Piotr Zolnierczuk
A5045253518- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Atomic and Subatomic Physics Research
- Nuclear Physics and Applications
- Lipid Membrane Structure and Behavior
- Nuclear physics research studies
- Spectroscopy and Quantum Chemical Studies
- Quantum, superfluid, helium dynamics
- Advanced NMR Techniques and Applications
- Material Dynamics and Properties
- Force Microscopy Techniques and Applications
- Atomic and Molecular Physics
- Superconducting Materials and Applications
- Physics of Superconductivity and Magnetism
- Radiation Detection and Scintillator Technologies
- Scientific Research and Discoveries
- Particle accelerators and beam dynamics
- High-pressure geophysics and materials
- Nuclear reactor physics and engineering
- Advanced Condensed Matter Physics
- Particle Accelerators and Free-Electron Lasers
- Polymer Nanocomposites and Properties
- Hemoglobin structure and function
- Protein Structure and Dynamics
Oak Ridge National Laboratory
2015-2025
Spallation Neutron Source
2015-2023
Forschungszentrum Jülich
1998-2022
Office of Scientific and Technical Information
2022
National Technical Information Service
2022
Bethel University
2018-2019
Oak Ridge Associated Universities
2015
China Spallation Neutron Source
2015
University of Kentucky
1998-2008
Indiana University Bloomington
2003-2007
We report on measurements of the neutron spin asymmetries An1,2 and polarized structure functions gn1,2 at three kinematics in deep inelastic region, with x=0.33, 0.47, 0.60 Q2=2.7, 3.5, 4.8(GeV∕c)2, respectively. These were performed using a 5.7GeV longitudinally electron beam 3He target. The results for An1 gn1 x=0.33 are consistent previous world data and, two higher-x points, have improved precision by about an order magnitude. new show zero crossing around x=0.47 value x=0.60 is...
We have measured the transverse asymmetry ${A}_{{T}^{\ensuremath{'}}}$ in ${}^{3}\stackrel{\ensuremath{\rightarrow}}{\mathrm{He}}(\stackrel{\ensuremath{\rightarrow}}{e}{,e}^{\ensuremath{'}})$ quasielastic scattering Hall A at Jefferson Laboratory with high precision for ${Q}^{2}$ values from 0.1 to $0.6(\mathrm{GeV}/c{)}^{2}$. The neutron magnetic form factor ${G}_{M}^{n}$ was extracted based on Faddeev calculations ${Q}^{2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.1$ and...
We have measured the neutron spin asymmetry A(n)(1) with high precision at three kinematics in deep inelastic region x=0.33, 0.47, and 0.60, Q(2)=2.7, 3.5, 4.8 (GeV/c)(2), respectively. Our results unambiguously show, for first time, that crosses zero around x=0.47 becomes significantly positive x=0.60. Combined world proton data, polarized quark distributions were extracted. results, general, agree relativistic constituent models perturbative quantum chromodynamics (PQCD) analyses based on...
We investigated the molecular dynamics of unilamellar liposomes by neutron spin echo spectroscopy. report first experimental evidence a short-range motion at length scale size headgroup lipid. The associated mean squared displacement shows t0.26 dependence in pico- to nanosecond region that indicates another process beyond predictions Zilman–Granek (ZG) model (t0.66) and translational diffusion (t1). A comparison with theory observed low exponent is non-Gaussian transient trapping lipid...
Lipid extracts are an excellent choice of model biomembrane; however at present, there no commercially available lipid or computational models that mimic microbial membranes containing the branched-chain fatty acids found in many pathogenic and industrially relevant bacteria. We advance extract Bacillus subtilis as a standard for these diverse systems, providing detailed experimental description equilibrated atomistic bilayer included Supporting Information to this Letter...
Lateral organization of lipids in the cell membrane appears to be an ancient feature cell, given existence lipid rafts both eukaryotic and prokaryotic cells. Currently seen as platforms for protein partitioning, we posit that are capable playing another role: stabilizing physical properties over varying temperatures other environmental conditions. Membrane composition defines mechanical viscous bilayer. The also varies strongly with temperature, systematic changes partitioning high low...
Sodium chloride (NaCl) is a very common molecule in biotic and abiotic aqueous environments. In both cases, variation of ionic strength inevitable. addition to the osmotic posed by such perturbations, question whether interactions monovalent ions Na+ Cl–, especially with neutral head groups phospholipid membranes are impactful enough change membrane rigidity, still not entirely understood. We investigated dynamics 1,2-di-(octadecenoyl)-sn-glycero-3-phosphocholine (DOPC) vesicles zwitterionic...
Ergosterol, found in fungi and some protist membranes, is understudied compared with cholesterol from animal membranes. Generally, ergosterol assumed to modulate membranes the same manner as cholesterol, based on their similar chemical structures. Here we reveal fundamental structural dynamical differences between them. Neutron diffraction shows that embedded lipid bilayer much shallower than cholesterol. Ergosterol does not change membrane thickness does, indicating little condensation...
The popularity of electronic cigarettes and vaping products has launched the outbreak a condition affecting respiratory system users, known as electronic-cigarette/vaping-associated lung injury (EVALI). build-up vitamin E acetate (VEA), diluent some illicit oils, in bronchoalveolar lavage patients with EVALI provided circumstantial evidence target for investigation. In this work, we provide fundamental characterization interaction VEA cells pulmonary surfactant (PS) models to explore...
