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Grazing Incidence Neutron Spin Echo Spectroscopy (GINSES) opens new possibilities for observing the thermally driven dynamics of macromolecules close to a rigid interface. The information about the dynamics can be retrieved as a function of scattering depth of the evanescent neutron wave, on the length scale in the range of some 10-100 nm. Using a classical neutron spin echo spectrometer with a laterally collimated beam, dynamics can be measured in grazing incidence geometry. We show examples of how the interface modifies the dynamics of microemulsions, membranes and microgels. Instrumental details and possible improvements for this technique will be presented. The key issue is the low intensity for dynamics measurements with an evanescent neutron wave. Conceptual questions how a specialised instrument could improve the experimental technique will be discussed.

Structural electrolytes provide mechanical properties approaching structural resin combined with a high degree of ionic conductivity. Here, structural electrolytes based on bisphenol A diglycidyl ether and the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide (EMIM-TFSI) were synthesised through reaction induced phase separation (RIPS) using isophorone diamine (iPDA) as a curing agent. The microstructure and properties of the resulting materials were controlled through both the initial formulations and the curing temperature. Curing at room temperature generated a bi-continuous structure and improved both mechanical performance and ionic conductivity of the resulting structural electrolytes. The balance between properties can be systematically adjusted; for example, a promising Young’s modulus of 800 MPa was obtained simultaneously with an ionic conductivity of 0.28 mS cm−1, for a formulation containing 35 vol% EMIM-TFSI. The lengthscale of the structural features was reduced by an order of magnitude by introducing multifunctional block-copolymers (MF-bcP) based on glycidyl methacrylate (GMA) and quaternised (2-dimethylamino)ethyl methacrylate (DMAEMA). Small angle neutron scattering (SANS), obtained during curing, identified at least two structural phases of different length scale, for the formulations containing MF-bcP, in agreement with microstructures observed using scanning electron microscopy. Such structural electrolytes may be required when using structural electrodes that also have finer characteristic lengthscales. The addition of the MF-bcP to formulations containing 35 vol% EMIM-TFSI produced structural electrolytes with a Young’s modulus of 530 MPa and an ionic conductivity of 0.64 mS cm−1.

Small angle scattering methodologies have been evolving at fast pace over the past few decades due to the ever-increasing demands for more details on the complex nanostructures of multiphase and multicomponent soft materials like polymer assemblies and biomaterials. Currently, element-specific and contrast variation techniques such as resonant (elastic) soft/tender x-ray scattering, anomalous small angle x-ray scattering, and contrast-matching small angle neutron scattering, or combinations of above are routinely used to extract the chemical composition and spatial arrangement of constituent elements at multiple length scales and examine electronic ordering phenomena. Here we present some recent advances in selectively characterizing structural architectures of complex soft materials, which often contain multi-components with a wide range of length scales and multiple functionalities, where novel resonant scattering approaches have been demonstrated to decipher a higher level of structural complexity that correlates to functionality. With the advancement of machine learning and artificial intelligence assisted correlative analysis, high-throughput and autonomous experiments would open a new paradigm of material research. Further development of resonant x-ray scattering instrumentation with crossplatform sample environments will enable multimodalin situ/operando characterization of the system dynamics with much improved spatial and temporal resolution.

Small Angle Neutron Scattering (SANS) measures the angular distribution of neutrons scattered by the sample to calculate the momentum transfer in the scattering process. However, the incident neutrons may firstly undergo unwanted collisions with the detector’s structural material before they are registered. The detection of such spurious neutrons might lead to a biased interpretation to the microstructure of the inspected sample. A newly-designed boron-lined honeycomb converter based gaseous neutron detector is introduced in this study to provide a capability for suppressing the spurious neutrons. The simulation and experimental results indicate that a 3 to 10 times improvement for the spurious neutron suppression capability could be achieved.

