Simple Elaboration Research Articles

On the charge transport mechanism and the dielectric behavior of Fe-doped SnO2/rGO heterostructure

Graphene Oxide (GO) was associated to Fe-doped SnO2 nanoparticles (NPs) through a simple elaboration method to obtain Fe-doped SnO2/reduced graphene oxide (rGO) nanostructure. The effect of GO content on the structural, morphology, transport and dielectric properties of the SnO2/rGO nanocomposite was deeply investigated. X-ray diffraction (XRD) patterns depict the obtention of SnO2 rutile structure and revealed an effect of the NPs size the rGO layer to layer distance. However, transmission electron microscopy (TEM) exploration shows the formation of rGO nanospheres co-present with Fe-doped SnO2 NPs. The electrical properties of the obtained structure were examined through impedance analysis. The conductivity of the SnO2:Fe/rGO nanocomposite obviously increases with the GO amount. The analysis of the relaxation phenomenon shows an abrupt decrease of the relaxation time upon GO addition. A charge carriers transfer is suggested to occur between Fe-doped SnO2 NPs and rGO for high graphene oxide concentrations. Hydrogen bonds are suggested to be established between these NPs and rGO. The functional groups at the NPs/rGO interface were found to considerably contribute to the dielectric response of the heterostructure. Dielectric losses were also evaluated and are suggested to be particularly affected by the rGO functional groups. The explored electric and dielectric properties present the SnO2:Fe/rGO heterostructure as a potential candidate for supercapacitor and electrical battery electrodes.

A quick look at the recent advances, current state of utilization and expected future usage of artificial intelligence (AI) in the global textile manufacturing industry

A significant part of the current textile manufacturing industry around the world is managed and governed by individuals who are not sufficiently trained in information technology. While future textile engineers and technologists may come out sufficiently equipped to understand IT and its implications to the textile manufacturing industry, those running the industry today can benefit through simple elaboration of potentially useful IT tools and the many benefits they offer to the textile industry. This is especially true in the case of technologies that surfaced within the last two decades and are already making a sizable impact on products, production processes and the bottom lines of manufacturing industries. Artificial intelligence (AI) and related technologies fall under the category of rapidly emerging technologies that carry the potential to significantly re-shape the global manufacturing and service industries. This paper makes an attempt to describe these technologies and their potential benefits in such a way that textile industry leaders who are not IT experts can understand them to the extent of driving themselves to enthusiastically adopt them.

Simple elaboration of drug-SPION nanocapsules (hybridosomes®) by solvent shifting: Effect of the drug molecular structure and concentration

Drug nanocapsules coated with iron oxide nanoparticles (SPION) were elaborated by the simultaneous nanoprecipitation of the drug and the nanoparticles, through solvent shifting. We examined four drugs: sorafenib, sorafenib tosylate, α-tocopherol and paclitaxel, to cover the cases of molecular solids, ionic solids, and molecular liquids. We first investigated the formation of the drug core in the final mixture of solvents at different concentrations. A Surfactant-Free Micro-Emulsion domain (SFME, thermodynamically stable) was observed at low drug concentration and an Ouzo domain (metastable) at high drug concentration, except for the case of paclitaxel which crystallizes at high concentration without forming an Ouzo domain. When co-nanoprecipitated with the molecular drugs in the Ouzo domain (sorafenib or α-tocopherol), the SPION limited the coalescence of the drug particles to less than 100 nm, forming capsules with a drug encapsulation efficiency of ca 80 %. In contrast, larger capsules were formed from the SFME or when using the ionic form (sorafenib tosylate). Finally, the sorafenib-SPION capsules exhibit a similar chemotherapeutic effect as the free drug on the hepatocellular carcinoma in vitro.

Variação do dividend-yield como critério de seleção de ativos em estratégias de momento de fundos de investimentos imobiliários brasileiros

ABSTRACT We aimed at showing the usage of the dividend-yield (DY) variation as a criterion for selecting Brazilian real estate investment trusts (BR-REITs) in momentum strategies. The identification of momentum in BR-REITs with this selection criterion is, to the best of our knowledge, new and gives rise to different strategies that seize abnormal returns. This study allows a new understanding of the dynamics between prices and dividend payments, which compose BR-REITs returns. It is of major importance, considering the relevance of the DY ratio for the asset class. The studied strategies delivered results above the industry’s index with expressive magnitude, are of simple elaboration, and can be applied by any individual or institutional investor. Portfolios’ performances were measured by Sharpe ratio (SR), alpha of the Fama and French three-factor model, and excess returns obtained in relation to the BR-REITs’ index. Statistical tests were applied to verify the significance of the results. This study showed that strategies around the momentum effect that buy (sell) BR-REITs with greater (smaller) DY variations in previous months tended to have superior performance to the industry’s index.

