Variations In Supply Research Articles

КЛИНИЧЕСКАЯ АНАТОМИЯ КРОВОСНАБЖЕНИЯ И ИННЕРВАЦИИ ПЕРЕДНЕБОКОВОЙ БРЮШНОЙ СТЕНКИ В ПРАКТИКЕ ХИРУРГА

The arterial blood supply of the anterior abdominal wall comes from the superior, inferior, and superficial suprailiac arteries, the superficial and deep arteries enveloping the iliac crest, the external genital artery, the lumbar and intercostal arteries. The innervation of the anterior abdominal wall is carried out by the intercostal nerves, branches of the iliopsoas and iliac-subiliac nerves. All of these structures may have different topography in each particular patient. Most variations will not be pathologic, but they are worth keeping surgeons in mind when performing surgical interventions. For example, in severe sclerosis of the distal arteries or aorta, or in the case of aortic coarctation, there is significant vessel dilation to provide blood supply to the lower extremities. Transection of the epigastric arteries in such cases can lead to more severe bleeding and ischemia of the lower extremities. Variation in the location of the branch of the deep inferior epigastric artery, the crown of death, occurs in 77% of patients and can cause life-threatening hemorrhagic shock. Also of clinical importance is the replacement of the areas of sensitive innervation of the iliopsoas and iliac-subiliac nerves during operations on inguinal hernia and during blockade anesthesia. Thus, surgeons need to be aware of variations in the blood supply and innervation of the anterolateral abdominal wall during surgical interventions, particularly during trocar insertion and other surgical manipulations. In order to improve surgical technique, it is suggested to introduce convenient and relatively inexpensive neuroimaging or neuromapping methods into routine practice.

Operational Diagnostics System for Asymmetric Emergency Modes in Traction Drives with Direct Torque Control

This article presents an analysis of the causes behind the development of asymmetric modes in a traction drive system that features direct torque control (DTC) of a rolling stock with asynchronous traction motors. The development of asymmetric modes in the traction drive system was found to be caused by the asymmetry of the supply voltage system, the asymmetry of the traction motor windings, and transient processes triggered by a change in the inverter supply voltage and variation in the traction motor load. At the same time, the asymmetric modes caused by the asymmetry of the feed voltage system and the windings of the traction motor are the emergency modes. The influence of the asymmetry of the feed voltage system and asymmetry of the windings of traction motor on the starting characteristics of the phase currents and flux linkages of the stator in the steady-state mode was investigated. In these cases, the ratio of the amplitudes of phase currents and flux linkages of the stator of different phases was found to be constant. The effect of a variation in the feed voltage and load acting on the motor shaft on the starting characteristics of phase currents and flux linkages of the stator was investigated in the case of absence of the emergency modes. In these cases, the ratio of the amplitudes of phase currents and flux linkages of the stator of different phases was found to not be constant. The amplitudes of the phase current and stator flux linkage were proposed as criteria for diagnosis and identification of asymmetric emergency modes. An algorithm and a structural scheme have been proposed for the diagnosis of emergency asymmetric modes in the traction drive system with direct torque control. Modifications to the traction drive system with direct torque control are suggested in order to diagnose the presence of faulty asymmetric modes and identify the damaged traction drive element.

Spatial and temporal variation in the evolution of ancient aeolian dune-field. The Pennsylvanian Piauí Formation (Parnaíba Basin), Brazil

