Confinement Effects on the Crystalline Features of Poly(9,9-dioctylfluorene)

Typical device architectures in polymer-based optoelectronic devices, such as field effect transistors organic light emitting diodes and photovoltaic cells include sub-100 nm semiconducting polymer thin-film active layers, whose microstructure is likely to be subject to finite-size effects. The aim of this study was to investigate effect of the two-dimensional spatial confinement on the internal structure of the semiconducting polymer poly(9,9-dioctylfluorene) (PFO). PFO melts were confined inside the cylindrical nanopores of anodic aluminium oxide (AAO) templates and crystallized via two crystallization strategies, namely, in the presence or in the absence of a surface bulk reservoir located at the template surface. We show that highly textured semiconducting nanowires with tuneable crystal orientation can be thus produced. Moreover, our results indicate that employing the appropriate crystallization conditions extended-chain crystals can be formed in confinement. The results presented here demonstrate the simple fabrication and crystal engineering of ordered arrays of PFO nanowires; a system with potential applications in devices where anisotropic optical properties are required, such as polarized electroluminescence, waveguiding, optical switching, lasing, etc

Compensation of Thermal Gradients Effects on a Quartz Crystal Microbalance

Quartz Crystal Microbalances (QCM) are widely used instruments thanks to their stability, low mass, and low cost. Nevertheless, the sensitivity to temperature is their main drawback and is often a driver for their design. Though the crystal average temperature is mostly considered as the only disturbance, temperature affects the QCM measurements also through the in-plane temperature gradients, an effect identified in the past but mostly neglected. Recently, it has been shown that this effect can prevail over that of the average temperature in implementations where the heat for thermal control is released directly on the crystal through deposited film heaters. In this study, the effect of temperature gradients for this kind of crystal is analyzed, the sensitivity of frequency to the average temperature gradient on the electrode border is determined, and a correction is proposed and verified. A numerical thermal model of the QCM has been created to determine the temperature gradients on the electrode borders. The frequency versus temperature-gradient function has been experimentally determined in different thermal conditions. The correction function has been eventually applied to a QCM implementing a crystal of the same manufacturing lot as the one used for the characterization. The residual errors after the implementation of the correction of both average temperature and temperature gradients were always lower than 5% of the initial temperature disturbance. Moreover, using the correlation between the heater power dissipation and the generated temperature gradients, it has been shown that an effective correction strategy can be based on the measurement of the power delivered to the crystal without the determination of the temperature gradient

Measurement method for quality control of cylinders in roll-to-roll printing machines

This paper describes a measurement method for the quality control of cylinders for printing machines based on roll-to-roll presses. If the surface finishing of the cylinders is not adequate, the printing is unacceptable, and the defective cylinders must be reworked. The performed quality check of the cylinder surface roughness by means of contact methods was unable to identify the cylinder defects, and acceptance of the manufactured cylinders before integration was demanded to the visual inspection performed by trained operators. In this work a contactless measurement method based on the eddy current displacement sensor was proposed and validated as a tool for quality check as an alternative to optical roughness measurements. A test bench for the characterization of printer cylinders was designed and manufactured, allowing for the validation of the proposed method on different batches of cylinders and the identification of a threshold to guide the acceptance of tested cylinders prior to mounting on the roll-to-roll press

Process integration study of tail-end Ca-Looping process for CO2capture in cement plants