FLEXURAL ANALYSIS OF MODERATELY THICK POROUS MICROPLATE UNDER TRANSVERSE LOADING USING STRAIN GRADIENT AND TWO VARIABLE THEORY

Porous microplates have been greatly implemented in biomechanics equipment, such as biosensors, implantable probes, and structures. Hence, in this paper, static analysis of moderately thick, porous microplates is investigated. In order to obtain accurate results, strain gradient theory is developed, along with two variable plate theories, for precise modeling of moderately thick microplate. In addition to simple elaboration of these theories, which leads to the two decouple equilibrium equations for considering bending and shear effects, the contemplation of the length-scale parameter and thickness effect on the results is remarkable. In studying porous microplates and reinforced porous microplates, the porosity model plays a crucial role in the flexural rigidity of the plate. Therefore, various porosity models are utilized. Simply supported boundary conditions along all edges are considered for rectangular porous microplates. An analytical solution is employed for bending analysis of the porous microplate subjected to uniform distributed load. Results show that in the porous microplate, thickness, and length-scale parameter fluctuations lead to drastic change of the deflection and flexural rigidity of the microplate. Moreover, the flexural rigidity of the microplate decreases with increasing porosity. Therefore, thickness, length-scale parameter, and porosity are the main parameters in optimizing design of the microplates in different fields. Also, results indicate that the classical plate theory studying moderately thick, porous microplates rules out estimating microplate behavior.

TiO2 grafted activated carbon elaboration by milling: Composition effect on sorption and photocatalytic properties

Activated-Carbon/Titania composites (AC/TiO2) is a relevant option to gather the dual adsorption/photodegradation property within a single material. This work aimed to investigate the composition influence on the adsorption and photodegradation properties of AC/TiO2 composites against caffeine. TiO2 grafted AC powders covering the whole composition scale were synthesized by a one-step mechanical milling process. This original simple elaboration route led to the obtention of powders which particles size and composition were homogeneous and well controlled. When the adsorbent mass ratio varied in the range 0.01−0.75, the adsorption properties, i.e. apparent kinetic and maximum adsorption capacity of the composites increased respectively by 1 and 2-log. At the opposite, the photo-oxidation rate decreased significantly when the adsorbent ratio increased. The simple elaboration route explored produces flexible AC/TiO2 composites with adjustable properties that can easily be managed to meet the requirements of different target applications.

Facile fabrication of porous open-cell polymer structures from sacrificial “natural templates” and composite resins

In this paper, we investigate several types of “natural or bio sourced templates” (sugar, salt, bone, coral, PLA 3D-printed scaffolds) for a the simple elaboration of macro porous thermoplastic or thermosetting polymers, especially based on resins commonly used in composites manufacturing. Open-cell, macro porous polymer foams are obtained from resin impregnation of the template. The process consists of 3 simple steps: (a) impregnation (infiltration/infusion) of the template, (b) polymerization of the resin, (c) removal of template, mainly by water. We compared several resins and showed that a low viscosity and a sufficient wettability enable fast impregnation of templates, where impregnation times are < 4 min for samples on 10 to 30 mm thicknesses. The resulting polymeric porous structure is the overall replication of the template, exhibiting mainly open pores in the range of 100 to 500 μm, and densities from 0.25 to 0.4 g cm−3. Such open foams behave as sponges and can (re) absorb liquids either polar (water), alcohols or non polar liquids such as silicon oil, which are filling the entire void volume. We proved the feasibility of an easy and fast impregnation by composite resins to provide either rigid or soft porous polymers (or ‘foams’) that can be further chemically modified. On the other side, before polymerization, the introduction of a functional additive to the reactive infusion formulation, provides homogeneously functionalized foams. Here an impact modifier is tested.

Control of Dispersion and Particle Assembling Structures in Non-aqueous, Dense, and Multicomponent Slurries

Our recent study on design of partial complex of polyethyleneimine and fatty acids/anionic surfactants toward dispersion stability control of non-aqueous, dense, and multicomponent slurries were reviewed. A series of polyethyleneimine complex were successfully designed by simple mixing process and found to effectively adsorb on many species of particles which lead to stability improvement of non-aqueous, dense, multicomponent slurries. A simple elaboration in the mixing orders of powders, solvents, and polyethyleneimine complex also found to compatibly realize the particle assembling and dispersion improvements. An example for applying these dispersion/particle assembling techniques to microstructure design of ceramic green parts will also introduced.

