Statistical compatibility in the flash point by Pensky-Martens closed cup tester of diesel fuel

The authors' aim is to evaluate the statistical compatibility in the flash point by Pensky-Martens closed cup tester of diesel fuel. As the data set has non-normal behavior, Friedman's test is used. There is no statistical difference among technicians, in the meantime different architectures of equipment present statistically incompatible results.     

Study of MIG/MAG welding procedures for application of coatings of Inconel 625 nickel alloy on ASTM A387 Gr.11 structural steel

This work aims to study welding techniques applied to repair of components made of ASTM A387 Gr.11 steel, widely used in the oil and gas industry. Due to the working conditions, it is necessary to use materials having good strength and corrosion resistance. UNS N06625 Ni-based alloy (Inconel 625) was used as the filler metal. The MIG/MAG welding process was used to apply the temper bead welding technique with two layers. The methodology of this study was divided in stages, in the first one, exploratory trials were carried out to define the relevance of the studied control factors. In the second step, hardness and microstructure criteria were applied for defining the best heat input relations for the application of the double-layer technique. The double-layer technique was effective in improving the properties of the microstructure in heat-affected zone coatings, intense grain refinement was found. There was also a reduction in microhardness and hardness measurements. Both used shielding gases (Ar + 25% He and Ar + 4% CO2) have achieved heat input relations with positive deviations. In all these relations the heat input of the second layer is greater than the heat input of the first layer.     

Grinding performance by applying MQL technique: an approach of the wheel cleaning jet compared with wheel cleaning Teflon and Alumina block

The International Journal of Advanced Manufacturing Technology - Characterized by the high heat generation, grinding has great difficulty in dry machining. As an alternative, it is proposed to...     

User-defined challenges and desiderata for robotics and autonomous systems in health and social care settings

ABSTRACT

We report the needs and challenges identified by health and social care professionals and service users for robotics and autonomous systems that are of importance to researchers and policymakers. To this end, we held eight workshops in different locations across Cornwall (UK) in which we raised awareness of the applications and opportunities of assistive robots. The 223 participants could interact physically with four robots, watched a multimedia presentation including video and use-case scenarios and then took part in 33 focus groups. Content analysis was carried out based on summaries written by facilitators during the focus groups. The focus groups produced 163 challenges that may have digital solutions including 78 suitable for robotic assistive technology, in three main areas: maintaining independence at home, social isolation, and rurality. Although further research is needed with technology and its implementation, this study shows that health and social care professionals, patients, carers, and students are willing to consider using robotics and autonomous systems in health and social care settings.     

Hybrid Monoliths for Magnetically‐Driven Protein Separations

Monoliths represent powerful platforms for isolation of large molecules with high added value. This work presents a hybrid approach for antibody (Ab) capture and release. Using mostly natural polymers and clean processes, it is possible to create macroporous monoliths with well‐defined porous networks, tuneable mechanical properties, and easy functionalization with a biomimetic ligand specific for Ab. Magnetic nanoparticles (MNPs) are embedded on the monolith network to confer a controlled magnetic response that facilitates and accelerates Ab recovery in the elution step. The hybrid monolithic systems prepared with agarose or chitosan/poly(vinyl alcohol) (PVA) blends exhibit promising binding capacities of Abs directly from cell‐culture extracts (120 ± 10 mg Ab g^?1 support) and controlled Ab magnetically‐assisted elution yielding 95 ± 2% recovery. Moreover, a selective capture of mAbs directly from cell culture extracts is achieved yielding a final mAb preparation with 96% of purity.     

