General Technical Specifications Research Articles

Pantograph Slider Detection Architecture and Solution Based on Deep Learning.

Railway transportation has been integrated into people's lives. According to the "Notice on the release of the General Technical Specification of High-speed Railway Power Supply Safety Testing (6C System) System" issued by the National Railway Administration of China in 2012, it is required to install pantograph and slide monitoring devices in high-speed railway stations, station throats and the inlet and exit lines of high-speed railway sections, and it is required to detect the damage of the slider with high precision. It can be seen that the good condition of the pantograph slider is very important for the normal operation of the railway system. As a part of providing power for high-speed rail and subway, the pantograph must be paid attention to in railway transportation to ensure its integrity. The wear of the pantograph is mainly due to the contact power supply between the slide block and the long wire during high-speed operation, which inevitably produces scratches, resulting in depressions on the upper surface of the pantograph slide block. During long-term use, because the depression is too deep, there is a risk of fracture. Therefore, it is necessary to monitor the slider regularly and replace the slider with serious wear. At present, most of the traditional methods use automation technology or simple computer vision technology for detection, which is inefficient. Therefore, this paper introduces computer vision and deep learning technology into pantograph slide wear detection. Specifically, this paper mainly studies the wear detection of the pantograph slider based on deep learning and the main purpose is to improve the detection accuracy and improve the effect of segmentation. From a methodological perspective, this paper employs a linear array camera to enhance the quality of the data sets. Additionally, it integrates an attention mechanism to improve segmentation performance. Furthermore, this study introduces a novel image stitching method to address issues related to incomplete images, thereby providing a comprehensive solution.

Research on failure rate evaluation test method of energy meter in charging pile

Abstract To verify the failure rate of intelligent energy meter in charging pile and whether it can meet the reliability requirements in “general technical specification for single-phase intelligent electric energy meter (2020)”. Take 20 smart meter samples from four manufacturers, use the accelerated life model and carry out the accelerated test in the way of stress acceleration for a total of 4000 hours, and evaluate the failure rate indicators under normal working stress. The test results show that the single-phase intelligent watt hour meters produced by the four manufacturers can meet the reliability requirements such as annual failure rate index. The accelerated test theory is applied to the reliability life and failure rate evaluation of intelligent electric energy meter to shorten the test time, improve the test efficiency and reduce the test cost.

Development of Technical Specifications and Process System Requirements for the World’s Largest LH2 Refueling Station

Hydrogen is emerging as one of the premising energy sources to achieve carbon neutral society. To efficiently store and make use of the produced hydrogen by various methods, liquid hydrogen and liquid hydrogen refueling station (LHRS) are spotlighted as solutions for storage and utilization sector respectively. However, technical limitations of cryogenic pumps, heat exchangers and unconsolidated standards for LHRS led to hinder the wide spread of the stations. This paper reviews general technical specifications and safety standards of commercialized small-scale LHRS and suggests technical specifications and safety standards for large-scale LHRS. Especially, an application of separated cryogenic pumps and heat integration for the vaporizer specializes the designed station charging 1000kg of hydrogen per day in this paper from small-scale LHRS and other large-scale LHRS. The authors expect commercializing large-scale LHRS with the proposed technical specification and process system requirements to be able and the safety standards set for the designed station can contribute to the unification of world LHRS standards.

Comparative analysis of fuel cell and battery energy systems for Internet of Things devices

Most Internet of Things (IoT) devices are powered by electrical grids. Therefore, the supply of power to these devices is interrupted by critical grid failures, which can occur during natural disasters. To support the development of IoT devices that can operate during disasters, the most commonly used energy systems were evaluated. In this study, lithium-ion batteries and fuel cells were compared to evaluate and compare their operation time, output power, and general technical specifications. The operating time of the fuel cell 10W was 57 min because of the failure, which was shorter than the other systems. Moreover, an IoT device using Raspberry Pi was evaluated to determine the optimal energy system. Currently, batteries are more cost-effective, however as the cost of fuel cells comes down, the higher power density will be valuable.

Research on the general technical specification for biological filter for nitrogen

Biological filter for nitrogen removal is a new technology of wastewater treatment, which combines biological denitrification and physical filtration. In this paper, the operation status of biological filter for nitrogen removal at home and abroad, the necessity of developing the general technical specification of biological filter for nitrogen removal, and the general technical requirements of biological filter for nitrogen removal are described. Through the application of the research results of the general technical specifications of nitrogen removal biofilters, it is expected to promote the operational efficiency of China’s nitrogen removal biofilters and achieve significant economic, social and environmental benefits.

