Lower Valley Research Articles

Integration model and performance analysis of coupled thermal energy storage and ejector flexibility retrofit for 600 MW thermal power units

A flexible retrofitting method for thermal-energy-storage-coupled thermal power units is proposed. The exergy flow Sankey diagram and efficiency of the three charging methods was analyzed in detail, and comparative data were provided. The new thermal energy storage mode coupled with steam ejectors was the optimal solution, with a significantly higher round-trip efficiency than the published results. Further study of the mode revealed slight temperature variations in the molten salt did not affect system efficiency. As the extraction of reheated steam decreases and the extraction of main steam increases, the minimum generation capacity of the unit decreases continuously, reaching a minimum of 40 MW (6.67%). In contrast, the maximum output of the unit at 100% THA release can reach 682 MW, which caused the unit load to change from 26-100% to 6.67–113.67% before and after the retrofit. As the ejection coefficient increased, the round-trip efficiency increased significantly, corresponding to 73%, 77%, and 80% at the study points. The mathematical model based on principal component analysis can effectively characterize the relationship between the ejection coefficients, extraction of main steam, extraction of reheat steam, low valley peaking rate, peak modulation rate, and round-trip efficiency, providing a signal conversion basis for automatically controlling peaking commands during unit operation. Finally, the benefits before and after retrofitting were analyzed in terms of thermal plant operation, proving that the payback period of the system was 4.09 years. Peak tariff and auxiliary service revenue are the most critical parameters affecting the payback period, and a 10% reduction in the peak tariff corresponds to an increase in the payback period of one ∼ two years. The results of this study provide substantial theoretical and practical guidance for the flexible retrofitting of thermal power units.

Lineage diversification of the Sky Island treefrog Scinax curicica (Anura, Hylidae) in the Espinhaço Mountain Range

Abstract Sky Islands present unique landscapes for organismal evolution because they comprise high mountain peaks separated by low valleys with vastly different environmental conditions. The Espinhaço Mountain Range in eastern Brazil is formed of groups of Sky Islands in the states of Minas Gerais and Bahia. Several phylogeographic studies have discovered strong genetic structure among populations of organisms occupying the campo rupestre (rupestrian fields) in the mountains of the Espinhaço. In this study, we aimed to test the hypothesis of spatio-temporal structuring of populations of Scinax curicica in the campo rupestre of the Espinhaço. We recovered three lineages of S. curicica: one lineage occurs in the north portion of the Espinhaço (North Lineage) in an area called Chapada Diamantina, and other two occur in the south portion of the Espinhaço (South 1 and South 2 Lineages) in Minas Gerais. All three lineages showed stable population sizes through time, probably due to the climatic stability of mountaintop areas, which was supported by ecological niche modelling.

Comparing Acute Oral Mucosa Toxicity Associated with Minibeam and Conventional Radiotherapy

