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1.
Applied Sciences ; 13(11):6744, 2023.
Article in English | ProQuest Central | ID: covidwho-20236163

ABSTRACT

Amid concerns over airflow-induced transmission of the COVID-19 virus in buildings frequented by large numbers of people, such as offices, the necessity for radiant ceiling heating panels has increased. This is due to the concern that the airflows emitted from the convection heating systems installed near the ceiling or windows for winter heating may be a major cause of COVID-19 transmission. In this study, we aim to evaluate thermal comfort under various indoor and outdoor environmental conditions of a building and present the thermal output conditions of the radiant ceiling heating panel that can replace the convection heating system while ensuring comfort in the perimeter zone and handling the heating load. As a result, we were able to present, in a chart format, the thermal output conditions that can secure thermal comfort by analyzing the indoor airflow distribution depending on the surface temperature of the radiant ceiling heating panel, the interior surface temperature of the window, and the influence of internal heat generation. Moreover, through derived empirical formulas, we were able to determine the heating conditions of the panel that can secure the necessary heat dissipation while minimizing discomfort, such as downdrafts, even for indoor and outdoor conditions that were not evaluated in this study.

2.
Smart Materials in Medicine ; 2023.
Article in English | ScienceDirect | ID: covidwho-20231366

ABSTRACT

Nanodendrite particles (NDs) with densely branched structures and biomimetic architectures have exhibited great promise in tumor therapy owing to their prolonged in vivo circulation time and exceptional photothermal efficiency. Nevertheless, traditional NDs are deficient in terms of specific surface modification and targeting tumors, which restricts their potential for broader clinical applications. Here, we developed coronavirus-like gold NDs through a seed-mediated approach and using silk fibroin (SF) as a capping agent. Our results demonstrate that these NDs have a favorable drug-loading capacity (∼65.25%) and light-triggered release characteristics of doxorubicin hydrochloride (DOX). Additionally, NDs functionalized with specific probes exhibited exceptional surface-enhanced Raman scattering (SERS) characteristics, enabling high-sensitivity Raman imaging of unstained single cells. Moreover, these NDs allowed for real-time monitoring of endocytic NDs for over 24 h. Furthermore, ND@DOX conjugated with tumor-targeting peptides exhibited mild hyperthermia, minimal cytotoxicity, and effective targeting towards cancer cells in vitro, as well as responsiveness to the tumor microenvironment (TME) in vivo. These unique properties led to the highest level of synergistic tumor-killing efficiency when stimulated by a near-infrared (NIR) laser at 808 nm. Therefore, our virus-like ND functionalized with SF presents a novel type of nanocarrier that exhibits significant potential for synergistic applications in precision medicine.

3.
Energy Geoscience ; : 100199, 2023.
Article in English | ScienceDirect | ID: covidwho-20230710

ABSTRACT

Geothermal energy utilization in China had been promoted actively during the 13th Five-Year Plan period (2016–2020), with resultant achievements showing unique Chinese characteristics. Buildings (measured by areas) heated/cooled by intermediate to deep geothermal energy increased more rapidly than those by shallow geothermal energy. Geothermal power generation was restricted by the distribution of the resource and the sufficiency of local power supply. With the proposition of "dual carbon goal” by the central government of China and the coming era of great development of renewable energy, geothermal energy will be provided more development opportunities in room heating/cooling and power generation in the country ever than before. However, tackling technology bottlenecks and introduction of appropriate policy support are still urgently needed for nurturing a healthy environment for geothermal industry. Analysis suggests that a near-to medium-term development of geothermal energy shall be focused on a comprehensive and efficient utilization both through heating/cooling and power generation. Room heating/cooling by intermediate-to-deep and shallow geothermal energy shall be promoted nationwide according to local resource endowment and economic conditions. Geothermal power generation in Yunnan and Tibet shall be pushed forward in an orderly way. For medium- and long-term development, focus shall be put on power generation by using low to medium temperature geothermal energy and hot dry rocks. The "hot spring +" model shall be adapted in steps on a regular basis. To achieve these, measures including attaching importance to tackling key technologies, promoting standards for geothermal energy development and utilization, strengthening geothermal energy exploration and evaluation, and seeking for necessary policy support shall be taken.

