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Littérature scientifique sur le sujet « Mass fraction »

Auteur : Grafiati

Publié le 25 janvier 2025

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Articles de revues sur le sujet "Mass fraction"

Vanchikova, E. V., E. M. Lapteva, N. A. Vasilyeva, B. M. Kondratenok et E. V. Shamrikova. « Metrological Aspects of Studying the Granulometric Composition of Soil According to The Method of N.A. Kachinsky ». Počvovedenie, n^o 7 (19 décembre 2024) : 997–1018. https://doi.org/10.31857/s0032180x24070062.

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Based on a significant volume of soil samples of various genesis presented on the territory of the Komi Republic, a study of their granulometric composition (GC) was carried out in accordance with the Kachinsky method (MK). Calculated, procedural, random and systematic factors influencing the precision and correctness of measurement results performed in accordance with the MK prescription are considered. The influence of sample preparation (the degree of grinding of soil samples) and procedures for measuring the mass fraction of elementary soil particles (ESP) on the quality of the results of studying soil GS was assessed. The instability of measuring the mass fraction of fine sand (0.05–0.25 mm) and coarse dust (0.01–0.05 mm) fractions when using the MK recipe was shown. The dependence of the uncertainty of measurement results, caused by random factors, on the mass fraction of ECPs included in the granulometric fractions is noted – the lower the mass fraction of ECPs in the composition of the fractions, the higher the uncertainty of the measurement results. A modification of the Kaczynski method (MMK) has been developed to improve the quality of soil HS assessment results. It includes: (1) separation of fine sand particles using a sieve with a mesh diameter of 0.05 mm (instead of calculating this fraction by difference according to the MK recipe); (2) use of scales of the first class of accuracy to measure the mass fraction of dust and sludge particles; (3) control of the HS research process based on the summation of the measured values of the mass fraction of ESP of six fractions and acid-soluble compounds (losses from HCl treatment). The standard for operational control of the mass fraction of the amount of ECP after dividing them into fractions is (100 ± 5)%. A metrological study of the Kaczynski technique and its modifications was carried out. The proposed modification of Kaczynski’s technique made it possible to reduce the uncertainty in the measurement results of the mass fraction of ECP of small fractions (ωn 10%) and shift the lower limit of measurements to 1%.

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Heagy, William K., et Paul J. Sullivan. « The expected mass fraction ». Atmospheric Environment 30, n^o 1 (janvier 1996) : 35–47. http://dx.doi.org/10.1016/1352-2310(95)00282-4.

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Vladimir, Kozin, et Komlev Aleksei. « Asymmetric distributions of desired component mass fraction in point samples ». Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal 5 (20 octobre 2022) : 77–87. http://dx.doi.org/10.21440/0536-1028-2022-5-77-87.

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Introduction. Desired component mass fraction distributions in point samples at preparation plants are asymmetric, and it is due to the natural heterogeneity of ores. The theory of mass fractions distribution asymmetry in samples. The theory is based on the lump sampling of point samples. Mass fraction distributions here consist of two differentsized fractions: valuable mineral and rock. These distributions are always asymmetric. Lump dispersion for asymmetric distributions depends on the mass fraction of the valuable mineral for both released grains and aggregates. Mass fraction distribution in point samples with poor product mass fraction is described by the Poisson formula. Materials and methods of research. Mass fraction distribution correspondence to the Poisson formula was experimentally confirmed based on an artificial rock mass represented by quartz grit with colored markers. Point samples of different mass were collected from the rock mass. Experimental estimates. The distributions obtained experimentally correspond to the distributions calculated by the Poisson formula. The paper introduces a method for experimental determination of valuable mineral average grain size and ore texture index. These values were determined for asbestos ore to exemplify the method proposed. Results discussion. Sampling standards do not consider the asymmetry of mass fraction distributions in point samples. At preparation plants the asymmetry manifests itself in hurricane samples, positive product imbalance, and divergence of double weights analysis results, that exceed the acceptable limits. The asymmetry of components mass fraction distributions in concentrates should be taken into account in sampling standards and methods, as well as at preparation plants in general.

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Frohlich, B., M. Riederer et J. Tautz. « Comb-wax discrimination by honeybees tested with the proboscis extension reflex ». Journal of Experimental Biology 203, n^o 10 (15 mai 2000) : 1581–87. http://dx.doi.org/10.1242/jeb.203.10.1581.

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We used the proboscis extension reflex of honeybees to test their ability to discriminate between comb waxes of different ages (wax scales, 1-week-old wax, 2- to 3-year-old wax, 8- to 10-year-old wax). Such waxes differ in their chemical composition, and an ability to discriminate between them may aid the orientation of the bees in the nest. To train the bees, we used whole extracts of waxes and four different fractions of the whole extract based on different elutions of solid-phase extractions (extract I, fraction A eluted with hexane and fraction B with diethylether; extract II, fraction B further subdivided into fraction C by elution with isopropylchloride and fraction D by elution with diethylether). In a differential training regime (six learning and six test trials) with whole extracts or with the different fractions, we paired one type of wax with a reward and another with no reward. The bees learned to discriminate between all tested pairs of whole extracts. The two subfractions (fractions A and B) gave different results: the bees could discriminate between waxes of different ages when fraction B was used but not when fraction A was used. A further subdivision of fraction B into fractions C and D showed that only fraction D contained the elements that enabled bees to discriminate between old and new wax. Fraction D makes up only 5?8 % of the total wax mass and contains hydroxy alkyl esters (5?6 % of the total wax mass), primary alcohols (0.3?0.5 % of the total wax mass) and acids (0.06?1. 0 % of the total wax mass). Fractions A and C (together forming 62?64 % of the total wax mass), which consist of unbranched and branched aliphatic hydrocarbons and alkyl esters, could not be discriminated by the bees. The remaining wax mass (25?29 %) was eluted with a mixture of chloroform, methanol and water (13:5:1) as fraction E.

