Average Water Temperature Research Articles

Condensate loss estimation and transient solar-to-vapor conversion efficiency for effective performance evaluation of the inclined solar still

Previously, freshwater yields of the solar still were quantified only based on the actual distillate recovery, not considering condensate losses by any means. Likewise, solar-to-vapor conversion efficiencies of the solar still were conventionally considered and evaluated as one-off -rigid values- based on the latent heat of the average water temperature. In most cases, these approaches do not give a comprehensive performance details of the solar still. Thus, we suggest two considerations for effective performance evaluation of the inclined solar still. The first consideration is theoretical estimation of the condensate loss due to the condensate collection channel slope, while the other is the use of a transient method to evaluate the solar-to-vapor conversion efficiency. We demonstrated, geometrically, that the condensate loss on the inclined solar still can be significant—hence the need to consider it alongside the overall yield. We formulated a model to estimate the condensate loss and validated the model by comparing an estimated condensate loss with experimental loss. Similarly, we demonstrated a transient approach to evaluate the solar-to-vapor conversion efficiency by using the latent heat of the hourly water temperature. Accordingly, the optimum hourly efficiency of the investigated solar still prototype was 161.4%, with a daily average of 113.4% versus 108.4% from the conventional method. Overall, no study on the solar still had previously accounted for condensate losses by any means whatsoever, making our current study a reference and a pioneer in this concept and suggesting an advancement in the approach to report the performance productivity of the solar still.•Condensate loss on the inclined solar still due condensate collection channel slope was estimated geometrically and demonstrated to be significant.•Solar-to-vapor conversion efficiency was evaluated using an hourly transient approach.

Spatio-Temporal Variation of Dinoflagellates of the Genera <i>Ceratium</i> (Schrank 1793) and <i>Protoperidinium</i> (Bergh 1881) in Relationship with Some Abiotic Variables in the Atlantic Coast of Kribi (South Region—Cameroon)

A study to list Dinoflagellates species belonging to the genera Ceratium and Protoperidinium and some abiotic factors associated with them was carried out in the Kribi coast from February 2020 to February 2021 following a monthly sampling frequency. For the inventory, 60 L of water including 20 L on the surface, 20 L in the trophogen layer and 20 L in the tropholytic layer were filtered through a sieve of 20 μm and the retentate obtained was fixed whith lugol for identification and counting operations using an Olympus microscope. The morphotypes of the taxa were filmed using an Omax Toupvix eye camera. Physico-chemical results showed very good water oxygenation (89.35%), low Suspended Solid concentration (6.36 ± 4.71 mg/L), basic pH (8.53 ± 0.4 U.C), average salinity of 15.87 ± 3.1 g/L and conductivity around 26.73 ± 4.96 mS/cm. The average water temperature hovered around 29.51°C ± 1.28°C. The average values of nitrates and orthophosphates showed a progressive enrichment of the waters of the studied section with nitrate (1.52 ± 0.87 mg/L) and orthophosphate (1.84 ± 3.98 mg/L). This work allowed to identify 17 species of the genera Ceratium and 22 of Protoperidinium. The genera Protoperidinium was the most diverse while it was the taxa belonging to the genera Ceratium that had the highest densities. Ceratium furca was the only spatially and seasonally regular species with occurrence frequencies of 75.31% and 79.16% respectively. According to similar studies, 06 species reconized harmful were inventoried during this study. These are Ceratium furca, Ceratium fusus, Ceratium tripos, Protoperidinium divergens, Protoperidinium steinii, Protoperidinium crassipes. Temperature and oxygen are the abiotic factors that showed more affinities with the taxa inventoried in view of the significant correlations obtained. With a view to preventing blooms on the Cameroonian Atlantic coast, regular monitoring of the harmful species identified is desirable.

