scholarly journals The Role of Polypropylene Microfibers in Thermal Properties and Post-Heating Behavior of Cementitious Composites

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2676
Author(s):  
Mohammad R. Irshidat ◽  
Nasser Al-Nuaimi ◽  
Mohamed Rabie
Keyword(s):  
Melting Point ◽  
Heat Flow ◽  
Mass Loss ◽  
Failure Modes ◽  
Cement Mortar ◽  
Xrd Analysis ◽  
Cementitious Composites ◽  
Polypropylene Fibers ◽  
Scanning Calorimetry ◽  
Heating Behavior

This paper experimentally studied the effect of polypropylene (PP) microfibers on thermal and post-heating mechanical behaviors of cementitious composites. Cement mortars with small dosage of polypropylene fibers were prepared, heated at various temperatures (150 °C, 200 °C, 450 °C, and 600 °C), and then tested. The investigated parameters include residual compressive and flexural strengths, elastic modulus, fracture energy, stress intensity factors, failure modes, microstructure (scanning electron microscopy (SEM) imaging), thermal conductivity, heat flow (differential scanning calorimetry (DSC) test), mass loss (thermogravimetric analysis (TGA) test), and chemical composition (XRD analysis). The results showed the efficiency of PP fibers to enhance the post-heating behavior and the residual mechanical properties of cement mortar after heating. The presence of PP fibers did not affect the heat flow and the mass loss of cement mortar at room temperature. However, heating cement mortar at temperature beyond the melting point of the fibers negatively affected its thermal behavior. The presence of PP fibers played a major role in bridging the cracks and mitigating their propagation. Once the melting point of the polypropylene fibers is exceeded, the fibers melted and created extra voids in the microstructure of concrete.

scholarly journals Analysis of DSC (differential scanning calorimetry) thermograms of milk fat

2021 ◽  
Vol 5 (3(61)) ◽  
pp. 36-39
Author(s):  
Maltam Shamilova ◽  
Sevinj Hajiyeva
Keyword(s):  
Fatty Acids ◽  
Differential Scanning Calorimetry ◽  
Melting Point ◽  
Heat Flow ◽  
Heating Rate ◽  
Milk Fat ◽  
Oxidation Time ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Melting Properties

The object of current research is the oxidation and melting properties of milk fat samples in different heating rates. One of the most problematic issues is the evaluation dependence of temperature and oxidation time regarding to heat flow, and the estimation of attitude of enthalpy values to heating rates. In order to gain a comprehensive assessment of oxidation and melting properties of milk fat samples on differential scanning calorimeter in various heating rates, it is necessary to conduct experimental studies. The analysis was performed using the dynamic option of the differential scanning calorimetry (DSC) with the following sample heating rates: 2.5, 4, 5, 7.5, 10, 12.5, 15 °C⋅min–1. Analyses were performed on 14 samples of milk fat, thus, for each heating rate were intended to two milk fat samples. As a result of the analysis, in the proper heating rates increased, it was found, that the oxidation properties of milk fat depend on the heating rates on DSC examination. In the thermal DSC analysis, the start temperature (Ts) (inlet), the onset temperature (Ton), and the maximum heat flow-peak temperatures (Tp) of oxidation were rising gradually. All the value of oxidation increased gradually with increasing heating rate, only in the Tend values were chainable among all heating rates. However, the oxidation time of milk fat is inversely proportional to the various heating rates in DSC. The oxidation enthalpy was calculated according to the heating rates too. The masses of the samples differ from each other, albeit slightly, which the individuality in the value of enthalpy could be explained through this ratio and duration of exothermic. The melting point considers the important indicator to explain the purity of samples. Melting curves of extracted milk fat samples on DSC were characterized by endothermic behavior and observed with the mild peaks, the first and the second distinct peaks due to the low-melting triacylglycerols (with high unsaturated fatty acids content) and high-melting fats, which present in milk fat. In concluded results, the characteristics of DSC oxidation curves are melting point due to the chemical structure of the fatty acids which milk fat samples contain.

