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Post-Independence NU Dynamics Towards the Establishment of the NU Outline as a Decision of the Situbondo Congress 1945-1984

After Indonesian independence in 1945, NU began to be actively involved in practical politics. Its practical political role is channeled through the Masjumi Party, the NU Party, and PPP. Within these three political forums, NU experienced various dynamics which made NU finally decide to withdraw from practical politics. Apart from that, there was also influence from the Old Order and New Order governments which also triggered and encouraged the process of his withdrawal. All of this is part of the social process of the discourse of Khittah NU which emerged from 1959 until it was determined to be the decision of the 1984 Situbondo Muktamar. How was the development of the discourse on the Basic Strategies of NU 1959-1984? Why was the Khittah NU determined as the decision of the 1984 Situbondo Congress? Furthermore, as a study of the past, this study uses historical research methods which have 5 stages in the form of topic selection, source gathering, verification, interpretation, and writing. In addition, this study uses a sociological approach to capture the social dimension of every phenomenon found and uses social process theory to carry out analysis and synthesis. To provide a corridor in writing, the central circle model is used because it is considered relevant to research. The conclusion of this study shows that NU experiences all forms of social processes. Cooperation, competition, conflict and conflict, as well as accommodation have been experienced by NU as a social reality that must be faced together with various other groups. In its relationship with one party, NU does not only cooperate, sometimes NU has to compete and even fight with the group where various decisions are taken by bearing some risks while continuing to try to achieve wider benefits.

On the image in the torus of sparse points on dilating analytic curves

It is known that the image in ℝ2/ℤ2 of a circle of radius ρ in the plane becomes equidistributed as ρ → ∞. We consider the following sparse version of this phenomenon. Starting from a sequence of radii {ρn} ∞n=1 which diverges to ∞ and an angle ω ∈ ℝ/ℤ, we consider the projection to ℝ2/ℤ2 of the n’th roots of unity rotated by angle ω and dilated by a factor of ρn. We prove that if ρn is bounded polynomially in n, then the image of these sparse collections becomes equidistributed, and moreover, if ρngrows arbitrarily fast, then we show that equidistribution holds for almost all ω. Interestingly, we found that for any angle there is a sequence of radii growing to ∞ faster than any polynomial for which equidistribution fails dramatically. In greater generality, we prove this type of results for dilations of varying analytic curves in ℝd. A novel component of the proof is the use of the theory of o-minimal structures to control exponential sums.

The provenance of the raw material and the manufacturing technology of copper artefacts from the Copper Age hoard from Magyaregres, Hungary.

In 2016, a Stollhof-type copper hoard was found during an excavation in Magyaregres, Hungary. It was placed in a cooking pot, and deposited upside down within the boundaries of an Early Copper Age settlement. Similar hoards dating to the end of the 5th millennium BCE are well-known from Central Europe, however, this hoard represents the only one so far with thoroughly documented finding circumstances. The hoard contained 681 pieces of copper, 264 pieces of stone and a single Spondylus bead, along with 19 pieces of small tubular spiral copper coils, three spiral copper bracelets, and two large, spectacle spiral copper pendants. Until now, information on the provenance of raw materials and how such copper artefacts were manufactured has not been available. The artefacts were studied under optical microscopes to reveal the manufacturing process. Trace elemental composition (HR-ICP-MS) and lead isotope ratios (MC-ICP-MS) were measured to explore the provenance of raw materials. The ornaments were rolled or folded and coiled from thin sheets of copper using fahlore copper probably originating from the Northwestern Carpathians. A complex archaeological approach was employed to reveal the provenance, distribution and the social roles the ornaments could have played in the life of a Copper Age community. Evidence for local metallurgy was lacking in contemporaneous Transdanubian sites, therefore it is likely that the items of the hoard were manufactured closer to the raw material source, prior to being transported to Transdanubia as finished products. The method of deposition implies that such items were associated with special social contexts, represented exceptional values, and the context of deposition was also highly prescribed. The Magyaregres hoard serves as the first firm piece of evidence for the existence of a typologically independent Central European metallurgical circle which exploited the raw material sources located within its distribution.

