Cold water temperature anomalies on the Sodwana reefs and their driving mechanisms

The Sodwana reef system experiences short-term temperature fluctuations that may provide relief from bleaching and be crucial in the future survival of the system. These temperature fluctuations are best described as cold water temperature anomaly events that occur over a period of days and cause a drop in temperature of a few degrees on the reef. We explored the statistical link between the temperature anomalies and the regional hydrodynamics to elucidate the driving mechanisms of the temperature anomalies around Sodwana. Temperature measurements taken between 1994 and 2015 on Nine‑Mile Reef at Sodwana show that temperature anomalies occur on average three times per year at Sodwana and predominantly during the summer months. A conditional average of altimetry data at the peak of the temperature anomalies showed the emergence of a negative sea surface height (SSH) anomaly pattern and associated cyclonic eddy just offshore of the Sodwana region. The cyclonic eddies associated with the temperature anomalies originate on the southwestern edge of Madagascar and migrate westwards until they interact with the African coastline at Sodwana. Instantaneous altimetry SSH fields over the 21-year period were cross-correlated to the conditionally averaged SSH field within a 2° region around Sodwana. It was found that 33% of the temperature anomalies at Sodwana were not associated with the presence of cyclonic eddy systems. This finding suggests that an offshore cyclonic eddy interacting with the shelf is not the sole driving mechanism of the temperature anomalies.

ZOOBENTHOS OF WATERCOURSES IN THE BUKHTARMA RIVER BASIN (UPPER IRTYSH, SOUTH-WESTERN ALTAI) AT REFERENCE SITES AND IN THE IMPACT ZONE

The composition, structure, and spatial distribution of zoobenthos in streams of the Bukhtarma River basin are described and quantitative indicators of benthos in the lower course of the Bukhtarma River are given. The predominance of insects from the orders of mayflies, caddisflies, and freckles is characteristic of the water-courses in the Bukhtarma River basin and is associated with the presence of stony soils in the rivers, rapid flow, moderate-cold-water temperature regime, and high oxygen content in the water – factors that are most favorable for these groups of invertebrates. To assess the ecological state of surface waters in the streams under study by bioindication methods, TBI, BMWP, ASPT, and ERT biotic indices are used. The taxonomic composition of each of the studied watercourses and river sections is formed in accordance with specific environmental conditions associated with natural and anthropogenic factors. It is established that watercourses in the reference areas can be used as reference ones in accordance with the requirements of the EU Framework Water Directive, and the characteristics of invariant States of biocenoses of the lower course of the Bukhtarma River in the impact zone are also given using the criteria of the V. A. Abakumov system of ecological modulations.

Theoretical analysis of an improved adsorption desalination system under different operating conditions

This paper presents the development of an advanced adsorption desalination system (ADS) with heat and mass recovery. By means of internal heat and mass recovery, this adsorption desalination system (ADS), offers a significantly higher performance ratio compared to the conventional systems. After vapor desorption, the pressure difference in the hot bed is first transmitted to the cold bed using mass recovery. Then, the heat from the hot bed is transferred into the cold bed and, eventually, to the condenser and evaporator, by means of the cold water. Numerical simulations for this system are compared to a verified experimental model, and then developed to study the effect of the operating parameters. The level of SDWP or specific daily water production for this ADS was found to be 13.48 m^3/ton of silica gel/day at a hot water temperature of 92.5 (°C) and a cold water temperature of 30 (°C). Consequently, in these operating conditions, the SDWP of the advanced ADS was found to be 153% more than the conventional ADS. Also, at the same temperature conditions, the performance ratio of the ADS with heat and mass recovery was 35% higher than the ADS without heat and mass recovery.

Evaluation of Legionella spp. Colonization in Residential Buildings Having Solar Thermal System for Hot Water Production

Despite an increase of literature data on Legionella spp. presence in private water systems, epidemiological reports assert a continuing high incidence of Legionnaires’ disease infection in Italy. In this study, we report a survey on Legionella spp. colonization in 58 buildings with solar thermal systems for hot water production (TB). In all buildings, Legionella spp. presence was enumerated in hot and cold water samples. Microbiological potability standards of cold water were also evaluated. Legionella spp. was detected in 40% of the buildings. Moreover, we detected correlations between the count of Legionella spp. and the presence of the optimal temperature for the microorganism growth (less than 40 °C). Our results showed that cold water was free from microbiological hazards, but Legionella spp., was detected when the mean cold water temperature was 19.1 ± 2.2 °C. This may considered close to the suboptimal value for the Legionella growth (more then 20 °C). In conclusion, we observed the presence of a Legionnaires’ disease risk and the need of some strategies aimed to reduce it, such as the application of training programs for all the workers involved in water systems maintenance.

