bluuebunny/crossref_metadata_2025 huggingface dataset:
Factor’s Persistence in Foreign and Indigenous Doctoral Research Completion: University Teachers’ Perception
Authors: Et al., Memoona Bibi
Published: March 2021

The doctoral degree focuses on the training and application of research in a certain professional field instead of basic research to expand the knowledge of the field. Timely completion of a doctoral degree depends on many affecting factors. The study was aimed; to compare the persistence of factors between male and female and foreign and indigenous doctoral researchers. The research design of the study was qualitative in nature. 29 indigenous and 19 foreign interviews were conducted by the personal visit of the researcher. Collected data were analysed manually by thematic analysis. The findings of the study inferred that most of the foreign and indigenous had friendly relation with their supervisor. Most of the foreign respondents were highly satisfied with the departmental practices and policies whereas some of the indigenous respondents were not satisfied with the departmental practices and policies and the supervisor’s feedback. It was recommended that researchers may be devoted and honest towards doctoral research and departmental management may be cooperative with the doctoral research students.
A GIS Analysis of Intra-Site Spatial Patterning at the Early Paleoindian Mt. Albion West Site (AhGw-131)
Authors: Pilon Amelia K. , Watts Christopher M.
Published: March 2021

The Mt. Albion West (AhGw-131) Early Paleoindian site is one of only a handful of Late Pleistocene sites in Ontario. Excavated by Archaeological Services Inc. (ASI) between 1998 and 2004, the site is situated adjacent to the Red Hill valley on the Niagara Escarpment in Hamilton, Ontario. The project yielded detailed analyses concerning the tools and debitage recovered from the four discrete artifact concentration areas at this site in addition to a brief assessment of potentially significant intra-site patterning within one locus. In this paper, the four activity areas from Mt. Albion West are analyzed using Geographic Information Systems (GIS) to investigate these spatial relationships with an eye toward interpreting the duration and frequency of the site’s occupation(s) as well as its function(s) within the broader Gainey settlement system.
Experience of sand pit recultivation in the Northern taiga subzone
Authors: Осипенко Р.А. , Зарипов Ю.В. , Белов Л.А. , Морозов А.Е.
Published: March 2021

На основании обследования рекультивированных сухоройных карьеров в Западно-Сибирском северотаежном равнинном лесном районе Ханты-Мансийского автономного округа – Югры предпринята попытка оценки эффективности рекультивации нарушенных земель. Установлено, что рекультивационные работы на территории выработанных карьеров проводятся в два этапа. При этом технический этап рекультивации выполняется после завершения работ по добыче песка и заключается в очистке территории от мусора, демонтаже временных сооружений, планировке территории и внесении торфопесчаной смеси. Биологический этап рекультивации выполняется после технического этапа и включает посев семян многолетних трав и внесение удобрений. Несмотря на устоявшуюся практику подобной рекультивации выработанных песчаных карьеров, ее нельзя признать экологически и хозяйственно правильной. Поскольку участки под карьеры изымались из лесного фонда, их рекультивация после завершения работ по добыче песка должна включать посадку сеянцев сосны обыкновенной (Pinus sylvestris L.) с последующим переводом участков в покрытую лесной растительностью площадь. Посев многолетних трав не обеспечивает формирование древесной растительности из-за недостатка семян хвойных пород, особенно на карьерах большой площади.

An attempt was made to assess the effectiveness of disturbed lands reclamation by surveying rusk quarry in the western Siberian month taiga lowland forest region of Khanty-Mansiisk autonomous okrug – Jugra. At was established that on the territory of worked out quarries the recultivation works were carried out in two stages. At the same time, the technical stage of reclamation is carried out after the completion of sand extraction stage and consists in cleaning the territory from garbage, dismantling the temporary structures, planning the territory and peat and sand mixture introduction. Biologic stage of recultivation is carried out after technical one and includes sowing of perennial grasses and introducing of fertilizers. Despite of the well established practice application in worked out sand quarries it cannot be recognized as ecological and economic correct. Since the plots under the quarries were withdrawn from the forest fund their reclamation after the and extraction completion shoned include the planting of scots pine seedlings with the subsequent transfer of the site into an area covered with forest vegetation. Sowing of perennial grasses doesn’t provide for the formation of woody vegetation due to the lock of coniferous seeds, especially in open pits of a large area.
ACTIVATION OF ASPEN CHARCOAL
Authors: Евдокимова Е.В. , Мальцев Г.И.
Published: March 2021

Представлены результаты экспериментальных исследований по активации осинового угля зольностью 2,5 % водяным паром на выход и свойства полученного активного угля. Показано, что для активации лучше использовать уголь из спелой осины, а не из тонкомера, поскольку значения зольности у осинового угля из тонкомера сравнительно высокие и не могут гарантировать соблюдение этого показателя в товарном АУ. В этой связи необходимо применять технологию, обеспечивающую сравнительно высокий выход продукта. В наших исследованиях это условие выполнялось путем использования Z–образной вставки в печи активации.