Study on the Cavitation Suppression Mechanism of Axial Piston Pump

Gaseous and vaporous cavitation is extremely harmful to axial piston pumps, such as reducing flow rate, increasing flow pulsation, increasing vibration, increasing noise, and shortening life. To suppress the cavitation and improve the performance of axial piston pumps, a mathematical model for suppressing cavitation in the plunger chamber with a constant theoretical flow rate is innovatively established by combining the flow equation of the plunger pump and the pressure drop equation of the plunger chamber. Based on the model, two methods to suppress cavitation in the plunger chamber under the condition of a constant theoretical flow rate are proposed. The first method is to increase the distribution circle radius and correspondingly reduce the rotation speed, and the second method is to increase the plunger chamber radius and correspondingly reduce the rotation speed. To verify the effectiveness of these two methods, the CFD model of the axial piston pump is established, and the correctness of the model is verified by experiments. The results show that the two methods can effectively suppress cavitation in the plunger chamber, improve the actual flow rate, and reduce the flow pulsation under the condition of a constant theoretical flow rate. The research results can provide an important reference for the design and optimization of the plunger pump.

Rigid-Body Guidance Synthesis of Noncircular Gear-Five-Bar Mechanisms and Its Application in a Knee Joint Rehabilitation Device

At present, the research objects of rigid-body guidance synthesis are mostly limited to pure linkages, and there is little research on the combined mechanisms of gears or cams and linkages. In order to expand the research objects of rigid-body guidance and improve the kinematic mapping theory, this paper proposes a rigid-body guidance method of noncircular gear-five-bar combined mechanisms. A noncircular gear-five-bar mechanism can be regarded as a combination of a 2R (two revolute joints) open chain, a 3R (three revolute joints) open chain and a pair of noncircular gears. Firstly, the circle point curves and circle center point curves of the 2R and 3R open chains are obtained by using kinematic mapping, and they are formed into a double crank five-bar linkage. Secondly, the B-spline curve is used to fit the rotation angle relationship of the gear pair to obtain the pitch curves of noncircular gears. Finally, aiming at correcting patients’ abnormal gait, a noncircular gear-five-bar exoskeleton knee joint rehabilitation device is designed based on four task poses. The prototype is developed and the wear test is carried out. The test results verify the correctness of the rigid-body guidance synthesis method and the effectiveness of rehabilitation training.

A Global Multi-Scale Channel Adaptation Network for Pine Wilt Disease Tree Detection on UAV Imagery by Circle Sampling

Pine wilt disease is extremely ruinous to forests. It is an important to hold back the transmission of the disease in order to detect diseased trees on UAV imagery, by using a detection algorithm. However, most of the existing detection algorithms for diseased trees ignore the interference of complex backgrounds to the diseased tree feature extraction in drone images. Moreover, the sampling range of the positive sample does not match the circular shape of the diseased tree in the existing sampling methods, resulting in a poor-quality positive sample of the sampled diseased tree. This paper proposes a Global Multi-Scale Channel Adaptation Network to solve these problems. Specifically, a global multi-scale channel attention module is developed, which alleviates the negative impact of background regions on the model. In addition, a center circle sampling method is proposed to make the sampling range of the positive sample fit the shape of a circular disease tree target, enhancing the positive sample’s sampling quality significantly. The experimental results show that our algorithm exceeds the seven mainstream algorithms on the diseased tree dataset, and achieves the best detection effect. The average precision (AP) and the recall are 79.8% and 86.6%, respectively.

