bluuebunny/crossref_metadata_2025 huggingface dataset:
Lateral Variations Across the Southern San Andreas Fault Zone Revealed from Analysis of Traffic Signals at a Dense Seismic Array
Authors: Zhang Hao , Meng Haoran , Ben-Zion Yehuda
Published: March 2023

We image the shallow seismic structure across the Southern San Andreas
Fault (SSAF) using signals from freight trains and trucks recorded by a
dense nodal array, with a linear component perpendicular to SSAF and two
2D subarrays centered on the Banning Fault (BF) and Mission Creek Fault
(MCF). Particle motion analysis in the frequency band 2-5 Hz shows that
the examined traffic sources can be approximated as moving point sources
that primarily induce Rayleigh waves. Using several techniques, we
resolve strong lateral variations of Rayleigh wave velocities across the
SSAF, including 35% velocity reduction across MCF towards the
northeast. Additionally, we derive Q-values and find strong attenuation
around the BF and MCF. We further resolve 10% mass density reduction
and 45% shear modulus decrease across the MCF. These findings suggest
that the MCF is the main strand of the SSAF in the area with important
implications for seismic hazard assessments.
Climate Projections Very Likely Underestimate Future Volcanic Forcing and its Climatic Effects
Authors: Chim Man Mei , Aubry Thomas Jacques , Abraham Nathan Luke , Marshall Lauren , Mulcahy Jane Patricia , Walton Jeremy , Schmidt Anja
Published: March 2023

Standard climate projections represent future volcanic eruptions by a
constant forcing inferred from 1850-2014 volcanic forcing. Using the
latest ice-core and satellite records to design stochastic eruption
scenarios, we show that there is a 95% probability that explosive
eruptions could emit more sulfur dioxide (SO) into the
stratosphere over 2015-2100 than current standard climate projections
(i.e., ScenarioMIP). Our simulations using the UK Earth System Model
with interactive stratospheric aerosols show that for a median future
eruption scenario, the 2015-2100 average global-mean stratospheric
aerosol optical depth (SAOD) is double that used in ScenarioMIP, with
small-magnitude eruptions (< 3 Tg of SO)
contributing 50% to SAOD perturbations. We show that volcanic effects
on large-scale climate indicators, including global surface temperature,
sea level and sea ice extent, are underestimated in ScenarioMIP because
current climate projections do not fully account for the recurrent
frequency of volcanic eruptions of different magnitudes.
Overriding plate thickness as a controlling factor for trench retreat rates in narrow subduction zones
Authors: Gea Pedro J. , Mancilla Flor de Lis , Negredo Ana M , Hunen Jeroen van
Published: March 2023

Slab width plays a major role in controlling subduction dynamics and
trench motion. However, observations on natural narrow subduction zones
do not show any correlation between slab width and trench velocities,
indicating that other factors may have a greater impact. Here, we use 3D
numerical subduction models to evaluate the effect of slab width,
strength of slab coupling to the lateral plate and overriding plate
thickness on trench kinematics. Model results show that slab width has
little influence on trench migration rates for narrow subduction zones,
but that the thickness of the overriding plate plays a major role, with
trench velocities decreasing as the thickness increases. These results
explain trench velocities observed in natural narrow subduction zones
showing no relation with slab width but an inverse dependence on
overriding plate thickness. Finally, we find that the overriding plate
thickness also significantly affects the trench shape.
Characterizing the role of non-linear interactions in the transition to submesoscale dynamics at a dense filament
Authors: Freilich Mara A. , Lenain Luc , Gille Sarah T.
Published: March 2023

Ocean dynamics at the submesoscale play a key role in mediating
upper-ocean energy dissipation and dispersion of tracers. Observations
of ocean currents from synoptic mesoscale surveys at submesoscale
resolution (250 m–100 km) from a novel airborne instrument (MASS
DoppVis) reveal that the kinetic energy spectrum in the California
Current System is nearly continuous from 100 km to sub-kilometer scales,
with a k spectral slope. Although there is not a
transition in the kinetic energy spectral slope, there is a transition
in the dynamics to non-linear interactions at scales of O(1 km).
Barotropic kinetic energy transfer across spatial scales is enabled by
interactions between the rotational and divergent components of the flow
field at the submesoscale. Kinetic energy flux is intermittent but can
be large, particularly at submesoscale fronts. Kinetic energy is
transferred both downscale and upscale from 1 km in the observations of
a cold filament.
The influence of weather patterns and the Madden-Julian Oscillation on extreme precipitation over Sri Lanka
Authors: Deoras Akshay , Turner Andrew G , Hunt Kieran M. R. , Jayawardena I. M .Shiromani Priyanthika
Published: March 2023

Sri Lanka is affected by extreme precipitation events every year, which
cause floods, landslides and tremendous economic losses. In this study,
we use the ERA5 reanalysis dataset to understand their association with
30 weather patterns, which were originally derived to represent the
variability of the Indian climate during January–December 1979–2016.
We find that weather patterns that are most common during the northeast
monsoon (December–February) and second intermonsoon (October–November)
seasons produce the highest number of extreme precipitation events.
Furthermore, extreme precipitation events occurring during these two
seasons are more persistent than those during the southwest monsoon
(May–September) and first intermonsoon (March–April) seasons. We
analyse the modulation of extreme precipitation events by the
Madden-Julian Oscillation, and find that their frequency is enhanced
(suppressed) in phases 1–4 (5–8) for most weather patterns.
ENSO Feedback Biases Common to Atmosphere-Ocean Coupled and Atmosphere-Only Simulations of CMIP6 Climate Models
Authors: Hayashi Michiya
Published: March 2023

