Flat Edge Research Articles

THE EFFECT OF TAMARIND (TAMARINDUS INDICA) LEAF EXTRACT OINTMENT IN CONTROLLING THE GROWTH OF THE BACTERIA PROPIONIBACTERIUM ACNES THAT TRIGGERS ACNE

Tamarind (Tamarindus indica) is a versatile plant, findable in Indonesia (Java, Bali, North Sumatra, West Kalimantan, and South Sulawesi). The leaves are green to brown, round, 1-2.5 cm long and 4-8 mm wide, rounded tips, rounded base of blades, and flat edges. The content contained in tamarind leaves such as flavonoids, tannins, saponins, and alkaloids is believed to inhibit Propionibacterium acnes activity. This study aims to determine the effect of tamarind leaf extract ointment in controlling the growth of the bacteria Propionibacterium acnes that triggers acne. This study applied a Completely Randomized Design with 96% ethanol maceration method. Propionibacterium acnes was evidenced by the inhibition zone formed. The diameter of the inhibition zone of the 25% ointment was 1.235 cm, the 30% concentration was 1.385 cm, the 35% concentration was 1,680 cm, and the ointment base was 0 cm. The ANOVA test showed a significant value of 0.000<0.05, so there was a significant difference between the inhibition zone and the 95% confidence level. The results of Post Hoc test were P<0.05, meaning that there was a significant difference between the bases with formulas 1, 2, and 3. Thus, tamarind leaf extract ointment had a strong inhibitory effect on Propionibacterium acnes.

Thermoelectric performance in the binary semiconductor compound A2Se2(A = K, Rb) with host-guest structure

The host-guest structure compounds are potential candidates for high-efficiency thermoelectric (TE) materials because of their good electronic transport combined with ultralow thermal conductivity. In this paper, we theoretically investigate TE transport properties of the hexagonal ${A}_{2}{\mathrm{Se}}_{2}\phantom{\rule{4pt}{0ex}}(A$ = K, Rb) with strongly quartic anharmonicity based on an incorporation of first-principles calculations with self-consistent phonon theory and Boltzmann transport equations. The calculation results reveal that ${A}_{2}{\mathrm{Se}}_{2}\phantom{\rule{4pt}{0ex}}(A$ = K, Rb) have ultralow lattice thermal conductivities ${\ensuremath{\kappa}}_{L}$, e.g., 0.30--0.$34{\mathrm{W}\phantom{\rule{0.16em}{0ex}}\mathrm{m}}^{\ensuremath{-}1}\phantom{\rule{0.16em}{0ex}}{\mathrm{K}}^{\ensuremath{-}1}$ at room temperature, which are only one third of quartz glass. The calculated results indicate that the coexistence of small phonon lifetime ${\ensuremath{\tau}}_{\mathrm{ph}}$ and phonon group velocity ${\ensuremath{\upsilon}}_{\mathrm{ph}}$ is the reason for the ultralow ${\ensuremath{\kappa}}_{L}$ in these two host-guest structure materials. Additionally, due to the anisotropic electronic structure, that is, the coexistence of high dispersion and flat band edges, these two materials capture a high TE power factor along the $c$ axis. As a consequence, the anomalous high $\mathit{ZT}$ values of 2.95 and 2.17 at 500 K along the $c$-axis direction are captured in $n$-type ${\mathrm{K}}_{2}{\mathrm{Se}}_{2}$ and ${\mathrm{Rb}}_{2}{\mathrm{Se}}_{2}$, which break the long-term record of $\mathit{ZT}\phantom{\rule{4pt}{0ex}}<2$ in most TE materials reported so far. These findings reveal that ${A}_{2}{\mathrm{Se}}_{2}\phantom{\rule{4pt}{0ex}}(A$ = K, Rb) has broad prospects in TE applications.

