Impact of Penetrations of Connected and Automated Vehicles on Lane Utilization Ratio

Lane Utilization Ratio (LUR), affected by lane selection behavior directly, represents the traffic distribution on different lanes of road section for a single direction. The research on LUR, especially under Penetration Conditions of Connected and Automated Vehicles (PCCAV), is not comprehensive enough. Considering the difficulty in the conduction of real vehicle experiment and data collection under PPCAV, the lane selection model based on phase-field coupling and set pair logic, which considers the full-information of lanes, was used to carry out microscopic traffic simulation. From the analysis of microsimulation results, the basic relationships between Penetration of Connected and Automated Vehicles (PCAV), traffic volume, and Lane-Changing Times, also that between PCAV, traffic volume, and LUR in the basic section of the urban expressway were studied. Moreover, the influence of driving propensity on the effect of PCAVs was also studied. The research results could enrich the traffic flow theory and provide the theoretical basis for traffic management and control.

Thermal Analysis of a Solar Assisted Cold Storage Unit for the Storage of Agricultural Perishables Produce

A solar based cold storage unit for the preservation of food products is an excellent way to reduce post-harvest losses at lower energy costs. Energy optimization is essential to improve the reliability of the system. In the case of cooling, a major factor to reduce energy consumption is the uniform distribution of air inside the cooling chamber to maintain the even temperature of stored products. For this, a detailed thermal analysis is required to analyse the cooling process for energy saving and optimum conditions. In the current study, an energy and exergy based thermal analysis of a solar assisted cold storage unit is presented. A parametric investigation and a proper understanding about the influence of thermodynamics on the cooling process were obtained. All the experimentally calculated parameters (energy utilized, energy utilization ratio, energy loss and exergy efficiency) were subjected to a model curve fitting using Sigmaplot-12 and a polynomial cubic model was found best fitted based on the values of coefficient of determination. Thermal analysis showed variations in the rate of energy utilization, energy utilization ratio, exergy losses and exergy efficiency in the range of 3–18 kJ/s, 0.37–0.80, 0.8–2.25 kJ/s and 40–60%, respectively. The average value of COP of the system was found to be 3.95.

Quantum secure direct communication based on quantum homomorphic encryption

As one of the most important branches of quantum cryptography, quantum secure direct communication (QSDC) is used to transmit the secret message directly rather than distribute a random key. Quantum homomorphic encryption (QHE) enables arbitrary quantum transformation on encrypted data without decrypting the data. To date, the previously proposed QSDC schemes are mainly based on different quantum states. The research of the QSDC scheme based on QHE is still blank. In this paper, a QSDC scheme by taking advantage of the properties of QHE is proposed. The proposed protocol has applied QHE and decoy photons to prevent various types of attacks. The proposed scheme only utilizes the rotation operation to encode the secret message which is easy to implement with the current technologies. Moreover, the communication efficiency and the qubit-utilization ratio are analyzed in this paper, which shows that this protocol has good performance in the qubit-utilization ratio, and the qubit efficiency of the QSDC scheme has improved.

Central line-associated bloodstream infection trend in Brazilian adult intensive care units: an ecological study

Introduction: Central line-associated bloodstream infections are the second most frequent infection in intensive care units. It represents an adverse event of significant magnitude, thus threatening the patient safety. The aim of this study was to analyze the historical trend of central line-associated bloodstream infections in patients in intensive care units, the rate of infection, central venous catheter utilization ratio, type of pathogen and their antimicrobial resistance pattern. Methodology: This ecological study was performed at 42 intensive care units from a state capital of the Midwest region of Brazil. Central line-associated bloodstream infections notifications were collected from two databases, the Municipal Coordination for Patient Safety and Infection Control at Healthcare Services, from 2012-2016, and the FormSUS (National Health System Data Processing Company), from 2014-2016. Results: The incidence of central line-associated bloodstream infections was high and stationary in the period (incidence rate of 2.3 to 3.2 per 1,000 catheter days, central venous catheter utilization ratio average 56,9%). The most frequent microorganisms were coagulase-negative Staphylococcus, Klebsiella pneumoniae, Acinetobacter spp. and Pseudomonas aeruginosa. Resistance to 3rd and 4th generation cephalosporins and carbapenems were detected among Gram-negative bacteria, and resistance to oxacillin among Gram-positive bacteria. Conclusions: Central line-associated bloodstream infections incidence rates were high, however the historical trend remained stationary in adult intensive care units. Infections were mostly caused by coagulase-negative Staphylococcus, K. pneumoniae, Acinetobacter spp. and Pseudomonas aeruginosa, including multi-drug resistant organisms. These findings point to the need of educational strategies addressing the adherence to established preventive measures and to the rational use of antimicrobials.

Questionable Utility of the Eccentric Utilization Ratio in Relation to the Performance of Volleyball Players

The difference between squat jump (SJ) and countermovement jump (CMJ), termed eccentric utilization ratio (EUR), is frequently suggested as an outcome that can be used in athletic training design. Unlike performance in SJ and CMJ, which is associated with sports performance, the association between EUR and sports performance is almost unexplored. This study aimed to investigate whether EUR is associated with performance in approach jump, linear sprint and change of direction (CoD) tasks in volleyball players. Forty-five male volleyball players performed SJ, CMJ, 25 m linear sprint, approach jump and two CoD tasks (505 test and modified T-test). EUR was calculated based on jump height, peak power, peak force and average power. SJ and CMJ variables showed moderate to high correlation with approach jump performance (r = 0.42–0.70), small correlation with modified T-test (r = 0.33–0.40) and small to moderate correlation with sprint time (r = 0.35–0.49). EUR showed only small associations with performance variables (r = 0.31–0.34). In all linear regression models with performance outcomes as dependent variables, the CMJ height was always the only statistically significant predictor. Our results support the recent arguments that the EUR offers limited insight into the neuromuscular capabilities of athletes.