In this work, the integration of Calcium looping (CaL) process into a cement plant for post-combustion CO2capture is assessed via process simulations. In the proposed scheme, the carbonator of the CaL process is used as an end-of-pipe unit to capture the CO2from the cement kiln gas. From the results obtained, it is demonstrated that CO2capture efficiencies of the order of 90% are achievable, with CaL reactors operating in conditions not far from those demonstrated for application in power plants. The integration of the tail-end CaL process results in a significant increase of the total fuel consumption (about two to three times higher) compared to the benchmark cement plant without CO2capture. On the other hand, the heat from the CaL process can be recovered by a steam cycle producing decarbonized electric power that may exceed the needs of the plant auxiliaries (including the ASU and the CO2compression and purification unit), exporting in this way electricity to the grid and so resulting in CO2emission credits from a life cycle perspective. The resulting specific primary energy consumption for CO2avoided (SPECCA) highly depends on the reference power generation technology considered, and it ranges between 2.7 and 3.7 MJLHV/kgCO2in a coal-fired power generation scenario. As for the retrofittability of existing cement plants, the operation of the suspension preheating tower after the implementation of the CaL unit, as well as the position of the CaL carbonator with respect to the raw mill, have been assessed. Based on the results obtained, no critical issues have been found from a technical point of view in the adoption of the tail-end CaL process in existing cement kilns

A Simplified Approach Based on Cellular Automata for Describing Direct Reduced Iron Production in Different Reducing Conditions

A quick computation approach based on cellular automata is developed and implemented to describe the reduction of iron ore pellets by a mixture of reducing agents featured by different H2/CO ratios. The evolution of oxygen concentration inside the pellet is followed from the beginning to the end of contact between reducing agent and pellet. The variation of thermal state of pellets and gas mixture is computed based on their initial temperature, considering the heat involved and the convective heat exchange between pellet and gas mixture. The use of cellular automata and finite-difference method to solve the diffusion equation point out the absence of any diffusion coefficient value, allowing to make the model fit the experimental trial, because the problem is that it is not ruled just by diffusion but also by the concentration variation of reducing agent inside the pellet due to porosity increasing during reduction. The updating of the reducing agents concentration implies a sharp decrease of oxygen concentration that the cellular automata model considers. The developed model is able to provide the in-line control of reduction process and could be used to adjust the chemical concentration and temperature of injected reducing agents

Impact of palliative care in evaluating and relieving symptoms in patients with advanced cancer. Results from the demetra study

Background: Cancer patients experience multiple symptoms throughout the course of the disease. We aimed to provide a comprehensive analysis of the symptom burden in patients with advanced cancer at admission to specialist palliative care (PC) services and seven days later to estimate the immediate impact of PC intervention. Patient and methods: The analysis was based on an observational, prospective, multicenter study (named DEMETRA) conducted in Italy on new patients accessing network specialist PC centers during the period May 2017–November 2017. The prevalence and intensity of symptoms were assessed at baseline and after seven days using three tools including the Edmonton Symptom Assessment System (ESAS). Results: Five PC centers recruited 865 cancer patients. Thirty-three different symptoms were observed at the baseline, the most frequent being asthenia (84.9%) and poor well-being (71%). The intensity of the most frequent symptoms according to ESAS ranged from 5.5 for asthenia to 3.9 for nausea. The presence and intensity of physical symptoms increased with increasing levels of anxiety and depression. After seven days, prevalence of nausea and breathlessness as well as intensity of almost all symptoms significantly decreased. Conclusions: The study confirmed the considerable symptom burden of patients with advanced cancer. PC intervention has significantly reduced the severity of symptoms, despite the patients’ advanced disease and short survival

Quartz Crystal Microbalances for Space: Design and Testing of a 3D Printed Quasi-Kinematic Support