4.
2022 Geothermal Rising Conference: Using the Earth to Save the Earth, GRC 2022 ; 46:793-803, 2022.
Article in English | Scopus | ID: covidwho-2324409

ABSTRACT

Community greenhouses are important for the production of local food and reduction of food supply insecurities within cities. As we've seen with Covid-19, pandemics highlight the criticality of local food access to underprivileged urban districts. Since almost 60 % of the energy used in greenhouses is spent in heating and cooling, ground heat exchangers (GHEs) can play a significant role in supplying temperature regulation, but geothermal heat pump systems tend to be expensive for community organizations. An efficient way to reduce GHEs installation costs is to dig trenches to install the system horizontally and cover a part of heating and cooling loads only. In order to ensure cost effectiveness and optimize operations, this type of system was studied for urban greenhouses where ground space can be limited. Sizing calculations were performed for GHEs of a 7.62 m x 15.24 m greenhouse located on the Island of Montreal where the annual, monthly, and hourly energy consumption were estimated from previous building simulations. Three scenarios were used to specify sizing of the system in terms of excavation dimensions and percentage of the greenhouse peak loads covered;(1) number and length of trenches required for a horizontal GHE (HGHE) covering 100% of cooling and heating loads;(2) number and length of trenches required for an HGHE to cover 100% of peak heating loads and 60% of peak cooling loads and;(3) the percentage of heating and cooling peak loads that can be covered by an HGHE located under the greenhouse with similar dimensions (around 116 m2). Estimated excavation dimensions for cases 1 and 2 are 51.8 m x 8 m (414.4 m2) and 40.8 m x 8 m (326.4 m2). Estimated percentage of peak loads covered for case 3 is 40% of heating peak loads and 30% of cooling peak loads. © 2022 Geothermal Resources Council. All rights reserved.

5.
17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022 ; 2022.
Article in English | Scopus | ID: covidwho-2326754

ABSTRACT

Under the influence of COVID-19, it is recommended to ventilate to reduce the risk of infection in the room. In an air-conditioned room, window open can increased the ventilation rate that caused by indoor and outdoor temperature difference. However, there is a concern that opening window in the air-conditioned room will increase the heating and cooling load due to air leakage. In addition, it is difficult to maintain the appropriate ventilation rate because the outdoor air temperature changes time to time. To solve this problem, we have developed an automatic window opening system to control the natural ventilation rate. In this study, actual measurements were conducted to understand the operating performance of the system, and its effect on the indoor thermal environment. As a result, it was confirmed that the ventilation rate could be controlled by this system. © 2022 17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022. All rights reserved.

6.
Decision Analytics Journal ; : 100247, 2023.
Article in English | ScienceDirect | ID: covidwho-2316340

ABSTRACT

This study uses the wavelet leaders method to examine multifractal characteristics and multiscale entropy patterns in price returns of four energy markets, Brent, West Texas Intermediate (WTI), gasoline, and heating oil, before and during the COVID-19 pandemic. The results show that price returns in all energy markets exhibit multifractal properties before and during the pandemic. In addition, the level of multifractals intensified during the pandemic only in price returns of Brent, WTI, and gasoline markets. On the contrary, the level of multifractals decreased during the pandemic in price returns of the heating oil market. The empirical results based on multiscale entropy show strong evidence of a reduced irregularity in energy market price returns during the COVID-19 pandemic. Our empirical findings have important managerial implications for traders and investors in the energy market.

7.
International Journal of Pharmaceutical Research and Allied Sciences ; 12(2):23-32, 2023.
Article in English | EMBASE | ID: covidwho-2316298