Relaxation Dynamics in a Long-Range System with Mixed Hamiltonian and Non-Hamiltonian Interactions

Sometimes the dynamics of a physical system is described by non-Hamiltonian equations of motion, and additionally, the system is characterized by long-range interactions. A concrete example is that of particles interacting with light as encountered in free-electron laser and cold-atom experiments. In this work, we study the relaxation dynamics to non-Hamiltonian systems, more precisely, to systems with interactions of both Hamiltonian and non-Hamiltonian origin. Our model consists of $N$ globally-coupled particles moving on a circle of unit radius; the model is one-dimensional. We show that in the infinite-size limit, the dynamics, similarly to the Hamiltonian case, is described by the Vlasov equation. In the Hamiltonian case, the system eventually reaches an equilibrium state, even though one has to wait for a long time diverging with $N$ for this to happen. By contrast, in the non-Hamiltonian case, there is no equilibrium state that the system is expected to reach eventually. We characterize this state with its average magnetization. We find that the relaxation dynamics depends strongly on the relative weight of the Hamiltonian and non-Hamiltonian contributions to the interaction. When the non-Hamiltonian part is predominant, the magnetization attains a vanishing value, suggesting that the system does not sustain states with constant magnetization, either stationary or rotating. On the other hand, when the Hamiltonian part is predominant, the magnetization presents long-lived strong oscillations, for which we provide a heuristic explanation. Furthermore, we find that the finite-size corrections are much more pronounced than those in the Hamiltonian case; we justify this by showing that the Lenard-Balescu equation, which gives leading-order corrections to the Vlasov equation, does not vanish, contrary to what occurs in one-dimensional Hamiltonian long-range systems.

Phenomenology of quantum eigenstates in mixed-type systems: Lemon billiards with complex phase space structure.

The boundary of the lemon billiards is defined by the intersection of two circles of equal unit radius with the distance 2B between their centers, as introduced by Heller and Tomsovic [E. J. Heller and S. Tomsovic, Phys. Today 46, 38 (1993)0031-922810.1063/1.881358]. This paper is a continuation of our recent papers on a classical and quantum ergodic lemon billiard (B=0.5) with strong stickiness effects [Č. Lozej et al., Phys. Rev. E 103, 012204 (2021)2470-004510.1103/PhysRevE.103.012204], as well as on the three billiards with a simple mixed-type phase space and no stickiness [Č. Lozej et al., Nonlin. Phenom. Complex Syst. 24, 1 (2021)1817-245810.33581/1561-4085-2021-24-1-1-18]. Here we study two classical and quantum lemon billiards, for the cases B=0.1953,0.083, which are mixed-type billiards with a complex structure of phase space, without significant stickiness regions. A preliminary study of their spectra was published recently [ Č. Lozej, D. Lukman, and M. Robnik, Physics 3, 888 (2021)10.3390/physics3040055]. We calculate a very large number (10^{6}) of consecutive eigenstates and their Poincaré-Husimi (PH) functions, and analyze their localization properties by studying the entropy localization measure and the normalized inverse participation ratio. We introduce an overlap index, which measures the degree of the overlap of PH functions with classically regular and chaotic regions. We observe the existence of regular states associated with invariant tori and chaotic states associated with the classically chaotic regions, and also the mixed-type states. We show that in accordance with the Berry-Robnik picture and the principle of uniform semiclassical condensation of PH functions, the relative fraction of mixed-type states decreases as a power law with increasing energy, thus, in the strict semiclassical limit, leaving only purely regular and chaotic states. Our approach offers a general phenomenological overview of the structural and localization properties of PH functions in quantum mixed-type Hamiltonian systems.

Normal variation of infant hip development : patterns revealed by 3D ultrasound.

