Describing teacher conceptions of technology in authentic science inquiry using technological pedagogical content knowledge as a lens
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Biochemistry & Molecular Biology↗
SEARCH · Engineering Papers
Results for “content”
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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Moisture ingress in commercial steel drums: Water content determination, diffusion modelling and predicted permeation rates
Commercial steel drums underpin the global economy, playing a pivotal role in the storage and transportation of critical materials. Transported and stored materials, such as food, chemical and nuclear waste, can be sensitive to ambient conditions, particularly moisture that can enhance negative effects such as corrosion and material degradation. Although international standards and regulations are in place for the qualification of steel drums, there are no current testing requirements, established limits or boundaries for the permeation of moisture into the drums during transportation or storage. This work aims to provide insights into the moisture ingress over time into properly sealed steel drums and provides estimated moisture ingress rates over time through extrapolation. Water vapour transmission rate (WVTR) measurements through the gasket material at 10–40°C were 0.11–2.1 g/m 2 /day resulting in a permeation activation energy of 30.2 kJ/mol. Water sorption measurements and Karl Fischer titration (KFT) on ethylene propylene diene monomer (EPDM) gasket material revealed a decrease in equilibrium moisture saturation with increasing temperature. KFT measurements also revealed the presence of moisture within the adhesive and drum wall after exposure to ambient conditions. KFT and Fourier transform infrared spectroscopy (FTIR) show that moisture will desorb from the EPDM and drum wall after exposure to desiccating conditions, although a minimal amount of moisture will remain present. When sealed to the manufacturer's recommendations, the steel drums are effective in minimizing moisture ingress. In conclusion, in sealed empty drums, moisture ingress rates for 19-L drums were 0.4–1.5 mg/day at 25°C 15% relative humidity (RH) and increased to 7.1–8.8 mg/day at 40°C 90% RH, and moisture ingress rates for 210-L drums were 2.5 and 3.5 mg/day at field deployment conditions of 15.5°C 51.5% RH and 23°C 40% RH, respectively.
42 ENGINEERING↗
Total Carbohydrate Content Determination of Microalgal Biomass by Acid Hydrolysis Followed by Spectrophotometry or Liquid Chromatography
The carbohydrate fraction of microalgal biomass is complex and consists of a combination of neutral, acidic, amino sugars, and sugar alcohols. These carbohydrate amalgamations can be difficult to accurately quantify with the most analytical carbohydrate determination techniques. The method described here provides a straightforward two-step sulfuric acid hydrolysis followed by soluble carbohydrate quantification by either a spectrophotometric method (based on aldehyde functional group derivatization), for an overall combined monomeric sugar concentration determination, or a liquid chromatography method, for a more specific monomeric sugar profile.
09 BIOMASS FUELS↗
Shear Assisted Processing and Extrusion of Unhomogenized Aluminum Alloy 6063 Castings with High Iron Content
Shear Assisted Processing and Extrusion (ShAPE) was used to fabricate aluminum 6063 tubing directly from secondary scrap. Trimmings from an automotive manufacturing facility were cast into billets spiked with iron (0.3 wt% Fe) to explore the tolerance of ShAPE to Fe contamination. Billets were extruded in the unhomogenized condition to form tubing with an outer diameter of 12 mm and wall thickness of 2 mm. Tensile properties reached 0.2% YS = 206 MPa, UTS = 238 MPa, and U.E. = 16.3% in the T6 temper. Performance exceeds the ASTM minimum standard and is on par with ASM typical values for conventional extrusion of primary aluminum billets in the fully homogenized condition. Microstructural characterization shows extensive refinement of grain size along with dispersion and refinement of Fe-Al-Si intermetallic phases. This study suggests that ShAPE extrusion may offer a lower carbon manufacturing pathway through direct recycling of secondary aluminum scrap and elimination of the billet homogenization step.
