Brickwork Structures Research Articles

Machine Learning-Inspired Molecular Design, Divergent Syntheses, and X-Ray Analyses of Dithienobenzothiazole-Based Semiconductors Controlled by S⋅⋅⋅N and S⋅⋅⋅S Interactions.

Inspired by the previous machine-learning study that the number of hydrogen-bonding acceptor (NHBA) is important index for the hole mobility of organic semiconductors, seven dithienobenzothiazole (DBT) derivatives 1 a-g (NHBA=5) were designed and synthesized by one-step functionalization from a common precursor. X-ray single-crystal structural analyses confirmed that the molecular arrangements of 1b (the diethyl and ethylthienyl derivative) and 1c (the di(n-propyl) and n-propylthienyl derivative) in the crystal are classified into brickwork structures with multidirectional intermolecular charge-transfer integrals, as a result of incorporation of multiple hydrogen-bond acceptors. The solution-processed top-gate bottom-contact devices of 1b and 1c had hole mobilities of 0.16 and 0.029 cm2 V-1s-1, respectively.

Doddington Court: 160 Victoria Embankment, Durban

Doddington Court, with its striking brickwork structure, is both fascinating and amusing in the way it merges various architectural aspects. While the design respects the privacy of the inhabitants one cannot help noticing the skilled craftsmanship and solid durability throughout. Details in the decoration differ in character but are integrated with fine judgement. The building as a whole is charming: elements of style are fused into a unique synthesis and traces of the human touch are refreshing in a technological era.

Molecular "backbone surgery" of electron-deficient heteroarenes based on dithienopyrrolobenzothiadiazole: conformation-dependent crystal structures and charge transport properties.

Electron-deficient heteroarenes based on dithienopyrrolobenzothiadiazole (BTP) have been highly attractive due to their fascinating packing structures, broad absorption profiles, and promising applications in non-fullerene organic solar cells. However, the control of their crystal structures for superior charge transport still faces big challenges. Herein, a conformation engineering strategy is proposed to rationally manipulate the single crystal structure of BTP-series heteroarenes. The parent molecule BTPO-c has a 3D network crystal structure, which originates from its banana-shaped conformation. Subtracting one thiophene moiety from the central backbone leads to a looser brickwork crystal structure of the derivative BTPO-z because of its interrupted angular-shaped conformation. Further subtracting two thiophene moieties results in the derivative BTPO-l with a compact 2D-brickwork crystal structure due to its quasi-linear conformation with a unique dimer packing structure and short π-π stacking distance (3.30 Å). Further investigation of charge-transport properties via single-crystal organic transistors demonstrates that the compact 2D-brickwork crystal structure of BTPO-l leads to an excellent electron mobility of 3.5 cm2 V-1 s-1, much higher than that of BTPO-c with a 3D network (1.9 cm2 V-1 s-1) and BTPO-z with a looser brickwork structure (0.6 cm2 V-1 s-1). Notably, this study presents, for the first time, an elegant demonstration of the tunable single crystal structures of electron-deficient heteroarenes for efficient organic electronics.

Crystal-structure simulation of methylthiolated peri-condensed polycyclic aromatic hydrocarbons for identifying promising molecular semiconductors: discovery of 1,3,8,10-tetrakis(methylthio)peropyrene showing ultrahigh mobility.

The crystal structures of molecular semiconductors critically affect their carrier transport properties. One of the promising crystal structures that afford high carrier mobility is a brickwork structure recently reported for 1,3,6,8-tetrakis(methylthio)pyrene (MT-pyrene) showing ultrahigh mobility. However, such ultrahigh mobility was not realized in other methylchalocogenated pyrenes, owing to subtle differences in the molecular positions in their crystal structures. This means that, for developing superior molecular semiconductors, it is desirable to simulate the crystal structure with sufficient quality before time-consuming and labor-intensive synthetic trials. To realize this, we developed a new computational approach to simulating crystal structures of all methylchalocogenated pyrenes, which was then applied to MT-pyrene-related methylthiolated peri-condensed polycyclic aromatic hydrocarbons including perylene, peropyrene, and terrylene derivatives. Among these, 1,3,8,10-tetrakis(methylthio)peropyrene (MT-peropyrene) was expected to show high mobility based on the simulated crystal structures. We thus chose MT-peropyrene as the synthetic target and developed a new peropyrene synthesis method. Thus synthesized MT-peropyrene has virtually the same crystal structure as the simulated one, and its single-crystal field-effect transistors showed mobility as high as 30 cm2 V-1 s-1 and band-like transport behaviors. These results indicate that the present crystal-structure simulation is a powerful tool for exploring promising molecular semiconductors. This article is protected by copyright. All rights reserved.