The sedimentary record of aeolian systems is the result of a complex interplay between the size of the dune and interdune morphologic elements, the rate of bedform migration and the rate of aggradation. Since these parameters are not constant over the time and space, the resulting preserved deposits display a complex architecture characterized by sets of variable thickness and climb angle. Such complexity is observed in both wet and dry aeolian systems of the Pennsylvanian Piauí Formation and is studied here using a numerical reconstruction of the controlling parameters, including dune wavelength and angle of climb each of which varied both spatially and temporally. Through facies analysis and stratigraphic correlation, three genetic units were identified. Spatial variation in the first unit is characterized by a dry aeolian system in which the dimensions of dunes increased to the NW, suggesting deceleration of saturated winds from a dune-field margin to its center. The second and third units are characterized by wet aeolian systems marked by progressively thicker sandsheet deposits and a reduction of dune/interdune thickness ratio. In both units, the spatial variations are marked by a reduction in the dimensions of dunes to the NW, suggesting progressively lower sand availability most likely related to higher water table or its capillary fringe from a dune-field center to its margin. The temporal variation was inferred from the drying-upward cycles observed in all three units. Although the first unit is marked by aeolian cosets overlying thinner simple dune sets, the second and third units are composed by sandsheet deposits at the base overlain by the deposits of progressively larger dunes, in some case culminating with the preservation of aeolian cosets of strata. Such observation suggests that both dry and wet units are marked by an increase in sand saturation allowing the preservation of larger dunes over time. The results of this study suggest a highly dynamic nature of the aeolian dune system where variations in sand supply, availability and wind energy exerted a direct effect on the aeolian system, triggering expansion or contraction of the dune-field. These expansion and contraction phases observed in the Pennsylvanian Piauí Formation are related to glacio-eustatic changes documented during the Pennsylvanian period.

Decoding the Variations in the Female Labour Supply in Rural India: Empirical Evidences Based on Previous NSSO Datasets

The female labour force participation rate (LFPR) in India has been persistently declining and has exhibited an unusual pattern over the years, which deviates from the discourse of a U-shaped relationship between female LFPR and economic growth. The article is an attempt to provide some of the empirical foundations to the female LFPR in rural India, and further delves into a comprehensive understanding of the effects of different factors like household, social, economic and personal factors, empirically through previous NSSO data sets. The data sets used in the study are from NSSO 50, that is, from 1993-94 to NSSO 66, that is, 2009-10, to ascertain the factors that were significant over the years in determining the female LFPR in rural areas. These variables were tested to gain an understanding on the variations in female labour supply in rural India. Being cognisant and by problematising some of the significant factors that affected the female LFPR in the past, the article demands the state to exercise policies beyond its neoliberal framework and the ‘Keynesian welfare-state’ model of ‘superficial’ social security. Methodologically, three models were further created based on the NSSO 66 data set to showcase the perennial discouraged-worker effects among the females in LFPR in rural India. The article further empirically tests Jacob Mincer’s theory: ‘substitution effect dominating the income effect’ in the decision of females entering the labour market in rural India and shows empirically how it does not hold in the Indian context, thereby an attempt on debunking the mainstream theory. JEL Codes: J10, J21, J64, C18

The Use of Plantaris Muscle Flap for Facial Reanimation: A Comprehensive Anatomical Study.

Background: Functional facial reanimation remains challenging and the quest for optimization continues. Objective: To characterize the anatomical conditions of the plantaris muscle for facial reanimation. Study Design and Methods: Forty-two plantaris muscle specimens were obtained from 23 post-mortem chemically fixed cadavers. The muscles were dissected, evaluated, and measured. Mock facial reanimation was performed on three cadaver heads. Results: The plantaris muscle was a consistently available muscle. Mean muscle belly length was 10.1 cm (standard deviation [SD] 1.4), and mean width was 1.7 cm (SD 0.4). The mean tendon length of 30.1 cm (SD 2.8) is unique in the human body. The main artery supplying the muscle had a mean length of 1.4 cm (SD 0.4). The mean nerve length was 2.2 cm (SD 0.7). Sixteen variations of vascular supply were identified. Mock facial reanimations demonstrated a good size match, and great versatility of the long tendon for oral fixation. Conclusions: The plantaris muscle as a free flap for facial reanimation could offer new possibilities in terms of oral fixation and volumetric aesthetic conditions.

On-Line Evaluation and Monitoring of Security Features of an RO-Based PUF/TRNG for IoT Devices.

