bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlation of Some Anatomical Angles of the Shoulder with Rotator Cuff Syndrome
Authors: Candan Busra , Torun Ebru , Dikici Rumeysa , Avnioglu Seda , Gunal Mehmet Yalcin
Published: April 2023

Background:

Shoulder movement occurs through the coordinated work of muscles, tendons, ligaments, and bones, primarily that affect the glenohumeral joint. Some distances and the angles between the bones forming this joint are important in shoulder pathologies. In this study, we aimed to determine the evaluation of nine different radiological parameters related to acromion and humerus in rotator cuff syndrome and control group patients.

Materials and Methods:

A total of 400 patients’ routine clinic radiographs were retrospectively assessed, which have rotator cuff syndrome (n = 210), and control group (n = 190). We measured the critical shoulder angle (CSA), distance of glenoid-acromion (GA), distance of glenoid-humeral head (GH), acromial index, lateral acromial angle (LAA), total shoulder arthroplasty angle (TSA), reverse shoulder arthroplasty angle (RSA), Point T represents the superior border of the glenoid cavity, Point S represents the inferior border of the glenoid cavity, point R represents the intersection of the supraspinatus fossa line with the glenoid surface. RST angle, and greater tuberosity angle (GTA) angle. We determined the type of acromion.

Results:

We determined that the GH, TSA, RST, and GTA were significantly different between rotator cuff syndrome and control group patients. When we evaluated the acromion type, Type 2 was the most common type. Different from the literature, when we evaluated the relationship between acromion types and angles, we determined that LAA, GA, and TSA parameters were significantly different between acromion types.

Conclusions:

In this study, we determined the importance of measurements and angles in rotator cuff syndrome. We think that the relationship between acromion types and parameters can contribute to the literature. Moreover, we believe that our study will contribute to the literature in terms of gathering many angles that are important in shoulder pathologies in a single study.
Retromolar Canals and Mandibular Third Molar Position
Authors: Demire Oguzhan , Akbulut Aslıhan
Published: April 2023

Introduction:

The retromolar canal (RMC) is an anatomical variation of the posterior part of the mandibular canal. It is thought that this variation is related to histological vestiges of the gubernacular canal and RMC presence may be associated with mandibular third molar (MTM) malposition. This study aims to investigate the relationship between MTM position and RMC existence.

Material and Methods:

Patients who had undergone cone-beam computed tomography examination for various purposes were included in the study. All of the patients had unilateral or bilateral MTM teeth. MTM impaction patterns were classified according to Winter and Pell-Gregory classifications. RMC existence, type, retromolar foramen (RMF) position, RMF dimensions, and distance from RMF to second and third molars were recorded. Results: Three hundred and forty-six retromolar areas with MTM of 244 patients were evaluated. RMCs were present in 11.5% of the patients. No statistically significant relationship between RMC and MTM impaction patterns was observed. A1-type RMC was found to be the most prevalent. The mean distance from RMF to the third molar was 6.09 ± 4.20 mm and was found to be higher in male patients. The mean distance from RMF to the second molar was 15.28 ± 4.73 mm. The average dimensions of the RMF were 1.4 ± 0.47 mm.

Discussion and Conclusion:

RMC is a relatively common anatomical variation of the mandibular canal. Although no correlation was observed between MTM impaction pattern and RMC existence, further research including more samples may be helpful to explain a possible correlation.
Evaluation of the Brain Indexes of Subjects with and without Brain Atrophy Using Computed Tomography
Authors: Öksüzler Mahmut , Polat Sema , Tunç Mahmut , Vuralli Duygu , Göker Pinar
Published: April 2023

Introduction:

This study was undertaken to determine the values of brain indexes using computed tomography (CT) in our population.

Material and Methods:

This study was carried out on the 520 senior subjects (196 subjects having brain atrophy and 324 subjects having no brain atrophy) aged 60–90 years. Measurements of the brain indexes were taken from subjects having axial brain CT image in the radiology department. Furthermore, the data were analyzed according to age and gender.

Results:

The means and standard deviations of the measurements were as follows: the maximum distance between anterior horns, 37.35 ± 3.76 mm; minimum bicaudate nuclei distance, 20.76 ± 3.78 mm; maximum internal skull diameter, 135.66 ± 6.51 mm; maximum internal diameter of the frontal bone, 103.23 ± 6.23; internal skull diameter measured along the same line, 116.28 ± 6.60 mm; maximum external diameter of the skull, 144.08 ± 5.93 mm; and cella media width, 35.88 ± 6.93 mm; and the indices were calculated and found as follows: Huckman number, 58.11 ± 6.99 mm; bifrontal index, 0.36 ± 0.03; bicaudate frontal index, 0.55 ± 0.07; bicaudate index, 0.18 ± 0.03; bicaudate temporal index, 0.15 ± 0.03; and Schiersmann's index (SI), 4.22 ± 1.16 in subjects having brain atrophy. The same values were measured as 32.28 ± 3.19 mm; 15.32 ± 3.05 mm; 133.67 ± 6.71 mm; 102.05 ± 6.13 mm; 113.12 ± 6.04 mm; 141.14 ± 6.12 mm; 28.92 ± 5.79 mm; 47.59 ± 5.63 mm; 0.32 ± 0.03; 0.47 ± 0.08; 0.14 ± 0.03; 0.11 ± 0.02; and 5.09 ± 1.13 in healthy elderly subjects, respectively. There was a significant difference in all measurements (except SI) (P < 0.05).

