Mohammad Asif Equbal
@citranchi.ac.in
Associate Professor, Mechanical Engineering Department
Cambridge institute of Technology, Ranchi
7
Scopus Publications
187
Scholar Citations
3
Scholar h-index
3
Scholar i10-index
Scopus Publications
- Machine learning in additive manufacturing: A comprehensive insight
Md Asif Equbal, Azhar Equbal, Zahid A. Khan, and Irfan Anjum Badruddin
Elsevier BV - Sustainable coatings for green solar photovoltaic cells: performance and environmental impact of recyclable biomass digestate polymers
Aiyeshah Alhodaib, Zeinebou Yahya, Osama Khan, Azhar Equbal, Md Shaquib Equbal, Mohd Parvez, Ashok Kumar Yadav, and M. Javed Idrisi
Springer Science and Business Media LLC
AbstractThe underutilization of digestate-derived polymers presents a pressing environmental concern as these valuable materials, derived from anaerobic digestion processes, remain largely unused, contributing to pollution and environmental degradation when left unutilized. This study explores the recovery and utilization of biodegradable polymers from biomass anaerobic digestate to enhance the performance of solar photovoltaic (PV) cells while promoting environmental sustainability. The anaerobic digestion process generates organic residues rich in biodegradable materials, often considered waste. However, this research investigates the potential of repurposing these materials by recovering and transforming them into high-quality coatings or encapsulants for PV cells. The recovered biodegradable polymers not only improve the efficiency and lifespan of PV cells but also align with sustainability objectives by reducing the carbon footprint associated with PV cell production and mitigating environmental harm. The study involves a comprehensive experimental design, varying coating thickness, direct normal irradiance (DNI) (A), dry bulb temperature (DBT) (B), and relative humidity (C) levels to analyze how different types of recovered biodegradable polymers interact with diverse environmental conditions. Optimization showed that better result was achieved at A = 8 W/m2, B = 40 °C and C = 70% for both the coated material studied. Comparative study showed that for enhanced cell efficiency and cost effectiveness, EcoPolyBlend coated material is more suited however for improving durability and reducing environmental impact NanoBioCelluSynth coated material is preferable choice. Results show that these materials offer promising improvements in PV cell performance and significantly lower environmental impact, providing a sustainable solution for renewable energy production. This research contributes to advancing both the utilization of biomass waste and the development of eco-friendly PV cell technologies, with implications for a more sustainable and greener energy future. This study underscores the pivotal role of exploring anaerobic digestate-derived polymers in advancing the sustainability and performance of solar photovoltaic cells, addressing critical environmental and energy challenges of our time.Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 7 Given name: [Ashok] Last name [Kumar Yadav]. Also, kindly confirm the details in the metadata are correct.correct - Comparative analysis of machine learning and artificial intelligence models for optimizing mixed refrigerant characteristics in a hydrogen pre-cooling storage system
Md Shaquib Equbal, Osama Khan, Azhar Equbal, Mohd Parvez, Shadab Ahmad, Zeinebou Yahya, Aiyeshah Alhodaib, Ashok Kumar Yadav, and Ümit Ağbulut
Elsevier BV - Grey based Taguchi method for multi-response optimization of FSW of aluminium AA 6061 alloy
Pranav Ravindrannair, Azhar Equbal, Md. Asif Equbal, Kuldeep K. Saxena, and Md. Israr Equbal
Springer Science and Business Media LLC - A recent review on advancements in dimensional accuracy in fused deposition modeling (FDM) 3D printing
Azhar Equbal, Ramesh Murmu, Veenit Kumar, and Md. Asif Equbal
American Institute of Mathematical Sciences (AIMS)
<p>Fused deposition modeling (FDM) fabricated components have gained significant attention and widespread adoption across modern industries due to their versatility, serving as both prototypes and final products. FDM offers rapid and cost-effective prototyping and production capabilities; however, utilizing directly manufactured FDM parts is not practical. Secondary operations like post-processing, testing, and validation are typically required to ensure that the fabricated parts meet the necessary standards for their intended applications. Desired repeatability, reproducibility, reliability, and preciseness should be the main prerequisites of the part fabricated. It is desirable that additive manufacturing (AM) products should be produced with advanced control processes which should possess acceptable quality characteristics. Ensuring the dimensional accuracy of FDM parts is very crucial, and hence it is important to emphasize the key factors that influence the dimensional precision during their fabrication. Sharing insights into these critical factors is essential to steer scholars, researchers, and the AM industry towards informed decisions and future advancements in AM. We aimed to outline the significant factors influencing the dimensional accuracy of the FDM part. These research papers are collected from Scopus and web of science data using "FDM" and "dimensional accuracy" as the keywords. We include the latest papers published especially during 2020 to 2024, which were lacking in earlier research.</p> - A review on the rapid liquid printing (RLP): future 3D printing technology
