3,779 research outputs found
Optimization of multiple performance characteristics in turning using Taguchiâs quality loss function: An experimental investigation
Cutting force and chip reduction coefficient is the important index of machinability as it determines the power consumption and amount of energy invested in machining actions. It is primarily influenced by process parameters like cutting speed, feed and depth of cut. This paper presents the application of Taguchiâs parameter design to optimize the parameters for individual responses. For multi-response optimization, Taguchiâs quality loss function approach is proposed. In the present investigation, optimal values of cutting speed, feed and depth of cut are determined to minimize cutting force and chip reduction coefficient during orthogonal turning. The effectiveness of the proposed methodology is illustrated through an experimental investigation in turning mild steel workpiece using high speed steel tool
Time-Domain Protection and Fault Location of Wye-Connected Shunt Capacitor Banks Using Superimposed Current and Differential Voltage
This paper presents protection and fault location of wye-connected shunt capacitor banks used in medium or high voltage applications. The proposed method is sensitive to single element failure obtained by using voltage adaptive instantaneous superimposed current in each phase. The change in equivalent reactance computed using time-domain signals is used to find the number of failed capacitor element and types of fault. The location of the faulted capacitor is identified using sign of the voltage difference of the lower and upper halves of the shunt capacitor bank. The performance of the proposed method is tested for various cases including identical faults, simultaneous faults, system voltage unbalance in both single and double wye-connected shunt capacitor banks. The method is also validated using field data collected from a 400 kV SCB for an internal fault. The proposed technique is compared with available methods and found accurate
Glanzmannâs thrombasthenia: A rare case
Glanzmannâs thrombasthenia is an extremely rare autosomal recessive inherited bleeding disorder characterized by the impaired function of platelets leading to prolonged bleeding time. Patients may present with easy bruising, purpura, epistaxis, menorrhagia and gingival bleeding. Though the disease is rare, the prognosis is usually good with supportive care. Here, we report the case of Glanzmannâs thrombasthenia in a young male who presented with complaints of gum bleeding, epistaxis and a history of easy bruising. The patient improved with symptomatic and supportive care. The patient got discharged and is doing well under regular follow-up
Robust gold nanoparticles stabilized by trithiol for application in chemiresistive sensors
The use of gold nanoparticles coated with an organic monolayer of thiol for application in chemiresistive sensors was initiated in the late 1990s; since then, such types of sensors have been widely pursued due to their high sensitivities and reversible responses to volatile organic compounds (VOCs). However, a major issue for chemical sensors based on thiol-capped gold nanoparticles is their poor long-term stability as a result of slow degradation of the monothiol-to-gold bonds. We have devised a strategy to overcome this limitation by synthesizing a more robust system using Au nanoparticles capped by trithiol ligands. Compared to its monothiol counterpart, the new system is significantly more stable and also shows improved sensitivity towards different types of polar or non-polar VOCs. Thus, the trithiolâAu
nanosensor shows great promise for use in real world applications
Assessment of knowledge, attitude and self-care activities among type-2 diabetic patients attending a tertiary care teaching hospital
Background: Poor awareness, negative attitudes and inadequate self-care practices among diabetic patients are some of the important variables influencing the progression of diabetes and its complications, which are largely preventable through education and involvement of the patient.Methods: A hospital based cross sectional study was conducted among type 2 diabetics attending diabetes clinic in tertiary care hospital. Knowledge and attitude towards making lifestyle changes were evaluated using a semi structured questionnaire. To assess the diabetes self-care activities associated with glycemic control the Diabetes Self-care Management Questionnaire consisting of four subscales âGlucose managementâ, âDietary controlâ, âPhysical activityâ and âHealth Care Useâ was used.Results: A total of 61 diabetic patients consented and participated in the study of whom 56.66% were male and 43.33% female. Majority of the respondents (33.30%) were in the age group more than 60 years, 43.3 % belonged to upper middle class, 21.3 % were obese and majority had duration of disease between 5 to 10 years. Only 30 % of the total diabetic patients had achieved good glycemic control. There was a significant difference between knowledge (p <0.05) but not attitude towards self-care activities between the glycemic controlled versus the uncontrolled diabetic patients. Among self-care practices, following a controlled diet (p <0.05) and observing strict glucose management (p <0.05) were significantly associated with achieving glycemic control.Conclusions: As evidenced by the study, patients who were regularly involved in self-care practices (especially dietary control and glucose management) achieved better glycemic control. Therefore, interventions to increase diabetic patient self-care behaviour are needed to reduce poor glycemic control
A Cosine Similarity Based Centralized Protection Scheme for DC Microgrids
Unlike the phasor measurement based protection in AC systems, the protection of DC systems deals with complex fault transients which mandates the isolation of the faulted segment within few milliseconds as continued fault current leads to overheating issue in power electronic converters. To this end,several works have been suggested based on unit and nonunit protections for DC microgrids. Threshold selection and protection coordination are the challenges associated with nonunit protection. Similarly, communication delay and link failure limit the application of unit protection. To address these issues, this paper presents a robust centralized protection scheme for DC microgrids, which is resilient to communication delay and link failure. It uses current of each line segment to compute the similarity of current change at both ends of the line segment to derive the protection decision. To overcome the communication failure from one end of the line segment or even from multiple segments, the proposed method uses data from adjacent segments to derive the protection decision correctly. Using PSCAD/EMTDC environment, the performance of the proposed method is evaluated for various cases and compared with available techniques. Finally, the accuracy of the protection algorithm is validated under experimental conditions
Lead content in new decorative paints in India
The paint industry in India is broadly classified into two categories: organized sector and unorganized sector. Multinational and big Indian companies form the organized
sector, whereas the small- and medium-scale industries which produce paints for the local market form the unorganized sector. The present study was undertaken to determine the level of lead in decorative paints in India. A total of 148 paint samples sourced from four organized sector companies and six unorganized sector companies were analyzed for the total lead content. Results of this study reveal that 39 % of the total paints tested (n = 148)
contain lead more than 300 ppm, the voluntary limit prescribed by Bureau of Indian Standards, BIS (IS 15489:2011), and 45 % of the tested paints contain lead more than 90 ppm, the US limit. Further analysis of the data indicates that only 5 % of the tested paints manufactured by organized sector companies contain lead more than 300 ppm (n = 91), whereas 93 % of the tested paints manufactured by unorganized sector companies
contain lead more than 300 ppm (n = 57). Comparison with earlier reported data suggests that while organized sector companies are gradually abandoning the use of leadbased
compounds in their paints, the unorganized sector companies are still adding lead based compounds intentionally in their paints despite the potential health hazards associated
with it. The maximum concentration of lead obtained was 80,350 ppm in one of the paints manufactured by an unorganized sector company. The presence of high concentration of lead in yellow and green color paints indicates that color can be a predictor of lead content in decorative paints
Utjecaj prinosa mlijeka na funkcionalnu aktivnost neutrofila u krava kriĆŸanki Karan Fries (Holstein Friesian X Tharparkar) tijekom peripartusnog razdoblja.
