bluuebunny/crossref_metadata_2025 huggingface dataset:
Analytical Study on Flexural Behaviour of Light Gauge Steel Corrugated Section Encased in Concrete
Authors: Thilagar K. , Suresh Babu S.
Published: October 2021

Light gauge elements for integrated beams were used, and thin webs are typically needed in constructed beams’ economical design. However, the buckling problem may arise if the Web is fragile. This risk may be reduced by using thicker panels, web reinforcements, or web enhancements. The use of corrugated Web is a possible means of achieving adequate rigidity and shear resistance without hardeners. Analytical studies were conducted in this present work to study the bending behavior of the conventional beam and light-weight steel beam with corrugated, concrete enclosed Web. Analyzes of finite elements have been conducted using the ANSYS beam software. The results present the capacity for load carrying and the deformation of the concrete-covered corrugated web beams. This study’s main objective is to acquire a better knowledge of a concrete embedded steel beam’s behavior.
Design of Solar Charging Case for Mobile Phones
Authors: Gladwin Antony R , Hariharan S , Hari Haran D , Clement Raj C
Published: October 2021

Every day in this modern era, a new technology is introduced in a mobile phone, and one major concern that every mobile phone user has is its battery backup. Whatever the advancements in mobile phones, the chargers we use have remained consistent since the beginning. Our project’s goal is to create an integrated solar mobile charger that can be seamlessly incorporated into the protective case of the mobile phone. The proposed design traps solar energy and stores it in a rechargeable battery. This system has the ability to serve dual role, both as a protective case and act as power backup for the mobile phone.
Study on Engineering behavior of conventional cement concrete by partially replacing sea shell as Fine aggregate
Authors: Parthiban D. , Vijayan D.S. , andrews Sachu , sangma Sangsangrach , mohammed Arif
Published: October 2021

In this study, it was investigate about the engineering behavior of conventional concrete of grade M25, by replacing the fine aggregate by partially with crushed sea shell. On because of progression in the field of infrastructure, the dearth of construction material becomes upsurge day by day. All the investigator was observe to find the substitute construction materials to meet the demand of construction in world wide. The reason behind is, while continuous utilizing of the natural raw material for construction decline the resource of those materials and further, it leads to affect the routine function of the earth and made drastic change in the life cycle of living beings. Therefore, it is obvious to find out the possible alternative material to suit for all type of construction. In this study, the sea shell was used as a fine aggregate in the method of crushed powder in an apparent proportion such as 10%, 20% and 30% replacing in the place of fine aggregate sand. The compression and split tensile behavior of sea shell aggregate mixed concrete comparatively with plain sand concrete was studied under different curing periods such as 7 days, 14 days and 28 days. It was shows that at 20% replacement of crushed sea shell aggregate provide the compressive strength of 35 N/mm2 at 28 days of curing nearly with the design strength of M25 grade conventional concrete. It was also noticed that, the percentage increase of crushed sea shell decline the strength of concrete as radically. Hence it was acclaimed that, the percentage of crushed sea shell as fixed equal or below 10 % to get a better strength of concrete.
Discernment and Diminution of Black Hole Attack in Mobile Ad-Hoc Network using Artificial Intelligence
Authors: Srinivas K , Harsha Shastri V , Nassa Vinay Kumar , Prasad Gudapati Syam , Kumar Prathipati Ratna
Published: October 2021

The MANET is an interesting research topic that has movable nodes. The mobile ad hoc system is an important research area. The nodes are connected by wireless connections. Thus it is vital to have a stable network because information and interaction are crucial in diverse fields such as security and catastrophe emergency response.

Because of the decentralized system’s vibrant existence, these channels are vulnerable to various threats, including BHA, GHA, SHA. One of the well-known security issues in MANET is the black hole assault. Each node has a routing table containing information from the target node. The number of assaults in MANET is usually protocol networking assaults. The study focused on black hole attacks for discernment and decrease. A black hole attack node wrongly picks up all packet and collects them without passing them to an endpoint by taking a fresh path to the destination nodes. This paper presents BHA defence from assaults with the principle of Artificial Neural Network and calculates its efficiency according to the set of elements, such as efficiency, PDR and delay and energy utilization. This paper aims to devise an artificial neural network method for black hole discernment and reduction in MANET.
Characteristics Study on Leachate Samples of Laloor, Thrissur
Authors: Ispara Xavier S , Aravind Raj P S , Divahar R , Mohan Arun , Tr Nithin , Shamsad A C
Published: October 2021

Leachate generation is a biggest problem faced by municipal solid waste (MSW) landfills which causes significant hazard to surface water and groundwater. Leachate contains high concentration of pollution which can cause serious problems to the society. In this study, examining the characteristics of leachate generated from a landfill site situated in Laloor, In Thrissur, Standard methods were used to monitored, analyzed and examined the water and waste water. According to the standard methods for the Parameters were monitored included dissolved oxygen (DO), chemical oxygen demand (COD), biological oxygen demand (BOD), chlorides content, alkalinity, mpn, hardness and pH. After this study results are mapped by QGIS to confirm and show the impact of the leachate issue in laloor.
Design of Water Distribution System for Thirumitta code Grama Panchayat
Authors: Ispara Xavier S , Divahar R , Aravind Raj P S , Roy Astoria Femy , Athira P R , Maria Duna C B
Published: October 2021

