Static Device Research Articles

A Static Laser Weeding Device and System Based on Fiber Laser: Development, Experimentation, and Evaluation

To demonstrate the feasibility and improve the implementation of laser weeding, a static movable lift-adjustable closed fiber laser weeding device and system have been developed, followed by experiments and performance evaluations. Physical experiments were conducted on the energy required for laser cutting of weed stems, targeting four common larger weeds (Chenopodium album, Amaranthus spinosus, Setaria viridis, and Eleusine indica) in farmland and orchards. At the same irradiation distances, the energy required to cut the same type of large weed generally increases with increasing distances and stem diameters but decreases with increasing irradiation time. The variance of stems’ power density after irradiation was larger and the values were more dispersed for Chenopodium album and Setaria viridis weeds, and the values were relatively scattered, while the power density values of Amaranthus spinosus and Eleusine indica weeds were more concentrated. When the irradiation time was 10 s, the 3.892 W/mm2 laser was sufficient to eliminate weeds and plants with the irradiation distances of 2 m. The 2.47 W/mm2 laser was more effective, as it killed weeds within a distance of 1 m in less than 1 s. This work demonstrates the feasibility of the laser weeding device and system that can completely cut off the stems of large weeds, and this technology has the potential to promote sustainable agriculture.

A 10-year follow-up study on clinical outcomes of dental implant rehabilitation using surgical guide.

The surgical guide is a static computer-assisted device used for implant surgery planning and guidance. By taking an impression and referring to the patients' three-dimensional computed tomography scan of the desired implant site, a surgical guide can be created. During surgery, the surgical guide aids in achieving the designed implant placement position and direction. We examined and evaluated the long-term clinical outcomes of implant surgery using surgical guides. This study investigated a total of 15 patients with 32 implants that were placed using surgical guides from 2009 to 2011 with a mean follow-up period extended beyond 10 years. Patient demographics and implant survival rates were recorded. We analyzed marginal bone loss (MBL) by assessing the radiographs acquired at installation, three months after installation, and one month, one, two, and five years after prosthesis delivery. The mean patient age was 57.33 years at implant placement. Of the 32 implants, five implants were placed in the anterior region and 27 implants were in the posterior region. Six implants failed and three of them were replaced, resulting in an 81.25% survival rate. The mean follow-up period was 10 years and nine months. Mean MBL compared to post-installation was significantly higher than at three months after installation, and one month, one, two, and five years after prosthesis delivery. Mean MBL at three months after installation, and one month, one year, and two years were significantly higher compared to the previous visit (P<0.05). However, MBL at five years after prosthesis delivery did not differ significantly compared to at two years. In this study, implant rehabilitation assisted by surgical guides exhibited favorable survival rates. With the limitation of the sample amount in this study, further research and more samples are required to evaluate the long-term clinical effectiveness of surgical guides.

Static Strength Training Method for Type 2 Diabetic Mice.

The treatment of type 2 diabetes mellitus (T2DM) is a major difficulty in improving patient health. Exercise is one of the main interventions for T2DM. Static strength training is one of the key forms of traditional sports in China. Research shows that static strength training is an effective clinical method for T2DM intervention, but there is no experimental device suitable for static training in mice. One of the difficulties in moving from clinical to basic research is to design appropriate experimental devices. In order to further study the mechanism of static training intervention in T2DM, a simple method for making a static training device for mice is introduced in this paper. This device has the advantages of simple operation, cheap material, and high feasibility. Previous studies conducted under this protocol have shown that static training can effectively reduce blood glucose levels and improve the mitochondrial function of skeletal muscle cells in T2DM mice. The purpose of introducing this device is to promote research on the mechanism of traditional exercise in the intervention of T2DM and to lay a foundation for the quantitative intervention of exercise.

Isothermal vapor–liquid equilibria of binary mixtures containing (methanol, or propan-1-ol, or water, or acetonitrile) and 1-ethyl-3-methylimidazolium thiocynate ionic liquid: Measurements and modeling

Ionic liquid vapor–liquid equilibrium (VLE) measurements were performed on binary systems for1-ethyl-3-methylimidazolium thiocynate [EMIM][SCN] (2) + {methanol, or propan-1-ol or water or acetonitrile}(1) at range temperatures between 273.15 and 363.15 K. Experiments were undertaken at pressures between 15 Pa and 255 kPa using a static device. The reported data were successfully correlated by means of two models, namely NRTL or COSMO-RS, and the PC-SAFT equation of state. While results obtained in this study indicate that the phase behavior of systems involving the ionic liquid and alcohols, water or acetonitrile can be accurately described by these three models, it was found that experimental data may be represented with higher accuracy with PC-SAFT than NRTL and COSMO-RS models.

