Tuning Printability and Adhesion of a Silver-Based Ink for High-Performance Strain Gauges Manufactured via Direct Ink Writing.

Structural health monitoring (SHM) systems are critical in ensuring the safety of space exploration, as spacecraft and structures can experience detrimental stresses and strains. By deploying conventional strain gauges, SHM systems can promptly detect and assess localized strain behaviors in structures; however, these strain gauges are limited by low sensitivity (gauge factor, GF ∼ 2). This study introduces an approach to printing strain gauges with high sensitivity, while also considering stretchability and long-term durability.

Ring Currents in the Clar Goblet Calculated Using Configurational State Averaging.

The closed-shell Hückel-London-Pople-McWeeny formalism for ring currents is extended to Aufbau configurations with open shells calculated as configurational averages. The method is applied to the non-Kekulean benzenoid known as the Clar goblet, recently synthesized on the Au(111) surface. Multiplicity of the ground state is a complication: for the Clar goblet, Hund's rule of maximum multiplicity implies a triplet whereas Ovchinnikov's rule implies a singlet.

Optimization of CsPbBr/PVDF composite for enhanced UV photodetection application.

Halide perovskites have exhibited great research impact for developing innovative materials with novel properties. Here, we report the synthesis of different caesium lead bromide perovskites using different (Cs/Pb) molar ratios and fabrication of their corresponding perovskite/polyvinylidene fluoride (PVDF) composites, as well as study of their structural and UV-photodetection properties. Spin-coated perovskite/PVDF composite thin films revealed strong oriented XRD diffraction peaks along the -axis direction (00l) with homogeneously distributed perovskite microcrystals in the polymer matrix.

Synthesis of different organic ammonium-based bismuth iodide perovskites for photodetection application.

Bismuth-based perovskites are promising candidates for highly stable halide perovskites with low toxicity. Here, we report the synthesis of a series of bismuth iodide-based perovskites with different primary, secondary, and tertiary ammonium cations and study their structural, thermal, and optical properties, and the likelihood of photodetection. Interestingly, the variation of A-site organic ammonium cations, with different interlayer spacings between adjacent bismuth iodide monolayers, has exotic effects on the diffraction patterns and morphological structures of the perovskite crystals.

A bibliometric survey of research trends in vitrimer.

The recent trends of vitrimer studies enhance the thermoset material with superior properties, therefore, it is particularly important to address the critical scientific inquiries in this area using their research metrics. The reported vitrimer systems have been highly required for future real-time applications; however, the inquisitiveness of material exchange mechanisms extends the research studies further. Significantly, more scientific information's are required to achieve the evident prospective outcomes these materials.

Combined Additive and Laser-Induced Processing of Functional Structures for Monitoring under Deformation.

This research introduces a readily available and non-chemical combinatorial production approach, known as the laser-induced writing process, to achieve laser-processed conductive graphene traces. The laser-induced graphene (LIG) structure and properties can be improved by adjusting the laser conditions and printing parameters. This method demonstrates the ability of laser-induced graphene (LIG) to overcome the electrothermal issues encountered in electronic devices.

Accurate predictions of thermoset resin glass transition temperatures from all-atom molecular dynamics simulation.

To enable the design and development of the next generation of high-performance composite materials, there is a need to establish improved computational simulation protocols for accurate and efficient prediction of physical, mechanical, and thermal properties of thermoset resins. This is especially true for the prediction of glass transition temperature (), as there are many discrepancies in the literature regarding simulation protocols and the use of cooling rate correction factors for predicting values using molecular dynamics (MD) simulation. The objectives of this study are to demonstrate accurate prediction the with MD without the use of cooling rate correction factors and to establish the influence of simulated conformational state and heating/cooling cycles on physical, mechanical, and thermal properties predicted with MD.

Primary orbital melanoma arising in an atypical diffuse (plaque-like) blue naevus/melanocytosis: a case report and review of literature.

Background: Primary orbital melanoma is a rare disease and can occasionally develop from a pre-existing neoplasm of the blue naevus family of melanocytic lesions.

Case Presentation: Herein we report a rare case of primary orbital melanoma arising from an unusual atypical diffuse (plaque-like) blue naevus/melanocytosis. A 27 year old man presented with mild pain and swelling of the left eye.

Topological Ring Currents and Bond Currents in Neutral and Dianionic and Iterated of Benzene, Naphthalene, and Azulene.

In previous studies, the Hückel-London-Pople-McWeeny (HLPM) method was used to calculate the "topological" ring currents and bond currents that are associated with the mono-, and the doubly and triply iterated , of corannulene and coronene and their respective dianions. This gave rise to some intriguing patterns in these currents, which were partially rationalized by a detailed examination of the lone nonbonding orbitals that each of these structures possesses. In the present work, the same HLPM approach is used to investigate whether analogous changes in bond-current patterns are observed when going from the neutral species to the dianions of the iterated derived from some other, simpler, "parents" having molecular graphs with a nullity of zero.

