Blend of natural waxes as a matrix for aroma encapsulation

In this study, the possibility of using a blend of natural waxes (bees and carnauba) for encapsulation of some aroma compounds was investigated. Melt dispersion/melt solidification technique was applied for microbeads production. Since one of the most important characteristics of the particles are the size and shape, particle size distribution as well as morphological properties are tested. Thermal characteristics are also examined as significant properties for thermal behavior at elevated temperatures, important for application of encapsulated particles in food production processes. Different contents of the carnauba wax in the mixture with beeswax are investigated, from 10% to 50% (w/w). Since one of the potential applications of the encapsulated aroma is in feed additives production, the targeted particle size range was under 300 ?m to be suitable for handling and mixing with other powder substances. According to the obtained results, a higher carnauba wax content in the wax blend had an impact on particle size distribution. Also, it had an impact on the surface morphology and thermal properties. The obtained results may contribute to the development of methods of encapsulation of hydrophobic aromas in the natural wax matrix.

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Variation in Morphological Properties and Particle Size Distribution of Alfisols, Inceptisols and Entisols in the Gubi Soil Series, Bauchi, Nigeria

Journal of Applied Sciences ◽

10.3923/jas.2006.2821.2824 ◽

2006 ◽

Vol 6 (13) ◽

pp. 2821-2824 ◽

Cited By ~ 1

Author(s):

N. Voncir . ◽

T. Kparmwang . ◽

A.A. Amba . ◽

A.M. Hassan .

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Morphological Properties ◽

Soil Series

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Particle-size distribution of polybrominated diphenyl ethers (PBDEs) and its implications for health

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-8-12955-2015 ◽

2015 ◽

Vol 8 (12) ◽

pp. 12955-12992 ◽

Cited By ~ 2

Author(s):

Y. Lyu ◽

T. Xu ◽

X. Li ◽

T. Cheng ◽

X. Yang ◽

...

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Polybrominated Diphenyl Ethers ◽

Fine Particles ◽

Urban Site ◽

Deposition Flux ◽

Human Respiratory Tract ◽

Particle Size Range ◽

Peak Intensity

Abstract. In order better to understand the particle-size distribution of particulate PBDEs and their deposition pattern in human respiratory tract, we made an one year campaign 2012–2013 for the measurement of size-resolved aerosol particles at Shanghai urban site. The results showed that particulate PBDEs exhibited a bimodal distribution with a mode peak in the accumulation particle size range and the second mode peak in the coarse particle size ranges. As the number of bromine atoms in the molecule increased, accumulation mode peak intensity increased while coarse mode peak intensity decreased. This change was the consistent with the variation of PBDEs' sub-cooled vapor pressure. Absorption and adsorption process dominated the distribution of PBDEs among the different size particles. Evaluated deposition flux of Σ13PBDE was 26.8 pg h−1, in which coarse particles contributed most PBDEs in head and tracheobronchial regions, while fine mode particles contributed major PBDEs in the alveoli region. In associated with the fact that fine particles can penetrate deeper into the respiratory system, fine particle-bound highly brominated PBDEs can be inhaled more deeply into human lungs and cause a greater risk to human health.

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Effect of electronic cigarette (EC) aerosols on particle size distribution in indoor air and in a radon chamber

Nukleonika ◽

10.2478/nuka-2019-0004 ◽

2019 ◽

Vol 64 (1) ◽

pp. 31-38 ◽

Cited By ~ 6

Author(s):

Hyam Nazmy Khalaf ◽

Mostafa Y. A. Mostafa ◽

Michael Zhukovsky

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Indoor Air ◽

Size Range ◽

Aerosol Particles ◽

Ultrafine Particle ◽

Decay Product ◽

Electronic Cigarette ◽

Particle Size Range

Abstract Particle size distribution is an important factor governing whether aerosols can be deposited in various respiratory tract regions in humans. Recently, electronic cigarette (EC), as the alternative of tobacco cigarette, has become increasingly popular all over the world. However, emissions from ECs may contribute to both indoor and outdoor air pollution; moreover, comments about their safety remain controversial, and the number of users is increasing rapidly. In this investigation, aerosols were generated from ECs and studied in the indoor air and in a chamber under controlled conditions of radon concentration. The generated aerosols were characterized in terms of particle number concentrations, size, and activity distributions by using aerosol diffusion spectrometer (ADS), diffusion battery, and cascade impactor. The range of ADS assessment was from 10−3 μm to 10 μm. The number concentration of the injected aerosol particles was between 40 000 and 100 000 particles/cm3. The distribution of these particles was the most within the ultrafine particle size range (0–0.2 μm), and the other particle were in the size range from 0.3 μm to 1 μm. The surface area distribution and the mass size distribution are presented and compared with bimodal distribution. In the radon chamber, all distributions were clearly bimodal, as the free radon decay product was approximately 1 nm in diameter, with a fraction of ~0.7 for a clean chamber (without any additional source of aerosols). The attached fraction with the aerosol particles from the ECs had a size not exceeding 1.0 μm.

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Synchrotron X-Ray Scattering for the Structural Characterization of Catalysts

Advances in X-ray Analysis ◽

10.1154/s0376030800021534 ◽

1986 ◽

Vol 30 ◽

pp. 389-394

Author(s):

R. J. De Angelis ◽

A. G. Dhere ◽

M. A. Maginnis ◽

P. J. Reucroft ◽

G. E. Ice ◽

...

