Side Of Plane Research Articles

The Necessity of d-Thr in the New Antibiotic Teixobactin: A Molecular Dynamics Study.

Ever since the discovery of the new antibiotic teixobactin, studies of its structure-activity relationships have never ceased. Here we focus on the chirality of the threonine (Thr) residue, which belongs to the ring motif of teixobactin and plays an important role in the binding with its target, lipid II molecule. We study the structural propensity of the open and closed ring motifs with different chiral Thr residues as well as the teixobactin-lipid II complex with the help of molecular dynamics simulations. Our results suggest that different chiralities lead to different NH orientations of Thr with respect to the ring plane. Only in the closed ring motif with d-Thr is a favored binding cavity achievable with all four NH groups facing the same side of the ring plane. This study develops a deeper understanding of the binding mechanism of teixobactin and lipid II and is expected to be beneficial to new teixobactin-based drug design.

Ethyl 2-(4-benzyl-3-methyl-6-oxo-1,6-dihydropyridazin-1-yl)acetate: crystal structure and Hirshfeld surface analysis.

The title compound, C16H18N2O3, is constructed about a central oxopyridazinyl ring (r.m.s. deviation = 0.0047 Å), which is connected to an ethyl-acetate group at the N atom closest to the carbonyl group, and benzyl and methyl groups second furthest and furthest from the carbonyl group, respectively. An approximately orthogonal relationship exists between the oxopyridazinyl ring and the best plane through the ethyl-acetate group [dihedral angle = 77.48 (3)°]; the latter lies to one side of the central plane [the Nr-Nr-Cm-Cc (r = ring, m = methyl-ene, c = carbon-yl) torsion angle being 104.34 (9)°]. In the crystal, both H atoms of the N-bound methyl-ene group form methyl-ene-C-H⋯O(ring carbon-yl) or N(pyridazin-yl) inter-actions, resulting in the formation of a supra-molecular tape along the a-axis direction. The tapes are assembled into a three-dimensional architecture by methyl- and phenyl-C-H⋯O(ring carbon-yl) and phenyl-C-H⋯O(ester carbon-yl) inter-actions. The analysis of the calculated Hirshfeld surface indicates the dominance of H⋯H contacts to the overall surface (i.e. 52.2%). Reflecting other identified points of contact between mol-ecules noted above, O⋯H/H⋯O (23.3%), C⋯H/H⋯C (14.7%) and N⋯H/H⋯N (6.6%) contacts also make significant contributions to the surface.

Computed tomography method for characterising the zebrafish spine

BackgroundThe zebrafish is widely used in research due in part to its readily manipulable genome. Zebrafish models of spinal deformities including scoliosis were developed recently. However, the methods used to assess the spine in these models vary across studies. The primary objective of this study was to investigate the feasibility and modalities of local and regional spine structure evaluation by micro-CT in the normal zebrafish. The secondary objectives were to assess the feasibility of spinal angle measurements in normal zebrafish subjected to external stresses designed to mimic spinal deformities, to determine normal angle values in the coronal and sagittal planes, and to detail the micro-CT features of the zebrafish spine. HypothesisMicro-CT is an effective and reproducible tool for determining orthopaedic parameters to characterise the zebrafish spine. Material and MethodsTwo observers conducted preliminary analyses on 15 zebrafish including 12 adults (aged 18 months) and 3 juveniles (aged 12 weeks). For the analyses, 6 of the animals were placed in an artificial position to mimic a scoliosis spinal deformity. Micro-CT (Quantum FX Caliper™) was used with 59μm resolution and a 30-mm field of view. Image processing was with RadiAnt DICOM Viewer™ software. ResultsWe defined several assessment planes on the 3D micro-CT reconstructions to measure orthopaedic parameters in the sagittal plane (thoracic and maximal kyphotic curves with their apices, length of the various spinal segments, and sagittal index) and coronal plane (Cobb angles, apices, end-vertebrae, coronal alignment, and side of the convexity). Mean thoracic kyphosis was 20.5°±5.0° in the adults and 8.7° in the juveniles. No curvature was apparent in the coronal plane in the zebrafish left in the neutral position. In the zebrafish with artificially induced curves, micro-CT was effective in determining the Cobb angles and apical vertebrae. DiscussionThis work defines a standardised micro-CT method for assessing the zebrafish spine. In addition, spinal parameter values that can be considered normal were determined, namely, less than 30° of thoracic kyphosis in the sagittal plane and less than 10° in the coronal plane. Our method was effective in assessing induced spinal deformities on micro-CT reconstructions. We hope it will prove of value in future studies of the zebrafish model. Level of evidenceIV.

