Recovery Mode Research Articles

How to Choose a Hydrological Recovery Mode for Degraded Semiarid Wetland in China? A Case Study on Restoration of Phragmites australis Saline-Alkaline Wetland

Hydrological recovery is the basis for restoring the structure and function of wetlands in semiarid and arid areas of China. Selecting an appropriate hydrological recovery mode may be helpful for improving the effectiveness of wetland restoration. We conducted pot experiments to study the effects of the flooding frequency, duration, depth, and occurrence time on the height, biomass, ion contents, and photosynthetic physiology of Phragmites australis in degraded saline–alkaline marsh in the West Songnen Plain, China. At the end of the growing season, we found that the biomass, photosynthetic parameters, and water use efficiency (WUE) of the leaves increased, whereas the Na+ concentration decreased, and the K+ content remained unchanged under an increased flooding frequency treatment. As the flooding depth increased, the plant height increased, but there were no differences in the photosynthetic parameters, biomass, and WUE under flooding at 5 cm and 10 cm. Under different flooding duration treatments, the plant height and biomass were greater, but the photosynthetic parameters and Na+ and K+ contents were lower under a flooding duration of three months. The flooding occurrence time had little effect on the growth of P. australis. Our results indicate that the flooding frequency and duration had greater effects than the flooding depth and occurrence time in the hydrological recovery model for P. australis restoration. The biomass accumulated by P. australis was related to lower Na+ contents and the maintenance of a high K+/Na+ contents, and WUE increased by adjusting photosynthesis under a moderate flooding frequency and duration. These results have important implications for the restoration of degraded semiarid wetlands with man-made channel systems in conditions with limited freshwater resources.

Experimental investigation of permeability heterogeneity impact on the miscible alternative injection of formation Brine–Carbon dioxide

Water alternating gas injection is considered as efficient enhanced oil recovery techniques to increase oil cumulative production rate. The objective of this comprehensive study is to measure the profound impact of different permeability heterogeneities on the ultimate recovery factor of miscible alternative injection of formation brine–carbon dioxide processes. To evaluate the results of each heterogeneity types, three heterogeneity levels of homogeneous, layered, and composite were taken into consideration, and the ultimate recovery factor was explicitly investigated for each case. The ultimate oil recovery factor for the homogeneous sample had witnessed the highest value at the permeability ratio of 1 (about 86.4%). According to the results of this experiment, miscible water alternating gas (henceforth; WAG) injectivity as a secondary enhanced oil recovery (henceforth; EOR) mode provided higher recovery factor due to the higher interfacial contact among in-situ oil, carbon dioxide and higher values of permeability ratios have led to lower ultimate recovery factor. After the breakthrough, the impact of permeability sequence and heterogeneity had caused to differ the results of recovery factor for each scenario. It was about 90.4% for the homogeneous sample, 86.5% and 83.8% for the low-high-low and high-low-high respectively. Consequently, in the absence of crossflow, the recovery factor had provided higher values rather than crossflow presence.

In recovery mode: manufacturers try to bounce back after COVID-19 disruptions.

Manufacturers experienced significant disruptions in their operations and demand in 2020, as businesses struggled to cope with COVID-19 and its implications. To control the spread of the virus, governments initiated stay-at-home orders, and many firms were forced to close or limit operations. As a result, there were severe declines in production and employment, both in the United States and in global markets, often at record paces or rivaling the decreases seen in the Great Recession. While activity has started to rebound somewhat in this latest downturn, it will take time for output and hiring to return to pre-recessionary levels—perhaps not until at least 2022—with uncertainties in the outlook pervasive.

