scholarly journals Occurrence of Biting Midges (Diptera: Culicoides) on Dairy Farms in Eastern Slovakia in Relation to Abiotic Factors

2021 ◽  
Vol 65 (4) ◽  
pp. 47-56
Author(s):  
A. Kočišová ◽  
Z. Kasičová ◽  
M. Halán ◽  
P. Komorová
Keyword(s):  
Abiotic Factors ◽  
Air Flow ◽  
Airflow Rate ◽  
Air Humidity ◽  
Air Flow Rate ◽  
Biting Midges ◽  
Factors Affecting ◽  
Physiological Conditions ◽  
Biting Midge ◽  
Relative Air Humidity

Abstract Within the scope of our research, we have performed 59 trapping sessions and collected 15,756 biting midges from 20 species at four farms (Kluknava, Ostrov, Turňa nad Bodovou and Zemplínska Teplica), The most frequent types of captured insects were representatives of the Avaritia subgenus, C. obsoletus/C. scoticus, representing on average 85.1 % (13,295 individuals) of the fauna of the biting midges, with the exception of the farm in Ostrov where this group represented only 41.7 % of the fauna. At this particular farm, the most frequently trapped insects belonged to the Culicoides subgenus (54.1 %), in particular the C. bysta, C. lupicaris, C. newsteadi, C. Pulicaris and C. Punctatus species. During the trapping sessions, we monitored factors affecting the number of trapped biting midges, such as the temperature, relative air humidity and airflow rate: the air temperature during the trapping of the biting midges ranged from 9.8 to 26.2 °C; the relative air humidity ranged from 35.1 to 100 %; and the air flow rate ranged from no wind to a wind velocity of 8.2 m.s-1. However, in the final evaluation, we failed to observe a statistically significant correlation between the air flow and the number of trapped biting midges. The largest amounts of biting midges were trapped at temperatures ranging from 15.8 to 24.6 °C and at a relative air humidity ranging from 54.2 % to 68.6 %. While monitoring the seasonal dynamics of the physiological conditions of biting midge females at the selected farms, we confirmed that during the period from June to August, the most frequently trapped females were parous (50.1 %; 7,826 individuals). In addition, nulliparous females comprised 43.8 % (6,842 individuals) and were continuously trapped throughout the season (April— November).

Numerical and experimental investigation on the air flow characteristics of heating, ventilation, and air-conditioning module for a small electric vehicle

2019 ◽  
Vol 234 (6) ◽  
pp. 1597-1609
Author(s):  
Kang Li ◽  
Hao Gao ◽  
Peng Jia ◽  
Lin Su ◽  
Yidong Fang ◽  
...  
Keyword(s):  
Heat Pump ◽  
Flow Rate ◽  
Air Conditioning ◽  
Air Flow ◽  
Flow Characteristics ◽  
Cold Climate ◽  
Airflow Rate ◽  
Positive Temperature ◽  
Air Flow Rate ◽  
Pump System

In electrical vehicles, replacing positive temperature coefficient heater as heat source with an air source heat pump could improve the driving range and decrease energy consumption in cold climate. Design of the heating, ventilation, and air-conditioning module for heat pump system has a significant influence on its performance in each working mode. A newly designed heat pump heating, ventilation, and air-conditioning module was introduced in this paper. The air flow characteristics of the heat pump heating, ventilation, and air-conditioning module in four working modes were analyzed, and the air flow rate and wind resistance were obtained by numerical simulation. Experiments were also conducted for validating its airflow rate in each working mode. Results of these experiments show that some unfavorable phenomena such as flow maldistribution and vortex inside the heat pump heating, ventilation, and air-conditioning module exist, which could lead to insufficient utilization of the heat exchange area of heat exchangers and the generation of aerodynamic noise. Furthermore, the air flow rate of the original heating, ventilation, and air-conditioning module was also measured for comparison, and the designed heat pump heating, ventilation, and air-conditioning module shows nearly 15–20% decrease in each working mode.

