bluuebunny/crossref_metadata_2025 huggingface dataset:
Color image steganalysis based on quaternion discrete cosine transform
Authors: Xu Meng , Luo Xiangyang , Wang Jinwei , Wang Hao
Published: May 2023

With the rapid development and application of Internet technology in recent years, the issue of information security has received more and more attention. Digital steganography is used as a means of secure communication to hide information by modifying the carrier. However, steganography can also be used for illegal acts, so it is of great significance to study steganalysis techniques. The steganalysis technology can be used to solve the illegal steganography problem of computer vision and engineering applications technology. Most of the images in the Internet are color images, and steganalysis for color images is a very critical problem in the field of steganalysis at this stage. Currently proposed algorithms for steganalysis of color images mainly rely on the manual design of steganographic features, and the steganographic features do not fully consider the internal connection between the three channels of color images. In recent years, advanced steganography techniques for color images have been proposed, which brings more serious challenges to color image steganalysis. Quaternions are a good tool to represent color images, and the transformation of quaternions can fully exploit the correlation among color image channels. In this paper, we propose a color image steganalysis algorithm based on quaternion discrete cosine transform, firstly, the image is represented by quaternion, then the quaternion discrete cosine transform is applied to it, and the coefficients obtained from the transformation are extracted to design features of the coeval matrix. The experimental results show that the proposed algorithm works better than the typical color image steganalysis algorithm.
Linear barycentric rational collocation method for solving a class of generalized Boussinesq equations
Authors: Li Zongcheng , Li Jin
Published: May 2023

This paper is concerned with solving a class of generalized Boussinesq shallow-water wave (GBSWW) equations by the linear barycentric rational collocation method (LBRCM), which are nonlinear partial differential equations (PDEs). By using the method of direct linearization, those nonlinear PDEs are transformed into linear PDEs which can be easily solved, and the corresponding differentiation matrix equations of their discretization linear GBSWW equations are also given by a Kronecker product. Based on the error estimate of a barycentric interpolation, the rates of convergence for numerical solutions of GBSWW equations are obtained. Finally, three examples are presented to show theoretical results.
Global regularity and blowup for a class of non-Newtonian polytropic variation-inequality problem from investment-consumption problems
Authors: Li Zhi Guang
Published: May 2023

This paper studies variation-inequality problems with fourth order non-Newtonian polytropic operators. First, the test function of the weak solution is constructed by using the difference operator. Then global regularity of the weak solution is obtained by some difference transformation and inequality amplification techniques. The weak solution is transformed into a differential inequality of the energy function. It is proved that the weak solution will blow up in finite time. Then, the upper bound and the blowup rate estimate of the blow up are given by handling some differential inequalities.
Audio-visual multi-modality driven hybrid feature learning model for crowd analysis and classification
Authors: Swathi H. Y. , Shivakumar G.
Published: May 2023

The high pace emergence in advanced software systems, low-cost hardware and decentralized cloud computing technologies have broadened the horizon for vision-based surveillance, monitoring and control. However, complex and inferior feature learning over visual artefacts or video streams, especially under extreme conditions confine majority of the at-hand vision-based crowd analysis and classification systems. Retrieving event-sensitive or crowd-type sensitive spatio-temporal features for the different crowd types under extreme conditions is a highly complex task. Consequently, it results in lower accuracy and hence low reliability that confines existing methods for real-time crowd analysis. Despite numerous efforts in vision-based approaches, the lack of acoustic cues often creates ambiguity in crowd classification. On the other hand, the strategic amalgamation of audio-visual features can enable accurate and reliable crowd analysis and classification. Considering it as motivation, in this research a novel audio-visual multi-modality driven hybrid feature learning model is developed for crowd analysis and classification. In this work, a hybrid feature extraction model was applied to extract deep spatio-temporal features by using Gray-Level Co-occurrence Metrics (GLCM) and AlexNet transferrable learning model. Once extracting the different GLCM features and AlexNet deep features, horizontal concatenation was done to fuse the different feature sets. Similarly, for acoustic feature extraction, the audio samples (from the input video) were processed for static (fixed size) sampling, pre-emphasis, block framing and Hann windowing, followed by acoustic feature extraction like GTCC, GTCC-Delta, GTCC-Delta-Delta, MFCC, Spectral Entropy, Spectral Flux, Spectral Slope and Harmonics to Noise Ratio (HNR). Finally, the extracted audio-visual features were fused to yield a composite multi-modal feature set, which is processed for classification using the random forest ensemble classifier. The multi-class classification yields a crowd-classification accurac12529y of (98.26%), precision (98.89%), sensitivity (94.82%), specificity (95.57%), and F-Measure of 98.84%. The robustness of the proposed multi-modality-based crowd analysis model confirms its suitability towards real-world crowd detection and classification tasks.
4q interstitial and terminal deletion: clinical features comparison in two unrelated children
Authors: Pavone Piero , Pappalardo Xena Giada , Lubrano Riccardo , Savasta Salvatore , Verrotti Alberto , Parisi Pasquale , Falsaperla Raffaele
Published: May 2023