IoT based monitoring of distribution transformer

As transformer does not have any rotating parts hence it is called as static device, therefore it does not have mechanical losses, but internal stresses arose from abnormal system conditions like Over currents due to overloading on Transformer and short circuits, The faults can cause mechanical and thermal stresses inside the transformer winding and its connecting terminals. Thus transformer must be protected from above stresses. The aim of this project is to obtain real time data of transformer from remote places with the help of Internet of Things[ IOT] and then designing and implementing a Global system of Mobile communication [GSM] based technology to measure overvoltage, load current, and winding temperature. By measuring the condition of Transformer will help us to point out an any abnormalities before any serious damage that in turn leads to a greater credibility and significant cost savings

A comparative biomechanical study of the krackow suture technique with three common percutaneous suture techniques in the treatment of Achilles tendon ruptures

BackgroundThe aim of this study was to compare the biomechanical resistance under tensile forces of the Krackow suture technique with the frequently used Dresden, Carmont & Maffulli, and Ma & Griffiths percutaneous repair techniques in bovine models of Achilles tendon rupture. MethodsTransverse Achilles tendon rupture models were created from 4 cm proximal of the calcaneal insertion point in a total of 20 bovine Achilles tendon specimens. These were randomly allocated to 4 groups and repaired with configurations appropriate to the Dresden, Carmont & Maffulli, Ma & Griffiths and Krackow techniques. Failure mechanisms were recorded with force values (as Newton units) creating a 5 mm gap and load to failure under tensile loading at a rate of 10 mm/sec in a static testing device. ResultsIn the Dresden technique group, the force required for a 5 mm gap was mean 41.21 ± 13.19 N and for load to failure, mean 193.83 ± 30.16 N, which were evaluated as statistically significantly higher than in the other techniques (p < 0.05). The lowest values were determined in the Ma & Griffiths technique group (5 mm gap: 11.06 ± 8.12 N, load to failure: 97.73 ± 29.60 N) but these were not significantly lower than the values in the Krackow and Carmont & Maffulli technique groups (p > 0.05). ConclusionThe results of this study showed that the Dresden technique was biomechanically superior against tensile forces compared to the Krackow technique, and the other frequently used percutaneous techniques of Carmont & Maffulli and Ma & Griffiths.

Centre of mass of standard weights: another experiment with Lego and Tracker

Determine the centre of mass (CM) of standard weights is needed when two weights with different heights are compared. However, reproducing related experiments is difficult for high school or higher education institutions with non-expensive instrumentation or low budgets to construct specialised devices. This work addresses that problem in a two-way approach: dynamic video-based analysis and making a low-cost static device with Lego bricks. Published scientific papers support both methods. The experimental results of the video-based procedure were used to fit a polynomial regression model to find the CM location. On the other hand, the Lego device approach gives the ubication of the CM directly. Both methods were compared against geometric formulae publicly available to locate the CM of standard weights. The whole three stages project could be used in a senior high school or undergraduate physics course to teach about the comparison and compatibility of methods in experimental physics.

CSI-based WIFI Device Identification Solution

In recent years, wireless devices such as WIFI routers have become increasingly common in various fields. Rogue access point (RAP) is one of the threats that has persisted in wireless LAN (WLAN) for many years and can cause varying degrees of property damage and privacy leaks. In response to these threats, we propose a new security mechanism, called Rdi, which uses environment-independent features extracted from channel state information (CSI) as fingerprints for device identification. We found that the phase errors between multiple antennas on a single MIMO-OFDM (Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing) transmitter are not the same. This phase offset is due to the I/Q imbalance and imperfect oscillator of each WiFi network card, and it will not change with factors such as environment and time. Therefore, we inferred and verified that there must be some relationship between the phase errors of multiple groups of antennas, that is, the relative phase error (RPE). In addition, RPE will also vary with different WiFi devices. Compared with some similar fingerprint detection methods in the past, the use of specific connections between group phase errors between antennas can better reveal the different attributes between devices, thereby enhancing the uniqueness of features. Therefore, we believe that RPE can be used as an effective fingerprint to detect RAP attacks. We conduct a large number of experimental demonstrations on this, and innovatively built a multi-modal convolutional neural network (CNN) model to perform efficient classification work for our solution. Experiments on 22 WiFi devices and various scenarios show that the detection rate of Rdi can reach more than 98% in both dynamic and static device states.

