bluuebunny/crossref_metadata_2025 huggingface dataset:
Analisis Kehilangan Minyak (Oil Losses) Pada Proses Pengolahan CPO (Crude Palm Oil) Di PT. Perkebunan Nusantara IV Kebun ADOLINA
Authors: Damanik Rahmat Indrajaya , Zurairah Masdania , Rezeki Rahmad , Refiza Refiza
Published: October 2023

AbstractThis study intends to evaluate the degree of oil losses in CPO processing at the "x" business unit of the PTPN IV palm oil mill. You may examine the amount of oil loss that takes place as well as the causes of the oil loss using the seven tools technique. In order to ensure that CPO production consistently results in the best goods and preserves the quality of CPO, the PTPN IV "x" factory constantly works to ensure that oil losses that do occur are always within the company's norm threshold. As can be seen from the daily losses data, which indicates that the degree of oil loss is still beyond the company's norm threshold, the research findings indicate that oil loss throughout the CPO processing process is still quite high. The histogram shows that the Boiled Water and Final Drab stations experienced the highest average oil loss, with deviations from the average of 0.24% and 0.03%, respectively. The pressure is outside the control limits in the 20th data on the control chart at the Ampas station, with a UCL of 4.86% and an LCL of 3.07%. Oil losses are a result of four factors: machinery, human resources, raw materials, and methods. Starting with the most important, the causes of oil losses are human resources, followed by raw materials, machines, and processes. Keywords:Oil losses, Crude Palm Oil, Seven tools.  AbstrakTujuan dari penelitian ini adalah untuk menganalisis seberapa besar tingkat kehilangan minyak (oil losses) pada pengolahan CPO dipabrik kelapa sawit PTPN IV unit usaha “x”. Dengan metode seven tools dapat menganalisis seberapa besar tingkat kehilangan minyak yang terjadi serta dapat menganalisis faktor penyebab dari kehilangan minyak tersebut. Dalam proses produksinya pabrik PTPN IV “x” selalu berusaha agar kehilangan minyak yang terjadi selalu dibawa batas ambang norma perusahaan agar  produksi CPO selalu menghasilkan produk yang terbaik dan menjaga kualitas mutu CPO. Hasil penelitian ini menunjukan bahwa kehilangan minyak pada saat proses pengolahan CPO masi sangat tinggi, hal tersebut dapat dilihat dari data losses harian yang menunujukan bahwa tingkat kehilangan minyak masi berada diatas batas ambang norma perusahaan. Dengan histogram dapat diketahui rata-rata kehilangan minyak paling tinggi terjadi pada stasiun Air rebusan dan Drab akhir dengan selisih terhadap norma 0,24% dan 0,03 %. Pada peta kendali distasiun Ampas pressan berada diluar batas pengendalian pada data ke 20 sebesar 4,93 % dengan UCL 4,86 % dan LCL 3,07 %. Faktor penyebab kehilangn oil losses terdapat 4 faktor yaitu Mesin, SDM, Bahan Baku dan Metode. Penyebab kehilangan oil losses mulai dari yang paling dominan adalah SDM, bahan baku, mesin dan terakhir metode. Kata Kunci:                                      Kehilangan minyak, Minyak sawit mentah, Tujuh alat.
From Freak Shows to Freaknature
Authors: Schmidt Jenne
Published: October 2023

Within environmental discourses, more-than-human beings with corporeal differences are often represented and exhibited as unnatural, abnormal, monstrous, freakish, bizarre, and deformed—as freaknature—and ultimately used as evidence of the harms of human-caused environmental contamination. The article examines the construction of freaknature alongside histories of the nineteenth- and twentieth-century American freak show to consider how these contemporary portrayals of the more-than-human not only reinvigorate the ableist tropes that were central to the freak show, but also reinforce logics of gender essentialism, transphobia, white supremacy, Orientalism, and racial purity. Both freak shows and freaknature operate/d as a scientific apparatus constructing and exhibiting some human and more-than-human beings as unnatural while shoring up other corporeal formations as normal/natural. Together, these crip figures on display call into question the binaries at the foundation of Western science.
Beyond the Drake Equation: A Time-dependent Inventory of Habitable Planets and Life-bearing Worlds in the Solar Neighborhood
Authors: Madau Piero
Published: October 2023

We introduce a mathematical framework for statistical exoplanet population and astrobiology studies that may help direct future observational efforts and experiments. The approach is based on a set of differential equations and provides a time-dependent mapping between star formation, metal enrichment, and the occurrence of exoplanets and potentially life-harboring worlds over the chemo-population history of the solar neighborhood. Our results are summarized as follows: (1) the formation of exoplanets in the solar vicinity was episodic, starting with the emergence of the thick disk about 11 Gyr ago; (2) within 100 pc from the Sun, there are as many as 11,000(η
⊕/0.24) Earth-size planets in the habitable zone (“temperate terrestrial planets” or TTPs) of K-type stars. The solar system is younger than the median TTP, and was created in a star formation surge that peaked 5.5 Gyr ago and was triggered by an external agent; (3) the metallicity modulation of the giant planet occurrence rate results in a later typical formation time, with TTPs outnumbering giant planets at early times; and (4) the closest, life-harboring Earth-like planet would be ≲20 pc away if microbial life arose as soon as it did on Earth in ≳1% of the TTPs around K stars. If simple life is abundant (fast abiogenesis), it is also old, as it would have emerged more than 8 Gyr ago in about one-third of all life-bearing planets today. Older Earth analogs are more likely to have developed sufficiently complex life capable of altering their environment and producing detectable oxygenic biosignatures.
Effect of 38% silver diamine fluoride on fracture resistance of leucite reinforced feldspathic ceramic CAD/CAM class I inlay restorations
Authors: Sezen Egemen , Kaya Umut , Ak Asli Topaloglu , Ay Miray
Published: October 2023