scholarly journals A twin-fluid injector for FCC feed injection

2019 ◽  
Vol 4 (3) ◽  
pp. 109-115
Author(s):  
Deepak Kumar ◽  
Tushar Sikroria ◽  
Kushari A ◽  
Pramod Kumar ◽  
Sriganesh G
Keyword(s):  
Droplet Size ◽  
Flow Rate ◽  
Liquid Flow ◽  
Liquid Flow Rate ◽  
Air Flow ◽  
Product Yield ◽  
Droplet Velocity ◽  
Injection System ◽  
Airflow Rate ◽  
Air Flow Rate

In Fluidized Bed Catalytic Cracking (FCC) process, hydrocarbon feed undergoes vapour phase cracking in presence of hot regenerated catalyst to produce valuable products like LPG, Gasoline and Diesel. FCC feed injection system is most critical hardware component of FCC unit in order to get desired product yield by minimizing the undesirable dry gas and coke yield. Typically, twin-fluid nozzles (hydrocarbon and stream) are used to atomize the feed. In the present study, a twin-fluid injector, with an internal impactor to minimize the droplet size and velocity, is designed, developed and characterized. The performance of the feeding injector was evaluated using water and air as operating fluids and the droplet size and velocity were measured 150 mm downstream of the injector tip using a PDPA system for different water and air flow rates. The average droplet size (D32) showed an increase while the droplet velocity remained almost constant with the increase in the liquid flow rate for a given flow rate of air, consistent with the increase in droplet size with decreasing air-liquid ratio for twin–fluid atomizers. But, for a given liquid flow rate, the droplet SMD decreased and the droplet velocity increased with increasing airflow rate, which can be attributed to the increase in overall kinetic energy due to the increase in air flow rate. The flow rate of liquid was seen to be independent of air flow rate unlike conventional twin-fluid atomizers. The droplet size was found to be a function of ALR and the local volume flux of the droplets was found to be a function of the liquid flow rate.

scholarly journals Experimental Study and Performance Analysis of a Portable Atmospheric Water Generator

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 73 ◽  
Author(s):  
Wei He ◽  
Pengkun Yu ◽  
Zhongting Hu ◽  
Song Lv ◽  
Minghui Qin ◽  
...  
Keyword(s):  
Flow Rate ◽  
Reference Model ◽  
Air Flow ◽  
Operating Conditions ◽  
Water Yield ◽  
Air Humidity ◽  
Air Flow Rate ◽  
Thermoelectric Coolers ◽  
And Performance ◽  
The Impact

Found in some specific scenarios, drinking water is hard for people to get, such as during expeditions and scientific investigations. First, a novel water generator with only two thermoelectric coolers (Model A) is designed for extracting water from atmospheric vapor and then experimentally studied under a small inlet air flow rate. The impact of operating conditions on surface temperatures of cold/hot sides and water yield are investigated, including the air flow rate and humidity. Alternately, to determine the super performance of Model A, a comparative experiment between Model A and a reference model (Model B) is carried out. The results suggest that both the cold/hot temperature and water yield in Model A increases with the humidity and air flow rate rising. Seen in comparisons of Model A and Model B, it is found that, at an air humidity of 90% and air flow rate of 30 m3/h, the total water yield was increased by 43.4% and the corresponding value reached the maximum increment of 66.7% at an air humidity of 60% and air flow rate of 30 m3/h. These features demonstrate the advantage of Model A especially in low air humidity compared to Model B.

scholarly journals Abiotic factors drives floristic variations of fern’s metacommunity in an Atlantic Forest remnant

2018 ◽  
Vol 78 (4) ◽  
pp. 736-741 ◽  
Author(s):  
L. E. N. Costa ◽  
R. P. Farias ◽  
A. C. P. Santiago ◽  
I. A. A. Silva ◽  
I. C. L. Barros
Keyword(s):  
Soil Moisture ◽  
Atlantic Forest ◽  
Abiotic Factors ◽  
Northeastern Brazil ◽  
Air Humidity ◽  
Dissimilarity Index ◽  
Relative Air Humidity ◽  
Forest Remnant ◽  
Environmental Variations ◽  
Curtis Dissimilarity

Abstract We analyzed floristic variations in fern’s metacommunity at the local scale and their relationship with abiotic factors in an Atlantic Forest remnant of northeastern Brazil. Floristic and environmental variations were accessed on ten plots of 10 × 20 m. We performed cluster analyses, based on Bray-Curtis dissimilarity index to establish the floristic relationship. The influence of abiotic factors: luminosity, temperature, relative air humidity and relative soil moisture was evaluated from a redundancy analysis. We found 24 species belonging to 20 genera and 12 families. The fern’s flora showed high floristic heterogeneity (>75% for most of the plot’s associations). The fern’s metacommunity was structured along an abiotic gradient modulated by temperature, luminosity, and relative soil moisture.