Ti3C2Tx-based composite coating on AZ31B Mg alloy surface for improved anti-corrosion/wear-reducing properties

The poor wear resistance and corrosion resistance of AZ31B magnesium alloy are the main factors limiting its application. Herein, a simple spin-coating method was used to prepare MXene/polyvinyl alcohol (Ti3C2Tx/PVA) composite coating on the magnesium alloy surface. The results of corrosion resistance tests of the composite coating in a solution of 3.5% sodium chloride showed that the corrosion rate of the composite coating was about five orders of magnitude less than that of the substrate of the magnesium alloy. On the one hand, the layered structure of Ti3C2Tx could extend the corrosive media's diffusion path. On the other hand, PVA entering into the non-oxidized area of Ti3C2Tx could reduce the inherent defects of Ti3C2Tx and help to form a complete and continuous layer, resulting in a good barrier effect and improving the corrosion resistance of the substrate. In addition, the Ti3C2Tx/PVA coating has the best tribological properties with the lowest coefficient of friction (COF) and wear rate, with a wear rate approximately two orders of magnitude lower than that of the magnesium alloy substrate, approximately 4 × 10−5·mm3·N−1·m−1. Due to the excellent wear resistance of the layered Ti3C2Tx and the addition of PVA, the coating exhibits good bonding strength and presents an ordered brickwork structure through the hydrogen bonding network. Therefore, the suitable surface coating design combing Ti3C2Tx with PVA could endow the AZ31B Mg alloys with excellent corrosion/wear resistance.

17% efficiency for linear-shaped ADA-type nonfullerene acceptors enabled by 3D reticulated molecular packing

The fundamental principles governing photovoltaic properties of nonfullerene acceptors (NFAs) are essential for developing high-performance polymer solar cells. In this work, using three heteroheptacene-based acceptors (M-series) as model compounds, we systematically study the implication of heteroatoms in the heteroheptacene core on the molecular packing, morphology, optoelectronic, photophysical, and photovoltaic properties of the NFAs. It is found that replacing the oxygen atoms at the inner positions of the heteroheptacene core with sulfur atoms leads to the molecular packing mode change from a linear two-dimensional (2D) brickwork structure to a three-dimensional (3D) reticulated motif, which facilitates the formation of a desirable active layer with nanostructured phase separation morphology and improved charge transport. Meanwhile, the down-shifted highest occupied molecular orbital energy level of M36 induced by the sulfur substitution, matches better with that of polymer donor PM6 thereby leading to more efficient exciton dissociation and charge transfer. As a result, the best-performing photovoltaic device based on M36 affords an outstanding efficiency of 17%, which is among the highest values reported for all the ADA-type NFAs. Our work reveals the important role of the heteroatoms in the heteroheptacene core in constructing the 3D network of ADA-type NFAs, and the structure-property relationships herein shall provide an important guidance for designing high-performance NFAs.

Application of TLS Technology for Documentation of Brickwork Heritage Buildings and Structures

Remote measurement of historic buildings and structures using the technology of terrestrial laser scanning (TLS) is becoming a more and more popular approach for conducting inventory activities, documentation and conservation works. In this paper, TLS was harnessed for analysis of historic brickwork structures from the 19th century. During the research programme, chosen brickwork heritage buildings were scanned. Based on the collected geometric data of the point cloud, it was possible to create an exact model of the scanned objects. The obtained radiometric information of the point cloud allowed us to identify changes in the surface of walls, such as cavities, cracks and previous repairs. Moisture was also identified in some cases. The conducted tests enabled the identification of brickwork in need of urgent repair. It was possible to assess the general technical state of the tested structures. The possibilities and limitations of the TLS diagnostic methodology of analysing the quality of historic brickwork and its future possible applications were indicated.