Thermal Analysis of Ca1+xCu3Ti4O12+x Precursor in Nitrogen and Oxygen Environment at 1000 °C

2020 ◽  
Vol 1010 ◽  
pp. 268-273
Author(s):  
Julie Juliewatty Mohamed ◽  
Noruzaman Daud ◽  
Mohamad Johari bin Abu ◽  
Mohd Fariz Ab Rahman ◽  
Siti Roshayu binti Hassan ◽  
...  
Keyword(s):  
Mass Loss ◽  
Room Temperature ◽  
Single Phase ◽  
Xrd Analysis ◽  
Phase Changes ◽  
Oxygen Absorption ◽  
Atmospheric Gases ◽  
Scanning Calorimetry ◽  
Nitrogen Gas ◽  
Ca Ions

The thermal kinetic analyses are prepared on Ca1+xCu3Ti4O12+x powders using simultaneous thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC) measurement in a dual atmospheric gases environment. Initially, the nitrogen gas flowed from room temperature to 1000 °C, and then the environment was shifted and hold for 1 hour with oxygen. The result shows that the TGA patterns of the temperature and mass loss are disorderly with x values. The mass loss % patterns slightly decreased with increased additional Ca-based element. The decreased of oxygen absorption as the values of x increased also can be explained by the reduction of single-phase CCTO structure when excess Ca ions. The DSC pattern shows two prominent endothermic peaks and two exothermic peaks that relate to the melting point of the reactant and crystalline phase changes of samples, while the significant endothermic peak at 1000 °C is corresponding to the formation of CCTO compounds as identified by XRD analysis.

Mannose Conjugated Starch Nanoparticles for Preferential Targeting of Liver Cancer

2020 ◽  
Vol 17 ◽  
Author(s):  
Akhlesh Kumar Jain ◽  
Hitesh Sahu ◽  
Keerti Mishra ◽  
Suresh Thareja
Keyword(s):  
Side Effects ◽  
Liver Cancer ◽  
Entrapment Efficiency ◽  
Xrd Analysis ◽  
In Vitro Cytotoxicity ◽  
Physical Interaction ◽  
Scanning Calorimetry ◽  
Starch Nanoparticles

Aim: To design D-Mannose conjugated 5-Fluorouracil (5-FU) loaded Jackfruit seed starch nanoparticles (JFSSNPs) for site specific delivery. Background: Liver cancer is the third leading cause of death in world and fifth most often diagnosed cancer is the major global threat to public health. Treatment of liver cancer with conventional method bears several side effects, thus to undertake these side effects as a formulation challenge, it is necessary to develop novel target specific drug delivery system for the effective and better localization of drug into the proximity of target with restricting the movement of drug in normal tissues. Objective: To optimize and characterize the developed D-Mannose conjugated 5-Fluorouracil (5-FU) loaded Jackfruit seed starch nanoparticles (JFSSNPs) for effective treatment of liver cancer. Materials and methods: 5-FU loaded JFSSNPs were prepared and optimized formulation had higher encapsulation efficiency were conjugated with D-Mannose. These formulations were characterized for size, morphology, zeta potential, X-Ray Diffraction, and Differential Scanning Calorimetry. Potential of NPs were studied using in vitro cytotoxicity assay, in vivo kinetic studies and bio-distribution studies. Result and discussion: 5-Fluorouracil loaded NPs had particle size between 336 to 802nm with drug entrapment efficiency was between 64.2 to 82.3%. In XRD analysis, 5-FU peak was diminished in the diffractogram, which could be attributed to the successful incorporation of drug in amorphous form. DSC study suggests there was no physical interaction between 5- FU and Polymer. NPs showed sustained in vitro 5-FU release up to 2 hours. In vivo, mannose conjugated NPs prolonged the plasma level of 5-FU and assist selective accumulation of 5-FU in the liver (vs other organs spleen, kidney, lungs and heart) compared to unconjugated one and plain drug. Conclusion: In vivo, bio-distribution and plasma profile studies resulted in significantly higher concentration of 5- Fluorouracil liver suggesting that these carriers are efficient, viable, and targeted carrier of 5-FU treatment of liver cancer.

Analysis of the Samples of Fe-Cu-Nb-Si-B Amorphous Alloys Obtained by Dynamic Compacting Method

2005 ◽  
Vol 903 ◽  
Author(s):  
Victor A. Golubev ◽  
Andrey V. Strikanov ◽  
Grigory A. Potemkin ◽  
Ludmila V. Zueva ◽  
Aleksey V. Golubev ◽  
...  
Keyword(s):  
Shock Wave ◽  
Amorphous Alloys ◽  
Analysis Data ◽  
Xrd Analysis ◽  
Soft Magnetic ◽  
Scanning Calorimetry ◽  
Soft Magnetic Alloys ◽  
Nano Crystalline ◽  
The Impact ◽  
Magnetic Conductivity

