Volume Flow Research Articles

Optimizing turbine meter performance through geometrical parameter analysis: A simulation-based approach using TOPSIS

The number of blades and their angle in a turbine gas meter directly affect its performance and the amount of lift force, pressure drop and flow rate passing through the blades. In this research, the combination of software simulation and optimization method has been used as an effective research tool to investigate the effect of these geometric parameters on the amount of pressure drop, volume flow rate and lift force. First, the flow in a turbine gas meter is simulated using computational fluid dynamics. The set of governing equations including continuity, linear momentum and angular momentum have been solved by Fluent software. To simulate the turbulent flow, the standard k-ε model is used. In the next step, with the help of TOPSIS model, it has been optimized to check the effect of each of the parameters and determine their optimal values. The results of this research showed that by increasing the number of blades and increasing the blade angle, the lift force increases. Among the two parameters, the number of blades and the angle value, changing the number of blades has a significant effect. Reducing the number of blades and decreasing the blade angle can be effective strategies to minimize pressure drop. Also, the effect of changing the number of blades plays an important role in pressure drop. The pressure drop in the number of 20 blades is the highest and this's due to its large number of blades. In this article, 21 cases have been investigated with the help of TOPSIS and it can be seen that the angle of 30 ° with 12 blades is an optimal model. The ratio of lift force to drag force is observed at an angle of 30°, the number of 20 blades is the highest and its dimensionless value is 78.23. For an angle of 37.5°, the ratio of lift force to drag force for 20 blades has the highest value and its dimensionless value is 915.9. Also, for an angle of 45°, the ratio of lift force to drag force and the number of 20 blades has the highest value, and its dimensionless value is 1190.94.

A Multiperiod, Multicommodity, Capacitated International Agricultural Trade Network Equilibrium Model with Applications to Ukraine in Wartime

The world is facing immense challenges because of increasing strife and the impacts of climate change with accompanying disasters, both sudden-onset as well as slow-onset ones, which have affected the trade of agricultural commodities needed for food security. In this paper, a multiperiod, multicommodity, international, agricultural trade network equilibrium model is constructed with capacity constraints on the production, transportation, and storage of agricultural commodities. The model allows for multiple routes between supply and demand country markets, different modes of transport, and storage in the producing and consuming countries as well as in the intermediate countries. The generality of the underlying functions, coupled with the capacity constraints, allow for the modeling of competition among agricultural commodities for production, transportation, and storage. The capacity constraints also enable the quantification of various disaster-related disruptions to production, transportation, and storage on the volumes of commodity flows as well as on the prices. A series of numerical examples inspired by the effects of Russia’s full-scale invasion of Ukraine on agricultural trade is presented, and the results are analyzed to provide insights into food insecurity issues caused by the war.

Molecularly Imprinted Polyaniline as Solid‐Phase Material for the Extraction of UV Filters From Waters

ABSTRACTSolid‐phase extraction (SPE) using a polyaniline molecularly imprinted polymer (PANI@MIP) is optimized for the extraction of benzophenone‐4 (BP4) from aqueous matrices. First, the three main variables influencing the washing step of the SPE method—type, composition, volume, and percolation flow rate of the washing solvent—were investigated. The optimal conditions for the washing step using the new PANI@MIP‐SPE for maximum retention of BP4 and elimination of interfering molecules (benzophenone‐3 [BP3] and benzophenone [BP]) were determined as follows: 1.25 mL acetonitrile/acetic acid/hexane (45/05/50 v/v/v) as wash solvent at a flow rate of 1 mL min−1. A multiple linear regression model was validated using Student's t‐test to identify the most significant variables affecting this step, including the type and volume of each eluent solvent and the volume of the ternary mixture solvents. The reliability of the model was further confirmed by analysis of variance (ANOVA) and Fisher's F‐test at α = 0.05. The extraction recoveries of the target analyte exceeded 92% over the range of concentrations (from 0.1 to 120 mg L−1), and the maximum retention capacity of PANI@MIP‐SPE was 600 µg g−1, in contrast to 50 µg g−1 for PANI@NIP‐SPE.

