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Hyperledger Fabric is one of the most popular permissioned blockchain platforms widely adopted in enterprise blockchain solutions. To optimize and fully utilize the platform, it is desired to conduct a thorough performance analysis of Hyperledger Fabric. Although numerous studies have analyzed the performance of Hyperledger Fabric, three significant limitations still exist. First, existing blockchain performance evaluation frameworks rely on fixed workload rates, which fail to accurately reflect the performance of blockchain systems in real-world application scenarios. Second, the impact of extending the breadth and depth of endorsement policies on the performance of blockchain systems has yet to be adequately studied. Finally, the impact of node crashes and recoveries on blockchain system performance has yet to be comprehensively investigated. To address these limitations, we propose a framework called BlockLoader, which offers seven different distributions of load rates, including linear, single-peak, and multi-peak patterns. Next, we employ the BlockLoader framework to analyze the impact of endorsement policy breadth and depth on blockchain performance, both qualitatively and quantitatively. Additionally, we investigate the impact of dynamic node changes on performance. The experimental results demonstrate that different endorsement policies exert distinct effects on performance regarding breadth and depth scalability. In the horizontal expansion of endorsement policies, the OR endorsement policy demonstrates stable performance, fluctuating around 88 TPS, indicating that adding organizations and nodes has minimal impact. In contrast, the AND endorsement policy exhibits a declining trend in performance as the number of organizations and nodes increases, with an average decrease of 10 TPS for each additional organization. Moreover, the dynamic behaviour of nodes exerts varying impacts across these endorsement policies. Specifically, under the AND endorsement policy, dynamic changes in nodes significantly affect system performance. The TPS of the AND endorsement policy shows a notable decline, dropping from 79.6 at 100 s to 41.96 at 500 s, reflecting a reduction of approximately 47% over time. Under the OR endorsement policy, the system performance remains almost unaffected.

Nucleic acid methylations are important genetic and epigenetic biomarkers. The formation and removal of these markers is related to either methylation or demethylation. In this review, we focus on the demethylation or oxidative modification that is mediated by the 2-oxoglutarate (2-OG)/Fe(II)-dependent AlkB/TET family enzymes. In the catalytic process, most enzymes oxidize 2-OG to succinate, in the meantime oxidizing methyl to hydroxymethyl, leaving formaldehyde and generating demethylated base. The AlkB enzyme from Escherichia coli has nine human homologs (ALKBH1-8 and FTO) and the TET family includes three members, TET1 to 3. Among them, some enzymes have been carefully studied, but for certain enzymes, few studies have been carried out. This review focuses on the kinetic properties of those 2-OG/Fe(II)-dependent enzymes and their alkyl substrates. We also provide some discussions on the future directions of this field.

As a power output unit, Induction Motor (IM) is widely used in Electric Vehicles (EV) due to its unique advantages of higher power density and better torque ability. With more complicated motor controller system, there are some hardware and software failures which bring some risks including EV unexpected acceleration or deceleration, therefore it is necessary to build high-accuracy torque estimation and safety control strategy. Firstly, hazard and safety concept are analyzed to make sure function safety goals and levels for IM system. Secondly, a novel method of high-accuracy torque estimation is proposed based on a rotor dynamic and composite flux linkage observer. Then, fault diagnosis and handling mechanisms of motor torque are designed to avoid hazards when it is a significant difference between motor estimation torque and vehicle requested torque. Finally, power test and Hardware in Loop (HIL) bench are configured to verify torque estimation accuracy and fault protection mechanisms rationality by comparing test results and injecting related faults. Experiment result shows that motor torque accuracy is within ±5 Nm and fault protection mechanisms can bring motor to safety state promptly.

