Preparing Sampling Points for Sampling

The increase of temperature might affect the distribution and reproduction of seagrass. This research aims to determine the seagrass bed coverage and the ecosystem condition. Three line transects were established perpendicular to the coastal line with the distance of 50-100 m, or up to the border of the intertidal area. In each transect, sampling points were determined with a distance of 10-20 m. At the sampling points, a plot of 50 cm x 50 cm was established to measure the coverage percentage of seagrass vegetation. The seagrass species were also observed and recorded along the line transects. The percentage of seagrass coverage was measured using a method from Saito and Atobe (1994). The results showed that the coastal area of Jelenga has the highest percentage of seagrass coverage (>60%, healthy) among other coastal areas. This may be caused by the characteristic of Jelenga coast which was relatively calm, few visitors, low water turbidity, and high light penetration. While, other transects have percentage coverage of less than 60% (less healthy). There was one transect on Maluk coast which has coverage percentage of less than 29% (lack of seagrass species). The small coverage percentage on Maluk coast can be caused by the high number of visitors and high activity of fishing boats around the coast which results in high turbidity. Keywords: coverage, ecosystem condition, seagrass bed, west Sumbawa.

Download Full-text

Influence of Bacau City�s Antropic Activities on the Heavy Metals Concentration Measured on Bistrita and Siret River Sides

Revista de Chimie ◽

10.37358/rc.20.1.7856 ◽

2020 ◽

Vol 71 (1) ◽

pp. 350-354

Author(s):

Alexandra-Dana Chitimus ◽

Florin-Marian Nedeff ◽

Ion Sandu ◽

Cristian Radu ◽

Emilian Mosnegutu ◽

...

Keyword(s):

Heavy Metals ◽

Pollution Sources ◽

Municipal Waste ◽

Sampling Points ◽

River Banks

The main objective of the current research is to determine the content of heavy metals from the Bistrita and Siret River banks, respectively Siret River � in Bridge Holt area, Siret River � canal UHE and Siret River- downstream confluence Bistrita/Siret. The choice of sampling points took into consideration the areas where the pollution sources are located. Established maximum values were not exceeded in the case of mercury in the soil for all three sampling points Siret River � in Bridge Holt area, Siret River � canal UHE and Siret River- downstream confluence Bistrita/Siret. Exceeding values recorded in the sampling points Siret River � in Bridge Holt area, Siret River � canal UHE and Siret River- downstream confluence Bistrita/Siret (for cadmium, nickel and chrome) resulted from discharged residual waters, industrial platforms form Bacau city and the improper storage of municipal waste.

Download Full-text

Herd-Level and Individual Differences in Fecal Lactobacilli Dynamics of Growing Pigs

Animals ◽

10.3390/ani11010113 ◽

2021 ◽

Vol 11 (1) ◽

pp. 113

Author(s):

Emilia König ◽

Virpi Sali ◽

Paulina Heponiemi ◽

Seppo Salminen ◽

Anna Valros ◽

...

Keyword(s):

Species Diversity ◽

Growing Pigs ◽

General Management ◽

Immune Parameters ◽

Sampling Points ◽

Sequencing Technique ◽

Piglet Serum ◽

The Difference ◽

Over Time ◽

Fecal Sampling

We studied the fecal lactobacilli count and species diversity of growing pigs along with immune parameters associated with intestinal lactobacilli. Thirty pigs categorized as small (S, n = 12) or large (L, n = 18) at birth were followed from birth to slaughter in two commercial herds, H1 and H2. Herds differed in terms of their general management. We determined sow colostrum quality, colostrum intake, piglet serum immunoglobulins, and pig growth. We took individual fecal samples from pigs in the weaning and finishing units. We studied lactobacilli count and identified their diversity with 16S PCR. Total lactobacilli count increased in H1 and decreased in H2 between samplings. Lactobacilli species diversity was higher in H1 in both fecal sampling points, whereas diversity decreased over time in both herds. We identified altogether seven lactobacilli species with a maximum of five (one to five) species in one herd. However, a relatively large proportion of lactobacilli remained unidentified with the used sequencing technique. Small pigs had higher lactobacilli counts in both herds but the difference was significant only in H2 (p = 0.01). Colostrum quality was numerically better in H1 than in H2, where colostrum intake tended to be associated with total lactobacilli count (p = 0.05).

