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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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At least 1,765 records · Page 98
All sourcesNASA NTRSDOE OSTI
NASA NTRS1937

An analysis of lateral stability in power-off flight with charts for use in design

The aerodynamic and mass factors governing lateral stability are discussed and formulas are given for their estimation. Relatively simple relationships between the governing factors and the resulting stability characteristics are presented. A series of charts is included with which approximate stability characteristics may be rapidly estimated. The effects of the various governing factors upon the stability characteristics are discussed in detail. It is pointed out that much additional research is necessary both to correlate stability characteristics with riding, flying, and handling qualities and to provide suitable data for accurate estimates of those characteristics of an airplane while it is in the design stage.

Zimmerman, Charles H↗
NASA NTRS1995

Radial energy transport by magnetospheric ULF waves: Effects of magnetic curvature and plasma pressure

The 'radial' transport of energy by internal ULF waves, stimulated by dayside magnetospheric boundary oscillations, is analyzed in the framework of one-fluid magnetohydrodynamics. (the term radial is used here to denote the direction orthogonal to geomagnetic flux surfaces.) The model for the inhomogeneous magnetospheric plasma and background magnetic field is axisymmetric and includes radial and parallel variations in the magnetic field, magnetic curvature, plasma density, and low but finite plasma pressure. The radial mode structure of the coupled fast and intermediate MHD waves is determined by numerical solution of the inhomogeneous wave equation; the parallel mode structure is characterized by a Wentzel-Kramer-Brillouin (WKB) approximation. Ionospheric dissipation is modeled by allowing the parallel wave number to be complex. For boudnary oscillations with frequencies in the range from 10 to 48 mHz, and using a dipole model for the background magnetic field, the combined effects of magnetic curvature and finite plasma pressure are shown to (1) enhance the amplitude of field line resonances by as much as a factor of 2 relative to values obtained in a cold plasma or box-model approximation for the dayside magnetosphere; (2) increase the energy flux delivered to a given resonance by a factor of 2-4; and (3) broaden the spectral width of the resonance by a factor of 2-3. The effects are attributed to the existence of an 'Alfven buoyancy oscillation,' which approaches the usual shear mode Alfven wave at resonance, but unlike the shear Alfven mode, it is dispersive at short perpendicular wavelengths. The form of dispersion is analogous to that of an internal atmospheric gravity wave, with the magnetic tension of the curved background field providing the restoring force and allowing radial propagation of the mode. For nominal dayside parameters, the propagation band of the Alfven buoyancy wave occurs between the location of its (field line) resonance and that of the fast mode cutoff that exists at larger radial distances.

Kouznetsov, Igor↗
NASA NTRS1966

Bio-Medical Factors and External Hazards in Space Station Design

The design of space-station configurations is influenced by many factors, Probably the most demanding and critical are the biomedical and external hazards requirements imposed to provide the proper environment and supporting facilities for the crew and the adequate protective measures necessary to provide a configuration in which the crew can live and work efficiently in relative comfort and safety. The major biomedical factors, such as physiology, psychology, nutrition, personal hygiene, waste management, and recreation, all impose their own peculiar requirements. The commonality and integration of these requirements demand the utmost ingenuity and inventiveness be exercised in order to achieve effective configuration compliance. The relationship of biomedical factors for the internal space-station environment will be explored with respect to internal atmospheric constituency, atmospheric pressure levels, oxygen positive pressure, temperature, humidity, CO2 concentration, and atmospheric contamination. The range of these various parameters and the recommended levels for design use will be analyzed. Requirements and criteria for specific problem areas such as zero and artificial gravity and crew private quarters will be reviewed and the impact on the design of representative solutions will be presented. In the areas of external hazards, the impact of factors such as meteoroids, radiation, vacuum, temperature extremes, and cycling on station design will be evaluated. Considerations with respect to operational effectiveness and crew safety will be discussed. The impact of such factors on spacecraft design to achieve acceptable launch and reentry g levels, crew rotation intervals, etc., will be reviewed. Examples of configurations, subsystems, and internal a arrangement and installations to comply with such biomedical factor requirements will ber presented. The effects of solutions to certain biomedical factors on configuration weight, operational convenience, and program costs will be compared.