Introduction: Silver diamine fluoride (SDF) is a topical agent that has recently gained popularity for its ability to stop and prevent dental caries.

Aim: The aim of this study was to evaluate the effect of SDF applied to class I cavities of extracted non-caries molar teeth on the fracture resistance of CAD/CAM block.

Materials and methods: Twenty eight extracted noncarious molars were selected for the study. They were divided into two groups (n=14 per group). In each tooth, a diamond head was used to create Class I cavities that were 2 mm deep and 2 mm wide. The fracture strength test was carried out by applying a force at a speed of 5 mm/min, while continuously increasing the long axis of the tooth at the point corresponding to the central fossa.

Results: SDF application did not have a statistically significant effect on fracture resistance in teeth restored with Class I cavities CAD/CAM blocks. The two groups did not differ statistically significantly according to the two-way ANOVA [mean fracture force (N) ± standard deviation: without SDF 1138.19±581.65 and with SDF 1067.93±555.65; p=0.712].

Conclusions: This study showed that SDF did not have either a positive or negative effect on the fracture resistance for restoration or easy application in cavities. Long-term clinical studies with different mechanical tests are needed for the safe use of SDF in pre-restoration cavities with CAD/CAM blocks.
Análisis de fallos de los tubos de cobre utilizados en los intercambiadores de calor de los ventiloconvectores
Authors: Sargın Fatih , Kanbur Kürşat , Türkmen İlyas
Published: October 2023

Los intercambiadores de calor (IC) están formados por tubos de cobre y acero y se utilizan para calentar y enfriar el aire del ambiente. Uno de los principales problemas que se observan en los IC son las fugas en las tuberías de cobre. En este estudio, se examinaron en detalle muestras de tuberías de cobre fallidas y en buen estado de funcionamiento utilizadas durante diferentes periodos de tiempo. Los análisis microestructurales se realizaron mediante microscopía óptica (MO) y microscopía electrónica de barrido (MEB) para detectar los casos de corrosión en las superficies de las tuberías de cobre. Además, se definieron los productos de corrosión de las muestras mediante difracción de rayos X (DRX), espectroscopia de energía dispersiva (EDS) y análisis de espectroscopia infrarroja con transformada de fourier (FTIR). Se observó la formación de túneles interconectados en la sección transversal de la muestra de tubería de cobre fallida que tenían dimensiones microscópicas y productos de corrosión. En consecuencia, todos los resultados de los análisis que se obtuvieron de las muestras apuntaban a un mecanismo de corrosión conocido como corrosión por nido de hormiga. Se concluyó que la razón principal de la corrosión estaba relacionada con los aditivos de tipo etilenglicol que se utilizaban en los IC junto con el agua de red.
KINETICS AND ROLE OF PANCREATIC STONE PROTEIN AND MIDREGIONAL PROADRENOMEDULLIN AS PREDICTORS OF SEPSIS AND BACTEREMIA IN CHILDREN WITH HAEMATOLOGICAL MALIGNANCIES.
Authors: Antari Vasiliki , Skoura Lemonia , Tragiannidis Athanasios , Hatzipantelis Emmanuel , Tsinopoulou Vasiliki-Regina , Papakonstantinou Konstantina , Protonotariou Efthimia , Galli-Tsinopoulou Assimina
Published: October 2023

Background: To investigate the kinetics and prognostic value of pancreatic stone protein (PSP) and mid-regional proadrenomedullin (MR-proADM) during episodes of febrile neutropenia (FN) in children with haematological malignancies.

Material and methods: We evaluated prospectively a total of 70 FN episodes in 70 children with acute leukemias and lymphomas. Levels of CRP, PSP and MR-proADM were measured at the onset of the febrile episode (day 1), on day 3 and on day 7. The outcome and survival of children were evaluated during the study period until day 28. The performance of each marker in identifying sepsis or severe sepsis was assessed as area under a receiver operating characteristic (ROC) curve. For each biomarker, ROC curves were used to derive cut-offs for sensitivity and specificity in distinguishing sepsis from non-sepsis.

Results: During the 2-year study period, 70 febrile neutropenia episodes in 70 children with haematological malignancies were enrolled. Of 70 episodes of febrile neutropenia, in 17 (24%) a bacterial/fungal infection was documented. Criteria for sepsis were fulfilled for 31 (44%) and 7 (10%) patients were admitted to PICU. The median values of all biomarkers were higher on day 1 and differed significantly between patients with and without sepsis. The specificity of PSP, MR-proADM, and CRP were 0.82, 0.70, and 0.57, respectively. The sensitivity of PSP, MR-proADM and CRP were 0.84, 0.74, and 0.88, respectively.