Calculated Magnetic Properties of a Recently Synthesized Corannulene-Dibenzobistetracene Hybrid.

Comparison is made between two calculated magnetic properties of a recently synthesized 24-ring corannulene-dibenzobistetracene hybrid (Corannulene-DBT): nuclear independent chemical shifts published by Xu et al. and Hückel-London-Pople-McWeeny (HLPM) ring currents and bond currents that are presented here. There is agreement in 18 of the 24 rings in Corannulene-DBT.

Porosity Reducing Processing Stages of Additive Manufactured Molding (AMM) for Closed-Mold Composite Fabrication.

This article aims to merge two evolving technologies, namely additive manufacturing and composite manufacturing, to achieve the production of high-quality and low-cost composite structures utilizing additive manufacturing molding technology. This work studied additive manufacturing processing parameters at various processing stages on final printed part performance, specifically how altering featured wall thickness and layer height combine to affect final porosity. Results showed that reducing the layer height yielded a 90% improvement in pristine porosity reduction.

Topological Ring-Currents and Bond-Currents in Hexaanionic and Iterated of Corannulene and Coronene.

Previous studies of the Hückel-London-Pople-McWeeny (HLPM) ring-currents and bond-currents associated with the neutral and the dianionic , and iterated , of corannulene and coronene, are here extended to the hexaanions of ()-corannulene and ()-coronene, with = 1, 2, and 3. The magnetic properties of some of these species were originally studied by Monaco and Zanasi using the -centric approach, which is ab initio in nature. The "topological" HLPM method, by contrast, constitutes a parameter-free, quasi graph-theoretical model requiring knowledge only of the molecular graph of the conjugated system being considered and the areas assumed for its constituent rings.

Dielectric Properties for Nanocomposites Comparing Commercial and Synthetic Ni- and FeO-Loaded Polystyrene.

Nanomaterial-loaded thermoplastics are attractive for applications in adaptive printing methods, as the physical properties of the printed materials are dependent on the nanomaterial type and degree of dispersion. This study compares the dispersion and the impact on the dielectric properties of two common nanoparticles, nickel and iron oxide, loaded into polystyrene. Comparisons between commercial and synthetically prepared samples indicate that well-passivated synthetically prepared nanomaterials are dispersed and minimize the impact on the dielectric properties of the host polymer by limiting particle-particle contacts.

Assessing the Extent of π-Electron Delocalization in Naphtho-Annelated Fluoranthenes by Means of Topological Ring-Currents.

The extent of π-electron delocalization in the five-membered rings of 14 naphtho-annelated fluoranthenes has recently been assessed by means of several approaches, including application of the following indices: the energy effect (ef), bond resonance-energy (BRE), multicenter delocalization-energies (MCI), the index arising from the harmonic-oscillator model of aromaticity (HOMA), and nucleus-independent chemical shifts (NICS). The calculated Hückel-London-Pople-McWeeny (HLPM) ("topological") ring-current intensities (TRC) for the five-membered rings of these same structures are here compared with the above-named indices in order to assess how well TRC parallels these other criteria. The indices ef and BRE are the ones that correlate best with TRC, and it is suggested that this is because all three approaches are founded on the Hückel model.

Topological Ring-Currents and Clar Sextets in Fully Benzenoid Hydrocarbons. II. Large Structures Containing More than 18 Rings.

In previous work, π-electron ring currents in several fully benzenoid hydrocarbons were calculated by means of the quasi-graph-theoretical, parameter-free Hückel-London-Pople-McWeeny (HLPM) method. It was found that for fully benzenoid hydrocarbons formed from fewer than about 17 rings all ring currents in full rings are larger in intensity than the ring current in benzene, while ring currents in the empty rings are smaller than the benzene value. There was an indication that this distinction might break down when larger systems are considered.

Topological Ring-Currents and Clar Sextets in Fully Benzenoid Hydrocarbons I. Structures with Fewer than 18 Rings.

It is well-known that the very special family of conjugated systems described as "fully benzenoid hydrocarbons" have a unique Clar structure that causes all of their rings to be classified as either "full" or "empty". In this work, π-electron ring-currents in more than two dozen such structures are calculated by means of the quasi-graph-theoretical, parameter-free Hückel-London-Pople-McWeeny (HLPM) method. In the case of benzenoid hydrocarbons, the calculated values of such "topological" ring-currents depend on only the carbon-carbon connectivity of the system in question.

Topological Ring Currents and Bond Currents in Some Neutral and Anionic Altans and Iterated Altans of Corannulene and Coronene.

