Types Of Structures Research Articles

Alkyl sulfones: discovery of novel structural types with differentiated opportunities for insect control.

The discovery of novel chemical classes with novel modes of action for insect control form the backbone of innovation with the goal to deliver much-needed solutions into the hands of growers. Over the last decade, alkyl sulfones have emerged as one of the most versatile new classes and are under intensive investigation in many R&D programs in the industry, with Sumitomo Chemicals recently introducing oxazosulfyl as a first active ingredient to the market. In this review, we discuss some of our strategies to invent novel classes based upon ligand-based design, and also show how incorporation of physical chemical properties into our design enabled us to predictably control chewing and sucking pests. © 2024 Society of Chemical Industry.

Synthesis, Physical, and Magnetocaloric Properties of MgZn2-Type Gd2Al3Rh.

Gd2Al3Rh was synthesized from the elements using arc-melting techniques, along with subsequent annealing. The title compound adopts the hexagonal MgZn2 type structure (space group P63/mmc, hP12, Wyckoff sequence hfa) with the Gd atoms found on the Mg positions (4f), the Rh (2a) and Al (6h) atoms occupying the two Zn sites of the prototype. In addition, mixing of Rh and Al on both crystallographic positions is observed. The magnetic susceptibility and magnetization experiments were conducted indicating ferromagnetic ordering below the Curie temperature of TC = 51.3(1) K and very high magnetization of 6.96(1) μB at 3 K and 70 kOe. In addition, heat capacity and electrical resistivity measurements were conducted. The magnetocaloric properties of ferromagnetic Gd2Al3Rh have been determined by means of magnetization measurements. For a field change of ΔH = 0 → 50 kOe the magnetic entropy change equals ΔSMmax = -4.8 J kg-1 K-1, leading to a relative cooling power of RCP = 283 J kg-1 for the same field change. The adiabatic temperature change was estimated to be ΔTadmax = 2.1 K using the heat capacity data.

Directed Hydrothermal Synthesis of Aluminosilicates of Various Structural Types and Prospects for Their Use in Medicine

Directed Hydrothermal Synthesis of Aluminosilicates of Various Structural Types and Prospects for Their Use in Medicine

A Sodium Germanosilicide with Unusual Network Topology.

The germanosilicide Na4-xGeySi16-y (0.4 ≤ x ≤ 1.1, 4.7 ≤ y ≤ 9.3) was synthesized under high-pressure, high-temperature conditions. The novel guest-host compound comprises a unique tetrel framework with dual channels housing sodium and smaller, empty (Si,Ge)9 units. The arrangement represents a new structure type with an overall structural topology that is closely related to a hypothetical carbon allotrope. Topological analysis of the structure revealed that the guest environment space cannot be tiled with singular polyhedra as in cage compounds (e.g., clathrates). The analysis of natural tilings provides a convenient method to unambiguously compare related tetrel-rich structures and can help elucidate new possible structural arrangements of intermetallic compounds.

Ammonothermal Synthesis and Crystal Structure of the Ternary Amide Na2Ba(NH2)4

AbstractThe ternary amide Na2Ba(NH2)4 was synthesized at ammonothermal conditions (870 K, 135 MPa) in custom‐built high‐pressure autoclaves. The compound was structurally characterized using X‐ray diffraction and crystallizes in space group Pccn (no. 56) with lattice parameters a=10.6492(2), b=7.8064(2) and c=8.1046(2) Å. To the best of our knowledge, the structure type has not yet been observed in any ternary amide before and can be described as a defective variant of the NaCl structure type. The presence of amide ions in the compound is verified by Fourier‐transform infrared (FTIR) spectroscopy and the experimental spectrum is compared to the theoretical spectrum obtained through density functional theory (DFT) calculations. Na2Ba(NH2)4 complements the range of reported ternary alkali metal alkaline‐earth metal amides with the smallest Shannon radius ratio of rA/AE=0.76. The influence of this ratio on the formation of the new structure type is discussed as well. The characterization of intermediate species such as this ternary amide extends the understanding of the ammonothermal synthesis and can be useful for synthetic control in the formation of nitrides at ammonothermal conditions.