The aim of this project is to supply the water to client with acceptable grade and amount. Jal Jeevan Mission (JJM) has been launched that aims at providing practical functional household tap connection (FHTC) to each village unit by 2025 in Republic of India. This project aims on designing a water distribution system for the Thirumittacode gramma panchayath situated in Pattambi Municipality, Palakkad district, Kerala. This project revolves around population prediction of the general practitioner by 2024 and 2054, water demand calculations, planning the water distribution system with associate degree acceptable water resource and value estimation. Use of loop 4 software system adds on to the advancement of this project.
Numerical simulation of viscosity/implicit large-eddy steady turbulence with the Reynolds number dependency
Authors: Iwata Naoyuki , Suzuki Hiroki , Mochizuki Shinsuke
Published: October 2021

This study presents a numerical analysis that models small scale turbulence using numerical viscosity or implicit large-eddy simulation (LES). The motivation for focusing on these models is that the sub-grid scale components of LES are assumed to have a sufficiently high Reynolds number turbulence. The Reynolds number dependence of steady isotropic turbulence is used to validate the present analysis. Here, this dependency ranges from low to high Reynolds numbers. The results of this analysis are validated by comparing them with those of direct numerical simulation. The donor cell method and quick method are used as schemes of the numerical viscosity. Analysis based on the numerical viscosity can give accurate turbulent kinetic energy values at high Reynolds numbers and implicit LES at low Reynolds numbers. However, these models did not accurately predict static pressure fluctuations. These results were discussed by visualizing the large-scale turbulent structures.
Systematic analysis of additive manufacturing for printing on semi-finished parts
Authors: Kizak M , Matschinski A , Drechsler K
Published: October 2021

Additive manufacturing has gained significant interest in the industry, and fused filament fabrication in particular is a promising technology. In order to use the full potential of additive manufacturing, deeper understanding in this process is necessary. For this purpose, a profound analysis according to VDI 2206 guideline (“Design methodology for mechatronic systems”) is conducted for printing on semi-finished parts with fused filament fabrication. It presents the correlation of mechanical, electrotechnical and information processing components to detect the function chain. The relevant information, energy and material flow within the overall system are identified. New functional problems emerge from the analysis. For instance, the binding of the printed segment to the semi-finishes part needs to be considered. Moreover, the determination of the position and geometry of the semi-finished part poses a challenge. The analysis shows that the system needs to be expanded. To be able to print on semi-finished parts, a monitoring system, an advanced slicing software and a tempering ambience is necessary.
Aspect ratio and size effects of a metacomposite with interconnected Y-elements
Authors: Lim T C
Published: October 2021

An investigation on the size effect and aspect ratio is reported herein for a recently designed mechanical metamaterial that manifests perfect auxeticity based on inspiration from a Middle East geometrical pattern by interconnecting rigid Y-elements. An upper bound effective Young’s modulus was acquired by matching the strain energy of the restraining springs within each pair of the Y-elements and the conceptualised continuum strain energy of the entire metamaterial. Results show that the effective Young’s modulus is enhanced with decreasing size of the material. For a fixed amount of metamaterial units, the effective Young’s modulus can be increased by elongating or narrowing the metamaterial structure. This 2D structure is useful for applications which requires preservation of shape while permitting large change in size.
Low-cost activated carbon bio-wasted-based for enhanced capacitive properties of symmetric supercapacitor
Authors: Taer Erman , Sugianti Tiara Elvelin , Apriwandi  , Rini Ari Sulistyo , Malik Usman , Taslim Rika
Published: October 2021

Low-cost, abundant, simple, and facile approaches to exhibit bio-waste-based porous carbon are needed to enhance the high performance of electrode materials as energy storage devices. Here, the bio-waste-based activated carbon with a low-cost and easy-to-prepare approach was studied via chemical impregnation of ZnCl2at single-stage integrated high-temperature pyrolysis. Furthermore, the activated carbon is prepared in the form of a monolith by optimizing the self-adhesive properties of the precursor. The application of different chemical concentrations can significantly improve the material properties with relatively good amorphous carbon structures. Furthermore, the maximum surface area was found to be 1129 m2g−1. Moreover, it exhibits high electrochemical behavior with a specific capacitance of 145 Fg−1at a constant current density of 1.0 Ag−1. In addition, the highest energy density was found at 16.25 Whkg−1with a maximum power density of 82.70 Wkg−1in 1 M H2SO4aqueous electrolyte. These results confirm a low-cost and simple strategy for the synthesis of bio-waste-based activated carbon as an electrode material to enhance the capacitive properties of supercapacitors.
In Silico Analysis Towards Exploring Potential β Secretase 1 (BACE1) Inhibitors; The Cause of Alzhemier Disease
Authors: Frimayanti Neni , Aryani Fina , Rishanti Nina , Yaeghoobi Marzieh
Published: October 2021

