Aspiration System Research Articles

Percutaneous Thrombovegectomy as an Alternative to Surgery for Tricuspid Valve Endocarditis

BackgroundUndergoing an urgent valve surgical procedure to treat patients with tricuspid valve endocarditis carries a high risk of operative morbidity and mortality. Use of a percutaneous vacuum-assisted system to treat tricuspid valve endocarditis is an alternative to surgical procedures. MethodsThis study retrospectively analyzed data from 187 transcatheter vacuum-assisted aspiration procedures performed in 177 patients with tricuspid valve vegetations at 3 different centers between 2017 and April 2022. The device was deployed through the internal jugular or femoral vein into the right atrium by using transesophageal echocardiography and fluoroscopy guidance with the return cannula placed in the femoral vein. The following data were analyzed: intravascular material aspirated, collected in an external filter, and cultured; hospital length of stay; procedural complications; blood culture clearance; and tricuspid regurgitation. ResultsThe mean age of participants was 35.5 ± 10.8 years (range, 18-79 years). A total of 107 procedures (57.2%) were performed in female patients, and 163 (87.2%) procedures were performed in intravenous drug users. All patients survived the procedure, and there were no procedural complications. The average length of stay was 26.8 ± 18.5 days (range, 1-96 days). Most preoperative positive blood cultures showed Staphylococcus aureus (80.3%), with postoperative cultures converting to negative in 103 (70.1%) of 147 procedures. Tricuspid regurgitation remained unchanged after 95 (50.8%) procedures and worsened after 40 (21.4%) procedures. ConclusionsPercutaneous vacuum-assisted aspiration system provides a safe alternative to urgent tricuspid valve surgical procedures for removal of vegetations, especially in patients with endocarditis. Initial vegetation debulking can expedite clearance of blood cultures while avoiding major cardiac surgery operations and implantation of prosthetic valves in these high-risk patients.

A Retrospective Analysis of AngioVac Outcomes at a Tertiary Care Center

BackgroundThe AngioVac system is a vacuum aspiration device approved for removal of right-sided cardiac thrombi. It has also been used for management of right-sided endocarditis in selected cases. Retrospective case series have reported high success rate and acceptable 30-day mortality, but there is limited data regarding outcomes beyond the immediate postoperative period. The purpose of this study is to describe our institution's experience with the AngioVac system for thrombus, vegetation, and tumor removal with a significant improvement over previously reported 1-year survival rates. MethodsA retrospective review of AngioVac cases performed at our tertiary care center from 2016-2022 was done. From 2016-2022, 23 patients were identified, and their outcomes are described. ResultsOur review demonstrates 81.8% procedural success, 100% procedure survival, 90.9% survival to discharge, and 81.8% 30-day survival rates. One-year survival rate was 72.7%. Complications including an 18.2% rate of new vasopressor use, 54.5% rate of transfusion requirement, and 4.5% rate of acute renal failure requiring hemodialysis were identified. Intraprocedural embolization occurred in 1 case requiring venoarterial extracorporeal membrane oxygenation support and thrombectomy. One case was converted to open surgical intervention. ConclusionsOur review further supports the safety and efficacy of minimally invasive vacuum-assisted aspiration systems beyond the immediate postoperative period in intracardiac thrombus, tumor, and right-sided infective endocarditis. Our institution's experience emphasizes a team-based approach including interventional cardiology and cardiothoracic surgery with a standardized imaging approach with transesophageal echocardiogram. Future guidelines are needed to include an algorithmic approach to intracardiac masses.

RapidpulseTM cyclic aspiration system for acute ischemic stroke due to large vessel occlusions.