What Defines a Crystal Structure? Effects of Chalcogen Atoms in 3,7‐Bis(methylchalcogeno)benzo[1,2‐b:4,5‐b′]dichalcogenophene‐Based Organic Semiconductors†

Comprehensive SummaryTo understand the effects of chalcogen atoms on the crystal structure of the series of 3,7‐bis(methylchalcogeno)benzo[1,2‐b:4,5‐b′]dichalcogenophene‐based organic semiconductors, three benzodifuran derivatives (1—3) and dimethoxy derivatives of benzodithiophene and benzodiselenophene (4 and 7) were newly synthesized to complete the “3 × 3 matrix” of the oxygen‐, sulfur‐, and selenium‐derivatives (1—9). The crystal structures of 1—9 were classified into four classes, sandwich pitched π‐stack (1), dimeric (2 and 3), pitched π‐stack (4, 5, 7, 8, 9), and brickwork structure (6 and 9). The causes for the different crystal structures depending on the chalcogen atoms were investigated by the theoretical calculations, indicating that the chalcogen atoms in the core and substituents primarily affected the packing structures. Although the crystal growth in the vapor phase afforded different polymorphs, the relationship between the crystal structure and the carrier transport property was carefully investigated. With these comprehensive evaluations, we conclude that; i) methylchalcogenolation is a powerful tool to alter the packing structure, ii) each methylchalcogeno group has its features that largely influence the intermolecular interaction and electronic structure in the solid state, and iii) organic semiconductors being crystallizable into appropriate pitched π‐stack structures are promising as high‐performance active materials for FET applications.

Heptagon-Embedded π-Expanded Thieno- and N-Methylpyrrolo-Pyridazines with Substantial Out-of-Plane Dipole Moment.

Herein, we describe the synthesis and characterization of fully fused tetraphenylthieno[3,4-d]pyridazine 1 and N-methylpyrrolo[3,4-d]pyridazine 2 with two embedded seven-membered rings. Owing to the incorporated heptagon, 1 and 2 exhibited Cs-symmetric saddle conformations in the solid state with mean plane deviation around 0.38 Å. π-Expanded thienopyridazine 1 showed a one-dimensional (1-D) columnar packing along the b axis with net dipole moment aligning perpendicular to the b axis in the polar crystal system Pc. On the other hand, 2 formed a partially π-stacked brick-work structure. In addition to the Cs-symmetric saddle conformations found in the crystals, density functional theory (DFT) calculation found C2-symmetric twisted conformations of both 1 and 2 close in energy to the saddle conformations. The barrier of conformational interconversion was calculated to be 32 (1) and 31 kJ·mol-1 (2), and the interconversion occurs fast even at -60 °C as evidenced by variable-temperature (VT)-NMR studies. While 1 and 2 have moderately curved structures, optical and electrochemical studies revealed effective π-conjugation over the fused diphenylene units, which is also supported by DFT calculation. As the result of the intrinsic large dipole moment of thieno- and pyrrolo-pyridazines and the notably curved structure, 1 (2) has a substantial out-of-plane dipole moment of 2.0 (3.3) D in the saddle conformations.

"Manipulation" of Crystal Structure by Methylthiolation Enabling Ultrahigh Mobility in a Pyrene-Based Molecular Semiconductor.

Control and prediction of crystal structures of molecular semiconductors are considered challenging, yet they are crucial for rational design of superior molecular semiconductors. It is here reported that through methylthiolation, one can rationally control the crystal structure of pyrene derivatives as molecular semiconductors; 1,6-bis(methylthio)pyrene keeps a similar sandwich herringbone structure to that of parent pyrene, whereas 1,3,6,8-tetrakis(methylthio)pyrene (MT-pyrene) takes a new type of brickwork structure. Such changes in these crystal structures are explained by the alteration of intermolecular interactions that are efficiently controlled by methylthiolation. Single crystals of MT-pyrene are evaluated as the active semiconducting material in single-crystal field-effect transistors (SC-FETs), which show extremely high mobility (32 cm2 V-1 s-1 on average) operating at the drain and gate voltages of -5V. Moreover, the band-like transport and very low trap density are experimentally confirmed for the MT-pyrene SC-FETs, testifying that the MT-pyrene is among the best molecular semiconductors for the SC-FET devices.

Using modern CAE systems for assessing the building structures made of traditional building materials technical condition

Modern “computer-aided design” (CAD) systems allow to process difficult researches on building structures of buildings and constructions. Program complexes, allowing to calculate and get performance predictions of materials and constructions made from them, considered as CAE (Computer Aided Engineering). CAE systems are used not only for creating and researching new materials, but also widely used for rating of traditional material condition. For brick chimney technical condition research program complexes SolidWorks and «Lira-W» were used. Using these calculation complexes structural rigidity, brickwork structures strength ratings were made, the need for taking measures to strengthen the construction was set. Using numerical researches, hazardous locations were identified along the height of the structure. For hazardous locations, a comparative analysis of obtained values of stresses in masonry was carried out in two calculation complexes.