1,5 benzothiazepine chalcone derivative compounds were used as ligands and docked with protein target 2XFJ code from Hydrolase enzyme crystallographic structure. Molecular Operating Environment 2020.0901 (MOE) computer program was used as software to perform docking. The aim of this research is to determine the potentiality of 1,5 benzothiazepines as β secretase 1 (BACE1) inhibitors using molecular docking studies and also to predict their toxicity using SwissADME. Based on the docking results, some promising interactions were observed between 1,5 benzothiazepines and β secretase 1 (BACE1) receptors using Verubecestat as a positive control. Compounds MA2, MA4 and MA10 shown to have the potentiality as active inhibitors for the β secretase 1 (BACE1). These three compounds have binding free energy values of -4,6302 kcal/mol, -4,4268 kcal/mol, and -5,3427 kcal/mol, respectively. In addition, they also exhibited factor of binding (i. e. a measure of the probability of tested compounds to bind with the same amino acid that the positive control, Verubecestat). The predicted toxicity for these three compounds were measured using SwissADME and the results showed that MA2, MA4 and MA10 are not toxic and they can be used as reference for designing new inhibitors for β secretase 1 (BACE1).
Schlumberger’s Rules of Geolistric Resistivity Survey for the Study of Ground Water in Agricultural Land Palawija
Authors: Rahmalia Anisa , Juandi Muhammad
Published: October 2021

Marpoyan Damai sub-district has the potential as a palawija agricultural land. The obstacle faced by farmers is the difficulty of getting water when it is dry. Thenfore, a study is needed to see potential and presence of groundwater in that location. This study aims to identify the depth of the subsurface structures around the agricultural area. The data were taken from two routes in Marpoyan Damai District, namely at coordinates 0°26’44.232” LU, 101°26’4.866” BT and at coordinates 0°26’44.210” LU, 101°26’4.092” BT. Data processed from the progress software shows that at coordinates 0°26’44.232” LU, 101°26’4.866” BT, there is one aquifer layer in the fourth layer having a resistivity value of 80.76 Ωm with a thickness of 6.52 m and at coordinates 0°26’44.210” LU, 101°26’4.092” BT, there is one aquifer layer in the second layer having a resistivity value of 80.45 Ωm and a thickness of 9.99 m. The lithology data of each path shows the water flow pattern flowing from line one to line two. The results of this interpretation indicate that this research area can be used for agricultural areas.
Resistivity characteristics of soil saturated with variation of salt water-fresh water mixture
Authors: Islami Nur , Irianti Mitri
Published: October 2021

Peat soil has a specific physical character if compare with the other sediments. It has amount of organic matter and has relatively porosity and permeability. This preliminary research is to predict the salt water content in the soil and peat soil aquifer later on. This research is to investigate the resistivity characteristic of peat soil saturated with variation of salt water-fresh water mixture. Six undisturbed soil and peat soil samples were taken from difference sites in the coastal area. The soil and peat soil samples then saturated with difference amount of salt-fresh water mixture. The resistivity measurement then was measured to the soial and peat soil saturated with the salt-fresh water mixture. The result show that the resistivity decreases drastically as the increasing of a little amount of salt water in the salt-fresh water mixture.
Physical and Numerical Simulation of Wave Transmission Over Submerged Breakwater
Authors: Sutikno Sigit , Almanna Fajri , Rinaldi  , Mubarak  , Murakami Keisuke
Published: October 2021

Nowadays, the submerged breakwaters are becoming attractive to the coastal engineer because they have many advantages including keeping aesthetic value of coastal scenery and reasonable for wave energy reduction. However, on the other hand, their design is very complicated. So, it is very important to understand the characteristics and the impact of wave because of the submerged breakwaters. For this purpose, we developed both numerical and physical model for simulation of wave over submerged breakwaters. The numerical model was developed using CADMAS-SURF, which is widely used in a practice of business in Japan. Physical model studies were performed at the Coastal Engineering Research Laboratory, University of Miyazaki, Japan to assess the performance of submerged breakwaters under a wide range of design conditions. The tests include the use of single and double submerged breakwater, as well as the impact of interval between the breakwaters which will be useful references for submerged breakwater designing in the future. The results show that the transmission coefficients of the numerical simulation have a good agreement with the experiment result with the RMS error 0.14 and 0.19 for the single and double breakwater respectively. This study found that, the application of double breakwaters has no significant impact for reducing wave energy compared to the single breakwater for the wave steepness higher than 0.007 and 0.012 based on laboratory and numerical simulation respectively. The best relative breakwater spacings are 0.75, 0.4, 0.45 and 0.35 for any kind of wave with the period of 0.6, 0.8, 1.0 and 1.2 respectively. In those conditions, the transmission coefficients are on minimum value for each kind of wave, that means the double breakwaters have the good performance on energy reduction.
Nineth Grade Students Mistakes when Solving Congruence and Similarity Problem
Authors: Wijaya T T , Mutmainah I I , Suryani N , Azizah D , Fitri A , Hermita N , Tohir M
Published: October 2021

