176 research outputs found

    A study on plug-in hybrid electic vehicles

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    Plug-in hybrid electric vehicle (PHEV), which is a hybrid vehicle whose batteries can be recharged by plugging into an electric power source, is creating many interests due to its significant potential to improve fuel efficiency and reduce pollution. PHEVs would be the next generation of vehicles that are expected to replace conventional hybrid electric vehicles. This paper presents a study on PHEV. It gives a review of different drivetrain architectures associated with PHEVs. In addition, different control strategies that could bring about realization of advantages of PHEV capabilities are discussed and compared.<br /

    Folates: An Introduction

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    Folate is a naturally occurring essential nutrient which is vital for DNA replication and a necessary substrate in various enzymatic reactions which are involved in synthesis of amino acids and vitamin metabolism. The synthetic and oxidized form of folate is folic acid, it is mainly incorporated into fortified foods and dietary supplements for preventive measures against folate deficiency. Folate deficiency has been linked with several abnormalities in both mother (anemia, peripheral neuropathy) and fetus (congenital abnormalities). Folic acid supplementation taken around the time of conception has been known to alleviate the risk of neural tube defects in the off springs. Optimal intake and absorption of folates is required for the maintenance of the human body’s normal functioning and keeping the genomic integrity intact

    Colorimetric study of absorption behavior of madder natural dye on nylon using scanner

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    A scanner has been used as a low-cost instrument for measuring the colorimetric parameters of dyed nylon. The nylonfabric is dyed with madder natural dye using non-mordanting, pre-mordanting, and meta-mordanting. Then, the dyedsamples are scanned by a scanner and the RGB values of obtained image are converted to CIELab and HSL color spaces. Itis found that the scanner is able to evaluate the colorimetric characteristics of dyed samples. The obtained results are foundcomparable to the spectrophotometer results

    Effect of noise factors in energy management of series plug-in hybrid electric vehicles

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    It has been demonstrated that charge depletion (CD) energy management strategies are more efficient choices for energy management of plug-in hybrid electric vehicles (PHEVs). The knowledge of drive cycle as a priori can improve the performance of CD energy management in PHEVs. However, there are many noise factors which affect both drivetrain power demand and vehicle performance even in identical drive cycles. In this research, the effect of each noise factor is investigated by introducing the concept of power cycle instead of drive cycle for a journey. Based on the nature of the noise factors, a practical solution for developing a power-cycle library is introduced. Investigating the predicted power cycle, an energy management strategy is developed which considers the influence of temperature noise factor on engine performance. The effect of different environmental and geographic conditions, driver behavior, aging of battery and other components are considered. Simulation results for a modelled series PHEV similar to GM Volt show that the suggested energy management strategy based on the driver power cycle library improves both vehicle fuel economy and battery health by reducing battery load and temperature.<br /

    Post Covid-19 Syndromes, The Time line of Covid

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    BACKGROUND &amp; OBJECTIVES: Novel corona virus has claimed significant mortality and morbidity. Timeline of long-term complications and effects on humanity are yet to be explored. Current study aims to evaluate the spectrum of post Covid syndromes in our Covid survivors. METHODOLOGY: This observational study was conducted at Medicine Dept. RIHS Islamabad after ethical approval. 195 recovered COVID cases were selected and followed 3 monthly over a year. Inclusion criteria: Age &gt;12 years, both genders, Covid PCR+ve &gt;4 weeks earlier. Exclusion criteria: Malignancies, pregnancy, recurrent Covid and that lost follow-up. Patients were evaluated for new onset generalized symptoms, respiratory, cardiovascular, neurological, hematological, gastrointestinal, dermatological and genitourinary supported by relevant investigations. Data analyzed by SPSS-22 with significant p&lt;0.05. RESULTS: Amongst 195 cases, 102(52.3%) males and 93(47.7%) females, mean age was 42.35+14.31 years, mean duration since Covid recovery 32+24.47 weeks. There was history of mild COVID in 89(45.6%), moderate 71(36.4%), severe 32(16.4%) and life threatening 02(01%) having significant association with increased mean age and female gender (p&lt;0.05). ninety four (48.2%) cases had post COVID syndromes. persistent fatigue (58), fever (29), myalgia’s (27), &nbsp;dyspnea (26), persistent cough (19), weight loss/gain (18), smear positive TB (2), bronchitis (7), asthma exacerbations (3) and pleural effusion (1). X-ray findings showed lung fibrosis in 12, ground glass appearance 10. Spirometry showed reduced exercise capacity in 11. Anemia in 11, leukopenia 02, thrombocytopenia 02, pancytopenia 01 case. In CVS, retrosternal chest pain in 11, orthopnea/PND 05, myocarditis/myocardial fibrosis 04, pericardial effusion 01, new onset hypertension 03, worsened hypertensive control 02, palpitations 10 and POTS 03. Regarding ENT, sinusitis in 12 and mucor-mycosis 03. Reduced GFR 05 and COVAN 01. New onset diabetes 05, worsened diabetic control 06, bone-demineralization 03 and thyroiditis 01. Persistent diarrhea 06, IBS 04, gastritis 08, esophagitis 06, GERD 11. Seven of 93 females reported menstrual irregularities. Hair loss 15, rash 07. headache in 23, anxiety 17, disturbed sleep 14, depression 09, peripheral neuropathy 03, CVA 03, amnesia and PTSD 03 each. 03 cases expired with cardiopulmonary arrest. CONCLUSION: Post COVID syndrome observed in half of Covid survivors. The respiratory, cardiovascular, dermatological, neuropsychiatric and generalized symptoms were frequent. Authors suggest follow-up of Covid survivors. The clinical evaluation and timely management may improve quality of life and morbidity amongst survivors. KEY WORDS:&nbsp; COVID-19. Post Covid Syndromes. Long Covid syndrome. Covid complications. Persistent post-Covid syndrome (PPCS), Myocarditis. Lung Fibrosis. &nbsp

