An on-line condition monitoring system for induction motors via instantaneous power analysis

M. Irfan,N. Saad,R. Ibrahim,V. S. Asirvadam 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.4

Condition monitoring is an important factor in assuring well-being of motors. Existing approaches of condition monitoring are dependenton expensive special sensors. This paper reviews various forms of existing condition monitoring methods and highlights theneed for an economical intelligent fault diagnosis system. In this study, the methodology taken in developing a condition monitoringsystem for the motor bearing faults identification, utilizing the commonly available motor stator current and voltage is demonstrated. Thisunique diagnostic condition monitoring system provides continuous real time tracking of the various bearing defects and determines theseverity which can be adopted for fast decision making. The study on different bearing faults under no-load and full-load conditions iscarried out experimentally and analyzed, and the results on the real hardware implementation confirm the effectiveness of the proposedapproach.

Effects of Photobiomodulation Therapy on Glycemic and Lipid Profiles In Vitro

Abdulrahim R. Hakami,Sultan Alasmari,Mohammed Makkawi,Adel Abo Mansour,Irfan Ahmad,Mesfer Al Shahrani,Ali Alkhathami,Ayed A. Dera,Jaya Shanker Tedla,Saleh Almane,Abdulaziz Abudahish,Jawaher AbuHadhyah 대한의학레이저학회 2020 MEDICAL LASERS Vol.9 No.2

Background and Objectives This study aimed at examining the effects of photobiomodulation therapy (PBMT) on glucose, cholesterol, triglycerides, and low- and high-density lipoprotein (LDL and HDL, respectively) levels in vitro. Materials and Methods A total of 38 serum samples collected in plain (n=10) and heparinized tubes (n=28) were subjected to PBMT at 60 Joules (J)/cm2 for 2 min at 810 nm. The glucose and lipid profiles, cholesterol, triglycerides, LDL, and HDL of each sample was measured before and after PBMT. Results A statistically significant increase in glucose levels was observed in the PBMT-sera in 8 out of 10 samples in plain tubes. However, only two samples that were prepared in heparinized tubes showed an increase in glucose levels. The remaining heparinized samples that were exposed to PBMT presented lower glucose values. The treated sera exhibited a fluctuation in the lipid profiles after PBMT. However, high cholesterol levels were evident following PBMT. Similar trends with HDL and LDL in heparinized tubes were evident. Conclusion Together, the findings suggest that photobiomodulation exhibits an effect on glycemic and lipid profiles in vitro. Hence, the use of low-level laser therapy could have therapeutic potential. However, the differences between individual responses appear to indicate that the impact of PBMT may not always be beneficial.

Structural and Morphological Properties of Zn1−xZrxO with Room-Temperature Ferromagnetism and Fabricated by Using the Co-Precipitation Technique

M. Hassan,R. Irfan,S. Riaz,S. Naseem,S. S. Hussain,G. Murtaza 한국물리학회 2017 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.70 No.5

In this study, ZnO was doped with various concentrations of zirconium (xZr = 0 - 5 mole%), by using the co-precipitation method so as to achieve successful formation of a single-phase diluted magnetic semiconductor. X-Ray diffraction results showed that the crystal structure of Zn1−xZrxO was that of hexagonal wurtzite. The structural properties showed no additional phases at low impurity contents (xZr < 3%); however, impurity peaks belonging to ZrO2 appeared at high impurity contents (xZr 3%). The calculated ZnO lattice constants ‘a’ and ‘c’ were found to be 3.256 °A and 5.203 °A, respectively, which are in close match to the values found in the literature. For undoped ZnO, the average calculated particle size was 75.35 nm, and calculated bond length was 1.98 °A. The residual strains and the secondary phases of ZrO2 were found to affect the lattice parameters and the bond lengths. The scanning electron microscopy images showed a porous structure with non-uniform surface morphology. However, a few nano-scale dendrite-type structures were also present, indicating the potential applications of Zr-doped ZnO in nano-devices. Vibrating sample magnetometry (VSM) was employed to measure the magnetic properties, and the measurements showed undoped ZnO to be diamagnetic; however, doping with Zr induced a small ferromagnetic character at small magnetic fields. On the otherhand, a paramagnetic behavior was evident at higher magnetic fields. The magnetization at 1T was observed to degrade with increasing Zr content in the ZnO host lattice, which was due to the residual strains and the secondary phases.