The 4q deletion syndrome defines a disorder, which may involve patients affected by either the deletion of the interstitial region from the centromere to 4q31 or by the deletion of the terminal region from 4q31 to 4qter. Here, we describe clinical phenotypes of two unrelated children of the same age followed at the same time, with case 1 presenting with 4q interstitial and case 2 with terminal 4q deletion, and compare them each other and with those reported in the literature. Both children showed complex, heterogeneous clinical manifestations, including craniofacial features, pre-postnatal growth failure, speech and developmental delay. In case 2, thyroid and cholesterol dysfunction were also found. Analyzing these data, clinical differences between interstitial and terminal 4q deletions are scanty and no significant phenotype differences were found between the 4q regions deleted as observed in the comparison of the two children and the related cases of the literature. The term 4q deletion syndrome - inclusive for both the interstitial and terminal 4q regions deleted - seems to be appropriate. To note, the dysfunction of cholesterol metabolism and thyroid presented by case 2 may be clinically worthwhile, whether confirmed by other observations.
Dans les coulisses d’une « ZEP », par-delà les discours : le cas du Haut-du-Lièvre (Nancy) de 1982 à 2002
Authors: Riondet Xavier
Published: May 2023

En abordant le cas du quartier du Haut-du-Lièvre à Nancy et de la zone d’éducation prioritaire (ZEP) la plus emblématique du département de Meurthe-et-Moselle entre 1982 et 2002, cette étude s’intéresse, d’une part, au fonctionnement réel de la ZEP et à l’articulation locale de la politique d’éducation prioritaire avec la politique de la ville, et, d’autre part, aux discours médiatico-politiques portant sur ce contexte. Cette étude décrit la mise en place, au niveau local, d’une politique nationale comme celle de l’éducation prioritaire et contribue, par le détour des questions de politiques éducatives, à une meilleure connaissance de l’histoire sociale et politique de ce territoire et de l’agglomération nancéienne. Ce type de travail permet de rendre compte de l’écart entre les lectures politiciennes « révisionnistes » du passé et les interprétations à l’œuvre dans les nombreuses productions de données conservées dans les archives de l’éducation prioritaire.
Evaluation of Crystal Quality and Dopant Activation of Smart CutTM - Transferred 4H-SiC Thin Film
Authors: Gelineau Guillaume , Widiez Julie , Rolland Emmanuel , Vladimirova Krenema , Moulin Alexandre , Prudkovskiy Vladimir S. , Troutot Nicolas , Gergaud Patrice , Mariolle Denis , Barbet Sophie , Amalbert Vincent , Lapertot Gérard , Mony Karine , Rouchier Séverin , Boulet Romain , Berre Guillaume , Schwarzenbach Walter , Bogumilowicz Yann
Published: May 2023

The Smart CutTM process offers an advantageous opportunity to provide a large number of performance-improved SiC substrates for power electronics. The crystalline quality and the electrical activation of the 4H-SiC transferred layer are then at stake when it comes to the power device reliability. In this study, we find that the H+ ion implantation used for the Smart CutTM process leads to electrical deactivation of dopants and partially disorders the material. The transferred layer fully recovers its initial crystalline quality after a 1300°C anneal, with no further evolution beyond this temperature. At this point however, the n-type dopants are still inactive. The dopant reactivation occurs in the same temperature range than that of implanted nitrogen: between 1400°C and 1700°C. After 1700°C, the initial doping level of bulk SiC is recovered.
Dry Mix for Facade Self-Cleaning Silicate Paint
Authors: Yakovlev Grigory Ivanovich , Saidova Zarina , Ginchitskaia Iuliia , Kuzmina Natalia , Trofimova Diana , Buryanov Аleksandr F. , Elrefaei Ali E.M.M.
Published: May 2023

This paper presents the results of a study on one-component dry mix used for the preparation of silicate-based facade paint with self-cleaning properties. The advantages of the developed composition include the ease of the mix preparation and application, increased adhesion of the coating to the base, and improved aesthetic qualities of the coating provided by its ability to self-clean due to the addition of nanotitanium dioxide, which enhances photocatalysis. In the course of the research work, the optimal quantitative content of the main components and functional additives was established. Studies of the facade paint microstructure were carried out. Infrared spectral and differential thermal analysis of the composition confirmed the significant weather resistance of the facade paint, which is ensured by deep carbonization of the constituent components with their transformation into calcium carbonates, characterized by increased water resistance and chemical stability. Key words: facade coating, silicate paint, self-cleaning, photocatalysis, microstructure
Properties of Cement-Based Composites Modified with Metal/Carbon Nanocomposite
Authors: Semyonova Svetlana N. , Yakovlev Grigory Ivanovich , Polyanskikh Irina Sergeevna , Buryanov Аleksandr F. , Shaybadullina Arina Valentinovna
Published: May 2023