UJI AKTIVITAS ANTIBAKTERI EKSTRAK DAUN TABAT BARITO (Ficus deltoidea) TERHADAP BAKTERI Bacillus substillis DENGAN TINGKATAN POLARITAS PELARUT

Tabat barito leaf (Ficus deltoidea) is a single leaf of a sole form, the leaf has round tip with a flat edge and a pointed base. These leaves have a smooth surface, coloured green above and brownish yellow beneath. This study aims to determine the antibacterial activity of polar, semi-polar and non-polar compounds contained in Tabat barito leaf extract extracted with solvents of different polarity. The highest bacterial inhibition was also measured against Bacillus substillis which is a gram-positive bacterial. The maceration method uses 3 levels of solvents with different polarities, started with a non-polar solvent (n-hexan), a semi-polar solvent (ethyl acetate) and finally macerated with a polar solvent (methanol). The bacterial activity test was done with diffusion method. The results showed that the Tabat Barito leaf extract contained antibacterial compounds that were non-polar, semi-polar and polar. The highest inhibition of the hexane extract at concentration 15% with a clear zone diameter of 22.33 mm in very strong inhibition category against Bacillus substilis bacteria

Developing A Needle-Knife Surgical Device

Scope Nowadays, a new era of orthopedic surgery is taking place. Procedures like ultrasound-guided interventions, invasive pain orthopaedics interventions, started to be widely performed. Objective The aim of the project is a virtual development of a needle-knife surgical device to be useful for minimally invasive orthopaedic surgical procedures and other surgical procedures. Method Three different needle devices were compared. One is a base model 1 and the other two are experimental models 2 and 3. They are based on a metal guide for intravenous catheter 14Gx2’’. The base one model 1 is the metal guide for intravenous catheter 14Gx2’’; the experimental model 2 is a flat beveled edge, and experimental model 3 is a board bevel Edge. They are all graduated, parylene-coated, with a stop handle needle guard. The devices were developed by 3D Design 3D STEP Standard Format, Catia V5 Format, and 2D Format Design and 3D Model. They were biomechanically simulated with Virtual Biomechanical Strength Simulation (Software Simulia Abaqus).. The Strengths were assessed by Needle Strength Analysis (CAE Simulation). Results: The present study compares three models. A control base model 1 and two experimental models; model 2 and model 3. Model 3 presented similar features in rigidity to the baseline model 1 (3,6%). They have a similar performance. The tip of model 3 increased a tension of 15%; but does not mean fracture risk 22. S Conclusion: These devices seem suitable for eco assisted orthopaedic surgery interventions and other procedures according to virtual analisis. Further in vivo procedures must be performed.

Thermomechanical analysis of snap-buckling phenomenon in long FG-CNTRC cylindrical panels resting on nonlinear elastic foundation

Snap-buckling phenomenon in an infinitely long nanocomposite cylindrical panel subjected to uniformly distributed transverse pressure loading is analyzed in this research. It is assumed that the functionally graded (FG) carbon nanotube reinforced composite (CNTRC) shell is resting on nonlinear elastic foundation. The uniform thermal field is also included into the formulation. Thermomechanical properties of the shell are assumed to be temperature dependent. The CNTs distribution pattern can be uniform or functionally graded through the shell thickness. The shell is formulated using a general high-order shear deformation theory. Governing equilibrium equations of the shell which undergoes thermal–mechanical coupling loading are established via the virtual displacement principle. To capture the large deflections, the von Kármán type of kinematic assumptions is utilized. Two types of edge conditions are considered for the shell with infinite length which are immovable simply supported and clamped–clamped. To obtain the limit buckling load of the shell, the two-step perturbation technique and Galerkin procedure are used. Results of this study reveal that the snap-buckling phenomenon can take place in a shallow cylindrical panel subjected to lateral pressure loading. This attractive behavior is observed due to the immovability of the flat edges of the shell. It is shown that the snap-buckling phenomenon in a long cylindrical panel is highly dependent upon the elastic foundations, thermal environments, geometrical parameters and material properties.

Revisiting the flattened Brazilian disc configuration - Part I: The actual boundary conditions

In a recently presented analytic solution for the Flattened Brazilian Disc (FBD), it was shown that under the usually adopted assumption of uniform pressure on the flat edges of the FBD these edges turn to appear bent after deformation. Taking into account the high rigidity and flatness of the loading platens this bent sounds somehow unnatural. In the present study an attempt is undertaken to confront this unnatural bent by considering alternative non-uniform stress distributions on the flat edges of the FBD. In this context, the present paper, which is the first part of an ongoing research project, deals with the 1st fundamental problem for a FBD when it is compressed between two rigid flat stamps of the same length with the flat edge of the FBD. The distribution of the normal compressive stresses, and that of the respective frictional ones, imposed to the flat edge of the FBD are adopted from the approach of Muskhelishvili for the contact problem of a rigid flat stamp compressed against an elastic half plane, here the FBD in question. After obtaining the complex potentials for this 1st fundamental problem for the FBD, the stresses and the displacements are calculated in closed form everywhere on the FBD’s cross section. For the assessment of the analytic solution, a numerical model is also developed, with the aid of the Finite Element Method. The agreement between the theoretical and numerical analyses is satisfactory.

