keyword
MENU ▼
Read by QxMD icon Read
search

Particle physics

keyword
https://www.readbyqxmd.com/read/28213163/active-compound-diffusivity-of-particle-size-reduced-s-aromaticum-and-c-cassia-fused-starch-edible-films-and-the-shelf-life-of-mutton-capra-aegagrus-hircus-meat
#1
C Chandra Mohan, K Radha Krishnan, S Babuskin, K Sudharsan, Vajiha Aafrin, U Lalitha Priya, P Mariyajenita, K Harini, D Madhushalini, M Sukumar
In the present study, mathematical models were used to examine the effect of active compound diffusion from edible film (supplemented with S. aromaticum and C. cassia) on the microbial, physical and chemical quality of mutton stored at 4 and 10°C. Cinnamaldehyde and eugenol release from edible film into liquid was found to be 80% and 75% of the equilibrium concentration. Active compound release into meat was 42-51% for cinnamaldehyde and 38-48% for eugenol, in storage temperatures of 4-15°C. Developed mathematical models showed the diffusivity of cinnamaldehyde (0...
February 5, 2017: Meat Science
https://www.readbyqxmd.com/read/28212703/optimal-shielding-thickness-for-galactic-cosmic-ray-environments
#2
Tony C Slaba, Amir A Bahadori, Brandon D Reddell, Robert C Singleterry, Martha S Clowdsley, Steve R Blattnig
Models have been extensively used in the past to evaluate and develop material optimization and shield design strategies for astronauts exposed to galactic cosmic rays (GCR) on long duration missions. A persistent conclusion from many of these studies was that passive shielding strategies are inefficient at reducing astronaut exposure levels and the mass required to significantly reduce the exposure is infeasible, given launch and associated cost constraints. An important assumption of this paradigm is that adding shielding mass does not substantially increase astronaut exposure levels...
February 2017: Life Sciences in Space Research
https://www.readbyqxmd.com/read/28212075/towards-photoplethysmography-based-estimation-of-instantaneous-heart-rate-during-physical-activity
#3
Delaram Jarchi, Alex Casson
OBJECTIVE: Recently numerous methods have been proposed for estimating average heart rate using photoplethysmography (PPG) during physical activity, overcoming the significant interference that motion causes in PPG traces. We propose a new algorithm framework for extracting instantaneous heart rate from wearable PPG and ECG signals to provide an estimate of heart rate variability during exercise. METHODS: For ECG signals we propose a new spectral masking approach which modifies a particle filter tracking algorithm, and for PPG signals constrains the instantaneous frequency obtained from the Hilbert transform to a region of interest around a candidate heart rate measure...
February 13, 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28211726/realization-of-translational-symmetry-in-trapped-cold-ion-rings
#4
Hao-Kun Li, Erik Urban, Crystal Noel, Alexander Chuang, Yang Xia, Anthony Ransford, Boerge Hemmerling, Yuan Wang, Tongcang Li, Hartmut Häffner, Xiang Zhang
We crystallize up to 15 ^{40}Ca^{+} ions in a ring with a microfabricated silicon surface Paul trap. Delocalization of the Doppler laser-cooled ions shows that the translational symmetry of the ion ring is preserved at millikelvin temperatures. By characterizing the collective motion of the ion crystals, we identify homogeneous electric fields as the dominant symmetry-breaking mechanism at this energy scale. With increasing ion numbers, such detrimental effects are reduced. We predict that, with only a ten-ion ring, uncompensated homogeneous fields will not break the translational symmetry of the rotational ground state...
February 3, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28211469/soil-wettability-can-be-explained-by-the-chemical-composition-of-particle-interfaces-an-xps-study
#5
Susanne K Woche, Marc-O Goebel, Robert Mikutta, Christian Schurig, Matthias Kaestner, Georg Guggenberger, Jörg Bachmann
Soil wettability (quantified in terms of contact angle, CA) is crucial for physical, chemical, and biological soil functioning. As the CA is determined by components present within the outmost nanometer of particles, this study applied X-ray photoelectron spectroscopy (XPS) with a maximum analysis depth of 10 nm to test the relationship between CA and surface elemental composition, using soil samples from a chronosequence where CA increased from 0° (0 yrs) to about 98° (120 yrs). Concurrently, as seen by XPS, C and N content increased and the content of O and the mineral-derived cations (Si, Al, K, Na, Ca, Mg, Fe) decreased...
