Abstract: The structures obtained with the use of sandwich
technologies combine low weight with high energy absorbing
capacity and load carrying capacity. Hence, there is a growing and
markedly interest in the use of sandwiches with aluminum foam core
because of very good properties such as flexural rigidity and energy
absorption capability. In the current investigation, the static threepoint
bending tests were carried out on the sandwiches with
aluminum foam core and glass fiber reinforced polymer (GFRP)
skins at different values of support span distances aiming the analyses
of their flexural performance. The influence of the core thickness and
the GFRP skin type was reported in terms of peak load and energy
absorption capacity. For this purpose, the skins with two different
types of fabrics which have same thickness value and the aluminum
foam core with two different thicknesses were bonded with a
commercial polyurethane based flexible adhesive in order to combine
the composite sandwich panels. The main results of the bending tests
are: force-displacement curves, peak force values, absorbed energy,
collapse mechanisms and the effect of the support span length and
core thickness. The results of the experimental study showed that the
sandwich with the skins made of S-Glass Woven fabrics and with the
thicker foam core presented higher mechanical values such as load
carrying and energy absorption capacities. The increment of the
support span distance generated the decrease of the mechanical
values for each type of panels, as expected, because of the inverse
proportion between the force and span length. The most common
failure types of the sandwiches are debonding of the lower skin and
the core shear. The obtained results have particular importance for
applications that require lightweight structures with a high capacity
of energy dissipation, such as the transport industry (automotive,
aerospace, shipbuilding and marine industry), where the problems of
collision and crash have increased in the last years.
Abstract: The authors propose the identification, analysis and
prognosis of the quantitative and qualitative evolution of the elderly
population in the functional urban areas. The present paper takes into
account the analysis of some representative indicators (the weight of
the elderly population, ageing index, dynamic index of economic
ageing of productive population etc.) and the elaboration of an
integrated indicator that would help differentiate the population
ageing forms in the 48 functional urban areas that were defined based
on demographic and social-economic criteria for all large and
medium cities in Romania.
Abstract: The first part of the paper analyzes the dynamics of
the total fertility rate both at the national and regional level, pointing
out the regional disparities in the distribution of this indicator. At the
same time, we also focus on the collapse of the number of live births,
on the changes in the fertility rate by birth rank, as well as on the
failure of acquiring the desired number of children. The second part
of the study centres upon a survey applied to urban families with 3
and more than 3 offspring. The preliminary analysis highlights the
fact that an increased fertility (more than 3rd rank) is triggered by the
parents’ above the average material condition and superior education.
The current situation of Romania, which is still passing through a
period of relatively rapid demographic changes, marked by numerous
convulsions, requires a new approach, in compliance with the recent
interpretations appropriate to a new post-transitional demographic
regime.
Abstract: PhilSHORE is a multi-site, multi-device and multicriteria
decision support tool designed to support the development of
tidal current energy in the Philippines. Its platform is based on
Geographic Information Systems (GIS) which allows for the
collection, storage, processing, analyses and display of geospatial
data. Combining GIS tools with open source web development
applications, PhilSHORE becomes a webGIS-based marine spatial
planning tool. To date, PhilSHORE displays output maps and graphs
of power and energy density, site suitability and site-device analysis.
It enables stakeholders and the public easy access to the results of
tidal current energy resource assessments and site suitability
analyses. Results of the initial development show that PhilSHORE is
a promising decision support tool for ORE project developments.