To study the immunological activities of neutrophils, blood samples were collected from 6 high yielding (HY) and 6 low yielding (LY) Karan Fries (KF) cows on -15,-7, -5, -3, -2, -1 days prepartum, at calving and on 1, 2, 3, 5, 7 and 15 days postpartum. Plasma cortisol levels, phagocytic activity (PA), enzyme (Elastase, Collagenase and Cathepsin G) levels and expression of TLR-2, TLR-4 and IL-8 were also studied. Both HY KF and LY KF cows were found to have increased blood Total leukocyte counts (TLC) and neutrophil percent at calving, but HY KF cows had significantly (P<0.05) higher levels than LY KF cows. The number of band neutrophils were also significantly (P<0.05) higher in HY cows. Significant (P<0.05) immunosuppression in relation to PA was found for HY as compared to LY KF cows throughout the peripartum period, with the lowest immunosuppression at calving in both groups of cows. Cortisol levels were significantly (P<0.01) higher during calving and negatively correlated with neutrophilic functions. The difference between the two groups also remained significant (P<0.05) as higher level of cortisol were found in HY KF cows. Elastase, collagenase and cathepsin were significantly (P<0.05) decreased during parturition. Elastase was reduced approximately 2.5 times on the day of calving in LY KF cows, but no such major reduction was observed for HY KF cows. Collagenase and cathepsin levels were significantly (P<0.05) higher in LY cows. Expression of the TLR-2 gene was significantly (P<0.05) lower in HY cows during the whole peripartum period than in LY cows. Expression of the TLR-4 gene was significantly (P<0.05) lower on days 15 pre- and post-calving in HY cows. IL-8 differed significantly (P<0.05) only during the prepartum days. Lower neutrophilic function in cross bred cows with high production potential, provides lower disease resistance and makes the cows more susceptible to peripartum infection.S ciljem istraĆŸivanja imunoloĆĄke aktivnosti neutrofila, od ĆĄest visokoproizvodnih (VP) i ĆĄest niskoproizvodnih (NP) Karan Fries (KF) krava prikupljeni su uzorci krvi -15, -7, -5, -3, -2, -1 dana prije partusa, zatim tijekom partusa, te 1, 2, 3, 5, 7 i 15 dana nakon partusa. Analizirana je razina kortizola u plazmi, aktivnost fagocita (AF), razine enzima (elastaze, kolagenaze, katepsina G) te ekspresija TLR-2, TLR-4 i IL-8. Kod obje skupine krava, VP KF i NP KF, utvrÄeno je poveÄanje ukupnog broja leukocita (UBL) i postotka neutrofila pri teljenju, ali razine su kod VP KF krava bile signifikantno viĆĄe (P<0,05) nego kod NP KF krava. Broj nesegmentiranih neutrofila bio je takoÄer signifikantno (P<0,05) viĆĄi kod VP krava. Signifikantna (P<0,05) imunosupresija u odnosu na AF utvrÄena je kod VP u usporedbi sa NP KF kravama tijekom peripartusnog razdoblja, s najniĆŸom razinom imunosupresije pri teljenju obje skupine krava. Razine kortizola bile su signifikantno (P<0,01) viĆĄe tijekom teljenja i negativno povezane s funkcijom neutrofila. Razlike izmeÄu skupina takoÄer su ostale signifikantne (P<0,05) i u sluÄaju viĆĄe razine kortizola utvrÄene kod VP KF krava. Elastaza, kolagenaza i katepsin signifikantno su (P<0,05) opadali tijekom teljenja. Elastaza je smanjena za pribliĆŸno 2,5 puta na dan teljenja NP KF krava dok kod VP KF krava takvo jako smanjenje nije opaĆŸeno. Razine kolagenaze i katepsina bile su signifikantno (P<0,05) viĆĄe kod NP krava. U odnosu na NP krave, ekspresije TLR-2 gena kod VP krava bile su signifikantno (P<0,05) niĆŸe tijekom cijelog peripartusnog razdoblja. Ekspresija TLR-4 gena bila je signifikantno (P<0,05) niĆŸa 15. dan prije i poslije teljenja VP krava. IL-8 je bio signifikantno razliÄit (P<0,05) samo tijekom prepartusnog razdoblja. SniĆŸena funkcija neutrofila kod krava kriĆŸanki s visokim proizvodnim potencijalom doprinosi njihovoj manjoj otpornosti na bolesti i Äini ihosjetljivijima na infekcije tijekom peripartusnog razdoblja
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