Pumping Capacity Research Articles

Role of pumped hydro storage plants for flood control

Climate change has intensified precipitation patterns and led to more frequent and severe flooding in many locations worldwide. This paper investigates the role of pumped hydro storage (PHS) plants in mitigating floods in Rio Grande do Sul, Brazil. PHS plants can enhance basin water storage, allowing conventional reservoir dam (CRD) to focus on flood control. The paper also suggests the construction of hybrid PHS plants that can be used to store energy during normal operation and be used to pump water during flood events. The results compare the floodwater volume in Guaíba Lake and Patos Lagoon (27 km3) to the 13 km3 displacement capacity of four proposed PHS projects, which could have reduced the total flood level of the Guaiba Lake from 5.33 m to 3.5 m. This would cost 2.7 billion USD, which is similar to the costs of the impact resulted from the flood in May 2024. This infrastructure would significantly reduce the impact of the floods and make the state of Rio Grande do Sul more resilient to climate change in the future. By analyzing the flood water storage capacity required and the storage and pump capacity provided by these solutions, the study aims to prevent future floods and mitigate climate change impacts in the region.

Watering the Seeds of the Rural Economy: Evidence from Groundwater Irrigation in India

ABSTRACT This study explores the impact of private investment in groundwater extraction for irrigation on the spatial and sectoral distribution of rural economic activity in India. Exploiting a kink in access to groundwater, generated from an absolute technological constraint on the operational capacity of irrigation pumps with depth of the water table, there is evidence of a significant improvement in agricultural production accompanied with modest consumption gains. Groundwater extraction causes a substantial increase in population density, but has no effect on the employment rate or labor reallocation between sectors of the economy. Furthermore, irrigated agriculture appears to provide additional employment opportunities for waged labor from surrounding non-irrigated villages.

Modification of Additional Check Valves and Tube Pressure to Enhance Hydram Pump Capacity and Performance for Agricultural Applications

Pump that operates automatically by relying on natural power from water without using great cost and trouble by pumping hydram. Hydram pumps are one of the types of pumps that are driven by kinetic power, it was discovered by a 1796 Montgolfier in Italy. The purpose is to determine the most optimal water speed of the hydram pump by using different numbers of pressure tubes and several check valves. This research uses a factorial Randomised Group Design (RGD) method. The first treatment is valve variation and the second is variation in the number of tubes. The results showed that the average river water flow velocity was 0.154 meters/second with an average water discharge of 2.61 m3/second under normal flow conditions. The average water flow in the intake pipe is 0.717 meters / second and the volume of water in the pipe is 15.19 liters with an average water discharge entering the intake pipe is 10.804 m3 / second. A combination of three valves and three tube treatments consistently produces greater water discharge than other combinations. The highest efficiency of the hydram pump is found in the combination of three checks.

Matching analysis between the heating/cooling capacity of PVT heat pumps and the heating/cooling demand of residential buildings across various regions in China

PVT-HP (Photovoltaic-Thermal Heat Pump) is a novel type of energy saving technology. Existing researches on PVT-HP technology focuses only on its operating performance under some specific conditions, ignoring the matching of its energy supply capacity with the energy demand of buildings, which is very important for its engineering design and application. In this paper, the matching relationship between the heating/cooling capacity of the PVT-HP system and the heating/cooling demand of residential buildings in major cities of China has been analyzed. To achieve this goal, a novel prediction model used to calculate the heating/cooling performance of the PVT-HP system has been proposed. And the daily heating guarantee rate and daily cooling guarantee rate have been put forward to evaluate the matching relationship. Based on the evaluation indexes, the applicable matching relationship between the installed capacity of the PVT-HP system and the heating/cooling area of residential buildings has been analyzed. The result of case study shows that for the selected cities of Shenyang, Beijing and Wuhan, the heating/cooling area of residential building for PVT-HP system with installed capacity of 1hp should not exceed 17 m2, 31 m2 and 25 m2, respectively. Further matching analysis of major cities in China shows that the PVT-HP system is more suitable for application in hot summer and cold winter zones of China, in where the suggested heating/cooling area for the PVT-HP system with installed capacity of one horse power is within the range of 30 m2–37 m2.

