scholarly journals Extraction of underwater fragile artifacts: research status and prospect

2022 ◽  
Vol 10 (1) ◽  
Author(s):  
Xue-Qiang Chen ◽  
Ke Xia ◽  
Wenjing Hu ◽  
Ming Cao ◽  
Kai Deng ◽  
...  
Keyword(s):  
Controlled Environment ◽  
First Choice ◽  
Protective Strategy ◽  
Long Time ◽  
Archaeological Artifacts ◽  
Underwater Sites ◽  
Difficult Situations ◽  
Long Term Preservation

AbstractThere are still many difficulties in the recovery and long-term preservation of underwater archaeological artifacts, in situ preservation should be the first choice before further procedures are considered. However, the materials, preservation status, and preservation environment of underwater artifacts are diverse, resulting in many fragile artifacts facing difficult situations. In order to prevent serious damage, it is a safe protective strategy to preserve them in a controlled environment for a long time after excavation. Extraction and transfer of fragile cultural relics are vital parts of this strategy. Due to the complexity of the underwater environment and the vulnerability of fragile artifacts, safety in extraction and transfer still faces enormous challenges. Researchers have developed new materials and technologies to tackle this problem. This paper focuses on introducing and developing prospects to different preservation techniques for fragile artifacts from underwater sites.

scholarly journals Aerosol decadal trends – Part 2: In-situ aerosol particle number concentrations at GAW and ACTRIS stations

2013 ◽  
Vol 13 (2) ◽  
pp. 895-916 ◽  
Author(s):  
A. Asmi ◽  
M. Collaud Coen ◽  
J. A. Ogren ◽  
E. Andrews ◽  
P. Sheridan ◽  
...  
Keyword(s):  
Time Series ◽  
Aerosol Particle ◽  
Particle Number ◽  
Cloud Condensation Nuclei ◽  
Temperature Changes ◽  
Long Time ◽  
Modelling Studies ◽  
Infrastructure Project

Abstract. We have analysed the trends of total aerosol particle number concentrations (N) measured at long-term measurement stations involved either in the Global Atmosphere Watch (GAW) and/or EU infrastructure project ACTRIS. The sites are located in Europe, North America, Antarctica, and on Pacific Ocean islands. The majority of the sites showed clear decreasing trends both in the full-length time series, and in the intra-site comparison period of 2001–2010, especially during the winter months. Several potential driving processes for the observed trends were studied, and even though there are some similarities between N trends and air temperature changes, the most likely cause of many northern hemisphere trends was found to be decreases in the anthropogenic emissions of primary particles, SO2 or some co-emitted species. We could not find a consistent agreement between the trends of N and particle optical properties in the few stations with long time series of all of these properties. The trends of N and the proxies for cloud condensation nuclei (CCN) were generally consistent in the few European stations where the measurements were available. This work provides a useful comparison analysis for modelling studies of trends in aerosol number concentrations.

scholarly journals Mediterranean Sea climatic indices: monitoring long-term variability and climate changes

2018 ◽  
Vol 10 (4) ◽  
pp. 1829-1842 ◽  
Author(s):  
Athanasia Iona ◽  
Athanasios Theodorou ◽  
Sarantis Sofianos ◽  
Sylvain Watelet ◽  
Charles Troupin ◽  
...  
Keyword(s):  
Time Series ◽  
Mediterranean Sea ◽  
Climate Changes ◽  
Salt Content ◽  
Climatic Indices ◽  
Long Time ◽  
In Situ Observations ◽  
The Mediterranean