Climate models reproduce sea surface temperature (SST) variability of El
Niño/Southern Oscillation (ENSO) despite systematic feedback errors.
Atmospheric feedback in response to ENSO’s SST anomalies remains biased
even in atmosphere-only simulations, but the reason therein is unclear.
This study focuses on atmospheric internal processes to reveal ENSO
feedback biases common to the atmosphere-ocean coupled historical and
atmosphere-only simulations of CMIP6. The net heat flux feedback becomes
comparable to observations once the observed SST is prescribed, but the
central Pacific zonal wind feedback is yet underestimated albeit a
realistic equatorial precipitation-SST relation. The wind feedback bias
is attributed to the wind responses to the equatorial precipitation
anomalies that seasonally erroneously decline in boreal late winter,
common to both the coupled and atmosphere-only simulations. The model’s
mean state with peak-reduced and broad deep convective areas is
favorable for enhancing the wind-precipitation relation and thus ENSO
dynamic feedback.
The Source Parameter of S1222a Marsquake obtained from Spectral Analyses using Empirical Green's Function
Authors: Kawamura Taichi , Xu Zongbo , Xiao Wanbo , Margerin Ludovic , Menina Sabrina , Lognonné Philippe , Banerdt William Bruce
Published: March 2023

NASA InSight mission revealed that Mars is seismically active today and
identified a region with high activity called Cerberus Fossae. Since
then, the origin of marsquakes has been an important question in Mars
seismology. On 2022/05/04, InSight seismometer detected the largest
marsquake during the mission, named S1222a. The source was estimated to
be outside the Cerberus Fossae and it would be important to constrain
the source parameters of this remarkable event. In this study, we
estimate the source parameters of S1222a through spectral analyses.
Since we found that seismic spectra of S1222a are heavily contaminated,
we performed Empirical Green’s Function analyses. We found that the
corner frequencies are 0.34-0.54 Hz for the P wave and 0.17-0.24 Hz for
the S wave. These values are slightly higher than those of seismic
events at Cerberus Fossae, which implies a faster rupture at the source
and different origin for S1222a.
A Stable Neural Network-Based Eikonal Tomography using Hard-Constrained Measurements
Authors: Taufik Mohammad , Alkhalifah Tariq , Waheed Umair
Published: March 2023

Eikonal tomography, or travel time inversion, has been one of the
primary seismological tools for decades and has been used to understand
Earth’s properties and dynamic processes. At the heart of the inversion
process is the need for an accurate, and preferably flexible, eikonal
solver to compute the travel time field. Most of the conventional
eikonal solvers, however, suffer from first-order convergence errors and
difficulties in dealing with irregular computational grids.
Physics-informed neural networks (PINNs) have been introduced to tackle
these problems and have shown great success in addressing those
challenges. Nevertheless, these approaches still suffer from slow
convergence and unstable training dynamics due to the multi-term nature
of the loss function. To improve on this, we propose a new formulation
for the isotropic eikonal equation, which imposes boundary conditions as
hard constraints. We employ the theory of functional connections to the
eikonal tomography problem, which allows for the utilization of a single
loss term for training the PINN model. Through rigorous numerical tests,
its efficiency, stability, and flexibility in tackling a variety of
cases, including topography-dependent and 3D models, are attested, thus
providing an efficient and stable PINN-based eikonal tomography.
Generalizing Reservoir Operations using a Piecewise Classification and Regression Approach
Authors: Ford Lucas , Sankarasubramanian Arumugam
Published: March 2023

Inflow anomalies at varying temporal scales, seasonally varying storage
mandates, and multi-purpose allocation requirements contribute to
reservoir operational decisions. The difficulty of capturing these
constraints across many basins in a generalized framework has limited
the accuracy of streamflow estimates in Land Surface Models for
locations downstream of reservoirs. We develop a Piece Wise Linear
Regression Tree to learn generalized daily operating policies from 76
reservoirs from four major basins across the coterminous US. Reservoir
characteristics, such as residence time and maximum storage, and daily
state variables, such as storage and inflow, are used to group similar
observations across all reservoirs. Linear regression equations are then
fit between daily state variables and release for each group. We
recommend two models – Model 1 (M1) that performs the best when
simulating untrained records but is complex, and Model 2 (M2) that is
nearly as performant as M1 but more parsimonious. The simulated release
median root mean squared error is 49.7% (53.2%) of mean daily release
with a median Nash-Sutcliffe Efficiency of 0.62 (0.52) for M1 (M2).
Long-term residence time is shown to be useful in grouping similar
operating reservoirs. Release from low residence time reservoirs can be
mostly described using inflow-based variables. Operations at higher
residence time reservoirs are more related to previous release variables
or storage variables, depending on the current inflow. The ability of
the models presented to capture operational dynamics of many types of
reservoirs indicates their potential to be used for untrained and
limited data reservoirs.
Ice Concentration Scaling Laws for Freshwater Lakes in Numerical Weather and Climate Prediction
Authors: Mackay Murray
Published: March 2023

