery tube or muzzle designed to be brought into alignment with any one of a plurality of fuel channels. The delivery tube is located within the pressure shell and it is also disposed within shielding barriers while the fuel cantridges or slugs are forced through the delivery tube by an externally driven flexible ram.

49 CFR 173.161 - Chemical kits and first aid kits.

Code of Federal Regulations, 2013 CFR

2013-10-01

... requirements of subpart B of this part and may not exceed 30 kg (66 pounds) gross weight; (5) Except for Carbon... kits must include sufficient absorbent material to completely absorb the contents of any liquid...

49 CFR 173.161 - Chemical kits and first aid kits.

Code of Federal Regulations, 2011 CFR

2011-10-01

... requirements of subpart B of this part and may not exceed 30 kg (66 pounds) gross weight; (5) Except for Carbon... kits must include sufficient absorbent material to completely absorb the contents of any liquid...

49 CFR 173.161 - Chemical kits and first aid kits.

Code of Federal Regulations, 2014 CFR

2014-10-01

... requirements of subpart B of this part and may not exceed 30 kg (66 pounds) gross weight; (5) Except for Carbon... kits must include sufficient absorbent material to completely absorb the contents of any liquid...

Stable fixation with absorbable sutures in craniofacial surgery.

PubMed

Linz, C; Kunz, F; Krauß, J; Böhm, H; Wirth, C; Hartmann, S; Wirbelauer, J; Schweitzer, T

2016-05-01

The present study analyses the exclusive use of absorbable suture material (Vicryl(®), Ethicon, Germany) in the fixation of transposed bone segments in craniofacial surgery without modification of the osteotomy design. Among 129 children up to 24 months of age, osteosynthesis was conducted exclusively with Vicryl(®) sutures. The stability of postoperative results was evaluated and possible foreign body reactions were examined within the framework of clinical and radiological routine checks. All examined children exhibited stable postoperative conditions while the length of hospital stay was not affected. X-ray examinations of the skull in two planes demonstrated good bony union in all cases. Relevant foreign body reactions were not observed. The exclusive application of absorbable suture material enables stable and cost effective osteosynthesis. Significant foreign body reactions were not observed. The exclusive use of absorbable sutures did not alter the osteotomy design. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

MOX fuel assembly design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reese, A.P.; Crowther, R.L. Jr.

1992-02-18

This patent describes improvement in a boiling water reactor core having a plurality of vertically upstanding fuel bundles; each fuel bundle containing longitudinally extending sealed rods with fissile material therein; the improvement comprises the fissile material including a mixture of uranium and recovered plutonium in rods of the fuel bundle at locations other than the corners of the fuel bundle; and, neutron absorbing material being located in rods of the fuel bundle at rod locations adjacent the corners of the fuel bundles whereby the neutron absorbing material has decreased shielding from the plutonium and maximum exposure to thermal neutrons formore » shaping the cold reactivity shutdown zone in the fuel bundle.« less

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

PubMed

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.

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

PubMed

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 < .05). After the introduction of rams, preovulatory peaks of LH (ηg/ml) occurred at 28 (T1), 44 (T2) and 48 (T3) hr in SI 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.

Surface Composition and Physical Mixture State of the Regoliths of Outer Solar System Satellites: The Role of Scattering and Absorption by the non-Ice Components and Implications for Rayleigh Absorption and Rayleigh Scattering

NASA Astrophysics Data System (ADS)

Clark, R. N.; Perlman, Z. S.; Pearson, N.; Hendrix, A. R.; Cuzzi, J. N.; Cruikshank, D. P.; Bradley, E. T.; Filacchione, G.; Nicholson, P. D.; Hedman, M. M.; Brown, R. H.; Buratti, B. J.; Baines, K. H.; Sotin, C.; Nelson, R. M.

2014-12-01

Many outer Solar System satellites have surfaces dominated by water ice and a mysterious material(s) causing strong visible to ultraviolet absorption along with trace other compounds with infrared absorptions, including CO2 and organics. Various mechanisms have been proposed for the UV absorber, including tholins, iron oxides, and nano-sized metallic iron particles (e.g. see Clark et al., 2012, Icarus v218 p831, and references therein). We have constructed extensive laboratory analog measurements and radiative transfer modeling of the materials and scattering conditions that can contribute to the optical properties seen on outer Solar System satellites. We have successfully modeled Rayleigh absorption and Rayleigh scattering to produce spectral shapes typical of those seen in spectra of icy Solar System satellites, including those in the Saturn system observed with the Cassini UVIS and VIMS instruments. While it is easy to create these absorptions with radiative transfer modeling, it has been more difficult to do with laboratory analogs. We are finding that laboratory analogs refine and restricts the possible mixing states of the UV absorber in icy satellite surfaces. We have found that just because a particle is highly absorbing, as in metallic iron, if the particle is not embedded in another matrix, scattering will dominate over absorption and Rayleigh absorption will not be observed. Further, the closer the indices of refraction match between the absorbing particle and the matrix, there will be less scattering and more absorption will occur. But we have also found this to be true with other absorbing material, like Tholins. It is very difficult to obtain the very low reflectances observed in the UV in icy satellite spectra using traditional intimate mixtures, as scattering and first surface reflections contribute significantly to the reflectance. The solution, both from radiative transfer modeling and laboratory analogs point to embedded absorbing materials. For example, nano-phase metallic iron embedded in a less absorbing silicate matrix as meteoritic dust infall onto satellitesurfaces is one explanation. An alternative would be tholins embedded in the ice. Spectral features should be able to distinguish between these and other possibilities and will be explored.

Fabrication of Organic Radar Absorbing Materials: A Report on the TIF Project

DTIC Science & Technology

2005-05-01

thickness, permittivity and permeability. The ability to measure the permittivity and permeability is an essential requirement for designing an optimised...absorber. And good optimisations codes are required in order to achieve the best possible absorber designs . In this report, the results from a...through measurement of their conductivity and permittivity at microwave frequencies. Methods were then developed for optimising the design of

Impact resistant battery enclosure systems

DOEpatents

Tsutsui, Waterloo; Feng, Yuezhong; Chen, Weinong Wayne; Siegmund, Thomas Heinrich

2017-10-31

Battery enclosure arrangements for a vehicular battery system. The arrangements, capable of impact resistance include plurality of battery cells and a plurality of kinetic energy absorbing elements. The arrangements further include a frame configured to encase the plurality of the kinetic energy absorbing elements and the battery cells. In some arrangements the frame and/or the kinetic energy absorbing elements can be made of topologically interlocked materials.

Supplementation of soybean lecithin-based semen extender by antioxidants: complementary flowcytometric study on post-thawed ram spermatozoa.

PubMed

Sharafi, Mohsen; Zhandi, Mahdi; Akbari Sharif, Abbas

2015-06-01

The purpose of the current study was to evaluate the effects of cysteine (C) and glutathione (G) on the post-thawed ram sperm quality. Collected semen samples from four mature rams were diluted with five soybean lecithin (SL)-based extenders containing: no antioxidant (SL-0), 5 mM cysteine (SL-C5), 10 mM cysteine (SL-C10), 5 mM glutathione (SL-G5) and 10 mM glutathione (SL-G10). After freeze-thawing process, motion and velocity parameters, plasma membrane integrity and functionality, morphological abnormality, lipid peroxidation, acrosomal status, mitochondria activity, and apoptosis status of post-thawed ram spermatozoa were assessed. The results showed that SL-C10 increased the total motility and plasma membrane integrity (p < 0.05) of post-thawed ram spermatozoa (55.86 ± 1.37 and 60.57 ± 1.34 %) compared to other extenders. Progressive motility was significantly higher in SL-C10 (24.71 ± 1.13 %) compared to SL-0 (20 ± 1.13 %) and SL-G10 (15 ± 1.13 %). Mitochondrial activity was significantly higher in SL-C10 (56.83 ± 2.29 %) compared to SL-G10 (38.75 ± 2.29 %). Capacitation and acrosomal status, lipid peroxidation, and the percentage of dead spermatozoa were not affected by different extenders. The percentage of live spermatozoa was higher in SL-C10 (56.33 ± 1.35 %) compared to other extenders. Also, SL-C10 resulted in a lower percentage of apoptotic spermatozoa (14.17 ± 0.53 %) compared to other extenders. The results of this study showed that supplementation of SL-based ram semen extender with 10 mM cysteine resulted in an improved quality of post-thawed ram spermatozoa.

Pretreatment resistance to hepatitis C virus protease inhibitors boceprevir/telaprevir in hepatitis C virus subgenotype 1a-infected patients from Manitoba.