A novel concept for performance enhancement of immersion-cooled data center servers

Efficient thermal management of highly densified data centers is important for carbon-neutral strategies. To this end, this work experimentally explored the most promising single-phase immersion cooling (SPIC) systems. Moreover, it proposed an active performance enhancement technology for SPIC systems. The results indicate that increasing the coolant immersion height helps to improve the SPIC performance, and the resulting increase in flow resistance is negligible. Increasing the volume flow rate improves heat transfer performance while also increasing flow resistance. Moreover, there exists a critical volume flow rate (i.e., 8 L/min) beyond which fails to significantly enhance the SPIC performance. The cooling water temperature is positively correlated with the device temperature but negatively correlated with flow resistance. The micropump-based flow turbulence enhancement and the fan-based flow redistribution techniques reduce the maximum CPU surface temperature by 6.1 % and 5.0 %, respectively. Compared to the micropump method, the fan-based technique degrades the thermal uniformity of coolants but does not significantly increase flow resistance. The economic benefit of the micropump-based strategy is greater for upstream CPUs than downstream CPUs, while the fan-based method is more economically advantageous for downstream CPUs. Moreover, the micropump-based strategy outperforms the fan-based method and demonstrates a 21.39 % increase in energy-economic performance.

Normal menstrual flow volume range and its characteristics measured from sanitary napkins in Japanese women: Discrepancy between measured and subjective menstrual flow volume.

The 2018 International Federation of Gynecology and Obstetrics abnormal uterine bleeding System-1 defines menstrual flow volume on a 3-point scale based on subjective assessment. However, the normal flow range has not been established, and it is unclear whether subjective assessment is accurate. We investigated the normal menstrual flow volume range in Japanese women and whether the actual measured menstrual flow volume agreed with the subjective evaluation. We included female menstruating volunteers aged 18-49 years in this prospective observational study. Menstrual napkins were weighed before and after use for up to three cycles, and the values were recorded in an online diary. Overall, 211 participants were recruited. All items were completed by 167 participants, and 497 menstrual cycles were included in the analysis. The median total menstrual flow volume per cycle for 497 cycles was 56.7 g. The 5th-95th percentile values ranged from 15.7 to 166.4 g. The mean value was 77.6 ± 99.6 g, with no significant differences according to age group. In the 25 cycles corresponding to heavy flow, that is, above the 95th percentile of measured flow volume, 92% were underrated as "normal" by subjective evaluation, and only 8% were correctly rated as "heavy." Our results clarify the actual menstrual flow volume in the Japanese population; this will contribute toward making women aware of the normal range of menstrual flow volume, which may facilitate appropriate preconception care.

Migration for Business: A Case Study of Goa

As the government eases out of economic activities and its role as an employer declines over time, there is a growing focus on attracting business and entrepreneurship and creating a conducive environment for their growth. Goa witnesses high rates of in-migration from the rest of India. However, census data reveal that of the total migration to Goa, only 2.7% of it is for business. This study uses census data to analyse the relative importance of population, distance, literacy and gross state domestic product (GSDP) in the volume and direction of migration flows through a gravity model analysis. In the case of population, it is observed that a high population at the source state means a higher degree of outmigration. This may be due to greater competition for scarce resources and lower costs of setting up business in the destination. The highest numbers of business migrants are from the neighbouring states of Maharashtra and Karnataka, which indicates that distance may be a deterrent to mobility, especially among women migrants. Educational attainment is not a very important determinant of migration for business. Similarly, economic growth does not seem to deter outmigration, indicating that better opportunities and cost-minimization at the destination may spur migration in spite of high economic growth in the home state. From the field study, it is observed that the majority of the businesspersons are Hindu males from the general caste. While economic factors serve as important push and pull factors, social factors are an important pull factor and determine the ease of settlement in the host state. They come to Goa for the long term and intend to settle here. They own land and housing. Though many are small businesses, through their consumption and investment activities, they play an important role in promoting growth in the state. The process of migration is self-sustaining as many bring their family members, relatives and neighbours and help settle them in business in related fields.