Effect of activation temperature on photon-stimulated desorption from Ti-Zr-V coated copper chambers

Non-evaporable getter (NEG) films featuring distributed pumping properties and low photon-stimulated desorption (PSD) are widely utilized in particle accelerators, especially in diffraction limited storage rings (DLSR) with compact design. Activation is a requisite operation to sustain the pumping capacity of NEG films. Meanwhile, the vacuum properties of NEG films vary with activation temperature. In this work, the dependence of the PSD from NEG films is evaluated with the activation temperature. The columnar Ti-Zr-V films were deposited on the inner surface of the copper vacuum chamber by DC magnetron sputtering. The effect of activation temperature ranging from 150 to 200 °C and nitrogen venting on the PSD of Ti-Zr-V films was investigated. The results indicate that with elevating the activation temperature, the initial PSD yield of the Ti-Zr-V coated chamber consistently declines. Furthermore, the initial desorption of Ti-Zr-V films after nitrogen venting is between that of the non-activated state and the activated state.

The human lower leg muscle pump functions as a flow diverter pump, maintaining low ambulatory venous pressures during locomotion

ObjectiveAmbulatory venous pressure (AVP) is the drop of pressure observed in the superficial veins of the lower leg during movement. This phenomenon has been linked to the function of the calf muscle pump (CMP) and the competence of venous valves. Nevertheless, the concept of the CMP function remains controversial. This study aimed to elucidate the association between lower leg muscles activity, changes in pressure in distinct venous segments, and lower extremity arterial blood supply in healthy subjects during various types and intensities of exercise. MethodsTwelve legs of nine healthy volunteers were enrolled in the study. Continuous pressure (intramuscular vein [IV] and three great saphenous vein [GSV] points) and surface electromyography data (gastrocnemius and anterior tibial [ATM] muscles) were recorded during treadmill walking, running, and plantar flexion exercises. The pressure gradient (ΔP, mmHg) between adjacent points of measurement was calculated. Minute unit power of muscle pump ejection and suction (NE, and NS, MPa/min) were calculated and compared with the arterial blood supply of the lower extremity (LBF, L/min). ResultsΔP demonstrated a consistent pattern of changes during walking and running. In GSV, the ΔP was observed to be directed from the thigh to the mid-calf (retrogradely) and from the ankle to the mid-calf (anterogradely) throughout the entire stride cycle. However, its value decreased with increasing stride cycle frequency. The dynamics of ΔP between the IV and GSV were as follows: It was directed from the IV to GSV during gastrocnemius contraction and was reversed during anterior tibial muscle contraction and gastrocnemius relaxation (swing phase). LBF, NE, and NS demonstrated similar exponential growth with increasing stride frequency during walking and running. ConclusionsDuring natural locomotion, the muscle pump acts as a flow diverter pump, redirecting the flow of blood from the superficial veins to the intramuscular veins via the perforating veins. During ambulation, the pressure in the superficial venous network depends upon the capacity of the muscle pump to provide output that matches the changes in arterial blood flow.

Mine Drainage System Planning At PT Putra Coal in The North Kalimantan Region

Coal is a deposit of plant fossils that has undergone a peat process over a long period of time. A company in Malinau Regency, North Kalimantan Province, requires replanning for the existing drainage system because its holding pond or sump, which is a former pit, will be re-mined. Therefore, this research re-plans the drainage system to overcome this problem. The methods for data processing comprised the Gumbel method, the Monobe equation, the Seyhan equation, and the calculations of open channels and holding pond dimensions, as well as pump capacity. The mine drainage system creates channels or ditches that function to prevent runoff water from entering the mining area. The channel capacity was 0.6 m3 /second, or 2,261 m3 /hour, with a large runoff of 0.146 m3 /second, or 63 m3 /hour. The channel would be made in a trapezoid shape. Meanwhile, the mine dewatering method used a pumping system to release water into the sump. Using 1 pump of MF-420EX, the total flow of water that could be pumped reached 50,537 m3 /hour with working hours of 20 hours. The sump capacity was 28,825 m3 in a trapezoid shape with dimensions of 95 m surface length, 70 m surface width, 85 m base length, 60 m base width, and 5 m depth.