The best strategy to achieve optimal reperfusion outcomes during mechanical thrombectomy remains to be defined. The RapidPulseTM Cyclic Aspiration System is a novel technology, delivering high-frequency pulsed vacuum forces to increase the efficiency of aspiration thrombectomy. Prospective, multicenter, open-label, core lab-adjudicated, two-arm study comparing safety and efficacy of a feasibility version of the RapidPulseTM system compared with contemporary controls. Primary endpoint was the rate of mTICI ≥ 2c after first-pass effect (FPE). Additional efficacy endpoints were the rates of mTICI 2b after first pass (modified FPE (mFPE)), last pass with study device defined as frontline technical success, and after all passes including rescue therapy. The primary safety endpoints included symptomatic ICH (sICH) within 24 h post-procedure. Between February 2022 to December 2022, 80 subjects were consented and enrolled in the study (n = 40 treatment arm, n = 40 control arm). In the intent to treat (ITT) population, mean age was 67.8 ± 11.5 years; 19 (47.5%) were male. Median NIHSS score was 16 (IQR: 13-22). Median ASPECTS score was 9 (IQR: 8-10). The rate of mTICI ≥ 2c after first pass was 53.9% in ITT population (60.0% in per-protocol population) versus 38.5% in the corresponding control population. Functional independence (mRS 0-2) at 90 days was achieved in 61.1% (22/36) in the RapidPulseTM arm and 52.8% (19/36) in the control arm. In the RapidPulseTM arm, no sICH within 24 h and no device-related morbidity or mortality occurred. Preliminary data suggests RapidPulseTM Aspiration System is highly effective and safe for recanalization of large vessel occlusions.

Use of the Indigo CAT RX aspiration system during percutaneous coronary intervention.

The use of the Indigo CAT RX Aspiration System (Penumbra Inc.) during percutaneous coronary intervention has received limited study. We retrospectively examined the clinical, angiographic, and procedural characteristics, outcomes, and follow-up of patients who underwent mechanical aspiration thrombectomy with the Indigo CAT RX system (Penumbra Inc.) at a large tertiary care hospital between January 2019 and April 2023. During the study period, 83 patients (85 lesions) underwent thrombectomy with the Indigo CAT RX. Mean patient age was 64.9 ± 14.48 years and 31.2% were women. The most common presentations were ST-segment elevation myocardial infarction (MI) (66.2%) and non-ST-segment elevation MI (26.5%). A final thrombolysis in MI flow grade of 3 and final myocardial blush grade of 3 were achieved in 76% and 46% of the cases, respectively. Technical success was achieved in 88.9% of the cases that included Indigo CAT RX treatment only, compared with 57.1% of the cases that also included manual aspiration. There were no device-related serious adverse events. At 30-day postprocedure, the incidence of major adverse cardiac events (composite of cardiovascular death, recurrent MI, cardiogenic shock, new or worsening New York Heart Association Class IV heart failure, stroke) was 8.5%: 1.3% stroke (postprocedure, in-hospital), 1.3% MI, 6.1% cardiac death, and 7.5% developed cardiogenic shock. Use of the Indigo CAT RX system is associated with high technical success and acceptable risk of complications, including stroke.

HYKYHT: A versatile, affordable, and open-source 3D-printed liquid aspiration system

This paper aims to provide the details for making affordable single and multichannel liquid aspirators for wet labs. A liquid aspirator is a basic laboratory device that can cost several hundred Euros. We present a < €25 3D print solution that performs equally well in daily lab routines and is compatible with various vacuum sources, including an aquarium pump or household vacuum cleaner. Presently, commercial aspirators cost more than a decent entry-level 3D printer capable of producing all the parts listed in this manuscript. The models were designed with Tinkercad, with easy printing and minimal support in mind. The versatility and the ultra-low-cost solution we presented could ease the daily workflow of researchers in various research fields. Furthermore, it is valuable to high school or undergraduate student labs and community wet labs for science enthusiasts, where funding is generally limited.

Catheter-directed therapies for high and intermediate-high risk patients with acute pulmonary embolism: Results from a multiparametric follow-up protocol

Introduction: Intermediate-high- and high-risk pulmonary embolism (PE) patients treated with anticoagulation alone are associated with a considerable risk of circulatory collapse, death, or long-term pulmonary hypertension. Pulmonary Embolism Response Teams (PERT) have been created to deliver PE patients a better care. Catheter-Directed Therapies (CDT), with mechanical thrombolysis and/or local fibrinolysis allow faster reperfusion and hemodynamic improvement without the systemic bleeding risk of systemic fibrinolysis. However, clinical evidence of its safety and benefits are lacking. Objectives: This analysis aims to describe the hemodynamics, morphological and perfusion improvement over time in intermediate-high- and high-risk acute PE patients submitted to CDT. Methods: Prospective registry of consecutive intermediate-high- and high-risk PE patients submitted to CDT (mechanical thrombolysis with Penumbra aspiration system and/or intrapulmonary local fibrinolysis with alteplase) in a single tertiary center. A multiparametric follow-up protocol was designed to evaluate echocardiographic, CT-scan, pulmonary angiogram, and right heart catheterization data at admission and at 3 months after CDT.