PubMed

Andonov, Anton; Kadkhoda, Kamran; Osiowy, Carla; Kaita, Kelly

2013-07-01

Traditional therapy with pegylated interferon and ribavirin combined with the new protease inhibitors boceprevir or telaprevir has demonstrated improved outcomes in hepatitis C virus (HCV)-infected patients. Prevalence data regarding pre-existing drug-resistant variants to these two new virus inhibitors in the Canadian population are not available. To detect pre-existing mutations conferring resistance to boceprevir and⁄or telaprevir in Canadian patients infected with HCV genotype 1a. Resistance-associated mutations (RAMs) were evaluated in 85 patients infected with HCV genotype 1a who had not yet received antiviral therapy. The NS3 protease gene was sequenced and common RAMs were identified based on a recently published list. The overall prevalence of pre-existing RAMs to boceprevir and telaprevir was higher compared with other similar studies. All of the observed RAMs were associated with a low level of resistance. A surprisingly high proportion of patients had the V55A RAM (10.6%). None of the mutations associated with a high level of resistance were observed. The simultaneous presence of two low-level resistance mutations (V36L and V55A) was observed in only one patient. Three other patients had both T54S RAM and V55I mutations, which may require a higher concentration of the protease drugs. The prevalence of various mutations in Aboriginal Canadian patients was higher (37.5%) compared with Caucasians (16.39%) (P=0.038). The present study was the first to investigate pre-existing drug resistance to boceprevir⁄telaprevir in Canadian HCV-infected patients. A relatively high proportion of untreated HCV genotype 1a patients in Manitoba harbour low-level RAMs, especially patients of Aboriginal descent, which may contribute to an increased risk of treatment failure.

Effects of immunization against alpha-inhibin using two adjuvants on daily sperm production and hormone concentrations in ram lambs.

PubMed

Voge, J L; Parker, J B; Wheaton, J E

2009-11-01

Twenty-five ram lambs were immunized against alpha-inhibin peptide emulsified in Freund's adjuvant (FRA), Emulsigen (EML) containing an oligodeoxynucleotide as an immunostimulant, or adjuvant without alpha-inhibin antigen (control). Four immunizations were administered during an 85-d period, after which testes were obtained for determination of daily sperm production (DSP) and histological evaluation. alpha-Inhibin antibody (Ab) titers were 70-fold greater in lambs treated with FRA than in EML-treated ram lambs. alpha-Inhibin immunization had no effect on testes weight or on plasma concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone. Mean DSP/g tended (P=0.1) to be greater in alpha-inhibin-immunized (EML=17.6x10(6); FRA=15.8x10(6)) ram lambs than in control animals (14.4x10(6)). One of the 8 control ram lambs had an elevated DSP/g, which was a statistical outlier. Without data from this lamb, DSP/g was increased (P<0.01) in alpha-inhibin-immunized ram lambs by 28% over controls. No association was found between the titer of alpha-inhibin Ab developed and DSP/g. Histologically, the percentage of testicular area occupied by seminiferous tubules differed (P=0.01) by treatment and was greatest (82%) in EML-treated ram alpha-inhibin-immunized lambs and lowest (74%) in control animals. Percentage tubular area and DSP/g were correlated (r=0.57, P=0.003). Findings show that (1) the extent of the increase in DSP/g is not dependent on the titer of alpha-inhibin Ab; (2) the increase in DSP/g is achieved through an increase in the mass of seminiferous tubules; and (3) FRA elicits a greater alpha-inhibin Ab titer than EML containing an oligodeoxynucleotide.

Evaluation of Rectoanal Mucosal Swab Sampling for Molecular Detection of Enterohemorrhagic Escherichia coli in Beef Cattle.

PubMed

Agga, Getahun E; Arthur, Terrance M; Hinkley, Susanne; Bosilevac, Joseph M

2017-04-01

Cattle are a primary reservoir of enterohemorrhagic Escherichia coli (EHEC), and contaminated beef products are a source of human infections. The U.S. Department of Agriculture Food Safety and Inspection Service declared seven EHEC serogroups (O26, O45, O103, O111, O121, O145, and O157) as adulterants in raw ground beef. Sampling a large number of animals for EHEC surveillance or evaluations of EHEC-focused preharvest interventions requires a convenient and robust sampling method. We evaluated the diagnostic performance of rectoanal mucosal swab (RAMS) for the detection of the top seven EHEC serogroups. Paired fecal grab (FG) and RAMS samples were collected from 176 beef cattle and tested using the NeoSEEK Shiga toxin-producing E. coli (STEC) confirmation method. The prevalence of virulence-associated genes (stx 1 , stx 2 , stx 2c , eae, and nleB) was higher in RAMS than in FG samples. The results of the two methods had poor agreement, as indicated by kappa statistics, for the detection of the seven serogroups. When FG and RAMS results were combined for comparison, RAMS was more sensitive than FG for the detection of serogroups O103 (82% versus 39%), O157 (75% versus 67%), and O45 (79% versus 73%) with similar sensitivity for the detection of serogroup O145 (67%). Serogroups O111 and O121 were detected from one and two samples, respectively, by FG and were not detected by RAMS. Serogroup O26 was not detected with either method. RAMS appears to be equivalent or superior to FG sampling for detection of the top seven EHEC serogroups in the feces of beef cattle with the NeoSEEK STEC confirmation test.

Rumination relates to reduced autobiographical memory specificity in formerly depressed patients following a self-discrepancy challenge: the case of autobiographical memory specificity reactivity.

PubMed

Raes, Filip; Schoofs, Hanne; Griffith, James W; Hermans, Dirk

2012-12-01

Reduced Autobiographical Memory Specificity (rAMS) is a hypothesized vulnerability factor for depression. Rumination is thought to be one of the processes underlying rAMS, but research has failed to show an association between trait rumination and rAMS in individuals who are not currently depressed (e.g., community samples, college samples, and formerly depressed samples). The present study tested whether a challenge procedure that induces a self-discrepancy focus can elicit an association between trait rumination and rAMS in formerly depressed participants. Trait rumination was assessed via self-report. Measures of psychopathology and cognitive function, including depression, were assessed via self-report and interview. Autobiographical Memory Specificity (AMS) was evaluated before and after the induction of a self-discrepancy focus in formerly depressed participants. Results showed that trait rumination was indeed negatively correlated with AMS after, but not before the induction. Moreover, high trait ruminating participants showed a decrease in AMS following the induction. In other words, memory specificity was reactive to the induction, but no such decrease was observed in low trait ruminating individuals. This study is mostly of women. These results may not generalize well to men. Our experimental control was within-subjects, which, although powerful and economical, cannot rule out certain confounding processes including natural changes in self-discrepancy, or non-specific or unintended effects of the induction. In order to detect rAMS in formerly depressed individuals or to observe associations between rAMS and trait measures of rumination, state ruminative processing needs to be activated. Results are discussed by framing rAMS as an example of cognitive reactivity, a general type of processing that is associated with depression. Copyright © 2012 Elsevier Ltd. All rights reserved.

Long Duration Exposure Facility (LDEF) preliminary findings: LEO space effects on the space plasma-voltage drainage experiment

NASA Technical Reports Server (NTRS)

Blakkolb, Brian K.; Yaung, James Y.; Henderson, Kelly A.; Taylor, William W.; Ryan, Lorraine E.

1992-01-01

The Space Plasma-High Voltage Drainage Experiment (SP-HVDE) provided a unique opportunity to study long term space environmental effects on materials because it was comprised of two identical experimental trays; one tray located on the ram facing side (D-10), and the other on the wake facing side (B-4) of the LDEF. This configuration allows for the comparison of identical materials exposed to two distinctly different environments. The purpose of this work is to document an assessment of the effects of five and three quarters years of low Earth orbital space exposure on materials comprising the SP-HVDE (experiment no. A0054). The findings of the materials investigation reported focus on atomic oxygen effects, micrometeor and debris impact site documentation, thermal property measurements, and environmentally induced contamination.

Absorbent pads for Containment, Neutralization, and Clean-Up of Environmental Spills Containing Chemically-Reactive Agents

NASA Technical Reports Server (NTRS)

Davis, Dennis D. (Inventor)

1997-01-01

A pad for cleaning up liquid spills is described which contains a porous surface covering, and an absorbent interior containing chemically reactive reagents for neutralizing noxious chemicals within the spilled liquid. The porous surface and the absorbent component would normally consist of chemically resistant materials allowing tentative spill to pass. The absorbent interior which contains the neutralizing reagents can but is not required to be chemically resilient and conducts the liquid chemical spill towards the absorbent interior containing the chemically reactive reagents where the dangerous and undesirable chemicals within the chemical spill are then neutralized as well as removed from the premises.

10.4% Efficient triple organic solar cells containing near infrared absorbers

NASA Astrophysics Data System (ADS)

Meerheim, Rico; Körner, Christian; Oesen, Benjamin; Leo, Karl

2016-03-01

The efficiency of organic solar cells can be increased by serially stacked subcells with spectrally different absorber materials. For the triple junction devices presented here, we use the small molecule donor materials DCV5T-Me for the green region and Tol2-benz-bodipy or Ph2-benz-bodipy as near infrared absorbers. The broader spectral response allows an efficiency increase from a pure DCV5T-Me triple cell to a triple junction containing a Ph2-benz-bodipy subcell, reaching 10.4%. As often observed for organic photovoltaics, the efficiency is further increased at low light intensities to 11%, which allows improved energy harvesting under real outdoor conditions and better performance indoor.

