End Part Research Articles

A Phase Canceling Technique to Improve SAW Duplexer Isolation.

Spectrum resources are becoming increasingly crowded, and the isolation interval between different systems is getting smaller and smaller. This puts forward higher requirements for the duplexer. The duplexer is an important part of the radio frequency front end, and the isolation requirement is becoming higher. This paper presents a phase canceling circuit to improve the performance of the duplexer to meet the requirement of the communication system for isolation. A phase canceling circuit is an effective method to enhance the isolation through use of a surface acoustic wave (SAW) on-chip circuit. It contains a duplexer and a branch. The branch is designed for diminishing the leakage signal of the duplexer. Compared with the leakage signal, the branch consists of two attenuators and a phase shifter to generate a signal which has equal extent and reverse phase. As a result, this method is capable of increasing the isolation of band 5 by 12 dB in the downlink frequency. Meanwhile, it neither affects other factors, such as insertion loss or return loss, nor increases the size of the chip. The phase canceling circuit is expected to promote the quality of duplexer to satisfy the strict requirements in 4G and 5G systems.

Functional Filaments: Creating and Degrading pH-Indicating PLA Filaments for 3D Printing

With the rapid pace of advancements in additive manufacturing and techniques such as fused filament fabrication (FFF), the feedstocks used in these techniques should advance as well. While available filaments can be used to print highly customizable parts, the creation of the end part is often the only function of a given feedstock. In this study, novel FFF filaments with inherent environmental sensing functionalities were created by melt-blending poly(lactic acid) (PLA), poly(ethylene glycol) (PEG), and pH indicator powders (bromothymol blue, phenolphthalein, and thymol blue). The new PLA-PEG-indicator filaments were universally more crystalline than the PLA-only filaments (33-41% vs. 19% crystallinity), but changes in thermal stability and mechanical characteristics depended upon the indicator used; filaments containing bromothymol blue and thymol blue were more thermally stable, had higher tensile strength, and were less ductile than PLA-only filaments, while filaments containing phenolphthalein were less thermally stable, had lower tensile strength, and were more ductile. When the indicator-filled filaments were exposed to acidic, neutral, and basic solutions, all filaments functioned as effective pH sensors, though the bromothymol blue-containing filament was only successful as a base indicator. The biodegradability of the new filaments was evaluated by characterizing filament samples after aging in soil and soil slurry mixtures; the amount of physical deterioration and changes in filament crystallinity suggested that the bromothymol blue filament degraded faster than PLA-only filaments, while the phenolphthalein and thymol blue filaments saw decreases in degradation rates.

Nonlinear dynamic verification of the boron injection lances for the Atucha-I Nuclear Power Plant

This work deals with the nonlinear transient dynamic verification of the boron injection lances for the Atucha-1 Pressurized Heavy Water Reactor backup shutdown system. The lances inside the moderator tank constitute the end part of the fast boron injection piping. The current dynamic verification of the lances is performed in the context of modifications in the piping and valve configuration for Atucha-I Long Term Operation (LTO). It is intended to ensure the structural integrity of the lances in the event of Loss of Coolant Accidents (LOCA) and spurious opening of level control valves (Spurious) scenarios. All boundary conditions have been provided by Nucleoeléctrica Argentina S.A. (NA-SA), and a 3-D numerical model of the lances was built and analyzed with the open-source suite Salome-Meca v2019 using the Code_Aster finite element solver. Results indicate that the displacement of the lances does not produce collisions with other reactor internals and that stresses on the lances and their fastening bolts are low enough to ensure the correct function of the system during LTO period.

UN FONDO DI HYDRIA RITAGLIATO E ISCRITTO DA MOZIA: CONVIVENZA DI ALFABETI E LINGUE DIVERSE

During the XLII season (2022) of excavations in Zone D at Motya, under the floor levels of the “House of Triton’s Horn”, Sounding IVr eached a pit filled up with archaic ceramic fragments. Here a cut-out bottom of a Greek hydria inscribed on both sides with different scripts and languages was found. The finding spot, the associated ceramics,the ceramological and epigraphic examination of the fragment allowed to hypothesize that it probably belonged to one of the merchants who used to live in that residential part of Motya towardsthe end of 7thand the beginning of the 6thcentury BC. Other finds from the same stratigraphic context, including an Etruscan amphora, some fragments of bucchero and the Etruscan inscription found in 2017, show the international connections of the local trade élite, suggesting for a certain while a specific Tyrrhenian vocation.