Clinical case of treatment of true drowning in fresh water

Drowning is the third leading cause of unintentional injury death worldwide. The largest number of victims of drowning falls on the young able- bodied population.Objective. There are no recent intensive care protocols for drowning, it is relevant to formulate guidelines for the treatment of drowning. Clinical observation. A 25-year-old female patient was taken by an ambulance team to the intensive care unit with a directional diagnosis ‘drowning in fresh water’ of three degree of severity. The patient had got on ventilator with closed aspiration system. Emergency bronchoscopy was performed during which 200 ml of fluid aspirated into the lungs was removed. Respiratory support was determined by stepwise increase of the PEEP level and decrease in FiO2 level taking into account respiratory index. Given the development of a pro-inflammatory mediator response, lactatacidosis, hemolysis, hyperhydration, a high risk of infectious complications, it was decided to start extracorporeal treatment early by continuous veno-venous hemodiafiltration and de-escalation of systemic antibacterial therapy with meropenem by prolonged infusion. Against the background of the ongoing treatment, we managed to achieve target respiratory parameters and stabilize central hemodynamic parameters by the end of the first day, prevent the development of renal damage, correct water-electrolyte and metabolic disorders, and avoid severe septic complications. Vasopressor support was discontinued on the 4th day, and on the 5th day the patient was switched to independent breathing. The patient`s stay in the intensive care unit was 6 days.Conclusions. Stepwise respiratory therapy using closed suction systems and urgent bronchoscopy prevent direct damage to the alveoli and ongoing translocation of fluid into the vascular bed. Prescribing broad-spectrum antibiotics prior to the growth of clinical and laboratory signs of infectious lung lesions allows to reduce the risk of severe septic complications with pulmonary destruction parenchyma. Early onset extracorporeal treatment by CVVHDF allows to correct homeostasis disorders, eliminate hypervolemia, prevent the development of acute renal damage as a result of hemolysis.

Analysis of the aspiration system and gas cleaning for the cooling zone of the sintering machine for phosphorite ore

This study describes the gas emission aspiration and purification system, which is a crucial component of the life support system for a mining and processing plant. The aspiration system aims to maintain favorable working conditions and prevent the increase of dust content and harmful emissions in the air of working areas beyond the maximum permissible values. This study addresses the cleaning of aspiration and gas emissions in the technological zones of sintering machines during the sintering of ore phosphate material. It provides technical solutions for cleaning gases during the sinter cooling process, considering the condensation of moisture from gases inside exhausters. The text also reveals the technological parameters for the functioning of foam apparatuses, cyclones, and splash catchers. The process of cleaning gases in the technological cooling zone of the sintering machine is carried out in two parallel foam apparatus, using both dry and wet methods.

Surgical smoke: a matter of hygiene, toxicology, and occupational health.

