M2 Of Area Research Articles

Stocking density as a possible etiological factor in the development of keel “bubbles” in turkeys

A significant increase in demand among the population for turkey meat makes turkey farming one of the most competitive and economically profitable agribusinesses and the fastest growing segment of poultry farming. The investment attractiveness of growing turkeys increases annually by 20–30 %, and the profitability is from 20 to 25 %. Consumer demand, which ensures a constant sales market, sufficient fodder base, availability of labor resources, and several other factors became prerequisites for the transformation of turkey farming from small homestead enterprises into large industrial complexes, which, as a rule, implement intensive production technology. The desire of the owners to increase profits, using the minimum amount of production space for this purpose, quite often leads to the violation of established sanitary and hygienic requirements, which regulate the density of poultry planting per 1 m2 of area. An increase in the number of animals or birds in a specific territory leads to a deterioration of the body's physiological state and a decrease in resistance. It is also the cause of the emergence and development of diseases, both infectious and non-infectious etiology. With the intensive technology of growing turkeys, there is a rapid growth of muscle tissue, in particular, the sternum, which is much more likely to be injured due to a high density of planting, which can be one of the etiological factors of the formation and development of keel "bubbles."The research was carried out at “Indykat” LLC and “UPG-Invest” LLC, which are located in the village of Kadubivtsi and village Mamaivtsi, Chernivtsi region, as well as the “Dobrobut” MPP of the village. Berezdivtsi of the Lviv region on turkeys of the Big-6 breed, in which the density of planting turkeys was different. To establish the dependence of the number of cases of damage to the bird by the keel "bubbles" on the density of its landing on 30, 60, 90, 120, and 150 days of cultivation, an examination of the entire flock was carried out, which included an examination and palpation of the sternum. During the final period of both females and males rearing, the number of lesions was determined based on the post-mortem examination of the carcasses. It was established that in all experimental farms, the density of poultry housing was more significant than the established sanitary and hygienic norms. The slightest deviation from the regulated indicators, which ranged from 16.7 to 37.5 %, in all age groups, was in the form of LLC “UPG-Invest”, and the largest, from 30.2 to 39.4 %, was in the MPP “Welfare”. The pathology of the keel in turkeys in the form of “bubbles” was clinically manifested from the 61st day of their rearing. The most minor incidence, which ranged from 5.2 to 13.9 %, was in the age group of 61–90 days, increased with age and, in the period from 91 to 120 days, ranged from 15.4 to 20.9 %, and from 121 to 150 days – from 18.4 to 23.9 %. According to such indicators, the average incidence of the indicated age groups in experimental poultry farms was 10.3, 17.4, and 20.6 %, respectively. The least affected (13.1 %) was the poultry at UPG-Invest LLC, where the stocking density exceeded the maximum permissible values by only 0.7–1.2 birds/m2, and the most (18.9 %) was at the MPP farm “Dobrobut”, in which the density of accommodation was more significant than the established sanitary and hygienic standards by 1.3–2.6 birds/m2.

CEMETERY OF THE COSSACK AGE ON THE MIDDLE DNIEPER

In 2006, the Stayky team of the Northern Expedition of the Institute of Archaeology discovered the multi-layered settlements on the edge of the plateau north of the village and on the Dnieper islands opposite it and carried out the rescue excavations of the well-known center including the various settlements and a Cossack cemetery. The materials of the settlement structure have already been published, as well as the exploration of the historical and cultural heritage of the settlement. The paper describes the results of research of the cemetery.
 During the campaign ca. 250 m2 of area with 26 burials made according to the canons of Christian rituals have been unearthed. They have no grave goods, except, probably, of burial 16, just below of which a coin blank or demonetized product and a silver Riga solid from the Baltic possessions of Sweden, minted in 1653 by Queen Christina, were found. The absence of other synchronous materials in the layers of the site allows to connect these finds not with the settlement structures but with the cemetery. And the single artifacts of previous ages, collected in two graves, belong to the surrounding layer.
 Despite the partial destruction of some burials by the quarry and the damage of shallow pits by further household activities it was observed that the skeletons laid supine with arms crossed on the chest or abdomen, although during skeletonization the arms could move to the pelvis and along the body. Certain deviations are noted in the position of the head and lower jaw in particular.
 The graves are 0.35—0.90 m deep, the deceased were directed with the head to the west with a slight deviation to the south, usually associated with the seasonal place of the Sun above the horizon. Gender and age differences have not been traced by the depth or direction of burials, although a higher concentration of graves, possibly a family plot, was found in one of the excavation area. Mutual overlaps of burials are few, although the damage of some graves with a moving of bones was observed. Processing of anthropological materials by specialists allowed to trace the peculiarities of ethnic features and physical development of the inhabitants of the site.