AbstractThe Dynamic Compacting (DC) method is promising method to produce considerable-size nonporous wares. The phenomenon is based on the impact of shock wave on the initial powders of amorphous alloys. Every time when the shock wave propagates through the bulk of substance then the temperature rises substantially. Therefore there is a need of study of the DC’s effect on the structure and properties of the amorphous alloys. The results of the thermal analysis (in particular, Differential Scanning Calorimetry) of the samples of the soft magnetic alloys are presented in the report. These results concern with amorphous alloys of 5BDSR, GM414, 10NSR trademarks before DC and after DC, respectively. It is shown there is single low-temperature endothermic peak (near 300C) and there are several high temperature exothermic peaks (near 540C, 650C, and 700C). The first peak is related to glass-transition, the following peaks are related to formation of nano-crystalline phases. It was proved by XRD analysis data. The optimal regimes of the thermal processing of final wares were chosen on the base of thermal- and XRD-analysis. The study of the effects of these regimes on the properties (magnetic conductivity, specific losses etc.) of the circular magnetic conductors was executed. In particular, thermal- as well as thermo-magnetic processing of magnetic conductors based on 5BDSR amorphous alloy (after DC) essentially improves their magnetic properties. For example, magnetic conductivity fÝ increases approximately by factor 17 with respect to the magnitude before DC.

MICROSTRUCTURAL EVOLUTION OF Al-Cu-Mg-Ag ALLOY WITH TRACE Zr ADDITION DURING TWO-STEP HOMOGENIZATION

2009 ◽  
Vol 23 (06n07) ◽  
pp. 855-862 ◽  
Author(s):  
FEIYUE MA ◽  
ZHIYI LIU
Keyword(s):  
Melting Point ◽  
Grain Boundaries ◽  
Microstructural Evolution ◽  
Cast Alloy ◽  
Scanning Calorimetry ◽  
Zr Addition ◽  
Homogenization Time ◽  
The Matrix ◽  
Higher Temperature ◽  
Lower Temperature

The microstructural evolution in an Al - Cu - Mg - Ag alloy with trace Zr addition during homogenization treatment was characterized by Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM) and Energy-dispersive X-ray Spectroscopy (EDS). It was shown that the low-melting-point phase segregating toward grain boundaries is Al 2 Cu , with a melting point of 523.52°C. A two-step homogenization process was employed to optimize the microstructure of the as-cast alloy, during which the alloy was first homogenized at a lower temperature, then at a higher temperature. After homogenized at 420°C for 6 h, Al 3 Zr particles were finely formed in the matrix. After that, when the alloy was homogenized at an elevated temperature for a longer time, i.e., 515°C for 24 h, most of the precipates at the grain boundaries were removed. Furthermore, the dispersive Al 3 Zr precipitates were retained, without coarsening greatly in the final homogenization step. A kinetics model is employed to predict the optimal homogenization time at a given temperature theoretically, and it confirms the result in present study, which is 420°C/6h+515°C/24h.

scholarly journals Effect of the dispersion of the chromophore on the optical performances of polarizers from polyethylene and 5”-thio- (3-butyl)nonyl-2,2’:5’,2”-terthiophene

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Andrea Pucci ◽  
Letizia Moretto ◽  
Giacomo Ruggeri ◽  
Francesco Ciardelli
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Melting Point ◽  
Drawing Ratio ◽  
Scanning Calorimetry ◽  
Affine Deformation ◽  
Ultra High Molecular Weight ◽  
Scanning Electron

AbstractA new polyethylene-compatible terthiophene chromophore, 5”-thio-(3- butyl)nonyl-2,2’:5’,2”-terthiophene, with melting point lower than 0°C was prepared and used for linear polarizers based on ultra-high-molecular-weight polyethylene (UHMWPE). Differential scanning calorimetry and scanning electron microscopy indicate that the new chromophore is dispersed uniformly in films of UHMWPE obtained by casting from solution. The films show excellent dichroic properties (dichroic ratio 30) at rather low drawing ratio (≈ 20) . Moreover, qualitative agreement is observed with the Ward pseudo-affine deformation scheme.

scholarly journals A Facile Synthesis and Characterization of Highly Crystalline Submicro-Sized BiFeO3

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3035
Author(s):  
Dovydas Karoblis ◽  
Diana Griesiute ◽  
Kestutis Mazeika ◽  
Dalis Baltrunas ◽  
Dmitry V. Karpinsky ◽  
...  
Keyword(s):  
Bismuth Ferrite ◽  
Cost Effective ◽  
Xrd Analysis ◽  
Synthetic Approach ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Dsc Measurements ◽  
Optimal Annealing Temperature ◽  
Synthesized Materials