Discussion and Conclusion:

The brain index dimensions of Turkish population provide important and useful knowledge for the clinicians in terms of comparison of abnormalities and atrophy of the brain.
Amelanotic Mucosal Melanoma of the Nasal Cavity
Authors: Jaiprakash Padmapriya , Mathew Mary , Singh Varun Kumar , Nayak Dipak Ranjan
Published: April 2023

Mucosal melanomas are rare head-and-neck tumors and have a distinct etiology and genetic profile different from cutaneous counterparts. They are most commonly seen in sixth–seventh decade of life and have aggressive behavior. The patients usually present with nodal metastasis, which is the most important poor prognostic indicator for mucosal melanomas. We present a case of mucosal melanomas in a young male (30 years), who presented with nonpigmented, polypoidal mass in the right nasal cavity simulating an inverted papilloma. Histological examination showed small to large pleomorphic cells and no melanin pigment. Based on the immunopositivity of the tumour cells were positive for HMB45 and S100 confirming a diagnosis of amelanotic mucosal melanoma. The partied had a localized disease to the right nasal cavity with no nodal involvement and no recurrences in the available follow-up of 24 months.
Case Report of Persistent Left Superior Vena Cava with Absent Papillary Muscle – Unusual Coexistence
Authors: Umamaheswaran Divya , Sakkarai Jayagandhi , Devi Rema
Published: April 2023

Persistent left superior vena cava (PLSVC) is uncommon with an incidence of 0.3%–1.3%. The incidence of absent papillary muscle is unknown. Congenital anomalies of a thoracic venous system associated with absent papillary muscle are very rare. During dissection of a 55-year-old male cadaver, PLSVC with absent papillary muscle was found. Although these congenital anomalies are incidentally found, it is worthwhile following such patients to look for the evolution of any cardiac symptoms. Sound knowledge and awareness of such congenital anomalies are required for radiologists, cardiothoracic surgeons, and critical care physicians.
Numerical Chromosomal Aberrations in Acute Lymphoblastic Leukemia in North Indians
Authors: Shri Indu , Verma Rakesh Kumar , Rani Archana , Kumar Navneet
Published: April 2023

Introduction:

Alterations in chromosome number have a strong impact on outcome in childhood ALL. Genetic findings may predict the prognosis and biologic properties of the leukemia more consistently than does morphology. To see the numerical aberrations in ALL in North Indian population

Material and Methods:

Culture and chromosome banding of bone marrow and blood sample of 51 North Indian patients of ALL (44 males and 7 females) from the age group of 2 to 42 years were done. Only 39 shows good chromosomal spread, so 39 karyograms were prepared and observed for the chromosomal gain or loss and their frequency. Results: Numerical abnormalities were observed in 14 patients (35.9%) of the 39 cytogenetically analysed cases. Trisomy 21 was found in 3 cases. Trisomy of chromosome number 13 and 14 were found in 5.12% cases. Trisomy of chromosome number 3, 4, 6, 8, 11, 15, 17 and 18 were present in 2.56% cases (Fig. 21, 30, 31, 34, 35, 42). Gain of chromosome X was seen in 5.12% cases while only in one case (2.56%) gain of chromosome Y was detected.

Discussion and Conclusion:

Numerical chromosomal abnormality in this study was 15.38% which was different from other population described in previous studies. Trisomy 21 is most common in this study. The findings of the present study may be useful for the clinician in predicting outcome, remission, survival and treatment response in ALL.
Perceived social support among pregnant women attending the antenatal clinic of a tertiary care hospital
Authors: Raghuveer Pracheth , Haleema Mubeena
Published: April 2023

BACKGROUND:

Social support among pregnant women is identified to have a positive influence on maternal, fetal outcome, personal competence, and self-esteem. This study was conducted with the aim to assess the social support as perceived by pregnant women and to find out the association between perceived social support and sociodemographic, obstetric variables.

MATERIALS AND MATERIALS:

After obtaining approval from the Institutional Ethics Committee, a cross-sectional study was carried out among pregnant women attending the Antenatal Clinic of a Tertiary Care Hospital for a period of two months. The Multidimensional Scale of Perceived Social Support (MSPSS) was used to assess social support among study participants.

RESULTS:

A total of 111 pregnant women were included. Majority, 98 (88.30%), were educated till High School. Nearly 87 (78.40%) were in the third trimester and 68 (61.30%) were primigravidae. Mean MSPSS score was found to be 5.36 ± 0.83. Majority, 75 (67.60%), had high social support (mean total score of 5.1-7.0). Those engaged in occupation had 2.922 odds for high social support (adjusted odds ratio = 2.92, 95% confidence interval = 0.612-13.95) when compared to housewives (P < 0.05). Women in third trimester had 2.104 odds for high social support, when compared to those in first and second trimesters (adjusted odds ratio = 2.014, 95% confidence interval = 0.715-6.185).