The objective of this research is to study and analyse the properties of a cement-based composite modified with nickel/carbon nanocomposite (Ni/C NC). According to previous studies carried out by scientists in the field of nanostructures, it was assumed that metal/carbon nanostructures can increase the strength and impart electrically conductive properties to composite materials [9,12]. To confirm this hypothesis, in this research, mechanical strength tests and measurements of the electrical resistance of the modified samples were carried out. It was found that the addition of nickel/carbon nanocomposite in the amount of 0.05% increases the compressive strength of silicate composites by 35%. Moreover, by measuring the electrical conductivity of the samples, it was established that with the introduction of additives in the amount of 0.01-0.05% in relation to Portland cement, the resistance decreases by 80-84%. Further, the structural effect of Ni/C NC on the cement matrix was studied by the methods of IR spectral, differential thermal analyses, X-ray microanalysis. As a result of the analysis, it was revealed that the dispersions are crystallization centers during cement hydration and create chemical bonds with silicon oxide in the composition of the silicate composite. Ni/C NC has a structuring effect on the silicate binder matrix through the formation of a denser packing, which affects the mechanical properties and electrical conductivity of the material. The results of the study can be used to obtain electrically conductive materials with desired properties that can perform the functions of heating, monitoring the state of structures during operation, and protecting against an electromagnetic pulse.
Characterization of Prismatic Slip in SiC Crystals by Chemical Etching Method
Authors: Hu Shanshan , Fang Shuai , Liu Yafei , Cheng Qian Yu , Peng Hong Yu , Chen Ze Yu , Gao Yu Han , Gao Chao , Raghothamachar Balaji , Dudley Michael
Published: May 2023

In 4H-silicon carbide crystals, basal plane slip is the predominant deformation mechanism. However, prismatic slip is often observed in single crystals grown by the physical vapor transport method as the diameter expands to 6 inches or larger. Thermal modeling has shown that occurrence of prismatic slip is attributed to increased radial thermal gradients. While X-ray topography can be used to characterize the presence and extent of prismatic slip, the feasibility of using the chemical etching method to assess the extent of prismatic slip in an industrial setting is investigated. The distribution of scallop shaped etch pits oriented along the directions that correspond to prismatic dislocations, correlate well with the results of the thermal model that predicts the occurrence of prismatic slip dislocations. This capability of the etch pit method to characterize prismatic slip can be used to manage radial thermal gradients during PVT growth.
The Effect of Heat Treatment on Wear Properties of Ni-B-CNT Electroless Coating with Different Carbon Nanotube Concentration on AISI 4340 Steel
Authors: Wais Alaa Mohammed Hussein , Abid Ali Abdul Raheem
Published: May 2023

Study wear resistance for heat treatment of Ni-B-CNT electroless coatings. Different concentrations for CNT (0 ,0.35 and 0.7 g/l Ni-B-CNT composite coatings deposition on 4340 steel. After the procedure of coating, all samples were heat treatment. The test wear of a coating was valued with pin on disk technique. Preparation of Ni–B–CNT electroless coatings are with using nickel chloride in alkaline bath, borohydride and Multi walled carbon nanotubes. characterization with FESEM, micro hardness, XRD and surface roughness. Study for surfaces of worn with EDS and FESEM. Micro hardness results are show that the larger hardness1010 HV is gained by heat treatment for coating (Ni-B- 0.35 g/L CNT) because of concentration CNT caused structure conversion for coating Ni-B from amorphous to crystalline. Also, CNT prevent maximum heat production and decrease of the friction coefficient during test wear. CNT aggregation was noted result the presence for more particles (Ni-B - 0.7g/l CNT) that occur create roughness and also lead to increase in rate of wear because of big particles with weakly joined in matrix of Ni.
Evaluation of Hysteresis Response in Achiral Edges of Graphene Nanoribbons on Semi-Insulating SiC
Authors: Mathew Sobin , Abedin Saadman , Kurtash Vladislav , Lebedev Sergey P. , Lebedev Alexander A. , Hähnlein Bernd , Stauffenberg Jaqueline , Jacobs Heiko O. , Pezoldt Jörg
Published: May 2023

Hysteresis response of epitaxially grown graphene nanoribbons devices on semi-insulating 4H-SiC in the armchair and zigzag directions is evaluated and studied. The influence of the orientation of fabrication and dimensions of graphene nanoribbons on the hysteresis effect reveals the metallic and semiconducting nature graphene nanoribbons. The hysteresis response of armchair based graphene nanoribbon side gate and top gated devices implies the influence of gate field electric strength and the contribution of surface traps, adsorbents, and initial defects on graphene as the primary sources of hysteresis. Additionally, passivation with AlOx and top gate modulation decreased the hysteresis and improved the current-voltage characteristics.
Quantification of Secondary Electron Doping Contrast in the Scanning Electron Microscope on 4H-SiC
Authors: Moser Maximilian , Pobegen Gregor , Smoliner Jürgen
Published: May 2023

We discuss the quantification of the secondary electron doping contrast in the scanningelectron microscope on 4H-SiC. It has been observed and studied at length mostly on silicon, but noconclusive theoretical model has been proposed yet. Therefore, we propose a simple physical modelthat allows for a quantification of the doping contrast. It is based on the changes in effective ionizationenergy for different doping concentrations and types. For a better agreement between our model andthe experiment, a locally increased temperature of the electron system or separate quasi Fermi levelsfor electrons and holes have to be assumed. A line profile of the sample under investigation is comparedwith a SRIM simulation of the corresponding implant and shows very good agreement.
PL Signatures from Decoration of Dislocations in SiC Substrates and Epitaxial Wafers
Authors: Chung Gil , Lee Charles , Soukhojak Andrey , Rana Tawhid
Published: May 2023

