Tuning cracks by exploiting the shape of particles and external magnetic field

Drying of a colloidal dispersion usually leads to the formation of particulate film with random cracks. The cracks in particulate film can have periodic arrangement with tuneable spacing and are known to be useful for practical applications such as for fabrication of lithographic templates and nano-channels. Various methodology has been adopted to generate the parallel and ordered cracks, the common one is via applying an external field such as magnetic field or electric field. We report here the controlled manipulation of crack orientation for colloidal films consisting of magnetically active particle (hematite ellipsoids), using an external magnetic field. Drying sessile drop experiments are performed in the presence and absence of magnetic field and a coffee ring like particle deposits are observed. The dried region consists of circular cracks in the absence of field while linear cracks (along the chord of the ring) in the presence of field. Moreover, we found that the crack orientations can be systematically altered by tuning magnetic field strength. We conjecture that the competition between the hydrodynamic torque and magnetic torque experienced by the particles during the drying of colloidal dispersion decides the final orientation of the particles and the cracks. The alteration of crack direction by controlling the orientation of ellipsoids in the particulate films by application of magnetic field is presented in detail. Please click Additional Files below to see the full abstract

Van Kampen's expansion approach in an opinion formation model

We analyze a simple opinion formation model consisting of two parties, A and B, and a group I, of undecided agents. We assume that the supporters of parties A and B do not interact among them, but only interact through the group I, and that there is a nonzero probability of a spontaneous change of opinion (A->I, B->I). From the master equation, and via van Kampen's Omega-expansion approach, we have obtained the "macroscopic" evolution equation, as well as the Fokker-Planck equation governing the fluctuations around the deterministic behavior. Within the same approach, we have also obtained information about the typical relaxation behavior of small perturbations.Comment: 17 pages, 6 figures, submited to Europ.Phys.J.

Phase transition in the Sznajd model with independence

We propose a model of opinion dynamics which describes two major types of social influence -- conformity and independence. Conformity in our model is described by the so called outflow dynamics (known as Sznajd model). According to sociologists' suggestions, we introduce also a second type of social influence, known in social psychology as independence. Various social experiments have shown that the level of conformity depends on the society. We introduce this level as a parameter of the model and show that there is a continuous phase transition between conformity and independence

Nursing Assignment: Understanding Covid-19 Vaccines: Specific Strategies to Encourage and Educate Your Patients

Understanding Covid-19 Vaccines: Specific Strategies to Encourage and Educate Your Patients This assignment focuses on the difference in Covid-19 vaccinations. The nursing student will discuss the different vaccinations and form a teaching plan for the patient in order to encourage the vaccination process. The student will then explore the patients expectations concerning vaccination. As a presentation the students will be able to evaluate, share and reflect on teaching method

Feasibility of ultrafast picosecond laser cleaning of soiling on historical leather buckles

The aim of the research is to present a system recently developed and used for automated cleaning of artworks and to examine the suitability of using this ultrafast and precise computed-scanning picosecond laser (1064 nm) with a repetition rate of 10 kHz and a temporal pulse length of 10 ps for the removal of soiling from leather buckles without damaging the leather substrate. Preliminary tests will be performed with the model artificially aged vegetable tanned samples to determine the leather damage threshold fluence and the soiling ablation threshold fluence before using a laser for the removal of the soiling from a historical leather buckle. As laser cleaning requires a physical parameterization for optimization of cleaning accompanied with an assessment of the morphological and chemical changes of leather, an investigations were performed to determine the leather damage and ablation threshold fluences of artificially aged and historical vegetable tanned leather using a number of analytical techniques including differential scanning calorimetry, optical microscopy, scanning electronic microscope with energy dispersive X-ray analysis, colorimetry and Fourier transform infrared spectroscopy have been used. Following optimization trials of the picosecond laser cleaning parameters on model leather samples, satisfactory removal of the soiling over the historical leather surface is achieved

Magnetic coiffure: Engineering of human hair surfaces with polyelectrolyte-stabilised magnetite nanoparticles

Here we report a spontaneous electrostatic coating of human hair with aqueous Fe3O4 colloids capable to tailor magnetic properties to hair, orienting and even moving them under the influence of the external magnetic field. Magnetite particles were modified by cationic and anionic polyelectrolytes and then successfully deposited in dense arrays, starting from cuticle gaps and spreading further over a major hair surface. These biocompatible and biodegradable magnetic nanoparticles may serve as carriers for drug loading and delivery for topical pharmaceutical treatments. The deposition process was imaged in real-time using dark-field microscopy. The hair specimens were further studied using a number of characterisation techniques. Under application of an external magnetic field, the nanoparticle magnetic ordering was obtained resulting in the hair alignment and attraction along the field applied. We believe the technology reported here will find a range of applications in topical drug delivery and hair care

Fish Welfare in Urban Aquaponics: Effects of Fertilizer for Lettuce (Lactuca sativa L.) on Some Physiological Stress Indicators in Nile Tilapia (Oreochromis niloticus L.)

The combination of hydroponics and aquaculture, or aquaponics, normally requires adding fertilizer to recirculated water to ensure optimal plant growth, but the effect of that fertilizer on fish welfare has not been studied in detail, especially for small urban and coupled aquaponic systems. In this study, a commercial fertilizer was placed in two small aquaponic systems (less than 250 liters each) to test its effect on the stress levels of Nile tilapia (Oreochromis niloticus) compared to controls without any fertilizer. Fish production parameters were not significantly different between treatments, nor were physiological indicators of fish stress (plasma cortisol, glucose, and triglycerides). On the other hand, lettuce growth (leaf and root weight and length) was up to three times higher in the treatment that received fertilizer. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

Lead Optimization of Dual Tubulin and Hsp27 Inhibitors

Tubulin and heat shock protein 27 (Hsp27) are well-characterized molecular targets for anti-cancer drug development. We previously identified lead compounds that inhibited both Hsp27 and tubulin. These compounds exhibited extensive anti-cancer activities against the proliferation of various human cancer cell lines. In the current study, a systematic ligand based structural optimization led to new analogs that significantly inhibited the growth of a panel of breast cancer cell lines. Furthermore, the most potent compounds were examined with tubulin polymerization assay and Hsp27 chaperone activity assay. The compounds showed potent tubulin polymerization inhibition but no Hsp27 inhibitory effect. The structural optimization dissected the dual activity and improved the selectivity of the compounds for tubulin. The results revealed several structural moieties of the lead compounds that are critical for Hsp27 inhibition. The modification of these structural fragments eliminated Hsp27 inhibition, but did not harm tubulin-targeting effects of the compounds. This result further defined the structureeactivity relationship between the tubulin and Hsp27 effects of these compounds

Analysis of the essential literature on project management in Spanish

The advancement of science and engineering projects is brewing major changes in the various phases of a project. These changes have produced more rigorous aspects of project management that tracks the research fronts of engineering and project management becomes key. However, research in engineering and project management in Spanish is hindered by access to information to enable the person concerned to ascertain the most recent and current research, limiting the exchange of information and strengthening research networks in this field interest with great implications in business, industry and scientific issues. Therefore, the article aims to present the state of the art of engineering research and project management in Spanish, using the analysis of scientific domains and network analysis of the research literature to identify and analyze relationships between authors and documents that establish the base and research fronts topic under study. The results also provide statistics on the contribution of international research in Spanish and scientific collaboration networks