A Supervisory Algorithm Against Intermittent and Temporary Faults in Consensus-Based Networks

In this paper, the consensus problem is addressed for multi-agent networks in which some nodes are expected to possibly misbehave as a consequence of temporary faults or errors. The solution proposed is based on the counteraction of a prescribed subset of nodes through the injection of additional corrective signals. Such corrections are the output of a fault compensation algorithm based on a simple elaboration of local data, whose structure is based on some input-output theoretical results achieved in this paper. A thorough discussion is reported on how to retrieve the algorithm coefficients using local data, so that the algorithm can be fully performed without any network topology knowledge in advance. Simulation results show the behavior of the adopted strategy in several different faulty conditions, and robustness of the compensation algorithm with respect to errors in the computation of the coefficients is also investigated. The results show that the proposed algorithm performs well in several scenarios of networked systems, and it can be suited to easily restore the consensus value to the original one, in spite of the drift initially caused by the fault.

O jogo didático “qual é o bicho?” no ensino de zoologia dos vertebrados

O emprego de recursos alternativos no ensino de ciências tem gerado discussões acerca da validação desses materiais no processo de ensino-aprendizagem. Os jogos didáticos, por exemplo, são tidos como ferramentas pedagógicas relevantes para o desenvolvimento cognitivo, psicomotor e afetivo dos alunos por envolverem fatores que não se limitam a simples elaboração de conceitos, fruto do ensino tradicional, na qual o professor tem a função de transmitir seus conhecimentos científicos como “verdades imutáveis e inquestionáveis”. Esse artigo tem como objetivo relatar a aplicação de um jogo didático denominado “Qual é o Bicho?” a alunos do sétimo ano do ensino fundamental de uma escola da rede municipal de Dourados- M.S. e discutir sobre o uso desses recursos para o desenvolvimento dos alunos, uma vez que eles contemplam não apenas o domínio cognitivo, mas também habilidades relacionadas aos domínios afetivo e psicomotor. A partir da aplicação do jogo e por meio de observação direta e um questionário avaliativo constatou-se que os jogos beneficiam a aprendizagem significativa e ainda oportunizam aos alunos um ambiente interativo, a partir da relação estabelecida entre aluno-professor-conhecimento.

Ordered Nanoporous Thin Films by Nanosphere Lithography and Diazonium Electroreduction: Simple Elaboration of Ultra‐Micro‐Electrode Arrays

AbstractHighly ordered ultra‐micro‐electrode arrays are obtained using nanosphere lithography combined with electrochemical reduction of an aryl diazonium salt. A template made up of 2D hexagonally close‐packed polystyrene (PS) spheres was first deposited on indium tin oxide or glassy carbon substrates. Then, a thin layer of bisthienylbenzene (BTB) was grafted onto the interstices between the spheres. After dissolution of the PS spheres, the presence of micro‐hole arrays on the substrates was evidenced by atomic force microscopy. The electrochemical response of these micro‐hole arrays was investigated as a function of the size of the spheres used. Depending on their radius and the distance between adjacent holes, they behave as a partially blocked surface or as ultra‐microelectrode arrays (UMEAs).

Explanatory Notes on Some Important Statistical Topics

This paper describes and elaborates on some statistical topics that will be of importance to research workers in ART (Assisted Reproduction Technology). The aim is to provide fairly elementary and easily accessible descriptions of those topics. The topics included will of course have been well covered in statistical texts, but in a manner that may be alien to biologists. Simplicity and accessibility will therefore be the keynote. The selection of topics for ventures of this sort will of course be a personal matter, but those selected in this paper appear to the writer to be the most important, and in need of a simple elaboration. The anticipated readership will be research workers in the field of ART (Assisted Reproduction Technology).