Cumulative effects of natural and anthropogenic processes on groundwater chemistry of a small karst island—case study of Vis (Croatia)

Many coastal and island communities depend on groundwater as the only source of freshwater, making it an invaluable resource. In the Mediterranean region, groundwater resources are highly vulnerable to natural and anthropogenic pressures, such as overexploitation, climate change, seasonal variations in precipitation, and seawater intrusion. Hence, an understanding of hydrogeological processes and groundwater chemistry is a basis for the sustainable management of coastal and island groundwater resources. Vis, a small and remote karst island in the Adriatic Sea, exhibits peculiar geological and hydrogeological settings, resulting in the island’s autonomous water supply. The current pumping capacity (maximum of 42 l/s) meets most of the demand, but intensive summer tourism and climate change exert high stress on groundwater resources during the dry season. Consequently, in the last decade, occasional reductions for consumers occurred. Monitoring of in situ physicochemical parameters and groundwater sampling for chemical and isotopic analyses were conducted from 2020 to 2023 at deep borewells, shallow dug wells, and springs. Hydrochemical interpretation indicated that groundwater chemistry was affected primarily by carbonate and sulfate rock dissolution, mixing with seawater, reverse ion exchange, and dedolomitization. The majority of groundwater samples exhibit Ca–HCO3 hydrochemical facies, followed by Na–Cl and mixed facies. The low percentage of seawater in the mixture indicated that seawater intrusion is not too extensive even during prolonged dry periods, implying a favorable hydrostatic regime with relatively small but sufficient groundwater reserves of the island’s aquifers, although the investigated period was characterized by significantly lower precipitation with respect to the 30-year average.

CSP+MED Plant Coupled to a Seawater Pipeline from the Mining Industry in Northern Chile: A Case Study

The study evaluated the use of mining seawater pipelines in a CSP+MED plant at commercial scale based on solar tower molten salts technology, with 111.2 MWe and 13 hours of thermal energy storage in northern Chile. The plant is coupled to the biggest seawater pipeline in the country, from Centinela mining facility. Results shown that the CSP+MED plant required all the seawater pumping capacity of the pipeline in order to cool the thermal cycle of the CSP plant using the MED plant. In terms of electricity production, the MED plant integration affects significantly the annual electricity production of the plant, when compared with an optimized CSP plant and to a CSP plant with the same design but without the MED plant and considering a once through cooling system, lowering the electricity production an 46.05% and 25.82% respectively. On the other hand, the CSP+MED plant integration produces 14.06 hm3 of freshwater annually, which translated in an additional income equivalent to 28.14 MM USD each year, which is substracted from the OPEX costs of the plant for the LCoE calculations. For this reason, the results showed that the lowest LCoE is reached by the CSP+MED plant configuration, but is highlighted that the economic analysis assumed an ideal situation, and further business models must be studied in order to share the benefits of the seawater pipeline integration between the CSP+MED plant owner and the mining facility that owns the seawater pipeline.

Effect of thermoelectric subcooling on COP and energy consumption of a propane heat pump

The building sector has an important impact on the environment, being responsible for 30 % of the total greenhouse gas emissions. Knowing that the energy consumption devoted to HVAC systems accounts for 50 % of the total energy consumption of buildings, it is paramount to develop environmentally friendly technologies able to provide green space heating to the building sector. To that purpose, this manuscript presents a computational study on propane vapor compression heat pumps which include thermoelectric subcooling to boost their operation. The combination of these technologies has been proven in the past to be very beneficial for refrigeration systems and this study concludes for the first time that propane heat pumps can highly benefit from thermoelectric subcooling. The widely conducted research includes the following parameters: ambient temperatures from −20 to 15 °C, voltage supplies to the thermoelectric modules from 0.5 to 10 VDC, number of thermoelectric subcooling blocks from 1 to 8 and two water inlet temperatures, 40 and 55 °C to study their influence on heating capacity, compressor and thermoelectric power consumptions, subcooling degree, propane mass flow, compressor capacity, COP, energy consumption and SCOP of the combined heat pump. The obtained results are very conclusive, COP enhancements up to 12.29 % are achieved when a thermoelectric subcooler with 16 modules is included in a propane heat pump already provided with an internal heat exchanger for an ambient temperature of −20 °C and a water inlet temperature of 55 °C. Additionally, improvements in Seasonal COP up to 9.98 % are achieved if the above-mentioned technologies integration between a vapor compression heat pump and a thermoelectric subcooler substitutes a conventional propane heat pump with an internal heat exchanger for space heating a single-story two-family house.