Calculation of Continuous Reinforced Concrete Bridges And Overpasses Inseismically Hazardous Areas

In recent years, in the Republic, the design and construction of continuous reinforced concrete bridges and overpasses were conducted at a colossal pace. Foreign advanced technologies, methods, and software systems were taken into account. Foreign experience in studying rubber-metal bearing parts of bridges and overpasses was analyzed. The article presents the calculation of a continuous reinforced concrete overpass for seismic impacts using the finite element method in the framework of the linear spectral theory. Numerical calculations have shown that the bearing part of the right end of the overpass does not allow the span to fall from the abutment because the maximum displacement of the rubber-metal bearing part is 0.2 m. As a result, the span structure and overpass supports have an overestimated margin of safety for an 8-point earthquake, according to MSK-64.

Technical and technological Solutions for environmentally safe Irrigation with wide-reach Sprinklers

It is known that sprinkling can cause surface runoff of irrigation water and water erosion of soils, which leads to deterioration of water-physical and agrochemical properties of soils, its fertility decreases. The purpose of the research was to ensure environmentally safe irrigation with wide-reach sprinklers by improving the designs of sprinklers and their placement along the pipeline. The developed sprinklers were equipped with sprinklers “Frigate” DMU-B463-90. Studies have shown that the volume of surface runoff of irrigation water during the irrigation season when watering with sprinklers with developed sprinklers was less, and as a percentage of the irrigation norm was: in 2020, when watering DM with sprinklers having a rotating deflector – 6.3%, when watering with a machine with sprinklers having a double deflector – 3.9%; in 2021 respectively – 6.6 and 4.1%, in 2022 – 6.0 and 3.9%. The conducted studies allowed us to recommend installing sprinklers with a rotating deflector or cascade versions at high irrigation rates in the end part of the machine.

Development of recommendations on partial transfer of land to gravity irrigation in zone of Bandyhan - I substandard pumping station with compensation of expenses from Tupolang reservoir

Based on the analysis of the work of the Khazarbagh irrigation system, water use plans, the household regime of the Tupolang River, the operation mode of the pumping station–I, proposals have been developed for the partial transfer of machine irrigation lands to gravity for the zone, the Bandyhan–I subcommand pumping station. With a two–fold accumulation of water in the Tupolang reservoir up to 40-60 million m3 and the use of this water for compensation through the end part of the Khazarbag canal, the distributor P – I in the Bandyhan canal, we recommend turning off the pumping station for the period from February to the first decade of June and from September to November. At the same time, the energy savings amount to 8.38 million kWh.

Investigation of forming of end parts in pipe tension reduction using QForm program

The paper deals with issues of longitudinal stresses during pipe rolling pipes on a three-roll stretching and reduction mill. Opportunities and problems in pipe reduction under tension are described. A research program aimed on reduction and evaluation of all input parameters that affect the parameters of the end parts of pipes based has been developed on the finite element model (FEM) base. Computer study on the FEM basis of stretching and reduction rolling of pipes using the Qform-3D program was carried out. When setting up the experiment using the FEM, the relative variation of the pipe wall thickness at the end parts of the pipe was chosen as the parameter for examination. Reduction of the pipe in its diameter in the pass, ovality of the pipe, geometric parameters of the initial pipe, front and rear tension of the pipe and friction coefficient were the main factors that determine the studying values. Geometric parameters of the end parts of the simulated pipe were measured after modeling. A statistical analysis of the results of a computational experiment of data on variation of pipe wall thickness was carried out. Regression dependence was built using the MATLAB program, and the most significant factors were selected according to the level of their importance. The model that describes the behavior of wall thickness during rolling in a stand of a stretching and reduction mill has been constructed.

Specifying boundary conditions for the operation of pipe heating systems with impact on the building energy balance

Unaddressed boundary conditions in the design of heating systems affect the energy balance of buildings, especially in buildings with very low energy consumption. Buildings with very low energy consumption are very sensitive to any heat flow and neglecting realistic heating water parameters affects their energy balance. Two simulation models of the end part of the heating system have been developed. The first simulation model shows the effect of the inaccuracy of the designed heating element on the calculated room temperature. The second model shows the hydraulic behaviour of the connection pipes of the designed heating element.