The proliferation of devices for the Internet of Things (IoT) and their implication in many activities of our lives have led to a considerable increase in concern about the security of these devices, posing a double challenge for designers and developers of products. On the one hand, the design of new security primitives, suitable for resource-limited devices, can facilitate the inclusion of mechanisms and protocols to ensure the integrity and privacy of the data exchanged over the Internet. On the other hand, the development of techniques and tools to evaluate the quality of the proposed solutions as a step prior to their deployment, as well as to monitor their behavior once in operation against possible changes in operating conditions arising naturally or as a consequence of a stress situation forced by an attacker. To address these challenges, this paper first describes the design of a security primitive that plays an important role as a component of a hardware-based root of trust, as it can act as a source of entropy for True Random Number Generation (TRNG) or as a Physical Unclonable Function (PUF) to facilitate the generation of identifiers linked to the device on which it is implemented. The work also illustrates different software components that allow carrying out a self-assessment strategy to characterize and validate the performance of this primitive in its dual functionality, as well as to monitor possible changes in security levels that may occur during operation as a result of device aging and variations in power supply or operating temperature. The designed PUF/TRNG is provided as a configurable IP module, which takes advantage of the internal architecture of the Xilinx Series-7 and Zynq-7000 programmable devices and incorporates an AXI4-based standard interface to facilitate its interaction with soft- and hard-core processing systems. Several test systems that contain different instances of the IP have been implemented and subjected to an exhaustive set of on-line tests to obtain the metrics that determine its quality in terms of uniqueness, reliability, and entropy characteristics. The results obtained prove that the proposed module is a suitable candidate for various security applications. As an example, an implementation that uses less than 5% of the resources of a low-cost programmable device is capable of obfuscating and recovering 512-bit cryptographic keys with virtually zero error rate.

Spatiotemporal Changes in the Watershed Ecosystem Services Supply and Demand Relationships in the Eastern Margin of the Qinghai-Tibetan Plateau

Clarifying the spatiotemporal changes in the supply and demand relationship of ecosystem services (ESs) is essential for optimizing ESs management. However, several studies have reported the ESs supply and demand risk in complex mountainous areas. In this study, we quantitatively analyzed the spatiotemporal variation in ESs supply, demand, and their trade-off and synergy, including water yield, soil conservation, and food provision in the Bailongjiang watershed (BLJW) in western China. The results showed that the total supply and demand of water-yield and soil-conservation services rose with a surplus from 2002 to 2018, except for food provision. A high value characterizes the water-yield and soil-conservation supply in the south, but there are low values in the east BLJW. The spatial distribution of water and food supply–demand featured a high demand in the subareas with population aggregation. Soil-conservation demand is high in the northwest and south of Wudu. The dominant spatial matching type of supply and demand in water yield was a high supply with a low demand. Soil conservation was associated with a low supply and low demand, and food provision with a high supply and increased demand. A synergy existed between water yield and soil conservation. Trade-offs existed between water yield, food provision, and soil conservation. The spatial distribution of trade-off intensity showed distinctive patterns. The supply–demand ratio of WY and SC decreased with the increasing trade-off intensity. This study comprehensively considers ES and supply–demand conflicts, thus providing a new perspective and approach for enhancing ecosystem services and high-quality regional development.

Millennial-scale variability of water supply, vegetation and fire activity on a tropical wetland in central Brazil

The Pandeiros wetland is a tropical wetland located in the ecotone between the Cerrado and the Caatinga, in central Brazil. It has a key ecological importance for vegetation biodiversity, hydrological cycles, fauna reproduction and feeding, and for local human populations. Here, we investigate millennial-scale variability of water supply, vegetation structure and fire activity in the Pandeiros wetland during the Late Holocene and discuss forcing mechanisms that affected flooding, vegetation cover and fire regime within this fragile ecosystem. Our study is based on the previously studied pollen record of the Pandeiros palm swamp and on new charcoal analyses of two sediment cores that cover the last 4500 cal years, and their comparison to modern pollen and to available paleoclimatic data. Our results show that both local rainfall at the Pandeiros River basin and southern rainfall at the upper São Francisco River were important in maintaining water supply for the Pandeiros wetland during the last millennia. Our data also suggest that during Late Holocene the arboreal cover declined in the Cerrado of the Pandeiros Basin, an opposite trend to that observed in the wetter Cerrado-Atlantic Forest ecotone. We propose that increasing summer insolation in Southern Hemisphere was an important factor in maintaining low arboreal cover and open savanna vegetation on the drier areas around the Pandeiros wetland. Regarding fire activity, we suggest that until around 2600 cal yr BP, climate conditions were the most important driver of fire activity, in which drier conditions favored the intensification of fire, whereas subsequently, anthropic activities appear to have become an important fire inducer. Our findings highlight the multiple environmental aspects that have influenced the Pandeiros wetland history during the last four thousand years, including monsoon variability, insolation variation and human occupation.

