bluuebunny/crossref_metadata_2025 huggingface dataset:
Extend Syngas Yield through Increasing Rich Limit by Stratified Air Injection in a Single Cylinder Engine
Authors: Wang Yanyu , Conway Graham , Williams D. Ryan , Chadwell Christopher
Published: April 2020

Dedicated exhaust gas recirculation (D-EGR®) concept developed by Southwest Research Institute (SwRI) has demonstrated a thermal efficiency increase on many spark-ignited engines at both low and high load conditions. The syngas (H2+CO) produced in the dedicated cylinder (D-cyl) by rich combustion helps to stabilize combustion at highly dilute conditions at low loads and mitigate knock at high loads. The dedicated cylinder with 25% EGR can typically run up to equivalence ratio of 1.4, beyond which the combustion becomes unstable. By injecting fresh air near the spark plug gap at globally rich conditions, a locally lean or near-stoichiometric mixture can be achieved, thus facilitating the ignitability of the mixture and increasing combustion stability. With more stable combustion a richer global mixture can be introduced into the D-cyl to generate higher concentrations of syngas. This in turn can further improve the engine thermal efficiency.

This study investigated the possibility of extending the rich limit by stratified air injection in a single cylinder engine. A custom modified spark plug with air passage was used to realize stratified air injection. The emissions were sampled with a Horiba 5-gas analyzer. The exhaust was also bag-sampled and H2 concentration was analyzed.
An LQR Approach of Automatic Transmission Upshift Control Including Use of Off-Going Clutch within Inertia Phase
Authors: Cvok Ivan , Deur Josko , Ivanovic Vladimir , Zhang Yijing , Fujii Yuji
Published: April 2020

This paper considers using linear quadratic regulation (LQR) for multi-input control of the Automatic Transmission (AT) upshift inertia phase. The considered control inputs include the transmission input/engine torque, oncoming clutch torque, and traditionally not used off-going clutch torque. Use of the off-going clutch has been motivated by discussed Control Trajectory Optimization (CTO) results demonstrating that employing the off-going clutch during the inertia phase along with the main, oncoming clutch can improve the upshift control performance in terms of the shift duration and/or comfort by trading off the transmission efficiency and control simplicity to some extent. The proposed LQR approach provides setting an optimal trade-off between the conflicting criteria related to driving comfort and clutches thermal energy loss. It ensures tracking a linear-like profile of oncoming clutch slip speed reference, which was found to be nearly optimal based on control trajectory optimization results. A special attention is given on proper implementation of nonlinear energy loss term through LQR cost function cross term and using a clipped optimal control approach to provide that the clutches (described as torque source elements) can only dissipate energy. The LQR approach was applied to a fifth-order powertrain model and different upshift control scenarios ranging from the use of single clutch towards using both clutches and transmission input/engine torque reduction. It is shown that the LQR approach can reproduce Pareto frontiers obtained by multi-objective control parameter optimization demonstrating that apart from being used in closed loop controls, the proposed LQR approach can also be exploited for computationally efficient (off-line) optimization purposes.
Analysis of Vehicle Front Impact Pulse Severity in US NCAP
Authors: Wu Jianping , Shi Yibing , Beaudet Brian
Published: April 2020

There have been multiple studies on the effect of vehicle impact pulses on occupant responses, and studies on the previous and current US NCAP (New Car Assessment Program) vehicle pulses. This paper analyzes 35 mph (56.3 kph) front impact vehicle pulses and occupant responses in US NCAP tests conducted by the NHTSA from 2011 to 2019. Based on the occupant response analysis, a simple generic occupant restraint force-relative displacement model has been created. This generic model captures the fundamental restraint characteristics of the vehicles in the recent years, and together with the vehicle pulse, they provide several occupant response predictors. Furthermore, this paper proposes a new pulse severity metric PSD (Pulse Severity by Displacement) based on the vehicle impact data statistics, and uses the pulse severity to compare with other pulse severity definitions. It explains the shortcomings of using the vehicle dynamic crush and TTZV (Time-To-Zero Velocity) as pulse severity metrics, and shows how improvements can be made with simple modifications. Data regression methods are used to assess relationships among different metrics and variables. The paper also provides statistics of the vehicle pulses, the trend of pulse severity and characteristics over the years.
Optimization of Fuel Economy Using Optimal Controls on Regulatory and Real-World Driving Cycles
Authors: Lodaya Dhaval , Zeman Jonathan , Okarmus Marcin , Mohon Sara , Keller Philip , Shutty John , Kondipati Nithin
Published: April 2020