solid phase processing, AA 6063, extrusion, Shear ↗
The photon content of the neutron
In this work, we complete our CT18qed study with the neutron’s photon parton distribution function (PDF), which is essential for the nucleus scattering phenomenology. Two methods, CT18lux and CT18qed, based on the LUXqed formalism and the DGLAP evolution, respectively, to determine the neutron’s photon PDF have been presented. Various low-Q 2 non-perturbative variations have been carefully examined, which are treated as additional uncertainties on top of those induced by quark and gluon PDFs. The impacts of the momentum sum rule as well as isospin symmetry violation have been explored and turned out to be negligible. A detailed comparison with other neutron’s photon PDF sets has been performed, which shows a great improvement in the precision and a reasonable uncertainty estimation. Finally, two phenomenological implications are demonstrated with photon-initiated processes: neutrino-nucleus W-boson production, which is important for the near-future TeV–PeV neutrino observations, and the axion-like particle production at a high-energy muon beam-dump experiment.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Testing the neutrino content of the muon at muon colliders
Collinear emission of W bosons off a high-energy muon induces a large muon-neutrino component among the Parton Distribution Functions (PDFs) of a muon. In this paper we study the phenomenology related to the ν$_{μ}$ PDF at future high-energy muon colliders. We examine total rates and differential distributions of the $ e{\overline{\nu}}_e $ and Wγ production processes, which receive a large, and often dominant, contribution from this PDF, allowing for a detailed experimental study. As a demonstration of the impact the ν$_{μ}$ PDF could have for searches of new physics, we study the charged-current pair production of a couple of heavy states, components of a SU(2)$_{L}$ doublet. In both $ e{\overline{\nu}}_e $ production and charged-current pair production of heavy states, we compare results obtained using PDFs with those of a fixed-order simulation.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
The photon content of the proton
The photon PDF of the proton is needed for precision comparisons of LHC cross sections with theoretical predictions. In a recent paper, we showed how the photon PDF could be determined in terms of the electromagnetic proton structure functions F 2 and F L measured in electron-proton scattering experiments, and gave an explicit formula for the PDF including all terms up to next-to-leading order. In this paper we give details of the derivation. We obtain the photon PDF using the factorisation theorem and applying it to suitable BSM hard scattering processes. We also obtain the same PDF in a process-independent manner using the usual definition of PDFs in terms of light-cone Fourier transforms of products of operators. We show how our method gives an exact representation for the photon PDF in terms of F 2 and F L , valid to all orders in QED and QCD, and including all non-perturbative corrections. This representation is then used to give an explicit formula for the photon PDF to one order higher than our previous result. We also generalise our results to obtain formulæ for the polarised photon PDF, as well as the photon TMDPDF. Using our formula, we derive the P γi subset of DGLAP splitting functions to order αα s and α 2 , which agree with known results. We give a detailed explanation of the approach that we follow to determine a photon PDF and its uncertainty within the above framework.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
A plant malonyl-CoA synthetase enhances lipid content and polyketide yield in yeast cells
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Wang, Yechun↗
R2 relaxometry based MR imaging for estimation of liver iron content: A comparison between two methods
Purpose: To compare the reproducibility and accuracy of R2-relaxometry MRI for estimation of liver iron concentration (LIC) between in-house analysis and FDA-approved commercially available third party results. Methods: All MR studies were performed on a 1.5T scanner. Multi-echo spin-echo scans with a fixed TR and increasing TE values of 6 ms, 9 ms, 12 ms, 15 ms, and 18 ms (spaced at 3 ms intervals) were used. Post-processing of the images to calculate mean relaxivity, R2, included drawing of regions of interest to include the whole liver on mid-slice. The relationship between liver R2 values and estimated LIC calculated with in-house analysis and values reported by an external company (FerriScan{sup ®}, Resonance Health, Australia) were assessed with correlation coefficients and Bland–Altman difference plots. Continuous variables are presented as mean ± standard deviation. Significance was set at p value < 0.05. Results: 474 studies from 175 patients were included in the study (mean age 10.4 ± 4.2 years (range 1–18 years); 254 studies from girls, 220 studies from boys). LIC ranged from 0.6 to 43 mg/g dry tissue, covering a broad range from normal levels to extremely high iron levels. Linearity between proprietary and in-house methods was excellent across the observed range for R2 (31.5 to 334.8 s{sup −1}); showing a correlation coefficient of r = 0.87, p < 0.001. Bland–Altman R2 difference plot between the two methods shows a mean bias of + 21.5 s{sup −1} (range − 47.0 to + 90.0 s{sup −1} between two standard deviations). LIC reported by FerriScan{sup ®} compared with LIC estimated in-house with R2 as reported by FerriScan{sup ®} agreed strongly, (r = 1.0, p < 0.001). Conclusion: R2 relaxometry MR imaging for liver iron concentration estimation is reproducible between proprietary FDA-approved commercial software and in-house analysis methods.