If lake ice is assumed to deform and fail as a linear viscoelastic
material under the action of wind stress, then a simple ice
concentration scaling law can be constructed suitable for
one-dimensional lake models embedded within environmental prediction
systems. Most 1-D lake models assume no ice mechanics at all, while
others adapt the viscous-plastic rheology common in ice-ocean models for
the purpose of estimating ice fraction. Elastic buckling is generally
disregarded as a significant failure mechanism in ice under low stress
conditions at geophysical scales. However, by adding viscosity to the
constitutive equation, the conditions for viscoelastic buckling seem
quite plausible over a wide range of lake size and ice thickness. An ice
concentration scaling law based on this process is evaluated here in
multiannual simulations over North America and found to produce superior
ice phenology statistics compared with simulations based on plastic
failure or no ice mechanics.
Influence of Stratosphere Polar Vortex Variability on the Mesosphere, Thermosphere, and Ionosphere
Authors: Pedatella Nicholas Michael
Published: March 2023

The Whole Atmosphere Community Climate Model with
thermosphere-ionosphere eXtension (WACCM-X) is used to investigate the
influence of stratosphere polar vortex variability on the mesosphere,
thermosphere, and ionosphere during Northern Hemisphere winter. Based on
40 simulated Northern Hemisphere winters, the mesosphere and lower
thermosphere (MLT) residual circulation is found to depend on whether
the stratosphere polar vortex is strong or weak. In particular, during
weak stratosphere polar vortex time periods, the MLT circulation
anomalies are characterized by clockwise and anti-clockwise flow in the
Northern and Southern Hemispheres, respectively. Opposite, though
weaker, anomalies are found to occur during time periods when the
stratosphere polar vortex is strong. The MLT circulation anomalies
influence the composition of the lower thermosphere, leading to ±5%
changes in the thermosphere column integrated atomic oxygen to molecular
nitrogen ratio (O/N2). Large differences between strong and weak
stratosphere polar vortex events are also found to occur in the
semidiurnal migrating tide (SW2) in the MLT, which leads to ±15-20%
differences in the SW2 component of the ionosphere total electron
content (TEC) at low latitudes. The WACCM-X simulation results indicate
that variability in the stratosphere polar vortex can explain
~30% and ~18% of the quiet time
variability in thermosphere O/N2 and the SW2 component of TEC during
Northern Hemisphere winter, respectively.
Spatial organisation affects the pathway to precipitation in simulated trade-wind convection
Authors: Radtke Jule , Vogel Raphaela , Ament Felix , Naumann Ann Kristin
Published: March 2023

We investigate whether and how spatial organisation affects the pathway
to precipitation in realistic large-domain large-eddy simulations of the
North Atlantic trades. We decompose the formation of surface
precipitation (P) into a production phase, where cloud condensate is
converted into rain, and a sedimentation phase, where rain falls towards
the ground while some of it evaporates. With strengthened organisation,
rain forms in weaker updrafts from smaller mean cloud droplets so that
cloud condensate is less efficiently converted into rain. At the same
time, organisation creates a locally moister environment and modulates
the microphysical conversion processes shaping rain properties. This
acts to reduce evaporation so that more of the produced rain reaches the
ground. Organisation thus affects how the two phases contribute to P. It
only weakly affects the total precipitation efficiency. We conclude that
the pathway to precipitation differs with spatial organisation and
suggest that organisation buffers rain development.
Automated Detection and Tracking of Low Latitude Plasma Bubbles Utilizing Global-Scale Observations of the Limb and Disk (GOLD) 135.6 nm Data
Authors: Adkins Vincent James , England Scott L
Published: March 2023

Plasma bubbles are regions of depleted plasma within the upper
thermosphere/ionosphere that form during post-sunset hours near the
magnetic equator. These structures tend to align with local geomagnetic
field lines, extend upwards hundreds of kilometers along geomagnetic
longitudes, and thousands of kilometers along geomagnetic latitudes.
These large scale plasma density gradients can attenuate lower frequency
radio waves, while small scale structures along the walls can interfere
with centimeter scale wavelengths via Fresnel and Bragg scattering.
Large scale statistical analysis of this phenomenon can further
understanding of their occurrence and subsequent behavior. The current
study utilizes Global-Scale Observations of the Limb and Disk (GOLD)
135.6 nm nightglow data from October 5, 2018 to September 30, 2022. GOLD
has a unique perspective from geostationary orbit, allowing a constant
and consistent view of nightglow and structures over the Americas and
Atlantic. A plasma bubble detection method is developed and used to
generate a database of plasma bubble occurrences. Occurrences are used
to calculate plasma bubble drift speeds and separations. Clear
seasonality in plasma bubble occurrence rate is evident. Overall
occurrences peak during December solstice months and minimize during
June solstice for longitudes seen by GOLD. Within GOLD’s field of view,
higher occurrences are seen to the west during December solstice and
east during June solstice. Plasma bubble drift speeds and separations
show consistent distributions regardless of magnetic region, geographic
region, season, or local time. This suggests plasma bubbles behave
consistently and regularly once formed, at least on spatial scales seen
by GOLD.
The influence of natural variability on extreme monsoons in Pakistan
Authors: Ashfaq Moetasim , Johnson Nathaniel , Kucharski Fred , Diffenbaugh Noah S. , Abid Muhammad Adnan , Horan Matthew F. , Singh Deepti , Mahajan Salil , Ghosh Subimal , Ganguly Auroop R. , Evans Katherine J. , Islam Shafiqul
Published: March 2023

