Spin glass behavior and critical analysis across the magnetic phase transition in Gd2CoMnO6: dc magnetization and ac susceptibility study

Bhatti Ilyas Noor,Bhatti Imtiaz Noor 한국물리학회 2022 Current Applied Physics Vol.39 No.-

We report here on critical analysis across magnetic phase transition and spin dynamics in Gd2CoMnO6. We found that this material behaves differently below and above the applied magnetic field of 20 kOe. The magnetic phase transition switches from nearly mean-field type to unusual class and Tc shifts towards the high temperature above 20 kOe field. The nature of the magnetic phase transition is explored by carrying out critical analysis at low as well as at high magnetic field. The critical exponents obtained at low field using Kouvel-Fisher method are β = 0.65 (2) γ = 0.90 (2), δ = 2.43 and Tc = 120 K. Apparently, these values of critical exponents appear close to mean-field model. For high field the critical exponents are β = 1.24 (2) γ = 0.64 (5), δ = 1.51 (3) and Tc = 128 K. The critical exponents show significant deviation from any universal class. This switchover in the nature of the magnetic phase transition is unique and not seen in many compounds. The formation of non-Griffiths-like clusters in this compound can be a reason for such unique behavior. Further, ac susceptibility has been measured to understand the spin dynamics in detail. The dispersion of frequency-dependent χac below Tc confirms a spin glass state in this material. The observed value of τo and To indicate the slow dynamic spin which is caused by co-existence of Co/Mn spin magnetic moments. The magneto-caloric effect is also presented for Gd2CoMnO6 in this study. The magnetic study and critical analysis across the phase transition reveal a switchover in the nature of phase transition in this material. A non-Griffiths like cluster formation above Tc is found and dynamic susceptibility study reveals a spin glass state below Tc in Gd2CoMnO6.

Photo-physical studies of pyridine capped ZnO nanostructures

Bhatti, H. S.,Singh, Karamjit,Kumar, Sunil,Choubey, R. K. Pleiades Publishing 2014 Russian journal of physical chemistry Vol.88 No.7

Spatial correlation based analysis of soft combination and user selection algorithm for cooperative spectrum sensing

Bhatti, Dost Muhammad Saqib,Nam, Haewoon IET 2017 IET Communications Vol.11 No.1

<P>This study presents an analytical method that shows how spatial correlation degrades the overall performance of cooperative spectrum sensing. In a cooperative spectrum sensing, where all secondary users (SUs) report their sensing information to the fusion centre (FC), sensing information is correlated for closely located users due to the similar surrounding environment. Considering the soft combining at the FC, this study shows how detection performance of correlated SUs is different from uncorrelated SUs. Furthermore, an algorithm is proposed which selects best uncorrelated SUs among all SUs of the network based on received power to the FC from SUs. The simulation results confirm the performance analysis of cooperative spectrum sensing with spatial correlation on the sensing data.</P>

Cytoprotective role of vitamin E in porcine adipose-tissue-derived mesenchymal stem cells against hydrogen-peroxide-induced oxidative stress

Bhatti, Fazal Ur Rehman,Kim, Song Ja,Yi, Ae-Kyung,Hasty, Karen A.,Cho, Hongsik Springer-Verlag 2018 Cell and tissue research Vol.374 No.1

Selection of Sahiwal Cattle Bulls on Pedigree and Progeny

Bhatti, A.A.,Khan, M.S.,Rehman, Z.,Hyder, A.U.,Hassan, F. Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.1

The objective of the study was to compare ranking of Sahiwal bulls selected on the basis of highest lactation milk yield of their dams with their estimated breeding values (EBVs) using an animal model. Data on 23,761 lactation milk yield records of 5,936 cows from five main Livestock Experiment Stations in Punjab province of Pakistan (1964-2004) were used for the study. At present the young A.I bulls are required to be from A-category bull-dams. Dams were categorized as A, B, C and D if they had highest lactation milk yield of ${\geq}$2,700, 2,250-2,699, 1,800-2,249 and <1,800 litres, respectively. The EBVs for lactation milk yield were estimated for all the animals using an individual animal model having fixed effect of herd-year and season of calving and random effect of animal. Fixed effect of parity and random effect of permanent environment were incorporated when multiple lactation were used. There were 396 young bulls used for semen collection and A.I during 1973-2004. However, progeny with lactation yields recorded, were available only for 91 bulls and dams could be traced for only 63 bulls. Overall lactation milk yield averaged 1,440.8 kg. Milk yield was 10% heritable with repeatability of 39%. Ranking bulls on highest lactation milk yield of their dams, the in-vogue criteria of selecting bulls, had a rank correlation of 0.167 (p<0.190) with ranking based on EBVs from animal model analysis. Bulls' EBVs for all lactations had rank correlation of 0.716 (p<0.001) with EBVs based on first lactation milk yield and 0.766 (p<0.001) with average EBVs of dam and sire (pedigree index). Ranking of bulls on highest lactation yield of their dams has no association with their ranking based on animal model evaluation. Young Sahiwal bulls should be selected on the basis of pedigree index instead of highest lactation yield of dams. This can help improve the genetic potential of the breed accruing to conservation and development efforts.

