Fault detection model for a variable speed heat pump

The impact of the COVID pandemic has resulted in many people cultivating a remote working culture and increasing building energy use. A reduction in the energy use of heating, ventilation, and air-conditioning (HVAC) systems is necessary for decreasing the energy use in buildings. The refrigerant charge of a heat pump greatly affects its energy use. However, refrigerant leakage causes a significant increase in the energy use of HVAC systems. The development of refrigerant charge fault detection models is, therefore, important to prevent unwarranted energy consumption and CO2 emissions in heat pumps. This paper examines refrigerant charge faults and their effect on a variable speed heat pump and the most accurate method between a multiple linear regression and multilayer perceptron model to use in detecting the refrigerant charge fault using the discharge temperature of the compressor, outdoor entering water temperature and compressor speed as inputs, and refrigerant charge as the output. The COP of the heat pump decreased when it was not operating at the optimum refrigerant charge, while an increase in compressor speed compensated for the degradation in the capacity during refrigerant leakage. Furthermore, the multilayer perception was found to have a higher prediction accuracy of the refrigerant charge fault with a mean square error of ± 3.7%, while the multiple linear regression model had a mean square error of ± 4.5%. The study also found that the multilayer perception model requires 7 neurons in the hidden layer to make viable predictions on any subsequent test sets fed into it under similar experimental conditions and parameters of the heat pump used in this study.

Failure to respond to a coral disease epizootic in Florida: causes and consequences

Stony coral tissue loss disease (SCTLD) was first observed in September 2014 near Virginia Key, Florida. In roughly six years, the disease spread throughout Florida and into the greater Caribbean basin. The high prevalence of SCTLD and high resulting mortality in coral populations, and the large number of susceptible species affected, suggest that this outbreak is one of the most lethal ever recorded. The initial recognition and management response to this catastrophic disease in Florida was slow, which delayed the start of monitoring programs and prevented coordinated research programs by at least two years. The slow management response was a result of several factors that operated concurrently. First, the Port Miami dredging project was ongoing during the coral disease epidemic and dredging rather than SCTLD was blamed by some managers and local environmental groups for the extreme coral losses reported in the project's compliance monitoring program. Second, this blame was amplified in the media because dredging projects are intuitively assumed to be bad for coral reefs. Third, during this same time State of Florida policy prohibited government employees to acknowledge global warming in their work. This was problematic because ocean warming is a proximal cause of many coral diseases. As a result, the well-known links between warming and coral disease were ignored. A consequence of this policy was that the dredging project provided an easy target to blame for the coral mortality noted in the monitoring program, despite convincing data that suggested otherwise. Specifically, results from the intensive compliance monitoring program, conducted by trained scientific divers, were clear. SCTLD that was killing massive numbers of corals throughout Florida was also killing corals at the dredge site - and in the same proportions and among the same suite of species. While eradication of the disease was never a possibility, early control measures may have slowed its spread or allowed for the rescue of significant numbers of large colonies of iconic species. This coral disease outbreak has similarities to the COVID-19 pandemic in the United States and there are lessons learned from both that will improve disease response outcomes in the future, to the benefit of coral reefs and human populations.

Biogeography of northeastern Atlantic Neogene chitons (Mollusca, Polyplacophora): New data from the Pliocene of Portugal

Based on extensive new material, 2088 valves resulting from search sampling of ~500 kg of sediment, the Pliocene chiton biodiversity of the Mondego Basin (Portugal) is reassessed. Twelve species were identified, assigned to seven genera. Eight species are new for the Pliocene of Portugal, as well as two of the genera: Hanleya, Acanthochitona. Two taxa are described as new: Ischnochiton loureiroi n. sp. and Lepidochitona rochae n. sp. Until now, the polyplacophoran European Neogene record was too poorly known to be of help in generating a clear picture of the Miocene to present-day biogeography of the group. This new wealth of data from western Iberia, in conjunction with recent data from the Loire Basin Upper Miocene assemblages (France), allows clarification the Late Miocene to Recent eastern Atlantic and Mediterranean biogeography of the Polyplacophora. The northern range of warm-water northeast Atlantic and Mediterranean Polyplacophora experienced a sharp contraction since, at least, Late Miocene to Early Pliocene times. Warm-water chiton species represented in the Upper Miocene of the Loire Basin of NE France (European-West African Province) and the Pliocene of the Mondego Basin of central-west Portugal (Pliocene French-Iberian Province) are today confined to the southern Mediterranean-Moroccan Molluscan Province.UUID: http://zoobank.org/a2a550c0-caed-449a-aa45-9492c45f882e

