bluuebunny/crossref_metadata_2025 huggingface dataset:
Sub-millimeter wave nanoantenna-a review
Authors: Mohan Nadar Akila P , Indhumathi K
Published: May 2023

Electromagnetic waves that have a wavelength of less than one millimeter are referred to as sub millimeter waves. In sub millimeter wave-based devices and systems, antennas are critical components that are vital to their operation. Antennas are used in situations when a transition between a directed wave and a free-space wave is needed. Since, electromagnetic characteristics for receiving and transmission of the nano antenna are mutually invertible, the properties of nano antenna are analyzed in sub millimeter wave frequencies and this overcomes the limitations of conventional antenna design. They are very small in size, provide more efficiency, and do not cause health threat. This paper reviews the applications of nano antenna, which operates at sub-millimeter wave frequency, in the field of energy harvesting, space technology, IoT applications, 5G network, smart clothing, bio sensing, communication, etc? Also, the nano antenna fabricated by 3D printing technology is also reviewed. The world’s ever-increasing energy need necessitates the development of alternate energy sources. There is a lot of research and development going on right now to enhance photovoltaic systems so that they can be more efficient, but the constraint is that they can only collect energy from the visible area of the electromagnetic spectrum. As a result, a novel device known as a Nano antenna has been developed to convert heat energy taken from the infrared spectrum into electricity. In the not-too-distant future, it will have an impact on a wide range of fields, such as mobile communication (5G), radar detection, and higher order frequency applications. Space communication, broadband wireless communications, wireless optical communication, and mobile communication will also benefit from its implementation.
Students’ Facial Expression Recognition Based on Multi-head Attention Mechanism
Authors: Dai Xiaojun , Wei Pengcheng , Zeng Yushan , Zhang Qi
Published: May 2023

As there are a far greater number of students in the classroom than teachers, it is difficult for teachers to grasp the learning of all students. Especially during the epidemic period, when online teaching becomes a trend, this problem is more prominent. The issue of how to grasp the learning of each student more comprehensively remains a problem to be solved in teaching. Under such circumstances, students’ facial expression recognition emerges as one of the most important solutions. In this paper, an improved facial expression recognition model based on the multi-head attention mechanism is proposed. The model is tested on two student expression databases, the JAFFE and the OL-SFED, and the recognition rate reaches 99.5% and 100%, respectively. In addition, to compare it with the models developed by other researchers, it is also tested on the RAF-DB, recording the best recognition rate of 90.35% and an average recognition rate of 83.66%, which represents the best level so far.
Modeling of Ship Turning Motion Prediction Based on BP Neural Network
Authors: Zhou Yue , Li Mingjie , Ma Jianwen
Published: May 2023

To more correctly grasp the ship turning performance and provide better references for initial design and safe handling of the ship, combined with the ship turning motion characteristics, a simulation prediction model of the ship turning motion is created by using the BP neural network method, which takes the transverse and longitudinal distance of the ship turning motion as the output. Within that study, the neural network model is trained by utilizing 12 real ship motion data as training examples. This research generates predictions using data from two more real ships as test samples once the training is complete. The discrepancy between the estimated and real ship outcomes is also compared, and the error is examined. The results verify that the constructed prediction model has stronger generalization ability and better accuracy, indicating that the model can successfully realize the simulation prediction for the ship turning motion.
Fault Diagnosis Method Based on CND-SMOTE and BA-SVM Algorithm
Authors: Wang Sheng , Ma Liling , Wang Junzheng
Published: May 2023

The problem of unbalanced data classification has gotten extensive attention in the past few years. Unbalanced sample data makes the fault diagnosis and classification accuracy rate low, and the capability to classify minority-class fault samples is restricted. To address the problem that the classification algorithm in machine learning has the insufficient capability to identify minority class samples for unbalanced sample data classification problems. Therefore, this paper proposes an improved support vector machine (SVM) classification method based on the synthetic minority over-sampling technique (SMOTE). For the sampler, an improved synthetic minority over-sampling technique based on the characteristics of neighborhood distribution (CND-SMOTE) algorithm is used to equilibrate the minority class samples and the majority class samples. For the classifier, the parameter optimization method of support vector machines based on the bat algorithm (BA-SVM) is used to solve the multi-classification problem of faulty samples. Finally, experimental results prove that the CND-SMOTE+BA-SVM algorithm can synthesize high-quality minority fault samples, increase the classification accuracy rate of fault samples, and decrease the time spent on the classification.
TS2VLGNN-based prediction of water temperature at the outlet valve of a valve cooling system
Authors: Zhou Hai-Jia
Published: May 2023