Basic and Applied Studies of the RAM Accelerator as a Hypervelocity Projectile Launcher

DTIC Science & Technology

1993-12-10

The quasi-steady, one-dimensional "blackbox" model of thermally choked ram accelerator performance 18 that has been widely used by the authors and...the thermal choke point is assumed to be in equilibrium, the conditions can be determined by an equilibrium chemistry combustion routine. This model ...to operation, the details of the flow field must be examined. I The simplest model of the thermally choked ram accelerator flow field treats the flow

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

NASA Astrophysics Data System (ADS)

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.

The oviducal protein, heat-shock 70-kDa protein 8, improves the long-term survival of ram spermatozoa during storage at 17°C in a commercial extender.

PubMed

Lloyd, R E; Fazeli, A; Watson, P F; Holt, W V

2012-01-01

Poor fertility rates are often observed when fresh ram semen stored in conventional extenders is used for cervical artificial insemination (AI). Heat-shock 70-kDa protein 8 (HSPA8), found within the oviduct, prolongs boar, ram and bull sperm survival at body temperatures in vitro. Here, we aimed to determine whether supplementing extenders (INRA-96 and RSD-1) with HSPA8 (4 µg mL⁻¹) would improve their performance in maintaining freshly collected ram sperm viability and sperm nuclear DNA integrity during storage over 48 h at 17°C. Sperm function was assessed at 1, 6, 24 and 48h and this experiment was repeated using 25 × 10⁶ and 800 × 10⁶ spermatozoa mL⁻¹. INRA96 supplemented with HSPA8 maintained sperm viability significantly better than INRA96 alone at both sperm concentrations. However, sperm nuclear DNA fragmentation (DF) increased significantly during storage using the higher sperm concentration, irrespective of the extender and the protein treatment used. Increasing levels of sperm nuclear DF over time could explain why poor fertility rates are often observed following cervical AI using stored ram semen. However, further research is required to ascertain whether supplementing the commercially available INRA96 extender with HSPA8 will improve fertility rates following cervical AI using stored ram semen.

Galactic star formation enhanced and quenched by ram pressure in groups and clusters

NASA Astrophysics Data System (ADS)

Bekki, Kenji

2014-02-01

We investigate how ram pressure of intragroup and intracluster medium can influence the spatial and temporal variations of star formation (SF) of disc galaxies with halo masses (Mh) ranging from 1010 to 1012 M⊙ (i.e. from dwarf irregular to Milky Way-type) in groups and clusters with 1013 ≤ Mh/M⊙ ≤ 1015 by using numerical simulations with a new model for time-varying ram pressure. The long-term evolution of SF rates and Hα morphologies corresponding to the distributions of star-forming regions are particularly investigated for different model parameters. The principal results are as follows. Whether ram pressure can enhance or reduce SF depends on Mh of disc galaxies and inclination angles of gas discs with respect to their orbital directions for a given orbit and a given environment. For example, SF can be moderately enhanced in disc galaxies with Mh = 1012 M⊙ at the pericentre passages in a cluster with Mh = 1014 M⊙ whereas it can be completely shut down (`quenching') for low-mass discs with Mh = 1010 M⊙. Ram pressure can reduce the Hα-to-optical-disc-size ratios of discs and the level of the reduction depends on Mh and orbits of disc galaxies for a given environment. Disc galaxies under strong ram pressure show characteristic Hα morphologies such as ring-like, one-sided and crescent-like distributions.

Mitigation of High Altitude and Low Earth Orbit Radiation Effects on Microelectronics via Shielding or Error Detection and Correction Systems

NASA Technical Reports Server (NTRS)

Gupta, Kajal (Technical Monitor); Kirby, Kelvin

2004-01-01

The NASA Cooperative Agreement NAG4-210 was granted under the FY2000 Faculty Awards for Research (FAR) Program. The project was proposed to examine the effects of charged particles and neutrons on selected random access memory (RAM) technologies. The concept of the project was to add to the current knowledge of Single Event Effects (SEE) concerning RAM and explore the impact of selected forms of radiation on Error Detection and Correction Systems. The project was established as an extension of a previous FAR awarded to Prairie View A&M University (PVAMU), under the direction of Dr. Richard Wilkins as principal investigator. The NASA sponsored Center for Applied Radiation Research (CARR) at PVAMU developed an electronic test-bed to explore and quantify SEE on RAM from charged particles and neutrons. The test-bed was developed using 486DX microprocessor technology (PC-104) and a custom test board to mount RAM integrated circuits or other electronic devices. The test-bed had two configurations - a bench test version for laboratory experiments and a 400 Hz powered rack version for flight experiments. The objectives of this project were to: 1) Upgrade the Electronic Test-bed (ETB) to a Pentium configuration; 2) Accommodate more than only 8 Mbytes of RAM; 3) Explore Error Detection and Correction Systems for radiation effects; 4) Test modern RAM technologies in radiation environments.

Effect of dispersion on convective mixing in porous media

NASA Astrophysics Data System (ADS)

Wen, Baole; Hesse, Marc; Geological porous media Group Team

2017-11-01

We investigate the effect of dispersion on convection in porous media by performing direct numerical simulations (DNS) in a 2D Rayleigh-Darcy domain. Scaling analysis of the governing equations shows that the dynamics of this system is not only controlled by the classical Rayleigh-Darcy number based on molecular diffusion, Ram , and the domain aspect ratio, but also controlled by two other dimensionless parameters: the dispersive Rayleigh number Rad = H /αt and the dispersivity ratio r =αl /αt , where H is the domain height, αt and αl are the transverse and longitudinal dispersivities, respectively. For Ram << Rad , the effect of dispersion on convection is negligible; for Ram >> Rad , however, the flow pattern is determined by Rad while the mass transport flux F Ram at high- Ram regime. Our DNS results also show that the increase of the mechanical dispersion (i.e. decreasing Rad) will broaden the plume spacing and coarsen the convective pattern. Moreover, for r >> 1 the anisotropy of dispersion destroys the slender columnar structure of the primary plumes at large Ram and therefore reduces the mass transport rate. This work was supported by the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award Number DE-SC0001114.

Development of low-cost technology for the next generation of high efficiency solar cells composed of earth abundant elements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agrawal, Rakesh

2014-09-28

The development of renewable, affordable, and environmentally conscious means of generating energy on a global scale represents a grand challenge of our time. Due to the “permanence” of radiation from the sun, solar energy promises to remain a viable and sustainable power source far into the future. Established single-junction photovoltaic technologies achieve high power conversion efficiencies (pce) near 20% but require complicated manufacturing processes that prohibit the marriage of large-scale throughput (e.g. on the GW scale), profitability, and quality control. Our approach to this problem begins with the synthesis of nanocrystals of semiconductor materials comprising earth abundant elements and characterizedmore » by material and optoelectronic properties ideal for photovoltaic applications, namely Cu2ZnSn(S,Se)4 (CZTSSe). Once synthesized, such nanocrystals are formulated into an ink, coated onto substrates, and processed into completed solar cells in such a way that enables scale-up to high throughput, roll-to-roll manufacturing processes. This project aimed to address the major limitation to CZTSSe solar cell pce’s – the low open-circuit voltage (Voc) reported throughout literature for devices comprised of this material. Throughout the project significant advancements have been made in fundamental understanding of the CZTSSe material and device limitations associated with this material system. Additionally, notable improvements have been made to our nanocrystal based processing technique to alleviate performance limitations due to the identified device limitations. Notably, (1) significant improvements have been made in reducing intra- and inter-nanoparticle heterogeneity, (2) improvements in device performance have been realized with novel cation substitution in Ge-alloyed CZTGeSSe absorbers, (3) systematic analysis of absorber sintering has been conducted to optimize the selenization process for large grain CZTSSe absorbers, (4) novel electrical characterization analysis techniques have been developed to identify significant limitations to traditional electrical characterization of CZTSSe devices, and (5) the developed electrical analysis techniques have been used to identify the role that band gap and electrostatic potential fluctuations have in limiting device performance for this material system. The device modeling and characterization of CZTSSe undertaken with this project have significant implications for the CZTSSe research community, as the identified limitations due to potential fluctuations are expected to be a performance limitation to high-efficiency CZTSSe devices fabricated from all current processing techniques. Additionally, improvements realized through enhanced absorber processing conditions to minimize nanoparticle and large-grain absorber heterogeneity are suggested to be beneficial processing improvements which should be applied to CZTSSe devices fabricated from all processing techniques. Ultimately, our research has indicated that improved performance for CZTSSe will be achieved through novel absorber processing which minimizes defect formation, elemental losses, secondary phase formation, and compositional uniformity in CZTSSe absorbers; we believe this novel absorber processing can be achieved through nanocrystal based processing of CZTSSe which is an active area of research at the conclusion of this award. While significant fundamental understanding of CZTSSe and the performance limitations associated with this material system, as well as notable improvements in the processing of nanocrystal based CZTSSe absorbers, have been achieved under this project, the limitation of two years of research funding towards our goals prevents further significant advancements directly identified through pce. improvements relative to those reported herein. As the characterization and modeling subtask of this project has been the main driving force for understanding device limitations, the conclusions of this analysis have just recently been applied to the processing of nanocrystal based CZTSSe absorbers -- with notable success. We expect the notable fundamental understanding of device limitations and absorber sintering achieved under this project will lead to significant improvements in device performance for CZTSSe devices in the near future for devices fabricated from a variety of processing techniques« less

Acute dermal toxicity and sensitization studies of novel nano-enhanced UV absorbers.

