RAFIQ AHMED

Dr. RAFIQ AHMED

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 November 2021 in Journal of Petroleum Exploration and Production Technology
Verified
Journal Article
Open access
PDF file
SLShaine Mohammadali Lalji
Shaine Mohammadali Lalji
SASyed Imran Ali
Syed Imran Ali
RARAFIQ AHMED
RAFIQ AHMED
Saud HashmiSaud Hashmi
Saud Hashmi
Zahoor ul Hussain AwanZahoor ul Hussain Awan
Zahoor ul Hussain Awan
Swelling of shale potentially occurs when it is exposed to water-based drilling fluid. The migration of hydrogen ions (H+) in the nano-interlayered platelets of the shale rock is utterly responsible for the swelling behavior in the shale. Conventionally, swelling behavior of any shale formation can be experimentally determined by linear dynamic swell meter. However, it is extremely important to validate these experimental results; hence, this research study aims in conducting a comparative performance analysis for different kinetic models, namely Peleg’s model, first-order exponential association equation and pseudo-second-order kinetic model, and a newly developed scaling swelling model in estimating the experimental results of three different shale samples, namely Talhar, Ranikot and Murree, obtained from different regions of Pakistan. It was found that the performance of the scaling swelling model was the most accurate in predicting the experimental swelling results with accuracy greater than 95% in all the three samples. Peleg’s model is found to be the most inaccurate with $$p \mathrm{values}< \alpha (0.05)$$ p values < α ( 0.05 ) in all the three formations. The equilibrium state in all the three samples was unable to attain by the use of this model. This clearly shows that the transient states continue throughout the course of experimentation, thus demonstrating a higher water activity in the shale samples. Moreover, when comparison was made between the two remaining kinetic adsorption models, it was perceived that pseudo-second-order kinetic was far superior to first-order exponential association equation with $${\mathrm{mean}}_{\mathrm{model}}\simeq {\mathrm{mean}}_{\mathrm{experiment}}$$ mean model ≃ mean experiment and less dispersion in the dataset. Nevertheless, the performance of this model also suffers with the increase in clay content. Furthermore, all these analyses were further validated by different statistical error analysis that includes MAE, APRE% and ANOVA.

24 March 2022 in Arabian Journal of Geosciences
Verified
Journal Article
Closed access
PDF file
SLShaine Mohammadali Lalji
Shaine Mohammadali Lalji
SASyed Imran Ali
Syed Imran Ali
RARAFIQ AHMED
RAFIQ AHMED
Saud HashmiSaud Hashmi
Saud Hashmi
Zahoor ul Hussain AwanZahoor ul Hussain Awan
Zahoor ul Hussain Awan
SQSyed Wajahat Ali Qazi
Syed Wajahat Ali Qazi

30 December 2022 in Chemosphere
Verified
Journal Article
Closed access
SHSaud Hashmi
Saud Hashmi
RARAFIQ AHMED
RAFIQ AHMED
ARAdeel Ur Rehman
Adeel Ur Rehman
AGAlberto García-Peñas
Alberto García-Peñas
AZAwan Zahoor
Awan Zahoor
Florian StadlerFlorian Stadler
Florian Stadler

26 October 2024 in Processes
Verified
Journal Article
Open access
PDF file
ANAsra Nafees
Asra Nafees
Saud HashmiSaud Hashmi
Saud Hashmi
RARAFIQ AHMED
RAFIQ AHMED
The escalating demand for sustainable rubber products has spurred research into alternative reinforcing fillers, driven by concerns regarding the detrimental effects of using conventional fillers like carbon black and silica. In this investigation, nano-crystalline cellulose (NCC), derived from micro crystalline cellulose (MCC), sourced from sugarcane bagasse via acid hydrolysis, serves as a bio-filler to reinforce Nitrile Butadiene Rubber (NBR) matrices. NBR-NCC nano-composites were prepared using a two-roll mill, varying NCC from 1–5 parts per hundred rubber matrices, followed by hot press curing. NCC and NBR-NCC nano-composites were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), curing characteristics, thermo-mechanical testing, thermal aging and motor oil resistance. Chemical interactions between the NCC and NBR matrix were verified with FTIR. The SEM images of the NCC showed a combination of rod-like and spherical morphologies and a homogenous dispersion of NCC in NBR-NCC nano-composites with some agglomeration, notably at higher percentages of NCC. It is shown that the cure time decreases with increasing NCC loading which mimics a shorter industrial production cycle. The results also showed an increase in tensile strength, hardness, oil resistance and a rise in degradation temperature when compared to NBR at approximately 34%, 36%, 38% and 32 °C, respectively, at 3 phr NCC loading. Furthermore, NBR-NCC nano-composites showed a lower decrease in mechanical properties after aging when compared to NBR. The findings of this research suggest that the NBR-NCC nano-composites may find applications in high oil resistance seals and rubber gloves where higher thermal stability is strictly required.

26 April 2022 in Arabian Journal of Geosciences
Verified
Journal Article
Closed access
PDF file
SLShaine Mohammadali Lalji
Shaine Mohammadali Lalji
SASyed Imran Ali
Syed Imran Ali
RARAFIQ AHMED
RAFIQ AHMED
Saud HashmiSaud Hashmi
Saud Hashmi
Zahoor ul Hussain AwanZahoor ul Hussain Awan
Zahoor ul Hussain Awan
YJYunus Jawed
Yunus Jawed