Measuring harvest residue accumulations at New Zealand’s steepland log-making sites

Background: When harvesting plantation forests of Pinus radiata (D.Don) in New Zealand, large residue piles commonly accumulate on or adjacent to processing sites. While the merchantable volume that is transported to market is carefully measured, little is known of the quantity of the piled, residual material. A working knowledge of residues is becoming more important as it is not only a potentially merchantable product for the bioenergy market, but when stored in perpetuity it can present a risk of self-ignition, and specifically on steep slopes, it presents a mobilisation risk if not stored correctly. Methods: The area, bulk volume and depth of residue piles at 16 recently harvested steepland sites were measured from a wide geographic spread across New Zealand. Unmanned Aerial Vehicle imagery was used to build georeferenced photogrammetric models of residue piles (94 per cent of the studied volume). Pile area was determined from interpreting boundaries from orthophotos and volumes determined by interpolating the obscured terrain surfaces on duplicate photogrammetric models. The remaining 6 per cent of pile volume was measured with handheld GPS tracking of the perimeters and on-site estimation of average pile depth. Results: For a mean harvest area of 18.9 ha, there was a mean of 2.4 piles per harvest site, 2600 m3 bulk volume and 2900 m2 of area covered. For every hectare harvested, a bulk volume of 170 m3 is piled at the landing, or alternatively, 0.23 m3 of bulk pile volume per tonne harvested. The manual terrain interpolation methodology was tested against collecting georeferenced pre-harvest terrain surfaces, yielding an average difference of 19% across two sites and six residue piles. Conclusions: This research demonstrates the ability to investigate the bulk volume and site coverage of landing residue piles with equipment and software tools available to today’s forester. Mean values for pile area and volume are presented to reflect the current state of knowledge and can be a reference point for future initiatives.

Влияние биоудобрения и густоты стояния растений на урожайность люцерны

In this work, under closed ground conditions, experiments were carried out on the dependence of the yield (weight of green mass) of alfalfa on plant density and on the amount of applied biofertilizer prepared according to a special technology based on waste of organic origin. The experiments were carried out under closed ground conditions in five variants, where the plant density had the following values: I variant S1 (average distance between two adjacent plants in one row) 10 cm; S2 (average distance between rows) 10 cm; II option S1 = 8.3 cm; S2 = 8.3 cm; III option S1 = 6.25 cm; S2 = 6.25 cm; IV option S1 = 5 cm; S2 = 5 cm; V option S1 = 4 cm; S2 = 4 cm. The location of plants and the characteristic distance in the control variant was taken identically as in the main variant. For alfalfa plants in the control variant, the value of the scalar standing density was determined, which corresponds to the maximum weight of the harvested green mass. Leaving the standing density, the same as the corresponding control options, as a result of the use of biofertilizer with the calculation of 1 kg per 1 m2 of area, the weight of green mass increased at the same time and the maximum standing density shifted to the right to the side of increasing placement density. This is due to the fact that an increase in the proportion of nutrients has reduced the degree of competition between neighbors. The increase in yield, that is, the increase in the weight of green mass with the use of biofertilizers, was approximately 36%.