A study of capacity demands for heat pumps intermittent heating of China’s residences

Heat pump heating is one of the most promising solutions for transitioning residential heating in China’s cold regions, as well as hot summer and cold winter regions from centralized, continuous heating to decentralized, intermittent heating, promoting low-carbon transformation. However, the fundamental issue of the actual capacity requirements for heat pumps in intermittent heating has not yet been addressed. In view of this, this study developed a numerical model that considers the dynamic coupling characteristics between the heat pump and the building environment. Using the model, the worst startup conditions for heat pumps in intermittent heating, actual heat pump capacity demands, and the differences in capacity compared to continuous heating mode for residential buildings in 230 Chinese cities are analyzed. The findings revealed an exponential relationship between intermittent heating capacity demands and time constraints, as well as a linear relationship with heating temperature. Specifically, the impact of the set temperature on capacity demands in cold regions and hot summer and cold winter regions is 22.8 W/(m2·°C) and 32 W/(m2·°C), respectively. These findings provide insights into the planning and design of future intermittent heating renovation projects in China.

A Double-Rotating Ferrofluid Vane Micropump with an Embedded Fixed Magnet

This paper introduces the prototype design, magnetic field analysis and experimental test of a double-rotating ferrofluid vane micropump with an embedded fixed magnet. The micropump is based on the working principle of a positive-displacement pump, as well as the magnetic characteristics and flow properties of magnetic fluid. Through the numerical analysis of the pump cavity magnetic field and the experimental test, the structural parameters of the micropump are optimized reasonably. The pumping flow and pumping height of the micropump were characterized at different driving speeds. The maximum pumping flow rate is approximately 410 μL/min, and the maximum pumping height is approximately 111.4 mm water column. The micropump retains the advantages of simple structure, easy manufacture, flexible control, self-sealing, self-lubrication, low heat production, etc., and can block the pumped liquid backflow. The resulting double-rotating ferrofluid blades can improve pumping efficiency and pumping capacity, and can improve pumping reliability and stability to a certain extent.

Evaluation of the effect of hydrogen evolution reaction on the performance of all-vanadium redox flow batteries

The exceptional advantages of vanadium redox flow batteries (VRFBs) have garnered significant attention, establishing them as the preferred choice for large-scale and long-term energy storage solutions. However, side reactions such as hydrogen evolution reaction (HER) lead to suboptimal performance of VRFB parameters, resulting in an overall decrease in VRFB performance. Therefore, it is imperative to investigate the mechanism by which HER affects VRFB performance and identify effective methods to mitigate its impact. In light of this, critical parameters such as charge-discharge curve, internal resistance, pressure-drop, pump power consumption, efficiency, and capacity retention rate are selected to evaluate the impact of HER on VRFB performance. Experimental results demonstrate that HER causes an increases in voltage during charging and a decrease during discharging stages leading to voltage loss; additionally, bubble generation significantly increases pressure drop and pump power consumption; furthermore, blockage of flow channels and electrodes due to bubbles leads to an increase in ohmic resistance. Finally, HER has a substantial impact on efficiency and capacity with an average energy efficiency of 2.92 %. After 60 cycles, the capacity retention rate decreased by nearly 7.69 %.

Enhancement of cooling process of hot blocks mounted inside a horizontal channel using flexible baffles — Alternative arrangement

In this paper, two heated blocks and three flexible baffles that are alternately placed on the upper and bottom sides of a rectangular channel are used to replicate the transient heat and air movement. The novelty of this research is the use of flexible baffles to destruct the thermal boundary layer with maintaining little pressure drop, and thus reducing the required pumping capacity. The finite thickness blocks are subject to a constant heat flux, while the baffles are very thin and deforms depending on the strength of the flow of coolant (air). Finite element method with arbitrary Lagrangian–Eulerian approach is used for solving such deforming domain problem. The problem is inspected transiently by varying the dimensionless time (τ=0.0 to 10) and two salient parameters which are Reynolds number Re=10−500, and baffle elasticity parameter E=105−108. Results show that the flexibility feature of the baffles contributes not only in directing the coolant towards the hot blocks, but also contributes in reducing the skin friction and pressure drop through the channel. At Re=150, the skin friction and pressure drop of the flexible baffles are 13.2% and 16.5%, respectively lesser than the rigid baffles. The improvement of Nusselt number with flexibility parameter is marginal and within a limited low Reynolds number, where the maximal improvement is about 3.4% at Re=150.