Compaction, Relaxation, and Linearization of Megadalton-Sized DNA Plasmids: DNA Structures Probed by CD-MS.

High purity plasmid DNA is a raw material for recombinant protein production as well as an active ingredient in DNA vaccines. There are four primary plasmid structures that can be observed in a typical plasmid formulation: supercoiled, relaxed (circular), linearized, and condensed. Determining what structures are present in a sample is important, as the structure can affect activity; the supercoiled structure has the highest activity, and >90% supercoiled is desired for industry standards. Recently, charge detection mass spectrometry (CD-MS) was used to distinguish two of the structures, supercoiled and condensed, by measuring the charge deposited on the ions by positive mode electrospray. Here, CD-MS is used to probe the structures of DNA plasmids during compaction with polycations, and through enzymatic treatment to relax and linearize plasmids. We find that all four structural types for plasmid DNA have unique charging profiles that can be distinguished using CD-MS. The extent of mechanical shearing of the DNA plasmids during electrospray is strongly influenced by the structural type.

ABa6Cu31Te22 (A = K, Rb, Cs) Featuring Polyanionic Copper-Telluride Frameworks with Ultralow Thermal Conductivity.

Three polyanionic tellurides, ABa6Cu31Te22 (A = K, Rb, Cs), were synthesized in salt flux. The isostructural tellurides crystallize in a new structure type, in the cubic Pa3 space group with a Wyckoff sequence of d10c2b1 and large unit cell volumes of over 5500 Å3. The structures feature a framework of [CuTe4] tetrahedra and [CuTe3] trigonal pyramids with disorder in the Cu sites. The polyanionic frameworks have large square antiprism and cuboctahedral voids where Ba and alkali metal cations are situated, forming [BaTe8] and [ATe12], respectively. The overall compositions are close to being charge balanced. The large [ATe12] cuboctahedra allowed for significant anisotropic displacement of the A cations, as observed from both single crystal X-ray diffraction and heat capacity studies. Alkali cations rattling together with Cu atom displacement and disorder leads to the dispersion of phonons, thus softening the lattice and subsequently reducing the thermal conductivity. Evaluations of the electronic band structure revealed the occurrence of a narrow bandgap together with the presence of a flat band near the valence band maximum, giving rise to the high thermopower. The Cs and Rb analogues show a slope change in the temperature dependence of electrical resistivity around room temperature, which is typical for semimetals or degenerate semiconductors. For the as-synthesized and unoptimized materials, high values of the thermoelectric figure-of-merit of ∼0.2 were observed at 623 K.

Genomic patterns of selection in morphometric traits across diverse Indian cattle breeds.

This study seeks a comprehensive exploration of genome-wide selective processes impacting morphometric traits across diverse cattle breeds, utilizing an array of statistical methods. Morphometric traits, encompassing both qualitative and quantitative variables, play a pivotal role in characterizing and selecting livestock breeds based on their external appearance, size, and physical attributes. While qualitative traits, such as color, horn structure, and coat type, contribute to adaptive features and breed identification, quantitative traits like body weight and conformation measurements bear a closer correlation with production characteristics. This study employs advanced genotyping technologies, including the Illumina BovineSNP50 Bead Chip and next-generation sequencing methods like Reduced Representation sequencing, to identify genomic signatures associated with these traits. We applied four intra-population methods to find evidence of selection, such as Tajima's D, CLR, iHS, and ROH. We found a total of 40 genes under the selection signature, that were associated with morphometric traits in five cattle breeds (Kankrej, Tharparkar, Nelore, Sahiwal, and Gir). Crucial genes such as ADIPDQ, DPP6, INSIG1, SLC35D2 in Kankrej, LPL, ATP6V1B2, CDC14B in Tharparkar, HPSE2, PLAG1 in Nelore, PCSK1, PRKD1 in Sahiwal, and GNAQ, HPCAL1 in Gir were identified in our study. This approach provides valuable insights into the genetic basis of variations in body weight and conformation traits, facilitating informed selection processes and offering a deeper understanding of the evolutionary and domestication processes in diverse cattle breeds.

