Theoretical Analysis on the Constitution of Calorific Values of Biomass Fuels

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Fengqi Yao ◽  
Haihui Wang
Keyword(s):  
Chemical Species ◽  
Energy Utilization ◽  
Chemical Compositions ◽  
Chemical Bonds ◽  
Biomass Fuels ◽  
Conversion Model ◽  
Negative Role ◽  
First Time ◽  
Mass Increase ◽  
Heat Released

The present work explored the constitution of the calorific values of biomass fuels and the mechanism by which basic chemical compositions affect the fuel calorific data. For the first time, an energy conversion model was developed for the functional groups stored in biomass fuels by combustion. Validation of the model was performed by testing with various types of substances. By analyzing the effect of mass increase of individual chemical species on the amount of heat released by a fuel, it was confirmed that for ligno-cellulosic fuels, the species containing C–H, C–C and C=C bonds positively affect the fuel calorific values, whereas the species containing O–H, C–N, C–O, and C=O bonds have negative role in the increase of the fuel calorific values. A ratio parameter was then developed to quantitatively evaluate the potential of individual chemical bonds to contribute to the calorific values of biomass fuels, which well explained the existing techniques for treating biomass as fuels. The outcomes of this work serve as a theoretical basis for improving the efficiency in energy utilization of biomass fuels.

Chemical Species Identification in an SEM by Changes in Emitted X-Ray Energies

1974 ◽  
Vol 32 ◽  
pp. 570-571
Author(s):  
R. H. Duff
Keyword(s):  
Species Identification ◽  
Valence Electron ◽  
Chemical Species ◽  
X Rays ◽  
Chemical Bonds ◽  
Small Shift ◽  
X Ray ◽  
Electron Transitions ◽  
Peak Energy ◽  
Chemical Combination

A material irradiated with electrons emits x-rays having energies characteristic of the elements present. Chemical combination between elements results in a small shift of the peak energies of these characteristic x-rays because chemical bonds between different elements have different energies. The energy differences of the characteristic x-rays resulting from valence electron transitions can be used to identify the chemical species present and to obtain information about the chemical bond itself. Although these peak-energy shifts have been well known for a number of years, their use for chemical-species identification in small volumes of material was not realized until the development of the electron microprobe.

scholarly journals Comparative Study of Chemical Compositions and Antioxidant Capacities of Oils Obtained from 15 Macadamia (Macadamia integrifolia) Cultivars in China

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1031
Author(s):  
Xixiang Shuai ◽  
Taotao Dai ◽  
Mingshun Chen ◽  
Ruihong Liang ◽  
Liqing Du ◽  
...  
Keyword(s):  
Palmitoleic Acid ◽  
Linear Regression Analysis ◽  
Monounsaturated Fatty Acids ◽  
Multiple Linear Regression Analysis ◽  
Chemical Compositions ◽  
Macadamia Integrifolia ◽  
Antioxidant Capacities ◽  
Squalene Content ◽  
First Time ◽  
Insight Into

The planting area of macadamia in China accounted for more than one third of the world’s planted area. The lipid compositions, minor components, and antioxidant capacities of fifteen varieties of macadamia oil (MO) in China were comparatively investigated. All varieties of MO were rich in monounsaturated fatty acids, mainly including oleic acid (61.74–66.47%) and palmitoleic acid (13.22–17.63%). The main triacylglycerols of MO were first time reported, including 19.2–26.1% of triolein, 16.4–18.2% of 1-palmitoyl-2,3-dioleoyl-glycerol, and 11.9–13.7% of 1-palmitoleoyl-2-oleoyl-3-stearoyl-glycerol, etc. The polyphenol, α-tocotrienol and squalene content varied among the cultivars, while Fuji (791) contained the highest polyphenols and squalene content. Multiple linear regression analysis indicated the polyphenols and squalene content positively correlated with the antioxidant capacity. This study can provide a crucial directive for the breeding of macadamia and offer an insight into industrial application of MO in China.

scholarly journals Soil and Leaf Nutrients Drivers on the Chemical Composition of the Essential Oil of Siparuna muricata (Ruiz & Pav.) A. DC. from Ecuador