Surface integrity and fatigue life of Inconel 718 by ultrasonic peening milling

Inconel 718 is widely used in aeroengine hot end parts, such as turbine disks, blades, drive shafts and so on. Its excellent mechanical and thermal properties also lead to the poor machinability, poor surface integrity, thus affecting the fatigue life of the machined part. This paper proposes an ultrasonic peening milling (UPM) technology which can introduce ultrasonic impact to the machined surface during end milling by applying ultrasonic vibration perpendicular to the machined surface. The effects of vibration on the surface integrity and fatigue life of this material were investigated in comparison with conventional milling (CM). The results showed that the best fatigue life of 2.20 × 106 cycles was achieved by UPM. Compared to the CM process, UPM improved the fatigue life by 16.1 times due to better surface quality with fewer surface defects, thicker stress-affecting layers, and the reinforced machined surface achieved in UPM. The results and findings of this study could contribute to the development of new effective and anti-fatigue machining methods for Inconel 718 in the future.

Superimposed mineralization in the Tongbai composite orogen, central China: Revealed from geological and geochronological data of the Yindongpo gold deposit

Multi-period mineralizations commonly form superimposed deposits in the orogenic belt, resulting in some disputes about the ore geneses and metallogenic background. Here, we present a comprehensive geological and geochronological study on the Yindongpo super-large gold deposit in the Tongbai composite orogen, central China, to reveal the ages of multi-period gold mineralizations and their links to the complex tectonic evolution framework of the Tongbai orogen. The Yindongpo gold deposit is located in the Weishancheng ore field in the northern segment of the Tongbai orogen and is mainly hosted in the carbonaceous schist of the Waitoushan Formation. Zircon U-Pb dating of leptynite (445 ± 3 Ma) from the Waitoushan Formation shows that it was deposited in the Ordovician, in an island arc or back-arc basin setting during the accretionary orogeny. Orebodies at Yindongpo are strictly controlled by the Zhuzhuang anticline and related fault systems, and are mainly distributed in the turning end, the collapsed part of the dipping end, and the conjugate thrust shear zone of the limbs. Based on field and petrographic observations, two periods of mineralization and four paragenetic stages (stage I to IV) are recognized: the early period consists of the laminated quartz-molybdenite-pyrite stage (I) and laminated-disseminated pyrite stage (II), whereas the late period consists of the quartz-pyrite vein stage (III) and the quartz-polymetallic sulfide vein stage (IV). Molybdenite from stage I has a Re-Os model age of 409 ± 6 Ma, which broadly matches the U-Pb age of intergrown rutile grains (396 ± 4 Ma). These two ages, in combination with the mineralization characteristics, indicate that the early-period gold mineralization was generated by the metamorphism of the accreted terranes during the Early Devonian northward subduction of the oceanic plate. The timing of the late-period mineralization is constrained by the U-Pb age of monazite (127 ± 2 Ma) intergrown with gold-bearing pyrite from stage III and the 40Ar/39Ar ages of ore-related sericite (131 ± 1 Ma) from stage IV and altered sericite (133 ± 1 Ma) from the carbonaceous schist. Combined with the extensive development of coeval granitoids and porphyry Mo deposits in the region, the late-period gold mineralization at Yindongpo belongs to a unified large-scale metallogenic event related to the Early Cretaceous intensive granitic magmatism in an extensional tectonic setting. The results presented here thus reveal two discrete mineralization processes at Yindongpo related to the Tongbai composite orogeny: the early mineralization of Devonian accretionary orogeny and the later mineralization of Cretaceous intracontinental orogeny. Our study contributes to the knowledge of superimposed metallogenesis in composite orogen, and also highlights the decisive role of multi-mineral isotopic dating in revealing the metallogenic epoch of superimposed deposits.