Variability of thermohaline regime of see water of the Gulf of Mexico in 2005-2017

The Gulf of Mexico is a large, productive, marine and coastal ecosystem providing the coastal residents and neighbouring regions with goods and services. The Gulf of Mexico's water area plays a significant role in shaping the climate across the coastal zone and the thermal state of the region's water also has a major impact on development of atmospheric processes over the Atlantic and Europe. Long-term climate variability throughout the Gulf of Mexico may affect both the strength of the Gulf Stream and heat transfer patterns within the ocean and the economic activity and environmental stability of the entire Northwest Atlantic Region. This work aims at determining the characteristics of variability of temperature regime and salinity of the Gulf of Mexico over recent decades.
 The study was conducted based on the Gulf of Mexico Regional Climatology (GOM RC) data, version 2, available at the website of the NOAA's National Centers for Environmental Information (NCEI). It analyzes the temperature and salinity values at different depths for the period of 2005-2017. According to the analysis, over 2005-2017 the spatial distribution of the average annual water temperature on the Gulf of Mexico's surface demonstrates its decrease from south to north. Its highest value is observed next to the northwestern coast of Cuba and along the coastal area of the Bay of Campeche, and the lowest temperature is observed at Apalachee Bay located in the northeastern part of the Gulf of Mexico. Though significant horizontal temperature gradients are observed in winter, during the warm period the temperature field is more homogeneous. The minimum average monthly water temperature on the surface is observed in January, the maximum one – in September. The most distinct seasonal changes in temperature are observed in the water of the northern part of the Gulf of Mexico next to the United States' coast. The distribution of average annual salinity of the most of the Gulf of Mexico is homogeneous with the exception of its northern part, especially in the area where the Mississippi River water flows into it, where salinity decreases sharply. Graphs of water temperature and salinity distribution at different depths across different areas of the gulf were constructed in order to determine the water stratification.

Distribution and diversity of Meiobenthos in southern Caspian Sea (Mazandaran-Iran)

Biodiversity and distribution of benthic Meiobenthos in the sediments of the Southern Caspian Sea were studied in order to introduce and determine their relationship with the environmental factors. From 12 stations (ranging in depths from 5, 10, 20 and 50 meters), sediment samples were gathered for four seasons (2012). Temperature, salinity, dissolved Oxygen and pH were measured during sampling with CTD (conductivity, temperature and Depth). Percentage grain size and total organic matter and calcium carbonate were measured. The average water temperature ranged from 9.52 to 23.93 ͦC, dissolved Oxygen from 7.71 to 10.53 mg/L, salinity from 10.57±0.07 to 10.75±0.04 ppt., pH from 7.44±0.29 to 7.41±0.22, EC from 17.97±0.12 to 18.30±0.04 μs/cm2, TDS from 8.92±0.04 to 9.14±0.02 mg/L, total organic matter from 5.83±1.43 to 6.25±0.97% and calcium carbonate fluctuated from 2.36±0.36 to 1.68±0.19%. From the 4 groups of animals (Foraminifera, Crustacea, Worms and Mollusca), 40 species belonging to 29 genera of 25 families were identified Ammonia beccarii caspica, was the common species in all sampling stations. Depth was an important factor in the distribution of meiobenthos. Mean of maximum and minimum Shannon index were measured at depth of 5m and 50 m and were in the order of 0.93 and 0.43, respectively. Account of Shannon and Peilou's index showed that this area is under pressure and is not steady.

Upper thermal threshold of Lepidurus arcticus (Branchiopoda, Notostraca) in lakes on the southern outreach of its distribution range

