bluuebunny/crossref_metadata_2025 huggingface dataset:
The Spectrum of Anterior Cruciate Ligament Reconstruction Options for the Pediatric and Adolescent Patient: A Narrative Review
Authors: Rohde Matthew S. , Cinque Mark E. , LaPrade Christopher M. , Ganley Theodore J. , Shea Kevin G.
Published: April 2022

As youth sports participation has increased in recent years, injuries to the anterior cruciate ligament (ACL) have become increasingly common in pediatric patients. Historically, ACL reconstruction was delayed in pediatric patients to avoid physeal damage with the potential for leg-length discrepancy or angular deformity. Current research shows that delaying reconstruction or choosing nonoperative management is associated with increased rates of meniscal and chondral injuries, persistent knee instability, and low rates of return to previous activity. Early ACL reconstruction using techniques to avoid physeal growth disturbance is now widely accepted among physicians. The purpose of this review was to describe the pediatric ACL in terms of the relevant anatomy and biomechanics, physical examination, and diagnostic imaging. In addition, the importance of skeletal age and possible physeal injury is discussed in the context of ACL reconstruction options by skeletal age and remaining growth potential.
Linoporella vesiculifera n.sp., A New Calcareous Alga (Dasycladales) from the Upper Barremian of Mt. Biokovo (Karst Dinarides, Croatia)
Authors:   Croatian Geological Survey, Zagreb, Croatia, Sokač Branko
Published: April 2022

According to all the main characteristics, the new species belongsto the genus Linoporella. At the species-specific level, Linoporellavesiculifera n.sp. is characterized by visibly widened distal ends ofthe secondary branches, which gives a vesiculiferous appearance tothe outer surface of the thallus. The distal widenings are sphericallyor conically shaped and open outwards in a funnel-like form. A shortreview of the taxonomic validation of some Linoporella species isalso given. The new species is derived from the Barremian deposits ofMt. Biokovo (central Dalmatia, Croatia).
Stratigraphy and Palaeogeography of Miocene Deposits from the Marginal Area of Žumberak Mt. and the Samoborsko Gorje Mts. (Northwestern Croatia)
Authors:   Croatian Geological Survey, Zagreb, Croatia, Vrsaljko Davor , Pavelić Davor ,   Faculty of Mining Geology and Petroleum Engineering, University of Zagreb, Croatia, Bajraktarević Zlatan ,   Department of Geology and Palaeontology, Faculty of Science, University of Zagreb
Published: April 2022

Miocene sediments rimming the Palaeozoic–Mesozoic–Palaeogenerocks, form Žumberak Mt. and the Samoborsko Gorje Mts. Spatialanalysis of the setting and development of the surface Miocenestratigraphy, at the marginal areas of the Žumberak and SamoborskoGorje Mts., allows four palaeogeographic areas to be distinguished:Žumberak, Plešivica–Sveta Jana, Samobor–Sveta Nedelja and Grdanjci.In the Miocene deposits (totaling 350 m), within the area ofŽumberak, coarse-grained clastics from deltaic deposits of Pannonianage prevail. Here only, 50 m of sediments of Pliocene–Pleistoceneage overlie the Miocene deposits whereas Mesozoic carbonates representthe basement. The Plešivica–Sveta Jana area is characterizedby a 600 m sequence of Miocene deposits, mainly overlying Triassicdolomites, where finely-grained layers of marls and silts prevail.In this area, Miocene successions from the Badenian to the Pontianare characterized by a continuity of sedimentation with an inheriteddepositional environment. In the area of Samobor–Sveta Nedelja,the basement is diverse: Triassic dolomites, volcanogenic–sedimentarycomplex of Cretaceous age and a clastic–carbonate complex ofPalaeogene age. The Miocene succession shows a regressive trendfrom the Badenian to the Pontian and the total thickness is estimatedat 400 m. The area of Grdanjci differs considerably from the otherMiocene palaeorelief. An approximately 50 m-thick series of coarsegrained clastics with coal is distinguished, of unclear stratigraphic age (Ottnangian?). Miocene sediments of the Grdanjci area are represented by both a transgressive type of conglomerates and shallow water limestones of Badenian age, with a total thickness of about 100 m.The development of the Miocene stratigraphy of the Žumberakand Samoborsko Gorje Mts. is generally correlative with that in theother parts of the Pannonian area, though it does exhibit local variations.Comparison of the Miocene palaeorelief of Žumberak Mt. withthe Samoborsko Gorje Mts., together with neighbouring areas, enabledwider correlation with other parts of northern Croatia, and themore distant Western and Central Paratethys.
Zeolitization of Tuffaceous Rocks in the Keşan Region, Thrace, Turkey
Authors:   Geology Department, Istanbul Technical University, Turkey, Esenli Fahri , Uz Bektas ,   Geology Department, Istanbul Technical University, Turkey, Suner Fikret ,   Geology Department, Istanbul Technical University, Turkey, Esenli Vildan ,   Geology Department, Istanbul Technical University, Turkey, Ece Ö. Işık ,   Geology Department, Istanbul Technical University, Turkey, Kumbasar Işık ,   Geology Department, Istanbul Technical University, Turkey
Published: April 2022