Abstract. We present a new product composed of a set of thermohaline climatic indices from 1950 to 2015 for the Mediterranean Sea such as decadal temperature and salinity anomalies, their mean values over selected depths, decadal ocean heat and salt content anomalies at selected depth layers as well as their long time series. It is produced from a new high-resolution climatology of temperature and salinity on a 1∕8∘ regular grid based on historical high-quality in situ observations. Ocean heat and salt content differences between 1980–2015 and 1950–1979 are compared for evaluation of the climate shift in the Mediterranean Sea. The two successive periods are chosen according to the standard WMO climate normals. The spatial patterns of heat and salt content shifts demonstrate that the climate changes differently in the several regions of the basin. Long time series of heat and salt content for the period 1950 to 2015 are also provided which indicate that in the Mediterranean Sea there is a net mean volume warming and salinification since 1950 that has accelerated during the last two decades. The time series also show that the ocean heat content seems to fluctuate on a cycle of about 40 years and seems to follow the Atlantic Multidecadal Oscillation climate cycle, indicating that the natural large-scale atmospheric variability could be superimposed onto the warming trend. This product is an observation-based estimation of the Mediterranean climatic indices. It relies solely on spatially interpolated data produced from in situ observations averaged over decades in order to smooth the decadal variability and reveal the long-term trends. It can provide a valuable contribution to the modellers' community, next to the satellite-based products, and serve as a baseline for the evaluation of climate-change model simulations, thus contributing to a better understanding of the complex response of the Mediterranean Sea to the ongoing global climate change. The product is available in netCDF at the following sources: annual and seasonal T∕S anomalies (https://doi.org/10.5281/zenodo.1408832), annual and seasonal T∕S vertical averaged anomalies (https://doi.org/10.5281/zenodo.1408929), annual and seasonal areal density of OHC/OSC anomalies (https://doi.org/10.5281/zenodo.1408877), annual and seasonal linear trends of T∕S, OHC/OSC anomalies (https://doi.org/10.5281/zenodo.1408917), annual and seasonal time series of T∕S, OHC/OSC anomalies (https://doi.org/10.5281/zenodo.1411398), and differences of two 30-year averages of annual and seasonal T∕S, OHC/OSC anomalies (https://doi.org/10.5281/zenodo.1408903).

The Regulation of Restructuring: Corner Brook 1984

1995 ◽  
Vol 13 (3) ◽  
pp. 315-334 ◽  
Author(s):  
G Norcliffe
Keyword(s):  
Labour Force ◽  
Paper Mill ◽  
Social Regulation ◽  
Structural Rigidity ◽  
Single Industry ◽  
Plant Operations ◽  
Long Time ◽  
The Town

Restructuring is interpreted as an act of social regulation involving negotiations amongst corporate interests, labour, and the state. In Corner Brook, Newfoundland, these interests were brought together in 1984 when the long-time owners of the local paper mill, the main employer in this single-industry town, put it up for sale. Restructuring was essential in order to secure the long-term future of the mill and the town, but its achievement in situ required difficult negotiations. The new forms of production needed to modernise the mill entailed greater structural rigidity in plant operations, matched by greater flexibility of the labour force. This goal was to be achieved through costabilisation of the various elements forming the local regime of accumulation, with the local state playing a key role as facilitator, guarantor, and promoter of restructuring. It culminated in the passage of two controversial acts by the provincial legislature to satisfy the demands of the potential corporate purchaser of the mill.

scholarly journals Challenges in Quantifying Changes in the Global Water Cycle

2015 ◽  
Vol 96 (7) ◽  
pp. 1097-1115 ◽  
Author(s):  
Gabriele C. Hegerl ◽  
Emily Black ◽  
Richard P. Allan ◽  
William J. Ingram ◽  
Debbie Polson ◽  
...  
Keyword(s):  
Water Cycle ◽  
Internal Variability ◽  
Anthropogenic Aerosols ◽  
Long Term Stability ◽  
Global Water Cycle ◽  
Ocean Salinity ◽  
Long Time ◽  
Global Water

Abstract Understanding observed changes to the global water cycle is key to predicting future climate changes and their impacts. While many datasets document crucial variables such as precipitation, ocean salinity, runoff, and humidity, most are uncertain for determining long-term changes. In situ networks provide long time series over land, but are sparse in many regions, particularly the tropics. Satellite and reanalysis datasets provide global coverage, but their long-term stability is lacking. However, comparisons of changes among related variables can give insights into the robustness of observed changes. For example, ocean salinity, interpreted with an understanding of ocean processes, can help cross-validate precipitation. Observational evidence for human influences on the water cycle is emerging, but uncertainties resulting from internal variability and observational errors are too large to determine whether the observed and simulated changes are consistent. Improvements to the in situ and satellite observing networks that monitor the changing water cycle are required, yet continued data coverage is threatened by funding reductions. Uncertainty both in the role of anthropogenic aerosols and because of the large climate variability presently limits confidence in attribution of observed changes.