Concerning the assessment of requirements for the permissible limits of measurement uncertainty for color coordinates of the State Flag of Ukraine

The color of the flag reflects the color preferences of the people and is a constitutive symbol of the nation and state; its stability is too important in the struggle for their existence and survival. In Ukraine, the standard DSTU 4512:2006 ‟The State Flag of Ukraine. General Technical Specifications” is currently in force, which sets out the conditions for the manufacturing of the flag, as well as the requirements for the color characteristics of yellow and blue colors with a limit for the color coordinates in the form of a plane on the graph. The article shows the need to create an appropriate means of comparison, suitable for monitoring the colors of flags, which are manufactured and checked at the enterprises, with reasonable accuracy, and which would meet the requirements specified in the standard DSTU 4512:2006 ‟The State Flag of Ukraine. General Technical Specifications”. As a result of the studies, the substantiated requirements for the uncertainty of certified values of the reference material (working standard) necessary for calibrating an automatic spectrophotometer, which is used in routine (serial, ongoing) measurements to determine and verify the color coordinates of the samples of the State Flag of Ukraine at enterprises, are also considered. A certified reference material should be used to obtain color coordinate units in the measurement processes for determining the color coordinates of the fabrics from which the Flags of Ukraine have been or are being made. According to the key requirement established by the Guidance on reference materials, the reference material (standard sample) must be “created in such a way as to be suitable for the intended use in the measuring process”. The article provides reasonable options of reference materials that meet this requirement. A possible option is also proposed for improving the requirements for standardizing the characteristics of colors given in DSTU 4512:2006 ‟The State Flag of Ukraine. General Technical Specifications”, based on the study and comparison of several possible options.

Стандарт вида общие технические условия как инструмент повышения качества консервов

Стандарт вида общие технические условия как инструмент повышения качества консервов

SERVICEABILITIES AND IDENTIFICATION OF CARBOXYL-CONTAINING ANTIFREEZING AGENTS

All major types of cooling liquids for motor vehicles are describes herein. Various liquids are used to cool internal-combustion engines. Water is the best cooling liquid in the warm season, when the air temperature is above 00С. Liquids with a low freezing point, namely antifreeze agents are used at temperatures below 00С. Low-freezing coolants – antifreeze agents are prepared by mixing water with one or more components that have the ability to lower the freezing point of the solution. The best low-freezing coolants are mixtures of water with glycols – ethylene glycol and propylene glycol. An additive package is added to the antifreeze compound to improve performance. Depending on the nature of the additives, modern antifreeze agents are divided into three types: traditional, carboxylate and hybrid. Traditional antifreeze agents (”tosol cooling agent” and modifications) contain inorganic additives and have a small (no more than 2 years) service life, while they do not stand high (more than 1080C) temperatures. According to the classification of the Volkswagen Audi Group proposed by the group of companies, traditional antifreezes with inorganic additives are designated with symbol G11. Hybrid antifreeze agents (G11+) contain organic and inorganic inhibitors (usually silicates or phosphates). Their service life is up to 3 years. Carboxylate antifreeze agents (G12) contains corrosion inhibitors based on salts of higher carboxylic acids (carboxylates). Carboxylate antifreezes obtain the longest operating life of up to 5 years. When conducting operational tests of various types of antifreeze agents for compliance with the requirements of National State Standard 28084-89 (СТ СЭВ 2130-80), “Low-freezing cooling liquids. General technical specifications” it was found that carboxylate antifreezes are inert to products (automobile radiators) made of aluminum and aluminum alloys, while traditional and hybrid antifreezes have a corrosive effect on aluminum and its alloys. An urgent task in the study of cooling fluids for motor vehicles is the establishment of the nature of additives. For the identification of carboxylate additives in antifreeze agents, it has been proposed to use the method of molecular spectroscopy in the infrared region of the spectrum. For the study, evaporated samples of antifreeze agents are used. Carboxylate additives are characterized by the presence of absorption bands caused by vibrations of carboxyl groups (COOH) at 1560 cm-1 to 1580 cm-1. The abovementioned absorption bands are not typical for traditional (G11) and hybrid (G11+) antifreeze agents and can be used to identify carboxylate additives in the composition of cooling liquids. This makes it possible to differentiate antifreeze agents by species. Key words: automobile antifreeze, operational properties, identification, spectral method.

