Minimum Air Research Articles

Минимально допустимый расход наружного воздуха для удаления из помещения веществ с учетом эффекта суммации вредного действия

For the first time it was proposed when assessing safety of the air environment by the sum of relative concentrations of the harmful substances with the effect of summation of action, to consider not only the substances emitted in the room, but also other substances entering the room only with the supply air. To calculate minimum allowable intake air flow rate L, which ensures safety of the substances with the summation of the action, the formula is proposed, which is obtained by jointly solving the air safety conditions, and the dependences of the concentrations of harmful substances in the working area on the air flow rate, its contamination, and other factors. The example of an illustrative calculation of the minimum allowable intake air flow rate for three substances with a summation of the harmful effect is given. Of these, the first two substances are released in the room and come with the supply air, and the third substance enters the room only with the supply air. It is shown that when the air flow rate is found, the sum of the relative concentrations of three substances in the room is equal to one, that is, the safety condition is met at the limit. At the same time considering the substance in the supply air, which was not released in the room, required (in the example considered) an increase in the air consumption L by 20 %. Similar calculations L were performed based on the method of SP 60.13330.2020, according to which, when several harmful substances with the effect of summation of action are released in the room, the air exchange L should be determined by the sum of the air consumption Lв calculated for each substance. It was established that the expenses found by this method turned out to be 20–30 % less safe, therefore, they are not correct and do not ensure safety. The new method for calculating L, described in the article, is proposed to be considered in the regulatory documents.

ОЦЕНКА ОБРАЩАЕМОСТИ ПАЦИЕНТОВ С БОЛЕЗНЯМИ СЕРДЕЧНО-СОСУДИСТОЙ СИСТЕМЫ ЗА МЕДИЦИНСКОЙ ПОМОЩЬЮ В НЕБЛАГОПРИЯТНЫЕ ПО МЕТЕОФАКТОРАМ ДНИ

Relevance. The impact of weather factors on the occurrence of exacerbations of diseases in weather-dependent people is currently one of the actively studied problems of medicine. A number of authors draw attention to the need to correct the functional status of weather-dependent patients with cardiovascular diseases in unfavorable weather conditions. Aim: to assess the possible relationship between the manifestations of exacerbations of cardiovascular pathology and adverse weather factors. Material and methods. The materials of the regional center for Hydrometeorology and environmental monitoring were used, and a database was formed that includes information on the average daily, maximum and minimum atmospheric air temperatures, and atmospheric pressure for each day of 2018. Results. Meteorological risk factors for exacerbation of cardiovascular diseases in the Central European part of Russia include uncharacteristic heat (above +30 0C) or severe frost (below -20 0C), sudden changes in air temperature (by 8 0C or more, both in the direction of its increase and decrease), atmospheric pressure drops of more than 6 mm Hg during the day. It is established that the range of changes in meteorological indicators during the annual cycle is quite wide. Conclusions. Evaluation of the relationship between the treatment of patients with leading forms of cardiovascular diseases for medical care and meteorological indicators (average daily, maximum and minimum atmospheric air temperatures, atmospheric pressure) showed that with the advance of the case of the disease by 1 day (hypertensive disease without heart failure, brain vascular lesions, cerebrovascular disease, hypertensive disease with heart failure, angina pectoris), statistically significant links of weak and moderate strength were revealed.