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Do, Dinh Nhat, Dinh Phuc Nguyen, Viet-Duc Phung, Xuan-Tien Le, Tuan Minh Le, Van Manh Do, Bui Quang Minh et Xuan Cuong Luu. « Fractionating of Lemongrass (Cymbopogon citratus) Essential Oil by Vacuum Fractional Distillation ». Processes 9, n^o 4 (29 mars 2021) : 593. http://dx.doi.org/10.3390/pr9040593.

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Lemongrass essential oil has many compounds appropriate for application in foods, cosmetics, and pharmaceutical products. Of these, citral is a high-value compound of interest to industry. This work aims to evaluate the use of vacuum fractional distillation to separate lemongrass essential oil compounds, producing essential oil fractions containing high citral content. The effect of process parameters, namely vacuum pressure, type column, and energy input, on the fractionation time, content, and recovery of citral in the fractions, was investigated. The fractionation of lemongrass oils successfully provided five fractions, i.e., fraction 1 (F1), fraction 2 (F2), fraction 3 (F3), fraction 4 (F4), and fraction 5 (F5). GC-MS (Gas Chromatography-Mass Spectrometry) spectra showed that the main compound contained in F1 and F2 fractions was β-myrcene (>70%). Meanwhile, F4 and F5 were the two main fractions for citral recovery. The optimal conditions of the fractional distillation system included a column height of 400 mm, power input of 165 W, and pressure of 15 mmHg. These conditions correspond to the highest total citral content of 95%, with a recovery of 80% at the F4 and F5 fractions. Therefore, fractional vacuum distillation may be an effective method to upgrade lemongrass essential oil.

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Yang, Xingyun, et Karen L. Masters. « How Bar Fraction Depends on Baryon Fraction ». Research Notes of the AAS 6, n^o 10 (6 octobre 2022) : 206. http://dx.doi.org/10.3847/2515-5172/ac9735.

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Abstract We use Galaxy Zoo 2 morphologies (based on SDSS Legacy Imaging) alongside the completed Arecibo Legacy Fast ALFA survey measuring H i to investigate the correlation between bar fraction and an estimate of baryonic mass fraction for a sample of nearby (z < 0.06) disk galaxies (M ⋆ > 109 M ⊙). As expected from theoretical considerations, and as seen in previous work using different samples/morphological classifications, we find clear evidence of an increase in bar fraction, particularly strong bar fraction in galaxies with larger baryonic mass fractions (i.e., heavier discs for their dark matter halo).

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Kumar, Vickal V., Christian Jakob, Alain Protat, Christopher R. Williams et Peter T. May. « Mass-Flux Characteristics of Tropical Cumulus Clouds from Wind Profiler Observations at Darwin, Australia ». Journal of the Atmospheric Sciences 72, n^o 5 (1 mai 2015) : 1837–55. http://dx.doi.org/10.1175/jas-d-14-0259.1.

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Abstract Cumulus parameterizations in weather and climate models frequently apply mass-flux schemes in their description of tropical convection. Mass flux constitutes the product of the fractional area covered by convection in a model grid box and the vertical velocity in cumulus clouds. However, vertical velocities are difficult to observe on GCM scales, making the evaluation of mass-flux schemes difficult. Here, the authors combine high-temporal-resolution observations of in-cloud vertical velocities derived from a pair of wind profilers over two wet seasons at Darwin with physical properties of precipitating clouds [cloud-top heights (CTH), convective–stratiform classification] derived from the Darwin C-band polarimetric radar to provide estimates of cumulus mass flux and its constituents. The length of this dataset allows for investigations of the contributions from different cumulus cloud types—namely, congestus, deep, and overshooting convection—to the overall mass flux and of the influence of large-scale conditions on mass flux. The authors found that mass flux was dominated by updrafts and, in particular, the updraft area fraction, with updraft vertical velocity playing a secondary role. The updraft vertical velocities peaked above 10 km where both the updraft area fractions and air densities were small, resulting in a marginal effect on mass-flux values. Downdraft area fractions are much smaller and velocities are much weaker than those in updrafts. The area fraction responded strongly to changes in midlevel large-scale vertical motion and convective inhibition (CIN). In contrast, changes in the lower-tropospheric relative humidity and convective available potential energy (CAPE) strongly modulate in-cloud vertical velocities but have moderate impacts on area fractions. Although average mass flux is found to increase with increasing CTH, it is the environmental conditions that seem to dictate the magnitude of mass flux produced by convection through a combination of effects on area fraction and velocity.

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Tiven, Nafly Comilo, et Tienni Mariana Simanjorang. « Effect of Substitution of Beef and Broiler Meat with Tuna Meat on Chemical and Sensory Quality of Meatballs ». Food Technology and Biotechnology 62, n^o 3 (juillet 2024) : 314–25. http://dx.doi.org/10.17113/ftb.62.03.24.8278.