Abstract: Depositional environment and source potential of the
different organic-rich levels of Devonian age (up to 990m thick) from
the onshore EC-1 well (Southern Tunisia) were investigated based on
the analysis of more than 130 cutting samples by different
geochemical techniques (Rock-Eval pyrolysis, GC-MS). The
obtained results including Rock Eval Pyrolysis data and biomarker
distribution (terpanes, steranes and aromatics) have been used to
describe the depositional environment and to assess the thermal
maturity of the Devonian organic matter. These results show that the
Emsian deposits exhibit poor to fair TOC contents. The associated
organic matter is composed of mixed kerogen (type II/III), as
indicated by the predominance of C29 steranes over C27 and C28
homologous, that was deposited in a slightly reduced environment
favoring organic matter preservation. Thermal maturity assessed from
Tmax, TNR and MPI-1 values shows a mature stage of organic
matter. The Middle Devonian (Eifelian) shales are rich in type II
organic matter that was deposited in an open marine depositional
environment. The TOC values are high and vary between 2 and 7%
indicating good to excellent source rock. The relatively high HI
values (reaching 547 mg HC/g TOC) and the low values of t19/t23
tricyclic terpane ratio (< 0.2) confirm the marine origin of the organic
matter (type II). During the Upper Devonian, the organic matter was
deposited under variable redox conditions, oxic to suboxic which is
clearly indicated by the low C35/C34 hopanes ratio, immature to
marginally mature with the vitrinite reflectance ranging from 0.5 to
0.7 Ro and Tmax value of 426°C-436 °C and the TOC values range
between 0.8% to 4%.
Abstract: This work is undertaken to develop a methodology to enhance the management of dredged marine and river sediments in the North of France. The main objective of this study is to determine the main characteristics of these sediments. In this order, physical, mineralogical and chemical properties of both types of sediments are measured. Moreover, their potential impacts on the environment are assessed throughout leaching tests. From the obtained results, the potential of their use in road engineering is discussed.
Abstract: Flow blockages referring to the increase in flow are
being considered as a vital equipment for marine current energy
conversion. However, the shape of these devices will result in
extracted energy under the operation. The present work investigates
the effect of two configurations of a grating, convergent and
divergent that located upstream, to the water flow velocity. The flow
characteristics are studied by Computational Fluid Dynamic
simulation by using the ANSYS Fluent solver for these specified
arrangements of the grating. The results indicate that distinguished
characteristics of flow velocity between “convergent” and
“divergent” grating placements is up to 10% in confined conditions.
Furthermore, the velocity in case of convergent grating is higher
than that of divergent grating.
Abstract: Diminished antioxidant defense or increased
production of reactive oxygen species in the biological system can
result in oxidative stress which may lead to various
neurodegenerative diseases including Alzheimer’s disease (AD).
Microglial activation also contributes to the progression of AD by
producing several proinflammatory cytokines, nitric oxide (NO) and
prostaglandin E2 (PGE2). Oxidative stress and inflammation have
been reported to be possible pathophysiological mechanisms
underlying AD. In addition, the cholinergic hypothesis postulates that
memory impairment in patient with AD is also associated with the
deficit of cholinergic function in the brain. Although a number of
drugs have been approved for the treatment of AD, most of these
synthetic drugs have diverse side effects and yield relatively modest
benefits. Marine algae have great potential in pharmaceutical and
biomedical applications as they are valuable sources of bioactive
properties such as anticoagulation, antimicrobial, antioxidative,
anticancer and anti-inflammatory. Hence, this study aimed to provide
an overview of the properties of Malaysian seaweeds (Padina
australis, Sargassum polycystum and Caulerpa racemosa) in
inhibiting oxidative stress, neuroinflammation and cholinesterase
enzymes. These seaweeds significantly exhibited potent DPPH and
moderate superoxide anion radical scavenging ability (P
Abstract: This study was conducted in the area of Vlora Bay,
Albania. Data about Sea Turtles Caretta caretta and Chelonia mydas,
belonging to two periods of time (1984 – 1991; 2008 – 2014) are
given. All data gathered were analyzed using recent methodologies.
For all turtles captured (as by catch), the Curve Carapace Length
(CCL) and Curved Carapace Width (CCW) were measured. These
data were statistically analyzed, where the mean was 67.11 cm for
CCL and 57.57 cm for CCW of all individuals studied (n=13). All
untagged individuals of marine turtles were tagged using metallic
tags (Stockbrand’s titanium tag) with an Albanian address. Sex was
determined and resulted that 45.4% of individuals were females,
27.3% males and 27.3% juveniles. All turtles were studied for the
presence of the epibionts. The area of Vlora Bay is used from marine
turtles (Caretta caretta) as a migratory corridor to pass from
Mediterranean to the northern part of the Adriatic Sea.