A 33 metre thick pyroclastic-rich zone of the Mezardere formationof Oligocene age is exposed in the Keşan region of Thrace, Turkey.In this zone, vitreous tuffs of dacitic composition have altered primarilyto zeolites, including mordenite, heulandite–clinoptilolite andanalcime. Silicification and alteration to clay minerals are common.Zeolite minerals have developed from volcanic glass, whereas somemordenites have formed from dissolution of heulandite-group zeolites.Although authigenic mineral paragenesis does not vary laterally,there is a marked vertical variation, particularly in zeolites. Mordenite(+heulandite–clinoptilolite) and analcime do not coexist and haveformed in different stratigraphic levels. This suggests that their chemicalenvironment is controlled by different hydrologic systems.Whole rock composition shows the relationship between chemistryand secondary mineralogy. For example, whole rock trace elementgeochemistry indicates the natural selectivities of zeolites. There isalso stratigraphic control on the chemistry and texture of mordenites.Specifically, (Na+K)/(Ca+Mg) ratios of mordenites decrease fromthe lower to the upper levels. Mordenites of the lower level show afibrous habit while the upper level mordenites are needle-like inshape. The average Si/Al ratio in mordenites is 3.90, in heulanditegroupminerals 3.95, and in analcimes 2.34.
Granulometric and Chemical Composition of the Danube River Sediments, Batina Village, Croatia
Authors:   Ruđer Bošković Institute, Zagreb, Croatia, Oreščanin Višnja , Lulić Stipe ,   Ruđer Bošković Institute, Zagreb, Croatia, Medunić Gordana ,   Department of Mineralogy and Petrology, Faculty of Science, University of Zagreb, Croatia, Mikelić Luka ,   Ruđer Bošković Institute, Zagreb, Croatia
Published: April 2022

The size-fractionated recent sediments of the Danube river, from Batina, were assayed for the total concentrations of 15 elements: Ca, Cr, Cu, Fe, K, Mn, Ni, Pb, Rb, Sr, Ti, V, Y, Zn and Zr. It was found that trace metals increased with decreasing particle size, whereas the highest levels of organic matter from loss on ignition tests were found in the 0.5–1 mm fraction. The exchangeable phase accounted for a very minor proportion of the total heavy metal concentrations. Seasonal patterns of exchangeable Pb, Zn, Cu, Ni, Mn and Fe were more irregular than those of total metal levels, both generally reflecting a decrease in concentrations during spring. Rubidium normalization of the Pb, Cu, Zn, Ni, Cr, Mn and Fe concentrations was applied on the <0.063 mm fraction. A certain amount of the Cu and Ni concentrations may be related to anthropogenic rather than natural processes upstream of the study area and around one of the localities.
As-needed intranasal corticosteroid spray for allergic rhinitis: a systematic review and meta-analysis
Authors: Hoang M.P. , Chitsuthipakorn W. , Seresirikachorn K. , Snidvongs K.
Published: April 2022

Background: As-needed intranasal corticosteroid spray (INCS) is commonly used by patients with allergic rhinitis (AR) who have suboptimal symptom control. This systematic review aimed to assess the effectiveness of as-needed INCS for treating AR. Methodology: Systematic searches for randomized controlled trials studying the effects of as-needed INCS compared to regular INCS, as-needed antihistamine, or placebo were performed. Primary outcomes were total nasal symptom score (TNSS) and disease-specific quality of life (DSQoL). Results: Eight studies (882 participants) met the criteria. Regular use of INCS showed greater improvements than as-needed INCS in TNSS, DSQoL, nasal peak inspiratory flow, sneezing, and nasal congestion scores with small effect sizes. There were no differences between regular and as-needed INCS usage for ocular symptoms, symptom-free days, nasal itching, and rhinorrhea scores. As-needed INCS was superior to as-needed antihistamine and placebo with medium effect sizes. There were no differences in risk of adverse events between the groups in all three comparisons. Conclusions: Regular use of INCS improved total nasal symptoms score and DSQoL better than as-needed INCS. However, as-needed INCS improved TNSS better than as-needed antihistamine and placebo. The effects of as-needed INCS were closer to regular INCS usage than to placebo or as-needed AH usage.
The Portrayal of Women in TVC and Film: An Analysis in the Gender Perspective
Authors: Rahman Md. Aliur , Ullah Rahmat , Jerin Israt , Hossain Md Rakib
Published: April 2022