Resistance of selected aggregates from igneous rocks to alkali-silica reaction: verification

The paper presents investigations into the reactivity of aggregates from igneous rock, carried out in accordance with the procedures contained in the GDDKiA General Technical Specification "Concrete pavements". The aim of the investigations was evaluation of the suitability of the aggregates for road structures and pavements built using cement based concrete technology. Aggregates produced from extrusive rocks (basalt, melaphyre and porphyry) and from intrusive rocks (granite and gabbro) were analysed. The mineral composition of the aggregates was evaluated with regard to their reactive SiO2 content. Expansion tests on mortar bar and concrete prism specimens with analysed aggregates and a microscopic analysis of the alkali-aggregate reaction products were carried out. A considerable amount of reactive minerals: chalcedony, tridymite and microcrystalline quartz and volcanic glass were found in the grains of the porphyry and melaphyre aggregates. On the basis of the conducted investigations the two aggregates made of igneous rocks (melaphyre and porphyry) were classified into category R1 (moderately reactive). The basalt aggregate, the granite aggregate and the gabbro aggregate were assigned to category R0 (non-reactive).

Preparation, Characterization and Modeling of Unbound Granular Materials for Road Foundations

A wide range of granular soils were laboratory prepared as base and sub-base materials in flexible pavements technology. The samples were produced according to the requirements defined in the Spanish General Technical Specifications for Roads and Bridge Works (PG-3), which links to the American Unified Soil Classification System (USCS). The lab-prepared granular soils were characterized by means of particle size distribution, Atterberg limits, non-standard Proctor and California Bearing Ratio (CBR). The determination of CBR has been performed considering the evolution of the penetrability up to one, two, three and four days of immersion. The results show that repeatable values within an acceptable degree of accuracy can be obtained, which indicates good quality laboratory testing conditions. Detailed analytical study is performed on the relationship between CBR index and maximum dry density, finding that a predicting model can be obtained from density variation to estimate representative CBR values for design. The results were compiled in a decision matrix using the Analytical Hierarchy Process (AHP) to estimate a California bearing ratio value (CBR) versus maximum dry density.

Formation and study of the properties of finishing coatings of a circuit board with tin–zinc alloy instead of tin–lead alloy coatings

A formation technique of electroplating coatings of tin–zinc alloy (50) based on using low-toxicity lactic acid as surfactant, ligand, and buffer addition was developed. The dependences of alloy composition and cathodic yield on the alloy current and the coating quality on the concentration of tin and zinc ions in the solution, the content of lactic acid, the solution acidity (pH), the temperature, and the current cathodic density were investigated. The optimum conditions of the process carrying out were determined. The performance characteristics of obtained coatings were investigated. It was proven that the coating with this alloy meets the requirements of GOST (State Standard) 23752–79 “Circuit Boards. General Technical Specifications” and can be used for the circuit boards of products of the instrument-making industry instead of tin–lead alloy, which will make it possible to reduce the environmental risk of production, as well as increase the efficiency and maintainability of devices and systems.

Feasibility of Using Unbound Mixed Recycled Aggregates from CDW over Expansive Clay Subgrade in Unpaved Rural Roads.

Social awareness aims to increase practical skills, such as sustainable development, which seeks to increase the use of different types of waste in construction activities. Although insufficient attention is sometimes given to these actions, it is essential to spread information regarding new studies in the field of waste recycling, which encourages and promotes waste use. Reusing and recycling construction waste in the creation of buildings and infrastructure are fundamental strategies to achieving sustainability in the construction and engineering sectors. In this context, the concept of waste would no longer exist, as waste would become a material resource. Therefore, this study analyses the behaviours of two unbound mixed recycled aggregates (MRA) in the structural layers of an unpaved rural road with low traffic (category T43). The sections were built on inappropriate soil (A-7-6) with a high degree of free swelling. The experimental road consisted of three sections: the first was made with natural aggregates (NA) that were used as a control, the second was composed of MRA in the subbase and NA in the base, and the third section was completely composed of MRA. The materials were characterised in the laboratory. The behaviours of the structural layers in the experimental road were determined by controlling compaction (“in situ” density and moisture) and measuring the deflections and load capacity (deflectometer) during the 18 months after construction. The results show that the sections made with recycled aggregates meet the technical specifications required by General Technical Specifications for Road and Bridge Works (PG-3). Therefore, the water-soluble sulphate content and Los Angeles abrasion coefficient limits can be increased for recycled aggregates without compromising the quality of this type of road with low traffic. To the best of our knowledge, this is the first study regarding the use of unbound MRA made from construction and demolition waste (CDW) in the construction of an unpaved rural road with low traffic on an expansive clay subgrade.