A weak topological insulator state in quasi-one-dimensional bismuth iodide.

The major breakthroughs in understanding of topological materials over the past decade were all triggered by the discovery of the Z2-type topological insulator-a type of material that is insulating in its interior but allows electron flow on its surface. In three dimensions, a topological insulator is classified as either 'strong' or 'weak'1,2, and experimental confirmations of the strong topological insulator rapidly followed theoretical predictions3-5. By contrast, the weak topological insulator (WTI) has so far eluded experimental verification, because the topological surface states emerge only on particular side surfaces, which are typically undetectable in real three-dimensional crystals6-10. Here we provide experimental evidence for the WTI state in a bismuth iodide, β-Bi4I4. Notably, the crystal has naturally cleavable top and side planes-stacked via van der Waals forces-which have long been desirable for the experimental realization of the WTI state11,12. As a definitive signature of this state, we find a quasi-one-dimensional Dirac topological surface state at the side surface (the (100) plane), while the top surface (the (001) plane) is topologically dark with an absence of topological surface states. We also find that a crystal transition from the β-phase to the α-phase drives a topological phase transition from a nontrivial WTI to a normal insulator at roughly room temperature. The weak topological phase-viewed as quantum spin Hall insulators stacked three-dimensionally13,14-will lay a foundation for technology that benefits from highly directional, dense spin currents that are protected against backscattering.

High-efficiency AMC loaded dipole above FR4 substrate

AbstractThis paper presents a novel artificial magnetic conductor (AMC) loaded dipole above FR4 substrate. The proposed AMC consists of two metal layers that shield the wave from the lossy substrate leading to a significant increase in the dipole efficiency over a wide bandwidth. The dipole is fed through vias that are connected to a wideband balun placed on the opposite side of the ground plane. The proposed assembly is fabricated and characterized. Measurements, which are in a very good agreement with the electromagnetic simulations, show that the operating fractional bandwidth achieves the value of 16.2%, 1.927–2.267 GHz, with peak radiation efficiency of 72.5%.

Proximity of the Coracoid Process to the Neurovascular Structures in Various Patient and Shoulder Positions: A Cadaveric Study

To examine and compare the distances from the anteromedial aspects of the coracoid base and the coracoid tip to the neurovascular structures in various patient positions. The experiment was conducted in 15 fresh-frozen cadavers. We dissected 15 right and 15 left shoulders to measure the distances from the anteromedial aspects of the coracoid base and the coracoid tip to the lateral border of the neurovascular structures in the horizontal, vertical, and closest planes. The measurements were performed with the cadavers in the supine, lateral decubitus, and beach-chair positions. With cadavers in the beach-chair position, we evaluated 5 arm postures (arm at side, 45° of abduction, 90° of abduction, 45° of forward flexion, and 90° of forward flexion). The shortest distance from the coracoid base to the neurovascular structures was found in the beach-chair position with arm at side in the horizontal plane (27.4 ± 4.9mm) and 90° of abduction in the vertical (21.8 ± 4.2mm) and closest (19.5 ± 4.2mm) planes. The distances in each plane were statistically significant compared with the supine and lateral decubitus positions (P < .005). Between the coracoid tip and the neurovascular structures, the shortest distance was found in the beach-chair position with 90° of abduction, with 29.3 ± 7.7mm, 20.8 ± 4.9mm, and 18.5 ± 5.1mm in the horizontal, vertical, and closest planes, respectively. The distances were statistically significant in all planes compared with the supine and lateral decubitus positions (P < .005). Shoulder surgery in the area of the coracoid process is safe, especially with the patientin the supine position. The distance from the coracoid process to the neurovascular structures was closest in thebeach-chair position with 90° of arm abduction. This study determined the distances between the coracoid process and the neurovascular structures during surgery around the coracoid process.