Studies of infant hip development to date have been limited by considering only the changes in appearance of a single ultrasound slice (Graf's standard plane). We used 3D ultrasound (3DUS) to establish maturation curves of normal infant hip development, quantifying variation by age, sex, side, and anteroposterior location in the hip. We analyzed 3DUS scans of 519 infants (mean age 64 days (6 to 111 days)) presenting at a tertiary children's hospital for suspicion of developmental dysplasia of the hip (DDH). Hips that did not require ultrasound follow-up or treatment were classified as 'typically developing'. We calculated traditional DDH indices like α angle (αSP), femoral head coverage (FHCSP), and several novel indices from 3DUS like the acetabular contact angle (ACA) and osculating circle radius (OCR) using custom software. α angle, FHC, and ACA indices increased and OCR decreased significantly by age in the first four months, mean αSP rose from 62.2° (SD 5.7°) to 67.3° (SD 5.2°) (p < 0.001) in one- to eight- and nine- to 16-week-old infants, respectively. Mean αSP and mean FHCSP were significantly, but only slightly, lower in females than in males. There was no statistically significant difference in DDH indices observed between left and right hip. All 3DUS indices varied significantly between anterior and posterior section of the hip. Mean 3D indices of α angle and FHC were significantly lower anteriorly than posteriorly: αAnt = 58.2° (SD 6.1°), αPost = 63.8° (SD 6.3°) (p < 0.001), FHCAnt = 43.0 (SD 7.4), and FHCPost = 55.4° (SD 11.2°) (p < 0.001). Acetabular rounding measured byOCR indices was significantly greater in the anterior section of the hip (p < 0.001). We used 3DUS to show that hip shape and normal growth pattern vary significantly between anterior and posterior regions, by magnitudes similar to age-related changes. This highlights the need for careful selection of the Graf plane during 2D ultrasound examination. Whole-joint evaluation by obtaining either 3DUS or manual 'sweep' video images provides more comprehensive DDH assessment.Cite this article: Bone Jt Open2022;3(11):913-923.

Changes in Light Disturbance Analyzer Evaluation in SMILE for High Myopia and Astigmatism.

To study the objective change in light disturbance around a glare source using the Light Disturbance Analyzer (LDA) (Binarytarget Lda) and correlate this with the validated subjective quality of vision (QoV) questionnaire in small incision lenticule extraction (SMILE) for high compound myopic astigmatism. This was a prospective study recruiting 114 patients undergoing SMILE with attempted spherical equivalent refraction (SEQ) correction from -9.00 to -13.00 diopters (D), and cylinder up to 5.00 D. The LDA was used before and 3 and 12 months after surgery to evaluate the Light Disturbance Area, Light Disturbance Index, Best Fit Circle Radius, and Best Fit Circle Irregularity. Patients completed the Rasch-validated QoV questionnaire before and 12 months after surgery. Correlation analysis was performed between the LDA parameters and the QoV frequency, severity, and bothersomeness for halos and starbursts. At 12 months, there was a non-statistically signifcant change of 11.9% for Light Disturbance Area and Light Disturbance Index and 6.5% for Best Fit Circle Radius. There was an increase of 81.9% for Best Fit Circle Irregularity (P = .017). Light Disturbance Area, Light Disturbance Index, and Best Fit Circle Radius correlated with bothersomeness for QoV halos, and with frequency, severity and bothersomeness for QoV star-bursts (P < .05), albeit with a low correlation coefficient (R2 < 0.13). There was no correlation between increase in Best Fit Circle Irregularity and the halo and starburst scores from the QoV questionnaire. LDA Best Fit Circle Irregularity was found to increase following high myopic SMILE. Other LDA parameters appeared to increase, but a much larger sample would be required to find statistical significance. The change in LDA parameters was only weakly correlated with QoV halo and starburst metrics, representing the wide variation in inter-subject perception. [J Refract Surg. 2022;38(11):725-732.].

