Superheated Steam Drying: An Overview of Pilot and Industrial Dryers with a Focus on Energy Efficiency

According to the principle of sustainability, modern industry should preserve nonrenewable energy sources and develop more efficient processes, especially in terms of energy consumption. The depletion of fossil energy reserves, the environmental impact of greenhouse gases, and the possible threats of environmental taxes are the main reasons to develop new processes in general, and new drying processes in particular, for the existing industries. Using superheated steam as a drying medium instead of hot air can improve the energy efficiency by reusing the energy from exhausted steam and prevent gas emission into the atmosphere by condensation. The present review is focused on both lab-scale pilots—including impingement jet, fluid bed, kiln, fixed bed, and flash drying—described in the literature and existing industrial facilities, with a specific analysis focused on energy efficiency. The usefulness of superheated steam drying pilots for experimental research and for the design of industrial dryers is analyzed. The impact on quality specifications of the dried product for different operating conditions is also presented. Documentation on industrial superheated steam dryers is very rare. Nevertheless, this work presents and analyses the key data available for superheated steam drying of beet, alfalfa, industrial pulp, and paint sludge. Energy recovery and process integration, with a focus on specific technological challenges for industrial dryer implementation, are also presented. This document will result in a discussion of some new ideas for possible R&D in superheated steam drying.     

Structure and Reactivity of Spruce Mechanical Pulp Lignins Part I. Bleaching and Photoyellowing of in situ Lignins

This paper reports the structural investigation of a series of in situ spruce lignins in wood, thermomechanical pulp (TMP) and the corresponding bleached (BTMP) and photoyellowed (YBTMP) samples. This was achieved by using an original two-step degradative technique, thioacidolysis followed by Raney nickel desulfuration. The determination of thioacidolysis monomeric and dimeric products allowed an estimate of various lignin building units and interunit bonds, respectively. It was observed that the thermomechanical and bleaching treatments did not affect spruce lignin structure to an appreciable extent. On the contrary, the photoyellowing treatment caused marked structural changes in lignin, particularly when run in severe conditions. These changes were essentially a decrease in the amount of β-O-4 and β-1 interunit bonds and a relative increase in catechol units and in vanillin end-groups.     

Thioacidolysis of Lignin: Comparison with Acidolysis

Abstract

Arylglycerol-ether bonds of lignin samples or model compounds vera selectively cleaved by treatment with dioxane-ethanethiol (9/1, v/v) and 0.2 N HBF₄ etherate or 0.2 N BF₃ etherate at 100°C for four hour3. Monomers resulting from “thioacidolysis” were identified by gas chroraatography-mass spectrometry of their trimethylslly derivatives. Compared to acidolysls (dloxane-water, 0.2 N HCL, 100°C 4h), thioacidolysis yields less complex mixtures of monomers. The monomer yields for lignin thioacidolysis were also higher than for acidolysls. This increase was particularly evident for hardwood lignins.     

Egg Consumption Modulates HDL Lipid Composition and Increases the Cholesterol-Accepting Capacity of Serum in Metabolic Syndrome

We recently demonstrated that daily whole egg consumption during moderate carbohydrate restriction leads to greater increases in plasma HDL-cholesterol (HDL-C) and improvements in HDL profiles in metabolic syndrome (MetS) when compared to intake of a yolk-free egg substitute. We further investigated the effects of this intervention on HDL composition and function, hypothesizing that the phospholipid species present in egg yolk modulate HDL lipid composition to increase the cholesterol-accepting capacity of subject serum. Men and women classified with MetS were randomly assigned to consume either three whole eggs (EGG, n = 20) per day or the equivalent amount of egg substitute (SUB, n = 17) throughout a 12-week moderate carbohydrate-restricted (25–30 % of energy) diet. Relative to other HDL lipids, HDL-cholesteryl ester content increased in all subjects, with greater increases in the SUB group. Further, HDL-triacylglycerol content was reduced in EGG group subjects with normal baseline plasma HDL-C, resulting in increases in HDL-CE/TAG ratios in both groups. Phospholipid analysis by mass spectrometry revealed that HDL became enriched in phosphatidylethanolamine in the EGG group, and that EGG group HDL better reflected sphingomyelin species present in the whole egg product at week 12 compared to baseline. Further, macrophage cholesterol efflux to EGG subject serum increased from baseline to week 12, whereas no changes were observed in the SUB group. Together, these findings suggest that daily egg consumption promotes favorable shifts in HDL lipid composition and function beyond increasing plasma HDL-C in MetS.     

