scholarly journals Experimental Investigation on Filtration and Cooling Effect of Kitchen Hood Ventilation System from Water-Mist Recirculation Spray: Water-Mist Spray Cycle

2021 ◽  
Vol 90 (1) ◽  
pp. 64-79
Author(s):  
Nor Adrian Nor Salim ◽  
Norzelawati Asmuin ◽  
Azian Hariri ◽  
M. Farid Sies ◽  
Hanis Zakaria ◽  
...  
Keyword(s):  
Fresh Water ◽  
Ventilation System ◽  
Current Method ◽  
Co2 Concentration ◽  
High Heat ◽  
Water Mist ◽  
Recirculation System ◽  
Current Water ◽  
Cooling Effects ◽  
The Difference

A Water-mist spray system in several heavy-duty kitchen hood canopies is installed to efficiently control the high heat loads and grease emissions produced from the cooking process and for safety purposes. The main purpose of this study is to reduce water consumption by introducing the water-mist recirculation system to replace the current method water-mist system since it is working as water loss. A standard ASTM 2519 and UL 1046 full-scaled experiment is developed in the laboratory. An existing Halton Europe/Asian water-mist operating system is adopted in this study. Twelve (12) cycles (at 24 hours of water-mist activation) have been studied to determine the maximum water-mist activation cycle. The data are collected at two (2) hours water-mist activation at every water-mist recirculation cycle. The water-mist spray fluids viscosity is 0.7 cP from fresh water until the 4th cycle (8 hours water-mist spray) and increase 14.29% (0.8 cP) at the 5th cycle to the 12th cycle. On average, the difference in gas emissions percentage for CO concentration between fresh water until the 4th cycle is 10.81 – 18.92% while the CO2 concentration is 12.33 – 18.22%. On average, the difference in cooling effects percentage for ducting temperature between fresh water until the 4th cycle is 5.55% while the hood temperature is 2.33%. From the study, the water-mist recirculation system could save up to 611,667 litres per year and 466,798.5 litres per year water for all U.S, European, and Asian kitchen hood designs per hood length. By adopting the new water-mist recirculation system to the current water-mist kitchen hood, the water operational cost for water successfully reduced to RM 4,889.63 per year and RM 6,977.86 per year for U.S design and European or Asian design per hood length respectively. The water-mist recirculation system has great potential to improve the current water-mist system for the commercial kitchen hood.

Comparison of two air sampling methods to monitor operating room air quality and assessment of air quality in two operating rooms with different ventilation systems in the national hospital of Sri Lanka

2016 ◽  
Vol 12 (3) ◽  
Author(s):  
Tshokey Tshokey ◽  
Pranitha Somaratne ◽  
Suneth Agampodi
Keyword(s):  
Air Quality ◽  
Sri Lanka ◽  
Operating Room ◽  
Ventilation System ◽  
Surgical Site Infections ◽  
National Hospital ◽  
Air Contamination ◽  
Acceptable Method ◽  
The Difference ◽  
Laminar Air Flow

Air contamination in the operating room (OR) is an important contributor for surgical site infections. Air quality should be assessed during microbiological commissioning of new ORs and as required thereafter. Despite many modern methods of sampling air, developing countries mostly depended on conventional methods. This was studied in two ORs of the National Hospital of Sri Lanka (NHSL) with different ventilation system; a conventional ventilation (CV) and a laminar air flow (LAF). Both ORs were sampled simultaneously by two different methods, the settle plate and sampler when empty and during use for a defined time period. Laboratory work was done in the Medical Research Institute. The two methods of sampling showed moderate but highly significant correlation. The OR with CV was significantly more contaminated than LAF when empty as well as during use by both methods. Overall, the difference in contamination was more significant when sampled by the sampler. Differences in contamination in empty and in-use ORs were significant in both ORs, but significance is less in LAF rooms. The consistent and significant correlation between settle plate and sampler showed that the settle plate is an acceptable method. The LAF theatre showed less contamination while empty and during use as expected. Air contamination differences were more significant when sampled with sampler indicating that it is a more sensitive method. Both CV and LAF ORs of the NHSL did not meet the contamination standards for empty theatres but met the standards for in-use indicating that the theatre etiquette was acceptable.

The difference in CO2 adsorption capacities of different functionalized pillar-layered metal-organic frameworks (MOFs)

2021 ◽  
Author(s):  
Xiang-Jing Gao ◽  
Hegen Zheng
Keyword(s):  
Co2 Adsorption ◽  
Metal Organic Frameworks ◽  
Co2 Concentration ◽  
Fossil Energy ◽  
Adsorption Capacities ◽  
Metal Organic ◽  
The Difference

The excessive use of fossil energy has caused the CO2 concentration in the atmosphere to increase year by year. MOFs are ideal CO2 adsorbents that can be used in CO2...

scholarly journals Evaluation of the performance of three advisory methods for nitrogen fertilization of sugar beet and potatoes.

