Short Transfer Times Research Articles

Boosting energy transfer between quantum devices through spectrum engineering in the dissipative ultrastrong coupling regime

The coherent energy transfer between two quantum devices (a quantum charger and a quantum battery) mediated by a photonic cavity is investigated, in presence of dissipative environments, with particular focus on the ultrastrong coupling regime. Here, very short transfer times and high charging power can be achieved in comparison with the usually addressed weak coupling case. Such phenomenology is further magnified by the presence of level crossings appearing in the energy spectrum and which reveal very robust against dissipative environmental effects. Moreover, by carefully controlling the physical parameters of the model, e.g., the matter-radiation coupling and the frequencies of the system, it is possible to tune these crossings making this device more flexible and experimentally feasible. Finally to broaden our analysis, we assume the possibility of choosing between a Fock and a coherent initial state of the cavity, with the latter showing better energetic performances. Published by the American Physical Society 2024

Effect of cationic lipid concentration on monomer transfer kinetics between zwitterionic lipid vesicles

The kinetics of spontaneous monomer transfer between vesicles consisting of zwitterionic phospholipids is dictated by the difference in desorption rate of lipid monomers from their donor vesicles and the concentration imbalance in the dispersion. In a system with two lipid species with the same headgroup, transfer is asymmetric, and takes place from the population of donor vesicles consisting of shorter chain lipids to acceptor ones of longer chain. Transfer typically proceeds until equilibrium is reached, resulting in populations of vesicles consisting of a binary mixture of both lipid species, whose concentration depends on the number of lipids in the precursor donor and acceptor vesicles before transfer.Upon the introduction of a second lipid species in the donor vesicle population, the desorption rate of monomers should change with time, since the composition of donor vesicles changes when monomers of a given lipid type desorb. To tackle this problem, we added a cationic lipid, 1,2-dimyristoyl-3-trimethylammonium-propane (DMTAP), into donor zwitterionic lipid vesicles and assessed how the concentration of DMTAP affects the lipid transfer process. Lipid transfer is the result of the interplay between the initial concentration of DMTAP in the donor vesicles (and related probability of desorption at short transfer times) and their concomitant time-dependent concentration (and thus desorption rate) change due to the depletion of monomer species as the transfer process proceeds.

Quantifying the bitter masking effect of drug-cyclodextrin complexation: NMR-ROESY mixing time approach

Taste, especially unpleasant taste, can be key for patient compliance. In the formulation development process, drug-cyclodextrin (CD) inclusion complexes are often used to improve the solubility of a drug and/or mask its bitterness. This study aimed to evaluate the bitter masking effect of CDs on different drugs using NMR-ROESY analysis, human sensory tests, and e-tongue measurements. The strength of inclusion complex formation between drugs and CDs was investigated by NMR-ROSEY, and these results were compared to human sensory test results. In the sensory test, participants identified which drug-CD inclusion complexes were not bitter. NMR-ROSEY results aligned with the sensory tests; short magnetization transfer times corresponded to masked bitterness. The electrical tongue was not able to detect the taste of any of the drug-CD inclusion complexes. Additionally, we used NMR-ROSEY to determine which drug-CD inclusion complex formed in a system with multiple drug substances present. This research offers valuable insights into the bitter masking effect of CDs on different drugs and presents a comprehensive evaluation approach using various methods. This knowledge has significant implications for the pharmaceutical industry, clinical practice, and patient care, contributing to improved patient compliance and satisfaction with bitter medications.

Interfacility Transfer Outcomes Among Children With Complex Chronic Conditions: Associations Between Patient-Level and Hospital-Level Factors and Transfer Outcomes.

