Comparison of Tool Wear, Surface Morphology, Specific Cutting Energy and Cutting Temperature in Machining of Titanium Alloys Under Hybrid and Green Cooling Strategies

Munish Kumar Gupta,P. Niesłony,Mehmet Erdi Korkmaz,Mustafa Kuntoğlu,G. M. Królczyk,Mustafa Günay,Murat Sarikaya 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.10 No.6

Cutting energy must be reduced in order to make machining processes more eco-friendly. More energy was expended for the same amount of material removed, hence a higher specific cutting energy (SCE) implies inefficient material removal. Usually, the type of coolants or lubricants affects the SCE, or the amount of energy needed to cut a given volume of material. Therefore, the present work deals with a study of SCE in the turning of Ti–3Al–2.5V alloy under green cooling strategies. In spite of this, the research effort is also focused on the mechanism of tool wear, surface roughness, and cutting temperature under hybrid cooling, i.e., minimum quantity lubrication (MQL) and cryogenic. The tool wear rate, were explored with tool mapping analysis, and the results were compared with dry, MQL, and liquid nitrogen (LN2) conditions. The tool wear rate analysis claims that the dry condition causes more built up edge (BUE) formation. In addition, the hybrid cooling conditions are helpful in reducing the SCE while machining titanium alloys.

Studies on Geometrical Features of Tool Wear and Other Important Machining Characteristics in Sustainable Turning of Aluminium Alloys

Munish Kumar Gupta,P. Niesłony,Murat Sarikaya,Mehmet Erdi Korkmaz,Mustafa Kuntoğlu,G. M. Królczyk 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.10 No.4

The aerospace and automotive industries make extensive use of aluminium and its alloys. Contrarily, machining of aluminium (Al) alloys presents a number of difficulties, including, but not limited to, poor surface finishing, excessive tool wear, decreased productivity etc. Therefore, it’s very important to measure the machining characteristics during machining of aluminium alloy with sustainable cooling strategies. In this work, a new approach of measurement was adopted to measure the critical geometrical aspects of tool wear, surface roughness, power consumption and microhardness while machining AA2024-T351 alloy under dry, minimum quantity lubrication (MQL), liquid nitrogen (LN2) and carbon dioxide (CO2) cooling conditions. Initially, the various aspects of tool wear were studied with the help of Sensofar Confocal Microscope integrated with Mountains map software and then, the other results such as surface roughness, power consumption and microhardness were measured as per the ISO standards. The outcome of these measurement studies confirms that LN2 and CO2 cooling is helpful in improving the machining characteristics of AA2024-T351 alloy. When compared to dry conditions, the surface roughness values of MQL, LN2, and CO2 all have values that are lowered by 11.90%, 30.95%, and 39.28% respectively, and also power consumption values were lowered by 3.11%, 6.46% and 11.5% for MQL, CO2 and LN2 conditions, respectively.

Modified Endoscopic Ultrasound Needle to Obtain Histological Core Tissue Samples: A Retrospective Analysis

Munish Ashat,Kaartik Soota,Jagpal S. Klair,Sarika Gupta,Chris Jensen,Arvind R. Murali,Randhir Jesudoss,Rami El Abiad,Henning Gerke 대한소화기내시경학회 2020 Clinical Endoscopy Vol.53 No.4

Background/Aims: Endoscopic ultrasound (EUS)-guided fine-needle aspiration is very effective for providing specimens forcytological evaluation. However, the ability to provide sufficient tissue for histological evaluation has been challenging due to thetechnical limitations of dedicated core biopsy needles. Recently, a modified EUS needle has been introduced to obtain tissue coresamples for histological analysis. We aimed to determine (1) its ability to obtain specimens for histological assessment and (2) thediagnostic accuracy of EUS-guided fine-needle biopsy (EUS-FNB) using this needle. Methods: We retrospectively analyzed consecutive cases of FNB using modified EUS needles for 342 lesions in 303 patients. Thecytology and histological specimens were analyzed. Diagnostic accuracy was calculated. Results: Adequate cytological and histological assessment was possible in 293/342 (86%) and 264/342 (77%) lesions, respectively. Diagnostic accuracy of the cytological specimen was 294/342 (86%) versus 254/342 (74%) for the histological specimen (p<0.01). Diagnostic accuracy of the combined cytological and histological assessment was 323/342 (94.4%), which was significantly higher thanthat of both histology alone (p<0.001) and cytology alone (p=0.001). Conclusions: EUS-FNB with the modified EUS needle provided histologic tissue cores in the majority of cases and achieved excellentdiagnostic accuracy with few needle passes.