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2949
Author(s):  
Juan I. Burneo ◽  
Ángel Benítez ◽  
James Calva ◽  
Pablo Velastegui ◽  
Vladimir Morocho
Keyword(s):  
Gas Chromatography ◽  
Chemical Composition ◽  
Secondary Metabolites ◽  
Essential Oil ◽  
Chemical Elements ◽  
Climatic Conditions ◽  
Gas Chromatography Mass Spectrometry ◽  
Chemical Compositions ◽  
Leaf Nutrients ◽  
First Time

Chemical compositions of plants are affected by the initial nutrient contents in the soil and climatic conditions; thus, we analyzed for the first time the effects of soil and leaf nutrients on the compositions of the essential oils (EOs) of Siparuna muricata in four different localities in Ecuador. EOs were obtained by hydrodistillation and analyzed by gas chromatography/mass spectrometry (GC/MS) and a gas chromatography/flame ionization detector (GC/FID). Enantiomeric distribution by GC/MS was determined, modifying the enantiomeric separation of β-pinene, limonene, δ-elemene, β-bourbonene, cis-cadina-1 (6), 4-diene and atractylone. A total of 44 compounds were identified. The most representative for L1 were guaiol, atractylone and 4-diene; for L2, cis-cadina-1(6),4-diene and myrcene; for L3, atractylone, myrcene and germacrene B; and finally, L4 germacrene B, myrcene and cis-cadina-1(6),4-diene. Correlations between soil- leaf chemical elements such as Al, Ca, Fe, Mg, Mn, N and Si in the different localities were significant with chemical composition of the essential oil of Siparuna muricata; however, correlations between soil and leaf K, P, and Na were not significant. Cluster and NMDS analysis showed high dissimilarity values of secondary metabolites between four localities related with changes in soil- leaf nutrients. Thus, the SIMPER routine revealed that not all secondary metabolites contribute equally to establishing the differences in the four localities, and the largest contributions are due to differences in guaiol, cis-cadina-1(6),4-diene, atractylone and germacrene. Our investigation showed for the first time the influences of altitude and soil- leaf chemical elements in the chemical composition of the EOs of S. muricata.

scholarly journals N.V. Gogol’s Works and Censorship

Literary Fact ◽  
2021 ◽  
pp. 238-256
Author(s):  
Igor A. Vinogradov
Keyword(s):  
Literary Criticism ◽  
Good Reason ◽  
Evidence Based ◽  
Previous Period ◽  
Analytical Review ◽  
Negative Role ◽  
The Common ◽  
The Government ◽  
First Time

For the first time, an analytical review of all, without exception, censorship stories of N.V. Gogol’s works is presented. An objective picture of Gogol's relationship with the censorship is being recreated. The findings of the study allow, with good reason, to judge about the interference of censors in the writer's works in a fundamentally different way, in comparison with the ideas offered by literary criticism of the previous period without solid evidence. Based on a thorough analysis, involving numerous archival sources, the common, stereotypical opinions about the extremely negative role of censorship in Gogol’s fate are being revised. The most significant negative result among all censorship interventions in Gogol's works was the activity of the censor of Westernizing views, opposed to the government, a professor at St. Petersburg University, A.V. Nikitenko. It is the numerous reductions of Nikitenko, И.А. Виноградов. Произведения Н .В. Гоголя и цензура 255 a friend of V.G. Belinsky, in Gogol's religious and patriotic book “Selected Passages from Correspondence with Friends” that the writer called “censorship murder”. No less significant was the intervention of the liberal censor in the texts of “Dead Souls”, “Theatrical Travel after the Presentation of a New Comedy” and other works of the writer. It is concluded that, with the exception of this “intrigue” against Gogol by the censor Nikitenko, on the whole Gogol's texts encountered relatively insignificant difficulties in censorship.

scholarly journals Fundamental laws of nature confirmed by free fall

2021 ◽  
Author(s):  
Grit kalies
Keyword(s):  
Laws Of Nature ◽  
Free Fall ◽  
Mass Conservation ◽  
History Of Physics ◽  
Conservation Of Energy ◽  
History Of ◽  
Real Mass ◽  
Level I ◽  
First Time ◽  
Mass Increase