CONCLUSION:

Majority scored high on MSPSS. Furthermore, involvement in occupation was found to be a significant predictor of high social support among the study participants.
Perception, perceived scope, and potential barriers towards developing nurse practitioners cadre among health care providers and beneficiaries: A pilot study from Northern India
Authors: Kodi Malar S , Sharma Suresh K. , Basu Somprakas
Published: April 2023

BACKGROUND:

The role of nurse practitioner (NP) emerged in early 1965 when general practitioners began working with nurses. Evidence across the world highlights the benefits achieved by the NP role. The Indian Nursing Council (INC) implemented a country-wide NP in critical care (NPCC) program with the approval of the ministry of health and family welfare (MoHFW) in 2017. The NP role is in its infancy in India. Hence, there is a need to assess the perception among beneficiaries and healthcare personnel. This study was conducted to assess the perception, perceived scope, and potential barriers for developing the role of NPs in India among beneficiaries and healthcare providers.

MATERIAL AND METHODS:

A descriptive, cross-sectional pilot study was conducted at AIIMS Rishikesh, Uttarakhand, India, among 205 participants (84 beneficiaries, 78 nurses, and 43 physicians) using a proportionate stratified random sampling technique. Likert scales and socio-demographic sheets were used to assess the perception, perceived scope of practice, and potential barriers in developing a NP cadre in India. Descriptive and inferential statistics were used for analyzing data.

RESULTS:

The mean age of beneficiaries was 37.98, nurses was 27.58, and physicians was 28.13 years, respectively. 121 (61%) of participants were highly favored, and 77 (38%) were in favor of developing NP cadre in India. They considered it to be necessary, feasible, and acceptable in India. The feasibility and necessity of the perception domain were highly significant (P < 0.001 and P < 0.003, respectively). Nurses (mean ± SD: 35.36 ± 3.55) considered that NPs could have a wide range of practice followed by beneficiaries (mean ± SD: 38.17 ± 3.68) than physicians (mean ± SD: 34.75 ± 5.95). Lack of awareness, the nonexistence of cadre structure, lack of acceptance of the role of physicians, and lack of clear policy were the key potential barriers to develop an NP cadre in India.

CONCLUSIONS:

In this study, participants had favorable views on employing NPs in India; thus, this role will improve healthcare access for beneficiaries. NPs can carry out a wide range of practices. However, a lack of awareness, no cadre structure, and a lack of a clear policy may hinder the development of the NP cadre in India.
Smartphone addiction and its impact on knowledge, cognitive and psychomotor skills among dental students in India: An observational study
Authors: Karishma  , Awinashe Minal V. , Jain Amol , Santhosh V. C. , Choudhury Basanta K. , Alessa Noura , Babaji Prashant
Published: April 2023

BACKGROUND:

Addictive behavior toward the use of smartphones has turned out to be a commonly present phenomenon in this digital era. An individual's overindulgence in smartphone devices has turned into an obsessive and compulsive disorder. This addiction has been found to influence the physical, social, and psychological wellbeing of the studied population. This observational study aimed to assess smartphone addiction and its impact on knowledge, cognitive, and psychomotor skills in students pursuing dentistry in India.

MATERIALS AND METHODS:

This prospective and cross-sectional survey-based study comprised 100 dental undergraduate students who were selected by a random sampling technique. The age range of subjects ranged between 18 and 22 years with equal gender distribution (50 each male and female). A prevalidated questionnaire containing 30 items encompassing five variables, that is, applications related to healthcare, entertainment, shopping, communication, and education were used to assess the response. Based on scores, patients were categorized as addicted or with no addiction. For evaluating the knowledge, cognitive, and psychomotor skills of students, theory-based examinations were held in different subjects as per the semester year of selected students while psychomotor skills were assessed by conducting clinical or preclinical examinations conducted by two separate examiners who following mutual agreement were assigned appropriate scores. All scores were categorized into four grades, that is, from grades I to VI.

RESULTS:

Students with smartphone addiction exhibited lower performance in both theory-based and clinical/preclinical assessment examinations with a majority of them scoring grade III or IV.

CONCLUSION:

Smartphone addiction reduces the academic knowledge, cognitive, and psychomotor skills of dental students.
Nurses' experiences of discrimination in health care: A qualitative study in Iran
Authors: Hosseinabadi-Farahani Mohammadjavad , Arsalani Narges , Hosseini Mohammadali , Mohammadi Eesa , Fallahi-Khoshknab Masoud
Published: April 2023

BACKGROUND:

Justice in health is one of the main concerns of health organizations, and discrimination in health care is one of the negative outcomes to achieving this goal. Hence, a full understanding of the phenomenon of discrimination in health care and adopting strategies to eliminate it is necessary. The present study was conducted to explore and describe the experiences of nurses of discrimination in health care.

MATERIALS AND METHODS:

The present qualitative content analysis study was conducted between 2019 and 2020. Data were collected through semi-structured interviews with 18 participants (two physicians, three nursing supervisors, two head nurses, four clinical nurses, two nursing assistants, and three hospitalized patients) in one public and one private hospital in the city of Tehran. The participants were selected by purposive sampling, which continued until saturation of data. Data obtained were analyzed using the Graneheim and Lundman method.