Ammonia Emissions and Building-Related Mitigation Strategies in Dairy Barns: A Review

In this systematic review, the PRISMA method was applied to examine publications from the last two decades that have investigated the noxious gaseous emissions from dairy barns. The aim was to analyse the outcomes from literature studies estimating the quantities of polluting gases produced in dairy barns, with a specific focus on ammonia (NH3) emissions. Various studies, among those reviewed, have used mixed effects models, mass balance approaches and dispersion methods, revealing significant variability due to different experimental protocols and environmental contexts. Key challenges include the lack of standardised measurement techniques and the limited geographical coverage of research, particularly in climatically extreme regions. This review also explores proposed methods to reduce the associated effects through mitigation strategies. Estimation of NH3 emissions is significantly influenced by the complex interactions between several factors; including animal management practices, such as controlling animal behavioural activities; manure management, like utilising practices for floor manure removal; the type of structure housing the animals, whether it is naturally or mechanically ventilated; and environmental conditions, such as the effects of temperature, wind speed, relative humidity, and ventilation rate on NH3 release in the barn. These influential components have been considered by researchers and targeted mitigation strategies have been identified. Despite growing attention to the issue, gaps in the scientific literature were identified and discussed, particularly regarding the analysis of mitigation strategies and their long-term impacts (i.e., environmental, economic and productivity-wise). The purpose of this review is to help improve research into sustainable agricultural practices and technological innovations, which are fundamental to reducing NH3 emissions and improving air quality in agricultural environments.

The Specifics of the Relationship between the State and Business in Modern India

India, a member of the BRICS and the SCO, can play an important role in deepening Eurasian integration. However, in order to make possible the use of its integration potential, it is necessary to fully understand the specifics of this country, the nature of its existing political and economic system, which, in particular, is determined by the established model of relations between the state and business.Aim. To identify the features of the system of relations between the state and business, which has developed in India during the period of economic reforms and determines the potential and specifics of its political and economic development.Tasks. To trace the main stages of the evolution of relations between the state and business in the Republic of India, to assess government policy in relation to the main types of business and various business structures, to identify the degree of influence of private business on the policy and dynamics of economic development of the country.Methods. Systematic and comparative analysis, scientific generalization, expert assessments. Results. The article provides a scientific generalization of the evolution of models and methods of interaction between the state and business of the Republic of India, an assessment of their effectiveness from the point of view of socio-economic development of the country.Conclusions. The formation of the system of relations between the state and business in modern India was determined by the needs of the economic and social development of the country, the essence and forms of which were determined by the dominance of the relevant political forces and ideologies. At the initial stage, the use of repressive and coercive regulatory methods led to the establishment of a patron — client relationship between the state and business in all industrial sectors, focused on obtaining rent. However, subsequently, the growing inefficiency of the Indian economy and the growth of corruption forced the country’s ruling elites to reconsider their political and economic views and switch to a policy of economic liberalization, as a result of which India began to acquire the characteristic features of a “development state”. Currently, in a regulated market economy, the state, on the one hand, seeks to ensure greater freedom of the market, private entrepreneurship, promote greater openness and internationalization of the economy, on the other hand, weaken and limit large capital to protect small and medium-sized enterprises. At the same time, the relations between the state and business continue to be largely clientelistic, which, according to many experts, hinders further economic liberalization and increasing the global competitiveness of the Indian economy.

A comparative study of fat body at different developmental stages in Bombyx mori (L.): Histological and ultrastructural aspects

AbstractThe fat body, originating from mesodermal tissue of coelomic cavities during embryogenesis, can be found throughout the insect's body. In some insects, the fat body has two types (peripheral and perivisceral fat bodies) according to its location. In the fat body, trophocytes are known to be the basic cell type. Other fat body cells differentiating from the trophocytes are urocytes, mycetocytes, chromatocytes and haemoglobin cells. The study aimed to demonstrate the general structure and cell types of the fat body during the postembryonic developmental stages of Bombyx mori (L.). With Haematoxylin–Eosin staining, there is a single type of fat body throughout the larval stages but during Pp and P0 stages it consists of perivisceral and peripheral fat bodies. We also observed that the compact structure of the fat body at the beginning of the larval stage began to loosen as it transformed into the pupal stage. In the adult stage, it was reorganized during the metamorphosis and it didn't show both fat bodies distinction. At this stage, the fat body appeared in a loose, lace‐like structure. We determined that B. mori fat body only consists of trophocytes and also among them; the fat body associated cells, oenocytes are detected.