Development of Highly Efficient Radiation-Convective Recuperator for Furnace of Secondary Aluminum Melting

The high efficient design of the radiation-convective recuperator with secondary emitters have been proposed, in which due to the rational arrangement of heating surfaces, as well as due to the installation of secondary emitters in flues, an increase in heat perception is transmitted to the secondary heat carrier – preheating air. High efficiency of air preheating is provided by two-stage heating: 1st stage of heating – the internal air ring channel with bilateral heating which is washed by combustion products from the parties of the central cylindrical and peripheral ring channels of combustion products; 2nd stage of heating – the external air ring channel in which unilateral heating by products of combustion from the peripheral ring channel of products of combustion is organized. Inner and outer annular air ducts (tanks), interconnected by bypass pipes. To increase the efficiency of heat transfer in the considered recuperator in the central channel of combustion products is placed emitter, which consisting of intersecting radial plates, and in the annular channel of combustion products are placed auxiliary emitters, which made in the form of flat radial edges. These emitters provide an increasing in total heat flux to the walls of the channels of the recuperator. On the basis of the conducted theoretical researches, engineering calculations and CFD – modelling the characteristics of operation of the recuperator for its installation on the furnace of secondary smelting of aluminium are defined. The main advantages of the new design of recuperator are high thermo-hydraulic efficiency, compactness and low metal consumption, ease of installation on the furnace and no need for placement in separate chimneys. It is established that the recuperator provides air heating ta,ex ~ 400 °C at an acceptable aerodynamic drag (pressure drop) on the air track (∆pa ~ 1000 Pa). Appropriate design documentation has been developed for the manufacture of the recuperator, which is installed on a pilot furnace of secondary aluminium smelting by California Die Casting (USA).

Instance Segmentation in Very High Resolution Remote Sensing Imagery Based on Hard-to-Segment Instance Learning and Boundary Shape Analysis

Although great success has been achieved in instance segmentation, accurate segmentation of instances remains difficult, especially at object edges. This problem is more prominent for instance segmentation in remote sensing imagery due to the diverse scales, variable illumination, smaller objects, and complex backgrounds. We find that most current instance segmentation networks do not consider the segmentation difficulty of different instances and different regions within the instance. In this paper, we study this problem and propose an ensemble method to segment instances from remote sensing images, considering the enhancement of hard-to-segment instances and instance edges. First, we apply a pixel-level Dice metric that reliably describes the segmentation quality of each instance to achieve online hard instance learning. Instances with low Dice values are studied with emphasis. Second, we generate a penalty map based on the analysis of boundary shapes to not only enhance the edges of objects but also discriminatively strengthen the edges of different shapes. That is, different areas of an object, such as internal areas, flat edges, and sharp edges, are distinguished and discriminatively weighed. Finally, the hard-to-segment instance learning and the shape-penalty map are integrated for precise instance segmentation. To evaluate the effectiveness and generalization ability of the proposed method, we train with the classic instance segmentation network Mask R-CNN and conduct experiments on two different types of remote sensing datasets: the iSAID-Reduce100 and the JKGW_WHU datasets, which have extremely different feature distributions and spatial resolutions. The comprehensive experimental results show that the proposed method improved the segmentation results by 2.78% and 1.77% in mask AP on the iSAID-Reduce100 and JKGW_WHU datasets, respectively. We also test other state-of-the-art (SOTA) methods that focus on inaccurate edges. Experiments demonstrate that our method outperforms these methods.