Abstract The principle of conservation of energy is often demonstrated by means of free fall. In mechanics, states of a body with potential and kinetic energy are energetically compared. Based on the mass concept of relativistic mechanics, energy conservation is considered to be linked with mass conservation. We show that the process of free fall can be interpreted more thoroughly, if the cause-effect principle and the mass concept of thermodynamics are applied. For the first time in the history of physics, the mechanism of energy conversion in free fall can be shown, which is valid for any object, whether body or elementary particle. The phenomenon of falling confirms the following facts to be valid of on a fundamental level: i) The principle of conservation of energy, ii) The equivalence of inertial and gravitational mass, iii) The real mass increase of any object with its velocity, and iv) The continuousness of space and time. At the end of the article we explain why the theory of general relativity is unsuitable to demonstrate the conservation of energy during free fall.

scholarly journals Using isothermal calorimetry and FT-Raman spectroscopy for step-by-step monitoring of maize seed germination: case study

2020 ◽  
Vol 142 (2) ◽  
pp. 755-763
Author(s):  
Iwona Stawoska ◽  
Aleksandra M. Staszak ◽  
Iwona Ciereszko ◽  
Jakub Oliwa ◽  
Andrzej Skoczowski
Keyword(s):  
Seed Germination ◽  
Isothermal Calorimetry ◽  
Thermal Power ◽  
Chemical Compositions ◽  
Maize Seeds ◽  
Time Regime ◽  
Ft Raman Spectroscopy ◽  
Secondary Structure Of Proteins ◽  
First Time ◽  
Ft Raman

Abstract Thermoanalytical methods are widely used to study seed germination processes. Our research aimed to use them in order to monitor the germination of maize seeds. To this end, we employed—for the first time—the isothermal calorimetric method with full oxygen access. Dry seeds were placed in ampoules with threaded caps, filled with distilled water. Heat flow was recorded in microwatts at 20 °C for 72 h in order to determine changes in thermal power associated with germination. In parallel with these measurements, in the same time regime, we measured FT-Raman spectra, which allowed us to analyze how endosperm and embryo changed their chemical compositions during imbibition and germination. Spectra obtained for endosperm reflected chemical changes resulting from catabolic processes. We also analyzed variations in the secondary structure of proteins in the embryo accompanying germination. Decomposition of amide I bands proved that during germination and protein hydrolysis, the content of helical and β-sheet structures decreased. Furthermore, in the embryos of dry seeds, S-S linkages were in both gauche–gauche-trans and trans-gauche-trans conformations, but after imbibition, only gauche–gauche-trans conformation can be identified.

scholarly journals Ab initio study of mechanism of forming a Si-heterocyclic spiro-Sn-heterocyclic ring compound by cycloaddition reaction of Me2Si=Sn: and ethene

2019 ◽  
Vol 44 (2) ◽  
pp. 114-121
Author(s):  
Xiaojun Tan ◽  
Xiuhui Lu
Keyword(s):  
Singlet State ◽  
Cycloaddition Reaction ◽  
Chemical Species ◽  
Heterocyclic Ring ◽  
Basis Set ◽  
Cycloaddition Reactions ◽  
Unoccupied Orbital ◽  
Donor Acceptor ◽  
Moller Plesset ◽  
First Time

X2Si=Sn: (X = H, Me, F, Cl, Br, Ph, Ar, etc.) are a new chemical species. The cycloaddition reactions of X2Si=Sn: are a new field of stannylene chemistry. The mechanism of the cycloaddition reaction between singlet state Me2Si=Sn: and ethene has been investigated for the first time here using second-order Møller-Plesset perturbation theory together with the 6-311++G** basis set for C, H and Si atoms and the LanL2dz basis set for Sn atoms. From the potential energy profile, it could be predicted that the reaction has one dominant reaction channel. The reaction process presented is that the 5p unoccupied orbital of Sn in Me2Si=Sn: and the π orbital of ethene form a π → p donor–acceptor bond resulting in the formation of an intermediate. The instability of this intermediate makes it isomerize to a four-membered Si-heterocyclic ring stannylene. Because the 5p unoccupied orbital of the Sn atom in the four-membered Si-heterocyclic ring stannylene and the π orbital of ethene form a π → p donor–acceptor bond, the four-membered Si-heterocyclic ring stannylene further combines with ethene to form another intermediate. Because the Sn atom in this intermediate assumes sp3 hybridization after the transition state, the intermediate isomerizes to a Si-heterocyclic spiro-Sn-heterocyclic ring compound. This result indicates the modes of cycloaddition reactions between X2Si=Sn: and symmetric π-bonded compounds, i.e. this study opens up a new field for stannylene chemistry.