Profile Map of Weld Beads and Its Formation Mechanism in Gas Metal Arc Welding

In order to investigate the profile map of weld beads and its formation mechanism in gas metal arc welding (GMAW), bead-on-plate welding was carried out with different average currents, and the dimensions of a weld bead were measured. The results show that the profile of weld beads can be divided into three stages according to the volume relationship between the melted filler metal and the weld pool. During the stages, the top surface of the reinforcement consisting of the central plane and the side plane mainly goes through inversed-U, W, V, and U shapes, which are mainly attributed to the change of flow pattern. Moreover, the role played by the bottom wall in determining the flow pattern and the resultant bead profile has been investigated as well. The experiment results show that with the bottom wall changing from the solid to the totally melted state, the role of redirecting, redistributing and bearing the molten metal played by the bottom wall gradually disappears. As a result, the side reinforcement is no longer covered by the liquid flowing backward. The top reinforcement is thoroughly collapsed when the width of the bottom reinforcement exceeds that of the top one by 1.1 mm.

Diagnosis and Surgical Outcomes of Facial Asymmetry According to the Occlusal Cant and Menton Deviation

Morphologic differences and surgical outcomes were compared between the ipsilateral type of facial asymmetry, in which the menton deviates to the side of the upward frontal occlusal plane (FOP) cant (FOPUP), and the contralateral type, in which the menton deviates to the side of the downward FOP cant (FOPDOWN), by using cone beam computed tomography (CBCT) images. This retrospective study included consecutive patients with skeletal Class III malocclusion and facial asymmetry who had undergone bimaxillary orthognathic surgery and serial CBCT before, 1month after, and 1year after surgery. CBCT images were reconstructed and analyzed for predictor (group and timing) and outcome (CBCT measurements over time) variables. The data were analyzed using independent t tests and paired t tests. The contralateral group (n=12) was selected first; the ipsilateral group (n=12) was selected by matching age, gender, and degree of FOP cant with those of the contralateral group. Before surgery, in the ipsilateral group, the ramal length was longer on the nondeviated (N-Dev) side than on the deviated (Dev) side (P<.05) whereas the mandibular body length showed no significant difference (P>.05). In the contralateral group, the ramal length was longer on the Dev side (P<.05) whereas the mandibular body length was longer on the N-Dev side (P<.01). One year after surgery, most measurements were corrected symmetrically in both groups (P>.05); however, the hemi-lower facial area remained asymmetrical in the contralateral group (P<.05). Differences in ramal lengths in the ipsilateral group and mandibular body lengths in the contralateral group between the Dev and N-Dev sides seemed to be the main cause of facial asymmetry. Although facial asymmetry improved after surgery in both groups, asymmetry in the soft tissue remained in the contralateral group 1year after surgery.

The Use of Panoramic and Cephalometric Images to Guide Needle Placement for Inferior Alveolar Nerve Block in 7- to 12-Years-Old Children

Introduction: Pain management is one of the most important aspects of behavioral controlling in pediatric dentistry. Local anesthesia by inferior alveolar nerve block (IANB) is the primary method used for pain controlling in pediatric dentistry, and access to the mandibular foramen is the prerequisites for the success of this technique. However, the position of the mandibular foramen relative to the occlusal plane is not the same in all individuals. The aim of this study was to evaluate the effect of age and vertical facial dimension on the relative location of mandibular foramen in children aged 7 to 12 years using panoramic and cephalometric images. Materials and Methods: In this descriptive-analytical study, the cephalometric and panoramic images archived in Zahedan Faculty of Dentistry, belonging to 150 patients aged 7 to 12 years, were analyzed. Based on cephalometric analysis, these images were divided into three groups of short, normal, and long in terms of facial height, and they were divided into three age groups as well. With the help of panoramic radiography, position of the mandibular foramen was studied from different directions. The association of age and vertical facial dimension with the location of mandibular foramen was studied through ANOVA analysis and Kruskal-Wallis test. Kolmogorov-Smirnov test was used for checking the normality. Results: The results indicated that the mean and standard deviation of the anterior-posterior position of mandibular foramen (P = 0.201), the distance between the foramen and the edge of the condyle (P = 0.217), and the distance from the lower edge of the mandible (p = 0.051) showed no significant difference in all age groups. However, the mandibular foramen distance from the occlusal plane in patients aged 7 to 8 years was significantly less than in patients in the age group of 9 to 10 and 11 to 12 years (P 0.05). Conclusion: According to the findings of this study, the needle should be inserted directly on the opposite side of the occlusal plane for the IANB anesthesia in case of children 7 to 8 years old. In other older age groups, the needle should be inserted parallel to the occlusal plane at a distance of 2 mm. ©2019 Dental Hypotheses | Published by Wolters Kluwer - Medknow.