During the operation of a power grid system, devices such as converter valves generate much heat, which leads to a constant increase in the device’s operating temperature, thus significantly reducing the stability and safety of the system. The temperature of the valve cooling system is critical to the stability of the system. In this paper, according to the limitations of traditional multivariate time series prediction methods, such as harrowing feature extraction and poor prediction performance, we propose a model TS2VLGNN to predict the valve cooling system’s outlet water temperature. TS2VLGNN first extracts the features of system variables through the time series-representation learning method TS2Vec and then combines the advantages of LSTM and GNN in multivariable time series prediction. Meanwhile, the GNN module is improved to predict the water temperature at the outlet valve. During the comparative experiment, the model was compared with several models, and the experimental results verified that the TS2VLGNN model has higher prediction performance. Finally, ablation experiments demonstrated each component of the model’s effectiveness.
Study on decoupling control of bearingless motorized spindle
Authors: Meng Jie , He Lihong , Liang Xi
Published: May 2023

Bearingless motorized spindle is a kind of spindle structure that combines a bearingless motor with a motorized spindle. It has the advantages of a motorized spindle and a bearingless motor, which can further improve the speed of the machine tool spindle. However, its complex electromechanical structure and the coupling relationship between the subsystems make it difficult to control its operation process accurately. In this paper, the voltage control decoupling method is used to decouple the torque and suspension system of a bearingless motorized spindle with an independent inverse system, then control the systems. Finally, the control of decoupled bearingless motorized spindle is simulated. The results show that when the speed, rotor radial displacement, and rotor flux change respectively, they will not influence each other. The speed and radial displacement are unaffected after the sudden load is applied. It proves the effectiveness of the decoupling control method.
The Use of Brunel Harmonics of Elliptically Polarized Laser Pulses for High-Resolved Detection of Terahertz and Mid-Infrared Radiation
Authors: Silaev A A , Romanov A A , Vvedenskii N V
Published: May 2023

We study the generation of low-order harmonics during the interaction of helium atoms with intense elliptically-polarized laser pulses in the presence of a static electric field. Based on the solution of the three-dimensional time-dependent Schrödinger equation, the spectra of generated radiation are calculated for various pulse ellipticities, intensities, and static-field strengths. We show the possibility of using the second harmonic generation in the free-electron current density by laser pulses with arbitrary (even circular) polarization for high-resolved measuring the waveforms of terahertz and mid-infrared radiation.
Excitation of Semiconductor Nanosystems by Multy-Frequency Quantum Field
Authors: Tereshchenko I A , Tikhonova O V
Published: May 2023

The formation of Frenkel excitons in a 2D semiconductor nanosystem induced by frequency-multimode non-classical electromagnetic field is investigated. Strong sensitivity of excitation dynamics to the initial states of quantum field modes is found. The possibility to manage the excitation dynamics and controllably enhance a certain excitation channel by varying field frequency detuning and by choosing a proper initial state of the non-classical multimode field is demonstrated. The specific features of the excitation arising due to efficient coupling and energy exchange between initially independent field frequency modes are demonstrated. The polarization response of the considered nanosystem on the multi-frequency field impact is studied and its peculiarities arising due to the quantum features of the affecting non-classical light are found.
Study of a laser method to control the condition of coatings of titanium and magnesium alloys for medical cryo instruments
Authors: Mogilnaya T.Yu. , Pagava L.L. , Petelin N.A. , Medvetskova V.N. , Sagitova E.A. , Krit B.L.
Published: May 2023

The work is devoted to the creation of a laser method for monitoring the virucidal properties of nanocoatings of medical instruments. The relationship between the intensity of the spectra of washes from silver-doped coatings and the concentration of pathogens was studied. Plasmon resonance was obtained using a DFB laser in order to be able to develop this method.
Effects of Laser Irradiation at 1265 nm in Melanoma Cells
Authors: Khokhlova A. V. , Dolgova D. R. , Poludnyakova L. V. , Gilmutdinova A. K. , Zolotovskii I. O. , Saenko Yu. V. , Sokolovskii S. G. , Rafailov E. U. , Stoliarov D. A. , Pogodina E. S. , Ribenek V. A. , Antoneeva I. I. , Fotiadi A. A.
Published: May 2023

Melanoma is the most dangerous type of cancer, with a high rate of metastasis. The conventional method of treating skin melanoma is photodynamic therapy, yet this type of phototherapy has several side effects. In addition, the photosensitizers used are relatively expensive and toxic. Thus, developing methods of treating melanoma cancer using laser only is a promising area of research.

Here we present in vitro effects in melanoma cell culture after 1265 nm laser irradiation exposure.
Nanoscale Sensing Glass Transition of Nanoconfined Polymers Through Thermoplasmonic
Authors: Chernykh E A , Kharintsev S S
Published: May 2023

It is known that downsizing of polymers at the nanoscale causes their physical properties, such as glass formation temperature, to deviate from the corresponding bulk properties. This fact requires the control of such parameters, since today nanoscale polymers are part of the architecture of many devices and are becoming increasingly important in modern technologies. To register temperature parameters in nanosized materials, localized heat sources are required. These can be metal nanostructures that generate heat on a nanoscale under the action of light. Enhanced absorption under conditions of plasmon resonance makes it possible to induce heat at the nanoscale and, therefore, as a result, plasmonic nanostructures can act as nano-heaters. We propose an approach to create enhanced heating of plasmonic nanostructures by nanostructuring the substrate surface (thermostat), which is demonstrated on titanium/silicon nitride (TiN:Si) hybrid structures using Raman thermometry. Using this approach, we detect the local glass transition temperature in nanosized polymers (PMMA and PMMA-DR1) by heating it with a thermoplasmonic metasurface using Raman spectroscopy.
Fragmentation of a trapped bosonic mixture
Authors: Alon O E , Cederbaum L S
Published: May 2023