Abstract Background The study looks at a changed in consumer’s eating and purchasing habits during COVID-19 period. There are several modes of transmission but transmission through food as being speculated is one area that has not been confirmed through research. The study, therefore, looks at how speculations about COVID-19 spreading through food has affected consumers' eating and purchasing habits. This study through probit model analysed how consumers' eating and purchasing habits have been influenced. Results The result shows that age, gender and education have negatively influenced consumer’s eating and purchasing habits during the COVID-19 pandemic compared to pre-pandemic period. The preference for imported food items, preference for frozen food, been infected or knowing someone who has been infected by the virus, and been infected through agricultural source or knowing someone who has been infected by the COVID-19 through agricultural source have negatively affected consumers' eating and purchasing habits compared to pre-pandemic period. The result, however, suggests that consumers who trust in the cold-chain food systems ability to limit the spread of the COVID-19 still maintain a positive eating and purchasing habits. Conclusions The study provides evidence on the impact of COVID-19 on consumer’s eating and purchasing habits. Therefore, there is the need to institute proper sanitary measures, especially at cold-chain food systems to help curb the spread and also boost consumers’ confidence.

This study aims to determine the sources of indoor particulate matter at the Potala Palace Museum in Tibet, China, and evaluate the potential hazards of these pollutants for cultural relics. Long-term monitoring of indoor and outdoor suspended particulate matter concentrations was conducted, and sediment particle samples were collected. The chemical composition of the deposited particles was determined using X-ray fluorescence analysis (XRF). The outdoor suspended particulate concentration was much lower than that indoors; the indoor PM1-10 concentration was much higher than that outdoors and was less affected by outdoor sources. The sources of indoor deposited particles in the high-plateau museum can be classified into four categories: soil dust brought in by tourists from the outdoors, incense ash, pollution from human activities, and ores. Based on data analysis and discussion, proper ventilation can dilute indoor suspended particulate matter, and the installation of air conditioning systems can control temperature and humidity at 20 °C and about 45–60%, respectively, and reduce the fluctuation value, so as to promote particle deposition and better protect the museum’s cultural relics.

Motor as well as its controller plays an important role in driving electric vehicle. As sole power device, it is closely related with actual torque accuracy to make sure security during EV driving. Due to complex controlling system for motor, there are some random failures of hardware and software which can bring a series of unexpected risks for EV acceleration or deceleration. A novel method based on motor parameters feature is proposed to estimate motor torque based on parameters feature extraction for three-phase of volts and currents. Additionally, Quality Factor ( QF ) and confidence coefficient are also adopted to judge whether motor estimation torque is reasonable or not and motor failure torque is limited to be output by setting fault flag in controller software. Finally, test bench is built to analyze torque accuracy compared with actual test value and verify security control strategy at failure modes, test results show that estimation torque accuracy is within ±5 Nm which is compared with actual test torque and motor system can effectively come into security state from failure state by security control strategy which is proposed in this paper.

The study looks at the factors that influence vegetable farmers' compliance to pesticide application guidelines and regulation. Compliance is measured by looking at whether vegetable farmers follow pesticide use regulations and guidelines or otherwise. To help achieve this objective, vegetable growing communities in Yunnan province were purposively selected for the study. Six hundred and thirty-two (632) vegetable farmers were selected through a systematic random sampling technique. The result shows that the number of years spent in schooling, quality driven motives, commercial oriented production, knowledge and experience in pesticide application, government supervision and extension support have positive statistical significance on compliance to pesticide guidelines and regulations. The result, however, reveals that vegetable farmers driven by quantity are less likely to comply with the pesticide use guidelines and regulations. The interactive effect of quantity and quality driven motives shows a positive significant effect on compliance. Programs and projects geared towards sensitizing farmers especially, vegetable farmers on correct usage of pesticide should be of concern to policy makers.Here we show for the first that interaction between quantity driven motive and quality driven motive has a positive effect on compliance with pesticide use guidelines and regulations.