Olling, Edward H.↗
DOE OSTI2015

Photochemical charges separation and photoelectric properties of flexible solar cells with two types of heterostructures

Photochemical charges generation, separation, and transport at nanocrystal interfaces are central to energy conversion for solar cells. Here, Zn{sub 2}SnO{sub 4} nanowires/Cu{sub 4}Bi{sub 4}S{sub 9} (ZTO/CBS), ZTO nanowires/CBS-reduced graphene oxide (ZTO/CBS-RGO), and bulk heterojunction (BHJ) solar cells were measured. The signals of steady state and electric field-induced surface photovoltage indicate that RGO with high electron mobility can evidently improve the photovoltaic response. Besides, ZTO/CBS and ZTO/CBS-RGO cells exhibit the excellent performance and the highest efficiencies of 1.2% and 2.8%, respectively. The internal relations of photoelectric properties to some factors, such as film thickness, direct paths, RGO conductive network, energy level matching, etc., were discussed in detail. Qualitative and quantitative analyses further verified the comprehensive effect of RGO and other factors. Importantly, the fine bendable characteristic of BHJ solar cells with excellent efficiency and facile, scalable production gives the as-made flexible solar cells device potential for practical application in future.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
NASA NTRS1992

Effects of prior exercise on the action of insulin-like growth factor I in skeletal muscle

Prior exercise increases insulin sensitivity for glucose and system A neutral amino acid transport activities in skeletal muscle. Insulin-like growth factor I (IGF-I) also activates these transport processes in resting muscle. It is not known, however, whether prior exercise increases IGF-I action in muscle. Therefore we determined the effect of a single exhausting bout of swim exercise on IGF-I-stimulated glucose transport activity [assessed by 2-deoxy-D-glucose (2-DG) uptake] and system A activity [assessed by alpha-(methylamino)isobutyric acid (MeAIB) uptake] in the isolated rat epitrochlearis muscle. When measured 3.5 h after exercise, the responses to a submaximal concentration (0.2 nM), but not a maximal concentration (13.3 nM), of insulin for activation of 2-DG uptake and MeAIB uptake were enhanced. In contrast, prior exercise increased markedly both the submaximal (5 nM) and maximal (20 nM) responses to IGF-I for activation of 2-DG uptake, whereas only the submaximal response to IGF-I (3 nM) for MeAIB uptake was enhanced after exercise. We conclude that 1) prior exercise significantly enhances the response to a submaximal concentration of IGF-I for activation of the glucose transport and system A neutral amino acid transport systems in skeletal muscle and 2) the enhanced maximal response for IGF-I action after exercise is restricted to the signaling pathway for activation of the glucose transport system.

Non-NASA Center↗
DOE OSTI2020

Nuclear moonlighting of cytosolic glyceraldehyde-3-phosphate dehydrogenase regulates Arabidopsis response to heat stress

Abstract Various stress conditions induce the nuclear translocation of cytosolic glyceraldehyde-3-phosphate dehydrogenase (GAPC), but its nuclear function in plant stress responses remains elusive. Here we show that GAPC interacts with a transcription factor to promote the expression of heat-inducible genes and heat tolerance in Arabidopsis. GAPC accumulates in the nucleus under heat stress. Overexpression of GAPC enhances heat tolerance of seedlings and the expression of heat-inducible genes whereas knockout of GAPCs has opposite effects. Screening of Arabidopsis transcription factors identifies nuclear factor Y subunit C10 (NF-YC10) as a GAPC-binding protein. The effects of GAPC overexpression are abolished when NF-YC10 is deficient, the heat-induced nuclear accumulation of GAPC is suppressed, or the GAPC-NF-YC10 interaction is disrupted. GAPC overexpression also enhances the binding ability of NF-YC10 to its target promoter. The results reveal a cellular and molecular mechanism for the nuclear moonlighting of a glycolytic enzyme in plant response to environmental changes.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1990

Comparison of dose estimates using the buildup-factor method and a Baryon transport code (BRYNTRN) with Monte Carlo results