Development of neural‐network‐based stereo bionic compound eyes with fiber bundles

SummaryThe compound eye system has many unique advantages, enabling organisms to quickly and accurately obtain the three‐dimensional spatial information of the target. Therefore, its bionic applications have great potential in object localization, dynamic tracking, and 3D reconstruction. However, the current bionic compound eye systems still have great difficulties in target detection. Most of the bionic compound eye systems only verify the possibility of three‐dimensional (3D) detection, and there is no suitable calibration and detection scheme. In this article, a fiber‐optic stereo bionic compound eye is designed, and a simple and rapid calibration method suitable for this system is selected by comparing two effective optical information. Further, the system quantitatively analyzes the detection performance of the target to achieve precise positioning and dynamic trajectory tracking. In the static detection experiment, the average detection errors of the 3D position at the horizontal angle, the elevation angle and the depth are 0.33°, 0.32° and 1.84 mm, respectively. In the dynamic trajectory tracking experiment, the circle radius errors in the X‐Z plane and Y‐Z plane are 0.04 and 2.20 mm, respectively. The proposed system provides a new perspective to understand the nature of the compound eye.

Why Can’t We Be Friends? John of Salisbury, Thomas Becket and the Discourse of Amicitia

There has been an almost universal tendency to treat Thomas Becket as a personal—even close and intimate—friend of John of Salisbury, based on their decades-long association. Evidence for this position has rested, for example, on the fact that the two writings that have primarily sustained John’s intellectual reputation through the centuries—the Policraticus and the Metalogicon—he chose to dedicate to Becket. During the Middle Ages, however, addressing a book to powerful and well-placed people did not necessarily suggest endorsement of their behaviour. Indeed, a dedication might indicate criticism or rebuke rather than affection or gratitude, as it does today. John’s actual attitude towards Becket cannot be separated from appreciation of the relationship between friends as understood in the twelfth century. John stood at or near the centre of a large friendship circle that encompassed mainly monks and secular clergy—a network held together by copious correspondence as well as face-to-face interaction. Such circles functioned as important means of constructing common intellectual and political agendas among literate but otherwise far-flung figures. Becket received no such expressions of friendship status from John of Salisbury.

Nonlinear axisymmetric buckling analysis of the FGM sandwich shallow spherical shells under thermomechanical loads

Functionally graded material (FGM) sandwich shallow spherical shells are promising composite sandwich structures for modern engineering applications. In this paper, the axisymmetric snap-through buckling of spherical shells under uniform external pressure and non-uniform temperature rise along the shell thickness was studied. Based on the classical shell theory and the Sanders nonlinear kinematics equations, we established a two-point boundary value problem (BVP) posed by the displacement-type nonlinear ordinary differential equations governing the axisymmetric buckling of the FGM sandwich shallow spherical shells and the clamped boundary conditions. Then, the solutions of the above BVP were obtained using the numerical shooting method. The influence of initial term numbers of the infinite series defining the non-uniform temperature field on the accuracy of the solution was examined. Numerical calculations showed that a considerable initial term number of the series were needed to obtain the applicable solutions for engineering. Some valuable conclusions were drawn through detailed parameter studies. As the radius of the bottom circle increases, the lower critical load of shells decreases, the jump amplitude of buckling increases, and the upper critical load remains almost unchanged. The upper and lower critical loads and the jump amplitude increase as the circle radius of the middle surface of shells decreases. When the thickness of shells increases, their upper and lower critical loads increase, whereas the jump amplitude of buckling reduces. The gradient index has a significant effect on the steady-state response of pre-buckling spherical shells but little effect on that of post-buckling spherical shells. When the temperature rises, the upper critical load and the buckling jump amplitude of shells increase, but the lower critical load decreases. When the gradient index is greater (less) than about 0.35, the upper critical load decreases significantly (increases slightly) with the increase in the relative thickness of the FGM core. The present numerical results are well consistent with the finite element results and those in the available literature.

Navigation Template Design and the Anatomic Measurement for Anterograde Transpubic Screws.