Why Is Reducing the Dead Zone in the Gulf of Mexico Such a Complex Goal? Understanding the Structure That Drives Hypoxic Zone Formation via System Dynamics

The Northern Gulf of Mexico hosts a severe dead zone, an oxygen-depleted area spanning 1,618,000 hectares, threatening over 40% of the U.S. fishing industry and causing annual losses of USD 82 million. Using a System Dynamics (SD) approach, this study examined the Mississippi–Atchafalaya River Basin (MARB), a major contributor to hypoxia in the Gulf. A dynamic model, developed with Vensim software version 10.2.1 andexisting data, represented the physical, biological, and chemical processes leading to eutrophication and simulated dead zone formation over time. Various policies were assessed, considering natural system variability. The findings showed that focusing solely on nitrogen control reduced the dead zone but required greater intensity or managing other inputs to meet environmental goals. Runoff control policies delayed nutrient discharge but did not significantly alter long-term outcomes. Extreme condition tests highlighted the critical role of runoff dynamics, dependent on nitrogen load relative to flow volume from upstream. The model suggests interventions should not just reduce eutrophication inputs but enhance factors slowing down the process, allowing natural denitrification to override anthropogenic nitrification.

Real-time regulation of detention ponds via feedback control: Balancing flood mitigation and water quality

Detention ponds can mitigate flooding and improve water quality by allowing the settlement of pollutants. Typically, they are operated with fully open orifices and weirs (i.e., passive control). Active controls can improve the performance of these systems: orifices can be retrofitted with controlled valves, and spillways can have controllable gates. The real-time optimal operation of its hydraulic devices can be achieved with techniques such as Model Predictive Control (MPC). A distributed quasi-2D hydrologic-hydrodynamic coupled with a reservoir flood routing model is developed and integrated with an MPC algorithm to estimate the operation of valves and movable gates in real-time. The control optimization problem is adapted to switch from a flood-related algorithm focusing on mitigating floods to a heuristic objective function that aims to increase the detention time when no inflow hydrographs are predicted. The case studies show the potential results of applying the methods developed in a catchment in Sao Paulo, Brazil. The performance of MPC compared to alternatives that do not change the operation over time with either fully or partially open valves and gates are tested. Comparisons with HEC-RAS 2D indicate volume and peak flow errors of approximately 1.4% and 0.91% for the watershed module. Simulating two consecutive 10-year storms shows that the MPC strategy can achieve peak flow reductions of 79%. In contrast, the passive scenario has nearly half of the performance (41%). A 1-year continuous simulation results show that the passive scenario with 25% of the valves opened can treat 12% more runoff compared to the developed MPC approach, with an average detention time of approximately 6 h. For the MPC approach, the average detention time is nearly 14 h, indicating that both control techniques can treat similar volumes; however, the proxy water quality for the MPC approach is enhanced due to the longer detention times achieved.

Demand study of freight transportation via railway of four commodity groups: A case study on Costa Rica's Pacific Coast Route

Having railway mobility as an option among transportation modes is of prime importance for the freight logistics of a country and the overall performance of its commerce sector. This work presents a case study in Costa Rica, where freight transportation via railway was formerly available during the last century but has not been in full service since 1995. Specifically, this paper assesses the link connecting the capital city of San Jose to the port of Caldera on the Pacific Ocean coast, henceforth referred to as the “Pacific Coast Route”. Although government institutions and industries alike have stressed the importance of its reactivation in recent years, few efforts have been made to specifically study this route with a level of detail that enables them to understand the composition of freight markets.This study presents a novel demand estimation differentiated by four types of commodities developed to calculate the potential amount of goods that could flow through this corridor, measured in monetary terms and as volumes. Trends in the expected share were analyzed to identify variables that may improve the attractiveness of the railway service and the participation of clients along the route from the country's main economic activities which includes the following: agriculture & livestock, manufacturing, minerals, and forestry.The four-step transportation model was chosen for its suitability towards this case study; where available data sets were limited, the information was aggregated into yearly values, and the network was defined with few transportation zones. Activity-based models were not feasible in this case due to the lack of information on complete routes and volume flows. The model evaluated a first scenario given the present design of the route and a second scenario involving improvements in the alignment and the addition of a new segment.Regarding the opportunities of moving goods according to their type, in terms of volume, minerals (48 %) and agricultural (31 %) have the largest shares of participation in this region, followed by manufacturing (20 %) and forestry products (1 %). However, the manufacturing sector stands out in financial terms, accounting for 71 % of the total value of goods mobilized in the study area.It was found that the demand is most sensible for changes in the service fare, while the benefits of shorter travel times and a larger attraction area in scenario 2 were not significant. A service fee of $USD 2.35/ton in average is recommended to reach a 30 % modal shift towards the railway (following the European Commission's goals to reduce CO2 emissions from freight transportation in 2030).Finally, recommendations for public policies are provided to the entities in the country in the sectors of Agriculture, Health, Energy and Environment, Transportation, and Public Services. The suggestions aim to develop the new railway project with a holistic perspective, considering the inclusion of less profitable economic activities of the surrounding communities that require connectivity, compliance with environmental commitments, and design for resilience while aiming for a financially feasible business model.