SPEEK-Tin dioxide proton conducting membranes: Effect of modifying agent of tin dioxide particles surface

Proton-conducting membranes based on sulphonated poly (ether ether ketone) (SPEEK) polymer matrix and tin dioxide have been synthesized. Their local structure has been studied by FTIR and XRD whereas their structural features at nanometer scale has been investigated by Small-Angle X-ray Scattering (SAXS) and transmission electron microscopy (TEM). SAXS and TEM results show that incorporation of the inorganic particles in SPEEK promotes dispersion of the hydrophilic sulfonic groups in the polymer matrix, inhibiting the formation of the water-filled ionic clusters usually observed in hydrated SPEEK membranes. The changes in SPEEK nanostructure are induced by incorporation of particles modified by Tiron that promotes the connectivity between hydrated channels and reduces diffusion of alcohol, as evidenced by permeability measurements. The resulting increase of proton conductivity compared to pristine SPEEK, particularly at medium temperature (80°C), combined to an improved dimensional stability, make this family of membranes very promising for future applications in fuel cell.     

Thermal Expansion,Heat Capacity,and Thermal Conductivity of Nickel Ferrite (NiFe2O4)

Nickel ferrite (NiFe₂O₄) is a major constituent of the corrosion deposits formed on the exterior of nuclear fuel cladding tubes during operation. NiFe₂O₄ has attracted much recent interest, mainly due to the impact of these deposits, known as CRUD, on the operation of commercial nuclear reactors. Although advances have been made in modeling CRUD nucleation and growth under a wide range of conditions, the thermophysical properties of NiFe₂O₄ at high temperatures have only been approximated, thereby limiting the accuracy of such models. In this study, samples of NiFe₂O₄ were synthesized to provide the thermal diffusivity, specific heat capacity, and thermal expansion data from room temperature to 1300 K. These results were then used to determine thermal conductivity. Numerical fits are provided to facilitate ongoing modeling efforts. The Curie temperature determined through these measurements was in slight disagreement with literature values. Transmission electron microscopy investigation of multiple NiFe₂O₄ samples revealed that minor nonstoichiometry was likely responsible for variations in the Curie temperature. However, these small changes in composition did not impact the thermal conductivity of NiFe₂O₄, and thus are not expected to play a large role in governing reactor performance.     

A real-time video quality estimator for emerging wireless multimedia systems

Wireless Mesh Networks (WMNs) are increasingly deployed to enable thousands of users to share, create, and access live video streaming with different characteristics and content, such as video surveillance and football matches. In this context, there is a need for new mechanisms for assessing the quality level of videos because operators are seeking to control their delivery process and optimize their network resources, while increasing the user’s satisfaction. However, the development of in-service and non-intrusive Quality of Experience assessment schemes for real-time Internet videos with different complexity and motion levels, Group of Picture lengths, and characteristics, remains a significant challenge. To address this issue, this article proposes a non-intrusive parametric real-time video quality estimator, called MultiQoE that correlates wireless networks’ impairments, videos’ characteristics, and users’ perception into a predicted Mean Opinion Score. An instance of MultiQoE was implemented in WMNs and performance evaluation results demonstrate the efficiency and accuracy of MultiQoE in predicting the user’s perception of live video streaming services when compared to subjective, objective, and well-known parametric solutions.     

Kinetic and Equilibrium Adsorption Studies for Removal of Naphthenic Acids Present in Model Mixture of Aviation Kerosene

In this work, the adsorbent Sr-MCM-41 was evaluated for its ability to remove naphthenic acids present in model mixture of aviation kerosene (jet fuel) by conducting kinetic and adsorption equilibrium studies in finite bath systems. The adsorption isotherm model of Brunauer, Emmett, and Teller (BET) was used for the equilibrium modeling. Additionally, the linear driving force model was used for the kinetic modeling. The analysis of variance was incorporated to judge the compatibility of the models. The kinetic study found that the system reached equilibrium after 480 min. The equilibrium study showed a maximum adsorption capacity of 2.0 g g^?1. The models represented the experimental data satisfactorily, and this was confirmed by the variance analysis. Under the conditions studied, the presented results show the technical potential of using the adsorbent for the removal of naphthenic acids from jet fuel.