Instructional and Business Continuity Amid and Beyond COVID-19 Outbreak: A Case Study from the Higher Colleges of Technology

With the announcement of COVID-19 as pandemic, and the call for social distancing, academic institutions reacted by shutting campuses and calling for the shift to virtual online delivery. In HCT, we conducted this study in an effort to sustain success in these global challenging times of crisis that is informed by strategic foresight.HCT called for an all-online delivery starting March 22, 2020 after a two-day pilot in the preceding week. HCT readiness is a result of orchestrating: an ecosystem perspective on digital transformation, a forth-looking institutional strategy that has technology utilization as a major pillar, an education technology strategy, and a comprehensive set of intelligent learning tools.Forward-looking scenarios were designed based on two critical uncertainties: (1) COVID-19 longevity and (2) socio-economic disruption. These scenarios are: Divine Mercy, Recovery Mode, New Norm, and Survival of the Fittest. Subsequently, the features of each scenario are assessed for implications on HCT’s business and support operations, and the proactive strategies are documented to cope with these implications.During the full online delivery mode period, HCT recorded 86% satisfaction amongst its faculty and 54% amongst its student body, delivered 234,000 hours through 61,000 online classes, and delivered over 21,000 hours of online professional development (PD). Over the same period, more than 1900 non-faculty employees have been running business as usual from home.Envisioning future scenarios and preparing the organization for them is a practice that should be deployed in parallel to emergency response efforts to ensure successful business continuity.

Experimental study on the condensing heat recovery performance of air source heat pump

Energy recycling and sustainable development problem is imminent and condensing heat recovery technology in air source heat pump has received considerable development and application in recent years. In this article the experimental method is used to mainly explore the performance of four kinds of condensing heat recovery system (e.g. the static type, circulation, paraffin, copper foam/paraffin) in full and partial condensing heat recovery mode. The results show that in the full condensing heat recovery mode, four systems can obtain relatively high performance, but the systems’ performance rapidly decays with time and can't provide enough cooling capacity and hot water production due to the short running time. In partial condensing heat recovery mode, the four systems’ shows better system efficiency compared with the systems without condensing heat recovery. And the circulation system performance increases significantly, which comprehensive efficiency coefficient can reach 5.67 and the average system heat recovery rate is 44.0%. The two phase change heat storage system run steadily and the adding of foam metal copper to paraffin not only enhance the performance of the system but also improve the stability of the system operation.

Control system of electric traction drive of electric vehicle

The growth rate of electric transport production is increasing every year, so the issues of its improvement and development are relevant. The developmentof a traction electric drive control system that would meet all the requirements, it is the aim of the article. There is a strong weakening of the field, providing a quick change in torque. The results of the created electric drive system are obtained with simulation in the MATLAB. The control system provides the engine in traction mode, recovery mode, reverse, and also allows you to develop high torque at low speeds. The result is a trapezoidal velocity diagram and an almost rectangular moment diagram. When operating at higher speeds up to 400 rad/s, the system works stably. At higher speeds, moment fluctuations appear and dynamics deteriorates. Fluctuations in flux linkage are observed at a speed of more than 700 rad/s. The modeling also showed that the system maintains a constant voltage in the field weakening mode. The development of the control system in order to increase the torque at low speeds is possible due to the introduction of the controller of the balances of the real current of the machine and the current calculated in the engine model. The introduction of a dynamic field attenuation circuit serves to provide high torque when it is not possible to further increase the voltage of the motor stator.

Envisaging wastewater-to-energy practices for sustainable urban water pollution control: Current achievements and future prospects

The organic carbon in municipal wastewater is an energetic substance and can be captured and reused for bioenergy production. A comprehensive evaluation of relevant technical advances and energy recovery potential is essential to provide guidance for sustainability improvement. Although several previous works have covered this topic, most of them have mainly focused on the technical evaluation of a single step, rather than the full treatment line. In this review the currently available processes and achievements related to the capture, recovery and reuse of organic carbon from municipal wastewater for bioenergy production are summarized. The techno-economic evaluation indicates that the biological capture process fails to achieve a good effluent quality when treating wastewater with a high soluble organic content. Chemical coagulants or membranes can be applied as effective methods to assist carbon capture. A fermentation-centered bioprocessing platform is beneficial for the conversion of captured carbon into versatile products. At present, bioenergy recovery is the most promising carbon recovery mode, and the global wastewater sector possesses a 51.06 billion kWh/year bioenergy production potential. Through hydrothermal or pyrolysis treatment, the organic residue arising from the bioprocessing platform can be circularly used. Based on the above analysis, a plant-wide wastewater-to-energy route including a carbon separation system, a bioprocessing platform, and a thermochemical conversion line is envisaged. Additionally, the challenges to achieving the proposed bioenergy production paradigm from municipal wastewater are examined. This review presents the gaps and future prospects in achieving sustainable municipal water pollution control.