The monsoons in Pakistan have been exceptionally harsh in recent
decades, resulting in extraordinary drought conditions and record
flooding events. The changing frequency of extreme events is widely
attributed to climate change. However, given this region’s long history
of floods and droughts, the role of natural climate variability cannot
be rejected without a careful diagnosis. Here, we examine how oceanic
and atmospheric variability has contributed to unusual precipitation
distributions in West South Asia. Variations in sea surface temperatures
in the tropical Pacific and northern Arabian Sea, and internal
atmospheric variability related to the circumglobal teleconnection
pattern and the subtropical westerly jet stream, explain more than 70%
of monthly summer precipitation variability in the 21st century. Several
of these forcings have co-occurred with record strength during episodes
of extreme monsoons, which have exacerbated the overall effect. Climate
change may have contributed to increased variability and the in-phase
co-occurrences of the identified mechanisms, but further research is
required to confirm any such connection.
Phase-field simulation of texture evolution in magmatic rocks
Authors: Kundin Julia , Steinbach Ingo , Chakraborty Sumit
Published: March 2023

The tool of phase-field modeling for the prediction of chemical as well
as microstructural evolution during crystallization from a melt in a
mineralogical system has been developed in this work. We provide a
compact theoretical background and introduce new aspects such as the
treatment of anisotropic surface energies that are essential for
modeling mineralogical systems. These are then applied to two simple
model systems - the binary olivine-melt and plagioclase-melt systems -
to illustrate the application of the developed tools. In one case
crystallization is modeled at a constant temperature and undercooling
while in the other the process of crystallization is tracked for a
constant cooling rate. These two examples serve to illustrate the
capabilities of the modeling tool. The results are analyzed in terms of
crystal size distributions (CSD) and with a view toward applications in
diffusion chronometry; future possibilities are discussed. The modeling
results demonstrate that growth at constant rates may be expected only
for limited extents of crystallization, that breaks in slopes of
CSD-plots should be common, and that the lifetime of a given crystal of
a phase is different from the lifetime of this phase in a magmatic
system. The last aspect imposes an inherent limit to timescales that may
be accessed by diffusion chronometry. Most significantly, this tool
provides a bridge between CSD analysis and diffusion chronometry - two
common tools that are used to study timescales of magmatic processes.
Flow structures with high Lagrangian coherence promote diatom blooms in oligotrophic waters
Authors: Hernández-Carrasco Ismael , Rossi Vincent , Navarro Gabriel , Turiel Antonio , Bracco Annalisa , Orfila Alejandro
Published: March 2023

Diatoms are among the most efficient marine organisms for primary
production and carbon sequestration, absorbing at least 10 billion
tonnes of carbon dioxide every year. Yet, the spatial distributions of
these planktonic organisms remain puzzling and the underlying physical
processes poorly known. Here we investigate what dynamical conditions
are conductive to episodic diatom blooms in oligotrophic waters based on
Lagrangian diagnosis and satellite-derived phytoplankton functional
types and ocean currents. The Lagrangian coherence of the flow is
diagnosed in space and time simultaneously to identify which structures
favor diatom growth. Observations evidence that flow structures with a
high degree of coherence (40 days or longer) in high turbulent kinetic
energy and vorticity sustain high concentrations of diatoms in the
sunlite layers. Our findings show that the integration of Eulerian
kinematic variables into a Lagrangian frame allows revealing new
dynamical aspects of geophysical turbulence and unveil transport
properties having large biological impacts.
Civic Habitus and the Challenges of Depoliticized Participatory Irrigation Management Reforms: Insights from Pakistan
Authors: Arfan Muhammad , Ward Mercedes , Ali Muhammad , Ullah Asmat , Ansari Kamran
Published: March 2023

In 1980, the World Bank began to promote Participatory Irrigation
Management (PIM) reforms to overcome disparities in the distribution of
public irrigation water for agricultural uses. Yet, in Pakistan as in
other countries, PIM was unable to achieve its objectives of equitable
resource distribution and financial sustainability. This paper examines
how the neoliberal understanding of citizens’
participation/participatory development as demonstrated in PIM fails
because its underlying theory of change overlooks power asymmetry
issues, institutional politics, and farmers’ engagement processes.
Drawing on quantitative and qualitative data collected through
structured and semi-structured interviews, focus group discussions, and
participant observation in Pakistan’s agrarian heartlands of Punjab and
Sindh, we argue that traditional irrigation bureaucracy, donor agency
technocrats, and depoliticized participatory development approach
intentionally or unintentionally ignore the muted voices of small and
landless peasants in the reform process. Under such circumstances,
reform cannot generate hydro-solidarity, trust, and collective action
from below. Moreover, the irrigation bureaucracy only mimics the
institutions of participation under an externally assisted push because
the PIM model was never adequately tested and implemented. We argue that
without active farmers’ agency—small and landless peasants, these
paper organizations cannot create multi-level accountability in
irrigation management. We elucidate an important but under-theorized
factor contributing to these failures: depoliticized irrigation
management transfer processes that fail to redistribute social power.
Donor articulations of the PIM “theory of change” do not make explicit
that a shift in social power – not just management authority and
responsibility – is necessary.
Modelling the response of mangroves and saltmarshes to sea-level rise: model development and validation
Authors: Rogers Kerrylee , Mogensen Laura A , Repina Oxana , Saintilan Neil
Published: March 2023