RESULTS:

Four main categories and 14 subcategories were extracted from data analysis: 1) habitual discrimination (everyday discrimination in health centers, ignoring patient rights, low levels of trust in medical staff); 2) interpersonal relationships (expectations of associates, respect for colleagues and friends, the possibility of the occurrence of similar situations, reciprocating people's favors); 3) shortage of health-care resources (shortage of medical equipment, heavy workload, infrastructure of medical centers, lack of access to physicians); and 4) favoritism (ethnicity, favoritism as a common method, and favoritism as the ultimate solution to treatment problems).

CONCLUSION:

The present study revealed certain dimensions of discrimination in health care that remain hidden in many quantitative studies. It appears that health system managers will be able to move toward eliminating discrimination in health care. Thus, designing effective models to reduce discrimination in health care based on the underlying concepts of this study is recommended.
Stigmatizing attitude towards mental illness, disabilities, emotional and behavioural disorders, among healthcare students in a Tropical University College of Health Sciences
Authors: Amaechi Ifeoma Adaigwe , Nwani Paul Osemeke , Akadieze Augustine Onyebuchi
Published: April 2023

BACKGROUND:

Stigma toward mental illness (MI), physical disability (DA), and emotional/behavioral disorders (EBD) has been identified as a form of violence and a cause of nontake-up of help by people in need. Stigmatization can aggravate an individual's feeling of rejection and incompetence and can be detrimental to treatment-seeking and adherence behaviors. This study evaluated the attitude of healthcare students toward MI, DA, and EBDs.

MATERIALS AND METHODS:

This study employed a cross-sectional survey method. A disproportionate stratified sampling technique was used to recruit participants. Sixty five consenting students who met the inclusion criteria were consecutively recruited from each clinical department of the college. The students were selected from the five clinical departments of the College (Nursing sciences, Medical Rehabilitation, Radiography, Medical laboratory science, and Medicine). The questionnaires on stigmatizing attitudes toward MI, EBD, and DA were self-administered. Descriptive statistics of frequency count, percentage, range, mean, and standard deviation were used to summarize participants' sociodemographic data and their questionnaire scores. Inferential statistics of Spearman rank order correlation was used to test for correlation; Mann-Whitney U test was used to test the influence of gender, religion, and family history; and Kruskal-Wallis test was used to test the influence of department of study and level of study. Alpha level was set at 0.05.

RESULTS:

Three hundred twenty seven students comprising 164 (50.2%) males and 163 (49.8%) females participated. Mean age of participants was 22.89 ± 2.05 years. 45.3% of the participants reported positive family history of one or a combination of MI, DA, and EBDs. The study observed poor attitude toward MI and fair attitude toward DA and EBD. There were significant correlations between attitudes toward MI and disability (r = 0.36, P = .000033), MI and EBD (r = 0.23, P = .000023), disability and EBD (r = 0.46, P = .000001), and age and attitude toward disability (r = 0.15, P = .009). Females had significantly more positive attitude toward disability (P = .03) and EBDs (P = .03). Nursing students also demonstrated the most positive attitudes toward MI (P = .03) and EBD (P = .000416), while final year students demonstrated the most positive attitudes toward MI (P = .00145) and EBDs (P = .03).

CONCLUSIONS:

There was a poor attitude toward MI and a fair attitude toward DA and EBD. Attitude toward MI, DA, and EBD correlated significantly with one another. Older students, females, and higher levels of training in the healthcare profession were associated with more positive attitudes toward MI, DA, and EBDs.
Real Time Bearing Defect Classification Using Time Domain Analysis and Deep Learning Algorithms
Authors: Gorantiwar Anish , Taheri Saied , Zahiri Feraidoon , Moslehi Bijan
Published: April 2023

Structural Health Monitoring (SHM), especially in the field of rotary machinery diagnosis, plays a crucial role in determining the defect category as well as its intensity in a machine element. This paper proposes a new framework for real-time classification of structural defects in a roller bearing test rig using time domain-based classification algorithms. Along with the bearing defects, the effect of eccentric shaft loading has also been analyzed. The entire system comprises of three modules: sensor module – using accelerometers for data collection, data processing module – using time-domain based signal processing algorithms for feature extraction, and classification module – comprising of deep learning algorithms for classifying between different structural defects occurring within the inner and outer race of the bearing. Statistical feature vectors comprising of Kurtosis, Skewness, RMS, Crest Factor, Mean, Peak-peak factor etc. have been extracted from the 1-D time series data for different defect cases. These features are then fed as input vectors to algorithms comprising of Support Vector Machines (SVM’s) and Multi-layered Perceptron (MLP) for defect classification. A dedicated hardware setup has been built to test the efficiency of the developed algorithms in real-time. These algorithms have been evaluated based on two criteria – examining the simultaneous defect classification accuracy for two sets of bearings and individually monitoring the class labels for a particular defect. It was observed that the developed framework was able to classify between different bearing defects with a classification accuracy of 97.8%.
Data Reduction Methods to Improve Computation Time for Calibration of Piston Thermal Models
Authors: Wright Stephen , Ravikumar Avinash , Redmond Laura , Lawler Benjamin , Castanier Matthew , Gingrich Eric , Tess Michael
Published: April 2023