Continuing efforts toward validating the buildup factor method and the BRYNTRN code, which use the deterministic approach in solving radiation transport problems and are the candidate engineering tools in space radiation shielding analyses, are presented. A simplified theory of proton buildup factors assuming no neutron coupling is derived to verify a previously chosen form for parameterizing the dose conversion factor that includes the secondary particle buildup effect. Estimates of dose in tissue made by the two deterministic approaches and the Monte Carlo method are intercompared for cases with various thicknesses of shields and various types of proton spectra. The results are found to be in reasonable agreement but with some overestimation by the buildup factor method when the effect of neutron production in the shield is significant. Future improvement to include neutron coupling in the buildup factor theory is suggested to alleviate this shortcoming. Impressive agreement for individual components of doses, such as those from the secondaries and heavy particle recoils, are obtained between BRYNTRN and Monte Carlo results.

Shinn, Judy L.↗
DOE OSTI2014

SU-E-T-491: Importance of Energy Dependent Protons Per MU Calibration Factors in IMPT Dose Calculations Using Monte Carlo Technique

Purpose: In intensity modulated proton therapy (IMPT), energy dependent, protons per monitor unit (MU) calibration factors are important parameters that determine absolute dose values from energy deposition data obtained from Monte Carlo (MC) simulations. Purpose of this study was to assess the sensitivity of MC-computed absolute dose distributions to the protons/MU calibration factors in IMPT. Methods: A “verification plan” (i.e., treatment beams applied individually to water phantom) of a head and neck patient plan was calculated using MC technique. The patient plan had three beams; one posterior-anterior (PA); two anterior oblique. Dose prescription was 66 Gy in 30 fractions. Of the total MUs, 58% was delivered in PA beam, 25% and 17% in other two. Energy deposition data obtained from the MC simulation were converted to Gy using energy dependent protons/MU calibrations factors obtained from two methods. First method is based on experimental measurements and MC simulations. Second is based on hand calculations, based on how many ion pairs were produced per proton in the dose monitor and how many ion pairs is equal to 1 MU (vendor recommended method). Dose distributions obtained from method one was compared with those from method two. Results: Average difference of 8% in protons/MU calibration factors between method one and two converted into 27 % difference in absolute dose values for PA beam; although dose distributions preserved the shape of 3D dose distribution qualitatively, they were different quantitatively. For two oblique beams, significant difference in absolute dose was not observed. Conclusion: Results demonstrate that protons/MU calibration factors can have a significant impact on absolute dose values in IMPT depending on the fraction of MUs delivered. When number of MUs increases the effect due to the calibration factors amplify. In determining protons/MU calibration factors, experimental method should be preferred in MC dose calculations. Research supported by National Cancer Institute grant P01CA021239.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

The role of hepatocyte nuclear factor 4-alpha in perfluorooctanoic acid- and perfluorooctanesulfonic acid-induced hepatocellular dysfunction

Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), chemicals present in a multitude of consumer products, are persistent organic pollutants. Both compounds induce hepatotoxic effects in rodents, including steatosis, hepatomegaly and liver cancer. The mechanisms of PFOA- and PFOS-induced hepatic dysfunction are not completely understood. We present evidence that PFOA and PFOS induce their hepatic effects via targeting hepatocyte nuclear factor 4-alpha (HNF4α). Human hepatocytes treated with PFOA and PFOS at a concentration relevant to occupational exposure caused a decrease in HNF4α protein without affecting HNF4α mRNA or causing cell death. RNA sequencing analysis combined with Ingenuity Pathway Analysis of global gene expression changes in human hepatocytes treated with PFOA or PFOS indicated alterations in the expression of genes involved in lipid metabolism and tumorigenesis, several of which are regulated by HNF4α. Further investigation of specific HNF4α target gene expression revealed that PFOA and PFOS could promote cellular dedifferentiation and increase cell proliferation by down regulating positive targets (differentiation genes such as CYP7A1) and inducing negative targets of HNF4α (pro-mitogenic genes such as CCND1). Furthermore, in silico docking simulations indicated that PFOA and PFOS could directly interact with HNF4α in a similar manner to endogenous fatty acids. Collectively, these results highlight HNF4α degradation as novel mechanism of PFOA and PFOS-mediated steatosis and tumorigenesis in human livers. - Highlights: • PFOA and PFOS cause decreased HNF4α protein expression in human hepatocytes. • PFOA and PFOS promote changes associated with lipid metabolism and carcinogenesis. • PFOA and PFOS induced changes in gene expression associated with cellular dedifferentiation. • PFOA and PFOS induce expression of Nanog, a transcription factor involved in stem cell development.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2020