Bangladesh is developing as a role model in the world by the great contribution of half of its population- the womenfolk. But recognition of their contribution in every sector including media are very negligible. Deliberately or unintentionally, the Bangladeshi media presents women as virago, petulant, subversive, subordinate, house maker, servant, etc. (Sharmeen,2011). Audio-visual media tends to use women's beauty as a symbol of sexuality in televisions and movies, as society views women in the same way. Though, audio-visual media have a vast potential to create awareness, educate people against gender discrimination and recognize women’s contribution to society. But we observed that, in Bangladeshi films, female characters usually revolve around a limited number of images; the lascivious beautiful heroine, the loving mother, the vamp, or the woman of crooked character (Haq, 2006). This article aims to understand the trend of the use of content in powerful audio-visual media like televisions and films and its gender sensitiveness. Content analysis and case study methods have been used for the analysis. The works of literature and content which are collected from primary and secondary sources are analyzed to enrich the study reflections of this paper. Based on the findings of the study this article concludes that in the social structure of Bangladesh patriarchal social system is prevalent and this dominance is observed in all spheres of society and the media is no exception.
ADVANTAGES AND CONSTRAINTS OF SPECIFIC AUTOCAD PLANT 3D FUNCTIONS FOR DYNAMIC MANAGEMENT - CASE STUDY FOR A HEAVY WATER DETRITIATION INSTALLATION AT CERNAVODA N.P.P.
Authors:   RATEN CITON, Pavel Nita Iulian , Olteanu A.R. ,   RATEN CITON, Coman Camelia ,   RATEN CITON, Beznila Hortensia ,   RATEN CITON
Published: April 2022

The advantages and constraints of the specific Autocad Plant 3D functions for dynamic management - production of technological diagrams, isometrics, orthogonal views, bills of materials and piping system erection projects for the future detritiation facility at the Cernavodă Nuclear Power Plant (Cernavoda N.P.P.) are presented in a case study. In last decades 3D modelling of the plant has been increasing used in design of new projects in nuclear power plant (NPP) both in design period but also in design changes required during life time and extended life time of a plant. In the proposed case we developed a model to make an engineering design application for plant design incorporating disciplines such as piping, piping support, equipment, civil and steel structure. Using 3D Plant capabilities we can improve design process, interdisciplinary check-out as well as project execution. The project could be updated after as built revision of isometric drawings in order to obtain a training model for the system to prepare plant operators to make scheduled and unscheduled maintenance and time estimation of different maintenance procedures that could be required during plant operation in order to reduce as low as reasonable possible dose received during detritiation installation maintenance.
MICRO-CHANNEL REACTOR FOR LOW LEVEL H2 OXIDATION WITHIN AN O2 STREAM: PRELIMINARY TESTS IN VIEW OF INTEGRATION IN A H2 GENERATOR WITHIN CECE PROCESS
Authors:   ICSI Rm. Valcea, Niculescu Alina , Ana George ,   ICSI Rm. Valcea, Bulubașa Gheorghe ,   ICSI Rm. Valcea, Stefan Iuliana ,   ICSI Rm. Valcea, Bucur Ciprian ,   ICSI Rm. Valcea, Bornea Anisia ,   ICSI Rm. Valcea
Published: April 2022

CECE (Combined Electrolysis Catalytic Exchange) process is the candidate for low level tritiated water detritiation within any application. The process consists mainly of a H2 generator, a LPCE (Liquid Phase Catalytic Exchange) column and an O2 striping column. During operation, tritium is being accumulated within the H2 generator in the form of tritiated water and the effluent streams (hydrogen and oxygen) show in time an increase concentration in tritium in the form of both tritiated water vapors and gas, which needs to be recovered. The tritium in the H2 stream is recovered in a LPCE column, while the tritium in the O2 stream is recovered in a striping column. In view of lowering the load onto the striping column and to recover the tritium in gas form, a micro-channel reactor is proposed to be included for H2 oxidation followed by vapor recovery. The design of the equipment together with the preliminary results of the tests done with H2 and air will be shown, prior to integration in the CECE process.
GEOLOGICAL AND GEOPHYSICAL CONSIDERATIONS REGARDING THE MINERAL AND GEOTHERMAL WATERS FROM THE RAMNICU VALCEA - GOVORA AREA
Authors:   Geological Institute of Romania, Asimopolos Laurentiu , Asimopolos Natalia-Silvia ,   Geological Institute of Romania, Asimopolos Adrian Aristide ,   University POLITEHNICA of Bucharest
Published: April 2022

For understanding of complex geological and geophysical phenomena, regarding the mineral and geothermal waters, we must base on the whole of knowledge and available data for the study area. The input data include: digital terrain models, geological and geophysical maps, sections, drill-holes and geological interpretation, for assemble together into the same space data from various sources, in order to ensure geometrical coherence. Also, the database includes measurements of deuterium (δD (‰)) and overall salt content (∆d (mg/l)) expressed as the difference in density between a distilled water taken as a standard and water sample. Are important to take into account the geology 'boundary' data (geology contacts, interfaces and limits), the deep geology and processing/filtering of geophysical data with properly algorithms. The type of filtering of gravimetric and magnetic data must be chosen based on the depth of the model we want to get. This is necessary because the values of the geophysical parameters recorded at the surface of the terrain contain weighted average information from both the surface and from different depths, even to the base of the Lithosphere. In this paper we made some geological and geophysical considerations regarding the mineral and geothermal waters from the Ramnicu Valcea - Govora area. The types of water sources targeted are mineral springs, boreholes and surface water in the area
A NEW METHOD TO GENERATE VERY LOW GAS FLOWS FOR CALIBRATION OF HYDROGEN PERMEATION MEASUREMENT. PART 1: CONCEPT AND FEASIBILITY TESTING
Authors:   ICSI Rm. Valcea, Bidica Nicolae , Ghimis Narcisa ,   ICSI Rm. Valcea
Published: April 2022

