Non-uniformity in outdoor CO2 concentration in city of Copenhagen

The accurate data of outdoor CO2 concentration are important for the proper design of ventilation and thus for indoor air quality and energy use in buildings. Typical design practice is to assume outdoor CO2 concentration to be 400 ppm. However, the outdoor CO2 concentration may be different in different areas of cities. This paper presents preliminary results of long-term (one year) outdoor CO2 concentration changes in four districts of Copenhagen (Denmark). The districts included downtown area and suburbs with different surroundings. Four buildings were selected for the measurements, one building in each district. Outdoor CO2 concentration measurements were performed at two levels – ground level and top of the buildings. Special attention was paid to use accurate measuring instruments. The instruments were carefully calibrated before the measurements. The calibration of the instruments was checked periodically. In this paper, preliminary results from summer and autumn measurements are presented. The outdoor CO2 concentration varied over the day and from day to day in the range between 340 and 450 ppm. The CO2 concentration at the ground of the buildings was usually 10 to 40 ppm higher than that at the top level in autumn. At the buildings in the suburbs, during the working hours, the outdoor CO2 concentration measured on the top level close to the intake duct was on average 408 ppm. At the building in the downtown area, that was on average 414 ppm. However, the outdoor CO2 concentration varied depending on the building, level and time. During the working hours, the 75 percentiles of outdoor CO2 concentration varied between 384 ppm and 442 ppm, which indicates that the required ventilation rate could be different over 10% depending on the building location site, measurement height and time. In order to ensure the required indoor limits of CO2 concentration, CO2 measurements must be performed close to the location of the outdoor air intake.

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Investigation of ventilation conditions associated with CO2 concentration changes in ultrasonographic exam room from the perspective of COVID-19 infection control

10.1101/2021.03.01.21252598 ◽

2021 ◽

Author(s):

Roka N Matsubayashi ◽

Shino Harada ◽

Mitsuhiro Tominaga

Keyword(s):

Carbon Dioxide ◽

Infection Control ◽

Co2 Concentration ◽

Ventilation Rate ◽

Adequate Ventilation ◽

Breast Examination ◽

Exam Room ◽

Concentration Changes ◽

Carbon Dioxide Co2 ◽

Almost All

AbstractObjectivesVentilation is an important factor in preventing COVID-19 infection. To clarify the state of ventilation in ultrasonic exam rooms, as an index of ventilation rate, the carbon dioxide (CO2) concentration in our exam rooms was measured.MethodsWe measured the CO2 concentration in each exam room before the examination and 0–15 minutes after end of the exam.The subjects were 70 cases (abdomen: 24, breast: 16, neck: 16, and musculoskeletal: 14). In infant cases, one parent accompanied the patient during the examination.ResultsThe highest CO2 concentration was 2261 ppm, observed after the breast examination. In all cases, the CO2 concentration in the exam room was highest immediately after the examination or two minutes after. Almost all cases had recovered to within 120% of the pre-examination CO2 concentrations within 15 minutes after the examination. The average CO2 concentration after ultrasonography was significantly higher for breast examinations than others.ConclusionsEven in a hospital with modern ventilation equipment, the CO2 concentration in the ultrasound room was high after the exam and it takes 15 minutes to recover to the pre-exam state. Care must be taken to ensure adequate ventilation in ultrasonographic facilities.

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Experimental Analysis of CO2 Concentration Changes in an Apartment Using a Residential Heat Recovery Ventilator

Sustainability ◽

10.3390/su131810302 ◽

2021 ◽

Vol 13 (18) ◽

pp. 10302

Author(s):

Kyungjoo Cho ◽

Dongwoo Cho ◽

Taeyeon Kim

Keyword(s):