PubMed

Piasecka-Zelga, Joanna; Zelga, Piotr; Górnicz, Magdalena; Strzelczyk, Paweł; Sójka-Ledakowicz, Jadwiga

2015-01-01

Many employees working outside are exposed to the harmful effects of UV radiation. A growing problem is also sensitization to textile materials and allergic reactions to active compounds. Groups of inorganic UV blockers with nanoparticles may provide superior properties over organic UV absorbers with relatively less potential of provoking dermatitis. To assess acute dermal irritation and sensitization of nano UV absorbers. Five UV absorbers with nano-sized particles (Z11, TiO2 - SiO2 [TDPK], TK44, TK11, A8G) and 2 vehicles (paste-based on 10% PEG, and dispersion with 1% HEC) were tested. Acute dermal irritation was tested using group of 3 rabbits for each absorber. The sensitization study was carried out on groups of 15 guinea pigs for each tested textile with a UV absorber showing an Ultraviolet Protection Factor (UPF)>40. This research was designed according to OECD Test Guideline No. 404 and 406, and 21 rabbits and 60 guinea pigs were used in the study. In acute dermal irritation, Z11 and A8G modifiers and the analyzed paste gave results of 0.047 to 0.33 which classifies them as barely perceptible irritants, whereas the other analyzed modifiers and dispersion gave results of 0.00 and were classified as nonirritating. Only the textile with TK 11 did not have UPF>40. The analyzed barrier materials were classified as nonsenitizers (TDPK, A8G) or mild sensitizers (TK44, Z11). None of the analyzed materials or modifiers induced major skin reactions in animals. Therefore, they present low risk of provoking skin reactions in humans.

Study of thermal effects and optical properties of an innovative absorber in integrated collector storage solar water heater

NASA Astrophysics Data System (ADS)

Taheri, Yaser; Alimardani, Kazem; Ziapour, Behrooz M.

2015-10-01

Solar passive water heaters are potential candidates for enhanced heat transfer. Solar water heaters with an integrated water tank and with the low temperature energy resource are used as the simplest and cheapest recipient devices of the solar energy for heating and supplying hot water in the buildings. The solar thermal performances of one primitive absorber were determined by using both the experimental and the simulation model of it. All materials applied for absorber such as the cover glass, the black colored sands and the V shaped galvanized plate were submerged into the water. The water storage tank was manufactured from galvanized sheet of 0.0015 m in thickness and the effective area of the collector was 0.67 m2. The absorber was installed on a compact solar water heater. The constructed flat-plate collectors were tested outdoors. However the simulation results showed that the absorbers operated near to the gray materials and all experimental results showed that the thermal efficiencies of the collector are over than 70 %.

Automated internal pipe cutting device

DOEpatents

Godlewski, William J.; Haffke, Gary S.; Purvis, Dale; Bashar, Ronald W.; Jones, Stewart D.; Moretti, Jr., Henry; Pimentel, James

2003-01-21

The invention is a remotely controlled internal pipe cutting device primarily used for cutting pipes where the outside of the pipe is inaccessible at the line where the cut is to be made. The device includes an axial ram within a rotational cylinder which is enclosed in a housing. The housing is adapted for attachment to an open end of the pipe and for supporting the ram and cylinder in cantilever fashion within the pipe. A radially movable cutter, preferably a plasma arc torch, is attached to the distal end of the ram. A drive mechanism, containing motors and mechanical hardware for operating the ram and cylinder, is attached to the proximal end of the housing. The ram and cylinder provide for moving the cutter axially and circumferentially, and a cable assembly attached to a remote motor provide for the movement of the cutter radially, within the pipe. The control system can be adjusted and operated remotely to control the position and movement of the cutter to obtain the desired cut. The control system can also provide automatic standoff control for a plasma arc torch.

[A Case of Recurrent Gastric Cancer with Grade 3 Proteinuria Caused by Ramucirumab plus Paclitaxel Therapy].

PubMed

Kimura, Yutaka; Makari, Yoichi; Mikami, Jota; Hiraki, Yoko; Kato, Hiroaki; Iwama, Mitsuru; Shiraishi, Osamu; Yasuda, Atsushi; Shinkai, Masayuki; Imano, Motohiro; Imamoto, Haruhiko; Fujita, Junya; Furukawa, Hiroshi; Yasuda, Takushi

2017-11-01

Proteinuria is one of the characteristic adverse events by ramucirumab(RAM)plus paclitaxel(PTX)combination therapy for advanced gastric cancer. We reported a case of recurrent gastric cancer with grade(gr)3 proteinuria caused by RAM plus PTX therapy. 77-year-old woman was underwent distal gastrectomy in 76 years old for gastric cancer that was diagnosed mucinous adenocarcinoma, fStage III C(T4aN3H0P0CY0M0)and received adjuvant chemotherapy of S-1 for 1 year. She suffered from peritoneal recurrence with ascites after 1 year and 4 months of the operation and RAM(8mg/kg; day 1 and 15)plus PTX(80mg/m2; day 1, 8 and 15)therapy was administrated as second-line chemotherapy. After 1 course, weekly PTX has been continued for gr 3 proteinuria and the ascites disappeared after 4 courses. This successful case might indicate that it was important for patients with gr 3 proteinuria as adverse event to consider discontinuance of RAM and continuation of PTX according to the proper usage guide of RAM.

Fragment Size Distribution of Blasted Rock Mass

NASA Astrophysics Data System (ADS)

Jug, Jasmin; Strelec, Stjepan; Gazdek, Mario; Kavur, Boris

2017-12-01

Rock mass is a heterogeneous material, and the heterogeneity of rock causes sizes distribution of fragmented rocks in blasting. Prediction of blasted rock mass fragmentation has a significant role in the overall economics of opencast mines. Blasting as primary fragmentation can significantly decrease the cost of loading, transport, crushing and milling operations. Blast fragmentation chiefly depends on the specific blast design (geometry of blast holes drilling, the quantity and class of explosive, the blasting form, the timing and partition, etc.) and on the properties of the rock mass (including the uniaxial compressive strength, the rock mass elastic Young modulus, the rock discontinuity characteristics and the rock density). Prediction and processing of blasting results researchers can accomplish by a variety of existing software’s and models, one of them is the Kuz-Ram model, which is possibly the most widely used approach to estimating fragmentation from blasting. This paper shows the estimation of fragmentation using the "SB" program, which was created by the authors. Mentioned program includes the Kuz-Ram model. Models of fragmentation are confirmed and calibrated by comparing the estimated fragmentation with actual post-blast fragmentation from image processing techniques. In this study, the Kuz-Ram fragmentation model has been used for an open-pit limestone quarry in Dalmatia, southern Croatia. The resulting calibrated value of the rock factor enables the quality prognosis of fragmentation in further blasting works, with changed drilling geometry and blast design parameters. It also facilitates simulation in the program to optimize blasting works and get the desired fragmentations of the blasted rock mass.

Establishment of new design criteria for GlidCop ® X-ray absorbers

DOE PAGES

Collins, Jeff T.; Nudell, Jeremy; Navrotski, Gary; ...