On the Static Stability of Plane Side Ship

On the Static Stability of Plane Side Ship

A planar UWB MIMO antenna with gain enhancement and isolation improvement for the 5G Mobile platform

AbstractA planar ultra‐wide band (UWB) multi‐input multi‐output (MIMO) antenna with gain enhancement and isolation improvement for the 5G mobile platform is proposed. The proposed antenna consists of two planar UWB low‐band antenna elements: a compact multi‐loop antenna and a ground‐slotted planar inverted F antenna (PIFA) located on the opposite side of the rectangular ground plane. These two antennas satisfy the 10‐dB return loss bandwidth from 2.90 to 6.94 GHz for multi‐loop antenna and from 2.79 to 7.23 GHz for slotted PIFA antenna, respectively. A high isolation level of greater than 20 dB is realized without applying any additional decoupling structures. The realized gains are larger than 2.9 dBi. The experimental and simulated results of the proposed antenna are in good agreement with each other.

CT assisted morphological study of lumbar endplate

To study and measure the anatomic structure of lumbar vertebral endplate structure in healthy adults by computed tomography(CT) technique in order to provide a useful guidance for the optimal design and clinical application of lumbar prostheses. Sixty healthy adults (male and female equals) were recruited for full-waist CT scan after signing the informed consent form in the imaging department of the Second Affiliated Hospital of Xi'an Jiaotong University. The scanning data was imported into the computer aided software Mimics 16.0 for 3D reconstruction and measurement. The acquisition indexes included median sagittal diameter, maximum coronal diameter, concavity depth, median sagittal depression angle, coronal depression angle and so on. Finally, the collected data were statistically analyzed by the statistical software. The median sagittal diameter and the maximum coronal diameter of the upper and lower endplates were not only different between the different sexes(P<0.05), but also were increased with the increase of the lumbar spine sequence. The concavity depth of upper and lower endplates had no gender differences(P>0.05), but had a little change from L₁ to L₅, fluctuating from 1.5 to 2.0 mm and from 2.2 to 3.9 mm, respectively. In the same sequence, the concavity depth of lower endplate in males was greater than that of upper endplate, and the difference was statistically significant(P<0.05), but there was no significant difference in the concavity depth of upper and lower endplate in females(P>0.05). Sagittal concavity angle and coronal concavity angle of upper and lower endplates changed slightly with the increase of vertebral order, and there was no gender difference in sagittal and coronal concavity angle of most vertebral sequences (P>0.05). Statistics showed that the largest concavity near the caudal lumbar endplate was located on the dorsal side of the endplate plane. The anatomical structure of the lumbar endplate is very complicated. It is important to master the anatomical parameters of the endplate and make full use of CT before operation for the development and clinical application of the lumbar prosthesis.