Determine patient- and referring hospital-level predictors of transfer outcomes among children with 1 or more complex chronic conditions (CCCs) transferred to a large academic medical center. We conducted a retrospective chart review of 2063 pediatric inpatient admissions from 2017 to 2019 with at least 1 CCC defined by International Classification of Diseases, Tenth Revision codes. Charts were excluded if patients were admitted via any route other than transfer from a referring hospital's emergency department or inpatient ward. Patient-level factors were race/ethnicity, payer, and area median income. Hospital-level factors included the clinician type initiating transfer and whether the referring-hospital had an inpatient pediatric ward. Transfer outcomes were rapid response within 24 hours of admission, Pediatric Early Warning Score at admission, and hours to arrival. Regression analyses adjusted for age were used to determine association between patient- and hospital-level predictors with transfer outcomes. There were no significant associations between patient-level predictors and transfer outcomes. Hospital-level adjusted analyses indicated that transfers from hospitals without inpatient pediatrics wards had lower odds of ICU admission during hospitalization (odds ratio, 0.46; 95% confidence interval, 0.22-0.97) and shorter transfer times (β-coefficient, -2.54; 95% CI, -3.60 to -1.49) versus transfers from hospitals with inpatient pediatrics wards. There were no significant associations between clinician type and transfer outcomes. For pediatric patients with CCCs, patient-level predictors were not associated with clinical outcomes. Transfers from hospitals without inpatient pediatric wards were less likely to require ICU admission and had shorter interfacility transfer times compared with those from hospitals with inpatient pediatrics wards.

Influence of organizational factors on the offer and success rate of a trial of labor after cesarean section in Belgium: an ecological study

BackgroundTrial of Labor After Cesarean is an important strategy for reducing the overall rate of cesarean delivery. Offering the option of vaginal delivery to a woman with a history of cesarean section requires the ability to manage a potential uterine rupture quickly and effectively. This requires infrastructure and organization of the maternity unit so that the decision-to-delivery interval is as short as possible when uterine rupture is suspected. We hypothesize that the organizational characteristics of maternity units in Belgium have an impact on their proposal and success rates of trial of labour after cesarean section.MethodsWe collected data on the organizational characteristics of Belgian maternity units using an online questionnaire. Data on the frequency of cesarean section, trial of labor and vaginal birth after cesarean section were obtained from regional perinatal registries. We analyzed the determinants of the proposal and success of trial of labor after cesarean section and report the associations as mean proportions.ResultsOf the 101 maternity units contacted, 97 responded to the questionnaire and data from 95 was included in the analysis. Continuous on-site presence of a gynecologist and an anesthetist was associated with a higher proportion of trial of labor after cesarean section, compared to units where staff was on-call from home (51% versus 46%, p = 0.04). There is a non-significant trend towards more trial of labor after cesarean section in units with an operating room in or near the delivery unit and a shorter transfer time, in larger units (> 1500 deliveries/year) and in units with a neonatal intensive care unit. The proposal of trial of labor after cesarean section and its success was negatively correlated to the number of cesarean section in the maternity unit (Spearman’ rho = 0.50 and 0.42, p value < 0.001).ConclusionsOrganizational differences in maternity units appear to affect the proposal of trial of labor after cesarean section. Addressing these organizational factors may not be sufficient to change practice, given that general tendency to perform a cesarean section in the maternity unit is the main contributor to the percentage of trial of labor after cesarean.

Description and analysis of the emergency obstetric interfacility ambulance transfers (IFTs) to Kawempe National Referral Hospital in Uganda.

In Uganda, 2% of women die from maternal causes with a mortality rate of 336 maternal deaths per 100,000 live births. According to the World Health Organization Uganda is one of the top three contributors to maternal mortality in sub-Saharan Africa. Uganda has parallel weak ambulance systems, government, and non-government-owned, that transport obstetric emergencies to higher-level facilities. These two operations lack standards of medical care and inter-facility transfer (IFT) protocols to direct care. Limited studies exist which assess the state of Emergency Care Services in Uganda and none has been performed to assess the ambulance referral services utilized to address obstetric emergencies. The present study was performed to describe the ambulance transfer processes of obstetric emergencies by analyzing cases arriving at Kawempe National Referral Hospital (KNRH) from outlying health facilities. The study was based at KNRH in Kampala, Uganda. It was a descriptive and analytic cross-sectional study. Trained research assistants enrolled participating patients who met the inclusion criteria consecutively on arrival by ambulance at the hospital. Utilizing a questionnaire, quantitative data was collected from the ambulance driver, the sending facility referral form, and the receiving hospital's ambulance log book for each case. The sample size was 215. The median age was 27 years and the majority of patients were referred because of hypertensive disorders (34.9%), obstructed labor (26.5%) and hemorrhage (20.9%). The median total response time for transfer of obstetric emergencies was 50min, from ambulance activation until the mother was received at KNRH. Differences were identified between government and non-government-owned ambulances in regards to the method of activation, medical escort staffing, number of vital signs recorded, and ambulance onboard medical care. Ambulances parked at the facility took the shortest transfer time and EMT-supported ambulances had the greatest number of vital signs taken. Recommendations are to develop an integrated ambulance system for both government and non-government ambulances with standards especially in regards to standardized scripted call-center calls analysis, dispatch activation time, response-to-patient time, and trained ambulance professional staffing and medical care whenever in patient transport mode.