Initial study of an alternative technology aimed at measuring and controlling the flow rate in air conditioning ducts

This paper states that there might have around 1000 small size business jets (until nine occupants) flying across the world equipped with flow control and regulating shut-off valves that uses hot wire anemometer devices to regulate massflow rate from the bleed airflow to supply the air-conditioning and pressurization systems. However, these valves present low reliability in the field. The purpose of this paper is to evaluate the implications of a flow control and regulating shut-off valve with a non-intrusive airflow measurer device under the perspective of fluid mechanics. The Venturi technology that is commonly used technology, given its construction simplicity, precision, and broad use in the industry, is selected to substitute the flow control and regulating shut-off valves with hot wire anemometer of the mentioned small size business jets applications. This paper has adopted a numeric simulation approach utilizing the ANSYS-CFX computational fluid dynamics software to verify both the differential pressure at the Venturi device and its correspondent mass flow rate to supply the air conditioning systems of some small size business jets, considering the mass-flow rate as requested by the FAA certification requirement (0.55 lb/min per occupant). This paper shows that a mass-flow rate control and regulating shut-off valve with a Venturi device, of 1 inch and β of 0.67, is compliant with the minimum fresh air flow requested by the FAA certification requirement to operate in some small size business jets. Besides that, the software ANSYS-CFX is also effective to support the engineering analysis of flow field characteristics inherent to the applications of internal compressible flow. The numeric simulation utilizing the ANSYS-CFX computational fluid dynamics software outlined herein can lay the basis for further research related to the design of a flow control and regulating shut-off valves with a Venturi device.

Climate Change in Rwanda: The Observed Changes in Daily Maximum and Minimum Surface Air Temperatures during 1961–2014

Rwanda has experienced high temperature rising phenomena over the last decades and hence, highly vulnerable to climate change. This paper examined the spatial and temporal variations of daily maximum and minimum surface air temperature (Tmin and Tmax) and diurnal temperature range (DTR). It studied variables at monthly, seasonal and annual time-scales from 1961 to 2014. The study applied various statistical methods such as ordinary least-square fitting, Mann-Kendall, Sen’ slope and Sequential Mann-Kendall statistical test to the new reconstructed ENACTS dataset that cover the period from 1983 to 2014 while pre-1983s recorded data from 24 meteorological stations have been added to complete the lengthiness of ENACTS data. The January to February season did not show a significant trend at seasonal time-scales. The authors decided only to consider March-to-May, June-to-August and October-to-December seasons for further analyses. Topography impacts on temperature classified stations into three regions: region one (R1) (1,000–1,500 m), region two (R2) (1,500–2,000 m) and region three (R3) (≥2,000 m). With high confidence, the results indicate a significant positive trend in both Tmin and Tmax in all three regions during the whole study period. However, the magnitude rate of temperatures change is different in three regions and it varies in seasonal and annual scale. The spatial distributions of Tmax and Tmin represent a siginificant warming trend over the whole country notably since the early 1980s. Surprisingly, Tmin increased at a faster rate than Tmax in R3 (0.27 vs. 0.07°C/decade in March-to-May) and (0.29 vs. 0.04°C/decade in October-to-December), resulting in a significant decrease in the DTR. This is another confirmation of warming in Rwanda. The mutation test application exhibited most of the abrupt changes in the seasonal and annual Tmax and Tmin trends between 1984 and 1990. The present work mainly focus on the spatial and temporal variability of Tmin, Tmax and DTR in Rwanda and their relationship with elevation change, leaving a gap in other potential cause factors explored in the future.

Long-term changes in the optimum planting date of gladiolus in southern Brazil

The objective of this work was to test long-term trends in the planting date of gladiolus to ensure marketing of these flowers on Mother’s Day and All Souls’ Day in Santa Maria (latitude: 29° 43’ S, longitude: 53° 43’ W, and altitude: 95 m), Rio Grande do Sul State, Brazil. Minimum and maximum air temperature data from 106 years were used (1912-2017) to simulate the optimum planting date indicated through the PhenoGlad model, aiming to harvest floral stems for both market dates for early, intermediate I, intermediate II and late cultivars. The homogeneity of the historical series was tested using the run test, and the historical trend was tested by the Mann-Kendal test. The magnitude of the trend was estimated with simple linear regression, and the descriptive statistics were calculated. For marketing on Mother’s Day, there was no historical trend that implied a change in the planting date of gladiolus for any of the development cycles. For marketing on All Souls’ Day, there was a positive historical trend only for the early and intermediate cycles I and II; thus, the increase in air temperature implied a delay of 9.2 days, 9.5 days and 6.9 days for the planting date, respectively, indicating that a shortening of the gladiolus development cycle occurred, mainly in late winter/early spring.