Study of eco-friendly static gas-solid centrifugal separator

Gas-solid separation is a common process in many industries, including transport and power engineering. A static centrifugal multivortex device has been developed for effective separating fine particles from gas streams. The work aims to numerically study the efficiency and pressure drop of the separator. It was found that a choice of the turbulence model does not affect the pressure drop. The efficiency of the static centrifugal separator is 64.3% at the input gas velocity of 7 m/s. The sloped blades located above the apertures made in the internal pipe results in the improvement of separation efficiency. Moreover, changing the slope of the blades does not affect the efficiency of the separator. The hydraulic resistance coefficient of the developed device is on average 20.6, with a Reynolds number from 11400 to 38000. The low pressure drop provides reduced energy cost, which promotes decarbonization efforts.

Study of an Automated Static Leveling Test Device for Settlement Monitoring

Study of an Automated Static Leveling Test Device for Settlement Monitoring

Research on pressure transmission and sealing performance of pyrophyllite in a cubic large chamber static high-pressure device

Owing to the need for a hydrostatic high-pressure cubic large cavity (hexahedral top) press used in high-pressure research and production of superhard material, two kinds of pyrophyllite powder compacts (A and B) from pyrophyllite mine in South Africa are prepared, and compared with the domestic yellow pyrophyllite powder compacts (Mentougou, Beijing) produced by the same process, to establish experimental methods and physical criteria for evaluating the pressure transmission and sealing performance of pyrophyllite. During the experiment, standard pressure materials such as Bi, Tl, and Ba are used to &lt;i&gt;in-situ&lt;/i&gt; calibrate the pressure at the central positions and sealing edges of the pyrophyllite pressure chambers from the three aforementioned compacts under normal pressure conditions. Additionally, the silver melting point method is employed to obtain the corresponding relationship between chamber pressure at high temperature and system loading when using these three types of pyrophyllite as load-transmitting sealing materials. The results show that under the same hydraulic pressure loading, the difference in pressure at the central position between South African pyrophyllite B powder blocks and domestically produced pyrophyllite powder blocks does not exceed 0.1 GPa. Furthermore, in pressurization process and depressurization processe, the differences in pressure between the central position and the sealing edge of the pyrophyllite blocks are notably similar. Compared with South African pyrophyllite A powder blocks, pyrophyllite B powder blocks exhibit a closer resemblance to domestically produced pyrophyllite powder blocks in terms of high-temperature load transmission and sealing performance. Pyrophyllite B powder blocks from South Africa have the potential to serve as a substitute for domestically produced pyrophyllite without changing the existing superhard material synthesis process, making them promising candidates for use as load-transmitting media and sealing materials. These research findings hold significant academic importance in the realms of high-pressure research and superhard material production. They provide valuable insights into the selection of suitable transmission and sealing materials and the optimization of high-pressure experimental conditions. Additionally, this study presents robust method and criteria for experimental procedures and performance assessment.

Analisis Pengaruh Skala Warna dan UV-Vis Terhadap Tingkat Penuaan Isolasi Minyak

A transformer is a static device that can transfer electrical energy using the principle of electromagnetic induction. In operating conditions, the increase of temperature in the transformer will cause the oil insulation having disturbance, which will cause the quality of the insulation to decrease. In this research, oil isolation type shell diala b was chosen which was placed in an accelerated thermal aging chamber experiment device. Then shell diala b oil insulation is heated to a temperature of 120 °C and 160 °C with three sampling times. After this, the oil insulation characteristics were tested which includes oil color scale testing and UV-Visible spectrophotometric testing of the oil. The research method used refers to the IEC 60216-3 2006 standard for aging time and ASTM D-1500 COLOR SCALE for color scale testing. After testing the characteristics of shell diala b oil insulation, it was found that the value of the color scale had increased. Besides that, there has been an increase in the absorption of UV-Visible rays within the oil insulation, which causes the color of the insulation become darker as the temperature and the aging duration in the accelerated thermal aging chamber increases.

