Portable Unit Research Articles

England RCT of air filtration to prevent respiratory infections (including covid-19) in care homes

Abstract Context There is evidence that portable high-efficiency-particulate-air (HEPA) filtration units remove microbial particles from the air, but it is unclear whether this is sufficient to reduce infections in care home residents. Objectives To investigate the effectiveness of portable HEPA filtration units for winter respiratory infection episode reduction in care home residents. Study design and analysis: Cluster controlled trial with intention-to-treat analysis. Setting: 90 residential care homes for older adults in England. Population: Residents expected to reside in the care home for ≥1 month. Intervention care homes: Five HEPA filtration units in communal rooms and one HEPA filtration unit in 10 to 16 bedrooms. Control care homes: Usual care. Outcome measures: The primary outcome is the number of symptomatic winter respiratory infection episodes recorded by care home staff. Secondary outcomes: other infection measures; falls /near falls; laboratory confirmed infections; hospitalisations; and staff sickness. Process evaluation to assess intervention acceptability and implementation. Results Care homes were randomised between January 2022 and February 2024, 43 to intervention and 47 to usual care. Respectively, in intervention and control group care homes: 43% and 45% provided nursing care; 87% and 87% dementia care; and median (IQR) number of communal rooms were 4 (3-5) in both groups. 1126 residents were consented, of whom 31 (3%) moved away; 151 (13%) died; and 5 stopped participating. Primary outcome data is 98% complete with 175,318 'resident days' symptom data collected. Comparing intervention and control group residents: median (IQR) age was 88 (81-92) and 88 (82-92) years; 33% and 43% were receiving nursing care; 58% and 57% had dementia; frailty scores were 6 (4-7) and 6 (5-7); 94% and 94% received influenza; and 97% and 95% COVID vaccines. Conclusions Final analytic results of this world-first RCT will be available for the conference. Key messages • This world-first RCT using HEPA filters in care homes will report the evidence of effectiveness of respiratory infection episode reduction in care home residents. • The trial will inform policy makers about the effectiveness, acceptability and implementation of HEPA filters in care homes.

Manoeuvring in shallow and confined water with model predictive track controllers

Abstract Autonomous and computer-assisted navigation, for example through portable pilot units and data-driven decision supportive systems, is in full development. Remote-controlled vessels (manned but without a captain steering continuously on board) are used in Belgium (by Seafar in inland shipping) but also in other countries. A model predictive controller has been used to investigate environmental and operational parameters for the passage of the river Seine in Paris by different ship types. These fast-time simulations have been compared with simulations in real time executed by skippers on a ship manoeuvring simulator or measured real life tracks. A good predictability of the real situation requires accurate manoeuvring models. But what if this accuracy cannot be guaranteed? An illustration is made by comparing the tracks if, in the prescience prediction phase for the controller, wind or bank effects are neglected or doubled. The development of model predictive deep reinforcement learning control algorithms for navigation will be one of the challenges of the Data-driven Smart Shipping project that started May 2024.

Energy expenditure prediction in preschool children: a machine learning approach using accelerometry and external validation

Objective.This study aimed to develop convolutional neural networks (CNNs) models to predict the energy expenditure (EE) of children from raw accelerometer data. Additionally, this study sought to external validation of the CNN models in addition to the linear regression (LM), random forest (RF), and full connected neural network (FcNN) models published in Steenbocket al(2019J. Meas. Phys. Behav.294-102).Approach.Included in this study were 41 German children (3.0-6.99 years) for the training and internal validation who were equipped with GENEActiv, GT3X+, and activPAL accelerometers. The external validation dataset consisted of 39 Canadian children (3.0-5.99 years) that were equipped with OPAL, GT9X, GENEActiv, and GT3X+ accelerometers. EE was recorded simultaneously in both datasets using a portable metabolic unit. The protocols consisted of a semi-structured activities ranging from low to high intensities. The root mean square error (RMSE) values were calculated and used to evaluate model performances.Main results.(1) The CNNs outperformed the LM (13.17%-23.81% lower mean RMSE values), FcNN (8.13%-27.27% lower RMSE values) and the RF models (3.59%-18.84% lower RMSE values) in the internal dataset. (2) In contrast, it was found that when applied to the external Canadian dataset, the CNN models had consistently higher RMSE values compared to the LM, FcNN, and RF.Significance.Although CNNs can enhance EE prediction accuracy, their ability to generalize to new datasets and accelerometer brands/models, is more limited compared to LM, RF, and FcNN models.