The Ordsall Chord, UK: conservation architecture and engineering – part 2: masonry repairs

The Ordsall Chord is a new railway connecting the main-line stations in Manchester, UK, for the first time, reducing congestion, introducing new passenger services and bringing significant economic benefits. The new railway intersects the line of George Stephenson’s 1830 Liverpool and Manchester Railway and connects to two further nineteenth-century railway viaducts. It had a significant physical and visual impact on highly sensitive heritage assets. The companion paper (part 1) summarises the project, explaining the history of the heritage structures, the consent process and the overall conservation approach. It discusses the design of new structures in the heritage context and the works undertaken to historic metal structures. This second part of the pair of companion papers addresses the brickwork and stonework structures affected. It reviews the condition of the structures at the project outset and describes how a bespoke project specification for repairs was developed. The Grade I-listed Stephenson’s Bridge is discussed in detail.

Analytical study on seismic performance of bed joint reinforced solid brick masonry walls

It is notable that brick work structures endure a lot of harm during seismic tremors, prompting huge loss of lives. Practically 75% of the disaster, credited to seismic tremor in a century ago, is because of breakdown of workmanship structures [1]. A greater part of the apartments in India are Unreinforced Masonry (URM) structures that are powerless and helpless much under moderate quakes and due to high wind forces out-of-plane action is acting on the wall which makes a severe damage at high wind loads and it is well known that Reinforced masonry construction has got a significant number of advantages than the masonry without reinforcement, whose application is very less in Indian construction practices and still there are no specified codes prescribed and in most constructions there been used shear walls instead of reinforced masonry walls even at the moderate earthquakes [2]. On the other hand, a great need to focus on understanding masonry buildings that are subjected to both axial loaded and seismic loads [3]. The main objective of this paper is to study the methods available in the literature to obtain the seismic vulnerability of un-reinforced masonry walls using linear static analysis [4]. To achieve this, analysis (Staad.Pro software) have been carried out as a part of this research. Two walls with same dimensions with an unreinforced and bed type reinforced masonry were analysed under uniaxial loading. A constant axial compressive load was maintained for each specimen during the analysis [5]. Idealized Load vs Deflection plots are used to describe the wall deflections and maximum stresses evolved by using STAAD.Pro. The final outcome of this performance analysis declares the efficiency of Reinforced masonry walls over the masonry walls without reinforcement under both axial and seismic loads (Load vs Maximum shear stress).

Correction: Evaporation-driven manipulation of nanoscale brickwork structures for the design of 1D, 2D, and 3D microarrays of rectangular building blocks

Correction for ‘Evaporation-driven manipulation of nanoscale brickwork structures for the design of 1D, 2D, and 3D microarrays of rectangular building blocks’ by Hiroaki Imai et al., CrystEngComm, 2019, 21, 6905–6914.

Evaporation-driven manipulation of nanoscale brickwork structures for the design of 1D, 2D, and 3D microarrays of rectangular building blocks

As children play with wooden building blocks, we would like to construct elaborate architectures through the one-by-one accumulation of nanocrystals.

Strengthening of Brick Masonry with Welded Wire Mesh

Unreinforced brickwork (URM) is the most established development method. URM being weak can't withstand the parallel burdens amid a seismic region. Consequently, it is important to locate an appropriate low-cost technique to fortify existing brickwork structures. In this paper flexural bond strength test was conducted on the rectangular brick masonry prisms with two types of welded wire meshes (epoxy coated mesh with the spacing of 12mm and galvanized iron wire mesh with the spacing of 15mm). Masonry prisms were cast and tested as per the guidelines are given in ASTM E518 /E518-15 standards. The results of the flexural bond strength embedded masonry prism show greater when comparing the prisms with no mesh embedment.

Brickwork structure influence on reliability of structures being constructed

The modern brickwork development is related to the material quality improvement and reliability level enhancement for structures. To solve the above problem, this work substantiates moving to the probabilistic standardization of structural behavior of brickwork units taking into account the multi-level hierarchical structure. The complexity of brickwork structure is assessed experimentally on the basis of deformations of structural elements along and across the load direction. The work considers the substantiated reliability level and assurance coefficient, settable during a brickwork test in standard samples. This approach allows the considerable increase of the quality of material, reliability and failure safety of brick structures being constructed.