1989 ◽  
Vol 37 (2) ◽  
pp. 143-155 ◽  
Author(s):  
J.J. Neeteson
Keyword(s):  
Crop Yields ◽  
Current Method ◽  
Early Spring ◽  
The Other ◽  
Fertilizer N ◽  
Potato Tubers ◽  
Current Recommendation ◽  
Mineral N ◽  
Fertilizer Recommendation ◽  
The Difference

The performances of 3 different N fertilizer recommendation methods were retrospectively tested with data obtained from 150 trials with sugarbeet and 98 trials with potatoes in the Netherlands in 1973-82. The recommendations consisted of applying a fixed N rate in all situations (126 kg N/ha for sugarbeet and 286 kg N/ha for potatoes), the current Dutch method, which takes only the amount of mineral N present in the soil in early spring into account, and a refinement of the current method, which also takes soil type and recent applications of organic manures into account. On av., significantly lower amounts of fertilizer N were recommended with the current method. The difference from the other methods was on av. 25 kg N/ha for sugarbeet and 30 kg N/ha for potatoes. With the refined current method the highest crop yields were obtained but the difference from the other methods was not significant and averaged only 0.3-0.4 t/ha for sugarbeet and 0.1-0.2 t/ha for potatoes. The recovery of fertilizer N by the potato tubers was 2% higher with the current method than with the other methods. Based on these findings it is concluded that the current recommendation method is preferable to the other methods. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Unprecedented strength of Hadley circulation in 2015–2016 impacts on CO<sub>2</sub> interhemispheric difference

2018 ◽  
Author(s):  
Jorgen S. Frederiksen ◽  
Roger J. Francey
Keyword(s):  
Global Warming ◽  
Hadley Circulation ◽  
Co2 Concentration ◽  
Transport Processes ◽  
Boreal Summer ◽  
Boreal Winter ◽  
Advective Transport ◽  
Interhemispheric Difference ◽  
Eddy Transport ◽  
The Difference

Abstract. The extreme El Niño of 2015 and 2016 coincided with record global warming and unprecedented strength of the Hadley circulation with significant impact on mean interhemispheric (IH) transport of CO2 and on the difference in CO2 concentration between Mauna Loa and Cape Grim (Cmlo-cgo). The relative roles of eddy transport and mean advective transport on IH CO2 annual differences from 1992 through to 2016 is explored. Eddy transport processes occur mainly in boreal winter-spring when Cmlo-cgo is large; an important component is due to Rossby wave generation by the Himalayas and propagation through the equatorial Pacific westerly duct generating and transmitting turbulent kinetic energy. Mean transport occurs mainly in boreal summer-autumn and varies with the strength of the Hadley circulation. The timing of annual changes in Cmlo-cgo is found to coincide well with dynamical indices that we introduce to characterize the transports. During the unrivalled 2009–2010 step in Cmlo-cgo indices of eddy and mean transport reinforce. In contrast for the 2015 to 2016 change in Cmlo-cgo the mean transport counteracts the eddy transport and the record strength of the Hadley circulation determines the annual IH CO2 difference. The interaction of increasing global warming and extreme El Niños may have important implications for altering the balance between eddy and mean IH CO2 transfer.

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

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.

scholarly journals Effects of External Acidification on the Blood Acid-Base Status and Ion Concentrations of Lamprey

1988 ◽  
Vol 136 (1) ◽  
pp. 351-361
Author(s):  
LEONA MATTSOFF ◽  
MIKKO NIKINMAA
Keyword(s):  
High Sensitivity ◽  
Co2 Concentration ◽  
Acid Base ◽  
Ion Concentrations ◽  
Ph Response ◽  
Ph Values ◽  
Blood Ph ◽  
Acid Base Status ◽  
The Difference ◽  
K Concentration

We studied the effects of acute external acidification on the acid-base status and plasma and red cell ion concentrations of lampreys. Mortality was observed within 24 h at pH5 and especially at pH4. The main reason for the high sensitivity of lampreys to acid water appears to be the large drop in blood pH: 0.6 and 0.8 units after 24 h at pH5 and pH4, respectively. The drop of plasma pH is much larger than in teleost fishes exposed to similar pH values. The difference in the plasma pH response between lampreys and teleosts probably results from the low buffering capacity of lamprey blood, since red cells cannot participate in buffering extracellular acid loads. Acidification also caused a decrease in both Na+ and C− concentrations and an elevation in K+ concentration of plasma. The drop in plasma Na+ concentration occurred faster than the drop in plasma Cl− concentration which, in turn, coincided with the decrease in total CO2 concentration of the blood.