Air distribution in convex wall jets for ventilation with a constant air flow

The scheme of air exchange organization using air supply above a working zone by convex wall jets that interact with each other has been substantiated. This scheme is advisable in cases where it is impossible to supply air directly to the working zone. It provides optimal microclimate parameters with minimal recirculation of polluted air from the upper zone. Simulation of the air exchange organization in an exhibition hall in International Exhibition Centre in Kyiv with ventilation at a constant air volume (CAV) has been performed. The floor area is 5258 m2, the height is 19 m, the minimum outdoor air flow is 21.667 m3/s (78000 m3/h). The current design scheme of air exchange organization is zonal. General air exchange is 43.3333 m3/s (156000 m3/h). Recirculation is accepted 50 %. The air flow supplied in the upper and middle zones is, respectively, 22.5 m3/s (81000 m3/h) and 20.833 m3/s (75000 m3/h). Inlet air has temperature 291.65 K (18.5 °C). It is supplied downward by twisted jets. There are 65 Trox VDL-AHLD-E3/800/0/0/0/RAL 9010 air diffusers with a diameter of 800 mm. The proposed scheme is single-zonal using 24 diffusers PES-D-8-10/15-0,9 4 m above the floor and air removal from the upper zone. This scheme allows halving the air exchange to the minimum outdoor air without recirculation. The air temperature should be decreased by 3.3 K to 288.35 K (15.2 °С). The number of air-conditioners is decreased twice. The calculated consumption of cold decreased by 65.58 W/m2 or 29 %, the calculated consumption of heat for the second heating – by 7.17 W/m2 or 18 %. Saving of capital investments in prices of February 2020 is 792.16 UAH/m2 or 55 %, and decrease of operating costs for the cooling period is 6.61 UAH/m2 or 15 %. Thus, the system is economically beneficial from the beginning of its installation. In the future, its operation will be simulated in a mode with a variable flow rate.

Rancang bangun alat two phase flow (air-udara) sebagai media pembelajaran dan praktikum mahasiswa skala laboratorium

The purpose of this research is to produce a two-phase flow tool as a learning media and practicum based on the engineering approach (BPRT) to increase student motivation, abilities, skills, and understanding of two-phase flow courses. The research stages were carried out by designing the design and manufacturing or assembling of two-phase flow toolswith horizontal and vertical orientations into a complete unit, as well as testing the tools so that they can be used for practicum. Data collection and retrieval were adjusted to the test instruments. The results of this research is a learning media tool and practicum to test the characteristics, determine or look for a pressure drop, and a two-phase flow pattern. This two-phase flow device can operate in horizontal and vertical pipe test sections with minimum water and air flow rate of 0.00017 m3/s or 600 liters/hour while a maximum of 0.0005 m3/s or 1800 liters/hour. The minimum pressure allowed on this tool is 0.3 bar and the maximum is 0.83 bar. Keywords: two phase flow, pressure drop, flow pattern, practicum

A Long-Term, 1-km Resolution Daily Meteorological Dataset for Modeling and Mapping Permafrost in Canada