Record-Breaking Slow Temperature Evolution of Spring Water During 2020 and Its Impacts on Spring Bloom in the Yellow Sea

Unprecedented retardation of spring water temperature rising during the 2020 pandemic year was identified in the Socheongcho Ocean Research Station within the northeastern basin of the Yellow Sea: an exceptionally high water temperature anomaly in March and a contrasted low-temperature anomaly in May. The slowest temperature evolution was principally caused by the significant increase in latent heat releases in April (117% higher than the climatology of 1982-2019). Strong northwesterly winds generated these exceptional heat fluxes associated with the dipole-like atmospheric circulation pattern over Siberia and the East Sea (Japan Sea). Besides, warm winter water facilitated the enhanced release of latent heat fluxes as a precondition. The oceanic heat redistribution partially supported the cold anomaly in the surface layer up to the middle of May through positive feedback between the low surface temperature and the active entrainment associated with tidal turbulent mixing. The resultant low temperature at the surface weakened the vertical stratification, both impeding the activation of phytoplankton's photosynthesis albeit under the eutrophic surface layer, consequently resulting in the delayed and suppressed spring bloom during 2020. Since such extreme events are anticipated to occur more frequently under global warming, our results highlight the importance of continuously monitoring multi-disciplinary environmental conditions, climate extremes, and their impact on the Yellow Sea marine ecosystem.

Water Management Best Practices During And After Low or No Occupancy

At the time of this column's writing, public buildings across the country and around the world had been closed or were seeing low to no occupancy. Many states had issued "shelter in place" directives,1 and millions of Americans were working from home. The hospitality industry was hit particularly hard, seeing steep declines in occupancy and a rash of closures. Water stagnation causes several issues. Ordinarily, disinfectant levels in public drinking water can manage harmful bacteria in the distribution system and even help slow or stop its growth in buildings. However, during times of water stagnation, disinfectants can dissipate, leaving building systems vulnerable to increased pathogen growth. Maintaining good water quality, and therefore public health, is top of mind across the globe. It is critical for building owners, operators and water treaters to ensure that building water stagnation does not contribute to increased risk from L. pneumophila and Legionnaires' disease. There are several water management best practices to follow while public buildings have low or no occupancy.

A Study on the Release Persistence of Microencapsulated Tea Tree Essential Oil in Hotel Hot Spring Water

To improve business performance and achieve sustainable development through the concept of hot spring resource reuse, this study investigated the antibacterial effect of alginate-coated tea tree essential oil microcapsules and the effect of alginate microcapsules on the release of tea tree essential oil. The results revealed that 450 μm alginate/tea tree essential oil microcapsules (containing 720 ppm of tea tree essential oil) prepared using microfluidic assemblies effectively inhibited total bacteria, Escherichia coli, and Staphylococcus aureus in hot spring water. For alginate/tea tree essential oil microcapsules prepared under different conditions, at a fixed concentration of cross-linking reagents, the release time increased with the cross-linking time (10 min > 5 min > 1 min). At a fixed cross-linking time, the release time increased with the concentrations of cross-linking reagents (1 M > 0.5 M > 0.1 M). When the concentrations of cross-linking reagents and the cross-linking time were the same, the release time of cross-linking reagents increased with the strength of metal activity (Ca > Zn).

Practitioners' perspective on the prevalent water quality management practices for Legionella control in large buildings in the United States

Managing building water systems is complicated by the need to maintain hot water temperatures high enough to control the growth of Legionella spp. while minimizing the risk of scalding. This study assessed water quality management practices in large buildings in the United States. Surveys conducted with building water quality managers found that more than 85% of buildings have hot water temperatures that are consistent with scald risk mitigation guidelines (i.e., < 122..F/50..C). However, nearly two thirds and three quarters of buildings do not comply with the common temperature guidance for opportunistic pathogen control, i.e., water heater setpoint > 140..F (60..C) and recirculation loop > 122..F (50..C), respectively;median values for both setpoint and recirculation loop temperatures are 10..F (6..C) or more below temperatures recommended for opportunistic pathogen control. These observations suggest that many buildings are prone to Legionella spp. risk. The study also found that 27% of buildings do not comply with guidelines for time to equilibrium hot water temperature, over 33% fail to monitor temperature in the recirculation loop, more than 70% fail to replace or disinfect showerheads, more than 40% lack a written management plan, and only a minority conduct any monitoring of residual disinfectant levels or microbiological quality. Given the rise in Legionellosis infections in recent years, coupled with highlighted water quality concerns because of prolonged water stagnation in plumbing, such as in buildings closed due to COVID-19, current management practices, which appear to be focused on scald risk, may need to be broadened to include greater attention to control of opportunistic pathogens. To accomplish this, there is a need for formal training and resources for facility managers.