Conclusions: Both PSP and MR-proADM are promising biomarkers for early diagnosis of sepsis during FN episodes in children with haematological malignancies. PSP has the higher sensitivity and specificity.
Reviewers
Authors: Xu Peijun
Published: October 2023

Reviewers
Enhancing Autonomous Vehicle Safety in Cold Climates by Using a Road
Weather Model: Safely Avoiding Unnecessary Operational Design Domain
Exits
Authors: Almkvist Esben , David Mariana Alves , Pedersen Jesper Landmér , Lewis-Lück Rebecca , Hu Yumei
Published: October 2023

This study investigates the use of a road weather model (RWM) as a virtual
sensing technique to assist autonomous vehicles (AVs) in driving safely, even in
challenging winter weather conditions. In particular, we investigate how the AVs
can remain within their operational design domain (ODD) for a greater duration
and minimize unnecessary exits. As the road surface temperature (RST) is one of
the most critical variables for driving safety in winter weather, we explore the
use of the vehicle’s air temperature (AT) sensor as an indicator of RST. Data
from both Road Weather Information System (RWIS) stations and vehicles measuring
AT and road conditions were used. Results showed that using only the AT sensor
as an indicator of RST could result in a high number of false warnings, but the
accuracy improved significantly with the use of an RWM to model the RST.
ROC-curve analysis resulted in an AUC value of 0.917 with the AT sensor and
0.985 with the RWM, while the true positive rate increased from 67% to 94%. The
study also highlights the limitations of relying on dashboard cameras to detect
slippery driving conditions, as it may not be accurate enough to distinguish
between, for example, wet and icy road conditions. As winter maintenance often
prevents slippery roads, the vehicles often measured wet or moist roads, despite
RST < 0°C. Our calculations indicate that the vehicle should be able to
detect 93% of slippery occasions but the rate of false warnings will be as high
as 73%, if using a dashboard camera along with the AT sensor. There are clear
benefits of using a RWM to improve road safety and reduce the risk of accidents
due to slippery conditions, allowing AVs to safely extend their time within
their ODD. The findings of this study provide valuable insights for the
development of AVs and their response to slippery road conditions.
Model Free Time Delay Compensation for Damped Impedance Method Interfaced Power System Co-Simulation Testing
Authors: Buraimoh Elutunji , Ozkan Gokhan , Timilsina Laxman , Arsalan Ali , Papari Behnaz , Chamarthi Phani Kumar , Edrington Christopher
Published: October 2023

The joint real-time co-simulation, which involves the virtual integration of laboratories located in different locations, is met with challenges, especially the communication latency or delay, which significantly affects co-simulation accuracy and system stability. The real-time power system co-simulation is particularly susceptible to these delays and could lose synchronism, which affects the simulation fidelity and limits dynamic and transient studies. This paper proposes a model-free framework for predicting and compensating delays in the virtual integration of real-time co-simulators through the damped impedance interface method to address this issue. The framework includes an improved co-simulation interface algorithm called the Damping Impedance Method (DIM) and a model-free predictor system designed to predict and compensate for delays without decomposing and reconstructing signals at coupling points. The predictor systems use one design parameter and two design parameters to achieve delay compensation through a first-order time delay compensation system. The framework enhances the accuracy and stability of the system, making it suitable for dynamic and transient studies.
Online Identification of Vehicle Driving Conditions Using Machine-Learned Clusters
Authors: Marrone John Francis , Kwok Ian , Fraser Roydon
Published: October 2023

Modern electrified vehicles rely on drivers to manually adjust control parameters to modify the vehicle's powertrain, such as regenerative braking strength selection or drive mode selection. However, this reliance on infrequent driver input may lead to a mismatch between the selected powertrain control modifiers and the true driving environment. It is therefore advantageous for an electric vehicle's powertrain controller to make online identifications of the current driving conditions. This paper proposes an online driving condition identification scheme that labels drive cycle intervals collected in real-time based on a clustering model, with the objective of informing adaptive powertrain control strategies. HDBSCAN and K-means clustering models are fitted to a data set of drive cycle intervals representing a full range of characteristic driving conditions. The cluster centroids are recorded and used in a vehicle controller to assign driving condition identification labels to the most recently recorded interval of vehicle data. The accuracy of the driving condition identifications of each model is compared by deploying the online identification scheme on the powertrain controller of an electrified vehicle and performing a real-world drive cycle of known driving conditions. The HDBSCAN clusters resulted in superior online driving condition identifications compared to alternative schemes. The main contribution of this paper is the novel application of clustering in an online identification scheme for use in a real-world embedded vehicle controller. By enabling accurate online identification of driving conditions, this approach can improve the powertrain control strategies of electrified vehicles and enhance the driving experience. Future research can leverage the online identification of driving conditions and explore the use of subsequent adaptive control schemes for reducing energy consumption, enhancing safety, and advancing the development of intelligent transportation systems.
Efficiency Enhancement and Lean Combustion Performance Improvement by Argon Power Cycle in a Methane Direct Injection Engine
Authors: Wang Chenxu , Deng Jun , Su Xiang , Cui Wenyi , Tang Yongjian , Li Liguang
Published: October 2023