The Arctic tadpole shrimp Lepidurus arcticus has a circumpolar distribution and the Scandes (Fennoscandian Mountains) marks its southernmost limit in Europe. Within this area, 391 natural and 88 regulated lakes with L. arcticus have been identified, of which 87% are above the treeline. The lakes hosting L. arcticus decrease in altitude from south to north, which results from its temperature preferences. The majority of the locations are at a lower lake air temperature than 11°C which is equivalent to a water temperature near 14°C. This is assumed to be near the upper thermal threshold for L. arcticus. In lakes that exceed this average summer water temperature (1 July – 15 September), sustainable populations seem to be rare. In warmer lakes, life cycle mismatches are assumed to explain the absence of L. arcticus, most likely by affecting the embryo and juvenile stages. The distribution appears to be dichotomous, with one large northern area north of 65°N and one separated southern “island”. Only two locations of L. arcticus are known for the area between latitudes 62.88 and 64.39°N. In this part of the Scandes, the lakes are likely too warm to host L. arcticus as most of them are situated below 700 m a.s.l. This may also be the case in the northernmost region, north of 70°N, where only 11 populations are recorded. Most of the lakes in this area typically occurs below 400 m a.s.l. L. arcticus populations are sensitive to fish predation, and dense fish populations may be another stressor limiting its distribution. In contrast to water bodies in the High Arctic where L. arcticus only exists in shallow, fishless ponds, in the Scandes they co-exist with fish in 97% of the findings. Global warming has already modified the environment of the Scandes, and populations of L. arcticus are at threat in many of the small and shallow water bodies at low altitudes.

Temperature Estimates of Lower Miocene (Burdigalian) Coastal Water of Southern India Using a Revised Otolith “Clumped” Isotope Paleothermometer

AbstractCarbonate clumped isotope thermometry is based on the ordering of 13C and 18O in the carbonate lattice and is based on the relative abundance of 13C18O16O in CO2 produced through acid digestion of carbonate minerals. The major advantage of this technique is its non‐dependency on the δ18O value of water from which the carbonate precipitated. Ghosh et al. (2007, https://doi.org/10.1016/j.gca.2007.03.015) previously published calibration data for fish otoliths referenced to heated gases and used the Gonfiantini 17O parameter set in their data evaluation. Herein, we present a new clumped isotope (Δ47) calibration for aragonitic fish otoliths in the absolute reference frame using the International Union of Pure and Applied Chemistry 17O correction. Our revised calibration equation for otolith is: . To test the accuracy of this calibration, we apply it to otoliths of modern Lutjanus lutjanus from the Bay of Bengal. The estimated average temperature (22.3°C ± 4.2°C) for the Bay of Bengal and δ18OV‐SMOW composition of waters of −1.7‰ (±0.5) are consistent with the onsite observations. We also apply the new calibration to well‐preserved otoliths of “genus Ambassidarum” sp. and “genus Gobiidarum” sp. from lower Miocene (Burdigalian) sediments of the Quilon Formation, India to quantify coastal water conditions. Estimated average environmental water temperatures in their habitats were 12.9°C ± 1.7°C, and the average δ18OV‐SMOW of ambient waters calculated yielded a value between −3.5‰ and −2.6‰ (V‐SMOW) (mean: −2.9‰ ± 0.4) and −4.4‰, respectively. These results indicate δ18O values reflect the kinetic effects impacting the δ18O of fish otoliths independently of Δ47, although we cannot fully preclude diagenesis.

DIFFERENT DENSITIES OF COMMON SNOOK REARED IN MARINE CAGES IN SOUTHERN BRAZIL

Two growth stages of juvenile snook (Centropomus undecimalis) under three different densities were evaluated: 10, 20, and 40 fish m-3, in 2.5-m3 cages with 12-mm mesh. In phase I, snooks of 72.0 g and 21.2 cm were raised for 270 days. In phase II, snooks of 204.6 g and 29.2 cm were raised for 202 days. The average water temperature and salinity were 24.3°C and 34.5, respectively, at Santa Catarina Island, Brazil. The data were evaluated using regression models. Density increase did not influence survival rate, with 51.0% (phase I) and 88.7% (phase II). The density of 20 fish m-3 provided the best results, such as body weight, in the two phases, with 215.7 and 364.7 g, respectively. Water temperature was the main limiting factor for the growth of snook. Therefore, in a subtropical climate, it is recommended to start growing in the spring (> 24°C) and avoid handling fish when the temperature is below 20°C. Regression analysis on the final weight showed that densities of 24 fish m-3 could be indicated for common snook under the conditions of this study.

