Dense Coverage Research Articles

Optimizing Task Offloading Energy in Multi-User Multi-UAV-Enabled Mobile Edge-Cloud Computing Systems

With the emergence of various new Internet of Things (IoT) devices and the rapid increase in the number of users, enormous services and complex applications are growing rapidly. However, these services and applications are resource-intensive and data-hungry, requiring satisfactory quality-of-service (QoS) and network coverage density guarantees in sparsely populated areas, whereas the limited battery life and computing resources of IoT devices will inevitably become insufficient. Unmanned aerial vehicle (UAV)-enabled mobile edge computing (MEC) is one of the most promising solutions that ensures the stability and expansion of the network coverage area for these applications and provides them with computational capabilities. In this paper, computation offloading and resource allocation are jointly considered for multi-user multi-UAV-enabled mobile edge-cloud computing systems. First, we propose an efficient resource allocation and computation offloading model for a multi-user multi-UAV-enabled mobile edge-cloud computing system. Our proposed system is scalable and can support increases in network traffic without performance degradation. In addition, the network deploys multi-level mobile edge computing (MEC) technology to provide the computational capabilities at the edge of the radio access network (RAN). The core network is based on software-defined networking (SDN) technology to manage network traffic. Experimental results demonstrate that the proposed model can dramatically boost the system performance of the system in terms of time and energy.

The search of genome-wide associations of single-nucleotide substitutions with the productivity of beef cattle

It has been found in scientific papers devoted to the search for new QTL and deciphering their significance and contribution to real indicators in cattle that these loci are most often breed-specific. Detailed research of the molecular genetic characteristics of each breed is an important tool for breeding and improving the efficiency of breeding farms. From the point of view of the choice of the object of study, Kazakh White-headed and Auliekol breeds are of considerable interest, since being related breeds bred for a long time in the same climatic territory, each of them is a carrier of unique productive traits. The purpose of the research was to search for SNP complexes for QTL marking of meat productivity in cattle of Auliekol and Kazakh White-headed breeds of Kazakh breeding based on data from genome-wide DNA typing. The results of SNP typing of cattle of Kazakh White-headed and Auliekol breeds using GeneSeek GGP Bovine 150K biochip with an average coverage density of 150,000 SNP (Illumina Inc., USA) have been presented the article. The genome-wide association study (GWAS) was performed using Plink, a set of genome-wide association analysis tools designed to perform a number of basic large-scale analyses. Sixty seven significant SNPs associated with traits of growth were found. Eight of these SNPs belong to Auliekol breed, 59 to Kazakh White-headed breed. For Auliekol breed significant associations were found for the indicators of live weight at birth, at weaning and live weight of one-year-old bulls (the threshold of significance for all traits was 0.001). In Kazakh White-headed breed was found associations with the live weight at birth, at weaning, as well as the average daily gain of live weight in bulls.

Genome-wide search for associations with QTL of beef productivity in cattle of Kazakh White-headed and Auliekol breeds

Genomic breeding is a very young field of science, which has quickly become the most modern methodology in the world for selecting breeding schemes for farm animals, especially cattle. The high efficiency of genomic selection is due to the identification at an early age of genetically elite animals based on information about the state of single-nucleotide polymorphisms of DNA genome. With the help of increased accuracy of selection at a young age, generation intervals can be shortened and genetic progress in animal husbandry can be signifi cantly accelerated. The purpose of the work was a genome-wide search for associations with QTL of beef productivity in cattle of Kazakh Whiteheaded and Auliekol breeds. The results of the genome-wide search for SNP associations of beef cattle of Kazakh White-headed and Auliekol breeds with QTL responsible for traits of beef productivity have been reflected in the paper. SNP typing of animals was carried out using a GeneSeek GGP Bovine 150K biochip with an average coverage density of 150 000 SNP (Illumina Inc., USA). The genome-wide association study was performed using Plink. Polymorphic sites were annotated with rs identifiers using the SNP ChimpV3 database. Using rs identifiers, polymorphic sites were annotated using the Ensembl database to obtain information about the type of mutation, localization in the gene, potential effect, etc. Identifiers rs were also used to annotate SNPs using QTL using the cattle QTL database. It is shown that in both breeds at a significance level of 0,00001 and 0,001, QTL are detected that are not described in the QTL Cattle DB databases. The analysis of the distribution of significant SNPs by chromosomes was given.

