scholarly journals Influence of the fermentation methods on the resistant starch formation by X-ray diffraction

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Sachio Kanazawa ◽  
Melissa Sanabria ◽  
Magna Monteiro

AbstractThis work consists of a study about the influence of the fermentation methods on the resistant starch (RS) formation. Crystalline phases at the white bread after production and during the staling were evaluated. The bakery formulation was proportionally the same for the two fermentation methods used, except for the yeast. A commercial dry yeast and sourdough were used for the direct method (DM) and indirect method (IM), respectively. The temperature and cooking time, as well as the packaging and storage, were kept constant for all samples. Characterizations were performed on both samples by XRD and FTIR-ATR. It is possible to affirm that the fermentation method greatly influences the crystalline and microstructural properties of bread, mainly on the RS. The bread produced by IM presented more significant changes in its microstructure and degree of crystallinity than bread made by DM. These microstructural differences may be directly related to the microorganisms present in the sourdough, which can influence the bread resistant starch during the cooking and storage time.

2021 ◽  
Vol 105 (1) ◽  
pp. 77-84
Author(s):  
Patrícia Guricová ◽  
Ondřej Čech ◽  
Tomáš Kazda

Extraction of the cathode material from disassembled Samsung 18650 cell with LiCoO2 (LCO) chemistry was performed. The effect of dissolving with industrially used organic solvents is compared with the effect of selected ecological options. In successfully separated powders were studied structural changes as a function of aging and storage time. Ex-situ X-ray diffraction analysis was used for observation of differences between materials separated from cell in a fresh state and aged cell. Phase transition happening in the LiCoO2 material during cycling of the battery but also when in contact with air are discussed. Shift of the main peak (0 0 3) and (1 0 4) for the aged cathode material are displayed and discussed.


Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 98
Author(s):  
Valentina Loganina ◽  
Kristina Sergeeva ◽  
Roman Fediuk ◽  
Sergey Klyuev ◽  
Nikolai Vatin ◽  
...  

Lime mixes are the primary material for restoration work in historic buildings. The research object of this study is modifying lime binders with specially synthesized calcium silicate hydrates (CSHs). This study aimed to improve lime render mixes’ weather resistance. The following factors were considered: the density of the liquid glass, the amount of the precipitating additive, the rate of introduction of the precipitating additive, the drying mode of the precipitate, and the storage time of the precipitate. The research methods were X-ray diffraction analysis, differential thermal analysis, Fourier transform infrared spectrometry, and optical and electron microscopy. It was revealed that lime compositions with CSH have a higher strength gain rate than the control compositions. A mathematical model of the kinetics of hardening a lime composite based on a binder filled with CSH was obtained. The regularities of the change in the lime composite’s strength depending on the filler grinding’s fineness, its content, and the amount of mixing water have been established. It was revealed that the introduction of CSH into the lime composition increases the weather resistance of facade lime mixtures by reducing the porosity and increasing the volume of closed pores of the composite.


MRS Advances ◽  
2016 ◽  
Vol 1 (22) ◽  
pp. 1631-1636 ◽  
Author(s):  
Boya Cui ◽  
D. Bruce Buchholz ◽  
Li Zeng ◽  
Michael Bedzyk ◽  
Robert P. H. Chang ◽  
...  

ABSTRACTThe cross-plane thermal conductivities of InGaZnO (IGZO) thin films in different morphologies were measured on three occasions within 19 months, using the 3ω method at room temperature 300 K. Amorphous (a-), semi-crystalline (semi-c-) and crystalline (c-) IGZO films were grown by pulsed laser deposition (PLD), followed by X-ray diffraction (XRD) for evaluation of film quality and crystallinity. Semi-c-IGZO shows the highest thermal conductivity, even higher than the most ordered crystal-like phase. After being stored in dry low-oxygen environment for months, a drastic decrease of semi-c-IGZO thermal conductivity was observed, while the thermal conductivity slightly reduced in c-IGZO and remained unchanged in a-IGZO. This change in thermal conductivity with storage time can be attributed to film structural relaxation and vacancy diffusion to grain boundaries.


2019 ◽  
Vol 14 (29) ◽  
pp. 55-72
Author(s):  
Bushra A. Hasan

Alloys of InxSe1-x were prepared by quenching technique withdifferent In content (x=10, 20, 30, and 40). Thin films of these alloyswere prepared using thermal evaporation technique under vacuum of10-5 mbar on glass, at room temperature R.T with differentthicknesses (t=300, 500 and 700 nm). The X–ray diffractionmeasurement for bulk InxSe1-x showed that all alloys havepolycrystalline structures and the peaks for x=10 identical with Se,while for x=20, 30 and 40 were identical with the Se and InSestandard peaks. The diffraction patterns of InxSe1-x thin film showthat with low In content (x=10, and 20) samples have semicrystalline structure, The increase of indium content to x=30decreases degree of crystallinity and further increase of indiumcontent to x=40 leads to convert structure to amorphous. Increase ofthickness from 300 to 700nm increases degree of crystallinity for allindium content. Transmittance measurements were used to calculaterefractive index n and the extinction coefficient k using Swanepole’smethod. The optical constants such as refractive index (n), extinctioncoefficient (k) and dielectric constant (εr, εi) increases for low indiumcontent samples and decreases for high indium content samples,while increase of thickness increases optical constants for all xvalues. The oscillator energy E0, dispersion energy Ed, and otherparameters have been determined by Wemple - DiDomenico singleoscillator approach.