The effect of water alternating solvent based nanofluid flooding on heavy oil recovery in oil-wet porous media

Solvent flooding is considered as one of the effective methods to recover heavy oil from non water-wet reservoirs where thermal processes are inefficient. We have recently proposed and tested a solvent recovery technique called solvent based nanofluid flooding followed by waterflooding to improve sweep efficiency and recover a medium viscosity heavy oil (100 mPas) in oil-wet porous media. Although solvent based nanofluid improved displacement efficiency as a result of in-situ emulsification, the overall efficiency of the displacement was compromised by solvent gravity override. The objective of this study is to overcome the gravity override effect by conducting water alternating solvent based nanofluid flooding followed by waterflooding. Different injection scenarios with different slug sequences were designed, and the displacement patterns were monitored with a CT-scanner. Moreover, solvent based nanofluid flooding was conducted in a tertiary recovery mode to assess sweep efficiency and oil recovery performances. Imaging showed that solvent based nanofluid was effective in redistributing the preferential flow paths of water slugs and chase water; effluent analysis showed the improvement was due to the in-situ formation of emulsions. However, the overall efficiency of the process suffered from gravity override when conducting the process in a tertiary mode or starting the alternating slug process with the solvent phase. Starting the alternating slug process with the brine phase reduced override and enabled a substantial increase in recovery.

Effect of active versus passive recovery on performance-related outcome during high-intensity interval exercise.

It has been suggested that recovery mode may contribute to performance during high-intensity interval exercise. However, there is no consensus regarding the effects of active and passive recovery modes on subsequent performance. The aim of this study was to compare the effect of active versus passive recovery on performance during repeated high-intensity interval exercise. Two reviewers independently conducted a search using the PRISMA systematic approach in three electronic databases (PubMed, Scopus and Cochrane Central) searching for randomized controlled trials (RCTs) comparing the effects of recovery mode on performance (until February 2020). Twenty-six studies were included for analysis (17 for power output, nine for repeated-sprint ability and two for distance covered). Four studies found higher mechanical performance for passive recovery compared with active recovery. Six out of nine studies reported faster sprinting performance with passive recovery compared to active recovery. Two studies demonstrated that passive recovery resulted in a greater distance covered during intermittent sprint exercise. This systematic review suggests that performing high-intensity interval exercise with passive recovery results in greater performance when compared with active recovery.

Inclusive Economic Sustainability: SDGs and Global Inequality

In view of the 2020 global health crisis and its repercussions on the global economy, the need to redirect conventional economic thinking towards securing global economic sustainability is most critical. The Sustainable Development Goals (SDGs) are a significant move in this direction. However, in the past few years, a clearer understanding of inclusive economics and sustainability indicators have progressed our ability to reduce economic exclusion, chiefly represented by global inequality. Collective wellbeing within the “global village” is shaped largely by these avenues/directions, thus presenting the question: can an improved combination of sustainability priorities be identified that would substantially enhance countries’ adoption of the SDGs? New, inclusive paths to economic progress are essential to a world economy in crisis recovery mode. The aim of the paper is to qualitatively identify key indicators from these different directions to, collectively, address some of the most significant drivers of global inequality, thus improving the adoption rate of the SDGs. As its main contribution, the study found that for economic inclusivity to realistically reduce global inequality its full integration into three areas is necessary: business models, public policy and community development. This should also be supported by “social covenants” to facilitate improved SDG adoption by countries.