Outgassing or thruster’s generated contaminants are critical for optical surfaces and optical payloads because scientific measurements and, in general, the performances can be degraded or jeopardized by uncontrolled contamination. This is a well-known issue in space technology that is demonstrated by the growing usage of quartz crystal microbalances as a solution for measuring material outgassing properties data and characterizing the on-orbit contamination environment. Operation in space requires compatibility with critical requirements, especially the mechanical and thermal environments to be faced throughout the mission. This work provides the design of a holding structure based on 3D printing technology conceived to meet the environmental characteristics of space application, and in particular, to face harsh mechanical and thermal environments. A kinematic mounting has been conceived to grant compatibility with a large temperature range, and it has been designed by finite element methods to overcome loading during the launch phases and cope with a temperature working range down to cryogenic temperatures. Qualification in such environments has been performed on a mockup by testing a prototype of the holding assembly between −110 °C and 110 °C and allowing verification of the mechanical resistance and stability of the electrical contacts for the embedded heater and sensor in that temperature range. Moreover, mechanical testing in a random environment characterized by an RMS acceleration level of 500 m/s2 and excitation frequency from 20 to 2000 Hz was successfully performed. The testing activity allowed for validation of the proposed design and opened the road to the possible implementation of the proposed design for future flight opportunities, also onboard micro or nanosatellites. Moreover, exploiting the manufacturing technology, the proposed design can implement an easy assembling and mounting of the holding system. At the same time, 3D printing provides a cost-effective solution even for small series production for ground applications, like monitoring the contaminants in thermo-vacuum chambers or clean rooms, or depositions chambers

state of the art and perspectives of inorganic photovoltaics

In the last decade, the fast increase of the global energy consumption, mainly related to the strong economic growth in the Far East, and the progressive depletion of the fossil fuels induced a run-up in the world oil price. Both these economic concerns and the growing global pollution pointed out that a transition toward renewable energies is mandatory. Among renewables, the conversion of sunlight into electricity by photovoltaic (PV) devices is a reliable choice to cope the growing energy consumption, due to the huge potentially extractable power (up to 120000 TW). The most important classes of inorganic PV devices developed in the last sixty years will be reviewed in this paper, in order to depict the state of the art of the technologies which dominate the PV market. Some novel concepts which could have an important role in the future of PV will be also described

Clinical care conditions and needs of palliative care patients from five italian regions: Preliminary data of the demetra project

In order to plan the right palliative care for patients and their families, it is essential to have detailed information about patients’ needs. To gain insight into these needs, we analyzed five Italian local palliative care networks and assessed the clinical care conditions of patients facing the complexities of advanced and chronic disease. A longitudinal, observational, noninterventional study was carried out in five Italian regions from May 2017 to November 2018. Patients who accessed the palliative care networks were monitored for 12 months. Sociodemographic, clinical, and symptom information was collected with several tools, including the Necesidades Paliativas CCOMS-ICO (NECPAL) tool, the Edmonton Symptom Assessment System (ESAS), and interRAI Palliative Care (interRAI-PC). There were 1013 patients in the study. The majority (51.7%) were recruited at home palliative care units. Cancer was the most frequent diagnosis (85.4%), and most patients had at least one comorbidity (58.8%). Cancer patients reported emotional stress with severe symptoms (38.7% vs. 24.3% in noncancer patients; p = 0.001) and were less likely to have clinical frailty (13.3% vs. 43.9%; p < 0.001). Our study confirms that many patients face the last few months of life with comorbidities or extreme frailty. This study contributes to increasing the general knowledge on palliative care needs in a high-income country

Ternary organic photodetectors based on pseudo–binaries nonfullerene–based acceptors

The addition of a third component to a donor:acceptor blend is a powerful tool to enhance the power conversion efficiency of organic solar cells. Featuring a similar operating mechanism, organic photodetectors are also expected to benefit from this approach. Here, we fabricated ternary organic photodetectors, based on a polymer donor and two nonfullerene acceptors, resulting in a low dark current of 0.42 nA cm−2 at −2 V and a broadband specific detectivity of 1012 Jones. We found that exciton recombination in the binary blend is reduced in ternary devices due to the formation of a pseudo-binary microstructure with mixed donor–acceptor phases. With this approach a wide range of intermediate open-circuit voltages is accessible, without sacrificing light-to-current conversion. This results in ternary organic photodetector (TOPD) with improved Responsivity values in the near-infrared. Moreover, morphology analyses reveal that TOPD devices showed improved microstructure ordering and consequentially higher charge carrier mobilities compared to the reference devices