Auxiliary Source Research Articles

An auxiliary source-based near field source localization method with sensor position error

In order to avoid the influence of errors brought by simplified model and sensor position error on near-field source location, a non-uniform linear array source location algorithm using precise model and based on auxiliary source (AS) is proposed under the condition of sensor position error. The array model used in this algorithm has position errors except for reference sensor. AS method is used to accurately estimate the position of the special sensor. Then, the generalized eigenvalue including the estimated position of the special sensor is obtained by using the fourth-order cumulant and the idea of Least Squares-Estimating Signal Parameter via Rotational Invariance Techniques (LS-ESPRIT). Finally, the estimation results of the source location can be obtained by using the correlation formula. In addition, the Cramér Rao Lower Bound (CRLB) is proposed for the parameter estimation problem, which determines a lower bound for the variance of any unbiased estimator. Two cases of near - field source and mixed source are simulated respectively. The results show that the proposed algorithm is applicable to both cases and has very accurate source location estimation results.

Effects of heat source type on the thermodynamic performance and economy of domestic hot water system

In this paper, a solar assisted air source heat pump (SA-ASHP) domestic hot water (DHW) system is designed and built, the thermal performance of the system and the effect of heat source type on the energy consumption and carbon emission are studied by simulation and experiment. The static investment payback period of transforming the auxiliary heat source from electric boiler (EB) to ASHP is determined by economic analysis. The results show that the coefficient of performance of SA-ASHP system (COPS) varies from 2.76 to 6.26 and the coefficient of performance of ASHP unit (COPH) varies from 2.62 to 3.93 throughout the year. In the four typical heat source hot water systems, the SA-ASHP system has the lowest energy consumption, operation cost and CO2 emission. Compared with the solar assisted electric boiler (SA-EB) system, the power consumption per unit hot water, per capita power consumption and per capita water consumption of the SA-ASHP system decreased significantly, while the average heat collection efficiency and solar fraction increase obviously. Based on the actual operation data and economic analysis, the static payback period and CO2 emission reduction of transforming a SA-EB system into a SA-ASHP system have been analysed.

Implementation and performance analysis of a novel sliding mode controller for bidirectional DC to DC converter in aircraft application

Purpose The purpose of this paper is to implement a closed loop regulated bidirectional DC to DC converter for an application in the electric power system of more electric aircraft. To provide a consistent power supply to all of the electronic loads in an aircraft at the desired voltage level, good efficiency and desired transient and steady-state response, a smart and affordable DC to DC converter architecture in closed loop mode is being designed and implemented. Design/methodology/approach The aircraft electric power system (EPS) uses a bidirectional half-bridge DC to DC converter to facilitate the electric power flow from the primary power source – an AC generator installed on the aircraft engine’s shaft – to the load as well as from the secondary power source – a lithium ion battery – to the load. Rechargeable lithium ion batteries are used because they allow the primary power source to continue recharging them whenever the aircraft engine is running smoothly and because, in the event that the aircraft engine becomes overloaded during takeoff or turbulence, the charged secondary power source can step in and supply the load. Findings A novel nonsingular terminal sliding mode voltage controller based on exponential reaching law is used to keep the load voltage constant under any of the aforementioned circumstances, and its performance is contrasted with a tuned PI controller on the basis of their respective transient and steady-state responses. The former gives a faster and better transient and steady-state response as compared to the latter. Originality/value This research gives a novel control scheme for incorporating an auxiliary power source, i.e. rechargeable battery, in more electric aircraft EPS. The battery is so implemented that it can get regeneratively charged when primary power supply is capable of handling an additional load, i.e. the battery. The charging and discharging of the battery is carried out in closed loop mode to ensure constant battery terminal voltage, constant battery current and constant load voltage as per the requirement. A novel sliding mode controller is used to improve transient and steady-state response of the system.

