Evaluation of the effect of heat input in superduplex stainless steel deposition by the plasma powder process*

Plasma powder surfacing is one of the latest processes for application of coatings, with control of dilution as its main feature. Surfacing with superduplex stainless steels is an interesting option for the construction and repair of equipment for applications in a highly corrosive environment, allowing the desired characteristics to be achieved: corrosion resistance and good mechanical properties. The aim of this work is to assess the ferrite content in the weld metal and the mechanical characteristics via microhardness profiles in surfacing of C-Mn steel pipes with deposition of UNS S32760 by plasma powder surfacing. Welding operations were carried out on pipes with deposition of SDSS, employing three welding heat input levels, varying the welding speed or the welding current. Then the geometry was analysed, the ferrite content in the weld metal was quantified and the microhardness profile was recorded. Variation in welding heat input caused changes in weld bead geometry, with variation in the welding current producing the most significant changes. Increase in heat input caused decrease in ferrite content of the weld metal. Regarding microhardness, only the condition with a higher level of welding current gave sufficiently high levels of microhardness in the weld metal.     

A comparative study of the behavior of Chlamydomonas reinhardtii and Spirulina platensis in solar catalytic pyrolysis

The aim of this study was to investigate the behavior of two distinct microalgae species during solar catalytic pyrolysis and the influence of their chemical composition and the process variables (biomass charge, reaction time, and catalyst percentage) on the product yields and bio-oil composition. For this purpose, solar catalytic pyrolysis of Spirulina platensis and Chlamydomonas reinhardtii was performed using hydrotalcite-derived mixed oxides as the catalyst. To gain more insight into the effect of composition on pyrolysis behavior, the biomasses were analyzed using various analytical techniques. The results indicated that a high percentage of catalyst (47.1%) culminated in liquid yields of 42.48% and 21.31% for Chlamydomonas pyrolysis and Spirulina pyrolysis, respectively. Additionally, Spirulina pyrolysis resulted in higher solid yields compared with Chlamydomonas pyrolysis. The results also showed that Spirulina bio-oil was rich in oxygenated compounds, probably due to its high carbohydrate content, whereas Chlamydomonas bio-oil was rich in nitrogenated compounds because of its higher protein content. The microalgae composition (lipids, protein, carbohydrates) exerted a large influence on the catalytic pathways and led to differences in yield and product distribution. A high percentage of catalysts preferentially promoted a deoxygenation of the bio-oil obtained from Spirulina solar pyrolysis compared with that obtained from Chlamydomonas pyrolysis.     

Design,Synthesis, Radiosynthesis and Biological Evaluation of Fenretinide Analogues as Anticancer and Metabolic Syndrome-Preventive Agents

Fenretinide (4-HPR) is a synthetic derivative of all-trans-retinoic acid (ATRA) characterised by improved therapeutic properties and toxicological profile relative to ATRA. 4-HPR has been mostly investigated as an anti-cancer agent, but recent studies showed its promising therapeutic potential for preventing metabolic syndrome. Several biological targets are involved in 4-HPR's activity, leading to the potential use of this molecule for treating different pathologies. However, although 4-HPR displays quite well-understood multitarget promiscuity with regards to pharmacology, interpreting its precise physiological role remains challenging. In addition, despite promising results in vitro, the clinical efficacy of 4-HPR as a chemotherapeutic agent has not been satisfactory so far. Herein, we describe the preparation of a library of 4-HPR analogues, followed by the biological evaluation of their anti-cancer and anti-obesity/diabetic properties. The click-type analogue 3 b showed good capacity to reduce the amount of lipid accumulation in 3T3-L1 adipocytes during differentiation. Furthermore, it showed an IC₅₀ of 0.53±0.8 μM in cell viability tests on breast cancer cell line MCF-7, together with a good selectivity (SI=121) over noncancerous HEK293 cells. Thus, 3 b was selected as a potential PET tracer to study retinoids in vivo, and the radiosynthesis of [¹⁸F] 3b was successfully developed. Unfortunately, the stability of [¹⁸F] 3b turned out to be insufficient to pursue imaging studies.     

Performance evaluation and tuning of an IEEE 802.11 audio video multicast collision prevention mechanism

Wireless Networks - Since the introduction of the original IEEE 802.11 medium access mechanism, the definition of the multicast access mechanism has been the subject of numerous amendments and...     

Predicting the research performance of early career scientists

Scientometrics - This paper examines how early career-related factors can predict the future research performance of computer and information scientists. Although a few bibliometric studies have...     

A Stretchable and Flexible Cardiac Tissue–Electronics Hybrid Enabling Multiple Drug Release,Sensing, and Stimulation

Replacement of the damaged scar tissue created by a myocardial infarction is the goal of cardiac tissue engineering. However, once the implanted tissue is in place, monitoring its function is difficult and involves indirect methods, while intervention necessarily requires an invasive procedure and available medical attention. To overcome this, methods of integrating electronic components into engineered tissues have been recently presented. These allow for remote monitoring of tissue function as well as intervention through stimulation and controlled drug release. Here, an improved hybrid microelectronic tissue construct capable of withstanding the dynamic environment of the beating heart without compromising electronic or mechanical functionality is reported. While the reported system is enabled to sense the function of the engineered tissue and provide stimulation for pacing, an electroactive polymer on the electronics enables it to release multiple drugs in parallel. It is envisioned that the integration of microelectronic devices into engineered tissues will provide a better way to monitor patient health from afar, as well as provide facile, more exact methods to control the healing process.     

Efficient very‐high‐gravity fermentation of sugarcane molasses by industrial yeast strains

In this study industrial strains were inoculated, in successive cycles, at high cell density into a sugarcane‐based juice containing normal (22%, w/v) and very high sucrose (30%, w/v) levels and supplemented with peptone as a nitrogen source. At 30 °C, in shaken cultures, in the normal gravity situation, efficient sucrose utilization occurred in both the supplemented and unsupplemented medium. At higher sugar concentrations, supplementation with peptone induced a more efficient fermentation compared with the unsupplemented medium, with higher biomass accumulation and maintenance of cell viability, and ethanol levels as high as 16% (v/v). Trehalose was also high during the cycles, probably as a necessary response of the yeast to the high stress fermentation conditions. This suggests that it is possible to increase ethanol production by using very‐high‐fermentation technology and that nutritional supplementation would have a positive effect on the fermentation, allowing for efficient sugar consumption and cell viability maintenance. Copyright © 2016 The Institute of Brewing & Distilling