Collector Section Research Articles

Modeling of Traffic Noise along Urban Arterials in Irbid City of Jordan

Traffic-related noise pollution is a recurring problem in large and medium-sized cities. The objective of this study is to quantify traffic-noise levels along selected urban arterials and model the generated traffic noise based on traffic and pavement characteristics. Urban arterial and collector streets in Irbid city, Jordan, were taken as a case study. The city is considered an example of a medium-sized city. 65 urban arterial and collector sections were selected to achieve the stated objective. For each section, ten noise measurements were taken using a time interval of 2.5 minutes for each observation. The statistical pass-by method was used to measure 650 externalnoise observations. In addition, data on traffic, pavement and section geometric characteristics was obtained through field measurements. The collected traffic characteristics, including traffic flow, percentage of trucks and speed in each direction of travel, were obtained. In addition to the measurement of pavement macrotexture depth, an international roughness index was measured using a smartphone application. Investigation of the collected noise data indicated that urban streets experienced high noise levels, reaching maximum and average values of 82 and 77.2 dB(A), respectively. The results of the analyses showed that an increase in each of the included traffic characteristics resulted in significantly higher noise levels. For example, an increase in speed from 35 to 55 km/h would increase noise by 2.7 dB(A). In addition, the interaction term of roughness index and pavement macrotexture depth was found to increase the generated noise. Finally, the results of the analysis indicated that both multivariate linear -and exponential-regression models are suitable to model the generated traffic noise. Each model explained approximately 54% of the noise variability. Probably, traffic composition and vehicle-power type heterogeneity might reduce the level of explained variability. Keywords: Traffic noise, Urban arterials, Pass-by method, Noise modeling, Jordan.

Evaluating the optimum electric power consumption for forced convection of an EHD induced circulating flow through a circular tube: A numerical study

In this study, the effect of using EHD forced convection heat transfer through a circular tube is numerically investigated to prepare the required data sets to find the optimum configuration considering the Nusselt number and friction factor. To gain the required results, the Reynolds numbers and the applied voltages are set to 3000–7000 and 9–13.5 kV, respectively. Moreover, the variety of using miscellaneous placement positions of the central wire emitter, up to 30%, in combination with collector section angles in the range of θ = 90°–360°, are simultaneously investigated. The results of different section angles show that the Nusselt number has increased between 2.35 and 4.76 times compared to the non-EHD mode. Similarly, for the various eccentricities, the Nusselt number has increased between 2.35 and 5.05 times. In the final step, upon the gathered data, a Pareto front of optimal points was deduced for the hydraulic-thermal performances against the power consumption, and the optimum design was highlighted.

Evaluation of the distribution of spray deposits within a vine canopy from measurements on artificial targets and real leaves

Understanding the distribution of intercepted spray deposits is important for the study of the dose-response relationship of spraying a targeted pathogen and for the optimisation of the spraying process. However, carrying out exhaustive measurements of canopy spray deposits is difficult, particularly in production situations. This new experimental method for use in commercial vineyards was based on the installation of artificial targets (PVC collectors) within the canopy. To evaluate the quality of this experimental method for estimating the statistical distribution of deposition it was compared to an intensive manual method of foliar deposition measurements on real leaves. Intercepted deposition data on the real leaves and artificial targets were collected in a regular grid pattern within 12 non-contiguous vegetation sections. The results showed that although the means were similar, the variance in deposition appeared to differ between the distributions on artificial targets and real foliage, with CV values of between 37.4-52.7 % and 69.4-80.5 % respectively. Therefore, any central statistics must be supplemented with a statistical distribution analysis to account for the dispersion of deposition values within the vegetation. The results from comparisons between the cumulative distributions of intercepted deposition on the real leaves and on the PVC collector sections showed that the deposition estimates averaged over three-vine sections gave relevant, repeatable estimates for both approaches. The results also showed that for low deposition values, the experimental method led to a correct estimation of deposition on real leaves. However, above 230 ng dm² per 1 g/ha, the experimental method underestimated the deposition on real leaves by 13.6 %. Using these methodological results, it may be possible to develop models capable of predicting the distribution of deposition within the plant canopy. It would thereby be possible to develop an approach for variable-rate sprayer control that takes into account the phytosanitary risk and the site-specific variable structure of the vegetation during the season.

