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The correspondence of the coastal grain size distribution to the offshore bathymetry-sympathetic for sustainable coastal management
Get PDFGrain size distribution (GSD) of beach sediments helps to understand the morphological
changes take place along the coastal environment. Thus, giving insights to the coastal
sediments will be beneficial for the maintenance and the sustainable development in potential
coasts. Particularly, the eastern coast of Sri Lanka is mostly undeveloped and has good future
economic potential with China's Belt and Road Initiative (BRI). Therefore, it is noteworthy to
assess the sedimentary environment of this undeveloped coast with respect to the present
natural settings. There was lack of studies to understand the probable factors that affect the
grain size distributions along the said coast. During this study we aimed to find a relationship
between GSD of beach and the offshore hydrodynamics precisely on bathymetry. The coast
includes main morphological components naming Vendalose bay, Kalkhudah bay,
Valachchenai lagoon and Batticaloa lagoon with in-between linear coastlines. Surface
sediment samples were collected from three different levels of the beach profile at 35 stations
and granulometric analysis was done following the standards. The GSD data and statistical
parameters were compared with hydrodynamic data obtained from relevant agencies. Within
the 20 to 25 km distance from the beach, the marine depth reaches about 1000 m whereas, for
about 45 km distances it reaches about 3500 m depth. The study area shows parallel isobaths
to the coastline for about 3 km distance with an average depth of 20 m. A narrow canyon
(reaches 100 m depths within 5 km distance) is noted at the edge of the Punnakuda point which
outspreads perpendicular to the beach. However, the sediment grain sizes do not show any
significant change except the river load dumping sites. The mean grain size is medium sands
with a unimodal GSD pattern indicating unique depositional environment for the studied
coastline. The wave hindcast data and tidal data suggested the northeast monsoon driven
longshore sedimentation upheld with the local river dumping is the governing factor for the
sediment distribution. Remarkably, no influence was observed for the GSDs by the presence
of a shallow marine canyon along the study beach. Further studies are reasonable to identify
whether the canyon is ingesting the coarse fractions of the littoral drift or narrow continental
shelf controls the sediment sizes by winnowing processes and yielding the coarse fractions
The impact of pre-annealing temperature on the performance of sb2s3 film in planar solar cell structure
Get PDFSb2S3 has recently been widely used as a light-harvesting material in
thin-film solar cells due to its exciting optical and electrical properties. Various
strategies such as different precursor solutions and vacuum and non-vacuum
deposition have been used to enhance the photovoltaic properties. Since the
temperature impacts the optical absorption and crystallization of Sb2S3 films, the
performance of the devices could be improved by the annealing temperature. This work
aims to investigate the solar cell’s performance based on pre-annealing temperature.
In this work, the Sb2S3 precursor was prepared by dissolving thiourea and SbCl3 in 2-
methoxyethanol and spin-coated on a dense compact TiO2 (c-TiO2) layer at 4000 rpm
for 30 s. Coated Sb2S3 films were pre-annealed at 155, 170, 185, and 200oC for 1
minute. After getting cool down, these thin films were annealed at 280oC for 10 mins
in the tube furnace under the N2 stream. This system used compact TiO2 and P3HT as
electron and hole transport materials, respectively. By increasing the annealing
temperature, the devices were analyzed using UV-Vis absorption spectroscopy,
Current Density-Voltage (J-V) measurement, Incident Photon to current conversion
efficiency (IPCE), X-ray diffraction (XRD), and Impedance (EIS). The well-defined
crystallization structure (Stibnite) of Sb2S3 was obtained in our study. The photovoltaic
parameters were enhanced by increasing the pre-annealing temperature up to 185oC
as 10.6-14.2 mA/cm2 of Jsc, 433-526.1 mV of Voc, and 31-41% of FF. The IPCE
spectra were in very good agreement with the short circuit current of the devices,
showing the highest EQE of 55%, and the series and charge transfer resistances data
supported the performance changes with pre-annealing temperature. The performance
of the Sb2S3 solar cell can preciously be controlled by pre-annealing temperature, due
to changes in optical and electrical properties and the device fabricated at 185oC
harvested the sunlight effectively with 3.04% of efficienc
Physiochemical and microbial changes during organic liquid fertilizer preparation using animal and plant materials under anaerobic conditions
Get PDFThe recycling of organic wastes from
biological fermentation processes for agricultural
production is a fast development of bioconversion
strategy. Microbes play a major role on
physiochemical changes during Organic Liquid
Fertilizer (OLF) preparation. Hence, this study
investigated the Physiochemical changes such as pH,
EC,TDS , nutrient availability and microbial
count..The OLF was produced prepared compost,
banana peels, wild sunflower leaves, and goat manure
at the rates of 80g:50g:80g:80g (w/w) respectively.