The results of experimental studies on the activation of aspen coal with an ash content of 2.5 % by water steam on the yield and properties of the resulting activated carbon are presented. It is shown that for activation it is better to use coal from ripe aspen, rather than from thin aspen, since the ash content of aspen coal from thin aspen is relatively high and cannot guarantee compliance with this indicator in the commercial activated carbon. In this regard, it is necessary to use a technology that provides a relatively high yield of the product. In our studies, this condition was met by using a Z-shaped insert in the activation furnace.
Influence of soil on the composition of young stands formed on former agricultural lands
Authors: ЖИЖИН С.М. , МАГАСУМОВА А.Г.
Published: March 2021

Проанализировано формирование древесной растительности на бывших сельскохозяйственных угодьях на территории муниципального образования «Игринский район» Республики Удмуртия. Указанная территория относится к подзоне южной тайги и входит в состав южно-таежного лесного района европейской части Российской Федерации. На основании данных натурных обследований и дешифрирования космических снимков высокого пространственного разрешения предпринята попытка определения площади пашни, зарастающей древесной растительностью, после исключения ее из активного сельскохозяйственного оборота. На основе почвенных карт, составленных специалистами акционерного общества Агрохимцентр «Удмуртский», проведено сопоставление доминирующих в составе формирующихся молодняков видов древесных пород с характеристиками почв. Установлено, что в составе формирующихся молодняков на бывших пашнях доминируют береза повислая (Betula pendula Roth.), ель европейская (Picea abies (L.) Korst.), сосна обыкновенная (Pinus sylvestris L.) и различные виды ив (Salix L.). Состав формирующихся молодняков зависит от многих факторов, в том числе от типа и гранулометрического состава почв. Наличие во всех формирующихся молодняках сосны и ели свидетельствует о возможности формирования высокопроизводительных смешанных насаждений. С учетом специфики лесорастительных условий и особенностей формирования насаждений на бывших пашнях рекомендуется разработка системы лесоводственных мероприятий в подобных насаждениях.

The article deals with the formation of woody vegetation on the territory of the municipal formation «Igrinskiy region» of the Republic of Udmurtia. The territory belongs to the subzone of the southern taiga and is the part of the Southern taiga forest region of the Russia Federation European part. Based on the data al field surveys and interpretation of lingh spatial resolution satellite images, an attempt was made to determine the area of arable land overgrown with woody vegetation after its exclusion from active agricultural turnover. On the base of soil maps compiled by the specialist of the joints stock company agrochemical centre «Udmurtskiy», the dominant in composition of the emerging young stands tree species were compared with the characteristics of soils. It was established that in the composition of the young growts on the former arable land drooping birch (Betula pendula Roth.), European spruce (Picea abies (L.) Korst.) and some of willow (Salix L.) dominate on these arable lands. The composition of the emerging stands depends on many factors including the type and granulometric composition of soils. The presence of pine and spruce in all emerging young stands indicate the possibility al formation of highly productive mixed stands. Taking in to account the specifics of forest growing conditions and the peculiarities of the formation of plantings on the former arable lands. It is recommended to develop a system of silvicultural measures in such plantations.
Identifying source regions of air masses sampled at the tropical
high-altitude site of Chacaltaya using WRF-FLEXPART and cluster
analysis
Authors: Aliaga Diego , Sinclair Victoria A. , Andrade Marcos , Artaxo Paulo , Carbone Samara , Kadantsev Evgeny , Laj Paolo , Wiedensohler Alfred , Krejci Radovan , Bianchi Federico
Published: March 2021

Abstract. Observations of aerosol and trace gases in the remote troposphere are vital to quantify background concentrations and identify long term trends in atmospheric composition on large spatial scales. Measurements made at high altitude are often used to study free tropospheric air however such high-altitude sites can be influenced by boundary layer air masses. Thus, accurate information on air mass origin and transport pathways to high altitude sites is required. Here we present a new method, based on the source-receptor relationship (SRR) obtained from backwards WRF-FLEXPART simulations and a k-means clustering approach, to identify source regions of air masses arriving at measurement sites. Our method is tailored to areas of complex terrain and to stations influenced by both local and long-range sources. We have applied this method to the Chacaltaya (CHC) GAW station (5240 m a.s.l.,16.35° S, 68.13° W) for the 6-month duration of the “Southern hemisphere high altitude experiment on particle nucleation and growth” (SALTENA) to identify where sampled air masses originate and to quantify the influence of the boundary layer and the free troposphere. A key aspect of our method is that it is probabilistic and for each observation time, more than one air mass (cluster) can influence the station and the percentage influence of each air mass can be quantified. This is in contrast to binary methods, which label each observation time as influenced either by boundary layer or free troposphere air masses. We find that on average, 9% of the air sampled at CHC, at any given observation time, has been in contact with the surface within 4 days prior to arriving at CHC, 24% of the air was located below 1.5 km above ground level and consequently, 76% of the measured air masses at CHC represent free tropospheric air. However, pure free-tropospheric influences are rare and often samples are concurrently influenced by both boundary-layer and free-tropospheric air masses. A clear diurnal cycle is present with very few air masses that have been in contact with the surface being detected at night. The 6-month analysis also shows that the most dominant air mass (cluster) originates in the Amazon and is responsible for 29% of the sampled air. Furthermore, short-range clusters (origins within 100 km of CHC) have high temporal frequency modulated by local meteorology driven by the diurnal cycle whereas the mid- and long-range clusters’ (>200 km) variability occurs on timescales governed by synoptic-scale dynamics. To verify the reliability of our method, in-situ sulfate observations from CHC are combined with the SRR clusters to correctly identify the (pre-known) source of the sulfate: the Sabancaya volcano located 400 km northwest from the station.
The effect of (NH4)2SO4 on the freezing properties of non-mineral dust ice nucleating substances of atmospheric relevance
Authors: Worthy Soleil E. , Kumar Anand , Xi Yu , Yun Jingwei , Chen Jessie , Xu Cuishan , Irish Victoria E. , Amato Pierre , Bertram Allan K.
Published: March 2021