Models of the response of mangrove forests and saltmarshes to sea-level
rise are needed to inform coastal decision making. Zero-dimensional
models that simulate evolution of a point are foundational for
developing spatially explicit landscape models projecting coastal
wetland extents under future sea-level rise scenarios. However, both
zero-dimensional and spatially explicit landscape models have suffered
from insufficient calibration and inadequate validation. In this study,
a zero-dimensional model framework was parameterised using real data
from four sub-sites exhibiting varying rates of mineral and organic
matter addition and autocompaction. The model was calibrated to
correspond to tidal parameters at each sub-site and validation was
undertaken across three timescales to assess model efficacy. Short-term
validation encompassed the period over which measurements of surface
elevation gain were determined using a network of surface elevation
tables (~20 years); medium-term validation encompassed
the period when higher resolution colour aerial photography was
available (~35 years); and long-term validation focussed
on the period of landscape evolution occurring since the mid-Holocene.
The model performed well at the medium to long-term scale and was within
the range of variability arising from surface elevation table
measurements. This study demonstrates the critical need for
site-specific data, a crucial component that is undervalued, often
insufficiently resourced to generate useful data, and commonly addressed
by extrapolating parameters generated from elsewhere. Validation has
provided the necessary confidence for further model development at the
landscape scale that will account for processes operating both
vertically and laterally, such as shoreline erosion and tidal creek
extension.
Eddy tracking from in situ and satellite observations
Authors: Erickson Zachary K , Fields Erik , Johnson Leah , Thompson Andrew F. , Dove Lilian A. , D'Asaro Eric A , Siegel David A.
Published: March 2023

Mesoscale eddies are a dominant source of spatial variability in the
surface ocean and play a major role in the biological marine carbon
cycle. Satellite altimetry is often used to locate and track eddies, but
this approach is rarely validated against in situ observations. Here we
compare measurements of a small (under 25 km radius) mode water
anticyclonic eddy over the Procupine Abyssal Plain using CTD and ADCP
measurements from 3 ships, 2 gliders, 2 profiling floats, and one
Lagrangian float with those derived from sea level anomaly. In situ
estimates of the eddy center were estimated from maps of the thickness
of its central isopycnal layer, from ADCP velocities at a reference
layer, and from the trajectory of the Lagrangian float. These were
compared to three methods using altimetric SLA: one based on maximizing
geostrophic rotation, one based on a constant SLA contour, and one which
maximizes geostrophic velocity speed along the eddy boundary. All
algorithms were used to select CTD profiles that were within the eddy.
The in-situ metrics agreed to 97\%. The altimetry
metrics showed only a small loss of accuracy, giving
$>90$\% agreement with the in situ
results. This suggests that current satellite altimetry is adequate for
understanding the spatial representation of even relatively small
mesoscale eddies.
Seasonal and elevational variability in dwarf birch VOC emissions in Greenlandic tundra
Authors: Rieksta Jolanta , Li Tao , Davie-Martin Cleo Lisa , Simin Tihomir , Aeppli Laurids Christian Brogaard , Høye Toke Thomas , Rasmussen Morten Arendt , Rinnan Riikka
Published: March 2023

Rising temperatures amplify biogenic volatile organic compound (VOC)
emissions from arctic vegetation, causing feedbacks to the climate
system. Changes in climate also alter plant physiology and vegetation
composition, all of which can influence VOC emissions. Moreover, leaf
development and biotic stresses cause highly variable emissions during
the growing season. Therefore, linking VOC emissions with plant traits
and tracking responses to climate change might provide better
understanding of VOC emission regulation under future conditions.

We measured VOC emissions and other plant traits in dwarf birch
(Betula glandulosa) at two elevations in Narsarsuaq, South
Greenland. The measurements were performed in warming experiments that
have run since 2016. We collected VOCs using the branch enclosure method
from early June until late July 2019 (n = 200).

Emissions of green leaf volatiles (GLVs), oxygenated monoterpenes
(oMTs), and homoterpenes followed a seasonal trend. VOC emission rates
and the diversity of the VOC blend decreased at the end of the
measurement period. Differences in VOC emission rates between elevations
were most pronounced early in the season. Most traits did not explain
the variation in VOC emissions.

We show strong seasonal variability in VOC emissions within the growing
season, which are likely driven by leaf phenology. While the diversity
of VOCs was greater at the milder low-elevation site, VOC emission rates
were higher or similar at the harsher high-elevation site, showing
stronger VOC emission potentials than previously assumed. Seasonal
variations in the VOCs are crucial for accurate predictions of current
and future VOC emissions from arctic ecosystems.
Synergistic Effect of BaCl2 on Corrosion Inhibition of Copper by Mentha Spicata Oil in 1M Nitric Acid: Gravimetric and Raman Spectroscopy Studies
Authors:   Centre de Recherche Scientifique et Technique en Analyses Physico-Chimiques. BP 384, zone industrielle 42004 Tipaza, Algérie, Belarbi Nadia ,   Laboratoire de Spectrochimie et pharmacologie Structurale, Département de chimie, Faculté des sciences, Université Abou-Bekr Belkaïd, BP 119 Imama, 13000 Tlemcen, Algérie., Dergal Fayçal ,   Centre de Recherche Scientifique et Technique en Analyses Physico-Chimiques. BP 384, zone industrielle 42004 Tipaza, Algérie,   Laboratoire de Catalyse et Synthèse en Chimie Organique, Faculté des Sciences, Université de Tlemcen, BP 119, 13000 Tlemcen, Algérie, Chikhi Ilyas ,   Laboratoire de Catalyse et Synthèse en Chimie Organique, Faculté des Sciences, Université de Tlemcen, BP 119, 13000 Tlemcen, Algérie,   Université Belhadj Bouchaib, BP 284, Ain Témouchent, 46000 Algérie, Lerari Djahida ,   Centre de Recherche Scientifique et Technique en Analyses Physico-Chimiques. BP 384, zone industrielle 42004 Tipaza, Algérie, Dahmani Benamar ,   Laboratoire de Spectrochimie et pharmacologie Structurale, Département de chimie, Faculté des sciences, Université Abou-Bekr Belkaïd, BP 119 Imama, 13000 Tlemcen, Algérie., Choukchou-Braham Noureddine ,   Laboratoire de Catalyse et Synthèse en Chimie Organique, Faculté des Sciences, Université de Tlemcen, BP 119, 13000 Tlemcen, Algérie, Bachari Khaldoun ,   Centre de Recherche Scientifique et Technique en Analyses Physico-Chimiques. BP 384, zone industrielle 42004 Tipaza, Algérie
Published: March 2023

