Scrubbing Method Research Articles

Hand Scrub Methods and Their Effect on Bacterial Flora

Background: Hand disinfection is a critical component of infection control in surgery. Various solutions and techniques are used for hand scrubbing, but these often produce conflicting results. Objectives: This study aims to compare the effectiveness of four different hand scrubbing techniques in reducing hand bacterial colonies. Methods: A total of 30 participants were selected through convenience sampling based on specific criteria. They were randomly assigned to perform one of four hand scrub techniques: (1) Iodine scrub alone; (2) Decocept alone; (3) a combination of iodine scrub followed by Decocept; and (4) a combination of Decocept followed by an iodine soak. Microorganism cultures were taken before, immediately after, and one hour after scrubbing. Staff satisfaction was measured after each method using the Visual Analog Scale (VAS). Results: The study examined the effectiveness of the four scrubbing techniques in reducing skin microorganism levels. Coagulase-negative Staphylococcus was the most frequently detected microorganism, appearing in the majority of cases, with no significant variation between the groups. While all scrubbing methods reduced microbial counts, no statistically significant differences were found between the techniques. Conclusions: The use of Decocept alone may be considered a viable alternative to other hand scrubbing methods in operating rooms.

OPTIMIZING WATER USAGE: THE IMPACT OF ALCOHOL HAND RUBS IN LOWER LIMB PRIMARY ARTHROPLASTY

Alcohol hand rubs, endorsed by WHO and NICE guidelines, are integral to modern surgical practices. Our objective was to assess how different scrubbing methods impact overall water usage by the surgical team, shedding light on variations among team members and their environmental implications.Over three consecutive arthroplasty lists spanning a week, water usage during scrubbing was observed for the operating team. Blinding all team members, including the anesthetist, consultant surgeon, orthopaedic registrar, orthopaedic SHO, and scrub nurse, during water usage calculations was implemented. Automated taps, using motion sensors, posed a challenge due to variable water quantity, necessitating water flow calculations per sensor movement. The senior surgeon, with over 20 years of experience, follows a traditional approach, starting with a morning prescrub and using an alcohol tub for each case, except when hands are soiled.We observed a total of 14 cases of lower limb primary arthroplasty. The cumulative water usage for scrubbing by the entire team was 193 liters, yielding a mean of 13.8 liters (±1.85) per case. The anaesthetist demonstrated the most conservative water usage, utilizing a total of 11.85 liters with a mean of 0.84 liters per case. Notably, alcohol rub was employed for half of the observed time, contributing to this efficient use. The senior operating surgeon used a total of 15.6 liters, averaging 1.1 liters per case. In contrast, the SHO and the registrar exhibited the highest water consumption, totaling 121.6 liters and yielding a mean of 5.7 liters per case. The nurses’ collective water usage for scrubbing amounted to 44.8 liters.Adopting alcohol rub, as endorsed by WHO, results in a remarkable 10-fold reduction in water usage, aligning with global health guidelines. This highlights significant potential for resource conservation in surgical procedures, presenting a practical and environmentally conscious approach to surgical scrubbing practices.

A new approach for upgrading Biogas produced at a local wastewater treatment plant

<p>Biogas is globally recognized as a crucial source of renewable energy. After undergoing proper treatment, the purified form of biogas, known as "biomethane", has the potential to be injected into existing natural gas infrastructure or compressed for use as a vehicle fuel. The principal pollutants which cause a reduction in the energy density of biogas and impede its utilization, specifically in engines, are carbon dioxide, hydrogen sulfide, and siloxanes. Furthermore, the presence of carbon dioxide in biogas has a significant impact on global warming. In this study, the water scrubbing method, which is the most used method in biogas upgrading processes, was utilized due to its low operating cost. With the decreasing availability of clean water resources around the world and the challenges of utilizing them, the reuse of treated wastewater has become increasingly important. Therefore, in this study, treated wastewater was used as scrubbing water for biogas instead of clean water. In addition, the biogas used in the study is the gas produced in the wastewater treatment plant of a local municipality, thus contributing to the uniqueness of the study. Prior to upgrading, the biogas content produced in the plant had CH4 and CO2 values of 62% and 37%, respectively. However, after the implementation of upgraded technology, these values increased to 96% (CH4) and 3% (CO2). These results clearly demonstrate the success of the new method.</p>