Abstract. A wide range of materials including mineral dust, soil dust, and bioaerosols have been shown to act as ice nuclei in the atmosphere. During atmospheric transport, these materials can become coated with inorganic and organic solutes which may impact their ability to nucleate ice. While a number of studies have investigated the impact of solutes at low concentrations on ice nucleation by mineral dusts, very few studies have examined their impact on non-mineral dust ice nuclei. We studied the effect of dilute (NH4)2SO4 solutions on immersion freezing of a variety of non-mineral dust ice nucleating substances including bacteria, fungi, sea ice diatom exudates, sea surface microlayer, and humic substances using the droplet freezing technique. We also studied the effect of (NH4)2SO4 on immersion freezing of mineral dust particles for comparison purposes. (NH4)2SO4 had no effect on the median freezing temperature of nine of the ten tested non-mineral dust materials. There was a small but statistically significant decrease in the median freezing temperature of the bacteria X. campestris (change in median freezing temperature ∆T_50 = -0.43 ± 0.19 °C) in the presence of (NH4)2SO4 compared to pure water. Conversely, (NH4)2SO4 increased the median freezing temperature of four different mineral dusts (Potassium-rich feldspar, Arizona Test Dust, Kaolinite, Montmorillonite) by 3 °C to 8 °C. This significant difference in the response of mineral dust and non-mineral dust ice nucleating substances when exposed to (NH4)2SO4 suggests that they nucleate ice and/or interact with (NH4)2SO4 via different mechanisms. This difference suggests that the relative importance of mineral dust to non-mineral dust particles for ice nucleation in mixed-phase clouds could increase as these particles become coated with ammonium sulfate in the atmosphere. This difference also suggests that the addition of (NH4)2SO4 to atmospheric samples of unknown composition could be used as an indicator or assay for the presence of mineral dust ice nuclei.
Global methane budget and trend, 2010–2017: complementarity of inverse analyses using in situ (GLOBALVIEWplus CH4 ObsPack) and satellite (GOSAT) observations
Authors: Lu Xiao , Jacob Daniel J. , Zhang Yuzhong , Maasakkers Joannes D. , Sulprizio Melissa P. , Shen Lu , Qu Zhen , Scarpelli Tia R. , Nesser Hannah , Yantosca Robert M. , Sheng Jianxiong , Andrews Arlyn , Parker Robert J. , Boesch Hartmut , Bloom A. Anthony , Ma Shuang
Published: March 2021

Abstract. We use satellite (GOSAT) and in situ (GLOBALVIEWplus CH4 ObsPack)
observations of atmospheric methane in a joint global inversion of methane
sources, sinks, and trends for the 2010–2017 period. The inversion is done
by analytical solution to the Bayesian optimization problem, yielding
closed-form estimates of information content to assess the consistency and
complementarity (or redundancy) of the satellite and in situ data sets. We
find that GOSAT and in situ observations are to a large extent
complementary, with GOSAT providing a stronger overall constraint on the
global methane distributions, but in situ observations being more important
for northern midlatitudes and for relaxing global error correlations
between methane emissions and the main methane sink (oxidation by OH
radicals). The in-situ-only and the GOSAT-only inversions alone achieve 113 and 212 respective independent pieces of information (DOFS) for
quantifying mean 2010–2017 anthropogenic emissions on 1009 global model grid
elements, and respective DOFS of 67 and 122 for 2010–2017 emission trends. The joint
GOSAT+ in situ inversion achieves DOFS of 262 and 161 for
mean emissions and trends, respectively. Thus, the in situ data increase the global
information content from the GOSAT-only inversion by 20 %–30 %. The
in-situ-only and GOSAT-only inversions show consistent corrections to
regional methane emissions but are less consistent in optimizing the global
methane budget. The joint inversion finds that oil and gas emissions in the US
and Canada are underestimated relative to the values reported by these
countries to the United Nations Framework Convention on Climate Change
(UNFCCC) and used here as prior estimates, whereas coal emissions in China are
overestimated. Wetland emissions in North America are much lower than in the
mean WetCHARTs inventory used as a prior estimate. Oil and gas emissions in the US
increase over the 2010–2017 period but decrease in Canada and Europe. The
joint inversion yields a global methane emission of 551 Tg a−1 averaged
over 2010–2017 and a methane lifetime of 11.2 years against oxidation by
tropospheric OH (86 % of the methane sink).
Late-spring and summertime tropospheric ozone and NO2 in western Siberia and the Russian Arctic: regional model evaluation and sensitivities
Authors: Thorp Thomas , Arnold Stephen R. , Pope Richard J. , Spracklen Dominick V. , Conibear Luke , Knote Christoph , Arshinov Mikhail , Belan Boris , Asmi Eija , Laurila Tuomas , Skorokhod Andrei I. , Nieminen Tuomo , Petäjä Tuukka
Published: March 2021