Molecular dynamics study on the effect of cementite structure on the mechanical properties of pearlite

The effect of cementite structure on the mechanical properties of pearlite were investigated using molecular dynamics simulations. Three types of cementite structures were considered: single crystal, nanocrystalline, and a mixture of nanocrystalline and amorphous structures. The study found that regardless of the cementite structure, the ferrite phase in the pearlite exhibited plastic deformation first due to the activation of its internal {112} 〈111〉 slip system during tensile loading, resulting in macroscopic yielding of the pearlite. However, the difficulty of plastic deformation in the ferrite phase varied with different cementite structures. Compared to the other two types of cementite structures, the ferrite phase in the pearlite containing single crystal cementite exhibited the most difficult plastic deformation, leading to the highest peak stress. As the strain increased, the plastic deformation in the ferrite transferred through the ferrite-cementite interface to the cementite. After the plastic deformation transferred to the cementite, the different cementite structures exhibited distinct mechanical responses: the single crystal cementite structure experienced cleavage fracture, the nanocrystalline cementite structure underwent plastic deformation induced by grain boundary slip, while the nanocrystalline-amorphous mixture cementite structure showed shear deformation in the amorphous cementite and plastic deformation induced by grain boundary slip in the nanocrystalline cementite. Due to the influence of cementite mechanical response mechanism, the flow stress of the pearlite was minimal when the cementite in the pearlite were in single crystal structure. The study also revealed that when the cementite was in nanocrystalline structure, the flow stress of pearlite decreases with the grain size decreasing from 4.25 nm to 2.68 nm. When the cementite is a mixture of nanocrystalline and amorphous structure, the flow stress of pearlite decreases as the thickness of amorphous layer increases from 1 nm to 2 nm.

Improvement of switching uniformity in TiO2-based resistive random access memory with graphene oxide embedded film

TiO2-based resistive random access memory (RRAM) devices has the potential to fabricating nonvolatile memory applications. However, the memories based on TiO2 have severe problems like large resistive switching parameter fluctuations, poor cycling endurance and so on, which can be a limitation of the device in practical applications. Graphene oxide (GO) is a novel material that has attracted much attention and is often applied to enhance the performance of memories due to its own special properties. In this work, two types of bilayer structure based on TiO2 for RRAM devices were fabricated. The significant improvement in uniformity of operating voltages and high HRS/LRS ratio of the TiO2-based RRAM were realized by inserting a two-dimensional GO film between TiO2 and FTO. The presence of the GO film would prevent the ion exchange between the electrodes and the switching layer as well as its insulating properties. The conduction mechanisms of all the devices in low and high resistance states were dominant by the Ohmic conduction mechanism and the space charge limited conduction mechanism, respectively. This research manifests the promising potential of two-dimensional GO embedded layer for improving resistive switching performance of RRAMs.

Fabrication characterization and compression failure analysis of Ni-based alloy ABD-900AM TMPS structures via laser powder bed fusion

The novel high-strength and high-temperature nickel-based alloy developed for additive manufacturing, i.e., ABD-900AM, shows great potential in next-generation aircraft engines. However, there are limited investigations about the printing capability of ABD-900AM with complex structure as well as compression behaviors of this new alloy system. To meet the lightweight requirement, ABD-900AM with triply periodic minimal surface (TPMS) is fabricated by selective laser melting (SLM) in the present work, and the printing quality and compression performance of different TPMS structures are analyzed utilizing both experimental and computational methods. First, six types of TPMS structures are designed, and the external contours fabricated by SLMed ABD-900AM are detected through 3D optical scanning. In general, high fabrication quality is achieved with the proper process parameters, while the positive deviations are observed at the lateral surfaces and edges, and the negative deviations are observed at the upper regions of the cellular structures. Further, compression tests of SLMed ABD-900AM TPMS structures are conducted, and the failure mechanisms are evaluated. The equivalent elastic modulus is ranked as Diamond > Split-P > Primitive > Gyroid > I-WP > Lidinoid. The SLMed ABD-900AM TPMS structures shows advantages compared to these TPMS structures fabricated using typical metal alloys. Finally, the computational models of SLMed ABD-900AM TPMS structures are built up in the commercial software ABAQUS. The stress-strain behaviors and the failure process of different SLMed ABD-900AM TPMS structures are successfully reproduced.