SPATIO-TEMPORAL PARAMETERS OF THE FRONT OF THE FORCE FIELD IN THE SYSTEM OF ELONGATED CHARGES

Purpose and task is to study the nature of the formation of the force field in the heel region by the interaction of the upper end parts of adjacent charges.Research results. Based on the fact that outside the zone of plastic deformations the force field is created by stresses close to elastic, analytical studies used a simplified computing apparatus based on known data on the shape and numerical values of force and time parameters of a single pulse from a single cylindrical charge of a given mass and length. The main results. The regularities of the formation of the force field in the boundary zones of action of the system of adjacent elongated charges are considered. The phenomenon of field degradation observed near the end part of the charges, which has a negative effect on the overall mechanical effect of the mass explosion, is analyzed.Conclusions and practical consequences. The shape of the total field of maximum stresses on the middle axis between adjacent charges initiated simultaneously from the lower end should have manifestations of the cumulative effect in the area of the upper end areas of adjacent charges.Therefore, after the inclined counter power fronts, counter mass shifts should take place, generally directed towards the superbore layer of the rock mass at the level of the stamping. The technique of forming upward movements in the intercharging volume of the rock is a new technological element that takes over the experience of conducting mass blasting operations according to an effective traditional system of switching a network of wells in the form of a horizontal wedge or trapezoidal cut. Such a traditional scheme initiates successive pairwise counter mass shifts with short decelerations in the direction of the lateral slope of the ledge. In contrast to this scheme, the new technology of mass explosion is based on a combined technique of simultaneous lower charge initiation in groups of 2-3 rows and the use of traditional short decelerations between groups to prevent excessive seismic effect. Thus, in groups the combined scheme of KSP "vertical wedge" which promotes additional destruction of the top layer of the planted rock block and reduction of an exit ofoversized fraction at the level of a stamping is realized.Keywords: charges, cumulative effect, rock mass, intercharging volume, explosion, seismic effect, vertical wedge.

Li pre-doping technique using perforated electrodes for the cells with a rubber-derived sulfur composite cathode

We attempted to develop a disassembly- and reassembly-free Li pre-doping technique using perforated electrodes in order to develop Li-ion batteries containing a rubber-derived sulfur composite cathode. The Li pre-doping of the anodes was performed using perforated electrodes by external shorting between the anodes and Li metal electrodes provided on both end parts of the stacked electrodes within the cell, in which the degree of the Li pre-doping could be determined by the open circuit voltage measurement between the anodes and Li metal electrodes. The Li pre-doping of the graphite anodes in the cell composed of rubber-derived sulfur composite cathodes and graphite anodes was successfully conducted using this technique without disassembly and reassembly of the cell. After the Li pre-doping treatment, a stable charge-discharge was achieved between the rubber-derived sulfur composite cathodes and Li pre-doped graphite anodes. The Li pre-doping technique using the perforated electrodes was demonstrated to be applied even for practical 5 Ah cell. Furthermore, the Li pre-doping of the SiO anodes could be achieved in the cell composed of the perforated rubber-derived sulfur composite cathodes and SiO anodes, in which the cell showed a stable cycling performance and excellent charge-discharge rate performance.

Application of the Falciform Ligament Patch for the Prevention of Duodenal Stump Leakage After Gastrectomy: Technical Report on a Case Series.

Background: Duodenal stump leakage (DSL) is a serious complication after gastrectomy. In this study, we developed a novel prevention technique using a falciform ligament patch (FLP) to prevent DSL among high-risk patients after gastrectomy. Materials and Methods: From January 2019 to July 2021, 14 patients who were judged to be at high risk for DSL during preoperative examinations or surgery were included in this retrospective study, and the FLP was applied to the duodenal stump. The falciform ligament was separated from the liver after duodenal transection during gastrectomy; the end part was used to cover the duodenal stump and was fixed using nonabsorbable polypropylene sutures. Results: In total, 14 patients who underwent FLP had one or two risk factors that were identified: 5 patients, gastric cancer duodenal invasion; 4 patients, gastric outlet obstruction (GOO); 1 patient, cancer involving the distal resection margin; 1 patient, duodenal gastrointestinal stromal tumor involving the distal resection margin; 1 patient, gastric cancer duodenal invasion and GOO; and 2 patients, cancer involving the distal resection margin and GOO. FLP construction was successful, and no patient developed complications of DSL. The average hospital stay was 11.9 days, and the patients were discharged without any morbidities after surgery. Conclusions: Therefore, the FLP can be used to prevent DSL among high-risk patients after gastrectomy.