Numerical study on the dynamic performance of combined sensible-latent heat packed-bed thermocline tank

Thermal energy storage (TES) using thermocline technology with phase change materials (PCMs) is a promising technique for peak shaving operation in cogeneration units. One of the disadvantages of this connotation is the use of the highly-cost PCM capsules in a water tank. To circumvent this issue, a new thermocline tank connotation is proposed. The tank is packed with a mixture of solid filler pills and PCMs capsules, forming a multi-layer packed-bed system. A transient concentric-dispersion model is developed to assess the dynamic performance of a solid-PCM multi-layer packed-bed (SPMLPB) tank. The influences of the PCMs volume fraction (VF) and the charge and discharge dimensionless cut-off temperatures criterion on the dynamic performance have been investigated. The results show that the VF of PCMs influences the system's behavior, both in terms of energy storage and release. As the PCMs volume fraction increases from 10% to 40%, the amount of energy storage, energy release, and latent utilization ratio increased by 82.65%, 73.94%, and 55%, respectively, while the exergy overall efficiency falls by 6.3%. Besides, increasing both the charge and discharge cut-off temperatures (ST*ch/ST*dish) enhances the total utilization ratio and energy recovered. As ST*ch increases from 0.27 to 0.7, total utilization ratio and energy recovered increased by 63.63% and 28.67% respectively by maintains ST*dish = 0.26.

The water dispatching of river basins during dry periods under the most stringent water management system in China

Since 2011, China has implemented its most stringent water management system to effectively protect water resources and guarantee socioeconomic development. More basin-scale water division schemes have been developed to act as references for basin-scale water resources management. Water dispatching during dry periods is an effective way to guarantee the water supply for the river basin, and is also an important component of basin-scale water resources management. Given this, the present study proposes a framework for the water dispatching of river basins during dry periods under the most stringent water management system in China. This framework mainly consists of the analysis and forecasting of rainfall and inflow, the dispatching requirements for the main water users, major reservoirs, and sections, as well as safeguard measures. The Jian River Basin in South China is presented as a case study. The total discharge of the Gaozhou Reservoir in 2017 was 25 million m3 more than the target discharge specified in the water dispatching scheme, and the total water storage utilization ratio during the dispatch period was 4.7% higher than the target utilization ratio. These factors demonstrate the effectiveness and applicability of the proposed framework. HIGHLIGHT The proposed framework for the water dispatching of river basins during dry periods provides reliable technical support for water use security under the most stringent water management system in China, and is demonstrated to be both effective and applicable.

On-Board Liquid Hydrogen Cold Energy Utilization System for a Heavy-Duty Fuel Cell Hybrid Truck

In this paper, a kind of on-board liquid hydrogen (LH2) cold energy utilization system for a heavy-duty fuel cell hybrid truck is proposed. Through this system, the cold energy of LH2 is used for cooling the inlet air of a compressor and the coolant of the accessories cooling system, sequentially, to reduce the parasitic power, including the air compressor, water pump, and radiator fan power. To estimate the cold energy utilization ratio and parasitic power saving capabilities of this system, a model based on AMESim software was established and simulated under different ambient temperatures and fuel cell stack loads. The simulation results show that cold energy utilization ratio can keep at a high level except under extremely low ambient temperature and light load. Compared to the original LH2 system without cold energy utilization, the total parasitic power consumption can be saved by up to 15% (namely 1.8 kW).

Using High-Resolution Signal Controller Data in the Calibration of Signalized Arterial Simulation Models

Calibration of traffic simulation models is a critical component of simulation modeling. The increased complexity of the transportation network and the adoption of emerging vehicle- and infrastructure-based technologies and strategies have motivated the development of new methods and data collection to calibrate the simulation models. This study proposes the use of high-resolution signal controller data, combined with a two-level clustering technique for scenario identifications and a multi-objective optimization technique for simulation model parameter calibration. The evaluation of the calibration parameters resulting from the multi-objective optimization based on travel time and high-resolution signal controller data measures indicate that the simulation model that uses these optimized parameters produces significantly lower errors in the split utilization ratio, green utilization ratio, arrival on green, and travel time compared with a simulation model that uses the software’s default parameters. When compared with a simulation model that uses calibration parameters obtained based on the optimization of the single objective of minimizing the travel time, the multi-objective optimization solution produces comparably low travel time errors but with significantly lower errors for the high-resolution signal controller data measures.

Comparison of metrics used to track central-line–associated bloodstream infections (CLABSIs) and catheter-associated urinary tract infections (CAUTIs) across a regional network

The paradoxical relationship between standardized infection ratio and standardized utilization ratio for catheter-associated urinary tract infections (CAUTIs) in contrast to central-line–associated bloodstream infections (CLABSIs), in addition to CAUTI definition challenges, incentivizes hospitals to focus their prevention efforts on urine culture stewardship rather than catheter avoidance and care.