Pengukuran Kinerja Mesin Sewage Treatment Plant (STP) menggunakan Metode Overall Equipment Efeectiveness

One of the important things in supporting the operational management of the building which is part of the building's mechanical and electrical aspects is the building's domestic liquid waste management system. The availability of liquid waste production cannot be separated from the performance of the Sewage Treatment Plan (STP) machine as a work tool that produces domestic liquid waste production in HDI Hive Menteng Building. STP machine maintenance is one of the important factors in ensuring the quality of liquid waste production in accordance with the Environmental Service (DLH) quality standards. The machine maintenance system can be used as a benchmark for measuring the effectiveness of STP machines. Machine performance with a high rhythm without stopping 24 hours which continues to increase and is comparable to the tenant accoupancy level, of course requires anticipatory action for machine breakdown problems. Overall Equipment Effectiveness (OEE) is a method used to measure and maximize machine effectiveness based on three categories, namely Availability rate, Performance rate, Quality rate. From the results of calculating the OEE value for the STP machine at PT. Gaia Care International) of 82.96%, in general the OEE value is still below the JIPM standard value, namely greater than 85%. For this reason, in this research, an analysis was carried out using a fishbone diagram, which is used to determine the causes and effects of not achieving the effectiveness of the STP machine. Based on the results of the Fish Bone Diagram analysis with several factors including; Machines, methods, people and materials can be concluded as factors that cause a decrease in the OEE value of STP machines, namely rework losses which are quite high so that they affect the Quality OEE value in STP machine measurements. The proposal given to increase the effectiveness of the STP Machine for controlling Rework Losses is to improve the general cleaning routine and increase the Backwash Pump Capacity in the aeration tank and Inlet.

Usulan Perancangan Pemasangan Alarm Detector dan Sprinkler pada Kampus C Universitas Dirgantara Marsekal Suryadarama

The building facilities currently used by Universitas Dirgantara Marsekal Suryadarma (Unsurya) is Campus A and Campus B and the new Campus C. In this research examined campus C Unsurya, which is a three (3) floor building. The building must be equipped with reliable fire safety facilities. There are several functions of space that can trigger fires, namely electrical installations and flammable building materials. Based on the background above, adequate active protection means are needed in accordance with applicable regulations. Cause-and-effect diagrams / Fishbone diagrams are used to analyze the factors that cause fire hazards. The factors that influence and cause fire hazards can generally be classified as follows: Workers, Raw Materials, Machines, Methods, and Environment. 5W+1H Quality using to determine recommendation. Based on calculations, it was determined to place 132 sprinklers to overcome the danger of fire with a quantity of ¾" pipe material with a pipe line 460 meters long. Meanwhile, the water supply is 277 m3/minute. With the required water supply, a pump with a pump capacity capable of producing 277 m3/minute is needed. With this capacity, three pumps with a capacity of 100 m3 /hour and one spare pump can be used. A water storage tank is needed for 300 m3 for 60 minutes with a length of 4 meters, width of 5 meters and depth of 1.5 meters. It is proposed to use a Standard Operating Procedure (SOP) regarding K3 or safety and how to handle fire hazards in the Unsurya Campus C building which includes improvements to human factors, materials, machines, methods and the environment of the Campus C Unsurya.

Design of Automatic Flood Control System in Kulon Progo, Special Region of Yogyakarta, Indonesia

The construction of Yogyakarta International Airport has resulted in land use changes and increased the topography in the area by up to 9 m, which has led to potential flooding. A spatial analysis was conducted on the flow direction after the airport's construction, specifically in the West Carik watershed. It was discovered that the flow direction was uncertain and trapped upstream of the airport. A polder system with automation is proposed as a solution to the drainage problem. An automation system is designed for pump operation with the objective of improving efficiency. The system is expected to reduce the volume of water in the polder by reducing human involvement and providing ease in monitoring. The results of hydrological analysis with a 50-year return period flood resulted in a design flood discharge of 11.73 m3/s. The polder has a storage capacity of 63,312 m3, a depth of 4 m, and a surface area of 1.58 ha. It requires a total pump capacity of 8.4 m3/s, consisting of three pump units, with one unit having a capacity of 1.8 m3/s and two units with 3.3 m3/s. One additional pump with a capacity of 3.3 m3/s is also planned as a backup pump. The pump automation system simulation employs an Arduino UNO as the controller, water level sensor, and relay. This system successfully fulfills the desired operational system for the pump. In the actual implementation, a Programmable Logic Controller (PLC) is required as the controller, with water level sensors, relays, and contactors as inputs and outputs.