Argon Power Cycle (APC) is an innovative future potential power system for high efficiency and zero emissions, which employs an Ar-O2 mixture rather than air as the working substance. However, APC hydrogen engines face the challenge of knock suppression. Compared to hydrogen, methane has a better anti-knock capacity and thus is an excellent potential fuel for APC engines. In previous studies, the methane is injected into the intake port. Nevertheless, for lean combustion, the stratified in-cylinder mixture formed by methane direct injection has superior combustion performances. Therefore, based on a methane direct injection engine at compression ratio = 9.6 and 1000 r/min, this study experimentally investigates the effects of replacing air by an Ar-O2 mixture (79%Ar+21%O2) on thermal efficiencies, loads, and other combustion characteristics under different excess oxygen ratios. Meanwhile, the influences of varying the methane injection timing are studied. Results indicate that by replacing air with an Ar-O2 mixture, thermal efficiencies and loads have a significant improvement, the operation boundary of excess oxygen ratio is extended from 1.73 to 2.91, the combustion duration period is shortened 3.5 - 7.0 °CA, and the cycling stability is significantly improved. For the APC, when the excess oxygen ratio is 1.34 and the methane injection timing is -130 °CA ATDC, the highest net indicated thermal efficiency of 51.1% and the gross indicated thermal efficiency of 53.1% are achieved, which are elevated by approximately 27.8% compared to the air cycle. Meanwhile, the maximum net indicated mean effective pressures of APC increases by 17.6% from 0.80 MPa to 0.68 MPa. The improvements in thermal efficiency are mainly attributed to the increase of thermal conversion efficiency. Moreover, compared to the air cycle, the higher in-cylinder temperature and pressure of APC allows for easier ignition and faster combustion, also leading to an increase in the thermal efficiency.
A Novel Approach to Constructing Reactivity-Based Simplified Combustion Model for Dual Fuel Engine
Authors: Li Ang , Zhang Zhenyingnan , Li Zhuohang , Zhu Lei , Huang Zhen
Published: October 2023

To achieve higher efficiencies and lower emissions, dual-fuel strategies have arisen as advanced engine technologies. In order to fully utilize engine fuels, understanding the combustion chemistry is urgently required. However, due to computation limitations, detailed kinetic models cannot be used in numerical engine simulations. As an alternative, approaches for developing reduced reaction mechanisms have been proposed. Nevertheless, existing simplified methods neglecting the real engine combustion processes, which is the ultimate goal of reduced mechanism. In this study, we propose a novel simplified approach based on fuel reactivity. The high-reactivity fuel undergoes pyrolysis first, followed by the pyrolysis and oxidation of the low-reactivity fuel. Therefore, the simplified mechanism consists of highly lumped reactions of high-reactivity fuel, radical reactions of low-reactivity fuel and C0-C2 core mechanisms. We have applied this methodology to a dual-fuel engine fueled with poly(oxymethylene) dimethyl ether 3 (PODE3) and ammonia. Species concentrations and ignition delay times have been used to validate our reaction mechanism. In conclusion, combustion chemistry simplification can be formulated by a reactivity-based approach. In the future, numerical simulations will be used to investigate the combustion characteristics of a PODE3/ammonia dual-fuel engine based on this method to optimize the combustion strategy.
Numerical Research on the Effects of Pre-Chamber Orifice Scheme on the Performance in a Large-Bore Natural Gas Engine
Authors: Li Bo , Cao Jianlin , Tian Liu , Fan Liyun , Xiao Ge , Long Wuqiang
Published: October 2023

Pre-chamber ignition is one of the advanced technologies to improve the combustion performance for lean combustion natural gas engine, which could achieve low NOx, simultaneously. The designing scheme of the orifices, which connects the pre-chamber and the main chamber, is the main challenge limiting the further improvement. In this work, the three-dimensional computational fluid dynamics calculation based on a four-stroke engine with 320 mm cylinder bore was conducted to investigate the effects of orifice structure on the combustion and NOx performance. The results show that the schemes with 7 and 9 orifices lead to the delayed high-temperature jets formation due to the asymmetrical airflow in the pre-chamber, which retards the ignition timing but enhances the combustion in the main chamber. The 6 orifices scheme leads to the insufficient distribution of the high-temperature jets, and the 10 orifices result in the serious interference between the adjacent high-temperature jets. The increased orifice draft angle has strengthened the formation of the high-temperature jets because of the throttling effects, resulting in the higher indicated power. Although the central orifice strategy has delayed the high-temperature jets, the main chamber combustion process has been enhanced significantly due to the ignition below the pre-chamber. Compared to the baseline, the output indicated power with 2.0 mm central diameter has been increased by 3.2%, and the NOx with 2.5 mm central diameter has been reduced by 34.6%. The layered orifice strategy can effectively improve the interference and enlarge the high-temperature jets distribution in the main chamber. However, the advanced combustion and more high-temperature regions produce more NOx. According to the sensitivity analysis, the orifice number and the central orifice diameter present more significant effects on the output indicated power and the NOx.
Gasoline Simulated Distillation Profiles of U.S. Market Gasoline and Impacts on Vehicle Particulate Emissions
Authors: Geng Pat , Butler Aron , Studzinski William , Salyers John , Jetter Jeff
Published: October 2023