Azhar Equbal, Md. Asif Equbal, Zahid A. Khan, and Irfan Anjum Badruddin
Springer Science and Business Media LLC - RSM-BASED STATISTICAL APPROACH TO ENHANCE THE COMPRESSIVE PERFORMANCE OF ABS P400 PARTS FABRICATED VIA FDM TECHNOLOGY
AZHAR EQUBAL, MD. ASIF EQUBAL, RABNAWAZ AHMAD, MANOJ KUMAR, OSAMA KHAN, ZEINEBOU YAHYA, AIYESHAH ALHODAIB, and ASHOK KUMAR YADAV
World Scientific Pub Co Pte Ltd
This research investigates the performance of ABS P400 parts under compressive loading. These ABS P400 parts are fabricated by fused deposition modeling (FDM) process using omnidirectional printing. The effects of three critical parameters, raster angle (A), air gap (B), and raster width (C), each at three different levels, were analyzed on three different performance measures, i.e. total deformation up to failure ([Formula: see text]) measured in %, maximum energy ([Formula: see text]) in MJ/m3 and break energy ([Formula: see text]) in MJ/m3. Results of experimentations were analyzed using analysis of variance (ANOVA), perturbation curve and 3D surface plots. The research established the anisotropic nature, durability and less brittleness of the FDM fabricated ABSP400 part, which leads to lower strength and also influence the energy absorbing behavior while deformation under compression. Complex relationships were exhibited between the chosen parameters and studied measures. It was also observed that [Formula: see text] is noticeable due to less brittleness of ABS P400 however, [Formula: see text] and [Formula: see text] vary in a contradictory fashion with changes in process parameters. The models were validated using normality plots. Multi-objective optimization was done using the desirability approach to determine the optimal combination of FDM process parameters for optimum responses. The desirability result showed that the optimized input parameter is [Formula: see text][Formula: see text]mm, and [Formula: see text][Formula: see text]mm which yield maximized optimum responses as [Formula: see text]%, [Formula: see text][Formula: see text]MJ/m3, and [Formula: see text][Formula: see text]MJ/m3. The work not only reflects the effect of three FDM parameters on the total deformation up to failure ([Formula: see text] in %) but, in addition, energy absorption behavior of FDM parts under compression is also investigated. The study on the behavior of energy at ultimate stress or ultimate load and breaking stress or breaking load were rarely investigated in earlier research which reflects the novelty of our research. - Evaluating CNC Milling Performance for Machining AISI 316 Stainless Steel with Carbide Cutting Tool Insert
Azhar Equbal, Md. Asif Equbal, Md. Israr Equbal, Pranav Ravindrannair, Zahid A. Khan, Irfan Anjum Badruddin, Sarfaraz Kamangar, Vineet Tirth, Syed Javed, and M. I. Kittur
MDPI AG
The present study investigates the CNC milling performance of the machining of AISI 316 stainless steel using a carbide cutting tool insert. Three critical machining parameters, namely cutting speed (v), feed rate (f) and depth of cut (d), each at three levels, are chosen as input machining parameters. The face-centred central composite design (FCCCD) of the experiment is based on response surface methodology (RSM), and machining performances are measured in terms of material removal rate (MRR) and surface roughness (SR). Analysis of variance, response graphs, and three-dimensional surface plots are used to analyse experimental results. Multi-response optimization using the data envelopment analysis based ranking (DEAR) approach is used to find the ideal configuration of the machining parameters for milling AISI 316 SS. The variables v = 220 m/min, f = 0.20 mm/rev and d = 1.2 mm were obtained as the optimal machine parameter setting. Study reveals that MRR is affected dominantly by d followed by v. For SR, f is the dominating factor followed by d. SR is found to be almost unaffected by v. Finally, it is important to state that this work made an attempt to successfully machine AISI 316 SS with a carbide cutting tool insert, to investigate the effect of important machining parameters on MRR and SR and also to optimize the multiple output response using DEAR method. - Characteristics of Conventional and Microwave Sintered Iron Ore Preform