Symmetry and curvature effects on spin waves in vortex-state hexagonal nanotubes

Analytic and numerical studies on curved magnetic nano-objects predict numerous exciting effects that can be referred to as magneto-chiral effects, which do not originate from intrinsic Dzyaloshinskii-Moriya interaction or interface-induced anisotropies. In constrast, these chiral effects stem from isotropic exchange or dipole-dipole interaction, present in all magnetic materials, which acquire asymmetric contributions in case of curved geometry of the specimen. As a result, for example, the spin-wave dispersion in round magnetic nanotubes becomes asymmetric, namely spin waves of the same frequency propagating in opposite directions along the nanotube exhibit different wavelenghts. Here, using time-resolved scanning transmission X-ray microscopy experiments, standard micromagntic simulations and a dynamic-matrix approach, we show that the spin-wave spectrum undergoes additional drastic changes when transitioning from a continuous to a discrete rotational symmetry, i.e. from round to hexagonal nanotubes, which are much easier to fabricate. The polygonal shape introduces localization of the modes both to the sharp, highly curved corners and flat edges. Moreover, due to the discrete rotational symmetry, the degenerate nature of the modes with azimuthal wave vectors known from round tubes is partly lifted, resulting in singlet and duplet modes. For comparison with our experiments, we calculate the microwave absorption from the numerically obtained mode profiles which shows that a dedicated antenna design is paramount for magnonic applications in 3D nano-structures. To our knowledge these are the first experiments directly showing real space spin-wave propagation in 3D nano objects.

First Report of Pseudomonas aeruginosa Causing Basal Stem Rot of Solanum lycopersicum in China.

Tomato (Solanum lycopersicum L.) is economically important crop in China and elsewhere where it is grown. A previously unreported basal rot of tomato affecting as much as 15% of the stems was firstly observed in greenhouses in Northwest China (Jingyuan County, Baiyin City, Gansu Province) in March of 2015, and then the same disease of tomato was observed every year from 2016 -2021 in the region. The loss of local agricultural income caused by this plant disease in greenhouse is up to 2 million ¥ (CNY) each year. Symptoms on the basal stems were initially characterized by water-soaked lesions, which and developed rapidly into a soft, watery, decayed mass within 5 to 10 days after their appearance. Ten symptomatic stem samples were collected from basal stems exhibiting decay and were processed for microbiological analysis. Three strains of the bacteria (BBSR1~3) isolated from symptomatic samples were gram-negative, rods with a single polar flagellum, 0.5 to 1.0 × 1.5 to 3.5 µm in size. Colonies on nutrient agar (NA) medium were round, smooth, translucent, with flat edges and elevated center ("fried egg" appearance), and yellowish green to light purple in color. All isolates were positive for oxidase, gelatin liquefaction, denitrification, lipase, arginine dihydrolase, growth at 41 oC; utilization of mannitol, and production of pyocyanin. In contrast, they were negative for levan formation, lecithinase, hydrosis of starch, growth at 4 oC, utilization of maltose, xylose, γ-aminobutyrate and ethylene glycol; and growth in media supplemented with 8.5% NaCl. The representative bacterium (BBSR1) was identified as Pseudomonas aeruginosa using Biolog based Bacterial Identification System version 4.2 (Biolog Inc., Hayward, CA), revealing 0.88 similarities to P. aeruginosa in the Omnilog Biolog database. The identity was further confirmed as P. aeruginosa based on 16S rRNA sequence (1,387 bp) analysis with universal primers 27F (5'-AGAGTTTGATCCTGGCTCAG-3') and 1492R (5'-GGTTACCTTGTTACGACTT-3'). A BlastN search of GenBank revealed a 100% identity to that of Pseudomonas aeruginosa strains JCM5962 (LC069033), SM-1 (KP794924), and KUN4 (KR025537). The 16S rRNA gene sequence of strain BBSR1 (1,387 bp) was deposited in GenBank (KT454095). The representative strain BBSR1 was further evaluated in pathogenicity tests. 1-month-old tomato (cv. Tomo608) potted plants were spray inoculated with BBSR1 bacterial suspensions (≈ 3×108 CFU/ml) and wounded with a sterilized needle prior to inoculation. Controls were wounded similarly and inoculated with sterile water. This experiment was maintained at 28°C with 80 to 85% relative humidity in a greenhouse. Three replicates were used for each treatment and three mature plants in each pot. Symptoms developed within 14 days and were similar to those originally observed, whereas symptoms did not occur on the control plants. Strains recovered on NA were identified as P. aeruginosa based on physiological and biochemical characteristics and Biolog (Biolog, Hayward, CA). Although Pseudomonas aeruginosa is generally regarded as a human conditional pathogen, it has been reported to cause disease on a variety of plants including ginseng (Gao et al. 2014), tinda (Mondal et al. 2012), onion (Abd-Alla and Bashandy 2012) and sweet basil (Walker et al. 2004). This is the first report of P. aeruginosa causing basal stem rot on tomato in Gansu Province, China. Under the globalization, human beings should give great importance to the bacterial pathogens that cross kingdom to cause infection and become co-pathogenic in plant and animal.