In recent years, electrification of vehicle powertrains has become more mainstream to meet regulatory fuel economy and emissions requirements. Amongst the many challenges involved with powertrain electrification, developing supervisory controls and energy management of hybrid electric vehicle powertrains involves significant challenges due to multiple power sources involved. Optimizing energy management for a hybrid electric vehicle largely involves two sets of tasks: component level or low-level control task and supervisory level or high-level control task. In addition to complexity within powertrain controls, advanced driver assistance systems and the associated chassis controls are also continuing to become more complex. However, opportunities exist to optimize energy management when a cohesive interaction between chassis and powertrain controls can be realized. To optimize energy management along a given route, certain information such as the projected vehicle route, driver behavior, and battery charge level should be considered. In this paper, simulation models of a parallel P0/P4 hybrid electric vehicle are presented, which optimize powertrain controls using the Dynamic Programming approach. This virtual vehicle model is exercised through the HWFET and FTP-75 regulatory driving cycles to establish a performance baseline in a controlled driving environment. For comparison to off-cycle driving, the virtual vehicle is then also exercised through a real-world driving scenario over real-world roads, with similar trip characteristics to the regulatory tests, but with real traffic conditions during the day. This comparison provides insights into how optimized real-world fuel economy results can differ compared to the controlled testing environment, and how predictive powertrain controls can offer “in-situ” optimization of energy management.
Spatially Optimized Diffusion Alloys: A Novel Multi-Layered Steel
Material for Exhaust Applications
Authors: Kotrba Adam , Quan Tony , Wei Winston , Detweiler Zachary , Keifer David , Bullard Daniel
Published: April 2020

A novel Spatially Optimized Diffusion Alloy (SODA) material has been developed
and applied to exhaust systems, which are an aggressive environment subject to
high temperatures and loads, as well as excessive corrosion. Traditional
stainless steels disperse chromium homogeneously throughout the material, with
varying amounts ranging from 10% to 20% dependent upon its grade (e.g. 409, 436,
439, 441, and 304). SODA steels, however, offer layered concentrations of
chromium, enabling an increased amount along the outer surface for much needed
corrosion resistance and aesthetics. This outer layer, typically about 70μm
thick, exceeds 20% of chromium concentration locally, but is less than 3% in
bulk, offering selective placement of the chromium to minimize its overall
usage. Since this layer is metallurgically bonded, it cannot delaminate or
separate from its core, enabling durable protection throughout manufacturing
processes and full useful life. The core material may be comprised of various
grades, however, this study employs interstitial free steel (low carbon), which
eases manufacturing operations, as it is more formable than stainless steel
grades. The material and its manufacturing process are described, including
characterization measurements comparing its forming and corrosion resistance
response to baseline exhaust materials. Rolled mufflers are manufactured with
high-volume manufacturing equipment and processes without incident,
demonstrating the ease of material substitution versus aluminized 409 stainless
steel (409AL). Each application is exposed to various test conditions, including
fatigue, corrosion, and thermal cycling and compared against baseline materials.
Results overall demonstrate favorable performance, even along exposed and welded
edges, which may be further protected locally with cold spray. SODA offers
unique value in performance versus baseline materials, enabling a competitive
alternative with much less chromium.
Loads Simplification on Multi Input Axle Systems
Authors: Goncalves Raphael Paulino , Bishop Neil , Kerr Stuart , Vinturini Caio
Published: April 2020

The time domain is currently the most widely chosen option in fatigue testing to fully represent random events occurring in multiple simultaneous input channels. In vehicles for example, time domain tests can represent the same conditions of the road, by applying the same loads at the hard points of the vehicle along a time history. The main drawback of this methodology is the extensive testing duration and hardware cost. Time domain based fatigue tests are composed of a complex hardware, which requires servo motors to work, in order to induce the specific amount of load at a specific time window. These tests are time consuming, since they require the same length duration of the event they are reproducing, times the required repetitions. The frequency domain method for fatigue testing, on the other hand, requires simpler hardware, since there are no need for servomotors and the test length is reduced, since there is no need to run the full event times the required repetitions. The drawback in this case is the ability to represent random events with multiple simultaneous input channels. For this reason, frequency domain tests are mainly applied for simple round-robin tests, unable to represent random events like a road condition. In this work, we will present a new methodology that uses the fatigue result as input, reversing it in order to find the loads that would be required to originate it in frequency domain. This new methodology can help future developments in fatigue test, replacing time domain tests without losing accuracy and the ability to represent random events occurring in multiple simultaneous input channels.
Using Transmission Data to Isolate Individual Losses in Coastdown Road Load Coefficients
Authors: Moskalik Andrew
Published: April 2020

As part of the U.S. Environmental Protection Agency’s (EPA’s) continuing assessment of advanced light-duty automotive technologies in support of regulatory and compliance programs, the National Vehicle Fuels and Emissions Laboratory has benchmarked multiple transmissions to determine their efficiency during operation. The benchmarking included a modified “coastdown test,” which measures transmission output drag as a function of speed while in neutral. The transmission drag data can be represented as a second-order expression, like that used for vehicle coastdown test results, as F0 + F1V + F2V2, where V is the vehicle velocity. When represented in this fashion, the relationships among the three coefficients were found to be highly predictable. The magnitude of these coefficients can be quite large, and for some tested transmissions the deviation between the quadratic regression and the measured drag at individual velocities can be significant.