Air flow and sediment transport dynamics on a foredune with contrasting vegetation cover

AbstractWind flow and sediment transport across a northern California beach‐foredune system with two adjacent vegetation types are examined for the same incident wind conditions. The invasive Ammophila arenaria was taller (c. 1 m) with denser coverage than the neighbouring Elymus mollis alliance canopy (c. 0.65 m), which consisted of a variety of interspersed native plants. Wind flow was measured with rotating cup and sonic anemometry, while sediment transport was measured using laser particle counters. Wind speed profiles over the two canopies were significantly different because of differing vegetation height, coverage density, and stem stiffness. In both cases, there was a lower zone of semi‐stagnant air (below about 0.3 m) that transitioned upward to a shear zone comprising the upper part of the canopy and immediately above. The shear zone above the Elymus canopy was relatively thin (confined to 0.3–0.5 m above‐ground) whereas the shear zone in the Ammophila canopy was thicker extending from a height of about 0.5h (h is average plant height) to about 1.5h. Vertical profiles of Reynolds shear stress (RSS) and turbulence kinetic energy (TKE) are consistent with the shear layer structure over these two contrasting vegetation canopies. The degree of topographically‐forced and vegetation‐enhanced flow steering was significant, with Ammophila strongly shifting the highly oblique (55°) incident wind to essentially shore‐perpendicular trajectories. In comparison, the shore‐perpendicular steering effect was not as pronounced for the Elymus canopy. Sediment transport intensity on the beach was continuous, but decreased progressively to the dune toe, and then dropped to essentially zero once the vegetation canopy was encountered (on the stoss slope). Overall, the study illustrates the significant differences in wind flow and turbulence conditions that may occur in contrasting plant canopies on foredunes, suggesting that greater attention needs to be placed on vegetation roughness characteristics in models of foredune morphodynamics and sediment transport potential.

Kelp Forest Distribution in the Nordic Region

Kelp forests are productive coastal ecosystems that provide a range of ecosystem services. Mapping the distribution and area occupied by kelp forests is a critical step to identify their ecosystem functions and services, including their role in the carbon cycle, and to detect changes in their distribution. We compiled quantitative data of the dominant generaLaminariaandSaccharinaacross the Nordic region, allowing us to separate kelp forests (areas with dense or moderately dense kelp coverage) from occurrences of single or few individuals. By fitting boosted regression trees to the compiled data, we modelled and predicted the distribution of kelp forests across the Nordic region. Despite the large scale of the analyses, the models captured well the kelps’ environmental affinities and predicted the presence of kelp forests with high accuracy. Dense kelp forests are found along the rocky shores of all the Nordic countries, except in the brackish Baltic Sea, with largest areas in Norway, Greenland and Iceland. The results of this study set the scene for future studies on the importance of kelp forests in the Nordic region, including their contribution to the marine carbon budget.

Images of the East African Rift System by Global Adaptive‐Resolution Surface‐Wave Tomography

AbstractIn this study we map the entire East African Rift System (EARS) within a global surface‐wave velocity model to better constrain the structure of the underlying mantle, as well as patterns that might be associated with its continuation in the Mozambique Channel. We use all publicly available seismograms from the African continent, amounting to 1296 stations and more than 30 years of recordings. From these data, we obtain dispersion curves using both ambient noise and teleseismic earthquakes. To our measurements, we add global counterparts and jointly invert them for phase‐velocity maps. We exploit a linearized inversion based on the ray theory, with an adaptive parameterization that allows for maximizing the resolution of the final maps based on the density of data coverage. We thus image the main African cratons and also some of the Archean blocks within them. We highlight the discontinuous nature of magmatic activity along the EARS and also display low‐velocity anomalies beneath the Comores Archipelago, Madagascar and Bassas da India volcanic islands and seamounts. This last low‐velocity anomaly is in the direct continuation of the EARS and could unveil an important magmatic system in the Mozambique Channel.