Flow Rate ◽

Experimental Analysis ◽

Heat Recovery ◽

Co2 Concentration ◽

Infiltration Rate ◽

Ventilation Rate ◽

Living Room ◽

Air Flow Rate ◽

Concentration Changes ◽

Ventilation Systems

Korean law requires at least three levels of control for apartment ventilation systems, including 0.5 air change per hour (ACH). When this law was enacted, it was believed that a 0.5 ACH air flow rate would be sufficient for apartments following building completion. However, ventilation systems cause different air qualities in each space within a unit, depending on infiltration rate and number of occupants. In addition, the current ventilation rate standard is based on an apartment unit’s total area, assuming that all room doors are open. In this study, changes in CO2 concentration were experimentally analyzed based on the number of occupants and various ventilation frequencies with closed doors to analyze air quality differences among rooms in a typical 85 m2 apartment unit in Korea. When the 0.5 ACH ventilation was performed, maintaining 1000 ppm or less was difficult if four people stayed for more than two hours in the living room or two people stayed for more than one hour in the bedroom with closed doors. Our results indicate that it is challenging to maintain a CO2 concentration of 1000 ppm when doors are closed as standards are calculated based on a unit’s total area. Therefore, ventilation systems should be required to provide different air volumes for each room.

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1848: Revolix 70 Watt 2 Micron Continuous Wave Laser Vaporesection of the Prostate. Preliminary Results After a One Year Follow-Up

The Journal of Urology ◽

10.1016/s0022-5347(18)32021-4 ◽

2007 ◽

Vol 177 (4S) ◽

pp. 614-614

Author(s):

Thorsten Bach ◽

Thomas R.W. Herrmann ◽

Roman Ganzer ◽

Andreas J. Gross

Keyword(s):

Continuous Wave ◽

Continuous Wave Laser ◽

Preliminary Results ◽

Wave Laser ◽

One Year

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AB0310 TOLERABILITY AND SAFETY OF 23-VALENT POLYSACCHARIDE PNEUMOCOCCAL VACCINE IN PATIENTS WITH ANTIPHOSPHOLIPID SYNDROME, PRELIMINARY RESULTS

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2021-eular.1447 ◽

2021 ◽

Vol 80 (Suppl 1) ◽

pp. 1180.3-1181

Author(s):

G. Tarasova ◽

B. Belov ◽

M. Cherkasova ◽

E. Aseeva ◽

T. Reshetnyak ◽

...

Keyword(s):

Antiphospholipid Syndrome ◽

Lupus Erythematosus ◽

Pneumococcal Vaccine ◽

Respiratory Infections ◽

Vascular Complications ◽

Initial Increase ◽

Post Vaccination ◽

Preliminary Results ◽

One Year ◽

Polysaccharide Pneumococcal Vaccine

Background:Antiphospholipid syndrome (APS) is an autoimmune disease often associated with severe, life-threatening vascular complications. The majority of patients (and in case of secondary APS, in 100% of cases) receive immunosuppressive therapy. Immunization with pneumococcal vaccines in patients with both primary APS (PAPS) and APS+SLE or secondary (sAPS) is necessary to prevent severe respiratory infections in these patients.Objectives:Purpose of the study - to study the tolerance and safety of 23-valent polysaccharide pneumococcal vaccine (PPV-23) in patients with PAPS and sAPS.Methods:At this stage, the study included 28 patients with APS, of which 10 with PAPS, 18 with sAPS proceeding against the background of systemic lupus erythematosus (SLE), of which 23 women (82%), 5 men (18%). The average age (Me) of patients was 43 (35.5; 53.0) g. 20 patients received glucocorticoids (GC) 5-30 mg/day equivalent to prednisone, 17- hydroxychloroquine, 6- cytostatics (3-cyclophosphamide, 2-azathioprine, 1- mycophenolate mofetil), 8- biologics: 5-rituximab (RTM), 3-belimumab (BLM); 20-received anticoagulants (direct-10, indirect-10).1 dose (0.5 ml) of PPV-23 was administered subcutaneously. The follow-up time was 1 year in 23 patients and 5-5.5 months in 5-5.5 months. During the visits, standard clinical and laboratory tests were performed, immunological blood test and the level of antibodies to S.pneumoniaeResults:Vaccination was well tolerated in all patients. In 29% of cases, vaccine reactions of mild severity were observed: in 7 (25%) - a local reaction (pain in the arm for 1-3 days-at 7, redness up to 2 cm at the injection site-at 1), in 1 (3,6%), the patient experienced general weakness (moderately pronounced) for 1 month. Vaccinal reactions were completely reversible and did not require additional prescriptions. Post-vaccination complications develop, as a rule, in the first 1-2 months after vaccination. During the observation period, none of the patients had an exacerbation of the disease, reliably associated with the vaccination. There was no recurrence of thrombosis, both in patients receiving anticoagulant therapy and without it. No new autoimmune phenomena, both clinical and laboratory, were identified. The dynamics of the production of anti-streptococcal antibodies during the year was followed in 16 patients. One year after vaccination, 31% of patients showed a significant (more than 2-fold compared to the initial) increase in the concentration of antibodies to polysaccharides of the cell wall of S. pneumoniae (“responders”), 69% of patients were “non-responders” to the vaccine. At the same time, all 5 patients with PAPS were “non-responders”, and 45.5% “respondents” with sAPS.Conclusion:Preliminary results show that patients with APS tolerate PPV-23 vaccination well. In the next post-vaccination period, exacerbations of the disease, thrombosis were not recorded. Attention is drawn to the large number of “non-responders” in PAPS, however, to obtain statistically reliable results, it is necessary to continue the study and recruit more patients.Disclosure of Interests:None declared