3D printing in the planning and teaching of endovascular procedures.

The introduction of 3D printing in the medical field led to new possibilities in the planning of complex procedures, as well as new ways of training junior physicians. Especially in the field of vascular interventions, 3D printing has awide range of applications. 3D-printed models of aortic aneurysms can be used for procedural training of endovascular aortic repair (EVAR), which can help boost the physician's confidence in the procedure, leading to abetter outcome for the patient. Furthermore, it allows for abetter understanding of complex anatomies and pathologies. In addition to teaching applications, the field of pre-interventional planning benefits greatly from the addition of 3D printing. Especially in the preparation for acomplex endovascular aortic repair, prior orientation and test implantation of the stent grafts can further improve outcomes and reduce complications. For both teaching and planning applications, high-quality imaging datasets are required that can be transferred into adigital 3D model and subsequently printed in 3D. Thick slice thickness or suboptimal contrast agent phase can reduce the overall detail of the digital model, possibly concealing crucial anatomical details. Based on the digital 3D model created for 3D printing, another new visualization technique might see future applications in the field of vascular interventions: virtual reality (VR). It enables the physician to quickly visualize adigital 3D model of the patient's anatomy in order to assess possible complications during endovascular repair. Due to the short transfer time from the radiological dataset into the VR, this technique might see use in emergency situations, where there is no time to wait for aprinted model.

Can Quality Improvement Methodologies Derived from Manufacturing Industry Improve Care in Cardiac Surgery? A Systematic Review.

Objectives: Healthcare is required to be effectively organised to ensure that growing, aging and medically more complex populations have timely access to high-quality, affordable care. Cardiac surgery is no exception to this, especially due to the competition for and demand on hospital resources, such as operating rooms and intensive care capacity. This is challenged more since the COVID-19 pandemic led to postponed care and prolonged waiting lists. In other sectors, Quality Improvement Methodologies (QIM) derived from the manufacturing industry have proven effective in enabling more efficient utilisation of existing capacity and resources and in improving the quality of care. We performed a systematic review to evaluate the ability of such QIM to improve care in cardiac surgery. Methods: A literature search was performed in PubMed, Embase, Clarivate Analytics/Web of Science Core Collection and Wiley/the Cochrane Library according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis methodology. Results: Ten articles were identified. The following QIM were used: Lean, Toyota Production System, Six Sigma, Lean Six Sigma, Root Cause Analysis, Kaizen and Plan-Do-Study-Act. All reported one or more relevant improvements in patient-related (e.g., infection rates, ventilation time, mortality, adverse events, glycaemic control) and process-related outcomes (e.g., shorter waiting times, shorter transfer time and productivity). Elements to enhance the success included: multidisciplinary team engagement, a patient-oriented, data-driven approach, a sense of urgency and a focus on sustainability. Conclusions: In all ten papers describing the application of QIM initiatives to cardiac surgery, positive results, of varying magnitude, were reported. While the consistency of the available data is encouraging, the limited quantity and heterogenous quality of the evidence base highlights that more rigorous evaluation, including how best to employ manufacturing industry-derived QIM in cardiac surgery is warranted.

Disparities in Insurance Status Are Associated With Outcomes but Not Timing of Trauma Care.