An Investigation of the Seismic Behaviour of an Ancient Masonry Bastion Using Non-Destructive and Numerical Methods

Determining the structural behavior of masonry structures is a challenge due to their lack of homogeneity. The seismic behavior of masonry structures is especially complex. The aim of this study was to examine the structural behavior of Zaganos Bastion using both experimental and numerical methods. The Operational Modal Analysis technique, including the Enhanced Frequency Domain Decomposition Method, and the Stochastic Subspace Identification Method were used to illustrate experimentally the dynamic characteristic of the bastion. A finite element model was developed using ANSYS software in order that the dynamic characteristics of the bastion, including natural frequencies and mode shapes, could be calculated numerically. Seismic analysis was carried out using the 1999 Kocaeli earthquake ground motion record to determine the linear and nonlinear seismic behavior of the bastion. The Turkish Earthquake Code and its general technical specifications were used to evaluate the seismic results. The results show that the maximum and minimum principal stresses exerted on the masonry components exceeded the code requirements at some points, but in general the requirements for the stresses were satisfied.

A study on seismic behaviour of masonry mosques after restoration

Historical masonry structures have an important value for cultures and it is essential for every society to strengthen them and confidently transfer to the future. For this reason, determination of the seismic earthquake response, which is the most affecting factor to cause the damage at these structures, gain more importance. In this paper, the seismic earthquake behaviour of Kaya Çelebi Mosque, which is located in Turkey and the restoration process has still continued after 2011 Van earthquake, is determined. Firstly the dynamic modal analysis and subsequently the seismic spectral analysis are performed using the finite element model of the mosque constructed with restoration drawings in SAP2000 program. Maximum displacements, tensile, compressive and shear stresses are obtained and presented with contours diagrams. Turkish Earthquake Code and its general technical specifications are considered to evaluate the structural responses. After the analyses, it is seen that the displacements and compressive/shear stresses within the code limits. However, tension stresses exceeded the maximum values at some local regions. For this mosque, this is in tolerance limits considering the whole structure. But, it can be said that the tension stresses is very important for this type of the structures, especially between the stone and mortar. So, some additional strengthening solutions considering the originality of historical structures may be applicable on maximum tensile regions.

On the Geotechnical Properties of Lateritic Gravels from the Quarries of Lam-Lam and Mont-Rolland (Western Senegal) – Implications for Their Use in Road Construction

Samples of laterite soils from the quarries of Lam-Lam and Mont-Rolland (Thies Department/Western Senegal) were investigated in the laboratory following the standard procedures suggested by the French norms. The main objective was directed at evaluating the geotechnical properties and the suitability for use as aggregates in road construction. The investigation revealed low load-bearing capacity (CBR of 61-65) as the primary technical parameter that constrained their suitability in road structure based on the general technical specifications. The bulk material meets the requirement for use as aggregates in road sub-grades, but does not fulfill the criteria for use as sub-bases in road construction; thus there is the need for necessary pretreatment in order to enhance their mechanical performance. The observed low bearing capacity can be attributed to the relative abundance of fines particles which tends to decrease the mechanical resistance and performance of aggregates, particularly in wet conditions.

Recycled aggregate in road construction following the Spanish General Technical Specifications for Roads and Bridge Works (PG-3): a case study

This research characterizes four samples of recycled aggregate for their potential use in road construction projects in consonance with the Spanish General Technical Specifications for Roads and Bridge Works (PG-3). Although some fractions were of sufficient quality for the construction of embankments, backfills, and quarry-run fills, they were ultimately found to be unsuitable for the construction of underground drainage, granular structural layers, soil stabilization and concrete pavements. They were negatively evaluated because of their particle size distribution and sulfate content. Nevertheless, the quality of this recycled aggregate could be substantially improved by manually removing the gypsum before the crushing process at the plant or by selecting the material with greater care at the beginning of the process. Finally, we suggest that Construction and Demolition (C&D) waste plant managers should modify the manufacturing process to obtain a suitable particle size distribution in accordance with PG-3 requirements and the projected use of the aggregate.