Prediction of alpha factor values for fine pore aeration systems

2008 ◽  
Vol 57 (8) ◽  
pp. 1265-1269 ◽  
Author(s):  
S. Gillot ◽  
A. Héduit
Keyword(s):  
Flow Rate ◽  
Oxygen Transfer ◽  
Air Flow ◽  
Domestic Wastewater ◽  
Aeration Tank ◽  
Air Flow Rate ◽  
Factors Affecting ◽  
Domestic Wastewater Treatment ◽  
Alpha Factor ◽  
The Impact

The objective of this work was to analyse the impact of different geometric and operating parameters on the alpha factor value for fine bubble aeration systems equipped with EPDM membrane diffusers. Measurements have been performed on nitrifying plants operating under extended aeration and treating mainly domestic wastewater. Measurements performed on 14 nitrifying plants showed that, for domestic wastewater treatment under very low F/M ratios, the alpha factor is comprised between 0.44 and 0.98. A new composite variable (the Equivalent Contact Time, ECT) has been defined and makes it possible for a given aeration tank, knowing the MCRT, the clean water oxygen transfer coefficient and the supplied air flow rate, to predict the alpha factor value. ECT combines the effect on mass transfer of all generally accepted factors affecting oxygen transfer performances (air flow rate, diffuser submergence, horizontal flow).

Diurnal? Calling activity patterns reveal nocturnal habits in the aposematic toad Melanophryniscus rubriventris

2016 ◽  
Vol 94 (7) ◽  
pp. 497-503 ◽  
Author(s):  
L.C. Pereyra ◽  
M.S. Akmentins ◽  
E.A. Sanabria ◽  
M. Vaira
Keyword(s):  
Abiotic Factors ◽  
Activity Patterns ◽  
Diel Activity ◽  
High Plasticity ◽  
Air Humidity ◽  
Diel Pattern ◽  
Relative Air Humidity ◽  
Calling Activity ◽  
Mating Opportunities ◽  
Male Calling

In diurnal species with short breeding seasons, an extension of diel activity to the night hours could be favoured to maximize mating opportunities, but individuals must deal with physiological and behavioural constraints. We tested this hypothesis in the Yungas Red-belly Toad (Melanophryniscus rubriventris (Vellard, 1947)). We registered the diel pattern of male calling activity in two localities using automated recording systems, and related it to abiotic factors such as temperature, relative air humidity, and precipitation. The diel pattern of vocalization was mainly diurnal. Interestingly though, nocturnal calling activity was a common feature, representing between 40% and 43% of call records in both localities. Vocal activity was significantly influenced by time of the day and presence of rainfall. Calling males showed high plasticity, with activity in the entire environmental range of relative air humidity and temperature. Nocturnal calling seems to play an important role in the mating strategy of males, and it is probably more frequent in the genus Melanophryniscus than currently assumed. We discuss the implications of our findings in relation to different aspects of ecology of the species and suggest that bright colouration in M. rubriventris might result from a compromise between several nonconflicting functions (e.g., aposematism and thermoregulation).

Experimental Study of Solar Air Heating System Based on Unglazed Transpired Collector

2011 ◽  
Author(s):  
Lixin Gao ◽  
Hua Bai ◽  
Xiumu Fang
Keyword(s):  
Surface Temperature ◽  
Air Temperature ◽  
Flow Rate ◽  
Temperature Rise ◽  
Air Flow ◽  
Heating System ◽  
Airflow Rate ◽  
Air Flow Rate ◽  
Air Heating ◽  
Collector Efficiency