The use of devices for tissue dissection and hemostasis during surgery is almost unavoidable. Electrically powered devices such as electrocautery, ultrasonic and laser units produce surgical smoke containing more than a thousand different products of combustion. These include large amounts of carcinogenic, mutagenic and potentially teratogenic noxae. The smoke contains particles that range widely in size, even as small as 0.007 µm. Most of the particles (90%) in electrocautery smoke are ≤6.27 µm in size, but surgical masks cannot filter particles smaller than 5 µm. In this situation, 95% of the smoke particles which pass through the mask reach deep into the respiratory tract and frequently cause various symptoms, such as headache, dizziness, nausea, eye and respiratory tract irritation, weakness, and abdominal pain in the acute period. The smoke can transport bacteria and viruses that are mostly between 0.02 µm and 3 µm in size and there is a risk of contamination. Among these viruses, SARS-CoV-2, influenza virus, HIV, HPV, HBV must be considered. The smoke may also carry malignant cells. The long-term effects of the surgical smoke are always ignored, because causality can hardly be clarified in individual cases. The quantity of the smoke changes with the technique of the surgeon, the room ventilation system, the characteristics of the power device used, the energy level at which it is set, and the characteristics of the tissue processed. The surgical team is highly exposed to the smoke, with the surgeon experiencing the highest exposure. However, the severity of exposure differs according to certain factors, e.g., ventilation by laminar or turbulent mixed airflow or smoke evacuation system. In any case, the surgical smoke must be removed from the operation area. The most effective method is to collect the smoke from the source through an aspiration system and to evacuate it outside. Awareness and legal regulations in terms of hygiene, toxicology, as well as occupational health and safety should increase.

Advances in Single-Cell Techniques for Linking Phenotypes to Genotypes.

Single-cell analysis has become an essential tool in modern biological research, providing unprecedented insights into cellular behavior and heterogeneity. By examining individual cells, this approach surpasses conventional population-based methods, revealing critical variations in cellular states, responses to environmental cues, and molecular signatures. In the context of cancer, with its diverse cell populations, single-cell analysis is critical for investigating tumor evolution, metastasis, and therapy resistance. Understanding the phenotype-genotype relationship at the single-cell level is crucial for deciphering the molecular mechanisms driving tumor development and progression. This review highlights innovative strategies for selective cell isolation based on desired phenotypes, including robotic aspiration, laser detachment, microraft arrays, optical traps, and droplet-based microfluidic systems. These advanced tools facilitate high-throughput single-cell phenotypic analysis and sorting, enabling the identification and characterization of specific cell subsets, thereby advancing therapeutic innovations in cancer and other diseases.

Методы и технические средства управления пожарной безопасностью производственных аспирационных систем

Purpose. For enterprises where flows containing flammable gases, vapors of flammable and combustible liquids, and combustible dust are generated and circulated, an industrial aspiration system is a key element in ensuring fire safety. As a result of studying the regularities of the cleaning process in dust filters, methods and technical means have been developed to reduce hazards in industrial aspiration systems. Methods. Experimental studies of the total pressure drop on filtering partitions of dust filters of various types have been conducted, the obtained data have been analyzed and summarized. Common patterns have been derived. Findings. The results of the studies are the identified patterns describing the kinetics of pressure drops on the filter during different periods of its operation, which made it possible to develop methods for monitoring this process and the design of industrial aspiration system filters. Research application field. The results can be used in organizing activities in the field of fire safety of industrial enterprises. Conclusions. The use of filters to clean flows from combustible dust is the most effective method to reduce fire risks in production with circulating combustible dust, but the lack of data on the specifics of operation in emergency modes becomes a prerequisite for potential risks. The result of the study is the development of a method for determining filter operation modes in case of fire or explosion, and the designs developed on the basis of this method make it possible to reduce fire risk of the process by regulating filter operation modes.

Neuro-tracking catheter technology for coronary thrombus extraction: Indigo CAT RX Continuous Aspiration System - first use in Poland.

Neuro-tracking catheter technology for coronary thrombus extraction: Indigo CAT RX Continuous Aspiration System - first use in Poland.

Percutaneous Removal of an Old Calcified Free-Floating Harmful Thrombus in a Patient with Severe Pulmonary Embolism and at Risk for Surgical Treatment

We present a case of a 53-year-old male patient with recurrent pulmonary embolism due to a free-floating right atrial thrombus formation. While thrombolysis was contraindicated due to previous intracranial hemorrhage, and the patient was at high risk for surgical thrombectomy, interventional removal using a percutaneous thrombus aspiration system (AngioVasc) was considered. Despite it’s calcified, free- floating and vulnerable nature, the thrombus aspiration could be carried out safely and the patient feels well. This case highlights the complexities associated with managing high-risk patients with recurrent embolism and the importance of considering modern interventional approaches in cardiac thrombus removal discussions.