Physicochemical properties and in vitro release of formononetin nano-particles by ultrasonic probe-assisted precipitation in four polar organic solvents

Although formononetin has a considerable biological activity, its therapeutic use is limited by its low solubility. Formononetin was dissolved in ethanol, methanol, N, N-dimethylformamide (DMF), and dimethyl sulfoxide (DMSO) in this investigation, the antisolvent precipitation procedure with the assistance of an external ultrasonic probe was used to manufacture the formononetin nano-particles. The ideal parameters for response surface BBD optimization are as follows: feed volume flow rate of 6 mL/min; ultrasonic power of 860 W; and liquid-liquid ratio of 1:12.5. The formononetin nano-particles have a smaller particle diameter than raw sample; the lowest size can be as small as (329 ± 1.99) nm, which is 45 times smaller than raw. An in vitro digestion test using a solution that simulated intestinal solution revealed that the release rate of the nano-particle was 1.75 times than that of the raw formononetin. The formononetin nano-particles generated by the aforementioned four solvents have the following order of diameter: ethanol > methanol > DMF > DMSO. This study provided a technical reference for the functional food components in deep processing.

Experimental and numerical investigation of water flow in different media models at multiple scales

ABSTRACT The study of the flow behavior in pores, fractures, and pore-fracture dual media plays a crucial role in understanding the mechanisms of sudden water inrush and sand flow. In this study, laboratory experiments were conducted using a custom-made transparent porous model to investigate the flow characteristics of fluids in complex media. Additionally, finite element simulations were employed to explore the flow features at multiple scales. A detailed analysis at the micrometer scale was conducted to examine the variations in the water velocity, volumetric flow rate, Reynolds number, flow field, and permeability under different porosity and pressure drop conditions. The results indicate that within the studied range of flow velocities and pressures, the fluid flow in all the media models adhered to Darcy’s law. The improvement in structural connectivity in the random pore model has made the flow channels of fluids in the random pore network more diverse, resulting in an increase in the peak water flow velocity from 4.89E–5 m/s to 4.19E–4 m/s. The fluid accelerated while bypassing the protruding solid particles, resulting in the formation of high-velocity zones in the vicinity. As the pressure drop increases, the volume flow rate of the random dual-medium model with a porosity of 0.6 can increase to 1.01E–9 m3/s, with the highest growth rate. We also simulate the fluid flow of a regular dual-medium model at different porosities and find that the permeability rapidly increases from 5.65E–13 m2 to 1.01E–11 m2, demonstrating that the presence of fractures can significantly improve the permeability performance of the medium. The research findings deepen our understanding of the migration behavior of water in complex geological environments and provide theoretical guidance for groundwater resource protection and underground engineering.

Enhanced control and efficiency in millimeter-scale composite droplets preparation

