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.

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.

An Approach for Designing a UMTS and CDMA2000 Dual Standard Compatible Baseband ASIC

Kumar Amit,Bansal Munish,Kumar Ratnam V. Raja Korea Institute of Information and Telecommunicati 2004 정보통신설비학회논문지 Vol.3 No.1

The Third Generation (3G) cellular mobile communication systems aim at providing higher data rates, improved quality of service, support for multimedia applications and global roaming. Cdma2000 and Universal Mobile Telecommunication System (UMTS) have emerged as two leading 3G standards in USA and European countries, respectively. Both the standards are capable of delivering high bandwidth data, voice and multimedia services to users of mobile equipment, but are not directly interoperableand are not available across different geographic areas, due to which global roaming is not possible in true sense of using single mobile equipment. However, both UMTS and cdma2000 are based on wideband code division multiple access (WCDMA) as the access method. Due to this, there exist some inherent commonalities between them. In this paper we will try to exploit the commonalities between the two standards in order to design an ASIC, which can provide dual standard capability. This paper discusses the physical layer aspects of the two standards and proposes an approach to design an ASIC which can be mapped to baseband processing part of the physical layer and is capable of delivering for either of the two aforementioned standards.

MDP Feature Extraction Technique for Offline Handwritten Gurmukhi Character Recognition

Munish Kumar,M. K. Jindal,R. K. Sharma 한국산학기술학회 2013 SmartCR Vol.3 No.6

Character recognition is intricate work because of the various writing styles of different individuals. Most of the published work on handwritten character recognition problems deals with statistical features, and a few works deal with structural features, in general, and Gurmukhi script, in particular. In the present work, we propose a methodology for offline handwritten Gurmukhi character recognition by using a modified division points (MDP) feature extraction technique. We also compare this technique with other recently used feature extraction techniques, namely zoning features, diagonal features, directional features, intersection and open end points features, and transition features. To select a representative set of features is the most significant task for a character recognition system. After feature extraction, the classification stage makes use of the features extracted in the previous stage to recognize the character. In this work, we used linear-support vector machines (linear-SVM), k-nearest neighbor (k-NN), and multilayer perceptron (MLP) classifiers for recognition. For experimental analysis, we used 10,500 samples of the isolated, offline, handwritten, basic 35 akhars of Gurmukhi script. The proposed system achieved a maximum recognition accuracy of 84.57%, 85.85% and 89.20% with linear-SVM, MLP and k-NN classifiers, respectively, with a five-fold cross validation technique.

PCA-based Offline Handwritten Character Recognition System

Munish Kumar,M. K. Jindal,R. K. Sharma 한국산학기술학회 2013 SmartCR Vol.3 No.5

Principal component analysis (PCA) has been used widely in pattern recognition to reduce the extent of the data. In this paper, we explore using this technique to recognize offline handwritten Gurmukhi characters, and a system for offline handwritten Gurmukhi character recognition using PCA is proposed. The system first prepares a skeleton of the character so that meaningful feature information about the character can be extracted. For classification, we used k-nearest neighbor, Linear-SVM, polynomial-SVM and RBF-SVM based approaches and combinations of these approaches. In this work, we collected 16,800 samples of isolated offline handwritten Gurmukhi characters. These samples were divided into three categories. In category 1 (5600 samples), each Gurmukhi character was written 100 times by a single writer. In category 2 (5600 samples), each Gurmukhi character was written 10 times by 10 different writers, and in category 3 (5600 samples), each Gurmukhi character was written by 100 different writers. The set of the basic 35 akhars of Gurmukhi has been considered here. A partitioning strategy for selecting the training and testing patterns is also explored in this work. We used zoning, diagonal, directional, transition, intersection and open end point, parabola curve fitting?based and power curve fitting?based feature extraction in order to find the feature set for a given character. The proposed system achieves a recognition accuracy of 99.06% in category 1, 98.73% in category 2 and 78.30% in category 3.

[기고] An Approach for Designing a UMTS and CDMA2000 Dual Standard Compatible Baseband ASIC

Amit Kumar,Munish Bansal 한국정보통신설비학회 2004 정보통신설비학회논문지 Vol.3 No.1

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.