This research aims to know the difficulty level and the difficulties faced by students on congruent and similar problems. The test is taken from students’ mid-semester exam in march 2021. Students’ learning condition is under the coronavirus pandemic. This research uses a mix-method to process its data which are the qualitative and quantitative methods. The quantitative method is used to analyze the difficulty level and the qualitative method will explain the difficulties faced by students when solving congruent and similar problems. There are 9 questions given in this research that consists of 8 visual problems and one combined problem. The difficulties of the problems are four questions with easy difficulty and five questions with medium difficulty. The sample of this research is 61 9th grade students from SPMN 47, Bandung, Indonesia. The data is taken by using the google platform. The second data will be taken from teachers’ interview results following the analysis of students’ difficulties when solving congruent and similarity problems. The test result average is 64.77 and teachers’ interview result shows that the poor test result is because teachers are not prepared with the teaching condition during the coronavirus pandemic. A recommendation for teachers is that they can improve their ability by integrating technology in mathematics.
Durability of Fly Ash Geopolymer Hybrid Concrete in Seawater, Sulfuric Acid, and Fire Resistant – A Review
Authors: Rizaldi Niko , Abdurrahman Habib , Wijaya Miguel Felix , Wibisono Gunawan , Olivia Monita
Published: October 2021

Fly ash is a hazardous and toxic waste material from burning coal. However, it can be used as a material of geopolymer concrete because it contains high amounts of silica and alumina. Recent research on geopolymer concrete is still being conducted because it is part of green building material. This review aims to determine and analyzed the durability of fly ash geopolymer hybrid concrete in aggressive environments. The environment studied included seawater, sulfuric acid, and elevated temperature. OPC concrete is a high calcium material; therefore it is susceptible to aggressive environments compared with OPC concrete, geopolymer concrete contains aluminosilicate and low calcium material, which is not reactive with aggressive environment. The method used in this study is a literature review of several relevant research sources, and data were collected and analyzed. The results showed that fly ash geopolymer hybrid concrete had increase compressive strength compared to OPC concrete. In the seawater environment, the compressive strength of geopolymer concrete increases from 10%-15%. The compressive strength of geopolymer concrete also increases in a sulfuric acid environment up to 360 days of test age, and it is resistant to fire up until 800 °C. Likewise, the porosity of the geopolymer fly ash concrete decreased while the OPC concrete increased. According to the analysis and discussion results, it was resumed that fly ash geopolymer concrete is more environmentally friendly and durable than OPC concrete, especially in seawater, sulfuric acid, and post-fire environments.
Effect of opening depth of oblique weir with an opening on river bed morphology
Authors: Une H , Ohmoto T , Kuranaga K
Published: October 2021

In this study, we focused on the fact that an oblique weir with an opening activates the fluidity of the sediment compared with a conventional continuous fixed one and examined the removal function of the sediment deposited upstream of the weir. Experimental results showed that the weir with the opening increased the fluidity of the sediment deposited upstream of the weir and lowered the riverbed. The scouring section upstream of the weir was divided into a gradually varied flow section and a local flow section based on the bed topography. In the gradual flow section, the descent of water level and riverbed increases linearly as the opening depth increases. In addition, it was shown that the local scour shapes upstream and downstream of the weir were similar to each other as a result of normalization on the representative scale of vertical and transverse shapes. By creating the opening of the oblique weir, the magnitude of the downward flow generated near the left bank was reduced from 45% to 34% of the non-open weir.
Preliminary study of the origin of mafic mineral megacrysts in volcanic rocks in the southwestern part of Kulon Progo Mountains, Indonesia
Authors: Aryani L , Hakim F , Titisari A D , Nugraha G , Mahardika C A
Published: October 2021

The Bagelen district in the southwestern part of Kulon Progo Mountains has a unique aspect in the form of the occurrence of mafic mineral megacrysts in volcanic rocks. This research is conducted to determine the type, the distribution, and the origin of those megacrysts, which are abundant in pyroclastic rocks. Detailed geological mapping on an area of 4 x 4 km with a scale of 1: 25,000 and petrographic analysis were done to explain the geological aspects that led to the presence of mafic mineral megacrysts in the study area. Petrographic analysis shows that the types of mafic mineral megacryst are hornblende, clinopyroxene, and plagioclase. Their features under the microscope observation are oscillatory zoning, half oscillatory zoning, sieve, and breakdown texture. These minerals are found as single crystal fragments and also as clinopyroxene and hornblende cumulate fragments in pyroclastic breccia. Based on mineralogical composition and texture, these mafic mineral megacrysts were formed by fractional crystallization process in the form of crystal settling mechanism. These minerals were initially accumulated in the bottom of magma chamber, then carried upward by rapid magma rising in association with explosive eruption event of Mount Ijo. These minerals were then transported on the surface through the mechanism of pyroclastic flow and were deposited in the valley to form an alluvial fan morphology in the southwestern part of Kulon Progo Dome.
Assessing the undiscovered resources of uranium and thorium in Mamuju, West Sulawesi
Authors: Cakrabuana W , Ciputra R C , Syaeful H
Published: October 2021

