The effect of a superplasticizer (from cashew nut shell liquid) on the properties of concrete and mortar

The paper describes a new, cheaper water-reducing compound obtained from cashew nut shell liquid (CNSL). The properties of mortars, namely flow, setting time and compressive strength, were determined in the presence of 0.1 to 1.0% superplasticizer. The compressive strength of mortar containing the superplasticizer from CNSL was higher than that of the control     

Docking-based virtual screening for ligands of G protein-coupled receptors: not only crystal structures but also in silico models

G protein-coupled receptors (GPCRs) regulate a wide range of physiological functions and hold great pharmaceutical interest. Using the β(2)-adrenergic receptor as a case study, this article explores the applicability of docking-based virtual screening to the discovery of GPCR ligands and defines methods intended to improve the screening performance. Our controlled computational experiments were performed on a compound dataset containing known agonists and blockers of the receptor as well as a large number of decoys. The screening based on the structure of the receptor crystallized in complex with its inverse agonist carazolol yielded excellent results, with a clearly delineated prioritization of ligands over decoys. Blockers generally were preferred over agonists; however, agonists were also well distinguished from decoys. A method was devised to increase the screening yields by generating an ensemble of alternative conformations of the receptor that accounts for its flexibility. Moreover, a method was devised to improve the retrieval of agonists, based on the optimization of the receptor around a known agonist. Finally, the applicability of docking-based virtual screening also to homology models endowed with different levels of accuracy was proved. This last point is of uttermost importance, since crystal structures are available only for a limited number of GPCRs, and extends our conclusions to the entire superfamily. The outcome of this analysis definitely supports the application of computer-aided techniques to the discovery of novel GPCR ligands, especially in light of the fact that, in the near future, experimental structures are expected to be solved and become available for an ever increasing number of GPCRs.     

Cybersecurity: Exploring core concepts through six scenarios

The authors introduce and explain core concepts of cybersecurity through six engaging practical scenarios. Presented as case studies, the scenarios illustrate how experts may reason through security challenges managing trust and information in the adversarial cyber world. The concepts revolve around adversarial thinking, including understanding the adversary; defining security goals; identifying targets, vulnerabilities, threats, and risks; and devising defenses. They also include dealing with confidentiality, integrity, availability (known as the “CIA triad”), authentication, key management, physical security, and social engineering. The authors hope that these scenarios will inspire students to explore this vital area more deeply.

The target audience is anyone who is interested in learningabout cybersecurity, including those with little to no background in cybersecurity. This article will also interest those who teach cybersecurity and are seeking examples and structures for explaining its concepts. For students and educators, the authors include selected misconceptions they observed in student responses to scenarios. The contributions are novel educational case studies, not original technical research.

The scenarios comprise responding to an e-mail about lost luggage containing specifications of a new product, delivering packages by drones, explaining a suspicious database input error, designing a corporate network that separates public and private segments, verifying compliance with the Nuclear Test Ban Treaty, and exfiltrating a USB stick from a top-secret government facility.     

Determination of magnetic vortex polarity from a single Lorentz Fresnel image

Nanoscale confinement of the magnetization in a magnetic element often results in the creation of a vortex structure. The vortex equilibrium state is characterized by the curling of the in-plane magnetization (chirality) and an out-of-plane core magnetization. The polarity of the vortex core can point up or down, independent of the chirality, and, thus, magnetic elements with a vortex core are interesting as four-state logic elements. We present an easy-to-use, quantitative method for the determination of both chirality and polarity from a single Fresnel image. This method offers direct evidence of the three-dimensional structure of a magnetic vortex and has significant advantages over the more complex methods currently in use.     

An aqueous developable photoimageable silver conductor composition for high density electronic packaging

In our preliminary work, we have formulated aqueous developable photoimageable thick film conductor pastes, consisting of ‘inhouse processed’ submicron sized silver powders (functional material), micron sized lead borosilicate glass frits (permanent binder), epoxy acrylate resin with pendant –COOH group (base photoimageable polymer/temporary binder/organic vehicle) and 2,2′-dimethoxy-2-phenylacetophenone (photoinitiator). The conductor pastes thus formulated were manually screen printed on the alumina substrates, dried, exposed to the ultra-violet light through the desired test patterns, developed in a 1% aqueous sodium carbonate solution, and subjected to a standard one-hour thick film firing cycle. Solid content of the polymer appears to influence the paste performance. Prima facie observations indicate that the paste with the organic:inorganic ratio of 28:72 (corresponding to solid content of 89.9% of the polymer system) exhibits better electrical conductivity, relatively smooth surface finish and line/space resolution of 100 μm with ±5 μm accuracy. Investigations related to the effect of glass content on the properties of photoimageable conductor paste are also furnished in this communication.     

Dyshormonogenetic goitre with clear cell change resembling parathyroid adenoma--a case report

A 3-d-old neonate presented with fever, hepatosplenomegaly, coagulopathy, thrombopenia and anaemia. Secondary haemophagocytic lymphohistiocytosis was suspected, as persistent cytopenias were associated with hypofibrinogenaemia, haemophagocytosis in bone marrow and decreased NK cell. There was no positive family lymphohistiocytosis history or parental consanguinity. Bacterial investigation proved negative. The diagnosis of enterovirus maternofoetal infection was carried out. The infant's condition improved with symptomatic therapy from day 7. Follow up at 1 y was normal without relapse. This is the first report of a neonatal enteroviral infection that was responsible for excessive macrophage activation.     

High-Temperature Thermal Expansion and Stability of V2AlC Up To 950°C

Herein, we report on the thermal expansion and stability of V₂AlC in the 25°–950°C temperature range. The sample was heated in an Argon atmosphere in a quartz capillary and the thermal expansion was measured using a X-ray synchrotron radiation source. Up to the maximum temperature explored, there were no signs of decomposition or phase transitions. The temperature variation of volumetric thermal expansion is given by α_v=2.53(5) × 10⁻⁵+5.75(3) × 10⁻⁹ T °C⁻¹. At ≈9.40 × 10⁻⁶°C⁻¹, the thermal expansions along both the a and c lattice directions are quite comparable; in other words, there is little thermal expansion anisotropy in V₂AlC.     

Electrochemical co-deposition of ternary Sn–Bi–Cu films for solder bumping applications

This paper reports the co-deposition of Sn–Bi–Cu films using stannic salt bath which has good stability for up to a week. The effect of current density and bath stirring on the film composition and microstructure has been studied. The deposited films are rich in the more noble metal Bi at current densities up to 5 mA cm⁻² but stabilize to about 49 wt. % Bi, 47 wt. % Sn and 4 wt. % Cu at 10 mA cm⁻² and beyond, indicating the effect of limiting current density. There is improvement in the microstructure with stirring or aeration, but the film composition reverts to the Bi rich state, with close to 90 wt. % Bi for deposition at 5 mA cm⁻². This is attributed to the dispersion of Sn²⁺ ions generated at the cathode during the two-step reduction of Sn⁴⁺ ions, due to stirring. The bath is suitable for near eutectic compositions of Sn–Bi with <5 wt. % Cu content.