Integrated experimental and theoretical studies for unravelling CO2 capture of dual function CeO2-CaO bio-based sorbents

Solid CaO-based sorbents for CO2 capture represent a promising alternative technology compared to traditional amine scrubbing methods. However, CaO-based sorbents are rapidly sinter and easily decrease CO2 uptake capacity with regenerated carbonation–calcination cycle. Thus, in this study, doping CaO with CeO2 make it an excellent candidate for improving stability and facilitating CO2 capture efficiency. The dual function of CaO bio-based sorbents with varying ratios of cerium (Ce) were derived from naturally occurring blood clam using the gel-combustion method. Their nanostructures and physicochemical properties were characterized through the specific methods, including in situ XAS, CO2 chemisorption and physisorption, XPS, XRD, and SEM. An in-depth understanding of CO2 adsorption mechanism was further emphasized using a density functional theory (DFT) simulation. The results demonstrate that nanosized CeO2-CaO, with a mole ratio of 1:9, exhibited the highest performance for CO2 capture (6.44 mmol CO2/g sorbent). It is postulated that Ce serves as a physical barrier, effectively partitioning adjacent CaO grains and thereby diminishing the sintering rate. CaO is identified as the primary adsorption site, in contrast to CeO2. Mixing the Ce-Ca dual oxide initiates the electron-rich O at the O’ site. The electron localization at the O’ active site improves the activity of O’, making the performance CeCa(200) for capturing CO2 capture dominant. This discovery suggests that CeO2-CaO holds promise as a sustainable alternative sorbent for future CO2 capture applications.

Photothermal-driven flow with water droplets for effective removal of indoor fine particulate matters

Airborne particulate matter (PM) causes hazardous problems in human health, and water droplets have been utilized for PM removal in the air. However, since conventional wet scrubbing techniques mostly rely on mechanically generated water droplets, they have intrinsically limited in collection efficiencies of a single droplet. In addition, PM capturing strategies for removal of fine PM need to be established to enhance PM removal performance based on flow dynamics. Here, we propose a steam flow of water droplets generated by a photothermal membrane for air purification. The generated flow captures PM efficiently by the aid of the coupled effects of water droplets and hydrodynamic flow. The flow achieves high and sustainable deposition constants of 0.458 and 0.472 h−1 for PM1.0 and PM2.5 within 1 h at 4 solar intensity, which is 2.20 and 2.24 times higher than those of without solar irradiation, respectively. The deposition constants of PM using steam flow were higher than that of previous wet scrubbing methods despite a low volume of water usage. Our photothermal-driven flow with water droplets could be utilized as effective indoor air purification system that is low cost, energy-efficient, and environmentally-friendly.

Survey of Activated Cleaning Chemistries for Low-Stress Post-Chemical Mechanical Planarization Cleaning of Silicon Carbide

Integrated Circuit (IC) technologies have begun transitioning to wide band gap (WBG) substrates (i.e., Silicon carbide (SiC)) due to the intrinsic properties (i.e., high capacitance, thermal stability, and wear resistance) of these semiconducting materials. This has led to the development of Chemical Mechanical Planarization (CMP) processes that use aggressive chemical conditions and increasing mechanical forces to reach optimal material removal rates (MRR). The harsh CMP process parameters often result in contamination/defectivity (i.e., organic residue, abrasive particles, etc.) left on post-polish substrate surfaces and thus posing difficulty within the post-CMP cleaning process. Traditionally, post-CMP cleaning utilizes a polyvinyl alcohol (PVA) brush scrubbing method on the substrate surface. This has been shown to cause secondary defects (i.e., scratches, particle agglomerations, etc.) that inevitably lead to overall device failure. Alternative post-CMP methods utilize non-contact cleaning via megasonic energy to target removing defects (i.e., organic residue, pad debris, particle agglomerations, etc.) and avoid secondary defect generation. This research surveys post-CMP cleaning processes (contact and non-contact) on SiC substrates with various cleaning chemistries (i.e., supramolecular surfactants, catalytic complexes for generating reactive oxygen species (ROS), non-metal catalyst). Initial results show that supramolecular surfactants can produce high particle removal efficiency (PRE) due to their ability to be broken down into their monomeric units and encapsulate any removed residue under both brush and megasonic conditions Additionally, increased ROS generation disrupts the non-covalently adsorbed defects to the SiC surface and leads to an increased cleaning efficiency while decreasing the overall variability of particle removal results. Combining the ROS systems' disruptive power with surfactants' encapsulation mode, a highly efficient clean with low variability can be achieved under low-stress conditions.