LibERI-A portable and performant multi-GPU accelerated library for electron repulsion integrals via OpenMP offloading and standard language parallelism.

A portable and performant graphics processing unit (GPU)-accelerated library for electron repulsion integral (ERI) evaluation, named LibERI, has been developed and implemented via directive-based (e.g., OpenMP and OpenACC) and standard language parallelism (e.g., Fortran DO CONCURRENT). Offloaded ERIs consist of integrals over low and high contraction s, p, and d functions using the rotated-axis and Rys quadrature methods. GPU codes are factorized based on previous developments [Pham et al., J. Chem. Theory Comput. 19(8), 2213-2221 (2023)] with two layers of integral screening and quartet presorting. In this work, the density screening is moved to the GPU to enhance the computational efficacy for large molecular systems. The L-shells in the Pople basis set are also separated into pure S and P shells to increase the ERI homogeneity and reduce atomic operations and the memory footprint. LibERI is compatible with any quantum chemistry drivers supporting the MolSSI Driver Interface. Benchmark calculations of LibERI interfaced with the GAMESS software package were carried out on various GPU architectures and molecular systems. The results show that the LibERI performance is comparable to other state-of-the-art GPU-accelerated codes (e.g., TeraChem and GMSHPC) and, in some cases, outperforms conventionally developed ERI CUDA kernels (e.g., QUICK) while fully maintaining portability.

Validity and Reliability of Wearable Technology Devices during Simulated Pickleball Game Play

Pickleball is a popular sport. Also popular is wearable technology usage. Because the validity and reliability of wearable technology during pickleball is unknown, the purpose of this research was to evaluate the ability of common devices to return heart rate and estimated energy expenditure during pickleball activity. Twenty adult participants were outfitted with a portable metabolic unit and heart rate monitor (criterion measures). Experimental devices were a Garmin Instinct, Polar Vantage M2, Polar OH1, and Polar Verity Sense. Participants played simulated pickleball for 10 min. Validity measures included mean absolute percent error (MAPE) and Lin’s Concordance Correlation Coefficient (CCC), whereas reliability measures included coefficient of variation (CV) and intraclass correlation coefficient (ICC). The heart rate returned lower than 10% MAPE across all devices (Instinct = 5.73–6.32%, Verity Sense = 2.92–2.97%, OH1 = 3.39–3.45%) and greater than 0.85 CCC (Instinct = 0.85–0.88, Verity Sense = 0.96–0.96, OH1 = 0.93–0.94). The CV was below 10% (Instinct = 9.30%, Verity Sense = 2.68%, OH1 = 5.01%), and ICC was above 0.7 (Instinct = 0.77, Verity Sense = 0.98, OH1 = 0.91). The energy expenditure MAPE was greater than 10% (Instinct = 27.67–28.08%, Vantage M2 = 18.87–23.38%) with CCC lower than 0.7 (Instinct = 0.47–0.49, Vantage M2 = 0.62–0.63). Reliability thresholds were met in the Vantage M2 (CV = 6%, ICC = 0.98) but not in the Instinct (CV = 15%, ICC = 0.86). The Instinct was neither valid nor reliable for estimated energy expenditure, while the Polar Vantage M2 was reliable but not valid. All devices returned valid and reliable heart rates during pickleball.

Transforming CO2 into Synthetic Fuels: Modeling, Simulation, and Optimization Analysis of Methanol Production from Industrial Wastes

Carbon capture and utilization (CCU) has emerged in recent years as a promising decarbonization solution for hard-to-abate industries. Compared to carbon capture and storage (CCS), CCU aims not for the storage of carbon dioxide (CO2) but for its use in the production of synthetic fuels, such as synthetic methanol (MeOH). Synthetic MeOH is produced through CO2 hydrogenation, utilizing green hydrogen (H2). Efficient use of CO2 and H2 feedstocks is essential to maximize the carbon reduction potential and energy efficiency of the process. This study performed an optimization analysis on a small-scale, containerized, and portable CO2 hydrogenation unit with a 5 kg MeOH/h production capacity goal, focusing on carbon conversion efficiency (CCE), MeOH yield, H2 consumption, and MeOH purity. The analysis was conducted using Aspen Plus V12. A single-pass model was used first to evaluate an initial reactor design. The reactor was then re-designed according to the results of the gas hourly space velocity (GHSV). The model was then expanded to include a recycling loop and the final reactor design was validated, aiming to maximize overall efficiency. The effects of the operational parameters including the reactor inlet temperature, reactor pressure, thermal fluid temperature, and condensation temperature were examined. The model was then further expanded to include the MeOH distillation process, and the effect of the distillation temperature was examined. The final product of the analysis was a fully-defined and optimized unit, achieving an 87.97% CCE and an 84.99% MeOH yield, consuming 1.11 kg H2/h for the production of 5.01 kg MeOH/h of 99.86 wt% purity. This study can provide valuable information and guidelines for designing small-scale, containerized, and portable CO2 hydrogenation units, which can serve as alternative solutions to address issues of H2 production and transportation related to large-scale installations.