Bi-directional tuning of thermal transport in SrCoO x with electrochemically induced phase transitions

Unlike the wide-ranging dynamic control of electrical conductivity, there does not exist an analogous ability to tune thermal conductivity by means of electric potential. The traditional picture assumes that atoms inserted into a material’s lattice act purely as a source of scattering for thermal carriers, which can only reduce thermal conductivity. In contrast, here we show that the electrochemical control of oxygen and proton concentration in an oxide provides a new ability to bi-directionally control thermal conductivity. On electrochemically oxygenating the brownmillerite SrCoO 2.5 to the perovskite SrCoO 3–δ , the thermal conductivity increases by a factor of 2.5, whereas protonating it to form hydrogenated SrCoO 2.5 effectively reduces the thermal conductivity by a factor of four. This bi-directional tuning of thermal conductivity across a nearly 10 ± 4-fold range at room temperature is achieved by using ionic liquid gating to trigger the ‘tri-state’ phase transitions in a single device. We elucidated the effects of these anionic and cationic species, and the resultant changes in lattice constants and lattice symmetry on thermal conductivity by combining chemical and structural information from X-ray absorption spectroscopy with thermoreflectance thermal conductivity measurements and ab initio calculations. This ability to control multiple ion types, multiple phase transitions and electronic conductivity that spans metallic through to insulating behaviour in oxides by electrical means provides a new framework for tuning thermal transport over a wide range.

36 MATERIALS SCIENCE↗
DOE OSTI2015

SU-E-T-71: A Radiochromic Film Based Quantitative Assessment of Thermoplastic Mask Bolus Effect in Head and Neck IMRT/VMAT

Purpose: To quantify the factors leading to thermoplastic mask bolus-associated-increased skin dose in head and neck IMRT/VMAT using EBT2 film. Methods: EBT2 film placed beneath a dual layer 3-point ORFIT head, neck and shoulder mask was used to test the effect of mask thickness, beam modulation, air gap, and beam obliquity on bolus effect. Mask thickness was varied based on the distribution of 1.6mm Orfilight layer on top of 2 mm Efficast layer. Beam modulation was varied by irradiating the film with an open field (no beam modulation) and a step and shoot field (beam modulation). Air gap between mask and film was varied from 0 to 5mm. Beam obliquity was varied by irradiating the film at gantry angles of 0°, 35°, and 70°.Finally, film strips placed on a Rando phantom under an Orfit mask, in regions of expected high dose, were irradiated using 5 IMRT and 5 VMAT plans with various modulation levels (modulation factor 2 to 5) and the results were compared with those obtained placing OSLDs at the same locations. Results: An 18–34% increase in mask bolus effect was observed for three factors where the effect of beam obliquity ≥ beam modulation > mask thickness. No increase in mask bolus effect was observed for change in air gap. A 6–13% increase in dose due to mask bolus effect was observed on film strips. Conclusion: This work underlines the role of beam obliquity and beam modulation combined with thermoplastic mask thickness in increasing mask bolus-associated skin dose in head and neck IMRT/VMAT. One possible method of dose reduction, based on knowledge gained from this work, is inclusion of skin as an avoidance structure in treatment planning. Another approach is to design a mask with the least amount of thermoplastic material necessary for immobilization.

60 APPLIED LIFE SCIENCES↗
NASA NTRS1972

Fundamental concepts of structural loading and load relief techniques for the space shuttle

The prediction of flight loads and their potential reduction, using various control system logics for the space shuttle vehicles, is discussed. Some factors not found on previous launch vehicles that increase the complexity are large lifting surfaces, unsymmetrical structure, unsymmetrical aerodynamics, trajectory control system coupling, and large aeroelastic effects. These load-producing factors and load-reducing techniques are analyzed.