Experimental and numerical investigations on a solar energy-based active heating method for achieving frost-resistant embankments

The primary objective of this study is to address the embankment frost heave issues in cold regions with an active heating method. The applicability of various heat sources was compared with the heating demands of embankments, and the results demonstrated that the seasonally frozen areas of China are rich in solar energy resources. A specialized device for heating embankments, comprising a solar collector section and an embankment heater section, was developed. The device integrates energy conversion, storage, and transfer with no moving parts and can therefore be used for self-driven operations on an “isolated island”. Performance tests showed that the maximum heating temperature exceeds 60 °C with an average range of 20–40 °C, which increases with solar radiation. The effective heat utilization rate of the soil is approximately 26%. A predictive model that considers latitude and the daily ordinal number was proposed for heating temperature. The long-term heating performance of the embankment was numerically simulated. The results revealed that the heating mode in all seasons is capable to overcome the limitations of existing insulation measures and effectively enhance the potential of frost-resistant embankments in winter.

АЛГОРИТМ РАСЧЕТА СОВМЕЩЕННОЙ ЗАКРЫТОЙ ОСУШИТЕЛЬНО-УВЛАЖНИТЕЛЬНОЙ СЕТИ В СОСТАВЕ ОСУШИТЕЛЬНО-УВЛАЖНИТЕЛЬНЫХ СИСТЕМ

The aim of the research is to develop an algorithm for calculating the combined closed drainage and humidification network as part of the drainage and humidification systems. The technical literature was used as the main source material for the calculation of closed collectors of drainage systems and closed pressure pipelines. The construction of the algorithm was carried out in accordance with the provisions of GOST 19.701-90 (ISO 5807-85). To develop a general algorithm for calculating a combined closed drainage and humidification network, a procedure was drawn up for calculating the lengths of collector sections according to the ac-cepted diameters and a procedure for calculating the diameters of humidifying pipelines in the form of an algorithm, while the calculated dependencies were used from publicly available sources. A calculation scheme for a combined closed drainage and humidification network and a form for outputting the calculation results have been developed. The developed algorithm includes the calculation of the diameters of the collectors for the drainage drainage and the diameters of the humidification pipelines for supplying water for humidification, as well as the coordination of the diameters of the drainage collectors and humidification pipelines

The Application of Mix Delphi-AHP Method in Identification and Prioritization Competencies Needed by National Tax Collector

This study aimed to identify and prioritize competencies needed by the national tax collector. This study was conducted in two regional offices of the Directorate General of Taxes that consists of sixteen tax offices. Fourteen former national tax collector’s top performers from the 2017 to 2020 periods participated as the expert panel in two online Delphi surveys on different rating scales (five-point and nine-point) to clarify the list of competencies identified by the researcher from literature reviews and documentation studies. The Delphi panel reached a consensus for sixteen competencies in both surveys representing three categories: managerial, technical, and sociocultural competencies. The Analytic Hierarchy Process (AHP) was used to analyze the priority of competencies. Forty-six respondents, which consists of the National Tax Collector and the Head of the Audit, Appraisal, and Tax Collector Section, were participated in the AHP survey. The result shows that technical competency was the top priority among the category of competencies followed by sociocultural and managerial competencies. Based on the overall scores, the competencies' priority rankings from the top to the lowest, respectively, are sociocultural adaptation, soft collection, adhesive and unifying the nation, hard collection, tax knowledge, identification and profiling of tax bearer, integrity, compliance risk management, ICT literacy, communication, result orientation, decision-making, teamwork, public service, managing change, and developing self and others. Keywords: Competency, Delphi, Analytic Hierarchy Process, Tax Collector.