The effect of Mentha Spicata oil and the mixture of BaCl2 and Mentha Spicata oil on corrosion of copper in 1M HNO3 have been investigated using weight loss methods and Raman spectroscopy. The study revealed that copper is more efficiently inhibited by Mentha Spicata oil in the presence of BaCl2 than pure oil. The inhibition efficiencies increased with increased concentration of the additives. The highest inhibition efficiency of 56.12 % was observed with single Mentha Spicata oil. An improved inhibition efficiency of 75.13 % was observed with the mixture of Mentha Spicata oil and BaCl2 at 298 K in 1M HNO3, an effect attributed to synergism between Mentha Spicata oil and BaCl2. Inhibition efficiency decreased with increase in temperature from 298-328 K. The adsorption of inhibitor molecules on metal surface followed Frumkin and Langmuir isotherm. Thermodynamic parameters such as enthalpy ∆H, free energy of adsorption ∆G and entropy of adsorption are obtained from experimental temperatures ranging from 298-328 K. Raman Spectroscopy and mapping were used to characterize the surface layers.
Activation of Mo2B Catalyst in the Epoxidation Reaction of α-Ethylallyl Ethyl Acrylate with tert-Butyl Hydroperoxide
Authors:   Lviv Polytechnic National University, 12, S.Bandery St., Lviv 79013, Ukraine, Komarenska Zoryana , Oliynyk Lilianna ,   Lviv Polytechnic National University, 12, S.Bandery St., Lviv 79013, Ukraine, Makota Oksana ,   Lviv Polytechnic National University, 12, S.Bandery St., Lviv 79013, Ukraine
Published: March 2023

The regularities of Mo2B catalyst activation in the epoxidation reaction of alfa-ethylallyl ethyl acrylate with tert-butyl hydroperoxide have been studied. It has been shown that the catalyst activation process is described by the Avrami-Erofeev topokinetic equation and includes two successive stages – the nucleation and formation of a new phase active in the epoxidation reaction. The formation of epoxy only occurs in the presence of the activated form of the catalyst. The effective and topochemical process constants have been calculated.
Synthesis, Sorption Properties, and Evaluation of Silica Gel with Adsorbed Poly[8-Oxyquinoline Methacrylate] as a Sorbent for Cu(II), Cd(II), Pb(II) and Fe(III) Ions
Authors:   Taras Shevchenko National University of Kyiv, 12 L. Tolstogo St., 01033 Kyiv, Ukraine, Savchenko Irina , Yanovska Elina ,   Taras Shevchenko National University of Kyiv, 12 L. Tolstogo St., 01033 Kyiv, Ukraine, Sternik Dariusz ,   Maria Curie-Skłodowska University, Maria Curie-Sklodowska Sq., 20-031 Lublin, Poland, Kychkyruk Olga ,   Ivan Franko Zhytomyr State University, 42 Pushkina Str., 10008 Zhytomyr, Ukraine
Published: March 2023

In the present study, a novel functionalized silica composite was prepared by adsorption of poly[8 oxyquinoline methacrylate] on the surface of silica gel. Immobilization of poly[8 oxyquinoline methacrylate] on the silica gel surface was confirmed using IR spectroscopy and thermogravimetric analysis combined with mass spectrometry. Scanning electron microscopy revealed that the polymer almost completely covers the surface of the silica gel in the form of agglomerates of different geometric shapes. The processes of sorption of Cu(II), Cd(II), Pb(II), and Fe(III) ions on the surface of the synthesized composite in the static mode have been studied.
Anomalous Sorption of Yttrium Ions by the Mutual Activated Hydrogels in the Interpolymer System of Poly(Methacrylic Acid) and Poly(4-Vinylpyridine)
Authors:   Bekturov Institute of Chemical Sciences, 106 Sh. Valikhanov St., 050010 Almaty, Kazakhstan, Jumadilov Talkybek , Totkhuskyzy Bakytgul ,   Kazakh National Women's Teacher Training University, 114 Gogol St., 050000 Almaty, Kazakhstan, Imangazy Aldan ,   Bekturov Institute of Chemical Sciences, 106 Sh. Valikhanov St., 050010 Almaty, Kazakhstan, Gražulevičius Juozas ,   Kaunas University of Technology, 73 K. Donelaičio St., 44249 Kaunas, Lithuania
Published: March 2023