The carbon sequestration potential of urban public parks of densely populated cities to improve environmental sustainability

With a rapid increase in population followed by urbanisation and higher land-use demands, there is a shortage of green spaces and urban parks in densely populated cities worldwide. The rise in energy demand and use, especially fossil fuels in the residential and industrial sector, is the leading cause of higher GHG emissions globally. Several decarbonisation methods and frameworks are currently present; however, very few discuss urban parks' role in carbon capture and storage. In this study, the case of Shaheed Zayan Chowdhury Playground of Banani, Dhaka, has been studied in-depth to understand the carbon sequestration potential of the existing vegetation and the centre turf of the park. A total of 156 trees of 21 different species alongside the centre turf were studied within the urban park with 1.73 acres or 17,016 m2 of area. The total amount of CO2 equivalent sequestrated over the entire life span of the urban park is equal to 660.8 tCO2e with a rate of 33.24 tCO2e annually. Moringa Oleifera, Mangifera Indica, and Delonix Regia have the highest carbon storage potential and sequestration, while Cassia Fistula's lowest. This is a unique project in Dhaka with highly encouraging results towards decarbonisation through carbon sequestration in such multipurpose urban parks. This project should inspire the C sequestration calculation and potential for other urban parks within Dhaka North City Corporation.

Influence of soil and relief on productivity of clover-timothy herbage

Relevance. The article is devoted to the topical problem of studying the influence of soil conditions and the relief of an agricultural landscape on the yield of clover-timothy herbage on drained soils, knowledge of which makes it possible to optimize the production process of crops in the mode of adaptive landscape farming.Methods and results. The studies were carried out in 1998–2020 at the test site of the All-Russian Research Institute of Reclaimed Lands (VNIIMZ) – a branch of the Federal Research Centre Soil Science Institute named after V.V. Dokuchaev (Tver region), located within the end-moraine hill. The purpose of the research is to study the influence of soil conditions and the relief of the agricultural landscape on the yield of clover-timothy herbage of 1 year of use. Grass productivity monitoring was carried out on a transect – a field crossing the main microlandscape positions (relief elements) and elementary soil combinations of the agrolandscape. Crop productivity and other parameters of the vegetation and soil cover on the transect were taken into account on 30 systematically located plots, within which there are 4 replicates, 23 m2 in area, spaced 10 m from each other.Results of studies on productivity were processed by correlation and multivariate analysis of variance. Studies have shown that the relief and soil features of the agricultural landscape have almost the same effect on the crop yield. Each of these factors, on average, determined 18–16% of the spatial variability in productivity. About 2/3 of the variability in the yield of herbs depends on factors that are difficult to take into account. It was found that the degree of influence of the relief and soils on the yield of grasses is not constant over time and ranges from 2 to 33%. In the time series of observations, periods of synchronous and asynchronous fluctuations in the degrees of influence of soil and relief on the yield were distinguished. Synchronization of temporal fluctuations in the degrees of impact on the productivity of grasses of different elements of the landscape occurs with a decrease in the amount of precipitation and active temperatures. On the basis of the revealed patterns, it is possible to develop measures to adapt technologies for growing perennial grasses to the natural conditions of farms in the mode of adaptive landscape fodder production.

КАРТОГРАФИРОВАНИЕ НАЛЕДЕЙ В ТРАНСГРАНИЧНОМ БАССЕЙНЕ Р. ЧИКОЙ

The basin of the transboundary Chikoy River is the largest in terms of area among the catchment areas of the main tributaries of the Selenga River. The Selenga basin as a whole is characterized by a wide distribution of icing. The paper presents the results of mapping icings and their distribution according to various physical and geographical characteristics. Based on the Landsat-8 satellite imagery for 2019, a cartographic database of icings was compiled for the first time for this territory. The database includes 6,319 objects on a total area of 140 km2. The largest icing is 671.13 thousand m2 in area. The mean value, median, and mode are 22.16, 12.86, and 10.24 thousand m2, respectively. Most of the icings are located at altitudes of 900–1,200 m and on the slopes of the eastern exposure. Icings were not found in the western part of the Chikoy River basin and in the near-top belt of the ridges. Fissure rocks are predominant in the study area, which indicates the leading role of groundwater in the formation of icing. The greatest icing coverage is found in areas with annual precipitation in the range of 350–460 mm and with an average annual temperature of –2.5 ... –3℃. In the landscape structure, icing is common in low- and mid-mountain taiga larch-dark coniferous landscapes. About 80% of the icings are located on the complexes of soddy podburs, podburs, soddy podzols, and other associated soils. The level of icing coverage was found to be not proportional to the natural resources of groundwater, which can be caused by both the imperfection of the original groundwater map and the uncharacteristic manifestation of icing in 2019. The resulting database will become the basis for retrospective and predictive assessments of the icing dynamics in the Chikoy and Selenga River basins.