A calorimetric system for charge and kinetic energy characterizations of pulsed electron beams

The monitoring of the cross-sectional distribution of an electron beam plays a significant role in scientific research and applications. A sectioned calorimeter system combined with a detector of total electron beam current by Faraday cup was developed for estimating the charge and energy distribution of pulsed electron beams. The calorimeter, consisting of a collector with 61 sections and a matrix of remote thermal sensors (pyrometers), allows measuring the cross-sectional energy distribution of pulsed electron beam with an electron kinetic energy up to 700 keV, energy density within 3.6 J/cm2, and total beam energy up to 50 J/pulse. The response of each section is separately monitored and the total current from all the collector sections is measured for beam charge calculation. The charge distribution is estimated in proportion to the total energy distribution. The system was tested with a pulsed electron beam ejected into the atmosphere (accelerating voltage 270 kV, current 140 A, 100 ns FWHM). The difference in the output between the developed system and diagnostics equipment of the accelerator is within 10%. With measured total energy of 4 J/pulse and transferred charge of 13.6 μC/pulse, an average electron kinetic energy of 115 keV was estimated, fulfills the monitoring of cross-sectional energy density and the estimation of the average electron kinetic energy.

Trajectory Analysis in a Collector with Multistage Energy Recovery for a DEMO Prototype Gyrotron. Part I. Idealized Magnetic Field Distribution

This paper presents the results of simulation of the collector of a prototype gyrotron designed for the DEMO project. Trajectory analysis in a collector with four-stage recovery of the residual beam energy based on the method of spatial separation of electrons in crossed azimuthal magnetic and axial electric fields was carried out. In this part of the research, the azimuthal magnetic field was formed using a conductor located on the axis of the device. The study was carried out for a spent electron beam with a particle velocity and coordinate distribution close to those obtained in experiments with high-power gyrotrons. As a result of optimizing the geometry and potentials of the collector sections, an overall efficiency of the gyrotron higher than 80% was achieved, which is close to the maximum efficiency with ideal separation of electron beam fractions with different energies. The data obtained will be used to design a toroidal solenoid for creating an azimuthal magnetic field.

Heat Transfer Augmentation Using Water-in-Glass Evacuated Tube Coupled with Parabolic Trough in Rack Dryer in the Drying of Capsicum Frutescens

Open drying is practiced for drying Capsicum frutescens in the cottage industries of India. In order to improve drying, an experimental set-up of solar rack dryer is constructed and studied different heat transfer augmentation techniques. A passive heating coil extended from the header of a water-in-glass evacuated tube coupled with parabolic trough is used to augment the heat in the collector section of the dryer. The drying rate in rack dryer is found to be 62% higher than that of open air drying of green chillies. Moreover, the drying rate in augmented rack dryer is found to be 7% higher than that of rack dryer. In addition to this, an effective design for the dryer cabinet with respect to air circulation is arrived through computational fluid dynamics analysis. Through this new design, the drying rate is improved further by 3%. Based on energy analysis, the specific energy consumption during the drying of this particular product using the augmented dryer is found to be 1.27 kWh/kg. The exergy efficiency of the drying chamber is found to be in the range of 4%-45% with an average of 16% for Capsicum frutescens.

Траекторный анализ в коллекторе с многоступенчатой рекуперацией энергии для прототипа гиротрона DEMO. Часть I. Идеализированное распределение магнитного поля

The results of modeling of collector for the gyrotron prototype being developed for the DEMO project are presented. A trajectory analysis in a collector with a 4-stage recovery of the residual beam energy based on the method of spatial separation of electrons in crossed azimuthal magnetic and axial electric fields was performed. In this part of the study, the formation of the azimuthal magnetic field was carried out using a conductor located on the axis of the device. The study was performed for a spent electron beam with a velocity and coordinate distribution of particles close to those obtained in experiments with powerful gyrotrons. Due to a thorough choice of the geometry of the collector sections, a total gyrotron efficiency of more than 80% was achieved, which is close to maximum efficiency with perfect separation of fractions of an electron beam with different energies. The data obtained will be used for development of a toroidal solenoid designed to create an azimuthal magnetic field.