Pengembangan Uji Eksperimental Penuaan Dipercepat Sistem Isolasi Kertas Terendam Minyak Transformator

A transformer is a static electric device that is used to change the alternating voltage to a higher or lower level and is used to transfer energy from one electric circuit to another without changing the frequency. When the transformer is working, there is a temperature rise in the transformer which affects the degradation of the insulating paper and transformer oil. This accelerated aging tester applies the drying and vacuuming process as well as the arrangement of paper insulation racks to achieve maximum test results. The research method refers to IEC 60216-3 2006 for aging time, IEC TS 62332-1 2014 and IEC TS 62332-1 2011 as a reference for the Development of Accelerated Aging Experimental Test Cells for Transformer Oil-immersed Paper Insulation Systems. After achieving the existing goals, the addition of the drying process resulted in quite good Breakdown Voltage test results, not only that after the addition of vacuum it produced a good oil color according to ASTM D1500 as well as after the presence of paper placement racks the results of good tensile strength testing were proven by a graph which relatively decreased from sample 1 to sample 3.

Fabrication and Switching Performance of 8 A–500 V D‐Mode GaN MISHEMTs

In this work, the design, fabrication, static device testing, and double‐pulse switching performance of multi‐finger D‐mode GaN metal–insulator–semiconductor high‐electron‐mobility transistors (MISHEMTs) on silicon are discussed. Utilizing an metal‐organic chemical vapor deposition‐grown GaN high‐electron‐mobility transistors stack with a superlattice buffer, field‐plated devices with a meandering gate geometry and a total gate width of 30 mm are fabricated. Plasma enhanced chemical vapor deposition SiNx is used as the gate dielectric, followed by an optimized bilayer SiNx passivation scheme. Devices with 100 μm gate width have an ON/OFF ratio of ≈108. They are analyzed for dynamic Ron (normalized Ron = 3 at 100 μs) and time‐dependent dielectric breakdown for gate reliability, resulting in a β value of 2.65 from the Weibull plot. Devices with a 30 mm gate width exhibit a maximum ON current of 8 A at zero gate voltage and a three‐terminal breakdown of ≈500 V. The devices are diced, wire‐bonded to a printed circuit board, and a double‐pulsed test is performed for switching transient characterization under clamped inductive load. The OFF‐state and ON‐state energy loss are estimated to be Eon = 14 μJ and EOFF = 27 μJ, respectively, when switched at 5 A, 50 V. In this study, the potential of GaN MISHEMTs with bilayer SiNx passivation for low‐power D‐mode switching applications (5 A, 50 V) is demonstrated.

Four-Leg Sustained Dynamic Compression Staple and Screw Generates Superior Lapidus Construct as Compared to Plate and Screw: A Biomechanical Study

