REDUCING OVERHEAD OF SELF-STABILIZING BYZANTINE AGREEMENT PROTOCOLS FOR BLOCKCHAIN USING HTTP/3 PROTOCOL: A PERSPECTIVE VIEW

Today, there is a tendency to reduce the dependence on local computation in favor of cloud computing. However, this inadvertently increases the reliance upon distributed fault-tolerant systems. In a condition that forced to work together, these systems often need to reach an agreement on some state or task, and possibly even in the presence of some misbehaving Byzantine nodes. Although non-trivial, Byzantine Agreement (BA) protocols now exist that are resilient to these types of faults. However, there is still a risk for inconsistencies in the application state in practice, even if a BA protocol is used. A single transient fault may put a node into an illegal state, creating a need for new self-stabilizing BA protocols to recover from illegal states. As self-stabilization often comes with a cost, primarily in the form of communication overhead, a potential lowering of latency - the cost of each message - could significantly impact how fast the protocol behaves overall. Thereby, there is a need for new network protocols such as QUIC, which, among other things, aims to reduce latency. In this paper, we survey current state-of-the-art agreement protocols. Based on previous work, some researchers try to implement pseudocode like QUIC protocol for Ethereum blockchain to have a secure network, resulting in slightly slower performance than the IP-based blockchain. We focus on consensus in the context of blockchain as it has prompted the development and usage of new open-source BA solutions that are related to proof of stake. We also discuss extensions to some of these protocols, specifically the possibility of achieving self-stabilization and the potential integration of the QUIC protocol, such as PoS and PBFT. Finally, further challenges faced in the field and how they might be overcome are discussed.

THE ABILITY OF THE CONTINUOUSLY VARIABLE TRANSMISSION TO CONTROL THE ENGINE AT MAXIMUM POWER: LITERATURE REVIEW

Good ride performance is one of the most important key attributes of a passenger vehicle. One of the methods to achieve this is by using Continuously Variable Transmission (CVT). This is because a CVT can provide an almost infinite ratio within its limits smoothly and continuously. The flexibility of a CVT allows the driving shaft to maintain a constant angular velocity over a range of output velocities. New developments in gear reduction and manufacturing have led to ever more robust CVTs, allowing them to be applied in more diverse automotive applications. As CVT development continues, costs will be reduced further, and the performance will continue to improve, making further development and application of the CVT technology desirable. This cycle of improvement will offer CVT a solid foundation in the world's automotive infrastructure. This paper aims to provide some background and relevant information that is necessary for this study. Specifically, a brief description of CVT, advantages and their brief history is presented. This paper also evaluates the current state of CVT, investigate the technology frontline of drivetrain control and the development of CVT. The stepless transmission is able to maintain the engine running at its maximum power.

CHLORIDE SENSOR FABRICATION BASED ON SPE Ag/AgCl THROUGH CYCLIC VOLTAMMETRIC TECHNIQUE: SCAN RATE EFFECT

The Cyclic Voltammetric (CV) technique is one of the Ag/AgCl fabrication processes. In electrochemical processes using this CV technique, the microstructure of the surface of a substrate or electrode can affect the scan rate. Thus, this study aims to identify the scan rate effect of the Cl-ion sensor fabrication process using the CV technique on the performance of the Cl-ion sensor. First, the CV process was carried out in one cycle to grow the AgCl layer on the Ag surface. Then, this process was carried out at varied scan rates of 20, 40, 60, 80, and 100 mV/s. After completing the Ag/AgCl fabrication process, it was followed by the characterization process, selectivity coefficient test, lifetime test, and validation test to compare the test results of the Cl SPE Ag/AgCl ion sensor with Ag/AgCl commercial. The results showed that the optimum Cl-ion sensor response was obtained at the scan rate of 60 mV/s. Then, based on the validation test, the Cl-ion in the two samples did not show significant differences. Therefore, it indicates that the SPE Ag/AgCl ion sensor has the same performance as the Ag/AgCl commercial.