Aqueous carboxymethyl gum kondagogu as vehicle for ocular delivery

Ashok Kumar,Munish Ahuja 한국약제학회 2014 Journal of Pharmaceutical Investigation Vol.44 No.4

Aqueous solutions of carboxymethyl gumkondagogu (CMGK), an anionic bioadhesive polymer wereevaluated as vehicles for ophthalmic delivery using tropicamideas a model drug. Aqueous ophthalmic solution oftropicamide (1 %, w/v) in CMGK (5 %, w/v) dispersionswere formulated. The aqueous CMGK vehicle, formulatedtropicamide eye drops and commercial tropicamide formulationswere assessed comparatively for ex vivo oculartolerance using hen’s egg chorioallantoic membrane assay. The results indicated ocular tolerability of aqueous CMGKvehicle. The results of comparative ex vivo corneal permeationstudy of tropicamide from the aqueous CMGKvehicle (5 %, w/v) conducted across isolated goat cornearevealed a no significant difference in the corneal permeationof tropicamide from the CMGK vehicle based formulationas compared to the commercial formulation. Further, the results of in vivo mydriatic response studyconducted in rabbits revealed a non significant differencein the mydriatic response of tropicamide from the aqueousCMGK vehicle and commercial formulations. In conclusion,CMGK can be used as an ocularly tolerable polymerfor formulating ophthalmic dosage forms.

Outcomes of Fast-Track Multidisciplinary Care of Hip Fractures in Veterans: A Geriatric Hip Fracture Program Report

Vikas Kulshrestha,Munish Sood,Santhosh Kumar,Pramila Sharma,Yash Kumar Yadav 대한정형외과학회 2019 Clinics in Orthopedic Surgery Vol.11 No.4

Background: Hip fractures are a significant cause of morbidity and mortality in the elderly. Fast-track multidisciplinary co-management of these patients, rapid preoperative optimization, early surgery, and expeditious rehabilitation may minimize morbidity and mortality. In this study, we evaluated outcomes of fixation of hip fractures in the elderly patients managed by Geriatric Hip Fracture Program at a military hospital in India. Methods: A total of 114 patients above 60 years of age with hip fractures were enrolled. They were comanaged by a team of specialists and fast-tracked to surgery. Independent ambulation with support of a walker was achieved before discharge to home. Patients were followed up for 1 year. Results: The average age of the 114 patients was 77 years; 24 patients were octogenarian. Eighty-four percent of injuries were due to a domestic fall. Hypertension (41%) and diabetes (22%) were the most common comorbidities. All patients were optimized before surgery. The average delay from injury to admission was 1.7 days (range, 0 to 14 days) and that from admission to surgery was 1.8 days (range, 0 to 19 days). Hence, the average time from injury to surgery was 3.5 days. The length of stay in hospital was, as per rehabilitative milestones achieved, 2 to 5 days in 40% of the patients and 6 to 15 days in 60% of the patients. At 1 year after surgery, 95 patients were independently ambulant (56 patients with support and 39 patients without support). Twenty-three percent of the patients had postoperative complications and eight patients died (7.7%) at 1-year follow-up; 11 patients were lost to follow-up. Conclusions: Elderly hip fracture has a high risk of mortality (14%–58%). Thus, expeditious surgery within 24 hours of admission has been advocated in the Western literature to minimize mortality. Mortality rate at 1 year after surgery remains at 10% to 24%. In our study, even with aggressive co-management, the average delay to hip fracture fixation was more than 3 days; however, the 1-year mortality was relatively low (7.7%). This indicates the importance of preoperative optimization and postoperative rehabilitation for independent ambulation and mortality reduction in the elderly population.

Evaluation of mucoadhesive property of gum ghatti

Shelly Jangra,Munish Ahuja,Ashok Kumar 한국약제학회 2013 Journal of Pharmaceutical Investigation Vol.43 No.6

Gum ghatti is a high molecular weight anionic polysaccharide used in food and pharmaceutically applied as binder, thickener, emulsifier and sustained release matrix as promising polysaccharide which has not been explored as mucoadhesive polymer. The present study was carried out to evaluate gum ghatti as mucoadhesive polymer by preparing buccal disc using metronidazole as model drug. The effect of varying concentration of gum ghatti and compression pressure on ex vivo bioadhesion time and in vitro release was studied using 2-factor 3-level central composite experimental design. Metronidazole loaded gum ghatti buccal discs were evaluated by weight uniformity,thickness, friability and content uniformity. Ex vivo bioadhesion time of buccal disc was measured as time taken by buccal disc to detach from chicken buccal pouch. In vitro release behavior was studied by adhering disc to the bottom of vessel using USP type II (TDT-08L Electrolab,Mumbai, India) dissolution release apparatus. The release data was fitted into various kinetic models. The prepared buccal discs were of uniform average weight,thickness, drug content and having friability less than 1 %. The results of optimization study revealed that increasing the proportion of gum ghatti results in increase in bioadhesion time and decrease the release rate while increasing compression pressure was found to increase the release rate. The present work concluded that gum ghatti is promising mucoadhesive polymer which can be used effectively.