Acute oral mucosa toxicity is associated with ulceration, severe pain, and nutritional deficiencies that may lead to treatment interruptions and a decreased quality of life for head and neck cancer patients. Minibeam radiotherapy (MRT) is a type of spatially fractionated radiotherapy that delivers an alternating pattern of sub-millimeter wide peaks of high dose immediately adjacent to much lower valley doses. By delivering a non-uniform dose distribution, MRT allows for elevated peak doses while maintaining extraordinary normal tissue tolerance. In this study, we used an acute oral mucosa toxicity mouse model to test the hypothesis that MRT provides superior tissue sparing compared to conventional radiotherapy (CRT). A total of 33 female C57BLJ6 mice were randomized by body weight (BW) across two CRT groups (n = 4/group) receiving open field radiation of 16 and 20 Gy and five MRT groups (n = 5/group) receiving peak:valley doses of 48:8, 72:12, 96:16, 96:8, and 152:8 Gy. All radiation was given in one fraction. The CRT groups were irradiated with a 10 mm circular field using a 225 kVp PA x-ray beam encompassing the oral cavity and oropharynx. The MRT groups were irradiated with the same arrangement, but the beam was collimated into 0.5 mm wide minibeams spaced 1.1 mm center-to-center using tungsten collimators of 0.5, 1, and 2.5 mm thickness to deliver peak-to-valley ratios (PVRs) of 6:1, 12:1, and 19:1. Acute effects in the oral mucosa were studied using changes in BW as a surrogate for clinically significant oral mucositis. BWs were measured daily starting on the day of treatment, and BW changes were computed relative to the day of treatment. The toxicity endpoint was defined such that mice losing >20% BW were humanely euthanized. Doses of 20 Gy CRT and 96:16 Gy MRT were highly toxic, with all animals in these groups reaching the toxicity endpoint between 9-11 days post-RT, compared to only one animal in the 16 Gy CRT group, and no animals in the other MRT groups. The BWs of all surviving animals returned to baseline within 15 days post-RT. The groups 48:8, 96:8, and 152:8 Gy showed similar BW loss and full recovery patterns. Additionally, the groups 48:8, 72:12, and 96:16 Gy showed that, for the same PVR, increasing the valley dose resulted in increased BW loss. Lastly, animals did not tolerate 96:16 Gy, but those in the 96:8 Gy group fully recovered. Despite the extreme toxicity caused by 20 Gy CRT, animals in the MRT groups tolerated peak doses up to 152 Gy when the valley dose was 8 Gy. These results confirm the superior normal tissue sparing capacity of MRT compared to CRT in an oral mucosa mouse model. We delivered tolerable MRT peak doses an order of magnitude larger than toxic CRT doses. Importantly, our results suggest that valley dose is the most useful parameter to assess acute toxicity when using MRT. Our data may prove useful for eventual clinical applications of MRT in head and neck cancers.

Variable mechanism of electrical impedance for MCT high voltage switch under synergetic action of the mechanical and electric loads

To study the electromechanical coupling effect of Metal Oxide Semiconductor Controlled Thyristor (MCT) high voltage switch under the synergistic action of mechanical load and strong voltage in the actual use of penetrating hard targets and launching, the universal testing machine was used to simulate the overload environment. The rising edge time, falling time and impedance changes in the conduction path of MCT under different stress–strain were tested, respectively. Experimental results showed that the rise time of MCT decreased from 0.08 ms to 0.03 ms when the uniaxial compressive stress increased from 1.20 MPa to 7.3 MPa, and the rising edge time after unloading was 0.04 ms. The falling time had no obvious change with the increase of stress. The total resistance in the path decreased from 833.30 Ω to 564.22 Ω with the increase of strain. The stress–strain of each part of MCT under different uniaxial compressive stress was collected by COMSOL Multiphysics finite element software. Based on the Schrödinger equation, the potential energy operator was established. By introducing the strain Hamiltonian H ε,ν , the E(k)-k model near the minimum value of the conduction band of Si was established by using the k·p perturbation method. Combined with the physical field interface of Schrödinger equation in COMSOL Multiphysics, the valence band structure of Si material under uniaxial strain was studied on the basis of strain Hamiltonian perturbation. The results showed that the 6-degree degenerate valley (Δ6) in the conduction band was split into a 2-degree degenerate valley (Δ2) and a 4-degree degenerate valley (Δ4) due to the stress effect. The strain caused more electrons to occupy the lower Δ4 energy valley, resulting in a decrease in the effective mass of the total conductivity. Therefore, the electron mobility of Si was increased under uniaxial strain. The uniaxial compressive stress could more effectively reduce the curvature radius of valence band top, the effective mass of carriers and the interband scattering between light and heavy hole bands, which was beneficial to improve the hole mobility.

