Linear versus nonlinear determinations of equilibrium melting temperatures of poly(trimethylene terephthalate) and miscible blend with poly(ether imide) exhibiting multiple melting peaks

2002 ◽  
Vol 40 (15) ◽  
pp. 1571-1581 ◽  
Author(s):  
Pi-Ling Wu ◽  
E. M. Woo
2001 ◽  
Vol 33 (12) ◽  
pp. 920-926 ◽  
Author(s):  
Yu-Hsiao Kuo ◽  
Ea Mor Woo ◽  
Tong-Yin Kuo

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 572
Author(s):  
Cristian Olmo ◽  
María Casas ◽  
Juan Martínez ◽  
Lourdes Franco ◽  
Jordi Puiggalí

Copolyamides derived from even 1,4-butanediamine and different mixtures of odd dicarboxylic acids with a great difference in the number of methylene groups (i.e., glutaric and azelaic acids with 3 and 7 groups, respectively) have been synthesized, characterized and structurally studied. Calorimetric analyses revealed a complex behavior with multiple melting peaks associated to lamellar reordering and the presence of defective crystals. Equilibrium melting temperatures were evaluated and showed a eutectic behavior with composition. Copolymers were able to crystallize even for samples with comonomer percentages close to 50%. Negative and ringed spherulites from the melt state and small lath-like lamellar crystals from dilute solution crystallizations were attained. Furthermore, calorimetric data pointed out the exclusion of the less abundant monomer from the lattice of the predominant structure. All samples at room temperature showed a similar crystalline structure (form I) defined by two predominant reflections at spacings close to 0.430 and 0.380 nm, which has been related for even-odd nylons with a two-hydrogen bonded structure. Real time synchrotron experiments showed that melt crystallized samples have two polymorphic transitions on heating, which were practically reversible and consequently were also detected during cooling from the melt state. Interestingly, a different behavior was detected among solution crystallized samples and specifically the transition to the intermediate structure (form II) was not detected during heating for samples enriched on the azelate component or more precisely when they were exclusively crystallized in the form I.


Entropy ◽  
2021 ◽  
Vol 23 (6) ◽  
pp. 727
Author(s):  
Eric J. Ma ◽  
Arkadij Kummer

We present a case study applying hierarchical Bayesian estimation on high-throughput protein melting-point data measured across the tree of life. We show that the model is able to impute reasonable melting temperatures even in the face of unreasonably noisy data. Additionally, we demonstrate how to use the variance in melting-temperature posterior-distribution estimates to enable principled decision-making in common high-throughput measurement tasks, and contrast the decision-making workflow against simple maximum-likelihood curve-fitting. We conclude with a discussion of the relative merits of each workflow.


Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 199
Author(s):  
Xiaochun Zhang ◽  
Huan Yu ◽  
Qi Yang ◽  
Ziwei Wang ◽  
Ruocheng Xia ◽  
...  

In recent years, trafficking and abuse of hallucinogenic mushrooms have become a serious social problem. It is therefore imperative to identify hallucinogenic mushrooms of the genus Psilocybe for national drug control legislation. An internal transcribed spacer (ITS) is a DNA barcoding tool utilized for species identification. Many methods have been used to discriminate the ITS region, but they are often limited by having a low resolution. In this study, we sought to analyze the ITS and its fragments, ITS1 and ITS2, by using high-resolution melting (HRM) analysis, which is a rapid and sensitive method for evaluating sequence variation within PCR amplicons. The ITS HRM assay was tested for specificity, reproducibility, sensitivity, and the capacity to analyze mixture samples. It was shown that the melting temperatures of the ITS, ITS1, and ITS2 of Psilocybe cubensis were 83.72 ± 0.01, 80.98 ± 0.06, and 83.46 ± 0.08 °C, and for other species, we also obtained species-specific results. Finally, we performed ITS sequencing to validate the presumptive taxonomic identity of our samples, and the sequencing output significantly supported our HRM data. Taken together, these results indicate that the HRM method can quickly distinguish the DNA barcoding of Psilocybe cubensis and other fungi, which can be utilized for drug trafficking cases and forensic science.


Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4164
Author(s):  
Elizabeth Diederichs ◽  
Maisyn Picard ◽  
Boon Peng Chang ◽  
Manjusri Misra ◽  
Amar Mohanty

Three-dimensional (3D) printing manufactures intricate computer aided designs without time and resource spent for mold creation. The rapid growth of this industry has led to its extensive use in the automotive, biomedical, and electrical industries. In this work, biobased poly(trimethylene terephthalate) (PTT) blends were combined with pyrolyzed biomass to create sustainable and novel printing materials. The Miscanthus biocarbon (BC), generated from pyrolysis at 650 °C, was combined with an optimized PTT blend at 5 and 10 wt % to generate filaments for extrusion 3D printing. Samples were printed and analyzed according to their thermal, mechanical, and morphological properties. Although there were no significant differences seen in the mechanical properties between the two BC composites, the optimal quantity of BC was 5 wt % based upon dimensional stability, ease of printing, and surface finish. These printable materials show great promise for implementation into customizable, non-structural components in the electrical and automotive industries.


2021 ◽  
Vol 143 (7) ◽  
pp. 2801-2811
Author(s):  
Mengtan Liu ◽  
Ryan D. McGillicuddy ◽  
Hung Vuong ◽  
Songsheng Tao ◽  
Adam H. Slavney ◽  
...  
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document