Sentinel-2 Data in an Evaluation of the Impact of the Disturbances on Forest Vegetation

In this article, we investigated the detection of forest vegetation changes during the period of 2017 to 2019 in the Low Tatras National Park (Slovakia) and the Sumava National Park (Czechia) using Sentinel-2 data. The evaluation was based on a time-series analysis using selected vegetation indices. The case studies represented five different areas according to the type of the forest vegetation degradation (one with bark beetle calamity, two areas with forest recovery mode after a bark beetle calamity, and two areas without significant disturbances). The values of the trajectories of the vegetation indices (normalized difference vegetation index (NDVI) and normalized difference moisture index (NDMI)) and the orthogonal indices (tasseled cap greenness (TCG) and tasseled cap wetness (TCW)) were analyzed and validated by in situ data and aerial photographs. The results confirm the abilities of the NDVI, the NDMI and the TCW to distinguish disturbed and undisturbed areas. The NDMI vegetation index was particularly useful for the detection of the disturbed forest and forest recovery after bark beetle outbreaks and provided relevant information regarding the health of the forest (the individual stages of the disturbances and recovery mode). On the contrary, the TCG index demonstrated only limited abilities. The TCG could distinguish healthy forest and the gray-attack disturbance phase; however, it was difficult to use this index for detecting different recovery phases and to distinguish recovery phases from healthy forest. The areas affected by the disturbances had lower values of NDVI and NDMI indices (NDVI quartile range Q2–Q3: 0.63–0.71; NDMI Q2–Q3: 0.10–0.19) and the TCW index had negative values (Q2–Q3: −0.06–−0.05)). The analysis was performed with a cloud-based tool—Sentinel Hub. Cloud-based technologies have brought a new dimension in the processing and analysis of satellite data and allowed satellite data to be brought to end-users in the forestry sector. The Copernicus program and its data from Sentinel missions have evoked new opportunities in the application of satellite data. The usage of Sentinel-2 data in the research of long-term forest vegetation changes has a high relevance and perspective due to the free availability, distribution, and well-designed spectral, temporal, and spatial resolution of the Sentinel-2 data for monitoring forest ecosystems.

Trace fossils from the Lower Triassic of North China — a potential signature of the gradual recovery of a terrestrial ecosystem

The Permian–Triassic Mass Extinction (PTME) resulted in the most severe loss of life in the history of the earth, both marine and terrestrial ecosystems suffered heavy losses simultaneously, and the biotic recovery process was difficult for both. There are many studies on the timing and pattern of this mass extinction, however, the consistency of the recovery between the marine and terrestrial facies remains controversial. In particular, few metazoans survived and the deposits were dominated by the microbialites during the Early Triassic. The reappearance of the metazoans signified the beginning of the biotic recovery. In this paper, we measured the trace fossils of the Heshanggou Formation in western Henan, North China, which plays an important role in the transformation from the flourishing of the microorganisms to the recovery of metazoans. We quantitatively described the characteristics and measured the diameter, depth, abundance and diversity of the trace fossils. Based on the acquired data, the lower part of the Heshanggou Formation is confined to simple, small, vertical burrows, suggesting that the ecological environment was suitable for the survival of special species. In the middle part, the vertical burrows become deeper, which may be due to the adaptation of organisms to the harsh environment. Disturbance is more intense and the diversity clearly increases in the upper part. Through the increasing bioturbation and diversity of the trace fossils, we found a gradual biotic recovery pattern in the Early Triassic, and the recovery mode is similar to marine ichnofossils in South China.

Tmall Recycling Logistics Solution Research

In the online shopping process, because users only rely on pictures and text description to make the purchase decision, it is easy to have impulsive consumption or purchase goods that are not suitable for them. In the process of online shopping logistics, due to improper packaging and handling, it will cause damage to the goods. In addition, the inevitable product production process, the improvement of consumers’ awareness of rights protection and other factors all contribute to the reverse logistics of tmall mall shopping. This paper analyzes the advantages of reverse logistics, the general process of recycling logistics, the present situation and existing problems of Tmall return logistics, and the optimization scheme of reverse logistics based on the joint recovery mode is proposed. Finally, the feasibility of the scheme is analyzed.