Soil moisture observation in a forested headwater catchment: combining a dense cosmic-ray neutron sensor network with roving and hydrogravimetry at the TERENO site Wüstebach

Abstract. Cosmic-ray neutron sensing (CRNS) has become an effective method to measure soil moisture at a horizontal scale of hundreds of metres and a depth of decimetres. Recent studies proposed operating CRNS in a network with overlapping footprints in order to cover root-zone water dynamics at the small catchment scale and, at the same time, to represent spatial heterogeneity. In a joint field campaign from September to November 2020 (JFC-2020), five German research institutions deployed 15 CRNS sensors in the 0.4 km2 Wüstebach catchment (Eifel mountains, Germany). The catchment is dominantly forested (but includes a substantial fraction of open vegetation) and features a topographically distinct catchment boundary. In addition to the dense CRNS coverage, the campaign featured a unique combination of additional instruments and techniques: hydro-gravimetry (to detect water storage dynamics also below the root zone); ground-based and, for the first time, airborne CRNS roving; an extensive wireless soil sensor network, supplemented by manual measurements; and six weighable lysimeters. Together with comprehensive data from the long-term local research infrastructure, the published data set (available at https://doi.org/10.23728/b2share.756ca0485800474e9dc7f5949c63b872; Heistermann et al., 2022) will be a valuable asset in various research contexts: to advance the retrieval of landscape water storage from CRNS, wireless soil sensor networks, or hydrogravimetry; to identify scale-specific combinations of sensors and methods to represent soil moisture variability; to improve the understanding and simulation of land–atmosphere exchange as well as hydrological and hydrogeological processes at the hillslope and the catchment scale; and to support the retrieval of soil water content from airborne and spaceborne remote sensing platforms.

Characterization of Distant and Moderate Earthquakes with Inexpensive MEMS Sensors: Application to the Mw 6.3, 29th December 2020, Petrinja Event.

In this work, we evaluate the suitability of a new MEMS sensor prototype, called ASX1000 (ADEL s.r.l., Modena, Italy), for the monitoring of distant and moderate seismic events. This device is an inexpensive capacitive accelerometer with a relatively low level of instrumental noise; it can record both local and far seismic events. An experimental network built with ASX1000 MEMS, located in northern Italy, was able to record the Mw 6.3 Petrinja earthquake that occurred in December 2020; it had an epicentral distance of more than 350 km. We retrieved the strong motion parameters (PGA, pseudo-absolute velocity, and pseudo-absolute spectral acceleration) from the acceleration time histories recorded by the MEMS sensors. The obtained parameters were compared with the ones obtained by the closer high-quality seismometers, belonging to the INGV National Seismic Network. The comparison to the highest-quality sensors confirms a reasonable agreement of the inferred parameters. This work suggests that—in the near future—MEMS sensors could be adopted to integrate the existing seismic network. A denser coverage of sensors can sample more accurately the seismic wavefield, taking into account the large spatial variability of local geology and the relative differences in seismic response.

Microstructural, interfacial, biological and electrical activity in sputtered Hydroxyapatite-Barium strontium titanate bilayered thin films

The article reports bilayered thin films of Ca10(PO4)6(OH)2, and Ba0.5Sr0.5TiO3 as coatings for implants in biomedical use. The films are fabricated using radio frequency magnetron sputtering, and two deposition conditions: Ba0.5Sr0.5TiO3 layer on top, Ca10(PO4)6(OH)2 beneath (both of same thickness), and Ca10(PO4)6(OH)2 layer on top and Ba0.5Sr0.5TiO3 beneath are considered in the study. The deposited films are then analyzed for their microstructural, surface, and electrical properties, along with their biocompatibility. In the microstructural analysis, the top layer of the films showed dominance in the X-ray diffraction pattern, and the scanning electron micrographs revealed highly dense uniform coverage over the substrates, a characteristic of sputtered films. Furthermore, the bilayers displayed hydrophobicity and are manifested in their excellent cell viability (>100%) that improved substantially with time. The dielectric properties revealed a modest dielectric constant in the range of 35–45, which can generate an internal polarized field that can assist the fracture healing process in the absence of the external stimulation. These insights help understand the role of electrical properties for healing wounds, which are scarcely studied but are found to play a dominant role in biomedical applications. In conclusion, the loss mechanisms in the films (leakage current) are analyzed to determine the parameters regulating the decay of polarized fields that can delay the healing process. The article essentially blends two critical phenomena: the hydrophobicity and electrical properties that are sparsely considered for understanding their biological implications that may aid in generating smart and advanced biomedical devices.