Also, brown sugar (25g/l of water) was added as a
fermenting agent. The anaerobic fermentation was
allowed up to 30 days. The results significantly
(P<0.05) showed that, maximum EC (9.93 dS/m), TDS
(6200 mg/L), lower pH (4.6), higher total nitrogen
(513.4 mg/L), and total phosphorous (588.19 mg/L) at
15 DAF than at 30 DAF. Anyhow, significantly higher
total potassium (6.42 mg/L) was reported at 30 DAF
than at 15 DAF. Further, the increased number of
microbes did not significantly influence on
physiochemical changes of OLF, but s bacteria
(14.09±0.3), Actinomycets (16.1±0.2)
and fungus
count (11±0.3) were significantly increased at 30DAF.
It is concluded that except for potassium level,
parameters such as EC, pH, TDS, N, P and microbial
performance were highly recorded at 15DAF. Hence,
a short fermentation time period (15 Days) would be
recommended to achieve the best physiochemical
parameters during the OLF preparation
Prediction of depression in social network posts using machine learning algorithms
Get PDFDepression is a serious mental disorder and its extreme or worst
condition can lead to suicidal action. The number people who suffer from depression
is drastically increasing day by day, particularly in teenagers who express it explicitly
or keep it invisible which means the depressive feeling is hidden in deep down of
their mind. Some of them manages to acknowledge it and some of them even do not
know that they are in a depressed mindset. However, this feeling can be emitted in
social media pool if the candidate has a habit of posting every event and situation on
social networks. Depression silently kills may teenagers and their friends are
unknown about it. Since many people maintain social network as an open diary and
share everything related to their state of mind, the network users can have the
possibility to know the partial scene of the user’s situation. If there is a system that
can measure the level of depression from users’ continuous posts for a certain period
of time and give an alert or pop-up notification to friends and family (followers), then
we can save many young lives from this tragedy, Therefore, the objective of this work
is to build a model by utilizing users continuous posts for a certain period of time. For
this, we have investigated machine learning algorithms such as Naïve Bayes,
Random Forest, Linear Regression, Support Vector Machine to select a best one
with highest accuracy and Support Vector Machine performed better with highest
classification performance for the prediction
Fish waste to fish meal: potential, sustainability and emerging issues related to micro plastics and regulations
Get PDFMassive growth in global fisheries and aquaculture production driven by the development of
fishing technologies and exerted by the world population pressure has resulted in a remarkable increase
in fish waste. The annual average discard amount was estimated to be 7.3 million t for the period from
2016 to 2020. The discard from marine capture commercial fisheries globally is a major concern in terms
of environmental sustainability and cost of disposal. Production of fish meal is considered a practicable
solution for the utilization of these wastes in a sustainable manner with a significant economic return due
to the increasing demand from aquaculture and livestock industries, and occasionally for the utilization
as a high-quality organic fertilizer. Fish meal is enriched with a protein source and could be utilized
as a feed ingredient due to its excellent amino acid profile, excellent digestibility, high palatability, lack
of anti-nutritional factors, and large acceptance by farmers. Due to climate change, habitat degradation
and overfishing, wild fish catches used for fish meal are in decline, thus necessitating the increased
utilization of fish waste to produce fish meal. However, the inclusion of microplastics in the fish meal
and legal and regulatory issues, i.e., intra-species mixing, contamination with endangered fish species,
and illegal, unreported, and unregulated fishing, need to be taken into account while utilizing the fish
waste to produce fish meal. The review suggests that the utilization of fish waste for fish meal is vital
for the future expansion of the fish meal industry, and also for the subsequent expansion of aquaculture
and livestock industries in a sustainable manner while driving a circular economy and ensuring
environmental sustainability
Exploring genetic diversity of maize (ZEA MAYS l.) accessions in Sri Lanka by employing SSR markers on photosynthetic, canopy architectural and grain yield traits
Get PDFPurpose: The favorable alleles identified in maize landraces are treasurable resources to enhance the
genetic base of crop breeding efforts. Therefore, our pioneering research aimed to explore SSR markers
related to maize canopy architectural, photosynthetic and yield traits and hence to study the genetic
diversity of 19 local maize accessions compared with the high-performing maize cultivar Bhadra, as the
standard variety.
Research Method: Genomic DNA extraction was done from young leaves of maize seedlings using standard
protocols. The SSR markers employed were phi065, phi116, umc1065, umc1066, umc1222, umc1231,
umc1545, bnlg155, bnlg249 and bnlg1805. Data analysis was performed using GenAlex and DARwin
software.