Research on Reverse Supply Chain under O2O Classified Recovery Mode

In recent years, due to the continuous growth of social needs and the continuous innovation of science and technology, the demand for various products has grown rapidly. Fierce market competition has accelerated the upgrading of various products, resulting in a shortened product life cycle and a large number of obsolete products. At the same time, the development of the Internet has brought a new path for recycling-the O2O classification recycling model, which simplifies the product recycling path from consumers to manufacturers. Therefore, research based on the O2O classification recovery model has become the key to solving the waste product recovery.

Research on the Recycling Model of Waste Mobile Phone Based on System Dynamics

Mobile phone replacement is accelerating, the waste of mobile phone will not only cause a lot of waste of resources, after the simple landfill, the heavy metal infiltration into the soil, rivers and groundwater, but also soil and water pollution, bring serious harm to the animals and plants in contact with the soil and water. Efficient and standardized recycling of increasingly used mobile phones has become an urgent social problem to be solved. The emergence and continuous improvement of “Internte plus” recycling mode of used mobile phones make it possible to solve this problem. On the various influence factors of recovery efficiency, and their relations on the basis of the analysis of building “Internte plus” old cell phone recycling model of system dynamics model, using Vensim software to draw causal loop diagram and in view of the old cell phone recycling price, information security and logistics cost effect on the recovery mode efficiency is analyzed. Research shows that information security is the most important factor affecting the efficiency of “Internte plus” waste mobile phone recycling model.

Rheumatoid Meningitis a Rare Extra-Articular Manifestation of Rheumatoid Arthritis: Report of 6 Cases and Literature Review.

Objectives. Central neurological manifestations of rheumatoid arthritis (RA) like rheumatoid meningitis (RM) are rare, little known and have a high rate of morbi-mortality. METHODS. We described six cases of RM that were directly related to RA activity after exhaustive assessment. RESULTS. They were mainly women, aged of 50 to 69. All were positive for anti-cyclic citrullinated peptide antibodies and half for rheumatoid factors. RA activity, duration, and treatments were heterogeneous including oral steroids, conventional synthetic disease modifying anti-rheumatic drugs (DMARDs) and biologic DMARDs. Symptoms were various, with acute or progressive beginning; main were: generalized or focal seizure (4/6), fever (3/6), headaches (3/6), and frontal syndrome (2/6). Imaging lesions were four leptomeningitis, one pachymeningitis, and one association of both. MRI usually showed hypersignal in various territories in T2-FLAIR (fluid attenuated inversion recovery) mode, and enhancement in T1-weighted mode after gadolinium injection. All patients had lumbar puncture that found sterile cerebrospinal fluid, no neoplasic cell, elevated cell count in 5/6 cases and elevated proteins concentration in 3/6 cases. Cerebral biopsy was possible for three patients, and definitively confirmed the diagnosis of aseptic lepto- or pachymenintis, excluding vasculitis and lymphoma. Different treatments were used like intravenous high dose steroids, immunoglobulins or biologic DMARDs, with variable clinical and imaging outcome: one death, one complete recovery, and four recoveries with sequelae. Conclusions. Clinical symptoms, imaging, lumbar puncture, and serological studies are often nonspecific, only histologic examination can confirm the diagnosis of RM. Any central neurological manifestation in RA patients, even in quiescent and ancient RA, should warn the physician.

Performance study of the cross-flow Maisotsenko cycle in humid climate conditions

This paper presents a first numerical analysis of the cross-flow Maisotsenko cycle (M-Cycle) below dew-point evaporative cooler for humid climates with model including the water vapor condensation phenomenon. Proposed solution allows to cool ambient air below its dew-point temperature, by utilizing cooling energy in air extracted from the building, due to that it can be used as effective pre-cooling solution for traditional systems. Proposed unit has significant advantage over traditional counter and cross-flow units operating in heat recovery mode, hence it is almost insensitive on temperature of exhaust air. This is caused by effective pre-cooling of the exhaust air in its initial part. Operation in humid climates using cold extracted air results in condensation occurrence in the primary air channels, and hence partial dehumidification of the primary airflow (which allows to cool the air before its dew- point temperature). The Maisotsenko cycle exchanger used to recover heat in the air-conditioning system is compared with Maisotsenko exchanger that operates only on the ambient airflow and does not allow to recover heat from the exhaust airflow from a conditioned space. Achieved results showed that M-Cycle below dew-point air cooler can operate more effectively in humid climates than traditional cross-flow Maisotsenko cycle exchanger.