Abstract: Wet scrubbers have found widespread use in cleaning
contaminated gas streams because of their ability to remove
particulates and based on the applications of scrubbing of marine
engine exhaust gases by spraying sea-water. In order to examine the
flow characteristics inside the scrubber, the model is designated with
flow properties of hot air and water sprayer. The flow dynamics of
evaporation of hot air by the injection of water droplets is the key
factor considered in this paper. The flow behavior inside the scrubber
was investigated from the previous works and to sum up the
evaporation rate with respect to the concentration of water droplets are
predicted to bring out the competent modelling. The numerical
analysis using CFD facilitates in understanding the problem better and
empathies the behavior of the model over its entire operating envelope.
Abstract: Brown seaweeds are abundant in Portuguese coastline
and represent an almost unexploited marine economic resource. One
of the most common species, easily available for harvesting in the
northwest coast, is Saccorhiza polyschides grows in the lowest shore
and costal rocky reefs. It is almost exclusively used by local farmers
as natural fertilizer, but contains a substantial amount of valuable
compounds, particularly alginates, natural biopolymers of high
interest for many industrial applications.
Alginates are natural polysaccharides present in cell walls of
brown seaweed, highly biocompatible, with particular properties that
make them of high interest for the food, biotechnology, cosmetics
and pharmaceutical industries. Conventional extraction processes are
based on thermal treatment. They are lengthy and consume high
amounts of energy and solvents. In recent years, microwave-assisted
extraction (MAE) has shown enormous potential to overcome major
drawbacks that outcome from conventional plant material extraction
(thermal and/or solvent based) techniques, being also successfully
applied to the extraction of agar, fucoidans and alginates. In the
present study, acid pretreatment of brown seaweed Saccorhiza
polyschides for subsequent microwave-assisted extraction (MAE) of
alginate was optimized. Seaweeds were collected in Northwest
Portuguese coastal waters of the Atlantic Ocean between May and
August, 2014. Experimental design was used to assess the effect of
temperature and acid pretreatment time in alginate extraction.
Response surface methodology allowed the determination of the
optimum MAE conditions: 40 mL of HCl 0.1 M per g of dried
seaweed with constant stirring at 20ºC during 14h. Optimal acid
pretreatment conditions have enhanced significantly MAE of
alginates from Saccorhiza polyschides, thus contributing for the
development of a viable, more environmental friendly alternative to
conventional processes.
Abstract: Aluminum hybrid reinforcement technology is a
response to the dynamic ever increasing service requirements of such
industries as transportation, aerospace, automobile, marine, etc. It is
unique in that it offers a platform of almost unending combinations of
materials to produce various hybrid composites. This article reviews
the studies carried out on various combinations of aluminum hybrid
composite and the effects on mechanical, physical and chemical
properties. It is observed that the extent of enhancement of these
properties of hybrid composites is strongly dependent on the nature
of the reinforcement, its hardness, particle size, volume fraction,
uniformity of dispersion within the matrix and the method of hybrid
production.
Abstract: Marine Protected Areas can benefit from nature based
tourism, monitoring environmental impacts and also become target
for human presence. From more than 3 million tourists visiting
Cozumel Island every year, an average of 2,8 million arrive by cruise
ship, and 41% are estimated to have motivation for water activities.
The destination is relying so much on the tourism activity, that scuba
diving and snorkeling in the National Park Reef of Cozumel sustain
the major economic activity. In order to achieve the sustainable
development indicator designed for regional environmental
development, the PNAC offers a training course to tourism providers
to access the protected area. This way, the update of the last 5 years
of such training is directed to diving staff, boat crew and
professionals, making them able to assist in managing the natural
resource. Moreover, the case study is an example to be used for
raising awareness among tourists visiting protected areas.