Design of Antennas through Artificial Intelligence: State of the Art and Challenges

The antenna is a critical part of the RF front end of a communication system. In this study, we present some of the major applications of artificial intelligence (AI) to antenna design. We review the previous research and applications of several AI techniques such as evolutionary algorithms, machine learning, and knowledge representation ontologies. Applications may vary from antenna design to antenna features evaluation in a research field, which is rapidly growing. Finally, we summarize the challenges of new AI techniques in antenna design based on the current state of the art and predict its future research directions.

Aligning Orifice of the Renal Artery with Fish-Mouth FIXation Technique During Endovascular Aortic Aneurysm Repair for Hostile Neck Anatomy.

Background: As the success of endovascular aortic aneurysm repair (EVAR) depends on sufficient proximal fixation of the endograft to the aortic wall, the proximal hostile neck anatomy (HNA) is the major potential treatment-limiting factor in EVAR. The Aorfix endovascular stent graft was designed to operate on highly angulated aortic necks. The Aligning Orifice of the Renal artery with fish-mouth FIXation (AORFIX) technique uniquely and accurately aligns the trough part of the proximal stent end with the orifice of the lower renal artery and is used to optimize the proximal fish-mouth design for maximum proximal seal use. Herein, we aimed to evaluate the usefulness of the AORFIX technique for EVAR in patients with HNA. Methods: Eighty-one consecutive patients who underwent EVAR with the AORFIX technique (+AORFIX technique group, n = 16) and without (standard group, n = 65) were evaluated. The HNA was defined as any of the following: neck angulation ≥60°, neck length ≤15mm, or neck thrombus or calcification ≥50% of the circumference and conical neck. Results: Each HNA criterion was similar between the two groups. However, the average number of HNA criteria was significantly higher in the +AORFIX technique group (1.9 ± .2 vs. 1.3 ± .1; P < .01). The two groups showed 100% procedural success. The concurrent renal angioplasty and stenting rates (88% vs. 4.6%; P < .01) were significantly higher in the +AORFIX technique group. There were no 30-day deaths in either group and no in-hospital device-related events in the +AORFIX technique group. The median follow-up period was 39months, and there was no significant between-group difference in freedom from reintervention rate (+AORFIX group vs. standard group, 100% vs. 91.0%; P = .327). Conclusion: EVAR using the AORFIX technique might be useful even in patients with more complex HNA.

Finite element comparative analysis of three different internal fixation methods in the treatment of Pauwels type III femoral neck fractures

BackgroundComparison of 4 cannulated lag screws (3 inverted triangular cannulated screws + anti-rotating screws;4 CLS), dynamic hip screws + derotational screws (DHS + DS), and femoral neck fixation system (FNS) in the treatment of Biomechanical properties of middle-aged Pauwels type III femoral neck fractures.MethodsThe femur CT data of a healthy young volunteer was selected and imported into Mimics software to construct a three-dimensional model of a normal femur. Pauwels type III femoral neck fractures were simulated according to the 70° fracture line. Use Geomagic and SolidWorks software to optimize and build CLS, DHS + DS, and FNS fracture internal fixation models. Finally, Ansys software was used to analyze the stress distribution, peak value, and maximum displacement of the proximal fracture fragment and internal fixation; the displacement distribution, and peak value of the fracture surface at the fracture end.Results① The stress peaks of the proximal fracture fragments in the three groups were concentrated near the femoral calcar. The peak stress of the FNS group was the largest, and the DHS + DS group was the smallest. ②The displacement of the fracture fragments was all located at the top of the femur. The peak displacement of the FNS group was the largest, and the DHS + DS group was the smallest. ③ The internal fixation stress of the three groups is concentrated in the middle part of the device. The stress distribution of the first two groups of models is more uniform than that of FNS. The peak stress of FNS is the largest and the CLS is the smallest. ④ The internal fixed displacements are all located at the top of the model. The peak displacement of the CLS is the largest, and the DHS + DS is the smallest. ⑤ The displacement of the fracture surface is in the upper part of the fractured end. The peak displacement of the FNS group was the largest, and the DHS + DS group was the smallest.ConclusionCompared with the other two internal fixation methods, dynamic hip screw + derotational screw (DHS + DS) showed good biomechanical stability. When Pauwels type III femoral neck fracture occurs in young adults, DHS + DS can be given priority as the preferred treatment for this type of fracture.