A series of study of the conformational change of bovine serum albumin (BSA) induced by pH and additive has been conducted by small angle scattering (SANS) technique. The unfolding process occur by increasing the solvent acidity of the buffer. The previous work from SANS scattering profile shows that BSA unfolded into a cylinder-like structure at pH 2. In this work, the role of sorbitol in refolding process of BSA in acid solution was studied. Sorbitol, at concentrations from 0 to 3 M, led to the progressive restoration of BSA globular structure. The SANS scattering data show the conformational change from cylinder-like structure of pure BSA at pH 2 undergo to ellipsoid-like structure in the addition of 3M sorbitol. In the absence, 1M and 2M sorbitol, the SANS scattering profile of BSA fitted to flexible cylinder model. Meanwhile in the present of 3M sorbitol, it fitted to triaxial ellipsoid model. These results are confirmed with ab initio low-resolution shape calculation model analysis using GNOM and DAMMIN obtaining the three-dimensional structure model.

Testing and evaluation of velocity selector control system of small angle neutron scattering (SANS) spectrometer has been done. It applied a unit of speed control variable AC, Optidrive Invertek Drives. This system is designed to be manually controlled and computerized. To control the Optidrive in manual mode, it can be done by keypad on the unit. The Optidrives can be controlled using computer by connecting the unit into a computer via USB port and OptiTools Studio software. Optidrive Invertek Drives need alternative current (AC) voltage one phase 220 volt with three phase out 220 volt. This out voltage is used as voltage source for moving the motor of disk in SANS neutron velocity selector. The speed of the disk in SANS neutron velocity selector is changed by adjusting the frequency from the Optidrive Invertek Drives. The numbers of speed of the disk determine the neutron wavelength passed through SANS neutron velocity selector. It is observed that every increasing frequency of 1 Hz, it will increase the disk speed by 59.929 rpm. The calibration that has been done for this system using silver behenate, obtain wavelength of the neutrons dependent to the disk speed. They are 3.10, 3.09, 3.41, 3.76, 4.23, 4.71, and 5.39 Å for disk speed 6500, 6000, 5500, 5000, 4500, 4000, and 3500 rpm respectively.

We present the status of development of a novel neutron spin filter based on the strong spin dependence of the neutron scattering on protons. Using photo-excited triplet states for the dynamic nuclear polarization (DNP) process, proton polarization values of 80% can now be achieved in pentacene doped single crystals of naphthalene at a field of 0.36 T in a simple helium flow cryostat. Careful sample preparation lead to extremely long polarization decay times under moderate conditions that allowed us to develop a transportable device. The filter is polarized in the lab under well controlled conditions and is then transferred to the neutron beam line where it can be operated during several days with almost constant polarization while requiring only a minimum of equipment. We describe briefly the main features of the spin filter and its use as a spin analyzer in a small-angle neutron scattering (SANS) experiment probing the magnetic structure of a nanocrystalline soft magnetic material. Furthermore the procedure for performing the background and spin leakage corrections of the neutron data is outlined in detail.

We report the density measurement through e-^(3)He elastic scattering with a 1.23 GeV electron beam in Jefferson Lab experiment E06-010. The extracted 3He density is (9.26±0.06) amagats and the N_(2)/^(3)He ratio is (1.49±0.08)%. In addition, these results are consistent with the deduced target densities based on pressure broadening measurement.

We have developed two Rheo-Small-Angle Neutron Scattering (Rheo-SANS) apparatuses at spectrometer SANS-Suanni of the 20 MW China Mianyang Research Reactor (CMRR). The first apparatus is a Couette cell based on a constant stress, Anton Paar GmbH EC-Twist 502 system. The second one is a home-made extensional rheometer. The Rheo-SANS instruments are installed for soft matter investigation of CMRR. We give a brief report of these environmental equipments and the Rheo-SANS experiments performed, demonstrating the utility of such measurements.