Catalyst-aided Regeneration of Amine Solvents for Efficient CO₂ Capture Process

Bhatti, Umair H.,Sultan, Haider,Cho, Jin Soo,Nam, Sungchan,Park, Sung Youl,Baek, Il Hyun The Korean Society for Energy 2019 에너지공학 Vol.28 No.4

Thermal amine scrubbing is the most advanced CO₂ capture technique but its largescale application is hindered due to the large heat requirement during solvent regeneration step. The addition of a solid metal oxide catalysts can optimize the CO₂ desorption rate and thus minimize the energy consumption. Herein, we evaluate the solvent regeneration performance of Monoethanolamine (MEA) and Diethanolamine (DEA) solvents without and with two metal oxide catalysts (TiO₂ and V₂O₅) within a temperature range of 40-86℃. The solvent regeneration performance was evaluated in terms of CO₂ desorption rate and overall amount of CO₂ desorbed during the experiments. Both catalysts improved the solvent regeneration performance by desorbing greater amounts of CO₂ with higher CO₂ desorption rates at low temperature. Improvements of 86% and 50% in the CO₂ desorption rate were made by the catalysts for MEA and DEA solvents, respectively. The total amount of the desorbed CO₂ also improved by 17% and 13% from MEA and DEA solvents, respectively. The metal oxide catalyst-aided regeneration of amine solutions can be a new approach to minimize the heat requirement during solvent regeneration and thus can remove a primary shortfall of this technology.

Compact PIFA for Mobile Terminals Supporting Multiple Cellular and Non-Cellular Standards

Bhatti, R.A.,Yun-Taek Im,Seong-Ook Park IEEE 2009 IEEE transactions on antennas and propagation Vol.57 No.9

<P>A novel multiband planar inverted-F antenna (PIFA) covering ten frequency bands has been proposed for personal wireless communications terminals. The design is based on the combination of various techniques that are used for designing multiband/broadband antennas. We used a shorted parasitic patch efficiently coupled to the driven patch, a quarter-wave resonator connected to the feed strip in parallel with the main patch, and four slits in the main radiator to excite various current modes in the antenna structure. The antenna is designed within a volume of 4.0 times 2.0 times 0.8 cm<SUP>3</SUP> and it can be used to serve the following wireless communication systems: Global System for Mobile Communications (GSM-900), Digital Communications System (DCS), Personal Communication Service (PCS), Universal Mobile Telecommunications System (UMTS), WiBro at 2.35 GHz, Bluetooth, Satellite-Digital Multimedia Broadcasting (SDM-B) at 2.65 GHz, WiMAX at 3.5 GHz, and the two bands (5.15-5.35 GHz and 5.725-5.875 GHz) for the wireless Local Area Network (WLAN) standards. A prototype antenna was fabricated and tested for input reflection coefficient and radiation performances. The measured and simulated results have been presented and discussed. Important geometrical parameters determining the multiband performances of the antenna have been explained in the paper.</P>

Comparison between Early and Late Onset Breast Cancer in Pakistani Women Undergoing Breast Conservative Therapy: is There any Difference?