Layer-Averaged Water Temperature Sensing in a Lake by Acoustic Tomography with a Focus on the Inversion Stratification Mechanism.

Continuous sensing of water parameters is of great importance to fluid dynamic progress study in oceans, coastal areas and inland waters. The acoustic tomography technique can perform water temperature field measurements horizontally and vertically using sound wave travel information. The layer-averaged water temperature can also be measured with the acoustic tomography method. However, investigations focusing on the stratified mechanism, which consists of stratification form and its influence on inversion error, are seldom performed. In this study, an acoustic tomography experiment was carried out in a reservoir along two vertical slices to observe the layer-averaged water temperature. Specifically, multi-path sound travel information is identified through ray tracing using high-precision topography data obtained via a ship-mounted ADCP during the experiment. Vertical slices between sound stations are divided into different layers to study layer division inversion methods in different preset types. The inversion method is used to calculate the average water temperature and inversion temperature error of every layer. Different layer methods are studied with a comparison of results. The layer division principle studied in this paper can be used for layer-averaged water temperature sensing with multi-path sound transmission information.

The effect of environmental factors on the occurrence and densities of immature stages of Anopheles stephensi (Liston, 1901) and A.pulcherrimus (Theobald, 1902) mosquitoes in Basra city.

The study included collecting monthly samples of the aquatic stage of Anopheles mosquitoes for the period from January 2009 to December 2010 for a number of permanent and temporary stations in Basra city, which included the areas of Al-Faw, Abu Al-Khasib, Shatt Al-Arab, Karma Ali, Al-Sweib and Al-Madina. A range of environmental factors was measured, such as water temperature, salinity, and pH and dissolved oxygen. The monthly changes for a full year showed the effect of these factors on the presence and density of immature stage, so the water of the fixed five sample collection stations tended to be neutral to basic during most of the study period and that it had an oxygen content of 11.2 mg / liter and did not reach the critical limit at any time. The average water temperature ranged from 7.5 to 32.2 degrees, the salinity rates ranged between 2.5 and 5.3 parts per thousand. The results also showed a difference in the distribution and spread of these roles, so it appeared that individuals of the species A. stephensi were more present than the members of the species A.pulcherrimus in Basra city, where the eggs of the A. stephensi appeared in just five months, with a total of 6-25 eggs, and larvae were present in all the study months except for July, the study recorded its highest density in October 2009, which was 277.5 larvae / half liter of water, while the lowest density of 7 larvae / half liter of water was in August, and the virginity density ranged between 1.3-22 virgin / pint of water. Regarding the species A.pulcherrimus, the annual number of eggs ranged between 3-8 eggs, while the highest density of its larvae in March reached 163 larvae / half a liter of water, and the lowest density was recorded at 2/1 pint of water in June and August 2990, and it did not appear in July and September, the annual density of virgins ranged between 0.7 and 19 virgins per liter of water.

CFD and Machine Learning based Simulation of Flow and Heat Transfer Characteristics of Micro Lattice Structures

In this paper, systematic CFD analysis using ANSYS Fluent was carried out to generate the dataset for developing the Machine Learning model, which predicts the average final temperature of water and the pressure drop from the set of input parameters considered for applications. There are six micro lattice structures, kagome, tetrahedral, pyramidal, hexagonal, windward bent and hexagonal-windward bent, modelled for this study using FUSION 360 by Autodesk. The study of heat transfer between liquid water and the micro lattice structures realized with the independent variables, initial fluid flow velocity, lattice temperature, and fluid temperature as well as lattice materials and its different structures. About 2146 output data of average final fluid temperature and the pressure drop were collected from the CFD simulations by varying input parameters. To predict the output parameter against the set of input parameters, Machine Learning model with regression based classification algorithm was adopted while training the ML model. The quality metric of the ML model was calculated using residual sum of squares method. The final average temperature of the fluid and pressure drop as predicted by the ML model is closer to simulated data.

