Laboratory Device Research Articles

Simulation and Experiments on Optimization of Vortex-Induced Vibration Power Generation System Based on Side-by-Side Double Blunt Bodies

In order to improve the utilization efficiency of converting low-flow current energy into electric energy for Reynolds number 10,000 ≤ Re ≤ 40,000, this paper proposes a vortex-induced vibration power generation system based on a side-by-side double blunt body. In this system, the side-by-side double blunt body structure is used in the current energy capture part to enhance the collection of low-flow current energy; the permanent magnet linear motor is used in the electric energy conversion part to improve the efficiency of electric energy conversion; and a laboratory device is constructed for testing. The effects of the blunt body structure parameters and the center spacing ratio on the energy harvesting performance of the system are qualitatively explained by constructing a simulation model. Compared with the single blunt body energy capture structure, the side-by-side double blunt body structure increases the vibration amplitude by 1.04 times and the lift by 1.14 times at the center spacing S/D = 2.4. Meanwhile, energy harvesting can be realized at a lower flow velocity, increasing the vortex-induced vibration’s energy capture range. Finally, the power generation system was experimentally verified in the laboratory, and the results showed that the vibration amplitude of the double blunt body structure was increased by 1.12 times compared to the single blunt body. The maximum output power of the generator is 10.55 W when the water velocity is 0.7 m/s. The energy conversion efficiency of the power generation system can reach a maximum of 52.93%, which is 12.33% higher than that of a single blunt body structure, which proves that the system has a higher power conversion efficiency than that of a conventional single conversion system.

Factors associated with failure of intraosseous access in prehospital trauma treatment by military medical personnel

IntroductionIntraosseous devices have become an alternative to peripheral intravenous (PIV) access. Despite the established success of intraosseous devices in laboratory and simulator studies, there is a lack of data regarding...

A-349 Evaluation of i-STAT® Point of Care Blood Gas Cartridges and Competitor Blood Gas Devices Against Reference Standard for PCO2 and PO2

Abstract Background The i-STAT System provides laboratory quality results in minutes at the patient’s bedside. Accurate and rapid test results are critical for clinical decision making in the presence of blood gas disorders, including oxygenation and acid-base status, where the partial pressure oxygen (PO2) and partial pressure carbon dioxide (PCO2) are needed. The purpose of this study was to compare the analytical performance of the PO2 and PCO2 tests in the i-STAT G3+ and i-STAT CG8+ cartridges to the theoretical PO2 and PCO2 in prepared reference standards. Two other blood gas instruments, a benchtop device and a laboratory device were also compared to the reference PO2 and PCO2. Methods Venous whole blood samples were contrived using saturation tonometry with U.S. NIST (National Institute of Science and Technology) traceable gas tanks to prepare the reference standards, which were value assigned to theoretical PO2 or PCO2 levels based on the molar composition of the gas mixture used. Eleven levels spanning the reportable range of each PO2 (5 mmHg - 800 mmHg) and PCO2 (5 mmHg - 130 mmHg) were prepared and tested in duplicate on the i-STAT G3+ and i-STAT CG8+ cartridges, benchtop device, and the laboratory device. Passing-Bablok linear regression analysis was performed to evaluate the slope and correlation coefficient, comparing each blood gas device against the reference PO2 and PCO2 values. Study designs followed CLSI (Clinical and Laboratory Standards Institute) EP09C-ED3:2018, Measurement Procedure Comparison and Bias Estimation using Patient Samples, 3rd Edition. Passing-Bablok regression analysis was also performed for the i-STAT cartridges and benchtop device against the laboratory device. Results The regression analysis was performed against the reference standards. For PO2, slopes for the i-STAT cartridges ranged from 0.93 - 0.97, the slope for the benchtop device was 0.99, and the slope for the laboratory device was 0.97. Correlation coefficients for all devices were 1.00. For PCO2, slopes for the i-STAT cartridges ranged from 0.98 - 1.02, the slope for the benchtop device was 0.85, and the slope for the laboratory device was 1.01. Correlation coefficients were 1.00 for the i-STAT cartridges and laboratory device, and 0.99 for the benchtop device. The regression analysis was also performed against the laboratory device. For PO2, slopes for the i-STAT cartridges ranged from 0.96 - 1.00, and the slope for the benchtop device was 1.02. Correlation coefficients for all devices were 1.00. For PCO2, slopes for the i-STAT cartridges ranged from 0.97 - 1.01, and the slope for the benchtop device was 0.85. Correlation coefficients were 1.00 for the i-STAT cartridges and 0.99 for the benchtop device. Conclusions The study demonstrated that the i-STAT G3+ and i-STAT CG8+ cartridges used with the i-STAT System were shown to provide laboratory quality results within 2 minutes, showing good agreement to both reference standards and laboratory quality devices. For PCO2, the i-STAT System was shown to have better agreement to both theoretical reference standards and the laboratory device than the benchtop device. These studies were funded by Abbott Laboratories.