The small-angle neutron scattering spectrometer, SANS-Suanni, of the 20 MW China Mianyang Research Reactor (CMRR), was upgraded recently to improve its performance and anti-risk capability. The major modifications include: (i) installing a new mechanical velocity selector consisting of a rotor with helical slots; (ii) a replacement of the front of the detector tank to decrease the minimum sample-to-detector distance; (iii) installing a laser locator and a set of fixed lenses in collimator chamber. After the modifications, firstly, a higher maximum-q (qmax) can be achieved up to 6.3 nm−1. With the help of rotating the detector tank, qmax can be further increased to 10.5 nm−1. Secondly, a higher neutron flux at sample position up to 1.18 ×107 cm−2s−1 (at neutron wavelength of 0.53 nm) is obtained. Thirdly, a convenient and user-friendly beam center finding operation for environmental devices is available. The actual performance after the modifications is demonstrated with the measurements of standard samples.

Large-area position-sensitive thermal neutron detector plays an important role in the small angle neutron scattering (SANS) technique. Considering the shortage of 3He supply, a detector module composed of 64 boron coated straw (BCS) tubes was developed in the present work for the time-of-flight (TOF) SANS instrument that will be deployed on the Compact Pulsed Hadron Source (CPHS) at Tsinghua University. In this paper, 64 straw tubes were tightly packed into 8 rows by 8 columns. A multiplex readout system was utilized to locate the straw tube that has registered a neutron deposition event in the detector module, and to reconstruct the longitudinal position according to the charge division method. Several key aspects, including the pulse height spectrum, the spatial resolution and the position linearity, have been studied using the CPHS neutron beams generated by 3 MeV protons. The results indicated that the detector module can achieve an average axial spatial resolution of 5.8± 0.2 mm with a good position linearity. The neutron detection efficiency of the detector module was simulated with Geant4 code and was found to be larger than 39% for the neutrons at CPHS operated with 13 MeV proton beams in the future. It was concluded that the BCS tubes can be used to build the two-dimensional position-sensitive area detector for the TOF-SANS instrument at CPHS.

A new design for Small Angle Neutron Scattering instrument based on utilization of multi-pinhole collimator is presented. The 7-pinhole structure has been proposed for 30 years by Glinka[1]. But due to the crosstalk issue, the SNR is not as high as traditional single pinhole system. Luckily, software nowadays helps us to analyze the system and optimize the parameters of the collimator. With the help of 7-pinhole collimator instead of single-pinhole, we can approach almost one magnitude higher flux than before, which is valuable especially in compact pulsed neutron source, whose flux is a big issue.

We have investigated the effect of the annealing conditions (heating rate and temperature) on the magnetic microstructure of sintered Nd-Fe-B magnets by means of magnetometry, scanning electron microscopy, high-energy synchrotron x-ray diffraction, and small-angle neutron scattering (SANS). While the temperature treatment has a strong effect on the coercivity (reduction by about 50% on annealing), the associated changes in the microstructure do surprisingly not show up (or at best only very weakly) in the neutron-scattering signal, which probes a mesoscopic real-space length scale ranging between about 1–300 nm. On the other hand, the x-ray data reveal microstructural changes in the Nd-rich phases, presumably due to modifications in grain-boundary regions. Moreover, we observe an unusual diamond-shaped angular anisotropy in the SANS cross section, which strongly points towards the existence of texture in the nuclear microstructure.

Preliminary small-angle neutron scattering investigations on aqueous suspensions of several cobalt doped ferrites (CoxFe3-xO4, x=0; 0.5; 1) nanoparticles prepared by chemical co-precipitation method, are reported. The measurements were accomplished at the YuMO instrument in function at the IBR-2 reactor. Results of intermediary data treatment are presented and discussed.

Polyvinyl alcohol (PVA) hydrogels, cross-linked with varying concentrations of borax, were studied with small angle neutron scattering (SANS), x-ray diffraction (XRD) and differential thermal analysis (DTA). The SANS data satisfy the Ornstein–Zernike approximation. The hydrogels are modelled as PVA chains bound by borate cross-links. Water occupies the spaces within the three-dimensional hydrogel network. The mesh size ξ indicates reentrant behaviour i.e. at first, ξ increases and later decreases as a function of borax concentration. The behaviour is explained on the basis of the balance between the charged di-diol cross-links and the shielding by free ions in the solvent. XRD and DTA show the molecular size of water in the solvent and the glass transition temperature commensurate with reentrant behaviour.