Photoluminescence (PL) signatures of 4H-SiC bare and epitaxial wafers from a surface inspection tool have been studied. Large variations in PL black or white dot densities were confirmed for comparable crystal quality and growth process conditions. Comparison with KOH etching results confirms that both PL black and white dots are tied to discrete threading dislocations. PL spectra results suggest dislocation decoration by donor-acceptor pairs.
Temperature Dependent Electrical Properties of N-Type 4H-SiC Substrates
Authors: Lichtenwalner Daniel J. , Park Jae Hyung , Rogers Steven , Dixit Hemant , Scholtze Andreas , Bubel Simon , Ryu Sei Hyung
Published: May 2023

High-quality, low resistivity n-type (nitrogen-doped) single crystal 4H-SiC wafers are needed to grow high-quality epitaxial SiC layers used for the active blocking layers of high-voltage power devices. The resistance of the substrate constitutes a portion of the device resistance for vertical devices, and therefore the SiC substrate properties must be fully characterized. In this study we report the 4H-SiC substrate electrical properties as a function of temperature measured using van der Pauw structures to measure resistivity from 4-point measurements, and carrier concentration and mobility from Hall effect measurements. We find that the SiC substrate resistivity has a minimum around 425K for typical substrate doping levels, due to a competition between the decreasing mobility and increasing carrier concentration with increasing temperature. The measured energy levels of the N donor (hexagonal / cubic sites) are extracted for a 5.8×1018 cm-3 N-doped substrate, and found to be 15 meV and 105 meV, respectively.
Systematic Review and Meta-Analysis on Global Prevalence of Tooth Fracture amongst Visually Impaired Individuals
Authors: Dash Kabir Suman , Mathur Anmol , Hegde-Shetiya Sahana , Kale Sonal
Published: May 2023

Traumatic dental injuries (TDIs) are a significant concern affecting oral health status, and visually impaired people are more prone to these injuries than their counterparts. This systematic review aimed to determine the overall prevalence of TDIs across the globe. A systematic search was conducted in electronic databases for the studies from inception till 31 December 2021. Cross-reference of the selected manuscripts was also searched and handsearching was done for the studies whose full text was not available through the electronic search. Grey literature was also searched for the studies according to the relevance of this review. Studies published in the English language were able to be translated into the English Language. For the meta-analysis, studies reporting the prevalence of tooth fractures were included. Studies were assessed for quality with the help of the Joanna Briggs Institute critical appraisal tool for studies reporting prevalence data, and the studies were categorised into high/medium/low quality. The random effects model was used for performing a meta-analysis of dental trauma prevalence as the heterogeneity between the studies was high. The search strategy yielded 167 manuscripts after screening through titles and abstracts, full text and removing duplicates. In the end, 27 manuscripts were included in a systematic review and meta-analysis according to the pre-set eligibility criteria. Through meta-analysis, the pooled prevalence for all studies shows an overall prevalence of tooth fractures to be 31.55%. The present review has emphasised the prevalence of dental trauma amongst visually impaired individuals. Sighting the high prevalence of dental trauma amongst this subgroup of the population, there is an urgent need for both comprehensive and incremental dental care for this subgroup of the population. Hence, oral health education should be provided to visually impaired people, parents and caretakers regarding the prevention and availability of treatment for tooth fractures.
Left Atrial Appendage Closure Device Embolization under the Anterior Leaflet of Mitral Valve: Echocardiographic Diagnosis and Management
Authors: Ceresa Fabrizio , Leonardi Aurora , De Donno Filomena Bruna , Palermo Auguto , Mammana Liborio Francesco , Patanè Francesco
Published: May 2023

A 76-year-old man with history of previous coronary artery bypass grafting, permanent atrial fibrillation in novel oral anticoagulation therapy, and gastrointestinal bleedings underwent percutaneous left atrial appendage closure. The procedure was complicated by intraoperative device embolization, which caused a dynamic obstruction of the left ventricular outflow tract leading to severe hemodynamic instability. Transesophageal echocardiography showed a device in the ventricle site of the mitral anterior leaflet. The coronary angiography showed also patency of both arterial grafts in stable coronary artery disease. After failing the percutaneous retrieval with a snare, emergent surgery was planned. A moderate calcified aortic valve stenosis was also found, but in consideration of the unstable clinical conditions of the patient, we thought of performing a transcatheter aortic valve replacement (TAVR) in a second time. We have carefully planned the surgical retrieval of the device embolized paying attention of his several comorbidities. The strategy to remove the device with cardiopulmonary bypass without cross-clamping the aorta through a right mini-thoracotomy has been preferred.
Expanding the Role of SGLT2 Inhibitors Beyond Diabetes: A Case-Based Approach
Authors: Wong Elaine , Nguyen Timothy V.
Published: May 2023

Sodium glucose co-transporter-2 (SGLT2) inhibitors have been of substantial interest to clinicians, initially in connection to diabetes management. Beyond its expected antihyperglycemic effects, this drug class is associated with properties such as promoting diuresis, improving cardiac
remodeling, and decreasing albuminuria. Considering these beneficial outcomes, the potential roles for SGLT2 inhibitors have evolved to include other therapeutic areas. This review uses a case-based approach to showcase the expanded indications of SGLT2 inhibitors in the setting of heart failure
and chronic kidney disease for patients without diabetes.
Equivalence of Besov spaces on p.c.f. self-similar sets
Authors: Cao Shiping , Qiu Hua
Published: May 2023