Ice-on and ice-off dynamics of ciliates and metazooplankton in the Łuczański Canal (Poland)

The ciliate–metazooplankton trophic coupling is well documented from both laboratory and field experiments. The knowledge about these relationships during winter ice-covered periods is very scarce. The abundance and composition of planktonic ciliates, rotifers and crustaceans were studied during the ice-covered and ice-free periods in the Łuczański Canal (Masurian Lakeland, Poland). We hypothesised that in winter, rotifers play a major role in the top-down control of ciliates and that ciliate–metazooplankton relationships differ not only between the ice-covered and ice-free periods, but also between ice-covered months. Our study showed that ciliates formed a significant part of zooplankton biomass during the winter ice-covered period when crustaceans occurred in very low abundances. Despite cold water temperature and the presence of ice cover, time was probably a cue that initiates zooplankton development. The ciliate, rotifer and crustacean numbers and biomass, as well as chlorophyll a concentrations, were lower in February than in ice-free periods. In the winter month with ice cover, bottom-up control by resources was more important than top-down control by zooplankton grazing in regulating ciliates. In the spring month with ice cover, crustaceans and rotifers may include ciliates as an important part of their diets. In April, the studied groups of organisms were not related to each other in contrast to the summer, when zooplankton communities were closely related to each other. In autumn, rotifers may play an important role in controlling ciliates. The abundance, composition and ciliate–metazoan relationships can vary considerably not only across seasons, but also across ice-covered months.

Financial Analysis of the Use of Two Horizontal Drain Water Heat Recovery Units

The growing interest in the use of unconventional energy sources is a stimulus for the development of dedicated devices and technologies. Drain water heat recovery (DWHR) units can be an example of such devices. They allow the recovery of part of the heat energy deposited in grey water. This paper describes the results of research on the assessment of the financial profitability of the use of two horizontal heat exchanger solutions, taking into account the actual distribution of cold water temperature during the operating year in the plumbing and two operating regimes of the premises as the residential and service facilities. The analysis showed that the use of a horizontal heat exchanger with increased efficiency in a dwelling in a 15-year life cycle allowed for achieving more than twice as much savings (reaching up to EUR 1427) compared to a classic horizontal heat exchanger. At the same time, it was shown that the installation of this type of equipment was more profitable the greater the water consumption of the premises. The article also notes the impact of cold water temperature in the installation on the results of the analysis. It was featured that taking temperature on the basis of installation design recommendations led to significant distortions in the financial analysis. On the other hand, comparing the method of averaging the cold water temperature (daily, monthly and yearly), it was determined that averaging the temperature over the annual cycle was an acceptable simplification of the model. The research results presented in the paper have a practical aspect and may constitute guidelines for designers and potential investors. In addition, they can be an incentive to continue research on heat exchangers by other scientific centers, which on a global scale will increase the universality of their use.

Fabrication of Hot & Cold Water Cum Air Conditioning Dispenser System

In this paper, an experimental work was develop to produce the hot and cold water simultaneously along with them conditioned air is also obtained all the above stated conditions are obtained by using a one third horse power of the compressor that means it is able to produce the hot and cold water along with conditioning air. The single unit are be helpful enough to survive as a water cooler, geyser and air conditioning. This unit are be utilizes the electricity needed for air conditioner and are be able to survive different purpose by this it is possible to reduce electricity consumption. A hot water at a temperature of 80°c, cold water temperature at 4ºc and air condition temperature 22°c are produced with this unit. The thermo couples wants to fixed at different points and a digital temperature indicator (dti) by which temperature is be taken through the dti and could calculated the COP of refrigeration and air conditioning and mass flow rate of refrigerant. A heater is provide which help in varying the loads on the unit through the cop of the unit is calculated at the respective loads.

Heat transfer Augmentation of Gravity Assisted Multi Heat pipe Induced Heat Exchanger

Heat transfer augmentation of a heat exchanger with a multi-heat pipe has been investigated with the influence of gravity assistance. The working fluids used to analyse the performance are methanol and acetone. Water is used as a heat transfer fluid. In which, the analysis is carried out with the gravity-assisted angles of 0º, 45º and 90º. In this work, various parameters such as temperatures of hot water ranges 50ºC, 60ºC, 70ºC, and cold water temperature are observed as 32.5ºC throughout the investigation. Hot water mass flow rates as 40 LPH to 120 LPH with an increase of 20 LPH, cold water as 20 LPH to 60 LPH with an increase of 10 LPH. The result reveals that increase in effectiveness occurs at an angle of 0º for Acetone with 60ºC and 100 LPH is 71.5% of an increase in effectiveness is achieved than methanol for optimum said conditions.

Colonization of Legionella spp. in Hot and Cold Water Networks of Residential Buildings in Pisa District (Tuscany, Italy): A Five-Years Survey

Literature data on Legionella spp. presence in houses water networks have been increasing during the last years, but epidemiological reports assert a high incidence of Legionnaires’ disease infection in Italy. Updating our previously published data, we report a five-year survey on Legionella spp. colonization in 235 buildings with an independent hot water production (IB); 82 buildings with a central hot water production (CB); and 58 buildings with a solar thermal system for hot water production (TB). In all the 375 buildings Legionella spp. was researched in hot and cold water samples and microbiological potability standards of cold water were evaluated. Legionella spp. was detected in 27% of the water networks, mostly in CB and TB. We detected correlations between the presence of bacteria and some physical-chemical parameters (low chlorine level and optimal temperature for Legionella spp. growth). Cold water resulted free from microbiological hazards, except for coliform bacteria isolated in three separate cases, and Legionella spp., detected when cold water temperature was about 20°C. After a five-year survey we confirm the presence of a Legionnaires’ disease risk and the need of training programs for all the workers involved in residential water systems management.