The spin-polarization S and the spin-polarization parameters U and T of the elastically scattered electrons from Hg atoms have been computed for scattering angles 0°–180° in the energy range 1 eV . An optical model approach is employed using a complex optical potential within the framework of the Dirac relativistic partial wave analysis. We compare our results with recent experiments and available theoretical calculations and find a reasonable agreement with experiments over a wide range of energies.

The microscopic optical potential of nucleus-nucleus interaction is presented via a folding method with the isospin dependent complex nucleon-nuclear potential, which is first calculated in the framework of the Dirac–Bruecker–Hartree–Fock approach. The elastic scattering data of 6He at 229.8 MeV on 12C target are analyzed within the standard optical model. To take account of the breakup effect of 6He in the reaction an enhancing factor 3 on the imaginary potential is introduced. The calculated 6He+12C elastic scattering differential cross section is in good agreement with the experimental data. Comparisons with results in the double-folded model based on the M3Y nucleon-nucleon effective interaction and the few the body Glauber-model calculations are discussed. Our parameter free model should be of value in the description of nucleus-nucleus scattering, especially unstable nucleus-nucleus systems.

The second Born approximation (SBA) theory is applied to the study of electron-atom scattering in the presence of a CO2 laser field.The absolute differential cross sections of e-Ar scattering are calculated with multiphoton exchange in two special scattering geometries G1 (for small-angle scattering) and G2. For geometry G1, compared with the results of two different model potentials for electron elastic scattering by atoms, it is found that electron-atom polarization potential plays an important role in laser-assisted electron-atom scattering. Some calculational results in geometries G2 are given. Our results are found to be better than other theoretical results as compared with the experimental data in geometries G1 and G2.

The elastic resonance scattering of 12C+p has been studied in inverse kinematics via a novel thick target method at GIRAFFE facility of HI-13 tandem accelerator laboratory, Beijing. The recoil protons were measured by a ΔE-E counter telescope based on a large area double-sided silicon strip detector at laboratory angles around θ0 = 15°. The excitation function for 12C(p,p) elastic scattering has been obtained over a wide energy range of Ec.m.=0.31–3.45 MeV, which was explained quite well by the R-matrix calculation with known resonance parameters of the first three levels in 13N nucleus. Thus it is demonstrated that the present setup can be directly applied to the study of elastic resonance scattering with secondary radioactive beams.

The scattering of light by metallic nanostructures is one of the key phenomena to understand how the light couples to surface plasmons. The local field enhancement and the surface plasmon resonances are two other associated effects of special importance for surface enhanced Raman scattering. The size, shape and material of the structures determine the light scattering efficiency at its angular spectrum, in a very complex way. Only simple shapes have been reasonably well modelled so far. Therefore, measurement of the scattering properties of complex structures, in different illumination conditions, is fundamental to test scattering models. Using an approach analogous to x-ray diffraction, we investigated the light scattering of arrays of nanoparticles using total internal illumination. Arrays of particles of different size, shape and lattice constants were investigated this way. It was observed that the shape of the particle and its material have a strong influence on the distribution of the intensities of the Bragg diffraction patterns. Moreover, the validity of different models of light scattering form factors can be tested by comparison with the measurements. In addition, we built an experimental set-up to measure the dispersion relation of arrays of nanoparticles, or two-dimensional gratings, using total internal illumination.

Bioactive fluormica–fluorapatite glass-ceramic materials offer a very encouraging solution to the problem of efficient restoration and reconstruction of hard tissues. To produce material with the desired crystalline phases, a five-stage heat treatment must be performed. This thermal processing has a large impact on the microstructure and ultimately the final mechanical properties of the materials. We have examined the thermal processing of one of our most promising machinable biomaterials, using time-resolved small angle neutron scattering and neutron diffraction to study the nucleation and growth of crystallites. The processing route had already been optimized by studying the properties of quenched samples using x-ray diffraction, mechanical measurements and differential thermal analysis. However these results show that the heat treatment can be further optimized in terms of crystal nucleation, and we show that these techniques are the only methods by which a truly optimized thermal processing route may be obtained.