Applicability, optimization and performance comparison of self-preheated solar collector/regenerator

In this paper, a self-preheated solar collector/regenerator (C/R) is proposed to conquer the anti-regeneration phenomenon of traditional solar C/R in order to increase its regeneration efficiency. Through numerical simulation, the applicability of the self-preheated C/R in Northern and Southern cities of China and parameter optimization as well as the performance comparisons with the traditional C/R are conducted. The research results show the self-preheated C/R has good applicability for the 24 cities chosen in China, but the length of collector section is selected in the optimum ranges. The optimal proportion of collector length in the southern China is in the range of 0.4–0.55 while it focusing on 0.35–0.5 in the northern China. In the optimization of parameters, the best flow-rates of air and solution for the unit area of C/R fall into the ranges of 50–100 kg/(m2·h) and 3–6 kg/(m2·h) respectively, and the height of C/R glazing should be maintained at 0.04–0.06 m for higher regeneration efficiency of the device. By comparing to the performance of traditional C/R, the self-preheated solar C/R has greater superiority at higher ambient relative humidity, lower solution temperature and higher solution concentration as well as lower solar radiation intensity. The increased extent can reach as much as 22% at ξin = 0.4 kg/kg. The total length of self-preheated C/R has an optimal value on the performance of device. All these results can provide guidance for performance analysis and application of the novel solar collector/regenerator.

Trench IGBT with stepped doped collector for low energy loss

In this paper, a novel technique of variation doping profile in collector region for trench IGBT is proposed. The collector region is segregated in three sections such that the section with higher concentration lies towards emitter side while section with lower concentration lie towards gate side. The presence of lightly doped collector section increases the recombination rate by injecting lesser charge carrier leading to reduction in carrier lifetime. This effect further improves turn-off process for proposed device. However, due to increased recombination rate, collector current density reduces. But, this reduction is counter balanced by heavily doped collector section which injects higher charge carriers and maintains current flow through proposed device. The electrical characteristics of proposed and conventional device is simulated and analyzed. It is inferred that proposed device exhibits 48% reduction in turn-off time further minimizing energy loss by 53.3%. The lower doping profile of collector region also reduces corner electric field but due to p++-col section the net electric field increases hence, improving the breakdown voltage by 8.7%. Additionally, proposed structure exhibits 16.7% increment in Baliga figure of merit as compared to conventional design.

Entropy generation analysis of convective airflow in a solar updraft tower power plant

AbstractThe main objective of this numerical investigation is to interpret the entropy generation for free convection airflow in a solar tower updraft system. The ground surface is subjected to uniform hot temperature and the collector cover is maintained at lower constant temperature while the chimney wall is adiabatic. Two dimensionless equations of steady laminar free convective airflow are discretized using the finite volume approach. Numerical solutions were accomplished for different values of the Rayleigh number. Results are given in terms of isotherms, velocity magnitude, local entropy generation associated with thermal and fluid friction, local total entropy generation and local Bejan number contours for Rayleigh number ranging between 103 and 108. The reported results show that thermal and frictional irreversibilities are proportional to the Rayleigh number. Also, it was found that, at lower Rayleigh, total irreversibility is attributable to the thermal irreversibilities and occurs essentially in the collector section. At higher Rayleigh, frictional irreversibilities are increased significantly and become the dominant source of irreversibility in the solar tower, and the chimney section is the main contributor in the total irreversibility in the system.

Conceptualization of system dynamic for patchouli oil agroindustry development

AbstractPatchouli oil industry is one of the sectors that should be developed in Indonesia because Indonesia supplies around 90% patchouli oil in the world. This study aims to identify the data required for making agroindustry development decisions using system dynamic. This research was designing the stock flow diagrams (SFD) of patchouli oil from the plantation to the exporter. There are four types of SFD patchouli oil agroindustry, namely, plantation section, farmer section, collector section, and exporter section. The results of the study can identify the data needed as input for the dynamic system model. Input data must be determined first to run the model. Input data for each stage of SFD must be available if the government wants to do the development of patchouli oil agroindustry using a dynamic system model.

