704 research outputs found
Thermogravimetry and neutron thermodiffractometry studies of the H-YBa2Cu3O7 system.
The high Tc superconducting oxide YBa2Cu3O7¿x reacts with hydrogen gas. Thermogravimetric, X-ray and neutron scattering experiments allow us to propose a two-step type of hydrogen bonding. Firstly, a few hydrogen atoms fill some oxygen vacancies and may favourably modify the electron state, giving rise to a slight increase in the critical temperature. Secondly, after a prolonged heating period, the collapse of the YBa2Cu3O7¿x type framework and of superconductivity were observed, and a new, highly hydrogenated material appeared
Recent insights into the complexity of Tank-binding kinase 1 signaling networks: The emerging role of cellular localization in the activation and substrate specificity of TBK1
AbstractTank-binding kinase 1 (TBK1) serves as an important component of multiple signaling pathways. While the majority of research on TBK1 has focused on its role in innate immunity, critical functions for TBK1 in autophagy and cancer are beginning to emerge. This review highlights recent structural and biochemical studies that provide insights into the molecular mechanism of TBK1 activation and summarizes what is known to date about TBK1 substrate selection. Growing evidence suggests that both processes rely on TBK1 subcellular localization, with a variety of adaptor proteins each directing TBK1 to discrete signaling complexes for different cellular responses. Further study of TBK1-mediated pathways will require careful consideration of TBK1 mechanisms of activation and specificity for proper dissection of these distinct signaling cascades
Do we understand the single-spin asymmetry for inclusive production in pp collisions?
The cross section data for inclusive production in collisions is
considered in a rather broad kinematic region in energy , Feynman
variable and transverse momentum . The analysis of these data is
done in the perturbative QCD framework at the next-to-leading order. We find
that they cannot be correctly described in the entire kinematic domain and this
leads us to conclude that the single-spin asymmetry, for this process,
observed several years ago at FNAL by the experiment E704 and the recent result
obtained at BNL-RHIC by STAR, are two different phenomena. This suggests that
STAR data probes a genuine leading-twist QCD single-spin asymmetry for the
first time and finds a large effect.Comment: text modified, version to be published in Eur. Phys. J. C, 6 pages, 5
figure
BIM-based LCSA application in early design stages using IFC
Life Cycle Sustainability Assessment (LCSA) is an integrated method that combines environmental, economic, and social assessments. Its methodological development remains under discussion, mainly regarding the building design. This paper aims to provide a systematic, interoperable, and open-source approach towards implementing LCSA in Building Information Modelling (BIM) in five steps. A harmonized data structure that enriches BIM objects is proposed. Automation in the principal evaluation step is provided by integrating new parameters into the current Industry Foundation Classes (IFC4). A Dynamo script verifies its utility in a case study in Spain using real-time calculations and visualizations. Two alternative structural systems are assessed, and identification is made of the lowest CO2 emitter, the lowest cost, and the most beneficial system for local employment. The approach can be employed to evaluate other indicators and building systems in other countries. Challenges and limitations in the standardization and harmonization of the three dimensions are identified
Thermodynamics of the incommensurate state in Rb_2WO_4: on the Lifshitz point in A`A``BX_4 compounds
We consider the evolution of the phase transition from the parent hexagonal
phase to the orthorhombic phase that occurs in several
compounds of family as a function of the hcp lattice parameter
. For compounds of type with larger than the threshold
value 1.26 the direct first-order transition is characterized
by the large entropy jump . For compounds , ,
with this transition occurs via an intermediate
incommensurate phase. DSC measurements were performed in
to characterize the thermodynamics of the transitions. It
was found that both transitions are again of the first order with entropy jumps
0.3Rln2c/a ~ 1.26A'A''BX_{4}BX_{4}$ tetrahedra
orientation as a possible source of the transitions discontinuity.Comment: 13 pages,1 Postscript figure. Submitted as Brief Report to Phys. Rev.