Experimental Study on Thermal Performance of Pre-formed Thin Heating Floor Filled with Shaped PCM

A shape-stabilized phase change material (PCM) with high-density polyethylene was prepared as the supporting material to be added to a pre-fabricated light and dry-type heating floor. A system for underfloor heating experiments was set up in the laboratory to test the effects of average supply and return water temperatures and different temperature differences on the thermal performance of two floor heating systems under 10 different operating conditions, respectively. The results show that the surface heat-flux density of a phase change floor (PCF) is higher than that of an ordinary one at the stable stage. The proportion of heat transfer to the heating room is about 13% higher in the phase change system compared to the normal system, and the heat loss is reduced by more than 10%. At the cooling stage, the surface temperature of PCF decreases slowly, compared to the rapid decrease of the ordinary one.

Assessment of Physico-chemical Properties of Different Water Reservoirs of Barishal City, Bangladesh

There are many man-made water reservoirs found in Barishal City. This study was aimed to assess the existing condition of physico-chemical properties of four different water reservoirs, namely Bibir Pukur (pond), Amtala Lake, Choumatha Lake and City Corporation Pond of Barishal City of Bangladesh. To evaluate the physico-chemical properties, the average of the parameters such as water temperature, total dissolved solids, electric conductivity (EC), pH, salinity, as well as depth, color, and transparency of water were analyzed. The highest average water temperature was found in the City Corporation Pond, which determined as 31.77±0.09 °C. Electric conductivity (ms/cm) and total dissolved solids (ppm) of Amtala Lake were 0.413 ±0.009 and 199±1.15. The highest average pH 7.88±0.01 and lowest salinity 140±1.73 were found in City Corporation Pond and Choumatha Lake respectively. The water depth of Bibir Pukur was 260.33± 13.98 cm which is the highest among the four water reservoirs. The highest values of dissolved oxygen and phosphate were 2.03±0.12 mg/l and 294.12±3.92 μg/l.