Abstract. We use a regional chemistry transport model (Weather Research and Forecasting model coupled with chemistry, WRF-Chem) in conjunction with
surface observations of tropospheric ozone and Ozone Monitoring Instrument
(OMI) satellite retrievals of tropospheric column NO2 to evaluate
processes controlling the regional distribution of tropospheric ozone over
western Siberia for late spring and summer in 2011. This region hosts a
range of anthropogenic and natural ozone precursor sources, and it serves as a
gateway for near-surface transport of Eurasian pollution to the Arctic.
However, there is a severe lack of in situ observations to constrain
tropospheric ozone sources and sinks in the region. We show widespread
negative bias in WRF-Chem tropospheric column NO2 when compared to OMI
satellite observations from May–August, which is reduced when using
ECLIPSE (Evaluating the
Climate and Air Quality Impacts of Short-Lived Pollutants) v5a emissions (fractional mean bias (FMB) = −0.82 to −0.73) compared with the EDGAR (Emissions Database for Global Atmospheric Research)-HTAP (Hemispheric
Transport of Air Pollution) v2.2
emissions data (FMB = −0.80 to −0.70). Despite the large negative bias, the
spatial correlations between model and observed NO2 columns suggest
that the spatial pattern of NOx sources in the region is well
represented. Scaling transport and energy emissions in the ECLIPSE v5a
inventory by a factor of 2 reduces column NO2 bias (FMB = −0.66 to −0.35), but with overestimates in some urban regions and little change to a
persistent underestimate in background regions. Based on the scaled ECLIPSE
v5a emissions, we assess the influence of the two dominant anthropogenic
emission sectors (transport and energy) and vegetation fires on surface
NOx and ozone over Siberia and the Russian Arctic. Our results suggest
regional ozone is more sensitive to anthropogenic emissions, particularly
from the transport sector, and the contribution from fire emissions
maximises in June and is largely confined to latitudes south of
60∘ N. Ozone dry deposition fluxes from the model simulations show
that the dominant ozone dry deposition sink in the region is to forest
vegetation, averaging 8.0 Tg of ozone per month, peaking at 10.3 Tg of ozone
deposition during June. The impact of fires on ozone dry deposition within
the domain is small compared to anthropogenic emissions and is negligible
north of 60∘ N. Overall, our results suggest that surface ozone in
the region is controlled by an interplay between seasonality in atmospheric
transport patterns, vegetation dry deposition, and a dominance of transport
and energy sector emissions.
Comparability of calibration strategies for measuring mercury concentrations in gas emission sources and the atmosphere
Authors: de Krom Iris , Bavius Wijnand , Ziel Ruben , McGhee Elizabeth A. , Brown Richard J. C. , Živković Igor , Gačnik Jan , Fajon Vesna , Kotnik Jože , Horvat Milena , Ent Hugo
Published: March 2021

Abstract. A primary mercury gas standard was developed at Van Swinden Laboratory (VSL) to establish an International System of Units (SI)-traceable reference point for mercury concentrations at emission and background levels in the atmosphere. The majority of mercury concentration measurements are currently made traceable to the empirically determined vapour pressure of mercury. The primary mercury gas standard can be used for the accurate and precise calibration of analytical systems used for measuring mercury concentrations in air. It has been especially developed to support measurements related to ambient air monitoring (1–2 ng m−3), indoor and workplace-related mercury concentration levels according to health standards (from 50 ng m−3 upwards) as well as stationary source emissions (from 1 µg m−3 upwards). The primary mercury gas standard is based on diffusion according to ISO 6154-8. Calibration gas mixtures are obtained by combining calibrated mass flows of nitrogen and air through a generator holding diffusion cells containing elemental mercury. In this paper, we present the results of comparisons between the primary gas standard and mercury calibration methods maintained by NPL (National Physical Laboratory in the United Kingdom), a National Metrology Institute (NMI), and the Jozef Stefan Institute (JSI), a Designated Institute (DI). The calibration methods currently used at NPL and JSI are based on the bell-jar calibration apparatus in combination with the Dumarey equation or a NIST (National Institute of Standards and Technology in the United States) reference material. For the comparisons, mercury was sampled on sorbent traps to obtain transfer standards with levels between 2 and 1000 ng with an expanded uncertainty not exceeding 3 % (k=2). The comparisons performed show that the results for the primary gas standard and the NIST reference material are comparable, whereas a difference of −8 % exists between results traceable to the primary gas standard and the Dumarey equation.
Tracking aerosols and SO2 clouds from the Raikoke eruption: 3D view from satellite observations
Authors: Gorkavyi Nick , Krotkov Nickolay , Li Can , Lait Leslie , Colarco Peter , Carn Simon , DeLand Matthew , Newman Paul , Schoeberl Mark , Taha Ghassan , Torres Omar , Vasilkov Alexander , Joiner Joanna
Published: March 2021

Abstract. The June 21, 2019 eruption of the Raikoke volcano (Kuril Islands, Russia, 48°N, 153°E) produced significant amounts of volcanic aerosols (sulfate and ash) and sulfur dioxide (SO2) gas that penetrated into the lower stratosphere. The dispersed SO2 and sulfate aerosols in the stratosphere were still detectable by multiple satellite sensors for three months after the eruption. For this study of SO2 and aerosol clouds we use data obtained from two of the Ozone Mapping Profiler Suite (OMPS) sensors on the Suomi National Polar-orbiting Partnership (SNPP) satellite: total column SO2 from the Nadir Mapper (NM) and aerosol extinction profiles from the Limb Profiler (LP) as well as other satellite data sets. The LP standard aerosol extinction product at 674 nm has been re-processed with an adjustment correcting for limb viewing geometry effects. It was shown that the amount of SO2 decreases with a characteristic period of 8–18 days and the peak of sulfate aerosol recorded at a wavelength of 674 nm lags the initial peak of SO2 by 1.5 months. Using satellite observations and a trajectory model, we examined the dynamics of unusual atmospheric feature that was observed, a stratospheric coherent circular cloud (CCC) of SO2 and aerosol from July 18 to September 22, 2019.
Total ozone column retrieval from OMPS-NM measurements
Authors: Orfanoz-Cheuquelaf Andrea , Rozanov Alexei , Weber Mark , Arosio Carlo , Ladstätter-Weißenmayer Annette , Burrows John P.
Published: March 2021