Effect of TiB2/Gr Hybrid Reinforcements in Al 7075 Matrix on Sliding Wear Behavior Analyzed by Response Surface Methodology

S. Sivasankaran,K. R. Ramkumar,Fahad A. Al‑Mufadi,Osama M. Irfan 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.6

Al 7075 alloy matrix reinforced with different weight percentage of titanium borides (TiB2, 0, 1.5, 3, 4.5 and 6 wt%) and1 wt% graphite (Gr) hybrid composites were synthesized by in-situ liquid metallurgy route, then the sliding wear characteristicswere performed and investigated in this research work. TiB2reinforced as 0, 1.5, 3, 4.5 and 6 wt% by the in situchemical reaction of KBF4and K2TiF6salts and 1 wt% Gr with the Al 7075 matrix were added constantly in the melt. Severalexperiments were carried out to examine the wear behavior of the fabricated composite specimens through a tribometer atambient temperature. The weight percentage of reinforcement (TiB2 particles), the applied load, the sliding velocity (SV),and the sliding distance (SD) were selected as process parameters at five different levels. The response surface methodology(RSM) was used to conduct the experiments as RSM is the feasible and accurate method employed for optimizing to set theparameters. To check the significance of the developed model by RSM, ANOVA and confirmatory tests were also accomplished. FESEM surface morphology was also carried out to illustrate the uniform dispersion of the TiB2–Gr particulatesin Al 7075 matrix. The predicted wear characteristics from the developed model were well agreed with the experimentalresults. The obtained results were explained that both the increase in the percentage of RF and SV have dropped the wearloss (WL) curve whereas the load at all SVs and the SDs were uplifted the WL. The worn surface morphology explainedthat the adhesive mechanisms were dominated during the sliding wear test. Further, severe and mild wear occurred duringhigher load and lower load respectively.

Development of New Robust Bivoltine Silkworm Hybrid SR2 × SR5 for Rearing throughout the Year

P. Sudhakara Rao,A. R. Narasimha Nayaka,M. Mamatha,T. S. Sowmyashree,Ifat Bashir,Irfan Ilahi 한국잠사학회 2007 International Journal of Industrial Entomology Vol.14 No.2

Microstructural Evolutions, Hot Deformation and Work Hardening Behaviour of Novel Al–Zn Binary Alloys Processed by Squeezing and Hot Extrusion

S. Sivasankaran,K. R. Ramkumar,Hany R. Ammar,Fahad A. Al‑Mufadi,Abdulaziz S. Alaboodi,Osama Mohamed Irfan 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.4

The main goals of this work were to manufacture novel Al–Zn extruded alloys by varying the Zn content (0, 10, 20, 30 wt%),investigate the microstructural evolutions, hot deformation, and work hardening behaviour by hot compression test at differenttemperatures (25 °C, 75 °C, 150 °C, 225 °C, 300 °C). Al–20Zn alloy microstructure revealed α-Al and uniform distributionof (α + η) phases, coherent (α + η) crystals in GBs with casting defect-free surfaces, and effective interactions of pinningdislocations which led to improve mechanical performance of Al–20Zn alloy, as compared to the other alloys. The observedengineering stress–strain curve results revealed the decrease of stress with increasing of temperature due to flow softening,dynamic recovery and dynamic recrystallization. These results displayed also an increase of stress value with increasingof Zn content due to the precipitation of high density (α + η) phase in the matrix and GBs, increasing of forest and mobiledislocations density with strain fields, and the formation of fine dendrites. Work hardening rate (WHR) of extruded samplesdisplayed three stages: stage I, WHR decreased slightly with increasing of temperature up to 75 °C and decreased drasticallyfrom 75 °C to 300 °C due to softening; stage II, WHR maintained constant due to balance between dislocation generationsand dislocation annihilation; stage III, WHR slightly increased due to strain hardening of (α + η) phase. WHR was observedto increase considerably with increasing of Zn content due to the formation and dispersion of high density of (α + η) phasein the Al matrix and GBs. Deformation micro-localization in terms of different characteristics was examined and reportedon the deformed samples after hot-compression test through SEM micrographs.