Recovery of non-stationary free field with double-layer pressure measurements

Abstract To remove the non-stationary incoming field from the back side of the measurement plane and the non-stationary scattered field caused by the incoming wave falling on the surface of the target source, a recovery method of the non-stationary free field with double-layer pressure measurements is proposed. In this method, the time-evolving mixed pressures on double-layer measurement planes are first measured and transformed into the time-wavenumber domain. Then, with the aid of these time-wavenumber pressure spectrums and the impulse response function, the non-stationary incoming and outgoing fields are separated by the conventional non-stationary sound field separation method. Subsequently, the time-wavenumber spectrum of the surface reflection coefficient of the target source is employed to establish the relationship between the non-stationary scattered and incoming fields, based on which the non-stationary scattered field is calculated. Finally, the non-stationary scattered field is removed from the outgoing field and the non-stationary sound field that would be radiated by the target source in free field is recovered. Numerical simulation with an exciting planar steel plate as the target source and a monopole source as the disturbing source is used to examine the feasibility of the proposed method. The recovered results demonstrate that the proposed method not only removes the influence of the incoming field in the time and space domains, but also clears the non-stationary scattered field, thus providing more accurate recovered results than the non-stationary sound field separation method. The experiment further proves the validity of the proposed method.

MATHEMATICAL MODELING OF METAL FLOW IN CRYSTALLIZER AT ITS SUPPLY FROM SUBMERSIBLE NOZZLE WITH ECCENTRIC HOLES

Flow of liquid melt in the crystallizer is a little-studied process. Analytical solutions of melt flow in general case refer to complex mathematical problems, therefore numerical methods are used to model it. The purpose of this work is to use numerical method proposed by Professor V.I. Odinokov, based on finite-difference representation of the initial system of equations. This method has been successfully used in mechanics of continuous media, in foundry industry in mathematical modeling of strained deformed state of shell molds on investment models,as well as in other technological works, which indicates its universality. In the present study, the object of research is hydrodynamic flows of liquid metal during steel casting into a rectangular section mold when fed from a submerged nozzle with eccentric holes, and the result is a spatial mathematical model describing the flows of liquid metal in the crystallizer. To simulate the processes occurring in the crystallizer, the software complex “Odyssey” was used. The theoretical calculation is based on fundamental equations of hydrodynamics and approved numericalmethod. Solution of differential equations system formulatedin the work was carried out numerically. Investigated area was divided into elements of finite dimensions, for each element the resulting system of equations was written in the difference form. The result of the solution is velocity field of metal flow in crystallizer volume. To solve the system of algebraic equations obtained, a numerical scheme and a calculation algorithm were developed. Based on developed numerical scheme and algorithm, a computation program was compiled in Fortran-4. Mathematical model makes it possible to vary geometric dimensions of the crystallizer and cross-section of metal exit openings from the immersion nozzle, and it can also help to understand the flow pattern of the cast metal that affects heat dissipation of crystallizer walls and to find the optimal parameters for liquid metal outlet from the gravy glass at various casting modes. As an example it is given calculation of steel casting into a rectangular mold with a height of 100 cm and a section of 2000×40 (cm) in plan. Casting was carried out from immersion nozzle eccentrically in both sides in a horizontal plane. The calculation results are presented in graphical form. The movement of liquid metal flows is shown, their magnitudes and intensity are determined.

Assessment of cortical bone material distribution in medial column of proximal humerus with computed tomography

Objective: To evaluate the cortical bone characteristics in the medial column of proximal humerus. Methods: A total of one hundred and three healthy adults who underwent shoulder computed tomography scanning in Tianjing Hospital were included in this study.The subjects were divided into three groups according to the age: group A (20-39 years), group B (40-59 years), and group C (>60 years). Cortical bone mapping (CBM) was used to analyze ordinary clinical CT scans using Stradwin 5.2 software.Colors thickness maps were created for each proximal humerus.The region of interest (ROI) 1-6 were set at three levels of the lateral and medial column of proximal humerus.Cortical thickness (CTh), cortical mass surface density (CMSD), and endocortical trabecular bone mineral density (ECTD) were assessed in the three slices in proximal metaphysis.The impact of age, gender to the cortical bone indices of medial column of proximal humerus were investigated with relative analysis.Cortical indices of the lateral and medial column were compared with independent samples t test. Results: In ROI 2 and 3, men had higher cortical bone values than women, and significant differences in ECTD and CMSD were found in ROI 2, 3 and ROI 2 (t=2.100, 2.238, 2.530, all P<0.05). The lineal regression analysis showed that all cortical indices in ROI 1-3 decreased significantly with age for both women and men (r(2)=0.042-0.248, all P<0.05). In group A-C, the medial columns had higher CTh and CMSD values than lateral sides in plane 1, although significant differences were found only in group A (t=3.696, 3.749, both P<0.05). The highest CTh, CMSD and ECTD of the medial compact bone was detected in ROI 1, followed by ROI 2 and 3 in group A (F=5.867, 6.776, 19.062, all P<0.05). The medial columns had approximately equivalent cortica indices values in ROI 1-3 in group B and C. Conclusion: It indicated that significant regional variation in all cortical parameters exists in the medial column of proximal humerus, and the indices are influenced by gender and age.