Non-Destructive Fluorine Depth Profiling as Quality Assurance for the Oxidation Protection of TiAl Turbine Blades

2010 ◽  
Vol 638-642 ◽  
pp. 1384-1389 ◽  
Author(s):  
Sven Neve ◽  
Kurt Stiebing ◽  
Lothar P.H. Schmidt ◽  
Hans Eberhard Zschau ◽  
Patrick J. Masset ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Ion Beam ◽  
Turbine Blades ◽  
Depth Profiling ◽  
Temperature Oxidation ◽  
Beam Analysis ◽  
Before And After ◽  
First Time ◽  
Non Destructive ◽  
Mass Increase

Using the halogen effect TiAl-alloys can be protected against high-temperature oxidation. Two different fluorination methods were applied to turbine blades. The mass increase due to oxidation can be drastically reduced compared to untreated specimen. A new vacuum chamber for ion beam analysis was developed to analyze the real parts. Using PIGE-technique the F-content as a function of depth before and after oxidation was detected. Thickness and composition of the oxide scale were measured by RBS. Both ion beam methods were non destructive and thus enabled for the first time quality assurance of the halogen treatment on real components.

scholarly journals Comparative Study of the Chemical Compositions and Antioxidant Activities of Fresh Juices from Romanian Cucurbitaceae Varieties

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5468
Author(s):  
Anna Cazanevscaia Busuioc ◽  
Andreea-Veronica Dediu Botezatu ◽  
Bianca Furdui ◽  
Costel Vinatoru ◽  
Filippo Maggi ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Chemical Composition ◽  
High Performance ◽  
Antioxidant Activities ◽  
Fruit Juices ◽  
Antioxidant Potential ◽  
Chemical Compositions ◽  
Beneficial Effects ◽  
Benincasa Hispida ◽  
First Time

Cucurbitaceae is a family of health-promoting plants due to their compounds with beneficial effects. The aim of this study was to analyze, for the first time, the chemical composition, the antioxidant activity and the metal chelating properties of fruit juices obtained from four different species of the Cucurbitaceae family cultivated in Romania, namely Momordica charantia, Cucumis metuliferus, Benincasa hispida and Trichosanthes cucumerina. The samples of juice were analyzed by high-performance liquid chromatography (HPLC) and all the four species displayed high levels of the two triterpenes, oleanolic and ursolic acids, and also in phenolic compounds, including catechin, (−)-epicatechin and gallic acid. The juices demonstrated significant antioxidant activity against the free radical 2,2-diphenyl-1-picrylhydrazyl (ranging from 20 to 95%,), a good iron binding ability (ranging from 7.45 ± 0.28% to 86.95 ± 0.97%) and also promising antioxidant potential against the ABTS radical (ranging from 4.97 to 32.60 μETx/mL juice). Our findings raise interesting questions for further research on Cucurbitaceae fruit juices and, consequently, their very good antioxidant potential suggests these fruits should be further explored for their protective effect against oxidative damage. This is the first time the chemical composition and antioxidant activities of fruit juices from these four Romanian Cucurbitaceae varieties have been investigated.

scholarly journals Molecules in Comets: A Tool to Estimate the Low Energy Cosmic Ray Flux Outside the Solar System?

1987 ◽  
Vol 120 ◽  
pp. 443-445
Author(s):  
Valerio Pirronello
Keyword(s):  
Solar System ◽  
Chemical Species ◽  
Cosmic Ray ◽  
Low Energy ◽  
Chemical Modifications ◽  
Cometary Nuclei ◽  
First Time ◽  
Cosmic Ray Flux

It is described a method for evaluating the low energy cosmic ray flux outside the heliosphere. It is based on the chemical modifications induced in cometary nuclei by impinging ions and on the release of synthesized chemical species by comets entering for the first time into the inner solar system.

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