Potential impacts of Fukushima nuclear wastewater discharge on nutrient supply and greenhouse gas emissions of food systems

Seafood plays a critical role in promoting a nutritious and climate-friendly food system but faces challenges from marine contamination that pose food safety risks. To address these challenges, we developed a Marine Pollution-induced Food System Risk Assessment and Response (MP-FSRAR) model to assess the impact of consumer perceptions of marine pollution risk events on nutrient supply and greenhouse gas (GHG) emissions. Applying this model to the proposed Fukushima Nuclear Wastewater Discharge (FNWD) into the Pacific Ocean, we identified the potential variation in nutrient supply and GHG emissions resulting from changes in Chinese consumers' willingness to consume seafood under 12 scenarios. Our analysis revealed nutrient supply gaps in daily protein, minerals, vitamins, and fatty acids, ranging from 1.5 to 2.7 g/person, 2.5–4.5 mg/person, 5.6–10.3 mcg/person, and 0.08–0.14 g/person, respectively. Closing the protein gap in China would require an additional 3.2–15.8 billion kg yr−1 protein-rich foods, including aquatic, livestock, dairy, and pulses. Additional food supply would increase extra GHG emissions by 1–79 billion kg CO2e yr−1, resulting in potential GHG emissions being transmitted to other countries through the trade chain. Furthermore, we found that the livestock-based food substitution pathway had 40 times higher GHG emissions than the plant-based one. Our MP-FSRAR model provides global stakeholders with new perspectives on the potential consequences of consumer perceptions of marine pollution risks and offers valuable insights for developing countermeasures to build a more resilient and low-carbon food system.

Assessment of causes and consequences of food and agricultural raw material loss and opportunities for its reduction

The article summarizes and systematizes the causes and consequences of food loss and waste. The uncontrolled accumulation and inefficient management of loss and waste is a serious problem of food security in many countries. Moreover, the world annually loses or wastes about a third of food produced while natural resources are inefficiently used. A significant number of definitions and terms in the field of food loss and waste cause international inconsistency in management systems. So, systematization of terms and research methods for food loss and waste has been carried out. The review analyzes the stages of food supply chain, i.e. the production of agricultural raw materials, their collection, processing, transportation and consumption, where the largest loss and waste occur. Furthermore, environmental, social and other problems associated with the accumulation of loss and waste are considered. Prevention of food loss and waste has been shown to be a potential strategy to improve the balance of food supply and demand and is essential for improving food security while reducing environmental impact and providing economic benefits to various participants in the food supply chain. Separately, the actions taken by the Russian Federation in the field of waste management and reduction of food loss are considered. Attention is drawn to the fact that the difficulties in solving these problems are associated with insufficient progress in legislation and low funding of relevant research projects. Possible approaches for simulation and optimization of actions to support specific strategies to reduce loss and waste are considered, taking into account the following factors: improving the management of various inventories; developing a clear strategy for planning and allocating resources; forming the supply chain based on variability (uncertainty) of customer demand and supply. Knowledge comparison and integration, as well as optimization of food supply chain management are essential for development of strategies and decisions about where and how to focus efforts to most effectively ensure the reduction of loss and waste at each stage of food supply chain. The main decisions and practices for FLW prevention and management have been systematized.