A DIVER WITH SWIMMING-INDUCED PULMONARY EDEMA AND CARDIAC ARREST

TOPIC: Occupational and Environmental Lung Diseases TYPE: Medical Student/Resident Case Reports INTRODUCTION: Swimming-induced pulmonary edema (SIPE) is classically considered to be a self-resolving, non-fatal condition that occurs in high exertion surface swimmers and divers. We report an unusual case of a scuba diver who had both SIPE and presumed cardiac arrest. CASE PRESENTATION: A 71-year old man with atrial fibrillation on apixaban, diabetes mellitus, and hypertension developed shortness of breath during a scuba dive at 50 feet of seawater. The maximum dive depth was 70 feet with an average water temperature of 67° Fahrenheit. He ascended per protocol. After being pulled onto the boat, the patient syncopized. Chest compressions and rescue breaths were initiated, and he regained consciousness 2-3 minutes later. Upon EMS arrival, the patient had oxygen saturation by pulse oximetry in the mid-70s. He was placed on 15 L/min of supplemental oxygen and transported to the hospital by helicopter. EKG and telemetry showed atrial fibrillation with a normal rate. Chest radiograph showed pulmonary edema, and CTA chest showed pulmonary edema with no pulmonary embolism. Transthoracic echocardiogram showed an ejection fraction of 55-60%, mild valvular disease, and no evidence of hypertrophy or shunting. Coronary angiogram showed mild non-obstructive coronary artery disease. The patient's hypoxia resolved within 24 hours of presentation, with resolution of the pulmonary edema on repeat chest radiograph. DISCUSSION: Swimming-induced pulmonary edema is primarily thought to be self-resolving and non-fatal. However, this case prompts the question of an association between SIPE and cardiac arrest that has not been described to our knowledge. The patient was presumed to have cardiac arrest, as opposed to non-cardiogenic syncope, given continued loss of consciousness during chest compressions. Coronary angiogram was pursued because the arrest was indistinguishable between sudden cardiac arrest (SCA) and provoked cardiac arrest, for example from hypoxia. SIPE is hypothesized to be a hydrostatic pulmonary edema that occurs due to elevated pulmonary artery pressures from increased peripheral vascular resistance and central redistribution of blood flow. Meanwhile, SCA is typically due to coronary disease, structural disease, or congenital arrhythmias. The absence of these pathologies in this patient suggest that SIPE may have played a distinct role in his SCA. Water immersion has been proposed to cause SCA through "autonomic conflict," whereby simultaneous sympathetic activation from exertion and parasympathetic activation from immersion increases likelihood of arrhythmia. However, the precise impact of SIPE on cardiac activity is not clear. CONCLUSIONS: Swimming induced pulmonary edema may have contributed to this patient's cardiac arrest. The possibility for life-threatening secondary complications of SIPE such as cardiac arrest warrants further investigation. REFERENCE #1: Spencer S, Dickinson J, Forbes L. Occurrence, Risk Factors, Prognosis and Prevention of Swimming-Induced Pulmonary Oedema: a Systematic Review [Internet]. Sport. Med. - Open. 2018 [cited 2021 Apr 28];4(1):43. REFERENCE #2: Moon RE, Martina SD, Peacher DF, et al. Swimming-induced pulmonary edema - Pathophysiology and Risk Reduction with Sildanefil. Circulation [Internet] 2016 [cited 2021 Apr 28];133(10):988–996. REFERENCE #3: Shattock MJ, Tipton MJ. 'Autonomic conflict': a different way to die during cold water immersion? J Physiol [Internet] 2012 [cited 2021 Apr 28];590(14):3219–3230. DISCLOSURES: No relevant relationships by Christopher Androski, source=Web Response Advisory Committee Member relationship with Actelion Please note: $5001 - $20000 by Richard Channick, source=Web Response, value=Consulting fee Consultant relationship with Actelion Please note: $5001 - $20000 by Richard Channick, source=Web Response, value=Consulting fee Advisory Committee Member relationship with Arena Please note: $5001 - $20000 by Richard Channick, source=Web Response, value=Consulting fee Advisory Committee Member relationship with Bayer Please note: $5001 - $20000 by Richard Channick, source=Web Response, value=Consulting fee Advisory Committee Member relationship with United Therapeutics Please note: $5001 - $20000 by Richard Channick, source=Web Response, value=Consulting fee No relevant relationships by Estebes Hernandez, source=Web Response No relevant relationships by Laura Santoso, source=Web Response No relevant relationships by Michael Tripp, source=Web Response

Sand production and building of borehole storage facilities in Russia’s Far North

The environmental problems that arise in the course of gas–condensate and oil field development in the conditions of the Russian Far North are discussed. It is urgent to boost theoretical advancement in the area of design as well as structural and process decision-making when justifying parameters for building underground storage facilities for liquid and solid waste of drilling. Building of borehole storage facilities belongs in the class of physicochemical geotechnologies, which supposes that a part of natural rock mass is removed via a borehole drilled from ground surface (borehole hydraulic technology). The main processes involved in the building are thermal destruction of permafrost sandy and clay rocks and the lift of sand and return water from bottomhole to ground surface. The lifting parameters should ensure removal of sand and water from boreholes at the preset flow rate and at the controlled water–air interface position in compliance with the underground storage facility building program. It is found that the average washout capacity in permafrost sandy rocks during construction of an underground storage facility is linearly dependent on the product of average reduced rate of thermal destruction and average temperature of water in borehole, which proves the accepted washout design procedure. In the zone of a future underground storage facility in permafrost sandy rocks, it is typical that rock properties are highly variable both along and across sand strata. The air-lift parameters depend on the air-lift capacity and on the density of fluid to be lifted. The stable air-lift of sandy slurry is possible when the slurry density is not higher than 1.4 g/cm3, which conforms to the water content round 54 %.