Measuring the availability of human resources for health and its relationship to universal health coverage for 204 countries and territories from 1990 to 2019: a systematic analysis for the Global Burden of Disease Study 2019

SummaryBackgroundHuman resources for health (HRH) include a range of occupations that aim to promote or improve human health. The UN Sustainable Development Goals (SDGs) and the WHO Health Workforce 2030 strategy have drawn attention to the importance of HRH for achieving policy priorities such as universal health coverage (UHC). Although previous research has found substantial global disparities in HRH, the absence of comparable cross-national estimates of existing workforces has hindered efforts to quantify workforce requirements to meet health system goals. We aimed to use comparable and standardised data sources to estimate HRH densities globally, and to examine the relationship between a subset of HRH cadres and UHC effective coverage performance.MethodsThrough the International Labour Organization and Global Health Data Exchange databases, we identified 1404 country-years of data from labour force surveys and 69 country-years of census data, with detailed microdata on health-related employment. From the WHO National Health Workforce Accounts, we identified 2950 country-years of data. We mapped data from all occupational coding systems to the International Standard Classification of Occupations 1988 (ISCO-88), allowing for standardised estimation of densities for 16 categories of health workers across the full time series. Using data from 1990 to 2019 for 196 of 204 countries and territories, covering seven Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) super-regions and 21 regions, we applied spatiotemporal Gaussian process regression (ST-GPR) to model HRH densities from 1990 to 2019 for all countries and territories. We used stochastic frontier meta-regression to model the relationship between the UHC effective coverage index and densities for the four categories of health workers enumerated in SDG indicator 3.c.1 pertaining to HRH: physicians, nurses and midwives, dentistry personnel, and pharmaceutical personnel. We identified minimum workforce density thresholds required to meet a specified target of 80 out of 100 on the UHC effective coverage index, and quantified national shortages with respect to those minimum thresholds.FindingsWe estimated that, in 2019, the world had 104·0 million (95% uncertainty interval 83·5–128·0) health workers, including 12·8 million (9·7–16·6) physicians, 29·8 million (23·3–37·7) nurses and midwives, 4·6 million (3·6–6·0) dentistry personnel, and 5·2 million (4·0–6·7) pharmaceutical personnel. We calculated a global physician density of 16·7 (12·6–21·6) per 10 000 population, and a nurse and midwife density of 38·6 (30·1–48·8) per 10 000 population. We found the GBD super-regions of sub-Saharan Africa, south Asia, and north Africa and the Middle East had the lowest HRH densities. To reach 80 out of 100 on the UHC effective coverage index, we estimated that, per 10 000 population, at least 20·7 physicians, 70·6 nurses and midwives, 8·2 dentistry personnel, and 9·4 pharmaceutical personnel would be needed. In total, the 2019 national health workforces fell short of these minimum thresholds by 6·4 million physicians, 30·6 million nurses and midwives, 3·3 million dentistry personnel, and 2·9 million pharmaceutical personnel.InterpretationConsiderable expansion of the world's health workforce is needed to achieve high levels of UHC effective coverage. The largest shortages are in low-income settings, highlighting the need for increased financing and coordination to train, employ, and retain human resources in the health sector. Actual HRH shortages might be larger than estimated because minimum thresholds for each cadre of health workers are benchmarked on health systems that most efficiently translate human resources into UHC attainment.FundingBill & Melinda Gates Foundation.