Optical multi-context scrubbing operation on a redundant system.

This paper presents a proposal of the world-first optical multi-context scrubbing operation on a redundant system that can maintain the state of a sequential circuit and the operation continuously without any interruption on a radiation-hardened optically reconfigurable gate array even after a permanent failure suddenly happens on the sequential circuit or a flip-flop by radiation. Up to now, a high-speed optical scrubbing operation has been demonstrated on a radiation-hardened optically reconfigurable gate array. In addition, a multi-context scrubbing operation based on the high-speed optical scrubbing operation has already been demonstrated. Although the multi-context scrubbing operation presents the benefit that it can treat both soft-errors and permanent failures caused by radiation simultaneously, the conventional contributions have never presented how to maintain the state of a sequential circuit after a permanent failure occurs on flip-flops. Therefore, in the conventional multi-context scrubbing operation, all the operations must be restarted from the initial condition each time a permanent failure occurs on a programmable gate array. As a result, conventional multi-context scrubbing operations could not be applied for real-time systems. The proposed optical multi-context scrubbing method that can solve the issue has been experimentally evaluated on a radiation-hardened optically reconfigurable gate array.

A Survey on Fluorinated Greenhouse Gases in Taiwan: Emission Trends, Regulatory Strategies, and Abatement Technologies

Fluorinated greenhouse gases (F-gases), including hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF6), and nitrogen trifluoride (NF3), are used in a variety of applications, but they are potent greenhouse gases (GHGs). Therefore, they have been blanketed into the list of items to be phased out under international protocols or treaties. During the desk research, the updated statistics of Taiwan’s National Inventory Report (NIR) were used to analyze the trends of F-gases (i.e., HFCs, PFCs, SF6, and NF3) emissions during the period of 2000–2020. Furthermore, the regulatory strategies and measures for the reduction of the four F-gas emissions will be summarized to be in accordance with the national and international regulations. With the rapid development in the electronics industry, the total F-gas emissions indicate a significant increase from 2462 kilotons of carbon dioxide equivalents (CO2eq) in 2000 to the peak value (i.e., 12,643 kilotons) of CO2eq in 2004. However, it sharply decreased from 10,284 kilotons of CO2eq in 2005 to 3906 kilotons of CO2eq in 2020 due to the ongoing efforts of the regulatory requirements and the industry’s voluntary reduction in time sequence. It was also found that the most commonly used method for controlling the emissions of F-gases from the semiconductor and optoelectronic industries in Taiwan is based on the thermal destruction-local scrubbing method.

Salivary fluoride concentrations following toothbrushing with experimental toothpaste containing surface pre-reacted glass-ionomer (S-PRG) filler.