УТИЛИЗАЦИЯ МЕТАЛЛИЧЕСКОГО ПОРОШКА ВЫСОКОУГЛЕРОДИСТОГО ФЕРРОХРОМА МЕТОДОМ САМОРАСПРОСТРАНЯЮЩЕГОСЯ ВЫСОКОТЕМПЕРАТУРНОГО СИНТЕЗА (СВС)

This article discusses the methods of recycling high-carbon ferrochrome metal powder by self-propagating high-temperature synthesis. The article is devoted to the study of aspiration metal dusts formed during the production of ferroalloys. The article analyzes the composition of the source material, its physicochemical properties, and the impact on the testing process. The publication touches upon the relevance of this topic and the advantages of the self-propagating high-temperature synthesis method. Particular attention was paid to comparative analyses of this method from other traditional material processing processes. This article will help to consider the problem of environmental pollution and the impact of traditional metallurgical processes on the ecosystem. The authors also analyze in detail the physical properties of the original powder samples and their combustion temperature mode. The publication shows the process flow charts, laboratory devices, and the type of resulting material. This article provides a detailed analysis of the types of laboratory devices, their physical and mechanical properties. The publication provides a thorough and detailed chemical analysis of the resulting material. In the course of the study, the expected results were obtained, which are presented in the form of tables and a figure. The article consists of an introduction, main part, conclusion, conclusion and list of references.

Autoimmune Optic Neuropathy

Autoimmune optic neuropathy represents a chronic, heterogeneous disease that is usually accompanied by bilateral vision loss and is caused by injury occurring through autoimmune mechanisms. Autoimmune optic neuropathy can occur as a component of autoimmune or collagen vascular diseases, as well as it can be seen in an isolated way. Plasmapheresis and monoclonal antibodies are used together with steroids in the treatment of autoimmune optic neuropathy, the pathophysiology of which is not yet fully understood despite advances in existing laboratory and imaging devices. This rare clinical picture usually results in vision loss when it is not properly diagnosed, treated quickly and effectively.

An at-home and electro-free COVID-19 rapid test based on colorimetric RT-LAMP.

In the fight against virus-caused pandemics like COVID-19, diagnostic tests based on RT-qPCR are essential, but they are sometimes limited by their dependence on expensive, specialized equipment and skilled personnel. Consequently, an alternative nucleic acid detection technique that overcomes these restrictions, called loop-mediated isothermal amplification following reverse transcription (RT-LAMP), has been broadly investigated. Nevertheless, the developed RT-LAMP assays for SARS-CoV-2 detection still require laboratory devices and electrical power, limiting their widespread use as rapid home tests. This work developed a flexible RT-LAMP assay that gets beyond the drawbacks of the available isothermal LAMP-based SARS-CoV-2 detection, establishing a simple and effective at-home diagnostic tool for COVID-19. A multiplex direct RT-LAMP assay, modified from the previously developed test was applied to simultaneously identify the two genes of SARS-CoV-2. We used a colorimetric readout, lyophilized reagents, and benchmarked an electro-free and micropipette-free method that enables sensitive and specific detection of SARS-CoV-2 in home settings. Forty-one nasopharyngeal swab samples were tested using the developed home-testing RT-LAMP (HT-LAMP) assay, showing 100% agreement with the RT-qPCR results. This is the first electrically independent RT-LAMP assay successfully developed for SARS-CoV-2 detection in a home setting. Our HT-LAMP assay is thus an important development for diagnosing COVID-19 or any other infectious pandemic on a population scale.

