60 research outputs found

    An Efficient & Less Complex Solution to Mitigate Impulsive Noise in Multi-Channel Feed-Forward ANC System with Online Secondary Path Modeling (OSPM)

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    This paper deals with impulsive noise (IN) in multichannel (MC) Active Noise Control (ANC) Systems with Online Secondary Path Modelling (OSPM) employing adaptive algorithms for the first time. It compares performance of various existing techniques belonging to varied computational complexity range and proposes four new methods, namely: FxRLS-VSSLMS, VSSLMS-VSSLMS, FxLMAT-VSSLMS and NSS MFxLMAT-VSSLMS to deal with modest to very high impulsive noise (IN). Simulation results show that these proposed methods demonstrated improved performance in terms of fast convergence speed, lowest steady state error, robustness and stability under impulsive environment in addition to modelling accuracy for stationary as well as non-stationary environment besides reducing computational complexity many folds

    Infected non-union of tibia treated with ilizarov external fixator: Our experience

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    Introduction: Tibia is the most common long bone fractured due its vulnerable subcutaneous location and most often associated with acquired complications of delayed union or non-union due to infection. Amongst the various treatment options to treat them, the Ilizarov external fixator application is considered superior due to its multiple advantages. The objective of this study was to analyse the role of Ilizarov fixation in infected tibial non-union, as well as to assess bony union and associated functional outcomes. Materials and Methods: A retrospective review was conducted for the duration between 1st January 2005 to 31st December 2016. Total of fifty-one patients with tibial non-union associated with infection who treated with the Ilizarov fixator were included in the study. Patient records were reviewed for union of bone, bone and functional outcomes and complications. Results: The most common organism for infection was identified to be Staphylococcus Aureus. At the time of final follow-up all patients had achieved union except two, one of whom had to undergo amputation due to non-union and sepsis. Majority of the patients had an excellent score as per ASAMI grading system for bone and function results. The most common complication noted was pin track infections. Conclusion: In our experience, Ilizarov external fixator is better suited for infected non-union of tibia because it can provide a stable mechanical environment, bone transport, correct deformities, and enable weight bearing and hence we recommend its use for the same

    Parametric optimisation of friction stir welding on aluminium alloy (EN AW-1100) plates

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    Friction stir welding is a solid-state welding process used extensively for aluminium alloys. EN AW-1100 alloy is mostly used for its exceptional corrosion resistance, high ductility, high thermal and electrical conductivities, and cost-effectiveness. This study is focused on the optimisation of friction stir welding parameters to achieve enhanced mechanical properties of 5mm thick EN AW-1100 alloy plates welded with a single pass, using Taguchi L9 orthogonal array and ANOVA analysis. Experimental results revealed that maximum tensile strength of 79 MPa and percentage elongation of 38.87 % were achieved. The maximum Vickers hardness achieved in the stir zone was 34.15. These results were used for optimisation using Minitab and it was determined that 2000 RPM, 30 mm·min−1 traverse speed and square probe profile came out to be the best parameters for maximum tensile strength. 4000 RPM, 30 mm·min−1 traverse speed and square probe geometry were the best parameters for maximum hardness in the stir zone. ANOVA analysis showed that the most significant parameter for tensile strength was traverse speed. None of the considered parameters were influencing the hardness value in the stir zone at a 95 % confidence level

    Dyspeptic Symptoms In Type 2 Diabetes Patients

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    Background: Nearly half of the patients with diabetes experience diabetic gastroparesis. Some diabetic patients present with complaints of epigastric pain, vomiting, nausea, or postprandial fullness, however only a few have severe symptoms. Objective: To determine the frequency of dyspepsia among T2DM patients. Methods: This cross-sectional study was performed in Ziauddin Hospital Kemari Branch, Karachi, Pakistan after acquiring ethical approval from the hospital ethics committee. Short-Form Leeds Dyspepsia Questionnaire (SF-LDQ) was used to identify the presence of dyspepsia. Based on the sum of the frequency of symptoms, a cut-off value of 4 and above was used for the presence of dyspepsia. Results: A total of 368 patients were included in the study with a median age of 68.6 ± 14.2 years. The majority were females (62.8%). The mean duration of diabetes was 15 ± 10.4 years. The frequency of indigestion, heartburn, regurgitation, and nausea was 35.3%, 30.7%, 31.5%, and 11.4% respectively. Out of 368, 168 (45.7%) patients were found to have dyspepsia. The risk of dyspepsia was significantly lower among younger age, male gender, and patients having controlled glycemic status, patients doing physical activity twice a week, taking all three meals on time, and always having their breakfast early. The odds of having dyspepsia were higher among those who are currently and formerly addicted to alcohol, current and former smokers, having comorbidity, consuming <8 glasses of water per day, and those who were always or sometimes sleeping within two hours of having dinner. Conclusion: This study analyzed that dyspeptic symptoms including indigestion, heartburn, and regurgitation were common in T2DM patients, and about half of these patients had dyspepsia which was common among patients with poor glycemic control and those with unhealthy lifestyles

    Green photosensitisers for the degradation of selected pesticides of high risk in most susceptible food: a safer approach