Court precedent as a source of constitutional law of foreign countries

In modern conditions, the study of the sources of constitutional law of foreign countries is extremely relevant. The scientific article determined that judicial precedent is the main source of constitutional law of the states of the Anglo-Saxon legal system and an auxiliary source of constitutional law in the Romano-Germanic legal system.
 The scientific article also focuses on the fact that on February 23, 2006, a fundamental Law was adopted in Ukraine – the Law of Ukraine «On the Implementation of Decisions and Application of the Practice of the European Court of Human Rights». It was determined that the adoption of the above-mentioned legislative act had at one time not only a theoretical significance for legal science, but primarily a practical significance for the functioning of the courts, since the requirement of this legislative act is the strict implementation of the decisions of the European Court of Human Rights, which in turn recognizes precedential law.
 The work also determined that earlier, court precedent in Ukraine was not a universally recognized source of constitutional law. However, over time, court precedent began to take on extremely important importance, and domestic courts increasingly operate with the practice of higher courts when making certain decisions. Therefore, the scientific article substantiates the importance of the study of judicial precedent as a source of constitutional law in foreign countries, since the relationship to this source of constitutional law in common law states and continental law states is fundamentally different.
 Also, in the scientific article, special attention is paid to issues related to the practice of applying judicial precedent in each of the modern legal systems. In particular, it is determined what influence the court precedent had on the development of constitutional law, whether courts act as subjects of judicial law-making or not, the main aspects of the court precedent and its relationship with judicial practice are determined.
 The scientific article also highlights how judicial precedent is applied in France, Germany, Great Britain, as well as specific features of its application in Ukraine.
 As a result, it was determined that judicial precedent is determined by law as a special source of constitutional law of foreign countries, and therefore for Ukraine it should also occupy a particularly important place in the system of sources of constitutional law, although at the same time it is inferior to the normative legal act as a fundamental source of constitutional law - the German legal system, which includes Ukraine.

PERFORMANCE IMPROVEMENTOF SOLAR DRYER USINGAN AUXILIARY HEAT SOURCE UNDER DIFFERENT VALUES OF AIRFLOW RATES

One of the most crucial methods for preserving agricultural produce is solar drying. The major focus of this paper is increasing solar drying systems' effectiveness. The development of new methods and variables that may have an impact on the functionality of solar dryers aids in enhancing their efficiency. An indirect-type solar dryer for drying agricultural products is proposed and developed in this study. A dryer consisting of a solar flat plate air collector, an insulated drying chamber, an auxiliary (electric) heat source, and an electric fan is constructed to improve the dryer's performance. The dryer's most typical function is to blow hot air at the product, forcing the water in it to evaporate. The effect of air temperature and velocity on evaporation rate has been studied experimentally. Tests with three different airflow rates—0.042, 0.0735, and 0.105 m3/s—are conducted. When there is little or no solar radiation, an auxiliary heater is used to provide sufficient heat. For varying airflow rates, solar mode and electrical mode were tested experimentally with only one energy source in each mode. The findings revealed that using a different heat source in addition to solar radiation will allow you to keep the air temperature in the drying chamber between 32oCand 42oC. Also, it was found that for the whole drying process at high air velocities, the temperature had less influence on the dryer's performance.

Exergy-economic modelling of the integration of two black start diesel engines into the combined cycle gas turbine for rapid-cold start-up

Exergy-economic modelling of the integration of two black start diesel engines (BSDEs) into the combined cycle gas turbine (CCGT) provides an analysis of the potential of utilizing the heat from exhaust gases and cooling water released by the operation of the two BSDEs, which is currently being wasted into environment. In the case of non-voltage for the CCGT rapid-cold start-up, two BSDEs can provide not only electricity, but also thermal energy for heating the high-pressure drum (HPD) of the heat recovery steam generator (HRSG), which is essential for a rapid-cold start-up of the plant. This is exactly where the originality and innovation of this study are shown as so far this type of analysis has not been carried out. However, for a rapid-cold start-up of the system, it must be preheated to at least 393 K as per instructions of the HRSG manufacturer. In addition to using the heat of the exhaust gases to preheat the HPD, the heat of the cooling water of both BSDEs is also used for the purposes of heating buildings. The advantage of using the heat from the exhaust gas and cooling water of the BSDE is, therefore, reflected in increased energy and exergy efficiency allowing the use of the BSDE also in other cases of increased demand for electricity. A vital aspect of the optimisation is the secure supply of heat to the HPD, which cannot be provided by the existing auxiliary sources in the event of a power grid failure. The exergy-economic modelling of BSDE integration into a combined cycle gas turbine (CCGT) has shown that it is possible to maintain the temperature in the high-pressure drum (HPD) needed for rapid-cold starting the CCGT installation by installing an additional heat transfer system in the BSDE exhaust system. The results of the model show that the two BSDEs can use their exhaust gases to preheat the HPD of the HRSG to the temperature of 393 K in as little as 16 min. The heating time, however, depends on the load of both BSDEs. The use of heat from both BSDEs also increases the energy and efficiency.