Fragmentation of bosons and pairs in a trapped imbalanced bosonic mixture is investigated analytically using an exactly solvable model, the generic harmonic-interaction model for mixtures. Closed-form expressions for the eigenvalues and eigenfunctions of the reduced one-particle and two-particle density matrices as a function of all parameters, the masses, numbers of bosons, and the intraspecies and interspecies interactions, are obtained and analyzed. As an application, we consider a system made of N
1 = 100 non-interacting species 1 bosons embedded in a bath made of N
2 = 106 non-interacting species 2 bosons, and show how fragmentation of the system’s bosons and pairs emerges from the system–bath interaction only. Interestingly, the lighter the bosons comprising the bath are the stronger is the system’s fragmentation. Further applications are briefly discussed.
Vacuum Birefringence Measurement via All-Optical Interferometric Schemes
Authors: Ataman Stefan
Published: May 2023

All-optical vacuum birefringence experiments will get increasingly closer to feasibility as multi-petawatt laser facilities become operational around the World. Thus, the availability of focused laser intensities in the order of IL
∼ 1022 −1024 W/cm2 are to be expected in a focused spot size ∼ 3 − 5 μm. With these values, vacuum refraction indices in the order of Δn ∼ 10−11 − 10−9 are possible with an induced phase delay on a counterpropagating optical probe beam in the order of Δφ ∼ 10−9 −10−7 radians. We discuss two all-optical interferometric schemes and detail the Mach-Zender interferometric proposal. We consider this interferometric scheme fed by both classical and non-classical input light and with two detection schemes. We outline scenarios that are likely to lead to a feasible experimental implementation.
The worldline formalism in strong-field QED
Authors: Schubert Christian
Published: May 2023

The worldline formalism provides an alternative to Feynman diagrams that has been found particularly useful for external-field calculations in quantum electrodynamics. Here I summarize its present range of applications, which includes Schwinger pair creation, photon splitting in constant fields and plane-wave backgrounds, as well as non-linear Compton scattering in constant fields.
Optimal Voltage Control of Wind Farm with Distributed Energy Storage System
Authors: Wang Pengda , Shen Feifan , Huang Sheng , Shen Yangwu , Zhang Min , Zhang Yuzhou , Sun Jieyi , Le Xuxin , Pang Jiameng
Published: May 2023

This paper proposes an optimal voltage control method for a wind farm (WF) combined with distributed energy storage systems (DESSs), where the DESSs are connected to the DC sides of wind turbines (WTs). In the proposed control method, the WT units and DESSs can be coordinated to minimize the voltage fluctuation of terminal buses, minimize the distance between the voltage of terminal buses and rated value, and minimize power losses inside the WF collection system. The optimal control (OPC)-based voltage control model is formulated to generate optimal active/reactive power output of WTs and active power output of energy storage units in the WF with DESSs. The DESSs can store active power from WTs to support more capacity of the reactive power output of WTs. The control performance of the proposed voltage control method based on OPC is validated by conducting case studies on the WF with 32*5 MW WTs.
Studies on Three-phase Imbalance Treatment Based on Beidou communication and Commutation Switch
Authors: Guo Jiangtao , Liu Lulu , Wang Tianjun , Jia Junqiang , Wei Maosheng
Published: May 2023

In this paper, genetic algorithm and commutation switch based three-phase imbalanced distribution network are studied. A genetic algorithm-based commutation switch three-phase imbalance management strategy was developed, and the three-phase current distribution station area was established. A mathematical model was developed for the multi-objective optimal commutation based on the minimum imbalance degree and the minimum switching times of the low-voltage load online automatic commutation device during the commutation process. Additionally, the real-time online governance control strategies were balanced. Finally, the effectiveness of the proposed method was verified using simulation studies.
Fault analysis of photovoltaic inverter
Authors: Zhang Xiuqi , Liu Hongqing , Miao Lifang
Published: May 2023

Photovoltaic power generation is one of the main forms of new energy utilization, and the reliable operation of a photovoltaic inverter, as the main component of a photovoltaic power generation system, is of great significance. Studying and mastering the faults of photovoltaic inverter and taking preventive measures is very important to ensure the stable and efficient operation of the photovoltaic power generation system. This paper expounds on the development of photovoltaic power generation and the composition of the photovoltaic power generation system, summarizes the typical faults of a photovoltaic inverter, analyzes the causes of the faults, and on this basis, puts forward the improvement measures to avoid the faults.
Numerical simulation of pneumatic transport of pulverized coal particles in pipelines
Authors: Tian Mingbo , Cheng Zhihai , Kang Zhifeng
Published: May 2023