Ryan, R. S.↗
DOE OSTI2014

Ligand-conjugated mesoporous silica nanorattles based on enzyme targeted prodrug delivery system for effective lung cancer therapy

Epidermal growth factor receptor antibody (EGFRAb) conjugated silica nanorattles (SNs) were synthesized and used to develop receptor mediated endocytosis for targeted drug delivery strategies for cancer therapy. The present study determined that the rate of internalization of silica nanorattles was found to be high in lung cancer cells when compared with the normal lung cells. EGFRAb can specifically bind to EGFR, a receptor that is highly expressed in lung cancer cells, but is expressed at low levels in other normal cells. Furthermore, in vitro studies clearly substantiated that the cPLA{sub 2}α activity, arachidonic acid release and cell proliferation were considerably reduced by pyrrolidine-2 loaded EGFRAb-SN in H460 cells. The cytotoxicity, cell cycle arrest and apoptosis were significantly induced by the treatment of pyrrolidine-2 loaded EGFRAb-SN when compared with free pyrrolidine-2 and pyrrolidine-2 loaded SNs in human non-small cell lung cancer cells. An in vivo toxicity assessment showed that silica nanorattles and EGFRAb-SN-pyrrolidine-2 exhibited low systemic toxicity in healthy Balb/c mice. The EGFRAb-SN-pyrrolidine-2 showed a much better antitumor activity (38%) with enhanced tumor inhibition rate than the pyrrolidine-2 on the non-small cell lung carcinoma subcutaneous model. Thus, the present findings validated the low toxicity and high therapeutic potentials of EGFRAb-SN-pyrrolidine-2, which may provide a convincing evidence of the silica nanorattles as new potential carriers for targeted drug delivery systems. - Highlights: • EGFRAb-SN developed for receptor-mediated Drug delivery system (DDS). • EGFRAb-SN-pyrrolidine-2 targeted DDS for cPLA2α inhibition in NSLC. • Study indicates EGFRAb-SN-pyrrolidine-2 as an efficient in target dug delivery carrier. • Study explains entire efficiency of EGFRAb-SN-pyrrolidine-2 in vitro and in vivo models.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Screening a phage display library for a novel FGF8b-binding peptide with anti-tumor effect on prostate cancer

Fibroblast growth factor 8b (FGF8b) is the major isoform of FGF8 expressed in prostate cancer and it correlates with the stage and grade of the disease. FGF8b has been considered as a potential target for prostate cancer therapy. Here we isolated 12 specific FGF8b-binding phage clones by screening a phage display heptapeptide library with FGF8b. The peptide (HSQAAVP, named as P12) corresponding to one of these clones showed high homology to the immunoglobulin-like (Ig-like) domain II(D2) of high-affinity FGF8b receptor (FGFR3c), contained 3 identical amino acids (AVP) to the authentic FGFR3 D2 sequence aa 163–169 (LLAVPAA) directly participating in ligand binding, carried the same charges as its corresponding motif (aa163–169) in FGFR3c, suggesting that P12 may have a greater potential to interrupt FGF8b binding to its receptors than other identified heptapeptides do. Functional analysis indicated that synthetic P12 peptides mediate significant inhibition of FGF8b-induced cell proliferation, arrest cell cycle at the G0/G1 phase via suppression of Cyclin D1 and PCNA, and blockade of the activations of Erk1/2 and Akt cascades in both prostate cancer cells and vascular endothelial cells. The results demonstrated that the P12 peptide acting as an FGF8b antagonist may have therapeutic potential in prostate cancer. - Highlights: ► A novel FGF8b-binding peptide P12 was isolated from a phage display library. ► The mechanisms for P12 peptide inhibiting cell proliferation were proposed. ► P12 caused cell cycle arrest at G0/G1 phase via suppression of Cyclin D1 and PCNA. ► P12 suppressed FGF8b-induced activations of Akt and MAP kinases. ► P12 acting as an FGF8b antagonist may have therapeutic potential in prostate cancer.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Leucine Biosynthesis Is Involved in Regulating High Lipid Accumulation in Yarrowia lipolytica

