Metabolic rate and thermal stability during honeybee foraging at different reward rates

2001 ◽  
Vol 204 (4) ◽  
pp. 759-766 ◽  
Author(s):  
L. Moffatt
Keyword(s):  
Thermal Stability ◽  
Metabolic Rate ◽  
Flow Rate ◽  
Sucrose Solution ◽  
Carbon Dioxide Production ◽  
Metabolic Power ◽  
Solution Flow ◽  
Flow Rates ◽  
Metabolic Heat ◽  
Air Temperatures

During honeybee foraging, the stabilization of thoracic temperature (Tth) at elevated values is necessary to meet the power requirements of flight at different air temperatures (T(a)). To understand how the bee achieves thermal stability at different reward rates, the metabolic rates of undisturbed foraging bees were measured at different T(a) values and different sucrose solution flow rates. Metabolic heat production, calculated from the rate of carbon dioxide production, decreased linearly from 49.7 to 23.4 mW as T(a) increased from 19 to 29 degrees C (sucrose flow rate 1.75 microl × min(−1), 50 % w/w). In contrast, crop load and inspection rate remained constant. Metabolic rate displayed a linear relationship with both T(a) and the logarithm of the flow rate of sucrose solution (range analyzed 0.44-13.1 microl × min(−1), 50 % w/w). Metabolic rate decreased by 3.13+/−0.52 mW (mean +/− s.e.m., N=37) for every 1 degrees C increase in T(a) and increased by 4.36+/−1.13 mW for a doubling in flow rate. These changes in metabolic power output might be used to achieve thermal stability during foraging. It is suggested that the foraging bee might increase its Tth in accordance with the reward rate.

scholarly journals Head lettuce production and nutrition in relation to nutrient solution flow

2020 ◽  
Vol 38 (1) ◽  
pp. 21-26
Author(s):  
Cleiton Dalastra ◽  
Marcelo CM Teixeira Filho ◽  
Marcelo R da Silva ◽  
Thiago AR Nogueira ◽  
Guilherme Carlos Fernandes
Keyword(s):  
Nutrient Solution ◽  
Flow Rate ◽  
Nutrient Accumulation ◽  
Solution Flow ◽  
Flow Rates ◽  
Hydroponic System ◽  
Optimum Flow Rate ◽  
Technical Performance ◽  
Use Efficiency ◽  
Optimum Flow

ABSTRACT The optimum flow rate of nutrient solution in hydroponic system can better nourish the crops, allowing healthy and faster growth of lettuce. However, flow also interferes with electric power consumption, so further researches are necessary, mainly on the effect of flow rate, nutrient accumulation and lettuce production. In this context, the aim of this study was to evaluate nutrition and production of head lettuce in relation to the nutrient solution flow in NFT hydroponic system. The treatments consisted of nutrient solution application at the flow rates 0.5; 1; 2, and 4 liters per minute in each cultivation channel. Five replicates per treatment consisted of 15 plants each. The flow in hydroponic systems to produce head lettuce alters the technical performance of the crop. Due to the greater nutrient accumulation in shoot and use efficiency of these elements, the highest production (g/plant) of head lettuce was obtained with a flow rate of 1 L/min of the nutrient solution.

Mechanisms of thermal stability during flight in the honeybee apis mellifera

1999 ◽  
Vol 202 (11) ◽  
pp. 1523-1533 ◽  
Author(s):  
S.P. Roberts ◽  
J.F. Harrison
Keyword(s):  
Thermal Stability ◽  
Heat Loss ◽  
Heat Production ◽  
Radiative Heat ◽  
Carbon Dioxide Production ◽  
Metabolic Heat Production ◽  
Evaporative Heat Loss ◽  
Radiative Heat Loss ◽  
Convective Heat Loss ◽  
Metabolic Heat

Thermoregulation of the thorax allows honeybees (Apis mellifera) to maintain the flight muscle temperatures necessary to meet the power requirements for flight and to remain active outside the hive across a wide range of air temperatures (Ta). To determine the heat-exchange pathways through which flying honeybees achieve thermal stability, we measured body temperatures and rates of carbon dioxide production and water vapor loss between Ta values of 21 and 45 degrees C for honeybees flying in a respirometry chamber. Body temperatures were not significantly affected by continuous flight duration in the respirometer, indicating that flying bees were at thermal equilibrium. Thorax temperatures (Tth) during flight were relatively stable, with a slope of Tth on Ta of 0.39. Metabolic heat production, calculated from rates of carbon dioxide production, decreased linearly by 43 % as Ta rose from 21 to 45 degrees C. Evaporative heat loss increased nonlinearly by over sevenfold, with evaporation rising rapidly at Ta values above 33 degrees C. At Ta values above 43 degrees C, head temperature dropped below Ta by approximately 1–2 degrees C, indicating that substantial evaporation from the head was occurring at very high Ta values. The water flux of flying honeybees was positive at Ta values below 31 degrees C, but increasingly negative at higher Ta values. At all Ta values, flying honeybees experienced a net radiative heat loss. Since the honeybees were in thermal equilibrium, convective heat loss was calculated as the amount of heat necessary to balance metabolic heat gain against evaporative and radiative heat loss. Convective heat loss decreased strongly as Ta rose because of the decrease in the elevation of body temperature above Ta rather than the variation in the convection coefficient. In conclusion, variation in metabolic heat production is the dominant mechanism of maintaining thermal stability during flight between Ta values of 21 and 33 degrees C, but variations in metabolic heat production and evaporative heat loss are equally important to the prevention of overheating during flight at Ta values between 33 and 45 degrees C.