A microfluidic device utilising the flow focusing method was designed and fabricated for the high-throughput and controllable preparation of millimeter-scale water-in-oil (W1/O/W2) droplets. Two distinct flow focusing modes were employed in order to prepare the composite droplets. In the flow-focused axisymmetric jetting mode, the continuous phase propels the dispersed phase, forming a cone, which subsequently leads to a jet formation downstream of the small hole. When the outer phase is activated, perturbation growth interferes with downstream fragmentation, resulting in composite droplets with excellent monodispersity. In the dripping mode, the dispersed phase fails to form a jet downstream, and the interface disintegrates, resulting in droplet formation at the exit of the small orifice. In the jetting mode, the size and shell-to-core ratio of the generated droplets can be controlled by adjusting the volume of flow of the outer and inner phases, as well as the applied frequency. Furthermore, the applied perturbation allows for precise control of droplet size, which significantly reduces satellite droplet formation and enhances droplet monodispersity. In the dripping mode, the shell-to-core ratio is adjusted by manipulating the ratio of inner to outer flow rates, which is tailored to the specific requirements of the flow-focused dripping mode. The prepared compound droplets exhibit good monodispersity. Finally, the rotational solidification method can be employed to obtain spherical shells with a shell thickness of less than 20 μm. In conclusion, the flow focusing method is an effective, controllable, and stable method for synthesising millimetre-sized composite droplets.

"Wire kissing technique" and "externalization and pull-through technique" for treating chronic total occlusion in hemodialysis vascular access: A case report.

The construction and utilization of dependable vascular access are essential for hemodialysis. Despite its importance, complications with vascular access are common, significantly impacting patient morbidity and mortality. This report presents a novel approach to treating chronic total occlusion (CTO) in hemodialysis vascular access using the "wire kissing technique" an "externalization and pull-through technique." An 82-year-old woman on hemodialysis had a thrombotic obstruction in her cephalic vein, which conventional methods failed to address. The wire kissing technique allowed the meeting of antegrade and retrograde wires within the CTO lesion, stabilizing the wire and facilitating balloon passage. The externalization and pull-through technique further enabled the balloon to cross the rigid CTO lesion, successfully completing percutaneous transluminal angioplasty (PTA). Post-procedure ultrasonography showed significant improvements in flow volume and resistance index. These techniques, commonly used in coronary and femoral arteries, have not been previously reported for dialysis vascular access. This case highlights a novel and effective solution for overcoming technical difficulties in crossing CTO lesions, potentially improving outcomes in vascular access for hemodialysis patients.

DETERMINING THE PERFORMANCE OF A HEAT EXCHANGER USED IN THE FOOD INDUSTRY

The study of heat transfer in the food industry is as important as in any other industry. Food products are constantly subjected to heat treatments. For this reason, a sunflower food oil, which undergoes heat treatment in the manufacturing process, was chosen for this study. The study was carried out on a laboratory plant and aimed to determine the heat transfer coefficients for three sets of determinations: partial heat transfer coefficient inside - where the warm sunflower oil circulates, partial heat transfer coefficient in the annular space - where cold water circulates and overall heat transfer coefficient, in a tube-in-tube heat exchanger made of copper. The obtained values of heat transfer coefficients were compared with literature data for the same type of food oil. This type of heat exchanger, tube-in-tube, is specific to the food industry. Countercurrent circulation of flows through the appliance was established from the outset, as this type of circulation is preferred from the point of view of determining the performance of heat exchange appliances. Efficiency values were also established for the three sets of experimental determinations. For the calculations, the values for the temperatures of the fluids, both at the inlet and outlet of the apparatus and the values for the volume flow rates of the fluids were required.

Simulation study of flow and heat transfer in wavy microchannel heat sink with manifolds and secondary channels composite

With the continuous increase in power density of electronic devices, traditional cooling methods have gradually shown their limitations. Microchannel heat sinks (MCHSs) have enormous potential in thermal management for electronic devices due to their excellent heat dissipation performance. To improve the flow and heat transfer performance of MCHSs, a numerical study was conducted on 56 types of wavy microchannel heat sinks with manifolds and secondary channels composite (WMCHS-MSCs). The results indicate that compared to the original manifold wavy microchannel heat sink (MWMCHS), the optimal WMCHS-MSC increases the thermal enhancement factor by 45.1 % when the inlet volume flow rate Q = 1.0 × 10−6 m³/s. At the same time, the overall thermal resistance, the maximum temperature difference on the bottom wall, and the pressure drop of the optimal WMCHS-MSC are reduced by 7.6 %, 21.9 %, and 10.6 %, respectively. Compared to the original MWMCHS, the increase in Q for WMCHS-MSCs results in an overall trend of increased thermal performance, decreased temperature non-uniformity and hydraulic performance, and initially increased and then decreased overall performance. The flow field distribution of the secondary channels of WMCHS-MSCs intuitively demonstrates the improved hydraulic and thermal performance brought about by disrupting the thermal boundary layer and mixing the flow. The study presents a novel approach for the design of wavy MCHSs, potentially paving the way for enhanced thermal management solutions in electronic devices.