Muslim Pilgrims' Use of Electronic Billboards (EBBs) and Message Recall: Examining the Effectiveness of the EBBs as a PSA Tool

The present study has examined the utility of the electronic billboards (EBBs) as a public service announcement (PSA) tool in the Holy Mosque area, Makkah Al-Mukarramah. Data were gathered from a non-probability sample of the Omrah pilgrims on the use, perceptions, and recall of the EBB messages. In-depth interviews with informants were also used to help interpret the data. Pilgrims’ attention to the billboards and their recall of the messages were used as factors of billboard utility and effectiveness. On the basis of frequency distribution analysis coupled with simple elaboration through contingency and partial contingency tables, and zero-order and 5th order partial correlations, the study concludes that despite their potential for high effectiveness the EBBs are not producing much of an impact on the pilgrims. Recommendations are proffered on how best to improve the EBBs utility as a PSA tool for the pilgrims.

From Cyclopentadiene to Isoxazoline-Carbocyclic Nucleosides; Synthesis of Highly Active Inhibitors of Influenza A Virus H1N1

The synthesis of isoxazolino-carbocyclic nornucleosides incorporating a quinoline moiety was tuned through nitrosocarbonyl intermediate chemistry, and a range of adenine analogues were attained through the linear construction of purine heterocyclic rings. The synthesis hinges on exo-selective 1,3-dipolar cycloaddition of quinolinenitrile oxide to the 2,3-oxazanorborn-5-enes and simple elaboration of the cycloadducts. The nucleoside derivatives were initially tested for their inhibitory activity against a variety of viruses, including HBV, PTV and Flu A virus H1N1. High antiviral activities were found for compounds 22aA and 22bA in the case of Flu A H1N1.

Beyond Counterarguing: Simple Elaboration, Complex Integration, and Counterelaboration in Response to Variations in Narrative Focus and Sidedness

This study attempts to advance theorizing about narrative persuasion by explicating types of thoughts, beyond counterarguing, generated in response to a short narrative with persuasive intent. We examine responses to four types of narratives (focus: individual vs. community; by sidedness: one- vs. two-sided) about causes and solutions for obesity in an attempt to increase support for policies to address the issue. Using a randomized experiment (n = 245), we show that narrative focus and sidedness interact to produce different patterns of thoughts, attributions, and policy support. Simple elaboration, counterelaboration, and counterarguing predicted causal attributions and policy support, but only simple elaboration mediated message effects on intended persuasive outcomes. We conclude by discussing the study's contributions to communication theory and practice.

Modelling physical properties of highly crystallized polyester reinforced with multiwalled carbon nanotubes

The effects of carbon nanotubes dispersion into thermoplastic polymers are complex and strongly dependent upon their aggregation state. A poly(ethylene terephthalate) (PET) matrix has been reinforced through addition of multiwalled carbon nanotubes (MWCNTs). Such an addition has generated an increase in flexural modulus and a decrease in flexural strength at room temperature, and an increase in both properties above the glass transition temperature (at 100 °C). These different behaviours, dictated by temperature, have been investigated through two different micromechanical models that have permitted to put forward hypothesis on failure mechanisms and to shed light on the role played by crystalline phase. The results of thermal analyses have shown that the heat capacity of PET nanocomposites varies according to the MWCNTs content as the flexural modulus. Such a similarity has suggested to modify the Halpin-Tsai equations (H-T), typically used to predict elastic properties of short fibres reinforced composites, in order to determine the relationships occurring between PET specific heat and aspect ratio of dispersed MWCNT. The analyses performed by means of either classical H-T (elastic modulus) or modified H-T (heat capacity) equations, provided very similar estimation of the MWCNT aspect ratios. In addition, a simple elaboration of the modified H-T equations permitted the calculation of rigid amorphous fraction (RAF) into PET. The obtained values were slightly higher than those evaluated by means of a procedure based on the loss tangent peak variation measured through dynamic mechanical experiments. The detected strength decrease at 25 °C have been attributed to crack propagation through a percolative path between crystalline coating layer of MWCNTs and PET (favoured by matrix brittleness), while at 100 °C the crack propagation is hampered by rubbery behaviour of the matrix.

Elaboration of nano-structured grafted polymeric surface

The surface grafting of multi-polymeric materials can be achieved by grafting as components such as polymers poly(N-isopropylacrylamide) and/or surfactant molecules (hexatrimethylammonium bromide, polyoxyethylene sorbitan monolaurate). The chosen grafting techniques, i.e. plasma activation followed by coating, allow a large spectrum of functional groups that can be inserted on the surface controlling the surface properties like adhesion, wettability and biocompatibility. The grafted polypropylene surfaces were characterized by contact angle analyses, XPS and AFM analyses. The influence of He plasma activation, of the coating parameters such as concentrations of the various reactive agents are discussed in terms of hydrophilic character, chemical composition and morphologic surface heterogeneity. The plasma pre-activation was shown inevitable for a permanent polymeric grafting. PNIPAM was grafted alone or with a mixture of the surfactant molecules. Depending on the individual proportion of each component, the grafted surfaces are shown homogeneous or composed of small domains of one component leading to a nano-structuration of the grafted surface.