A comparative study of recycled aggregates from concrete and mixed debris as material for unbound road sub-base

Seven different types of recycled aggregates from construction and demolition waste (CDW) have been evaluated as granular materials for unbound road sub-bases construction. The results showed that recycled concrete aggregates complied with all specifications for using in the construction of unbound structural layers (sub-base) for T3 and T4 traffic categories according to the Spanish General Technical Specification for Road Construction (PG-3). Some mixed recycled aggregates fell short of some specifications due to a high content of sulphur compounds and poor fragmentation resistance. Sieving off the fine fraction prior to crushing the mixed CDW reduce the total sulphur content and improve the quality of the mixed recycled aggregates, by contrast, pre-sieving concrete CDW had no effect on the quality of the resulting aggregates. The results were compared with a crushed limestone as natural aggregate.

Construction demolition wastes, Waelz slag and MSWI bottom ash: A comparative technical analysis as material for road construction

The objective of the study is to analyze the technical suitability of using secondary materials from three waste flows (construction and demolition waste (CDW), Waelz slag and municipal solid waste incineration (MSWI) bottom ash), under the regulations and standards governing the use of materials for road construction. A detailed technical characterization of the materials was carried out according to Spanish General Technical Specifications for Road Construction (PG3). The results show that Waelz slag can be adequate for using in granular structural layers, while CDW fits better as granular material in roadbeds. Likewise, fresh MSWI bottom ash can be used as roadbed material as long as it does not contain a high concentration of soluble salts. This paper also discusses the adequacy of using certain traditional test methods for natural soils when characterizing secondary materials for use as aggregates in road construction.

Assessment of Misalignments in Some Selected Buildings in Jordan and Their Structural Effects

Abstract A field survey was performed to assess horizontal and vertical misalignments and their structural effects in some selected buildings in Irbid City, Jordan. Fifty-two building units were selected as representative of the construction practice of residential buildings in Jordan after the Gulf War during the nineties. Buildings in the inventory were low-rise with one to four stories above ground. Story height ranged typically from 2.80 to 3.30 m. Field measurements for misalignments in the exterior elements of twentyone buildings were collected. Twelve of these buildings have concrete-backed stone masonry walls that serve as bearing walls, and nine buildings have skeletons which serve as reinforced concrete frames in-filled with hollow concrete blocks. Also, field measurements for misalignments in the interior elements of thirty-one buildings with skeletons of reinforced concrete frames filled in with hollow concrete blocks have been collected using the concept of the intersection algorithm. Average values of measured misalignments for every type of construction are compared with the tolerances according to the Jordanian Standards, General Technical Specifications for Buildings, and ACI Standards. All measured misalignments exceed the tolerances in both standards except for the vertical alignment of the interior reinforced concrete frames filled in with hollow concrete blocks. The maximum values for the ratio between the measured misalignments and the tolerances were in the exterior concretebacked stone masonry walls, which reached 31.5 for the horizontal misalignment, and 3.4 for the vertical misalignment, according to the Jordanian Code. The reason for the different ratios between the interior and the exterior misalignments is due to more difficult environmental conditions for outside construction compared with inside construction. The value 3.4 for vertical misalignment compared with 31.5 for horizontal misalignment reflects the importance of using checking and surveying equipment (such as level and plumb) for every stone course (25 cm height), while lines and other checking equipment are used for horizontal distances which range between 12 and 15 m. Moreover, misalignment sensitivity analysis was carried out for a typical reinforced concrete frame, which consisted of three spans continuous beam and four-story height, for the purpose of studying its effect on the static actions in the plane frame. Results indicated that horizontal misalignments have negligible effect on the static actions, however, vertical misalignment starts to have an effect at a value of 2.5% (e.g., at 3% vertical misalignment and 2.5% horizontal misalignment the required ratio of steel in the column has increased from 0.0100 to 0.0219).

Control of defect parameters of 300D90 pumps after overhaul

This article tests ten overhauled 300D90 pumps in order to determine the admissible deviations of pressure heads and efficiency, and in order to formulate general technical specifications (TS) for the overhaul of D-type pumps. The operation and maintenance of 300D90 pumps under Siberian conditions showed that the inner surfaces of the housing components of the pumps have to be restored by surfacing and the rotors and slot seals have to be replaced by those reconditioned in the repair works. The average head of the overhauled pump was 26.9 m and the average efficiency was 81.3%. A comparison of the values obtained with the specifications of new pumps showed that the overhauled pumps have a head 1.3 times higher and an efficiency 9.1% lower than those specified for new pumps. It is determined that the deviation of the parameters of the overhauled pumps from the rated parameters can be reduced by improving the repair quality.