The concept of time evolution was applied to the study of the neutron scattering by 58Ni nuclei. The interval of neutron energies from 500 to 800 keV was examined. The experimental data on the energy dependence of the total and differential cross sections and on the experimental-based resonance spaces and widths were used to determine the mean time delays and the time delay dispersions for the forward scattering. Both the energy autocorrelation function and the time probability density function for this process were calculated too. The time parameters were estimated for the diffraction part and the compound scattering components. The estimation of the average compound scattering cross section and the optical model volume absorption integral per nucleon have been done.

Combined studies of small-angle neutron scattering and small-angle x-ray scattering have been carried out for the direct observation of counterion condensation on charged micelles of two cationic surfactants, cetyltrimethylammonium bromide (CTABr) and cetyltrimethylammonium chloride (CTACl) in aqueous electrolyte solutions. The addition of the electrolytes KCl and KBr in the CTABr and CTACl micellar solutions, respectively, yields an increase in the counterion condensation as well as the exchange of the counterions. It is found that the counterions in CTABr/KCl and CTACl/KBr micellar solutions are exchanged to the extent of maintaining the same concentration gradient for both the counterions (Br− and Cl−) around the charged micelles with respect to the solution.

Aiming at realising neutron scattering experiments under B = 40T magnetic fields, we are developing diffusive techniques for neutron diffraction with a long pulse magnet. For the present experiments, we succeeded in observing the spin-flop transition of the antiferromagnet MnF2 around B = 10T using a 20T pulsed magnet on a neutron spectrometer installed at a reactor. 35T pulsed magnetic fields were also successfully generated.

The distorted wave is introduced into the relativistic impulse approximation to generate the Dirac optical potentials for proton elastic scattering. Those potentials, produced by folding the target ground state wavefunction with the free nucleon-nucleon interactions, are used to reevaluate scattering observables, such as differential cross section, analysing power and spin rotation function, for proton elastic scattering from 12C and 16O at Elab = 200 MeV, respectively. The inclusion of the distorted wave in the original relativistic impulse approximation has brought out better results of the observables, especially at small scattering angles.

Experimental studies made on different ferrofluid samples under shear flow have shown that an increase of magnetic field strength yields an increase of the fluid's viscosity, the so-called magnetoviscous effect, while increasing shear rate leads to a decrease of the viscosity. The change of the viscosity with magnetic field strength can be theoretically explained as an effect of chain-like structure formation and therefore can be related to the modification of the microstructure of ferrofluids. Using a specially designed rheometer, ferrofluids having different magnitude of the magnetoviscous effect were investigated by small angle neutron scattering (SANS). Correlated to the structure formation in the fluid, the scattered intensity shows a variation with magnetic field and shear rate only for fluids with a high magnetoviscous effect. The results obtained show a good agreement with the qualitative model elaborated to explain the magnetoviscous effect, indicating a strong connection between the rheological behaviour of ferrofluids and their microstructure.

Polarized small angle neutron scattering (SANSPOL) was used to investigate the microstructure of various ferrofluids (FF) where magnetic materials (Co, Fe magnetite), stabilization mechanisms (electrostatic, monolayers and bilayers of surfactants) and carrier liquids (water, organic solvents) have been systematically varied. Magnetic core–shell particles, non-magnetic micelles and magnetic aggregates were identified and size distributions and density, composition, and magnetization profiles were determined. Partial penetrations of solvent molecules inside the surfactant layer and formation of non-magnetic oxide coatings were established. The magnetic nanostructure in diluted samples consists of non-interacting ferromagnetic single domain particles. In concentrated Co FF a pseudo-crystalline ordering was found to be induced by an external magnetic field where cobalt core–shell particles are arranged in hexagonal planes. The particle ordering and magnetic moment direction followed the direction of the applied field. In addition, segments of uncorrelated dipolar chains were found to be present. The dynamics of the field induced ordering was studied by means of time-resolved SANS. Individual particle moments are stuck by field induced dipolar interactions in domains of local hexagonal ordering which relax by rotational diffusion when the field is switched off, with a characteristic time of a few seconds. (Some figures in this article are in colour only in the electronic version)