Coal powder transportation technology is usually used in power plant, chemical industry and other industries. The forces of pulverized coal particles are very complicated and changeable during transportation, this study used pulverized coal particles as transport materials to carry out transport experiments. Computational fluid dynamics (CFD) method was used to model and analyze the flow of pulverized coal particles through the powder feeding pipe in fluidized pneumatic transport, and its gas-solid flow characteristics were numerically simulated. In CFD simulation, discrete phase model is used to analyze the flow behavior of Coal powder. On this basis, the influence of flow characteristics of pulverized coal particles on the formation of output deviation of different pipelines is studied. The deviation from the minimum wind speed is calculated through simulation. The simulation results show that there is a negative correlation between the particle velocity of pulverized coal and the output deviation of the pulverized coal feeding pipe, which provides a reference for further understanding the output deviation characteristics of the pulverized coal feeding pipe.
Analysis of synchronous oscillation of MMC-HVDC in offshore wind farm
Authors: Yan Renwu , Fu Fuwei
Published: May 2023

Due to the special meteorological conditions of offshore wind power generation and the large wind turbines used, offshore doubly-fed wind turbines have larger shafting elastic coefficients than onshore doubly-fed wind turbines. When the offshore wind farm is connected to the grid through MMC-HVDC, two kinds of sub-synchronous oscillations are caused. One is the natural torsional vibration of the wind turbine shaft system, and the other is the sub-synchronous oscillation caused by the interaction between the wind turbine and the devices in the MMC-HVDC converter control system. In view of the above problems, the MMC-HVDC grid connection model of the offshore doubly-fed wind farm is established. The eigenvalue analysis method and participation factor are used to identify the oscillation mode of the interaction between the wind turbine shafting torsional vibration and the converter device, as well as the corresponding strong correlation state variables. According to the correlation of the state variables obtained, the parameter suppression strategy of the CCSC controller based on MMC valve optimization is proposed. The effectiveness of the proposed suppression strategy is verified by PSCAD/EMTDC electromagnetic transient simulation software.
A non-resonant piezoelectric sensor for measuring 50Hz or 60Hz electric currents
Authors: He Wei , Niu Sixian , Luo Mingshan , Liu Shuanghua
Published: May 2023

A non-resonant piezoelectric sensor for measuring power-frequency (50 Hz or 60 Hz) electric currents is proposed to be applied in electric power systems. The device consists of a magnetic circuit, two piezoelectric plates, and fixed plates. The magnetic circuit is made up of three NdFeB magnets and two permalloy yokes. The high sensitivity of the device is attributed to the magnetic field concentration and the induced shear stresses. A prototype has been fabricated and the feasibility of the self-powered sensor was validated. The average sensitivity reaches 28.56 mV/A in the range of 1 A to 10 A, and the accuracy is 0.02089 mV at a current of 3.5 A. A current variation of 0.02 A is distinguished under the non-resonant condition of 50 Hz. The self-powered, highly sensitive, non-resonant, and high-resolution characteristics make the device favorable for measuring real-time electric currents in electric power systems.
Primary Frequency Control of Wind-solar-storage Power Station Considering Discrete Control Nonlinearity
Authors: Zhang Xiaodi , Wang Cheng , Bi Tianshu
Published: May 2023

With the gradual advancement of dual-carbon goals, the wind-solar-storage power station has become the mainstream trend in constructing new energy stations due to their wind energy and luminous complementary characteristics. However, the current research on primary frequency control of new energy stations is still focused on a single-machine strategy. The communication delay and control period caused by long control links are not considered. It is difficult to describe the influence of the difference in dynamic characteristics of wind-solar-storage power on primary frequency control performance. Therefore, this paper takes the multi-layer control link wind-solar-storage power station as the research object, establishes the nonlinear control model considering the influence of control delay and control period, and puts forward the wind-solar-storage power plant primary frequency control method, which is suitable for participating in the frequency control of power grid.
A Power Grid Fault Diagnosis Method Considering Online Dynamic Alarm Information
Authors: Du Mingxuan , Wang Zirui , Zhang Ziqi , Wang Yixian , Zhang Xu
Published: May 2023

With the continuous development of the smart grid and the gradual improvement of the demand for grid reliability and power grid self-healing capability, a large number of artificial intelligence technologies have been applied to the power grid. In order to improve the automation of the power grid, realize automatic fault identification and diagnosis after a power grid failure, and improve the efficiency of fault handling by the dispatching department, it is of great practical significance to use alarm information to achieve accurate fault judgment. However, the difference between the dynamic reading of alarm information flow and static samples in engineering applications is often ignored in the research of fault diagnosis using alarm information, which makes it difficult to apply fault diagnosis methods in engineering practice. Based on the characteristics of the LSTM algorithm, such as deep knowledge extraction ability, data mining ability and time series knowledge processing ability, this paper studies the power grid fault diagnosis method based on LSTM to adapt to the data of each sampling time window in the process of online fault diagnosis, solves the problems faced by the application of traditional diagnosis methods in engineering practice, and effectively improves the reliability of fault diagnosis.
Influence of Rubber Particles on Performance of Asphalt Mixture
Authors: Wang Xiaoming
Published: May 2023