Patient factors influence outcomes after injury. Delays in care have a crucial impact. We investigated the associations between patient characteristics and timing of transfer from the emergency department to definitive care. This was a review of adult trauma patients treated between January 1, 2016, and December 31, 2018. Bivariate analyses were used to build Cox proportional hazards models. We built separate logistic and negative binomial regression models for secondary outcomes using mixed-step selection to minimize the Akaike information criterion c. A total of 1219 patients were included; 68.5% were male, 56.8% White, 11.2% Black, and 7.8% Asian/Pacific Islander. The average age was 51±21y. Overall, 13.7% of patients were uninsured. The average length of stay was 5d and mortality was 5.9%. Shorter transfer time out of the emergency department was associated with higher tier of activation (relative risk [RR] 1.39, 95% confidence interval [CI] 1.09-1.77; P=0.0074), Injury Severity Score between 16 and 24 points (RR 1.57, 95% CI 1.04-2.32; P=0.0307) or ≥25 (RR 3.85, 95% CI 2.45-5.94; P=0.0001), and penetrating injury. Longer time to event was associated with Glasgow coma scale score ≥14 points (RR 0.47, 95% CI 0.27-0.85; P=0.0141). Uninsured patients were less likely to be admitted (odds ratio 0.29, 95% CI 0.17-0.48; P=0.0001) and more likely to experience shorter length of stay (incidence rate ratio 0.34, 95% CI 0.24-0.51; P=0.0001). Injury characteristics and insurance status were associated with patient outcomes in this retrospective, single-center study. We found no disparity in timing of intrafacility transfer, perhaps indicating that initial management protocols preserve equity.

Effects of solar radiation pressure on asteroid surface hopping transfers for high area/mass ratio rovers

The high area/mass ratio hopping rovers have potential applications in future asteroid surface exploration. This paper systematically investigates the effects of solar radiation pressure (SRP) on ballistic surface hopping transfers for the asteroid 101955 Bennu. Effects of SRP on the traveled distance and the trajectory design of hopping transfers are analyzed and summarized. The simulation results indicate that it is necessary to take SRP into account to ensure the success of hopping transfers and the proper use of SRP can help design the trajectories of hopping transfers with low initial impulses and short transfer times. It also reveals the potential possibility in using SRP to control the post-hopping transfers with specific control policies in the future surface exploration of asteroids.

Overview of current implementation and limitations of point-of-care ultrasound in the emergency department: a nationwide survey in Belgium

ABSTRACT Objective Giving an overview of the current implementation and limitations of point-of-care ultrasound (POCUS) in Belgian Emergency Departments (EDs). Methods A survey, consisting of questions regarding demographics, practice patterns, policies, difficulties of implementing ultrasound (US) and training of emergency physicians was sent out to all Belgian EDs (n = 109). Results Seventy-two percent of all the EDs responded. Eighty percent of these had an US device, 10% intended to have one in the near future whilst the remaining 10% had no intention of obtaining one. The main reasons for not having US were insufficient training (50%), no budget to purchase a device (31%), resistance from other specialties (31%), no return from investment (25%) and uncertainty about liability (19%). Eighty-four percent of the responding hospitals had a prehospital MUG (Mobiele Urgentiegroep) – team or SMUR (Service Mobile d’Urgence et de Réanimation). In 29% of these, prehospital US (PHUS) was used, 18% were in the process of purchasing a device whilst 53% had no intention of implementing PHUS. The main reasons for not implementing PHUS were short transfer times (38%), insufficient training (33%), the cost of a device (25%), no return from investment (19%), the assumption that PHUS delays administering urgent care (19%) and the uncertainty about liability (8%). Nationwide, 40% of all emergency physicians have had some form of US training. Conclusions POCUS is regularly used in Belgian EDs for diagnostic and management purposes. Further implementation of POCUS will depend on how barriers are being addressed in the near future.

Drip-and-ship versus mothership for endovascular treatment of acute stroke: A comparative effectiveness analysis.

Triage for suspected acute stroke has two main options: (1) transport to the closest primary stroke center (PSC) and then to the nearest comprehensive stroke center (CSC) (Drip-and-Ship) or (2) transport the patient to the nearest CSC, bypassing a closer PSC (mothership). The purpose was to evaluate the effectiveness of drip-and-ship versus mothership models for acute stroke patients. A Markov decision-analytic model was constructed. All model parameters were derived from recent medical literature. Our target population was adult patient with sudden onset of acute stroke within 8 h of onset over a one-year horizon. The primary outcome was quantified in terms of quality-adjusted-life-years (QALYs). The base case scenario show that the drip-and-ship strategy has a slightly higher expected health benefit, 0.591 QALY, as compared to 0.586 QALY in the mothership strategy when the time to PSC is 30 min and to CSC is 65 min, although the difference in health benefit becomes minimal as the time to PSC increases towards 60 min. Multiple sensitivity analyses show that when both PSC and CSC are far from place of onset (>1.5 h away), drip-and-ship becomes the better strategy. Mothership strategy is favored by smaller difference between distances to PSC and CSC, shorter transfer time from PSC to CSC, and longer delay in reperfusion in CSC for transferred patients. Drip-and-ship is favored by the reverse. Drip-and-ship has a slightly higher utility than mothership. This study assesses the complex issue of prehospital triage of acute stroke patients and can provide a framework for real-world data input.