February 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28211360/the-effect-of-silica-thickness-on-nano-tio2-particles-for-functional-polyurethane-nanocomposites
#6
Chao Chen, Wei Wu, William Z Xu, Paul A Charpentier
In order to help reduce the agglomeration of TiO2 nanoparticles in polyurethane coatings while enhancing their photoactivity and mechanical/physical properties, this work examined encapsulating TiO2 nanoparticles in a thin layer of SiO2, prior to their nanocomposite polymerization. By applying a Stöber process, varying thicknesses of SiO2 were successfully coated onto the surface of anatase and rutile TiO2 nanoparticles. The methylene blue results showed that different loadings of SiO2 onto the TiO2 surface significantly influenced their photocatalytic activity...
March 17, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28210967/core-shell-drug-carrier-from-folate-conjugated-chitosan-obtained-from-prawn-shell-for-targeted-doxorubicin-delivery
#7
Md Sazedul Islam, Papia Haque, Taslim U Rashid, M Nuruzzaman Khan, Abul K Mallik, M Nazrul I Khan, Mala Khan, Mohammed Mizanur Rahman
A multifunctional drug carrier with dual targeting (magnetic and folate-receptor) and pH sensitive core-shell hybrid nanomaterial has been developed to carry an anticancer drug doxorubicin.Superparamagnetic iron oxide nanoparticles (IONPs) were used as core of the carrier and cross-linked folate conjugated chitosan (FA-CS) was acted as shell in which doxorubicin was physically entrapped. Transmission electron microscopy (TEM) analysis confirmed the average particle size of IONPs and FA-CS coated IONPs 8.2 and 15...
April 2017: Journal of Materials Science. Materials in Medicine
https://www.readbyqxmd.com/read/28210434/effect-of-the-tio2-nanoparticles-on-the-selected-physical-properties-of-mineral-trioxide-aggregate
#8
Mohammad Samiei, Maryam Janani, Naser Asl-Aminabadi, Negin Ghasemi, Baharak Divband, Sajjad Shirazi, Kayvan Kafili
BACKGROUND: Some of the efforts to improve the properties of Mineral Trioxide Aggregate (MTA) include incorporation of some nanoparticles such as Titanium dioxide (TiO2). The aim of this study was to evaluate the effect of TiO2 nanoparticles on the setting time, working time, push-out bond strength and compressive strength of MTA. MATERIAL AND METHODS: The physical properties to be evaluated were determined using the ISO 6786:2001 and 9917 specifications. Fifteen samples of each material (MTA or MTA with 1% weight ratio of TiO2 Nanoparticles) were prepared for any evaluated physical property...
February 2017: Journal of Clinical and Experimental Dentistry
https://www.readbyqxmd.com/read/28209171/integrated-strategy-for-in-vitro-characterization-of-a-bileaflet-mechanical-aortic-valve
#9
Francesca Maria Susin, Stefania Espa, Riccardo Toninato, Stefania Fortini, Giorgio Querzoli
BACKGROUND: Haemodynamic performance of heart valve prosthesis can be defined as its ability to fully open and completely close during the cardiac cycle, neither overloading heart work nor damaging blood particles when passing through the valve. In this perspective, global and local flow parameters, valve dynamics and blood damage safety of the prosthesis, as well as their mutual interactions, have all to be accounted for when assessing the device functionality. Even though all these issues have been and continue to be widely investigated, they are not usually studied through an integrated approach yet, i...
February 16, 2017: Biomedical Engineering Online
https://www.readbyqxmd.com/read/28208801/atomic-force-microscopy-a-powerful-tool-to-address-scaffold-design-in-tissue-engineering
#10
Marica Marrese, Vincenzo Guarino, Luigi Ambrosio
Functional polymers currently represent a basic component of a large range of biological and biomedical applications including molecular release, tissue engineering, bio-sensing and medical imaging. Advancements in these fields are driven by the use of a wide set of biodegradable polymers with controlled physical and bio-interactive properties. In this context, microscopy techniques such as Atomic Force Microscopy (AFM) are emerging as fundamental tools to deeply investigate morphology and structural properties at micro and sub-micrometric scale, in order to evaluate the in time relationship between physicochemical properties of biomaterials and biological response...