Findings: Four of the used markers (umc1066, bnlg1805, phi116, and phi065) had PIC values higher
than that of the overall mean (0.692), showing their potential in this genetic diversity study. These markers
are mainly associated with leaf area index, plant height, leaf chlorophyll content and quantum efficiency
of photosystem II. The highest genetic diversity measures were observed in SEU2, SEU17, SEU18 and
SEU23, compared to Bhadra while the lowest was in SEU3. The level of inbreeding was higher in SEU8.
Cluster analysis identified three major genetic groups and the landraces collected from various areas did
not exhibit any geographical association.
Research Limitations: A large number of SSR markers are needed to explore biomass and grain yield traits.
Originality/value: These results will explore the potential uses of Sri Lankan maize accessions to identify
the best genetic clusters of germplasm with enhanced plant canopy architecture, photosynthesis and grain
yield to be utilized in maize breeding programs
The ultraviolet protective and antibacterial properties of a pigment isolated from a marine bacterial strain from the West Coast of Sri Lanka
Get PDFMarine microorganisms are a potential source of secondary metabolites that include
biopigments produced in response to harsh environmental conditions as a defence
mechanism. The current study aimed to extract, isolate and characterise marine
biopigments in addition to assessing their potential Ultraviolet (UV) protective and
antimicrobial properties. Pigment producing bacterial strains were isolated from marine
samples obtained from various Western coastal regions of Sri Lanka by following
standard microbial isolation protocols. The isolates were grown on Marine Nutrient
Agar and the most prominent pigmented bacterial strain isolated from Negombo was
chosen for extraction and characterization. The strain was characterised via standard
morphological and biochemical testing for tentative identification. The pigment was
extracted via ultrasonication and characterised by Thin Layer Chromatography using
methanol as a solvent. The Ultraviolet protective and antimicrobial properties were
determined through Sun Protection factor (SPF) assay and Kirby-Bauer Well-Diffusion
method respectively. The findings indicate that the isolate protection was a yellow
pigmented bacterial strain tentatively identified to be belonging to the Micrococcus
genus. The extracted pigment was speculated to be a member of the carotenoid group of
pigments. Using the Mansur method, the pigment was found to have a Sun Protection
factor of 24.80 which falls within the range of commercially available sunscreens.
Moreover, the pigment exhibited antibacterial activity against Gram positive bacteria:
Staphylococcus aureus, Zone of Inhibition (ZOI) =15 mm, Bacillus cereus, ZOI =25
mm and Gram-negative bacteria Escherichia coli, ZOI=18 mm while antifungal activity
was also evident against Candida albicans (ZOI=21 mm) These findings suggest that
the pigment ventures promising applications in sunscreen formulations as well as a
potential adjunct in antimicrobial therapy. Further characterization of pigment could
determine its organic nature and better its understanding for application in both the
cosmetic and medical industry
E-learning adoption for sustainable higher education
Get PDFElectronic learning (E-L) is a profound transition that is occurring in education as a new learning
platform in countries across the globe. The COVID-19 pandemic has forced all higher education institutions in Sri Lanka to adopt e-learning to maintain sustainable teaching. This study identified
the relationships between the main influencing factors of e-learning usage behavior and, in turn,
sustainability in teaching. The theory of Planned Behaviour (TPB) was used to formulate the research
framework and hypotheses. The population of the study was comprised of permanent academics
attached to Sri Lankan public universities under the patronage of UGC. The sample size was 357
for the given population size of 5399, and a stratified sampling technique was used to select the
sample. The study used a quantitative method under the philosophical assumption of positivism.
The researchers have applied Structural Equation Modelling (SEM) to test the path association
among factors. The result explores the path relationship between exogenous and mediating
variables, mediating to an endogenous variable. The research outcome shows that attitude and
perceived behavioral control influence e-learning usage but not the subjective norm. While
behavioral intention mediates the relationship between attitude and perceived behavioral
control and e-learning usage, the latter mediates the association between behavioural intention
and sustainability in teaching. Gender, academic position, and computer literacy level moderate
the causal relationships of the factors influencing sustainability in teaching. Finally, this study
concludes that Attitude, Perceived Behavioural Control, Behavioural Intention, and E-learning
Usage Behaviour is the factor influencing sustainability in teaching. This study recommends
universities develop infrastructures, train staff members and establish an office for sustainability
development. Furthermore, it recommends that future researchers do longitudinal studies and
adopt decomposed TPB