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Investigating Primary Factors Affecting Electricity Consumption in Non-Residential Buildings Using a Data-Driven Approach

Energies ◽

10.3390/en12214046 ◽

2019 ◽

Vol 12 (21) ◽

pp. 4046 ◽

Cited By ~ 3

Author(s):

Sooyoun Cho ◽

Jeehang Lee ◽

Jumi Baek ◽

Gi-Seok Kim ◽

Seung-Bok Leigh

Keyword(s):

Energy Consumption ◽

Energy Use ◽

Simulation Analysis ◽

Residential Buildings ◽

Electric Energy ◽

Electricity Consumption ◽

Building Energy ◽

Major Effect ◽

Measuring Instruments ◽

Building Energy Consumption

Although the latest energy-efficient buildings use a large number of sensors and measuring instruments to predict consumption more accurately, it is generally not possible to identify which data are the most valuable or key for analysis among the tens of thousands of data points. This study selected the electric energy as a subset of total building energy consumption because it accounts for more than 65% of the total building energy consumption, and identified the variables that contribute to electric energy use. However, this study aimed to confirm data from a building using clustering in machine learning, instead of a calculation method from engineering simulation, to examine the variables that were identified and determine whether these variables had a strong correlation with energy consumption. Three different methods confirmed that the major variables related to electric energy consumption were significant. This research has significance because it was able to identify the factors in electric energy, accounting for more than half of the total building energy consumption, that had a major effect on energy consumption and revealed that these key variables alone, not the default values of many different items in simulation analysis, can ensure the reliable prediction of energy consumption.

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Geographic Aspects of Temperature and Concentration Feedbacks in the Carbon Budget

Journal of Climate ◽

10.1175/2009jcli3161.1 ◽

2010 ◽

Vol 23 (3) ◽

pp. 775-784 ◽

Cited By ~ 16

Author(s):

G. J. Boer ◽

V. Arora

Keyword(s):