Contributions to simulation of the non-permanent movement in sewerage collectors

The water movement of the sewer collectors is of a non-permanent type because of the variation in flow over time. Non-permanent movement in collectors is mathematically modelled by the Saint Venant equations. To solve the equation system, the characteristic method was used, provided that both equations are quasi-linear in the unknown h and Q. Non-dynamic contouring conditions are given by the hydraulic feature of the collectors / tanks located on the collector. Dynamic contour conditions are rendered by the collector-specific equations (river level effluent hydrograph, manoeuvring parameters of the boiler, manoeuvring characteristics at pumping stations, etc.). For the mathematical model implementation, a computational program was developed in the Matlab programming environment (Variation Gradual Collector Program). The program was used to simulate the non-permanent movement in the main sewerage collector “Cacaina” from the sewerage network of the city of Iasi. The simulation of the non-permanent movement was done in two collector evacuation scenarios (gravity and pumping). The analysis of the results obtained for scenario 2 highlights the differential operation of the eight collector sections separated by the side feeders. Simulation of the movement has highlighted the exceeding of the minimum and maximum values of the parameters imposed by the operating rules.

Optimal sizing of roof gutters and hopper for rainwater harvesting.

Bernoulli's equation was applied to a section of hopper collector to determine the appropriate dimensions of the hopper for rainwater harvesting. Also, the hopper surface area (SFA) for a given volume was minimized by differentiating it in relation to the slant angle (SA). Combining the rational formula-Manning's equation and the best hydraulic section criteria-expressions were obtained for the optimum sizes of rectangular and circular gutters. Minimum hopper SFA for a given volume was found to occur at an optimum hopper SA of 35.282°. With the optimum conditions, design charts were produced for the hopper, circular, and rectangular roof gutters. The ratio of hopper larger radius to the smaller radius designated as (α) gave hopper dimensions with excessively wide upper radius for values of 0.1 ≤ α ≤ 0.2. Alpha (α) values of 0.8 and 0.9 gave values of R and Z which are almost too close to be distinguished. The valid range of α for hopper design was found to be 0.292 ≤ α ≤ 0.8. The study revealed that roof plan area has more effect on hopper dimensions than gutter slope. In addition, the case of excessive long gutters can be addressed by placing the hopper at the lateral epicenter of the eaves. In this regard, regions with abundant rainfall can solve water scarcity issues if proper design parameters of RWH components are considered in order to avoid waste of water through the overflow of water collection systems.

Comparative evaluation of the performance of an improved solar-biomass hybrid dryer

A solar biomass hybrid dryer intially designed with a front pass flat plate solar air heater and a biomass heating stove was redesigned, reconstructed in order to minimize the excessive convective heat losses and its performance re-evaluated. Due to poor design and contruction of the biomass heating and solar collector sections, the efficiency of the initial design was low. It is believed that the drying efficiency of the dryer could be enhanced if a back pass solar collector and a biomass heating stove incorporated with a gas to gas heat exchanger to ensure that the hot air reaching the samples is clean, smokeless and ash free, substitute for the original solar collector and biomass unit respectively in the improved version. The system’s drying performance was tested on both no load and full capacity load under different meteorological conditions within Nsukka (Lat. 7oN) for two weeks. The testing results showed that the incorporation of a new back pass solar collector and the heat exchanger enhanced the trays temperatures on no load test. Similarly, the efficiency of the dryer based on solar, biomass and solar-biomass heating in drying of fresh okra, fresh groundnut and fresh cassava chips increased from 5.19 – 16.04%, 0.23 – 3.34% and 1.636 – 8.96% respectively over the initial construction. This shows that the dryer can help improve the post-harvest processing and storage quality of farm produce by drying if further optimized.