ABSTRACT

Coronavirus disease is a contagious respiratory ailment that has spread significantly around the world. Most cases of COVID-19 are spread from person to person by coming into contact with respiratory droplets that are released when an infected person coughs or sneezes. In this manuscript, we have highlighted the possible transmission of COVID-19 through food, water, air and paper. In the case of food, we have extensively covered the transmission of COVID-19 through meat, frozen foods, food packaging and food market along with the incidences worldwide. In the nextsection, we have highlighted the different components of air which are responsible for the transmission and also covered its relation with PM 2.5 incidence. The SARS-CoV-2 was isolated from sewage water/wastewater of various countries namely the United States, India, Australia, Netherlands and France signifying that wastewater can be a mode of virus transmission. The paper circulation by the infected COVID-19 patients can also be a virus conveyance route. It can be concluded that SARS-CoV-2 can therefore be transmitted indirectly through food via the workers involved in food packing or food marts.By following general safety precautions (wearing masks, using hand sanitisers, cleaning and disinfecting contact surfaces, and avoiding close contact), heating and using chemicals like ethanol (67-71%), sodium hypochlorite (0.1%) and hydrogen peroxide (0.5%) on environmental surfaces, along with vaccination, it is possible to reduce the spread of the SARS-CoV-2 virus.Copyright © 2023 The International Journal of Pharmaceutical Research and Allied Sciences (IJPRAS).

8.
Journal of Manufacturing Technology Management ; 34(4):507-534, 2023.
Article in English | ProQuest Central | ID: covidwho-2313321

ABSTRACT

PurposeThis work aims at proposing a novel Internet of Things (IoT)-based and cloud-assisted monitoring architecture for smart manufacturing systems able to evaluate their overall status and detect eventual anomalies occurring into the production. A novel artificial intelligence (AI) based technique, able to identify the specific anomalous event and the related risk classification for possible intervention, is hence proposed.Design/methodology/approachThe proposed solution is a five-layer scalable and modular platform in Industry 5.0 perspective, where the crucial layer is the Cloud Cyber one. This embeds a novel anomaly detection solution, designed by leveraging control charts, autoencoders (AE) long short-term memory (LSTM) and Fuzzy Inference System (FIS). The proper combination of these methods allows, not only detecting the products defects, but also recognizing their causalities.FindingsThe proposed architecture, experimentally validated on a manufacturing system involved into the production of a solar thermal high-vacuum flat panel, provides to human operators information about anomalous events, where they occur, and crucial information about their risk levels.Practical implicationsThanks to the abnormal risk panel;human operators and business managers are able, not only of remotely visualizing the real-time status of each production parameter, but also to properly face with the eventual anomalous events, only when necessary. This is especially relevant in an emergency situation, such as the COVID-19 pandemic.Originality/valueThe monitoring platform is one of the first attempts in leading modern manufacturing systems toward the Industry 5.0 concept. Indeed, it combines human strengths, IoT technology on machines, cloud-based solutions with AI and zero detect manufacturing strategies in a unified framework so to detect causalities in complex dynamic systems by enabling the possibility of products' waste avoidance.

9.
Food Environ Virol ; 2023 May 08.
Article in English | MEDLINE | ID: covidwho-2315463

ABSTRACT

Respiratory diseases are significant recurrent threats to global public health. Since the 1918 Spanish flu pandemic, seasonal influenza viruses continue to cause epidemics around the world each year. More recently, the COVID-19 global pandemic conducted a public health crisis with more than 6 million deaths and it also severely affected the global economy. Due to the phenomenon that people get infection from objects carrying viruses, it has aroused people's attention to home disinfection. As there is no ideal existing common domestic disinfectant, new and safer antiviral disinfectants are urgently needed. Lysozyme is a natural antibacterial agent widespread in nature and widely used in healthcare and food industry because of is recognized safety. Recently, it has been shown that thermally denatured lysozyme has the ability to kill murine norovirus and hepatitis A virus. In our study, we also demonstrated that heat-denatured lysozyme (HDLz) had an antiviral effect against H1N1 influenza A virus, and we optimized its antiviral activities by testing different heating denaturation conditions, to generalize this property, using pseudotype virus neutralization assay, we found that HDLz can also inhibit the entry of H5N1, H5N6, and H7N1 avian influenza viruses as well as SARS-CoV and SARS-CoV-2 particles in cell with IC50 at the ng/mL range. Finally, using western blot analysis, we provide evidence that HDLz polymerization correlates with antiviral effect, which may be a precious possible quality control test. Altogether, our data support HDLz as a powerful anti-respiratory virus disinfectant as a sole or additive of current disinfectants to reduce concentration of toxic component.