2017-02-20

Here, an engineering research program has been conducted at the Advanced Photon Source (APS) in order to determine the thermomechanical conditions that lead to crack formation in GlidCop ®, a material commonly used to fabricate X-ray absorbers at X-ray synchrotron facilities. This dispersion-strengthened copper alloy is a proprietary material and detailed technical data of interest to the synchrotron community is limited. The results from the research program have allowed new design criteria to be established for GlidCop ® X-ray absorbers based upon the thermomechanically induced fatigue behavior of the material. X-ray power from APS insertion devices was used to exposemore » 30 GlidCop ® samples to 10000 thermal loading cycles each under various beam power conditions, and all of the samples were metallurgically examined for crack presence/geometry. In addition, an independent testing facility was hired to measure temperature-dependent mechanical data and uniaxial mechanical fatigue data for numerous GlidCop ® samples. Data from these studies support finite element analysis (FEA) simulation and parametric models, allowing the development of a thermal fatigue model and the establishment of new design criteria so that the thermomechanically induced fatigue life of X-ray absorbers may be predicted. It is also demonstrated how the thermal fatigue model can be used as a tool to geometrically optimize X-ray absorber designs.« less

Establishment of new design criteria for GlidCop ® X-ray absorbers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Collins, Jeff T.; Nudell, Jeremy; Navrotski, Gary

Here, an engineering research program has been conducted at the Advanced Photon Source (APS) in order to determine the thermomechanical conditions that lead to crack formation in GlidCop ®, a material commonly used to fabricate X-ray absorbers at X-ray synchrotron facilities. This dispersion-strengthened copper alloy is a proprietary material and detailed technical data of interest to the synchrotron community is limited. The results from the research program have allowed new design criteria to be established for GlidCop ® X-ray absorbers based upon the thermomechanically induced fatigue behavior of the material. X-ray power from APS insertion devices was used to exposemore » 30 GlidCop ® samples to 10000 thermal loading cycles each under various beam power conditions, and all of the samples were metallurgically examined for crack presence/geometry. In addition, an independent testing facility was hired to measure temperature-dependent mechanical data and uniaxial mechanical fatigue data for numerous GlidCop ® samples. Data from these studies support finite element analysis (FEA) simulation and parametric models, allowing the development of a thermal fatigue model and the establishment of new design criteria so that the thermomechanically induced fatigue life of X-ray absorbers may be predicted. It is also demonstrated how the thermal fatigue model can be used as a tool to geometrically optimize X-ray absorber designs.« less

Discriminating electromagnetic radiation based on angle of incidence

DOEpatents

Hamam, Rafif E.; Bermel, Peter; Celanovic, Ivan; Soljacic, Marin; Yeng, Adrian Y. X.; Ghebrebrhan, Michael; Joannopoulos, John D.

2015-06-16

The present invention provides systems, articles, and methods for discriminating electromagnetic radiation based upon the angle of incidence of the electromagnetic radiation. In some cases, the materials and systems described herein can be capable of inhibiting reflection of electromagnetic radiation (e.g., the materials and systems can be capable of transmitting and/or absorbing electromagnetic radiation) within a given range of angles of incidence at a first incident surface, while substantially reflecting electromagnetic radiation outside the range of angles of incidence at a second incident surface (which can be the same as or different from the first incident surface). A photonic material comprising a plurality of periodically occurring separate domains can be used, in some cases, to selectively transmit and/or selectively absorb one portion of incoming electromagnetic radiation while reflecting another portion of incoming electromagnetic radiation, based upon the angle of incidence. In some embodiments, one domain of the photonic material can include an isotropic dielectric function, while another domain of the photonic material can include an anisotropic dielectric function. In some instances, one domain of the photonic material can include an isotropic magnetic permeability, while another domain of the photonic material can include an anisotropic magnetic permeability. In some embodiments, non-photonic materials (e.g., materials with relatively large scale features) can be used to selectively absorb incoming electromagnetic radiation based on angle of incidence.

Apollo couch energy absorbers

NASA Technical Reports Server (NTRS)

Wesselski, C. J.; Drexel, R. E.

1972-01-01

Load attenuators for the Apollo spacecraft crew couch and its potential applications are described. Energy absorption is achieved through friction and cyclic deformation of material. In one concept, energy absorption is accomplished by rolling a compressed ring of metal between two surfaces. In another concept, energy is absorbed by forcing a plastically deformed washer along a rod. Among the design problems that had to be solved were material selection, fatigue life, ring slippage, lubrication, and friction loading.

Optical supercavitation in soft matter.

PubMed

Conti, C; DelRe, E

2010-09-10

We investigate theoretically, numerically, and experimentally nonlinear optical waves in an absorbing out-of-equilibrium colloidal material at the gelification transition. At a sufficiently high optical intensity, absorption is frustrated and light propagates into the medium. The process is mediated by the formation of a matter-shock wave due to optically induced thermodiffusion and largely resembles the mechanism of hydrodynamical supercavitation, as it is accompanied by a dynamic phase-transition region between the beam and the absorbing material.

Optical Supercavitation in Soft Matter

NASA Astrophysics Data System (ADS)

Conti, C.; Delre, E.

2010-09-01

We investigate theoretically, numerically, and experimentally nonlinear optical waves in an absorbing out-of-equilibrium colloidal material at the gelification transition. At a sufficiently high optical intensity, absorption is frustrated and light propagates into the medium. The process is mediated by the formation of a matter-shock wave due to optically induced thermodiffusion and largely resembles the mechanism of hydrodynamical supercavitation, as it is accompanied by a dynamic phase-transition region between the beam and the absorbing material.

Material Model Evaluation of a Composite Honeycomb Energy Absorber

NASA Technical Reports Server (NTRS)

Jackson, Karen E.; Annett, Martin S.; Fasanella, Edwin L.; Polanco, Michael A.

2012-01-01

A study was conducted to evaluate four different material models in predicting the dynamic crushing response of solid-element-based models of a composite honeycomb energy absorber, designated the Deployable Energy Absorber (DEA). Dynamic crush tests of three DEA components were simulated using the nonlinear, explicit transient dynamic code, LS-DYNA . In addition, a full-scale crash test of an MD-500 helicopter, retrofitted with DEA blocks, was simulated. The four material models used to represent the DEA included: *MAT_CRUSHABLE_FOAM (Mat 63), *MAT_HONEYCOMB (Mat 26), *MAT_SIMPLIFIED_RUBBER/FOAM (Mat 181), and *MAT_TRANSVERSELY_ANISOTROPIC_CRUSHABLE_FOAM (Mat 142). Test-analysis calibration metrics included simple percentage error comparisons of initial peak acceleration, sustained crush stress, and peak compaction acceleration of the DEA components. In addition, the Roadside Safety Verification and Validation Program (RSVVP) was used to assess similarities and differences between the experimental and analytical curves for the full-scale crash test.

Energy absorber uses expanded coiled tube

NASA Technical Reports Server (NTRS)

Johnson, E. F.

1972-01-01

Mechanical shock mitigating device, based on working material to its failure point, absorbs mechanical energy by bending or twisting tubing. It functions under axial or tangential loading, has no rebound, is area independent, and is easy and inexpensive to build.

Techno-Economic Analysis of Solar Water Heating Systems inTurkey.

PubMed

Ertekin, Can; Kulcu, Recep; Evrendilek, Fatih

2008-02-25

In this study, solar water heater was investigated using meteorological and geographical data of 129 sites over Turkey. Three different collector types were compared in terms of absorber material (copper, galvanized sheet and selective absorber). Energy requirement for water heating, collector performances, and economical indicators were calculated with formulations using observed data. Results showed that selective absorbers were most appropriate in terms of coverage rate of energy requirement for water-heating all over Turkey. The prices of selective, copper and galvanized absorber type's heating systems in Turkey were 740.49, 615.69 and 490.89 USD, respectively. While payback periods (PBPs) of the galvanized absorber were lower, net present values (NPVs) of the selective absorber were higher than the rest. Copper absorber type collectors did not appear to be appropriate based on economical indicators.

Techno-Economic Analysis of Solar Water Heating Systems in Turkey

PubMed Central

Ertekin, Can; Kulcu, Recep; Evrendilek, Fatih

2008-01-01

In this study, solar water heater was investigated using meteorological and geographical data of 129 sites over Turkey. Three different collector types were compared in terms of absorber material (copper, galvanized sheet and selective absorber). Energy requirement for water heating, collector performances, and economical indicators were calculated with formulations using observed data. Results showed that selective absorbers were most appropriate in terms of coverage rate of energy requirement for water-heating all over Turkey. The prices of selective, copper and galvanized absorber type's heating systems in Turkey were 740.49, 615.69 and 490.89 USD, respectively. While payback periods (PBPs) of the galvanized absorber were lower, net present values (NPVs) of the selective absorber were higher than the rest. Copper absorber type collectors did not appear to be appropriate based on economical indicators. PMID:27879764

Realization of Minimum and Maximum Gate Function in Ta2O5-based Memristive Devices

NASA Astrophysics Data System (ADS)

Breuer, Thomas; Nielen, Lutz; Roesgen, Bernd; Waser, Rainer; Rana, Vikas; Linn, Eike

2016-04-01

Redox-based resistive switching devices (ReRAM) are considered key enablers for future non-volatile memory and logic applications. Functionally enhanced ReRAM devices could enable new hardware concepts, e.g. logic-in-memory or neuromorphic applications. In this work, we demonstrate the implementation of ReRAM-based fuzzy logic gates using Ta2O5 devices to enable analogous Minimum and Maximum operations. The realized gates consist of two anti-serially connected ReRAM cells offering two inputs and one output. The cells offer an endurance up to 106 cycles. By means of exemplary input signals, each gate functionality is verified and signal constraints are highlighted. This realization could improve the efficiency of analogous processing tasks such as sorting networks in the future.

Lightweight and efficient microwave absorbing materials based on walnut shell-derived nano-porous carbon.

