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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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All sourcesNASA NTRSDOE OSTI
NASA NTRS1989

Aerospace Vehicle Design, Spacecraft Section. Volume 1: Project Groups 3-5

Three groups of student engineers in an aerospace vehicle design course present their designs for a vehicle that can be used to resupply the Space Station Freedom and provide an emergency crew return to earth capability. The vehicle's requirements include a lifetime that exceeds six years, low cost, the capability for withstanding pressurization, launch, orbit, and reentry hazards, and reliability. The vehicle's subsystems are analyzed. These subsystems are structures, communication and command data systems, attitude and articulation control, life support and crew systems, power and propulsion, reentry and recovery systems, and mission management, planning, and costing.

Source record↗
DOE OSTI2011

Comparison of Four Cisplatin-Based Radiochemotherapy Regimens for Nonmetastatic Stage III/IV Squamous Cell Carcinoma of the Head and Neck;Head-and-neck cancer; Cisplatin-based radiochemotherapy; Toxicity; Treatment outcomes

Purpose: To compare the outcomes of four cisplatin-based radiochemotherapy regimens in 311 patients with Stage III/IV squamous cell carcinoma of the head and neck. Methods and Materials: Concurrent chemotherapy consisted of three courses of cisplatin 100 mg/m{sup 2} on Day 1 (Group A, n = 74), two courses of cisplatin 20 mg/m{sup 2} on Days 1-5 plus 5-fluorouracil 1,000 mg/m{sup 2} on Days 1-5 (Group B, n = 49), two courses of cisplatin 20 mg/m{sup 2} on Days 1-5 plus 5-fluorouracil 600 mg/m{sup 2} on Days 1-5 (Group C, n = 102), or two courses of cisplatin 20 mg/m{sup 2} on Days 1-5 (Group D, n = 86). The groups were retrospectively compared for toxicity and outcomes, and 11 additional factors were evaluated for outcomes. Results: No significant difference was observed among the groups regarding radiation-related acute oral mucositis and radiation-related late toxicities. Acute Grade 3 skin toxicity was significantly more frequent in Group B than in the patients of the other three groups (p = .013). The chemotherapy-related Grade 3 nausea/vomiting rate was 24% for Group A, 8% for Group B, 9% for Group C, and 6% for Group D (p = .003). The corresponding Grade 3 nephrotoxicity rates were 8%, 1%, 2%, and 1% (p = .019). The corresponding Grade 3-4 hematologic toxicity rates were 35%, 41%, 19%, and 21% (p = .027). Chemotherapy could be completed in 50%, 59%, 74%, and 83% of the Group A, B, C, and D patients, respectively (p = .002). Toxicity-related radiotherapy breaks occurred in 39%, 43%, 21%, and 15% of Groups A, B, C, and D, respectively (p = .005). The 3-year locoregional control rate was 67%, 72%, 60%, and 59% for Groups A, B, C, and D, respectively (p = .48). The corresponding 3-year metastasis-free survival rates were 67%, 74%, 63%, and 79% (p = .31), and the corresponding 3-year survival rates were 60%, 63%, 50%, and 71% (p = .056). On multivariate analysis, Karnofsky performance status, histologic grade, T/N category, preradiotherapy hemoglobin level, completion of chemotherapy, and radiotherapy breaks were associated with the outcome. Conclusion: The four compared radiochemotherapy regimens were not significantly different regarding treatment outcomes. Two courses of cisplatin 20 mg/m{sup 2} on Days 1-5 were better tolerated than the other three regimens.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Status of Cross-section Data Libraries for MCNP

The Data Team, part of the XCP-5 group at LANL, uses the NJOY code and other codes to prepare the cross-section data files used by the Monte Carlo codes MCNP5, MCNPX, and MCNP6. They perform extensive quality assurance checking of those data files. The cross-section data files are included with the releases of MCNP that are distributed by RSICC. MCNP5 is developed and supported by the Monte Carlo Codes group (XCP-3) at LANL. MCNPX is developed and supported by the NEN-5 group at LANL. MCNP6 is a merger of MCNP5 and MCNPX, with numerous additional features, and is jointly developed and supported by the XCP-3 and NEN-5 groups. MCNP5 and MCNPX are "frozen" codes, and all new development is being carried out only in the MCNP6 code. In the past, when new types of data or improved representations were developed, the Data Team would incorporate the changes into the cross-section data files, and the Monte Carlo groups would make corresponding changes to the MCNP codes to use the new data. At present, however, only MCNP6 is updated to handle new data representations; MCNP5/X are not.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2016