scholarly journals LIMITER – CONSTRUCTIVE COMPONENT, NECESSARY FOR DETERMINING A SUBJECT SHORT-POINTED WEAPONS

2020 ◽  
pp. 350-360
Author(s):  
V. Bolshakov ◽  
Yu. Maznichenko ◽  
Yu. Holub ◽  
M. Molyboha ◽  
I. Samoilenko
Keyword(s):  
Current Method ◽  
Special Forces ◽  
Technical Standards ◽  
Systematic Analysis ◽  
Physical Strength ◽  
Technical Requirements ◽  
Current State ◽  
The Us ◽  
The Difference ◽  
Definition Of

The systematic analysis of the world experience of civilian use of knives not as cold weapons showed that at present the knife did not become the main attribute of equipping tourists, fish men and even hunters. In particular, today there are very few types of hunting, during which the knife is used to finish off the beast or to protect against it. At the same time, as the practice of hunting management proves, during hunting there are many uses for the knife, even without considering it as a means for cooking. This, in particular, sharpening various stakes (for a tent, a hut, a campfire), skinning a game, preparing chips for a fire, scraping ice from skis or marsh mud from shoes. To do this, in accordance with current state technical standards, any folding knife must have a lock, and the blades of all knives must be of sufficient thickness so as not to break from the load. Handles of hunting knives should be comfortable to hold so that your hand will not get tired during long-term work. For all knives, according to the technical requirements, the length and thickness of the blade must be consistent, as well as the angle of inclination of the tip relative to the axis of the blade. With regard to the above, an interesting example is the collection of knives by the Swedish company Eriksson, consisting of four models, made in the configuration of the Swedish finca. The knives have a handle and a blade of a classic Finnish knife, but with a one-sided stopper. Their blades, depending on the color of the handle, are made of different types of steel. Knives with blue plastic handles have stainless steel blades, and knives with red handles are made of carbon steel. It is believed that in Sweden almost every construction worker walks with such a knife in his pocket. It should be noted that according to the current method of forensic investigation of cold weapons and structurally similar products in it, these knives can be attributed to cold weapons by the size of the blade. It is also interesting an urban-type knife, which is not a cold weapon of the Worden Tactical Medium Company. Renowned wizard Kelly Warden, an instructor for American Rangers, designs this knife. Since 2001, Kelly Warden has been the main consultant on impact and blade weapons of Detachment 1 of the US Special Forces. He trains Special Forces hand-to-hand combat with the use of a knife, machete, baton, sticks, as well as the method of forceful detention. The blade length of the knife described is 74 mm, thickness – 3.8 mm; the handle has a sub-finger protrusion to prevent the arm from slipping on the blade. The knife does not have a standard stopper, which, in addition to protecting it from slipping the hand on the blade, must prevent the hand from sinking into the victim’s body. By all measures, this knife is not a cold weapon in accordance with the requirements of the criminal law of Ukraine. Kelly Warden believes that the knife as a means of self-defense levels the difference in weight, height and physical strength, but its main drawback is its damaging ability. The proposed article is devoted to this circumstance, the definition of the role of the restrictor in classifying a knife as a cold weapon.

An Attempt to Improve Air Quality in Primary Schools

2017 ◽  
Author(s):  
Marek Telejko ◽  
Ewa Zender-Swiercz
Keyword(s):  
Air Quality ◽  
Primary School ◽  
Indoor Air ◽  
Primary Schools ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Co2 Concentration ◽  
School Buildings ◽  
Maximum Value

Most primary school buildings in Poland rely on natural ventilation. This fact is attributed to the age of these buildings constructed more than dozen or even several tens of years ago. Few of them were fitted with a mechanical ventilation system allowing for the adjustment of microclimate parameters. The national requirements for gravity ventilation provide general guidelines, specifying strict description only for the airtightness of windows and doors and the minimum airflow to be supplied to the rooms. The minimum airflow supplied is independent of the number of occupants and purpose of the room. Low indoor air quality (IAQ) can impact occupants’ health and lead to poor productivity or low academic performance. Therefore the provision of good IAQ in classrooms and laboratories is very important. This paper presents the results of the investigation devoted to the quality of indoor air in classrooms of selected Polish primary school. Six primary school in a town with a population of 200 000 inhabitants were involved in the investigations. The participating school buildings were built between 1976 and 1994 and had gravity ventilation systems. The variability of basic IAQ parameters, i.e., temperature, relative humidity and carbon dioxide level, was analysed and the assessment of the classrooms in terms of microbiological purity was performed. The outcomes confirmed the low quality of the indoor air in these buildings. The maximum value of CO2 concentration amounted to more than 4000 ppm. Certain modifications aimed at improving IAQ were proposed during the investigations. Two solutions were implemented. The results of this study indicate that the proposed solution offers the potential to improve IAQ within classrooms.