Negative Feedback ◽

Carbon Concentration ◽

Carbon Budget ◽

Co2 Concentration ◽

Atmospheric Co2 ◽

Climate Feedback ◽

Climate Modelling ◽

Emission Scenarios ◽

Temperature Feedback ◽

Concentration Changes

Abstract The geographical distribution of feedback processes in the carbon budget is investigated in a manner that parallels that for climate feedback/sensitivity in the energy budget. Simulations for a range of emission scenarios, made with the Canadian Centre for Climate Modelling and Analysis (CCCma) earth system model (CanESM1), are the basis of the analysis. Anthropogenic CO2 emissions are concentrated in the Northern Hemisphere and provide the forcing for changes to the atmospheric carbon budget. Transports redistribute the emitted CO2 globally where local feedback processes act to enhance (positive feedback) or suppress (negative feedback) local CO2 amounts in response to changes in CO2 concentration and temperature. An increased uptake of CO2 by the land and ocean acts to counteract increased atmospheric CO2 concentrations so that “carbon–concentration” feedbacks are broadly negative over the twenty-first century. Largest values are found over land and particularly in tropical regions where CO2 acts to fertilize plant growth. Extratropical land also takes up CO2 but here the effect is limited by cooler temperatures. Oceans play a lesser negative feedback role with comparatively weak uptake associated with an increase in the atmosphere–ocean CO2 gradient rather than with oceanic biological activity. The effect of CO2-induced temperature increase is, by contrast, to increase atmospheric CO2 on average and so represents an overall positive “carbon–temperature” feedback. Although the average is positive, local regions of both positive and negative carbon–temperature feedback are seen over land as a consequence of the competition between changes in biological productivity and respiration. Positive carbon–temperature feedback is found over most tropical land while mid–high-latitude land exhibits negative feedback. There are also regions of positive and negative oceanic carbon–temperature feedback in the eastern tropical Pacific. The geographical patterns of carbon–concentration and carbon–temperature feedbacks are comparatively robust across the range of emission scenarios used, although their magnitudes are somewhat less robust and scale nonlinearly as a consequence of the large CO2 concentration changes engendered by the scenarios. The feedback patterns deduced nevertheless serve to illustrate the localized carbon feedback processes in the climate system.

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Observed decreases in on-road CO<sub>2</sub> concentrations in Beijing during COVID-19 restrictions

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-4599-2021 ◽

2021 ◽

Vol 21 (6) ◽

pp. 4599-4614

Author(s):

Di Liu ◽

Wanqi Sun ◽

Ning Zeng ◽

Pengfei Han ◽

Bo Yao ◽

...

Keyword(s):

Urban Areas ◽

Low Cost ◽

Working Hours ◽

Weather Conditions ◽

Co2 Concentration ◽

Mobile Platforms ◽

Local Standard ◽

Transportation Emissions ◽

Enhancement Method ◽

The Difference

Abstract. To prevent the spread of the COVID-19 epidemic, restrictions such as “lockdowns” were conducted globally, which led to a significant reduction in fossil fuel emissions, especially in urban areas. However, CO2 concentrations in urban areas are affected by many factors, such as weather, biological sinks and background CO2 fluctuations. Thus, it is difficult to directly observe the CO2 reductions from sparse ground observations. Here, we focus on urban ground transportation emissions, which were dramatically affected by the restrictions, to determine the reduction signals. We conducted six series of on-road CO2 observations in Beijing using mobile platforms before (BC), during (DC) and after (AC) the implementation of COVID-19 restrictions. To reduce the impacts of weather conditions and background fluctuations, we analyze vehicle trips with the most similar weather conditions possible and calculated the enhancement metric, which is the difference between the on-road CO2 concentration and the “urban background” CO2 concentration measured at the tower of the Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences. The results showed that the DC CO2 enhancement was decreased by 41 (±1.3) parts per million (ppm) and 26 (±6.2) ppm compared to those for the BC and AC trips, respectively. Detailed analysis showed that, during COVID-19 restrictions, there was no difference between weekdays and weekends during working hours (09:00–17:00 local standard time; LST). The enhancements during rush hours (07:00–09:00 and 17:00–20:00 LST) were almost twice those during working hours, indicating that emissions during rush hours were much higher. For DC and BC, the enhancement reductions during rush hours were much larger than those during working hours. Our findings showed a clear CO2 concentration decrease during COVID-19 restrictions, which is consistent with the CO2 emissions reductions due to the pandemic. The enhancement method used in this study is an effective method to reduce the impacts of weather and background fluctuations. Low-cost sensors, which are inexpensive and convenient, could play an important role in further on-road and other urban observations.