Intra-Annual Variation in Mesophotic Benthic Assemblages on the Insular Slope of Southwest Puerto Rico as a Function of Depth and Geomorphology

There is limited information on the intra-annual variability of mesophotic coral ecosystems (MCEs), worldwide. The benthic communities, measured as % cover, of two geomorphologically different mesophotic sites (El Hoyo and Hole-in-the-Wall) were examined during 2009–2010 in southwest Puerto Rico. Depths sampled were 50 and 70 m. At each site/depth combination, two permanent transects, measuring 10-m long by 40-cm wide, were surveyed by successive photoquadrants, 0.24 m2 in area. Scleractinian corals, octocorals, macroalgae, crustose coralline algae (CCA), sponges and unconsolidated sediment were the main components along the transects. Significant community differences were observed both among sites and among depths. Differences among sites were greater at 50 m than at 70 m. The El Hoyo site at 50 m was the most divergent, and this was due to a lower coral and sponge cover and a higher algal cover (Amphiroa spp., Peyssonnelia iridescens, turf) relative to the other site/depth combinations. As a consequence, the differences in community structure with depth were larger at El Hoyo than at Hole-in-the-Wall. The communities at 70 m were distinguished from those at 50 m by the greater proportion of the corals Agaricia undata, Madracis pharensis and CCA, and a reduced cover of the cyanobacterium Schizothrix. Temporal variation in the benthic assemblages was documented throughout the year. For both mesophotic sites, the magnitude of change at 50 m was significantly greater than at 70 m. For both depths, the magnitude of change at El Hoyo was significantly greater than at Hole-in-the-Wall. All assemblages experienced almost the same temporal patterns, despite the differences in species composition across sites and depths. Changes in temporal patterns are driven by an increase in the percent cover of the macroalgae Dictyota spp., and a decrease in the percent cover of non-colonized substrata (sand, pavement or rubble). Relatively rapid, intra-annual changes are dictated by the negative correlation between cyclic Dictyota spp. cover and open substrata cover. Other observed mechanisms for rapid community changes in the photoquadrants were diseases and collapses of substrata along with their associated fauna indicating that small-scale disturbance processes may play an important role within MCEs.

Allometric models for estimating leaf biomass of sisal in a semi-arid environment in Kenya

Biomass is a key variable for crop monitoring and for assessing carbon stocks and bioenergy potential. This study aimed to develop an allometric model for predicting the dry leaf biomass of sisal, an agave plant with crassulacean acid metabolism grown for fibre production in the tropics and subtropics and whose biomass can be utilised as a feedstock to produce biogas through anaerobic digestion. The allometric model was used to estimate leaf biomass and productivity across different stand ages in a sisal plantation in semi-arid region in south-east Kenya (annual rainfall 611 mm and temperature 24.9 °C). Based on a sample of 38 leaves, the best predictor for biomass was leaf maximum width and plant height used as a combined variable in a log-log regression model (cross-validated R2 = 0.96 and root-mean-square error = 7.69 g). The mean productivity in nine 26- to 36-month-old plots was 11.1 Mg ha−1 yr−1, which could potentially yield approximately 3000 m3 CH4 ha−1 yr−1. The leaf biomass in 55 field plots (400 m2 in area) ranged from 2.7 to 42.7 Mg ha−1, with mean at 13.5 Mg ha−1, which equals to 6.3 Mg C ha−1. The yielded allometric equations can be utilised for predicting the leaf biomass of sisal in similar agro-ecological zones. The estimates on plantation biomass can be used in assessing the role of sisal plantations as a regional carbon storage. In addition, the results provide reference on the productivity of agave and crassulacean acid metabolism in semi-arid regions of East Africa, where such reports are few.