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Research background. Tuna meat is rich in protein and polyunsaturated fatty acids (PUFA), but low in cholesterol and fat, which makes it an excellent candidate for replacing beef and broiler chicken to produce higher quality meatballs. The aim of this study is to determine how substituting beef and broiler meat with tuna meat affects the chemical and sensory characteristics of meatballs. Experimental approach. In this study, 1000 g of meatballs were prepared from 60 % of beef or broiler chicken. Each meat was replaced with tuna meat at mass fractions of 0, 20 and 40 %. The meat was finely ground and mixed with mass fractions (in %) of: tapioca flour 20, garlic 1.2, salt 2, ground pepper 0.5, egg white 0.3 and ice cubes 16. The tested variables included the chemical quality (moisture, protein, fat, ash, cholesterol and fatty acids) and sensory quality (colour, aroma, elasticity, texture and taste) of the meatballs. The data obtained were statistically analysed using a completely randomised factorial design analysis of variance. Results and conclusions. The results show that increasing the mass fraction of tuna as a substitute for beef and broiler meat significantly increased (p<0.01) the moisture, protein and PUFA mass fractions and colour, but decreased (p<0.01) the cholesterol and fat mass fraction of the meatballs. A significant interaction (p<0.01) was observed between the tuna mass fraction and the type of meat, which affected the mass fractions of moisture, protein, cholesterol and fat as well as colour of the meatballs. In particular, increasing the tuna mass fraction to 40 % significantly increased (p<0.01) the moisture mass fraction of the beef meatballs, as well as the protein mass fraction and colour of the beef and chicken meatballs. However, the moisture mass fraction of chicken meatballs and the fat and cholesterol mass fraction of beef and chicken meatballs decreased significantly (p<0.01). In conclusion, replacing 40 % of beef and chicken meatballs with tuna can improve protein content and colour, and reduce fat and cholesterol content. Novelty and scientific contribution. These results suggest that tuna can be used as a substitute for beef and chicken to produce higher quality meatballs that are rich in protein but low in cholesterol and fat. This approach can also be applied to other processed meat products such as sausages and nuggets to improve their nutritional quality.

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Chamberlain, Katie, Gurtina Besla, Ekta Patel, Vicente Rodriguez-Gomez, Paul Torrey, Garreth Martin, Kelsey Johnson et al. « A Physically Motivated Framework to Compare Pair Fractions of Isolated Low- and High-mass Galaxies across Cosmic Time ». Astrophysical Journal 962, n^o 2 (1 février 2024) : 162. http://dx.doi.org/10.3847/1538-4357/ad19d0.

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Abstract Low-mass galaxy pair fractions are understudied, and it is unclear whether low-mass pair fractions evolve in the same way as more massive systems over cosmic time. In the era of JWST, Roman, and Rubin, selecting galaxy pairs in a self-consistent way will be critical to connect observed pair fractions to cosmological merger rates across all mass scales and redshifts. Utilizing the Illustris TNG100 simulation, we create a sample of physically associated low-mass (108 < M * < 5 × 109 M ⊙) and high-mass (5 × 109 < M * < 1011 M ⊙) pairs between z = 0 and 4.2. The low-mass pair fraction increases from z = 0 to 2.5, while the high-mass pair fraction peaks at z = 0 and is constant or slightly decreasing at z > 1. At z = 0 the low-mass major (1:4 mass ratio) pair fraction is 4× lower than high-mass pairs, consistent with findings for cosmological merger rates. We show that separation limits that vary with the mass and redshift of the system, such as scaling by the virial radius of the host halo (r sep < 1R vir), are critical for recovering pair fraction differences between low-mass and high-mass systems. Alternatively, static physical separation limits applied equivalently to all galaxy pairs do not recover the differences between low- and high-mass pair fractions, even up to separations of 300 kpc. Finally, we place isolated mass analogs of Local Group galaxy pairs, i.e., Milky Way (MW)–M31, MW–LMC, LMC–SMC, in a cosmological context, showing that isolated analogs of LMC–SMC-mass pairs and low-separation (<50 kpc) MW–LMC-mass pairs are 2–3× more common at z ≳ 2–3.

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Donovan, John J., Nicholas E. Pingitore et Andrew Westphal. « Compositional Averaging of Backscatter Intensities in Compounds ». Microscopy and Microanalysis 9, n^o 3 (23 mai 2003) : 202–15. http://dx.doi.org/10.1017/s1431927603030137.

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We present high-precision measurements of pure element stable isotope pairs that demonstrate mass has no influence on the backscattering of electrons at typical electron microprobe energies. The traditional prediction of average backscatter intensities in compounds was pragmatically based on elemental mass fractions. Our isotopic measurements establish that this approximation has no physical basis. We propose an alternative model to mass fraction averaging, based on the number of electrons or protons, termed “electron fraction,” which predicts backscatter yield better than mass fraction averaging. We also present an improved backscatter (electron loss) factor based on a modified electron fraction average for the ZAF atomic number correction that provides a significant analytical improvement, especially where large atomic number corrections are required.

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Thèses sur le sujet "Mass fraction"

Petracca, Fernanda <1983&gt. « Constraints on neutrino mass fraction using Redshift Space Distortions ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6728/1/Fernanda_Petracca_tesi.pdf.

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Redshift Space Distortions (RSD) are an apparent anisotropy in the distribution of galaxies due to their peculiar motion. These features are imprinted in the correlation function of galaxies, which describes how these structures distribute around each other. RSD can be represented by a distortions parameter $\beta$, which is strictly related to the growth of cosmic structures. For this reason, measurements of RSD can be exploited to give constraints on the cosmological parameters, such us for example the neutrino mass. Neutrinos are neutral subatomic particles that come with three flavours, the electron, the muon and the tau neutrino. Their mass differences can be measured in the oscillation experiments. Information on the absolute scale of neutrino mass can come from cosmology, since neutrinos leave a characteristic imprint on the large scale structure of the universe. The aim of this thesis is to provide constraints on the accuracy with which neutrino mass can be estimated when expoiting measurements of RSD. In particular we want to describe how the error on the neutrino mass estimate depends on three fundamental parameters of a galaxy redshift survey: the density of the catalogue, the bias of the sample considered and the volume observed. In doing this we make use of the BASICC Simulation from which we extract a series of dark matter halo catalogues, characterized by different value of bias, density and volume. This mock data are analysed via a Markov Chain Monte Carlo procedure, in order to estimate the neutrino mass fraction, using the software package CosmoMC, which has been conveniently modified. In this way we are able to extract a fitting formula describing our measurements, which can be used to forecast the precision reachable in future surveys like Euclid, using this kind of observations.