For pelvic ring fractures, screw fixation became a popular technique for its good biomechanical performance. The safe insertion of anterograde the transpubic screw is important for patients with anterior pelvic ring fractures. This paper is to research the anatomical parameters of the anterograde transpubic screw corridor and evaluate the safety of anterograde transpubic screw placement assisted by the assembled navigation template. Fifty subjects with normal pelvic, 25 men and 25 women, age from 20 to 60 were enrolled, and their ilium were 3D reconstructed. The ilium was divided into zone I, zone II and zone III. Zone I and zone III was defined as medial and lateral to the obturator foramen, respectively. Zone II is located between zones I and III. The corridor A is formed by zone I and zone II and corridor B is formed by zone I, zone II and zone III. The diameter and length of the inner circle, the distance from the center of the inner circle to the posterior superior and to the inferior iliac spine of corridor A and corridor B were measured, respectively. Nine patients with pelvic fractures underwent anterograde transpubic screw and transverse sacroiliac screw placement assisted by the assembled navigation template and were retrospectively analyzed. Operation time, blood loss, incision length and fluoroscopy times were recorded. Grading score and Matta score were evaluated after surgery. In the 50 subjects, the diameter of corridor A was 11.16 ± 2.13 mm, and that of corridor B was 8.54 ± 1.52 mm. The length of corridor A was 86.39 ± 9.35 mm, and that of corridor B was 117.05 ± 5.91 mm. The surface distance from the screw entry point to the posterior superior iliac spine in corridor A was 109.31 ± 11.06 mm, and that in corridor B was 127.86 ± 8.23 mm. The surface distance from the screw entry point to the posterior inferior iliac spine in corridor A was 91.16 ± 10.34 mm, and that in corridor B was 106.92 ± 7.91 mm. A total of 18 sacroiliac transverse screws and 11 anterograde transpubic screws were inserted assisted by assembled navigation templates for nine patients. The average operation time was 108.75 ± 25.71 min, the blood loss was 141.11 ± 50.21 ml, the incision length was 14 ± 4.62 cm, and the intraoperative fluoroscopy was 17.89 ± 4.01 times. Transpubic screw corridor can be obtained by 3D reconstruction. For the majority of patients, the anterograde pubic ramus corridor accommodated a 6.5 mm diameter screw. It is safe to use anterograde transpubic screw placement assisted by an assembled navigation template.

Multi-body modeling and dynamic analysis of the heavy-load multi-axle vehicle Based on 6S/6M ABS control

The study investigates the braking characteristics of heavy-load five-axle special vehicle to improve the braking safety of it. The mechanical system with strong coupling is studied by means of multi-body dynamics analysis method, and the refined vehicle dynamics model including braking system, suspension system, steering system, and other components is established via platform of Adams/Car. Through road test experiments, the accuracy and reliability of the model under conditions of 80 m constant turning radius circle and emergency braking of 60 km/h initial speed are verified. The classical ABS (Anti-lock Braking System) control strategy with logic threshold including a road recognition module and a slip ratio calculation module is established in Simulink, which matches the ABS control system of 6 S/6 M for the five-axle special vehicle well. By changing adhesion conditions of a single road and the control channel modes of the split-mu road, the control effect of the ABS control system on the braking performance of the five-axle vehicle is determined by the co-simulation. The experimental and simulation results indicate the following: (1) The vehicle dynamics model can effectively simulate the structure of the actual vehicle mechanical system and mechanical constraints, and has good braking performance and steering performance; (2) ABS external control system and heavy-load five-axle vehicle model can be matched, and during the control process, logic thresholds need to be repeatedly adjusted to adapt to different types of roads. (3) The change of road adhesion coefficient will affect the control effect of ABS. The baking performance can be improved more in low adhesion road than in high adhesion road. (4) Split-mu road is more special and has a great impact on the lateral stability of braking. It can be seen through comparative analysis of high-selection and low-selection control that braking safety is better under low selection control mode.

The Relative Preservation of the Central Retinal Layers in Leber Hereditary Optic Neuropathy.

