Thiophene-based molecular and polymeric semiconductors for organic field effect transistors and organic thin film transistors

Organic electronics has been a popular field for the last two decades, due to its potential to commercialize cheap-price and large-area flexible electronics. The devices based on organic compounds heavily rely on organic semiconductors (OSs). Primary challenge for materials chemist is the new OSs construction that has ameliorated attainment in organic thin film transistors (OTFTs) and organic field effect transistors (OFETs). The construction of air-stable (stable in air) n-channel OSs (electron-conducting materials) is particularly needed with capability comparable to that of p-channel materials (hole-conducting materials). In the last 10 years, there have been significant advancements in thiophene-based OSs. Thiophene-mediated molecules have a prominent role in the advancement of OSs. The main significance in thiophene-based molecules is their cheap-price (in comparison to silicon), processability at low temperature, structural flexibility, ability to be applied on flexible substrates, and high charge transport characteristics. In this paper, we review the progress in the performance of thiophene-based OSs that has been reported in the last 18 years, with a major emphasis on the last 10 years. This approach provides a crisp introduction to organic devices and catalogs progress toward the fabrication of thiophene containing p, n and ambipolar channel OSs, and discusses their characteristics. Finally, review discusses current challenges and future research directions for thiophene based OSs. This review would be beneficial for further developments in the technological performance. Moreover, this review will serve to accelerate knowledge and lays the foundation for improved applications. Hopefully, this struggle pushes the reader’s mind to consider new perspectives, think differently and forge new connections.     

Improving the dispersion of MWCNT and MMT in PVDF melts employing controlled extensional flows

Poly (vinylidene fluoride) (PVDF) has been widely explored to produce polymer nanocomposites possessing outstanding combinations of properties. In this work, the impact of extensional melt flows on the dispersion, relaxation and crystallinity of PVDF nanocomposites filled with multiwalled carbon nanotubes (MWCNT) and montmorillonites (MMT) was studied. Extrusion was employed to produce nanocomposites containing 3 wt% of fillers, named: (i) PVDF/3 wt% MWCNT, (ii) PVDF/3wt%MMT, and (iii) PVDF/1.5wt%MWCNT/1.5 wt% MMT. The results showed that applying a sequence of extensional flows through the melts improved the dispersion of both fillers in the PVDF matrix. Moreover, extensional flows significantly enhanced the viscosity and relaxation of MWCNT nanocomposite, but had marginal effects on MMT nanocomposite. On the other hand, MMT favored the crystallization of the β piezoelectric phase of PVDF over the α phase and the extensional flow enhanced its crystallinity content. Therefore, these new insights prospect a vast horizon toward the use of extensional flows for tailoring synergic combinations of properties in hybrid PVDF/MWCNT/MMT systems.     

ENERGY AND GDP

Understanding of the role of energy use at the national level requires the understanding of the relationship of energy use to economic activity and social well-being. Gross domestic product (GDP) measures the value of goods and services produced in a country in one year. There is a close relationship between energy supply, energy consumption, and GDP, which indicates the economic development of a country. The living standard of a country is often measured by the per capita GDP. This article presents the evaluations and future projections of energy and energy resources of the Organization for Economic Cooperation and Development (OECD). The total primary energy supply, total final energy consumption, and energy intensities for supply and consumption are analysed. The energy data for all OECD countries are presented and analyses of the differences in energy and GDP ratios are conducted at an aggregate level by examining differences in the factors that affect the energy intensities. To provide accurate projections for the future, new correlations are developed between average GDP, total primary energy supply, total final consumption, total per capita primary energy supply, total per capita final consumption and total OECD population. © 1997 by John Wiley & Sons, Ltd.     