A gasoline’s distillation profile is directly related to its hydrocarbon composition and the volatility (boiling points) of those hydrocarbons. Generally, the volatility profiles of U.S. market fuels are characterized using a very simple, low theoretical plate distillation separation, detailed in the ASTM D86 test method. Because of the physical chemistry properties of some compounds in gasoline, this simple still or retort distillation has some limitations: separating azeotropes, isomers, and heavier hydrocarbons. Chemists generally rely on chromatographic separations when more detailed and precise results are needed.

High-boiling aromatic compounds are the primary source of particulate emissions from spark ignited (SI), internal combustion engines (ICE), hence a detailed understanding and high-resolution separation of these heavy compounds is needed. This paper presents analysis of 159 U.S. market gasoline samples using D86 distillation and ASTM D6730 detailed hydrocarbon analysis (DHA). The samples ranged in Particulate Matter Index (PMI) from 0.925 to 2.540 or Particulate Evaluation Index (PEI) of 0.584 to 2.715. Additional analysis was performed on 80 of the samples using ASTM D7096, a chromatographic method, to generate higher resolution simulated distillation (SimDis) profiles. SimDis cutpoints (%-off values) in the range of T95 to T98 show good correlation to PMI and PEI, demonstrating that SimDis analysis can provide a useful assessment of the PM-formation tendency of market gasolines.
Comparative Analysis of the Lubrication, Friction, and Wear of Injection System Materials, with Synthetic Paraffinic Kerosene, Jet-A, and ULSD
Authors: Soloiu Valentin , Davis Zachary , Molina Gustavo J. , Myrthil Christopher , Willis James , Weaver Amanda
Published: October 2023

Alternative fuels are sought after because they produce lower emissions and sometimes, they have feedstock and production advantages over fossil fuels, but their wear effects on engine components are largely unknown. In this study, the lubricity properties of a Fischer-Tropsch Gas-to-Liquid alternative fuel (Synthetic Paraffinic Kerosene-S8) and of Jet-A fuel were investigated and compared to those of Ultra Low Sulphur Diesel (ULSD). A pin-on-disk tribometer was employed to test wear and friction for a material pair of an AISI 316 steel ball on an AISI 1018 steel disk when lubricated by the fuels in this research work. Advanced digital microscopy was used to compare the wear patterns of the disks. Viscosity and density analysis of the tested fluids were also carried out.

Tribometry for the fuel showed that S8 fell between Jet-A and ULSD when friction force was calculated and showed higher wear over time and after each test when compared to that of Jet-A and ULSD. An initially higher running-in friction force of 0.35N to 0.38N was observed for all three tested fluids, and then quasi-steady-state lower values of friction force of .310N for S8, 0.320 N for Jet-A and 0.295N for ULSD (the lowest observed).Wear values obtained by mass loss of the tested AISI 108 steel disks show that Jet-A and the reference fuel ULSD may yield lower wear (which is associated to better lubricity) than that of S8, and microscopy images are consistent with the wear results.
Experimental Investigation on Near-Nozzle and Macroscopic Structure of a Supercritical Fuel Injected into Subcritical Environment
Authors: Liu Rui , Huang Li , Ni Xinmin , Ju Dehao , Yi Ran , Ma Yue
Published: October 2023

The supercritical fluid combustion technology was regarded as an effective method to increase fuel gas mixing rate and performance. During the injection process, critical characteristics dominate the jet development to behave as different spray structure. Due to the limited researches about supercritical gasoline-like fuel injection characteristics, macroscopic and near-nozzle microscopic spray structures of supercritical n-heptane injected into atmosphere condition were observed and compared with the injection of cryogenic nitrogen in this work. A supercritical fuel injection device was designed able to heat the fuel temperature up to 773 K and maintain the fuel injection pressure stable at 4 MPa. Backlight illumination and schlieren imaging technologies were applied to capture the liquid and overall jet structure. The effect of initial fuel temperature on the spray structure was analyzed and some novel near-nozzle structures were also discussed. Results show that with the increase of initial fuel temperature, the jet behaves as narrow linear structure at first, and then transforms to gray mist along radial direction, and almost vanishes except for near-nozzle region at last. As for the microscopic spray structure, there is a closed shock structure near the nozzle. The axial distance of the Mach disk of the shock can be predicted by empirical correlations which are suitable for the ideal gas, but the radial distance of the Mach disk is larger than that of the ideal gas.
Performance of the Mixture of Ammonia and Ammonia Decomposition Products as a Carbon-Free Fuel for Spark Ignition Engines
Authors: Zaev Ivan , Smirnov Sergey , Gordeev Vladislav
Published: October 2023