La cabane no 5 du site paléolithique de Gontsy (Ukraine)

The dwelling 5 is the largest of the six mammoth bone dwellings in the Gontsy Mezinian settlement (Poltava region, Ukraine). The dwelling 5 is a complex structure, consisting of a circular outer perimeter about 8 meters in diameter and a central oval structure of 4.5×3.5 m2 dimensions, separated by an intermediate area. After quickly presenting the Gontsy site, the history of the excavations, the settlement and its spatial organization, and finally the six huts, the paper develops the particular method that is the excavation of mammoth bone swelling, or rather the structure it presents, totally different from stripping a thin occupation level. It has been shown that this structure is a dwelling collapse structure, with an external and inner stratigraphy showing from bottom to top: level of occupancy/level of loess giving flowed from the walls/level bones of the walls having tipped outwards and the inside/level of fragmented bones. The outer edge is a collapsed wall built on a circle of foundation skulls, alveoli planted in the ground, mounted with large bones different depending on the location: wall skulls, mandibles, pelvis, scapulae and long bones, and consolidated by lœss extracted from adjacent pits. The central structure is an oval dwelling, about 15 m2 in area, with an accumulation of burnt bones in the center. Its walls are made up of skulls, tusks, pelvis, scapulae and long bones. In the centre, tusks and reindeer antlers come from the hut's roofing system. The intermediate area, which separates the outer edge from the central area, delivered whole or broken bones, which fell from the outer edge and the central structure. It is also a circulation area with two areas of activity marked by a concentration of stones, flint, dye, rodent bones and mammoth rib fragments. The dwelling 5 also delivered the remains of rodents (hare, marmot) and furry carnivores (polar fox, wolf). Some remains of bison and reindeer are also present. The lithic industry, by its knapping, tooling and raw materials, is no different here from other parts of the settlement and corresponds to an industry of the Mezinian. Stones, in the form of granite and shale slabs or pebbles, are significantly present and are associated with activity areas. A bone industry and adornment elements complete the inventory. The study concludes that the dwelling 5 is a structure consisting of a circular protective enclosure, an intermediate area that is a place of varied activity and a central structure, which is a collapsed swelling. The hypothesis of a ritual structure is totally contradicted by the data.

항공사진 및 지상라이다를 활용한 독도 자갈해빈의 시계열적 변화분석

In this study, the changes in morphology of Dokdo’s gravel beach and its responses due to a storm event were analyzed using the aerial photos and 3D LiDAR data obtained during an ecosystem survey of the Dokdo in 2020. Dongdo Island’s gravel beach, shown by aerial photo analysis, increased in area due to sedimentation after the construction of a dock, but there was no more significant changes in area after having grown to Sutdolbawi inside the dock. The changes in volume of the gravel beach were indicated based on 3D data acquired in May and November 2020. A strong typhoon that passed in September, 2002, caused erosion on the backshore and sedimentation on the foreshore and formed the berm by about 1.5 to 2 m high. The analysis showed that the sedimentation was 94.76 m3 in volume and 329 m2 in area and the erosion was 250.75 m3 in volume and 603m2 in area, which suggested that the overall change of the gravel beach was erosion. The changes in the morphology of the gravel beach on Seodo Island occurred with the seasons along with the changes in area. In addition, berms of different altitudes appeared on the southern and northern sides of the spit, which was also estimated to have formed by the seasonal current direction and wave energy.

Evaluation of structure from motion (SfM) photogrammetry on the measurement of rill and interrill erosion in a typical loess