2.8 μm pulsed Er3+:ZBLAN fiber laser based on external gain modulation

We report the generation of stable pulses in a ∼2.8 μm Er3+:ZBLAN fiber laser by varying the population inversion of active ions with an external 1973 nm auxiliary pump source. When we increase the 976 nm master pump power to beyond the chaotic self-pulsing stage, stable pulse trains can be obtained immediately with the switch-on of the 1973 nm auxiliary pump source. The pulse repetition rate can be tuned from 22.47 kHz to 63.98 kHz by adjusting the 1973 nm pump power, and the corresponding pulse width is varied from 4.47 μs to 1.99 μs. The underlying mechanism of the pulsed Er3+:ZBLAN fiber laser with external gain modulation is also discussed.

Design of smart battery charging circuit via photovoltaic for hybrid electric vehicle

AbstractThis paper proposes an intelligent battery charging scheme for hybrid electric vehicles (HEVs) with a fuel cell as the primary energy source and solar photovoltaic (PV) and battery as the auxiliary energy sources. While dealing with the PV, a minimized oscillation‐based improved perturb and observe (I‐P&O) maximum power point (MPP) tracking (MPPT) scheme is designed to mitigate the impact of oscillations around MPP and loss of tracking direction. The DC–DC boost and DC–DC buck power converters are connected in a cascade manner to harvest optimal power from PV and as a charging circuit for HEV, respectively. An intelligent fuzzy logic‐based proportional integral derivative (PID) (F‐PID) controller is employed for the buck converter to get the constant voltage and constant current for the effective charging of the battery. The two primary objectives of this work are (1) maximum utilization of the designed PV array via the I‐P&O MPPT scheme to enhance the system efficacy, reduce system cost, and reduce complexity. (2) To obtain minimum battery losses and an enhanced life cycle of HEV. The proposed MPPT scheme provides a maximum 99.80% tracking efficiency of the considered PV array at an insolation level of 1000 W/m2. Moreover, almost nominal voltage and current ripples have appeared in HEV's proposed intelligent battery charging circuit.

Research on Improving Methods of Power Quality of Diesel Generators with Millisecond Pulse Load

Modern radar is a typical millisecond pulse load (MPL). Still, the independent power supply system of radar with a diesel generator (DG) as the main power source will have serious frequency fluctuation and voltage distortion problems. In practical applications, the main method to solve these problems is to increase the power supply capacity. This method will cause a serious waste of resources, and the mobility of the system will deteriorate. This paper takes the diesel generator with a millisecond pulse load system (DG_MPL) as the research object. It proposes a method to improve the power quality of DG_MPL by connecting the energy storage system (ESS) on the AC side. The system uses DG as the main power source and ESS as the auxiliary power source. The equivalent frequency regulation model is studied when the inverter control mode of ESS is selected PQ, Droop, and VSG, respectively. Finally, the system operating characteristics and power quality of several common improvement methods are compared and analyzed. The results prove that the proposed method can effectively improve the system frequency and voltage distortion problems.

Dietary Practices and Nutrient Intake of Internally Displaced School Children in the West Region of Cameroon.