2021 ◽  
Vol 116 ◽  
pp. 5-14
Author(s):  
Marta Babicka ◽  
Magdalena Woźniak ◽  
Kinga Szentner ◽  
Sławomir Borysiak ◽  
Krzysztof Dwiecki ◽  
...  

The aim of this study was to compare parameters of nanocellulose obtained by two different procedures: hydrolysis with ionic liquids (1-allyl-3-methylimidazolium chloride and 1-ethyl-3-methylimidazolium acetate) and hydrolysis with ionic liquids in combination with hydrolysis using a cellulolytic enzyme from Trichoderma reesei. Avicel cellulose was treated with two ionic liquids: 1-allyl-3-methylimidazolium chloride (AmimCl) and 1-ethyl 3-methylimidazolium acetate (EmimOAc). In the two-step hydrolysis cellulose after treatment with ionic liquids was additionally hydrolyzed with a solution of enzymes. In order to characterize the obtained material, the following analyses were used: infrared spectroscopy, X-ray diffraction and dynamic light scattering. The results indicated that cellulose obtained by two-step nanocellulose production methods (first hydrolysis with ionic liquids and then with enzymes) showed similar parameters (particle size, XRD patterns and degree of crystallinity) as the material after the one-step process, i.e. hydrolysis with ionic liquids.


Fibers ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 47 ◽  
Author(s):  
Miguel A. Rivero Crespo ◽  
Dolores Pereira Gómez ◽  
María V. Villa García ◽  
José M. Gallardo Amores ◽  
Vicente Sánchez Escribano

Serpentinite powdered samples from four different regions were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), SBET and porosity measurements, UV-Vis and Infrared Spectroscopy of the skeletal region and surface OH groups. SEM micrographs of the samples showed a prismatic morphology when the lizardite was the predominant phase, while if antigorite phase prevailed, the particles had a globular morphology. The few fibrous-shaped particles, only observed by SEM and weakly detected by XRD on MO-9C and MO13 samples, were characteristic of the chrysotile phase. All diffraction XRD patterns showed characteristic peaks of antigorite and lizardite serpentine phases, with crystallite sizes in the range 310–250 Å and with different degrees and types of carbonation processes, one derived from the transformation of the serpentine, generating dolomite, and another by direct precipitation of calcite. The SBET reached values between 38–24 m2∙g−1 for the samples less crystalline, in agreement with the XRD patterns, while those with a higher degree of crystallinity gave values close to 8–9 m2∙g−1. In the UV region all electronic spectra were dominated by the absorption edge due to O2− → Si4+ charge transfer transition, with Si4+ in tetrahedral coordination, corresponding to a band gap energy of ca 4.7 eV. In the visible region, 800–350 nm, the spectra of all samples, except Donai, presented at least two weak and broad absorptions centred in the range 650–800 and 550–360 nm, associated with the presence of Fe3+ ions from the oxidation of structural Fe2+ ions in the serpentinites ((MgxFe2+1−x)3Si2O5(OH)4). The relative intensity of the IR bands corresponding to the stretching modes of the OH’s groups indicated the prevalence of one of the two phases, antigorite or lizardite, in the serpentinites. We proposed that the different relative intensity of these bands could be considered as diagnostic to differentiate the predominance of these phases in serpentinites.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Guiyun Yi ◽  
Baolin Xing ◽  
Jianbo Jia ◽  
Liwei Zhao ◽  
Yuanfeng Wu ◽  
...  

Macroporous TiO2photocatalyst was synthesized by a facile nanocasting method using polystyrene (PS) spherical particles as the hard template. The synthesized photocatalyst was characterized by transmission electron microscope (TEM), scanning electron microscopy (SEM), thermogravimetry-differential thermogravimetry (TG-DTG), X-ray diffraction (XRD), and N2-sorption. TEM, SEM, and XRD characterizations confirmed that the macroporous TiO2photocatalyst is composed of anatase phase. The high specific surface area of 87.85 m2/g can be achieved according to the N2-sorption analysis. Rhodamine B (RhB) was chosen as probe molecule to evaluate the photocatalytic activity of the TiO2catalysts. Compared with the TiO2materials synthesized in the absence of PS spherical template, the macroporous TiO2photocatalyst sintered at 500°C exhibits much higher activity on the degradation of RhB under the UV irradiation, which can be assigned to the well-structured macroporosity. The macroporous TiO2material presents great potential in the fields of environmental remediation and energy conversion and storage.


2007 ◽  
Vol 29-30 ◽  
pp. 337-340 ◽  
Author(s):  
M.A. Sawpan ◽  
K.L. Pickering ◽  
Alan Fernyhough

The potential of hemp fibre as a reinforcing material for Poly(lactic acid) (PLA) was investigated. Good interaction between hemp fibre and PLA resulted in increases of 100% for Young’s modulus and 30% for tensile strength of composites containing 30 wt% fibre. Different predictive ‘rule of mixtures’ models (e.g. Parallel, Series and Hirsch) were assessed regarding the dependence of tensile properties on fibre loading. Limited agreement with models was observed. Differential scanning calorimetry (DSC) and x-ray diffraction (XRD) studies showed that hemp fibre increased the degree of crystallinity in PLA composites.


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