Download Full-text

Geological Modeling Method Based on the Normal Dynamic Estimation of Sparse Point Clouds

Mathematics ◽

10.3390/math9151819 ◽

2021 ◽

Vol 9 (15) ◽

pp. 1819

Author(s):

Tiandong Shi ◽

Deyun Zhong ◽

Liguan Wang

Keyword(s):

Point Cloud ◽

Minimum Spanning Tree ◽

Point Clouds ◽

Original Method ◽

Modeling Method ◽

Geological Modeling ◽

Improved Method ◽

Normal Estimation ◽

Sampling Points ◽

Correct Point

The effect of geological modeling largely depends on the normal estimation results of geological sampling points. However, due to the sparse and uneven characteristics of geological sampling points, the results of normal estimation have great uncertainty. This paper proposes a geological modeling method based on the dynamic normal estimation of sparse point clouds. The improved method consists of three stages: (1) using an improved local plane fitting method to estimate the normals of the point clouds; (2) using an improved minimum spanning tree method to redirect the normals of the point clouds; (3) using an implicit function to construct a geological model. The innovation of this method is an iterative estimation of the point cloud normal. The geological engineer adjusts the normal direction of some point clouds according to the geological law, and then the method uses these correct point cloud normals as a reference to estimate the normals of all point clouds. By continuously repeating the iterative process, the normal estimation result will be more accurate. Experimental results show that compared with the original method, the improved method is more suitable for the normal estimation of sparse point clouds by adjusting normals, according to prior knowledge, dynamically.

Download Full-text

Research on heavy metal level and co-occurrence network in typical ecological fragile area

Journal of Environmental Health Science and Engineering ◽

10.1007/s40201-021-00625-w ◽

2021 ◽

Author(s):

Yiwei Zhao ◽

Liangmin Gao ◽

Fugeng Zha ◽

Xiaoqing Chen ◽

Xiaofang Zhou ◽

...

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Human Factors ◽

Human Life ◽

Mining Area ◽

Parent Material ◽

Control Value ◽

Pollution Levels ◽

Soil Parent Material ◽

Sampling Points

AbstractDue to the special sensitivity of typical ecologically fragile areas, a series of human life, mining, and other activities have a greater impact on the environment. In this study, three coal mines in Ordos City on the Loess Plateau were selected as the study area, and the pollution levels of heavy metals in the area were studied by measuring As, Hg, Cr, Cd, Cu, Ni, and Pb in the soil of 131 sampling points. Combined with the concept of “co-occurrence network” in biology, the level of heavy metals in soil was studied using geostatistics and remote sensing databases. The results showed that the concentrations of Hg, Cr, Ni, Cu, and Pb in more than half of the sampling points were higher than the local environmental background value, but did not exceed the risk control value specified by China, indicating that human factors have a greater influence, while Cd and As elements are mainly affected Soil parent material and human factors influence. Heavy metal elements have nothing to do with clay and silt but have an obvious correlation with gravel. Cd, Pb, As and Ni, Cd, Cr are all positively correlated, and different heavy metals are in space The distribution also reflects the autocorrelation, mainly concentrated in the northeast of the TS mining area and the middle of the PS mining area.

Download Full-text

Five-Year Enhanced Natural Attenuation of Historically Coal-Tar-Contaminated Soil: Analysis of Polycyclic Aromatic Hydrocarbon and Phenol Contents

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18052265 ◽

2021 ◽

Vol 18 (5) ◽

pp. 2265

Author(s):

Arkadiusz Telesiński ◽

Anna Kiepas-Kokot

Keyword(s):