Development of New Robust Bivoltine Silkworm Hybrid $SR2{\times}SR5$ for Rearing throughout the Year

Rao, P. Sudhakara,Nayaka, A. R. Narasimha,Mamatha, M.,Sowmyashree, T. S.,Bashir, Ifat,Ilahi, Irfan Korean Society of Sericultural Science 2007 International Journal of Industrial Entomology Vol.14 No.2

A Silkworm breeding programme was designed to develop a robust but productive bivoltine silkworm hybrid of Bombyx mori L. suitable for rearing throughout the year in tropical climate by utilizing indigenous polyvoltine and productive bivoltine breeds. The breeding was carried out under high temperature ($36^{\circ}C{\pm}1^{\circ}C$) and low humidity ($50{\pm}5%$) conditions in the environmental chamber. By $F_{12}$, three oval and three dumbbell breeds were isolated with higher survival and productive merits. These breeds were utilized in the hybrid evaluation along with other popular breeds. Based on combining ability test results, the hybrid $SR_2{\times}SR_5$ was selected for large scale testing and evaluated in different seasons. The evaluation studies indicated that the hybrid has higher viability and productive merits and it is suitable to rear throughout the year. The hybrid $SR_2{\times}SR_5$ recorded a survival of 92.0%, cocoon shell weight of 0.417 g, cocoon shell percentage of 23.0 and a filament length of 1042 meters under hot and dry conditions of environmental chamber compared to the control thermo-tolerant hybrid $CSR18{\times}CSR19$.

A Nationwide Analysis Evaluating the Safety of Using Acellular Dermal Matrix with Tissue Expander-Based Breast Reconstruction

Jessica Luo,Whitney D. Moss,Giovanna R. Pires,Irfan A. Rhemtulla,Megan Rosales,Gregory J. Stoddard,Jayant P. Agarwal,Alvin C. Kwok 대한성형외과학회 2022 Archives of Plastic Surgery Vol.49 No.6

Background In March 2021, the United States Food and Drug Administration (FDA) safety communication cautioned against the use of acellular dermal matrix (ADM) products in breast reconstruction and reiterated that the FDA does not approve ADM use in breast surgery. This study aims to assess the safety of ADM use in breast reconstruction. Methods Women who underwent ADM and non-ADM assisted tissue expander (TE)- based breast reconstruction were identified using the National Surgical Quality Improvement Program database (2012–2019). Trends of ADM use over time, and 30-day outcomes of surgical site infection (SSI), dehiscence, and unplanned reoperation were assessed. Results Of the 49,049 TE-based breast reconstructive cases, 42.4% were ADM assisted and 57.6% non-ADM assisted. From 2012 to 2019, the use of ADM increased from 26.1 to 55.6% (relative risk [RR] ¼1.10; p<0.01). Higher rates of SSI (3.9 vs. 3.4%; p¼0.003) and reoperation (7.4 vs. 6.0%; p<0.001) were seen in the ADM cohort. There was no significant difference seen in dehiscence rates (0.7 vs. 0.7%; p¼0.73). The most common reoperation within 30 days for the ADM group (17.6%) was removal of TE without insertion of implant (current procedural terminology: 11,971). ADM-assisted breast reconstruction was associated with increased relative risk of SSI by 10% (RR¼1.10, confidence interval [CI]: 1.01–1.21; p¼0.03) and reoperation by 15% (RR¼1.15, CI: 1.08–1.23; p<0.001). Conclusions ADM-assisted breast reconstruction more than doubled from 2012 to 2019. There are statistically higher complication rates of SSI (0.5%) and reoperation (1.4%) with ADM use in TE-based breast reconstruction, suggesting that reconstruction without ADM is safe when comparing immediate postoperative outcomes.