Long-term glacial and fluvial system coupling in southern Greece and evidence for glaciation during Marine Isotope Stage 16

Pleistocene glacial activity was a major influence on runoff and sediment supply in many river systems across the Mediterranean. The geomorphological impacts of changes in sediment supply between glaciated headwater terrains and downstream depocentres spanning several glacial cycles are, however, poorly understood. By applying uranium-series and optically stimulated luminescence dating to fluvial and glacial sediments preserved on Mount Chelmos (2355 m a.s.l.) in southern Greece, we show how changes in the long-term coupling between glacial and fluvial systems are preserved within a major glaciofluvial outwash fan system that functioned during multiple cold stages. We also present evidence in the form of a cemented till unit, stratigraphically below younger Middle Pleistocene glacial deposits, yielding a U-series age close to the limit of the technique, indicating glaciation during Marine Isotope Stage (MIS) 16 - one of the most severe cold stages recorded in the Mediterranean. This is the first time such early glaciation has been directly recorded in Greece and the wider Balkans and is defined here as the Valvousian Stage based on glacial deposits on Mount Chelmos. Geomorphological and geochronological data point to the formation of a more extensive plateau ice field over Chelmos during MIS 12, another severe glacial period in the Balkans that corresponds with the Skamnellian Stage glaciation of Northern Greece. During this phase, very strong coupling of glacial and fluvial systems led to meltwater flood events transferring large volumes of sediment to lower valley zones culminating in the formation of an extensive glaciofluvial outwash fan complex and glaciofluvial terraces. A smaller plateau ice field during MIS 6 and localised valley glaciers between MIS 5d to 5c correlate with the Vlasian and early Tymphian Stage glaciations in Greece, respectively. The delivery of much less meltwater and sediment through a single valley during MIS 6 and MIS 5b to MIS 4 signalled the transition to progressively weaker glacial and fluvial system coupling. After MIS 4 the uncoupling of depositional zones from sediment sources in glaciated catchments led to fluvial incision of glaciofluvial outwash deposits in several valleys. Despite this incision, the glaciofluvial outwash fans preserve a record of glacial and fluvial system interactions during the Middle Pleistocene and early stages of the Late Pleistocene.

Estimation of Tritium Concentration in the Rain- and Groundwater in the Dry River of Hafr Al Batin, Saudi Arabia

Natural tritium is widely dispersed in the environment, leading to human exposure to tritium through water ingestion, inhalation of tritium gas, and absorption through the skin. High levels of tritium in the environment can pose significant health risks due to the potential carcinogenic effects of tritium. Therefore, this study aims to estimate the tritium concentration in spiked water, rainwater, and groundwater by a liquid scintillation counter (LSC). Due to the lower detection levels of the LSC, an enrichment process of tritium ten- to thirtyfold was carried out using the electrolysis process. The enriched water was then analyzed to estimate the tritium concentration. Five reference samples were prepared by diluting a standard with known concentrations (spiked sample) to verify the precision of the measurement technique. The estimated tritium levels of the rainwater and the groundwater were within the 0.3 to 3.5 tritium units (TU) range. A comparatively higher tritium concentration was estimated for the shallow wells in the lower valley of the monitored areas. However, relatively lower concentrations were detected for wells located in the hillside areas. These findings will assist regulatory authorities in formulating strategies to ensure public safety by mitigating human exposure to tritium.

Predictive spatial analysis for a critical assessment of the preservation potential of Palaeolithic record in the Leiria region (central Portugal)

Predictive spatial analysis in archaeology refers to the use of geostatistical and computational techniques to assess the relationships between the distribution of archaeological sites and the environmental context. It is increasingly becoming an essential tool in scientific-academic research and rescue archaeology. In the interconnection between these two working contexts, this study aims to explore the advantages of applying an inductive approach, combining Geographical Information Systems (GIS) and geostatistical methods, to identify areas with different degrees of probability for the preservation of the Palaeolithic record in the lower valley of the Lis River (Leiria region, central Portugal). Topographic, hydrographic, geological, and geomorphological data were collected, processed, and integrated into a spatial database, using a GIS, to define the environmental conditioning factors. After applying a spatial multicollinearity procedure, slope, topographical position index, cost-weighted distance to access the watercourses, heat load index and lithology were chosen as input variables for the predictive modelling. Archaeological data, corresponding to the location of known Palaeolithic sites, were also retrieved from the official records. Three models were implemented using regression and multi-criteria methods; for Model 1 a Generalised Additive Model (GAM) was applied, while for Model 2 and Model 3 two distinct combinations of Probabilistic Frequency Ratio (PFR) and Analytic Hierarchy Process (AHP) were used. The spatial cross-tabulation between the obtained predictive maps and the location of the known Palaeolithic sites shows that all the models are acceptable. However, the combinations of PFR + AHP seem to evidence greater efficacy compared to the GAM. Model 3 offers the best performance (90%), followed by Model 2 (87%) and Model 1 (68%). Possible sources of inaccuracies in the input data and the spatial modelling results were critically discussed. Model 3 generated the most robust and reliable predictive prototype map. The maps produced can serve local and regional agencies as a complement and aid decision-making in public policies for spatial planning, and in the conservation/management of cultural heritage. These cartographic representations can provide quicker identification of areas of interest, for example, in the context of rescue archaeology, along with a substantial reduction in time and costs for project promoters, as well as helping in the environmental impact assessments.