A high precision measurement of the transverse spin-dependent asymmetry ${A}_{{T}^{\ensuremath{'}}}$ in ${}^{3}\mathrm{He}\ensuremath{\rightarrow}(\stackrel{\ensuremath{\rightarrow}}{e}{,e}^{\ensuremath{'}})$ quasielastic scattering was performed Hall at Jefferson Lab values squared four-momentum transfer, ${Q}^{2},$ between 0.1 and 0.6 $(\mathrm{G}\mathrm{e}\mathrm{V}/{c)}^{2}.$ is sensitive to neutron magnetic form factor, ${G}_{M}^{n}.$ Values ${G}_{M}^{n}$ ${Q}^{2}=0.1$...
We have measured the transverse asymmetry AT' in quasielastic 3He→(e→,e') process with high precision at Q2 values from 0.1 to 0.6(GeV/c)2. The neutron magnetic form factor GMn was extracted of and 0.2(GeV/c)2 using a nonrelativistic Faddeev calculation which includes both final-state interactions (FSI) meson-exchange currents (MEC). Theoretical uncertainties due FSI MEC effects were constrained measurement spin-dependent threshold region 3He→(e→,e'). also 0.3 0.6(GeV/c)2 based on plane wave...
The mean life of the positive muon has been measured to a precision 11 ppm using low-energy, pulsed beam stopped in ferromagnetic target, which was surrounded by scintillator detector array. result, tau(micro)=2.197 013(24) micros, is excellent agreement with previous world average. new average 019(21) micros determines Fermi constant G(F)=1.166 371(6)x10(-5) GeV-2 (5 ppm). Additionally, measurement positive-muon lifetime needed determine nucleon pseudoscalar coupling g(P).
The association of ionizable polymers strongly affects their motion in solutions, where the constraints arising from clustering groups alter macroscopic dynamics. interrelation between on multiple length and time scales is fundamental to a broad range complex fluids including physical networks, gels, polymer–nanoparticle complexes long-lived associations control structure Using neutron spin echo fully atomistic, multimillion atom molecular dynamics (MD) simulations carried out times...
We present the first measurement of Q2 dependence neutron spin structure function g2(n) at five kinematic points covering 0.57 (GeV/c)2 < or = 1.34 x approximately 0.2. Though naive quark-parton model predicts g2 0, nonzero values occur in more realistic models nucleon which include quark-gluon correlations, finite quark masses, orbital angular momentum. When scattering from a noninteracting quark, can be predicted using next-to-leading order fits to world data for g1(n). Deviations this...
Neutron spin-echo spectrometers with a position-sensitive detector and operating extended time-of-flight-tagged wavelength frames are able to collect comprehensive set of data covering large range wavevector Fourier time space only few instrumental settings in quasi-continuous way. Extracting all the information contained raw mapping them suitable physical most efficient way is challenge. This article reports algorithms employed dedicated software, DrSpine (data reduction for spin echo),...
Aurein 1.2 (aurein) is a short but active α-helical antimicrobial peptide discovered in Australian tree frogs (Litoria aurea). It shows inhibition on broad spectrum of bacteria and cancer cells. With well-defined helicity, amphipathicity, cationic charges, it readily binds to membranes causes membrane change disruption. This study provides details how aurein interacts with charged lipid by using neutron diffraction (NMD) spin echo (NSE) spectroscopy complex peptide-membrane systems. NMD...
Block copolymer (BCP) structure and dynamics were studied using small-angle neutron scattering (SANS), spin echo (NSE) spectroscopy, molecular (MD) simulations to obtain a fundamental understanding of the impact an interfacial block on chain dynamics. A glassy acted as interface, rubbery was studied. The protonated near interface in one sample end another observe effect polymer. Analysis revealed that confined layered morphologies exhibited much slower than chain-end dispersed matrix. showed...
The p+p→π++d reaction is studied at excess energies between 0.275 and 3.86 MeV. Differential total cross section were measured employing a magnetic spectrometer with nearly 4π acceptance in the center of mass system. anisotropies 0.008 0.29 indicate that p wave not negligible even so close to threshold. data are compared other offering no evidence for charge symmetry breaking or time reversal violation. s-wave p-wave contributions threshold deduced.Received 24 July...
Physical networks formed by ionizable polymers with ionic clusters as crosslinks are controlled coupled dynamics that transcend from through chain motion to macroscopic response. Here, the dynamics, across length scales, in toluene swollen polystyrene sulfonate networks, were directly correlated, electrostatic environment of physical was altered. The multiscale insight is attained coupling neutron spin echo measurements molecular simulations, carried out times typical relaxation solutions....
Sterols are an important class of lipids that regulate many biological processes. Among them, ergosterol in fungi and some protists is surprisingly understudied compared to cholesterol from animal membranes. Based on their similarity chemical structure, assumed modulate membrane the similar fashion as cholesterol. In this study, however, we revealed very different interaction between lipid Using Neutron Membrane Diffraction, found embedded much shallower than bilayer. It doesn’t change...