Methods of increasing the efficiency of dust-laden air cleaning from the aspiration system of the UHK cleaning unit

Methods of increasing the efficiency of dust-laden air cleaning from the aspiration system of the UHK cleaning unit

Catheter-directed therapies impact on intermediate-high- and high-risk pulmonary embolism patients

Abstract Introduction Intermediate-high- and high-risk pulmonary embolism (PE) patients treated with anticoagulation alone are associated with a considerable risk of circulatory collapse, death, or long-term pulmonary hypertension. Pulmonary Embolism Response Teams (PERT) have been created to deliver PE patients a better care. Catheter Directed Therapies (CDT), with mechanical thrombolysis and/or local fibrinolysis allow faster reperfusion and hemodynamic improvement without the systemic hemorrhagic effects of systemic fibrinolysis. The clinical evidence of its benefits is lacking. Objectives This analysis aims to describe the hemodynamics, morphological and perfusion improvement in intermediate-high- and high-risk acute PE patients submitted to CDT. Methods Prospective registry of consecutive intermediate-high- and high-risk PE patients submitted to CDT (mechanical thrombolysis with PenumbraÔ aspiration system and/or intrapulmonary local fibrinolysis with alteplase) in a single tertiary center. A multiparametric follow-up protocol was designed to evaluate echocardiographic, CT-scan, pulmonary angiogram, and right heart catheterization data at admission and at 3 months after CDT. The paired samples t-Test was used for the analysis of the variables. Results 26 PE patients (42.3% male, mean age 59 years old) were submitted to CDT (19% combined Penumbra and local fibrinolysis, 12% isolated Penumbra and 69% isolated local fibrinolysis). Baseline characteristics, laboratorial, imaging and procedure data are summarized in the figure 1. No major bleeding was seen during or after the procedure. 1 pulmonary artery dissection and 1 Penumbra burr partial avulsion occurred, both with conservative treatment with good result. 3 patients died during the follow-up (1 for oncologic disease, 1 for septic shock and 1 after discharge with undetermined cause). Of the remaining, 18 patients completed the 3-month follow-up protocol. At 3 months, a significant improvement was seen in the patients’ hemodynamics with 3.3mmHg mean drop of RA pressure (p 0.007), 16.1mmHg mean drop of systolic PA pressure (p &amp;lt;0.001), 8.0mmHg mean drop of mean PA pressure (p&amp;lt;0.001), 1.4L/min and 0.7L/min/m2 mean increases in cardiac output and index (p 0.003, p 0.001), and a tendency to a 0.8 Wood units decrease in the pulmonary vascular resistance (p 0.093). It was also seen an improvement in the perfusion defects with a mean drop of 7.9 points in the modified Miller index (p &amp;lt;0.001) and an improvement in the RV function with a mean decrease of 0.5 in the RV/LV ratio by CT-scan (p &amp;lt;0.001), a mean increase of 5.6mm in TAPSE (p &amp;lt;0.001) and a decrease of median NT-proBNP levels in 2866pg/ml (p &amp;lt;0.001). Conclusions In patients with intermediate-high- and high-risk PE, the use of CDT with mechanical thrombolysis and/or local fibrinolysis is safe and associated with improvement in hemodynamics, RV function and perfusion defects.Table 1.baseline characteristicsTable 2.results

Abstract 13750: Concomitant Transcatheter Debulking of Right Heart Vegetations During Extraction of Transvenous Device System for Endocarditis: An Eight Case Series