The exploration of nuclear minerals in Mamuju, West Sulawesi has been started in 2013 by the Center for Nuclear Minerals Technology (CMNT) – Badan Tenaga Nuklir Nasional (BATAN). There is a strong indication of uranium (U) and thorium (Th) minerals occurrences in the location. To follow the exploration result up, a resources assessment is needed. Due to the limited early exploration data, the concept of undiscovered resources can be used. Of all resource assessment methods suggested by International Atomic Energy Agency (IAEA), Energy Research and Development Administration (ERDA) method is the most appropriate method to be applied in the Mamuju case. In this research, Pocos de Caldas, Brazil (Osamu Utsumi Mine for U reference and Morro do Ferro Area for Th reference) was selected as control area due to its similarity on the geological condition and its more-advanced exploration stage compared to Mamuju. All the parameters for the assessment can be determined with the ERDA method based on the available information of the control area.
Simulation of operating modes of the refrigerating machine and the heat pump when drying fish
Authors: Semenov A E , Andreev A I , Tsyplakov A A
Published: October 2021

Saving energy resources in the fishing industry is an important task. The purpose of the study is to determine rational schemes and operating modes of air conditioning systems for drying fish. The methodology for calculating the air conditioning system for drying fish and on its basis a computer program in the mathematical package MathCAD is developed. Two air conditioning schemes are considered: a scheme using an air heater and a chiller and a scheme using a chiller and a heat pump. The schemes were analyzed from the standpoint of energy indicators. The parameters of the air supplied to the drying chamber were taken for calculations on the basis of the need to maintain the parameters set by the fish processing technology. In this paper, air conditioning schemes for drying fish are considered, an analysis of the main energy costs during the operation of equipment is carried out. On the basis of calculations, the advantages and disadvantages of the systems, their energy costs for maintaining the specified technological modes are shown. The influence of temperature and flow rate of cold outdoor air and the use of heat recovery units for the exhaust air are shown. It was established that when using outside air with heat exchangers, it is possible to significantly reduce the consumption of heat energy for the technological mode in the cold season. In the absence of heat sources, the scheme with a refrigeration machine and a heat pump has an advantage. The research results were introduced at the fish enterprise of the Astrakhan region by the LLC “Technology of comfort”.
Obtaining new products in the PVC/AL joinery industry applying the TIPS method - case study
Authors: Ciubotariu V A , Radu C M , Grigoraș C C , Zichil V
Published: October 2021

Obtaining a new product, in the current stage, can no longer be achieved by waiting for it by chance, as it happened in the past, but by systematically, perseveringly, and scientifically looking for it. This paper is a case study on the application of a systematic methodology for generating solution concepts in the case of the PVC and AL joinery accessories industry. Considering that one of the requirements was that the new connector part should mount on several standardized profiles, by approaching the TIPS tools kit, a modular connector with superior strength characteristics (3%) and low complexity was obtained. Also, by rethinking the product, a reduction of 15% of the required material (PA type 6) was obtained, as well as a decrease by approximately 11% of the tools cost necessary for the manufacturing process. For the preliminary evaluation of the new product, finite element analysis was necessary and the SolidWorks Simulation 2019 software was used. The numerical data was compared with the experimental data provided by the beneficiary, the differences being within the limit of 3.5%. These data encourage the beneficiary to study in detail the new product from several points of view, considering the option of introduction into manufacturing.
Exhaust Gas Recirculation (EGR) valve, design and computational fluid dynamic analysis
Authors: Dumitrache C L , Hnatiuc B , Deleanu D
Published: October 2021

All EGR systems used on contemporary cars operate on the principle of “external” exhaust gas recirculation. A certain proportion of the engine exhaust gases is extracted and transmitted back into the fresh air-gasoline mixture by means of a control valve. Exhaust gas recirculation valve is generally controlled by a pneumatic or mechanical system designed to dose the exhaust gases in accordance with certain factors such as: engine speed; intake manifold pressure; engine temperature. This paper presents the design steps of the EGR valve using NX SIEMENS. After making the 3D model, it was imported into ANSYS where a study of the flow of fluids (flue gases CO2 and liquid coolant) was made. In this study it was considered that the valve was actuated and the exhaust gases enter the engine while they are also cooled by the liquid coolant. From the fluid flow modeling process it can be seen that the coolant does not take much of the flue gas temperature, its role being more to maintain a proper temperature of the body valve.
Metamaterial optical filter with maximal absorption coefficient
Authors: Ionescu D , Apreotesei G
Published: October 2021