A 65-dB-SNDR Pipelined SAR ADC Using PVT-Robust Capacitively Degenerated Dynamic Amplifier

This article presents a process, voltage, and temperature (PVT)-robust capacitively degenerated dynamic amplifier as the residue amplifier of the low-power pipelined successive-approximation-register (SAR) analog-to-digital converter (ADC). The proposed dynamic amplifier achieves a voltage gain of 16 with a two-stage configuration and high linearity over a wide temperature range with an on-chip timing generator. This work solves problems related to the low voltage gain and high temperature–sensitivity of the capacitively degenerated dynamic amplifier, while retaining the advantages of high linearity, wide output swing, and high energy efficiency. The prototype ADC is implemented in a 65-nm CMOS process and achieves 65-dB signal-to-noise-and-distortion ratio (SNDR) and 79.8-dB spurious free dynamic range (SFDR) at a sampling rate of 50 MS/s, while consuming only 0.46 mW. The power overhead of the timing generator is only 10% of the overall power consumption. It shows only 0.7-dB and 1.86-dB SNDR variations at 0.8–1.0-V supply variation and 0 °C–100 °C temperature variation, respectively.

Yearly Variations in Nutrient Supply in the East China Sea Due To the Zhejiang Coastal Upwelling and Kuroshio Intrusion

AbstractThe East China Sea (ECS) is a marginal sea with high productivity, especially in summer. In the Zhejiang coastal region of ECS, the large phytoplankton biomass in summer is attributed to the nutrients pumped up by Zhejiang coastal upwelling (ZCU), and oceanic nutrients supplied by the Kuroshio intrusion (KI) onto continental ECS. However, the yearly variations in these two processes are not consistent, which complicates coastal nutrient supplies. In this study, to understand the contributions of ZCU and KI to the nutrient supplies, nutrient concentrations, and phytoplankton biomass in ECS as well as their yearly variations, a physical‐biochemical coupled model was applied. According to model results and observations, the years 2013 and 2018 were identified as strong and weak ZCU years during 2010–2018 period, respectively. In 2013, nutrient and chlorophyll‐a concentrations were higher than 2018 in nearshore areas, but nutrient concentrations were lower than 2018 at the bottom of wide offshore areas. Strong wind stress in 2013 induced strong ZCU and shoreward net nutrient flux along the 60‐m isobath, which was seaward in 2018. The fewer nutrient supplies from KI in the spring of 2013 decreased the nutrient concentrations at the bottom of offshore areas, but its influence on nearshore nutrient concentrations was not as obvious as that caused by ZCU. Phytoplankton biomass in the nearshore and offshore areas reflected different mechanisms of nutrient supplies. In conclusion, the intensity of ZCU, rather than KI, is the principal factor influencing the coastal primary productivity of ECS in summer.

Ultra‐low line sensitivity and high PSRR sub‐threshold CMOS voltage reference

AbstractThis paper presents a nanowatt CMOS voltage reference (VR) with ultra‐low line sensitivity (LS) and high‐power supply ripple rejection (PSRR). The proposed VR consists of two simple nanowatt two‐transistor (2T) VRs. Two current mirrors are associated with these VRs. The outputs of the current mirrors have different magnitudes but the same power supply dependence slope. For this purpose, the primary 2T VR has been designed with long‐channel MOSFETs, while the secondary VR utilizes medium‐channel length transistors. Low dependence on the power supply variations is achieved by subtracting these two currents, whereas the subtracted current is almost independent of the power supply. The temperature coefficient (TC) minimization is achieved separately by adjusting the transistor sizes of the primary VR. Post‐layout simulation is performed using 0.18 µm standard CMOS technology, which shows a nominal output voltage of 0.15 V, obtaining an average TC of 21.4 ppm/°C over a temperature range of 0–120°C. It achieves an excellent line sensitivity of 0.0039%/V when the supply voltage varies from 0.4 to 2 V. The dc PSRR values at 0.4 and 1 V of supply voltage are −80.1 and ‐114.2 dB, respectively at room temperature.