(1) Background: The purpose of this study was to evaluate the thickness of retinal layers in Leber hereditary optic neuropathy (LHON) in the atrophic stage compared with presumably inherited bilateral optic neuropathy of unknown cause with the aim of seeing if any LHON-specific patterns exist. (2) Methods: 14 patients (24 eyes) with genetically confirmed LHON (LHON group) were compared with 13 patients (23 eyes) with negative genetic testing results (mtDNA + WES) and without identified etiology of bilateral optic atrophy (nonLHON group). Segmentation analysis of retinal layers in the macula and peripapillary RNFL (pRNFL) measurements was performed using Heidelberg Engineering Spectralis SD-OCT. (3) Results: In the LHON group, the thickness of ganglion cell complex (GCC) (retinal nerve fiber layer (RNFL)—ganglion cell layer (GCL)—inner plexiform layer (IPL)) in the central ETDRS (Early Treatment Diabetic Retinopathy Study) circle was significantly higher than in the nonLHON group (p < 0.001). In all other ETDRS fields, GCC was thinner in the LHON group. The peripapillary RNFL (pRNFL) was significantly thinner in the LHON group in the temporal superior region (p = 0.001). Longitudinal analysis of our cohort during the follow-up time showed a tendency of thickening of the RNFL, GCL, and IPL in the LHON group in the central circle, as well as a small recovery of the pRNFL in the temporal region, which corresponds to the observed central macular thickening. (4) Conclusions: In LHON, the retinal ganglion cell complex thickness (RNFL-GCL-IPL) appears to be relatively preserved in the central ETDRS circle compared to nonLHON optic neuropathies in the chronic phase. Our findings may represent novel biomarkers as well as a structural basis for possible recovery in some patients with LHON.

Design of continuous-flow microwave reactor based on a leaky waveguide

Using microwave heating for biodiesel production has several advantages, including an accelerated reaction rate and improved product quality. However, large-scale microwave-assisted biodiesel production still suffers from low efficiency and uneven heating, which limit its industrial applicability. To address these issues, in this study, a reactor based on leaky waveguide is proposed for continuous microwave-assisted biodiesel production. Firstly, a radiator based on a leaky waveguide is designed to realize a uniform distribution of microwave energy along the axial and longitudinal directions. Then, a multi-physics model based on electromagnetism, heat transfer in fluids, chemical engineering, and laminar flow is developed to simulate the continuous microwave-assisted biodiesel production process. Compared to the traditional bottom-fed and cylinder-fed reactors, the leaky-waveguide reactor has the potential to improve the heating uniformity and energy efficiency, and the microwave energy utilization efficiency can more than 95 % and the value of the outlet COV can be reduced to 1.51 × 10−3. Experiments were carried out to validate the proposed model, and the experimental results are in good agreement with the simulated results. Finally, the effects of the pitch circle radius, radius, and number of turns (screw pitch) of the helical tube used for the microwave-assisted biodiesel production process were analyzed. The radius and number of turns (screw pitch) have a greater effect on the system than pitch circle radius. This continuous microwave-assisted biodiesel production reactor provides a possibility for large-scale industrial production and can also be widely applied to the chemical engineering with pressure continuous flow reactor and food industry.

Photodetector module of optoelectronic control systems for tracking the moving objects

An algorithm has been developed for modelling the signals of four-plane photodetector, when moving an axisymmetric light spot along its surface. The form of direction-finding characteristics of photodetector has been calculated for different schemes of illumination of sensitive surface of the detector, which are used in optoelectronic automatic control systems, in particular in the motion control systems for tracking moving objects. Some samples of specialized focusing microprism devices with the distribution of light spot in the focal plane as a central circle with a light ring at its periphery, which are made using diamond micro-cutting based on our simulation results, have been experimentally investigated.