An experimental rig was set up to test the thermal performance of a solar air heating system based on an unglazed transpired collector of 2.5 m2. The experiment was carried out at Harbin Institute of Technology in the city of Harbin, which is located in northeastern China, at latitude 45°41′ N and longitude 126°37′ E. The tests were spread over a number of days, in which the 4-day experimental data within the period were selected as the sample for analysis. Experimental results show that solar collector’s surface temperature and exit air temperature increase with increasing solar irradiation. The influence of ambient temperature on surface temperature and exit temperature is negligible. Temperature rise decreases with increasing air flow rate, while collector efficiency increases with increasing air flow rate. For an air flow rate of 100 m3/h in Test 1, the average air temperature rise and collector efficiency were 28.86°C and 72% respectively; for an air flow rate of 235 m3/h in Test 2, the average air temperature rise and collector efficiency were 11.52°C and 78% respectively. Higher airflow rate tends to operate the collector at lower surface temperature, which results in lower overall heat losses from the collector to the surroundings, therefore increasing airflow rate reduces air temperature rise and enhances the collector efficiency. The average efficiency of the experimental solar air heating system in the 4-day experiment period was 72%, 78%, 61%, and 72% respectively, which are higher than most conventional glazed flat-plate solar air collectors. With better coordination with architectural design at early stage in a project, this building-integrated solar air heating system can be both aesthetically and technically viable.

scholarly journals Vpliv pretoka zraka na sušenje krme na sušilnih napravah

2019 ◽  
Vol 114 (1) ◽  
pp. 5
Author(s):  
Janez BENEDIČIČ ◽  
Rajko BERNIK
Keyword(s):  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Energy Consumption ◽  
Flow Rate ◽  
Air Flow ◽  
Air Humidity ◽  
Flow Rates ◽  
Positive Effects ◽  
Grass Silage ◽  
Relative Air Humidity

Drying grass fodder in Europe’s Alpine countries is becoming increasingly important due to positive effects on the fatty acid composition of milk. A proper approach and technology of fodder drying can raise its quality to the level of grass silage. In principle, drying fodder means extracting water from fodder by means of ventilation – the air, the key to the speed of drying. Besides low relative air humidity, its flow rate through the fodder is also important. In the literature, the lower- and upper-bound limits of air flow rates can be found, with a difference of 85 % between the two. The article describes a test, measuring energy consumption and the efficiency of drying at a low air flow, often used in practice, and a high air flow. It was found that a high air flow results in 38 % higher energy consumption per kilogramme of extracted water, compared to a low air flow. The executed test has proved that drying at a higher air flow will not have a proportionally greater effect.

scholarly journals Pengaruh Laju Aliran Udara Terhadap Efisiensi Penyisihan Organik di dalam Air Lindi dengan Menggunakan Teknik Oksidasi Lanjut (O3/H2O2)

2021 ◽  
Vol 22 (1) ◽  
pp. 009-017
Author(s):  
Mohamad Rangga Sururi ◽  
Mayang Afi Fadiyah ◽  
Siti Ainun Saleh ◽  
Mila Dirgawati
Keyword(s):  
Mass Transfer ◽  
Dissolved Oxygen ◽  
Flow Rate ◽  
Air Flow ◽  
Colorimetric Method ◽  
Airflow Rate ◽  
Air Flow Rate ◽  
Leachate Treatment ◽  
Grab Sampling ◽  
Filter Disc