Recent advances on ion-imprinted polymers

Selective recognition of metal ions is a real challenge for a large range of applications in the analytical field (from extraction to detection and quantification). For that purpose, ion-imprinted polymers (IIPs) have been increasingly developed during the last 15 years on the principle of molecularly imprinted polymers (MIPs). Those imprinted materials are designed to mimic the binding sites of biological entities and assure an improved recognition of the template species. The aim of this review is to give the current state of the art in the conception of IIPs from the components to the polymerization process. Some applications of those materials will be also discussed.     

Implicit Bayesian Inference Using Option Prices

Abstract. A Bayesian approach to option pricing is presented in which posterior inference about the underlying returns process is conducted implicitly via observed option prices. A range of models allowing for conditional leptokurtosis, skewness and time‐varying volatility in returns are considered, with posterior parameter distributions and model probabilities backed out from the option prices. Models are ranked according to several criteria, including out‐of‐sample predictive and hedging performance. The methodology accommodates heteroscedasticity and autocorrelation in the option pricing errors, as well as regime shifts across contract groups. The method is applied to intraday option price data on the S&P500 stock index for 1995. While the results provide support for models that accommodate leptokurtosis and skewness, no one model dominates when all criteria are considered.     

The Role of α1-Adrenoceptor Antagonists in the Treatment of Prostate and Other Cancers

This review evaluates the role of α-adrenoceptor antagonists as a potential treatment of prostate cancer (PCa). Cochrane, Google Scholar and Pubmed were accessed to retrieve sixty-two articles for analysis. In vitro studies demonstrate that doxazosin, prazosin and terazosin (quinazoline α-antagonists) induce apoptosis, decrease cell growth, and proliferation in PC-3, LNCaP and DU-145 cell lines. Similarly, the piperazine based naftopidil induced cell cycle arrest and death in LNCaP-E9 cell lines. In contrast, sulphonamide based tamsulosin did not exhibit these effects. In vivo data was consistent with in vitro findings as the quinazoline based α-antagonists prevented angiogenesis and decreased tumour mass in mice models of PCa. Mechanistically the cytotoxic and antitumor effects of the α-antagonists appear largely independent of α 1-blockade. The proposed targets include: VEGF, EGFR, HER2/Neu, caspase 8/3, topoisomerase 1 and other mitochondrial apoptotic inducing factors. These cytotoxic effects could not be evaluated in human studies as prospective trial data is lacking. However, retrospective studies show a decreased incidence of PCa in males exposed to α-antagonists. As human data evaluating the use of α-antagonists as treatments are lacking; well designed, prospective clinical trials are needed to conclusively demonstrate the anticancer properties of quinazoline based α-antagonists in PCa and other cancers.     

Discovery of Highly Potent Dual Orexin Receptor Antagonists via a Scaffold‐Hopping Approach

Starting from suvorexant (trade name Belsomra), we successfully identified interesting templates leading to potent dual orexin receptor antagonists (DORAs) via a scaffold‐hopping approach. Structure–activity relationship optimization allowed us not only to improve the antagonistic potency on both orexin 1 and orexin 2 receptors (Ox1 and Ox2, respectively), but also to increase metabolic stability in human liver microsomes (HLM), decrease time‐dependent inhibition of cytochrome P450 (CYP) 3A4, and decrease P‐glycoprotein (Pgp)‐mediated efflux. Compound 80 c [{(1S,6R)‐3‐(6,7‐difluoroquinoxalin‐2‐yl)‐3,8‐diazabicyclo[4.2.0]octan‐8‐yl}(4‐methyl‐[1,1′‐biphenyl]‐2‐yl)methanone] is a potent and selective DORA that inhibits the stimulating effects of orexin peptides OXA and OXB at both Ox1 and Ox2. In calcium‐release assays, 80 c was found to exhibit an insurmountable antagonistic profile at both Ox1 and Ox2, while displaying a sleep‐promoting effect in rat and dog models, similar to that of the benchmark compound suvorexant.