The rubber material produced by waste tires greatly pollute the environment. Adding it to the asphalt mixture can improve its performance of the asphalt mixture. The elastic asphalt pavement paved with it has strong durability and can reduce the noise hazard to a certain extent. Adding large-diameter rubber particles into asphalt pavement materials can inhibit pavement icing and reduce the probability of traffic accidents caused by pavement skidding in winter. The results show that with the increase of the content of rubber particles, the ability of pavement to suppress ice formation is enhanced. However, when the temperature is below zero, with the decrease of temperature, the ice suppression effect of elastic material pavement is weakened; When the temperature is lower than -14 °C, the anti-icing performance of rubber particle asphalt pavement reaches the limit.
Study on Sound Absorption Performance of Aluminum Foam Combination
Authors: Jiang Tairu , Wang Yonghua , Xu Jinkai , Yu Huadong
Published: May 2023

Aluminum foam is a kind of new material with a large number of holes distributed in aluminum alloy. It has the characteristics of lightweight, sound absorption, energy absorption and vibration reduction, and other porous materials. Aluminum foam has good acoustic performance. However, its excellent sound absorption ability is only reflected in the middle and high-frequency bands. Besides, the low-frequency sound absorption ability is very poor and the frequency band is narrow. Therefore, in this paper, different types of perforated aluminum foams with different parameters are combined to explore the influence on acoustic performance and find that the combination of large porosity perforated sample and aluminum foam has a better sound absorption effect. The unperforated sample is placed in front of the perforated sample to improve the sound absorption coefficient of the low and medium frequencies. Finally, different types of perforated aluminum foam samples were properly combined, and it was found through the test that almost all sound waves in the band of 1200 HZ~2000 Hz could be absorbed by the combined structure.
Study on Biodegradation Rate of Konjac Polysaccharide Aerogel Filter Rod
Authors: Wang Hao , Xu Yueming , Zheng Han , Xie Jiao , Yue Baoshan , Wang Xixuan , Yu Yao , Wang Xu , Yu Tingting , Yu Jiang , Zhan Jianbo
Published: May 2023

The konjac polysaccharide aerogel filter rod has the functions of high filtration efficiency and cooling. The biodegradation rate of konjac polysaccharide aerogel filter rod prepared by vacuum freeze drying machine was studied in this paper. The results showed that at the end of the degradation experiment (the 106th day), the biodegradation rate of konjac polysaccharide gel filter rod reached 84.9%, which was close to the degradation rate of thin-layer chromatography grade cellulose, indicating that it had good biodegradability.
Discussion and application of ball mill in preparation of particle size samples of fine grained sedimentary rocks
Authors: Huang Lina
Published: May 2023

The grain size of clastic rocks is one of the most important structural characteristics of clastic sediments, which can directly reflect the hydrodynamic conditions of ancient sedimentary period. The preparation of conventional clastic rock particle size samples is usually done by hand wet grinding with a grinding hammer by experienced experimenter. For the fine-grained sedimentary rocks, the conventional method for preparing grain size samples has the disadvantages of long time and low efficiency. This paper introduces a method of preparing grain size samples of fine grained sedimentary rocks by separating rock particles with ball mill. By carrying out the experiments of separating rock particles by ball mill, the influence of different sample quality and ball mill parameters on the particle size and particle size distribution of fine grained sedimentary rock in the process of rock particle fragmentation by ball mill was discussed. The conditions for separating particles of fine grained sedimentary rocks by ball mill are determined as follows: sample mass is 0.14 g ~ 0.20 g, ball mill frequency is 10 Hz, ball milling time is 3 min, the efficiency of particle size sample preparation is greatly improved. The final particle suspension samples were tested by laser particle size analyzer, and the particle size distribution characteristics of fine-grained sedimentary rocks were given, which provides a basis for the study of lithology classification, lithofacies characteristics and hydrocarbon reservoir heterogeneity, and plays an important role in the exploration and development of unconventional oil and gas.
Luminescence properties of glass ceramics doped with Tb4O7 and containing Na3Gd (PO4)2
Authors: Chen Xi , Jia Wentao , Zhang Hongbo
Published: May 2023

It has been determined that 374 nm is the optimal excitation wavelength for Tb4O7 doped glass ceramics. XRD, SEM, UV spectrophotometer, and photoluminescence spectroscopy were used to study glass ceramics morphology and luminescence properties. 730°C is the optimal temperature for crystallizing. At 0.4mol% Tb4O7 concentration and 2h crystallization time, this is the optimum solution. The results of this study indicate that glass-ceramics doped with Tb3+ can be applied to green lasers and other systems.
Analysis of Constraint Factors for Bridge Maintenance in Poso District
Authors: Fauzan  , Nirmalawati  , Kusnindar
Published: May 2023