Aberrant brachial artery: case report of an anatomical variation

INTRODUCTION: The brachial artery and its terminal branches are the major arterial supply to the brachium and antebrachium. Variations in the vascular supply in the upper limbs have been previously documented to occur more in the radial artery, followed by the ulnar artery, but less commonly in the brachial arteryCASE: An embalmed cadaver was used for gross dissection during the gross anatomy dissection for postgraduate students at the department of human anatomy of the University of Rwanda.During the dissection of the right upper arm, an accessory brachial artery was found, branching from the axillary artery above the unification of the lateral and medial cords of the brachial plexus (the lateral and medial root of the median nerve).CONCLUSION: In our case, the aberrant brachial artery originated from the axillary artery and gave off a muscular branch in the middle third of the arm, which is of clinical importance.

Annual and decadal net morphological displacement of a small gravel‐bed channel

AbstractThe sediment supplied to a stream channel impacts the morphological trends experienced by that channel, and the long‐term trends are important to understand for many riverine applications. We introduce the term ‘net morphological displacement’ (NMD) to denote the net channel change revealed by the morphological method over multiple sediment transport events to make the concept more explicit for river management and use it to determine equilibrium or disequilibrium states. This study explores the morphological response of East Creek, a small threshold gravel‐bed channel in the Coast Mountains of British Columbia, Canada, to variations in flow and sediment supply at multiple spatial and temporal scales over 15 years. High‐resolution topographic data (HRTD) of the bed were combined with cross‐sectional surveys of the banks to determine the sediment supply that the channel responded to annually. The level of detection used to remove noise associated with HRTD was calibrated using an independent tracer stone dataset. The net effects from multiple floods caused distributions of bed elevation change to generally follow the log‐normal distribution, and mean depths of erosion and deposition were predominantly similar between morphological units. At the reach scale, the various reaches of East Creek responded differently to the same hydrological events due to the impacts from the varying supply conditions on the NMD. Shorter measurement periods would have resulted in inconclusive information that does not show the long‐term morphological trends of the channel. Determination of these trends can take years or decades, depending on the time and space scales of change, but there is generally a lack of long‐term channel monitoring programmes, notably after river restoration. More long‐term channel monitoring programmes are required to assess restoration projects and ensure their long‐term sustainability.

Policy Determinants of Budget Deficit in Indonesia

In this study, the causes of the budget deficit in Indonesia were examined using multiple regression analysis and the Error Correction Model (ECM) technique utilizing annual data for the years 1998 to 2020. The results show that in the short term, only inflation and government subsidies have a significant impact on the budget deficit in Indonesia when using the Error Correction Model (ECM) approach to analyze the effects of the chosen money supply variables, foreign exchange rates, inflation, and government subsidies.. Long-term estimations indicate that the government subsidies, inflation, foreign exchange rates, and money supply variables all have a positive and considerable impact on the budget deficit. Within 7 months, the equilibrium between the short- and long-terms can be restored. Policymakers are advised to keep an eye on changes in the money supply, foreign exchange rates, inflation, and government subsidies to avoid causing the budget deficit to rise above the allowable limits, which are 3 percent of the State Revenue and Expenditure Budget.

COMMERCIAL LOAN INTEREST RATE DETERMINANTS

This study aims to analyze which variables affect the commercial loan interest rates that banks use to their customers. The dependent variable used in the study is the commercial loan interest rate, and the independent variables are the inflation rate, deposit interest, dollar rate, and money supply. The data is compiled in CBRT evds sources and the time interval is monthly data between 01/2010-04/2021. The method of the study is the Ardl boundary Test and error correction model used in time series analysis. Within the framework of these models, problems such as trend effect and stasis of series that are frequently encountered in time series analysis were examined. According to the results obtained from the study, the effect of the deposit interest argument on the commercial loan interest rate in the short and long term was greater than that of other variables. It was concluded that inflation, exchange rate and M2 money supply variables had no effect in the long term.The effect of M2 money supply and exchange rate variables on short-term commercial loan interest is significant. It can be said that the effect of the three-period lag value of the exchange rate variable in the short term is also significant.