On post-critically finite self-similar sets, whose walk dimensions of diffusions are in general larger than 2, we find a sharp region where two classes of Besov spaces, the heat Besov spaces
$B^{p,q}_\sigma (K)$
and the Lipschitz–Besov spaces
$\Lambda ^{p,q}_\sigma (K)$
, are identical. In particular, we provide concrete examples that
$B^{p,q}_\sigma (K)=\Lambda ^{p,q}_\sigma (K)$
with
$\sigma>1$
. Our method is purely analytical, and does not involve heat kernel estimate.
The first-order theory of binary overlap-free words is decidable
Authors: Schaeffer Luke , Shallit Jeffrey
Published: May 2023

We show that the first-order logical theory of the binary overlap-free words (and, more generally, the
$\alpha $
-free words for rational
$\alpha $
,
$2 < \alpha \leq 7/3$
), is decidable. As a consequence, many results previously obtained about this class through tedious case-based proofs can now be proved “automatically,” using a decision procedure, and new claims can be proved or disproved simply by restating them as logical formulas.
Molecular Phylogenetic Analysis of Nemoura flexuosa Aubert, 1949 Based on Cytochrome Oxidase C Subunit-I Gene from Türkiye
Authors: Yusufoglu Famil , Uckan Fevzi
Published: May 2023

Plecoptera species are valuable both as freshwater indicators and as key role in the food chain of river ecosystems. Moreover, they constitute an order with a high speciation capacity. Therefore, identification at the species level by morphological analysis leads to reliability problems. Studies on the phylogeny of Nemoura flexuosa which belongs to this order are scarce in the literature. Samples were collected from Kocaeli-Türkiye and then morphological and phylogenetic descriptions of the specimens were made. The Cytochrome Oxidase C Subunit-I gene region in mitochondrial DNA was amplified and sequenced. Molecular analyses revealed that the samples belong to the N. flexuosa species. Phylogenetic analyses were carried out by comparing the gene sequences of N. flexuosa haplotypes in Europe with gene sequences of the same basepair length and with the gene sequence of Amphinemura borealis which was used as an outgroup. The two phylogenetic trees were consistent and the collected specimens were evolutionarily closer to the OK316196.1, OK316261.1, OK316397.1, MZ608304.1, KY261370.1 and JX905853.1 haplotype. The presence of N. flexuosa in Kocaeli and the phylogenetic status of the Türkiye haplotype were reported. Clarifying the phylogenetic status of ecologically important species provides basic information for biosecurity studies for possible future conservation and control programs.
Research on Seat Static Comfort Evaluation Based on Objective
Interface Pressure
Authors: Zhang Tianming , Ren Jindong
Published: May 2023

The interface pressure distribution is an important indicator for evaluating the
static comfort of the seat. At present, the interface pressure of a real person
is acquired through testing and used in assessing the seat comfort, which has
poor consistency and accuracy, and it is difficult to combine the test results
of different persons to make an objective evaluation. The idea is presented to
evaluate the seat static comfort by the objective interface pressure. The
H-point machine (HPM) is the standard loading device which can be used to
acquire the objective interface pressure. The test criterion was made, and the
measurement consistency of the standard loading device passed the experimental
verification. As a case study, five seats were selected to obtain the subjective
rating of static comfort and the objective interface pressure data. Based on
these data, the evaluation model of seat static comfort was established. The
above standard loading device, the objective interface pressure test criteria,
and the seat static comfort evaluation model form a comprehensive system for
assessing seat static comfort. By using the system in evaluating and optimizing
the studied seat and by the afterward validation, the method of evaluating the
seat static comfort by the objective interface pressure illustrated reliable and
accurate performance, which is easy to use and showed the good value of
engineering application.
Thin-Wire Thermocouple Design for Exhaust Gas Temperature Pulse
Measurements in Internal Combustion Engines
Authors: Venkataraman Varun , Stenlåås Ola , Cronhjort Andreas
Published: May 2023

Accurate exhaust gas temperature (EGT) measurements are vital in the design and
development process of internal combustion engines (ICEs). The unsteady ICE
exhaust flow and thermal inertia of commonly used sheathed thermocouples and
resistance thermometers require high bandwidth EGT pulse measurements for
accurate cycle-resolved and mean EGTs. The EGT pulse measurement challenge is
typically addressed using exposed thin-wire resistance thermometers or
thermocouples. The sensor robustness to response tradeoff limits ICE tests to
short durations over a few exhaust conditions. Larger diameter multiwire
thermocouples using response compensation potentially overcomes the tradeoff.
However, the literature commonly adopts weaker slack wire designs despite
indications of coated weld taut wires being robust. This study experimentally
evaluates the thin-wire thermocouple design placed in the exhaust of a
heavy-duty diesel engine over wide-ranging exhaust conditions for improving both
sensor robustness and accuracy of the measured EGT. The assessed design
parameters included the wire diameter (51 μm to 254 μm), the exposed wire
length, and the wires placed slack or taut with coated weld faces. All taut
wires with ceramic-coated weld faces endured over 3 h of engine operation, while
similar diameter slack wires (51 μm and 76 μm) were sensitive to the exhaust
condition and exposed wire length. Reducing the wire diameter from 76 μm to 51
μm significantly impacted response improvements as evidenced at certain test
conditions by a peak-peak EGT increase of 92 °C, a mean EGT drop of 26 °C, and a
doubling of the sensitivity of mean EGT cycle-to-cycle variations to ±12 °C.
Increasing the exposed wire length showed less significant response
improvements. The Type-K thin-wire thermocouples showed negligible drift,
thereby indicating the possibility of using smaller and longer wires built taut
with coated weld faces for improved accuracy of EGT measurements in ICEs.
Numerical Analysis of Armored Fighting Vehicle Escape Hatch Subjected
to Mine Blast Loading Using Coupled Eulerian-Lagrangian
Technique
Authors: Parthasarathy Sundaresan , Kumar J. Rajesh
Published: May 2023