Experimental and numerical investigation of the TBM disc cutter wear using a new tunnel boring machine laboratory simulator

One of the essential and practical issues on TBM performance is the wear during the excavation process of abrasive and resistant rock. The wear of the disc cutter, which is caused by the gradual and uniform reduction of the diameter of the disc cutter, is caused by the rock-machine interaction during excavation, and various factors can intensify this phenomenon and reduce the wear life of the disc cutter. To obtain a proper view of the relationship between the operating parameters of the excavation machine and the disc cutter wear, a new laboratory device has been designed and built in the mechanized excavation laboratory of the Sahand University of Technology. By using this device, the amount of wear of cutting tools in excavation machines can be obtained against rough rock samples, and from the results, the amount of wear of cutting tools of excavation machines can be minimized so that the efficiency of the excavation machine can be increased. In the current research, the laboratory wear results obtained from this device have been compared with those obtained from the numerical modelling of the same device in PFC3D discrete element software, both for the cutting blades and the sample itself. This research showed that in the first abrasion stage of the sample, the difference in the abrasion weight of the experimental study and numerical modelling for the samples varies from 0.91 to 0.768 g, and the average is 0.202 g. Also, the difference between the abrasion percentage of laboratory study and numerical simulation for the samples varies from 6 to 14 %, and the average is 10 %. In step 2 of abrasion, the difference in the abrasion weight of the experimental study and numerical modelling for the samples varies from 0.118 to 0.556 g, and the average is 0.278 g. Also, the difference in the abrasion percentage of laboratory study and numerical simulation for the samples varies from 7 to 14 %, and the average is 11 %. The results of the new tunnel boring machine laboratory simulator revealed insights into wear behavior during different stages of excavation.

Measuring the operational performance of an artificial intelligence-based blood tube-labeling robot, NESLI.

Laboratory testing, crucial for medical diagnosis, has 3 phases: preanalytical, analytical, and postanalytical. This study set out to demonstrate whether automating tube labeling through artificial intelligence (AI) support enhances efficiency, reduces errors, and improves outpatient phlebotomy services. The NESLI tube-labeling robot (Labenko Informatics), which uses AI models for tube selection and handling, was used for the experiments. The study evaluated the NESLI robot's operational performance, including labelling time, technical problems, tube handling success, and critical stock alerts. The robot's label readability was also tested on various laboratory devices. This research will contribute to the field's understanding of the potential impact of automated tube-labeling systems on laboratory processes in the preanalytical phase. NESLI demonstrated high performance in labeling processes, achieving a success rate of 99.2% in labeling parameters and a success rate of 100% in other areas. For nonlabeling parameters, the average labeling time per tube was measured at 8.96 seconds, with a 100% success rate in tube handling and critical stock warnings. Technical issues were promptly resolved, affirming the NESLI robot's effectiveness and reliability in automating the tube-labeling processes. Robotic systems using AI, such as NESLI, have the potential to increase process efficiency and reduce errors in the preanalytical phase of laboratory testing. Integration of such systems into comprehensive information systems is crucial for optimizing phlebotomy services and ensuring timely and accurate diagnostics.