Accuracy compensation method with the combined dissimilar measurement devices for enhanced measurement quality: a digital aircraft assembly technology

Purpose The pivotal aspect of aircraft assembly lies in precise measurement accuracy. While a solitary digital measuring tool suffices for analytical and small surfaces, it falls short for extensive synthetic surfaces like aircraft fuselage panels and wing spars. The purpose of this study is to develop a “combined measurement method” (CMM) that enhances measurement quality and expands the evaluative scope, addressing the limitations posed by singular digital devices in meeting measurement requirements across various aircraft components. Design/methodology/approach The study illustrated the utilization of the CMM by combining a laser tracker and a portable arm-measuring machine. This innovative approach is tailored to address the intricate nature and substantial dimensions of aircraft fuselage panels. The portable arm-measuring machine performs precise scans of panel components, while common points recorded by the laser tracker undergo coordinate conversion to reconstruct the fuselage panel’s shape. The research outlines the CMM’s measurement procedure and scrutinizes the data processing technique. Ultimately, the investigation yields a deviation vector matrix and chromatogram deviation distribution, pivotal in achieving enhanced measurement precision for the novel CMM device. Findings The use of CMM noticeably enhances fuselage panel assembly accuracy, concurrently reducing assembly time and enhancing efficiency compared to conventional measurement systems. Practical implications The research’s practical implication lies in revolutionizing aircraft assembly by mitigating accuracy issues through the innovative digital CMM for aircraft synthetic structure type product (aircraft fuselage panel). This ensures safer flights, reduces rework and enhances overall efficiency in the aerospace industry. Originality/value Introducing a new aircraft assembly accuracy compensation method through digital combined measurement, pioneering improved assembly precision. Also, it enhances aerospace assembly quality, safety and efficiency, offering innovative insights for optimized aviation manufacturing processes.

Feeling of Insecurity and Level of Tolerance among University Students

The purpose of the present study was to explore whether there is any relation between insecurity feeling and tolerance level of university students as a function of types of university, study year and family structure. This study was conducted on 240 respondents purposively selected from different areas of the Chittagong district. The Bangla version of Insecurity Questionnaire and Tolerance level scale used indicated that private university students showed more insecurity than public university students (F = 229.06, df = 1, 228, p < .001), First year students had more insecurity than Second-Fourth year and MS students (F = 15.04, df = 2, 228, p < .001). A significant interaction effect was found between types of university and study year (F = 04.04, df = 2, 228, p < .02) and types of university and family structure (F = 8.39, df = 1, 228, p < .01) in insecurity feeling. On the other hand, students in public universities showed more tolerance level than private university students (F = 341.78, df = 1, 228, p < .001), MS students had more tolerance level than First year and Second year to Fourth year students (F = 7.13, df = 2, 228, p <.001). A significant interaction effect was found between types of university and study year (F = 13.08, df = 2, 228, p < .001) in tolerance level. Finally, result also showed significant negative correlation between insecurity and tolerance level (r = -.64, p < .01). The Chittagong Univ. J. B. Sci., Vol. 10(1&2):15-29, 2020.