10.
Virol J ; 20(1): 84, 2023 05 02.
Article in English | MEDLINE | ID: covidwho-2315032

ABSTRACT

BACKGROUND: Thermal inactivation is a conventional and effective method of eliminating the infectivity of pathogens from specimens in clinical and biological laboratories, and reducing the risk of occupational exposure and environmental contamination. During the COVID-19 pandemic, specimens from patients and potentially infected individuals were heat treated and processed under BSL-2 conditions in a safe, cost-effective, and timely manner. The temperature and duration of heat treatment are optimized and standardized in the protocol according to the susceptibility of the pathogen and the impact on the integrity of the specimens, but the heating device is often undefined. Devices and medium transferring the thermal energy vary in heating rate, specific heat capacity, and conductivity, resulting in variations in efficiency and inactivation outcome that may compromise biosafety and downstream biological assays. METHODS: We evaluated the water bath and hot air oven in terms of pathogen inactivation efficiency, which are the most commonly used inactivation devices in hospitals and biological laboratories. By evaluating the temperature equilibrium and viral titer elimination under various conditions, we studied the devices and their inactivation outcomes under identical treatment protocol, and to analyzed the factors, such as energy conductivity, specific heat capacity, and heating rate, underlying the inactivation efficiencies. RESULTS: We compared thermal inactivation of coronavirus using different devices, and have found that the water bath was more efficient at reducing infectivity, with higher heat transfer and thermal equilibration than a forced hot air oven. In addition to the efficiency, the water bath showed relative consistency in temperature equilibration of samples of different volumes, reduced the need for prolonged heating, and eliminated the risk of pathogen spread by forced airflow. CONCLUSIONS: Our data support the proposal to define the heating device in the thermal inactivation protocol and in the specimen management policy.


Subject(s)
COVID-19 , Humans , COVID-19/prevention & control , Pandemics/prevention & control , Hot Temperature , Temperature , Water
11.
17th IBPSA Conference on Building Simulation, BS 2021 ; : 3521-3528, 2022.
Article in English | Scopus | ID: covidwho-2304495

ABSTRACT

The Covid-19 outbreak has resulted in new patterns of home occupancy, the implications of which for indoor air quality (IAQ) and energy use are not well-known. In this context, the present study investigates 8 flats in London to uncover if during a lockdown, (a) IAQ in the monitored flats deteriorated, (b) the patterns of window operation by occupants changed, and (c) more effective ventilation patterns could enhance IAQ without significant increases in heating energy demand. To this end, one-year's worth of monitored data on indoor and outdoor environment along with occupant use of windows has been used to analyse the impact of lockdown on IAQ. Moreover, using on-site CO2 data, monitored occupancy and operation of windows, the team has calibrated a thermal performance model of one of the flats to investigate the implications of alternative ventilation strategies. The results suggest that despite the extended occupancy during lockdown, occupants relied less on natural ventilation, which led to significantly higher CO2 and PM10 concentrations. However, simple natural ventilation patterns or use of mechanical ventilation with heat recovery proves to be very effective to maintain acceptable IAQ. © International Building Performance Simulation Association, 2022

12.
NeuroQuantology ; 20(8):9756-9768, 2022.
Article in English | EMBASE | ID: covidwho-2301592

ABSTRACT

The Air borne transmission is a very big concern for highly infectious diseases like Covid-19 and other airborne diseases. A micro droplet and aerosol can be carried out in the air and can remain flowing in air over a distance in a confined space, leading to affecting high number of people getting prone to infection and it is very dangerous in enclosed spaces or shared spaces. Public places, shared facilities are the areas, where infectious aerosol can be present in the air for a long duration. Ventilation of closed spaces, shared spaces is the need of hour to have analysed and deep study in context of infectious airborne diseases. Introduction of fresh air into the enclosed environment at regular interval of times may lead to fast dilution of air present in the enclosed space. The prominent building codes and HVAC guidelines allows as to calculate ACPH (Air changes per hour) in an enclosed space as per the occupancy and flow rate. The age of air is the criteria to define the amount of air residing in the enclosed space when it enters the space till its exhaust from that space. The more the age of air in the particular area the more can be the infection probability among the occupants. It is predominant to study the airflow pattern caused due to ventilation which can be collaborated with age of air to know about the infection probability. Typically, a classroom geometry is assumed with inlet outlet boundary conditions where exhaust fan is playing a major role of displacement ventilation. Study of air recirculation zones and dead zones is the point of interest of this study. Computational fluid dynamics is the most powerful tool in the present era to study the air flow pattern in enclosed and shared spaces.Copyright © 2022, Anka Publishers. All rights reserved.