Variable Legionella Response to Building Occupancy Patterns and Precautionary Flushing.

When stay-at-home orders were issued to slow the spread of COVID-19, building occupancy (and water demand) was drastically decreased in many buildings. There was concern that widespread low water demand may cause unprecedented Legionella occurrence and Legionnaires' disease incidence. In lieu of evidenced-based guidance, many people flushed their water systems as a preventative measure, using highly variable practices. Here, we present field-scale research from a building before, during, and after periods of low occupancy, and controlled stagnation experiments. We document no change, a > 4-log increase, and a > 1.5-log decrease of L. pneumophila during 3- to 7-week periods of low water demand. L. pneumophila increased by > 1-log after precautionary flushing prior to reoccupancy, which was repeated in controlled boiler flushing experiments. These results demonstrate that the impact of low water demand (colloquially called stagnation) is not as straight forward as is generally assumed, and that some flushing practices have potential unintended consequences. In particular, stagnation must be considered in context with other Legionella growth factors like temperature and flow profiles. Boiler flushing practices that dramatically increase the flow rate and rapidly deplete boiler temperature may mobilize Legionella present in biofilms and sediment.

Assessment of Palm Jumeirah Island’s Construction Effects on the Surrounding Water Quality and Surface Temperatures during 2001–2020

Climate change stressors like rising and warmer seas, increased storms and droughts, and acidifying oceans are rapidly threatening coastal zones, which are the world’s most densely inhabited places. This research assesses the effects of Palm Jumeirah Island (PJI) construction on its surrounding water quality and temperature, using Landsat-7 and 8 spectral and thermal bands for the years 2001, 2014, 2016, 2019, and 2020. To aid in this goal, the changes in water spectral reflectance was observed and interpreted, based on previous research and measurements, to discover the correlation between water quality and its spectral reflectance. Then, the sea surface temperature (SST) was calculated for the years under review and changes in water temperature were evaluated. Finally, the Green Normalized Difference Vegetation Index (GNDVI) and the Normalized Difference Turbidity Index (NDTI) were calculated to estimate water chlorophyll levels and water turbidity, respectively, and changes were observed and interpreted for the time period under review. The present study showed that the PJI construction not only increased the water reflectance in the 0.5–0.8 µm of wavelength, which can be considered to be the increase of suspended sediments and chlorophyll but the water temperature also increased by 7.5 °C during the 19 years. In addition, a gradual increase in the values of GNDVI (by 0.097–0.129) and NDTI (by 0.118~0.172) were observed. A drop in chlorophyll and suspended sediment spectral reflectance and GNDVI and NDTI values were also observed in 2020 compared to 2019 which can be attributed to the 63 to 82% decrease in tourists in Dubai in 2020 as a result of the COVID-19 pandemic. This study aims to draw attention to environmental issues by clarifying the effect of creating artificial islands in the sea and our analysis and results are a suitable reference for specialized hydrological and environmental studies based on spectral information and distance measurements, as presented in this paper.

Discussion on Influencing Factors and Control Range of Disinfection Effect in Waterworks during the COVID-19 Outbreak

This paper studied the influencing factors of disinfection effect in water purification process and the influence of external demand on the water purification process to ensure that the effective virus inactivation rate of waterworks can meet the requirements of microbiological safety during the COVID-19 outbreak. The results showed that the effluent turbidity should be no more than 0. 3 NTU to meet the requirements of coagulation sedimentation filtration process for virus 2-lg removal rate under the condition of the fixed source water temperature and pH value. On the basis of the above,with the monitoring of the effluent turbidity,water level of clean water tank,water quantity of waterworks and residual chlorine by real-time online instruments,the CT value of the clean water tank was controlled and adjusted within an appropriate range in real time,so that it not only met the 4-lg virus inactivation rate but also reduced the risk of disinfection by-products. Finally,a virus reduction rate of above 6-lg was achieved with the treatment process of waterworks,which could meet the biological safety requirements of drinking water during the epidemic,and have a sufficient safety margin.

Healing of Skin Biopsies in Wild Juvenile Green Turtles, Chelonia mydas

Skin biopsies are routinely collected from sea turtles for a variety of molecular analyses;however, almost no information exists on the natural healing rates at the site of the biopsy. Here, we monitored the healing rates of 17 juvenile green turtles (Chelonia mydas) for up to 488 d after we took a 6-mm biopsy tissue sample in Eleuthera, The Bahamas. Although scarring persisted for several months, biopsy sampling had a minimal long-term impact—tissue repair and maturation was observed after a year and a half, and there was no evidence of infection at any point during the healing process.