February 13, 2017: Journal of Functional Biomaterials
https://www.readbyqxmd.com/read/28208591/fusion-of-inertial-magnetic-sensor-measurements-and-map-information-for-pedestrian-tracking
#11
Shu-Di Bao, Xiao-Li Meng, Wendong Xiao, Zhi-Qiang Zhang
The wearable inertial/magnetic sensor based human motion analysis plays an important role in many biomedical applications, such as physical therapy, gait analysis and rehabilitation. One of the main challenges for the lower body bio-motion analysis is how to reliably provide position estimations of human subject during walking. In this paper, we propose a particle filter based human position estimation method using a foot-mounted inertial and magnetic sensor module, which not only uses the traditional zero velocity update (ZUPT), but also applies map information to further correct the acceleration double integration drift and thus improve estimation accuracy...
February 10, 2017: Sensors
https://www.readbyqxmd.com/read/28208482/aging-underdamped-scaled-brownian-motion-ensemble-and-time-averaged-particle-displacements-nonergodicity-and-the-failure-of-the-overdamping-approximation
#12
Hadiseh Safdari, Andrey G Cherstvy, Aleksei V Chechkin, Anna Bodrova, Ralf Metzler
We investigate both analytically and by computer simulations the ensemble- and time-averaged, nonergodic, and aging properties of massive particles diffusing in a medium with a time dependent diffusivity. We call this stochastic diffusion process the (aging) underdamped scaled Brownian motion (UDSBM). We demonstrate how the mean squared displacement (MSD) and the time-averaged MSD of UDSBM are affected by the inertial term in the Langevin equation, both at short, intermediate, and even long diffusion times...
January 2017: Physical Review. E
https://www.readbyqxmd.com/read/28207738/testing-the-limits-of-gradient-sensing
#13
Vinal Lakhani, Timothy C Elston
The ability to detect a chemical gradient is fundamental to many cellular processes. In multicellular organisms gradient sensing plays an important role in many physiological processes such as wound healing and development. Unicellular organisms use gradient sensing to move (chemotaxis) or grow (chemotropism) towards a favorable environment. Some cells are capable of detecting extremely shallow gradients, even in the presence of significant molecular-level noise. For example, yeast have been reported to detect pheromone gradients as shallow as 0...
February 16, 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28201917/parallel-tempering-monte-carlo-combined-with-clustering-euclidean-metric-analysis-to-study-the-thermodynamic-stability-of-lennard-jones-nanoclusters
#14
Henrique M Cezar, Gustavo G Rondina, Juarez L F Da Silva
A basic requirement for an atom-level understanding of nanoclusters is the knowledge of their atomic structure. This understanding is incomplete if it does not take into account temperature effects, which play a crucial role in phase transitions and changes in the overall stability of the particles. Finite size particles present intricate potential energy surfaces, and rigorous descriptions of temperature effects are best achieved by exploiting extended ensemble algorithms, such as the Parallel Tempering Monte Carlo (PTMC)...
February 14, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28198875/dynamic-particle-enhancement-in-limited-view-optoacoustic-tomography
#15
X Luís Deán-Ben, Lu Ding, Daniel Razansky
Limited-view artifacts are commonly present in optoacoustic tomography images, mainly due to practical geometrical and physical constraints imposed by the imaging systems. Herein, a new approach called dynamic particle-enhanced optoacoustic tomography (DPOT) is proposed for improving image contrast and visibility of optoacoustic images under limited-view scenarios. The method is based on a nonlinear combination of a temporal sequence of tomographic reconstructions representing sparsely distributed moving particles...