New palaeodirections and palaeointensity data from extensive profiles through the Ediacaran section of the Volyn Basalt Province (NW Ukraine)

SUMMARY Changes in the geomagnetic field over geologic timescales can be used to study the evolution and processes of its sources in Earth's deep interior. As a stark contrast to the geomagnetic field behaviour of the recent past, the field in the late Neoproterozoic is defined by ambiguous polar wander paths, ultralow field strengths and a period of extreme reversal hyperactivity. Palaeointensity data from this time are still scarce and conclusions made from these data suffer from large uncertainties brought by a low sampling density. In this study, we present new palaeomagnetic and palaeointensity data from quarry outcrops and five deep drill cores, covering the longest and most complete profiles through the Ediacaran units in the Volyn Basalt Province (NW Ukraine) to date. Palaeodirectional analysis of thermal and alternating field demagnetization experiments reveals at least six reversals in the profile as well as four palaeopoles that agree with previously published poles. Whole-rock palaeointensity estimates are derived from a multimethod approach that utilizes thermal and microwave Thellier experiments performed using Coe and IZZI protocols as well as Wilson and double-heating Shaw experiments. These produce instantaneous site-mean palaeointensity estimates in the range of 2.1 ± 0.4 to 11.1 ± 3.5 µT and virtual dipole moments in the range of 0.31 ± 0.06 × 1022 to 1.67 ± 0.53 × 1022 A m2. Small-scale variations of palaeointensities throughout the profile not only show extremely weak field strengths around polarity changes but could also suggest that the field strength never fully recovered between reversals. These new results increase the density of intensity data coverage for Baltica in the Late Ediacaran and, in combination with previously published Ediacaran dipole moments, support an extremely weak field that seems to increase in strength towards the Ediacaran–Cambrian transition.

Construction of an ultra-high-density consensus genetic map and analysis of recombination rate variation in Sorghum bicolor

Abstract. Satrio RD, Nikmah IA, Fendiyanto MH, Pratami MP, Awwanah M, Sari NIP, Farah N, Nurhadiyanta. 2022. Construction of an ultra-high-density consensus genetic map and analysis of recombination rate variation in Sorghum bicolor. Asian J Agric 6: 47-54. Sorghum is one of the most widely grown cereal crops on a global scale. A consensus map is a method for combining genetic information from multiple populations, and it is an effective way to increase genome coverage and marker density. This study constructed a consensus map by combining publicly available marker data from four mapping populations. A total of 3449 non-redundant polymorphic markers at the nucleotide level were used to construct a single consensus map on 10 sorghum chromosomes. This study generated an ultra-high-density sorghum consensus map consisting of a large number of markers spanning 1571.68 cM and averaging one marker per 0.46 cM. Due to the high density of the markers, it is only 0.06% of the markers had an interval greater than 5 cM. The rates of local recombination were estimated using a set of all markers genetic and physical positions along each of the 10 chromosomes. The analysis of the recombination rate on 10 sorghum chromosomes revealed that it decreased as the centromere position was getting closer. The consensus map generated in this study can be used to integrate information related to sorghum genetic resources and QTLs to the genome sequence, thereby accelerating the discovery of novel potential genes in sorghum.

Private electoral finance and democratic theory

Private electoral finance and democratic theory

Intraoperative microseizure detection using a high-density micro-electrocorticography electrode array.

One-third of epilepsy patients suffer from medication-resistant seizures. While surgery to remove epileptogenic tissue helps some patients, 30–70% of patients continue to experience seizures following resection. Surgical outcomes may be improved with more accurate localization of epileptogenic tissue. We have previously developed novel thin-film, subdural electrode arrays with hundreds of microelectrodes over a 100–1000 mm2 area to enable high-resolution mapping of neural activity. Here, we used these high-density arrays to study microscale properties of human epileptiform activity. We performed intraoperative micro-electrocorticographic recordings in nine patients with epilepsy. In addition, we recorded from four patients with movement disorders undergoing deep brain stimulator implantation as non-epileptic controls. A board-certified epileptologist identified microseizures, which resembled electrographic seizures normally observed with clinical macroelectrodes. Recordings in epileptic patients had a significantly higher microseizure rate (2.01 events/min) than recordings in non-epileptic subjects (0.01 events/min; permutation test, P = 0.0068). Using spatial averaging to simulate recordings from larger electrode contacts, we found that the number of detected microseizures decreased rapidly with increasing contact diameter and decreasing contact density. In cases in which microseizures were spatially distributed across multiple channels, the approximate onset region was identified. Our results suggest that micro-electrocorticographic electrode arrays with a high density of contacts and large coverage are essential for capturing microseizures in epilepsy patients and may be beneficial for localizing epileptogenic tissue to plan surgery or target brain stimulation.