PubMed

Qiu, Xu; Wang, Lixi; Zhu, Hongli; Guan, Yongkang; Zhang, Qitu

2017-06-08

Lightweight microwave absorbing materials have drawn tremendous attention. Herein, nano-porous biomass carbon materials have been prepared by carbonization with a subsequent potassium hydroxide activation of walnut shells and the microwave absorption properties have also been investigated. The obtained samples have large specific surface areas with numerous micropores and nanopores. The sample activated at 600 °C with a specific surface area of 736.2 m 2 g -1 exhibits the most enhanced microwave absorption performance. It has the maximum reflection loss of -42.4 dB at 8.88 GHz and the effective absorption bandwidth (reflection loss below -10 dB) is 1.76 GHz (from 8.08 GHz to 9.84 GHz), corresponding to a thickness of 2 mm. Additionally, the effective absorption bandwidth can reach 2.24 GHz (from 10.48 GHz to 12.72 GHz) when the absorber thickness is 1.5 mm. Three-dimensional porous architecture, interfacial polarization relaxation loss, and the dipolar relaxation loss make a great contribution to the excellent microwave absorption performance. In contrast, the non-activated sample with lower specific surface area (435.3 m 2 g -1 ) has poor microwave absorption performance due to a poor dielectric loss capacity. This comparison highlights the role of micropores and nanopores in improving the dielectric loss property of porous carbon materials. To sum up, porous biomass carbon has great potential to become lightweight microwave absorbers. Moreover, KOH is an efficient activation agent in the fabrication of carbonaceous materials.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schuett, K.J.; Pawlak, J.P.; Traina, L.

No. 13 Blast Furnace at US Steel`s Gary Works is a 35 tuyere furnace with a 36.5 ft. hearth capable of producing over 9,000 tons of hot metal per day. The current casthouse design was placed in service following the second reline in the fall of 1979. This design anticipated daily production rates averaging 7,500 tons of hot metal per day and provided for removable troughs at two of the three tapholes. At the time, the troughs were rammed with a high alumina/silicon carbide granular ramming material that provided the operators with trough campaign lives between 60,000--70,000 tons of hotmore » metal produced. As refractory technology progressed, low cement/low moisture castables were introduced to the trough systems on No. 13 Blast Furnace. The immediate success of the castables was tempered by emergence of a new unexpected problem. That problem was the thermal expansion of the castable. The paper describes the problems that resulted in the need to modify the trough design, the new design of the trough, and its improvement in iron trough campaign life and reliability.« less

Organic matrix composite protective coatings for space applications

NASA Technical Reports Server (NTRS)

Dursch, Harry W.; George, Pete

1995-01-01

Successful use of composites in low earth orbit (LEO) depends on their ability to survive long-term exposure to atomic oxygen (AO), ultraviolet radiation, charged particle radiation, thermal cycling, and micrometeoroid and space debris. The AO environment is especially severe for unprotected organic matrix composites surfaces in LEO. Ram facing unprotected graphite/epoxy flown on the 69-month Long Duration Exposure Facility (LDEF) mission lost up to one ply of thickness (5 mils) resulting in decreased mechanical properties. The expected AO fluence of the 30 year Space Station Alpha mission is approximately 20 times that seen on LDEF. This exposure would result in significant material loss of unprotected ram facing organic matrix composites. Several protective coatings for composites were flown on LDEF including anodized aluminum, vacuum deposited coatings, a variety of thermal control coatings, metalized Teflon, and leafing aluminum. Results from the testing and analysis of the coated and uncoated composite specimens flown on LDEF's leading and trailing edges provide the baseline for determining the effectiveness of protectively coated composites in LEO. In addition to LDEF results, results from shuttle flight experiments and ground based testing will be discussed.

A study of the switching mechanism and electrode material of fully CMOS compatible tungsten oxide ReRAM

NASA Astrophysics Data System (ADS)

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.

Infertility in a Ram Associated with a Knobbed Acrosome Abnormality of the Spermatozoa

PubMed Central

Savage, N. C.

1984-01-01

A yearling Rambouillet ram with an asymmetrical scrotum was examined for potential breeding soundness prior to use in a synchronized mating program in a purebred flock of 20 ewes. Initial sperm cell evaluation revealed 78% knobbed acrosomes associated with few other abnormalities of the head and midpiece. Use of the ram resulted in no conception in one group of ten synchronized ewes. One month later, the proportion of sperm cells with knobbed acrosomes was 80%. ImagesFigure 1.Figure 2. PMID:17422370

Non-Volatile Memory Technology Symposium 2001: Proceedings

NASA Technical Reports Server (NTRS)

Aranki, Nazeeh; Daud, Taher; Strauss, Karl

2001-01-01

This publication contains the proceedings for the Non-Volatile Memory Technology Symposium 2001 that was held on November 7-8, 2001 in San Diego, CA. The proceedings contains a a wide range of papers that cover current and new memory technologies including Flash memories, Magnetic Random Access Memories (MRAM and GMRAM), Ferro-electric RAM (FeRAM), and Chalcogenide RAM (CRAM). The papers presented in the proceedings address the use of these technologies for space applications as well as radiation effects and packaging issues.

Additive manufacturing of RF absorbers

NASA Astrophysics Data System (ADS)

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.

The “ram effect”: new insights into neural modulation of the gonadotropic axis by male odors and socio-sexual interactions

PubMed Central

Fabre-Nys, Claude; Kendrick, Keith M.; Scaramuzzi, Rex J.

2015-01-01

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 luteinizing hormone (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 4 h) 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 2 h 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 also the specific mechanisms by which male cues can overcome negative steroid feedback and trigger LH release and ovulatory cycles. PMID:25914614

Fertility in South Australian commercial Merino flocks: aspects of management.

PubMed

Kleemann, David O; Grosser, Timothy I; Walker, Simon K

2006-05-01

Wide variation in reproductive performance of commercial Merino flocks in south central Australia is the result of genetic and environmental influences that are both amenable to change through decisions of management. Relationships of reproductive traits (estrus, ovulation, fertility, fecundity, lamb survival, and lambs weaned) with variables that graziers can change or modify (strain of Merino, day or month of exposure of ewes to rams, ram effect or teasing, length of the mating period, ram percentage, days between weaning and next mating, stocking density and flock size at lambing, ewe liveweight, and condition) are reported in this paper, the third in a series. Small differences were observed between medium and strong-wool South Australian Merino strains for reproductive traits. Choosing the time of year that ewes are exposed to rams, between late spring to autumn, may result in reduced ovulation rate during early summer (December) giving a potentially smaller net reproductive efficiency (lambs weaned). The ram effect or teasing, used by about 50% of graziers to synchronise lambing, could be effectively employed to the end of January. The technique was not reproductively advantageous when compared with flocks that were not teased. The percentage of rams mated to ewes varied widely (approximately 1-3%) and did not alter flock fertility, suggesting that a substantial proportion of graziers could safely reduce the number of rams purchased. A positive relationship between incidence of estrus during the first 14 d of the cycle and the number of days from weaning to next mating and a negative relationship of returns to service with the same variable indicates that managers should consider increasing the time allowed for recovery of liveweight and body condition by adjusting age at weaning, length of the mating period, or both. Lamb survival was curvilinearly related to flock size and not stocking intensity, with the optimum size at about 400 ewes. The number of lambs weaned per 100 ewes exposed to rams increased by 1.0 kg(-1) increase in liveweight at mating. We concluded that the major factor controlling net reproductive efficiency is nutritional in origin through its effects on ewe liveweight and condition, and is a factor that can be largely manipulated through management.

Rare emergence of drug resistance in HIV-1 treatment-naïve patients receiving elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide for 144 weeks.

PubMed

Margot, Nicolas; Cox, Stephanie; Das, Moupali; McCallister, Scott; Miller, Michael D; Callebaut, Christian

2018-06-01

The single tablet regimen (STR) composed of elvitegravir (E), cobicistat (C), emtricitabine (F), and tenofovir alafenamide (TAF) (E/C/F/TAF) was compared to the STR composed of E, C, F, and tenofovir disoproxil fumarate (TDF) (E/C/F/TDF) in 2 phase 3 studies in 1733 HIV-1 infected treatment-naïve adults. Superior efficacy of E/C/F/TAF compared to E/C/F/TDF was demonstrated at Week 144 with 84% treatment success compared to 80%, respectively, along with significantly better outcomes of bone and renal safety. Analyze the emergence of HIV-1 resistance in treatment-naïve adults receiving E/C/F/TAF for 144 weeks. We conducted an integrated resistance analysis of the 2 Phase 3 studies, comprising pretreatment HIV-1 sequencing for all participants (N = 1733) and post-baseline HIV-1 resistance analysis for participants with virologic failure (HIV-1 RNA ≥400 copies/mL). Primary resistance-associated mutations (RAMs) were observed pre-treatment in 7.4% (NRTI-RAMs), 18.1% (NNRTI-RAMs), and 3.3% (PI-RAMs) of enrolled subjects. Baseline HIV-1 subtype or pre-existing RAMs did not affect E/C/F/TAF treatment response at week 144. Virologic failure resistance analyses were conducted for 28/866 (3.2%) and 30/867 (3.5%) patients in the E/C/F/TAF and E/C/F/TDF arms, respectively. Over the 3-year study, the rate of resistance emergence remained low at 1.4% in each group (12/866 in E/C/F/TAF; 12/867 in E/C/F/TDF). Resistant virus emerged in 24 patients who developed resistance to antiretrovirals in the regimens (E/C/F/TAF: M184V/I [1.3%], INSTI-RAMs [0.9%], K65R/N [0.2%]; E/C/F/TDF: M184V/I [1.0%], INSTI-RAMs [0.9%], K65R/N [0.5%]). Resistance emergence was rare (1.4%) with similar patterns of emergent mutations in both groups. M184V/I was the most prevalent RAM (1.2% overall). Copyright © 2018 Elsevier B.V. All rights reserved.