Numerical Investigation of a Rectangular Jet Exhausting over a Flat Plate with Periodic Surface Deformations at the Trailing Edge

Multiple competing factors are forcing aircraft designers to reconsider the underwing engine pod configuration typically seen on most modern commercial aircraft. One notable concern is increasing environmental regulations on noise emitted by aircraft. In an attempt to satisfy these constraints while maintaining or improving vehicle performance, engineers have been experimenting with some innovative aircraft designs which place the engines above the wings or embedded in the fuselage. In one configuration, a blended wing concept vehicle utilizes rectangular jet exhaust ports exiting from above the wing ahead of the trailing edge. While intuitively one would think that this design would reduce the noise levels transmitted to the ground due to the shielding provided by the wing, experimental studies have shown that this design can actually increase noise levels due to interactions of the jet exhaust with the aft wing surface and flat trailing edge. In this work, we take another look at this rectangular exhaust port configuration with some notional modifications to the geometry of the trailing edge to determine if the emitted noise levels due to jet interactions can be reduced with respect to a baseline configuration. We consider various horizontal and vertical offsets of the jet exit with respect to a flat plate standing in for the aft wing surface. We then introduce a series of sinusoidal deformations to the trailing edge of the plate of varying amplitude and wave number. Our results show that the emitted sound levels due to the jet–surface interactions can be significantly altered by the proposed geometry modifications. While sound levels remained fairly consistent over many configurations, there were some that showed both increased and decreased sound levels in specific directions. We present results here for the simulated configurations which showed the greatest decrease in overall sound levels with respect to the baseline. These results provide strong indications that such geometry modifications can potentially be tailored to optimize for further reductions in sound levels.

Geometric and kinematic parameters of vibrating knife in the development of cutting machines

The process of cutting with a blade is largely applied in agricultural equipment and is used to process raw materials with different physical and mechanical properties. Nonetheless, the functional relation between the kinematic parameters of a vibroblade and the crucial power parameters of the vibration processing has not yet been studied in great depth so far. This type of studies is essential to create databases for further investigation and design of novel cutting machinery or technologies to ensure effective processing of vibrocutting. Our objective was to obtain the power characteristics of vibrocutting through laboratory experiments [using the example of vibrocutting of common reed (Phragmites australis)] and define the combination of factors (i.e., vibration amplitude, frequency and the blade feeding speed) at the minimum cutting force. The following relation of the blade feeding speed (V) and vibration speed of the toothed blade (Vt) has been established as optimal kinematic regime: K≅0.004. Tests have indicated that use of toothed blades for vibrocutting of the raw products of plant origin offers a greater advantage over the blades with flat edges. An optimal cutting regime, when energy expenses are at a minimum, was ensured with the following parameters of the vibroblade: vibration amplitude: 14 mm, frequency: 33.32 s–1, the blade feeding speed: 7.5×10–3 m.

The Average Bacterial Growth of the Ethanolic Extract of Fragrant Pandan Leaves Based on the Length of Maceration

The purpose of this study was to determine the potential antibacterial activity of the ethanol extract of fragrant pandan leaves at various temperatures and extraction concentrations against Escherichia coli and Hellicobacter Pylori bacteria. The purpose of this study was to determine the potential antibacterial activity of the ethanolic extract of fragrant pandan leaves at various extraction concentrations against Escherichia coli and Hellicobacter Pylori bacteria. Provide scientific information about the chemicals contained in fragrant pandan leaf extract as an inhibitor of bacterial growth. Fragrant pandanus has a round stem with leaves sitting, branching, creeping, and taproots out around the base of the stem and branches. Fragrant pandanus grows to a height of between 0.5 – 1 m, but can grow up to 2 m. Single leaf, sitting with the base hugging the stem, and arranged in three rows in a spiral line. The leaves are ribbon-shaped, thin, smooth, pointed tip, flat edge, parallel boned, 40-80 cm long, 3-5 cm wide, spiny attached to the lower surface of the leaf bone at the ends, and green. Based on this, a lot of research and development of knowledge has now been carried out to find drugs or antibacterials derived from natural ingredients from various types of plants that are considered important and can provide new contributions and hopes to find antibacterials naturally through the process. which has been tested, and subsequently conducting various studies to motivate people to want to use traditional and natural treatment.