According to the United Nations (UN), about 70% of the world’s population projected to live in urban areas by 2050. Therefore, cities are experiencing an enormous urban transition the world has ever seen, accounting for 80% of global carbon dioxide emissions, consuming over two-thirds of the world’s energy, and producing 1.3 billion tons of waste per year. Leaders, governments, architects, urban designers, developers, planners and business leaders need to make decisions and find solutions for how billions of urbanites will live in the future. Therefore, future cities will require new design principles to face their urban challenges and problems such as pollution, poverty, poor environment, land use management, green-house gas emissions and socio-economic and environmental risks. In this context, the case study area of this paper will be El Raval district, which is in a medieval quarter of Barcelona. This area considered as one of the oldest and a significant part of the city that contains many heritage buildings and unique traditional urban context going back to hundreds of years. The district has an influx of immigrants, which has transformed its label from an industrial neighbourhood into a residential one and low rents that have attracted many people of low income, making it a vibrant and multicultural community. Therefore, the main aim of this paper is to address the implementation of innovative solutions, advanced technologies, ICT and IoT that might enhance people participation in the urban design processes and respond to urban futures challenges. The result of this research will lead to creating a platform to resolve the conflicting values of architectural heritage and smart cities principles, sourcing new sustainable technologies and the integration of the smart infrastructure systems.DOI: https://doi.org/10.20365/disegnarecon.23.2019.14

The actual power capacity of permanent magnet synchronous machine for electric vehicles is usually limited by rotor temperature, and rotor overheating is one of the major reasons for permanent magnet synchronous machine failure. Therefore, an approach of rotor temperature estimation is proposed to improve motor peak power utilization and protect permanent magnet synchronous machine from serious demagnetization due to thermal damage. A real-time iterative algorithm is provided based on the equivalent thermal model for rotor temperature. First, the heat generating principle of each part as well as the power flow transferring of the motor system is analyzed. Second, rotor temperature model is built based on the conservation of energy loss from the stator and real-time superposition of temperature variation rate for the rotor. Finally, the motor performance test bench is built to validate the proposed algorithm and numerical models are also constructed to simplify estimation parameters for rotor temperature model. The algorithm accuracy is improved and verified by optimizing control parameters with given environment temperature and power load. The experimental result shows that the maximum error between actual test value and estimation value is within ±10°C, and it meets the requirement of algorithm accuracy and also benefits on system performance and manufacture cost efficiently.

Investment in R & D in the agricultural sector is one of the means to propel the growth of the sector, but failure to ensure the efficient use of resources allocated to agricultural R & D would lead to wastage and underproduction. Based on this, the paper seeks to look at the efficiency of investment in agricultural R& D in relation to the food production index in the West Africa sub-region. To achieve this objective, the number of full-time researchers and spending in terms of percentage of the share of agriculture to GDP were treated as inputs and the food production index as an output (agriculture output). The study used panel data from 2009 to 2014. The Malmquist index approach was adopted to measure the efficiency of food production in selected West African countries. The mean Malmquist index of 0.991, 1.032, 0.976, 0.995, 1.051, 0.908, 0.966, and 0.961 for Ghana, Benin, Burkina-Faso, Ivory Coast, Niger, Nigeria, Senegal, and Togo, respectively, were recorded. Benin and Niger experienced growth in food production within the period. The remaining countries, however, did not experience growth in food production as their respective means were less than 1 (Mi <1), which was an indication of inefficiencies in the application of investments committed to agricultural R & D. To help identify the role played by various components, technical efficiency change and technological progress change for the respective countries were also calculated. The results of the study show the need to go beyond mere allocation of resources to the agricultural sector and push towards efficient use of resources. The allocation of resources without measures to ensure their proper use would not yield the desired outcome. Various countries exhibited some levels of inefficiency across the dimensions assessed. This, therefore, calls for close attention to the use of agricultural resources. There is a need to ensure efficient use of resources committed to agricultural research and development across respective countries. Measures should be put in place to reduce wastage and redundancy in the allocation of resources for agricultural research and development, to improve efficiency and productivity in the agricultural sector. [ABSTRACT FROM AUTHOR]