Abstract. A scientific total ozone column product from the Ozone Mapping and Profiler Suite Nadir Mapper (OMPS-NM) observations and its retrieval algorithm are presented. The retrieval employs the Weighting Function Fitting Approach (WFFA), a modification of the Weighting Function Differential Optical Absorption Spectroscopy (WFDOAS) technique. The total ozone columns retrieved with WFFA are in very good agreement with other datasets. A mean difference of 0.6 % with respect to ground-based Brewer and Dobson measurements is observed. Seasonal and latitudinal variations are well represented and in agreement with other satellite datasets. The comparison of our product with the scientific product of OMPS-NM indicate a mean bias of around 0.1 %. The comparison with the Tropospheric Monitoring Instrument products (S5P/TROPOMI) OFFL and WFDOAS, shows a persistent negative bias of about −0.5 % for OFFL and –2 % for WFDOAS. Larger differences are only observed in the polar regions. This data product is intended to be used for trend analysis and the retrieval of tropospheric ozone combined with the OMPS limb profiler data.
Examining the sensitivity of the terrestrial carbon cycle to the expression of El Niño
Authors: Teckentrup Lina , De Kauwe Martin G. , Pitman Andrew J. , Smith Benjamin
Published: March 2021

Abstract. The El Niño‐-Southern Oscillation (ENSO) influences the global climate and the variability in the terrestrial carbon cycle on interannual timescales. Two different expressions of El Niño have recently been identified: (i) central Pacific (CP) and (ii) eastern Pacific (EP). Both types of El Niño are characterised by above-average sea surface temperature anomalies at the respective locations. Studies exploring the impact of these expressions of El Niño on the carbon cycle have identified changes in the amplitude of the concentration of interannual atmospheric carbon dioxide (CO2) variability following increased tropical near-surface air temperature and decreased precipitation. We employ the dynamic global vegetation model LPJ-GUESS (Lund–Potsdam–Jena General Ecosystem Simulator) within a synthetic experimental framework to examine the sensitivity and potential long-term impacts of these two expressions of El Niño on the terrestrial carbon cycle. We manipulated the occurrence of CP and EP events in two climate reanalysis datasets during the latter half of the 20th and early 21st century by replacing all EP with CP and separately all CP with EP El Niño events. We found that the different expressions of El Niño affect interannual variability in the terrestrial carbon cycle. However, the effect on longer timescales was small for both climate reanalysis datasets. We conclude that capturing any future trends in the relative frequency of CP and EP El Niño events may not be critical for robust simulations of the terrestrial carbon cycle.
Reconstructing past hydrology of eastern Canadian boreal catchments using clastic varved sediments and hydro-climatic modelling: 160 years of fluvial inflows
Authors: Gagnon-Poiré Antoine , Brigode Pierre , Francus Pierre , Fortin David , Lajeunesse Patrick , Dorion Hugues , Trottier Annie-Pier
Published: March 2021

Abstract. Analysis of short sediment cores collected in Grand Lake, Labrador, revealed that this lake is an excellent candidate for the preservation of a laminated sediment record. The great depth of Grand Lake, the availability of fine
sediments along its tributaries and its important seasonal river inflow
have favoured the formation of a 160-year-long clastic varved sequence.
Each varve represents 1 hydrological year. Varve formation is mainly
related to spring discharge conditions with contributions from summer and
autumn rainfall events. The statistically significant relation between varve
parameters and the Naskaupi River discharge observations provided the
opportunity to develop local hydrological reconstructions beyond the
instrumental period. The combined detrital layer thickness and the particle
size (99th percentile) series extracted from each varve yield the strongest
correlations with instrumental data (r=0.68 and 0.75 respectively) and have been used
to reconstruct the respective Naskaupi River mean and maximum annual discharges over the 1856–2016 period. The reconstructed Q-mean series
suggest that high Q-mean years occurred during the 1920–1960 period, and a
slight decrease in Q-mean took place during the second half of the
20th century. Independent reconstructions based on rainfall–runoff
modelling of the watershed from historical reanalysis of global geopotential
height fields display a significant correlation with the reconstructed
Naskaupi River discharge based on varve physical parameters. The Grand Lake
varved sequence contains a regional hydrological signal, as suggested by the
statistically significant relation between the combined detrital layer
thickness series and the observed Labrador region Q-mean series extracted
from five watersheds of different sizes.
Atlantic hurricane response to Saharan greening and reduced dust emissions during the mid-Holocene
Authors: Dandoy Samuel , Pausata Francesco S. R. , Camargo Suzana J. , Laprise René , Winger Katja , Emanuel Kerry
Published: March 2021