Single-blind 9 case comparative studies were conducted to evaluate salivary fluoride concentrations following toothbrushing using experimental toothpaste containing surface pre-reacted glass-ionomer (S-PRG) fillers. Preliminary tests were conducted in order to determine the volume of usage as well as the concentrations (wt %) of S-PRG filler. Based on the results given these experiments, we compared the salivary fluoride concentrations following toothbrushing with 0.5g of 4 different types of toothpastes: 5 wt % S-PRG filler, 1400ppm F AmF (amine fluoride), 1500ppm F NaF (sodium fluoride), and MFP (monofluorophosphate) containing toothpaste. Of the 12 participants, 7 participated in the preliminary study and 8 in the main study. All participants brushed their teeth using the scrubbing method for 2min. At first, 1.0 and 0.5g of 20 wt % S-PRG filler toothpastes were used to compare, then followed by 0.5g of 0 (control), 1, and 5 wt % S-PRG toothpastes, respectively. The participants spat out once and rinsed with 15mL of distilled water for 5s. Saliva was collected for 3min each at different time intervals of 0 (baseline), 5, 10, 15, 30, 60, 120, and 180min after the rinsing. Fluoride concentrations were determined using a fluoride electrode, and the area under the salivary clearance - time curve (AUC: ppm‧min) of each toothpaste was calculated as the salivary fluoride retention. The main study was then conducted to evaluate the salivary fluoride concentrations as well as the AUC value using 0.5g of 5 wt % S-PRG filler toothpaste, followed by NaF, MFP, and AmF toothpastes. Since there were no statistical differences between using 1.0 and 0.5g of 20 wt % S-PRG toothpastes in salivary fluoride concentrations as well as the AUC value throughout the 180min measurement, the volume was set as 0.5g for the following studies. Concentrations of 5 and 20 wt % S-PRG toothpastes retained 0.09ppm F or more in saliva even after 180min. No statistical differences were seen in the salivary fluoride concentrations at any time intervals as well as the AUC value between 5 and 20 wt % S-PRG toothpastes. Based on these results, the concentration of 5 wt % S-PRG toothpaste was used for the main comparative study. MFP toothpaste resulted in by far the lowest salivary fluoride concentrations (0.06ppm F at 180min) and the AUC value (24.6ppm‧min), whereas 5 wt % S-PRG toothpaste (0.15ppm F at 180min, 92.3ppm‧min) displayed retention on par with AmF toothpaste which appeared to result in higher values (0.17ppm F at 180min, 103ppm‧min), compared to NaF toothpaste (0.12ppm F at 180min, 49.3ppm‧min). The salivary fluoride concentrations following toothbrushing with 0.5g of 5 wt % S-PRG filler containing toothpaste showed retention similar to the best performing 1400ppm F AmF toothpaste even 180min after toothbrushing.

MTTR reduction of FPGA scrubbing: Exploring SEU sensitivity

SRAM-based FPGAs are widely used for developing many critical systems due to their huge capacity, flexibility, and high performance. However, their applicability in the presence of the Single Event Upsets (SEUs) should be ensured using mitigation techniques for specific critical systems e.g. space applications or automotive industry. Among all existing mitigation techniques, the scrubbing scheme is considered the most reliable technique that particularly avoids SEU accumulation in Configuration Memory (CM) that is the most SEU vulnerable component in an SRAM-based FPGAs. In spite of that, the error repair time realized by Mean Time to Repair (MTTR) attained by scrubbing is a pressing concern for real-time systems. To reduce MTTR, the impact of SEU in CM bits on correct circuit operation is considered in state-of-the-art scrubbing methods. In this paper, we examine the MTTR reduction taking into account multiple proposed precision levels to identify CM sensitive bits; i.e. bits have an adverse impact on correct circuit operation when infected by SEU. Two scrubbing methods are proposed based on these precision levels. Experimental results show an average of 20% \\45% \\46.5% MTTR reduction if the proposed precision-aware scrubbing methods taking into account sensitive bits recognized with low \\medium \\high precision compared to with very low precision. Experiments also show that higher MTTR reduction was achievable for non uniform structure like FFT (i.e about 68%). Thus the cost of distinguishing sensitive bits with higher precision is worth only when the circuit has a non-uniform structure in CM.

Less is more: balancing noise reduction and data retention in fMRI with data-driven scrubbing