Transfer of Patients with Spontaneous Intracranial Hemorrhage who Need External Ventricular Drain: Does Admission Location Matter?

IntroductionPatients with spontaneous intracranial hemorrhage (sICH) are associated with high mortality and require early neurosurgical interventions. At our academic referral center, the neurocritical care unit (NCCU) receives patients directly from referring facilities. However, when no NCCU bed is immediately available, patients are initially admitted to the critical care resuscitation unit (CCRU). We hypothesized that the CCRU expedites transfer of sICH patients and facilitates timely external ventricular drain (EVD) placement comparable to the NCCU.MethodsThis is a pre-post study of adult patients transferred with sICH and EVD placement. Patients admitted between January 2011–July 2013 (2011 Control) were compared with patients admitted either to the CCRU or the NCCU (2013 Control) between August 2013–September 2015. The primary outcome was time interval from arrival at any intensive care units (ICU) to time of EVD placement (ARR-EVD). Secondary outcomes included time interval from emergency department transfer request to arrival, and in-hospital mortality. We assessed clinical association by multivariable logistic regressions.ResultsWe analyzed 259 sICH patients who received EVDs: 123 (48%) CCRU; 81 (31%) 2011 Control; and 55 (21%) in the 2013 Control. The groups had similar characteristics, age, disease severity, and mortality. Median ARR-EVD time was 170 minutes [106–311] for CCRU patients; 241 minutes [152–490] (p < 0.01) for 2011 Control; and 210 minutes [139–574], p = 0.28) for 2013 Control. Median transfer request-arrival time for CCRU patients was significantly less than both control groups. Multivariable logistic regression showed each minute delay in ARR-EVD was associated with 0.03% increased likelihood of death (odds ratio 1.0003, 95% confidence interval, 1.0001–1.006, p = 0.043).ConclusionPatients admitted to the CCRU had shorter transfer times when compared to patients admitted directly to other ICUs. Compared to the specialty NCCU, the CCRU had similar time interval from arrival to EVD placement. A resuscitation unit like the CCRU can complement the specialty unit NCCU in caring for patients with sICH who require EVDs.

IAT-TiMeS: Intra-Arterial Thrombectomy Transfer Metric Study in Texas

ObjectiveWe aim to report intra-arterial thrombectomy transfer metrics for ischemic stroke patients that were transferred to hub hospitals for possible intra-arterial thrombectomy in multiple geographic regions throughout the state of Texas and to identify potential barriers and delays in the intra-arterial thrombectomy transfer process. MethodWe prospectively collected data from 8 participating Texas comprehensive stroke/thrombectomy capable centers from 7 major regions in the State of Texas. We collected baseline clinical and imaging data related to the pre-transfer evaluation, transfer metrics, and post-transfer clinical and imaging data. ResultsA total of 103 acute ischemic stroke patients suspected/confirmed to have large vessel occlusions between December 2016 to May 2019 that were transferred to hubs as possible intra-arterial thrombectomy candidates were enrolled. A total of 56 (54%) patients were sent from the spoke to the hub via ground ambulance with 47 (46%) patients traveling via air ambulance. The median spoke arrival to hub arrival time was 174 min, median spoke arrival to departure from spoke was 131 min, and median travel time was 39 min. The spoke arrival time to transfer initiation was 68 min. CT-perfusion obtained at the spoke and earlier initiation of transfer were statistically associated with shorter transfer times. ConclusionTransfer of intra-arterial thrombectomy patients in Texas may take over 4 h from spoke arrival to hub arrival. This time may be shortened by earlier transfer initiation and acceptance.