Оценка функционирования дозиметрического оборудования при проведении измерений в полях импульсного микросекундного фотонного излучения с известными характеристиками

This paper continues the series of articles [1,2,3] devoted to the determination of the main dosimetric characteristics of the fields of high-energy pulsed microsecond photon radiation generated by medical linear electron accelerator (LINAC for short) and assessment of the possibility of using LINAC as a source of reference radiation field for calibration of dosimetric equipment. This publication presents the results of evaluation of the portable dosimeter DKSAT1123 and detection unit BDKG-206 when measuring in such fields under different modes of LINAC operation. The possibility of this dosimetric equipment operation in the fields was assessed by comparing dosimeter readings with reference values of dosimetric characteristics of these fields, namely: average ambient dose equivalent rate H*(10), measured with the help of high-precision reference dosimeter DKS-AT5350. It was found that the deviation of H*(10) measurements conducted with the help of the DKS‑AT1123 and BDKG-206 from the reference values strongly depends on the radiation properties, namely the H*(10) value in the pulse. It is shown that at the H*(10) value in the pulse less than 0,2 mSv/s the deviation does not exceed 10%, at the H*(10) value in the pulse 0,2–0,4 mSv/s the deviation does not exceed 33%, and at the H*(10) value in the pulse more than 0,5 mSv/s the deviation can reach 72%.

A portable inflatable soft wearable robot to assist the shoulder during industrial work.

Repetitive overhead tasks during factory work can cause shoulder injuries resulting in impaired health and productivity loss. Soft wearable upper extremity robots have the potential to be effective injury prevention tools with minimal restrictions using soft materials and active controls. We present the design and evaluation of a portable inflatable shoulder wearable robot for assisting industrial workers during shoulder-elevated tasks. The robot is worn like a shirt with integrated textile pneumatic actuators, inertial measurement units, and a portable actuation unit. It can provide up to 6.6 newton-meters of torque to support the shoulder and cycle assistance on and off at six times per minute. From human participant evaluations during simulated industrial tasks, the robot reduced agonist muscle activities (anterior, middle, and posterior deltoids and biceps brachii) by up to 40% with slight changes in joint angles of less than 7% range of motion while not increasing antagonistic muscle activity (latissimus dorsi) in current sample size. Comparison of controller parameters further highlighted that higher assistance magnitude and earlier assistance timing resulted in statistically significant muscle activity reductions. During a task circuit with dynamic transitions among the tasks, the kinematics-based controller of the robot showed robustness to misinflations (96% true negative rate and 91% true positive rate), indicating minimal disturbances to the user when assistance was not required. A preliminary evaluation of a pressure modulation profile also highlighted a trade-off between user perception and hardware demands. Finally, five automotive factory workers used the robot in a pilot manufacturing area and provided feedback.

Portable Isolation Unit with Positive and Negative Pressure, for Contaminated People’s Transportation

Abstract Portable isolation units (PIUs) represent a critical component in the management of chemical, biological, radiological and nuclear (CBRN) threats, as well as for addressing broader medical needs during infectious disease outbreaks. These units are designed to offer a controlled environment that can be easily deployed to isolate individuals either suspected of carrying infectious agents or contaminated with hazardous materials. The functionality of PIUs is enhanced by their ability to maintain specific atmospheric conditions, such as positive or negative pressure, to prevent the spread of contaminants. In the context of CBRN threats, PIUs provide a safe space for decontamination and initial medical treatment, reducing the risk of broader environmental contamination and exposure. Similarly, during pandemics or outbreaks of highly infectious diseases, PIUs are indispensable for containing pathogens and protecting both healthcare personnel and the public. This study outlines the design and testing of the BIOEVAC portable isolation unit, which can operate with both positive and negative pressure for transporting contaminated individuals. Originally developed as a technological demonstrator during the COVID-19 pandemic for emergency use, its capabilities have been enhanced and it has now been transferred to the industry for mass production.