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Profile Analysis ◽

Average Particle Size ◽

Initial Slope ◽

Average Particle ◽

Particle Size Range ◽

Diffraction Profile ◽

X Ray

Discussions exist in the literature concerning the application of single x-ray diffraction profile analysis to determine the average particle size, particle size distribution and root mean squared strain in catalytic systems. Nandi et al. have shown that the single order analysis can give erroneous strain results and is subject to error in the large particle size range. They further indicated that the initial slope of Stokes corrected Fourier coefficients gives more reliable average p article size than that which is calculated from single order peak shape analysis. There is apparent agreement that the average particle size and the particle size distribution measured by single order profile analysis, in small metal particle systems, are reliable.

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New Theoretical and Methodological Approaches to the Study of Heat Transfer in Coal Dust Combustion

Energies ◽

10.3390/en12010136 ◽

2019 ◽

Vol 12 (1) ◽

pp. 136

Author(s):

Evgeniy Toropov ◽

Konstantin Osintsev ◽

Sergei Aliukov

Keyword(s):

Heat Transfer ◽

Mathematical Model ◽

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Coal Dust ◽

Thermal Characteristics ◽

Combustion Chambers ◽

Methodological Approaches ◽

Methodological Principles

The existing theories of heat transfer in combustion chambers of boiler units fail to take into account a number of important factors that affect the reliability of results, and the methodological approaches to optimizing combustion processes can be revised in view of the spatial and temporal parameters of flame. Hence, the research aimed to improve the fundamental theoretical and methodological principles of studying heat transfer in coal dust combustion in the combustion chambers of industrial steam generators. The authors proposed to extend the theory of heat transfer with the mathematical description of particle size distribution of coal dust. In addition, the authors used the developed mathematical model of coal dust combustion based on a continuous curve of the particle size distribution in the ensemble. The mathematical model is consistent with the aeromechanical and thermal characteristics of flame. This work introduced a concept of flame continuum as a continuous medium, where the processes of combustion and heat transfer are studied. To achieve the research aim, in this paper, the methods of combustion chamber zoning, the equations of stationary and non-stationary heat conduction, radiation, and convective heat transfer, were used. These methods were tested on a number of high-temperature units.

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The Effects of Initiators Mixture on Suspension Polymerization of Vinyl Chloride and its Comparison with other Productivity-Enhancing Procedures

10.20944/preprints201805.0166.v1 ◽

2018 ◽

Author(s):

Reza Darvishi ◽

Aref Shahi

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Vinyl Chloride ◽

Suspension Polymerization ◽

Three Dimensional ◽

Control Process ◽

Morphological Properties ◽

Polymerization Process ◽

Sem Images

Molecular and morphological properties of poly(vinyl chloride) grains produced by suspension polymerization of VCM in the presence of a mixture of three kind of initiators (i.e. fast, mild and slow) (named as Cok process) was experimentally investigated in a pilot-scale reactor. The results obtained here were initially compared with a isothermal regular process (named as control process) and then with those obtained already for other productivity-enhancing polymerization techniques (i.e. nonisothermal and fast initiator dosage process). The results showed that, in contrast to nonisothermal and fast initiator dosage process, the addition of initators mixture at the beginning of the reaction has the smallest influence on molecular weight and polydispersity index compared to control process. It is obvioused that Cok-PVC grains have the lowest cold plasticizer absorption and porosity among these mentioned processes. Scanning electron microscopy (SEM) showed that the particles produced by Cok process are more regularly shaped, with a smoother surface compared with the control product. According to the literatures, all three productivity-enhancing techniques lead to an apparent quality enhancement, higher flowability and greater bulk density of final grains. While both processes of continous initiator dosage and nonisothermal polymerization broaden the particle size distribution of final PVC grains, applying initiator mixture produces particles with the same particle size distribution as control process. The SEM images processing showed that Cok process deccelerates the formation of a three-dimensional skeleton of primary particles relative to the control polymerization. In comparison with nonisothermal trajectory and continous fast initiator dosage system, the Cok polymerization process leads to the most delay of motionless conversions and fusion time as well.

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Size distributions of polycyclic aromatic hydrocarbons in urban atmosphere: sorption mechanism and source contributions to respiratory deposition

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-2971-2016 ◽

2016 ◽

Vol 16 (5) ◽

pp. 2971-2983 ◽

Cited By ~ 30

Author(s):

Yan Lv ◽

Xiang Li ◽

Ting Ting Xu ◽

Tian Tao Cheng ◽

Xin Yang ◽

...

Keyword(s):

Particle Size ◽

Polycyclic Aromatic Hydrocarbons ◽

Particle Size Distribution ◽

Size Distribution ◽

Respiratory System ◽

Aromatic Hydrocarbons ◽

Size Range ◽

Particle Size Range ◽

Polycyclic Aromatic ◽

Human Respiratory System

Abstract. In order to better understand the particle size distribution of polycyclic aromatic hydrocarbons (PAHs) and their source contribution to human respiratory system, size-resolved PAHs have been studied in ambient aerosols at a megacity Shanghai site during a 1-year period (2012–2013). The results showed the PAHs had a bimodal distribution with one mode peak in the fine-particle size range (0.4–2.1 µm) and another mode peak in the coarse-particle size range (3.3–9.0 µm). Along with the increase in ring number of PAHs, the intensity of the fine-mode peak increased, while the coarse-mode peak decreased. Plotting of log(PAH / PM) against log(Dp) showed that all slope values were above −1, suggesting that multiple mechanisms (adsorption and absorption) controlled the particle size distribution of PAHs. The total deposition flux of PAHs in the respiratory tract was calculated as being 8.8 ± 2.0 ng h−1. The highest lifetime cancer risk (LCR) was estimated at 1.5  ×  10−6, which exceeded the unit risk of 10−6. The LCR values presented here were mainly influenced by accumulation mode PAHs which came from biomass burning (24 %), coal combustion (25 %), and vehicular emission (27 %). The present study provides us with a mechanistic understanding of the particle size distribution of PAHs and their transport in the human respiratory system, which can help develop better source control strategies.

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