This paper considers the effect of mutual activation of poly(methacrylic acid) (PMAA) and poly-(4 vinylpyridine) (P4VP) hydrogels during their remote interaction on the degree of yttrium ions sorption from an aqueous medium. Electrochemical properties were studied by conductometry and pH measurements to predict the activation possibility of these hydrogels. pH measurements showed that at 0.1 hour, the pH values were the lowest, indicating a high content of H+ ions in the aqueous solution. An increase in the interaction time to 24 hours leads to an increase in pH values, indicating a decrease in the content of H+ ions in the solution. The dependences of the specific electrical conductivity were studied. The experiments showed that the maximum values were observed at the ratios of 3 : 3 and 1 : 5 (gPMAA : gP4VP), which coincided with the result of pH measurements. The obtained results indicate the significant changes occurred in the electrochemical and conformational values of the initial macromolecules in the interpolymer system. Our research confirms the presence of remote interaction between hydrogels and their mutual activation.
Green Synthesis of Functionalized Poly(3-Glycidoxypropyl-Trimethoxysilane) Using an Eco-Catalyst (Treated Montmorillonite)
Authors:   Laboratoire de Chimie des Polymères, Département de Chimie Univerité Oran1, BP N° 1524 El M’Naouar, 31100 Oran, Algeria, Embarek Nadia , Sahli Nabahat ,   Laboratoire de Chimie des Polymères, Département de Chimie Univerité Oran1, BP N° 1524 El M’Naouar, 31100 Oran, Algeria
Published: March 2023

Telechelic poly(3-glycidoxypropyltrimetho¬xysilane) (PGPTMS) with acetate and methacrylate end groups was successfully synthesized by an efficient and solvent-free approach, with anhydrides (acetic anhydride (AA) and methacrylic anhydride (MA)), by cationic ring-opening polymerization of 3 glycidoxypropyl¬trimetho-xysilane (GPTMS), using an ecologic solid catalyst Maghnite-H+ (Mag-H+), instead of electrophilic catalysts, such as, Bronsted and Lewis acids which are very noxious and corrosive. Mag-H+ is a montmorillonite sheet silicate clay exchanged with protons. The structure of the obta¬ined macromonomers was confirmed by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic reso¬nance (NMR) and UV-visible spectroscopy. The presence of the methacrylate end groups of bis-macromonomers was determined by UV-visible spectroscopy. In order to find the optimal reaction conditions, effects of reaction time and the amount of anhydrides (AA and MA) on the yield of macromonomers were investigated.
Synthesis of Copolymer from 1,3,5-Trioxane and -Caprolactone Catalysed by Treated Bentonite as Eco-Catalyst
Authors:   Laboratory of Polymer Chemistry, Department of Chemistry, Faculty of Exact and Applied Sciences, University Oran 1, Ahmed Ben Bella, BP N°1524 EL M’Naouer, 31000, Oran, Algeria, Mahi Hanane Benmoussa , Issam Ferrahi Mohammed ,   Laboratory of Polymer Chemistry, Department of Chemistry, Faculty of Exact and Applied Sciences, University Oran 1, Ahmed Ben Bella, BP N°1524 EL M’Naouer, 31000, Oran, Algeria
Published: March 2023

This study presents a novel green method for copolymerizing 1,3,5-trioxane (TOX) with ε caprolactone (CL). This technique uses Maghnite-H+ (Mag-H+) as a bulk green catalyst. Various techniques were used to confirm the structure of the resulting copolymer. The influencing factors on the copolymerization reaction were also studied. The results show that the best copolymer yield (46.3 %) was obtained via bulk copolymerization at a temperature of 353 K for a reaction time of 8 h.
Characterization, Antioxidant Activity, and In Silico Molecular Docking of Chitosan from Snail Shell Waste by Ultrasonic Technique
Authors:   Doctoral student of Biology, Faculty of Mathematic and Natural Sciences, University of Brawijaya, Malang 65145, East Java, Indonesia, Umarudin Umarudin ,   Department of Pharmacy, Diploma III Pharmacy, Academy Pharmacy of Surabaya, Surabaya 60231, East Java, Indonesia, Rahayu Sri ,   Department of Biology, Faculty of Mathematics and Natural Sciences, University of Brawijaya, Malang 65145, East Java, Indonesia, Widyarti Sri ,   Department of Biology, Faculty of Mathematics and Natural Sciences, University of Brawijaya, Malang 65145, East Java, Indonesia, Warsito Warsito ,   Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Brawijaya, Malang 65145, East Java, Indonesia,   Essential Oil's Institute, University of Brawijaya, Malang 65145, East Java, Indonesia
Published: March 2023

Snails are often found in Indonesia, especially at Kediri, but the snail shell has no commercial value. This research report describes the characterization and antioxidant activity of chitosan from snail shell waste (chitosan-SSW) by ultrasonic technique and analyzes the potential of chitosan as an inhibitor of receptors of free radicals using an in silico molecular docking method. Characterization of chitosan-SSW was performed to analyze the content of water, protein, and functional groups as well as molecular weight, particle size, mor-phology, antioxidant activity, and in silico molecular docking. We found that chitosan-SSW with ultrasonic treatment had a high degree of deacetylation (DD) and high molecular weight (MW). The characteristic of chitosan-SSW was found to be as follows: water content of 0.43 %, protein content of 1.59 %, molecular weight of 2.198 kDa, and deacetylation degree value of 79.50 %. Importantly, chitosan-SSW had high antioxidant activity to potentially reduce free radical of DPPH with IC50 value of 2.44 µg/mL. Chitosan is predicted to have the potential as an inhibitor of lipoxygenase, CYP2C9, and NADPH-oxidase.
Land Cover Changes Based on Landsat Imagery Interpretation
Authors: Rahayu Chairiyah Umi , Indarto Indarto , Pradiksa Alfian Wiji , Putra Bayu Taruna Wijaya , Nadzirah Rufiani
Published: March 2023