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Barratt, Ian Robert. « Radiometric determination of the true mass flow rate of solids in a pneumatic suspension ». Thesis, University of Greenwich, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313221.

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Melia, F. « Constancy of the cluster gas mass fraction in the Rh=ct Universe ». The Royal Society, 2016. http://hdl.handle.net/10150/615118.

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The ratio of baryonic to dark matter densities is assumed to have remained constant throughout the formation of structure. With this, simulations show that the fraction $f_{\rm gas}(z)$ of baryonic mass to total mass in galaxy clusters should be nearly constant with redshift $z$. However, the measurement of these quantities depends on the angular distance to the source, which evolves with $z$ according to the assumed background cosmology. An accurate determination of $f_{\rm gas}(z)$ for a large sample of hot ($kT_e> 5$ keV), dynamically relaxed clusters could therefore be used as a probe of the cosmological expansion up to $z< 2$. The fraction $f_{\rm gas}(z)$ would remain constant only when the ``correct" cosmology is used to fit the data. In this paper, we compare the predicted gas mass fractions for both $\Lambda$CDM and the $R_{\rm h}=ct$ Universe and test them against the 3 largest cluster samples \cite{1,2,3}. We show that $R_{\rm h}=ct$ is consistent with a constant $f_{\rm gas}$ in the redshift range $z\lesssim 2$, as was previously shown for the reference $\Lambda$CDM model (with parameter values $H_0=70$ km s$^{-1}$ Mpc$^{-1}$, $\Omega_m=0.3$ and $w_\Lambda=-1$). Unlike $\Lambda$CDM, however, the $R_{\rm h}=ct$ Universe has no free parameters to optimize in fitting the data. Model selection tools, such as the Akaike Information Criterion (AIC) and the Bayes Information Criterion (BIC), therefore tend to favor $R_{\rm h}=ct$ over $\Lambda$CDM. For example, the BIC favours $R_{\rm h}=ct$ with a likelihood of $\sim 95\%$ versus $\sim 5\%$ for $\Lambda$CDM.

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Tunc, Mehmet Sefik. « Relationship between Alkaline Pulp Yield and the Mass Fraction and Degree of Polymerization of Cellulose in Pulp ». Fogler Library, University of Maine, 2003. http://www.library.umaine.edu/theses/pdf/TuncMS2003.pdf.

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Srzic, Veljko. « Significance of transport dynamics on concentration statistics and expected mass fraction based risk assessment in the subsurface ». Doctoral thesis, KTH, Mark- och vattenteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-133455.

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This thesis relies on a Langrangian framework used for conservative tracer transport simulations through 2-D heterogeneous porous media. Conducted numerical simulations enable large sets of concentration values in both spatial and temporal domains. In addition to the advection, which acts on all scales, an additional mechanism considered is local scale dispersion (LSD), accounting for both mechanical dispersion and molecular diffusion. The ratio between these two mechanisms is quantified by the Peclet (Pe) number. In its base, the thesis gives answers to contaminant concentration features when influenced by: i) different log-conductivity variance; ii) log-conductivity structures defined by the same global variogram but with different log conductivity patterns cor-related; and iii) for a wide range of Peclet values. Results conducted by Monte Carlo (MC) analysis show a complex interplay between the aforementioned pa-rameters, indicating the influence of aquifer properties to temporal LSD evolu-tion. A stochastic characterization of the concentration scalar is done through moment analysis: mean, coefficient of variation (CVC), skewness and kurtosis as well as through the concentration probability density function (PDF). A re-markable collapse of higher order to second-order concentration moments leads to the conclusion that only two concentration moments are required for an accurate description of concentration fluctuations. This explicitly holds for the pure advection case, while in the case of LSD presence the Moment Deriv-ing Function (MDF) is involved to ensure the moment collapse validity. Fur-thermore, the expected mass fraction (EMF) concept is applied in groundwater transport. In its origin, EMF is function of the concentration but with lower number of realizations needed for its determination, compared to the one point PDF. From practical point of view, EMF excludes meandering effect and incorporates information about exposure time for each non-zero concentration value present. Also, it is shown that EMF is able to clearly reflect the effects of aquifer heterogeneity and structure as well as the Pe value. To demonstrate the uniqueness of the moment collapse feature and ability of the Beta distribution to account for the concentration frequencies even in real cases, Macrodisper-sion Experiment (MADE1) data sets are used.

QC 20131104

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Vogel, Alexander L. [Verfasser]. « Complementary mass spectrometric techniques for the characterization of the organic fraction in atmospheric aerosols / Alexander L. Vogel ». Mainz : Universitätsbibliothek Mainz, 2014. http://d-nb.info/1048498255/34.

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LAZZATI, ZELDA. « Speciation of particulate matter's organic fraction and its mechanis of action on human health ». Doctoral thesis, Università degli Studi di Milano-Bicocca, 2009. http://hdl.handle.net/10281/7466.

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Three main researches have been employed for the implementation of a protocol analysis for the characterization and quantification of the lignin fraction in the particulate matter at the concentration matrix level; the implementation of different methods of analysis of the toxic interesting pollutants, Oxy-PAHs; Nitro-PAHs and the Bisphenol A, that together with the large set of performed analysis, allowed the characterization of some PM fractions in relation with Indoor and Outdoor concentrations, human exposure and Urban – Rural – Remote sites composition. At last an in silica method was developed for the research of the proteins involved in the interaction with the pollutants of interest, optimized on Bisphenol A because of its history and recent interaction study with the Nuclear Receptors. From the involved pathway the Blood Serine Proteases are used to test the accuracy and reproducibility of obtained Autodock4.0 and Dock4.0 data. The method results useful for research on the biological mechanism of action in relation with both matrix concentrations and in vivo and in vitro studies. The data predicted will be confirmed by NMR analysis. The newest docking program gives more and more reproducible data, accurate and empirically shaped on the domain problem, at last the experimental data had to confirm or not confirm the predictions.