Fatigue analysis of pistons is reliant on an accurate representation of the high temperatures to which they are exposed. It can be difficult to represent this accurately, because instrumented tests to validate piston thermal models typically include only measurements near the piston crown and there are many unknown backside heat transfer coefficients (HTCs). Previously, a methodology was proposed to aid in the estimation of HTCs for backside convection boundary conditions of a stratified charge compression ignition (SCCI) piston. This methodology relies on Bayesian inference of backside HTC using a co-simulation between computational fluid dynamics (CFD) and finite element analysis (FEA) solvers. Although this methodology primarily utilizes the more computationally efficient FEA model for the iterations in the calibration, this can still be a computationally expensive process. In this paper, several data reduction methods, such as principal component analysis, data clustering and resampling, sensor reduction, and uniform bin sampling are investigated to improve computation time while minimizing reduction in accuracy of the inference results. Each data reduction method is compared to a control case to determine change in accuracy and improvement in run time. Results indicate that most reduction methods were no more effective than using a smaller Latin hypercube design to inform the Gaussian process within the Bayesian inference code. Reduced error was observed for the structured sensor reduction method, indicating that further studies on the value of individual sensor locations to the overall calibration might be a viable path to reduce the computation time of the calibration methodology without compromising accuracy.
Study of Phase Change Thermal Management Architecture for Series-Hybrid Powertrain in Unmanned Aerial Vehicles
Authors: Kokate Rohan , Virk Akashdeep Singh , Park Chanwoo , Mitsingas Constandinos , Johnson Matthew , Kweon Chol-Bum
Published: April 2023

The applications of unmanned aerial vehicles (UAV) are growing exponentially with advances in hybrid powertrain architecture design tools. The thermal management system (TMS) as an integral part of the powertrain architecture greatly affects the system performance of aerial vehicles. In this study, a comparative analysis of two types of thermal management technologies for a UAV with a series-hybrid powertrain architecture was performed. Conventional TMS based on single-phase (no phase change) cooling technologies using air and liquid (e.g., antifreeze water mixture and oil) as heat transfer fluid has been commonly used because of simple design and operation, although it is considered to be inefficient and bulky. As advanced designs, phase change-based TMS is being slowly adopted although it promises superior cooling capabilities. A parametric study was performed to analyze UAV cooling performance in terms of weight, volume, and required pumping power of TMS by varying the heat dissipations of heat-generating components (ICE, generator, motor, and battery) at different ambient temperature varied by UAV altitudes. In this study, as a baseline design, liquid cooling was applied for internal combustion engine (ICE), electric generator and motor and air cooling was considered for rechargeable battery system. Furthermore, latent-energy thermal energy storage using a phase change material is considered for the TMS architecture study, which is specifically helpful in highly transient operations, to help reduce temperature fluctuations. The conventional TMS was compared, under fixed temperature constraints, with an advanced TMS using a pumped two-phase loop for the engine cooling by replacing the single-phase liquid cooling. From the analysis, it was found that the advanced TMS reduces the weight, volume, and pumping power consumption by 12, 10, and 23 %, respectively, as compared to the conventional TMS.
Mathematical formulation and Analysis of Brake Judder
Authors: S Gurumoorthy , Bhumireddy Yugandhar , Bourgeau Alyssa , Bhimchand Naresh
Published: April 2023

The Brake judder is a low-level vibration caused due to Disc Thickness Variation (DTV), Temperature, Brake Torque Variation (BTV), thermal degradation, hotspot etc. which is a major concern for the past decades in automobile manufacturers. To predict the judder performance, the modelling methods are proposed in terms of frequency and BTV respectively. In this study, a mathematical model is constructed by considering full brake assembly, tie rod, coupling rod, steering column, and steering wheel as a spring mass system for identifying judder frequency. Simulation is also performed to predict the occurrence of brake judder and those results are validated with theoretical results. Similarly, for calculating BTV a separate methodology is proposed in CAE and validated with experimental and theoretical results.
Effects of Injector Included Angle on Low-Load Low Temperature Gasoline Combustion Using LES
Authors: O'Donnell Patrick Christopher , Lawler Benjamin , Sofianopoulos Aimilios , Lopez Pintor Dario
Published: April 2023

A novel advanced combustion strategy that employs the kinetically controlled compression ignition of gasoline whose autoignition is sensitive to fuel concentration is termed Low Temperature Gasoline Combustion. The LTGC method can achieve high thermal efficiency with a commercially available fuel while generating ultra-low soot and NOx emissions relative to the conventional combustion modes. At high loads, a double direct injection (D-DI) strategy is used where the first injection generates a background premixed charge while a second compression stroke injection controls the level of fuel stratification on a cycle-to-cycle basis to manage the heat release rates. With lower loads, this combustion performance of this D-DI strategy decreases as the background charge becomes increasingly lean. Instead, a single direct injection (S-DI) is used at lower loads to maintain an adequate combustion efficiency. But the distribution of fuel with this S-DI approach must be such that the relatively rich regions of local equivalence (ϕ > 0.7) that reach higher combustion temperatures and generate NOx and the overly lean regions (ϕ < 0.3) that cause combustion inefficiency and instability are both minimized. This work investigates the implications of injector included angle and injection pressure at a low-load operating condition on the in-cylinder fuel stratification through the use of three-dimensional computational fluid dynamics (3D-CFD) simulations coupled with Large Eddy Simulation (LES) turbulence modeling. A computational model was developed and validated against experimental data collected at two low-load conditions on a medium-duty single cylinder LTGC engine at Sandia National Laboratories. Fuel stratification is analyzed using in-cylinder cut-planes based on local equivalence ratio as well as fuel mass-weighted joint probability density functions (jPDFs). Observed trends in combustion performance and emissions formation are presented in the context of the fuel stratification generated by increased injection pressure and a wider injector included angle.
Acoustic and Aerodynamic Performances of One Phononic Crystal Duct with Periodic Mufflers
Authors: Liu Panxue , Zuo Shuguang , Wu Xudong , Yin Bin , Li Shanran
Published: April 2023