To evaluate the effect of transmission losses in vehicle coastdown tests, the coastdown target and dynamometer set coefficients were pulled from the EPA’s published “Data on Cars used for Testing Fuel Economy” for an entire model year. The same relationships seen among transmission coefficients were observed in the vehicle coefficients contained in these data. Therefore, the vehicle coefficients can be used directly to estimate the transmission and drivetrain losses and eliminate them from the coastdown values. With transmission losses eliminated, the remaining losses can be divided to extract more accurate estimations of aerodynamic losses and rolling losses. This process can be applied fleet-wide, using only the reported coastdown and dynamometer test coefficients to estimate the losses from individual sources. The resulting data can then be used to independently evaluate the effects of reducing each separate loss, without the need for detailed information on each vehicle in the fleet.
Internal Nozzle Flow Simulations of the ECN Spray C Injector under Realistic Operating Conditions
Authors: Guo Hengjie , Torelli Roberto , Bautista Rodriguez Abian , Tekawade Aniket , Sforzo Brandon , Powell Christopher , Som Sibendu
Published: April 2020

In this study, three-dimensional large eddy simulations were performed to study the internal nozzle flow of the ECN Spray C diesel injector. Realistic nozzle geometry, full needle motion, and internal flow imaging data obtained from X-ray measurements were employed to initialize and validate the CFD model. The influence of injection pressure and fuel properties were investigated, and the effect of mesh size was discussed. The results agreed well with the experimental data of mass flow rate and correctly captured the flow structures inside the orifice. Simulations showed that the pressure drop near the sharp orifice inlet triggered flow separation, resulting in the ingestion of ambient gas into the orifice via a phenomenon known as hydraulic flip. At higher injection pressure, the pressure drop was more significant as the liquid momentum increased and the stream inertia was less prone to change its direction. Two fuels were tested in both experiments and simulations, namely iso-octane and n-dodecane. With the former, the gas species in the low-pressure region consisted of both fuel vapor and non-condensable gas. With n-dodecane, due to its low saturation pressure, fuel vapor was practically absent. Furthermore, it was found that fuel cavitation might not be the only phenomenon able to trigger flow separation, as “pseudo-cavitation” caused by non-condensable gas expansion played a similar role in promoting the conditions that led the flow to detach from the wall. Finally, it was found that a minimum mesh size of 10 μm within the orifice was sufficient to ensure the main flow features were captured. However, it was shown that finer meshes allowed for better resolution of the near-wall gas layer, resulting in more flow features to be resolved.
Robust xEV Battery State-of-Charge Estimator Design Using a Feedforward Deep Neural Network
Authors: Vidal Carlos , Kollmeyer Phillip , Naguib Mina , Malysz Pawel , Gross Oliver , Emadi Ali
Published: April 2020

Battery state-of-charge (SOC) is critical information for the vehicle energy management system and must be accurately estimated to ensure reliable and affordable electrified vehicles (xEV). However, due to the nonlinear temperature, health, and SOC dependent behaviour of Li-ion batteries, SOC estimation is still a significant automotive engineering challenge. Traditional approaches to this problem, such as electrochemical models, usually require precise parameters and knowledge from the battery composition as well as its physical response. In contrast, neural networks are a data-driven approach that requires minimal knowledge of the battery or its nonlinear behaviour. The objective of this work is to present the design process of an SOC estimator using a deep feedforward neural network (FNN) approach. The method includes a description of data acquisition, data preparation, development of an FNN, FNN tuning, and robust validation of the FNN to sensor noise. To develop a robust estimator, the FNN was exposed, during training, to datasets with errors intentionally added to the data, e.g. adding cell voltage variation of ±4mV, cell current variation of ±110mA, and temperature variation of ±5ºC. The error values were chosen to be similar to the noise and error obtained from real sensors used in commercially available xEVs. The robust FNN trained from two Li-ion cells datasets, one for a nickel manganese cobalt oxide (NMC) cell and the second for a nickel cobalt aluminum oxide (NCA) chemistry cell, is shown to overcome the added errors and obtain a SOC estimation accuracy of 1% root mean squared error (RMSE).
Improving Winter Fuel Economy by Using Weather Information
Authors: Oshikiri Rino , Hirabayashi Hidekazu , Cosgrove David
Published: April 2020