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Golon, Agnieszka [Verfasser]. « Characterization of complex mixtures of the light shredder waste fraction and caramelization processes by mass spectrometry / Agnieszka Golon ». Bremen : IRC-Library, Information Resource Center der Jacobs University Bremen, 2013. http://d-nb.info/1037012488/34.

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Capasso, Raffaella. « The gas mass fraction and the dynamical state in x-ray luminous clusters of galaxies at low redshift ». Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/7913/.

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Gli ammassi di galassie sono le strutture gravitazionalmente legate con le più profonde buche di potenziale, pertanto è previsto che questi contengano una frazione di barioni non molto diversa da quella cosmologica. Con l’introduzione di modelli sempre più accurati di fisica barionica all’interno di simulazioni idrodinamiche è stato possibile predire la percentuale cosmica di barioni presente negli ammassi di galassie. Unendo questi modelli previsionali con misure della frazione di gas in ammassi e informazioni sulla densità di barioni dell’Universo si può ottenere una stima della densità di materia cosmica Ωm. L'obiettivo di questo lavoro di Tesi è la stima di Ωm a partire dalla frazione di gas osservata in questi sistemi. Questo lavoro era stato già fatto in precedenza, ma tenendo in considerazione solo gli ammassi più massivi e dinamicamente rilassati. Usando parametri che caratterizzano la morfologia della distribuzione di brillanza superficiale nei raggi X, abbiamo classificato i nostri oggetti come rilassati o disturbati, laddove presentassero evidenze di recenti attività di interazione. Abbiamo dunque valutato l’impatto degli oggetti disturbati sulla stima del parametro cosmologico Ωm, computando il Chi2 tra la frazione di massa barionica nell’Universo e quella da noi ricavata. Infine abbiamo investigato una relazione tra il valore della frazione di gas degli ammassi rilassati e quello dei disturbati, in modo da correggere quindi questi ultimi, riportandoli nei dintorni del valore medio per i rilassati e usarli per ampliare il campione e porre un vincolo più stringente su Ωm. Anche con il limitato campione a nostra disposizione, è stato possibile porre un vincolo più stretto su Ωm, utilizzando un maggior numero di oggetti e riducendo così l’errore statistico.

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Livres sur le sujet "Mass fraction"

M, Cotterell E., et United States. National Aeronautics and Space Administration., dir. Determination of solid mass fraction in partially frozen hydrocarbon fuels. [Washington, DC : National Aeronautics and Space Administration, 1986.

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M, Cotterell E., et United States. National Aeronautics and Space Administration, dir. Determination of solid mass fraction in partially frozen hydrocarbon fuels. [Washington, DC : National Aeronautics and Space Administration, 1986.

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Griepink, B. The additional certification of the content (mass fraction) of iodine in two spiked samples of skim milk powder : CRM no.150-151. Luxembourg : Commission of the European Communities, 1986.

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Griepink, B. The certification of the contents (mass fraction) of carbon, hydrogen, nitrogen, chlorine, arsenic, cadmium, manganese, mercury, lead, selenium, vanadium and zinc in three coals : Gas coal CRM No.180, coking coal CRM No.181, steam coal CRM No.182. Luxembourg : Commission of the European Communities, 1986.

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Yonaga, Kouki. Mass Term Effect on Fractional Quantum Hall States of Dirac Particles. Singapore : Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-9166-9.

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Mai, Dawei, et Michael Peter Kennedy. Wandering Spurs in MASH-Based Fractional-N Frequency Synthesizers. Cham : Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-91285-7.

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Chanane, B. Input-output maps for nonlinear systems, fractional integration and rational representations. Sheffield : University of Sheffield, Dept. of Automatic Control and Systems Engineering, 1994.

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C, Ku Jerry, et United States. National Aeronautics and Space Administration., dir. Brief communication : Soot volume fraction maps for normal and reduced gravity laminar acetylene jet diffusion flames. [Washington, DC : National Aeronautics and Space Administration, 1997.

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Griepink, B. The certification of the contents (mass fractions) of calcium, potassium, iron, phosphorus and nitrogen in a single cell protein (CRM no.273). Luxembourg : Commission of the European Communities, 1985.

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Chapitres de livres sur le sujet "Mass fraction"

Deng, Peng, Zhiwei Niu, Kun Yang, Yan Liu et Xianglong Zhang. « Effect of Water-Binder Ratio, Alkali Mass Fraction and Lightweight Aggregate Size on Mechanical Properties of Alkali-Activated Concrete ». Dans Lecture Notes in Civil Engineering, 3–11. Singapore : Springer Nature Singapore, 2024. https://doi.org/10.1007/978-981-97-6238-5_1.

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AbstractAlkali-Activated Ceramsite Concrete (AACC), a novel green building material, is important for the reutilization of industrial waste. Although there has been considerable progress in research on AACC, further investigation is still needed on ceramsite size, early strength, etc. In this paper, 11 groups containing 198 standard cubic specimens were fabricated to investigate the effects of water-binder ratio, alkali mass fraction and ceramsite diameter on compressive strength and splitting tensile strength at different ages. And the slump constant of the mixtures was tested for different water-binder ratios and alkali mass fractions during fabrication. The results showed that the slump and strength increased with the increase of water-binder ratio. As the alkali mass fraction increased the slump decreased and then increased but the strength increased and then decreased. Therefore the proper value of alkali mass fraction was about 6%. When the diameter of ceramsite increased, the compressive strength first increased and then decreased. Thus the 5–15 mm diameter was the optimum. Splitting tensile strength always decreased with the increase of diameter of ceramsite.