Category: Ankle; Basic Sciences/Biologics Introduction/Purpose: Lapidus procedures are frequently used to treat moderate to severe hallux valgus in the setting of first tarsometatarsal instability or arthritis. The push for early weightbearing can lead to nonunion rates reaching 12%. A growing number of surgeons are utilizing orthopedic staples manufactured from NiTiNOL in foot and ankle arthrodesis procedures. These staples are inserted in an “open expanded” state which enables application of sustained dynamic compression (SDC) between bony segments, which can persist even when challenged with joint settling / bony resorption. The biomechanical performance of these devices has not been quantified in the setting of Lapidus procedures. This study determined the optimum SDC staple construct during Lapidus procedures, and to compare their performance to traditional plate and screw construct in an established model. Methods: Lapidus procedures were performed on synthetic bone replicates (Sawbones) using three SDC staple constructs and one static device construct: (1) dorsal four-leg inline SDC staple, (2) dorsal four-leg inline SDC staple with medial two-leg SDC staple (3) dorsal four-leg inline SDC staple with plantar medial-distal to lateral-proximal cannulated screw and (4) dorsomedial plate and distal dorsal to proximal plantar cannulated screw (FigA). Samples underwent four-point bending with calibrated servo- hydraulic machine (MTS). Max load and construct stiffness was calculated. Interfragmentary contact force, area, and pressure was measured with pressure sensor (Tekscan) and joint plantar gap measurements were completed with 3D motion capture system (Motion Analysis). Testing consisted of stepwise loading to 1, 2, and 3mm of crosshead displacement. For brevity, only data from 3mm displacement test are included herein. Data were analyzed with one-way ANOVA with Dunnett’s post hoc test (N=5/group). Results: The four-leg inline staple + two-leg staple and the four-leg inline staple + screw groups exhibited a 2.5x (p=0.03) and 7.5x (p &lt;.001) increase in joint contact force as compared to the plate + screw group, respectively (FigB). The four-leg inline staple + two-leg staple and the four-leg inline staple + screw groups demonstrated a 3.5x (p=0.002) and 6.6x (p &lt;.001) increase in joint contact area as compared to the plate + screw group, respectively (FigC). The four-leg inline staple + screw group exhibited a 65.1% reduction in plantar gap as compared to the plate + screw group (p=.039, FigD). Conclusion: The four-leg inline staple + screw group exhibited the optimal Lapidus construct biomechanical properties (greatest joint contact force, greatest joint contact area, and least plantar gap). The biomechanical testing performed herein was undertaken to simulate loading akin to early post-operative weight bearing. These data highlight the ability of the four-leg SDC NiTiNOL staple in combination with a static screw to provide meaningfully increased joint compression, uniformity of joint compression, and decreased construct motion as compared to the standard plate + screw construct that is frequently used clinically.

Laser speckle reduction using polymer-stabilized liquid crystals doped with Ag nanowires

Miniaturized and pure static devices are expected to be used in laser-imaging systems for speckle reduction. In this study, a pure static device based on polymer-stabilized liquid crystal (PSLC) doped with Ag nanowires was developed to effectively suppress laser speckles. The concentrations of the polymer and Ag nanowires in the PSLC were optimized, and then the PSLC devices were fabricated. A measurement system was set up to characterize the electro-optical properties of the fabricated PSLC devices. Subsequently, a laser projection system was built to demonstrate the speckle-reduction performance. Moreover, the degree of scattering and response time of the developed PSLC devices were investigated and discussed. A PSLC doped with 0.02 wt% Ag nanowires and 3 wt% polymer having a device size of 2 × 2 × 0.1 cm3 was demonstrated to produce a speckle-reduction efficiency of 51.4 % under very low driving voltages. The experimental results verified effectiveness and superiority of the developed speckle reduction method based on PSLC doped with Ag nanowires.

Microseismic Signal Characteristics of the Coal Failure Process under Weak-Energy and Low-Frequency Disturbance

In deep mining, “critical static stress + slight disturbance” is an important inducing form of coal mine rockburst disasters. In previous studies, the critical static stress has been shown to be consistent with the loading direction of a slight disturbance but cannot reflect all types of rockbursts. In addition, the research that uses microseismic (MS) signals to reflect the overall process and critical stages of coal failure and instability under weak-energy and low-frequency disturbance conditions is immature, and more information, such as the critical state, has not been fully revealed. The aims of this paper are to further elucidate the important role of weak-energy and low-frequency disturbances in the occurrence of rockburst disasters. First, briquette samples were prepared from the Tashan Coal Mine, which is severely affected by rockbursts, and their homogeneity was verified using ultrasonic longitudinal wave velocity. Second, the natural frequency of the coal sample specimens was measured using a testing system. Then, based on the self-developed static pressure loading system, dynamic and static combined loading test system and MS signal monitoring device, the MS signal characteristics during the process of coal body failure and instability were comprehensively analysed. Finally, a comparison was made between weak-energy and low-frequency disturbances and impact disturbances. The results are summarized as follows. (1) The longitudinal wave velocity test results reflect that the briquette samples prepared in the experiment have high homogeneity. The smaller the particle size is, the higher the density and moulding pressure, and the denser the sample. (2) The natural frequency of the briquette samples is between 30.79 Hz and 43.34 Hz, and most of them fluctuate at approximately 35 Hz. (3) During the static loading stage, the occurrence of more than three MS signals of larger magnitude in a continuous cluster is an important criterion for the critical failure of the samples. (4) The weak-energy and low-frequency disturbance actually leads to fatigue damage, and the briquette sample experiences three stages: the near-threshold stage, the high-speed expansion stage and the final fracture stage. The smaller the particle size of the coal sample, the denser the specimen, the stronger the amplitude and energy of the single effective MS signal formed during the destruction process, the longer the time duration of crack expansion from the near-threshold stage to the high-speed expansion stage, and the stronger the ability of the coal sample to resist weak-energy and low-frequency disturbances. This study may contribute to a more comprehensive understanding of the destabilization mechanism of coal bodies and MS signal characteristics under weak-energy and low-frequency disturbances and provide a reference for further research and discussion.