Tunable transmission and absorption coefficients in visible and infrared range have been obtained for metamaterial filters with a structure of metal on dielectric nanocomponents. Materials were stacks of nanoconstituents placed in alternate layers, which present a maximum or a minimum of the transmission coefficient and convenient values of the absorption coefficient when the periodicity is interrupted in a controlled manner. A simulational set-up with the metamaterial sample in a channel waveguide was conceived for obtaining the S parameters at the field propagation, using the HFSS program. The plasmon dispersion at the metal / dielectric interface was taken into account for calculating the frequency dependent surface plasmon wave vector, which can be adjusted by modifying the refractive index and the electric permittivities of the constituents. Transmission coefficients have been calculated for different structure geometries. The optimal metamaterial configurations have been chosen, in function of the desired filtering effect, for a range of incident field wavelength of 600 – 900 nm. A transmission variation of about 50 … 80 % at the central frequency, in comparison with the transmission effects in the side bands has been demonstrated for the proposed metamaterial filters.
The influence of Stress Concentration Factors and SN curves in assessing the reliability of jacket marine platforms
Authors: Joavina R , Popa M , Jenaru A
Published: October 2021

The design of offshore structures, generally located in a hostile environment, with complex and repetitive loads, with low and difficult intervention possibilities in case of accidents, is a challenge for engineer teams, starting from the design phase and ending with that of decommissioning. In addition to the approximations generated by the structural calculation, the specification of the level of effort concentration and the relationship between effort and fatigue life are also sources of uncertainties in estimating fatigue degradation. Analysis of the sensitivity of fatigue degradation to stress concentration factors (SCF) and S-N curves is an important factor in obtaining realistic results. The paper seeks to establish the optimal yield theory that can be used to evaluate the structural response to cyclic loads associated with computational assumptions by comparing fatigue conditions due to fatigue at the nodes of a complex lattice-type marine drilling structure, to minimize assessment errors of structural reliability. A structural model of jacket marine platform with dimensional and material characteristics corresponding to Romanian marine platforms of “Gloria” type it is analysed, for which is evaluate and compared the fatigue life generated by hydrodynamic loads, using stress concentration factors given by Kellog and Kuang, SN curves: AWS-X, modified AWS-x and respectively BS-F. The results show that for the self-erecting platforms with lattice beam type, with small dimension elements, the stress concentration factors determined by Kellog are closer to reality while Kuang factors gives more covering results.
Analysis of innovative decarbonation technologies by methanation
Authors: Macarie A C , Balcu I , Sfirloaga P , Panaitescu F V , Panaitescu M , Lazaroiu G
Published: October 2021

Abstract:In the development process of Romania, the energy sector for 2030 contributes essentially through its influence on the quality of life, the environment, the competitiveness of the economy, as well as the climate [1]. Thus, the energy sector from Romania must become more economically efficient, less polluting, and more technologically advanced.This paper presents the analysis of innovative methanation decarbonation technologies, the following aspects were pursued: methanisation, the reactions involved and the importance of the methanisation process, methanisation technologies and methane use, decarbonisation through methanisation, the importance of catalysts in methanation processes, decarbonisation with Carbon Capture Storage (CCS), catalyst enabled processes. Behind modern methanation decarbonization technologies is a history of over 100 years based on research and development [2]. At present, methanization is in the attention of scientists, industry, and energy companies, because: fossil fuels are a finite resource that will soon be exhausted; the energy system is constantly changing, and renewable energies are playing an increasingly important role in it; increasing levels of CO2 in the atmosphere contributes to global climate change.
Energy saving for wireless sensor network in manufacturing and administrative projects via Smart Nodes
Authors: Mahawish A A
Published: October 2021

The cost-effectiveness of the operation of Wireless Sensor Network (WSN) in manufacturing and administrative projects can highly boost the production of lower goods and services that in turn enhance the marketing ability. The lifetime increase of the batteries by reducing energy wastage is the main challenge and hence, in the current paper, there is an attempt to save energy via transmitting packets as quickly as can be expected while avoiding congestion and drop packets. The time synchronization allows nodes to sleep and wake at the same time to avoid consuming energy. The suggested algorithm, would, successfully deliver a packet with a fairly high rate and reduce dropping packets. Besides, it manages to avoid congestion and saves energy when reduce the retransmission the dropped packets.
Parametric modelling and finite elements study for the boom of a truck crane
Authors: Muscă(Anghelache) G D , Năstac S M
Published: October 2021