Climate warming is causing permafrost thaw and there is an urgent need to understand the spatial distribution of permafrost and its potential changes with climate. This study developed a long-term (1901–2100), 1-km resolution daily meteorological dataset (Met1km) for modeling and mapping permafrost at high spatial resolutions in Canada. Met1km includes eight climate variables (daily minimum, maximum, and mean air temperatures, precipitation, vapor pressure, wind speed, solar radiation, and downward longwave radiation) and is suitable to drive process-based permafrost and other land-surface models. Met1km was developed based on four coarser gridded meteorological datasets for the historical period. Future values were developed using the output of a new Canadian regional climate model under medium-low and high emission scenarios. These datasets were downscaled to 1-km resolution using the re-baselining method based on the WorldClim2 dataset as spatial templates. We assessed Met1km by comparing it to climate station observations across Canada and a gridded monthly anomaly time-series dataset. The accuracy of Met1km is similar to or better than the four coarser gridded datasets. The errors in long-term averages and average seasonal patterns are small. The error occurs mainly in day-to-day fluctuations, thus the error decreases significantly when averaged over 5 to 10 days. Met1km, as a data generating system, is relatively small in data volume, flexible to use, and easy to update when new or improved source datasets are available. The method can also be used to generate similar datasets for other regions, even for the entire global landmass.

Annual and daily patterns of calling activity in male Scinax fuscomarginatus (Anura: Hylidae) from Central Brazil

Bioacoustics is an effective way of recording detailed data during population surveys and monitoring. In the present study, we used an automated digital recorder (ADR) to describe the temporal variation in the calling activity of Scinax fuscomarginatus (Lutz, 1925) in central Brazil. We also evaluated the role of climatic variables (air temperature and precipitation) on calling activity by using a Generalized Additive Model (GAM). We conducted the recordings at five ponds in the Cerrado savanna of Rio Verde Municipality, in Goiás state between November 2013 and October 2014. The analysis of the 43.2 hours of acoustic recording showed that S. fuscomarginatus has a prolonged breeding pattern. The ADR provides a fine-scale description of the nocturnal calling pattern, as well as the oscillations between the rainy and dry seasons. The results of the analytical model also indicate that calling patterns were related to minimum (but not maximum) air temperatures and precipitation, which may be related to their reproductive and thermoregulatory requirements. Based on these findings, we conclude that the ADR method has potentially valuable applications for the collection of data on the natural history of anuran species, as well as supplying important insights for conservation initiatives.

Modeling the Applicability of a Displacement Ventilation System

Due to its significant role in improving indoor air quality, displacement ventilation system is widely adopted in current literature. This paper proposes a displacement ventilation system for room conditions with ceilings that are relatively low, internal heat load could be high, walls could be sunlit, and occupants doing the low physical activity. These conditions are prevalent in the Philippines, being a tropical country. Input parameters to the design process such as heat load, the height of the ceiling, comfort, and indoor air quality requirements were generated, and the main output parameters are the stratification height and ventilation airflow rate. To demonstrate the proposed displacement ventilation system, four cases were generated. Results show that the ventilation airflow rates obtained from the four cases were greater than the minimum outdoor air requirements for health in conference rooms and large assembly areas which are 17.5 and 3.5 liters/sec*person respectively, for smoking and no smoking rooms.

A comprehensive, multisource database for hydrometeorological modeling of 14,425 North American watersheds

The Hydrometeorological Sandbox - École de technologie supérieure (HYSETS) is a rich, comprehensive and large-scale database for hydrological modelling covering 14425 watersheds in North America. The database includes data covering the period 1950–2018 depending on the type and source of data. The data include a wide array of hydrometeorological data required to perform hydrological and climate change impact studies: (1) watershed properties including boundaries, area, elevation slope, land use and other physiographic information; (2) hydrometric gauging station discharge time-series; (3) precipitation, maximum and minimum daily air temperature time-series from weather station records and from (4) the SCDNA infilled gauge meteorological dataset; (5) the NRCan and Livneh gridded interpolated products’ meteorological data; (6) ERA5 and ERA5-Land reanalysis data; and (7) the SNODAS and ERA5-Land snow water equivalent estimates. All data have been processed and averaged at the watershed scale, and provides a solid basis for hydrological modelling, climate change impact studies, model calibration assessment, regionalization method evaluation and essentially any study requiring access to large amounts of spatiotemporally varied hydrometeorological data.