The Aspects About of Objectively Appraisals of Modeling Gypsum Quality and Composites of Phonic-Absorbent and Orthopedic on Base of Gypsum

NASA Astrophysics Data System (ADS)

Pop, P. A.; Ungur, P. A.; Lazar, L.; Marcu, F.

2009-11-01

The EU Norms about of protection environment, outside and inside ambient, and human health demands has lead at obtain of new materials on the base of airborne material, with high thermo and phonic-absorbent properties, porous and lightweight. The α and β-modeling gypsum plaster quality and lightweight depend on many factors as: fabrication process, granulation, roast temperature, work temperature, environment, additives used, breakage, etc. Also, the objectively appraisal of modeling gypsum quality depends of proper tests methods selection, which are legislated in norms, standards and recommendations. In Romanian Standards SR EN 13279-1/2005 and SR EN 13279-2/2005, adaptable from EU Norms EN 13279-1/2004 and EN 13279-2/2004, the characteristics gypsum family tests are well specification, as: granule-metric analysis, determination of water/plaster ratio, setting time, mechanical characteristics, adhesions and water restrain. For plaster with special use (phonic-absorbent and orthopedic materials, etc.) these determinations are not concluding, being necessary more parameters finding, as: elastic constant, phonic-absorbent coefficient, porosity, working, etc., which is imposed the completion of norms and standards with new determinations.

Carbonyl iron powder surface modification of magnetorheological elastomers for vibration absorbing application

NASA Astrophysics Data System (ADS)

Chen, Dong; Yu, Miao; Zhu, Mi; Qi, Song; Fu, Jie

2016-11-01

With excellent characteristic of magnetic-control stiffness, magnetorheological elastomer (MRE) is well suited as a spring element of vibration absorber. To improve the vibration attenuation performance of MRE vibration absorbers, this paper expects to improve the mechanical strength and reduce the loss factor of MRE by interface modification. The surface of carbonyl iron powder (CIP) was modified with silica coating by a simple and convenient approach. Several MRE samples, with different proportions of modified CIPs were fabricated under a constant magnetic field. The morphology and composition of modified CIP were characterized by scanning electron microscope and Fourier transform infrared spectra. The results indicated that the modified CIPs were coated with uniform and continuous silica, which can make a better combination between particle and matrix. The tensile strength, magnetorheological properties and the damping properties of the MRE samples were tested by material testing machine and rheometer. The experimental results demonstrated that the loss factor of the MRE which incorporated with modified CIPs decreased markedly, and the tensile strength of such material has been much improved, at the same time this kind of MRE kept high MR effect. It is expected that this MRE material will meet the requirements of vibration absorber.

Mechanical and optical characterization of bio-nanocomposite from pineapple leaf fiber material for food packaging

NASA Astrophysics Data System (ADS)

Nikmatin, Siti; Rudwiyanti, Jerry R.; Prasetyo, Kurnia W.; Yedi, Dwi A.

2015-01-01

The utilization of Bio-nanocomposite material that was derived from pineapple leaf fiber as filler and tapioca starch with plasticizer glycerol as a matrix for food packaging can reduce the use of plastic that usually was made from petroleum materials. It is important to develop and producethis environmental friendly plastic because of limited availability of petroleum nowadays. The process of synthesize and characterization tapioca starch with the plasticizer glycerol bionanocomposites using print method had been conducted. There were 3 samples with different filler concentration variation; 3%, 4% and 5%.The results of mechanical test from each sample showed that bio-nanocomposite with 5% filler concentration was the optimum sample with 4.6320 MPa for tensile strength test and 24.87% for the elongation test. Based on the result of optical test for each sample was gained that along with the increasing of concentration filler would make the absorbance value of the sample became decreased, bio-nanocomposite with 5% filler concentration had several peaks with low absorbance values. The first peak was in 253 nm of wavelength regionwith absorbance of 0.131%, and the second peak was in 343 nmwavelength region and absorbance was 0.087%.

Porcelain enamel neutron absorbing material

DOEpatents

Iverson, D.C.

1987-11-20

A porcelain enamel composition as a neutron absorbing material can be prepared of a major proportion by weight of a cadmium compound and a minor proportion of compound of boron, lithium and silicon. These compounds in the form of a porcelain enamel coating or layer on several alloys has been found to be particularly effective in enhancing the nuclear safety of equipment for use in the processing and storage of fissile material. The composition of the porcelain enamel coating can be tailored to match the coefficient of thermal expansion of the equipment to be coated and excellent coating adhesion can be achieved. 2 figs.

Porcelain enamel neutron absorbing material

DOEpatents

Iverson, Daniel C.

1990-01-01

A porcelain enamel composition as a neutron absorbing material can be prepared of a major proportion by weight of a cadmium compound and a minor proportion of compounds of boron, lithium and silicon. These compounds in the form of a porcelain enamel coating or layer on several alloys has been found to be particularly effective in enhancing the nuclear safety of equipment for use in the processing and storage of fissile material. The composition of the porcelain enamel coating can be tailored to match the coefficient of thermal expansion of the equipment to be coated and excellent coating adhesion can be achieved.

Porcelain enamel neutron absorbing material

DOEpatents

Iverson, Daniel C.

1990-02-06

A porcelain enamel composition as a neutron absorbing material can be prepared of a major proportion by weight of a cadmium compound and a minor proportion of compounds of boron, lithium and silicon. These compounds in the form of a porcelain enamel coating or layer on several alloys has been found to be particularly effective in enhancing the nuclear safety of equipment for use in the processing and storage of fissile material. The composition of the porcelain enamel coating can be tailored to match the coefficient of thermal expansion of the equipment to be coated and excellent coating adhesion can be achieved.

The Development of a Ram Air Decelerator for the Recovery of Artillery Shells

DTIC Science & Technology

1993-01-01

number of specialized services help round out the - rogram’s diverse offerings, including creating custom thesauri, translating material to or from...the Internet to help((i sti.nasa.gov "* Write to: Accesslon For NASA Access Help Desk I IS QRA&I , NASA Center for AeroSpace Information DTIC TAB 0...radial linesNme N,,,no Defnii’ projecting from the center outwards midway aeaewute, tips Wn R• • 6. 7& Wm of each of die lobes. When spmn, the sea

Reverse Logistics at the Commander, Naval Surface Forces Real-time & Reutilization Asset Management (R-RAM) San Diego Warehouse

DTIC Science & Technology

2008-12-01

Asset Management) in December 2000 when the system was converted from UADPS to a Commercial-of-the-Shelf (COTS) product from a company called Lawson...materials and disposal (Stock, 1992, p. 25). In 1998, Carter and Ellram stated that Reverse Logistics is a process whereby companies can become...35 billion (p. 275). In the white paper authored by Dr. James Stock in 1998, he highlighted the benefits achieved by companies practicing reverse

Ultrafast Target Recognition via Super-Parallel Holograph Based Correlator, RAM and Associative Memory

DTIC Science & Technology

2008-03-11

JTC) 2𔃾 based on a dynamic material answers the challenge of fast correlation with large databases. Images retrieved from the SPHRAM and used as the...transform (JTC) and matched spatial filter or VanderLugt ( VLC ) correlators, either of which can be implemented in real-time by degenerate four wave-mixing in...proposed system, consisting of the SPHROM coupled with a shift-invariant real-time VLC . The correlation is performed in the VLC architecture to

An Evaluation of the Service Failure of Aluminum Nose Cones Using Four Test Techniques.

DTIC Science & Technology

1987-03-01

13 LIST OF ILLUSTRATIONS 1. Schematic of nose cone. 14 2. Subsize Charpy specimen. 15 3. Simulation test fixture. 16 4. Force displacement plot from...Figure 1. Schematic of nose cone. 14 LD 0.06 03-a 0.30L IL 1.602 Figure 2. Subsize Charpy specimen. i5 RAM DISPLACEMENT COLLART WV Ualz APPLIED FORCE...between threaded and tapered regions. In all, four measurements were made on each nose cone. The two material property measurements were made using Charpy

Solar concentrator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Melchior, B.