The novel series of conjugated systems called altans, defined nearly a decade ago, was subsequently extended to multiple ("iterated") altans, and their magnetic properties were calculated by Monaco and Zanasi using the ab initio ipso-centric formalism. Such properties of the single ("mono") altans of corannulene and coronene, calculated by this sophisticated ab initio approach, had earlier been compared with those calculated via the rudimentary Hückel-London-Pople-McWeeny (HLPM) method-a parameter-free topological, quasi graph-theoretical approach requiring knowledge only of the conjugated system's molecular graph and the areas of its constituent rings. These investigations are here extended to double and triple altans.

Engineering Crack Formation in Carbon Nanotube-Silver Nanoparticle Composite Films for Sensitive and Durable Piezoresistive Sensors.

We report highly sensitive and reliable strain sensors based on silver nanoparticle (AgNP) and carbon nanotube (CNT) composite thin films. The CNT/AgNP was prepared by a screen printing process using a mixture of a CNT paste and an AgNP ink. It is discovered that the sensitivity of such sensors are highly dependent on the crack formation in the composites.

Topological ring-current and bond-current properties of the altans of certain K-factorizable conjugated systems containing "fixed" single-bonds.

The rudimentary Hückel-London-Pople-McWeeny (HLPM) formalism, which frequently mimics the predictions of more-sophisticated ab initio approaches, is used to investigate the π-electron ring-current and bond-current properties of four novel altan-structures, the parents of three of which are conjugated structures with "fixed" single carbon-carbon bonds: namely, acenaphthylene, fluoranthene, and perylene. Such structures are nowadays sometimes called "K-factorizable". Non-K-factorizable peropyrene is also considered, for comparison.

A stewardship approach to shaping the future of public health supply chain systems.

Guiding Principles: (1) Governments should see themselves as stewards of supply chains, providing vision, guidance, and oversight, not necessarily as operators of supply chains. (2) Governments should not be afraid to leverage the multiple supply chain actors and diverse options available; these can be woven into a coherent, integrated system, providing flexibility and reducing risk. (3) Governments will need new skills in leadership, regulation, market research, contract design, oversight of outsourced providers, financial analysis, and alliance-building.

Topological ring-currents and bond-currents in the altan-[r,s]-coronenes.

π-Electron ring-currents for the altans of the four regular [r,s]-coronenes are calculated by the topological HLPM approach. The bond-current pattern of the parent structure is generally preserved in the core of the corresponding altan. Altan-[10,5]-coronene appears to support an anomalous diamagnetic current in its [4n]-periphery.

π-Electron ring-currents and bond-currents in some conjugated altan-structures.

Ring-currents and bond-currents calculated using the Hückel-London-Pople-McWeeny (HLPM) method are reported for a series of altan-structures recently explored by Monaco et al. and to which these authors have applied the ab initio ipso-centric formalism in order to calculate the structures' π-electron current-density maps. Two aspects of the conclusions of their ab initio study are confirmed by means of the much more simplistic HLPM formalism adopted here: namely (a) that the inner core in these altan-structures generally displays similar current patterns to those previously reported for the parent fragments, and (b) that the unexpected diamagnetic circulation in the outer [4n]-perimeter of altan-kekulene reported by Monaco et al.

Topological Hückel-London-Pople-McWeeny ring currents and bond currents in altan-corannulene and altan-coronene.

The Hückel-London-Pople-McWeeny (topological) approach for calculating π-electron ring currents and bond currents in conjugated systems is applied to the structures altan-corannulene and altan-coronene, recently designed by Monaco and Zanasi. These authors applied the ab initio ipso-centric formalism to calculate π-electron current-density maps and individual bond current intensities in these structures. In a parallel investigation the key findings of Monaco and Zanasi's ab initio study are here qualitatively confirmed by this much more rudimentary topological assessment: namely, that, in their three layers, the two structures altan-corannulene and altan-coronene reveal patterns of contra-rotating paramagnetic/diamagnetic/paramagnetic π-electron circulations in their innermost, middle, and outer cycles, respectively.

π-Electron ring-currents and bond-currents in [10,5]-Coronene and related structures conforming to the 'Annulene-Within-an-Annulene' model.

A series of hypothetical conjugated structures is defined; the series is called the p-Coronenes and the first four members of it are shown to respect the 'Annulene-Within-an-Annulene' (AWA) model when tested by means of Hückel-London-Pople-McWeeny (HLPM) π-electron ring-current and bond-current calculations. The first member of this series, 5-Coronene, is also a member of the regular [r,s]-Coronene series, where it is known as [10,5]-Coronene. It is shown that, as p is varied (with p always odd, and with p > 3) through the values 5, 7, 9, 11, etc.