Abstract. We use a high-resolution regional climate model to investigate the changes in Atlantic tropical cyclone (TC) activity during the period of the mid-Holocene (MH: 6000 years BP) with a larger amplitude of the seasonal cycle relative to today. This period was characterized by increased boreal summer insolation over the Northern Hemisphere, a vegetated Sahara and reduced airborne dust concentrations. A set of sensitivity experiments was conducted in which solar insolation, vegetation and dust concentrations were changed in turn to disentangle their impacts on TC activity in the Atlantic Ocean. Results show that the greening of the Sahara and reduced dust loadings (MHGS+RD) lead to a larger increase in the number of Atlantic TCs (27 %) relative to the pre-industrial (PI) climate than the orbital forcing alone (MHPMIP; 9 %). The TC seasonality is also highly modified in the MH climate, showing a decrease in TC activity during the beginning of the hurricane season (June to August), with a shift of its maximum towards October and November in the MHGS+RD experiment relative to PI. MH experiments simulate stronger hurricanes compared to PI, similar to future projections. Moreover, they suggest longer-lasting cyclones relative to PI. Our results also show that changes in the African easterly waves are not relevant in altering the frequency and intensity of TCs, but they may shift the location of their genesis. This work highlights the importance of considering vegetation and dust changes over the Sahara region when investigating TC activity under a different climate state.
PALEOSTRIPv1.0 – a user-friendly 3D backtracking software to reconstruct paleo-bathymetries
Authors: Colleoni Florence , De Santis Laura , Pochini Enrico , Forlin Edy , Geletti Riccardo , Brancatelli Giuseppe , Tesauro Magdala , Busetti Martina , Braitenberg Carla
Published: March 2021

Abstract. We present PALEOSTRIPv1.0, a MATLAB open-source software designed to perform 1D, 2D and 3D backtracking of paleo-bathymetries. PALEOSTRIP comes with a Graphical User Interface (GUI) to facilitate computation of sensitivity tests and to allow the users to switch on and off all the different processes and thus separate the various aspects of backtracking. As such, all physical parameters can be modified from the GUI. It includes 3D flexural isostasy, 1D thermal subsidence and possibilities to correct for prescribed sea level and dynamical topography changes. In the following we detail the physics embedded within PALEOSTRIP and we show a few applications on a drilling site (1D), a transect (2D) and a map (3D), taking the Ross Sea (Antarctica) as a case study. PALEOSTRIP has been designed to be modular and to allow user to insert their own implementations.
The precipitation variability of the wet and dry season at the interannual and interdecadal scales over eastern China (1901–2016): the impacts of the Pacific Ocean
Authors: Gao Tao , Cao Fuqiang , Dan Li , Li Ming , Gong Xiang , Zhan Junjie
Published: March 2021

Abstract. The spatiotemporal variability of rainfall in the dry (October–March)
and wet (April–September) seasons over eastern China is examined from 1901–2016 based on the
gridded rainfall dataset from the University of East Anglia Climatic Research
Unit. Principal component analysis is employed to identify
the dominant variability modes, wavelet coherence is utilized to investigate
the spectral features of the leading modes of precipitation and their coherences
with the large-scale modes of climate variability, and the Bayesian dynamical
linear model is adopted to quantify the time-varying correlations between
climate variability modes and rainfall in the dry and wet seasons. Results show
that first and second principal components (PCs) account for 34.2 %
(16.1 %) and 13.4 % (13.9 %) of the variance in the dry (wet) season, and
their variations are roughly coincident with phase shifts of the El
Niño–Southern Oscillation (ENSO) in both seasons. The anomalous moisture
fluxes responsible for the occurrence of precipitation events in eastern
China exhibit an asymmetry between high and light rainfall years in the dry
(wet) season. The ENSO has a 4- to 8-year signal of the statistically positive
(negative) association with rainfall during the dry (wet) season over eastern
China. The statistically significant positive (negative) associations
between the Pacific Decadal Oscillation (PDO) and precipitation are found with a
9- to 15-year (4- to 7-year) signal. The impacts of the PDO on rainfall in
eastern China exhibit multiple timescales as compared to the ENSO episodes,
while the PDO triggers a stronger effect on precipitation in the wet season than the dry
half year. The interannual and interdecadal variations in rainfall over
eastern China are substantially modulated by drivers originated from the Pacific
Ocean. During the wet season, the ENSO exerted a gradually weakening effect on
eastern China rainfall from 1901 to 2016, while the effects of the PDO decreased
before the 1980s, and then shifted into increases after the 2000s. The finding
provides a metric for assessing the capability of climate models and
guidance of seasonal prediction.
Spatialized flood resilience measurement in rapidly urbanized coastal areas with a complex semi-arid environment in northern Morocco
Authors: Satour Narjiss , Raji Otmane , El Moçayd Nabil , Kacimi Ilias , Kassou Nadia
Published: March 2021

Abstract. Enhancing resilience is critical for coastal urban systems to cope with and minimize flood disaster risks. This issue is certainly more important in Africa, where the increase in flood frequency is a significant concern for many areas. In this context, urban planners need accurate approaches to set up a standard for measuring the resilience to floods. In Morocco, this issue is still not fully covered by the scientific community despite the obvious need for a new approach adapted to local conditions. This study applied a composite index and geographic-information-system approach to measure and map resilience to floods in three northern coastal municipalities. The approach is also based on a linear ranking of resilience parameters, offering a more optimal classification of spatial resilience variation. The results allowed us to identify specific areas with different resilience levels and revealed the relationship between urban dimensions and the flood resilience degree. This approach provides an efficient decision-support tool to facilitate flood risk management, especially in terms of prioritizing protective actions.
Seismic signature of the COVID-19 lockdown at the city scale: a case study with low-cost seismometers in the city of Querétaro, Mexico
Authors: De Plaen Raphael S. M. , Márquez-Ramírez Víctor Hugo , Pérez-Campos Xyoli , Zuñiga F. Ramón , Rodríguez-Pérez Quetzalcoatl , Gómez González Juan Martín , Capra Lucia
Published: March 2021