Transient optimization of a new solar-wind multi-generation system for hydrogen production, desalination, clean electricity, heating, cooling, and energy storage using TRNSYS

In the current study, a renewable system with two potential wind and solar energies for electricity production, cooling, and heating has been investigated. The proposed system included reverse osmosis, heat pumps, fuel cell subsystems, wind turbines, photovoltaic/thermal panel units, battery storage, and a hydrogen storage tank. Given Iran's high potential for renewable energy, a performance analysis of six cities, Esfahan, Zanjan, Bandar Anzali, Ahvaz, Bandar Abbas, and Tabriz was done to determine where the proposed power plant should be located. Six decision factors were analyzed for system performance: solar panel angle, solar panel count, wind turbine count, cooling capacity, heating capacity, and fuel cell power. The findings demonstrate that the number of solar panels, wind turbines, and fuel cells significantly influences power, fuel consumption, and system costs. Finally, the outcomes were analyzed by the Response surface method to choose the best system that can satisfy the demand for residential units for one year. To evaluate the effectiveness of the suggested method, a 100-unit apartment building with a 196-square-meter floor space was considered. The results also showed that the combination of hydrogen units and battery storage reduced variations in supply and demand and correctly stabilized the stored energy during a drop in output. The suggested system has a life cycle cost of 674278.4$/h and the capacity to generate 225694.8 kWh of surplus power for residential units with a thermal comfort index. According to the optimization results, the system's optimal panel count was 106, the optimal angle was 26°, the optimal fuel cell power was 65.6 kW, the ideal wind turbine count was 24, the ideal heating capacity was 20.2 kW, and the optimal cooling capacity was 48.7 kW.

Insights into magma dynamics at Etna (Sicily) from SO2 and HCl fluxes during the 2008–2009 eruption

Abstract Magma convection, where low-viscosity, gas-rich magma ascends, degasses, and crystallizes before sinking down the same conduit in either annular or side-by-side flows, has been proposed for active basaltic volcanoes, where excess gas fluxes relative to erupted lava volume can be observed. Experimental studies show that convection is produced by buoyant ascending gas-rich magma and descending degassed magmas following density difference contrast, while geophysical studies point to the endogenous growth of active volcanoes through magma accumulation in plutons. However, many aspects of the convection process remain unclear, in particular, the depth to which magma ascends before overturning. Models have been proposed where overturn occurs near the surface and also at depths greater than 2 km from the top of the magma-filled conduit. The long-term monitoring of volcanic gas compositions may reveal new insights into the convection process, as each gas has a unique solubility-pressure profile. We report measurements of SO2 and HCl gas fluxes from Etna between October 2007 and May 2011, in which an ~90% collapse in halogen flux was observed together with an effusive eruption. This observation indicates that the halogen fluxes, during quiescent periods on Etna, require both magma supply to the shallowest levels and a period of residence. The lava effusion has the effect of reducing the shallow residence time, drastically reducing the halogen flux. These results provide a new interpretative framework for the degassing process and gas composition monitoring to explain subtle variations in magma supply and residence times in basaltic volcanism.

Housing Supply under Long-term Uncertain Situation: A Counterfactual Framework Based on ARMA Model

The monthly supply of houses is a critical part in housing markets in US. It reflects the condition of economy and conversely exerts an influence to the economy. It is an important number for sellers to have in mind when planning the sale of a property investment and buyer can based on it to make their decision in making purchases. Across the United States, the COVID-19 pandemic has resulted in considerable confirmed cases every month which might influence people’s decisions in changing locations and buying new houses, thus affected the variation of the monthly supply. This paper judges the negative impact of COVID-19 on the real estate industry in the United States by establishing the difference in DF value obtained by ARMA model, discusses the possible reasons for the fluctuation of new house supply in the United States, and puts forward some suggestions on how to deal with the crisis of the real estate industry in similar situations in the future, so as to avoid the economic downturn of real estate enterprises in similar situations and achieve the stability of the housing economy. Data analysis process was conducted by the use of R statistical programming.