Experimental demonstration of an air-source heat pump application using an integrated phase change material storage as a desuperheater for domestic hot water generation

Heat pumps with a three-media refrigerant/phase change material (PCM) water heat exchanger (RPW-HEX), integrated in the hot superheated section after the compressor, have a promising potential for electric energy savings. The RPW-HEX operates as a desuperheater that stores the sensible energy provided by the hot gas during heating and cooling operation for later heat transfer to domestic hot water (DHW) storage devices. So far, such a system has not yet been implemented and analysed in an overall system suitable for heating, cooling and DHW generation. In the present work, the operation of a prototypical heat pump with integrated RPW-HEX connected to three artificial apartments, was demonstrated in the laboratory under controlled ambient conditions. For this purpose, two RPW-HEX modules with a total storage capacity of about 5kWh were integrated into an R32 air-source heat pump with a heating power of about 7.7kW at −10∘C ambient temperature and a feed water temperature of 45∘C. Technical feasibility and operation with rule-based control strategies have been successfully demonstrated for realistic use cases. Besides individual tests, the heat pump was operated over 48hours with and without RPW-HEX at an ambient temperature of −2∘C, a feed water temperature for the heating system of 40∘C. Both systems, achieved the same average COP, but the system with RPW-HEX was able to provide a 10K higher average feed water temperature for DHW generation compared to the system without RPW-HEX. For the same feed water temperatures for DHW generation, an enhancement of about 3.1% of the average COP can be expected with the current system. This is about 60% of the theoretically possible value. Furthermore, for a low feed water temperature for heating of about 32∘C at −2∘C, an enhancement of the average COP up to 9.4% can be expected for the analysed heating and DHW scenario with an improved design.

THE EFFECT OF PLATE GEOMETRY OF FLAT PLATE SOLAR COLLECTOR UNDER VARIABLE HEAT FLUX

In the current study, the effect of different plate geometry namely smooth plate (traditional model) and V-corrugated plate (new model) on the output of the FPSC is conducted numerically and experimentally. The outdoor experimental work has been done in Baghdad- Iraq. All geometric models and the numerical simulations were carried out in the current study using the commercial CFD method, ANSYS 19. R3. The results indicated that the difference between numerical results and experimental findings is 8.12 % for average water temperature in a tank, while the working fluid temperature at the exist of riser pipe is about 8.36 %. The thermal performance for the new model is found higher than that for traditional model. The thermal performance of new model in terms of water temperature inside the tank was found higher than traditional model by 10.7 %. In addition, the overall thermal efficiency of collector for the new model has been increased about 9.9 % than traditional model.

Nutrient Solution Temperature Affects Growth and °Brix Parameters of Seventeen Lettuce Cultivars Grown in an NFT Hydroponic System

Nutrient solution temperature in a hydroponic system affects °Brix and yield of lettuce; thus, it is important to maintain the water temperature within an appropriate range. Nutrient-film technique (NFT) trials were conducted to investigate the effects of different water temperatures (18.3 °C, 21.1 °C, and ambient) on growth and °Brix of 17 cultivars from five different types (Loose leaf, Romaine, Butterhead, Salanova, and Batavian) of lettuce. The average daily water temperature for ambient treatment was recorded to be 20 to 26.5 °C. The study was conducted in a split-plot design with three replications over time. Results indicated that water temperature affected root and shoot fresh and dry weight, plant width, and °Brix for lettuce. Lettuce grown at 21.1 °C were 15% greater for shoot fresh weight than plants grown at ambient conditions. All the growth and quality parameters of lettuce were found to be affected by cultivars, with “Coastal Star” showing the best results in both growth and °Brix parameters. All the cultivars of the Romaine type showed greater growth and °Brix, while Salanova lettuce did not perform well in all treatments compared to other lettuce types. For CO2 assimilation, the interaction between water temperature and cultivars was significant, with “Parris Island” having the greatest rate at ambient water temperature. These results suggested that maintaining water temperature at 21.1 °C produced lettuce with greater growth and biomass but had 26% lower °Brix than lettuce grown at 18.3 °C.