White‐faced and Black‐faced ibises foraging on predictable anthropogenic food subsidies in Patagonia, Argentina

AbstractWaste associated with human activities can benefit opportunistic species at the individual and population levels but could also expose them to pathogens or toxins. We provide information on unreported foraging habits of White‐faced ibis (Plegadis chihi) and Black‐faced ibis (Theristicus melanopis) in the Chubut River Valley, an urban and agricultural landscape in eastern Patagonia, Argentina. Both species were recorded during monthly counts made between February and June 2021 at anthropogenic food sources along the lower river valley, although almost exclusively at those sites offering waste from livestock production. This is the first record of both species foraging at this type of food source of human origin. White‐faced and Black‐faced ibises were present in numbers that varied between 2 and 679 individuals and between 1 and 18 individuals, respectively, depending on the site and month. Both species were recorded walking over carcasses and viscera and probing into these remains or on the soft soil surrounding the ponds where liquids generated by rendering processes were disposed. Given the current growth in livestock production in the area, further monitoring and assessment at other months of the year are needed to adequately interpret the species trophic ecology and the potential conflicts with human populations.

26Al and 10Be concentrations from alluvial drill cores across the Indo-Gangetic plain reveal multimillion-year sediment-transport lag times

Sediment burial can lead to significant lag times during sediment transport and is an important component of the sediment cycle. The Indo-Gangetic Plain (IGP) is a large sediment conveyer belt and understanding sediment lag times on various time scales is important for short- and long-term sediment transport and denudation-rate estimations. In this study, we have quantified the transport lag time in terms of burial duration with 14 different alluvial drill cores from 4 major Himalayan river basins, including the Ghaggar, Paleo-Yamuna, Ganges, and Kosi rivers. We rely on 56 samples using the paired cosmogenic radionuclides, 26Al and 10Be. The coring locations of paleo-Yamuna and Kosi, along with one of the Ghaggar cores are within ∼100 km from the mountain front, while the Ganges cores are ∼350 km away. The coring locations cover an E-W distance of ∼1200 km on the IGP and the depositional ages range from ∼120 kyr BP to the present day based on previous age estimations. Out of 56 samples, 39 samples show a burial signal ranging from 0.61±0.33 Myr to 3.75±1.9 Myr, with outlier values as large as ∼6 Myr.We show that the Kosi samples due to their proximity to the mountain front show no burial or a lower mean burial duration of ∼1.01 Myr, compared to the samples from the coring locations well within the IGP, such as the Ghaggar (∼2.48 Myr) and the Ganges (∼2.36 Myr). However, despite its proximity to the mountain front, the paleo-Yamuna samples have a mean burial duration of ∼2.20 Myr. Along with the floodplains and megafan surface of the IGP, we identify two potential major sediment-lag sources in the Himalayan catchment: The high and low elevation broad valleys and the Siwaliks. Increased storage spaces in the valleys north of the main Himalayan crest, including drainage-captured catchments are likely to provide long burial durations such as in the case of the Kosi and Ghaggar basins. The upper and middle Siwaliks with burial duration in the range of up to ∼6 Myr constitute a second source. We attribute the no-burial signals of 7 samples of the Kosi basin to rapid sediment generation and transportation, driven by dynamic hillslope erosion and fluvial dynamics.Importantly, our data suggest that even samples close to the mountain front exhibit million years of burial duration. These findings suggest that denudation rates derived from modern river sands or in paleo settings will need to account for burial duration and associated processes.