Abstract. Seismometers have detected the social response to lockdown measures
implemented following the onset of the COVID-19 pandemic in cities around
the world. This long-lasting pandemic has been a particular challenge in
countries such as Mexico, where the informal economy constitutes most of the
working population. This context motivated the monitoring of the mobility of
populations throughout the various phases of lockdown measures
independently of people's access to the internet and mobile technology. Here we use the variation of anthropogenic seismic noise in the city of
Querétaro (central Mexico) recorded by a network of low-cost Raspberry
Shake seismic stations to study the spatial and temporal variation of human
activity in the city throughout the pandemic and during sporting events. The
results emphasize the importance of densifying urban seismic networks and of
tracking human activities without the privacy concerns associated with
mobile technology.
The tipping points and early warning indicators for Pine Island Glacier, West Antarctica
Authors: Rosier Sebastian H. R. , Reese Ronja , Donges Jonathan F. , De Rydt Jan , Gudmundsson G. Hilmar , Winkelmann Ricarda
Published: March 2021

Abstract. Mass loss from the Antarctic Ice Sheet is the main source
of uncertainty in projections of future sea-level rise, with important
implications for coastal regions worldwide. Central to ongoing and future
changes is the marine ice sheet instability: once a critical threshold, or
tipping point, is crossed, ice internal dynamics can drive a self-sustaining
retreat committing a glacier to irreversible, rapid and substantial ice
loss. This process might have already been triggered in the Amundsen Sea
region, where Pine Island and Thwaites glaciers dominate the current mass
loss from Antarctica, but modelling and observational techniques have not
been able to establish this rigorously, leading to divergent views on the
future mass loss of the West Antarctic Ice Sheet. Here, we aim at closing
this knowledge gap by conducting a systematic investigation of the stability
regime of Pine Island Glacier. To this end we show that early warning
indicators in model simulations robustly detect the onset of the marine ice
sheet instability. We are thereby able to identify three distinct tipping
points in response to increases in ocean-induced melt. The third and final
event, triggered by an ocean warming of approximately 1.2 ∘C from
the steady-state model configuration, leads to a retreat of the entire
glacier that could initiate a collapse of the West Antarctic Ice Sheet.
PERENCANAAN GEDUNG SEKOLAH MENENGAH ATAS DENGAN SISTEM PELAT SATU ARAH DAN DUA ARAH
Authors: Rahmatullah Saepudin Putra Rizky Iqbal , Suhendi Cece , Lestari Asti Maulani
Published: March 2021

Pelat merupakan salah satu komponen struktur yang memiliki peran penting dalam meningkatkan fungsi kegunaan bangunan. Dalam pelaksanaannya, pelat dapat dibagi menjadi dua yaitu sistem pelat satu arah dan sistem pelat dua arah. Perbedaannya terletak pada asumsi distribusi beban yang disalurkan ke balok. Pada beberapa model bangnunan, terdapat model yang hanya cocok dengan sistem pelat dua arah, begitu pun sebaliknya. Oleh karena itu perlu dilakukan studi perbandingan dilihat dari segi efisiensi biaya dan kebutuhan material. Pengambilan data dilakukan dengan observasi langsung ke lapangan untuk mendapatkan ukuran lahan. Objek penelitian berupa gedung sekolah dua lantai dengan ukuran denah kelas 9x8 meter, dilakukan analisa dengan metode perencanaan elastis. Setiap dimensi komponen struktur dibuat serupa antara sistem pelat satu arah dan dua arah. Hasil penelitian menunjukkan bahwa selisih anggaran biaya antara sistem pelat satu arah dan dua arah senilai 2%, lebih ekonomis sistem pelat dua arah. Perbedaan yang signifikan terletak pada volume beton. Sistem pelat satu arah lebih boros pada balok anak senilai 35%. Sementara untuk besi tulangan, sistem pelat satu arah 10% lebih banyak daripada sistem pelat dua arah
ANALISIS KETERLAMBATAN PENYEDIAAN MATERIAL TERHADAP KETEPATAN WAKTU PEMBANGUNAN
Authors: Huqban Amdiya , Madkarsan Paikun , Suhendi Cece
Published: March 2021

Analisis keterlambatan material terhadap ketepatan waktu pembangunan Keterlambatan proyek sering kali terjadi pada setiap pekerjaan pembangunan. Penyebab tersebut biasa terjadi karena kurangnya penjadwalan proyek secara matang. Oleh sebab itu managemen waktu adalah cara bagaimana untuk mengatur dan meminimalisir terjadinya keterlambatan proyek. Analisa ini di maksudkan untuk membuat penjadwalan ulang proyek dengan adanya keterlambatan material. Analisa ini di batasi hanya mengambil material-material terbesar pada setiap item pekerjaan. Dengan analisa diagram grafik curva s dan diagram batang maka telah teridentifikasi material yang terlambat secara signifikan yaitu hebel, genteng, nok, keramik dan gypsum rata-rata mengalami keterlambatan hingga 90%. Metode yang di pakai untuk meneyelasaikan ketepatan waktu ini, dengan menggunakan metode critichal path metode (CPM) namun dalam metode ini tidak masukan biaya, metode hanya di pakai untuk menghitung waktu/jalur kritis pekerjaan saja. Dalam keterlambatan material yang telah di ketahui, maka dilakukanlah penjadwalan ulang atau Critichal Path Metode (CPM) Rekayasa. Metode ini di lakukan dengan cara mendahulukan item pekerajaan sebelum pasangan dinding hebel dan hasil yang di dapat yaitu waktu pekerjaan tetap 12 minggu dengan ketentuan untuk material struktur beton tidak mengalami keterlambatan yang signifikan
Gobernanza corporativa en pequeñas y medianas empresas: una revisión sistemática de literatura
Authors: Mejía-Franco Natalia , Echeverri-Rubio Alejandro , Vieira-Salazar Jaime Andrés
Published: March 2021