British Skull Base Society Clinical Consensus Document on Management of Head and Neck Paragangliomas

2020 ◽  
Vol 163 (3) ◽  
pp. 400-409
Author(s):  
Simon Lloyd ◽  
Rupert Obholzer ◽  
James Tysome ◽  
Keyword(s):  
Head And Neck ◽  
Skull Base ◽  
Quality Care ◽  
Risk Groups ◽  
Primary Treatment ◽  
Consensus Document ◽  
First Choice ◽  
Long Term Preservation ◽  
Head And Neck Paragangliomas

The management of head and neck paragangliomas (HNPGLs) has changed significantly in recent years. There is, however, an absence of guidance in the literature regarding the optimal means of managing this challenging disease. This consensus document, developed by the British Skull Base Society, sets out recommendations for management of HNPGLs. A preliminary document was produced on the basis of current practice in 3 large UK skull base centers, incorporating relevant peer-reviewed evidence. This document was then modified by discussion within these units, through a national survey of British Skull Base Society members, and through discussion with stakeholders. A consensus was reached on the management of all forms of HNPGL. All patients should be managed by a multidisciplinary team and require initial surgical, endocrine, and genetic assessments as well as magnetic resonance imaging of the head, neck, chest, abdomen, and pelvis. Long-term preservation of function is the primary treatment goal, with conservative management the first choice treatment for most tumors. Radiotherapy is a safe, effective treatment for growing tumors in most cases, although there is a limited role for surgery. Screening of family members in high-risk groups is mandatory. These guidelines should help standardize high-quality care for patients with HNPGLs.

scholarly journals The effect of Substance P/Heparin conjugated PLCL polymer coating of bioinert ePTFE vascular grafts on the recruitment of both ECs and SMCs for accelerated regeneration

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Donghak Kim ◽  
Justin J. Chung ◽  
Youngmee Jung ◽  
Soo Hyun Kim
Keyword(s):  
Substance P ◽  
Vascular Remodeling ◽  
Vascular Grafts ◽  
The Body ◽  
Sd Rats ◽  
Artificial Grafts ◽  
Long Time ◽  
Double Coating

AbstractArtificial vascular grafts consisting of ePTFE have been mainly used in clinics for the treatment of cardiovascular disease. However, artificial grafts can become clogged after a long time due to thrombosis, as graft maturation by endothelialization is limited. The strategy introduced in this study is to induce graft remodeling through interaction between the bioinert graft and the body. The Substance P (SP) and heparin were covalently conjugated with PLCL, an elastic biocompatible copolymer and the Substance P-conjugated PLCL (SP-PLCL) and/or heparin-conjugated PLCL (Hep-PLCL) were vacuum-coated onto ePTFE vascular grafts. To assess the effectiveness of the coating, coated samples were evaluated by implanting them subcutaneously into SD-Rats. Coatings allow grafts to be remodeled by creating a microenvironment where cells can grow by infiltrating into the grafts while also greatly enhancing angiogenesis. In particular, a double coating of Hep-PLCL and SP-PLCL (Hep/SP-PLCL) at four weeks showed markedly improved vascular remodeling through the recruitment of mesenchymal stem cells (MSCs), vascular cells (ECs, SMCs) and M2 macrophages. Based on these results, it is expected that when the Hep/SP-PLCL-coated ePTFE vascular grafts are implanted in situ, long-term patency will be assured due to the appropriate formation of an endothelial layer and smooth muscle cells in the grafts like native vessels.

scholarly journals Lyophilization as a method for pathogens long term preservation

2007 ◽  
pp. 203-210 ◽  
Author(s):  
Mirjana Milosevic ◽  
Sladjana Medic-Pap ◽  
Maja Ignjatov ◽  
Dragana Petrovic
Keyword(s):  
Pseudomonas Syringae ◽  
Plant Material ◽  
Freeze Drying ◽  
Plant Pathogens ◽  
Development Stage ◽  
Vegetable Crops ◽  
Nutritive Medium ◽  
Long Time ◽  
Long Term Preservation