Feeling of Insecurity and Level of Tolerance among University Students

The purpose of the present study was to explore whether there is any relation between insecurity feeling and tolerance level of university students as a function of types of university, study year and family structure. This study was conducted on 240 respondents purposively selected from different areas of the Chittagong district. The Bangla version of Insecurity Questionnaire and Tolerance level scale used indicated that private university students showed more insecurity than public university students (F = 229.06, df = 1, 228, p < .001), First year students had more insecurity than Second-Fourth year and MS students (F = 15.04, df = 2, 228, p < .001). A significant interaction effect was found between types of university and study year (F = 04.04, df = 2, 228, p < .02) and types of university and family structure (F = 8.39, df = 1, 228, p < .01) in insecurity feeling. On the other hand, students in public universities showed more tolerance level than private university students (F = 341.78, df = 1, 228, p < .001), MS students had more tolerance level than First year and Second year to Fourth year students (F = 7.13, df = 2, 228, p <.001). A significant interaction effect was found between types of university and study year (F = 13.08, df = 2, 228, p < .001) in tolerance level. Finally, result also showed significant negative correlation between insecurity and tolerance level (r = -.64, p < .01). The Chittagong Univ. J. B. Sci., Vol. 10(1&2):15-29, 2020.

Rerefinement of the crystal structure of BiF5

The crystal structure of bismuth pentafluoride, BiF5, was rerefined from single-crystal data. BiF5 crystallizes in the α-UF5 structure type in the form of colorless needles. In comparison with the previously reported crystal-structure model [Hebecker (1971). Z. Anorg. Allg. Chem. 384, 111–114], the lattice parameters and fractional atomic coordinates were determined to much higher precision and all atoms were refined anisotropically, leading to a significantly improved structure model. The Bi atom (site symmetry 4/m..) is surrounded by six F atoms in a distorted octahedral coordination environment. The [BiF6] octahedra are corner-linked to form infinite straight chains extending parallel to [001]. Density functional theory (DFT) calculations at the PBE0/TZVP level of theory were performed on the crystal structure of BiF5 to calculate its IR and Raman spectra. These are compared with experimental data.

Rerefinement of the crystal structure of BiF5

The crystal structure of bismuth pentafluoride, BiF5, was rerefined from single-crystal data. BiF5 crystallizes in the α-UF5 structure type in the form of colorless needles. In comparison with the previously reported crystal-structure model [Hebecker (1971). Z. Anorg. Allg. Chem. 384, 111–114], the lattice parameters and fractional atomic coordinates were determined to much higher precision and all atoms were refined anisotropically, leading to a significantly improved structure model. The Bi atom (site symmetry 4/m..) is surrounded by six F atoms in a distorted octahedral coordination environment. The [BiF6] octahedra are corner-linked to form infinite straight chains extending parallel to [001]. Density functional theory (DFT) calculations at the PBE0/TZVP level of theory were performed on the crystal structure of BiF5 to calculate its IR and Raman spectra. These are compared with experimental data.

Research on residual behavior of tensile stiffened welded hollow spherical joints after exposure to fire

Space grid structures are subject to fire like other building structures, but they rarely collapse as a whole after exposure to fire. The welded hollow spherical joints are the main joint types of space grid structures. It is particularly critical to accurately identify the mechanical behavior of welded hollow spherical joints after exposure to fire to confirm whether the grid structure needs reinforcement or demolition for reconstruction. Therefore, the mechanical behavior of tensile stiffened welded hollow spherical joints after exposure to fire without load was studied by experiment. The failure modes of stiffened welded hollow spherical joints after exposure to fire are pull-out failures and oblique splitting pull failures. The initial axial stiffness of stiffened welded hollow spherical joints declines with the increase of exposure temperature, and the cooling method has little effect on it. When the exposure temperature is low, the cooling method has no impact on the load-bearing capacity of the joint. The load-bearing capacity of the air-cooling joints decreases linearly with the progress of exposure temperature, while the water-cooling joints present an opposite trend. The ductility of the air-cooling joints increases rapidly with the growth of exposure temperature, while the water-cooling joints fluctuate up and down. The strain of the tensile stiffened welded hollow spherical joints closely relates to its location. The numerical model of the joint after exposure to fire without load and with load was established, and the model was verified against experimental results. Through the numerical simulation, a method for calculating the residual mechanical behavior of stiffened welded hollow spherical joints after exposure to fire without load and with load was presented.