Structure from motion (SfM) photogrammetry is a cost-effective topographic survey tool capable of producing high-quality 3-dimensional structure of a landform. Yet its application has rarely been reported in rill and interrill erosion at the relatively small spatial scales, especially when taking place in the loess that is vulnerable to erosion. The objective was to examine the accuracy and limits of SfM in quantifying rill and interrill erosion occurring in a typical loess during consecutive rainfall simulations. The loess collected from the plough layer of a cropland in the Loess Plateau of China was packed into a 200 × 100 × 35 cm runoff plot and received simulated rainfall at the intensity of 90 mm h−1 on three slopes of 10°, 15° and 20°. A portable laser scanner (LS) and SfM were used to measure soil surface at every 30 min until rill emergence and after another 30-min rainfall aiming to study rill development. Meanwhile, runoff and sediment samples were collected at the plot outlet and oven-dried to calculate the soil loss. The results showed that the elevation differences calculated by subtracting digital elevation models (DEMs) derived by SfM and LS mainly fell between −2 and 2 mm. Moreover, the root mean square error (RMSE) and mean absolute error (MAE) were mostly smaller than 3 mm, suggesting accurate soil erosion measurement made by SfM at the plot scale. Considering the surface variations, the relative RMSE and MAE, i.e., dividing over the mean elevations measured by LS, were found to decrease as soil erosion proceeded and rills emerged. The rill morphology comparison, however, suggested a better fit of SfM for rills larger than 9 cm in maximum surface width, 6.0 × 10−2 m2 in area and 0.9 × 10−3 m3 in volume. In accordance with DEM comparisons, the soil losses estimated by SfM and LS were statistically similar. Nevertheless, these values were much greater than the amount of sediments collected for the early simulation runs, which might be explained primarily by the settling of loess when subject to heavy rainfall. But as rainfall continued and rills further developed, the misestimations made by LS and SfM remarkably dropped, i.e., from −17.8% to 4.9% and from −18.1% to 4.3%, respectively. These findings suggest a generally higher accuracy of SfM in quantifying rill erosion with more fluctuating soil surface than in interrill erosion measurement.

Life Cycle Based Carbon Footprint Assessment of Indonesian's Geothermal Energy Exploration Project

Indonesia is committed to increase the contribution of renewable energy to at least 23 % of the total Indonesian energy mix by 2025. The geothermal energy resource of Indonesia could potentially help achieve this target, but there are environmental challenges associated with geothermal energy exploration. This study is aimed to estimate the carbon footprint of the geothermal exploration project using a life cycle assessment (LCA) approach. Literature published to date did not consider the use of LCA to specifically assess the environmental impacts of geothermal energy exploration. A geothermal energy exploration project in West Java, Indonesia, has been taken as a case study to conduct an LCA considering four main activities, namely land clearing, access road improvement, slim-hole well pad, and standard-hole well pad construction. ReCiPe impact assessment analysis was used to convert inputs and outputs of these activities to carbon footprints of 1 m2 of area of geothermal energy exploration. The result showed that the total carbon footprint of geothermal energy exploration stages was 53.2 kg CO2-eq/m2/y. The two most significant contributors to carbon footprints were the construction of a standard-hole well pad (56 %) and a slim-hole well pad (43 %). Diesel fuel and chemicals were two main carbon footprint sources of geothermal energy exploration project. In terms of inputs, the utilization of caustic soda for neutralization during the drilling activity contributed 64.5 % of the total carbon footprint, followed by diesel fuel consumption (27 %), bentonite (4.04 %) and barium sulphate (4.43 %) for the high carbon footprint for standard-hole well pad construction. The effective utilization of caustic soda and diesel by preparing standard operational procedure (SOP) and implementing ISO quality and environmental management systems (ISO 90001 and 14001) could increase the environmental performance of geothermal energy exploration.

Morphodynamics of short-lived wetlands of coastal dune slacks, Manawatū, New Zealand

While coastal sand dunes are common in New Zealand, dune slack wetlands are one of the country's most rare and threatened ecosystems, containing a number of rare turf species of seasonally aquatic habitats. To understand changes in such wetlands, historical aerial images were analysed for three study sites along the prograding Manawatū coast and mapped using GIS. Morphometrics, times of origin, turnover and longevity of wetlands were derived. Dune slack wetlands are located amongst depressions in parabolic dune fields, about every 250 m along the coast, have a grand mean of 6130 m2 for area of open water, with a maximum of 8 ha, and are 2.3 times longer than wide, with the long axis mostly oriented 113 degrees from the strandline. They maintain seasonally wet areas for an average of 20–30 years, before being gradually infilled by aeolian sand. New wetlands can recur at the same place as previous wetlands, but adjacent plantations of exotic pines appear to alter their morphodynamics. These results indicate that Manawatū's dune slack wetlands form very dynamic, short-lived ecosystems, which may be internationally unique. They need to be better understood to formulate adequate management initiatives, essential for the perpetuation of the rare plant communities that inhabit them.