Bridge maintenance is a routine activity that must be carried out by the manager but the implementation of bridge maintenance in the Poso Regency has various obstacles. So the research will be carried out to know the constraint factors in the implementation of bridge maintenance. This type of research is descriptive, population of PUPR employees in the field of maintenance and contractors who have handled bridge maintenance projects, totalling 40 respondents. Calculation of data analysis using factor analysis. The results showed that there were six factors that hindered the implementation of bridge maintenance, namely: (1) Implementation of Construction Management during procurement & execution of work, (2) Project Resource Planning & Weather, (3) Implementation of project resources and communications, (4) Monitoring of project resources and resource conditions, (5) Commitment and material availability, (6) The quality of equipment in the field. The six factors influence 80,462%, and the remaining 19,538 % are influenced by other factors. It is suggested that the management needs to make these six inhibiting factors as a reference in determining the strategy or planning for the implementation of routine maintenance projects.
Numerical Study of Castellated Beam with Stiffener – Case on Cantilever Structure
Authors: Haris S , Sari P K , Masrilayanti
Published: May 2023

A castellated beam is designed to increase the depth of the beam by slicing the beam web longitudinally in a specified form and re-unite both pieces using welding to obtain a higher flexural capacity of the beam. Due to the increase in cross-sectional height and the presence of openings in the web plate, some potential failures may occur, for example buckling of the web and stress concentration on the opening. Addition of stiffener on the web is useful to prevent those potential failures. This paper presented a numerical study of castellated beam with additional stiffeners which is applied on a cantilever structure using MSC Nastran software. The castellated beam was added by stiffeners placed on three different zones. There were stiffeners on the perimeter of opening, on the web between openings, and on the web of opening. The cantilever beam was subjected by a point load increased monotonically until ultimate condition reached. It was found that applying of the stiffeners on perimeter of opening will increase ultimate load up to 7.48 % comparing to the original castellated beam. On contrary, stiffeners on the web between openings and the web of opening will decrease the ultimate load within the range of 0.40% - 4.86 %. The beam stiffness will slightly increase because of these three types of additional stiffeners. Regarding ductility of the beams, adding of stiffeners on the castellated beam showed vary numbers. Overall, the stiffeners on perimeter of opening become an alternative to increase the performance of the castellated beam in term of the ultimate load, beam stiffness and ductility.
Enhanced digital water level measurement for irrigation channel
Authors: Loekito J A , Tallar R Y , Pattipawaej O , Sutandi M C , Sihombing T O , Yapinus P P , Chandra J , Tanubrata M , Lesmana H , Karsten L , Tonny  , Efferiki  , Madvi H A S P , Purba F P
Published: May 2023

Indonesia needs to improve its irrigation system by implementing respectable technology. Recently, Indonesian irrigation systems have intended to switch from analog to digital technology. However, it appeared that Indonesia was having some issues applying digital technology in many areas. For instance, delivering water from water sources to irrigation subversives requires a computer infrastructure. A manual water level monitoring tool has been used in irrigation canals to gauge the water level that flows through them. The major goal of this project is to design a digital measuring device for water level and water temperature in the irrigation channel. The appropriate information must be entered into the irrigation channels. An experimental investigation has been conducted into the accuracy of digital instrument design for detecting water level and water temperature in irrigation channels. The creation of the digital water level measurement design will be tested against manual measurement to determine the percentage difference. The percentage difference between the traditional water level measurement and the digital water level measurement is the anticipated outcome. It is possible to infer that it is crucial to use digital tools, especially when determining the water level in irrigation channels.
A conceptual framework for implementing lean construction and building information modeling (BIM) in post-disaster housing reconstruction projects
Authors: Syaputra T A , Rarasati A D
Published: May 2023

The occurrence of natural disasters in Indonesia every year results in massive damage to people’s homes. It requires a fast and appropriate post-disaster housing reconstruction (PDHR) strategy. The building firm or contractor is among the most significant contributors; in post-disaster conditions, the contractor has to work in a project environment that is much more complicated than conventional projects, and this often results in poor contractor performance. An approach to improve contractor performance is the application of Lean Construction. In line with this linking, the function of the Building Information Modelling (BIM) tool in the application of Lean has also proven effective in conventional projects. However, studies focusing on its simultaneous application to PDHR projects are still lacking. A conceptual framework that can be applied to specific Lean and BIM implementations in PDHR projects is needed to address this issue. This paper proposes a conceptual framework by identifying and analyzing various previous studies as a proper basis. The study shows several Lean Construction and BIM factors relevant to contractor performance indicators in post-disaster housing reconstruction projects.
Utilizing information technology towards reducing forest and peatland fire risk in Riau Province, Indonesia
Authors: Eklou R J , Widana I D K K , Suwito
Published: May 2023

Forest and peatland fires have become a seasonal challenge experienced in Riau Province. This disaster causes huge economic and environmental losses, accompanied by its alarming impact on human health. The haze as a result of land burning in this province is known to disrupt activities in neighbouring countries causing political and diplomatic tensions. To reduce the risk of forest and peatland fire, the Riau Regional Police developed the Lancang Kuning Nusantara (LKN) digital application. This study examines the general role of the application in reducing forest and peatland fire risks. A qualitative descriptive approach is adopted in analysing the primary data obtained through focus group discussion. Data from secondary sources were also obtained. Results from this study indicate that the use of the LKN digital application in Riau Province has helped immensely in the area of disaster risk communication and logistics support.
Effects of argon plasma pretreatment of Si wafers on Si-Si bonding based on Mo/Au interlayers
Authors: Qu Yongfeng , Bai Haiyang , Hu Wenbo , Yuan Yuan , Wu Shengli , Wang Hongxing , Fan Huiqing
Published: May 2023