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Kumar, D., M. Alam et J. Sanjayan. « A Novel Concrete Mix Design Methodology ». Dans Lecture Notes in Civil Engineering, 457–68. Singapore : Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-3330-3_46.

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AbstractConcrete mix design is the methodology for mixing binder, aggregate and water to achieve required physical, mechanical, and thermal properties. In particular, the physical properties depend on the volume fraction of each element in the concrete recipe. In this study we considered cement mortar, complying with ASTM C105, as the reference concrete with cement as the binder and silica sand as the aggregate. The reference mortar was denser with high thermal conductivity and compressive strength at given rheological properties. A denser concrete presents difficulty in material handling and imposes a safety risk, and high thermal conductivity increases building energy consumption. Therefore, lightweight concrete (LWC) has been developed by replacing silica sand with porous materials. LWC includes cement as the binder, with silica sand and other porous materials as the primary and binary fillers. The mass of the filler materials is determined by their particle density and volume fraction. LWC has low thermal mass, thereby exacerbating the summertime overheating and peak cooling demand of buildings. Therefore, there is a need to design a LWC with high thermal mass by incorporating phase change materials (PCM), which are mainly incorporated as tertiary filler. Here, we propose a novel concrete mix design methodology to incorporate PCM composite as a partial replacement of the porous material without changing binding materials.

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Paperzh, Kirill, Elizaveta Moguchikh, Aleksey Nikulin et Irina Gerasimova. « Highly Stable Pt/C Catalysts with Different Mass Fraction of Platinum ». Dans Springer Proceedings in Materials, 3–13. Cham : Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-76481-4_1.

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Levitt, David G., Dympna Gallagher et Steven B. Heymsfield. « Physiological Basis of Regression Relationship Between Body Mass Index (BMI) and Body Fat Fraction ». Dans Handbook of Anthropometry, 441–57. New York, NY : Springer New York, 2012. http://dx.doi.org/10.1007/978-1-4419-1788-1_24.

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Lisienko, Dmitry G., Margarita A. Dombrovskaya et Eugeniya D. Kubrina. « Manufacturing and Certification of Reference Materials for the Mass Fraction of Boron in Silumin ». Dans Reference Materials in Measurement and Technology, 67–76. Cham : Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-32534-3_7.

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Koga, R., M. Kosaka, Y. Hamamoto, E. Tomita et H. Sano. « Measuring the Mass Fraction Burned of a Methane-Air Mixture by Diode-Laser Absorption Spectrometry ». Dans Laser Diagnostics and Modeling of Combustion, 147–54. Berlin, Heidelberg : Springer Berlin Heidelberg, 1987. http://dx.doi.org/10.1007/978-3-642-45635-0_19.

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Ettori, Stefano. « The Gas Mass Fraction in Local and Z > ; 0.7 Galaxy Clusters : Constraints on Cosmology ». Dans 3K, SN’s, Clusters : Hunting the Cosmological Parameters with Precision Cosmology, 177–86. Dordrecht : Springer Netherlands, 2004. http://dx.doi.org/10.1007/978-94-017-0559-2_14.

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Franzen, David W., Keith Goulding, Antonio P. Mallarino et Michael J. Bell. « How Closely Is Potassium Mass Balance Related to Soil Test Changes ? » Dans Improving Potassium Recommendations for Agricultural Crops, 263–82. Cham : Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-59197-7_10.

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AbstractThe exchangeable fraction of soil potassium (K) has been viewed as the most important source of plant-available K, with other sources playing smaller roles that do not influence the predictive value of a soil test. Thus, as K mass balance changes, the soil test should change correspondingly to be associated with greater or reduced plant availability. However, soil test changes and the availability of K to plants are influenced by many other factors. This chapter reviews research on soil test K changes and the relation to crop uptake and yield. A mass-balance relationship is rarely achieved from the measurement of exchangeable K because of the potential for buffering of K removal from structural K in feldspars and from interlayer K in primary and secondary layer silicates. Similarly, surplus K additions can be fixed in interlayer positions in secondary layer silicates, or potentially sequestered in sparingly soluble neoformed secondary minerals, neither of which is measured as exchangeable K. In addition, soil moisture, temporal differences in exchangeable K with K uptake by crops, K leaching from residues, clay type, organic matter contribution to the soil CEC, and type of K amendment confound attempts to relate K additions and losses with an exchangeable K soil test. Research is needed to create regionally specific K soil test procedures that can predict crop response for a subset of clays and K-bearing minerals within specific cropping systems.

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Wang, Laixin, Shengli Wu, Minyin Kou, Xinliang Liu, Yujue Wang et Weidong Zhuang. « Influence of Operation Parameters on Mass Fraction of Sulfur in the Hot Metal in COREX Process ». Dans 7th International Symposium on High-Temperature Metallurgical Processing, 327–34. Cham : Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-48093-0_41.

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Rivera, J., F. Ventura, J. Caixach, A. Figueras, D. Fraisse et V. Blondot. « FAB Mass Spectrometric Study of the Non Volatile Organic Fraction in Raw and Drinking Water Extracts ». Dans Organic Micropollutants in the Aquatic Environment, 77–88. Dordrecht : Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-4660-6_7.

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Actes de conférences sur le sujet "Mass fraction"

BAUNCHALK, R. « High-mass-fraction booster demonstration motor test ». Dans 26th Joint Propulsion Conference. Reston, Virigina : American Institute of Aeronautics and Astronautics, 1990. http://dx.doi.org/10.2514/6.1990-2326.

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Shayler, P. J., M. W. Wiseman et T. Ma. « Improving the Determination of Mass Fraction Burnt ». Dans International Congress & Exposition. 400 Commonwealth Drive, Warrendale, PA, United States : SAE International, 1990. http://dx.doi.org/10.4271/900351.