Properly Cleaning Portable Milking Units: A Step-by-Step Guide

This article aims to help small dairy producers learn how to properly clean portable milking machines so they can improve milk quality and prolong the life of milking equipment. This publication is accompanied by one brochure that aims to summarize the steps for proper cleaning of portable milking units. Written by Izabella Toledo and Chris Decubellis, and published by the UF/IFAS Department of Animal Sciences, April 2024.

Expedient Bayesian prediction of subfossil bone protein content using portable ATR-FTIR data

Rapid and minimally destructive methods for estimating the endogenous organic content of subfossil bone save time, lab consumables, and valuable ancient materials. Fourier transform infrared (FTIR) spectroscopy is an established method to estimate bone protein content, and portable spectroscopes enable field applications. We review the ability of benchtop and portable FTIR indices to predict %N and %collagen from 137 bone specimens drawn from eight taxa. We also explore associations of these indices with the endogenous DNA content estimated for 105 specimens. Bulk bone elemental abundance and crystallinity index data reflect diagenetic alteration of these specimens, which come from a variety of depositional environments in four countries (Madagascar, Greece, Monaco, and Germany). Infrared (IR) indices from benchtop and portable units perform similarly well in predicting observed sample N content and collagen yields. Samples that include little collagen (0–5 wt%) tend to have similar IR index values, and we present a Bayesian approach for the prediction of collagen yields. Bone type best explains variation in target species DNA content (endogenous DNA being particularly abundant in petrosals), but low IR index values were consistently associated with minimal DNA content. We conclude that, although portable FTIR fails to distinguish collagen preservation among poorly preserved samples, a simple approach with minimal sample preparation can effectively screen bone from a variety of taxa, elements, and environments for the extraction of organics.

Portable Arduino-Based Multi-Sensor Device (SBEDAD): Measuring the Built Environment in Street Cycling Spaces.

The built environment's impact on human activities has been a hot issue in urban research. Compared to motorized spaces, the built environment of pedestrian and cycling street spaces dramatically influences people's travel experience and travel mode choice. The streets' built environment data play a vital role in urban design and management. However, the multi-source, heterogeneous, and massive data acquisition methods and tools for the built environment have become obstacles for urban design and management. To better realize the data acquisition and for deeper understanding of the urban built environment, this study develops a new portable, low-cost Arduino-based multi-sensor array integrated into a single portable unit for built environment measurements of street cycling spaces. The system consists of five sensors and an Arduino Mega board, aimed at measuring the characteristics of the street cycling space. It takes air quality, human sensation, road quality, and greenery as the detection objects. An integrated particulate matter laser sensor, a light intensity sensor, a temperature and humidity sensor, noise sensors, and an 8K panoramic camera are used for multi-source data acquisition in the street. The device has a mobile power supply display and a secure digital card to improve its portability. The study took Beijing as a sample case. A total of 127.97 G of video data and 4794 Kb of txt records were acquired in 36 working hours using the street built environment data acquisition device. The efficiency rose to 8474.21% compared to last year. As an alternative to conventional hardware used for this similar purpose, the device avoids the need to carry multiple types and models of sensing devices, making it possible to target multi-sensor data-based street built environment research. Second, the device's power and storage capabilities make it portable, independent, and scalable, accelerating self-motivated development. Third, it dramatically reduces the cost. The device provides a methodological and technological basis for conceptualizing new research scenarios and potential applications.

Novel cryotherapy technique for pulpotomy in mature permanent teeth with symptomatic irreversible pulpitis- a randomized controlled trial.

To assess the effect of cryotherapy on haemostasis, post-operative pain, and the outcome of full pulpotomy performed in mature permanent teeth with symptomatic irreversible pulpitis. The study included sixty mature permanent mandibular molar teeth with symptomatic irreversible pulpitis and no periapical rarefaction. After coronal pulp tissue amputation, teeth were randomly allocated to one of two groups (n = 30 each). In group I (conventional pulpotomy), a sterile cotton pellet moistened with 2.5% NaOCl was used for haemostasis. In group II (cryotherapy), the pulp chamber was continuously lavaged with 2.50C normal saline solution for haemostasis using an indigenous portable cryotherapy irrigation unit. Following haemostasis, the pulp was capped with mineral trioxide aggregate and the tooth was restored with resin composite. The time taken to achieve haemostasis was recorded. Preoperative and 24, 48 and 72h postoperative pain was measured using the Numerical Rating Scale. The pulpotomy outcome was assessed at the 12-month follow-up. Data were analyzed using Fischer's exact test, two-sample t-test, two-sample Wilcoxon rank-sum test, Friedman Test, and Wilcoxon Signed Rank Test. The cryotherapy group achieved haemostasis in less time (p < 0.05). There was a significant pain reduction at 24 and 48h in the cryotherapy group when compared with the conventional pulpotomy group (P < 0.005). The overall success rate of pulpotomy after 12 months was 88% (n = 22) in both study groups(p < 0.05). Cryotherapy application reduces postoperative pain and has no adverse effect on the outcome of pulpotomy in permanent teeth with symptomatic irreversible pulpitis. The cryotherapy can be incorporated in pulpotomy protocol as an adjunct to minimize post-operative pain.