Poor diets and subsequent malnutrition are among the greatest current societal challenges triggering immense health and economic burden especially among populations that are forcibly displaced. It is indispensable to establish the dietary patterns of any population, especially in displaced populations, in order to develop and effectively implement interventions for the specific population. A cross-sectional study was conducted to assess dietary practices and nutrient adequacy of 307 internally displaced pupils aged between 5 and 15 years in the West Region of Cameroon. Pretested, structured interviewer questionnaires were used to collect data on the demographic and socioeconomic status of the children and their caregivers, the nutrition knowledge of caregivers, the dietary practices of the children, dietary diversity, their food sources, and coping strategies that were used during food shortage. SPSS version 23 was used to analyze the data. The dietary diversity of the children was assessed at the individual level using FAO method of assessing women's dietary diversity score. Out of the total 307 children, 148 (48.2%) were boys and 159 (51.8%) were girls. During food shortages, most of the mothers/caregivers (72%) used borrowing as the main auxiliary food source and others (28%) used food as payment for work or begging. A majority of the children (56%) usually ate only two times in a day. Most of the children were of unacceptable or low dietary diversity (66.2%). The most frequently consumed food group was cereals as it was eaten by 21% of the children, seven or more times per week; meanwhile, the least was animal products with only 3% of the children consuming it seven or more times weekly. Their diets were energy-deficient (1640.5 ± 1.64 kcal) and unbalanced with daily inadequate protein (18.45 ± 1.13 g), vitamin A (470.27 ± 1.38 μg), and iron (4.02 ± 0.08 mg) intake. The nutrition knowledge of the mothers/caregivers was poor as less than half (41%) of them had an acceptable nutrition knowledge. The high prevalence of poor dietary patterns and poor nutrition knowledge imposes the necessity of developing nutritional interventions and education strategies aimed at promoting healthy eating habits in the children.

Life Cycle Cost Analysis for Scotland Short-Sea Ferries

The pathway to zero carbon emissions passing through carbon emissions reduction is mandatory in the shipping industry. Regarding the various methodologies and technologies reviewed for this purpose, Life Cycle Cost Analysis (LCCA) has been used as an excellent tool to determine economic feasibility and sustainability and to present directions. However, insufficient commercial applications cause a conflict of opinion on which fuel is the key to decarbonisation. Many LCCA comparison studies about eco-friendly ship propulsion claim different results. In order to overcome this and discover the key factors that affect the overall comparative analysis and results in the maritime field, it is necessary to conduct the comparative analysis considering more diverse case ships, case routes, and various types that combine each system. This study aims to analyse which greener fuels are most economically beneficial for the shipping sector and prove the factors influencing different results in LCCA. This study was conducted on hydrogen, ammonia, and electric energy, which are carbon-free fuels among various alternative fuels that are currently in the limelight. As the power source, a PEMFC and battery were used as the main power source, and a solar PV system was installed as an auxiliary power source to compare economic feasibility. Several cost data for LCCA were selected from various feasible case studies. As the difficulty caused by the storage and transportation of hydrogen and ammonia should not be underestimated, in this study, the LCCA considers not only the CapEx and OpEx but also fuel transport costs. As a result, fuel cell propulsion systems with hydrogen as fuel proved financial effectiveness for short-distance ferries as they are more inexpensive than ammonia-fuelled PEMFCs and batteries. The fuel cost takes around half of the total life-cycle cost during the life span.

SgsR: a structurally guided sampling toolbox for LiDAR-based forest inventories

Abstract Establishing field inventories can be labor intensive, logistically challenging and expensive. Optimizing a sample to derive accurate forest attribute predictions is a key management-level inventory objective. Traditional sampling designs involving pre-defined, interpreted strata could result in poor selection of within-strata sampling intensities, leading to inaccurate estimates of forest structural variables. The use of airborne laser scanning (ALS) data as an applied forest inventory tool continues to improve understanding of the composition and spatial distribution of vegetation structure across forested landscapes. The increased availability of wall-to-wall ALS data is promoting the concept of structurally guided sampling (SGS), where ALS metrics are used as an auxiliary data source driving stratification and sampling within management-level forest inventories. In this manuscript, we present an open-source R package named sgsR that provides a robust toolbox for implementing various SGS approaches. The goal of this package is to provide a toolkit to facilitate better optimized allocation of sample units and sample size, as well as to assess and augment existing plot networks by accounting for current forest structural conditions. Here, we first provide justification for SGS approaches and the creation of the sgsR toolbox. We then briefly describe key functions and workflows the package offers and provide two reproducible examples. Avenues to implement SGS protocols according to auxiliary data needs are presented.

Increasing coverage of mono-layer graphene grown on hexagonal boron nitride

Graphene sitting on hexagonal boron nitride (h-BN) always exhibits excellent electrical properties. And the properties of graphene on h-BN are often dominated by its domain size and boundaries. Chemical vapor deposition (CVD) is a promising approach to achieve large size graphene crystal. However, the CVD growth of graphene on h-BN still faces challenges in increasing coverage of monolayer graphene because of a weak control on nucleation and vertical growth. Here, an auxiliary source strategy is adapted to increase the nucleation density of graphene on h-BN and synthesis continuous graphene films. It is found that both silicon carbide and organic polymer e.g. methyl methacrylate can assist the nucleation of graphene, and then increases the coverage of graphene on h-BN. By optimizing the growth temperature, vertical accumulation of graphitic materials can be greatly suppressed. This work provides an effective approach for preparing continuous graphene film on h-BN, and may bring a new sight for the growth of high quality graphene.

