scholarly journals SURVEYING, MODELING AND 3D REPRESENTATION OF A WRECK FOR DIVING PURPOSES: CARGO SHIP “VERA”

Author(s):  
A. Ktistis ◽  
P. Tokmakidis ◽  
K. Papadimitriou

This paper presents the results from an underwater recording of the stern part of a contemporary cargo-ship wreck. The aim of this survey was to create 3D representations of this wreck mainly for recreational diving purposes. The key points of this paper are: a) the implementation of the underwater recording at a diving site; b) the reconstruction of a 3d model from data that have been captured by recreational divers; and c) the development of a set of products to be used by the general public for the ex situ presentation or for the <i>in situ</i> navigation. The idea behind this project is to define a simple and low cost procedure for the surveying, modeling and 3D representation of a diving site. The perspective of our team is to repeat the proposed methodology for the documentation and the promotion of other diving sites with cultural features, as well as to train recreational divers in underwater surveying procedures towards public awareness and community engagement in the maritime heritage.

2019 ◽  
Vol 40 (3) ◽  
pp. 265-290 ◽  
Author(s):  
Valarie Thomas ◽  
Yu Wang ◽  
Pascale Van Rooij ◽  
Elin Verbrugghe ◽  
Vojtech Baláž ◽  
...  

Abstract The infectious chytrid fungus Batrachochytrium salamandrivorans (Bsal) has been responsible for severe population declines of salamander populations in Europe. Serious population declines and loss of urodelan diversity may occur if appropriate action is not taken to mitigate against the further spread and impact of Bsal. We provide an overview of several potential mitigation methods, and describe their possible advantages and limitations. We conclude that long-term, context-dependent, multi-faceted approaches are needed to successfully mitigate adverse effects of Bsal, and that these approaches should be initiated pre-arrival of the pathogen. The establishment of ex situ assurance colonies, or management units, for species threatened with extinction, should be considered as soon as possible. While ex situ conservation and preventive measures aimed at improving biosecurity by limiting amphibian trade may be implemented quickly, major challenges that lie ahead are in designing in situ disease containment and mitigation post-arrival and in increasing public awareness.


Rodriguésia ◽  
2018 ◽  
Vol 69 (4) ◽  
pp. 1603-1612
Author(s):  
Tania Maria Cerati

Abstract Engage, educate and raise public awareness of the importance of plant diversity is the means through which plant conservation can be achieved. The Global Strategy for Plant Conservation (GSPC) is a programme to halt the loss of plant diversity and recognize botanical gardens as a partners. This paper investigates the implementation of targets 14 and 15 GSPC in Brazilian botanic gardens specially in education and awareness about plant diversity and trained people. A survey was carried out on the institutional websites of 21 gardens registered in the National System of Botanical Gardens Registration to identify actions that follow the guidelines of these two targets. Websites outdated, difficult access and lack online resources for the public shows us that internet tools are poorly used to divulgation. The target 14's activities performed in most gardens are educational visits and environmental interpretation and explore collections in situ and ex situ from representative species of regional flora. Trained people is held in all gardens but some stand out as important research centers and graduate programs. Despite the efforts Brazilian botanical gardens need improve the public communication and develop strategies to measure the targets progress.


2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Margus Kodu ◽  
Tea Avarmaa ◽  
Hugo Mändar ◽  
Rando Saar ◽  
Raivo Jaaniso

Rare earth oxycarbonates are potential candidate materials for constructing simple and low-cost chemiresistive sensors for monitoring carbon dioxide (CO2) gas in the living and working environment for personal comfort and health reasons. Also, measurement of CO2 concentrations is needed in many industrial processes. Specifically, sol-gel made nanoparticles of Nd and La oxycarbonates have been studied previously as novel CO2 gas sensor materials. In this paper, pulsed laser deposition of La oxycarbonate (La2O2CO3) thin films was studied and structural properties of obtained thin films were characterized. Also, CO2 gas sensing ability of synthesized films was evaluated. The films deposited under CO2 partial pressure in various conditions were all Raman amorphous. In situ or ex situ annealing procedure at high CO2 partial pressure was needed for obtaining crystalline La2O2CO3 films, whereby hexagonal and monoclinic polymorphs were obtained in ex situ and in situ processes, respectively. Sensor structure, made using in situ process, was sensitive to CO2 gas and showed relatively fast response and recovery characteristics.