The acoustic muffler is one of the practical solutions to reduce the noise in ducts. The acoustic and aerodynamic performances are two critical indices of one muffler for the air intake system of a hydrogen fuel cell electric vehicle (FCEV). In this study, the concept of phononic crystal is applied to design the muffler to obtain superior acoustic performance. One duct with periodic and compact resonator-type mufflers is designed for broadband noise attenuation. The two-dimensional (2D) transfer matrix method and bandgap theory are employed to calculate the transmission loss (TL) and acoustic bandgap. It is numerically and theoretically demonstrated that broadband noise attenuation could be acquired from 500Hz to 3500Hz. Afterwards, the three-dimensional (3D) computational fluid dynamics (CFD) approach is applied to predict the pressure distribution. The results indicate that the proposed hybrid muffler and the phononic crystal duct possess low pressure loss values. Furthermore, the influence of inlet flow velocity and air temperature on the transmission loss and pressure drop are investigated through a systematic study. The two factors primarily work on sound attenuation in the high-frequency range. The increase of the inlet flow velocity might cause the TL amplitude to decrease around the peaks, while the enhancement of the inlet air temperature might make the TL curve move towards the high-frequency domain. It shows that acoustic resonator-type mufflers are conducive to broad noise attenuation with the low-pressure loss and a compact structure. It provides one avenue to control the noise in the duct.
Verification and Validation for Modular Development Platforms
Authors: Leighton Michael , RAY RAKESH
Published: April 2023

As electrified powertrains trends towards the new norm in development, the need to consider modular development approaches becomes more prevalent. Modular system developments seek to offer an adaptable product range by considering each system component (transmission, e-motor, inverter, battery, etc.) and system element (park-lock, disconnect, differential, etc.) as interchangeable. This can result in a lower cost development process overall to increase the returns for tier1 suppliers by expanding the marketability of the platform.

Such an approach has hitherto held relatively low commercial interest as the rate of technological advancement negated the benefits of a modular development due to the lack of long-term competitivity. Previously large technological advances between successive productions and the relatively limited EV market, centred around SUV and small car applications, reduced the value in committing to a platform development. The slowing of the technological advance and the increasing range of electrified powertrain applications has reduced that barrier.

This study will explore the modular platform development from the verification and validation perspective and evaluate the necessary changes in the approach and the potential savings that can be expected relative to a classical, bespoke-product approach. Consideration will be given to the verification and validation of sub-systems and system components for a range of applications, each with unique requirements. Which verification and validation activities to conduct at which system level and what extent of the verification and validation can be extended to a new application will also be considered.
Battery Sizing, Parametric Analysis, and Powertrain Design for a Class 8 Heavy-Duty Battery Electric Truck
Authors: Salek Farhad , Halder Pobitra , Thomas Leonard Aiden , Babaie Meisam , Resalati Shahaboddin , Zare Ali
Published: April 2023

Electrification of the transportation sector requires an energy-efficient electric powertrain supported by renewable sources of energy to limit the use of fossil fuels. However, the integration of battery electric powertrains in heavy-duty trucks seems more challenging than other types due to the high battery demand and negative impacts on the truck’s cargo capacity. In this paper, the battery sizing of a 41-tons Mercedes Actros truck is performed based on battery safety zone operating conditions. A parametric study is conducted to assess the impacts of sizing on a truck’s total cargo capacity as well as the body dynamic parameters. The numerical model of the Mercedes Actros electric powertrain is developed in AVL CRUISETM M software. The hybrid pulsed power characterization tests are performed on 3Ah lithium-ion NMC cells in the lab for fitting the second-order equivalent circuit model’s parameters used in the analysis. There are 6 battery packs with 456 to 684 kWh capacity each installed as an energy source for the powertrain based on the conditions of standard long-haul driving cycle. In parametric analysis, the battery capacity increased in the pre-mentioned range and its impacts on the final state of charge (SoC), pack voltage and road force on the truck’s cabin are assessed. The results of the parametric study have indicated that for putting the battery energy storage system in a safe operating zone (SoC would be between 80% and 30%), each battery pack capacity should be around 104.5 kWh resulting in a reduction of cargo capacity by 24.88% after electrification. The sharp road inclinations above 5% would result in non-negligible effects of the battery pack size variations on the truck chassis load.
Tuning of Turbulence Model Closure Coefficients Using an Explainability Based Machine Learning Algorithm
Authors: Bounds Charles Patrick , Uddin Mesbah , Desai Shishir
Published: April 2023