When the air conditioning (A/C) is turned on, the intake air to the HVAC is cooled at the evaporator. This is not only used for cooling the air temperature but also to dehumidify. Therefore, for a typical automatic climate control system, A/C will automatically operate even in winter (cold ambient temperature conditions) in order to prevent the windows from fogging despite its effect on fuel economy. In some applications, a humidity sensor is installed on top of the windshield and when the probability of fogging is low the A/C operation is disabled automatically to prevent unnecessary compressor operation which can increase fuel consumption. However, humidity sensor is not widely adopted as it requires some space to be installed and the cost is relatively expensive compared with other HVAC equipped sensors. In this study, a system was invented that disables the compressor operation when the fogging probability is low without using the conventional humidity sensor. This system uses real-time weather information from out of car database with a data communication module (DCM) which is standardly equipped in many Toyota vehicles. Control logic was created that actively judges if the current probability of fogging is high or low by using weather information. In real-world driving test in Aichi, Japan, and Michigan, US, the system reduced 60 ~ 70 % of compressor operation in winter which demonstrated 1.5 ~ 1.6 % improvement in fuel consumption.
Further Study of the Vehicle Rattle Noise with Consideration of the Impact Rates and Loudness
Authors: Liang Linyuan , Li Peiran , Chen Shuming
Published: April 2020

With the prevalent trend of the pure electric vehicle, vehicle interior noise has been reduced significantly. However, other noises become prominent in the cabin. Especially, the BSR noise generated by friction between parts and the clearance between components become the elements of complaints directly affect the quality of vehicles. Currently, the BSR noises are subjectively evaluated by experts, and the noise samples are simply labeled as ‘qualified’ or ‘unqualified’. Therefore, it is necessary to develop an evaluation model to assess the BSR noise objectively. In this paper, we study the vehicle rattle noise intensively. Several types of rattle noise were recorded in a semi-anechoic room. The recorded signals were then processed in the LMS test lab. to extract the single impact segments. A pool of simulated signals with different impact rates (number of impacts per second) and various loudness was synthesized for analyzation. To verify the universality of the assessment, the in-vehicle background noises were also recorded. The in-vehicle background noises were added to the rattle noise samples to simulate the in-vehicle test environment. Sound metrics were calculated and compared for all the processed samples. Jury assessment with 5 experts were performed to evaluate the rattle noise samples. The correlation between the subjective evaluation and the impact rates as well as sound metrics were studied. Consequently, an objective assessing model for vehicle rattle noise was developed based on the above analysis. This study can be used to assess the rattle noise effectively, and it has bright prospect and great value in engineering.
Unified Power-Based Vehicle Fuel Consumption Model Covering a Range of Conditions
Authors: Phlips Patrick , Ruona William , Megli Thomas , Orpe Mrudula
Published: April 2020

Previously fuel consumption on a drive cycle has been shown to be proportional to traction work, with an offset for powertrain losses. This model had different transfer functions for different drive cycles, performance levels, and applied powertrain technologies. Following Soltic it is shown that if fuel usage and traction work are both expressed in terms of cycle average power, a wide range of drive cycles collapse to a single transfer function, where cycle average traction power captures the drive cycle and the vehicle size. If this transfer function is then normalized by weight, i.e. by working in cycle average power/weight (P/W), a linear model is obtained where the offset is mainly a function of rated performance and applied technology. A final normalization by rated power/weight as the primary performance metric further collapses the data to express the cycle average fuel power/rated power ratio as a function of cycle average traction power/rated power ratio. This final transfer function is mainly a function of technology. It was used to estimate the effectiveness of technologies deployed by manufacturers to improve fuel consumption. Compared to the naturally aspirated PFI engines and six-speed automatic transmissions of a decade ago, three different combinations of downsized turbo or Atkinson engines, with either 8+ speed transmissions or CVTs achieve similar substantial improvements in efficiency. The useful work or power definition is expanded to include electrical power for customer functions, and power to drive the air conditioning, so that the model can be applied to ‘real world’ driving.
Evaluation of Future Topologies and Architectures for High-Reliability Electrical Distribution Systems
Authors: Brabetz Ludwig , Ayeb Mohamed , Lehmann Janis , Löwer Benjamin
Published: April 2020

Within the scope of the development of autonomous vehicles, the mandatory reliability requirements of the electrical power supply, and consequently of the electrical distribution system (EDS), are increased considerably. In addition, the overall rising number of electrical functions leads to significantly higher electrical power demands, while strict cost, weight and packaging constraints must be upheld. Current developments focus on adding redundancies, enhancing physical robustness, or dimensioning critical components. New approaches address predictive power management, better diagnostic capabilities, and, the subject of this paper, alternative topologies and architectures [1]. These are derivations of the conventional tree structure, as well as ring- or linear-bus-based zonal architectures, which feature in part distributed storage devices or semiconductor switches that rearrange the power paths in case of a fault [2,3].