We present experimental and theoretical differential cross sections for elastic electron scattering from xenon. Two independent measurements were carried out at (1) Chungnam National University for incident electron energies of 10, 20, 30, 50 and 100 eV and scattering angles from 10° up to 180° and (2) the Institute of Physics in Belgrade for incident electron energies of 20, 30 and 50 eV and scattering angles from 10° up to 150°. While these latter measurements do not cover the full angular range up to 180°, they still extend somewhat higher in scattering angle than previous measurements. It would appear that the theoretical treatment of intermediate energy elastic scattering from xenon is sensitive to the inclusion of absorption effects, particularly at backward scattering angles. This observation plus the previous results for the case of krypton indicates that the role of absorption is generally quite important for the rare gases.

Understanding the state of the hydration water and the microstructure development in a cement paste is likely to be the key for the improvement of its ultimate strength and durability. In order to distinguish and characterize the reacted and unreacted water, the single-particle dynamics of water molecules in hydrated calcium silicates (C3S, C2S) and aluminates (C3A, C4AF) were studied by quasi-elastic neutron scattering, QENS. The time evolution of the immobile fraction represents the hydration kinetics and the mobile fraction follows a non-Debye relaxation. Less sophisticated, but more accessible and cheaper techniques, like differential scanning calorimetry, DSC, and near-infrared spectroscopy, NIR, were validated through QENS results and they allow one to easily and quantitatively follow the cement hydration kinetics and can be widely applied on a laboratory scale to understand the effect of additives (i.e., superplasticizers, cellulosic derivatives, etc) on the thermodynamics of the hydration process. DSC provides information on the free water index and on the activation energy involved in the hydration process while the NIR band at 7000?cm?1 monitors, at a molecular level, the increase of the surface-interacting water. We report as an example the effect of two classes of additives widely used in the cement industry: superplasticizers, SPs, and cellulose derivatives. SPs interact at the solid surface, leading to a consistent increment of the activation energy for the processes of nucleation and growth of the hydrated phases. In contrast, the cellulosic additives do not affect the nucleation and growth activation energy, but cause a significant increment in the water availability: in other words the hydration process is more efficient without any modification of the solid/liquid interaction, as also evidenced by the 1H-NMR. Additional information is obtained by scanning electron microscopy (SEM), ultra small angle neutron scattering (USANS) and wide angle x-ray scattering (WAXD) that characterize how additives affect both the hydrated microstructure development and the original grain size. In particular, SPs alter the morphology of the hydrated phases, which no longer grow with the classic fibrillar structure on the grain surface, but nucleate in solution as globular structures. All this information converges in a quantitative, and at molecular level, description of the mechanisms involved in the setting process of one of the materials most widely used by human beings.

We present a comparison between results of computer simulations and neutron scattering/electron microscopy observations on reaction-induced self-assembly of cellulose molecules synthesized via in vitro polymerization at specific sites of enzymes in an aqueous reaction medium. The experimental results, obtained by using a combined small-angle scattering (SAS) analysis of USANS (ultra-SANS), USAXS (ultra-SAXS), SANS (small-angle neutron scattering), and SAXS (small-angle x-ray scattering) methods over an extremely wide range of wavenumber q (as wide as four orders of magnitude) and of a real-space analysis with field-emission scanning electron microscopy elucidated that: (i) the surface structure of the self-assembly in the medium is characterized by a surface fractal dimension of D s = 2.3 over a wide length scale (∼30 nm to ∼30 μm); (ii) its internal structure is characterized by crystallized cellulose fibrils spatially arranged with a mass fractal dimension of D m = 2.1. These results were analysed by Monte Carlo simulation based on the diffusion-limited aggregation of rod-like molecules that model the cellulose molecules. The simulations show similar surface fractal dimensions to those observed in the experiments.