ABSTRACT Leachate has complex characteristics, and it is commonly processed biologically in the Leachate Treatment Plant (IPL) in Indonesia. However, as the landfill ages, the leachate becomes less biodegradable. An appropriate technique is needed to treat leachate at IPL, and one of the promising methods is advanced oxidation with O3/H2O2. This study examined the effect of air flow rate on the concentration of residual ozone (KSO) and its efficiency to remove organic compounds using the O3/H2O2 process. Leachate samples were collected as grab samples from TPA Sarimukti Bandung. As much as 1 L of leachate samples were placed in an ozone contactor equipped with a filter disc with a pore size of 100-160 µm. The dose of H2O2 was continuously added to 1.197 g/L. Compressor was used to provide airflow with variations of 2, 3, and 4 L/min. Dissolved Oxygen (DO) was measured to determine the concentration of residual ozone (KSO) and validated by examining KSO measurements with the Indigo colorimetric method. A strong relationship between KSO and DO (R2 = 0.99) was observed at an airflow rate of 4 L/min. The highest ozone mass transfer coefficient (KLa,O3) was recorded at a 4 L/minute flow rate with 0.0022 min-1 at 27 °C.  The best removal efficiency has occurred at the fastest air flow rate (4 L/min) with COD, and UV254 removal was 88.89% and 14.87%, respectively. Keywords: DO, flow variation, KSO, leachate, O3/H2O2, organic, mass transfer   ABSTRAK Karakteristik lindi sangatlah kompleks dan di Indonesia, Instalasi Pengolahan Lindi (IPL) pada umumnya menggunakan sistem pengolahan biologis. Namun demikian, seiring dengan pertambahan umur urugan sampah, lindi semakin tidak biodegradable. Teknik pengolahan tepat diperlukan untuk mengolah lindi di IPL. Salah satu teknik yang sering digunakan adalah oksidasi lanjut dengan O3/H2O2 dengan mentransferkan gas ozon ke dalam air lindi yang diukur sebagai Konsentrasi Sisa Ozon (KSO) dan menambahkan H2O2 untuk meningkatkan pembentukan OH? di dalam air.  Penelitian ini bertujuan untuk mengetahui pengaruh laju aliran udara terhadap KSO serta pengaruhnya terhadap efisiensi penyisihan senyawa organik pada proses O3/H2O2. Sampel lindi diambil secara grab sampling dari TPA Sarimukti Bandung. Sebanyak 1 L sampel ditempatkan pada kontaktor ozon yang dilengkapi filter disc dengan pori berukuran 100-160µm. Dosis H2O2 yang diberikan tetap sebesar 1,197 g/L. Udara dialirkan dengan air compressor dengan variasi debit udara 2, 3, dan 4 L/menit. Pada penelitian ini, pengukuran Dissolved Oxygen (DO) digunakan sebagai pendekatan untuk mengukur KSO. Validasi dilakukan dengan meneliti hubungan antara KSO dan DO dan pengukuran KSO dilakukan dengan metode indigo colorimetric method.  Hasil penelitian menunjukkan KSO dan DO memiliki hubungan yang kuat (R2 = 0,99) pada variasi aliran udara 4 L/menit. Laju aliran udara tercepat terjadi ketika nilai koefisien transfer masa ozon (KLa,O3) mencapai nilai tertinggi (0,0022 menit-1) pada suhu 27 oC. Hasil penelitian membuktikan efisiensi penyisihan COD (88,89%) dan UV254 (14,87%) tertinggi terjadi pada laju aliran udara tercepat selama 180 menit. Kata kunci: DO, aliran udara KSO, lindi, O3/H2O2, organik, transfer masa

scholarly journals Air flow humidification for air-assisted boom sprayer

2014 ◽  
Vol 34 (1) ◽  
pp. 48-56
Author(s):  
Wilson M. Stanislavski ◽  
Ulisses R. Antuniassi ◽  
Rodolfo G. Chechetto
Keyword(s):  
High Temperatures ◽  
Air Temperature ◽  
Air Flow ◽  
Weather Conditions ◽  
Air Humidity ◽  
Middle Point ◽  
Air Curtain ◽  
Maximum Change ◽  
Relative Air Humidity ◽  
Low Humidity

The air-assisted ground spray is fairly widespread. However, due to the unpredictable weather conditions, the operational efficiency is impaired by stops on grounds of low humidity and high temperatures. The aim of this work was to assess an air humidification method and evaluate its impact on temperature and air humidity for the air curtain of the air-assisted sprayer. With respect to relative air humidity, it has increased in 6.59%, being the maximum change when inserting 1.92 L min-1. So, it is concluded that the pipeline humidification might significantly reduce temperature and enhance air humidity. The treatments performed in this study consisted of a varied flow of a humidity device, related to weather conditions. Temperature and relative air humidity were measured at 1.0 m height from right to left of middle point of the machine, corresponding to the end of the spray boom, in the middle and end of right spray boom. The readings were also performed at three different distances from the end of the pipeline and at 0.25 and 0.50 m from that to the soil. The results show that 0.48 L min-1 in the humidification system has promoted a better efficiency in reducing air-temperature, on average 2.52 ºC when compared to the non-humidified one.

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