Background: Right heart (RH) infective endocarditis (IE) is a rare but serious complication of transvenous devices (TVD) often requiring system extraction. Surgery is often necessary for large vegetations or when bacteremia persists despite antibiotics. Objective: To evaluate outcomes of patients who underwent transcatheter debulking of IE-related RH vegetations in the setting of a transvenous device endocarditis. Methods: Patients with TVD and IE with RH vegetations were included in this analysis. Half of the patients were debulked using a thrombus aspiration system, while in the other half a hydrodynamic thrombectomy system was used. This was completed via a femoral approach with intracardiac echocardiography guidance. Intra and post-procedural outcomes were recorded. Results: Eight patients with a median age of 58 years, 62.5% male, with TVD, IE, and RH vegetations were included. Vegetations were located on the TV (2), RA lead (4), RV lead (2) and the floor of the RA along the cavotricuspid isthmus (1). The largest vegetation in this series was 5 cm by 2 cm with a volume of 62.83 cm3 and the smallest was 0.4 cm by 0.3 cm with a volume of 0.15 cm3. All patients had substantial vegetation burden causing clinically significant valve dysfunction. The vegetations were successfully debulked in all eight cases. Post-procedure imaging in all eight patients showed at least a 80% reduction in vegetation burden. All patients with TVP leads underwent successful extraction of the pacing systems. All patients tolerated their procedures well and remained free of infection at follow-up after completing a 6-week course of intravenous antibiotics. There were no procedure-related adverse events recorded within 30 days of intervention. Conclusion: TCD is a potential alternative in patients with device infection and large vegetations who are not candidates for surgical intervention. Long-term implications of this intervention in this high-risk population needs further studies.

Safety and efficacy of mechanical aspiration thrombectomy for patients with acute lower extremity ischemia

ObjectiveAcute limb ischemia (ALI) is associated with high rates of amputation and consequent morbidity and mortality. The objective of this study is to report on the safety and efficacy of aspiration thrombectomy using the Indigo Aspiration System in patients with lower extremity (LE) ALI. MethodsThe STRIDE study was an international, multicenter, prospective, study that enrolled 119 participants presenting with LE-ALI. Patients were treated firstline with mechanical thrombectomy using the Indigo Aspiration System, before stenting or angioplasty, or other therapies as determined by treating physician. The primary end point was target limb salvage at 30 days after the procedure. Secondary end points within 30 days included technical success, defined as core laboratory-adjudicated Thrombolysis in Myocardial Infarction (TIMI) 2/3 flow rate immediately after the procedure, changes in modified Society for Vascular Surgery runoff score, improvement of Rutherford classification compared with before the procedure, patency, rate of device-related serious adverse events, and major periprocedural bleeding. Secondary end points that will be evaluated at 12 months include target limb salvage and mortality. ResultsOf the 119 participants enrolled at 16 sites, the mean age was 66.3 years (46.2% female). At baseline (n = 119), ischemic severity was classified as Rutherford I in 10.9%, Rutherford IIa in 54.6%, and Rutherford IIb in 34.5%. The mean target thrombus length was 125.7 ± 124.7 mm. Before the procedure, 93.0% (of patients 107/115) had no flow (TIMI 0) through the target lesion. The target limb salvage rate at 30 days was 98.2% (109/111). The rate of periprocedural major bleed was 4.2% (5/119) and device-related serious adverse events was 0.8% (1/119). Restoration of flow (TIMI 2/3) was achieved in 96.3% of patients (105/109) immediately after the procedure. The median improvement in the modified Society for Vascular Surgery runoff score (before vs after the procedure) was 6.0 (interquartile range, 0.0-11.0). Rutherford classifications also improved after discharge in 86.5% of patients (83/96), as compared with preprocedural scores. Patency at 30 days was achieved in 89.4% of patients (101/113). ConclusionsIn the STRIDE (A Study of Patients with Lower Extremity Acute Limb Ischemia to Remove Thrombus with the Indigo Aspiration System) study, aspiration thrombectomy with the Indigo System provided a safe and effective endovascular treatment for patients with LE-ALI, resulting in a high rate (98.2%) of successful limb salvage at 30 days, with few periprocedural complications.