To improve the bonding quality of Si-Si wafers bonded based on Mo/Au intermediate layers at room temperature, the surfaces of Si wafers were pretreated with argon plasma, and the effect of argon plasma pretreatment on Si-Si wafer bonding was analyzed by combining experimental and theoretical methods. Owing to the plasma treatment of Si wafers, the surface roughness of Si wafers was significantly reduced, and the bonded Si-Si samples had lower interfacial voidage. The average bonding strength of 11.46 MPa for the argon plasma pretreated Si-Si bonded samples is much higher than the bonding strength of 4.23 MPa for the unpretreated Si-Si bonded samples. The analysis of the fractured surface revealed that the fracture of the Si-Si bonded samples without argon plasma treatment occurred mainly at the Mo/Si interface, while the fracture of the plasma-treated Si-Si bonded samples arose mainly within the bulk Si. Molecular dynamics (MD) simulations suggest that strong atomic diffusion takes place at the Mo/Au interface, while Mo atoms hardly diffuse into the bulk Si. These results indicate that argon plasma pretreatment not only cleans and activates the Si wafer surface but also makes the Si wafer surface smooth, which helps to enhance the deposited Mo/Au film quality and the adhesion between the Mo film and the Si wafer.
Polarity switching via defect engineering in Cu doped SnSe0.75S0.25 solid solution for mid-temperature thermoelectric applications
Authors: Athithya S , Jibri K P Mohamed , Harish S , Hayakawa K , Kubota Y , Ikeda H , Hayakawa Y , Inatomi Y , Navaneethan M , Archana J
Published: May 2023

Solid solution SnSe0.75S0.25 has potential to improve thermoelectric performance via ultra-low thermal conductivity as compared to the pristine SnSe which originates from phonon scattering due to disordered atoms of selenium (Se) and sulfur (S). SnSe0.75S0.25 and Cu-doped SnSe0.75S0.25 compounds were prepared via high energy ball milling and pelletized by a spark plasma sintering (SPS) process. Dislocation and point defects were successfully introduced by SnSe0.75S0.25. The existence of S in the Se site induced mass fluctuation which favors high-frequency phonon scattering. This leads to an impressively ultra-low thermal conductivity (κT) value of 0.258 W mK−1 at 753 K for SnSe0.75S0.25. Next, the Cu dopant was selected to enhance the electrical conductivity, which improved from 514.44 S m−1 (SnSe0.75S0.25) to 725.08 S m−1 for Sn0.98Cu0.02Se0.75S0.25 at 738 K. Interestingly, the Cu dopant induced nanoprecipitates of Cu2Se inside the grains, which further strengthens the phonon scattering. The Cu2Se nanoprecipitates and various defects at the grain boundaries contributed to a lower κT of 0.295 W mK−1 at 753 K for a Sn0.94Cu0.06Se0.75S0.25 sample. Moreover, the maximum figure of merit of (ZT) ∼0.19 at 738 K was attained for the Sn0.98Cu0.02Se0.75S0.25 sample.
Innovative instrumentation to strong reduction of the noise levels inside newborn incubators used in the neonatal intensive care units
Authors: Ramos Paulo Roberto Medina , Zebende Gilney Figueira , Cruz Juan Alberto Leyva
Published: May 2023

In spite of the advent of medical technology, modern newborn incubators (NIs) do not protect them from high noise levels in the neonatal intensive care units (NICUs). Allied to bibliographical research carried out measurements were made inside the dome of a NIs and the results show that the sound pressure levels, or noises, are much more intense than the levels stipulated by the norm NBR IEC 60.601.2.19 of ABNT. These measurements revealed that the NIs air convection system motor is the main source of excess noise. In view of the above, a project was developed with the objective of significantly reducing the noise level inside the dome by modifying the air convection system. Thus, a quantitative study was developed, based on the experimental method, where a ventilation mechanism was designed, constructed and tested, which operated from the network of medical compressed air, present in the NICUs and maternity rooms. Respectively, before and after the modification of the air convection system, the data of relative humidity, air velocity, atmospheric pressure, air temperature and noise [(64.9% ur/33.1% ur); (0.27 m s−1/0.28 m s−1); (1.013.98 hPa/1.013, 60 hPa); (36.5 °C/36.3 °C); (45.9 dBA/30.2 dBA], were collected by electronic meters that registered the conditions of the external and internal environment of the dome of an NI with a passive humidification system. The noise measurements in the environment showed that there was a strong reduction of 15.7 dBA, or 34.2% of internal noise, measured after the modification of the ventilation system, showing a significative performance of the modified NI. Therefore, our results may be a good choose to improve NI acoustics to enable optimal care of the neonate in the neonatal intensive care units.
Noise reduction and power generation in blower duct using Helmholtz resonator with piezoelectric diaphragm
Authors: Tadokoro Chiharu , Ito Takuma , Nagamine Takuo
Published: May 2023