Experimental and Nonlinear Finite Element Analysis Data for an Innovative Buckling Restrained Bracing System to Rehabilitate Seismically Deficient Structures

This article presents experimental data and nonlinear finite element analysis (NLFEA) modeling for an innovative buckling restrained bracing (BRB) system. The data were collected from qualification testing of introduced BRBs per the AISC 341 test provision and finite element modeling. The BRB is made of three parts: core bar, restraining unit, and end units, in which duplicates of three different core bar cross sections (i.e., fully threaded, threaded notched, and smooth shaved) were tested. The BRBs introduced in this research come with innovative end parts, so-called fingers. These fingers provide the longitudinal gap required in every BRB system and simultaneously prevent buckling of the core bar at the end regions at both ends of the BRB sample, thus facilitating an easy core replacement if it gets damaged in the event of an earthquake. The measured parameters were the applied cyclic load and the corresponding displacement. Analysis of the acquired data illustrated an almost symmetric hysteric behavior with a little higher capacity under compression but a noticeable overall ductility of 4. Moreover, finite element modeling data for one type of core bar (fully threaded) were curated. The data presented in this paper will be valuable for fabricating BRBs in practice and further research on the topic considered.

Fault-Tolerant Control of Multi-Joint Robot Based on Fractional-Order Sliding Mode

In this paper, the problem of fault-tolerant control of actuators for multi-joint robots is studied. Aiming at the jitter problem in the design of fault-tolerant control law for conventional sliding mode controllers (SMC), a controller design method based on fractional-order sliding mode (FSMC) theory is proposed. At first, the mathematical model of the multi-joint robot is established and the fractional-order sliding mode surface is constructed according to the mathematical model. Then, the robust control law is designed based on the Lyapunov function. Finally, the experiments are carried out. Compared with the conventional sliding mode control, the experimental results show that the multi-joint robot is more stable under the control of fractional-order sliding mode, and it can achieve almost no jitter while tracking the reference. The steady-state error for joint1 and joint2 could reach 0.073 radians under the control of SMC, while it is 0.015 radians under the control of FSMC. The steady-state error data indicate that the fluctuation amplitude under FSMC is five times smaller than SMC for the end part of the multi-joint robot under actuator gain faults. The regulation time for joint1 and joint2 is about 0.11 s under the control of SMC, and it is around 0.04 s for FSMC. The regulation time is reduced to one of three or four. These data show the effectiveness of the FSMC proposed in this paper.

Implementation of the Haptic Tele-Weight Device Using a 10 MHz Smart Torch VLC Link.

Considering the prerequisite need for a protected e-commerce platform, absence of haptic interaction in head-mounted displays (HMD), and exploitation of faster communication technology, this research work aims to present an amended version of the tele-weight device that utilizes the 6G visible light communication (VLC) technology, is faster in performance, and deals with a heavier article. The enhanced version of the device is to be called the 'VLC tele-weight device' and the aim for the VLC tele-weight device is to get it affixed over the headset which will allow the user to have the weight-based sensation of the product ordered on the virtual store. The proposed device sending end and receiving end part performs communication over the VLC link. Furthermore, Arduino Nano is used as the microcontroller (MCU) in the project. Sending end circuitry measures the weight using the load cell and HX711 amplifier combination and transmits it via the connected LED. The pre-equalizer circuit is connected between the LED and sending end part to improve the bandwidth. On the receiver side, the post-equalizer circuit improves the shape of the received pulse. The received weight value is then displayed using the motor-gear combination. The sending end device is to be sited at the virtual store, while the receiving end is planned to be positioned over the VR headset. The performance of the device was measured by performing repeated trials and the percentage error was found to be between 0.5-3%. Merging the field of embedded systems, internet of things (IoT), VLC, signal processing, virtual reality (VR), e-commerce, and haptic sensing, the idea proposed in this research work can help introduce the haptic interaction, and sensational realization-based innovation in immersive visualization (IV) and graphical user interface (GUI) domain.