1984-04-03

A solar concentrator comprises a solid block of a transparent material having a planar incident surface positioned to receive solar rays and, opposite this surface, a curved reflective surface so that the material of the block completely fills the space between these surfaces. At the incident surface an absorber is provided and the curvature of the reflective surface is such that it is at least partly parabolical and adapted to reflect solar rays traversing the body through the body again to the absorber.

’Head-On’ Scattering of a Tubular Cylinder of Finite Length for Radar Target Identification Purposes

DTIC Science & Technology

1985-03-01

environment. The anechoic chamber is enclosed with aluminium plates and internally lined with a radio frequency absorbing material. The absorbing material...provides the necessary attenuation to the reflections from the walls, floor and ceiling, and the aluminium surface provides protection against external...inch aluminium sphere is used. Some measurements are taken with a cylinder with fins attached .The description of the cylinder with fins is shown in

Fluorescent refrigeration

DOEpatents

Epstein, Richard I.; Edwards, Bradley C.; Buchwald, Melvin I.; Gosnell, Timothy R.

1995-01-01

Fluorescent refrigeration is based on selective radiative pumping, using substantially monochromatic radiation, of quantum excitations which are then endothermically redistributed to higher energies. Ultimately, the populated energy levels radiatively deexcite emitting, on the average, more radiant energy than was initially absorbed. The material utilized to accomplish the cooling must have dimensions such that the exciting radiation is strongly absorbed, but the fluorescence may exit the material through a significantly smaller optical pathlength. Optical fibers and mirrored glasses and crystals provide this requirement.

Fluorescent refrigeration

DOEpatents

Epstein, R.I.; Edwards, B.C.; Buchwald, M.I.; Gosnell, T.R.

1995-09-05

Fluorescent refrigeration is based on selective radiative pumping, using substantially monochromatic radiation, of quantum excitations which are then endothermically redistributed to higher energies. Ultimately, the populated energy levels radiatively deexcite emitting, on the average, more radiant energy than was initially absorbed. The material utilized to accomplish the cooling must have dimensions such that the exciting radiation is strongly absorbed, but the fluorescence may exit the material through a significantly smaller optical pathlength. Optical fibers and mirrored glasses and crystals provide this requirement. 6 figs.

Optical response of strongly absorbing inhomogeneous materials: Application to paper degradation

NASA Astrophysics Data System (ADS)

Missori, M.; Pulci, O.; Teodonio, L.; Violante, C.; Kupchak, I.; Bagniuk, J.; Łojewska, J.; Conte, A. Mosca

2014-02-01

In this paper, we present a new noninvasive and nondestructive approach to recover scattering and absorption coefficients from reflectance measurements of highly absorbing and optically inhomogeneous media. Our approach is based on the Yang and Miklavcic theoretical model of light propagation through turbid media, which is a generalization of the Kubelka-Munk theory, extended to accommodate optically thick samples. We show its applications to paper, a material primarily composed of a web of fibers of cellulose, whose optical properties are strongly governed by light scattering effects. Samples studied were ancient and industrial paper sheets, aged in different conditions and highly absorbing in the ultraviolet region. The recovered experimental absorptions of cellulose fibers have been compared to theoretical ab initio quantum-mechanical computational simulations carried out within time-dependent density functional theory. In this way, for each sample, we evaluate the absolute concentration of different kinds of oxidized groups formed upon aging and acting as chromophores causing paper discoloration. We found that the relative concentration of different chromophores in cellulose fibers depends on the aging temperature endured by samples. This clearly indicates that the oxidation of cellulose follows temperature-dependent reaction pathways. Our approach has a wide range of applications for cellulose-based materials, like paper, textiles, and other manufactured products of great industrial and cultural interest, and can potentially be extended to other strongly absorbing inhomogeneous materials.

Application of Absorbable Hemostatic Materials Observed in Thyroid Operation

NASA Astrophysics Data System (ADS)

Li, Yan-Ming; Liang, Zhen-Zhen; Song, Yan

2016-05-01

To observe the application effects of the absorbable hemostatic materials in thyroid operation. Methods: From May 2014 to January 2015, 100 patients with thyroid surgery in our university affiliated hospital were selected as the research object. Randomly divided into experimental group and control group, 50 cases in each group. Application of absorbable hemostatic hemostatic materials in the experimental group during the operation, the control group using the traditional mechanical methods of hemostasis hemostasis to observe the operation time, bleeding volume, postoperative drainage volume, complications and hospital stay of the two groups. Results: The operation time, bleeding volume, postoperative drainage and hospital stay in the experimental group were significantly lower in the study group than in the control group, and the difference between the two groups was statistically significant (P< 0.05); The satisfaction of patients in the experimental group was significantly higher than that in the control group, the difference was statistically significant in the two groups (P < 0.05); There was no significant difference in the incidence of wound bleeding complications between the study group and the control group (P > 0.05). Conclusion: Absorbable hemostatic materials can effectively shorten the operation time, reduce intraoperative blood loss and postoperative drainage, reduce the length of hospital stay and improve the success rate of surgery and patient satisfaction, which is worthy to be popularized in clinical thyroid surgery.

Solar sustained plasma/absorber conceptual design

NASA Technical Reports Server (NTRS)

Rodgers, R. J.; Krascella, N. L.; Kendall, J. S.

1979-01-01

A space power system concept was evaluated which uses concentrated solar energy to heat a working fluid to temperatures as high as 4000 K. The high temperature working fluid could be used for efficient electric power production in advanced thermal or magnetohydrodynamic conversion cycles. Energy absorber configurations utilizing particles or cesium vapor absorber material were investigaed. Results of detailed radiant heat transfer calculations indicated approximately 86 percent of the incident solar energy could be absorbed within a 12-cm-dia flowing stream of gas borne carbon particles. Calculated total energy absorption in the cesium vapor seeded absorber configuration ranged from 34 percent to 64 percent of the incident solar energy. Solar flux concentration ratios of between approximately 3000 and 10,000 will be required to sustain absorber temperatures in the range from 3000 K to 4000 K.

Repair of orbital floor fractures with absorbable gelatin film.

PubMed

Mermer, R W; Orban, R E

1995-01-01

Many materials have been utilized for the repair of orbital floor fractures. Absorbable gelatin film is a bioabsorbable sheeting material that is manufactured from denatured collagen. This material is appropriate for the repair of smaller orbital floor defects (5 mm or less) and trapdoor-type fractures; it is used with larger defects as an interpositional graft material between the periorbital tissues and as an orbital floor reconstruction plate or mesh. Sixteen cases consisting of both types of defects were retrospectively examined clinically and radiographically. Satisfactory results were obtained in all of these cases, including no adverse ocular signs or implant rejection, good facial form, good function, and acceptable postoperative radiography results.

Wave Absorber with Fine Weatherability for Improving ETC Environment

NASA Astrophysics Data System (ADS)

Miura, Yu; Matsumoto, Kouta; Okada, Osamu; Hashimoto, Osamu

Wave absorber of rubber sheet containing natural rubber and EPDM is designed, fabricated and measured for improving ETC environment. As a result, proposed absorption material has fine weatherability and wave absorption satisfied with ETC standard can be realized theoretically before and after the weatherability test if the thickness of absorber is fabricated at the ranging from 2.26mm to 2.52mm. Moreover, absorber sheet sample based on theoretical values is fabricated and are measured. As a result, 20dB or more is also confirmed at the incident angle ranging from 5 to 55 degrees experimentally. Therefore, the wave absorber with fine weatherability being satisfied with ETC standard can be realized.

77 FR 49434 - 36(b)(1) Arms Sales Notification

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-16

... Standard (RAM/RS), with ancillary equipment, and machine guns. Also included are the upgrade of Brazil's... Maintainability/Rebuild to Standard (RAM/RS), with ancillary equipment, and machine guns. Also included are the...

Precise Restraightening of Bent Studs

NASA Technical Reports Server (NTRS)

Boardman, R. E.

1982-01-01

Special tool quickly bends studs back into shape accurately and safely by force applied by hydraulic ram, with deflection being measured by dial indicator. Ram and indicator can be interchanged for straightening in reverse direction.

Wireless data over RAM's Mobitex network

NASA Astrophysics Data System (ADS)

Khan, M. Mobeen

1995-12-01

Mobitex is a mobile data technology standard created by Eritel, now a wholly owned subsidiary of Ericsson, that has been in existence for about a decade. Originally designed as a low speed (1.2 kbps) data system with a voice dispatch overlay, it was significantly enhanced in 1990 for use in North America and the UK. The enhanced system is a data-only system using cellular architecture and multi-channel frequency reuse, store-and-forward capability, and an 8 kbps over-the-air data rate. The mission of RAM Mobile Data USA Limited Partnership ('RAM') is to provide high quality, cost efficient, wireless data communications solutions in its targeted market segments. RAM's Mobitex network is currently one of the two networks providing two way wireless data services nationwide using a long distance service provider of the customer's choice.