An XML-based approach for geo-semantic data exchange from BIM to VR applications

Virtual Reality (VR) and Building Information Modelling (BIM) have been steadily growing over the past decade and found practical applications in project planning, design review and construction planning analysis particularly in the Architecture, Engineering, Construction, and Facility Management (AEC/FM) industry. However, data exchange between BIM and VR is a complex and time consuming process, which has limited VR applications in practice. To address this challenge, this research proposes a novel method that enables an efficient interoperability of BIM and VR including geometry of each element along with required semantic data of the BIM model. In this method, geometry and semantic data are extracted from BIM models through an Extensible Markup Language (XML) file, which is then optimized to be efficiently imported and recreated into the VR environment. The backward communication is performed by converting XML file to IFC, which is then imported to the BIM application. A prototype was developed to implement the proposed methodology. A building case study was used to demonstrate the capability of the method including considerably short transfer time, high quality rendering and geo-semantic data exchange for design and construction. These capabilities promote VR applications in the AEC/FM industry as the required information for design and construction plan review including Architectural parameter (e.g., material, texture and dimensions), Engineering parameters (e.g., loads, R-Value), cost, schedule and clashes can be exchanged between BIM and VR in near real time.

Hospital volumes and the likelihood of stent implantation among patients undergoing catheterization of the left heart: more is more?

Abstract Background Percutaneous coronary intervention (PCI) is an established procedure, but recent studies analyzing the indication for stenting are going to change clinical practice. Previous studies suggested that hospital volume is inversely related to in-hospital mortality but its impact on likelihood of stent implantation and the number of stents remains unclear. Purpose There is a conflict of objectives between nationwide care including short transfer and intervention times and a few large centers with maximum technology and experience. We examine the effect of hospital volume on in-hospital mortality, likelihood of stent implantation, number of stents, length of hospital stay, and reimbursement in a recent nationwide cohort from Germany. Methods Using German national electronic health records, all patients who underwent coronary angiography with a documented coronary artery disease were identified by ICD and OPS codes. Risk-adjustment was applied using a predefined set of patient characteristics to account for differences in the risk factor composition of the patient populations between centers. Results In 2017, a total of 528,188 patients with a documented coronary artery disease underwent coronary angiography in Germany. Mean age was 69.8 years and 29.3% of patients were female. 55% of all patients received PCI, with a mean number of 1.01 stents implanted per patient. In-hospital mortality was 2.9%, length of hospital stay was 6.5 days and mean reimbursement was €5,531. Multivariable regression analyses showed a positive linear association between hospital volumes and the likelihood of stent implantation (p=0.003) as well as the number of implanted stents (p=0.020). No association was found between hospital volumes and in-hospital mortality (p=0.105), length of hospital stay (p=0.201) or reimbursement (p=0.108). Inspection of the non-linear impact of procedure volumes on stent implantation practices indicates a ceiling effect in the volume-outcome relationship: implantation likelihood and number of stents per patient are lowest in centers with less than 100 procedures per year (34.4% and 0.62, respectively). Then, implantation likelihood and number of stents constantly increase until the volume category of 500 procedures per year and center. For centers with &amp;gt;500 procedures per year, the likelihood of stent implantation and the number of implanted stents remained relatively constant (about 60% and 1.07, respectively). Conclusion Patients undergoing coronary angiography in low-volume centers are less frequently subject to PCI but at comparable risk for in-hospital mortality. Furthermore, the data suggest that more complex cases are treated in high volume centers with consistent mortality rates and thus constant safety is ensured in high volume hospitals. Thresholds are discussed. Impact of hospital volumes on PCI Funding Acknowledgement Type of funding source: None

Overcoming the Communication Challenges in Wireless Sensor and Actuat or Networks Isolated using DTN T echnologies