Multidisciplinary approach to investigate human-forest relationships in southern French Alps: How to estimate the impact of populations on the local mountain wood stock?

This study presents a multidisciplinary approach between palaeoecology and the analysis of historical archives to reconstruct forest history subjected to long-term human activities. We focus on a case study from the southern French Alps (the Bléone Valley), for which a rich historical corpus but little palaeoenvironmental data are available. We compared and contrasted (i) pedoanthracological data obtained along an altitudinal transect (ca 400 m), (ii) dendrochronological data from historical buildings and old living trees, and (iii) historical data from written sources on forest management and land-use change. The aim of this paper is to demonstrate that the comparison between different proxy data to understand the history of mountain forest ecosystems and human-forest interactions is very challenging. We show that the spatial distribution of forest and treeline position have been impacted by human activities, mainly due to agro-sylvo-pastoral practices through the use of fire and forest cutting to maintain open pasture lands and local building purposes. Despite centuries of local agro-sylvo-pastoral activities, the forest composition has remained relatively unchanged since the Middle Ages. Our comparison of historical documents with dendrochronological data on local buildings and soil charcoal data shows that the local demands of wood cannot explain the observed large-scale changes in forest spatial continuity. Curiously, the highest demand for wood by local residents did not occur in pace with modern demographic boom (17th century), as would be expected. Thus, we suggest that supra-regional external regulations and State's control played a more important role in forest management. Royal shipbuilding industry, more lucrative economic stakes, and expanded demand for timber for construction of buildings in urban areas of the lower valleys and plains are among the external factors which impacted forest exploitation during periods when logging was prohibited.

High-resolution local seismic zonation by cluster and correlation analysis

Site response analysis is essential for seismic hazard and risk assessment and for providing useful data for land-use planning. However, current regional site amplification models do not always have the resolution required for sites such as alpine valleys, in which site response is characterized by complex effects. In addition, even in local studies, site response is usually computed at a limited number of sites because it requires the recording of earthquakes through the installation of seismological stations. To spatially extend the site response to a denser grid of points inside the investigated area, we used k-means cluster and correlation analyses and Voronoi tessellation. The method was applied to the evaluation of the site response of the lower Sarca Valley on the northern shore of Lake Garda. Earthquakes were recorded at 19 sites to calculate site response in terms of amplification and duration functions of ground motion. The results show high amplification values (up to 10) at low frequencies (at about 0.7 Hz) in the center of the valley, where the sediments reach a thickness of about 420 m. Moderate amplification values and duration lengthening of several seconds in the range of 1–10 Hz are found instead at the edge of the valley on the sedimentary deposits, while a lack of amplification is observed for the sites located on the bedrock. Both the amplification and duration functions were assigned to the area covered by the single-station noise measurements to obtain a zonation of the study area, resulting in three zones to which Fourier amplification factors can be assigned for specific frequency values. The results obtained can be used directly for hazard and risk scenarios and to improve regional maps with lower resolution at the local level.

What Was the Level of Ground Motion across Europe during the Great A.D. 365 Crete Earthquake?

Abstract Historical and archeological data report that an earthquake was felt over the whole eastern Mediterranean on 21 July A.D. 365. The impact of the tsunami it generated, which may have caused several thousands of fatalities, has been widely studied, whereas the impact of the seismic waves has hardly been explored. Here, we present simulations of the ground motion caused by the A.D. 365 event at 316 sites now instrumented by seismological stations throughout Europe. The simulation approach is based on the modeling of a series of rupture scenarios coupled with empirical Green’s functions (EGFs) obtained at the stations from a recent Mw 6.4 earthquake. The broadband and remarkably also the accelerometric records in urbanized areas can be exploited at distances as far as ∼2000 km. Then, we use three empirical models to estimate the macroseismic intensity across Europe from the simulated peak ground accelerations and peak ground velocities. The presence of stations in thick sedimentary basins (lower Danube valley, Po plain, urban accelerometric network in the alpine valley of Grenoble) shows that local basin amplification effects can dominate acceleration values at frequencies favorable to human earthquake perception (~0.5–1 Hz), even for basins located at more than 1500 km from the earthquake. Thus, our simulations indicate that the A.D. 365 earthquake was likely felt by the populations as far as the Po plain and as the city of Grenoble, about 1800 km away, and presumably in other large European basins such as the Pannonian basin. It is possible that the perception of the earthquake up to such distances contributed to its “universal” character perpetuated in archival sources. At closer distances (300–500 km), the simulated intensity levels indicate that the earthquake probably caused no damage.