A Compact Dual-Band Planar Monopole Antenna Using Fractal Rings and A Y-Shaped Feeding Transmission Line

Abstract This paper presents a novel design approach of a compact dual-band monopole antenna with an overall size of 18.9x13x1.6mm3. The proposed antenna is composed of a fractal ring shaped patch fed by a Y-shaped transmission line on the top side of the substrate and a second fractal ring along with a U-shaped ground plane on the bottom side. The second fractal ring, identical to the radiating ring, is loaded and a rectangular slot is etched at the top side of the ground plane respectively, to achieve dual-band characteristic and improve the impedance matching. The effect of standard ground-plane (SGP) of a laptop computer is incorporated in the design; the antenna is mounted on a SGP in order to investigate its performance. The antenna covers widely the frequency bands of the WLAN 2.4 GHz (2.2–2.52 GHz) and WiMAX 3.5 GHz (3.32–4.35 GHz), and exhibits an omnidirectional radiation pattern in the H-plane and a monopole like radiation pattern in the E-plane. A good agreement between the simulated and measured results indicates that the proposed dual-band antenna design is suitable for WLAN/WiMAX applications.

Improved decryption quality with a random reference beam cryptosystem

The secure managing of sensible data is one of the main challenges nowadays. During the last years several advances have demonstrated the ability of optical encrypting systems to protect information. In spite of these developments, there are some evident issues to be solved. One of the main concerns is the limitation of the experimental cryptosystems in the size of the inputs that can be properly protected and recovered by the encrypting system. In the case of the experimental joint transform correlator (JTC) cryptosystem, the data to be encoded and the key are placed side by side in the input plane. Therefore, the size of the object to be encrypted is limited by the size of the encryption key and the separation between the input and the key. This limitation leads to degradation on the recovered data according the size and the spatial frequencies content of the object for a given recording media. In this work we experimentally implement an interferometric cryptosystem in which the encryption key is a ground glass diffuser (GGD) located in the reference arm. In the object arm, the information to be encoded is displayed in a spatial light modulator (SLM) and placed in contact with another GGD. This system allows the projection of the input object in the whole SLM area. The encryption process results from the interference between the reference beam and the Fourier transform of the input object plane. We experimentally analyze the quality of the decrypted object in relation with the size of the input original object. Then, we compare the performance of this system with the JTC cryptosystem. Finally, we implement a protocol for a multi-user environment under the rotation of the key. Experimental results show the viability, versatility and applicability of the proposal.

Complete structural and strain analysis of single GaAs/(In,Ga)As/GaAs core–shell–shell nanowires by means of in-plane and out-of-plane X-ray nanodiffraction