Assessment of Sonographic Parameters for Predicting Primary Patency Rate in Hemodialysis Patients With Venous Valve-Related Stenosis.

Ultrasonography is more frequently used in patients with arteriovenous fistula (AVF) stenosis. The aim of this study is to use sonographic parameters for predicting primary patency in hemodialysis patients with venous valve-related stenosis (VVRS) who are treated by ultrasound-guided percutaneous transluminal angioplasty (PTA). A total of 229 VVRS patients who underwent PTA between January 2017 and December 2021 were enrolled. Clinical characteristics were retrospectively collected. Sonographic parameters were measured both before and after PTA. Univariate and multivariate Cox analyses were performed to identify independent factors associated with primary patency rate. All measured sonographic parameters improved after PTA compared to before PTA. Before PTA, the diameter of VVRS > 1.0 mm, age ≤ 57 years, and body mass index (BMI) > 21.57 kg/m2 were associated with better outcomes. While the diameter of radial artery, proximal radial artery close to the anastomosis, brachial artery, the flow volume of brachial artery, the length and peak velocity (PV) of the VVRS, and the diameter and PV after the VVRS had no association with the primary patency rate. After PTA, only patients with a diameter of VVRS > 4.0 mm had favorable outcome. In addition, patients with a gain of diameter of VVRS > 2.4 mm after PTA had a trend of better outcomes. The diameter of VVRS before and after PTA could be served as markers to predict primary patency rate and second patency rate in AVF patients with VVRS. The gain of diameter of VVRS could also be a potential marker. Using simple markers of sonographic parameters, we could quickly identify patients with a higher risk of restenosis. These patients should be followed more closely in case of restenosis at early. It is also beneficial to the prevention of thrombosis. These measures help to preserve more valuable vascular for a long-term dialysis. Additionally, the physician should pay more attention on the dialysis-related complications in these risky patients, such as hemodialysis-related hypotension.

Study of an Impedance Function for Mixed Traffic Flows Considering the Travel Time–Cost Characteristics of Long-Distance Electric Vehicle Trips

To quantify the travel time and cost characteristics of mixed traffic involving electric vehicles (EVs) and fuel-powered vehicles on roads, in this paper, we comprehensively consider three factors affecting road impedance: queue length, waiting time, and service rate. Initially, a time characteristic function and a cost characteristic function for mixed traffic impedance are constructed. From the perspective of travel time, we consider the impact of EV penetration on the actual road capacity and introduce a capacity coefficient to modify the BPR (Bureau of Public Roads) road impedance function. Given that different types of vehicles might need to wait at charging stations, we employ queuing theory to calculate the queuing time at these stations and construct an impedance model that considers travel time. From the perspective of travel costs, we account for the energy consumption costs and road usage fees for different types of vehicles. The energy consumption cost for travel mileage is obtained by multiplying the unit mileage energy consumption cost of mixed traffic by the travel mileage. For road usage fees, we adopt the conventional method of multiplying the per-kilometer rate for each vehicle type by the travel mileage, thus constructing an impedance model that incorporates travel costs. Finally, in the numerical analysis section, based on the vehicle travel mileage, we categorize travel into short-, medium-, and long-distance trips for analysis. With the constructed mixed traffic impedance model, we conduct a detailed analysis of the travel time and cost characteristics of mixed traffic over different travel distances. We explore the specific impacts of the electric vehicle penetration rate, traffic flow volume, and travel mileage on road impedance. The results indicate that as the penetration rate of electric vehicles increases, the total energy consumption of the transportation system significantly decreases. Moreover, at high electric vehicle penetration rates, although an increase in traffic flow leads to higher traffic impedance and longer travel times, the overall travel costs are reduced. This demonstrates that increasing the penetration rate of electric vehicles positively contributes to reducing the energy consumption and costs of transportation systems.