ChemInform Abstract: Synthesis of Enantiopure Protected 3-Hydroxy-4-amino Pyrroline N-Oxides.

Abstract The synthesis of new five-membered enantiopure cyclic nitrones bearing protected cis vicinal amino and hydroxy functionalities is reported. The key step was a Mitsunobu reaction, which allowed placement of an azido group, with inversion of configuration, at the reacting centre. Cycloaddition of the novel nitrones to but-3-en-1-ol followed by simple elaboration of the adducts readily afforded protected amino dihydroxy indolizidines.

Infrared image analysis and elaboration for archaeology: The case study of a medieval “capsella” from Cimitile, Italy

Infrared reflectography, i.e. the use of images taken with infrared light, is currently applied in the field of cultural heritage mainly for paintings analysis to reveal the presence of underdrawings or alterations. Its use in archaeology for deciphering faded signs (texts, images, tattoos, etc.) is a lot more limited and in most cases no or simple data analysis and elaboration is performed. Here we show that infrared reflectography taken by using a wide spectral response (wavelength range from 400 to 2200 nm) VIDICON image acquisition system together with adequate post-elaboration, taking advantage from advanced techniques for data analysis (wavelet decomposition) and image registration and fusion, is able to produce high-quality ‘C&IR’ images. Such images can be obtained in a relatively easy way using the same hardware configuration generally used for infrared reflectographic analysis of paintings. The application to a medieval capsella (a small wooden relics container) from Cimitile, Italy, has shown that these results are of great interest for archaeologists.

Civil protection preparedness and response to the 2007 eruptive crisis of Stromboli volcano, Italy

Stromboli, one of the very few tourist volcanic islands in the world in permanent state of activity, has been the site of two important volcanic crises coupled with slope failure episodes in 2002–2003 and 2007. Due to the lucky circumstance that both crises have occurred in winter, the actual consequences on people were moderate. Nevertheless, the first crisis caused a few injuries, threatened the local population and caused relevant economic losses. The emotional impact on public opinion of the 30th December 2002 tsunami acted, in particular, as a trigger for civil protection initiatives aimed at structurally improving the standard volcano safety and preparedness measures to effectively deal with future crises. The main initiatives carried out during the 2003 crisis consisted in the setting up of: 1) new geophysical and geochemical volcano surveillance networks and 2) a local, permanent scientific/civil protection structure (COA, Centro Operativo Avanzato), where signals from volcano monitoring are visualized in real time and eventually used by the personnel of the Department of Civil Protection (DPC) for immediate activation of response procedures. This was followed by the setting up, in 2005, at the (DPC) in Rome, of a centre named “Centro Funzionale Centrale Rischio Vulcanico” (CFCRV), where the most relevant monitoring signals of Italian active volcanoes are visualized in real time and where activities of simple elaboration, for hazard assessment purpose are daily carried out and data sharing within the scientific community is coordinated by civil protection personnel with training in volcanic problems. The response effectiveness of the new system was tested on February–March 2007 when a new volcanic crisis occurred. An internal DPC “state of attention” was declared by the CF 15 days before the eruption onset when seismic and deformation parameters showed an abrupt increase up to values much higher than background. On February 27th the sudden onset of explosive activity outside the main craters and the occurrence of a small landslide down slope of the active craters were detected in real time on the screens of the CFCRV and by monitoring centres of the National Institute of Geophysics and Volcanology (INGV) and University of Florence (UNIFI). This enabled the DPC to immediately activate emergency crisis procedures and start a coordinated management of the crisis between civil protection personnel in Rome and COA. As accelerating slope movements were detected by ground deformation monitoring of UNIFI, a tsunami warning was launched shortly afterward. Warnings were also declared on 8th March and 15th March when slope movements resumed and a large explosion at the central craters occurred, respectively. From the end of February to May 2007 a scientific committee named “Scientific Synthesis Group” (SSG), appointed by the DPC, made daily evaluations of impending hazards in cooperation with CFCRV. During the crisis the DPC coordinated information activities with the media and island residents. The successful managing of the crisis consisted in minimizing risk for people and meanwhile facilitating normal activities and regular access to island.