Remotely sensed and surface measurement- derived mass-conserving inversion of daily NOx emissions and inferred combustion technologies in energy-rich northern China

Abstract. This work presents a new model-free inversion estimation framework (MFIEF) using daily TROPOspheric Monitoring Instrument (TROPOMI) NO2 columns and observed fluxes from the continuous emission monitoring system (CEMS) to quantify 3 years of daily scale emissions of NOx at 0.05∘×0.05∘ over Shanxi Province, a major world-wide energy-producing and energy-consuming region. The NOx emissions, day-to-day variability, and uncertainty on a climatological basis are computed to be 1.86, 1.03, and 1.05 Tg yr−1 respectively. The highest emissions are concentrated in the lower Fen River valley, which accounts for 25 % of the area, 53 % of the NOx emissions, and 72 % of CEMS sources. Two major forcing factors (10th to 90th percentile) are horizontal transport distance per day (63–508 km) and lifetime of NOx (7.1–18.1 h). Both of these values are consistent with NOx emissions to both the surface layer and the free troposphere. The third forcing factor, the ratio of NOx/NO2, on a pixel-to-pixel basis, is demonstrated to correlate with the combustion temperature and energy efficiency of large energy consuming sources. Specifically, thermal power plants, cement, and iron and steel companies have a relatively high NOx/NO2 ratio, while coking, industrial boilers, and aluminum oxide factories show a relatively lower ratio. Variance maximization is applied to daily TROPOMI NO2 columns, which facilitates identification of three orthogonal and statistically significant modes of variability, and successfully attributes them both spatially and temporally to (a) this work's computed emissions, (b) remotely sensed TROPOMI ultraviolet aerosol index (UVAI), and (c) computed transport based on TROPOMI NO2.

Instability in multi-valley semiconductors in external electric and magnetic fields

It is theoretically proved that the excited wave in two-valley semiconductors is growing. It is indicated that the directions of external fields play an essential role for the appearance of growing waves in the sample. It is shown that oscillations can occur at certain values of the sample dimensions L ,L ,L x y z Analytical formulas for the frequency of the growing waves are obtained. The interval of variation of the external electric field in a strong magnetic field μH>>c has been determined. The paper takes into account that the time of transition from the lower valley to the upper valley differs from the time of transition from the upper valley to the lower valley. It means τ12≠τ21 In the sample, the total concentration is constant, and therefore, n0=na+nb=const. The changes in the corresponding concentrations are equal to each other and have na'=-nb'. It is taken into account that at critical values of the electric and magnetic fields and the corresponding concentrations they change as a monochromatic wave. And the change in these quantities differs little from their equilibrium value. For simplicity of mathematical calculations, the external electric and magnetic fields are directed in the same way, i.e. in x direction. Since the current oscillations in one direction (for example, along x) are studied in the experiment, the following equalities were taken into account jy'=0, jz'=0. In the vicinity of the critical field at the beginning of the current oscillation in the sample, the current oscillation frequency is ϖ=ϖ0+iϖ1, ϖ1<<ϖ0. In addition, the magnitude of the critical electric field, at which the current fluctuation changes depending on the magnetic field as follows .

