Liquid air filtration and continuous monitoring: Customized indoor air quality

Air treatment in environmental air conditioning systems exposes the system to gases, contaminants, and often biological pollutants that cannot be solved by traditional mechanical filtration, motivating decision-makers to diagnose challenges and develop innovative strategies to mitigate the problem. More and more, in environments with high turnover of people (e.g., hospitals, hotels and shopping centers), fresh air ventilations are avoided and replaced by closed windows air purifier solutions to account for undesirable saturation of the atmosphere and the presence of pollutants such as PM10, PM2.5, PM1.0, nitrogen, and carbon oxides. The consensus is that polluting gases render the most efficient traditional filters ineffective. The ANSI/ASHRAE 62.1 and EN13779 standards reveal the absence of air treatment technologies that use the wet route in air conditioning systems. This work discusses the liquid air multi-venturi centrifugation technology of hydrodynamic precipitator purifiers in association with the synchronized and continuous monitoring of parameters (PM10, PM2.5, PM1.0, CO2) in the external urban environment and internal environments of a shopping center. It evaluates the performance of the wet route for the physical-chemical and biological treatment of air. Efficiency for retaining particulate matter in a single step without disposable filter reached levels above F9 (85-95% PM2.5), with a reduction of 82.4% for CO2. Wet route technology extends the air conditioner’s life, reducing external air flows and energy consumption by up to 13%, making IAQ a manageable and customizable variable. Among the conclusion of the investigation, the authors believe that the migration of industrial pollutant control technologies, such as liquid filtration promoted by gas scrubbers and hydrodynamic precipitators, should be considered as a first choice option due to the high efficiency achieved in the three types of pollutants to be controlled. That is micrometric particulate matter such as anthropogenic PM1.0 capable of reaching the lung alveoli, chemicals such as carbon dioxide and nitrogen, and biological assets such as viruses and bacteria that showed the vulnerability of HVAC-R systems during the COVID pandemic that rendered windowless corporate buildings unusable

Growth curve by Gompertz nonlinear regression model in female and males in tambaqui (Colossoma macropomum)

ABSTRACT Was evaluated the pattern of growth among females and males of tambaqui by Gompertz nonlinear regression model. Five traits of economic importance were measured on 145 animals during the three years, totaling 981 morphometric data analyzed. Different curves were adjusted between males and females for body weight, height and head length and only one curve was adjusted to the width and body length. The asymptotic weight (a) and relative growth rate to maturity (k) were different between sexes in animals with ± 5 kg; slaughter weight practiced by a specific niche market, very profitable. However, there was no difference between males and females up to ± 2 kg; slaughter weight established to supply the bigger consumer market. Females showed weight greater than males (± 280 g), which are more suitable for fish farming purposes defined for the niche market to larger animals. In general, males had lower maximum growth rate (8.66 g / day) than females (9.34 g / day), however, reached faster than females, 476 and 486 days growth rate, respectively. The height and length body are the traits that contributed most to the weight at 516 days (P <0.001)

Composição corporal e exigências de energia de mantença em bovinos Nelore, puros mestiços, em confinamento Body composition and net energy requirements for maintenance of feedlot purebred and crossbred Nellore young bulls

Objetivou-se estimar a composição corporal de gordura e proteína e as exigências de energia de mantença em bovinos Nelore puros e mestiços. Foram utilizados 72 bovinos machos (18 Nelore, 18 F1 Nelore x Angus, 18 F1 Nelore x Pardo- Suíço e 18 F1 Nelore x Simental) não-castrados, com 10 a 11 meses de idade e peso médio inicial de 286, 309, 333 e 310 kg, respectivamente. O delineamento utilizado foi o inteiramente casualizado, com quatro grupos genéticos, submetidos a quatro níveis de concentrado na ração (30, 40, 60 e 70%). No início do experimento, três animais de cada grupo genético foram alocados no grupo de alimentação restrita e três foram abatidos no grupo de abate inicial. As exigências líquidas de energia para mantença (ELm) foram obtidas pela regressão da produção de calor (kcal/kg0,75/dia) em função do consumo de energia metabolizável (CEM - Mcal/kg0,75/dia), extrapolando-se para o nível zero de ingestão de EM. Não houve diferenças nas exigências de energia líquida de mantença (ELm) entre os grupos genéticos. Verificou-se elevação de 260,2; 92,6 e 67,8% nos conteúdos corporais de gordura e proteína e na concentração de gordura (g/kg de peso corporal vazio - PCV), com elevação de 250 para 550 kg no peso vivo, ao passo que a concentração de proteína corporal reduziu em 10,9%. O teste de identidade de modelos não-lineares indicou não haver diferenças entre os grupos genéticos para a composição corporal de gordura, proteína e energia e nas ELm. Desse modo, o valor da ELm foi estimado em 79 kcal/kg0,75/dia.<br>The objectives of this trial were to estimate the body composition of fat and protein and the net energy requirements for maintenance of purebred and crossbred Nellore. Seventy-two young bulls averaging 10 to 11 months of age from four genetic groups were used: 18 Nellore, 18 F1 Nellore x Angus, 18 F1 Nellore x Brown Swiss and 18 F1 Nellore x Simental with initial average weights of 286, 309, 333 and 310 kg, respectively. A completely randomized design was adopted and bulls from the four genetic groups were fed diets containing: 30, 40, 60 and 70% of concentrate. Three animals from each genetic group were feed restricted while other three bulls were slaughtered at the beginning of the trial and used as reference. The net energy requirements of maintenance were obtained by regressing heat production (kcal/kg0.75/day) on metabolizable energy intake (Mcal/kg0.75/day) extrapolating to zero level of metabolizable energy intake. There was no difference in net energy requirements for maintenance among genetic groups. Body contents of fat, protein and fat concentration (g/kg EBW) increased, respectively, 260.2, 92.6 and 67.8% when body weight increased from 250 to 550 kg whereas body protein concentration reduced 10.9%. The identity test of the non-linear model indicated no significant differences among genetic groups for body composition of fat, protein and energy as well as for net energy requirements for maintenance. The estimated net energy requirement for maintenance was 79.45 kcal/kg0.75/day in this study