Wireless Sensor and Actuator Networks (WSAN) have represented a significant advance in wireless communication environments and their convergence with the phenomenon called the Internet of Things (IoT). One of the challenges studied in the WSAN field is to propose communication mechanisms to interconnect wireless sensor networks in isolated areas. Various studies have revealed the difficulty of achieving connectivity in this type of network. In this sense, we address the challenge of interconnecting isolated WSANs, which do not have end-to-end connection, with the Internet network infrastructure. For this, we consider the following characteristics of these environments, disruptive communications, long delays; devices with limited resources, very short transfer times and in contexts of mobility. We propose an integrated architecture that allows us to offer a service management framework based on the capabilities provided by WSAN, through an infrastructure based on cloud technologies. The functionalities that characterize service architectures in telecommunication networks and the integration of WSAN with cloud-based architectures are analyzed. Architectural capabilities such as Machine-to-Machine (M2M) and Machine Type Communication (MTC) are considered. The proposed architecture allows deliver applications and services can be reachable and shared with any host connected to Internet. WSAN data, hosted at remote sites or with limited communications, can be processed, stored and analyzed in the cloud, or locally by components of the architecture. The communication with the sensor network and actuators, is iterant, because of architecture provides support for long-delayed and disruptive tolerant services.

Development of a 6-kW-class Hall thruster for geostationary missions

To meet the growing demand for all-electric propulsion satellite, a 6-kW-class Hall thruster was newly fabricated and tested in laboratory. A Hall thruster that has an annular ceramic channel in 150-mm effective diameter and a centered hollow cathode was designed to optimize thrust performance with an appropriate channel-geometry and magnetic-field-topology combination. At an input power of 6 kW, both high thrust (392 mN) and high specific impulse (1940s) was demonstrated for 300 V discharge voltage with xenon propellant. In this case a thrust efficiency of 62.7% was obtained. The thruster also worked in a low power mode at 1.8 kW, in which 92.7 mN and 1870s were available for 400 V operation. In comparison with existing thrusters, this thruster enables lower-power and higher-Isp operation for station keeping with satisfactory discharge stability, which will improve the all-electric propulsion satellite not only by reducing the propellant mass during station keeping but also by increasing the electric power available for mission payloads. Analysis in this study showed that the 6-kW operation is suitable for orbit raising maneuvers of geostationary satellites from a launch orbit to a geostationary orbit because a satellite from 3-ton to 10-ton can be transferred with two- or up to four-6kW-thrusters with a high payload ratio and a relatively short transfer time of 4- to 6-months. After transferred to a geostationary orbit, station keeping operation will be executed by the lower power mode. The Hall thruster will hence play an important role in the field of geostationary satellites.

Disaggregation of energy storage operation by timescales

Abstract We discuss the ex-post disaggregation of electric storage operation by time differences between charging and discharging, i.e. by how long energy is stored prior to the discharge. This adds a new dimension to the analysis of storage time shifting revenue and allows for additional insights into the historic value loss of storage assets. We apply this method to stylized pumped hydro and battery storage systems operating on historic European (Swiss and German/Austrian) day-ahead electricity price curves (2007–2017). We find that historic trends of the disaggregated revenue are highly diverse depending on the timescales. Changes in relative revenue shares are primarily driven by the price profile distortion due to increasing photovoltaic electricity generation. In the battery storage case this results in a 1.5 h reduction of charging-discharging time differences between 2008 and 2012. The case of pumped hydro storage plants is more complex: Main revenue losses occur for time differences of 6 to 12 h. Revenues on other timescales are much more stable or even increasing. This especially holds for short transfer times between 0 and 6 h: In the German/Austrian market area, they contribute 17% to total pumped hydro storage revenue in 2016, as compared to 3% in 2008. The disaggregation also enables the analysis of contributions from hours with outlier electricity prices. These are found to be especially significant in the years 2007 and 2008. Overall, we find that storage operation has been increasingly diversified due to the historic price profile evolution. The often discussed revenue erosion offers new opportunities on different timescales.

Estimating epikarst water storage by time-lapse surface-to-depth gravity measurements

Abstract. The magnitude of epikarstic water storage variation is evaluated in various karst settings using a relative spring gravimeter. Gravity measurements are performed over a 1.5-year period at the surface and inside caves at different depths on three karst hydro-systems in southern France: two limestone karst systems and one dolomite karst system. We find that significant water storage variations occur in the first 10 m of karst unsaturated zone. The subsurface water storage is also evidenced by complementary magnetic resonance sounding. The comparison between sites of the depth gravity measurements with respect to net water inflow suggests that seasonal water storage depends on the lithology. The transmissive function of the epikarst on the seasonal scale has been deduced from the water storage change estimation. Long (&gt; 6 months) and short (&lt; 6 months) transfer times are revealed in the dolomite and in the limestone respectively.