Author(s):  
Talat Ara ◽  
Waqar-Un Nisa ◽  
Muzammil Anjum ◽  
Luqman Riaz ◽  
Aansa Rukya Saleem ◽  
...  

Abstract Pakistan is an agro-economy country where the hexachlorocyclohexane (HCH) pesticides is being used to improve the crop productivity, as a result, the risk of contamination of soil and sediment has been increased. HCH exhibits all the characteristics of persistent organic pollutants (POP), therefore; added to the list of ‘new POPs’ in 2009. This review report revealed that the major rivers of Pakistan such as Indus Basin, River Ravi, River Chenab and their tributaries all are contaminated with HCH and the highest residual concentration (4,090 ng/g) was detected in pesticide burial ground in Hyderabad city. Major sources of HCH contamination were identified as agricultural runoff, discharge of untreated industrial effluents and surface runoff. In order to manage HCH pollution, various ex-situ and in-situ remediation techniques along with their merits and demerits are thoroughly reviewed. Among these, microbial bioremediation is low cost, environment friendly, effective in-situ remediation technique for remediation of HCH. Overall, the information provided in this manuscript will provide a future reference to the scientific community and bridge the knowledge gap between HCH release in environment and their mitigation through proper treatment method.


2015 ◽  
Vol 1810 ◽  
Author(s):  
J. R. Kim ◽  
G. G. Amatucci

AbstractIncreased demand for low cost energy storage options has expanded the scope of Na+ batteries considerably; and with the growing interest in Na-based chemistries, the importance of high voltage positive electrodes is quickly realized as the Na/Na+ redox introduces lower operating voltages as compared to Li/Li+ based electrochemical cells. The 4.7V LiMn1.5Ni0.5O4 spinel has exhibited considerable properties as a high voltage Li+ positive electrode, with a host structure (λ-Mn0.75Ni0.25O2) that may provide an analogous high voltage Na+ positive electrode. Structural and electrochemical properties of NaxMn1.56Ni0.44O4 and NaxMn2O4 are investigated for the first time[1] utilizing ex-situ, in-situ X-ray diffraction, and high-resolution electrochemical techniques to provide an insightful study of the Na+ insertion mechanism.


Cerâmica ◽  
2019 ◽  
Vol 65 (374) ◽  
pp. 180-184
Author(s):  
H. P. Macedo ◽  
R. L. B. A. Medeiros ◽  
R. A. B. Nascimento ◽  
A. A. S. Oliveira ◽  
G. P. Figueredo ◽  
...  

Abstract In this work, zinc aluminate spinel powders were prepared by a fast, simple, eco-friendly and low-cost modified Pechini method using commercial gelatin as the organic precursor. The materials were calcinated at 600, 700 and 800 °C and characterized by thermogravimetric analysis, in situ and ex situ X-ray diffraction (XRD), N2-adsorption/desorption isotherms and scanning electron microscopy. The results showed that single phase ZnAl2O4 particles with spinel structure were successfully obtained resulting in a high purity, nanometric, homogeneous and mesoporous materials. The in situ XRD results showed that the crystalline spinel structure of ZnAl2O4 started forming at a temperature lower than 600 °C, revealing powders with crystallite size smaller than 40 nm, which increased with increasing the temperature (91% of increase between 600 and 800 °C). The effect of calcination time showed that the materials calcinated at 600 °C for 3 h presented the higher percentage of crystallite growth due to the increase of crystallinity. The ZnAl2O4 samples retained their pore size up to 700 °C.