Agroclimatic zoning of off-season (safrinha) corn for the first ten days of February in Goiás, Brazil

Through maps, agroclimatic zoning can help us understand the guidelines for the most suitable locations for sowing, minimizing risks of produce loss due to climatic adversities. The aim of the present study is to develop an agroclimatic zoning for the cultivation of a non-irrigated off-season (safrinha) corn in the state of Goiás, sown in the first ten days of February. The methodological steps were the delimitation of the representative bands of the climatic requirements for the crop; the spatialization of the climatic elements in the region; the spatial reclassification of climatic elements based on the climatic requirements for the crop; elaboration of the agroclimatic zoning map. Average, minimum, and maximum air temperature, accumulated precipitation, actual crop evapotranspiration and relative humidity of the air registered between February and July for the years 2013 to 2017 were used. The most suitable areas for the cultivation of the non-irrigated off-season corn sown in the first ten days of February in Goiás established by the agroclimatic zoning are concentrated in the South-Southwest and Northwest regions. The expressive presence of Latosol soil class and the proximity of the values of the climatic elements accumulated precipitation, temperature and altitude, which are proper for the development of the off-season corn, favour suitability of the areas.

Decreased temperature variance associated with biotic composition enhances coastal shrub encroachment

Regime shift from grasslands to shrub-dominated landscapes occur worldwide driven by altered land-use and climate change, affecting landscape function, biodiversity, and productivity. Warming winter temperatures are a main driver of expansion of the native, evergreen shrub, Morella cerifera, in coastal landscapes. Shrub establishment in these habitats alters microclimate, but little is known about seasonal differences and microclimate variance. We assessed influence of shrubs on microclimate variance, community composition, and community physiological functioning across three vegetation zones: grass, transitional, and shrub in a coastal grassland. Using a novel application of a time-series analysis, we interpret microclimatic variance modification and elucidate mechanisms of shrub encroachment at the Virginia Coast Reserve, Long-Term Ecological Research site. As shrub thickets form, diversity is reduced with little grass/forb cover, while transpiration and annual productivity increase. Shrub thickets significantly reduced temperature variance with a positive influence of one day on the next in maximum air, minimum air, and maximum ground temperature. We also show that microclimatic temperature moderation reduces summer extreme temperatures in transition areas, even before coalescence into full thickets. Encroachment of Morella cerifera on the Virginia barrier islands is driven by reduced local exposure to cold temperatures and enhanced by abiotic microclimatic modification and biotic physiological functioning. This shift in plant community composition from grassland to shrub thicket alters the role of barrier islands in productivity and can have impacts on the natural resilience of the islands.

Assessing the Impacts of Future Climate on Cotton Production in the Arizona Low Desert