The effects of general fatigue induced by incremental exercise test and active recovery modes on energy cost, gait variability and stability in male soccer players

The aerobic endurance is considered an important physiological capacity of soccer players which is examined by Incremental Exercise Test (IET). However, it is not clear how general fatigue induced by IET influences physiological and biomechanical gait features in soccer players and how players recover optimally at post-IET. Here, the effect of general fatigue induced by IET on energy cost, gait variability and stability in soccer players was investigated. To identify an optimal recovery mode, the effect of walking at Preferred Walking Speed (PWS), running at Individual Ventilation Threshold (IVT) (two active recovery modes), and Rest (a passive recovery mode) on aforementioned features were studied. Nine male players walked 4-min at PWS on a treadmill prior IET (PreT), which was followed by four 4-min walking trials (PosT-0, 1, 2, and 3) with three 4-min recovery intervals (PWS, IVT, or Rest) between them, in three sessions (one for each recovery mode) in a random order. Energy cost, gait variability and stability were examined at PreT (baseline), and at PosT-0, 1, 2, and 3 (intervals of respectively 0–4, 8–12, 16–20, 24–28 min at post-IET). Gait variability was assessed by the standard deviation of trunk angle and gait stability was assessed by the local dynamic stability of trunk angular velocity. Gait stability was not affected by IET, despite increases in gait variability and energy cost. Different from IVT, PWS and Rest recovery modes reduced energy cost at post-IET. Gait variability and energy cost recovered at PosT-1 and PosT-2, suggesting that 8–12 and 16–20 min recovery intervals, respectively, were required for returning to their baselines. No preference for active over passive recovery was found in terms of gait variability and energy cost.

Effect of Bypass Control and Room Control Modes on Fan Energy Savings in a Heat Recovery Ventilation System

This study makes a novel attempt to analyse the effect of the bypass control and room control modes on ventilation energy saving in an 84 m2 housing unit, which is the most frequently constructed unit-type among newly constructed apartment buildings in Korea. A heat recovery ventilation system was installed. The fan power consumption was measured via field experiments and analyses were made for potential energy savings. Experiments to confirm the power-saving effect owing to the application of the room control mode were performed under the heat recovery and bypass modes, using three air flow rates (0.5, 1.0 and 1.5 ACH). Additionally, the annual energy saving based on the application of the mixed mode (both bypass and room control modes) was calculated. The results obtained showed that when the mixed mode was employed, ventilation energy saving up to 10.76%–16.56%, which is greater than that obtained using only the heat recovery mode, was realized. Additionally, compared with all-room-ventilation, 26.69%–61.84% of ventilation energy could be saved if the mixed mode was applied only to the living room.

Performance improvement of adsorption desalination system by applying mass and heat recovery processes

Adsorption desalination system (ADS) is gaining growing attention for its capability to co-produce desalinated water and cooling by utilizing waste heat and renewable energy sources. In this paper, a new operation cycle for 2-bed ADS had been introduced with the heat and mass recovery between the adsorption beds, the condenser, and the evaporator. The appropriate ADS thermodynamic mathematical model was derived and evaluated by valid experimental data. In the recovery mode, the cold water extract heat from the beds and condenser to the evaporator and two beds were connected to each other through control valves to achieve a pressure equilibrium. The specific daily water production (SDWP) for this 2-bed ADS is 9.58 m^3 /ton of silica gel/ day at the hot water temperature of 95 (°C) and the cold water temperature of 30 (°C). As a result, the SDWP of the advanced 2-bed ADS is 66% more than the conventional 2-bed ADS.