The presented approach is a method for both the systematic description of EDS topologies and architectures and the assessment of their reliability. It is based on a data model designed for a simple but unique definition of the EDS, a graphical representation of the topology, an algorithm for the calculation of the reliability, and a straightforward cost assessment. It allows benchmarking and optimization of a large number of architectures, and enables the comparative analysis of the impact of both reliability- and cost-parameters, which often are not well known. In addition to the theoretical description, the paper presents comparative results for various EDS architectures and a Pareto- and sensitivity analysis, followed by a discussion of the next steps, for instance the application of an optimization algorithm using a rule-based generation of alternative architectures.
Anisotropic Material Damage Model of Randomly Oriented Thermoplastic Composites for Crash Simulation
Authors: Hayashi Seiji , Kan Mitsuharu , Saito Kei , Nishi Masato
Published: April 2020

In this research, a material model was developed that has orthotropic properties with respect to in-plane damage to support finite element strength analysis of components manufactured from a randomly oriented long-fiber thermoplastic composite. This is a composite material with randomly oriented bundles of carbon fibers that are approximately one inch in length. A macroscopic characteristic of the material is isotropic in in-plane terms, but there are differences in the tension and compression damage properties. In consideration of these characteristics, a material model was developed in which the damage evolution rate is correlated with thermodynamic force and stress triaxiality. In-plane damage was assumed to be isotropic with respect to the elements. In order to validate this material model, the results from simulation and three-point bending tests of closed-hat-section beams were compared and found to present a close correlation. However, in the case of axial compression of double-hat-section beams, it was found that although the initial peak load corresponded closely, the peak loads after the second peak did not match. As a cause for this, it is conceivable that the damage applied in the transverse direction differs from that of axial compression direction. A test that would identify the relationship between these different instances of damage was devised, and the damage characteristics were measured. It was found from the results of this test that the in-plane damage evolution would need to be given orthotropic properties. The orthotropic damage characteristics were additionally implemented in the material model and the load-stroke curves from axial compression testing of closed-hat-section beams and from simulation were compared. It was confirmed that the loads increased from the second load peak and on, suggesting that the conceptual approach of the material model was correct.
Hardware Supported Data-Driven Modeling for ECU Function Development
Authors: Nguyen Chinh , Gutjahr Tobias , Banker Adam , Burkard Dona , Scheibert Klaus , Bulmus Atilla
Published: April 2020

The powertrain module is being introduced to embedded System on Chips (SoCs) designed to increase available computational power. These high-performance SoCs have the potential to enhance the computational power along with providing on-board resources to support unexpected feature growth and on-demand customer requirements. This project will investigate the radial basis function (RBF) using the Gaussian process (GP) regression algorithm, the ETAS ASCMO tool, and the hardware accelerator Advanced Modeling Unit (AMU) being introduced by Infineon AURIX 2nd Generation. ETAS ASCMO is one of the solutions for data-driven modeling and model-based calibration. It enables users to accurately model, analyze, and optimize the behavior of complex systems with few measurements and advanced algorithms. Both steady state and transient system behaviors can be captured. The AMU computation engine is a floating-point unit designed to speed up the performance of critical applications by off-loading the computation from the central processing unit (CPU). This paper will share insight of addressable applications in automotive with focus on powertrain by utilizing ETAS ASCMO to provide the RBF model for the microcontroller integrated AMU hardware feature. We will illustrate the tool and hardware performance, and additionally, we will lay down the path to utilize AMU within the software environment.
Rear Axle Heat Exchanger - Utilization of Engine Coolant for Reduced CO
2
Emissions and Fuel Consumption
Authors: Schumaier Timothy , Bartlett Matthew , Laugen Alex , Scott Timothy , Singh Jasbir , Sopko Jay , Troy Paul
Published: April 2020

This paper describes the design, development, and operation of a rear axle dual-shell heat exchanger on the RAM 1500 Light Duty truck. This system has been proven to increase fuel economy and reduce exhaust emissions, particularly CO2, on the EPA Cold City schedule. The energy conversion strategy was first explored using math modeling. A PUGH analysis associated with concept selection is included. To refine the hardware and develop a control strategy prior to testing, a portable flow cart was developed to assess system performance and to correlate the multi-node heat transfer model. Bench testing focused on the durability and functional aspects of integrating the dual-shell axle cover with the axle and coolant delivery system through a comprehensive design and validation plan. Vehicle testing included various fuel economy and emissions related driving schedules to quantify the benefits.
Parametric Representation of the Entire Pressure Drop Evolution during Particulate Filter Loading
Authors: Konstandopoulos Athanasios G. , Metallinou Rozina
Published: April 2020