Ventilation duct systems are indispensable for air purification and room temperature management in industrial and commercial buildings. The noise generated by blowers for ventilating spaces should be as low as possible. In addition, to power the wireless nodes for monitoring the ventilation conditions such as temperature and pressure at any positions in all the ducts, electric power is preferred to be generated in situ without batteries and wired power supply. In this study, to demonstrate simultaneous noise reduction and in situ power generation using a Helmholtz resonator with a piezoelectric diaphragm in a straight circular pipe duct, the frequency properties of the sound pressure level (SPL) with/without the piezoelectric diaphragm and its generated voltage were measured using an in-house apparatus simulating an industrial blower duct. The experimental results show that the Helmholtz resonator with the piezoelectric diaphragm has a noise reduction performance similar to that without the piezoelectric diaphragm. Power generation was improved not only by impedance matching between the inner and outer resistance but also by the frequency resonance between the frequency of pressure fluctuation in the Helmholtz resonator and the natural frequency of the piezoelectric diaphragm. The Helmholtz resonator with the piezoelectric diaphragm achieved a noise reduction of 10 dB from an SPL of 103 dB and power generation of 12 μW at an SPL of 93 dB.
Comparison of Complication Rates Between Subpectoral vs Prepectoral Techniques in Prosthetic Breast Reconstruction
Authors: Hung Ya-Ching , McCarthy Jack T , Park Benjamin C , Chaker Sara C , Saad Mariam , Braun Stephan A , Perdikis Galen , Higdon Kent
Published: May 2023

Background

The location of tissue expanders in implant-based breast reconstruction remains controversial due to variation in surgical techniques and devices.

Objectives

The aim of this study was to provide a comprehensive assessment of early and late complication rates between prepectoral and subpectoral placement of tissue expanders.

Methods

A retrospective cohort study was conducted of all adult female patients who had undergone 2-stage implant-based breast reconstruction between 2013 and 2019 in our institution. Early complication was defined as complications that occurred within 30 days after surgery. Time-to-event analyses were performed and Cox proportional hazard models were used to adjust for confounders.

Results

In total, 854 patients were included; 76% of patients underwent a subpectoral tissue expander placement. After the first-stage procedure, the early complication rate was 34% and the late complication rate was 36.4%. After the second-stage procedure, the early complication rate was 16.3% and the late complication rate was 16.1%. Location of the tissue expander did not predict either overall early or late complication rates, regardless of the stages of reconstruction, after adjusting for confounders. Tissue expanders placed in prepectoral plane were associated with a higher hazard ratio (HR) for developing early and late infection after the first stage of reconstruction (HR, 2.1 and 2.4, respectively) as well as late infection after the second stage of reconstruction (HR, 5.3; all P < .05).

Conclusions

Location of tissue expanders did not predict risk of complication. However, the prepectoral group was associated with an increased risk of developing infection.

Level of Evidence: 4
The Functional Anatomy and Innervation of the Platysma is Segmental: Implications for Lower Lip Dysfunction, Recurrent Platysmal Bands, and Surgical Rejuvenation
Authors: Minelli Lennert , Wilson Jeremy L , Bravo Francisco G , Hodgkinson Darryl J , O’Daniel T Gerald , van der Lei Berend , Mendelson Bryan C
Published: May 2023

Background

Despite the central role of the platysma in face and neck rejuvenation, much confusion exists regarding its surgical anatomy.

Objectives

This study was undertaken to clarify the regional anatomy of the platysma and its innervation pattern and to explain clinical phenomena, such as the origin of platysmal bands and their recurrence, and the etiology of lower lip dysfunction after neck lift procedures.

Methods

Fifty-five cadaver heads were studied (16 embalmed, 39 fresh, mean age 75 years). Following preliminary dissections and macro-sectioning, a series of standardized layered dissections were performed, complemented by histology and sheet plastination.

Results

In addition to its origin and insertion, the platysma is attached to the skin and deep fascia across its entire superficial and deep surfaces. This composite system explains the age-related formation of static platysmal bands, recurrent platysmal bands after complete platysma transection, and recurrent anterior neck laxity after no-release lifting. The facial part of the platysma is primarily innervated by the marginal mandibular branch of the facial nerve, whereas the submandibular platysma is innervated by the “first” cervical branches, which terminate at the mandibular origin of the depressor labii inferioris. This pattern has implications for postoperative dysfunction of the lower lip, including pseudoparalysis, and potential targeted surgical denervation.

Conclusions

This anatomical study, comprised of layered dissections, large histology, and sheet plastination, fully describes the anatomy of the platysma including its bony, fascial, and dermal attachments, as well as its segmental innervation including its nerve danger zones. It provides a sound anatomical basis for the further development of surgical techniques to rejuvenate the neck with prevention of recurrent platysmal banding.