High Resolution Mapping of Bactericidal Monoclonal Antibody Binding Epitopes on Staphylococcus aureus Antigen MntC

The Staphylococcus aureus manganese transporter protein MntC is under investigation as a component of a prophylactic S.aureus vaccine. Passive immunization with monoclonal antibodies mAB 305-78-7 and mAB 305-101-8 produced using MntC was shown to significantly reduce S. aureus burden in an infant rat model of infection. Earlier interference mapping suggested that a total of 23 monoclonal antibodies generated against MntC could be subdivided into three interference groups, representing three independent immunogenic regions. In the current work binding epitopes for selected representatives of each of these interference groups (mAB 305-72-5 – group 1, mAB 305-78-7 – group 2, and mAB 305-101-8 – group 3) were mapped using Hydrogen-Deuterium Exchange Mass Spectrometry (DXMS). All of the identified epitopes are discontinuous, with binding surface formed by structural elements that are separated within the primary sequence of the protein but adjacent in the context of the three-dimensional structure. The approach was validated by co-crystallizing the Fab fragment of one of the antibodies (mAB 305-78-7) with MntC and solving the three-dimensional structure of the complex. X-ray results themselves and localization of the mAB 305-78-7 epitope were further validated using antibody binding experiments with MntC variants containing substitutions of key amino acid residues. These results provided insight into the antigenic properties of MntC and how these properties may play a role in protecting the hostagainst S. aureus infection by preventing the capture and transport of Mn 2+ , a key element that the pathogen uses to evade host immunity.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2017

Self-optimizing, highly surface-active layered metal dichalcogenide catalysts for hydrogen evolution [Surface-active metal dichalcogenide electrocatalysts with self-improving performance for hydrogen evolution]

Low-cost, layered transition-metal dichalcogenides (MX 2 ) based on molybdenum and tungsten have attracted substantial interest as alternative catalysts for the hydrogen evolution reaction (HER). These materials have high intrinsic per-site HER activity; however, a significant challenge is the limited density of active sites, which are concentrated at the layer edges. Here we unravel electronic factors underlying catalytic activity on MX 2 surfaces, and leverage the understanding to report group-5 MX 2 (H-TaS 2 and H-NbS 2 ) electrocatalysts whose performance instead mainly derives from highly active basal-plane sites, as suggested by our first-principles calculations and performance comparisons with edge-active counterparts. Beyond high catalytic activity, they are found to exhibit an unusual ability to optimize their morphology for enhanced charge transfer and accessibility of active sites as the HER proceeds, offering a practical advantage for scalable processing. In conclusion, the catalysts reach 10 mA cm –2 current density at an overpotential of ~50–60 mV with a loading of 10–55 μg cm –2 , surpassing other reported MX 2 candidates without any performance-enhancing additives.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2015

DNDO Report

My internship program was the Domestic Nuclear Detection Office Summer Internship Program. I worked at Los Alamos National Laboratory with Trevor A. Wilcox and Gregg W. McKinney in the NEN-5 group. My project title was “MCNP Physical Model Interoperability & Validation”. The goal of my project was to write a program to predict the solar modulation parameter for dates in the future and then implement it into MCNP6. This update to MCNP6 can be used to calculate the background more precisely, which is an important factor in being able to detect Special Nuclear Material. We will share our work in a published American Nuclear Society (ANS) paper, an ANS presentation, and a LANL student poster session. Through this project, I gained skills in programming, computing, and using MCNP. I also gained experience that will help me decide on a career or perhaps obtain employment in the future.