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Makovejev, I. I., V. S. Braguin et A. L. Makovejeva. « Moisture mass fraction determination on poultry meat defrosting ». Dans SCIENTIFIC AND TECHNICAL SUPPORT EFFICIENCY AND QUALITY PRODUCTION OF AGRICULTURAL PRODUCTS. VNIIPP, 2019. http://dx.doi.org/10.30975/978-5-9909889-2-7-2019-1-1-136-141.

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GLANTSCHNIG, W. J., et A. HOLLIDAY. « Characterization of porous soot boules by mass fraction profiling ». Dans Optical Fiber Communication Conference. Washington, D.C. : OSA, 1987. http://dx.doi.org/10.1364/ofc.1987.mh4.

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Béguin, C., É. Pelletier et S. Étienne. « Void Fraction Effect on Added Mass in Bubbly Flow ». Dans ASME 2014 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/pvp2014-28460.

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This paper proposes a relation for the added mass coefficient of spherical bubbles depending on void fraction based on results obtained by a semi-analytical method. This information is essential to completely characterize finely dispersed bubbly flows, where small spherical gas bubbles are present in a continuous liquid phase. Most of the closure relations for Euler-Euler or Euler-Lagrange models are obtained from experiments involving single bubbles. Their applicability to systems with high void fraction is therefore questionable. This paper uses solid harmonics to solve 3D potential flow around bubbles. Several configurations were calculated for different numbers of particles and spatial arrangements. Our results are compared with previous studies. Depending on the model proposed by previous authors, added mass forces could increase or decrease with the void fraction. This paper solves these discrepancies. The main purpose of this work is to develop simple formulas fitting our semi-analytical results. These simple formulas are suitable for further use, particularly as added mass models for multiphase flow averaged equations.

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Miadonye, A., N. Latour et V. R. Puttagunta. « Modelling Viscosity And Mass Fraction Of Bitumen - Diluent Mixtures ». Dans Technical Meeting / Petroleum Conference of The South Saskatchewan Section. Petroleum Society of Canada, 1999. http://dx.doi.org/10.2118/99-121.

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Mewes, Bernd, Gerd Bauer et Dieter Brüggemann. « Vapor/liquid mass fraction measurements by linear Raman spectroscopy ». Dans Laser Applications to Chemical and Environmental Analysis. Washington, D.C. : Optica Publishing Group, 1998. http://dx.doi.org/10.1364/lacea.1998.lwa.3.

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In almost all combustion systems the liquid fuel is injected into the combustor as a spray. Spray formation, vaporization, and mixing with the oxidizer determine the quality of the combustion process and thereby the amount of unwanted emissions. A laser diagnostic is needed which can monitor these processes in order to optimize them. Especially the distributions of vaporized fuel and of oxidizer are of interest including regions where liquid fuel is coexisting. A well-known method to discriminate between different phases of the fuel is the exciplex fluorescence technique developed by Melton and Verdieck [1]. Quantitative results are difficult to obtain if oxygen, the oxidizer in almost all combustion systems, is present. Another technique is based on the fluorescence of acetone which is practically independent of its phase. Phase discrimination is done by using the huge difference in molecular density [2]. The high absorption coefficient for the used UV light prevented saturation of the CCD camera by liquid droplets.

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Punanova, A. F., et I. V. Petrashkevich. « Deuterium fractionation in low-mass star-forming regions ». Dans Всероссийская с международным участием научная конференция студентов и молодых ученых, посвященная памяти Полины Евгеньевны Захаровой «Астрономия и исследование космического пространства». Ural University Press, 2021. http://dx.doi.org/10.15826/b978-5-7996-3229-8.41.

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In this work, we study how deuterium fraction changes depending on the physical conditions in cold cores embedded in the molecular clouds of Taurus, Perseus and Ophiuchus. The results show that the deuterium fraction in cold cores varies in different star-forming regions. In the densest and most turbulent of the studied regions, L1688 in Ophiuchus, the deuterium fraction is two times higher than that of L1495 in Taurus and B5 in Perseus. In L1495 and L1688, the deuterium fraction in the central parts of the cores and in their envelopes differ by a factor of 10, while in B5 only by a factor of 2—3.

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Cioncolini, Andrea. « Entrained Liquid Fraction in Annular Two-Phase Flow ». Dans The 7th World Congress on Momentum, Heat and Mass Transfer. Avestia Publishing, 2022. http://dx.doi.org/10.11159/icmfht22.002.

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Napolitano, Kevin L., Peter Kerrian et Eric Boekeloo. « Calculation of Modal Effective Mass Fraction and Rigid Body Mass Properties from Frequency Response Functions ». Dans AIAA SCITECH 2024 Forum. Reston, Virginia : American Institute of Aeronautics and Astronautics, 2024. http://dx.doi.org/10.2514/6.2024-0619.

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Rapports d'organisations sur le sujet "Mass fraction"

Vetter, Thomas W. Certification of Standard Reference Material® 2693a Bituminous Coal (Nominal Mass Fraction 0.5 % Sulfur). Gaithersburg, MD : National Institute of Standards and Technology, 2022. http://dx.doi.org/10.6028/nist.sp.260-230.

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Ramaye, Y., V. Kestens, J. Charoud-Got, S. Mazoua, G. Auclair, T. J. Cho, B. Toman, V. A. Hackley et T. Linsinger. Certification of Standard Reference Material® 1992 / ERM®-FD305 Zeta Potential – Colloidal Silica (Nominal Mass Fraction 0.15 %). National Institute of Standards and Technology, novembre 2020. http://dx.doi.org/10.6028/nist.sp.260-208.