Azhar Equbal, Mohammad Ali, Md. Asif Equbal, S. C. Srivastava, Zahid A. Khan, Md. Israr Equbal, Irfan Anjum Badruddin, Khalid Mohamed El-Hady, and Sarfaraz Kamangar
MDPI AG
In this study, compacted hematite (Fe2O3) preforms were made and sintered at various temperatures, such as 1250 °C and 1300 °C, using both conventional and microwave sintering methods. The density, porosity, microhardness, cold crushing strength, microphotographs, and X-ray diffraction (XRD) analysis of the sintered preforms were used to evaluate the performance of the two sintering methods. It was found that microwave sintered preforms possessed lesser porosity and higher density than conventionally sintered preforms owing to uniform heating of the powdered ore in microwave sintering method. Furthermore, it was also observed that microwave sintered preforms exhibited relatively higher cold crushing strength and hardness than conventionally sintered preforms. Thus, the overall results revealed that microwave sintering yielded better properties considered in the present study. - Investigating the dimensional accuracy of the cavity produced by abs p400 polymer-based novel edm electrode
Azhar Equbal, Asif Equbal, Zahid A. Khan, Irfan Anjum Badruddin, Mohamed Bashir Ali Bashir, and Hussein Alrobei
MDPI AG
In the present study, cylindrical ABS P400 polymer parts (diameter 6.5 mm) to be used as die-sinking EDM (electric discharge machining) novel electrodes were fabricated using a fused deposition modeling (FDM) process. To meet the conductivity requirement in EDM, ABS parts were metallized using an innovative method that comprised putting aluminum–charcoal (Al–C) on them followed by their copper electroplating. Real-time EDM of the mild steel workpiece was performed using novel electrodes, and machining performance of the electrodes, measured in terms of dimensional accuracy, i.e., change in diameter (ΔD) and change in depth (ΔH) of the cavity, under varying levels of three EDM factors, i.e., current (I), pulse on time (Ton), and pulse off time (Toff), was investigated. Machining results were analyzed using analysis of variance (ANOVA), perturbation graphs, and 3D surface plots. The optimal setting of the EDM parameters for minimizing ΔD and ΔH was determined using the desirability function approach. The suitability of the novel electrodes for EDM was ascertained by comparing their machining results with those of solid copper (SC) electrodes and electrodes fabricated by FDM and metallized using the electro-deposition method (FDM-EM), already reported in the literature, under similar machining conditions. From the results, it was found that ΔD and ΔH were less when EDM was performed using novel electrodes. - A Review and Reflection on Part Quality Improvement of Fused Deposition Modelled Parts
A Equbal, Md. A. Equbal, A K Sood, R Pranav, and Md. I. Equbal
IOP Publishing
Fused deposition modelling (FDM) is an extrusion based additive manufacturing process which fabricates the part by extruding semi-molten thermoplastic material through a small nozzle in a machine plateform. The material is deposited layer over layer and the part is fabricated following the bottom up approach. The process can built any complex part geometry in very less time without any tooling problem. Despite of having numerous advantages, fused deposition modelled part’s performance is poorer when measured in terms of part qualities like dimensional accuracy, surface roughness and mechanical strength. Considering the domestic and industrial usage of FDM technology various researchers have contributed their effort in improvement of these part qualities prior to its application. The present study is headed towards reviewing their efforts and reflecting the techniques used for optimization of FDM part qualities. - Optimisation of forging parameters of 35C8 steel using grey relational analysis
Md Israr Equbal, Azhar Equbal, Md Asif Equbal, and R. Pranav
Inderscience Publishers - A comparative study on electroplating of FDM parts
Azhar Equbal, Md. Israr Equbal, Anoop Kumar Sood, and Md. Asif Equbal
International Journal of Technology
Electroplating on fused deposition modeling parts through two different routes is presented in the study. One route follows the conventional method of electroplating using chromic acid for surface preparation or etching and the other route uses the novel method of electroplating using aluminium charcoal (Al-C) paste for surface preparation. Same plating conditions are used for both the routes employed. The result proposes that instead of shell cracking in few electroplated samples, Al-C route is also capable of producing good copper deposition on FDM samples. Cracks may develop in few samples electroplated through Al-C route, because of dissolution of paste at high operating condition during electroplating. Proper drying of electrolessly plated samples and adaptation of suitable operating condition reduces the risk of electroplated shell cracking. - A comprehensive model for supply chain performance measurement: Application in the coal beneficiation plant of steel manufacturing company