A simple model for heat and mass transfer in absorption cooling systems (ACSs)

The article presents a simple technique for the purpose of heat and mass transfer analysis in an ACS. The LiBr/water ACS was selected as an example. based on optimum operation conditions (i.e., the maximum cooling temperature delivered by the ACS), simple but effective expression were derived in terms of the mass flow rate of absorbent—the most important parameter for practical design calculations. The results show that the proposed technique provides, for practical application purposes, a useful tool for a general analysis of the ACS as well as for the system design purpose.     

miR-205-5p Downregulation and ZEB1 Upregulation Characterize the Disseminated Tumor Cells in Patients with Invasive Ductal Breast Cancer

Background: Dissemination of breast cancer (BC) cells through the hematogenous or lymphogenous vessels leads to metastatic disease in one-third of BC patients. Therefore, we investigated the new prognostic features for invasion and metastasis. Methods: We evaluated the expression of miRNAs and epithelial-to-mesenchymal transition (EMT) genes in relation to CDH1/E-cadherin changes in samples from 31 patients with invasive ductal BC including tumor centrum (TU-C), tumor invasive front (TU-IF), lymph node metastasis (LNM), and CD45-depleted blood (CD45-DB). Expression of miRNA and mRNA was quantified by RT-PCR arrays and associations with clinico-pathological characteristics were statistically evaluated by univariate and multivariate analysis. Results: We did not verify CDH1 regulating associations previously described in cell lines. However, we did detect extremely high ZEB1 expression in LNMs from patients with distant metastasis, but without regulation by miR-205-5p. Considering the ZEB1 functions, this overexpression indicates enhancement of metastatic potential of lymphogenously disseminated BC cells. In CD45-DB samples, downregulated miR-205-5p was found in those expressing epithelial and/or mesenchymal markers (CTC+) that could contribute to insusceptibility and survival of hematogenously disseminated BC cells mediated by increased expression of several targets including ZEB1. Conclusions: miR-205-5p and potentially ZEB1 gene are promising candidates for markers of metastatic potential in ductal BC.     

Application of a hop by‐product in brewing: reduction in the level of haze‐active prolamines and improved antioxidant properties of the beer

After supercritical CO₂ extraction of hops or formation of lupulin‐enriched pellets (type 45), polyphenol‐rich by‐products remain. These have some industrial and agricultural applications (preparation of polyphenol extracts and in the production of low‐bitterness beers). In this work, both materials were used in pilot‐scale brewing experiments for the production of beer enriched with polyphenols. Samples of beer made from these residues underwent analyses for haze‐active prolamines, total polyphenols, phenolic monomers, antioxidant capacity, bitterness and colour. An almost identical decrease in the content (from hopped wort to final beer) of the prolamines of approximately 30% was detected in standard beer as well as in the beer prepared from the hop residue (HR 1) after supercritical CO₂ extraction. In contrast, the level of prolamines was reduced by more than 50% in the beer following addition of the hop residue (HR 2) after production of lupulin enriched pellets. Both hop materials contributed to an increase in the antioxidant capacity of the final beer by 21.5 and 11.9%, respectively. Another part of this work was aimed at the investigation of colour and bitterness changes in beers made ??using hop by‐products. Addition of the material HR 2 into the wort caused an increase in colour and in bitterness of the matured beer by 20 and 11% rel., respectively. Copyright © 2014 The Institute of Brewing & Distilling     

Exploitation of Nanobifiller in Polymer/Graphene Oxide–Carbon Nanotube,Polymer/Graphene Oxide–Nanodiamond,and Polymer/Graphene Oxide–Montmorillonite Composite: A Review

In this article, a comprehensive review is presented regarding structure, synthesis, and properties of nanofillers such as graphene oxide, nanobifiller of graphene oxide, and their polymeric nanocomposite. The information about hybrid properties and synthesis of graphene oxide–carbon nanotube, graphene oxide–montmorillonite, and graphene oxide–nanodiamond is presented. Use of nanobifiller in polymer/graphene oxide–carbon nanotube, polymer/graphene oxide–montmorillonite, and polymer/graphene oxide–nanodiamond composites was summarized. Area of polymer and graphene oxide-based nanobifiller composites is less studied in literature. Therefore, nanobifiller technology limitations and research challenges must be focused. Polymer/graphene oxide nanobifiller composites have a wide range of unexplored potential in technological areas such as automobile, aerospace, energy, and medical industries.