scholarly journals Effect of Nutrient Solution Flow Rate on Hydroponic Plant Growth and Root Morphology

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1840 ◽  
Author(s):  
Bateer Baiyin ◽  
Kotaro Tagawa ◽  
Mina Yamada ◽  
Xinyan Wang ◽  
Satoshi Yamada ◽  
...  
Keyword(s):  
Plant Growth ◽  
Root Growth ◽  
Surface Area ◽  
Flow Rate ◽  
Root Morphology ◽  
Root Surface ◽  
Solution Flow Rate ◽  
Root Surface Area ◽  
Solution Flow ◽  
Flow Rates

Crop production under hydroponic environments has many advantages, yet the effects of solution flow rate on plant growth remain unclear. We conducted a hydroponic cultivation study using different flow rates under light-emitting diode lighting to investigate plant growth, nutrient uptake, and root morphology under different flow rates. Swiss chard plants were grown hydroponically under four nutrient solution flow rates (2 L/min, 4 L/min, 6 L/min, and 8 L/min). After 21 days, harvested plants were analyzed for root and shoot fresh weight, root and shoot dry weight, root morphology, and root cellulose and hemicellulose content. We found that suitable flow rates, acting as a eustress, gave the roots appropriate mechanical stimulation to promote root growth, absorb more nutrients, and increase overall plant growth. Conversely, excess flow rates acted as a distress that caused the roots to become compact and inhibited root surface area and root growth. Excess flow rate thereby resulted in a lower root surface area that translated to reduced nutrient ion absorption and poorer plant growth compared with plans cultured under a suitable flow rate. Our results indicate that regulating flow rate can regulate plant thigmomorphogenesis and nutrient uptake, ultimately affecting hydroponic crop quality.

scholarly journals GROWTH RATE DISPERSION (GRD) OF THE (010) FACE OF BORAX CRYSTALS IN FLOWING SOLUTION

2010 ◽  
Vol 4 (3) ◽  
pp. 145-148
Author(s):  
Suharso Suharso ◽  
Gordon Parkinson ◽  
Mark Ogden
Keyword(s):  
Growth Rate ◽  
Aqueous Solutions ◽  
Normal Distribution ◽  
Flow Rate ◽  
Growth Rates ◽  
Experimental Conditions ◽  
Solution Flow ◽  
Flow Rates ◽  
Growth Rate Distribution ◽  
Flowing Solution

The growth rates of borax crystals from aqueous solutions in the (010) direction at various flow rates were measured. The observed variations of the growth rate can be represented by a normal distribution.  It was found that there is no correlation between growth rate distribution and solution flow under these experimental conditions.   Keywords: Growth rate dispersion (GRD), borax, flow rate

Changes in the thoracic temperature of honeybees while receiving nectar from foragers collecting at different reward rates

2001 ◽  
Vol 204 (9) ◽  
pp. 1653-1658 ◽  
Author(s):  
W.M. Farina ◽  
A.J. Wainselboim
Keyword(s):  
Sucrose Solution ◽  
Activity Level ◽  
Solution Flow ◽  
Flow Rates ◽  
Food Exchange ◽  
Feeding Sites ◽  
Eusocial Insects ◽  
Thoracic Temperature ◽  
Nectar Source ◽  
Unloading Rate

Mouth-to-mouth food exchange in eusocial insects (trophallaxis) contributes to the organization of complex social activities. In the case of honeybees, foragers returning from a nectar source transfer the food collected to receiver colony-mates through oral contact. Previous studies have shown that the speed of nectar transfer within each contact (unloading rate) increases when foragers return from feeding sites with higher profitability, i.e. with more concentrated sugar solutions or higher solution flow rates. However, there is no evidence that the nectar unloading rate is actually evaluated by hive-mates during food exchange. To investigate this, trophallaxis between donor bees returning from a feeder with different flow rates of sucrose solution (range 1.0-8.2 microl min(−1) of 50% w/w sucrose solution) and receiver hive-mates was studied by combining behavioural and infrared thermal analysis. The results show that when foraging bees returned from a feeder delivering a higher flow rate they initiated unloading at higher thoracic temperatures and transferred the solution at higher speed. During these food exchanges, the thoraces of receiver bees warmed up faster in proportion to increasing forager temperature and unloading rate. Therefore, whatever the variable actually evaluated by receivers (mostly nectar processors, i.e. bees that handle nectar in the hive) during trophallaxis (unloading rate and/or donor thoracic temperature), they raised their activity level in proportion to that of the foragers. In this way, receiver bees will intensify their nectar processing when nectar foragers return from more profitable sites.