Functional MRI (fMRI) data may be contaminated by artifacts arising from a myriad of sources, including subject head motion, respiration, heartbeat, scanner drift, and thermal noise. These artifacts cause deviations from common distributional assumptions, introduce spatial and temporal outliers, and reduce the signal-to-noise ratio of the data—all of which can have negative consequences for the accuracy and power of downstream statistical analysis. Scrubbing is a technique for excluding fMRI volumes thought to be contaminated by artifacts and generally comes in two flavors. Motion scrubbing based on subject head motion-derived measures is popular but suffers from a number of drawbacks, among them the need to choose a threshold, a lack of generalizability to multiband acquisitions, and high rates of censoring of individual volumes and entire subjects. Alternatively, data-driven scrubbing methods like DVARS are based on observed noise in the processed fMRI timeseries and may avoid some of these issues. Here we propose “projection scrubbing”, a novel data-driven scrubbing method based on a statistical outlier detection framework and strategic dimension reduction, including independent component analysis (ICA), to isolate artifactual variation. We undertake a comprehensive comparison of motion scrubbing with data-driven projection scrubbing and DVARS. We argue that an appropriate metric for the success of scrubbing is maximal data retention subject to reasonable performance on typical benchmarks such as the validity, reliability, and identifiability of functional connectivity. We find that stringent motion scrubbing yields worsened validity, worsened reliability, and produced small improvements to fingerprinting. Meanwhile, data-driven scrubbing methods tend to yield greater improvements to fingerprinting while not generally worsening validity or reliability. Importantly, however, data-driven scrubbing excludes a fraction of the number of volumes or entire sessions compared to motion scrubbing. The ability of data-driven fMRI scrubbing to improve data retention without negatively impacting the quality of downstream analysis has major implications for sample sizes in population neuroscience research.

Semi-industrial technology tests of the sanitary cleaning of metallurgical enterprises waste gases from sulfur and nitrogen oxides

Nitrogen emissions in the form of NOx with flue gases from thermal power plants are the most serious pollutants generated during the combustion of coal. The calcium carbonate gas scrubbing process used today is expensive, generates a lot of waste, and leaves a significant amount of SO2 in the gas. Virtually no NOx removal. In this paper, we consider the behavior of nitrogen oxides during the purification of exhaust gases from thermal power plants with a carbonate melt of alkali metals. Based on the thermodynamic analysis of reactions between NOx and alkali metal carbonates, the possibility of reducing their concentrations in the exhaust gases is shown. It has been established that the process of NOx absorption in the temperature range of 573…823K is accompanied by the formation of stable potassium nitrite (KNO2) in the melt, as evidenced by the high negative values of the Gibbs energies of the reactions. The results of balance experiments fully confirm the established regularities. One can foresee that carbonate melt-based SO2 removal may become a practical and economical scrubbing method for sulfur-poor flue gases emitted by nonferrous metal production plants, thereby contributing to the limiting of harmful sulfur and NOx emissions into the atmosphere. The research was carried out within the framework of grant funding of the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan for 2020–2022 in the priority area “Rational use of natural resources, including water resources, geology, processing, new materials and technologies, safe products and structures” project No. AP08856384 “Development of a new high-tech technology for the utilization of the SO2 and CO2 from flue gases from thermal power plants and metallurgical plants with the production of marketable products”.

Task-based functional MRI challenges in clinical neuroscience: Choice of the best head motion correction approach in multiple sclerosis.

Functional MRI (fMRI) is commonly used for understanding brain organization and connectivity abnormalities in neurological conditions, and in particular in multiple sclerosis (MS). However, head motion degrades fMRI data quality and influences all image-derived metrics. Persistent controversies regarding the best correction strategy motivates a systematic comparison, including methods such as scrubbing and volume interpolation, to find optimal correction models, particularly in studies with clinical populations prone to characterize by high motion. Moreover, strategies for correction of motion effects gain more relevance in task-based designs, which are less explored compared to resting-state, have usually lower sample sizes, and may have a crucial role in describing the functioning of the brain and highlighting specific connectivity changes. We acquired fMRI data from 17 early MS patients and 14 matched healthy controls (HC) during performance of a visual task, characterized motion in both groups, and quantitatively compared the most used and easy to implement methods for correction of motion effects. We compared task-activation metrics obtained from: (i) models containing 6 or 24 motion parameters (MPs) as nuisance regressors; (ii) models containing nuisance regressors for 6 or 24 MPs and motion outliers (scrubbing) detected with Framewise Displacement or Derivative or root mean square VARiance over voxelS; and (iii) models with 6 or 24 MPs and motion outliers corrected through volume interpolation. To our knowledge, volume interpolation has not been systematically compared with scrubbing, nor investigated in task fMRI clinical studies in MS. No differences in motion were found between groups, suggesting that recently diagnosed MS patients may not present problematic motion. In general, models with 6 MPs perform better than models with 24 MPs, suggesting the 6 MPs as the best trade-off between correction of motion effects and preservation of valuable information. Parsimonious models with 6 MPs and volume interpolation were the best combination for correcting motion in both groups, surpassing the scrubbing methods. A joint analysis regardless of the group further highlighted the value of volume interpolation. Volume interpolation of motion outliers is an easy to implement technique, which may be an alternative to other methods and may improve the accuracy of fMRI analyses, crucially in clinical studies in MS and other neurological populations.