42 ENGINEERING↗
DOE OSTI2011

Elementary modes of excitation caused by the quadratic Zeeman term and the sensitivity of spin structures of small spin-2 condensates against the magnetic field

The response of spin-2 small condensates to an external magnetic field B is studied. The parameters of the interaction are considered as variable. The emphasis is placed on clarifying the modes of excitation caused by the quadratic Zeeman term. The theoretical method used is beyond the mean-field theory. A set of eigenstates with the U(5) superset of SO(5) superset of SO(3) symmetry is introduced to facilitate the analysis. To obtain a quantitative evaluation on the response, the fidelity susceptibility and the B-dependent average populations of spin components have been calculated. Mostly the particle number N=30 is assumed. The effect with a larger or smaller N is also considered. It was found that the sensitivity of the response depends strongly both on the interaction and on the inherent symmetry.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2020

Methanol to aromatics: isolated zinc phosphate groups on HZSM-5 zeolite enhance BTX selectivity and catalytic stability

HZSM-5 zeolite combined with unique zinc and phosphorus species, yields excellent selectivity (~85%) to BTX (benzene, toluene, xylenes) in aromatic products. It was found that both zinc and phosphorus species were highly distributed in the pores of the zeolite channel network to form isolated zinc phosphate groups, which directly bond to the surface of zeolite, leading to a strong Lewis acidic center and an optimized surface acidity distribution favorable for BTX formation and the hydrothermal stability of the catalyst.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Flipped GUT inflation

We analyse the prospects for constructing hybrid models of inflation that provide a dynamical realisation of the apparent closeness between the supersymmetric GUT scale and the possible scale of cosmological inflation. In the first place, we consider models based on the flipped SU(5)×U(1) gauge group, which has no magnetic monopoles. In one model, the inflaton is identified with a sneutrino field, and in the other model it is a gauge singlet. In both cases we find regions of the model parameter spaces that are compatible with the experimental magnitudes of the scalar perturbations, A{sub s}, and the tilt in the scalar perturbation spectrum, n{sub s}, as well as with an indicative upper limit on the tensor-to-scalar perturbation ratio, r. We also discuss embeddings of these models into SO(10), which is broken at a higher scale so that its monopoles are inflated away.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2014

SU(2s+1) symmetry and nonlinear dynamics of high spin magnets

The article is devoted to the description of dynamics of magnets with arbitrary spin on the basis of the Hamiltonian formalism. The relationship of quantum states and magnetic degrees of freedom has been considered. Subalgebras of Poisson bracket of magnetic values for spin s=1/2; 1; 3/2 have been established. We have obtained non-linear dynamic equations for the normal and degenerate non-equilibrium states of high-spin magnets with the SO(3), SU(4), SU(2)×SU(2), SU(3), SO(4), SO(5) symmetries of exchange interaction. The connection between models of magnetic exchange energy and the Casimir invariants has been discussed.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2011

On Certain Reductions of Integrable Equations on Symmetric Spaces

We derive a Z{sub 2}xZ{sub 2} reduced integrable system which is deeply connected with the famous Heisenberg ferromagnet equation. Its Lax pair is associated with the symmetric space SO(5)/SO(2)xSO(3). We study the spectral properties of the scattering operator, introduce the basic notions of its direct scattering problem and construct fundamental analytic solutions in terms of Volterra integral equations. We obtain recursion operator to describe the hierarchy of higher order equations associated with the same Lax operator L.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2016

Supersymmetry searches in GUT models with non-universal scalar masses

We study SO(10), SU(5) and flipped SU(5) GUT models with non-universal soft supersymmetry-breaking scalar masses, exploring how they are constrained by LHC supersymmetry searches and cold dark matter experiments, and how they can be probed and distinguished in future experiments. We find characteristic differences between the various GUT scenarios, particularly in the coannihilation region, which is very sensitive to changes of parameters. For example, the flipped SU(5) GUT predicts the possibility of ∼t{sub 1}−χ coannihilation, which is absent in the regions of the SO(10) and SU(5) GUT parameter spaces that we study. We use the relic density predictions in different models to determine upper bounds for the neutralino masses, and we find large differences between different GUT models in the sparticle spectra for the same LSP mass, leading to direct connections of distinctive possible experimental measurements with the structure of the GUT group. We find that future LHC searches for generic missing E{sub T}, charginos and stops will be able to constrain the different GUT models in complementary ways, as will the Xenon 1 ton and Darwin dark matter scattering experiments and future FERMI or CTA γ-ray searches.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2011