Water Lily-Inspired CNT@cotton towel solar evaporator with Marangoni effect and optimal water supply for achieving zero liquid discharge desalination and irrigation

Solar-driven interfacial evaporation is an environmentally friendly technology to address the global water scarcity crisis by efficiently purifying unavailable water resources (seawater, brackish water, high salinity wastewater and various water resources). However, the inevitable contradiction between salt deposition and highly efficient water evaporation during long-term desalination remains a major challenge. In this work, we report a self-floating bionic water lily evaporator with zero liquid discharge, consisting of CNT@cotton towel with the uneven-gap structure as the photothermal material and the square groove insulation foam with controllable water supply as edge-preferred crystallization support. The formed four-building-in ramp structure generates different surface tensions along the whole ramp and brings Marangoni flow. With the combination of Marangoni flow and optimal water supply volume, salt is spatially isolated from the CNT@CT surface, the biomimetic design can achieve continuous water evaporation and salt collection (79 g m-2h−1) for 84 h in 10 wt% NaCl under edge-preferred crystallization. The purified water meets drinking water standards and is applied to growing crops. This distinctive solar evaporator provides new insights for designing a low-cost and zero-liquid-discharge evaporator, advancing its application in high-saline brines, various water resources, and irrigation.

Deep, Comprehensive and Free Trade With The Euroepan Union For The Agricultural Sector of Georgia, Is it a Threat or an Opportunity Expansion?

In the article - "Deep, comprehensive and free trade with the European Union for the agricultural sector of Georgia, is it a threat or an opportunity expansion?" - the question raised is discussed from the perspective of the future development of Georgian agriculture. The article mentions that no country in the world can develop properly without foreign trade. So is Georgia. Therefore, the association agreement signed by the European Union with Georgia gave it wide opportunities to expand trade in the European Union countries and, therefore, to develop the economy. The article mentions that in Georgia agriculture, that is, the agro sector, is considered a priority field. The country should focus on the agricultural sector to expand exports to the European Union. Implementation of this policy has begun, but it faces many obstacles. In the article, it is substantiated by proper calculation that today the agro-food products of Georgia are not competitive in the European Union market. The reason for this is high costs, low quality, small volume of export flows and others. In turn, this is caused by the abundance of small farmers in the agro sector of Georgia, who are easily defeated in the market by large European agro-firms of the same profile. The article ends with the statement that no positive transformation has taken place in the agro-sector of Georgia associating with the European Union. The share of EU markets in its exports is minimal. Moreover, large European Union companies, which have the opportunity to sell products at a low price, are gradually capturing the domestic food market of Georgia. Keywords: Opportunity and threat; Agro-food products; EU market; Concurrency.

Thermodynamic and entropy generation analyses of Telsa-valve structured meso-scale combustors fuelled with hydrogen for thermophotovoltaic applications

The present work numerically examed the effects of hydrogen volume flow rates (Qv) and equivalence ratios (Φ) on thermal performances of meso-scale combustors structured with Tesla-vale type flow channels. Four distinct Tesla-valve configurations are implemented and then subsequently compared. The reverse-flow Tesla valve with counter-flow combustor (RC) structure shows a remarkable improvement of 72.6 % to the combustor wall temperature at Qv = 100 mL/min. The diodicity (Di) of the Tesla valve is found to be increased with a higher Qv, and a lower Φ contributes to a higher Di. Besides, Di is decreased when Φ goes up, stabilizing at Φ = 0.9. The reverse-flow Tesla valve exhibits a more uniform pressure distribution and entropy production than the forward-flow Tesla valve. At Φ = 0.9, the hydrogen-to-air ratio maximized heat release, producing the highest entropy. Tesla-valve structured combustors demonstrate near complete combustion before Φ reaching 0.9, the combustion efficiency (ηcombustion) is gradually decreased after Φ getting to 1.0. The RC construction achieved maximum combustion efficiency under conditions of insufficient oxygen. This present study demonstrates the feasibility of enhancing thermal and overall performances of meso-scale combustors structured with Tesla-valve channels, and revealing the key parameters effects on the combustion characteristics in these combustors.