B, this paper reports a new work in Theory and Experiment, directed to
Structural Phase Transition
Quantifying the effects of antibiotic treatment on the extracellular polymer network of antimicrobial resistant and sensitive biofilms using multiple particle tracking
Novel therapeutics designed to target the polymeric matrix of biofilms requires innovative techniques to accurately assess their efficacy. Here, multiple particle tracking (MPT) was developed to characterize the physical and mechanical properties of antimicrobial resistant (AMR) bacterial biofilms and to quantify the effects of antibiotic treatment. Studies employed nanoparticles (NPs) of varying charge and size (40–500 nm) in Pseudomonas aeruginosa PAO1 and methicillin-resistant Staphylococcus aureus (MRSA) biofilms and also in polymyxin B (PMB) treated Escherichia coli biofilms of PMB-sensitive (PMBSens) IR57 and PMB-resistant (PMBR) PN47 strains. NP size-dependent and strain-related differences in the diffusion coefficient values of biofilms were evident between PAO1 and MRSA. Dose-dependent treatment effects induced by PMB in PMBSens E. coli biofilms included increases in diffusion and creep compliance (P < 0.05), not evident in PMB treatment of PMBR E. coli biofilms. Our results highlight the ability of MPT to quantify the diffusion and mechanical effects of antibiotic therapies within the AMR biofilm matrix, offering a valuable tool for the pre-clinical screening of anti-biofilm therapies
Generational Differences and Determinants of Purchase Behavior towards Sustainable Clothing in a Developing Economy
The fashion industry contributes significant plastic pollution and greenhouse gas emissions globally. One approach to minimize the industry’s environmental impact is through a shift to sustainable clothing. This study determined the predictors of purchase behavior towards sustainable clothing in a developing economy, which is the Philippines. Furthermore, this paper compared Filipinos from Generations X and Z. Results of a multiple regression analysis from a sample of 212 participants in an online survey showed that generation and environmental knowledge predicted the purchase of sustainable clothing. Moreover, Gen Z scored higher in environmental knowledge and purchase of sustainable clothing. The findings provide insights on increasing the usage of sustainable clothing, which can significantly reduce the environmental impact of the fashion industry
An adaptive grid refinement strategy for the simulation of negative streamers
The evolution of negative streamers during electric breakdown of a
non-attaching gas can be described by a two-fluid model for electrons and
positive ions. It consists of continuity equations for the charged particles
including drift, diffusion and reaction in the local electric field, coupled to
the Poisson equation for the electric potential. The model generates field
enhancement and steep propagating ionization fronts at the tip of growing
ionized filaments. An adaptive grid refinement method for the simulation of
these structures is presented. It uses finite volume spatial discretizations
and explicit time stepping, which allows the decoupling of the grids for the
continuity equations from those for the Poisson equation. Standard refinement
methods in which the refinement criterion is based on local error monitors fail
due to the pulled character of the streamer front that propagates into a
linearly unstable state. We present a refinement method which deals with all
these features. Tests on one-dimensional streamer fronts as well as on
three-dimensional streamers with cylindrical symmetry (hence effectively 2D for
numerical purposes) are carried out successfully. Results on fine grids are
presented, they show that such an adaptive grid method is needed to capture the
streamer characteristics well. This refinement strategy enables us to
adequately compute negative streamers in pure gases in the parameter regime
where a physical instability appears: branching streamers.Comment: 46 pages, 19 figures, to appear in J. Comp. Phy
Engineering paper tubes to improve winding performance of various materials
Over the past 10 years, Sonoco has conducted fundamental, solid mechanics research concerning structural behavior of spirally wound paper tubes. The scope of this program has included experimental, numerical, and analytical mechanics approaches as documented in references (1-7). For recent non-linear finite element research, we have used ABAQUS and developed user-defined material subroutines. These subroutines feature a proprietary 3D constitutive model for paperboard. The model uses non-linear stress-strain properties of Sonoco paperboard measured in 3 principle directions. An important research objective is to develop innovative tube designs that enable our customers to improve their winding operations. To achieve this objective, we have developed several patented test devices that measure tube properties fundamental to winding applications. Tests to measure core radial stiffness on the inside and outside (Ec) with respect to an external pressure and radial strength have been developed. This paper describes the test methods and presents data to verify mechanics research findings by way of two core applications. These are examples of where cores were engineered using mechanics technology to improve winding capability: (1) development of an extremely high Ec core for winding low friction, coated aluminum, and (2) cores for winding textile yarns based on radial stiffness of inside diameter
Gelatin–chitosan–PVA hydrogels and their application in agriculture
This work demonstrated the ability of a fabrication process in the preparation of gelatin-chitosan-PVA hydrogels
for potential agricultural applications. The hydrogels showed a dense, tridimensional, interconnected and reticulated structure
that was more evident in the hydrogel loaded with inulin. The hydrogels showed a water absorption capacity of ≤12 times
its mass. FTIR and light microscopy demonstrated that the hydrogels were biodegradable. The percentage of degradation
of hydrogels in inoculated soil was higher than in sterile soil using the soil burial test. Hydrogel loaded with inulin was found
to be capable of inducing resistance in chili plants against Phytophthora capsici.ITESO, A.C
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