HighlightsCotton yield was reduced significantly under projected future climate conditions for the Arizona low desert (ALD). Of all the weather variables, yield reduction was primarily due to projected increases in daily maximum and minimum air temperatures.Cotton reproductive stages were more susceptible to heat stress than vegetative stages. Projected increases in air temperature may result in a slight increase in cotton growth or biomass production; however, heat stress significantly reduced fruit retention, leading to lower boll number and yield.Although future increases in CO2 may improve plant growth and productivity, the potential benefit of CO2 fertilization on cotton growth and yield in the ALD was offset by the projected increase in air temperature.The projected average seasonal irrigation requirement increased by at least 10%. This suggests that greater demand for freshwater withdrawal for agriculture can be expected in the future. Therefore, given the projected change in future climate, cotton cultivars tolerant of longer periods of high air temperature, changes in planting dates, and improved management practices for higher water productivity are critical needs for sustainable cotton production in the ALD.Abstract. Cotton is an important crop in Arizona, with a total cash value of approximately $200 million for fiber and cottonseed in 2018. In recent years, heat stress from increasing air temperature has reduced cotton productivity in the Arizona low desert (ALD); however, the effects of future climate on ALD cotton production have not been studied. In this study, the DSSAT CSM-CROPGRO-Cotton model was used to simulate the effects of future climate on cotton growth, yield, and water use in the ALD area. Projected climate forcings for the ALD were obtained from nine global climate models under two representative concentration pathways (RCP 4.5 and 8.5). Cotton growth, yield, and water use were simulated for mid-century (2036 to 2065) and late century (2066 to 2095) and compared to the baseline (1980 to 2005). Results indicated that seed cotton yield was reduced by at least 40% and 51% by mid-century and late century, respectively, compared to the baseline. Of all the weather variables, the seasonal average maximum (R2 = 0.72) and minimum (R2 = 0.80) air temperatures were most correlated with yield reductions. Under the future climate conditions of the ALD, cotton growth or biomass accumulation slightly increased compared to the baseline. Irrigation requirements in the ALD increased by at least 10% and 14% by mid-century and late century, respectively. Increases in irrigation requirements were due to an increase in crop water use; hence, greater demand for freshwater withdrawal for agricultural purposes is anticipated in the future. Therefore, cotton cultivars that are tolerant of long periods of high air temperature and improved management practices that promote efficient crop water use are critical for future sustainability of cotton production in the ALD. Keywords: . Arid region, CSM-CROPGRO-Cotton, Future climate, Gossypium hirsutum L., Heat stress, Irrigation demand.

Changes in Vegetation and Assessment of Meteorological Condition in Karst Ecologically Fragile Areas

Meteorological conditions have an important impact on changes in vegetation in karst ecologically fragile areas. This study aims to explore a method for quantitative evaluation of these meteorological conditions. We analyzed the changing trend characteristics of vegetation during 2000 to 2018 and the correlations between vegetation change and various meteorological factors in the karst rocky areas of Guangxi. The characteristics of meteorological factors in vegetation areas with varying degrees of improvement were also analyzed. Key meteorological factors at seasonal scale were selected for meteorological condition evaluation. A quantitative evaluation model of comprehensive influence of meteorological factors on vegetation was built using partial least-square regression (PLS). About 91.45% of the vegetation tended to be improved, while only 8.55% of the vegetation showed a trend of degradation from 2000 to 2018. Areas with evident vegetation improvement were mainly distributed in the middle and northeast, and those with obvious vegetation degradation were scattered. Meteorological factors affecting vegetation were significantly different among the four seasons. Overall, high air humidity, small temperature difference in spring and autumn, and low daily minimum temperature and air pressure were favorable conditions. Low temperature in winter and high temperature in summer and autumn were unfavorable conditions. Climate Vegetation Index (CVI) model was established by PLS using the maximum temperature, minimum temperature, average temperature, vapor pressure, rainfall, and air pressure as key meteorological factors. (Ehanced Vegetation Index (EVI) was well fitted by the CVI model, with R2 and RMSE average of 0.856 and 0.042, respectively. Finally, the assessment model of comprehensive meteorological conditions was built based on interannual differences in CVI. The meteorological conditions in the study area in 2014 were successfully evaluated by combining the model and selected seasonal key meteorological factors.

Accuracy of air temperature forecasts and its use for prediction of the reference evapotranspiration