Exoland Simulator, a Laboratory Device for Reflectance Spectral Analyses of Planetary Soil Analogs: Design and Simulation

In planetary science, visible (Vis) and near-infrared (NIR) reflectance spectra allow deciphering the chemical/mineralogical composition of celestial bodies’ surfaces by comparison between remotely acquired data and laboratory references. This paper presents the design of an automated test rig named Exoland Simulator equipped with two reflectance spectrometers covering the 0.38–2.2 µm range. It is designed to collect data of natural/synthetic rocks and minerals prepared in the laboratory that simulate the composition of planetary surfaces. The structure of the test rig is conceived as a Cartesian robot to automatize the acquisition. The test rig is also tested by simulating some project trajectories, and results are presented in terms of its ability to reproduce the programmed trajectories. Furthermore, preliminary spectral data are shown to demonstrate how the soil analogs’ spectra could allow an accurate remote identification of materials, enabling the creation of libraries to study the effect of multiple chemical–physical component variations on individual spectral bands. Despite the primary scope of Exoland, it can be advantageously used also for tribological purposes, to correlate the wear behavior of soils and materials with their composition by also analyzing the wear scars.

Foam-laid extensible paper for improved extensibility and press-forming performance

This study was motivated by the recent raising interest for the sustainable plastic-free dry 3D formable materials. 3D forming processes are capable to produce large unit quantities, but the process conditions for packaging applications have been typically very demanding for cellulose-based materials. This study covers some of the key factors affecting the extensibility of cellulose fibre-based materials and presents a laboratory-scale development study of a press-formable material concept. The investigation focused on comparisons of two refining concepts for bleached softwood kraft (BSK) pulp and two sheet forming concepts, namely water-laid and foam-laid forming. Additionally, influence of thermoplastic additives on the extensibility and 3D forming performance were investigated. In-plane compaction was applied with Expanda® laboratory device. Performance of the materials was evaluated by tensile tests and depth of the 3D formed shapes. In this study, in-plane compaction at first in cross-machine direction (CD) and then in machine direction (MD) led to over 30% elongation with BSK-based laboratory sheets containing latex as a binder and foaming agent. In addition to high elongation, optimal strength was needed for the best press-forming performances. In-plane compaction was the most significant factor regarding the elongation, but it also decreased the strength of the materials. Similar press-forming performance was found with two materials with either highly anisotropic or more isotropic elongation. The elongation anisotropy was created by one-way and two-way in-plane compactions. The results indicate that a reasonable performance for BSK-based materials for 3D forming applications can be reached using the presented concept.

Analisis Keamanan Jaringan Menggunakan Mikrotik Pada Lab Komputer STMIK Widuri

This study discusses the network security analysis using MikroTik devices in the computer laboratory of STMIK Widuri. The main objective of this research is to evaluate the level of network security in the computer laboratory by implementing appropriate configurations using MikroTik devices. The methods employed include literature review on network security, analysis of network topology in the laboratory, and implementation of security solutions using MikroTik devices. Data collected include security testing results, network performance, and user satisfaction levels. The research findings indicate that the implementation of security solutions with MikroTik effectively enhances network security in the computer laboratory of STMIK Widuri. This study contributes to a practical understanding of using MikroTik in improving network security in campus environments

Performance Evaluation of Physical Properties on Zinc Sulfide (ZnS)-based Field Effect Transistor

The paper presents the performance evaluation of physical properties on Zinc Sulfide (ZnS)-based Field Effect Transistor. The most famous III-V compound-based semiconductor devices have several affected to the environment and the toxic contents are directly responded to the society. Due to the lack of technology on nontoxic compound-based semiconductor device fabrications, the novel device with II-VI compound materials are challenging issues for the environments. The specific objectives of doing research on fabrication of II-VI compound-based semiconductor devices in advanced laboratories are to emphasize the numerical modeling of the device structure and designing the FET based on ZnS material, to contribute the mathematical model for physical characteristics of the FET structure and the modification of the device structure will be easily established by using numerical simulation. The mathematical analyses on physical properties of device structure with ZnS material are confirmed and observed the several properties of electrical and electronic characteristics. The detailed implementations for ZnS-based FET devices are performed and evaluated the performance of the developed FET devices. There are two steps analyses in physical properties of ZnS-based FET devices with numerical implementation by MATLAB languages. The results observed in this study could be confirmed with the recent works from several research laboratories and the developed ZnS-based FET devices could be utilized in high performance wide band applications on switching in the power electronics and amplification purposes in modern amplifier design in real world applications.