scholarly journals Experimental Analysis of Calculation of Fuel Consumption Rate by On-Road Mileage in a 2.0 L Gasoline-Fueled Passenger Vehicle

2018 ◽  
Vol 8 (12) ◽  
pp. 2390 ◽  
Author(s):  
Jaehyuk Lim ◽  
Yumin Lee ◽  
Kiho Kim ◽  
Jinwook Lee
Keyword(s):  
Fuel Consumption ◽  
Fuel Economy ◽  
Fuel Efficiency ◽  
Co2 Concentration ◽  
The United States ◽  
Traffic Conditions ◽  
Fuel Consumption Rate ◽  
Driving Cycles ◽  
The Difference ◽  
Consumption Value

The five-driving test mode is vehicle driving cycles made by the Environment Protection Association (EPA) in the United States of America (U.S.A.) to fully reflect actual driving environments. Recently, fuel consumption value calculated from the adjusted fuel consumption formula has been more effective in reducing the difference from that experienced in real-world driving conditions, than the official fuel efficiency equation used in the past that only considered the driving environment included in FTP and HWFET cycles. There are many factors that bring about divergence between official fuel consumption and that experienced by drivers, such as driving pattern behavior, accumulated mileage, driving environment, and traffic conditions. In this study, we focused on the factor of causing change of fuel efficiency value, calculated according to how many environmental conditions that appear on the real-road are considered, in producing the fuel consumption formula, and that of the vehicle’s accumulated mileage in a 2.0 L gasoline-fueled vehicle. So, the goals of this research are divided into four major areas to investigate divergence in fuel efficiency obtained from different equations, and what factors and how much CO2 and CO emissions that are closely correlated to fuel efficiency change, depending on the cumulative mileage of the vehicle. First, the fuel consumption value calculated from the non-adjusted formula, was compared with that calculated from the corrected fuel consumption formula. Also, how much CO2 concentration levels change as measured during each of the three driving cycles was analyzed as the vehicle ages. In addition, since the US06 driving cycle is divided into city mode and highway mode, how much CO2 and CO production levels change as the engine ages during acceleration periods in each mode was investigated. Finally, the empirical formula was constructed using fuel economy values obtained when the test vehicle reached 6500 km, 15,000 km, and 30,000 km cumulative mileage, to predict how much fuel consumption of city and highway would worsen, when mileage of the vehicle is increased further. When cumulative mileage values set in this study were reached, experiments were performed by placing the vehicle on a chassis dynamometer, in compliance with the carbon balance method. A key result of this study is that fuel economy is affected by various fuel consumption formula, as well as by aging of the engine. In particular, with aging aspects, the effect of an aging engine on fuel efficiency is insignificant, depending on the load and driving situation.

scholarly journals Comprehensive Assimilation of Fire Suppression Modeling and Simulation of Radiant Fire by Water and Its Synergistic Effects with Carbon Dioxide

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5850
Author(s):  
Hassan Raza Shah ◽  
Kun Wang ◽  
Xu Qing Lang ◽  
Jing Wu Wang ◽  
Jing Jun Wang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Synergistic Effects ◽  
Fire Suppression ◽  
Water Mist ◽  
Pool Fire ◽  
Water Suppression ◽  
Water Droplets ◽  
Film Forming ◽  
The Difference ◽  
Suppression Effects

Recently, water has been employed as a supportive agent for the preparation of multiple suppressing agents including aqueous film forming foams (AFFF), which is combined with different kinds of gases for its various applications. In this study, the water mist is chosen for the gas-suppressing agent such as carbon dioxide. Our work investigated the suppression effects of water droplets on the n-heptane pool fire, and its mixture with carbon dioxide, respectively. The size and frequency of droplets with their effect on temperature and suppression was compared to observe the difference in the suppression. Initially, it was found that the droplets having a larger droplet size were found to be more efficient as compared to the smaller droplets with respect to the heat release rate, temperature, and radiation. Afterwards, a mixture of water droplets and carbon dioxide was simultaneously discharged to compare the difference between these two suppressing agents. It was found that the synergistic effect of the mixture has higher advantages over the use of only water suppression. It helps reduce the hot gases that surround the pool fire and allows the water mist to travel efficiently towards the fuel. Both suppression mechanisms were set to similar initial parameters that lead to different outcomes.

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