Late Pleistocene-Holocene fossils from Mirim Lake, southern Brazil, and their paleoenvironmental significance: II – Mollusks

The fossil molluscan assemblages found on the shores of Mirim Lake, in southern Brazil and Uruguay, provide information about the environmental changes and geological evolution of that water body. The storm-generated shell deposits at Latinos Spit on the Brazilian shore are dominated by the estuarine bivalve Erodona mactroides, represented mostly by juveniles, and the gastropod Heleobia australis. Species previously unrecorded in this site include the marine gastropods Cylichnella bidentata, Buccinanops cochlidium and Pachycymbiola brasiliana, and the bivalves Tagelus plebeius, Ostrea puelchana, Crassostrea cf. praia, Mactra isabelleana, Anomalocardia flexuosa and Cyrtopleura costata. The two latter currently inhabit tropical areas to the north of Rio Grande do Sul, and their presence in Mirim Lake indicates average coastal water temperatures about 2–3 °C warmer than today. This condition promoted the precipitation of calcium carbonate from dissolved shells, thus cementing together sand and shells in the form of coquinas. The stratigraphic succession, OSL ages obtained in quartz sand from one coquina, radiocarbon dated shells, and δ13C and δ18O of five E. mactroides and five marine species indicate that Mirim Lake became a brackish lagoon around 7.6 ka ago, in response to the postglacial marine transgression (PMT), followed by fully marine conditions during the sea-level highstand of 6–5 ka BP. Marine influence was reduced after ∼4 ka BP as the result of sea-level fall and the closure of the connection with the ocean, related to the evolution of the sandy barrier that originated the modern shoreline. The environmental changes recorded in Mirim Lake help understand how coastal lagoons and their associated ecosystems respond to sea-level oscillations, which may be relevant to address future responses of these water bodies to the ongoing climate change.

Influence of environmental factors on the development and conservation of sturgeon young

Commercial sturgeon breeding is one of the promising areas of aquaculture. This is not only an integral part of the production of valuable protein products, but also the main source of replenishing the number of sturgeon fish, especially rare and endangered species. This paper examines studies on the influence of environmental factors on the development and safety of sturgeon fry in a sturgeon breeding enterprise in the Krasnodar Territory, carried out on juvenile Russian sturgeon. It was found that the control group was reared for 213 days, the experimental group for 152 days. The average water temperature during the growing period was 20.39°C for the control group and 21. 19°C for the experimental group. The oxygen concentration was at the level of 73.6% in the control group and 76.6% in the experimental one. The pH level in water for the control group was 8.15, for the experimental one – 7.51; the concentration of nitrites for the control group was 0.025, for the experimental group it was 0.017. The average nitrate index is 0.96 and 0.84, in the control and experimental groups, respectively. The weight growth of sturgeons of the first group was higher, with the same initial weight, the final weight of juveniles in the experimental group was 97.4 grams, which is 14.8 grams more than juveniles in the control group. And the weight gain was 174.4% in the control group, and 222.5% in the experimental group. The average linear growth was also higher in the experimental group – 25.8 cm, in the control group – 24.1 cm. The increase in length was 76.7% in the experimental group, 68.5% in the control group. The survival rate of juveniles in the experimental group was 90.7% (136 specimens of Russian sturgeon out of 150), in the control group it was 86%.

An Experimental Study on Operating Characteristic of Radiant Floor Cooling Integrated with Underfloor Ventilation System

In this paper, an experimental study on radiant floor cooling integrated with underfloor ventilation (RFCUV) system was conducted. Indoor environment temperatures, radiant floor cooling system parameters and underfloor ventilation system parameters were measured. Humane thermal comfort was analyzed experimentally. And the effects of disturbance variables and manipulated variables on controlled variables were analyzed. The results illustrated that operative temperature (OT), predicted mean vote (PMV) and predicted percent dissatisfied (PPD) decrease in the first two hours and then become stable in ISO7730 recommended value range. IAT and OT increase with the increasing of the disturbance variables and manipulated variables. The increasing ratio of indoor air temperature (IAT) and OT are relatively small when comprehensive outdoor air temperature is relatively high and indoor heat quantity or average water temperature is relatively low. IAT and OT increase approximately linearly with the increasing of supply air temperature.