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Ramaye, Y., V. Kestens, J. Charoud-Got, S. Mazoua, G. Auclair, T. J. Cho, B. Toman, V. A. Hackley et T. Linsinger. Certification of Standard Reference Material® 1993 / ERM®-FD306 Zeta Potential – Colloidal Silica (Nominal Mass Fraction 2.2 %). National Institute of Standards and Technology, novembre 2020. http://dx.doi.org/10.6028/nist.sp.260-209.

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Obermajer, M., M. G. Fowler, C. L. Riediger et N. Ejezie. Saturate fraction gas chromatography and mass spectrometry data for selected crude oils from Triassic reservoirs in Western Canada. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2011. http://dx.doi.org/10.4095/288060.

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Obermajer, M., K. Dewing et M. G. Fowler. Geological and geochemical data from the Canadian Arctic Islands. Part VIII : Saturate fraction gas chromatography-mass spectrometry data for organic extracts. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2008. http://dx.doi.org/10.4095/224969.

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Obermajer, M., K. Dewing et M. G. Fowler. Geological and geochemical data from the Canadian Arctic Islands. Part IX : Saturate fraction gas chromatography-mass spectrometry data for hydrocarbon samples. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2008. http://dx.doi.org/10.4095/226238.

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Bajwa, Abdullah, Tim Kroeger et Timothy Jacobs. PR-457-17201-R04 Residual Gas Fraction Estimation Based on Measured Engine Parameters - Phase IV. Chantilly, Virginia : Pipeline Research Council International, Inc. (PRCI), septembre 2021. http://dx.doi.org/10.55274/r0012176.

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Based on experimental characterization of the scavenging behavior of a cross-scavenged, piston-aspirated, two-stroke, natural gas engine in phase III of the current project, a computationally inexpensive simple scavenging model was improved in this phase. Experimental results using fast nondispersive infrared (NDIR) CO2 measurements from the cylinder and the exhaust, as well as experiments using unburned fuel pre-mixed in the scavenging chamber as a tracer for short-circuiting during scavenging, were used in this phase to validate the improved model. The model represents the fundamental phenomenological characteristics revealed by those experiments. The experiments and literature show that scavenging takes place by the following phenomena: blowdown, displacement of residuals by incoming air, mixing of residuals and air, and short-circuiting of fresh air. To reflect this, the improved hybrid model features the following: isentropic blowdown, non-isothermal perfect displacement, non-isothermal perfect mixing, and a concurrent direct short-circuiting of air (unmixed with residuals). The validated improved hybrid model rectified the primary shortcoming of the phase III model. By adding the discrete short-circuiting zone, trapped mass could be modeled at both medium and high crankshaft speeds, whereas the phase III model could not capture the full scope of scavenging inefficiencies at medium speed using its perfect mixing stage alone. Furthermore, using the hybrid model to predict NOx using an exponential NO and shy;x-TER curve fit revealed that the improved phase IV hybrid model predicts NOx approximately as well as the experimentally-calculated TER from the phase III experiments. Additionally, GT-Power, a 1D fluid dynamics and engine simulation software, was used to identify whether hybrid model tuning could be aided by relatively inexpensive 1D simulation rather than CFD or fast NDIR experiments. Using three-pressure analysis (with in-cylinder, exhaust, and scavenging chamber pressures as boundary conditions) and scavenging profiles derived from the hybrid model itself, GT-Power was shown to be a plausible tool for scavenging model tuning.

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Aubert, B. Determination of the Branching Fraction for B rightarrow X{sub c} ell nu Decays and of |V{sub cb}| from Hadronic-Mass and Lepton-Energy Moments. Office of Scientific and Technical Information (OSTI), avril 2004. http://dx.doi.org/10.2172/826861.

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Bajwa, Abdullah, et Timothy Jacobs. PR-457-17201-R03 Residual Gas Fraction Estimation Based on Measured In-Cylinder Pressure - Phase III. Chantilly, Virginia : Pipeline Research Council International, Inc. (PRCI), janvier 2021. http://dx.doi.org/10.55274/r0011996.

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An experimental study was carried out to characterize the scavenging behavior of a cross-scavenged, piston-aspirated, two-stroke, natural gas engine to aid in the development of computationally inexpensive simple scavenging models for onboard engine control by (1) studying the effects of changing operational parameters on the engine's scavenging performance, and (2) identifying the underlying phenomena driving the observed effects. Tracer based methods were used to quantify the scavenging and trapping performance of the engine - CO2 was used as a tracer for combustion products and pre-mixed fuel was used as a fresh charge tracer. CO2 concentration was measured on a crank angle resolved basis both in the engine cylinder and exhaust using portable NDIR sensors, while unburned fuel concentration was measured in the exhaust using the FID module of a standard five gas analyzer. It was found that scavenging took place in three stages, an initial perfect displacement type stage, followed by a short-circuiting, and a perfect mixing type stage. Engine speed and load changes were found to have the strongest effects on the trapping and scavenging performance of the engine; spark timing effects were less significant. Changes in measured scavenging and trapping efficiencies at different operating points resulted from a combination of influences, namely (1) reduced time for gas exchange at high speeds, (2) higher expansion and scavenging pressures at high loads and retarded spark timings, and (3) phasing of the reflected 'scavenging' and 'plugging' pulses in the exhaust pipe relative to BDC and EPC, respectively. Increasing engine load made the engine scavenge significantly better and increasing engine speed resulted in a larger fraction of the delivered air being trapped. The combined effect of these scavenging changes and changes in the engine's fuel conversion efficiency resulted in the engine running leaner at high speeds (more air delivered and higher trapping efficiency) and at low loads (higher trapped residuals). The results were then used to gauge the performance of the simple scavenging model (the hybrid model) developed in phase II of the project. While encouraging results were obtained at high speed, the trapped air mass was overestimated at medium speed; suggesting the need for adding a low scavenging efficiency sub-model. Recommendations have been made about adding a short-circuiting zone to address this limitation of the model.

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