Comparison of heat transfer characteristics of a heat exchanger with straight helical tube and a heat exchanger with coiled flow reverser

Vertical shell and coiled tube heat exchangers are an important aspect of numerous industrial processes and are renowned for their high heat transfer efficiency, versatility, compact design, easy manufacturability and maintenance. As a novel technique, a coiled flow reverser was used to enhance the thermal performance of shell and coiled tube heat exchangers. Therefore, the impact of employing a coiled flow reverser on the heat transfer characteristics and pressure drop in a counter-current shell and tube heat exchanger is investigated using both numerical and experimental approaches. The results are compared to a straight helical coiled tube heat exchanger. The numerical simulations were carried out by employing computational fluid dynamics (CFD) techniques, and the SIMPLE scheme was implemented through the second-order upwind discretization method. The laboratory device used for experimentation features a shell with an inner diameter of 15 cm, and the coil pitch and coil diameter of both coiled tubes are set at 3 cm and 12.1 cm, respectively. Results reveal that the overall heat transfer coefficient of the heat exchanger with a coiled flow reverser is 39.5 % to 49.9 % higher than that of the heat exchanger with a straight helical tube. The effectiveness ratio of the heat exchanger with coiled flow reverser to the straight helical tube heat exchanger ranges from 1.254 to 1.379. Optimal results are observed at a cold flow rate of 6 LPM and a hot flow rate of 1 LPM for both heat exchangers. Additionally, the coiled flow reverser enhances heat transfer performance at the cost of increased pressure drop. Numerical results are in good agreement with experimental findings, establishing the reliability of the study.

Development and testing of a stand for studying the dynamics of an inertial screen with two motor-vibrators

Purpose. To substantiate the design of a stand for studying the dynamics of transient modes of an inertial screen with two motor-vibrators and to develop a methodology for conducting a physical experiment to study the dynamics of the screen. The methods. To conduct a physical experiment, a laboratory stand was developed to study the dynamics of screens. The bench consists of an inertial screen with a piezoelectric acceleration sensor KD 35-2, a system of laboratory devices for acoustic and vibration measuring equipment Robotron, and a computer with installed software. The obtained data are analyzed using software that allows to display graphs of oscillations in different directions: vertical, horizontal and at an angle of 45. Findings. A stand for analyzing the dynamics of screens was developed and tested. The results show that the computer modeling data and physical measurements are consistent. The maximum amplitude of vertical vibrations in the center of the screen was 24.71 mm, horizontal displacements reached 18.6 mm, and amplitude vibrations at an angle of 45° – 26.41 mm. The average deviation between the experimental and modeled data does not exceed 9%, which confirms the accuracy of the calculations. The originality. This study presents for the first time a laboratory testbed for studying the dynamics of inertial two-drive screens using piezoelectric sensors and the Robotron vibrometry system. The uniqueness of the work lies in the development of a laboratory bench that allows for accurate measurement of amplitudes in real time, as well as the comparison of results with data from models developed in SolidWorks. Practical implementation. The results of the developed methodology for studying physical prototypes of inertial double-drive screens can be used to optimize the design of vibrating screens in industry. The proposed approach makes it possible to accurately assess the dynamic characteristics of screens and determine the optimal parameters of their operation, which helps to reduce energy consumption and increase the efficiency of the material sorting process.

Microcontroller-Optimized Measurement Electronics for Coherent Control Applications of NV Centers.