This article describes the research work taken to compare the effect of air blast
and surface-buried mine blast loading on an armored fighting vehicle (AFV)
escape hatch, using the coupled Eulerian-Lagrangian (CEL) technique. Two types
of escape hatch were considered for the study, namely, the flat plate version
and double-side curved-plate version. To evaluate the research methodology used
in this investigation, initially, a published experimental work on a circular
plate subjected to air blast was chosen and a benchmark simulation was carried
out using the CEL technique to establish the simulation procedure. Then the
established procedure was utilized for further analysis. It was observed that
the variation in the deformation between the published literature and the
simulation work was well within the acceptable engineering limits. After that,
numerical studies were conducted on the flat and double-side curved hatch by
subjecting it to both air blast and surface-buried mine blast loading using the
previously established CEL technique. The results of the peak central deflection
of the hatch and the transmitted impulse to the base structure were compared for
each type of loading case. It was systematically established that the
double-side curved hatch gives better protection to the crew against both air
blast loading and surface-buried mine blast loading situations.
Optimization of Operating Parameters of the Asphalt-Paver
Vibration-Screed System in Improving Compaction Efficiency and Pavement Quality
for Driving Vehicle Performance
Authors: Xiu Yun , Li Anding , Nguyen Vanliem , Mei Yundong , Li Qian , Li Jianwei
Published: May 2023

The operating parameters of the asphalt-paver vibration-screed system (AP-VSS)
including the excitation frequencies of the tampers and vibratory screed
(ft
 and fs
) and the angular deviations of the tampers (α
1 and α
2) affect not only the pavement quality but also compaction
efficiency. Based on the dynamic model of the AP-VSS and the interaction model
of the tamper and hot-mixed asphalt, the experimental and numerical simulation
studies of AP-VSS are performed to analyze in detail the influence of operating
parameters of the AP-VSS on AP-VSS pavement quality and compaction efficiency.
The maximum value of the root-mean-square acceleration
(ar.m.s
) of the AP-VSS and the maximum value of the root-mean-square
compaction force (Fr.m.s
) of the tampers are selected as the objective functions. The
experimental and simulation results indicate that by using the AP-VSS design
parameters, the pavement quality and compaction efficiency of the AP-VSS are
quite low. To enhance the AP-VSS performance, the operation parameters are then
optimized by the multi-objective optimization algorithm. The optimal result
shows that the compression energy of the tampers and hot-mixed asphalt
interaction is greatly increased by 36.2% in comparison without the
optimization. Concurrently, both the values of ar.m.s
 and Fr.m.s
 are also increased and uniformly distributed over the length of the
screed floor and surface of the hot-mixed asphalt in comparison without the
optimization. Therefore, the pavement quality and compaction efficiency of the
AP-VSS are remarkably improved.
Design Optimization of Four-Layer Fraction Slot Concentrated Winding
Spoke-Type Interior Permanent Magnetic Machine for Range
Extender
Authors: Xiao Congda , Yang Can
Published: May 2023

In this article, the design optimization of a four-layer fractional slot
concentrated winding (FSCW) interior permanent magnet (IPM) machine for range
extender is proposed for high energy efficiency and excellent
torque/back-electromotive force (EMF) performance. The design starts with the
comparison of four-layer FSCW patterns in terms of efficiency distribution based
on a predesign spoke-type rotor model. Magnet segments and rotor auxiliary
notches (ANs) are applied and optimized to reduce eddy current losses and torque
ripples in the permanent magnets (PMs). Then, an efficient two-step optimization
of multiple performances for a machine is presented. The rotor parameters are
designed by an analytical model with a Pareto optimizer for torque capacity and
ripple. An interpolation-based design method for adaptive stator slot parameters
and winding configurations is presented to quickly obtain the optimal stator
slot winding designs corresponding to the rotor design to achieve optimal
efficiency. The multi-bridge design is applied to rotor laminations to suppress
flux leakage, making the rotor core easy to manufacture. Finally, an 18s-16p
four-layer FSCW prototype was built and tested to verify the design optimization
results, with a maximum efficiency of 96% and rated shaft ripple as low as
3%.
Evaluation of Microstructure and Mechanical Properties of Additively- Manufactured Aluminium Alloy Automotive Component
Authors: Mohapatra Satya P. , DEBATA Mayadhar , Sengupta Pradyut , Panigrahi Ajit , Kaushik Harish C. , PATTANAYAK Deepak K.
Published: May 2023