Md. Asif Equbal, Azhar Equbal, Archana Kumari, and Rajkumar Ohdar
IEEE
Companies are looking for a single solution or a set of matrices that they can apply to measure their supply chain performance but literature reveals that such a single solution does not exist. An important component in supply chain design and analysis is the establishment of an appropriate performance measurement and evaluation system. An effective supply chain performance measurement system must align with a company's own supply chain processes. In this paper, a comprehensive supply chain performance measurement and evaluation (CSCPME) methodology based on the study of several established performance measurement models is developed. The critical performance measures reflect the five specific criteria, viz. effectiveness, efficiency, quality, productivity, and profitability. The proposed CSCPME is applied to a real case study for one of its performance measure (effectiveness) evaluation. The developed CSCPME methodology may provide a framework for companies to build their in-house supply chain performance measurement systems. - Optimization of process parameters of FDM part for minimiizing its dimensional inaccuracy
- A comprehensive supply chain performance measurement and evaluation (Cspme) methodology
- An investigation on sliding wear of FDM built parts
Anoop Kumar Sood, Asif Equbal, Vijay Toppo, R.K. Ohdar, and S.S. Mahapatra
Elsevier BV - Prediction of dimensional accuracy in fused deposition modelling: A fuzzy logic approach
Asif Equbal, Anoop Kumar Sood, and S.S. Mahapatra
Inderscience Publishers
In the present work, effect of five factors viz., layer thickness, part build orientation, raster angle, raster to raster gap (air gap) and raster width each at three levels together with their interactions is studied on dimensional accuracy of fused deposition modelling (FDM) build part. Four performance characteristics i.e. percentage change in length, width, thickness and diameter considered in this study are converted into an equivalent response known as grey relational grade. Optimum factor levels are determined for maximisation of grey relational grade using grey-based Taguchi method. A fuzzy inference system (FIS) is proposed for prediction of overall dimensional accuracy using Taguchi's orthogonal array for developing inference engine. The results of FIS are compared with prediction values obtained through artificial neural network. It has been demonstrated that fuzzy model is able to predict overall dimensional accuracy at all operating condition to a high degree of accuracy. - Prediction and analysis of sliding wear performance of fused deposition modelling-processed ABS plastic parts
A Equbal, A K Sood, V Toppo, R K Ohdar, and S S Mahapatra
SAGE Publications
Fused deposition modelling (FDM) is gaining distinct advantage in manufacturing industries because of their ability to manufacture parts with complex shapes without any tooling requirement and human interface. The properties of FDM-built parts exhibit high dependence on process parameters and can be improved by setting parameters at suitable levels. Resistance to wear is an important consideration for enhancing the service life of functional parts. Hence, the present work focuses on an extensive study to understand the effect of five important parameters such as layer thickness, part build orientation, raster angle, raster width, and air gap on the sliding wear of test specimen. Microphotographs are used to explain the mechanism of wear. The study not only provides insight into complex dependency of wear on process parameters but also develops a statistically validated predictive equation. The equation can be used by the process planner for accurate wear prediction in practice.
RECENT SCHOLAR PUBLICATIONS
- A critical review on electro-discharge machining of non-conductive materials
A Equbal, A Equbal, H VMS, I Equbal, IA Badruddin, S Kamangar, ...
Machining Science and Technology 28 (6), 1092-1128 2024 - Machine learning in additive manufacturing: a comprehensive insight
MA Equbal, A Equbal, ZA Khan, IA Badruddin
International Journal of Lightweight Materials and Manufacture 2024 - A review on the rapid liquid printing (RLP): future 3D printing technology
A Equbal, MA Equbal, ZA Khan, IA Badruddin
Progress in Additive Manufacturing, 1-17 2024 - RSM-BASED STATISTICAL APPROACH TO ENHANCE THE COMPRESSIVE PERFORMANCE OF ABS P400 PARTS FABRICATED VIA FDM TECHNOLOGY
A Equbal, MA Equbal, R Ahmad, M Kumar, HRISHIKESH, O KHAN, ...