Comparison of the Operator and Surrounding Dose When Using Portable Intraoral X-ray Devices

This study aimed to investigate the scattered radiation dose using three portable dental radiographic units: iRay D3, EZRay Air, and Epix. The absorbed dose was measured at 0.5 and 1 m distances, every 15° in the horizontal plane, using an ionization chamber. The maximum number of radiographs per day using the portable units was calculated considering a dose limit of 50 mSv/year and 20 mSv/year. The doses were higher in the Epix unit compared to the other two devices. Anterior exposure was generally higher than the sides or posterior exposure. With a dose limit of 50 mSv/year, considering a distance of 0.5 m between the operator and the X-ray unit, a maximum of 961, 565, and 38 radiographs are permitted daily using iRay D3, EZRay Air, and Epix, respectively. Considering a dose limit of 20 mSv/year, with a distance of 0.5 m between the operator and the radiographic device, a maximum of 384, 226, and 15 radiographs are permitted daily using iRay D3, EZRay Air, and Epix portable units, respectively. It is highly unlikely that an operator would reach occupational dose limits when using iRay D3 and EZRay Air. The Epix radiographic device allows for fewer daily radiographs and should be avoided for daily use.

Comparison of Metabolic Power and Energy Cost of Submaximal and Sprint Running Efforts Using Different Methods in Elite Youth Soccer Players: A Novel Energetic Approach.

Sprinting is a decisive action in soccer that is considerably taxing from a neuromuscular and energetic perspective. This study compared different calculation methods for the metabolic power (MP) and energy cost (EC) of sprinting using global positioning system (GPS) metrics and electromyography (EMG), with the aim of identifying potential differences in performance markers. Sixteen elite U17 male soccer players (age: 16.4 ± 0.5 years; body mass: 64.6 ± 4.4 kg; and height: 177.4 ± 4.3 cm) participated in the study and completed four different submaximal constant running efforts followed by sprinting actions while using portable GPS-IMU units and surface EMG. GPS-derived MP was determined based on GPS velocity, and the EMG-MP and EC were calculated based on individual profiles plotting the MP of the GPS and all EMG signals acquired. The goodness of fit of the linear regressions was assessed by the coefficient of determination (R2), and a repeated measures ANOVA was used to detect changes. A linear trend was found in EMG activity during submaximal speed runs (R2 = 1), but when the sprint effort was considered, the trend became exponential (R2 = 0.89). The EMG/force ratio displayed two different trends: linear up to a 30 m sprint (R2 = 0.99) and polynomial up to a 50 m sprint (R2 = 0.96). Statistically significant differences between the GPS and EMG were observed for MP splits at 0-5 m, 5-10 m, 25-30 m, 30-35 m, and 35-40 m and for EC splits at 5-10 m, 25-30 m, 30-35 m, and 35-40 m (p ≤ 0.05). Therefore, the determination of the MP and EC based on GPS technology underestimated the neuromuscular and metabolic engagement during the sprinting efforts. Thus, the EMG-derived method seems to be more accurate for calculating the MP and EC in this type of action.

SMART HOME MONITORING SYSTEM

The Project is about building a low-cost home automation system. It mainly focuses on creating an Internet based home automation system that can be automatically configured to run based on various conditions or that can be used to control multiple components through the internet. Wireless technology is used to enable remote access from a smartphone, PC, manually and voice command. The system is an accessible interface, affordable construction, and easy installation made it easier for controlling household electrical appliances and devices. The created system supports wireless control of lights, fans, air conditioners, televisions, Alarm, security cameras, electronic doors, computer systems, audio/visual devices, and more. It can be combined into a single portable unit. It is user friendly. Key Words: Wireless Control, Wi-Fi, Microcontroller, ESP RainMaker, Relay, Controlling of appliances, Monitoring.