The objective of this study was to verify the quality of the short-term forecasts made by some web sites, as well as the potential of its use in estimating reference evapotranspiration (ETo). For the period 2012-2013, every 4-days, the maximum (Tmax) and minimum (Tmin) air temperature forecasts for horizons of 24, 48, 72 and 96 hours provided by public sites for Uberlandia-MG were collected and used for calculating the reference evapotranspiration (ETo) by the Hargreaves-Samani (HS) calibrated equation. The sites www.accuweather.com (WEATHER); www.cemig.com.br (CEMIG); jornaldotempo.uol.com.br; (JORNAL) and www.climatempo.com.br (CLIMA) were evaluated. For the same period, the meteorological data were taken at the National Institute of Meteorology (www.inmet.gov.br). The performance of the Tmax and Tmin forecasts as well as the ETo estimates were made by regression analysis, the mean bias error (MBE), root mean square error (RMSE) and t-test. For all sites, there was a better performance in the prediction of Tmin when compared to Tmax, especially by a reduction in errors (MBE and RMSE) and an increase in coefficients b and R2. For ETo, the site CLIMA had lowest MBE and RMSE (0.9 mm d-1) following by the WEATHER and JORNAL. On the other hand, the site CEMIG presented higher values for MBE (-1.3 mm d-1) and RMSE (1.6 mm d-1). There was no worsening with an increase of the forecast horizon in these indices, except for R² values. The site CLIMA was the only one that did not differ significantly from the ETo values observed. The results of diagnostic verification procedures indicate the potential use of air temperature forecasts in irrigation management.

Multi-Fractal Analy is of Daily Air Temperature Time Series in Coastal Areas of China

In this article, the Multi-Fractal Detrended Fluctuation Analysis (MF-DFA) method is adopted to study the temperature, i. e., the maximum temperature (Tmax), mean temperature (Tavg) and minimum (Tmin) air temperature, multifractal characteristics and their formation mechanism, in the typical temperature zones in the coastal regions in Guangdong, Jiangsu and Liaoning Provinces. Following are some terms and concepts used in the present study. Multifractality is defined as a term that characterizes the complexity and self-similarity of objects, and fractal characteristics depict the distribution of probability over the whole set caused by different local conditions or different levels in the process of evolution. Fractality strength denotes the fluctuation range of the data set, and long-range correlation (LRC) measures the stability of the climate system and the trend of climate change in the future. In this research, it is found that the internal stability and feedback mechanism of climate systems in different regions show regional differences. Furthermore, the research also proves that the Tavg, Tmax and Tmin of the above three provinces are highly multifractal. The temperature series multifractality of each province decreases in the order of temperature series multifractality of Liaoning > temperature series multifractality of Guangdong > temperature series multifractality of Jiangsu, and the corresponding long-range correlations follow the same order. It reveals that the most stable temperature series is that of Liaoning, followed by the temperature series of Guangdong, and the most unstable one is that of Jiangsu. Liaoning has the most stable climate system, and it will thus be less responsive to the future climate warming. The stability of the climate system in Jiangsu is the weakest, and its temperature fluctuation will continue to increase in the future, which will probably result in the meteorological disasters of high temperature and heat wave there. Guangdong possesses the strongest degree of multifractal strength, which indicates that its internal temperature series fluctuation is the largest among the three regions. The Tmax multifractal strength of Jiangsu is stronger than that of Liaoning, while the Tavg and Tmin multifractal strength of Jiangsu is weaker than that of Liaoning, showing that Jiangsu has a larger internal Tmax fluctuation than Liaoning does, while it has a smaller fluctuation of Tavg and Tmin than Liaoning does. Guangdong and Liaoning both show the strongest Tmin multifractal strength, followed by Tavg multifractal strength, and the weakest Tmax multifractal strength. However, Jiangsu has the strongest Tmax, followed by Tavg, and the weakest Tmin. The research findings show that these phenomena are closely related to solar radiation, monsoon strength, topography and some other factors. In addition, the multifractality of the temperature time series results from the negative power-law distribution and long-range correlation, in which the long-range correlation influence of temperature series itself plays the dominant role. With the backdrop of global climate change, this research can provide a theoretical basis for the prediction of the spatial-temporal air temperature variation in the eastern coastal areas of China and help us understand its characteristics and causes, and thus the present study will be significant for the environmental protection of coastal areas.