Effect of Micronized Purified Flavonoid Fraction on Venous Hemodynamics Evaluated Using Digital Photoplethysmography in Patients with Chronic Venous Disease

Micronized purified flavonoid fraction (MPFF) is the most widely prescribed and well-studied venoactive drug available for the treatment of chronic venous disease (CVD). Photoplethysmography (PPG) is used to quantitatively measure venous hemodynamics and provide information about the overall function of the venous system. The aim of this study was to use digital PPG to evaluate the effects of MPFF on venous hemodynamics in patients with CVD. Patients diagnosed with CVD at an outpatient clinic in Bursa, Turkey between February 2018 and July 2020 were assessed for inclusion in this retrospective analysis. Patients who complied with the advised treatment strategy (MPFF 1,000mg tablets taken orally once daily and compression garments) and attended follow-up visits were included in the analysis. Digital PPG was used to measure venous refilling time (VRT) and venous pumping capacity (VPC) at diagnosis and 6months of follow-up. The Venous Clinical Severity Score (VCSS) was also obtained at these visits, and patients completed the 20-item Chronic Venous Insufficiency Questionnaire (CIVIQ-20). In total, 721 patients (mean age 52years) with C0-C4 CVD were included in the study. PPG showed that VRT and VPC increased significantly from 19.0sec to 2.0%, respectively, at diagnosis to 27.4 and 4.9%, respectively, at 6months (both P<0.05). Mean VCSS improved significantly from 7.9 at diagnosis to 3.1 at 6months (P<0.05). Mean CIVIQ-20 score also improved significantly at the 6-month follow-up (20.1 vs 38.6 at diagnosis; P<0.01). In patients with C0-C4 CVD, 6months of MPFF treatment plus the wearing of compression garments was associated with statistically significant improvements in venous hemodynamic parameters measured by PPG, as well as measures of clinical severity and quality of life.

The effect of impeller height and rotation speed on the Kambala reactor desulfurization process

To improve the utilization efficiency of desulfurizer in the Kambala reactor liquid iron desulfurization process and prolong the life of the impeller, the height of the impeller and its optimal matching rotation speed are optimized. Through numerical simulation, the mixing effect of different height impellers under different rotation speeds is studied, the movement and distribution modes of desulfurizer particles are analyzed, the pumping capacity and power are calculated, and the influence of impeller height and optimal matching rotation speed on the desulfurization effect has been clarified. The numerical simulation results show that the optimization of impeller height and optimal matching rotation speed can improve the mixing effect. The height of the impeller increases, and its optimal matching rotation speed decreases. Based on the results, in existing models, it is recommended to run at 60 r/min with an impeller height of 800 mm for optimal mixing performance.

The hard life of an octopus embryo is seen through gene expression, energy metabolism, and its ability to neutralize radical oxygen species

The reproductive process in Octopus maya was analyzed to establish the amount of reactive oxygen species that the embryos inherit from females, during yolk synthesis. At the same time, respiratory metabolism, ROS production, and the expression of some genes of the antioxidant system were monitored to understand the ability of embryos to neutralize maternal ROS and those produced during development. The results indicate that carbonylated proteins and peroxidized lipids (LPO) were transferred from females to the embryos, presumably derived from the metabolic processes carried out during yolk synthesis in the ovary. Along with ROS, females also transferred to embryos glutathione (GSH), a key element of the antioxidant defense system, thus facilitating the neutralization of inherited ROS and those produced during development. Embryos are capable of neutralizing ROS thanks to the early expression of genes such as catalase (CAT) and superoxide dismutase (SOD), which give rise to the synthesis of enzymes when the circulatory system is activated. Also, it was observed that the levels of the routine metabolic rate of embryos are almost as high as those of the maximum activity metabolism, which leads, on the one hand, to the elevated production of ROS and suggests that, at this stage of the life cycle in octopuses, energy production is maximum and is physically limited by the biological properties inherent to the structure of embryonic life (oxygen transfer through the chorion, gill surface, pumping capacity, etc.). Due to its role in regulating vascularization, a high expression of HIf-1A during organogenesis suggests that circulatory system development has begun in this phase of embryo development. The results indicate that the routine metabolic rate and the ability of O. maya embryos to neutralize the ROS are probably the maximum possible. Under such circumstances, embryos cannot generate more energy to combat the free radicals produced by their metabolism, even when environmental factors such as high temperatures or contaminants could demand excess energy.