Abstract: Since the marine environmental conditions are
extremely different from the other ones, marine actinomycetes might
produce novel bioactive compounds. Therefore, actinomycete strains
were screened from marine water and sediment samples collected
from the coastal areas of Northern Vietnam. Ninety-nine
actinomycete strains were obtained on starch-casein agar media by
dilution technique, only seven strains, named HP112, HP12, HP411,
HPN11, HP 11, HPT13 and HPX12, showed significant antibacterial
activity against both gram-positive and gram-negative bacteria
(Bacillus subtilis ATCC 6633, Staphylococcus epidemidis ATCC
12228, Escherichia coli ATCC 11105). Further studies were carried
out with the most active HP411 strain against Candida albicans
ATCC 10231. This strain could grow rapidly on starch casein agar
and other media with high salt containing 7-10% NaCl at 28-30oC.
Spore-chain of HP411 showed an elongated and circular shape with
10 to 30 spores/chain. Identification of the strain was carried out by
employing the taxonomical studies including the 16S rRNA
sequence. Based on phylogenetic and phenotypic evidence it is
proposed that HP411 to be belongs to species Streptomyces
variabilis. The potent of the crude extract of fermentation broth of
HP411 that are effective against wide range of pathogens: both grampositive,
gram-negative and fungi. Further studies revealed that the
crude extract HP411 could obtain the anticancer activity for cancer
cell lines: Hep-G2 (liver cancer cell line); RD (cardiac and skeletal
muscle letters cell line); FL (membrane of the uterus cancer cell line).
However, the actinomycetes from marine ecosystem will be useful
for the discovery of new drugs in the future.
Abstract: The Port of Townsville conducts regular annual
maintenance dredging to maintain depths of its harbor basin and
approach channels for the navigational safety of the vessels against
the natural accumulation of marine sediments. In addition to the
regular maintenance dredging, the port undertakes emergency
dredging in cases where large quantities of sediments are mobilized
and deposited in port waters by cyclone or major flood events. The
maintenance dredging material derived from the port may be
disposed at sea or on land in accordance with relevant state and
commonwealth regulations. For the land disposal, the dredged mud
slurry is hydraulically placed into containment ponds and left to
undergo sedimentation and self-weight consolidation to form fill
material for land reclamation. This paper provides an overview of the
maintenance dredging at the Port of Townsville and emphasis on
maintenance dredging requirements, sediment quality, bathymetry,
dredging methods used, and dredged material disposal options.
Abstract: There is an essential need for obtaining the mathematical representation of fish body undulations, which can be used for designing and building new innovative types of marine propulsion systems with less environmental impact. This research work presents a case study to derive the mathematical model for fish body movement. Observation and capturing image methods were used in this study in order to obtain a mathematical representation of Clariasbatrachus fish (catfish). An experiment was conducted by using an aquarium with dimension 0.609 m x 0.304 m x 0.304 m, and a 0.5 m ruler was attached at the base of the aquarium. Progressive Scan Monochrome Camera was positioned at 1.8 m above the base of the aquarium to provide swimming sequences. Seven points were marked on the fish body using white marker to indicate the fish movement and measuring the amplitude of undulation. Images from video recordings (20 frames/s) were analyzed frame by frame using local coordinate system, with time interval 0.05 s. The amplitudes of undulations were obtained for image analysis from each point that has been marked on fish body. A graph of amplitude of undulations versus time was plotted by using computer to derive a mathematical fit. The function for the graph is polynomial with nine orders.
Abstract: It is necessary to manage the fatigue crack growth (FCG) once those cracks are detected during in-service inspections. In this paper, a simulation program (FCG-System) is developed utilizing the commercial software ABAQUS with its object-oriented programming interface to simulate the fatigue crack path and to compute the corresponding fatigue life. In order to apply FCG-System in large-scale marine structures, the substructure modeling technique is integrated in the system under the consideration of structural details and load shedding during crack growth. Based on the nodal forces and nodal displacements obtained from finite element analysis, a formula for shell elements to compute stress intensity factors is proposed in the view of virtual crack closure technique. The cracks initiating from the intersection of flange and the end of the web-stiffener are investigated for fatigue crack paths and growth lives under water pressure loading and axial force loading, separately. It is found that the FCG-System developed by authors could be an efficient tool to perform fatigue crack growth analysis on marine structures.