Investigation of surface endothelialization on nitinol: Effects of composite hydrogel coatings

BackgroundDue to high metal coverage and high mesh density，flow diverters (FD) are widely used for endovascular reconstruction of cerebrovascular disease. However, incomplete endothelialization, restenosis, and thrombosis hamper the long term clinical success. Thus, an effective coating to accelerate the endothelialization of the cerebrovascular FD raw materials and reduce the incidence of thrombosis and restenosis is needed. MethodsA novel composite hydrogel composed of matrigel and sodium alginate (SA) with different blending ratios, which was cross-linked with calcium chloride, was successfully prepared. The hydrophilicity of the coating surface was detected by measurement of the contact angle, and the surface morphology of the nitinol (NiTi) before and after modification was characterized by scanning electron microscopy (SEM). The elastic modulus was utilized to verify the mechanical properties and plasticity of the coating, and the release experiment was conducted to characterize the composite hydraulic coagulation. Additionally, biocompatibility was tested by in vitro cellular experiments. ResultsThe SEM observations showed that when the concentrations of matrigel and SA were 5 and 3 mg/ml, respectively, cross-linking with 40 mg/ml calcium chloride solution was resulted in formation of the uniform M/SA composite hydrogel coating. The contact angle of M/SA-NiTi was only (32.28 ± 1.55°) (P < 0.0001), indicating a strong hydrophilicity of M/SA-NiTi. The 48 h coating release rate is 61.5%. In addition, M/SA-NiTi exhibited to have better biocompatibility and plasticity than B-NiTi and M-NiTi. ConclusionsMatrigel/sodium alginate composite hydrogel coating has good biocompatibility and low thrombosis characteristics, and strong drug-carrying capacity, which is expected to accelerate the endothelialization after FD implantation. It has also a great potential application value in the surface modification of biological materials.

Preparation of Non-Toxic Fluorescent Peptide-Coated Silica/PEG Nanoparticles from Peptide-Block Copolymer Conjugates

Peptide-decorated nanosystems have demonstrated higher stability and improved cellular uptake as compared to bare NPs and appear highly promising in diagnostics and theranostics of cancer. Herein, we discuss the preparation and structural characterization of peptide-functionalized silica/PEG NPs, starting from peptide–block copolymers, prepared in turn by conjugation of the peptides to block copolymers before NP formation. This synthetic design allowed full control of density and composition of peptide surface coverage. Preliminary experiments support the low toxicity of the fluorescent peptide–NPs and their ability of cell internalization.

CROWDSOURCED WIFI FINGERPRINT LOCALIZATION IN URBAN CANYON

Abstract. Although Global Navigation Satellite System (GNSS) has achieved success in outdoor localization, it does not often work well in urban canyon, which is due to the weak signals and the loss of satellites. WiFi technology is widely used at present, and the crowdsourced WiFi data has the advantages of rich sources and low cost. Therefore, utilizing the crowdsourced WiFi data for localization may effectively improve the deficiency of GNSS in the urban canyon. In this paper, we propose a novel method of crowdsourced WiFi fingerprint localization in urban canyon. Considering that the crowdsourced data is noisy, discontinuous and unstable, we carry out pre-processes for data refining, and grid-based statistical method for noise smoothing. Then in order to quickly locate the terminals in large-scale area, the AP coverage intersection method is proposed, in which the coverage range, centers and density of all APs are inferred, and the personal hotspots as well as the mobile APs are removed. To further enhance the positioning accuracy, the fine localization is carried out, which is based on the iterative KWNN algorithm. Extensive field tests are carried out in a typical urban canyon, results show that the average positioning error of our method is 16.82 m, which shows the effectiveness of the proposed method for crowdsourced positioning in urban canyon.