Surface Review and Letters, 2550021 2024 - Grey based Taguchi method for multi-response optimization of FSW of aluminium AA 6061 alloy
P Ravindrannair, A Equbal, MA Equbal, KK Saxena, MI Equbal
International Journal on Interactive Design and Manufacturing (IJIDeM) 18 (3 2024 - A recent review on advancements in dimensional accuracy in fused deposition modeling (FDM) 3D printing
A Equbal, R Murmu, V Kumar, MA Equbal
AIMS Materials Science 11 (5), 950-990 2024 - Optimizing the machining parameters during turning of EN 31 steel using TiN+ Al2O3+ TiCN coated tungsten carbide tool
J Prakash, A Equbal, P Ravindrannair, MA Equbal, MI Equbal
Materials Today: Proceedings 2023 - Analysis of The Crack in The Thick Pressure Vessel
A Kumar, MDA Equbal, B Prasad, MK Sahu
Materials and Structures 3 (01), 85-94 2023 - Study and Analysis of Failure Analysis of Wire Rope
RK Prasad, AR Ansari, MDA Equbal, MK Sahu
2023 - Evaluating CNC milling performance for machining AISI 316 stainless steel with carbide cutting tool insert
A Equbal, MA Equbal, MI Equbal, P Ravindrannair, ZA Khan, ...
Materials 15 (22), 8051 2022 - 5 Wearing Behaviour of Electrodes during
A Equbal, MA Equbal
Advanced Manufacturing Methods: Smart Processes and Modeling for 2022 - Wearing Behaviour of Electrodes during EDM of AISI 1035 Steel
A Equbal, MA Equbal
Advanced Manufacturing Methods, 101-112 2022 - Characteristics of Conventional and Microwave Sintered Iron Ore Preform
A Equbal, M Ali, MA Equbal, SC Srivastava, ZA Khan, MI Equbal, ...
Materials 15 (7), 2655 2022 - A Comparative Study on the Properties of the Iron Ore Perform Sintered Through Conventional and Microwave Sintering Methods
MI Equbal, M Ali, A Equbal, MA Equbal, ZA Khan, KK Saxena
Available at SSRN 4011869 2022 - Investigating the dimensional accuracy of the cavity produced by ABS P400 polymer-based novel EDM electrode
A Equbal, A Equbal, ZA Khan, IA Badruddin, MBA Bashir, H Alrobei
Polymers 13 (23), 4109 2021 - Application of machine learning in fused deposition modeling: a review
A Equbal, S Akhter, MA Equbal, AK Sood
Fused Deposition Modeling Based 3D Printing, 445-463 2021 - A Reflection on the Use of Additive Manufacturing in Nephrology for Education and Surgical Planning
A Equbal, S Akhtar, MA Equbal
Apollo Medicine 17 (4), 264-266 2020 - Multi-criterion decision method for roughness optimization of fused deposition modelled parts
A Equbal, MA Equbal, MI Equbal, AK Sood
Additive Manufacturing Technologies from an Optimization Perspective, 235-262 2019 - Effect of Temperature and Strain Rate of The Hot Deformation of V Microalloyed Steel on Flow Stress
MI Equbal, A Equbal, MA Equbal, RK Ohdar
International Journal of Materials Forming and Machining Processes (IJMFMP 2019 - An insight on current and imminent research issues in EDM
A Equbal, MI Equbal, MA Equbal, AK Sood
Non-Conventional Machining in Modern Manufacturing Systems, 33-54 2019
MOST CITED SCHOLAR PUBLICATIONS
- An investigation on sliding wear of FDM built parts
AK Sood, A Equbal, V Toppo, RK Ohdar, SS Mahapatra
CIRP Journal of Manufacturing Science and Technology 5 (1), 48-54 2012
Citations: 185 - Prediction of dimensional accuracy in fused deposition modelling: a fuzzy logic approach
A Equbal, AK Sood, SS Mahapatra
International Journal of Productivity and Quality Management 7 (1), 22-43 2011
Citations: 71 - Optimization of process parameters of FDM part for minimiizing its dimensional inaccuracy
A Equbal, AK Sood, AR Ansari, MA Equbal
International Journal of Mechanical and Production Engineering Research and 2017
Citations: 52 - Prediction and analysis of sliding wear performance of fused deposition modelling-processed ABS plastic parts
A Equbal, AK Sood, V Toppo, RK Ohdar, SS Mahapatra
Proceedings of the Institution of Mechanical Engineers, Part J: Journal of 2010
Citations: 40 - Metallization on FDM processed parts using electroless procedure
A Equbal, A Equbal, AK Sood
Procedia materials science 6, 1197-1206 2014
Citations: 30 - Evaluating CNC milling performance for machining AISI 316 stainless steel with carbide cutting tool insert
A Equbal, MA Equbal, MI Equbal, P Ravindrannair, ZA Khan, ...