Generating of very low (and well-known) gas flows meets a wide variety of needs in industry and research (especially in vacuum science and technology), but also among consumers and society (e.g: calibrations of vacuum gauges and leak detectors, leak testing to verify the tightness of many industrial products, assurance of product reliability and performance, environmental and other safety issues, and so on). So far, many methods and devices have been developed for generating very- and ultra-low flows, generally with the goal of setting flow standards for metrology. However, most of them are very complex, so that in case of certain particular research applications, new or adapted methods and devices appear to be more suitable. Such particular case is the calibration of the measurements of hydrogen isotopes permeation fluxes, when very low flows of hydrogen and/or deuterium are injected directly into the permeation cell which is operated in very different modes. This paper presents the concept of a new method proposed to accomplish this purpose, its corresponding mathematical model of flow, as well as the experiments performed to test the feasibility of the method. Briefly, the concept is based on two leaks of constant conductance through which a so-called reference flow is generated, with two stages of pressure reduction, as well as on a variable leak valve through which well-controlled flows (and over a wide range) are generated to be injected into the permeation cell.
SYNTHESIS OF TRITIUM LABELLED THYMIDINE AND URIDINE
Authors:   National Institute for Physics and Nuclear Engineering, Magurele, Romania, Postolache Cristian , Bubueanu George ,   Horia Hulubei National Institute for Physics and Nuclear Engineering IFIN HH, Magurele, Tuta Catalin Stelian ,   Horia Hulubei National Institute for Physics and Nuclear Engineering IFIN HH, Magurele, Cucoanes Andi Sebastian ,   Horia Hulubei National Institute of Nuclear Physics and Engineering, Bucharest
Published: April 2022

This study present tritium labeling methods for uridine and thymidine in the methyl position. The synthesis of tritiated thymidine has been performed using two different methods: catalytic hydrogenation of brominated derivative and respectively of hydroxymethyl deoxiuridine. The tritiated uridine has been synthesized by catalytic hydrogenation of 5-I Uridine. The labelled compounds were purified by Thin Layer Chromatography and characterized by determination of radioactive concentration, chemical concentration and radiochemical purities. The obtained tritiated thymidine and uridine have been used for in vitro studies for evaluation of radiation effects in cell cultures.
An Approach Towards Green Technology for Sustainable Development to Reduce Pollution Risk
Authors: Pandya Jilesh M.
Published: April 2022

The concept of green technology is a new paradigm which makes the use of technology to produce products that are environmentally friendly. Green technology is concerned with clean technology, which basically provides an idea related to products that improve operational performance as well as simultaneously by making the process economically feasible, with reduced energy consumption, and no or zero waste generation. The main objective of green technology is to preserve and protect the environment. Also, it repairs the damage created to the environment in the past years from the production process of various products. Now a days, the concept of green technology has also become the immerging area that has attracted enormous amount of capital investment. This paper focuses on the usage of green technology to overcome pollution problems for sustainable development.
Responding to Youth Violence through Youth Work
Authors: Seal Mike , Harris Pete
Published: April 2022

Drawing on the findings of a two-year European research project, this book presents a new model for responding meaningfully and effectively to the 'problem' of how to respond to violence involving young people that continues to challenge youth workers and policy makers.
Sports Criminology
Authors: Groombridge Nic
Published: April 2022

This is the first
book to provide a critical criminological perspective on sport
and the connections between sport and crime. Part of the New
Horizons in Criminology series, it draws on the
inter-disciplinary nature of criminology and incorporates
emerging perspectives like social harm, gender and sexuality,
and green criminology.
Philosophical Criminology
Authors: Millie Andrew
Published: April 2022

This accessible book is structured around six philosophical ideas concerning our relations with others: values, morality, aesthetics, order, rules and respect. Using examples from a range of countries, it provides a platform for engaging with important topical issues.
Challenging the Politics of Early Intervention
Authors: Gillies Val , Edwards Rosalind , Horsley Nicola
Published: April 2022

A vital challenge to the internationally accepted policy and practice consensus that intervention to shape parenting in the early years, underpinned by interpretations of brain science, is the way to prevent disadvantage.
Reimagining the Nation
Authors: Sutherland Claire
Published: April 2022

This book develops new ways of thinking beyond the nation as a form of political community by transcending ethnonational categories of 'us' and 'them'. Drawing on scholarship and cases spanning Pacific Asia and Europe, it provides a constructive agenda for critical nationalism studies.
Grassroots Youth Work
Authors: de St Croix Tania
Published: April 2022

This engaging book paints a picture of passionate grassroots youth workers, at a time when their practice is threatened by spending cuts, target cultures and market imperatives. Using interviews, dialogue and research diary excerpts, the author brings youth work practice and theory to life.
Supporting Struggling Students on Placement
Authors: Finch Jo
Published: April 2022

This book offers practical guidance that will further knowledge and engender confidence for any teachers, assessors and supervisors on courses with a practice learning component, based on the author's first-hand experience as well as international multi-disciplinary research and literature.
Coercion and Women Co-offenders
Authors: Barlow Charlotte
Published: April 2022