Use of unmanned aerial vehicle to calculate soil loss

ABSTRACT Satellite remote sensing systems are widely used in environmental studies for providing regional scale analyses with high temporal resolution. On the other hand, when local small scale spatial studies based on very high resolution data at specific moments are involved, unmanned aerial vehicles have been alternatively adopted. The present case study aimed to carry out the morphometric analysis and quantify the soil loss in two sinkholes located in Oxisol on carbonate rocks of the Paranoá Group, in an agricultural area of Niquelândia, Goiás state, Brazil, using unmanned aerial vehicle, in two periods. From the analyzed satellite images, it was estimated that the emergence period of the sinkholes was between December 2018 and April 2019. Based on the aerial survey carried out, 35.53 m2 of eroded area and 236.89 metric tons of soil loss were observed for the sinkhole 1, as well 299.96 m2 of area and 663.47 metric tons of loss in the first period and 961.66 m2 of area and 4,241.68 metric tons of loss after six months for the sinkhole 2.

Macrophytes banks as potential fish nursery areas in small hydropower reservoirs

Abstract: Aim This study verified if the macrophyte banks found in two reservoirs of small hydroelectric plants (SHPs) have a functional ecological role for the initial development of ichthyofauna. Additionally, we compared the differences in the structure of the fish assemblages along each reservoir compartment and between reservoirs. Methods Sampling was performed in March 2018, in lotic, intermediate, and lentic compartments of Palmeiras and Retiro reservoirs, Sapucaí-Mirim River (SP). Three distinct macrophyte banks in each stretch (triplicates), considering the most representative in terms of composition (recurrency/dominance), were sampled, resulting in 18 samples (nine per reservoir). For fish collection we used a sieve of 1 m2 of area, mesh size of 1 mm, which was manually hauled, from the boat, in the marginal aquatic vegetation (three hauls per sample). Simultaneously, we measured basic limnological parameters with a Horiba U-52 water probe, adjacent to the banks. Results The presence of juveniles of all fish orders found in the river, Characiformes, Siluriformes, Synbranchiformes, Gymnotiformes and Cichliformes, demonstrates that, at least in certain moment of their development cycle, the macrophyte banks are used by species with different ecological requirements. It was observed significant statistical differences in the structure of the ichthyofauna along the longitudinal axes of the reservoirs, but not between reservoirs. The same was seen for the limnological data (PCA). Conclusions The macrophyte banks found in the SHPs reservoirs have a potential role as nurseries for the local ichthyofauna, mainly, but not exclusively, for sedentary species and with parental care. This association is ecologically relevant, given the absence of typical lateral habitats for the initial development of the fish fauna. Additionally, despite the reservoirs small size, spatial organization was also important for the assemblage’s structure, with differences in terms of composition, size and development stages along the distinct sampling stretches.

Visible-light communication using high-power LED panel-lamp and low-complexity MOSFET circuit

A high-power light-emitting diode (LED) panel-lamp connected in series with a low-complexity modulation circuit using metal–oxide–semiconductor field-effect transistor (MOSFET) is proposed for an indoor visible-light communication system. The MOSFET modulation circuit consists of a high-speed MOSFET and a shunt resistor, in which the MOSFET gives a variable load driven by the data bit stream and the shunt resistor can tune the modulation depth of the transmitter. In addition, only focusing optical lens is employed in the receiver but no collimation optical lens is adopted in the transmitter to increase the working area. Although the largest data rate is limited to 2 Mbps, the longitudinal communication distances is as long as 6 m; moreover, the maximum horizontal distance is up to 5 m (~ 78.5 m2 in area) along with 3 m in longitudinal distance at the data rates of 1 Mbps. Compared with the traditional Bias-Tee configuration, the proposed MOSFET configuration leads to a lower data rate but a higher modulation depth as well as much larger working area. To the best of our knowledge, this is the largest working area at such a high data rate with on–off-keying using a single LED luminary without collimation optical lens. The system has the inherent ability to realize pulse amplitude modulation (PAM). The 4-PAM is demonstrated to double the data rates.