The present work focusses on development of AlSi10Mg alloy component from the pre-alloyed powder by laser powder bed fusion (LPBF), one of the popular additive manufacturing technologies. The effect of heat treatment on microstructure and mechanical properties has also been studied. In accordance with T6 heat treatment process, the LPBF specimens were solution treated at 535°C for 2 h, then water quenched and subsequently, artificially aged at 160°C for 10 h. The role of printing direction on microstructure and mechanical properties has also been investigated. The printing parameters such as laser power, scan speed and hatch space were optimized for defect free automotive component. The as-printed and heat treated components were subsequently evaluated to assess their performance.
“Aluminium Hot Forming: - Opportunities and Challenges in Automotive Light Weighting”
Authors: NIRGUDKAR SACHIN SURESH , Melotti PhD Federico
Published: May 2023

In today’s Automotive world, there is NO need to advocate “Light weighting”. Government policies for carbon footprint reduction combined with high safety standards are driving OEMs to adopt advanced manufacturing technologies.

Steel hot forming is selected as most preferred way to reduce weight as it is easy to adopt and commercially known. It had many advantages compare to conventional cold stamping of standard and high tensile steel. The process consists of heating blank to nearly 1000 °C and quenching it in tool to for martensitic structure. Higher strength up to 2000 MPa can be achieved by this process. There are many examples where part weight is reduced by 15 to 20 % by this method.

But Steel hot forming has limitation as specific density of steel is still high. Thus, there is limitation to its weight reduction capability. For further reduction, OEMs have started exploring Aluminium hot forming. This process, similar to steel hot forming improves hardness of the part by series of heating and cooling cycles.

Aluminium has been used in car for a while but mainly into cold forming and specifically to A and B class panels. Some efforts are made to produce Aluminium die cast parts for chassis. The main advantage was to have jointless parts, but the big disadvantage was “wall thickness” limitation of die casting process. Also, commercial viability is also a big question for large die casting parts.

Now hot form aluminium is used for Body-in-White which are strength driven applications. Aluminium hot forming is slowly making its way in mass production with many developments in process optimization. But in India, it has many challenges. “Raw material availability”, “New Technology”, “Tooling Know how” are some of the challenges in adopting this technology in larger scale.

A case study will explain the advantages of Aluminium Hot forming, specifically the HFQ® process.
Development of Mold in Color Plastics to Eliminate Paint without Compromising Aesthetic & Functional Requirements
Authors: jha Ashutosh , Hatwalne Mrunal R.
Published: May 2023

Vehicle aesthetic appearance is critical factor in the perceived quality of a vehicle. Auto OEM focuses on the improvement of perceived quality. The perceived quality of a vehicle is improved by achieving a superior finish on the visible parts. Plastic parts used in visible areas are painted to achieve a superior finish & aesthetic. However, the painting process is very energy intensive, releases a lot of harmful VOCs into the environment, emits carbon di-oxide into the environment & is a very costly process. Also, painted parts pose a challenge for recycling at the end of life. For painting one square meter area, around 6.5 Kg of co2 is released. Additionally, the painting cost contributes to around 60 % of the part cost. As the emphasis has increased on sustainability & reducing the cost, we took the challenge to develop novel mold in color material to eliminate the painting process without compromising the aesthetic & functional requirements of part. The challenge was to develop the mold in color (MIC) material having a similar appearance as the painted part with no compromise on functional performance and use the existing injection molding tool. This paper explains the development methodology of MIC material & application validation methodology to ensure a similar aesthetic & functional requirement as painted part.
Development of an Economical Water Spray Test Setup for Window Regulators
Authors: Gavhane Sudarshan , Babu Yugandhar , Prasannakumar Jithesh , Banjan Rohith
Published: May 2023

In an automotive vehicle, the Window Regulator is an electro-mechanical assembly that is mounted inside the door. The basic function of the Window Regulator is to raise or lower the glass when required and hold the glass in closed position or in any desired position. During Water servicing or rains, Water will typically enter inside the door through the seals and on to the Window Regulator mechanism. Hence these conditions must be physically tested in the laboratory to assess the Window Regulator’s functionality which could get affected by Water intrusion. The Water spray test conditions are based on mutual agreement between Inteva Products and the OEMs.

Water spray test involves moving the electric Window Regulator to upper stall position (Window closed) at a defined voltage and line resistance. The glass must be dwelled followed by spraying defined amount of Water which simulates the rain. The agreed number of test cycles would be around 4500 which lasts about 7 weeks. Hence, to prepare this test setup, a large area of floor space along with other testing peripherals were to be procured and this would involve good amount of space, cost, Water, and time. Hence the Test Lab team developed an economical in-house test setup using available resources and equipment to reuse and recycle which will lead to significant savings.

This test setup developed to conduct Water spray test was carried out by using the available electric control box and mechanical infrastructure along with re-circulation of Water. The primary objective of this test setup was to comply with the test requirements along with Water reusage. This significantly reduced the new procurement / development cost and time since the available resources in the test lab were reused (80% of the materials were used from inventory, available in-house and from multipurpose devices and 20% were purchased).
Quick Analysis of Elemental Composition of Automotive Materials Using Non-destructive Technique
Authors: Patil Yamini , Bawase Moqtik , Thipse Sukrut S
Published: May 2023

Energy dispersive X-ray fluorescence (EDXRF) analysis have made it possible to conduct elemental analysis on a variety of fields, including those with environmental, automotive, geological, chemical, pharmaceutical, archaeology, and biological origins. The ability of EDXRF to deliver quick, non-destructive, and multi-elemental analytical findings with increased sensitivity is of great importance. It is a vital tool for quality control and quality assurance applications. Thus, EDXRF plays an important role to compare batch-to-batch products for meeting quality standards.