Impact of Service Quality on Behavioural Intention to Use Fin Tech Payment Services: An Extension of SERVEQUAL Model

Vikas Sharma,Sanjay Taneja,Munish Gupta,KshitizJangir,Ercan Ozen 한국경영정보학회 2023 Asia Pacific Journal of Information Systems Vol.33 No.4

The study aims to determine the impact of quality outcomes on behavior intentions in Financial Technology (FinTech) payment services. The study is focused on the development and testing of the impact of the SERVQUAL model on the TAM, i.e., Technology Acceptance Model for the measurement of the behavioral intention of users to use fintech payment services. The sample entails 578 specific survey responses from northern India from October to December 2022. The respondents were users of FinTech. The PLS-SEM technique was employed to explain the implementation process. Consequently, it discovered a significant relationship between the SERVQUAL models and the impact on behavioral intentions identified by TAM. The study will provide insight into the factors that impact the quality outcomes and adoption of Fintech payment services to the providers. The paper demystifies FinTech payment services in the range of perception of service quality outcomes and provides essential theories. The TAM model reflects the customer’s sense of satisfaction, usefulness, and attitude. In contrast, the SERVQUAL model demonstrates the user’s assessment of service quality outcomes such as quality, trust, security, and service quality positively affects behavioral intention in FinTech payment services.

The “Rail Technique” for Correction of Cervicothoracic Kyphosis: Case Report and Surgical Technique Description

Alekos A. Theologis,Munish C. Gupta 대한척추신경외과학회 2020 Neurospine Vol.17 No.3

Cervicothoracic deformity correction often necessitates a shortening operation, consisting of a 3-column osteotomy (3CO). While effective, segmental compression and in situ and cantilever bending often place screws under considerable stress and may jeopardize deformity correction. In this report, we present the surgical technique of a novel method, the “rail technique,” to shorten across a vertebral column resection (VCR) for cervicothoracic deformity correction. A 65-year-old woman with a history of a C5-pelvis posterior instrumented fusion (PSIF) presented with chin-on-chest deformity after a prior proximal junctional failure/kyphosis at T4 (30° T3–5) above a prior T5-pelvis PSIF that was stabilized in situ. She underwent an uncomplicated revision C2–T10 PSIF with shortening across a T4 VCR using the “rail technique.” Postoperatively, radiographs demonstrated excellent restoration of and normalization of cervical sagittal alignment, thoracic kyphosis, focal T3–5 kyphosis (7°), and global sagittal alignment. At 1-year postoperation, she was without neck pain and reported significant improvements in self-image, mental health, satisfaction, and subscale Scoliosis Research Society-22 scores compared to preoperative values. The “rail technique” is a safe and effective method for shortening over a 3CO to correct the cervicothoracic deformity.

Performance Investigation of Dual-Halo Dual-Dielectric Triple Material Surrounding Gate MOSFET with High-κ dielectrics for Low Power Applications

Prashant Kumar,Neeraj Gupta,Nitin Sachdeva,Tarun Sachdeva,Munish Vashishath 대한전자공학회 2020 Journal of semiconductor technology and science Vol.20 No.3

The rapidly growth in semiconductor industry puts huge demand of scalable devices with low standby power for future VLSI chips. The further mitigation in device dimension becomes a challenging task due to the existence of unavoidable short channel effects. The introduction of gate stack and channel engineering in MOSFET devices open a new window for future generation devices. This paper presents gate stack structure with low-κ dielectric material as silicon oxide and replacement of various high-κ dielectric materials to analyze the device performance. The unification of new oxide material in the device enhances the immunity against SCEs and improves the gate leakage current. Dual-Halo Dual-Dielectric Triple Material Surrounding Gate (DH-DD-TM-SG) MOSFET has shown better performance with high dielectric constant materials. The device exhibits more value of transconductance with high-κ dielectrics.