Rapid climate changes and human dynamics during the holocene in the eastern mediterranean (Lower Strymon Valley, northern Greece)

The study was conducted in the southern part of the lower Strymon valley, in northern Greece, and revealed up to 25 m of fluvio-lacustrine sediments deposited over the last seven millennia. This sedimentary record represents a significant opportunity for high-resolution palaeoenvironmental studies of the period from 6 to 3 ka cal BP linked to land use and climate change. The results of geophysical investigations, multi-proxy sedimentological (grain size, magnetic susceptibility, loss-on-ignition), pollen and NPP analyses, based on high-precision radiocarbon dating enabled reconstruction of past landscapes as well as a comprehensive discussion of anthropogenic responses and their impact on the vegetation cover, especially during periods with well-known Holocene Rapid Climate Change events (5.6, 4.2 and 3.2 ka cal BP).During the 7–5.7 ka cal BP corresponding to the Late and Final Neolithic, wet conditions created an extended lake surrounded by the densely wooded Strymon watershed, followed by a shift to a shallower lake environment that lasted until ca. 4.5 ka cal BP. The continuous presence of anthropogenic taxa suggests the persistence of human activities even in the absence of formally recognized sites, suggesting the relocation of settlements. The first signs of human disturbance of the landscape at regional scale occurred toward 5.2 ka cal BP (onset of the Early Bronze Age). The so-called « 4.2 ka BP event », which coincided with the end of the Early Bronze Age and the transition to the Middle Bronze Age, is divided into three distinct periods (4.35–4.1, 4.1–3.95 and 3.95–3.75 ka cal BP). The first corresponds to gradual aridification before a period with severe dry conditions that marks a tipping point toward wetland contraction. From this period on, diversification, and multiplication of anthropogenic species including Olea, Juglans and Castanea reflect a global trend toward cultural landscapes. The later periods are characterized by dramatic climatic change around 3.2–3 ka cal BP, at the end of Late Bronze Age, and increasing impacts of agro-pastoral activities and forest clearing starting at the beginning of Antiquity, around 2.8 ka cal BP (Thracian period). After the 4.2 ka cal BP event and we suggest that climatic adversity may have acted as a stimulus to innovation and relocation rather than retarding societal development in the region. To conclude, environmental factors in the lower Strymon valley were not sufficient on their own to trigger a social crisis similar to that mentioned in the Middle East.

Characteristics and risk assessment of chilling injury on Morchella esculenta in Western Sichuan Plateau, China.

The development of precise climate risk zoning for chilling injury of Morchella esculenta can provide scientific basis for agricultural cultivation planning, dynamic assessment of chilling injury, and disaster prevention strategies. Based on meteorological data from 17 counties (cities) that located below the altitude of 3000 m in the Western Sichuan Plateau from 2011 to 2020, we analyzed the critical meteorological conditions for M. esculenta disasters in typical years. With the average yearly cold accumulation and cold injury frequency during the first day when the temperature remained stable between 5 ℃ and 10 ℃ during mushroom emergence as zoning indicators, we established a geographical spatial distribution model of the cold injury index, and then divided the risk level of M. esculenta cold injury in the Western Sichuan Plateau, evaluated the risk of cold injury. The results showed that the temperature index for chilling injury risk of M. esculenta in the study area was the daily minimum temperature ≤2.0 ℃. The daily average temperature <6.0 ℃ would cause slow growth or the cessation of growth, which was set as a warning indicator for chilling injury risk. Along the Dadu River and Minjiang River basins, the frequency of chilling injury on M. esculenta increased from south to north. Wenchuan, Maoxian, and Lixian had the fewest overall chilling injuries during the study period, whereas Jiulong, Yajiang, and Batang had the most. The duration for cold injury was mainly 1-3 d, followed by 4-5 d, and rarely for >5 d. The frequency of chilling injury lasting for more than 5 d in Xiangcheng, Batang, Jiulong, Yajiang, and Xiaojin was more than that lasting for 4-5 d. The annual average days of chilling injury of was 3.0-27.4 d, the daily average minimum temperature was -0.84-1.36 ℃, the extreme lowest temperature was -5.8-0.1 ℃, and the average accumulated cold was 0.16-9.64 ℃·d during the period of chilling injury. With the increases of elevation and latitude, the average days of chilling injury and the average accumulated cold increased. The largest duration of chilling injury was 3-20 d, the maximum accumulated cold was 0.44-13.34 ℃·d. The risk of chilling injury to M. esculenta increased from south to north and from low elevation to high elevation. The suitable planting areas were distributed in strips and branches along the direction of mountains and rivers, mainly in the flat areas of low mountains and valleys below the altitude of 2200 m, including Kangding, Luding, Danba, Wenchuan, Lixian, Maoxian, Jiuzhaigou, and Songpan.