Aromatic Hydrocarbons ◽

Natural Attenuation ◽

Soil Analysis ◽

Coal Tar ◽

Soil Samples ◽

Lower Intensity ◽

Sampling Points ◽

Polycyclic Aromatic ◽

Monoaromatic Hydrocarbons ◽

The Mean

The objective of this study was to assess the soil pollution on an industrial wasteland, where coal-tar was processed in the period between 1880 and 1997, and subsequent to assess the decline in the content of phenols and polycyclic aromatic hydrocarbons (PAHs) during enhanced natural attenuation. The soil of the investigated area was formed from a layer of uncompacted fill. Twelve sampling points were established in the investigated area for collecting soil samples. A study conducted in 2015 did not reveal any increase in the content of heavy metals, monoaromatic hydrocarbons (BTEX), and cyanides. However, the content of PAHs and phenols was higher than the content permitted by Polish norms in force until 2016. In the case of PAHs, it was observed for individual compounds and their total contents. Among the various methods, enhanced natural attenuation was chosen for the remediation of investigated area. Repeated analyses of the contents of phenols and PAHs were conducted in 2020. The results of the analyses showed that enhanced natural attenuation has led to efficient degradation of the simplest substances—phenol and naphthalene. The content of these compounds in 2020 was not elevated compared to the standards for industrial wastelands. The three- and four-ring hydrocarbons were degraded at a lower intensity. Based on the mean decrease in content after 5-year enhanced natural attenuation, the compounds can be arranged in the following order: phenols > naphthalene > phenanthrene > fluoranthene > benzo(a)anthracene > chrysene > anthracene.

Download Full-text

Research on Distance Transform and Neural Network Lidar Information Sampling Classification-Based Semantic Segmentation of 2D Indoor Room Maps

Sensors ◽

10.3390/s21041365 ◽

2021 ◽

Vol 21 (4) ◽

pp. 1365

Author(s):

Tao Zheng ◽

Zhizhao Duan ◽

Jin Wang ◽

Guodong Lu ◽

Shengjie Li ◽

...

Keyword(s):

Neural Network ◽

High Speed ◽

High Performance ◽

High Efficiency ◽

Semantic Segmentation ◽

Raspberry Pi ◽

Distance Transform ◽

Testing Stage ◽

Sampling Points ◽

Information Sampling

Semantic segmentation of room maps is an essential issue in mobile robots’ execution of tasks. In this work, a new approach to obtain the semantic labels of 2D lidar room maps by combining distance transform watershed-based pre-segmentation and a skillfully designed neural network lidar information sampling classification is proposed. In order to label the room maps with high efficiency, high precision and high speed, we have designed a low-power and high-performance method, which can be deployed on low computing power Raspberry Pi devices. In the training stage, a lidar is simulated to collect the lidar detection line maps of each point in the manually labelled map, and then we use these line maps and the corresponding labels to train the designed neural network. In the testing stage, the new map is first pre-segmented into simple cells with the distance transformation watershed method, then we classify the lidar detection line maps with the trained neural network. The optimized areas of sparse sampling points are proposed by using the result of distance transform generated in the pre-segmentation process to prevent the sampling points selected in the boundary regions from influencing the results of semantic labeling. A prototype mobile robot was developed to verify the proposed method, the feasibility, validity, robustness and high efficiency were verified by a series of tests. The proposed method achieved higher scores in its recall, precision. Specifically, the mean recall is 0.965, and mean precision is 0.943.

Download Full-text

Behavioral Parameters of Planarians (Girardia tigrina) as Fast Screening, Integrative and Cumulative Biomarkers of Environmental Contamination: Preliminary Results

Water ◽

10.3390/w13081077 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1077

Author(s):

Ana M. Córdova López ◽

Althiéris de Souza Saraiva ◽

Carlos Gravato ◽

Amadeu M. V. M. Soares ◽

Renato Almeida Sarmento

Keyword(s):