The Effect of Washing and Air Scouring on The Performance of Immersed Membrane Microfiltration

The quality of raw water in Surabaya is decreasing, and conventional treatment units are no longer efficient in treating raw water to become drinking water. Microfiltration membranes applied in sedimentation units can produce better quality results on limited land that uses a small number of chemicals. The material will be deposited on the membrane’s surface throughout the filtration process. The deposition of these materials can cause fouling, leading to a decrease in membrane productivity. This study involved a detailed investigation into the membrane washing method and air scouring implication in the microfiltration process to understand the most efficient technique to increase membrane productivity. Washing was done manually with a gentle scrubbing method and backwashing with time variation for 20 minutes and 10 minutes. Air Scouring was done with air pressure variations of 0,3 bar and 0,6 bar. The study showed that water flux was affected by the washing and air scouring method. Permeate quality was also found to be affected by washing and air scouring variation. Permeate quality analyses in this study are turbidity, TSS, micro-plastics, E-Coli, and organic substances.

Superior Iodine Uptake Capacity Enabled by an Open Metal-Sulfide Framework Composed of Three Types of Active Sites

Superior Iodine Uptake Capacity Enabled by an Open Metal-Sulfide Framework Composed of Three Types of Active Sites

Ultrasonic cleaning is effective in removing carbonized clots and tissue from the insulation-tipped diathermic knife-2.

ObjectivesSince carbonized clots and tissue (debris) tend to adhere firmly to the tip of the endoscopic submucosal dissection (ESD) knife as the procedure proceeds, manual removing the firm debris is often challenging and time‐consuming. Recently, effective ultrasonic cleaning for other medical devices has been reported. The aim of the present study was to clarify whether ultrasonic cleaning is effective in removing the debris on the insulation‐tipped diathermic (IT) knife‐2.MethodsThis study was an ex‐vivo experimental randomized study. A total of 40 IT knife‐2 knives with debris on their tip surfaces were prepared and randomly assigned to two groups (Group A and Group B). The knives in Group A were cleaned using the conventional scrubbing method for 30 s (conventional cleaning method), while those in Group B were cleaned using a combined method of scrubbing for 20 s and ultrasonic cleaning for 10 s (combined ultrasonic cleaning method). The tip electrode of the knife after cleaning was photographed under a microscope (40x). The 40 images of the knives were evaluated by independent three endoscopists and two clinical engineers using the five‐step evaluation criteria ranging from cleaning score 1 (dirty) to 5 (clean).ResultsThe mean cleaning score of 3.78 (range: 2.33–4.67) in Group B was significantly higher than that of 1.68 (range: 1.00–2.83) in Group A.ConclusionsThe combined ultrasonic cleaning method could remove debris adhering to the IT knife‐2 more effectively than the conventional cleaning method. Ultrasonic cleaning may be applied for real‐world ESD.