This work is devoted to assessment of the reactivity of the ammonia-based mixed fuels consisting of ammonia and products of its decomposition to hydrogen and nitrogen. For these purposes the thermodynamic, chemical kinetics and engine cycle simulations are performed. The dependence of the mixed fuels laminar flame speed, which is a measure of fuel reactivity, on ammonia decomposition degree is obtained. It is shown, that if about 37% of ammonia are decomposed and mixed with remaining ammonia (either hydrogen/nitrogen or pure hydrogen), then the reactivity of obtained mixture is similar to that of natural gas in a wide range of conditions. The engine performance parameters are estimated and compared for two fuels with the similar reactivity: natural gas or ammonia-based mixed fuels. It is shown, that the reduction of engine power by 8% is obtained when transferring from natural gas to considered ammonia-based mixed fuel. Reduction of NOx emissions is about 50% due to lower combustion temperature of the mixed fuel. Further studies imply the assessment of the engine knock limits for proposed ammonia-based mixed fuels, as well as assessment of the ammonia decomposition process effect on overall engine performance and operability limits.
Investigation of Performance of Fischer-Tropsch Coal-to-Liquid Fuel, IPK, in a Common Rail Direct Injection Compression Ignition Research Engine with Varying Injection Timing
Authors: Soloiu Valentin , Willis James , Weaver Amanda , O'Brien Brandon , Dillon Nicholas , Davis Zachary
Published: October 2023

An investigation of the performance and emissions of a Fischer-Tropsch Coal-to-Liquid (CTL) Iso-Paraffinic Kerosene (IPK) was conducted using a CRDI compression ignition research engine with ULSD as a reference. Due to the low Derived Cetane Number (DCN), of IPK, an extended Ignition Delay (ID), and Combustion Delay (CD) were found for it, through experimentation in a Constant Volume Combustion Chamber (CVCC). Neat IPK was analyzed in a research engine at 4 bar Indicated Mean Effective Pressure (IMEP) at three injection timings: 15°, 20°, and 25° BTDC. Combustion phasing (CA50) was matched with ULSD at 10.8° and 16° BTDC. The IPK DCN was found to be 26, while the ULSD DCN was significantly higher at 47 in a PAC CID 510. In the engine, IPK’s DCN combined with its short physical ignition delay and long chemical ignition delay compared to ULSD, caused extended duration in Low Temperature Heat Release (LTHR) and cool flame formation. It was found in an analysis of the Apparent Heat Release Rate (AHRR) curve for IPK that there were multiple Negative Temperature Coefficient (NTCR) regions before the main combustion event. The High Temperature Heat Release (HTHR) of IPK achieved a greater peak heat release rate compared to ULSD. Pressure rise rate for IPK was observed to increase significantly with increase in injection timing. The peak in-cylinder pressure was also greater for IPK when matching CA50 by varying injection timing. Emissions analysis revealed that IPK produced less NOx, soot, and CO2 compared to ULSD. CO and UHC emissions for IPK increased.
Combustion and Emission Characteristics of Ammonia Jet Flames, Based on a Controllable Activated Thermal Atmosphere
Authors: Ji Meng , Ferrari Alessandro , Shang Quanbo , Zhang Guanyu , Li Liguang , Deng Jun , Fu Lezhong
Published: October 2023

Ammonia is a new type of carbon-free fuel with low cost, clean and safe. The research and application of zero-carbon fuel internal combustion engines has become the mainstream of future development. However, there still exist problems should be solved in the application of ammonia fuel. Due to the lower flame laminar speed and higher ignition temperature, ammonia may have unstable combustion phenomena. In this work, the characteristics of ammonia combustion have been investigated, based on controllable thermal activated atmosphere burner. The ignition delay has been used to analyze the ammonia combustion characteristics. With the increase in co-flow temperature, the ignition delay of ammonia/air has an obvious decline. In order to investigate the emission characteristics of ammonia, CHEMKIN is used to validate the different chemical reaction mechanisms and analyse the ammonia emissions. With the increase in environmental temperature, the NOx increases and NO is the main pollutant; With the increase of pressure, N2O and NO2 increase, while NO decreases. At 1153K, compared to low pressure, the ignition delay at high temperature and pressure decreases rapidly, from 150 ms to 20 ms. With the increase in environmental pressure, NO continues to decrease, while N2O and NO have a slight increase. At the temperature of 1553K, if the pressure changes from 1MPa to 5MPa, the N2O changes from 1ppm to 2ppm. But as soon as the pressure increases in the 5MPa-9MPa range, the amount of increase is only 0.6ppm/4MPa. Above all, the study of the autoignition characteristics and emissions of ammonia turbulent flame is particularly important for the application to the ammonia engine.
Supporting the Transportation Industry: Creating the GC-LB and High-Performance Multiuse (HPM) Grease Certification Programs
Authors: Kaperick Joseph , Fish Dr Gareth , Coe Chuck , Cosgrove Bradley , Turner David , Mackwood Wayne , Mistry Kuldeep , Chichester Chad , Dudley Gary , Morris Dwaine , Brandon Keyth , Kunselman Michael
Published: October 2023

This paper outlines the history and background of the NLGI (formerly known as the National Lubricating Grease Institute) lubricating grease specifications, GC-LB classification of Automotive Service Greases as well as details on the development of new requirements for their High-Performance Multiuse (HPM) grease certification program.