This article discusses an application of Machine Learning (ML) tools to improve the prediction accuracy of Computational Fluid Dynamics (CFD) for external aerodynamic workflows. The Reynolds Averaged Navier-Stokes (RANS) approach to CFD has proved to be one of the most popular simulation methodologies due to its quick turnaround times and acceptable level of accuracy for most applications. However, in many cases the accuracy for the RANS models can prove to be suboptimal that can be significantly improved with model closure coefficient tuning. During the original turbulence model creation, these closure coefficients were chosen by somewhat ad hoc methods using simple canonical flows that do not transfer well to flows involving more complex objects, like the automotive bodies used in this work. This work presents a novel method of applying ML tools to CFD to optimize the turbulence closure coefficients by using model explainability tools such as Shapley Values, Shapley Additive exPlanations (SHAP), and ML surrogate models. The 25-degree slant Ahmed body model was used to obtain sampling data to tune closure coefficient in the Menter Shear Stress Transport (SST) turbulence model implemented in the open source CFD code, OpenFOAM v2012. Shapley additive values were then calculated using the samples which showed that β∗ has the strongest influence over the model predictions of lift and drag. ML surrogate models were then applied alongside SHAP providing a better overall sampling efficiency with Shapley additive values and more complete explanations of the model. The SHAP explanations showed that β∗ had the most influence on the force predictions followed by σω2, while σω1, σk1, and σk2 were shown to have little impact. The surrogate model was then used along with its explanations to provide optimized coefficients that reduced the error in the drag and lift predictions to -3.67% and -2.49% respectively, from -9.67% and -75.8%.
Collision Avoidance Study for Towbarless Aircraft Taxiing Systems on the Airport Apron Considering the Measuring Uncertainty
Authors: Zhu Hengjia , Xu ZiShuo , Zhang Baizhi , Zhang Wei
Published: April 2023

The towbarless aircraft taxiing system (TLATS) consists of the towbarless towing vehicle (TLTV) and the aircraft. The tractor realizes the towing work by fixing the nose wheel. During the towing process, the tractor driver may cause the aircraft to collide with an obstacle because of the blind spot of vision leading to the accident. The special characteristics of aircraft do not allow us to modify the structure of the aircraft to achieve collision avoidance. In this paper, three degrees of freedom (DOE) kinematic model of the tractor system is established for each of the two cases of pushing and pulling the aircraft, and the relationship between the coordinates of each danger point and the relatively articulated angle of the TLATS and the velocity of the midpoint of the rear axle is derived. Considering that there is an error between the velocity and relatively articulated angle measured by the sensor and the actual one, the effect of velocity and relatively articulated angle uncertainty on the traction trajectory of the aircraft-tractor system is investigated based on the Chebyshev expansion function. The calculation efficiency and the result range of Chebyshev method and those of Monte Carlo(MC) method are compared. An aircraft collision avoidance model on the apron is established based on Simulink. The simulation results show that the method can achieve the measurement of aircraft attitude and position and realize the anti-collision.
Intersecções entre percursos profissionais e associações
Authors: Chaves Idalena Oliveira , Leroy Henrique Rodrigues , Dos Santos Daniel , Gabas Tatiana Martins , Frazatto Bruna
Published: April 2023

Esta entrevista abre uma rodada de diálogos com associações de professores de português como língua estrangeira/adicional com o propósito de refletir sobre o campo de pesquisa, a formação e a atuação de professores na área. Para a primeira conversa, entrevistamos em 2021 dois presidentes da Associação Mineira de Professores de Português como Língua Estrangeira (AMPPLIE), Profa. Dra. Idalena Oliveira Chaves (Universidade Federal de Viçosa) e Prof. Dr. Henrique Leroy (Universidade Federal de Minas Gerais), à frente da associação nos mandatos de 2017-2021 e 2021-atual, respectivamente. Após contato inicial, foram propostas oito perguntas respondidas por e-mail por ambos os professores que, somadas a comentários adicionais dos entrevistadores, visaram apresentar e discutir a perspectiva da associação quanto à formação de professores de PLE/PLA e a atuação desses profissionais no mercado de trabalho. Dessa forma, pretendemos elucidar debates, atitudes e posicionamentos que associações de professores na área podem encaminhar à sociedade, de forma mais ampla, com o intuito de aproximar profissionais atuantes no mercado de trabalho (nos mais distintos vínculos) de ações que procurem construir institucionalidades para a atuação de professores de português como língua estrangeira/adicional.
Prediction Of Technical Feasibility For Building BridgesIn Nepal By Using Data Mining Technique
Authors: Om B Khadka  , Ayan Gupta  , Ayushmaan Paul  , Sayantan Adhikary  , Avijit Kumar chaudhari  , Dilip K.Banerjee  , Anirban Das
Published: April 2023