This is the first book to explore coercion as a pathway into crime for co-offending women. It analyses four cases of women co-accused of a crime with their partner who suggested that coercive techniques had influenced their involvement, and concludes by exploring the implications for public understanding of coercion and female offending.
Islamophobia
Authors: Zempi Irene , Awan Imran
Published: April 2022

Islamophobia examines the online and offline experiences of hate crime against Muslims, and the impact upon victims, their families and wider communities. It includes the voices of victims themselves, which leads to strategies for future prevention.
Young People Leaving State Care in China
Authors: Shang Xiaoyuan , Fisher Karen R.
Published: April 2022

Through the perspectives of young people themselves, this book reviews changes in policy and practices that affected the generation of young people who grew up in state care in China during the last twenty years.
Who Stole the Town Hall?
Authors: Latham Peter
Published: April 2022

Arguing that the UK government intends to privatise all local services through its devolution agenda, Peter Latham proposes a new basis for federal, regional and local democracy, including land value taxation and a wealth tax.
Raising the Thermal Limits of an Electrical Motor Based on an Air Gap Winding by Applying Improved Laminated Layers and Optimized Cooling Duct Geometries
Authors:   Otto-von-Guericke-University-Magdeburg, GERMANY, Sauerhering Joerg , Boye Gunar , Beyrau Frank , Perekopskiy Sergey , Stamann Olena
Published: April 2022

Due to their electro-mechanical behaviour, electrical motors are able to generate high power densities. For a 20 kg motor based on a modified air gap winding, a mechanical load of 80kW is theoretically possible. However, the achievable power density is generally limited by the thermal loads induced by Joule heating due to the Ohmic resistances in the motor's wiring. This paper discusses the potentials of cooling channel modifications, such as the overall geometry as well as surface variations, to enhance the convective heat transfer from the solid material in the coolant with focus on motors using an air gap winding. The convective heat transfer acts as a relevant thermal resistance, which becomes critical at elevated loads, because it is lies between the wiring, acting as a heat source, and the liquid coolant, acting as heat sink. The thermal resistance of the interface material between the wiring and the stator is in the same order of magnitude as the convective heat transfer. These non-metallic materials such as foils, coatings and glues for electrical insulation and mechanical bonding are highly limited in their temperature resistance. To evaluate the behaviour of modified cooling channels and investigate novel interface materials under motor-like conditions, experimental and numerical methods are employed to determine thermo-physical properties, heat and mass transfer and finally the temperature distributions. The experimental results are discussed in comparison with numerical and analytical models and validated thereby. Because of the limited possibilities for experimental investigations within a real electrical motor, a flat test bed, based on the boundary conditions of an existing 16" wheel hub motor was developed. The Ohmic heating was realised, applying a thin sheet foil of Inconel, so that specific heat loads up to 100 kW/mK could be realised. Here, the surface temperature could be measured contact-free at a high optical resolution, using infrared thermography. The most advantageous test bed feature is the optical accessibility of cooling channels which allows the visualisation of fluid flow regimes. As results, the influence of large-scale coolant duct geometry modifications on the motor temperatures and hydraulic characteristics as well as of small-scale modifications will be presented in comparison to non-modified geometries. Also, the outcomes and capabilities of novel thermal interface materials consisting of laminated foils will be discussed and an outlook on a modified motor design to increase the thermal limits will be given.
Simulation of Gasoline Engine Equipped with Cylinder Cycle-by-Cycle Deactivation Technology under Driving Conditions
Authors:   University of Zagreb, Faculty of Mechanical Engineering and Naval Architecture, CROATIA, Sjerić Momir , Kozarac Darko , Šagi Goran , Krajnović Josip , Kurtoić Martin , Jakoplić Marijo
Published: April 2022

The cylinder deactivation on the cycle-by-cycle basis represents the advanced engine technology which enables the firing cylinders to operate close to its best thermal efficiency due to reduced pumping losses. In such engine operation, the deactivation of cylinders from cycle to cycle is made by controlling the deactivation of intake and exhaust valves on each cylinder. The change of firing density over the time defines the output engine torque. The application of this engine technology can be performed in the spark ignition and compression ignition engines enabling the reduction of fuel consumption up to 15%. In this paper the naturally aspirated 4-cylinder spark ignition engine fueled by gasoline was numerically analyzed. The 1D/0D simulation model of engine performance was made in the commercial version of cycle simulation software AVL Boost™, while the vehicle performance and driving cycles were performed separately using the external in-house code. Within the first part of study, the commercial spark ignition engine was simulated with the adoption of conventional engine load regulation (throttle position variation) over the entire operating range. In the second part, the engine performance in the same operating points was simulated where the desired part load conditions were achieved with different firing densities over the time considering the imposed stability limit in terms of engine speed variation. The results of pumping losses, specific fuel consumption and exhaust emissions achieved within both parts were analyzed and compared. In the last part of study, the analysis of driving over the standardized vehicle driving cycles was made using the engine performance maps previously defined for the conventional and advanced load controlling. The simulation results achieved with the employment of cylinder deactivation technology over the driving conditions were compared with the results achieved by the throttle angle variation. This study will quantify the effect of advanced cylinder deactivation technology on the fuel consumption and exhaust gas emissions.
Combined Cycle Gas Turbine System Optimization for Extended Range Electric Vehicles
Authors:   Lebanese American University, UNITED STATES, Mansour Charbel , Barakat Aya
Published: April 2022