February 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/28198440/caesium-rich-micro-particles-a-window-into-the-meltdown-events-at-the-fukushima-daiichi-nuclear-power-plant
#16
Genki Furuki, Junpei Imoto, Asumi Ochiai, Shinya Yamasaki, Kenji Nanba, Toshihiko Ohnuki, Bernd Grambow, Rodney C Ewing, Satoshi Utsunomiya
The nuclear disaster at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March 2011 caused partial meltdowns of three reactors. During the meltdowns, a type of condensed particle, a caesium-rich micro-particle (CsMP), formed inside the reactors via unknown processes. Here we report the chemical and physical processes of CsMP formation inside the reactors during the meltdowns based on atomic-resolution electron microscopy of CsMPs discovered near the FDNPP. All of the CsMPs (with sizes of 2.0-3.4 μm) comprise SiO2 glass matrices and ~10-nm-sized Zn-Fe-oxide nanoparticles associated with a wide range of Cs concentrations (1...
February 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28197614/characterization-of-the-temperature-and-humidity-dependent-phase-diagram-of-amorphous-nanoscale-organic-aerosols
#17
Nicholas E Rothfuss, Markus D Petters
Atmospheric aerosols can exist in amorphous semi-solid or glassy phase states. These states are determined by the temperature (T) and relative humidity (RH). New measurements of viscosity for amorphous semi-solid nanometer size sucrose particles as a function of T and RH are reported. Viscosity is measured by inducing coagulation between two particles and probing the thermodynamic states that induce the particle to relax into a sphere. It is shown that the glass transition temperature can be obtained by extrapolation to 10(12) Pa s from the measured temperature-dependent viscosity in the 10(6) to 10(7) Pa s range...
February 15, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28197606/the-properties-and-behavior-of-%C3%AE-pinene-secondary-organic-aerosol-particles-exposed-to-ammonia-under-dry-conditions
#18
David M Bell, Dan Imre, Scot T Martin, Alla Zelenyuk
Chemical transformations and aging of secondary organic aerosol (SOA) particles can alter their physical and chemical properties, including particle morphology. Ammonia, one of the common atmospheric reactive constituents, can react with SOA particles, changing their properties and behavior. At low relative humidity, NH3 uptake by α-pinene SOA particles appears to be limited to the particle surface, which suggests that the reacted particles might not be homogeneous and have complex morphology. Here, we present a study aimed at detailed characterization of the effect of ammonia on the composition, density, morphology, shape, and evaporation kinetics of α-pinene SOA particles...
February 15, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28197597/the-effect-of-sodium-species-on-methanol-synthesis-and-water-gas-shift-cu-zno-catalysts-utilising-high-purity-zincian-georgeite
#19
Simon A Kondrat, Paul J Smith, James H Carter, James S Hayward, Geoffrey J Pudge, Greg Shaw, Michael S Spencer, Jonathan K Bartley, Stuart H Taylor, Graham J Hutchings
The effect of sodium species on the physical and catalytic properties of Cu/ZnO catalysts derived from zincian georgeite has been investigated. Catalysts prepared with <100 ppm to 2.1 wt% Na(+), using a supercritical CO2 antisolvent technique, were characterised and tested for the low temperature water-gas shift reaction and also CO2 hydrogenation to methanol. It was found that zincian georgeite catalyst precursor stability was dependent on the Na(+) concentration, with the 2.1 wt% Na(+)-containing sample uncontrollably ageing to malachite and sodium zinc carbonate...
February 15, 2017: Faraday Discussions
https://www.readbyqxmd.com/read/28195722/effects-of-relative-humidity-and-particle-phase-water-on-the-heterogeneous-oh-oxidation-of-2-methylglutaric-acid-aqueous-droplets
#20
Man Mei Chim, Chun Yin Chow, James F Davies, ManNin Chan
Organic aerosols can exist as aqueous droplets, with variable water content depending on their composition and environmental conditions (e.g. relative humidity (RH)). Recent laboratory studies have revealed that oxidation kinetics in highly concentrated droplets can be much slower from those in dilute solutions. However, it remains unclear whether particle phase water affects the formation of reaction products physically and/or chemically. In this work, we investigate the role of particle phase water on the heterogeneous chemistry of aqueous organic droplets consisting of 2-methylglutaric acid (2-MGA), measuring the reaction kinetics and the reaction products upon heterogeneous OH oxidation over a range of RH...
February 14, 2017: Journal of Physical Chemistry. A
keyword
keyword
44081
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"