Tannin was crosslinked with paraformaldehyde to prepare tannin-phenolic polymer(TP), TP immobilized on cellulose (TPPC) was prepared by the cross-linking reaction of TP and cellulose with epichlorohydrin as crosslinking agent. Tannin was crosslinked prior to being immobilized on cellulose, which could increase the effective phenolic hydroxyl content in cellulose skeleton and improve the adsorption property of TPPC for metal ions. The maximum adsorption capacity of TPPC for Cd(II) and Cu(II) ions were 80.11 mg/g and 55.97 mg/g, respectively. The adsorption equilibrium data for the metal solutions fitted the Langmuir model well. The adsorption rate data fitted well to a Pseudo-second-order model. The TPPC has potential application value in the field of metal wastewater treatment. [ABSTRACT FROM AUTHOR]

A bio-adsorbent was prepared by the crosslinking reaction of a tannin based phenolic resin and carboxymethyl cellulose with epichlorohydrin as crosslinker. The water absorption ratio of the adsorbent decreased due to the introduction of the phenolic resin based on tannin but the adsorption properties of the adsorbent for methylene blue were improved due to the introduction of the phenolic hydroxyl groups from the tannin in comparison with the carboxymethyl cellulose based adsorbent cross-linked with epichlorohydrin. The maximum adsorption capacity of the adsorbent for methylene blue was 1300mg/g and the adsorption process for methylene blue was exothermic. The adsorption ratio of the adsorbent for methylene blue was over 98% for an adsorbent dosage of 2.5 g/L when the concentration of methylene blue in solution was lower than 2000mg/L. The adsorbent can process wastewater containing methylene blue in the pH range of 4-12. [ABSTRACT FROM AUTHOR]

Poly-L-lactide (PLLA) is one of the most significant members of a group of bioabsorbable polymers. A new approach for fabricating PLLA material was investigated by one-step bulk polymerization. The focus of this paper was on the effect of reaction temperature and reaction time on the weight-average molar mass, the polydispersity index (PDI), and the flexural strength and modulus. Gel permeation chromatography (GPC), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and mechanical properties measurements were used to characterize the products. It was found that the optimal reaction conditions were at 140 oC for 24 h, under which the highest (5.02 × 105 Da) and the lowest PDI (1.16) were reached. In addition this material had the highest flexural strength and modulus, 74.58 ± 2.35 MPa and 1.62 ± 0.14 GPa, respectively. [ABSTRACT FROM AUTHOR]

Graphene oxide/polyamidoamines dendrimers (GO/PAMAMs) composites were synthesized via modifying GOwith 2.0 G PAMAM. The adsorption behavior of the GO/PAMAMs for acid Bordeaux B (ABB) was studied and the effects of media pH, adsorption time and initial ABB concentration on adsorption capacity of the adsorbent were investigated. The optimum pH value of the adsorption of ABB onto GO/PAMAMswas 2.5. Themaximumadsorption capacity increased from325.78 to 520.83mg/gwith the increase in temperature from298 to 328 K. The equilibriumdata followed the Langmuir isothermmodel better than the Freundlich model. The kinetic study illustrated that the adsorption of ABB onto GO/PAMAMs fit the pseudo-second-order model. The thermodynamic parameters indicated that the adsorption process was physisorption, and also an endothermic and spontaneous process. [ABSTRACT FROM AUTHOR]

The composite containing 10 wt% of osteoconductive porcine cortical bone (PCB) and 90 wt% of bioabsorbable poly(L-lactide) (PLLA) was manufactured. The degradation behaviors of the PLLA/PCB composite in-vitro up to 20 weeks, including water uptake, weight loss, mechanical properties, molecular weight and morphology, were investigated by soaking in phosphate-buffered solution (PBS). The results indicated that the water uptake and weight loss increased with increasing degradation time, while the mechanical properties and molecular weight decreased. There were a large number of microcracks and erosive holes on the surface and in the interior of the PLLA/PCB materials after 20 weeks. The degradation mechanism of PLLA component in the PLLA/PCB is indicative of an autocatalysis process. The degradation of PLLA complies with first-order kinetics, and the rate constant of the biodegradation process of PLLA component is 6.6 × 10-3 day-1. [ABSTRACT FROM AUTHOR]