Due to the continuous tightening of emissions regulations on passenger vehicles, in particular beyond 2025, vehicle manufacturers are exploring several alternative energy converters to replace the conventional internal combustion engine (ICE) in electrified powertrains, for the sake of reducing the fuel consumption to levels lower than 3 L/100 km. The purpose of this study is to investigate an alternative powertrain that is more efficient and environmentally friendly to replace the conventional ICE in an extended-range electric vehicle (EREV) with a series hybrid electric powertrain configuration. The Combined Cycle Gas Turbine (CCGT) system is investigated as an auxiliary power unit of the powertrain. This machine is more suitable for an EREV application as it offers many advantages compared to the ICE, namely a reduced number of moving parts, vibration-free operation, low maintenance cost, high durability, multi-fuel use capability and mostly a quasi-stable operation at the optimum efficiency. An exergo-technological explicit analysis is firstly conducted to assess the thermodynamic performance of the simple CCGT system using the REFPROP software. Then, based on the major sources of exergy destruction in the system, a list of CCGT configurations with several thermodynamic modifications is proposed in order to identify the most suitable CCGT topology for EREV. Energy and exergy analyses are then conducted on all proposed cycles using state-of-the-art physical parameters for the CCGT components. Then, a multi-objective Genetic Optimization Algorithm (NSGA) is used to obtain a Pareto graph for each configuration, optimizing for the overall efficiency and net specific work as function of the design parameters. The reheat gas turbine combined to a turbine reheat steam Rankine cycle system (ReGT-TReSRC) is prioritized among the studied CCGT configurations, and its optimal design parameters are identified. Results show 5% to 26% of efficiency improvement with the prioritized ReGT-TReSRC as compared to the ICE, depending on the material used in the turbine, allowing to extend the turbine inlet temperature from 950°C to 1250°C.
CFD Analysis of natural gas SI ICE Equipped with Scavenged Pre-Chamber
Authors:   Czech Technical University in Prague, CZECH REPUBLIC, Vitek Oldrich , Dolecek Vit , Syrovatka Zbynek , Vavra Jiri , Takats Michal , Mares Bohumil
Published: April 2022

The proposed paper deals with analysis of gas exchange process and combustion in a natural gas SI ICE equipped with scavenged pre-chamber. It is achieved by 3-D CFD simulation of the whole engine cycle while using LES as a turbulence model and ECFM as a combustion model to describe turbulent flame front propagation. Due to the nature of SI ICE operation and the fact that LES was applied, multiple cycles (typically 4) were calculated to consider cycle-to-cycle variations (CCV) as well. The model was verified versus experimental data for 2 different design variants of pre-chamber while considering different operating conditions for each one. After that, the model was used to test (virtually) different design variants while the main focus was put on configuration of connecting channels between pre-chamber and main combustion chamber. Sensitivity studies were carried out to evaluate the influence of different design parameters. The comparison considered both integral parameters (e.g., ROHR) and detailed 3-D CFD data (e.g., local space distribution of fuel in pre-chamber). The main conclusions are the following: • The scavenging strategy, which is based on pure fuel being flown into pre-chamber during late exhaust stroke and intake stroke, is sufficient in terms of pushing almost all burnt gases out of pre-chamber. The local equivalence ration at spark plug is within ignitable limits. • The mixture homogeneity inside pre-chamber at point spark ignition is reasonably homogeneous, however it can be improved. There are significant variations among the cycles. • There is always optimal value of different parameters: number/size of connecting channels, their space configuration, location of spark plug, etc. • Regarding the size of pre-chamber, 2 different cases were considered. The bigger one seems to be slightly better. Its particular shape is usually limited by design constraints, which leads to relatively tall design – this makes mixing in pre-chamber more problematic and may lead to strong mixture stratification.
Probabilistic design optimization of battery pack in considering the effect of external pressure with uncertainty
Authors:   Hyundai Motor Company, REPUBLIC OF KOREA, Choi Yonghwan , Seo Jeong-Hun , Lim Hae Kyu
Published: April 2022