Bhatti, Abu Bakar Hafeez,Jamshed, Aarif,Khan, Amina,Siddiqui, Neelam,Muzaffar, Nargis,Shah, Mazhar Ali Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.13

Background: Early onset breast cancer is associated with poor outcomes but variable results have been reported. It is a significant problem in Pakistani women but remains under reported. Breast conservation plays an important role in surgical management of this younger patient group. The objective of this study was to determine the outcome of breast conservative therapy in patients with early onset breast cancer in our population and compare it with their older counterparts. Materials and Methods: A review of patients with invasive breast cancer who underwent breast conservation surgery at Shaukat Khanum Cancer Hospital from 1997 to 2009 was performed. Patients were divided into two groups i.e. Group I age ${\leq}40$ and Group II >40 years. A total of 401 patients with breast cancer were identified in Group I and 405 patients in Group II. Demographics, histopathological findings and receptor status of the two groups were compared. The Chi square test was used for categorical variables. Outcome was assessed on basis of 10 year locoregional recurrence free survival (LRRFS), disease free survival (DFS) and overall survival (OS). For survival analysis Kaplan Meier curves were used and significance was determined using the Log rank test. Cox regression was applied for multivariate analysis. Results: Median follow up was 4.31 (0.1-15.5) years. Median age at presentation was 34.6 years (17-40) and 51.9 years (41-82) for the two groups. Groups were significantly different from each other with respect to grade, receptor status, tumor stage and use of neoadjuvant therapy. No significant difference was present between the two groups for estimated 10 year LRRFS (86% vs 95%) (p=0.1), DFS (70% vs 70%) (p=0.5) and OS (75% vs 63%) (p=0.1). On multivariate analysis, tumor stage was an independent predictor of LRRFS, DFS and OS. Conclusions: Early onset breast cancer is associated with a distinct biology but does not lead to poorer outcomes in our population.

Quad-Band MIMO Antenna Array for Portable Wireless Communications Terminals

Bhatti, R.A.,Jung-Hwan Choi,Seong-Ook Park IEEE 2009 IEEE antennas and wireless propagation letters Vol.8 No.-

<P>A low-profile quad-band antenna array for multiple-input-multiple-output (MIMO)-enabled wireless communication terminals has been presented in this letter. The proposed dual-element antenna array operates at the following frequency bands: 2.4-2.5 GHz, 3.4-3.6 GHz, 5.15-5.35 GHz, and 5.75-5.875 GHz. A combination of a C-shaped slot and a T-shaped slit is used to excite three current modes in a conventional single-band planar inverted-F antenna (PIFA). A lambda/4 resonator is integrated into the triband antenna structure in order to get an additional resonance for quad-band operation. The proposed array has been designed over a small ground plane measuring 50times100 mm<SUP>2</SUP>, whereas each element in the array occupies a volume of 0.63 cm<SUP>3</SUP>. Mean effective gain (MEG) and envelop correlation analysis have been used for the array analysis in addition to the capacity and diversity gain measurements in a reverberation chamber. The prototype array exhibits quite low mutual coupling with good input return losses at the desired four frequency bands.</P>

Outcomes of Triple-Negative Versus Non-Triple-Negative Breast Cancers Managed with Breast-Conserving Therapy

Bhatti, Abu Bakar Hafeez,Khan, Amina Iqbal,Siddiqui, Neelam,Muzaffar, Nargis,Syed, Aamir Ali,Shah, Mazhar Ali,Jamshed, Arif Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.6

Background: Triple negative breast cancer is associated with aggressive behavior and high risk of local and regional failure. Aggressive surgical intervention is considered suitable. This makes role of breast conserving therapy (BCT) debatable in these patients. The objective of this study was to compare outcome of BCT for triple negative versus non-triple negative breast cancer. Materials and Methods: Medical records of patients who underwent breast conserving therapy from 1999 to 2009 at Shaukat Khanum Cancer Hospital and had complete receptor status information were extracted. Patients were divided into triple negative breast cancer (TNBC) and non-TNBC. Patient characteristics, medical treatment modalities and adverse events were compared. Expected five year locoregional recurrence free, disease free and overall survival was calculated. The Cox proportional hazard model was used to identify independent predictors of outcome. Results: A total of 194 patients with TNBC and 443 with non-TNBC were compared. Significant difference was present for age at presentation (p<0.0001), family history (p=0.005), grade (p<0.0001) and use of hormonal therapy (p<0.0001). The number of locoregional failures, distant failures and mortalities were not significantly different. No significant difference was present in 5 year locoregional recurrence free (96% vs 92%, p=0.3), disease free (75% vs 74%, p=0.7) and overall survival (78% vs 83%, p=0.2). On multivariate analysis, tumor size, nodal involvement and hormonal treatment were independent predictors of negative events. Conclusions: Breast conserving therapy has comparable outcomes for triple negative and non-triple negative breast cancers.