Heavy neodymium isotopes in the interacting boson (IBA-2) model

The N>82 even neodymium isotopes were studied in the framework of the IBA-2 model. The analysis was performed by using a very schematic Hamiltonian, particularly suited to investigate the U(5) {yields} SU(3) transition. The evolution of the excitation energy patterns and of the spectroscopic properties along the isotopic chain can be correctly reproduced when the role played by states of mixed symmetry character is also taken into account.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2011

Gyromagnetic factors in {sup 144-150}Nd

The U(5) to SU(3) evolution of the nuclear structure in the even {sup 144-156}Nd isotopes has been investigated in the framework of the interacting boson approximation (IBA-2) model, taking into account the effect of the partial Z=64 subshell closure on the structure of the states of a collective nature. The analysis, which led to a satisfactory description of excitation energy patterns, quadrupole moments, and decay properties of the states (even when important M1 components were present in the transitions), is extended to the available data on g factors, in {sup 144-150}Nd. Their values are reasonably reproduced by the calculations.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2011

Hadronic absorption cross sections of B{sub c}

The cross sections of B{sub c} absorption by {pi} mesons are calculated using a hadronic Lagrangian based on the SU(5) flavor symmetry. Calculated cross sections are found to be in the ranges 2-7 mb and 0.2-2 mb for the processes B{sub c}{sup +}{pi}{yields}DB and B{sub c}{sup +}{pi}{yields}D*B*, respectively, when the monopole form factor is included. These results could be useful in calculating the production rate of B{sub c} mesons in relativistic heavy ion collisions.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2010

General gauge mediation in five dimensions

We use the ''general gauge mediation'' (GGM) formalism to describe a five-dimensional setup with an S{sup 1}/Z{sub 2} orbifold. We first consider a model independent supersymmetry breaking hidden sector on one boundary and generic chiral matter on another. Using the definition of GGM, the effects of the hidden sector are contained in a set of global symmetry current correlator functions and is mediated through the bulk. We find the gaugino, sfermion and hyperscalar mass formulas for minimal and generalized messengers in different regimes of a large, small and intermediate extra dimension. Then we use the five-dimensional GGM formalism to construct a model in which an SU(5) Intriligator, Seiberg and Shih (ISS) model is located on the hidden boundary. We weakly gauge a global symmetry of the ISS model and associate it with the bulk vector superfield. Compared to four-dimensional GGM, there is a natural way to adjust the gaugino versus sfermion mass ratio by a factor (Ml){sup 2}, where M is a characteristic mass scale of the supersymmetry breaking sector and l is the length of the extra dimension.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Collider signatures for the heavy lepton triplet in the type I+III seesaw mechanism

The minimal SU(5) theory augmented by the fermionic adjoint representation restores the coupling constant unification and gives realistic neutrino masses and mixing through the hybrid Type I and Type III seesaw. The crucial prediction of the theory is an SU(2) lepton triplet with the mass below TeV. We study the signature of these heavy leptons at the hadron and lepton colliders. The smoking gun evidence of the theory, as in general seesaw mechanisms, is {Delta}L=2 lepton-number violation through events of a pair of like-sign leptons plus four jets without significant missing energy at hadron colliders. We find that via this unique channel the heavy lepton can be searched for up to a mass of 200 GeV at the Tevatron with 8 fb{sup -1}, and up to 450 (700) GeV at the LHC of 14 TeV C.M. energy with 10(100) fb{sup -1}. The 7 TeV LHC run of 1 fb{sup -1} is expected to probe a mass window of 110-200 GeV. We also comment on how to distinguish this theory from other models with similar heavy leptons. Finally, we compare the production rates and angular distributions of heavy leptons in e{sup +}e{sup -} collisions for various models.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