Lithium-ion batteries have attracted wide attention as automotive applications with their advantages of high energy density and performance. The pouch type cell has been a preferred candidate based on their light weight, cost effectiveness, and design flexibility. However, due to the low mechanical stability, their characteristics are strongly influenced by environmental conditions. Especially, external pressure on cell surface directly affects the swelling phenomenon which is closely related to performance, life cycle and structural safety of the battery pack. In this paper, a novel framework for design optimization of battery pack is proposed to apply appropriate pressure on pouch cells. The effect of external pressure is investigated through cell cycling tests while thickness, pressure and capacity changes are measured. This investigation shows a recognizable correlation between pressure and cell degradation and also indicates the needs of certain pressure level which should be ensured by pack structures. The mechanical relation between cell and structural components is demonstrated in a free body diagram and utilized for deterministic analysis. To consider uncertainties in the external pressure formulation, the system is hierarchically decomposed and the uncertainty for each sub-component is analyzed. Then, the uncertainty propagation is conducted using Monte-Carlo Simulation to predict the distribution of external pressure in pack level. Based on the results, probabilistic design optimization is performed to minimize the weight of battery pack structure ensuring the external pressure range. The results of deterministic and probabilistic design optimization are compared. The deterministic analysis includes the safety factor based method and the arithmetic worst case based method. The probabilistic analysis is formulated for ensuring the minimum required pressure with the confidence level of 99.7%. After the pressure distribution analysis, the design of module and pack structure is modified to generate the appropriate pressure on the cell surface. The improved module and pack designs are verified by numerical simulations and tests. By adopting the probabilistic design optimization, it is expected that the life cycle reliability and the performance of battery pack can be improved. In addition, more than 17% of weight reduction can be achieved compared to conventional deterministic based design optimization. A novel framework for probabilistic design optimization of battery pack is proposed in considering the effect of external pressure on pouch cell. Various uncertainty factors in formulating external pressure are analyzed by using probabilistic method and compared with the deterministic method. This proposed design technique can be utilized for developing compatible automotive battery packs and improving reliability under uncertainty.
Application of PM Gearset in Automotive Gearbox
Authors:   CTU in Prague, CZECH REPUBLIC, Miláček Ondřej , Achtenová Gabriela
Published: April 2022

In case of automotive mass production is obvious in all production branches. This is true also for drivetrain, gearboxes and gearwheels. Almost all gearings have an involute profile. This is given by very effective manufacturing process. Tooth flank profile is already very precisely fine-tuned. So the way to cost reduction is no more in gearwheel geometry but in the gearwheel's material and its resistance against pitting. From this reason we tried to replace standard gearset made of case hardened steel by a new one - made by PM technology. Manufactured PM gearwheels were tested in original automotive gearbox to assure same loading conditions (shaft deflection, lubrication, housing deformation, etc.) as in the car. In our laboratory at the university there is a special back-to-back test rig. Standardly at these back-to-back test rigs only the gearset is tested. At our test rig the gearbox is placed in the same way as in the car - fastened by screws to engine cast and this whole assembly is than placed to the test rig frame using original rubber mounts. The circuit is then completed by joint shafts. To be able to set some loading torque in the circuit differencials at both gearboxes have to be disabled. Results of these tests are presented in this contribution. The target is to produce rough gearwheel profile by pressing from the powder metal and sintering to avoid expensive milling and turning operations. Of course this operation cannot include tooth flank modifications (e.g. crowning). Of course we are not able to make rough shape of helical gearset by pressing operation because appropriate tooling would be too expensive. From this reason we have decided to make few gear sets by gearing milling from pressed and sintered PM pucks with appropriate dimensions. The technology of "Hot Isostatic Pressure" to densify the flank surface was used. At this project we cooperate with Swedish company Höganäs AB, which is the owner of PM parts technology.
Modular Hybrid Powertrain Concept
Authors:   MAHLE Powertrain Limited, UNITED KINGDOM, Bassett Michael , Reynolds Ian , Cooper Adrian , Reader Simon , Berger Martin
Published: April 2022

Vehicle manufacturers are facing increasing pressure by legislation and economics to reduce vehicle emissions and deliver improved fuel economy. Over the coming years, significant reductions in carbon dioxide (CO2) emissions need to be achieved to meet fleet targets, whilst at the same time satisfying the more stringent forthcoming Euro7 emissions regulations. This focus on techniques to reduce the tailpipe CO2 is increasing the interest in hybrid and electric vehicle technologies. Pure electric vehicles require bulky and expensive battery packs, with a high embedded CO2 content, to enable an acceptable driving range. Range Extended Electric Vehicles (REEVs) partly overcome the limitations of current battery technology by having a range extender (REx) unit that allows a reduction of the traction battery storage capacity, whilst still maintaining an acceptable vehicle driving range. Building on previous research projects, focused on Rex and heavily downsized internal combustion engines, MAHLE have designed a plug-in hybrid driveline in which the systems have been fully integrated and optimised. The hybrid drive-line features a cost effective and high-efficiency, Miller-cycle, turbocharged, two-cylinder gasoline engine, with external exhaust gas re-circulation (EGR) and a pre-chamber combustion system, achieving over 40% brake thermal efficiency from a very low-cost architecture. This compact engine is combined with an electric traction system which can satisfy the full-dynamic requirements of the vehicle, even during pure-electric operation. The internal combustion engine can be operated in either series hybrid, or direct drive modes, via a compact multi-speed transmission. The paper will present the key features of the hybrid drivetrain and will describe the various modes of operation in the vehicle. Results of testing to validate the pre-chamber combustion system, coupled with a very high geometric compression ratio (CR) and external cooled EGR, will also be presented to support the efficiency claims made in the paper. Drive-cycle analysis, based on the engine test results, will also be used to show the efficiency of the entire system. Finally, the paper will present the scalability of the concept across a range of vehicle classes and performance levels.
Design and optimization of brake disc using Multi-Objective genetic algorithm
Authors:   Additive Manufacturing Institute of Science and Technology, University of Louisville, UNITED STATES, Kumar Swapnil ,   University of Louisville, UNITED STATES, Atre Sundar V
Published: April 2022