Improved understanding and compact descriptions of the pressure drop evolution of Particulate Filters (both for diesel and gasoline powered vehicles) are always in demand for intelligent implementations of exhaust emission system monitoring and control. In the present paper we revisit the loading process of a particulate filter focusing on a parametric description of the deep bed-to-cake transition in the light of recent progress in the understanding of soot deposit structure, growth dynamics and evolution. Combining experimental data, simulation models and information theoretic concepts we provide a closed-form representation of the entire evolution of pressure drop (from the initial clean state up to the evolving linear cake growth regime) parameterized in terms of the physical parameters of the system (filter and particle structure/geometry and flow properties). The representation is shown to be in excellent agreement with the available experimental data and it opens the door for improved on-board monitoring/control of particulate filter systems.
Oligomer and highly oxygenated organic molecule formation from oxidation of oxygenated monoterpenes emitted by California sage plants
Authors: Mehra Archit , Krechmer Jordan E. , Lambe Andrew T. , Sarkar Chinmoy , Khalaj Farzaneh , Guenther Alex , Jayne John , Coe Hugh , Worsnop Douglas R. , Faiola Celia , Canagaratna Manjula R. , Williams Leah
Published: April 2020

Abstract. Plants emit a diverse range of biogenic volatile organic compounds (BVOC) whose oxidation leads to secondary organic aerosol (SOA) formation. The majority of studies of biogenic SOA have focused on single or simple multi-component BVOC mixtures thought to be representative of Northern Hemispheric deciduous or mixed forest conditions. Gaps remain in our understanding of SOA formation from complex mixtures of real plant emissions in other environments. Towards the goal of understanding SOA in other regions, we conducted the first comprehensive study of SOA from oxygenated monoterpenes. These are the dominant emissions from the most common plant species in southern California’s coastal sage ecosystem: black sage (Salvia mellifera) and California sagebrush (Artemisia californica). Emissions from sage plants, and single compounds representing their major emissions (camphor, camphene and eucalyptol), were oxidised in an Aerodyne potential aerosol mass oxidation flow reactor (PAM-OFR). The chemical composition of SOA was characterised using a high-resolution time-of-flight iodide-anion chemical-ionization mass spectrometer equipped with a Filter Inlet for Gases and AEROsols (FIGAERO-I-HR-ToF-CIMS) under low and medium-NOx conditions. SOA from oxygenated monoterpenes showed higher order oligomer content and a greater presence of highly oxygenated organic molecules (HOM) than non-oxygenated monoterpenes, with HOM contributing 27–47 % and 12–14 % of SOA product signal from oxygenated and non-oxygenated monoterpenes, respectively. This study highlights the potential importance of oxygenated monoterpene emissions for SOA formation in woody shrub ecosystems.
Impact of a partly sealed fault on hydro-mechanical properties of a granite reservoir
Authors: Blöcher Guido , Kluge Christian , Cacace Mauro , Milsch Harald , Schmittbuhl Jean
Published: April 2020

The fluid flow in Enhanced Geothermal Systems (EGS) is dominated by hydraulically stimulated fractures and faults which are the key elements of their hydraulic performance and sustainability. At the fault scale, the flow performance is influenced by the aperture distribution which is strongly dependent on the fault roughness, the geological fault sealing, the relative shear displacement, and the amount of flow exchange between the matrix and the fault itself. On the mechanical side, stiffness and strength of partly sealed fault might alter or reinforced the mechanical behavior of the fault zone in particular with respect to new stimulations. In order to quantify the impact of chemical soft stimulation in EGS reservoir on the hydro-mechanical properties of a fault-rock system that includes fault-filling material, we conducted numerical flow through experiments of a granite reservoir hosting one single partly sealed fault of size 512x512 m². In order to mimic the chemical alteration of the fault-rock system we sequentially changed the distribution pattern of the fault-filling material by means of a hydro-poro-elastic coupled simulation. Navier-Stokes flow is solved in the 3-dimensional rough aperture and Darcy flow in the related poro-elastic matrix. By means of this model, an evaluation of the local channeling effect through the fault for various degrees of sealing was performed. Based on the obtained results, we derived a macroscopic change of the hydraulic-mechanical behavior of the fault-rock system, e.g. permeability change, fracture stiffness modulus.
The GF Convection Parameterization: recent developments, extensions, and applications
Authors: Freitas Saulo R. , Grell Georg A. , Li Haiqin
Published: April 2020

Abstract. We detail recent developments in the GF (Grell and Freitas, 2014, Freitas et al., 2018) convection parameterization and applications. The parameterization has been extended to a trimodal spectral size to simulate the interaction and transition from shallow, congestus and deep convection regimes. Another main new feature is the inclusion of a closure for non-equilibrium convection that resulted in a substantial gain of realism in the simulation of the diurnal cycle of convection, mainly associated with boundary layer forcing over the land. Additional changes include the transport of momentum, the use of three Probability Density Functions (PDF's) to describe the normalized vertical mass flux profiles from deep, congestus, and shallow plumes (respectively) in the grid box, and the option of using temporal and spatial correlations to stochastically perturb PDF's, momentum transport and the closures. Cloud water detrainment is proportional to mass detrainment and in-cloud hydrometeor mixing ratio, and transport of chemical constituents (including wet deposition) can be treated inside the GF scheme. Transport is handled in flux form and is mass conserving. Finally, the cloud microphysics has been extended to include the ice phase to simulate the conversion from liquid water to ice in updrafts with resulting additional heating release, and the melting from snow to rain within a user-specified melting vertical layer.
Using multiple methods to understand groundwater recharge in a semi-arid area
Authors: Barua Shovon , Cartwright Ian , Dresel P. Evan , Daly Edoardo
Published: April 2020