Immobilizing highly catalytically active Ni particles inside carbon matrix for enhanced photocatalytic degradation

Herein, we report a generalized strategy for the controlling synthesis of highly crystalline Ni particles embedded in a carbon matrix by the controlled thermolysis temperature and added auxiliary carbon source in coordination polymer (CPs). Firstly, a new Ni-based CP, namely, [Ni(3-padpm)(1,3-BDC)(H2O)] (Ni-CP, 3-padpm = 4,4′-bis(3-pyridylformamide)diphenylmethane and 1,3-H2BDC = 1,3-benzenedicarboxylic acid) has been synthesized and serves as a precursor to prepared single phase, crystalline metal and metal oxide particles, which are inherently passivated in the carbon matrix (which are denoted as Ni-CP-X, X = 500, 600, 700, 800, 900, 1000). Then, in order to achieve more purity and superior catalytic performances, we have selected fulvic acid (FA) as the highly active antioxidant to prepare carbon-coated pure metal materials (which are denoted as Ni-CP@FA-X). Finally, the properties of dye photocatalytic degradation by Ni-CP, Ni-CP-X and Ni-CP@FA-X have been also comparatively investigated in detail and show that the highest photocatalytic degradation rates were 99.51% for MB, 100% for RhB, 100% for GV, 97.33% for MO, and 90.48% for CR after 4 h. In addition, Ni-CP@FA-1000 shows stable catalytic efficiencies after five reaction cycles.

Topological Overview of Auxiliary Source Circuits for Grid-Tied Converters

This paper reviews different types of capacitors and auxiliary source circuit topologies and presents an introduction to control strategies used for circuit applications reducing DC-BUS capacitance. The paper argues in favor of replacing bulky electrolytic capacitors in capacitor-supported power electronic systems with auxiliary source circuits. DC-BUS capacitors are widely used in grid-tied power converters (rectifiers) and utilized for power balance, voltage ripple limitation, and short-term energy storage. The electrolyte capacitor is the Achilles heel of any rectifier and power converter due to its higher rate of failure than other circuitry components. Auxiliary source circuits are key components to qualitatively improve the reliability of the DC links, where they divert the instantaneous pulsating power into extra reliable storage components. Unlike previous work, this review serves to provide a clear picture of an auxiliary source circuit design, in favor of optimal solution selection according to the specific application. Therefore, energy storage components (capacitors), topologies, and control strategies of auxiliary source circuits are comprehensively reviewed in this paper. Additionally, detailed explanations, comparisons, and discussions of auxiliary source circuits are offered.

Adaptive-Energy-Sharing-Based Energy Management Strategy of Hybrid Sources in Electric Vehicles

The energy utilization of the transportation industry is increasing tremendously. The battery is one of the primary energy sources for a green and clean mode of transportation, but variations in driving profiles (NYCC, Artemis Urban, WLTP class-1) and higher C-rates affect the battery performance and lifespan of battery electric vehicles (BEVs). Hence, as a singular power source, batteries have difficulty in tackling these issues in BEVs, highlighting the significance of hybrid-source electric vehicles (HSEVs). The supercapacitor (SC) and photovoltaic panels (PVs) are the auxiliary power sources coupled with the battery in the proposed hybrid electric three-wheeler (3W). However, energy management strategies (EMS) are critical to ensure optimal and safe power allocation in HSEVs. A novel adaptive Intelligent Hybrid Source Energy Management Strategy (IHSEMS) is proposed to perform energy management in hybrid sources. The IHSEMS optimizes the power sources using an absolute energy-sharing algorithm to meet the required motor power demand using the fuzzy logic controller. Techno-economic assessment wass conducted to analyze the effectiveness of the IHSEMS. Based on the comprehensive discussion, the proposed strategy reduces peak battery power by 50.20% compared to BEVs. It also reduces the battery capacity loss by 48.1%, 44%, and 24%, and reduces total operation cost by 60%, 43.9%, and 23.68% compared with standard BEVs, state machine control (SMC), and frequency decoupling strategy (FDS), respectively.