Long coherence times at room temperature make the NV center a promising candidate for quantum sensors and quantum computers. The necessary coherent control of the electron spin triplet in the ground state requires microwave π pulses in the nanosecond range, obtained from the Rabi oscillation of the mS spin states of the magnetic resonances of the NV centers. Laboratory equipment has a high temporal resolution for these measurements but is expensive and, therefore, uninteresting for fields such as education. In this work, we present measurement electronics for NV centers that are optimized for microcontrollers. It is shown that the Rabi frequency is linear to the output of the digital-to-analog converter (DAC) and is used to adapt the time length π of the electron spin flip, to the limited pulse width resolution of the microcontroller. This was achieved by breaking down the most relevant functions of conventional laboratory devices and replacing them with commercially available integrated components. The result is a cost-effective handheld setup for coherent control applications of NV centers.

Towards the Optimization of a Photovoltaic/Membrane Distillation System for the Production of Pure Water.

The production of pure water plays a pivotal role in enabling sustainable green hydrogen production through electrolysis. The current industrial approach for generating pure water relies on energy-intensive techniques such as reverse osmosis. This study unveils a straightforward method to produce pure water, employing real-world units derived from previously simulated and developed laboratory devices. This demonstrated system is cost-effective and boasts low energy consumption, utilizing membrane distillation (MD) driven by the waste heat harnessed from photovoltaic (PV) panels. In a previous study, modeling simulations were conducted to optimize the multi-layered MD system, serving as a blueprint for the construction of prototype devices with a suitable selection of materials, enabling the construction of field-testable units. The most efficient PV-MD device, featuring evaporation and condensation zones constructed from steel sheets and polytetrafluoroethylene (PTFE) membranes, is capable of yielding high-purity water with conductivity levels below 145 μS with high flux rates.

Si,N co-doped carbon quantum dots in mesoporous molecular sieves: A fluorescence sensing platform for Cr(VI) detection

Carbon quantum dots (CQDs) are highly efficient fluorescent probes for metal ion detection; however, they are limited by non-uniform particle size, aggregation, and the inability to facilitate quantitative analysis. Herein, a smart host–guest strategy is utilized, wherein CQDs are immobilized in mesoporous molecular sieves, proving to be an effective method to minimize these drawbacks. Si,N-CQDs@SBA-15 is successfully synthesized by the one-step hydrothermal route using Si,N-CQDs precursor materials as guests and the mesoporous molecular sieve SBA-15 as the host. A good linear relationship between the concentration of Cr(VI) ions and fluorescent intensity is observed from 0 μM to 100 μM (R2 = 0.9986). Thelimitofdetection(LOD) is 0.213 μM, approximately three times lower than that of pristine Si,N-CQDs (0.677 μM). Additionally, Si,N-CQDs@SBA-15 exhibit good detection selectivity for Cr(VI) detection over other metal ions. Moreover, a smartphone-based laboratory device and RGB analysis app are employed to capture and analyze fluorescence images, revealing a LOD for Cr(VI) of 0.201 μM. Förster Resonance Energy Transfer (FRET) is identified as the possible mechanism for the fluorescence quenching of Si,N-CQDs@SBA-15 by Cr(VI) through UV–vis and fluorescence experiments. The practicability of the synthesized fluorescent probes is further validated in river water, yielding satisfactory spiked recoveries ranging from 99.24 % to 106.21 %.