Typically, core–shell–shell semiconductor nanowires (NWs) made from III–V materials with low lattice mismatch grow pseudomorphically along the growth axis, i.e. the axial lattice parameters of the core and shell materials are the same. Therefore, both the structural composition and interface strain of the NWs are encoded along directions perpendicular to the growth axis. Owing to fluctuations in the supplied growth species during molecular beam epitaxy (MBE) growth, structural parameters such as local shell thickness, composition and strain may differ between NWs grown onto the same substrate. This requires structural analysis of single NWs instead of measuring NW ensembles. In this work, the complete structure of single GaAs/(In,Ga)As/GaAs core–shell–shell NW heterostructures is determined by means of X-ray nanodiffraction using synchrotron radiation. The NWs were grown by MBE on a prepatterned silicon (111) substrate with a core diameter of 50 nm and an (In,Ga)As shell thickness of 20 nm with a nominal indium concentration of 15%, capped by a 30 nm GaAs outer shell. In order to access single NWs with the X-ray nanobeam being incident parallel to the surface of the substrate, a single row of holes with a separation of 10 µm was defined by electron-beam lithography to act as nucleation centres for MBE NW growth. These well separated NWs were probed sequentially by X-ray nanodiffraction, recording three-dimensional reciprocal-space maps of Bragg reflections with scattering vectors parallel (out-of-plane) and perpendicular (in-plane) to the NW growth axis. From the out-of-plane 111 Bragg reflection, deviations from hexagonal symmetry were derived, together with the diameters of probed NWs grown under the same conditions. The radial NW composition and interface strain became accessible when measuring the two-dimensional scattering intensity distributions of the in-plane 2{\overline 2}0 and 22{\overline 4} reflections, exhibiting well pronounced thickness fringes perpendicular to the NW side planes (truncation rods, TRs). Quantitative values of thickness, composition and strain acting on the (In,Ga)As and GaAs shells were obtained via finite-element modelling of the core–shell–shell NWs and subsequent Fourier transform, simulating the TRs measured along the three different directions of the hexagonally shaped NWs simultaneously. Considering the experimental constraints of the current experiment, thicknesses and In content have been evaluated with uncertainties of ±2 nm and ±0.01, respectively. Comparing data taken from different single NWs, the shell thicknesses differ from one to another.

The Morphology of the Outflow in the Grazing Envelope Evolution

We study the grazing envelope evolution (GEE), where a secondary star, which orbits the surface of a giant star, accretes mass from the giant envelope and launches jets. We conduct simulations of the GEE with different half-opening angles and velocities, and simulate the onset phase and the spiralling-in phase. We discuss the resulting envelope structure and the outflow geometry. We find in the simulations of the onset phase with narrow jets that a large fraction of the ejected mass outflows along the polar directions. The mass ejected at these directions has the fastest velocity and the highest angular momentum magnitude. In the simulations of the spiralling-in phase, a large fraction of the ejected mass concentrates around the orbital plane. According to our findings, the outflow with the highest velocity is closer to the poles as we launch narrower jets. The outflow has a toroidal shape accompanied by two faster rings, one ring at each side of the equatorial plane. The interaction of the jets with the giant envelope causes these outflow structures, as we do not include in our simulations the secondary star gravity and the envelope self-gravity.

Preparation of α-CaSO4·½H2O with tunable morphology from flue gas desulphurization gypsum using malic acid as modifier: A theoretical and experimental study

Huge amount of flue gas desulphurization (FGD) gypsum not only occupies the farmland but also causes severe pollution to the surrounding environment. The most effective way to achieve a high-value utilization of FGD gypsum is to prepare short columnar α-calcium sulfate hemihydrate (α-HH) since short columnar crystals show better mechanical strength than needle-like ones. Here, malic acid, a prolific, inexpensive and environment-friendly modifier was explored for the first time to effectively tune the crystal morphology of α-HH prepared from FGD gypsum in glycerol-water-NaCl solutions. When the concentration of malic acid reached 18.54 × 10−4 mol/kg, α-HH crystals with an average aspect (length-to-diameter) ratio of 1.9 (compared to 29.4 in the absence of malic acid) were prepared. The selective complexation of malic acid with Ca active sites on different α-HH crystal planes played a dominant role in the α-HH crystal morphology transformation, which was then explained by the surface broken bonds theory for the first time. The broken bond number per active Ca atom (Nbper Ca) and broken bond density of Ca atoms (DbCa) on the (2 0 4) end plane were larger than those on the (0 2 0) or (2 0 0) side planes. Therefore, the (2 0 4) end plane was more reactive with organics, resulting in the preferential adsorption of malic acid on the end planes, which reduced the specific surface energy of (2 0 4) and led to an increased exposure of this plane and a decreased exposure of (0 2 0) or (2 0 0) side planes in the final α-HH crystals. Consequently, using malic acid as modifier, the α-HH crystal gradually transformed from a needle-like shape to a short columnar one. This work provided important insights into and perspectives for the selection of crystal modifiers and explanation of the mechanism during the preparation of calcium-containing crystals with controllable morphology.