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    Pesticides are the leading defence against pests, but their unsafe use reciprocates the pesticide residues in highly susceptible food and is becoming a serious risk for human health. In this study, mint extract and riboflavin were tested as photosensitisers in combination with light irradiation of different frequencies, employed for various time intervals to improve the photo-degradation of deltamethrin (DM) and lambda cyhalothrin (λ-CHT) in cauliflower. Different source of light was studied, either in ultraviolet range (UV-C, 254 nm or UV-A, 320–380 nm) or sunlight simulator (> 380–800 nm). The degradation of the pesticides varied depending on the type of photosensitiser and light source. Photo-degradation of the DM and λ-CHT was enhanced by applying the mint extracts and riboflavin and a more significant degradation was achieved with UV-C than with either UV-A or sunlight, reaching a maximum decrement of the concentration by 67–76%. The light treatments did not significantly affect the in-vitro antioxidant activity of the natural antioxidants in cauliflower. A calculated dietary risk assessment revealed that obvious dietary health hazards of DM and λ-CHT pesticides when sprayed on cauliflower for pest control. The use of green chemical photosensitisers (mint extract and riboflavin) in combination with UV light irradiation represents a novel, sustainable, and safe approach to pesticide reduction in produce

    The Effect of the El Nino Southern Oscillation on Precipitation Extremes in the Hindu Kush Mountains Range

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    The El Nino Southern Oscillation (ENSO) phenomenon is devastating as it negatively impacts global climatic conditions, which can cause extreme events, including floods and droughts, which are harmful to the region’s economy. Pakistan is also considered one of the climate change hotspot regions in the world. Therefore, the present study investigates the effect of the ENSO on extreme precipitation events across the Upper Indus Basin. We examined the connections between 11 extreme precipitation indices (EPIs) and two ENSO indicators, the Southern Oscillation Index (SOI) and the Oceanic Niño Index (ONI). This analysis covers both annual and seasonal scales and spans the period from 1971 to 2019. Statistical tests (i.e., Mann–Kendall (MK) and Innovative Trend Analysis (ITA)) were used to observe the variations in the EPIs. The results revealed that the number of Consecutive Dry Days (CDDs) is increasing more than Consecutive Wet Days (CWDs); overall, the EPIs exhibited increasing trends, except for the Rx1 (max. 1-day precipitation) and Rx5 (max. 5-day precipitation) indices. The ENSO indicator ONI is a temperature-related ENSO index. The results further showed that the CDD value has a significant positive correlation with the SOI for most of the UIB (Upper Indus Basin) region, whereas for the CWD value, high elevated stations gave a positive relationship. A significant negative relationship was observed for the lower portion of the UIB. The Rx1 and Rx5 indices were observed to have a negative relationship with the SOI, indicating that El Nino causes heavy rainfall. The R95p (very wet days) and R99p (extreme wet days) indices were observed to have significant negative trends in most of the UIB. In contrast, high elevated stations depicted a significant positive relationship that indicates they are affected by La Nina conditions. The PRCPTOT index exhibited a negative relationship with the SOI, revealing that the El Nino phase causes wet conditions in the UIB. The ONI gave a significant positive relationship for the UIB region, reinforcing the idea that both indices exhibit more precipitation during El Nino. The above observations imply that while policies are being developed to cope with climate change impacts, the effects of the ENSO should also be considered

    A Two-stage Flow-based Intrusion Detection Model ForNext-generation Networks

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    The next-generation network provides state-of-the-art access-independent services over converged mobile and fixed networks. Security in the converged network environment is a major challenge. Traditional packet and protocol-based intrusion detection techniques cannot be used in next-generation networks due to slow throughput, low accuracy and their inability to inspect encrypted payload. An alternative solution for protection of next-generation networks is to use network flow records for detection of malicious activity in the network traffic. The network flow records are independent of access networks and user applications. In this paper, we propose a two-stage flow-based intrusion detection system for next-generation networks. The first stage uses an enhanced unsupervised one-class support vector machine which separates malicious flows from normal network traffic. The second stage uses a self-organizing map which automatically groups malicious flows into different alert clusters. We validated the proposed approach on two flow-based datasets and obtained promising results

    Association of high immunohistochemical expression of minichromosome maintenance 3 with human oral squamous cell carcinoma—a preliminary study

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    Background: Oral squamous cell carcinoma (OSCC) may arise from premalignant oral lesions (PMOL) in most cases. Minichromosome maintenance 3 (MCM3) is a proliferative marker that has been investigated as a potential diagnostic biomarker in the diagnosis of oral cancer. Objectives: To evaluate the association of MCM3 expression, its clinicopathologic parameters and to identify snuff (also called naswar) as a potential risk factor for changes in MCM3 expression in PMOL and OSCC. Methodology: Immunohistochemistry (IHC) of MCM3 was performed on 32 PMOL, 32 OSCC and 16 normal controls after optimization of IHC methodology. Histoscore (0–300) was used as a scoring system and seven different cut-offs were identified for analyses. Data were analyzed using various statistical tests. Results: Among the seven cutoffs, 40% strong positive cells were found to be a better cut-off as they were associated with many pathological variables (Broder’s grade, Aneroth’s grade, and mitotic activity). The differential MCM3 expression in oral lesions (PMOL and OSCC) was statistically significant (p = 0.03). Moreover, MCM3 expression is raised with increased duration and frequency of snuff use. Conclusion: High MCM3 expression is associated with disease progression and is a potential indicator of malignant transformations from PMOL to OSCC. Moreover, the use of snuff is associated with MCM3 over-expression
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