Author(s):  
C. R. Chen

Abstract Conventional FIB ex-situ lift-out is the most common technique for precise TEM sample preparation. But this method has some limitations and so in-situ lift-out technique was developed to overcome these drawbacks. The in-situ lift-out technique lifts-out the sample and then attaches the sample to a half-cut copper grid inside the FIB chamber by mini-probing system. This paper introduces a novel and simple technique that can overcome the above problems and a wide application of TEM samples preparation. The examples highlighted here demonstrate the novel method of low cost and high image quality TEM sample preparation. The method can reduce the amorphous phenomenon on the sidewall of specimen; no shield effect was found during the reprocess of thinning by ion-miller; and no contamination induced by the ion-miller sputtering was formed.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2180 ◽  
Author(s):  
Aaron Teo ◽  
James R. Guest ◽  
Mei Lin Neo ◽  
Kareen Vicentuan ◽  
Peter A. Todd

Most studies of coral reproductive biology to date have focused on oocyte numbers and sizes. Only one (ex situ) study has enumerated sperm numbers, even though these data have multiple potential applications. We quantified total coral sperm and eggs per gamete bundle collected from six speciesin situduring a synchronous spawning event in Singapore. Egg-sperm bundles were captured midwater as they floated towards the surface after being released by the colony. For each sample, a semi-transparent soft plastic bottle was squeezed and released to create a small suction force that was used to ‘catch’ the bundles. This technique provided several advantages over traditional methods, including low cost, ease of use, no diving prior to the night of collection needed, and the ability to target specific areas of the colony. The six species sampled wereEchinophyllia aspera,Favites abdita,F. chinensis,Merulina ampliata, M. scabriculaandPlatygyra pini. The mean number of sperm packaged within one egg-sperm bundle ranged from 2.04 × 106to 1.93 × 107. The mean number of eggs per egg-sperm bundle ranged from 26.67 (SE ± 3.27) to 85.33 (SE ± 17.79). These data are critical for fertilisation success models, but the collection technique described could also be applied to studies requiringin situspawning data at the polyp level.


Author(s):  
E. Zanchetta ◽  
G. Della Giustina ◽  
A. Gandin ◽  
V. Auzelyte ◽  
G. Brusatin

AbstractDirect printing of spin-on functional films is probably the most efficient method to develop low-cost novel photonic nanodevices, such as diffraction gratings, planar waveguides, nano- lasers, and antireflective coatings. For these applications high refractive index transparent materials are demanded; however, this class of materials generally requires inorganic oxides, well known for their hardness, typical of ceramic materials, and so incompatible with a soft character of printable resins. Herein, inorganic high refractive index TiO2 micro- and nano- structures, with unusual depth up to 600 nm and aspect ratio larger than 5, are obtained by combining thermal nanoimprint lithography (NIL) with UV curing. To achieve printed patterns, a hybrid organic-inorganic spin-on film is deposited at low-temperature by sol–gel processing. Two distinct bottom-up synthetic approaches are used, called in situ and ex situ, using titanium isopropoxide (90%) or TiO2 anatase nanoparticles (70%), respectively, and adding a silica sol modified by organic moieties. The two syntheses were optimized to obtain, after patterning by thermal imprint, amorphous or crystalline titania crack-free micro- and nano- patterns for in situ and ex situ, respectively. The further UV irradiation converts imprinted films to totally inorganic patterns, through the titania photocatalytic effect, allowing refractive indexes up to 1.82 at 632 nm to be achieved. This novel strategy of combining thermal imprint with UV exposure allows inorganic deep patterns to be fabricated without a calcination step, which is generally needed for inorganic resists processing. Eventually, a thermal treatment only at 300 °C can be applied to achieve a final refractive index of 2 at 632 nm.


Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove ◽  
R. T. Tung

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.


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