We investigated, using quasi-elastic and inelastic neutron scattering, the slow single-particle dynamics of water confined in laboratory synthesized nanoporous silica matrices, MCM-41-S, with pore diameters ranging from 10 to 18 A. Inside the pores of these matrices, the freezing process of water is strongly inhibited down to 160 K. We analysed the quasi-elastic part of the neutron scattering spectra with a relaxing-cage model and determined the temperature and pressure dependence of the Q-dependent translational relaxation time and its stretch exponent β for the time dependence of the self-intermediate scattering function. The calculated Q-independent average translational relaxation time shows a fragile-to-strong (FS) dynamic crossover for pressures lower than 1600 bar. Above this pressure, it is no longer possible to discern the characteristic feature of the FS crossover. Identification of this end point with the predicted second low-temperature critical point of water is discussed. A subsequent inelastic neutron scattering investigation of the librational band of water indicates that this FS dynamic crossover is associated with a structural change of the hydrogen-bond cage surrounding a typical water molecule from a denser liquid-like configuration to a less-dense ice-like open structure.

Petroleum is a mixture of organic material consisting of a series of molecules with increasing molecular weight but with decreasing carbon to hydrogen ratios. This monotonic trend leads to distinctive properties of each class, cut by solvents. Asphaltenes are a class soluble in toluene but not in heptane. The importance of asphaltenes lies in their relevance to petroleum operations. Many properties of petroleum liquids are due to the interplay between asphaltenes and other co-existing components. These complex interactions impact on petroleum phases, and thus the operations. So-called petroleomics is a scheme to link the molecular structures of the most relevant components in the petroleum liquid to its overall properties, similar to the proteomics widely accepted in biological sciences. However, though the asphaltene molecular structure and compositions are relevant to the macroscopic properties of petroleum liquids, their aggregates on the colloidal length scale could be the most relevant elementary unit that dictates the properties of the petroleum mixtures. In this regard, it is legitimate to use small angle x-ray scattering (SAXS) and small angle neutron scattering (SANS) techniques to bridge the molecular structures of asphaltenes and the operational parameters that are commonly applied in the field. In this review, the linkages between asphaltene molecules and their aggregates and the asphaltene aggregates and the macroscopic properties are described. Applications of small angle x-ray and neutron scattering for characterizing asphaltene aggregates and asphaltene emulsions are also discussed.

Different cross sections for the elastic scattering of electrons by N2 at impact energies of 10, 15, 20, 30, 40 eV have been calculated and compared with the experimental data and other theoretical results. The present results are obtained by the momentum space coupled channels optical method. In this method, the e–molecule system has a single centre and the interaction of e–nuclei is expanded by a multipole expansion.

Scattering of neutrons in the 24–150 keV incident energy range from H2O relative to that of D2O and H2O–D2O mixtures was reported recently by Moreh et al. This work is related to neutron Compton scattering experiments regarding the 'anomalous' scattering from protons, observed earlier at ISIS by Chatzidimitriou-Dreismann et al in the 5–100 eV range. Here we provide the complete data reduction scheme of time-of-flight integrated intensities measured at keV energy transfers, within the impulse approximation of standard theory and for single scattering events. Current investigations of multiple scattering events and the associated preliminary results are mentioned. Direct application of the theoretical results to the new keV scattering data reveals an anomalous ratio of scattering intensity of H2O relative to that of D2O of about 20%, thus being in good agreement with the earlier results of the original experiment at ISIS.

The elastic scattering properties for collisions between two 7Li atoms are investigated in the cold and ultracold regimes separately. Based on recent theoretical and experimental results, we present the improved hybrid potentials for the singlet X1∑g+ and triplet a3∑u+ ground states of the Li2. Our calculated values for the scattering lengths a and the effective ranges re are compared with previous ones and found them to be in good agreement. The scattering lengths are 34.6a0 for the singlet state and −27.6a0 for the triplet state. Shape resonances occur in the collisions at low energies. We also calculate the total cross sections and the energy positions of shape resonances for both X1∑g+ and a3∑u+ states.