OPTIMIZATION OF THE RESISTANCE SPOT WELDING PROCESS OF SECC-AF AND SGCC GALVANIZED STEEL SHEET USING THE TAGUCHI METHOD

This article present the optimization work describes out to joint the dissimilar galvanized steel of SECC-AF (JIS G 3313) and SGCC (JIS G 3302) material. A zinc coating on the surfaces of the galvanized steel sheets will decrease the weldability characteristic of the material. This study used dissimilar galvanised steel sheets to obtain the highest tensile shear strength from the specified resistance spot welding. This research used the Taguchi method with 4-variables and mixed-experimental levels. The mixed-experimental level, namely 2-experimental levels for the first variable and 3-experimental levels for other variables. The highest tensile shear strength was achieved in 5282.13 N. This condition is achieved at a squeezed time of 20 cycles, 27 kA-welding currents, welding time of 0.5 seconds, and holding time of 18 cycles. The S/N ratio analysis has shown the welding current had the most significant effect, followed by welding time, squeeze time, and holding time. The delta values of S/N ratio were 0.79, 0.64, 0.26 and 0.07, respectively. The ANOVA analysis has shown that the P-value of welding current and welding time is 0.006 (0.6%) and 0.015 (1.5%), respectively. This result is expected for optimizing resistance spot welding quality in other materials or significant aspects.

STUDY OF MAKING POLYESTER RESIN MATRIX COMPOSITES USING BASALT SCORIA POWDER FILLERS TO TENSILE STRENGTH AND COMPRESSIVE STRENGTH

An experimental study on the manufacture of polyester resin matrix composites using basalt powder as a reinforcing filler has been carried out. Basalt is a volcanic igneous rock often found in East Lampung and has not been utilised. Basalt is chosen as a reinforcing filler because basalt has advantages such as wear resistance, corrosion resistance, resistance to chemical reactions, and high hardness. The research parameters used were variations in the size of the basalt powder, the composition of the polyester resin matrix to the basalt powder, and the percentage of the catalyst. All parameters were mixed according to the research procedure, and all samples were formed under pressure 20 kN. Tensile test results showed the highest value of 0.961 kgf/mm2 from 60 mesh-25% polyester-1/30 catalyst variation parameter. The highest compressive strength value of 28.331 kgf/mm2 was obtained from the various parameters of 270 mesh-20% polyester-1/20 catalyst and 270 mesh-25% polyester-1/30 catalyst. The results were not much different from those, which is 27.787 kgf/mm2. The use of 1/30 hardener catalyst to the amount of polymer by 25 %wt gives optimal results on the characterisation material testing. However, the effect of the filler grain size gave different results for each test carried out. Therefore, to obtain the desired mechanical properties when using basalt rock powder as a filler, it is necessary to pay attention to the correct grain size.

TRIBOLOGICAL PROPERTIES OF AL2O3-ZrO2 COMPOSITE COATING BY LUBRICATION

Tribological investigations had been carried out on the plasma coating (Al2O3+ ZrO2) below dry and moist abrasion stipulations according to ASTM G134. Commercial motor oil 20W40 was used as a lubricant. At a rotational speed of 200 rpm, all experiments were carried out with ordinary loads of 10, 15 and 20 Nm. Electron microscopy for scanning and AFM was used to study of the layer sprayed with paint. The outcomes of the SEM and AFM evaluation confirmed that abrasive wear is normally decided by abrasive wear in dry abrasive conditions. The lubrication and moisture check confirmed a major reduce in wear from 10 to 15 N below regular loading, and a corrosion fee larger than 15 N was once discovered below regular loading. No impact of lubrication on wear used to discovered at high loading. No impact of lubrication on wear used to be discovered at high loads. It was also cited that the plasma coating manner to improve wear resistance. The experimental statistics acquired in this study are tremendous engineering functions such as reducing equipment and internal combustion engines.

FLUID FLOW STUDY IN VARIOUS SHAPES AND SIZES OF HORIZONTAL AXIS SEA CURRENT TURBINE

The ducted tidal turbine models have been developed to utilize the conversion of the kinetic energy on ocean currents. The research in refining the turbine characteristics has been carried out by modifying the turbine’s shape and size. This study investigated flow characteristics in the meridional section of five ducted turbines models for seawater flow with velocity U0 = 1.5 m/s. The ducted turbine design and construction have five different impeller house diameters and fixed inlet and outlet diameters. The potential energy flow theory and experimental data are used to analyze the flow characteristics of the model. The results show that flow velocity in the x-direction at the inlet and outlet cross-section is getting smaller, reducing the impeller house cross section. Each impeller house size reduction increases the flow speed in the impeller house cross-section and also pressure on all other cross-sections tested. In the inlet area, the increased pressure indicates a decrease in speed flow and discharge coefficient value. The discharge coefficient value decreases from CQ = 0.9 at the diameter ratio of dr = 1 to CQ = 0.56 at the diameter ratio of dr = 0.375. The maximum value of power coefficient was determined at dr = 0,61÷0.73 or dr = 0.69 which is equivalent to average internal flow velocity Vr =2.0÷2.6 m/s and the static pressure ps = 97.1÷ 94.4 kPa. At the ratio value of D0/D2 = 0.83, the optimal diameter ratio dropt=0,61÷0.73 is in line with the duct model of case 3 and case 4, but it may be determined solely as for case 4.