This paper presents application of EDXRF as an effective tool for quick qualitative and quantitative evaluation of given samples. A few simple case studies demonstrating application of EDXRF are presented, which includes identification of the filler contained in the polymer, coating thickness, elemental composition of the particulate matter collected on filter paper, multi-element analysis of printed circuit boards (PCB) and a delamination case. Such type of rapid and non-destructive technique provides an effective means for analysis of variety of materials used in automobiles.
Real Time Simulation of Various Loads and Validation of Radiator CAC Assembly Used in Commercial Vehicle Engines
Authors: G Manthiramoorthy , Narasimman Obuli Karthikeyan , Nagarajan Gopikannan , Siva Kumar Natarajan
Published: May 2023

Due to the emerging technologies and globalization, expectations of the customers on commercial vehicles are getting increased over the period. It is an important duty of an OEM to deliver a perfectly configured product to suit the customer requirements. When it comes to configuration of a vehicle, engine power is one of the key factors which indicate the performance of that vehicle. There is a tough competition between every OEM to increase the engine power for enhancing the overall operational performance. One method to increase power is to improve its volumetric efficiency. This is achieved with help of turbocharger and Charge Air Cooler (CAC). CAC improves volumetric efficiency by increasing intake air-charge density. Any failure on CAC leads to lower the volumetric efficiency and increase in turbocharger loading. This paper deals with the validation of CAC assembly using different test conditions by analyzing potential failure modes against the field issues. Optimum test conditions were derived and combination of various loads i.e. Vibration, pressure & thermal were simulated simultaneously during the validation. Test results were analyzed and discussed in detail.
Optimization of Casting Process to Increase Component Yield
Authors: Kumbhar Abhijit , Gosavi Sanjay , Pawar MD Anil
Published: May 2023

Casting is unique manufacturing processes for variety of reasons. Perhaps the most important reason is, it can produce complex components in any metal and weight ranging from grams to several tons. It is age old technology used to produce complex shapes and for mass production. The defects produced specifically inside the component, during casting process are difficult to identify. These defects in turn become cause of component failure in operating condition. FEA tools gives better understanding of process and can predict any defect produced in the casting process. It also helps to optimize entire process. Thus, use of software are becoming necessity in the industry to avoid rejections / last minute surprise.

This paper describes use of simulation to predict casting defects accurately in existing casting component. This provides in depth understanding of existing casting process. With understanding of existing process defects, suitable modifications in the casting design and process were carried out to eliminate persisting casting defect. Production trials were conducted with suggested modifications in the pattern and the process. With suggested modifications, casting defect were eliminated. The modified design also reduced the casting input material weight by ~3% thus improves casting yield.
Structural Design and Simulation of Battery Enclosure for an Electric Vehicle against Mechanical Abuse Test
Authors: Bharodiya Vishal , Sisodia Divyansh , Singh Pundan
Published: May 2023

Safety of a battery pack of an electric vehicle against impact is necessary as it possess a severe fire hazard. In this paper, a computer aided simulation is conducted to optimize the weight of a battery pack assembly. A numerical model, using commercially available FE code Abaqus, has been developed and studied against different load cases, crush, mechanical shock, and underfloor impact. The acceptance criteria of each test are studied, and the integrity of the design is checked against each test. The weight of the battery pack enclosure was reduced while keeping crashworthiness intact.
Use of Powder Metallurgy Based Connecting Rod for Diesel Engine Application
Authors: Chatterjee Pallav , Gopal Manish , Palkar Vishal , Kolhe Vivek M , Kumbhar Dipak , Ghotekar Sunil
Published: May 2023

The usage of forging a preformed, near net shape, compacted and sintered metal powder has been widely accepted since the eighties and is now one of the mainstays for producing Connecting rods in North America. However, its use in Indian subcontinent is limited as its counterpart i.e. conventional steel forging is still the most dominant. Powder metallurgy route has many advantages like good dimensional accuracy; minimum scattering of weight etc. Despite these advantages, the Powder metallurgy process is still not preferred predominantly due to technical (endurance) and infrastructural limitations. This work envisages combining the benefits of powder metallurgy process with the required mechanical properties viz. tensile and fatigue strength alongside design modifications to meet the requirements of a connecting rod for a 2-cylinder diesel engine. The connecting rods met the fatigue life at the required FOS equaling the performance of a conventionally forged connecting rod.
Recommended Practice for Braking, Stability, and Control Performance Test Procedure for Air Brake-Equipped Truck-Tractors
Authors:   Truck and Bus Brake Systems Committee
Published: May 2023

This SAE Recommended Practice provides a road test procedure for truck-tractors, to evaluate their compliance with Federal Motor Vehicle Safety Standard (FMVSS) 121. Units of measure are English in lieu of metric to be consistent with FMVSS 121.