13.
Physics of Fluids ; 35(4), 2023.
Article in English | Scopus | ID: covidwho-2298725

ABSTRACT

Given the current coronavirus (COVID-19) situation around the world, we may have to face a long-term battle with coronavirus. It is necessary to prepare and stay resilient with some other techniques to improve air quality in buildings, especially in clinics and hospitals. In this paper, we have developed Ultraviolet-C (UVC) light-emitting diode (LED) modules which can be implemented in air ducts in heating, ventilation, and air conditioning system for airborne disinfection. An LED module is designed with LED panels as the basic unit so that it is easy to scale up to accommodate for air ducts with different sizes. Both experiments and simulations are carried out to study its disinfection performance. The results show that more than 76% and 85% of the pathogen can be inactivated within 60 and 90 min, respectively, in a meeting room with a volume of 107 m3 by using one LED module. Simulations for two LED modules show that the disinfection efficacy is more than two times compared to that of one LED module. In addition to the pathogen used in the experiments, the disinfection performance of the LED module for inactivation of SARS-CoV-2 virus based on the literature is investigated numerically. It shows that more than 99.70% of pathogens receive UV dose larger than 4.47 J/m2, leading to an almost 89.10% disinfection rate for SARS-CoV-2 virus within one hour using the two LED modules in the same meeting room. © 2023 Author(s).

14.
IEEE Internet of Things Journal ; : 1-1, 2023.
Article in English | Scopus | ID: covidwho-2294973

ABSTRACT

The pandemics such as COVID-19 are worldwide health risks and result in catastrophic impacts on the global economy. To prevent the spread of pandemics, it is critical to trace the contacts between people to identify the infection chain. Nevertheless, the privacy concern is a great challenge to contact tracing. Moreover, existing contact tracing apps cannot obtain the macro-level infection risk information, e.g., the hotspots where the infection occurs, which, however, is critical to optimize healthcare planning to better control and prevent the outbreak of pandemics. In this paper, we develop a novel privacy-preserved pandemic tracing system, PRISC, to compute the infection risk through cellular-enabled IoT devices. In the PRISC system, there are three parties: a mobile network operator, a social network provider, and the health department. The physical contact records between users are obtained by the mobile network operator from the users’cellular-enabled IoT devices. The social contacts are obtained by the social network provider, while the health department has the records of pandemic patients. The three parties work together to compute a heatmap of pandemic infection risk in a region, while fully protecting the data privacy of each other. The heatmap provides both macro and micro level infection risk information to help control pandemics. The experiment results indicate that PRISC can compute an infection risk score within a couple of seconds and a few mega-bytes (MBs) communication cost, for datasets with 100,000 users. IEEE

15.
IEEE Transactions on Industrial Electronics ; : 1-10, 2023.
Article in English | Scopus | ID: covidwho-2275443

ABSTRACT

Ventilation improves indoor air quality and reduces airborne infections. It is particularly important at present because of the COVID-19 pandemic. Commercially available ventilation facilities can only be instantly turned on/off or at a set time with adjustable air volumes (high, middle, and low). However, maintaining the indoor carbon dioxide concentration while reducing the energy consumption of these facilities is challenging. Hence, this study developed clustering algorithms to determine the carbon dioxide concentration limit thus enabling real-time air volume adjustment. These limit values were set using the existing energy recovery ventilation (ERV) controller. In the experiment, dual estimation was adopted, and the constructing building energy models from data were sampled at a low rate to compare that the ventilation facilities are only turned on/off. In addition, switching control is closely related to fuzzy control;that is, fuzzy control can be considered a smooth version of switching control. The experimental results indicated that the limits of 600 and 700 ppm were suitable to effectively control the real-time air volume based on the ERV operation. An ERV-based carbon dioxide concentration limit reduced the energy consumption of ventilation facilities by 11%implications of this study. IEEE