Materials 15 (22), 8051 2022
Citations: 23 - A review and reflection on part quality improvement of fused deposition modelled parts
A Equbal, MA Equbal, AK Sood, R Pranav, MI Equbal
IOP Conference Series: Materials Science and Engineering 455 (1), 012072 2018
Citations: 14 - Investigating the dimensional accuracy of the cavity produced by ABS P400 polymer-based novel EDM electrode
A Equbal, A Equbal, ZA Khan, IA Badruddin, MBA Bashir, H Alrobei
Polymers 13 (23), 4109 2021
Citations: 12 - Application of machine learning in fused deposition modeling: a review
A Equbal, S Akhter, MA Equbal, AK Sood
Fused Deposition Modeling Based 3D Printing, 445-463 2021
Citations: 10 - A Comparative Study on Electroplating of FDM Parts
A Equbal, MI Equbal, A Sood, MA Equbal
Citations: 9 - A Comprehensive Supply Chain Performance Measurement and Evaluation (CSPME) Methodology
A Equbal, R Ohdar
International Journal of Mechanical and Production Engineering Research and 2017
Citations: 7 - An investigation on material removal rate of EDM process: a response surface methodology approach
A Equbal, AK Sood, MA Equbal, MI Equbal
World Acad Sci Eng Technol Int J Mech Aerospace Ind Mechatron Manuf Eng 11 2017
Citations: 6 - Machine learning in additive manufacturing: a comprehensive insight
MA Equbal, A Equbal, ZA Khan, IA Badruddin
International Journal of Lightweight Materials and Manufacture 2024
Citations: 5 - RSM-BASED STATISTICAL APPROACH TO ENHANCE THE COMPRESSIVE PERFORMANCE OF ABS P400 PARTS FABRICATED VIA FDM TECHNOLOGY
A Equbal, MA Equbal, R Ahmad, M Kumar, HRISHIKESH, O KHAN, ...
Surface Review and Letters, 2550021 2024
Citations: 4 - Grey based Taguchi method for multi-response optimization of FSW of aluminium AA 6061 alloy
P Ravindrannair, A Equbal, MA Equbal, KK Saxena, MI Equbal
International Journal on Interactive Design and Manufacturing (IJIDeM) 18 (3 2024
Citations: 4 - Multi-criterion decision method for roughness optimization of fused deposition modelled parts
A Equbal, MA Equbal, MI Equbal, AK Sood
Additive Manufacturing Technologies from an Optimization Perspective, 235-262 2019
Citations: 4 - Characteristics of Conventional and Microwave Sintered Iron Ore Preform
A Equbal, M Ali, MA Equbal, SC Srivastava, ZA Khan, MI Equbal, ...
Materials 15 (7), 2655 2022
Citations: 3 - An insight on current and imminent research issues in EDM
A Equbal, MI Equbal, MA Equbal, AK Sood
Non-Conventional Machining in Modern Manufacturing Systems, 33-54 2019
Citations: 3 - Optimisation of forging parameters of 35C8 steel using grey relational analysis
MI Equbal, A Equbal, MA Equbal, R Pranav
International Journal of Microstructure and Materials Properties 13 (3-4 2018
Citations: 3 - Optimizing the machining parameters during turning of EN 31 steel using TiN+ Al2O3+ TiCN coated tungsten carbide tool
J Prakash, A Equbal, P Ravindrannair, MA Equbal, MI Equbal
Materials Today: Proceedings 2023
Citations: 2