Comparative evaluation of the performance of an improved solar-biomass hybrid dryer

A solar biomass hybrid dryer intially designed with a front pass flat plate solar air heater and a biomass heating stove was redesigned, reconstructed in order to minimize the excessive convective heat losses and its performance re-evaluated. Due to poor design and contruction of the biomass heating and solar collector sections, the efficiency of the initial design was low. It is believed that the drying efficiency of the dryer could be enhanced if a back pass solar collector and a biomass heating stove incorporated with a gas to gas heat exchanger to ensure that the hot air reaching the samples is clean, smokeless and ash free, substitute for the original solar collector and biomass unit respectively in the improved version. The system’s drying performance was tested on both no load and full capacity load under different meteorological conditions within Nsukka (Lat. 7oN) for two weeks. The testing results showed that the incorporation of a new back pass solar collector and the heat exchanger enhanced the trays temperatures on no load test. Similarly, the efficiency of the dryer based on solar, biomass and solar-biomass heating in drying of fresh okra, fresh groundnut and fresh cassava chips increased from 5.19 – 16.04%, 0.23 – 3.34% and 1.636 – 8.96% respectively over the initial construction. This shows that the dryer can help improve the post-harvest processing and storage quality of farm produce by drying if further optimized.

Modeling and Improving the Performance of Cabinet Solar Dryer Using Computational Fluid Dynamics

Abstract In this study, a new approach for numerically modeling of an entire cabinet solar dryer is proposed. Collector, drying chamber and chimney are the three principle sections considered in the present modeling. The collector section containing a cover and an absorber plate is modeled applying energy and fluid flow equations to obtain temperature distribution inside the collector. Due to the non-linear behavior of the governing equations as well as variety of effective variables, an iterative method is employed for solution. Regarding the geometry complexity of the drying chamber along with the air compressibility (that in turn causes coupling of momentum and energy equations) drying chamber is simulated by CFD method. Chimney’s effect and effective parameters in suction are comprehensively considered in the present model. The numerical results are in line with experimental results which show that the model can be applied with certainty to employ the dryer for drying highly demanded and time-consuming products in a scientific, sanitary, and timely manner. The model is then optimized by adding some baffles to achieve higher efficiencies and accelerate the drying process.

A New Conversion Section for Parabolic Trough - Concentrated Solar Power (CSP-PT) Plants

One of the most important challenges facing our future is the balance between energy needs and production, in the framework of the CO2 commitments almost universally adopted. The total energy consumption is still a prerogative of fossil fuels, with a share close to 90%, [1]; renewable energy, apart from the energy production from hydro, photovoltaic, biomass, waste and others, counts 3-4% since many years ago. This discouraging result calls for new conversion technologies based on renewables, if the concept of sustainability is really adopted.Concentrated Solar Power (CSP) plants technology could make the difference with respect to the other renewable technologies, thanks to “bridity”n combining the concentrated solar energy source and the conventional power generation (actually steam turbine plants as energy conversion section). In the sector of energy production, parabolic trough (PT) type is more promising.Recently, the Authors showed in [2,3] how convenient could be the utilization of gases as Heat Transfer Fluid (HTF) with advantages from a technological point of view in the heat collector section and, mainly, from the conversion section point of view, having the possibility to use gas turbines in which the HTF directly expands.In this work, the Authors discuss some thermodynamic and engineering aspects concerning the use of gases as HTF, limiting the attention to air and CO2 and they further discuss the performances of an innovative gas turbine power plant. It is based on a sequence of compressions and expansions, intercooled and reheated (inside linear solar receivers) respectively, in order to increase cycle specific work and efficiency. The paper focuses the attention on the optimum number of compressions and expansions: when it changes, pressure levels change too, requiring a series of reheating processes which operate in parallel, so increasing the overall solar receiver length and, definitively, investment costs. The optimization has been done adopting as design parameter the power per unit of collector length [kW/m], which is the most sensible parameter defining investment cost.