In this study, a highly crystalline bismuth ferrite (BFO) powder was synthesized using a novel, very simple, and cost-effective synthetic approach. It was demonstrated that the optimal annealing temperature for the preparation of highly-pure BFO is 650 °C. At lower or higher temperatures, the formation of neighboring crystal phases was observed. The thermal behavior of BFO precursor gel was investigated by thermogravimetric and differential scanning calorimetry (TG-DSC) measurements. X-ray diffraction (XRD) analysis and Mössbauer spectroscopy were employed for the investigation of structural properties. Scanning electron microscopy (SEM) was used to evaluate morphological features of the synthesized materials. The obtained powders were also characterized by magnetization measurements, which showed antiferromagnetic behavior of BFO powders.

scholarly journals Influence of Rigid Segment Type on Copoly(ether-ester) Properties

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4614
Author(s):  
Konrad Walkowiak ◽  
Izabela Irska ◽  
Agata Zubkiewicz ◽  
Zbigniew Rozwadowski ◽  
Sandra Paszkiewicz
Keyword(s):  
Alternative Energy ◽  
Raw Materials ◽  
Tensile Modulus ◽  
Xrd Analysis ◽  
Thermoplastic Elastomers ◽  
Polymer Materials ◽  
Scanning Calorimetry ◽  
Soft Phase ◽  
Ecological Awareness ◽  
Fourier Transformed Infrared Spectroscopy

The growing ecological awareness of society created the tendency to replace petrochemically based materials with alternative energy carriers and renewable raw materials. One of the most requested groups of polymer materials with significant technological importance is thermoplastic elastomers (TPE). They combine the properties of elastomers such as flexibility with the typical properties of thermoplastics, like easy processing. Herein, one compares the influence of rigid segments on the properties of copoly(ester-ether). Thermoplastic polyesters based on bio-1,6-hexanediol and terephthalic (T), furanic (F), and napthalate (N) diesters, i.e., PHT, PHF, and PHN, were obtained employing melt polycondensation. Additionally, to grant elastic properties of polyesters, systems containing 50 wt.% of bio-based polyTHF®1000 (pTHF) with a molecular mass of 1000 g/mol, have been prepared. The composition and chemical structure have been determined by 1H nuclear magnetic resonance (NMR) and Fourier transformed infrared spectroscopy (FTIR) analyses. The temperatures corresponding to phase transition changes were characterized by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) analyses. The crystalline structure was examined by X-ray diffraction (XRD) analysis. Additionally, the influence of pTHF–rich segment on the tensile properties, water absorption, as well as thermal and thermo-oxidative stability, has been analyzed. It was found that incorporation of soft phase allows creation of thermoplastic elastomers with tensile characteristics comparable to the commercially available ones, by means of elongation at break higher than 500%, low values of tensile modulus, without exhibiting yield point.

scholarly journals Efecto del dióxido de titanio en las propiedades mecánicas y autolimpiantes del mortero

2021 ◽  
Vol 25 (109) ◽  
pp. 88-97
Author(s):  
Carlos Magno Chavarry Vallejos ◽  
Liliana Janet Chavarría Reyes ◽  
Xavier Antonio Laos Laura ◽  
Andrés Avelino Valencia Gutiérrez ◽  
Enriqueta Pereyra Salardi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tio2 Nanoparticles ◽  
Low Temperatures ◽  
Mechanical Performance ◽  
Cement Mortar ◽  
Physical And Mechanical Properties ◽  
Cementitious Composites ◽  
Palabras Clave ◽  
Self Cleaning