Evaluation of soil water losses under irrigation saving techniques in a semi-arid region in Tunisia

Abstract In arid and semi-arid regions, managing agricultural water for irrigation is essential to cope with water scarcity and maximize crop yields. In this study, an experiment was conducted on a potato crop in the Manouba region (lower valley of Medjerda, Tunisia). The experimental protocol consisted of four water treatments utilizing water-saving irrigation techniques: FI (Full Irrigation 100%): irrigation with 100% of crop water requirements. DI (Irrigation 75%): deficit irrigation with the application of 75% of crop water requirements. PRDRight (Irrigation 50% on the right side): Irrigation by partial root drying. PRDLeft (Irrigation 50% on the left side): Irrigation by partial root drying. Simulation of soil water profiles was carried out by the Hydrus-1D model. The soil hydraulic properties were calibrated according to the experimental conditions using an inverse modeling technique. According to the obtained results, simulated soil water profiles were close to those measured. Indeed, the calculated NRMSE values are low, indicating the reliability of Hydrus-1D as a decision support tool to optimize water irrigation management. These results were then used to investigate the effects of a 2 °C temperature increase on soil water loss, and it was determined that the impact was insignificant.

A Tale of Wonders in Performance: The Precious Scroll of Wang Hua in the Storytelling Tradition of Changshu, Jiangsu, China

Baojuan (precious scrolls) are a type of prosimetric literature in the vernacular language that flourished in the lower Yangzi valley between the late nineteenth and early twentieth centuries. Most baojuan texts are devoted to religious themes, often involving wondrous figures and events which can be characterized as “supernatural”. The Precious Scroll of Wang Hua (Wang Hua baojuan 王花寶卷) is a comparatively late text centered on the marvelous apparitions leading to the salvation of a lay person. It is a widespread text of the southern “scroll recitation” tradition as it survives in Changshu, Jiangsu, but to date, it has not received attention from scholars of Chinese popular literature and religion. Still, it is important for understanding the origins, development, and functions of precious scrolls and their contribution to the field of Chinese popular religion. The original text of the Precious Scroll of Wang Hua formed ca. end of the nineteenth century, but the present research mainly uses the manuscript version of a modern performer from the vicinity of Changshu (ca. 1995). This narrative combines two major topics of the wondrous manifestation of Bodhisattva Guanyin and the descent to Hell. Both topics can be traced back to the early “miracle tales”. Here, they have been adapted to the local life and cultural setting. The figure of the skeptical and egoistic Wang Hua who initially rejected the injunctions of Guanyin is a type well known to the modern audiences of baojuan. Thus, the supernatural elements serve the purpose of reconfirming traditional beliefs and values in the contemporary society.

Research on the Optimal Capacity Configuration Method of Park-type Wind-photovoltaic Storage Complementary Power Generation System

At present, China’s installed renewable energy capacity is growing at a fast rate, and reasonable allocation of the wind turbine, photovoltaic, and energy storage capacity is a prerequisite to ensure the economic and reliable operation of the system. For the park-type grid-connected operation of the wind-photovoltaic storage system, in order to improve the stability of the system and make full use of the distribution grid resources, the operation strategy of the park-type wind-photovoltaic storage system is proposed, and the model of wind-photovoltaic storage is established respectively, and the economy and reliability of the system are considered comprehensively. The objective function of capacity configuration and the constraints of power system operation specification are set up, combined with the time-of-use electricity price, the charging of energy storage battery is preferred at the low valley, and the objective function is solved by a genetic algorithm according to the energy use characteristics of the park, and three configuration schemes are selected from the Pareto front solution. Finally, through the typical day analysis, the results show that the wind-photovoltaic storage capacity allocation method can effectively improve the economy of park operation and the quality of the park power supply.

The ‘Deluge’ of 25 October 1822 in Genoa, Italy

The ‘Deluge’ of 25 October 1822 in Genoa, Italy