Abstract: Qatar’s primary source of fresh water is through
seawater desalination. Amongst the major processes that are
commercially available on the market, the most common large scale
techniques are Multi-Stage Flash distillation (MSF), Multi Effect
distillation (MED), and Reverse Osmosis (RO). Although commonly
used, these three processes are highly expensive down to high energy
input requirements and high operating costs allied with maintenance
and stress induced on the systems in harsh alkaline media. Beside that
cost, environmental footprint of these desalination techniques are
significant; from damaging marine eco-system, to huge land use, to
discharge of tons of GHG and huge carbon footprint.
Other less energy consuming techniques based on membrane
separation are being sought to reduce both the carbon footprint and
operating costs is membrane distillation (MD).
Emerged in 1960s, MD is an alternative technology for water
desalination attracting more attention since 1980s. MD process
involves the evaporation of a hot feed, typically below boiling point
of brine at standard conditions, by creating a water vapor pressure
difference across the porous, hydrophobic membrane. Main
advantages of MD compared to other commercially available
technologies (MSF and MED) and specially RO are reduction of
membrane and module stress due to absence of trans-membrane
pressure, less impact of contaminant fouling on distillate due to
transfer of only water vapor, utilization of low grade or waste heat
from oil and gas industries to heat up the feed up to required
temperature difference across the membrane, superior water quality,
and relatively lower capital and operating cost.
To achieve the objective of this study, state of the art flat-sheet
cross-flow DCMD bench scale unit was designed, commissioned, and
tested. The objective of this study is to analyze the characteristics and
morphology of the membrane suitable for DCMD through SEM
imaging and contact angle measurement and to study the water
quality of distillate produced by DCMD bench scale unit.
Comparison with available literature data is undertaken where
appropriate and laboratory data is used to compare a DCMD distillate
quality with that of other desalination techniques and standards.
Membrane SEM analysis showed that the PTFE membrane used
for the study has contact angle of 127º with highly porous surface
supported with less porous and bigger pore size PP membrane. Study
on the effect of feed solution (salinity) and temperature on water
quality of distillate produced from ICP and IC analysis showed that
with any salinity and different feed temperature (up to 70ºC) the
electric conductivity of distillate is less than 5 μS/cm with 99.99%
salt rejection and proved to be feasible and effective process capable
of consistently producing high quality distillate from very high feed
salinity solution (i.e. 100000 mg/L TDS) even with substantial
quality difference compared to other desalination methods such as
RO and MSF.
Abstract: Microalgae lipid is a promising feedstock for biodiesel production. The objective of this work was to study growth factors affecting marine mutant Synechococcus sp. (PCC 7002) for high lipid production. Four growth factors were investigated; nitrogen-phosporus-potassium (NPK) concentration, light intensity, temperature and NaNO3 concentration on mutant strain growth and lipid production were studied. Design Expert v8.0 was used to design the experimental and analyze the data. The experimental design selected was Min-Run Res IV which consists of 12 runs and the response surfaces measured were specific growth rate and lipid concentration. The extraction of lipid was conducted by chloroform/methanol solvents system. Based on the study, mutant Synechococcus sp. PCC 7002 gave the highest specific growth rate of 0.0014 h-1 at 0% NPK, 2500 lux, 40oC and 0% NaNO3. On the other hand, the highest lipid concentration was obtained at 0% NPK, 3500 lux, 30oC and 1% NaNO3.
Abstract: These SOAP project Pacific Ocean measurements reveal that phytoplankton blooms with sunny conditions make possible secondary organic contribution to ultrafine particles size and composition, and thus on cloud formation ability, and finally on climate. This is in agreement with other biologically active region observations about the presence of secondary organics even the exact fraction is also depending on the local marine life (e.g. plankton blooms, seaweeds, corals). An organic contribution is clearly needed to add to CLAW hypothesis.