Nature of the optical band shapes in polymethine dyes and H-aggregates: dozy chaos and excitons. Comparison with dimers, H*- and J-aggregates.

Results on the theoretical explanation of the shape of optical bands in polymethine dyes, their dimers and aggregates are summarized. The theoretical dependence of the shape of optical bands for the dye monomers in the vinylogous series in line with a change in the solvent polarity is considered. A simple physical (analytical) model of the shape of optical absorption bands in H-aggregates of polymethine dyes is developed based on taking the dozy-chaos dynamics of the transient state and the Frenkel exciton effect in the theory of molecular quantum transitions into account. As an example, the details of the experimental shape of one of the known H-bands are well reproduced by this analytical model under the assumption that the main optical chromophore of H-aggregates is a tetramer resulting from the two most probable processes of inelastic binary collisions in sequence: first, monomers between themselves, and then, between the resulting dimers. The obtained results indicate that in contrast with the compact structure of J-aggregates (brickwork structure), the structure of H-aggregates is not the compact pack-of-cards structure, as stated in the literature, but a loose alternate structure. Based on this theoretical model, a simple general (analytical) method for treating the more complex shapes of optical bands in polymethine dyes in comparison with the H-band under consideration is proposed. This method mirrors the physical process of molecular aggregates forming in liquid solutions: aggregates are generated in the most probable processes of inelastic multiple binary collisions between polymethine species generally differing in complexity. The results obtained are given against a background of the theoretical results on the shape of optical bands in polymethine dyes and their aggregates (dimers, H*- and J-aggregates) previously obtained by V.V.E.

Mineralogy and technology of bricks used for the construction of the XII century ducal castle on the island of Ostrów Tumski, Wrocław (SW Poland)

Abstract The historic bricks from the ducal castle on Ostrów Tumski (Wrocław), one of the first brickwork structures in the Lower Silesia, which dates back to the XII and XIII century, were studied and characterised by a combination of classical petrographic studies (polarising microscopy), scanning microscopy, thermal analysis and X-ray diffraction. The combined results of these methods suggest that the firing temperature ranges from 950°C, through the most common temperatures of 850–900°C, to the infrequent temperatures below 750°C. Most of the bricks were fired under oxidising conditions, occasionally over a sequence of oxidising and reducing steps, resulting in a sandwich structure. The results indicate, that low-calcareous raw materials were used, presumably Miocene-Pliocene ‘flamy clays’, exploited a few kilometres away from the castle and tempered with locally obtained sand from the Odra river. Only small differences have been recognized in: 1) clay to aplastic material ratio, 2) amount of accessory minerals, 3) grain-size distribution of aplastic materials, but no significant changes in the brick technology were observed. The observed variability corresponds well to the different constructing phases, identified previously on the basis of archaeological work. Thus, our work proves that a detailed mineralogical and petrological study may help to identify different construction phases in historic monuments.

ДАТИРОВКА ЗДАНИЙ ИСТОРИЧЕСКОЙ ЗАСТРОЙКИ ПО ХАРАКТЕРНЫМ ПРИЗНАКАМ СТРОИТЕЛЬНЫХ МАТЕРИ

During reconstruction and scientific restoration of historical buildings of Moscow there often rises a question on the history of house ownership and dating of its first construction and further reconstructions. The article considers the methods of determining the age of buildings according to some specific features of brickwork and metal structures. It is proposed to use such characteristics as brickwork type, processing technique of mortar seams, size of bricks and a brand on them as dating marks when inspecting buildings. Brands on bricks have been traced since middle 17th when they were of animalistic character, later they consisted of one letter. Since the beginning of the 17th brands consisted of two or three letters meaning the initials of a factory owner. In the end of the 19th there appeared signs with full surnames of owners. Letter seals were usually placed on bonders and seals with surnames, later also with factory names, were situated on stretchers and sometimes on bed of bricks. It is recommended to analyze dating of bricks using reference books on dating back of the brands to historical periods. At the same time one should take into account the possibility of secondary use of bricks in the construction. The main dating feature of metal structures is a trade mark. Attribution of marks with abbreviations of factories and initials of owners needs addressing to the history of plants and sometimes to biographic information of the owners. The authors present materials on steams on bricks and metal details educed during field studies of historical buildings of Moscow. The authors underline the necessity to use complex approach in case of certain age of a building, which takes into account all the dating features of structures.