Water Samples ◽

Feeding Rate ◽

Anthropogenic Activities ◽

Behavioral Responses ◽

Freshwater Ecosystems ◽

Sampling Point ◽

Total Chloride ◽

Fast Screening ◽

Sampling Points ◽

The Impact

The present study aims to use behavioral responses of the freshwater planarian Girardia tigrina to assess the impact of anthropogenic activities on the aquatic ecosystem of the watershed Araguaia-Tocantins (Tocantins, Brazil). Behavioral responses are integrative and cumulative tools that reflect changes in energy allocation in organisms. Thus, feeding rate and locomotion velocity (pLMV) were determined to assess the effects induced by the laboratory exposure of adult planarians to water samples collected in the region of Tocantins-Araguaia, identifying the sampling points affected by contaminants. Furthermore, physicochemical and microbiological parameters, as well as the presence of inorganic compounds (dissolved aluminum, total barium, total chloride, dissolved iron, total fluoride, total manganese, nitrates, nitric nitrogen, total sulfate, total zinc) and surfactants, were determined on each specific sampling point. The behavioral biomarkers (feeding rate and pLMV) of the freshwater planarians were significantly decreased when organisms were exposed to water samples from four municipalities (Formoso do Araguaia, Lagoa da Confusão, Gurupi and Porto Nacional), sites of the Tocantins-Araguaia hydrographic region—TAHR. Both behavioral biomarkers decreased up to ~37–39% compared to organisms in ASTM medium only. Our results showed that these behavioral biomarkers can be used for fast screening monitoring of environmental samples of freshwater ecosystems, since a decrease in feeding rate and locomotor activity was observed in sites impacted by anthropogenic activities. However, the absence of effects observed in some sampling points does not represent the absence of contamination, since several other classes of contaminants were not determined. In these negative results, the absence of deleterious effects on behavioral biomarkers might only be indicative that the potential presence of contaminants on such sites does not significantly affect the performance of planarians. This fast screening approach seems to be useful to determine contaminated sites in freshwater ecosystems for biomonitoring purposes. This knowledge will help to develop biomonitoring programs and to decide appropriate sampling sites and analysis.

Download Full-text

A Kriging-Assisted Multi-Objective Constrained Global Optimization Method for Expensive Black-Box Functions

Mathematics ◽

10.3390/math9020149 ◽

2021 ◽

Vol 9 (2) ◽

pp. 149

Author(s):

Yaohui Li ◽

Jingfang Shen ◽

Ziliang Cai ◽

Yizhong Wu ◽

Shuting Wang

Keyword(s):

Global Optimization ◽

Pareto Frontier ◽

Kriging Model ◽

Optimization Method ◽

Function Evaluation ◽

Sampling Point ◽

Constrained Global Optimization ◽

Multi Objective ◽

Sample Data ◽

Sampling Points

The kriging optimization method that can only obtain one sampling point per cycle has encountered a bottleneck in practical engineering applications. How to find a suitable optimization method to generate multiple sampling points at a time while improving the accuracy of convergence and reducing the number of expensive evaluations has been a wide concern. For this reason, a kriging-assisted multi-objective constrained global optimization (KMCGO) method has been proposed. The sample data obtained from the expensive function evaluation is first used to construct or update the kriging model in each cycle. Then, kriging-based estimated target, RMSE (root mean square error), and feasibility probability are used to form three objectives, which are optimized to generate the Pareto frontier set through multi-objective optimization. Finally, the sample data from the Pareto frontier set is further screened to obtain more promising and valuable sampling points. The test results of five benchmark functions, four design problems, and a fuel economy simulation optimization prove the effectiveness of the proposed algorithm.

Download Full-text

TDC Implementation Based on Internal Delay Module of FPGA

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.816-817.1063 ◽

2013 ◽

Vol 816-817 ◽

pp. 1063-1068

Author(s):

Rou Gang Zhou ◽

Yun Fei Zhou ◽

Guang Dou Liu ◽

Xiao Tu

Keyword(s):

Nuclear Physics ◽

Measurement Accuracy ◽

Laser Interferometer ◽

Interpolation Method ◽

Time Measurement ◽

Clock Signal ◽

Signal Delay ◽

Digital Conversion ◽

Sampling Points ◽

Stable Performance

Currently the time to digital converter (TDC) integrated in FPGA performs time-to-digital conversion in the carry chain mode and inter-slot offset is caused to be severe by internal wiring in the FPGA. Based on the carry chain interpolation method, this paper proposes the method for using a delay module in FPGA to achieve accurate signal delay. By calculating the phase difference of multi-clock signal between two latch sampling points, the interval between two sampling points was obtained. Experimental results indicate a measurement accuracy of 78ps or 52ps can be reached by precisely collecting time through the delay module in FPGA. Compared to the carry chain interpolation method, this method is significantly advantageous in small inter-slot offset, stable performance and convenient design and can meet the requirement for time measurement or requirement by laser interferometer with a nm-level accuracy in nuclear physics.

Download Full-text