The performance of commercial lubricating grease formulations through NLGI's Certification Mark using the GC-LB Classification system and the recently introduced HPM grease certification program will be discussed. These certification programs have provided an internationally recognized specification for lubricating grease and automotive manufacturers, users and consumers since 1989. Although originally conceived as a specification for greases for the re-lubrication of automotive chassis and wheel bearings, GC-LB is today recognized as a mark of quality for a variety of different applications. The main driving force to upgrade GC-LB was that six of the 12 property test methods utilized in ASTM D4950 had major issues, requiring either revised, alternative or new test methods. In addition to the issues associated with the test methods, NLGI recognized that advancements in materials, technologies and applications would be better served by newer specifications. The initiative that began as an update to the GC-LB specification then led to the introduction of the HPM specifications.

Analysis of GC-LB certified greases showed that most commercial greases also claimed other enhanced properties such as high load carrying, saltwater rust resistance, water resistance and long life in addition to meeting the GC-LB requirements. By 2019, NLGI’s Specification Working Group had developed a draft specification with proposed changes to upgrade the GC-LB classification. This draft was further modified through interviews, surveys and in-depth discussion with members of the lubricating grease industry. The initial focus was on updated specifications for a High-Performance Multiuse grease that could be used in a variety of bearings and applications which require similar lubricating properties. Additional specifications were defined as part of the HPM specification for all these properties except long life. Long life (+LL) and High Temperature (+HT) properties are currently being addressed in Phase 2 of the HPM Grease Certification Program. Additionally, the low temperature specification was added to the HPM specification after interest was shown during the interview and feedback process.
Low Temperature Performance of Novel Electric Vehicle Motor Lubricating Greases
Authors: Dodos George S. , Shah Rajesh
Published: October 2023

In this study the main focus is on the low temperature behavior and mobility of lubricating greases; a characteristic that has always been challenging for grease formulators. A series of lab-scale polyurea grease samples are prepared, with three different types of low viscosity synthetic base oils (ISO VG 32), and are examined in terms of their low temperature behavior as potential lubricants for electric motor bearings of electric vehicles (EVs) and hybrid electric vehicles (HEVs). The cold flow properties are analyzed by utilizing a Low Temperature Flow Tester following the DIN 51805-2 (Determination of flow pressure of lubricating greases according to Kesternich method) standard. The test matrix includes the cold flow pressure assessment at various temperatures ranging from -0oC to -40oC, whereas those measurements are also repeated after various relaxation periods - at selected temperatures - from 4h up to 8h before the actual determination. By employing this modified technique, the effect of an extended temperature control time on the relatively low temperature properties of the grease can be compared to the corresponding behavior at the standard test conditions. The comparative assessment of the results gives valuable information on the cold flow performance of upcoming advanced greases that can be utilized in electric vehicle motors.
Fuel Economy Estimates of Drive Cycles Developed in the Philippines
Authors: Corpus Robert Michael Baria , Lomotan Robert James , Vasquez Peter , BAYANI MELDANETTE
Published: October 2023

With greenhouse gas emissions (GHG) being identified as a major cause, climate change is considered as a major environmental concern in recent decades. Globally, policymakers have been trying to reduce GHG emissions through a variety of policies and strategies Given that the Philippine ratio of greenhouse gas (GHG) to gross domestic product (GDP) is above the global average, GHG production is predicted to escalate if it remains unaddressed This study presents various methods for fuel estimates of drive cycles developed in the Philippines. In estimating emission inventories, driving cycles can be considered as one of the significant travel-based models. The findings suggest that the pros and cons of using different methods of fuel economy in driving cycles must be taken into consideration. The study introduces energy road load methods to analyze drive cycles for different vehicle types, including air-conditioned and non-air-conditioned ones. It compares cycles from various routes using energy road load and driving behavior to assess fuel consumption, considering laboratory testing for future research. The findings also suggest that such method Micro-trip provides a good contemplation of fuel estimates and vehicular emissions, evaluates each stop-go condition that happens due to road network conditions, and uses a cycle based on actual driving data [1]. However, the starting point and end point of micro-trips cannot be determined due to specific speed, acceleration, and duration variations, especially considering different levels of service (LOS). The nature of being stochastic and repetitive makes it challenging to produce these micro-trip differences.
NVH Performance Prediction of Electrified Drive System under Influence of Electromechanical Excitations
Authors: Dambir Gaurav , Selukar Amol
Published: October 2023

Noise, Vibration and Harshness (NVH) has become crucial design parameter for automotives which is undergoing enormous technological advancements due to vehicle electrification where bulky, noisy IC Engine which mask driveline and other noises are being replaced by high-speed electric motor as a prime mover. In such electrified drive systems, along with power transmitting gears system, high speed electric motor also acts as source for generating vibrations and noise at vehicle level which are perceptible by end users. The combined effect of the electromechanical sources of excitation is even more severe which directly affect powertrain and subsequently vehicle performance in field. So, electrified drive systems need to be designed for better NVH performance considering motor characteristics curve, speed-torque requirements of application and to diligently capture voice of customer directed towards comfort with low noise levels. In view of this, assessing NVH performance of electrified drive system right at the design stage is of paramount importance.