Effects of aging treatment on the evolution of precipitated phase in CoCrFeNiTi0.6 high entropy alloys

In this study, the effect of aging time on the microstructure of precipitates in a face-centered cubic (FCC) CoCrFeNiTi0.6 high-entropy alloy (HEA) was investigated. The microstructure of precipitates was analyzed by SEM and TEM. The results showed that the CoCrFeNiTi0.6 alloy exhibited a typical dendritic structure, whose phase consisted of an ordered FCC solid-solution matrix (nanoscale L12-(Ni, Co)3Ti type particles) and intermetallic phases at 900 °C for different aging times. Meanwhile, the intermetallic compounds were composed of (Cr, Fe)-rich σ phases with a tetragonal structure and (Ni, Ti)-rich η phase with a long period stacking ordered (LPSO) structure. Additionally, the influence of aging time on the shape and structure of γ' precipitates was revealed. It was noticeable that the morphological transformation of nanoscale γ' precipitates evolved from an initially spheroidal to spheroidal-like shapes, following cuboidal-like shapes with flat edges, and finally, γ' precipitates with cuboidal shape were formed simultaneously with the appearance of the split with increasing aging time. Furthermore, the morphological evolution of γ' precipitates was quantitatively analyzed using a characteristic parameter's value of precipitates based on lattice misfit between the matrix and precipitates. This research would provide guidance for designing the precipitate structure in the L12-strengthened HEA and facilitate to establish the relationships between the microstructure of the precipitates and properties.

Experimental and microstructure analysis of the penetration resistance of composite structures

Abstract Composite structures (SiC/UHMWPE/TC4; SiC/TC4/UHMWPE) were designed using silicon carbide (SiC)ceramics, ultra-high-molecular-weight polyethylene (UHMWPE) laminate, and titanium alloys (TC4s). Penetration experiments and numerical simulations were carried out to study the anti-penetration mechanism and energy characteristics of the composite structures, and the microstructure of the TC4 was analyzed. The results show that the two composite structures designed have advantages in reducing mass and thickness. The energy proportion of the TC4 is the largest among the three materials, which mainly determines the anti-penetration performance. The microstructure of the TC4 in composite structure I shows rough edges of bullet holes, a large number of adiabatic shear bands (ASBs), ASB bends and bifurcates, and many cracks, which lead to spalling damage of the TC4. The microstructure of the TC4 in composite structure II shows flat edges of bullet holes, several straight ASBs, and no cracks, which leads to brittle fragmentation. The initiation, expansion, combination of ASBs and cracks lead to more energy consumption. Therefore, the combination form of composite structure I can give full play the energy dissipation mechanism of the TC4 and has better anti-penetration performance than composite structure II.

Isolation and Characterization of Inulinase Producing Bacteria Dahlia hybrida Hort

The use of enzymes in the industrial world is growing, one of which is inulinase. This enzyme can hydrolyze inulin to fructose. The use of fructose as a food or beverage sweetener is more beneficial than sucrose. Inulinase can be produced by plants containing inulin and microorganisms. The ability of bacteria to produce inulinase is more effective and efficient because it is able to live in an extreme environment and is easily manipulated genetically. The purpose of this study was to isolate and determine the characteristics of inulinase-producing bacteria from the Dahlia hybrida Hort rhizosphere. This research was conducted using a descriptive method which was carried out in the Laboratory of Microbiology, Biotechnology, and Biochemistry, Faculty of Mathematics and Natural Sciences, UNP and the Biotechnology Laboratory of Andalas University. The working procedure is inulin extraction, bacterial isolation, morphological, microscopic and molecular observations which include the process of bacterial DNA isolation and amplification using the 16S rRNA gene. Data on bacterial characteristics were analyzed descriptively including morphology, microscopy, and molecular.The results obtained were four isolates of inulinase-producing bacteria which were classified as gram-negative bacteria with bacillary-shaped cells. However, it has a different colony morphology, namely LK1 isolate irregular shape and uneven colony edges, LK2 isolate round and flat colony edges, LK3 isolate in the form of roots and branched colony edges like fine threads and LK4 isolate round and flat colony edges. DNA isolation of inulinase-producing bacteria was successfully carried out, but amplification of the 16S rRNA gene was not successful. This is probably due to the not optimal annealing temperature in the PCR cycle.