Design and development of Phase Change Material (PCM) based hybrid solar dryer for herbs and spices

Herbs (green leafy plant mass) are highly perishable in nature containing more than 80% moisture. Moisture needs to be removed to less than 11% for storing it for longer period of time. A phase change material (PCM) based solar dryer was developed consisting of collector of area 0.64m2 and three trays of 0.42 m2 of area each in the drying chamber. The dryer consists of a real time data acquisition system for recording the temperature, humidity and moisture loss. Collector was also filled with 20 kg paraffin wax as a latent heat storage material for continuous drying after sunshine. Performance of the developed dryer was evaluated by drying fresh mint and coriander leaves having initial moisture content of 82–86 % ( wb) and compared with developed dryer without PCM and shade drying considering both the drying parameters and quality parameters of the dried herbs. The developed dryer with PCM was found to produce significant difference in drying rate (P<0.0001) for both herbs compared to dryer without PCM and shade drying. All the quality parameters in terms of retention of the total phenolic content and flavonoid, magnesium and iron content found to have significance difference (P<0.0001) compared to without PCM and shade drying. The developed solar dryer provides a promising alternative for continual drying of other materials also including herbs even after sunshine hours with real time data acquisition system and also found to be superior in retaining quality.

Herbivorous Crabs Reverse the Seaweed Dilemma on Coral Reefs

Coral reefs are on a steep trajectory of decline, with natural recovery in many areas unlikely.1-3 Eutrophication, overfishing, climate change, and disease have fueled the supremacy of seaweeds on reefs,4,5 particularly in the Caribbean, where many reefs have undergone an ecological phase shift so that seaweeds now dominate previously coral-rich reefs.6-8 Discovery of the powerful grazing capability of the Caribbean's largest herbivorous crab (Maguimithrax spinosissimus)9 led us to test the effectiveness of their grazing on seaweed removal and coral reef recovery in two experiments conducted sequentially at separate locations 15km apart in the Florida Keys (USA). In those experiments, we transplanted crabs onto several patch reefs, leaving others as controls (n= 24 reefs total; each 10-20 m2 in area) and then monitored benthic cover, coral recruitment, and fish community structure on each patch reef for a year. We also compared the effectiveness of crab herbivory to scrubbing reefs by hand to remove algae. Crabs reduced the cover of seaweeds by 50%-80%, resulting in a commensurate 3-5-fold increase in coral recruitment and reef fish community abundance and diversity. Although laborious hand scrubbing of reefs also reduced algal cover, that effect was transitory unless maintained by the addition of herbivorous crabs. With the persistence of Caribbean coral reefs in the balance, our findings demonstrate that large-scale restoration that includes enhancement of invertebrate herbivores can reverse the ecological phase shift on coral reefs away from seaweed dominance.

Assessment of terrace gardens as modifiers of building microclimate

Hard concrete roofs cause excessive heat gain impacting thermal comfort in buildings. Terrace gardens promoting greening at higher levels of built structures are seen as one of the key mitigating strategies for modifying building microclimate and improving urban health. We have undertaken a research project to quantitatively assess the value of a terrace garden in a residential scale. A garden patch of about 15 m2 in area, a typical size available in most urban terraces is developed. Surface temperatures are measured over a period of 15 months between July 2018 to January 2020 using four thermocouple sensors, placed within and outside the garden bed, on and below the roof. We compare the thermal performance of the terrace garden across years, seasons, time of the day, presence or absence of garden bed and type and height of vegetation. The surface temperature data was found to correlate well with the ambient air temperature values. The results show that the terrace garden moderates and stabilises the ceiling temperatures and reduces it by about 2–3 °C in winter months and 5–7 °C in hot summers. The garden also provided nearly 400 g of fresh monthly vegetable harvest per m2 of garden. Further, the cooling impact of the terrace garden with natural, tall, wild vegetation is higher as compared to planted vegetation. The study demonstrates a sustainable approach to terrace garden design at residential scale through quantified dual benefits of temperature control within buildings and urban farming.