Comparative Study on Potential Landslide Identification with ALOS-2 and Sentinel-1A Data in Heavy Forest Reach, Upstream of the Jinsha River

Many SAR satellites such as the ALOS-2 satellite and Sentinel-1A satellite can be used in Interferometric Synthetic Aperture Radar (InSAR) to identify landslides. As their wavelengths are different, they can perform differently in the same area. In this study, we selected the alpine canyon heavy forest area of the Baishugong–Shangjiangxiang section of the Jinsha River with a strong uplift of faults and folds as the study area. The Small Baseline Subset (SBAS)–InSAR was used for landslide identification to compare the reliability and applicability of L-band ALOS-2 data and C-band Sentinel-1A data. In total, 13 potential landslides were identified, of which 12 potential landslides were identified by ALOS-2 data, two landslides were identified by Sentinel-1A data, and the Kongzhigong (KZG) landslide was identified by both datasets. Then, the field investigation was used to verify the identification results and analyze the genetic mechanism of four typical landslides. Both the Duila (DL) and KZG landslides are bedding slip, while the Jirenhe (JRH) and Maopo (MP) landslides are creep–pull failure. Then, the difference between ALOS-2 and Sentinel-1A data on KZG landslide was compared. A total of 35,961 deformation points on the KZG landslide were obtained using ALOS-2 data, which are relatively dense. Meanwhile, a total of 7715 deformation points were obtained by Sentinel-1A data, which are relatively scattered and seriously lacking, especially in areas with dense vegetation coverage. Comparing the advantages of ALOS-2 and Sentinel-1A data and the identification results of potential landslides, the reliability and applicability of ALOS-2 data in the identification of potential landslides in areas with dense vegetation cover and complex geological conditions were confirmed from the aspects of vegetation cover, topography, field investigation, and comparative analysis of typical landslides.

Enhanced adsorption and colorimetric detection of tetracycline antibiotics by using functional phosphate/carbonate composite with nanoporous network coverage

This work presents efficient tetracycline (TC) antibiotics adsorption using a functional porous phosphate/carbonate composite (PCC). The PCC was fabricated by anion-exchange of phosphate on the surface of vaterite-phase calcium carbonate particle scaffolds. The PCC, having dense nanoporous network coverage with large surface area and pore volume, exhibited excellent TC adsorption in solution. Its adsorption isotherm fitted well to the Freundlich model, with a maximum adsorption capacity of 118.72 mg/g. The adsorption process was spontaneous, endothermic, and followed pseudo-second-order kinetics. From the XPS analysis, the hydrogen bonding and surface complexation were the key interactions in the process. In addition, a colorimetric TC detection method was developed considering its complexation with phosphate ions, originating from PCC dissolution, during adsorption. The method was used to detect TC in mg/L concentrations in water samples. Thus, the multifunctional PCC exhibited potential for use in TC removal and environmental remediation.

Exploration and tuning of Al2O3/Mo composite for enhancement of anti-corrosion and tribological characteristics in zinc phosphate conversion coatings

Recently, phosphate conversion coatings have been modified by transition/non-transition metal oxide with distinguished characteristic features such as corrosion resistance, wear resistance, lubrication and adhesion. The present paper explores the development of Al2O3/Mo composite incorporated zinc phosphate coatings on galvanized steel for achieving higher corrosion-resistant characteristics with an added advantage of tribological performance. Incorporation of Mo leads to the phase transformation from γ to α-Al2O3, which ensures the subsequent crystallization of alumina particles by the anisotropic grain growth of Mo content. Particle size, elemental composition and morphology of the Al2O3/Mo composite are tuned for retaining the stable crystalline alpha phase of the composite. The optimum concentration of the tuned content of Al2O3/Mo composite in the phosphating solution can effectively perform as an active nucleating source for the establishment of more compact, homogeneous and dense zinc phosphate crystal growth and coverage in the galvanized steel surface by significantly reducing the activation energy during the phosphating process. The resultant composite phosphate coating ensures the formation of a large quantity of crystalline hopeite rich phase compared to other coatings, which effectively acts as an insulator during the electrochemical reaction by imparting a corrosion-resistant barrier between the substrate and corrosive media. Uniform distribution of composite particles at the grain boundaries and at the bulk grain composition is also achieved. Lower average surface roughness (Sa), root mean square surface roughness (Sq), maximum height (St), surface skewness (Ssk) and higher surface kurtosis (Sku) values are acquired for better anti-corrosion properties with excellent tribological performance. The higher Rp and Rct values with lower Cdl and corrosion rate values of the tuned composition of Al2O3/Mo composite based zinc phosphate coating confirms the better porosity and thereby enhances the corrosion-resistant performance due to the sealing action of the composite.