16.
Gogus-Kalp-Damar Anestezi ve Yogun Bakim Dernegi Dergisi ; 28(4):365-367, 2022.
Article in Turkish | EMBASE | ID: covidwho-2275268

ABSTRACT

Cold agglutinin disease(CAD) is an autoimmune disease that occurs against erythrocyte antigens. It is usually idiopathic, but some infections can also be a trigger. CAD becomes active in the peripheral circulation at lower temperatures more easily when exposed to cold, causing hemolysis or agglutination. In this article, the management of a coronary bypass case with CA formation in intraoperative period is presented. A 46-year-old diabetic and hypertensive male patient had COVID-19 2 months ago. Cardiopulmonary bypass(CPB) was initiated with adequate heparinization, and the patient was cooled to 32degreeC. It was noticed that there were clots in the cardioplegia delivery line(+1degreeC). Agglutinations were observed in the autologous blood of the patient whose ACT values were normal. After CPB, the operation was completed without any problems and the patient was discharged on the 5th day with recovery. A diagnosis of CAD was made with the results of peripheral smear and immunologic tests. Determination of antibody concentration and thermal amplitude in the preoperative period in patients with CAD is very important. While preparing such patients for surgery, heating of room, patient, fluids, planning of normothermic CPB, and using warm cardioplegia are required. The relationship between CAD and COVID has started to take place in the literature. The patient we presented had a COVID 2 months ago, cold agglutinin may have been induced by COVID or may have arisen idiopathic. Considering that many people may have had a COVID nowadays, care should be taken especially in the perioperative period of cardiac surgery.Copyright © Telif hakki 2022 Gogus-Kalp-Damar Anestezi ve Yogun Bakim Dernegi Dergisi - Available online at www.gkdaybd.org.

17.
Gogus-Kalp-Damar Anestezi ve Yogun Bakim Dernegi Dergisi ; 28(4):365-367, 2022.
Article in Turkish | EMBASE | ID: covidwho-2275267

ABSTRACT

Cold agglutinin disease(CAD) is an autoimmune disease that occurs against erythrocyte antigens. It is usually idiopathic, but some infections can also be a trigger. CAD becomes active in the peripheral circulation at lower temperatures more easily when exposed to cold, causing hemolysis or agglutination. In this article, the management of a coronary bypass case with CA formation in intraoperative period is presented. A 46-year-old diabetic and hypertensive male patient had COVID-19 2 months ago. Cardiopulmonary bypass(CPB) was initiated with adequate heparinization, and the patient was cooled to 32degreeC. It was noticed that there were clots in the cardioplegia delivery line(+1degreeC). Agglutinations were observed in the autologous blood of the patient whose ACT values were normal. After CPB, the operation was completed without any problems and the patient was discharged on the 5th day with recovery. A diagnosis of CAD was made with the results of peripheral smear and immunologic tests. Determination of antibody concentration and thermal amplitude in the preoperative period in patients with CAD is very important. While preparing such patients for surgery, heating of room, patient, fluids, planning of normothermic CPB, and using warm cardioplegia are required. The relationship between CAD and COVID has started to take place in the literature. The patient we presented had a COVID 2 months ago, cold agglutinin may have been induced by COVID or may have arisen idiopathic. Considering that many people may have had a COVID nowadays, care should be taken especially in the perioperative period of cardiac surgery.Copyright © Telif hakki 2022 Gogus-Kalp-Damar Anestezi ve Yogun Bakim Dernegi Dergisi - Available online at www.gkdaybd.org.