La gobernanza corporativa se ha convertido en un elemento significativo para el desempeño y crecimiento de las empresas, sin importar su tamaño. El objetivo de esta investigación, es sistematizar los estudios que relacionan la gobernanza corporativa en las Pymes con la intención de identificar las tendencias investigativas y los desafíos para su implementación. Para ello, se realizó una revisión sistemática de literatura considerando, a través de criterios de selección, 215 publicaciones de Scopus identificando no sólo el número de publicaciones, sino también los índices de productividad de los principales autores, las categorías de las fuentes de publicación y las tendencias de investigación. Este estudio, concluye que son casi nulas las investigaciones que consideran esta metodología para la relación de la temática, identifica cuatro tendencias investigativas: a) el papel de la gobernanza corporativa en la estrategia empresarial, b)la importancia de ésta en la capacidad de solvencia financiera y contable, c) esta gobernanza como estrategia de mediación entre los grupos de interés y d) su relación con la sostenibilidad empresarial, convirtiéndose éstas dos últimas en las nuevas tendencias. Por su parte, el mayor desafío se relaciona con la necesidad de que esta “forma de gobierno” se considere también en las Pymes, ya que incentiva su desempeño y crecimiento en el largo plazo.
Conciencia ambiental en contextos de emergencia sanitaria covid-19
Authors: Diaz Dumont Jorge Rafael , Ledesma Cuadros Mildred Jénica
Published: March 2021

La presente investigación tuvo como objetivo general describir las diferencias que existen en los factores más relevantes que componen la conciencia ambiental en la situación de emergencia sanitaria COVID-19, según la percepción de los ciudadanos de Lima Este. La investigación fue de enfoque cuantitativo, tipo descriptivo, diseño no experimental, nivel comparativo, de corte transversal. Los resultados indicaron que existen diferencias significativas en la conciencia ambiental en sus factores cognitiva, afectiva, conativa y activa; demostrándose, que existe preponderancia de un factor sobre otro, en la situación de emergencia sanitaria COVID-19, según la percepción de los ciudadanos de Lima Este; lo cual implica que se cuenta con evidencia científica para accionar y plantear estrategias, principalmente sobre la dimensión afectiva y así sucesivamente sobre las demás dimensiones activa, conativa y cognitiva.
La inversión del platonismo en Gilles Deleuze, herencia renovada de Nietzsche
Authors: Alcalá Rodríguez Francisco Javier
Published: March 2021

Este artículo trata de dilucidar el proyecto deleuzeano de la inversión del platonismo en relación con el de Nietzsche. Para ello, hemos realizado un bosquejo predominantemente historiográfico de la cuestión en ambos autores. En el caso de Nietzsche, nos interesamos tanto por la relación que la inversión del platonismo presenta en su filosofía con el problema del nihilismo como por la evolución que el tema experimenta a lo largo de su vasta producción intelectual, hasta llegar a su formulación definitiva. A propósito de Deleuze, ofrecimos un amplio recorrido en su obra orientado a rastrear la cuestión, desde su interpretación de la formulación nietzscheana, contrapuesta a la de Heidegger, hasta el meticuloso encaje de la misma en su propia filosofía como un desplazamiento de la esencia a favor del acontecimiento como fuente de singularidades.
¿Las clases léxicas y gramaticales de los hablantes tardíos podrían predecir a los futuros niños con TEL?
Authors: Benavides Alejandra Auza , Murata Chiharu
Published: March 2021

Hoy en día sigue siendo una incógnita la predicción sobre cuáles hablantes tardíos (HT) serán diagnosticados en un futuro próximo como niños con Trastorno Específico del Lenguaje (TDL/TEL). Poco se ha dicho sobre las clases de palabras que usan, a pesar de que se han estudiado a profundidad mediante los inventarios de habilidades comunicativas CDI. El presente estudio pretende ampliar la información acerca de las clases de palabras que emplean 15 hablantes tardíos entre 18 y 30 meses de edad en dos tiempos evaluados. Se busca diferenciar a un grupo de hablantes tardíos más lentos (llamados aquí HT Persistentes, según las clases de palabras, la Longitud Media de Emisión (LME) y la complejidad gramatical que producen y que son reportadas en el CDI. Los resultados mostraron que sí es posible diferenciar a un grupo de HTP de los hablantes tardíos clásicos (HTC), a través de las clases de palabras que emplean, especialmente el uso de verbos. También la LME y la complejidad gramatical reportadas en el CDI fueron útiles para este fin. Los diferentes patrones de producción léxica y gramatical de los subgrupos de hablantes tardíos en dos tiempos distintos de evaluación ofrecen pautas para futuros trabajos que traten de establecer un puente entre los hablantes tardíos persistentes y los niños con TEL.
Editorial Revista IGNIS 2016
Authors: Villamil Ivonne
Published: March 2021

La producción y circulación de conocimiento, en las condiciones actuales de Colombia, es una gran responsabilidad e implica un reto en la reconstrucción del tejido social. El alcance y las posibilidades de nuestro quehacer académico se instauran como un terreno fértil para cimentar el cambio que el mundo de hoy exige a sus individuos y colectividades, un cambio hacia una concientización de lo público, un giro hacia la reivindicación del ejercicio de la ciudadanía y prácticas del conocimiento que sean incluyentes en el contexto en que son vivenciadas. 

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