In this paper, multidisciplinary, combined approach to analytically predict NVH performance of electrified drive systems is being discussed in terms of vibration accelerations on housing and at mounting locations under influence of electric motor excitations and gear excitations. This helps to evaluate severity of excitation sources, system susceptibility for transferring vibrations and system response for different excitation sources. Frequency domain based predictive dynamic system model comprising of detailed sub-systems is being developed to evaluate component level contributions and subsequent system level impact. Motor orders are evaluated based on motor dynamic characteristics. Gear excitations are evaluated from gear transmission errors. System response is predicted under influence of electromechanical excitations using virtual accelerometers. The predictive model can be validated using physical testing by capturing acceleration data at defined accelerometer locations and analyzing corresponding sources. The proposed methodology can be extended to variety of electrified drive systems to develop respective predictive models. Actionable insights from predictive models become critical inputs to product designers and can be implemented at initial stage of product design to ensure design for NVH.
Integrated Simulation Methodology to Predict Engine Head, Block, and Piston Temperatures
Authors: Sahu Abhay Kumar , CHAKKAMADATHIL SHIRDI , Das Debasis
Published: October 2023

With the constant strive towards increase in performance and corresponding stringent emission standards of modern IC engine, engine components such as the head, block and piston are subjected to higher thermal loads. An integrated simulation methodology is proposed where the head, the block and the piston are integral part of the analysis. The CFD – CHT methodology is used to simulate and predict the temperature of these engine components. The head and block are run in a steady-state conjugate heat transfer framework while the transient multiphase volume of fluid (VOF) approach is used to predict piston temperatures. Combustion surfaces boundary conditions are derived from 3D CFD open-loop combustion simulation, while cooling and lubrication surface boundary condition are mapped from 1D system simulation or experimental data. The heat transfer boundary conditions are exchanged between the two simulations. The temperature field obtained from simulation is used further as input to perform the thermo-mechanical fatigue analysis to predict the useful life and durability of engine and piston. Physics involving nucleate boiling and contact resistance are also incorporated and studies are conducted to predict their sensitivity.

The simulation methodology is applicable and validated for both Spark Ignition (SI) and Compression Ignition (CI) engines. A good correlation is established between the simulation and experimental data. This study serves to predict the location of critical failures, optimize the design faster and save time and costs for the organization.
“Chamfer Analysis for Smooth Diagonal Shifting by Using ‘Creo-MECHANISM’ Tool”
Authors: patil Manoj Mahadev , MIRGE TUSHAR
Published: October 2023

In current competitive automobile sector, gear shift quality has become significant factor for vehicle evaluation. OEMs are sensibly focusing on improving gear shift quality to meet customer’s expectations.

Though there are different gear shifting habits in different drivers, diagonal shifting is the fastest way of shifting gears in manual transmission vehicle. So the components linked with shift system should be designed to facilitate smooth diagonal gear shift pattern.

This paper enlightens the process of defining chamfers on internal gear shifting components for smooth diagonal shifting movement of gear shift lever. It is hard to define chamfers by analytical or practical approach. Creo-mechanism is very useful simulation tool which can be used to understand diagonal shift patterns and to define the chamfers.
An Examination of Sensing Skins with Tailored Conductivity Distributions for Enhanced 2-D Surface Temperature Measurements Using Electrical Impedance Tomography (EIT)
Authors: Sjöberg Magnus
Published: October 2023

For 2D surface temperature monitoring applications, a variant of Electrical Impedance Tomography (EIT) was evaluated computationally in this study. Literature examples of poor sensor performance in the center of the 2D domains away from the side electrodes motivated these efforts which seek to overcome some of the previously noted shortcomings. In particular, the use of ‘sensing skins’ with novel tailored baseline conductivities was examined using the EIDORS package for EIT. It was found that the best approach for detecting a temperature hot spot depends on several factors such as the current injection (stimulation) patterns, the measurement patterns, and the reconstruction algorithms. For well-performing combinations of these factors, customized baseline conductivities were assessed and compared to the baseline uniform conductivity.

It was discovered that for some EIT applications, a tailored distribution needs to be smooth and that sudden changes in the conductivity gradients should be avoided to prevent the introduction of artifacts in the reconstructed conductivity field. Still, the benefits in terms of improved EIT performance were small for conditions for which the EIT measurements had been ‘optimized’ for the uniform baseline case. Within the limited scope of this study, only two specific cases showed benefits from customized distributions. For one case, a smooth tailored distribution with increased baseline conductivity in the center provided a better separation of two centrally located hot spots. For another case, a smooth tailored distribution with reduced conductivity in the center provided better estimates of the magnitudes of two hot spots near the center of the sensing skin.

Overall, the results at hand suggest that improved 2D surface temperature measurement are best served by continued development of measurements and reconstruction algorithms rather than the use of sensing skins with tailored baseline conductivity distributions.