Utilization of Waste of Enzymes Biomass as Biosorbent for the Removal of Dyes from Aqueous Solution in Batch and Fluidized Bed Column

2020 ◽  
Vol 71 (1) ◽  
pp. 1-12
Author(s):  
Salman H. Abbas ◽  
Younis M. Younis ◽  
Mohammed K. Hussain ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor ◽  
...  
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Particle Size ◽  
Adsorption Capacity ◽  
Fluidized Bed ◽  
Flow Rate ◽  
Fungal Biomass ◽  
Solution Flow Rate ◽  
Maximum Adsorption Capacity ◽  
Solution Flow

The biosorption performance of both batch and liquid-solid fluidized bed operations of dead fungal biomass type (Agaricusbisporus ) for removal of methylene blue from aqueous solution was investigated. In batch system, the adsorption capacity and removal efficiency of dead fungal biomass were evaluated. In fluidized bed system, the experiments were conducted to study the effects of important parameters such as particle size (701-1400�m), initial dye concentration(10-100 mg/L), bed depth (5-15 cm) and solution flow rate (5-20 ml/min) on breakthrough curves. In batch method, the experimental data was modeled using several models (Langmuir,Freundlich, Temkin and Dubinin-Radushkviechmodels) to study equilibrium isotherms, the experimental data followed Langmuir model and the results showed that the maximum adsorption capacity obtained was (28.90, 24.15, 21.23 mg/g) at mean particle size (0.786, 0.935, 1.280 mm) respectively. In Fluidized-bed method, the results show that the total ion uptake and the overall capacity will be decreased with increasing flow rate and increased with increasing initial concentrations, bed depth and decreasing particle size.

Hydraulic model of a water cooling system in a chemical plant

1988 ◽  
Vol 53 (4) ◽  
pp. 788-806
Author(s):  
Miloslav Hošťálek ◽  
Jiří Výborný ◽  
František Madron
Keyword(s):  
Flow Rate ◽  
Cooling System ◽  
Cooling Water ◽  
Graph Algorithm ◽  
Automatic Generation ◽  
Hydraulic Calculation ◽  
Return Flow ◽  
Flow Rates ◽  
Pressure Losses ◽  
Controlled Flow

Steady state hydraulic calculation has been described of an extensive pipeline network based on a new graph algorithm for setting up and decomposition of balance equations of the model. The parameters of the model are characteristics of individual sections of the network (pumps, pipes, and heat exchangers with armatures). In case of sections with controlled flow rate (variable characteristic), or sections with measured flow rate, the flow rates are direct inputs. The interactions of the network with the surroundings are accounted for by appropriate sources and sinks of individual nodes. The result of the calculation is the knowledge of all flow rates and pressure losses in the network. Automatic generation of the model equations utilizes an efficient (vector) fixing of the network topology and predominantly logical, not numerical operations based on the graph theory. The calculation proper utilizes a modification of the model by the method of linearization of characteristics, while the properties of the modified set of equations permit further decrease of the requirements on the computer. The described approach is suitable for the solution of practical problems even on lower category personal computers. The calculations are illustrated on an example of a simple network with uncontrolled and controlled flow rates of cooling water while one of the sections of the network is also a gravitational return flow of the cooling water.

scholarly journals Geometrical Optimization of a Venturi-Type Microbubble Generator Using CFD Simulation and Experimental Measurements

Designs ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 4
Author(s):  
Dillon Alexander Wilson ◽  
Kul Pun ◽  
Poo Balan Ganesan ◽  
Faik Hamad
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Cfd Simulation ◽  
Air Flow ◽  
Bubble Diameter ◽  
Diameter Ratio ◽  
Experimental Measurements ◽  
Cfd Model ◽  
Flow Rates ◽  
Throat Diameter

Microbubble generators are of considerable importance to a range of scientific fields from use in aquaculture and engineering to medical applications. This is due to the fact the amount of sea life in the water is proportional to the amount of oxygen in it. In this paper, experimental measurements and computational Fluid Dynamics (CFD) simulation are performed for three water flow rates and three with three different air flow rates. The experimental data presented in the paper are used to validate the CFD model. Then, the CFD model is used to study the effect of diverging angle and throat length/throat diameter ratio on the size of the microbubble produced by the Venturi-type microbubble generator. The experimental results showed that increasing water flow rate and reducing the air flow rate produces smaller microbubbles. The prediction from the CFD results indicated that throat length/throat diameter ratio and diffuser divergent angle have a small effect on bubble diameter distribution and average bubble diameter for the range of the throat water velocities used in this study.

Sign in / Sign up

Export Citation Format

Share Document