A bridge is a structure that spans a valley, road, river, body of water, or any other physical barrier. The architecture of a bridge may vary depending on the nature of the area where it will be built. The first bridge was created by nature itself, with a log falling across a stream or rocks in a river. The first man-made bridges were probably constructed using wood or timbers, and later, stones were used to support a crossbar system. Some early bridges used trees or bamboo poles to cross small tunnels or wells to get from one place to another. Lashing sticks, logs, and a common form of bridge construction involved the use of temporary branches woven together with long trunks or other fibers to form a connecting rope capable of withstanding weight. Mountainous areas pose a unique problem for constructing bridges due to varying climates, geological features, and hydrology parameters. Based on bridge sites and various constraints, types of bridges and construction methods are carefully selected for safe, profitable, and successful completion of the bridge. Human habitation and plants have spread up to 14,000 to 16,000 feet above mean sea level. An innovative idea would involve the installation of an adjunct bridge to provide services such as education, medical facilities, and workplaces. Data has been analyzed using the Random Forest method. In this research, we predicted the technical feasibility of building a trail bridge depending on factors such as total population, total households, river type, total DAG, DDH, DRH, etc. The model was evaluated using 50-50%, 66-34%, and 80-20% train-test splits, and 10-fold cross-validation, with an accuracy of approximately 97%.In this study, the authors collected data by mobilizing local NGOs and informing the public through local radio. A comprehensive study was conducted to collect nationwide bridge demand. With the project management information system developed by Om B Khadka, Head of IT and Knowledge Management, serves as the secondary source.
Socio economic conditions of depressed class women labour in construction sector of Bangalore city
Authors: S.Jayalakshmi Priya
Published: April 2023

The unfortunate socio-economic conditions of women workers on construction sites in major cities have become far worse than previously thought and seen.This was corroborated by the field survey conducted in construction sites of Bangalore city.The construction sites taken for survey were the new multi storeyed buildings from Bangalore Mysore Road, Kengeri and UllalUpanagara Koramangala and JP nagar.For this study 150 samples of migrant women workers were collected.The other factor was all of them were from scheduled castes .The rationale behind the study was firstly to find out if their conditions have improved post pandemic and secondly to understand how farthe government schemes and welfare boards have served their purpose? Has all these social security measures alleviated their problems to a certain extentnor not? The main objective were to find out if their socio economic status changed after migration and to find out if there was any possibility to avail help from the government schemes other than Pradhan Mantri Jeevan Jyoti Bhima Yojane and Prsdhan Mantri Suraksha Bhima Yojana or get help from NGO’s. Research gap showed that there was many shortcomings for these distressed groups as they were sidelined repeatedly but why was it so.? Did they avail of 1% cess meant for construction workers.? Research Methodology followed was using both primary and secondary data though it was a primary study. Descriptive analysis was followed. Simple random sampling was carried out and percentage method was used for data analysis. The findings indicated that most of the time they were not paid the full amount, often fell sick besides there was no prevention for the on site accidents and no immediate medical help was forth coming. Conclusion showed that this problem of distress migration arose because of severe drought conditions in many north Karnataka states and their inability to work as agricultural labourers as big farmers preferred to use tractors. Socially and economically they were a totally repressed lot and suffered more post pandemic in their quest to sustain themselves and their families.
How Two English Language Arts Teachers’ Beliefs and Practices Impact Their Students’ Academic and Emotional Success
Authors: Succar Christiana C.
Published: April 2023

This study commenced as part of a more extensive narrative inquiry about a literacy coach building relationships with two early-career sixth-grade English language arts teachers. The more extensive study revealed a gap in research about the teachers' beliefs and practices and their impact on their students' academic and emotional success. The research questions are: (1) in what ways do two teachers' beliefs and professional knowledge influence their teaching philosophies? (2) How do these teachers' identities influence student outcomes? The two teacher participants took part in interviews, observations, and reflections. By re-storying the data into narratives, three themes from each question emerged. The data shows that teachers firmly believe in their roles in student learning, pedagogical styles, content planning, and curriculum. Additionally, teacher identities influence student outcomes with their engagement, relationships, and comfort in the classroom environment. The results of this study add to the growing body of research on the impact of student success concerning how teachers' beliefs and practices play a role in academics and the social and emotional well-being of overall student achievement.
Co-Exploring Meaning in Everyday Life for People in Mental Health Recovery: A Photovoice Study
Authors: Tønnessen Siw , Ness Ottar , Klevan Trude
Published: April 2023

Research on mental health recovery points to an interdependent relationship between experiences of meaning and experiences of recovery; meaning in everyday life promotes recovery, and recovery promotes meaning in everyday life. In this study we address the following question: What do people with mental challenges find meaningful in their everyday life? To explore this question, we offered disposable cameras to people with mental health challenges and asked them to photograph whatever makes their life meaningful. As part of the collaborative procedure of the study, a competence group contributed to different stages of the research process and the visual data were analyzed by the participants themselves in a participant-driven thematic analysis. Through the analysis the participants constructed seven topics addressing the research question: (1) plants and trees, (2) poems and texts, (3) art, (4) music, (5) going for a walk, (6) esthetics, and (7) public movement. An important methodological implication of the study is how photovoice can be a useful way of generating knowledge from the first-person perspective. The participants’ findings may be interpreted as “small things” that are easily overlooked. When the competence group viewed the participants’ photos, they talked about photos they expected to see but found to be missing. Therefore, we offer a discussion related to the photovoice methodology and suggest the importance of considering absent but expected photographs in such a study.