Lyophilization (freeze-drying) is one of the most suitable methods used for a long term preservation of pathogens. The aim of this paper was the application of lyophilization for storage of three significant plant pathogens: Fusarium graminearum, Helminthosporium gramineum, and Pseudomonas syringae pv. gylicinea, respectively. The plant material was collected continuously (during a four year period 2002-2006), depending on a plant development stage, from different localities in Vojvodina. Pathogens were isolated from diseased parts with characteristic symptoms, and placed on nutritive media specific for a certain pathogen, using standard phytopathological methods. Lyophilization was carried out in marked and coded ampoules by freezing and drying of pathogen suspension and nutritive medium. Revitalization of lyophilized isolates was done after four days. High percentage of revitalization was characteristic for all studied isolates, and it ranged from 85-92%, confirming that lyophilized pathogens would be capable of keeping viability for a long time in the collection. Besides above mentioned pathogens, there were 200 isolates in the collection, originating mostly from field and vegetable crops. Each isolate that was put into the Collection, was followed by all the necessary data such as: name of the pathogen, number of isolates, locality, host plant year of isolation, name of the researcher and other relevant data.

The Role of Surface Layers in Glass Leaching Performance

1990 ◽  
Vol 212 ◽  
Author(s):  
J. K. Bates ◽  
W. L. Ebert ◽  
J. J. Mazer ◽  
J. P. Bradley ◽  
C. R. Bradley ◽  
...  
Keyword(s):  
Surface Layers ◽  
Release Process ◽  
Long Time ◽  
Selective Incorporation ◽  
Radionuclide Release ◽  
Reaction Processes ◽  
Glass Leaching

ABSTRACTThe examination of reacted layers that form as glass reacts can provide insight into reaction mechanisms that control long-term glass reaction, and into processes by which radionuclides are released to solution. Examples are given for the natural glasses obsidian and tektite, and the nuclear waste glasses 131 and 165, where the layers form both in-situ and precipitated from solution, where they are both amorphous and crystal 1ine, where selective incorporation of actinide elements Into stable phases may offer a barrier to release, and where sloughing of the layers from the glass acts as an alternative radionuclide release process to solubility-limited control.Several reaction processes occur simultaneously as glass reacts, and the projection of glass performance to long time periods requires the identification of those processes that dominate the long-term reaction.

scholarly journals Making Tycho Brahe’s Sky Accessible to Future Astronomers

2018 ◽  
Vol 13 (S349) ◽  
pp. 510-515
Author(s):  
Bertil Fabricius Dorch ◽  
Jakob Povl Holck ◽  
Kaare Lund Rasmussen ◽  
Majken Brahe Ellegaard Christensen
Keyword(s):  
Physical Analysis ◽  
Short Term ◽  
Astronomical Observations ◽  
Digital Curation ◽  
Long Time ◽  
Tycho Brahe ◽  
Future Work ◽  
Long Term Preservation ◽  
Answering Questions

AbstractCan we make a copy of Tycho’s “De Nova Stella” that can in fact survive a nova? At first, this may seem at best a nerdish, if not distinctly foolish question. However, it is also both a technological and a philosophical question: in fact, answering questions like this is linked to both technical, physical and sociological problems related to the long-term preservation and curation of objects from current and past civilizations.The undertaking presented here is two-fold: Firstly, we report on the results from a state-of the art short-term project, in which we have digitized and analysed three well-known rare books Pertain ing to astronomical observations by Tycho Brahe on the island of Hven. The project led to the creation of free e-books, enabling open access to the sky as recorded by Tycho.Secondly, we discuss some long-term issues related to the digital and physical preservation of scientific knowledge and heritage in general, exemplified by e.g. the works by Tycho.Future work includes further physical analysis of the books and fragments, a systematic extraction and digitization of the astronomical observations, digital curation and dissemination, as well as research into the possibility of creating representations and replicas of the works, durable on extremely long time-scales.

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