Parametric modelling and finite elements study for the crane boom was done in Catia V5R20 software. 3D modelling was done considering the load diagram. This is the basic feature for this study because it gives us information between the main elements (lifting capacity, outreach, boom length lifting height) which define crane operation possibilities. The truck crane is installed on the standard undercarriage of a truck or specially built undercarriages, the engine that drives the undercarriage serving either just for equipment travel or also for driving the crane mechanism. When the engine on undercarriage is only for travel, the truck crane is provided with an additional auxiliary engine, exclusively intended for crane mechanisms operation. The studied boom belongs to Liebherr crane. For parametric modelling measurements on an existing model were needed. Finite elements study was done on the basis of virtual model using a specialized soft. We did a static study by which we determined the static parameters of the structure (stresses, deformations, safety coefficient), for all own rates within interest range. The next aim, using the parameters, is to build the static model of reaction. Any static deformation of a structure can be represented as a weighted sum of structure’s own modes, each knot can be represented as a system with only one degree of freedom. This kind of study allows us to find which is the maximum deformation, the stresses and value of safety coefficient borne by a technical system or machinery under movement or static condition.
Synchronization of Measurement Data with the Reference System
Authors: Nalepa B , Gwiazda A
Published: October 2021

Today, most devices are equipped with sensors that enable the collection of process data that influences the control parameters. Sensors are to replace human senses and provide information from the environment to the control algorithm. In many cases, the sensors used are subject to reference measurements from an external diagnostic system, which is to eliminate possible errors in the installation of sensors or the operation of the control algorithm. For this purpose, external systems are most often used that do not duplicate any errors from the sensors used. Most often these are vision systems that are based on the measurement of markers mounted on the tested object. The most important effect of the reference system is the verification of sensor data or the correction of the control algorithm that processes sensor data. Often, when comparing two measurement systems, there is a problem with unequal sampling rates. The main problem is comparing the two graphs as the number of data / arguments is different. In order to compare two graphs, many methods are used to reduce or extend the number of arguments. The use of data expansion or reduction methods may result in an additional error. In this article, methods of reducing measurement data from IMU sensors and encoders connected to servo motors will be presented. There is a significant difference in sampling time for the two measurement systems shown. At the beginning, the methods and applications of algorithms in the literature will be discussed. Then, the measurement data will be compared with the data processed by the algorithms. The final point of work will be the combination of the data processed by the algorithm with the measurements. Two measurements were also compared in order to estimate the measurement error and a comparative algorithm was proposed.
Research on determining the state of stress by the finite element method in rehabilitation the welded structure
Authors: Nitoi D , Babis C , Chivu O , Petriceanu S , Dimitrescu A , Tăpîrdea A I
Published: October 2021

The study of stress is a very important problem especially in the case of welded structures. Very often the main causes of their failure are represented by the overlap of the stresses during operation with the remaining ones during the welding process. The article presents in the first part the experimental activity that regarding the realization of some fillet welded joints remedied by two processes that aim at reducing the internal stress. In the second part of the article, starting from the experimental part presented, a model was made by the finite element method. Based on it the different states of tension resulted in the initial structure as well as in the rehabilitated ones were simulated.
A Study of a Fluid Flow in the Jet Ejector System Used in Industrial Applications
Authors: Olaru I
Published: October 2021

Over time, numerous studies have been carried out for jet ejectors used in refrigeration systems for various industrial applications or in solar energy recovery. These ejectors use steam or water as a working fluid because the water has a low cost, chemical stability and is safe to use. Of course, depending on the application of these ejectors in the industry, other fluids can be used. When are made the ejectors, in addition to the selection of the refrigerant, which is very important, it is taken into account, as well as its constructive design has a strong influence on its performance. In general, the compression ratio depends on the nozzle and the diffuser geometry. Compared to other systems for industrial applications, ejector systems have some advantages: simplicity in construction, high spread and low cost. However, we cannot observe that they also have a lower coefficient of performance than conventional systems, which limited the widespread application of ejector systems.
Considerations on geometric modelling and finite element analysis for a trolley travel mechanism of an overhead crane
Authors: Potîrniche M A , Căpățână G F , Muscă (Anghelache) D G
Published: October 2021

Overhead cranes are complex lifting machines that have one or more mechanisms by which they perform the displacements of the loads. Overhead cranes move on high-rise ways without disturbing the activity that takes place on the ground. The trolley is one of the main components of the overhead crane and houses the wheels on which the crane moves. In this paper it was realized the 3D modelling of a trolley for an overhead crane, which was based on a real example of such a displacement mechanism and was made in the Autodesk Mechanical Desktop software. Next, the paper proposed to perform an analysis of stresses and deformations in static conditions of the trolley-type displacement mechanism under the action of its own weight. Finite element analysis was performed in Algor V23 software. This software gives the user ease in modelling but at the same time offers complete and particularly powerful analysis tools. Based on some simplifying hypotheses, a relatively simple model was obtained to analyze, but which led to obtaining results that can be a starting point for specialists in the domain of designing such equipment.
Conical Spring Inserts Effect on the Thermo- hydraulic Characteristics in Circular Copper Tube
Authors: Qasim M S , Ali S G , Freegah B
Published: October 2021