El presente artículo tiene como objetivo determinar la influencia de la adición del dióxido de titanio (TiO2) en el mortero de cemento Pórtland Tipo I. La investigación es descriptiva, correlacional, explicativo, con diseño experimental, longitudinal, prospectivo y estudio de cohorte. Se elaboró una mezcla patrón y tres mezclas de mortero con 5%, 7.5% y 10% de contenido de TiO2 como reemplazo del volumen de cemento para las propiedades autolimpiantes se realizó el ensayo de rodamina e intemperismo. La incorporación de dióxido de titanio disminuyó la resistencia a la compresión, incrementó la fluidez y tasa de absorción de agua; la prueba de rodamina dio que el mortero sin actividad fotocatalítico no contenía TiO2 porque no cumple con los factores de fotodegradación R4 y R26. Mediante la exposición de paneles al intemperismo favoreciendo la propiedad autolimpiante de los morteros con adición de TiO2 (5%). Palabras Clave: Actividad foto catalítico, dióxido de titanio, factores de fotodegradación, propiedades mecánicas y autolimpiante. Referencias [1]E. Medina and H. Pérez, “Influencia del fotocatalizador dióxido de titanio en las propiedades autolimpiables y mecánicas del mortero de cemento - arena 1:4 - Cajamarca,” Universidad Nacional de Cajamarca, 2017. [2]G. Abella, “Mejora de las propiedades de materiales a base de cemento que contienen TiO 2 : propiedades autolimpiantes,” Universidad Politécnica de Madrid, 2015. [3]J. Gonzalez, “El Dióxido de titanio como material fotocatalitico y su influencia en la resistencia a la compresión en Morteros,” Universidad de San Buenaaventura Seccional Bello, 2015. [4]D. Jimenez and J. Moreno, “Efecto del reemplazo de cemento portland por el dioido de titanio en las propiedades mecanicas del mortero,” Pontificia Universidad Javeriana, 2016. [5]L. Wang, H. Zhang, and Y. Gao, “Effect of TiO2 nanoparticles on physical and mechanical properties of cement at low temperatures,” Adv. Mater. Sci. Eng., 2018, doi: 10.1155/2018/8934689. [6]Comisión de Normalización y de Fiscalización de Barreras Comerciales no Arancelares, Norma Técnica Peruana. Perú, 2013, p. 29. [7]ASTM Internacional, “ASTM C150,” 2021. https://www.astm.org/Database.Cart/Historical/C150-07-SP.htm. [8]M. Issa, “( current astm c150 / aashto m85 ) with limestone and process addition ( ASTM C465 / AASHTO M327 ) on the performance of concrete for pavement and Prepared By,” 2014. [9]S. Zailan, N. Mahmed, M. Abdullah, A. Sandu, and N. Shahedan, “Review on characterization and mechanical performance of self-cleaning concrete,” MATEC Web Conf., vol. 97, pp. 1–7, 2017, doi: 10.1051/matecconf/20179701022. [10]C. Chavarry, L. Chavarría, A. Valencia, E. Pereyra, J. Arieta, and C. Rengifo, “Hormigón reforzado con vidrio molido para controlar grietas y fisuras por contracción plástica,” Pro Sci., vol. 4, no. 31, pp. 31–41, 2020, doi: 10.29018/issn.2588-1000vol4iss31.2020pp31-41. [11]D. Tobaldi, “Materiali ceramici per edilizia con funzionalità fotocatalitica,” Università di Bologna, 2009. [12]Norme UNI, “Norma Italiana UNI 11259,” 2016. http://store.uni.com/catalogo/uni-11259-2008?josso_back_to=http://store.uni.com/josso-security-check.php&josso_cmd=login_optional&josso_partnerapp_host=store.uni.com. [13]E. Grebenisan, H. Szilagyi, A. Hegyi, C. Mircea, and C. Baera, “Directory lines regarding the desing and production of self-cleaning cementitious composites,” Sect. Green Build. Technol. Mater., vol. 19, no. 6, 2019. [14]M. Kaszynska, “The influence of TIO2 nanoparticles on the properties of self-cleaning cement mortar,” Int. Multidiscip. Sci. GeoConference SGEM, pp. 333–341, 2018.

Effects of In and Sb addition on the thermal and wetting behavior of Sn-3.5Ag solder

2018 ◽  
Vol 30 (4) ◽  
pp. 233-240 ◽  
Author(s):  
Md Hasnine
Keyword(s):  
Differential Scanning Calorimetry ◽  
Melting Point ◽  
Thermal Behavior ◽  
Surface Finish ◽  
Design Methodology ◽  
Solder Alloys ◽  
Scanning Calorimetry ◽  
Content Type ◽  
Cu Substrate ◽  
Free Solder

Purpose This paper aims to investigate the effect of In and Sb additions on the thermal behavior and wettability of Sn-3.5Ag-xIn-ySb (x = 0, 1.0 and 1.5 Wt.%, y = 0, 1.0, 1.4 and 2.1 Wt.%) solder alloys. Design/methodology/approach The thermal behavior of the Pb-free solder alloys was studied using differential scanning calorimetry. Wetting balance experiments were performed in accordance with the IPC standard, IPC-TM-650 and at a temperature of 260°C. Also, a solder spread test was performed on a Cu surface finish using the JIS-Z-3197 solderability standard. Findings It is shown that among the selected Sn-3.5Ag-xIn-ySb (x = 0, 1.0 and 1.5 Wt.%, y = 0, 1.0, 1.4 and 2.1 Wt.%) alloys, Sn-3.5Ag-1.5In-1Sb showed the lowest melting point and the lowest undercooling temperature. The best wettability was achieved when the In and Sb contents were approximately 1.5 and 1.0 Wt.%, respectively. The effect of the combined addition of In and Sb on solder spreadability on a Cu substrate was also demonstrated. Originality/value It was found that adding approximately 1.5 and 1.0 Wt.% of In and Sb, respectively, in Sn-3.5Ag solder provided the best wetting performance and improved the solder spreadability.

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