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Ecosystem effects of CO<sub>2</sub> concentration: evidence from past climates

Climate of the Past Discussions ◽

10.5194/cpd-5-937-2009 ◽

2009 ◽

Vol 5 (2) ◽

pp. 937-963 ◽

Cited By ~ 2

Author(s):

I. C. Prentice ◽

S. P. Harrison

Keyword(s):

Forest Cover ◽

Dissolved Inorganic Carbon ◽

Net Primary Production ◽

Isotope Composition ◽

Late Quaternary ◽

Co2 Concentration ◽

C3 Plants ◽

Sea Level Changes ◽

Co2 Effects ◽

Concentration Changes

Abstract. Atmospheric CO2 concentration has varied from minima of 170–200 ppm in glacials to maxima of 280–300 ppm in the recent interglacials. Photosynthesis by C3 plants is highly sensitive to CO2 concentration variations in this range. Physiological consequences of the CO2 changes should therefore be discernible in palaeodata. Several lines of evidence support this expectation. Reduced terrestrial carbon storage during glacials, indicated by the shift in stable isotope composition of dissolved inorganic carbon in the ocean, cannot be explained by climate or sea-level changes. It is however consistent with predictions of current process-based models that propagate known physiological CO2 effects into net primary production at the ecosystem scale. Restricted forest cover during glacial periods, indicated by pollen assemblages dominated by non-arboreal taxa, cannot be reproduced accurately by palaeoclimate models unless CO2 effects on C3-C4 plant competition are also modelled. It follows that methods to reconstruct climate from palaeodata should account for CO2 concentration changes. When they do so, they yield results more consistent with palaeoclimate models. In conclusion, the palaeorecord of the Late Quaternary, interpreted with the help of climate and ecosystem models, provides evidence that CO2 effects at the ecosystem scale are neither trivial nor transient.

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METODE PERHITUNGAN MASSA GAS CO2 YANG DISERAP FOTOBIOREAKTOR DENGAN PERSAMAAN GAS IDEAL

Jurnal Teknologi Lingkungan ◽

10.29122/jtl.v11i2.1208 ◽

2016 ◽

Vol 11 (2) ◽

pp. 239

Author(s):

Arif Dwi Santoso

Keyword(s):

Gas Flow ◽

Co2 Concentration ◽

Ideal Gas ◽

Gas Absorption ◽

Flow Diagram ◽

Measuring Instruments ◽

Continuous Systems ◽

Co2 Gas ◽

Method Of Calculation ◽

The Ideal

BPPT conducted the mass of CO2 gas calculation in the gas absorption experiments with phytoplankton cultivation in the photobioreaktor (FBR) batch and continous syatem using the ideal gas equation. This study stated that the method of calculation with the ideal gas equation is more simple and practical in providing data analysis compared with biomass methods. Some things to note in this method include good knowledge about the movement of the gas flow diagram of inputs and outputs FBR, an appropriate gas sampling, and accuracy of measuring instruments. The required data in the mass calculation of CO2 gas in a batch photobioreactor system was resultant CO2 concentration during measurement. Meanwhile in a continuous systems, the requireddata was CO2 concentration at the reactor input and output , the rate and duration of the injection gas.Keywods : massa gas CO2, dry weight, ideal gas formula

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Effects of solar energy use on rural community: a study of Boyarjapha village in Paikgachha upazila

10.31235/osf.io/p4zv6 ◽

2020 ◽

Author(s):

Sajadul Alam Saimon ◽

Rakibul Ahasan

Keyword(s):

Solar Energy ◽

Renewable Resources ◽

Energy Demand ◽

Energy Use ◽

Solar Power ◽

Working Hours ◽

Remote Areas ◽

Rural And Remote Areas ◽

Solar Electricity ◽

Day By Day

Renewable energy is of great importance for today’s world which is generally produced from natural sources. Countries like Bangladesh has to use this energy to meet their energy demand. Day by day the demand of electricity is increasing in stormy pace but our resource is limited. So using renewable resources i.e. solar power to meet the demand of electricity is highly necessary especially rural and remote areas. This paper examined the nature and extent of solar energy in Boyarjapha village of Paikgachha Upazila of Khulna district to analyse the effects of solar panel in their daily life. Many positive impacts of solar power were found out such as better quality lighting, education, entertainment, communications, business, increasing working hours, women empowerment, increasing awareness etc. There are a few bad effects of solar energy too. But Government intervention is a must to ensure better quality results in coming future. Similarly, government has to take serious steps to advertise solar electricity in remote areas of Bangladesh

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