Combining catastrophe technique and regression analysis to deduce leading landscape patterns for regional flood vulnerability: A case study of Nanjing, China

Urbanization leads to changes in land use, and the expansion of impervious surfaces leads to an increase in flood vulnerability. Predicting and analyzing these landscape pattern changes are important in the early stages of urban planning. In practice, the threshold for obtaining comprehensive and detailed hydrological and meteorological data is high, which makes it difficult for landscape and urban planners to quickly evaluate urban floods. To compensate for these trends, we took Nanjing, China, as the study site and discussed the leading flood vulnerability landscape patterns based on quantitative assessments. We introduced catastrophe theory to integrate three indicators and seven subfactors for flood vulnerability assessment: exposure, including precipitation; sensitivity, including elevation, slope, soil and drainage density; and adaptability, including land use and forest coverage. Then, we calculated the landscape pattern metrics (shape index, fractal dimension index, related circumscribing circle, contiguity index and landscape division index) at the class level. Finally, we divided the city into four subregions, established regression models for the subregions and the whole city, and deduced the leading flood vulnerability landscape patterns in each region and the whole city. We found that the leading landscape patterns varied among different regions. According to the research results, the landscape pattern indexes identified in this paper can be interpreted intuitively, which can provide a reference for modifying the planning layout of regional green infrastructure, optimizing the vulnerability of urban floods, and providing a basis for further improving Nanjing urban planning and alleviating the urban flood vulnerability. The methods proposed herein also will benefit land use and green infrastructure management in other regions lacking meteorological and hydrological data.

New principles of shaping groove structures of high-aperture non-classical ruled toroidal diffraction gratings using pendulum-type ruling engines

Subject of study. Possible methods for increasing the range of optical parameters of fabricated high-aperture non-classical ruled toroidal diffraction gratings and new mathematical relations for describing the equations of curvilinear projections of grooves, laws of variation of the curvature radius of the closest vertex circle, and variable pitch for these groove projections are presented. Aim of study. The study aimed to improve the principles of designing pendulum-type ruling engines ensuring the implementation of a new method for fabricating high-aperture non-classical ruled concave toroidal diffraction gratings and derive analytical expressions for determining geometric parameters of curvilinear projections of the grooves of these gratings. Method of study. The investigation method was based on the theory of designing precision mechanisms, analytic geometry, and calculus. Main results. The possibility of solving the relevant issue of increasing the size, relative aperture, and relation between the curvature radii in meridional and sagittal cross-sections of high-aperture non-classical ruled toroidal diffraction gratings considering the optimization of their aberrations was demonstrated using pendulum-type ruling engines. In contrast to the available engines, pendulum-type ruling engines should be designed to ensure the intersection between the rotation axes of the diamond and blank carriages as well as alignment of the dimension chains of the structural parameters of the diamond and blank carriages according to the specified curvature radii in meridional and sagittal cross-sections of concave toroidal diffraction gratings. Considering that the cutting edge of the diamond tool must always be in contact with the concave toroidal surface of a substrate along the normal to the surface in all substrate points while ruling all grooves, we established that the system of curvilinear groove projections is described by a system of second-order curves, i.e., ellipse equations. With increasing discrete angle at which the grooves are ruled, the coordinates of the centers of the ellipses gradually shifted in the meridional cross-section from the origin of coordinates (grating vertex) in the direction of the edge light zone by a value directly proportional to the sine of the discrete angle and the difference between curvature radii in the meridional and sagittal cross-sections. Curvature radii of the closest vertex circles of the groove projections are variable parameters directly proportional to the product of curvature radii in the meridional and sagittal cross-sections of the grating and inversely proportional to the variable value of the specified coordinate. The variable pitch of the groove projections on the specified plane is a function that, to a first approximation, depends on the initial groove pitch at the grating vertex and the squared variable value of the specified coordinate and is inversely proportional to the squared curvature radius in the meridional cross-section of the grating. Practical significance. The proposed principles of shaping groove structures of the ruled toroidal diffraction gratings using pendulum-type ruling engines enable fabricating such gratings with extremely large relative aperture and optical size as well as increased range of ratios of their curvature radii in the meridional and sagittal cross-sections, which can be used to design novel advanced spectral instruments. The obtained analytical expressions describing the geometric parameters of the curvilinear groove projections enable correction of the first through third order aberrations of the gratings of the considered type.