АНАЛИЗ КОНСТРУКЦИЙ ПНЕВМОСЕПАРИРУЮЩИХ СИСТЕМ

One of the main methods of separating a grain heap is pneumatic separation based on the difference in the aerodynamic resistance of the components of the grain mixture to the air flow. A classification of pneumatic separating devices is given according to the following parameters: method of air flow circulation, number of separating channels, method of using systems, direction of air flow in separating channels and chambers, method of supplying air to the pneumatic separation zone, frequency of processing, shape of pneumatic separating channels, method of feeding grain mixture into the channel , type of devices for separating light impurities, method of regulating air flow in the channel. The formulas developed by different authors for the coefficient of particle resistance to air flow are generalized. The optimal dimensions of the pneumatic channel have been established: the depth of the channel should not exceed 200 mm, and the width should not exceed 1500 mm. It has been established that the most commonly used shape of the pneumatic channel is rectangular. It is shown that various devices are used to introduce grain material into the pneumatic channel: pitched boards, support nets, corrugated rollers, spreading discs, vibration, belt, pneumatic, and combined devices. According to the direction of the air flow, separators are distinguished: vertical, inclined, horizontal. It has been established that louvered inertial dust collectors are usually used to clean the air from dust. The most modern designs of cross-flow fans are considered. Based on the analysis performed, recommendations were given to developers of aspiration systems: to ensure a margin of pneumatic channel width so that with an increase in the supply of grain material, the efficiency of air cleaning does not decrease, but at the same time the uniformity of the air flow in the pneumatic channel does not decrease.

РАЗРАБОТКА, ИССЛЕДОВАНИЯ И ОПЫТНО-ПРОМЫШЛЕННОЕ ОСВОЕНИЕ ТЕХНОЛОГИИ АГЛОМЕРИРОВАНИЯ ТЕХНИЧЕСКОГО УГЛЕРОДА

The article examines the issues of agglomeration of polydisperse technogenic materials with low bulk density, in particular carbon black (CB). Patent-protected technical solutions and technology for processing organic solid technogenic materials obtained by processing MSW by low-temperature thermolysis (T≤500 C) are presented. Distinctive features of the developed technical means are: sealing loading and unloading units without access to air oxygen, geometric profile and configuration of internal working parts, a system for aspiration and condensation of a vapor-gas mixture, etc. A patent-protected design of a drum-screw unit for agglomeration of technical specifications of low-temperature thermolysis technology has been presented. Specification studies have been carried out, obtained by processing organic solid municipal waste using low-temperature thermolysis. A mechano-rheological model of the agglomeration process of the material under study has been developed. Theoretical studies of the mechano-rheological model of stage-by-stage agglomeration of polydisperse materials have been carried out. The fundamental principles of organizing technological processes of granule formation at each stage of material processing and granulate classification have been established. The necessity of using elements (Hooke, Newton, Saint-Venant, etc.) and mechano-rheological models of volumetric-spatial orientation of CB particles and agglomerated granulate constructed on their basis at various stages is substantiated. The combination of elements used in the models of Maxwell, Bingman, Shvedov, etc., at each stage of the agglomeration process is theoretically justified. On the basis of theoretical studies and modeling of stage-by-stage agglomeration processes, special devices have been developed, implemented in the patent-protected design of a combined-action drum-screw unit (DSU CA). Design documentation has been developed and a pilot industrial sample of BVA CD has been manufactured for agglomeration of technogenic polydisperse materials

The Opinion of Dental Technology Students about the Harmful Effects of the Materials Used During Practical Training and Means of Prevention

In the process of training in the special academic disciplines dental technology students are exposed to the harmful effects of various materials, volatile substances and dust particles. All of above can cause allergies, diseases of the respiratory system, neurological diseases, etc. The purpose of the present article is to study whether the students of the “Dental Technician” Educational Sector are familiar with the fact that some of the materials used in their practical training have a harmful effect on the body as well as to give information about means of prevention students can use. A sociological method using a specially designed for the purpose questionnaire was used to achieve the goal of this scientific study. The survey was conducted using Google forms in June 2023 and was distributed among first, second and third year (62.39 % in the study stage) Dental Technology students at the Medical College subordinate to the Medical University of Varna. For the presentation of the results a graphical analysis was used. It was found that a very large number of students know about the harmful effects of some of the materials they work with and more than half of them are worried about their health; not all of the students use protective equipment and there are some who do not use protective equipment at all ( 12.20 %). The following recommendations have been made to the educational institution and to the respondents based on the results, the conclusions and the students’ suggestions: it is recommended that the aducational laboratories are equipped with a central and individual aspiration system (for each working space), aspiration above worktops and fireplaces, hoppers for crushing the packaging mass when releasing the cast dental structure; students are also adviced to use personal protective equipment – uniforms, protective gloves, glasses, masks, helmets.