An overview on metal Oxide-based materials for iodine capture and storage

• Sources and reactions of various iodine species are summarized. • Metal oxide-based adsorbents’ potential abilities for iodine capture are discussed. • Metal oxides can form stable oxyiodide forms for long-term radioidine storage. • Silver and Bismuth oxides show better performance for iodine capture and storage. • Metalloid oxides are used as low-sintering temperature additives to limit iodine loss during storage. Long-lived 129 I, short-lived 131 I, and organic iodides released from nuclear plants are volatile and harmful to the ecosystem. For operational safety, and sustainable development of nuclear industries, effective means of trapping various iodine radioisotopes are of great concern. Wet scrubbing methods are often combined with adsorbents to entrap radioiodine species effectively, and thus the search for materials with high performance is still needed. Metal oxides are believed to be potential candidates for real applications. In this review, we documented the metal oxide-based materials for volatile radioactive iodine capture, with limitations on operating conditions, adsorption capacities, and long-term immobilization. Advantages, shortcomings of various metal oxides toward iodine capture, and metal oxide additives for a low-sintering temperature of iodide waste forms have been elucidated for helping in the long-term future development of efficient materials for iodine capture and storage.

Experimental investigation of CsI aerosol removal in containment spray system test facility of 700 MWe IPHWR

Post-accident management of the radionuclide in a nuclear reactor is always a focus point from the nuclear power plant safety point of view. A number of systems using different radionuclide scrubbing mechanisms are already deployed in the Indian nuclear reactors to safeguard the public during and post-accident scenario. However, it is always desirable to achieve “As Low As Reasonably Achievable” (ALARA) philosophy. In the same lines, to further strengthen the safety of Indian nuclear reactors, Containment Spray System (CSS) is introduced in 700 MWe Indian pressurized heavy water reactors to cater/mitigate the aftermath of the Design Basis Accidents (DBA) i.e., Loss Of Coolant Accident (LOCA) and Main Steam Line Break (MSLB). It provides the fast vapour suppression and radionuclide removal from containment during/post design basis accidents. In the present work the experimental investigation of the effect of water spray on the CsI aerosol scrubbing/CsI aerosol removal is studied in a scaled down facility. Experiments are also carried out for the CsI aerosol removal when spray is not operating. In order to encompass the containment pressures during DBA, 1.0 bar(g) initial vessel pressure is used to simulate the accident conditions. For simulation of aerosols after accident CsI nano particles (spherical) suspended in the air and CsI dry aerosols are used. The spray flow rate for all the experiment is kept constant approximately 11.3 lpm. However different Sauter Mean Diameter (SMD) (D32 = 590 µm, 745 µm, 1000 µm) are used to study the effect of droplet diameter on CsI aerosol removal. The temporal variation of the vessel relative pressure gas mean temperature and wall temperature is measured. Vessel depressurization rate with time is recorded. CsI aerosol removal/ CsI aerosol concentration variation with time is measured using two diverse measurements system namely scrubber method and Optical Particle Counter (OPC). Global decontamination factor and global collection efficiency is deduced based on the studies. Few tests without spray are also carried out to estimate the plate out effect on CsI aerosol removal.

The effectiveness of the scrubber method of cleaning exhaust gases in industry

Unfortunately, not all types of industry have a positive impact on the environment and people, for example, the processes of the chemical and textile industries can be accompanied by the release of toxic and harmful gases, dust and steam. And already, along with the exhaust gases, they are released into the atmosphere, while the negative impact on the overall environmental situation only doubles. That is why the importance of cleaning the emitted gases in the process of industrial activity cannot be underestimated. The most popular and most effective method of cleaning from dust emissions can be designated as the scrubber method of air purification, precisely at the moment when the air being eliminated has a relatively high temperature level. In addition, the use of the heat of condensation of water vapors contained in them is a particularly effective direction for increasing the depth of heat recovery of wet gas and steam generator gases leaving heat technology devices. This article is devoted to the study of the stages and models of the process of designing and constructing a device for wet cleaning of gases that are released into the atmosphere as a result of certain production activities. The study of the systems of utilization of secondary energy resources used at the present time was also carried out.

202 An ex vivo method to assay skin’s innate defense

The human skin has microbiological, chemical, and physical barriers that help it defend itself from invading pathogens and transient microbes. Measuring the functionality of such barriers has been challenging and requires direct application of the microbes to the test sites on human subjects. We have developed a novel ex vivo assay that can be used to measure the collective functionality of the skin defense components, especially the chemical barrier that includes antimicrobial peptides (AMPs) and antimicrobial lipids (AMLs), which can be extracted using buffer scrub methods.