Analysis of brake disc is carried out to depict the nature of Braking behavior with respect to bump, Analysis of brake disc is carried out to depict the behavior of the braking system with respect to bump, droop in endurance, maneuverability, hill Climb & acceleration. Design calculation and analysis have been carried out for the brake disc and subsequently, design calculations have also been carried out for the brake caliper. Structural, thermal, vibrational, computational fluid dynamics and fatigue analysis has been carried out to optimize and validate the performance of disc brakes. The design of experiments has been carried out for the brake disc in order to optimize the performance of the braking system. Ventilated disc brake with an outer diameter of 175 mm has been used and 83 % performance efficiency is achieved after all the proper validations and analysis. Very fine Meshing has been considered for analyzing the disc brake to obtain maximum efficient results. Stainless Steel (SS-410) Material configuration has been considered for disc brake and performance enhancement of ventilated disc brake is carried out using Matlab, Ansys, and Solidworks. The brake disc is going to be deployed as a common brake disc in the rear part of the ATV responsible for providing effective rear wheel locking. Piaggio double piston fixed calipers have satisfied the piston diameter for wheel locking conditions at rear wheels with DOT-4 Brake fluid in the master cylinder to provide effective braking. The rear disc brake was fixed on the gearbox output shaft and a caliper mount is welded on a rear member of the roll cage. A mathematical model has been generated for carrying out Multi-objective genetic algorithm optimization. The newly designed brake disc is optimum in terms of weight, a factor of safety, thermal dissipation, equivalent stress, vibration with enhanced airflow behavior. Converged residual plots have been obtained in computational fluid dynamics simulation by using 2nd-degree order. In order to meet the frequency of rear disc brake to firing frequency of engine, brake disc has been optimized in terms of vibration considering all the parameters.
A New Engine Concept to Control the Ignition Timing of HCCI Combustion: Piston Assisted Compression Ignition (PACI)
Authors:   Ghent University, BELGIUM, Sileghem Louis
Published: April 2022

HCCI engines have long been seen as the holy grail of internal combustion engines. These engines would combine a very high efficiency with ultra-low emissions. The bottleneck of HCCI engines is the lack of control over the ignition timing of the homogeneous air-fuel mixture. In this paper, a new engine concept is presented to solve this problem. In this new concept, next to the main compression of the engine, a secondary piston is provided in the combustion chamber to give an additional compression for a short duration close to the top dead center of the main piston. As a result, this new internal combustion engine concept is called "Piston Assisted Compression Ignition" or "PACI". This secondary piston provides the additional compression that is needed to ignite the air-fuel mixture at the right timing during the engine cycle for a range of different loads and different inlet temperatures. In the same way as the combustion is initiated by a spark in a spark ignition engine, this concept tries to initiate and control the combustion in a compression ignition engine by an additional mechanical compression near the top dead center. First, insights are given about the possibilities of this new engine concept and secondly, calculations of the ignition timings for a load range at different inlet temperatures are presented. The ignition timings are compared with the ignition timings that would be possible without the secondary piston. Calculations with methanol (single-stage autoignition) and PRF95 (two-stage autoignition) have shown the potential of this concept to better control the autoignition timings for a load and temperature range for both these fuels compared to the usual HCCI concept with a single compression stroke. To conclude, this research shows the potential of a radical new engine concept that could be an interesting way to solve the control problem of HCCI engines if possible mechanical challenges of this concept can be overcome.
Battery Cooling Structural Analysis Using Experimental Modal Method
Authors:   Honda R&D Japan, JAPAN, Minami Katsuya ,   ESTECH CORP., JAPAN, Ebihara Hiromichi
Published: April 2022

Lithium-ion batteries for battery electric vehicles need to be precisely thermo-controlled for maintaining the vehicle performance under strictly hot and cold environments and for preventing the battery aging. In general, battery modules mounted in a battery pack are cooled or warmed up via coolant liquid and the battery cooling structure consisting of a battery module, a cooling plate, thermal interfaces and mounting parts are required to have two major functionalities, sufficient heat transfer performance between the battery module and the cooling plate and the strength reliability of the composed parts against external loads in strict driving scenarios. A new structural analysis methodology was established to predict the vibrational behavior of the battery cooling structure under rough road condition. This analysis, which is a combination of measurements and simulations, consists of three steps, experimental modal analysis, finite element model correlation and transient response simulation. The resonance frequencies and the frequency response functions were measured with the cooling structure components under disassembled and assembled states. Additionally, the viscoelastic characteristics of thermal pads located between the battery module and the cooling plate were empirically acquired. The cooling structure modeled with finite element method was validated in comparison with the measured results. Then, the transient response behavior under vibrational input during driving was predicted using the validated models. This paper described developed analysis methodology and the results using the battery pack of the battery electric vehicle released in 2020. As the result, the simulated transient behavior of the battery cooling plate had good correlation to the vibration test results using the battery pack. Moreover, the contact state of heat transfer area between the battery module and the cooling plate under rough road driving condition was predicted through the developed simulation. It was demonstrated that developed analysis and series of work flow had enough accuracy to predict the vibrational behavior of the battery cooling structure and contribute to the structural design and the validation.