A State-of-the-Art Review on Recently Developed Sustainable and Green Cooling/Lubrication Technologies in Machining Metal Matrix Composites (MMCs)

Rashid Ali Laghari,Ning He,Muhammad Jamil,Muhammad Irfan Hussain,Munish Kumar Gupta,Grzegorz M. Krolczyk 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.10 No.6

Metal matrix composites (MMCs) are lightweight, hard materials applied in heavy-duty applications such as automobile, aerospace, and electronics, as well as sports equipment. MMCs reveal exceptional physical and mechanical properties, including high strength, corrosion, wear resistance, higher stiffness, and toughness. However, owing to poor surface finish, accelerated tool wear, and high material removal cost, MMCs are categorized as difficult-to-cut composites. This article reviews sustainable machining under different lubrication and cooling approaches and the economics of the operation for MMCs. The study focuses on optimizing machinability factors, such as surface integrity, chip formation, tool wear, and sustainability analysis. To attain this goal, the review evaluates suitable cutting parameters for Aluminum, Titanium, Magnesium, and Copper-based metal matrix composites, which hitherto have not been explored or summarized comprehensively. This study provides strong guidance regarding selection of precise cutting parameters for MMCs. The findings of this review suggest that different cooling/lubrication technologies can optimize and improve the sustainability and machinability characteristics, extend tool life and surface quality, during the cutting operation.

Novel Use of Cellulose Based Biodegradable Nano Crystals in the Machining of PPS Composites: An Approach Towards Green Machining

Serhat Şap,Üsame Ali Usca,Yavuz Selim Tarih,Adem Yar,Mustafa Kuntoğlu,Munish Kumar Gupta 한국정밀공학회 2024 International Journal of Precision Engineering and Vol.11 No.1

Because of their biodegradable and regenerative properties, cellulose nanocrystals derived primarily from naturally occurring cellulose fibers serve as a sustainable and environmentally beneficial material for most applications. Although these nanocrystals are inherently hydrophilic, they can be surface functionalized to suit a wide range of demanding requirements, such as those associated with the creation of high-performance nanocomposites in hydrophobic polymer matrices. Therefore, the present work deals with the application of cellulose-based biodegradable nanocrystals as a lubricant in the machining of PPS composites. In this study, milling process was considered to investigate the influence of the sustainable lubricating conditions on the machinability indexes of PPS composites. As a novel cooling approach, water-based solutions enriched by cellulose nanocrystals with different reinforcements (0.25%, 0.5%, and 1%) were used over known methods such as MQL, conventional flood, and dry. According to the research outcomes, cellulose nanocrystals-based nanofluids provided satisfying contributions on retarding the tool wear and reducing the cutting temperatures considerably. Despite the surface-related results such as roughness, topography and texture are promising for the developed strategy; further investigations will be useful to determine ideal water-particle concentration to improve the quality of the machined surface.

Outcomes of Surgical Treatment for Patients With Mild Scoliosis and AgeAppropriate Sagittal Alignment With Minimum 2-Year Follow-up

Justin K. Scheer,Justin S. Smith,Peter G. Passias,Han Jo Kim,Shay Bess,Douglas C. Burton,Eric O. Klineberg,Virginie Lafage,Munish Gupta,Christopher P. Ames 대한척추신경외과학회 2023 Neurospine Vol.20 No.3

Objective: The goal of this study was to determine if patients with mild scoliosis and ageappropriate sagittal alignment have favorable outcomes following surgical correction. Methods: Retrospective review of a prospective, multicenter adult spinal deformity database. Inclusion criteria: operative patients age ≥18 years, and preoperative pelvic tilt, mismatch between pelvic incidence and lumbar lordosis (PI–LL), and C7 sagittal vertical axis all within established age-adjusted thresholds with minimum 2-year follow-up. Health-related quality of life (HRQoL) scores: Oswestry Disability Index (ODI), 36-item Short Form health survey (SF-36), Scoliosis Research Society-22R (SRS22R), back/leg pain Numerical Rating Scale and minimum clinically important difference (MCID)/substantial clinical benefit (SCB). Two-year and preoperative HRQoL radiographic data were compared. Patients with mild scoliosis (Mild Scoli, Max coronal Cobb 10°–30°) were compared to those with larger curves (Scoli). Results: One hundred fifty-one patients included from 667 operative patients (82.8% women; average age, 56.4 ± 16.2 years). Forty-two patients (27.8%) included in Mild Scoli group. Mild Scoli group had significantly worse baseline leg pain, ODI, and physical composite scores (p < 0.02). Mean 2-year maximum coronal Cobb angle was significantly improved compared to baseline (p < 0.001). All 2-year HRQoL measures were significantly improved compared to (p < 0.001) except mental composite score, SRS activity and SRS mental for the Mild Scoli group (p > 0.05). From the mild Scoli group, 36%–74% met either MCID or SCB for the HRQoL measures. Sixty-four point three percent had minimum 1 complication, 28.6% had a major complication, 35.7% had reoperation. Conclusion: Mild scoliosis patients with age-appropriate sagittal alignment benefit from surgical correction, decompression, and stabilization at 2 years postoperative despite having a high complication rate.