ТЕХНОЛОГІЇ ОДЕРЖАННЯ ПОЛІМЕРНИХ КОМПОЗИЦІЙ ДЛЯ ВИГОТОВЛЕННЯ ПОГОНАЖНИХ ВИРОБІВ

The work is devoted to the characteristics of the technologies for obtaining a polymer composition for the manufacture of decorative products. Research is focused on the technology of manufacturing polymer composite material based on polyvinyl chloride for the production of rigid pipes, fittings, sidings, windows and doors, profiles, fences, railings, various devices, valves, housings of inspection lights, ventilation ducts, fans, heat exchange equipment, parts of chemical equipment , laboratory devices and other products. The paper describes the manufacturing technology of the PVC composition and investigates the important performance characteristics of the polymer melt. Three common technologies are presented, they are rolling, calendering and extrusion. The most common material for the manufacture of polymer. This composition is most often obtained by the extrusion method, so this section focuses on this technology in more detail resin products is a polyvinyl chloride composition. The stiffness of the polymer is characterized by the modulus of elasticity during bending. To determine this indicator, samples of polymer material without irradiation and with UV irradiation for a certain period of time were used. When the content of chalk in the recipe increases, the hardness increases. All compositions are characterized by approximately the same character - with exposure to six hours, the modulus of elasticity decreases, and with further exposure, it begins to gradually increase. The combination of а filler and a polymer is the most powerful for use in PVC compositions in the manufacture of decorative products.

Development and application of low-melting-point microencapsulated phase change materials for enhanced thermal stability in cementing natural gas hydrate layers

In the exploration of deep-water oil and gas resources, encountering natural gas hydrate (NGH) layers poses significant challenges, particularly during cementing operations critical for wellbore stabilization. This study proposes a strategy employing cement slurries integrated with micro-encapsulated phase change materials (MPCMs) to address the destabilization of NGH layers, a key obstacle in deep-water cementing. MPCMs containing BaCO3 shell and low-melting binary PCMs in the core were synthesized by the self-assembly method. The structure and thermal properties of MPCMs were thoroughly characterized. MPCMs exhibited a distinct core-shell structure with a hydrophilic and well-sealed shell. Their phase change temperatures were in closely matched the temperatures found in NGH formations, at 3.5 °C and 13.9 °C. A comprehensive evaluation of the fundamental properties of cement slurries containing MPCMs (CSM) was conducted, including thermal stability, setting time, pore structure, and mechanical strength. Additionally, a laboratory device was employed to simulate cementing operations, allowing for intuitive analysis of the impact of hydration heat evolution on NGH stability—a notably underexplored aspect in related literature. The results demonstrated that MPCMs effectively reduced the hydration heat generated by cement slurry within the initial 36 h. Specifically, at a 9% MPCMs dosage, the hydration heat of CSM decreased by 19.0%, resulting in the sustained stability of NGH. In contrast, the control group's cementing process directly led to the complete decomposition of NGH. Even at lower MPCMs concentrations, the decomposed NGH was more likely to recrystallize and return to a stable state due to the slower hydration heat release rate of CSM. This study not only provides evidence of the effectiveness of MPCMs as heat inhibitors in reducing the disruption of hydrate stability during well cementing but also provides theoretical guidance for the design and application of cement slurries for NGH reservoirs. By enhancing the stability of NGH layers, this work supports the safe and efficient exploitation of undersea hydrocarbon resources, contributing to shaping future global energy strategies.

Measuring Device Detecting Impact Forces on Impact Rollers

This paper presents laboratory devices on which measurements were carried out to prove the validity of the assumption about the reduction in vibrations transmitted to the conveyor belt structure generated by the impact forces of falling material grains in the places of transfer or on the hoppers of conveyor belts. In order to limit damage to the conveyor belts caused by the impact of the sharp edges of material grains, conveyor belts are supported by impact rollers or impact rubber rods. A special modification of the fixed conveyor idler is presented, which consists of inserting plastic brackets into the structurally modified roller axle holders of the fixed conveyor idler. Measurements showed that the specially modified fixed conveyor idler resulted in a higher damping of up to 15% of the impact forces of the falling weight on the rubberized hoop of the impact roller shell compared to the conventional fixed conveyor idler design. Measurements carried out show that the effective vibration velocity values detected at the points where the impact roller axis fits into the fixed roller table holder are higher than when using plastic brackets, up to 6% for a 108-mm-diameter roller, compared to steel impact roller brackets.