ABSTRACT The yeast Yarrowia lipolytica is a potent accumulator of lipids, and lipogenesis in this organism can be influenced by a variety of factors, such as genetics and environmental conditions. Using a multifactorial study, we elucidated the effects of both genetic and environmental factors on regulation of lipogenesis in Y. lipolytica and identified how two opposite regulatory states both result in lipid accumulation. This study involved comparison of a strain overexpressing diacylglycerol acyltransferase ( DGA1 ) with a control strain grown under either nitrogen or carbon limitation conditions. A strong correlation was observed between the responses on the transcript and protein levels. Combination of DGA1 overexpression with nitrogen limitation resulted in a high level of lipid accumulation accompanied by downregulation of several amino acid biosynthetic pathways, including that of leucine in particular, and these changes were further correlated with a decrease in metabolic fluxes. This downregulation was supported by the measured decrease in the level of 2-isopropylmalate, an intermediate of leucine biosynthesis. Combining the multi-omics data with putative transcription factor binding motifs uncovered a contradictory role for TORC1 in controlling lipid accumulation, likely mediated through 2-isopropylmalate and a Leu3-like transcription factor. IMPORTANCE The ubiquitous metabolism of lipids involves refined regulation, and an enriched understanding of this regulation would have wide implications. Various factors can influence lipid metabolism, including the environment and genetics. We demonstrated, using a multi-omics and multifactorial experimental setup, that multiple factors affect lipid accumulation in the yeast Yarrowia lipolytica . Using integrative analysis, we identified novel interactions between nutrient restriction and genetic factors involving regulators that are highly conserved among eukaryotes. Given that lipid metabolism is involved in many diseases but is also vital to the development of microbial cell factories that can provide us with sustainable fuels and oleochemicals, we envision that our report introduces foundational work to further unravel the regulation of lipid accumulation in eukaryal cells.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2014

NREL/SCE High-Penetration PV Integration Project: Report on Field Demonstration of Advanced Inverter Functionality in Fontana, CA

The National Renewable Energy Laboratory/Southern California Edison High-Penetration PV Integration Project is (1) researching the distribution system level impacts of high-penetration photovoltaic (PV) integration, (2) determining mitigation methods to reduce or eliminate those impacts, and (3) seeking to demonstrate these mitigation methods on actual high-penetration PV distribution circuits. This report describes a field demonstration completed during the fall of 2013 on the Fontana, California, study circuit, which includes a total of 4.5 MW of interconnected utility-scale rooftop PV systems. The demonstration included operating a 2-MW PV system at an off-unity power factor that had been determined during previously completed distribution system modeling and PV impact assessment analyses. Data on the distribution circuit and PV system operations were collected during the 2-week demonstration period. This demonstration reinforces the findings of previous laboratory testing that showed that utility-scale PV inverters are capable of operating at off-unity power factor to mitigate PV impacts; however, because of difficulties setting and retaining PV inverter power factor set points during the field demonstration, it was not possible to demonstrate the effectiveness of off-unity power factor operation to mitigate the voltage impacts of high-penetration PV integration. Lessons learned from this field demonstration are presented to inform future field demonstration efforts.

14 SOLAR ENERGY↗
DOE OSTI2020

Advanced Non-Tread Materials for Fuel-Efficient Tires

PPG Industries, Inc. proposes to develop a new silica filler that can increase fuel efficiency by 2% while maximizing key performance properties in non-tread tire components compared to current carbon black/silica filler blends. In this project PPG focused on a sidewall compound. The developed compounds/components will reduce energy losses by approximately 25%, with no more than a 5% loss of resistance to degradative forces (targeting better performance). PPG plans to achieve this goal by characterizing the impact the silica filler can have on rubber properties and then tuning the silica morphology and surface chemistry for this end use. PPG will also provide guidance in optimizing the compound formulation to make the best use of this new filler. A key aspect is to understand and maintain, if not improve, the aging performance as evaluated by crack growth resistance under ozone environment. Two key strategies were used to meet the rolling resistance goal while maintaining other performance properties. The first factor was understanding the surface treatments and chemical makeup of the silica and its effects on compound performance. The second factor was using the best performing silicas and determining the optimum compound modifications to achieve the final sidewall compound performance. Using statistical analysis throughout the optimization process, it was determined that changing the silica morphology played a role in improving the reduction of tear strength while reducing rolling resistance and the improvements observed varied depending on the CB type.

36 MATERIALS SCIENCE↗