Abstract. Understanding recharge in semi-arid areas is important for the sustainable management of groundwater resources. This study focuses on estimating groundwater recharge rates and understanding the impacts of land-use changes on recharge in a semi-arid area. Two adjacent catchments in southeast Australia were cleared ~180 years ago following European settlement; in one of these catchments eucalypt plantation forest was subsequently established ~ 20 years ago. Chloride mass balance yields recharge rates of 0.2 to 61.6 mm yr−1 (typically up to 11.2 mm yr−1). The lower of these values probably represent recharge rates prior to land clearing, whereas the higher likely reflects recharge rates following initial land clearing. The low pre-land clearing recharge rates are consistent with the presence of groundwater that has residence times that are up to 24,700 years (calculated using radiocarbon) and the moderate to low hydraulic conductivities (0.31 to 0.002 m day−1) of the clay-rich aquifers. Recharge rates estimated from tritium activities and water table fluctuations reflect those following the initial land clearing. However, recharge rates estimated using water table fluctuations (15 to 500 mm yr−1) are significantly higher than those estimated using tritium renewal rates (0.01 to 89 mm yr−1; typically
Bloomberg Professional Service
Authors: Phillips Ryan L.
Published: April 2020

Bloomberg Professional is a premium financial information platform by Bloomberg LP offering real-time data, pricing and reference information, with a suite of analytical and functional capabilities. The comprehensive product is used by finance professionals, investment managers, researchers,
journalists, as well as in academia by faculty, librarians, and undergraduate and post-graduate students. This review provides a summary of the content and navigation of the Bloomberg Professional Services, as well as an evaluation of its features and functionality.
Mason OER Metafinder
Authors: Stafford Daniel , Flatley Robert
Published: April 2020

The Mason OER Metafinder (MOM) is a federated search tool created by George Mason University Libraries that searches Open Educational Resources (OER) repositories. The tool features an interface that searches 21 resources including major OER sites like OpenStax and digital repositories
like Digital Public Library of America. The reviewers noted several issues with the tool and search results including ambiguous search terms and facets, confusion with the date functionality and search results that included copyrighted materials.
Scopus CiteScore and Clarivate Journal Citation Reports
Authors: Salisbury Lutishoor
Published: April 2020

This review compares Scopus CiteScore (free resource) and Clarivate Journal Citation Reports (subscription resource). It focuses on the similarities and differences in these two database(s) primarily their searching interfaces, elements included in the records; and the availability
of useful help. It uses two sets of journals to compare their content; highlight their assignments in various categories; in quartiles within these categories; and their difference and similarities of their Impact Factor.
Inequality Within the EU-15 Countries: Have Social Benefits Been Pro-poor, Pro-middle Class or Pro-rich?
Authors: Isiaka Abdulaleem Moyosore
Published: April 2020

This study utilizes static and dynamic panel models in investigating the impact of social benefits on the aggregate level of income inequality as well as on the income shares of different income groups within the EU-15 countries over the period 1995-2015. While the static panel regression models are estimated with Pooled Ordinary Least Squares (POLS) and Least Squares Dummy Variables (LSDV) techniques, the dynamic panel regressions are estimated using dynamic GMM-IV technique. Diagnostic tests indicate that the results from the GMM-IV technique are consistent and the associated instrumental variables are valid; hence this study gives preference to the results from this technique. The results indicate that social benefits generally have a significantly negative impact on the aggregate level of inequality, a positive impact on the income shares of the low and middle income groups, and a negative impact on the income shares of the high income groups. In the long run, the sign and significance of the parameter estimates remain unchanged but their sizes increase considerably. This research considers a variety of theories and finds that there exists much ambiguity in the theoretical literature. Based on its findings, this study recommends that policymakers address rising income inequality by intensifying efforts towards raising social benefits and ensuring that the welfare system is efficiently managed.
Assertiveness and Performance Tasks
Authors: Moneva Jerald C. , Bolos Nicole G.
Published: April 2020

Assertiveness is defined as a behavior in which an individual is confident and can express thoughts, feelings, and opinion in direct honest way. Whereas, performance task pertains to an activity which students are asked to perform or demonstrate their understanding. This study aims to assess the association between assertiveness as independent variable, and level of performance task as dependent variable using descriptive correlation design. The respondents are the senior high school students of Jagobiao National High School. Checklist is used as research instrument of the study. The data are analyzed through Chi-square test as statistical treatment. The result of this study shows that Jagobiao National High School students have high correlation between the two variables. To simplify the idea, level of assertiveness can influence the students’ performance in school.
Bullied Students and Their Self-Esteem
Authors: Moneva Jerald C. , Calunod Jhon France Larrie , Sumayang Judima A.
Published: April 2020