SUSTAINABLE DEVELOPMENT IN LOW CARBON, CLEANER AND GREENER ENERGIES AND THE ENVIRONMENT

The increased availability of reliable and efficient energy services stimulates new development alternatives. This article discusses the potential for such integrated systems in the stationary and portable power market in response to the critical need for cleaner energy technology. Several issues relating to renewable energies, environment, and sustainable development are examined from both current and future perspectives throughout the theme. It is concluded that green energies like wind, solar, ground source heat pumps, and biomass must be promoted, implemented, and demonstrated from the economic and/or environmental point of view. Biogas from biomass appears to have potential as an alternative energy source, potentially rich in biomass resources. The current literature is reviewed regarding the ecological, social, cultural and economic impacts of biogas technology. Finally, this article gives an overview of the present and future use of biomass as an industrial feedstock to produce fuels, chemicals and other materials. However, to be truly competitive in an open market situation, higher-value products are required. Results suggest that biogas technology must be encouraged, promoted, invested, implemented, and demonstrated, especially in remote rural areas. Anticipated future energy use patterns and consequent environmental impacts (acid precipitation, ozone depletion, greenhouse effect, or global warming) are discussed in this article. An approach is needed to integrate renewable energies in a way to meet high building performance. However, their ability to match demand is determined by adoption of one of the following two approaches: the utilisation of a capture area greater than that occupied by the community to be supplied, or the reduction of the community’s energy demands to a level commensurate with the locally available renewable resources. Adopting green or sustainable approaches to how society is run is seen as an important strategy in finding a solution to the energy problem. The key factors to reducing and controlling CO2, which is the major contributor to global warming, are the use of alternative approaches to energy generation and the exploration of how these alternatives are used today and may be used in the future as green energy sources.

STUDY ON URBAN RESIDUAL SPACE AS SOLUTIONS REVIEW FOR AREA PROBLEMS

In cities, spaces were intentionally formed, planned, or unintentionally unplanned. Unlike planned spaces, unplanned spaces in urban areas eventually tend to cause problems for the area. These spaces were referred to as residual spaces, which were generally vacant land or open space in various urban spaces. Urban residual space was also commonly found in tertiary activity centers in big cities like Jakarta, one of which was in the trade and service area of the city. Residual space in such areas grew and developed due to dense activity within the area, resulting building density, irregularity in some spatial use and environmental degradation. Due such conditions, several questions are significant to be raised. What are the typology, utilization, and its impacts on the area? Did it only cause a problem, or could it be a solution to problems within the area? This study aimed to examine the typology of residual space based on the shape, location, utilization, and impact of trade and service activities in South Jakarta, Kebayoran Lama area. The proposed approach used was a qualitative study of the residual spaces in predetermined trade and commercial areas. The study results of the physical, spatial, visual, and social conditions of urban residual space were explained descriptively to get a picture of the characteristics of the form, location, utilization, and impact on the area.

THE EFFECT OF COCONUT COIR FIBER POWDER CONTENT AND HARDENER WEIGHT FRACTIONS ON MECHANICAL PROPERTIES OF AN EPR-174 EPOXY RESIN COMPOSITE

The development of composite materials is increasingly widespread, which require superior mechanical properties. From many studies, it is found that the mechanical properties of composite materials are influenced by various factors, including the reinforcement content, both in the form of fibers and particle powder. However, those studies have not investigated the effect of the hardener weight fraction on the mechanical properties of resin composite materials. Even though its function as a hardener is likely to affect its mechanical properties, it might obtain the optimum composition of the reinforcing content and hardener fraction to get the specific mechanical properties. This study examines the effect of hardener weight fraction combined with fiber powder content on mechanical properties of EPR-174 epoxy resin matrix composite and determines the optimum of Them. The research was conducted by testing a sample of composite matrix resin material reinforced with coconut fiber powder. The Powder content was made in 3 levels, i.e.: 6%, 8%, and 10%. While the hardener fraction of resin was made in 3 levels, i.e.: 0.4, 0.5, and 0.6. The test results showed that pure resin had the lowest impact strength of 1.37 kJ/m2. The specimen with a fiber powder content of 6% has the highest impact strength i.e.: 4.92 kJ/m2. The hardener fraction of 0.5 has the highest impact strength i.e.: 4.55 kJ/m2. The fiber powder content of 8% produced the highest shear strength i.e.: 1.00 MPa. Meanwhile, the hardener fraction of 0.6 has the highest shear strength i.e.: 2.03 MPa.