Experimental and numerical investigation was conducted to study the thermo-hydraulic characteristics in circular tube fitted with conical spring inserts. The dimensions of circular copper tube are 100cm, 2.2cm and 2.4 cm which represent the length, inner and outer diameters respectively. The length of insert was 15cm, while the conical spring has 16mm diameter gradually decreases to 6mm with the length and the pitch between the coils was 20mm. The diameter of wire used to fabricate the conical spring insert was 4mm. Those inserts were arranged into eight categories (A1 to A8). In the numerical part, the governing equations were solved by using commercial ANSYS-Fluent package (2019 R3) with the assistance of solid works and Gambit software program. The finite volume approach was used in solving the equations to predict the pressure flow, heat transfer and temperature distribution along the tube. Experimental work included design and built a test platform for the experimental measurements. The aim of experimental study was to predict the behavior of heat transfer and pressure in the tube with two cases, plain tube and inserted tube at the effect of different parameters. All experimental tests were conducted at turbulent flow fully developed. The range of Reynolds number and heat flux were (3542-7522) (4549-10576 W/m^2) respectively. The results showed that the best augmentation in heat transfer was by using a category A5 of conical spring insert compared with plain tube. Results show good agreement between the numerical and experimental results with an error of 8%. Also results showed that the Nusselt number increases as the Reynolds number increasing.
Cloud Connected Power Inverter
Authors: Sintea S R , Pomazan C C
Published: October 2021

In the Industry 4.0 paradigm, the control of electrical power production and consumption in small energy nodes remains an important objective. The new energy production nodes are usually installed in locations with reduced power requirements. They can produce energy to cover the needs of the consumer and the excess can be pushed in the national power grid system. This paper proposes a scheme to control the balance between produced energy, the locally consumed energy and the energy pushed into the national power grid system, using grid controlled inverters. The inverter connects the local energy source, with the local consumer and also ensures a bidirectional connection to the national power grid system. The inverter can be programmed to satisfy the local consumer power requirements, from the local source or from the national power grid system, and it can also deliver the local excess energy to the national power grid system. The controller is connected with the Internet and is able to send data to an IoT server. This paper presents a solution, along with its supporting technology, to create a network infrastructure based on thinger.io IoT technology. We present this solution for control, monitoring and optimization the electrical power production and consumption for small consumers using the IoT technology. This device can be used in small farm areas where we can monitor and control the balance between energy production and energy consumption from local sources or from the national power grid system. The device can also be used to monitor and control energy flow in remote small industrial plants or agricultural farms.
Research regarding works ergonomics in automotive repair shop
Authors: Tanase M , Chivu O , Tapirdea A , Nitoi D , Petrescu V
Published: October 2021

Prevention of muskuloscheletal disorders is very important worldwide. Both governments and companies are very interested in reducing the risk of their occurrence because the process that occur in the illness of an employee are long and very expensive. Muskuloscheletal disorders exists in all area of activity and in all occupations cause physical and economic consequences for both the worker and the company. They are generally found where the activity involves repetitive actions with awkward workstations or when the individual human operator has to lift weights above or outside the ergonomic workspace of the upper limbs. The most common musculoskeletal disorders occur mainly in two areas of the human body, namely: the back and the upper limbs, respectively, because the activities take place with the help of muscle groups in these areas. For this reason, they are most affected. Paper carries out a study on the activity of a car service and the exposure of the human operator from a certain workplace. It aims to highlight modern methods for preventing musculoskeletal disorders, generated by repeated and long exposure to emerging risks in the automotive industry. The semi-direct OWAS method will identify the areas where possible stress points may appear in the muscles, as a result of repeated exposure in a short time to risk factors but will be studied also NIOSH and RULA methods. Through Process Simulate software we try modeling such an activity, around which musculoskeletal disorders can occurs. It must be taken into account that here the mechanical stress generated at the level of the human operator cannot be visualized, because they depend on the prolonged, repeated exposure of the risk factors and on the large volume of work in a certain period of time.
Prediction of the dynamic stiffness of boring bars
Authors: Astarloa A , Fernandes M H , Mancisidor I , Munoa J , Dombovari Z
Published: October 2021

The productivity of boring operations is limited by chatter vibrations, as an effect of the low dynamic stiffness and damping of these cantilevered structures. The origin of the beforementioned self-excited vibration is mainly related to the dynamic stiffness of the boring bar’s bending mode, which is influenced by the stiffness and damping of the machine tool interface. In this paper a dynamic model is presented, which uses Timoshenko beam theory for the boring bar itself, while the effect of the clamping is experimentally determined applying Receptance Coupling Substructure Analysis (RCSA). The important effect of the boring head at the tool tip is considered on the coupling as well. This way, once the machine interface is characterized, the Frequency Response Functions (FRF) of different boring bars can be predicted.