18.
Building Services Engineering Research & Technology ; 44(2):113-133, 2023.
Article in English | ProQuest Central | ID: covidwho-2270569

ABSTRACT

To assess risk factors for COVID-19 transmission and address the closure of mass gathering events since March 2020, the UK Government ran the Events Research Programme (ERP), following which it reopened live events in sports, music, and culture in July 2021. We report the rapid post-occupancy evaluation of Indoor Air Quality (IAQ) and associated long-range airborne transmission risk conducted in the Environmental Study of the ERP. Ten large venues around the UK were monitored with CO2 sensors at a high spatial and temporal resolution during 90 events. An IAQ Index based on CO2 concentration was developed, and all monitored spaces were classified in bands from A to G based on their average and maximum CO2 concentrations from all events. High resolution monitoring and the IAQ Index depicted the overall state of ventilation at live events, and allowed identification of issues with ventilation effectiveness and distribution, and of spaces with poor ventilation and the settings in which long-range airborne transmission risk may be increased. In numerous settings, CO2 concentrations were found to follow patterns relating to event management and specific occupancy of spaces around the venues. Good ventilation was observed in 90% of spaces monitored for given occupancies. Practical applications: High-resolution monitoring of indoor CO2 concentrations is necessary to detect the spatial variation of indoor air quality (IAQ) in large mass gathering event venues. The paper summarises COVID-19 ventilation guidance for buildings and defines a methodology for measurement and rapid assessment of IAQ during occupancy at live events that can be implemented by venue managers. Comparisons of the CO2 concentrations measured during the events identified the spaces at high risk of long-range transmission of airborne pathogens. Building operators should be mindful of the ventilation strategies used relative to the total occupancy in different spaces and the occupant's activities.

19.
Applied Thermal Engineering ; 226, 2023.
Article in English | Scopus | ID: covidwho-2269191

ABSTRACT

The nucleic acid detection is an effective way for the prevention and control of COVID-19. PCR amplification is an important process in the nucleic acid detection. At present, PCR amplification has the problem of low heating/cooling rates, and poor temperature uniformity. This paper proposes a microchannel temperature control device for the nucleic acid detection. Five groups of parallel serpentine channels are used to increase the cooling rate of the PCR amplification. A gradual thermal conductivity design is applied to the reaction module to increase the temperature uniformity. The experimental results show that the best temperature uniformity is obtained when the materials of the inner and outer layers of the reaction module are copper and aluminum alloys, respectively. The limit and average heating/cooling rate are 7.2, 6.12, 5.52 and 5.28 °C/s, respectively, when the input power of the thermoelectric cooler is 11.07 W/cm2, the temperature and flow rate of the cooling water are 15℃ and 700 ml/min, and the thermal conductivity of the thermal grease is 6 W/(m·K). Compared with the commercial fan-fin cooling method, the limit and average heating/cooling rates are increased by 38.02%, 80.82%, 86.49% and 208.77%, respectively, with the help of microchannel cooling method. © 2023 Elsevier Ltd

20.
ASME 2022 International Mechanical Engineering Congress and Exposition, IMECE 2022 ; 6, 2022.
Article in English | Scopus | ID: covidwho-2266889

ABSTRACT

The energy consumption of Heating Ventilation and Air Conditioning (HVAC) systems accounts for a large proportion of global energy usage so even a small percentage of energy savings in these systems will account for important absolute value savings. One such saving can be realized by better designs as well as optimizing existing air distribution system. The indoor air quality (IAQ) is also greatly impacted by the air distribution system. In this work, the task of optimizing both the placement and the design of diffusers is investigated so acceptable Air Changes per Hour (ACH) numbers are attained with less energy consumption and good thermal comfort. The ANSYS Fluent software was used to optimize the design and placement of a newly developed diffuser. The proposed air distribution system is design to produce conditions like what one would experience while standing outside in a small breeze while experiencing perfect weather (room temperature, uniform air temperature distribution, air speed less than 2 m/s) [1]). This work is an extension of a previous study where a new diffuser design was proposed, which takes advantage of the Coanda effect [2]. The numerical analysis includes realistic models of a 9 × 9 × 3 m (width × length × height) classroom, which is occupied by students and a teacher. To be more realistic, it includes furniture, a door and windows. The simulated Heating Ventilation and Air Conditioning (HVAC) system complies with ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) standards for acceptable air quality. This investigation proposes a template on how anyone can optimize the location and placement of the air diffusers while achieving both thermal comfort and good IAQ. While this work was inspired by the COVID-19 pandemic this is foreseen to be an important ongoing issue and could lead to future advances in HAVC system that improve IAQ and produce better thermal comfort with improved energy savings. Copyright © 2022 by ASME.

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