62 RADIOLOGY AND NUCLEAR MEDICINE↗
Laser Method of Measuring the Steam Content of Coolant in Water Nuclear Power Reactors
No abstract prepared.
22 GENERAL STUDIES OF NUCLEAR REACTORS↗
Reception of Sex Steroid Hormones in Thyroid Papillary Cancer Tissue and Relationship with Expression and Content of Transcription Factors Brn-3α and TRIM16
We studied reception of sex steroid hormones in the tissues of thyroid papillary cancer and benign tumor. Enhanced expression of AR and ERβ mRNA reflected malignant tumor growth. Nuclear factors Brn-3α and TRIM16 modulating expression of steroid hormones play an important role in the development of thyroid tumors. It was found that the level of TRIM16 mRNA is associated with the expression of ERβ, which seems to be mediated by its antiestrogen effect.
60 APPLIED LIFE SCIENCES↗
Beyond clay: towards an improved set of variables for predicting soil organic matter content
Not provided.
Environmental Sciences & Ecology↗
Comprehensive analysis of cellulose content, crystallinity, and lateral packing in Gossypium hirsutum and Gossypium barbadense cotton fibers using sum frequency generation, infrared and Raman spectroscopy, and X-ray diffraction
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biofuels (including algae and biomass), bio-inspir↗
Thermal constraints on growth, stoichiometry and lipid content of different groups of microalgae with bioenergy potential
Not provided.
Biotechnology & Applied Microbiology↗
Quantitative Analysis of Plutonium Content in Particles Collected from a Certified Reference Material by Total Nuclear Reaction Energy (Q Value) Spectroscopy
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Croce, Mark Philip↗
Optimization of the Dy Content in Single Crystalline GdBCO Bulk Superconductors Fabricated in Air Via Top-Seeded Infiltration Growth Process
Single-crystalline bulk GdBa{sub 2}Cu{sub 3}O{sub 7−δ} (GdBCO) superconductors were fabricated with top-seeded infiltration-growth technique (TSIG) in air by adding the different amounts of Dy{sub 2}BaCuO{sub 5} (Dy-211) particles (5, 10, 15, 20, 25, 30, 35, and 40 wt%). All the samples show superconducting critical temperature at ∼93 K with sharp transition irrespective of the chemical composition. X-ray diffraction measurements confirmed that all the samples were single domain with high alignment. Microstructural studies through scanning electron microscopy showed that TSIG-processed GdBCO samples contained 211 phase particles of two different sizes, i.e., ∼2–4 and ∼10 μ m. The addition of Dy-211 phase particles led to a significant enhancement of critical current density (J{sub c}) at 77 K. GdBCO superconductor with the addition of 20 wt% of Dy-211 showed the highest J{sub c} of 45.5 kA/cm {sup 2} at 77 K and self field.
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
Improvement in the Crystallographic Phase Content and Superconducting Properties of Mechanically Alloyed MgB{sub 2}
In this paper, the results of the superconductivity evaluation of MgB{sub 2} intermetallic-based superconducting materials prepared through mechanical alloying are reported. The formation of the MgB{sub 2} intermetallic phase took place through an intermediate phase reaction at the solid-state reaction temperature, which tends to favor single-phase materials. The annealing of mechanically milled Mg and B powders resulted in the highest mass fraction of MgB{sub 2} observed in this study, reaching more than 90% after annealing at 900 °C for 1 h. At that point, there were still second phases present consisting of Mg, MgO, and Fe{sub 2}B. Improved superconducting properties were obtained in samples sintered at temperatures of 850 °C and 900 °C that had a low resistivity, low critical temperature gap values, and a high residual resistivity ratio (RRR).
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