TOWARDS AN AUTOMATIC METEOROLOGICAL FORECAST VERIFICATION SYSTEM FOR THE STATE HYDROMETEOROLOGICAL SERVICE, REPUBLIC OF MOLDOVA

This paper presents a user-friendly application developed for assessing the quality of the meteorological forecasts issued by the Moldavian State Hydrometeorological Service (SHS). The scores are calculated using a method developed at Meteo Romania (National Meteorological Administration), which has been running operationally since 1996. The meteorological elements evaluated in this verification system are cloud cover, wind speed, fog, glazed frost, hail, frost, minimum and maximum air temperature, as well as the appearance, shape, distribution and intensity of precipitation. The automatic weather forecasting verification system is based on two graphical interfaces, both of them having a specific role in simplifying the user interaction with the database where the information is stored. This work was realized within the World Bank project "Development of a standardized verification mechanism and QMS for the Moldova SHS".

Ventilation Optimization for Reduction of Indoor Air Temperature of Main Transformer Room in Urban Indoor Substation by the Variational Method

Urban indoor substations are widely used for electrical power distribution in urban networks. However, they have the problems of heat dissipation and ventilation in main transformer room, which not only influence the thermal behavior of main transformer, but also decrease the lifetime, reliability, and precision of other electronic equipment. In this contribution, we developed a new ventilation optimization method based on the variational method to solve the aforementioned problems. First, we applied the minimum average temperature of indoor air as the optimization objective combined with some constrains to establish a Lagrange function, and employed the variational method to deduce some optimized governing equations that the optimum indoor patterns should meet the minimum indoor air average temperature. Finally, a typical main transformer room model was taken as an example to demonstrate the applications of the newly developed ventilation optimization method. It was concluded that the inflowing fresh air needed to sweep more area of heating walls to take away more heat, and reduce the average temperature of indoor air. Furthermore, based on the optimized air velocity distribution, we redesigned the ventilation arrangements and reduced the indoor average temperature prominently (from 337.44 K to 314.82 K), which can provide the guidance to design the ventilation of main transformer room to improve the reliability of electronic equipment in main transformer room.

Phenology and thermal requirements of disease-resistant genotypes (PIWI) grown in the Goethe Grape Valley region of Brazil

The Goethe Grape Valley (GGV) is a traditional southern Brazilian region for grape and wine production, mainly planted with hybrid vines. High temperatures and rainfall conditions hamper the cultivation of Vitis vinifera cultivars susceptible to disease, especially Plasmopara viticola. New PIWI (from the German word ‘Pilzwiderstandsfahige’) genotypes of V. vinifera with resistance to P. viticola are under evaluation in this region. The aim of this work was to characterize the phenology and thermal requirements of PIWI genotypes grown in the GGV. The experiment was carried out in an experimental vineyard (28°32’S 49°19’W, altitude 60 m a.s.l.), established in 2016, and evaluations were done for the 2018 vintage. The evaluated PIWI cultivars were ‘Aromera’, ‘Baron’, ‘Calardis blanc’ and ‘Felicia’. Minimum and maximum air temperatures were recorded daily, using 10°C as the low temperature threshold, 25°C as the optimum temperature for development, and 35°C as the upper temperature threshold of development. The evaluated phenological stages were budbreak to flowering, flowering to veraison and veraison to maturity. The total thermal requirement mean was 1360°C day; ‘Felicia’ showed the lowest thermal requirement (1260°C day), which contrasted with ‘Aromera’, which presented the highest thermal requirement (1454°C day). ‘Baron’ and ‘Calardis blanc’ needed 1337 and 1391°C day, respectively, to reach maturity. From budbreak to flowering, the average thermal requirement was 229°C day, from flowering to veraison the mean was 679°C day, and from veraison to maturity the mean was 452°C day. The four evaluated cultivars exhibited adaptive development in the field with thermal requirements compatible with the region of GGV. The results also revealed the lower thermal requirement, and consequently shorter cycle, for ‘Felicia’, as well as the greater thermal requirement of ‘Aromera’.