Investigation on overbreak and underbreak of pre-stressed tunnels under the impact of decoupled charge blasting

Decoupled charge blasting has shown its superior performance in achieving smooth tunnel profiles in underground excavation. In this study, through establishing an underground tunnel blasting similarity modeling (UTBSM) test system that incorporates a static stress loading device (SSL), a highspeed digital image correlation device (DIC) and a 3D laser scanning device (3DLS), field blast tests with concrete models involving set-aside circular and rectangular openings are first conducted to examine the influence of filling medium on the depth and area of overbreak and underbreak. Subsequently, a 3D finite element model is developed using LS-DYNA and validated against one of the test results, and the influences of decoupled coefficient, decoupled charge mode, filling medium, and in-situ stress condition are comprehensively investigated. Finally, an energy analysis encompassing internal energy and kinetic energy is performed. The experimental and numerical results show that water-decoupled blasting results in the largest overbreak and smallest underbreak due to the highest internal energy and kinetic energy, and the expanded polystyrene foam (EPS) effectively reduces the blasting energy exerted on concrete so that causes the minimum overbreak depth and volume. Both the overbreak and damage in burden decrease with increasing decoupled coefficient. Radial decoupled charge mode produces a higher energy transfer efficiency than axial charge mode, whereas eccentric charge mode outperforms in controlling overbreak and improving the excavation efficiency. Additionally, the increase of in-situ stress leads to a reduction in overbreak depth and damage volume in the burden, indicating that in-situ stress plays a favorable role in overbreak control during contour blasting. However, the restraining effect of in-situ stress on rock fracture warrants sufficient attention as it may result in blasting failure.

HIGHLY SECURED TRANSFORMER LOAD SHARING SYSTEM USING MICROCONTROLLER

Abstract-The transformer is a static device, which converts power from one level to another level. The aim of the paper is to protect the transformer under overload condition by load sharing. Due to overload on transformer, the efficiency drops and windings get overheated and may get burnt. Thus by sharing load on transformer, the transformer is protected. This will be done by connecting another transformer in parallel through a micro-controller. The microcontroller compares the load on the first transformer with a reference value. When the load exceeds the reference value, the second transformer will share the extra load. Therefore, the two transformer work efficiently and damage is prevented. In this project three modules are used to control the load currents. The first module is a sensing unit, which is used to sense the current of the load and the second module is a control unit. The last module is microcontroller unit and it will read the analogue signal and perform some calculation and finally gives control signal to a relay. A GSM modem is also used to inform the control station about switching. The advantages of the paper are transformer protection, uninterrupted power supply, and short circuit protection. When designing low-voltage power system to the supply large load currents, paralleled lower-current modules are often preferred over a single, large power converter for several reasons. These include the efficiency of designing and manufacturing standard modular converters which can be combined in any number necessary to meet a given load requirement and the enhanced reliability gained through redundancy. Key Word: Transformer, Load Sharing, Microcontroller, Relay Driver

Static Ejection Test for Separation Analysis of 2,000lb-Class Store

Static ejection tests were conducted using the 2,000lb-Class Store to provide ejector model for the store separation simulation. In this study, static ejection test device for 2,000lb-class store was constructed and reaction force applied to store was measured over time. In addition, the trajectories of the ejected store were obtained using photogrammetry and compared with the simulations using developed ejector model. The results of the static ejection test were analyzed to determine the cartridge-orifice combination to be used for store separation. Flight tests were performed by applying the analysis results and verified that the store was safely separated from the aircraft.