Bullying is one of the major problems among students in school. Bullies use scare tactics to bully smaller or weaker students that might affect their esteem. High self-esteem and positive self-concept are important characteristics of an individual. The study intends to determine the association of perceived bullying and self-esteem of the junior high school students in Jagobiao National High School. This study used the quantitative approach descriptive survey design to determine the association between level of perceived bullying and their self-esteem. The researchers used checklist as the research instrument. The checklist has two parts consisting 10 indicators in each part. The first 10 indicators are about perceived bullying and the next 10 parts are all about students’ self-esteem. The data gathered will be treated with the use sum, frequency and simple percentage, weighted mean and chi-square. The result shows that the students were sometimes bullied by lies and false rumors that were told by others to hurt them. The students sometimes do not trust their strength and capabilities. There is no significant association between bullying and students’ self-esteem. Perceived bullying among students has nothing to do with their self-esteem.
Evaluating Pfeiffer Chromatography for Its Validation as an Indicator of Soil Quality
Authors: Graciano Igor , Matsumoto Leopoldo Sussumu , Demétrio Gilberto Bueno , Mello Peixoto Erika Cosendey Toledo
Published: April 2020

Soil monitoring is fundamental to promote sustainability agroecosystems. It is necessary to consider indicators that bring together biological, physical, chemical and inter-relational attributes. Pfeiffer chromatography (PC) represents an important method for soil diagnosis, so the present study aims to analyze it in order to contribute to its validation. The soil samples of 12 production systems were evaluated in quintuplicate. The chromas were elaborated using Whatman no 4 filter paper, and the soil extract was performed by sodium hydroxide solution 1%. The results were obtained using revealing solution (AgNO3 0.5%) ascension by capillarity, and the chrome zones: central, internal, medium and external were correlated to soil penetration, chemical, biological and enzymatic parameters, respectively. Variance analysis was applied to the results that presented normal distribution and the means were compared by Scott-Knott test. T-test for Spearman correlations and principal component analysis were used to evaluate the correlations. There was negative correlation between the central zone and the average penetration resistance within the range 0-40 cm in depth. The internal, medium and external zones presented positive correlation with organic matter, carbon microbial biomass, and enzymatic activities, respectively. Quality standard features such as coloration, size and proportion of zones, presence of enzymatic clouds, peaks and radial lines were also confirmed. Thus, the standardization developed by this study contributed to validation of PC. Since PC is a low-cost and easy-to-perform method, it proves to be a useful tool allowing farmers autonomy to monitoring different agricultural systems, contributing to their production sustainable.
Information and Communication Technology (ICT) and Economic Growth in ASEAN-5 Countries
Authors: Yong Jing Amy Huong , Ab-Rahim Rossazana
Published: April 2020

Digital economy generally refers to a digital technology-based economy. The embrace of digital economy is transforming a nation's economic growth. Countries blessed with successful digitisation will improve their economic performance; hence, it could increase country's GDP growth. In this respect, ASEAN-5 countries becoming a major economic force driver in Asia as well as to the global growth. The goal of this research is therefore to investigate the relationship between ICT and economic growth in the ASEAN-5 countries over the 2003 to 2018 study period. Using static and dynamic panel data estimation, results shows that fixed telephone line subscription has the greatest impact on ICT on economic growth. The findings suggest countries shall focus on the innovation of ICT especially on the mobile-cellular telephone subscription and fixed telephone line subscription to achieve economic growth. Investments in ICT infrastructure foster co-operation in ICT technology as well as advancing ICT particularly on the rise in jobs in the ICT sector, transforming government services into digital form to enhance economic growth in the country.
The Nexus Between Good Governance Indicators And Human Development Index In Africa: An Econometric Analysis
Authors: Tsegaw Paulos C
Published: April 2020

This study examines the association between good governance indicators and the human development index in Africa. Accordingly, it uses the panel data of 49 African countries from 2000-2018 on the six World Bank governance indicators (WGIs) and the UNDP aggregate human development index (HDI). The data are analyzed using descriptive statistics and panel regression analysis. The descriptive statistical analysis shows that most of the countries that are scoring high in the governance indicators are also scoring high in the human development index. It also indicates that Africa's average score in all governance indicators from 2000-2018 ranges between 36.2 % and 40.4%, while the score for human development was 50.8%. Using a one-year moving average, the calculated improvement rates for the eighteen years in all the governance and human development indicators were meager. The finding from the panel regression analysis attests only the three good governance indicators - the rule of law, regulatory quality, and political stability and absence of violence - are significantly and directly associated with the human development index. The finding implies that policy makers in African countries should give emphasis on these three good governance indicators to augment their human development effort.