This paper presents the use of satellite data (i.e., Landsat-5 & Landsat-8) to interpret the change of land cover from 1997 to 2020. The study area covers the administrative boundary of Lumajang Regency. The land-cover map of the year 1997 derived from Landsat-5. The Land-cover map of the year 2020 interpreted from Landsat-8. This study uses two methods of image classifications (i.e., unsupervised and supervised). The procedure includes image enhancement, registration, and classification. Then, classification results evaluated by confusion-matrix (overall and kappa accuracy). The supervised classification produces 7 classes of Land cover (i.e., forest, pavement/urban area), paddy field, plantation, rural area, water body and sand mining area. Unsupervised classification produced four 5 class i.e., forest, built-area, paddy field, rural area, and plantation. Supervised classification done the overall and kappa accuracy = 86% and  82%, while unsupervised classification = 73% and 64% for 1997 imagery. Furthermore, for 2020 image, the Supervised classification reaches the overall and kappa accuracy = 93% and  90%, while unsupervised classification done 81% and 72%. The supervised classification method gives a better result than un-supervised. Comparison of 1997 to 2020, it also shows the increase in pavement or build-area, followed by paddy field, rural area, and sand-mining. The change also appears as the decrease in forest and plantation areas.Keywords:   Landsat-5, Landsat-8, Unsupervised, Supervised, Lumajang
Effect of Drying Temperature on Quality of Dried Red Ginger (Zingiber Officinale Var. Rubrum)
Authors: Nasution Addiena Syahvina , Hasbullah Rokhani , Hartulistiyoso Edy
Published: March 2023

Red ginger is a source of herbal medicines that contain phenolic compounds. The advantage of red ginger as an herbal medicine requires proper handling and treatment so that the phenolic compounds in red ginger are not damaged. Drying is the right method for obtaining red ginger extract. The aims of this study were to investigate the effect of temperature on the proximate composition of dried red ginger and to investigate the suitable temperature for drying red ginger. Red ginger drying was carried out at various temperatures (40, 50, and 60 °C). The simplicia of red ginger was then mashed and sieved. Measurement of the quality of the simplicia included yield, moisture content, ash content, fat content, protein content, crude fiber content, and carbohydrate content. Dried red ginger was observed that all parameters examined were affected by drying at various temperatures except for ash content. The result of drying temperature at 50 °C showed a better quality of dried red ginger based on yield (17,64%), moisture content (6,88%), protein content (1,80%), and crude fiber content (1,86%). Keywords: Drying, Proximate, Red ginger, Simplicia, Yield.
Arduino-Based Data Acquisition Device Design for Specific Heat Determination of Hot Vegetable Oil
Authors: Kusuma Redika Ardi , Radi Radi , Saputro Arifin Dwi
Published: March 2023

Vegetable oil is commonly used for cooking and frying at high temperatures. Information on the oil's specific heat in a process can help estimate the time and energy spent to reach a particular temperature. However, finding an accurate and affordable instrument for measuring specific heat at high temperatures was complex. This study aimed to design a prototype data acquisition device (DAQ) that can support the specific heat of high-temperature vegetable oil determination using the Joule experiment and Newton's correction. This study had two stages: prototype design/construction and prototype testing. The DAQ prototype consisted of a PZEM-003 power sensor, a PT100 temperature sensor, a relay, and an Arduino Mega 2560. The measurement results were displayed on an LCD and recorded in Microsoft data streamer. The prototype was tested by comparing the temperature, voltage, and current with commercial instruments resulting in accuracy and precision of 99.97% (99.95%), 99.97% (99.86%), and 99.99% (99.86 %), respectively. Performance tests showed that the specific heats of canola, corn, and sunflower oils at 100°C based on DAQ data analyzed separately were 2.119 J/kg.°C, 2.082 J/kg.°C, and 2.458 J/kg, respectively. The specific heat values were close to those in the reference, with an accuracy of 94.22%, 97.29%, and 99.80%, respectively. Keywords: ATmega2560, DAQ, Heat capacity, Hysteresis, Vegetable oil
Extraction of Phenolic Total Compound and Determination of Antioxidant Activity of Cocoa Leaves Extracted Using Various Solvents
Authors: Hartiningsih Subekti , Supriyanto Supriyanto
Published: March 2023

In the cultivation of cocoa plants there are by-products, one of which is cocoa leaves. This by-product comes from periodic pruning of cocoa plants which has not been utilized optimally. Phenolic compounds contained in the cocoa leaves are known as bioactive compounds which also have a role as antioxidants. The content of bioactive compounds in cocoa leaves can be extracted from plant tissues by extraction method. The objective of this research was to achieve cocoa leaf extract with the highest antioxidant content using the maceration method. Extraction by maceration on old cocoa leaves with a variety of solvents, namely methanol, acetone, and ethyl acetate. The results showed that the extract of old cocoa leaves with methanol as a solvent showed the highest content of polyphenolic compounds. A yield of 7,129% was attained from old cocoa leaves with total phenolic content of 349,952 ± 0,051 mg EAG/g sample, EC 50 antioxidant value of 287,958 ± 0.144, and antioxidant activity of 86,928 % RSA. The yield of phenolic compounds and antioxidant activity contained in cocoa leaf extract (sequentially from the highest) were obtained with methanol solvent, followed by acetone and ethyl acetate solvents. Keywords: Antioxidant activity, Bioactive, Cocoa leaf, Methanol solvent, Yield