Topological excitonic corner states and nodal phase in bilayer quantum spin Hall insulators

Interaction induced topological states remain one of the fascinating phases in condensed matter physics. The exciton condensate has recently sparked renewed interest due to the discovery of new candidate materials and its driving force to realize exotic topological states. In this work, we explore the exciton orders induced high-order topology in the bilayer quantum spin Hall insulators and find that the topological excitonic corner states can be realized by tuning the gate and magnetic field. When an in-plane Zeeman field is applied to the system, two or four excitonic boundary-obstructed corner states emerge in the bilayer system for distinct possible $s$-wave excitonic pairings. Besides, we also find a two-dimensional excitonic Weyl nodal phase, which supports flat band edge states connecting the bulk Weyl nodes.

Experimental numerical and analytical analysis of the penetration of a scaled double-hull tanker side structure

The paper presents experimental, numerical and analytical analyses of a small-scale double-hull structure quasi-statically punched at the mid-span by a rigid flat edge indenter, to examine its energy-absorbing mechanism and fracture. The present study aims to further validate the numerical analysis procedure and the analytical method of individual stiffened panels and web girders against the experiment of the double-hull structure. The specimen, scaled from a tanker's double side structure, includes three spans between the web frames and two spans between the stringers. The paper provides practical information to estimate the extent of structural damage within ship sides during collision accidents. The experimentally obtained force-displacement response and deformation shape show a good agreement with the simulations performed by the explicit LS-DYNA finite element solver. The analysis of the double-hull structure demonstrates the accuracy of the procedure for identifying standard inputs used in numerical codes, in particular the definition of material plastic hardening and the calibration of the critical failure strain by tensile test simulation. The experimental and numerical results are used to validate the analytical method proposed in previous investigations at the plastic deformation stage and a revised semi-analytical method is proposed in the present study for the large penetration stage.

Characteristics of Bow-Tie Antenna Structures for Semi-Insulating GaAs and InP Photoconductive Terahertz Emitters.

This work presents a study of photoconductive (PC) terahertz (THz) emitters based upon varied bow-tie (BT) antenna structures on the semi-insulating (SI) forms of GaAs and InP. The BT antennas have electrodes in the form of a Sharp BT, a Broad BT, an Asymmetric BT, a Blunted BT, and a Doubled BT. The study explores the main features of PC THz emitters for spectroscopic studies and sensors application in terms of THz field amplitude and spectral bandwidth. The emitters’ performance levels are found to depend strongly upon the PC material and antenna structure. The SI-InP emitters display lower THz field amplitude and narrower bandwidth compared to the SI-GaAs emitters with the same structure (and dimensions). The characterized Doubled BT structure yields a higher THz field amplitude, while the characterized Asymmetric BT structure with flat edges yields a higher bandwidth in comparison to the sharp-edged structures. This knowledge on the PC THz emitter characteristics, in terms of material and structure, can play a key role in future implementations and applications of THz sensor technology.

A new approach to evaluation of loess collapsibility based on quantitative analyses of colloid-clay coating with statistical methods

Collapsibility is of critical concern to mechanical properties of loess. It is fully characterised by its micro-structural features and determined by contents and locations of colloid-clay components. However, previous researches on collapsibility are mostly limited to qualitative descriptions when it comes to the colloid-clay effects over loess properties. The very few quantitative studies only consider the overall colloid-clay content as covariate in simple linear regressions. This leaves the research area of quantification of colloid-clay contents and spatial locations based on image analysis blank. This paper made novel application of a robust statistical method to extract the microstructural parameters from SEM scans where silt, colloid-clay and pore structures are satisfyingly segmented. Correlations between collapsibility and each of the microstructural parameters are discussed with the collapsibility behaviour further evaluated based on the spatial distribution of colloid-clay components. Colloid-clay components have the tendency to either fill in the gaps between sharp edges of particles or attach to flat and concave edges to round the particles; this is referred to as shape-surface selective fillings and attachments phenomenon. A simple circularity measurement is novelly introduced to justify such phenomenon with support of statistical hypothesis testings. The results showed robust estimates based on such statistical method in comparison to both experimental outcomes and previous researches. Both pore area ratios and circularity of particles have positive effects over loess collapsibility. The colloid-clay ratio act as a good indicator when describing collapsibility but it should be looked at combing with their spatial distribution. Despite the colloid-clay ratio presented adverse effect on collapsibility, more evenly distributed colloid-clay components prove the reasonableness in mechanism of loess collapsibility. This paper successfully provides a image segmentation method which allows one to draw connections between loess microstructural properties to collapsibility. It reveals the loess macro-behaviours from the internal structural perspective. Such application is also easily adaptable to other properties in future studies.