Mapping the Spatial Distribution of Natural Gamma Dose Rates as a Baseline Study in the Province of Asti, Italy

Natural background gamma rays and their effects on human health are essential components of both radiation protection and public concern. In the frame of these aspects, the mapping of the natural gamma dose rate values of the Province of Asti is given. The Asti Fire Brigade Command approved a project relating to the mapping of gamma radiation from the natural background in the territory of Asti. The project engaged both the Nuclear, Biological, Chemical, and Radiological (NBCR) and Topography Applied to Rescue (TAS) components of the Asti Command. Skilled personnel, comprising level 1 TAS operators for data collection and level 2 TAS operators for cartographic analysis, were deployed across the six working days. The methodology involved the use of two digital handheld radiation G-M detectors, in conjunction with a portable GPS unit, including the Global Mapper software. One of the significant findings of this study is the observation that the natural gamma dose rate levels were 201.25% higher in the streets of the city center compared to other areas, predominantly because the building materials in these locations contain a higher amount of natural radionuclides. The results indicated that the level of natural gamma dose rates in the studied region is close to the global average value.

Unit Testing in ASP Revisited: Language and Test-Driven Development Environment

Abstract Unit testing frameworks are nowadays considered a best practice, included in almost all modern software development processes, to achieve rapid development of correct specifications. Knowledge representation and reasoning paradigms such as Answer Set Programming (ASP), that have been used in industry-level applications, are not an exception. Indeed, the first unit testing specification language for ASP was proposed in 2011 as a feature of the ASPIDE development environment. Later, a more portable unit testing language was included in the LANA annotation language. In this paper we revisit both languages and tools for unit testing in ASP. We propose a new unit test specification language that allows one to inline tests within ASP programs, and we identify the computational complexity of the tasks associated with checking the various program-correctness assertions. Test-case specifications are transparent to the traditional evaluation, but can be interpreted by a specific testing tool. Thus, we present a novel environment supporting test-driven development of ASP programs.

Titanium dioxide–supported mercury photocatalysts for oxidative removal of hydrogen sulfide from the air using a portable air purification unit

Photocatalytic removal of gaseous hydrogen sulfide (H2S) has been studied through the control of key process variables using a prototype air purifier (AP) fabricated with titanium dioxide (TiO2)-supported mercury. The performance of Hg/TiO2 systems, prepared with different Hg mass proportions over TiO2 (such as 0.1%, 1%, 2%, and 5%), is measured against 5 ppm H2S at 160 L min-1 under UV irradiation. Accordingly, their removal efficiency (RE) values after 360 s are 40.3%, 74.8%, 99.3%, and 99.9%, respectively (relative to 33.5% of AP (TiO2)). An AP with a 2% Hg/TiO2 unit achieves a clean air delivery rate of 32 L min-1 with kinetic reaction rate (r (at 10% RE)) of 0.774 mmol h-1 g-1, quantum yield of 2.19E-02 molecules photon-1, and space-time yield of 1.46E-04 molecules photon-1 mg-1. The superior photocatalytic performance of Hg/TiO2 is supported by superoxide anion and hydroxyl radicals formed in dry air and humid nitrogen (N2) environments, respectively. A density functional theory simulation suggests that the presence of oxygen vacancies should promote the disparities in the electronic structure to subsequently affect the reaction pathways and energetics. The presence of moisture enhances the robust formation of a mercury-OH bond to favorably yield β-mercury sulfide from H2S.

Universal Portable Unit for Hydro-vacuum Dispersion of Metallic Melts: Improvement of the Technological Process

The development of the technology and techniques of dispersing metal alloys is important both from the point of view of improving the quality of powders, as well as increasing the volume of production and increasing the economic and ecological safety of the technosphere. Metal powder is an indispensable functional component for many modern branches of industry. Against the background of the growing demands for the production of metal powders, we have developed and optimized a new device for hydro-vacuum dispersion of melts, the essence of innovation and advantage of which lies in sucking and dispersing the melt in the direction opposite to the action of the force of gravity, under 150-200g gravity overload conditions, where the main work is performed by hydraulic rarefaction resulting from a sharp (on 162°) refraction of direction and rapid expansion of a high-pressure water annular flow, with the superimposition of spatial shock- pulsating waves generated in the outer shell of the formed cone-shaped vortex. The device is characterized by high production and low energy costs, while powders - by increased specific surface, improved purity and high activity.