Overproduction of Patchoulol in Metabolically Engineered Komagataella phaffii.

Patchoulol, a plant-derived sesquiterpene compound, is widely used in perfumes, cosmetics, and pharmaceuticals. Microbial production provides a promising alternative approach for the efficient and sustainable production of patchoulol. However, there are no systematic engineering studies on Komagataella phaffii aimed at achieving high-yield patchoulol production. Herein, by fusion overexpression of FPP synthase and patchoulol synthase (ERG20LPTS), increasing the precursor supply, adjusting the copy number of ERG20LPTS and PTS, and combined with adding auxiliary carbon source and methanol concentration optimization, we constructed a high-yield patchoulol-producing strain P6H53, which produced 149.64 mg/L patchoulol in shake-flask fermentation with methanol as the substrate. In fed-batch fermentation, strain P6H53 achieved the highest production (2.47 g/L, 21.48 mg/g DCW, and 283.25 mg/L/d) to date in a 5 L fermenter. This study will lay a good foundation for the development of K. phaffii as a promising chassis microbial cell for the synthesis of patchoulol and other sesquiterpenes with methanol as the carbon source.

Production of polyhydroxyalkanoate from sesame seed wastewater by sequencing batch reactor cultivation process of Haloferax mediterranei

Due to the high cost of bioplastic production, sesame wastewater, generated from the sesame seed hulling process, was investigated to be used as inexpensive and renewable carbon source for the production of biodegradable polyhydroxyalkanoate (PHA) by extreme Haloferax mediterranei. The sesame wastewater (SWW) was hydrolyzed using different concentrations of hydrochloric acid (0.4. 1.00 and 2.00 M) at different period of times (15, 60 and 90 min). The concentration of salt (NaCl) and nitrogen source (NH4Cl and yeast) required for H. mediterranei cells growth and the accumulation of PHA biopolymer was optimized. A maximum 0.53 g/L concentration of PHA was achieved when the SWW extract media was supplemented with 100 g/L NaCl and 6.0 g/L yeast extract. The cultivation was scaled-up using sequencing batch reactor (SBR) fermentation under non-sterile conditions. The SBR results showed that SWW needs an auxiliary carbon source to obtain high PHA production. Consequently, the system fed with SWW and glucose produced higher PHA (20.9 g/L) than the system fed with SWW.

A dual-projector three-dimensional measurement model for shading problem of micro-scale object complex surface

Considering the inherent defects of the traditional triangulation method, always a shadow area is produced in the image collected by the camera. In this work, based on the traditional monocular vision measurement system, an auxiliary light source was added to alleviate the shadow problem. Two symmetrical digital light processing (DLP) projectors were also employed to project the modulated monochrome red fringe patterns and the monochrome blue fringe patterns onto the object, whereas the distorted fringe patterns were captured by the colour camera. The image collected by the colour camera was separated, whereas the deformation fringe information of the measured object was obtained in the red channel and blue channel, respectively. Fusion of red and blue channels information to eliminate measurement shadows. From the experimental results, the root mean square error (RMSE) of the system was about 6µm, and this method can effectively solve the shadow problem in small object measurement.

Conversion of Escherichia coli into Mixotrophic CO2 Assimilation with Malate and Hydrogen Based on Recombinant Expression of 2-Oxoglutarate:Ferredoxin Oxidoreductase Using Adaptive Laboratory Evolution

We report the mixotrophic growth of Escherichia coli based on recombinant 2-oxoglutarate:ferredoxin oxidoreductase (OGOR) to assimilate CO2 using malate as an auxiliary carbon source and hydrogen as an energy source. We employ a long-term (~184 days) two-stage adaptive evolution to convert heterotrophic E. coli into mixotrophic E. coli. In the first stage of evolution with serine, diauxic growth emerges as a prominent feature. At the end of the second stage of evolution with malate, the strain exhibits mixotrophy with CO2 as an essential substrate for growth. We expect this work will open new possibilities in the utilization of OGOR for microbial CO2 assimilation and future hydrogen-based electro-microbial conversion.