    In Vitro Evaluation of Dynamic Viscosity, Surface Tension and Dentin Wettability of Silver Nanoparticles as an Irrigation Solution

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    Introduction: The aim of this study was to evaluate dynamic viscosity, surface tension and dentin wettability of a newly introduced imidazolium-based silver nanoparticle solution (Im AgNP) in comparison with three common root canal irrigants. Methods and Materials: The irrigants were Im AgNPs at 5.7×10-8 mol/L-1, 5.25% Sodium hypochlorite (NaOCl), 2% Chlorhexidine (CHX) and 17% Ethylenediaminetetraacetic acid (EDTA) and distilled water (control group). Dynamic viscosity was measured using rotational digital viscometer at 25, 37, 45 and 60°C. Surface tension was evaluated using dynamic contact angle analyzer at room temperature (25°C). Wettability was assessed by contact angle measurement for five groups of 10 dentin samples after each group was treated in each irrigant for 10 min. One-way ANOVA, and post hoc Tukey’s test were used for statistical analysis. Significance was set at P&lt;0.05. Results: Dynamic viscosity of all irrigants decreased as the temperature increased. 17% EDTA was the most viscous solution in all examined temperatures (P&lt;0.05). Viscosity of Im AgNP solution at 25, 37 and 45°C was significantly lower than that of 17% EDTA and 5.25% NaOCl (P&lt;0.05). Im AgNPs exhibited a higher surface tension than other irrigants except distilled water. The wettability of dentin increased when it was in contact with 2% CHX and 5.25% NaOCl while Im AgNPs decreased the wettability of dentin surfaces (P&lt;0.05). Conclusion: Im AgNP irrigant has the potential to reach apical portions of root canals due to its lower viscosity compared to the other tested irrigants. However, it may not bring better penetration inside dentinal tubules because of its higher surface tension. Furthermore, Im AgNPs can influence physiochemical properties of dentin by decreasing its surface wettability.Keywords: Irrigant; Silver Nano Particle; Surface Tension; Viscosity; Wettabilit

    A Heuristic Approach To The Index Tracking Problem: A Case Study Of The Tehran Exchange Price Index

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    Index tracking, the most popular form of passive fund management, is a portfolio selection problem in which the return of one of the stock market indexes is reproduced by creating a tracking portfolio consisting of a subset of the stocks included in the index. Index tracking has been known as an NP-Hard problem, and sophisticated approaches have been proposed in the literature to solve this problem. This paper presents an easyto-implement heuristic solution to this complex problem. The proposed approach was implemented to develop a tracking portfolio of 438 stocks listed in the Tehran Exchange Price Index. The numerical results indicate that the approach is able to identify quality solutions within reasonable model runtime

    Effective Knowledge Transfer: Application of the Media Richness Theory

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    Nowadays, information and knowledge are easily transmitted through communication and media types. Knowledge transfer must be in a manner that best meets the organization's business needs. The knowledge transfer quality depends on communication, and communication media have different levels of capability in transmitting knowledge; Media selection is based on various factors such as specific media features and the message content nature. The current research has been done by the library method. The necessary data were gathered through the study of printed and electronic information resources available in libraries, on the Internet, and in national and international databases. One of the success factors in transferring tacit knowledge depends on the selection of the appropriate knowledge transfer mechanism and communication media. Tacit knowledge (the most important type of knowledge) can be captured, stored, or transmitted using a specific type of technology based on the media enrichment theory. The main assumption of media richness theory is that person's performance in a communication situation is the result of proper conformity between the communication media features and intended task attributes. According to the media richness theory (MRT), each channel has its advantages and disadvantages, and as a result, each can be more ideal than the others for different scenarios. In the knowledge-sharing process after determining the implicit levels of knowledge (high, medium, low) by experts, based on media richness theory, the most appropriate media for transferring this type of knowledge is selected to ensure effectiveness

    Ferrocene/ β-cyclodextrin based supramolecular nanogels as theranostic systems

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    A supramolecular redox responsive nanogel (NG) with the ability to sense cancer cells and loaded with a releasing therapeutic agent was synthesized using hostguest interactions between polyethylene glycol-grafted-β-cyclodextrin and ferrocene boronic acid. Cyclic voltammetry matched with other spectroscopy and microscopy methods provided strong indications regarding host-guest interactions and formation of the NG. Moreover, the biological properties of the NG were evaluated using fluorescence silencing, confocal laser scanning microscopy, and cell toxicity assays. Nanogel with spherical core-shell architecture and 100–200 nm sized nanoparticles showed high encapsulation efficiency for doxorubicin (DOX) and luminol (LU) as therapeutic and sensing agents. High therapeutic and sensing efficiencies were manifested by complete release of DOX and dramatic quenching of LU fluorescence triggered by 0.05 mM H2O2 (as an ROS component). The NGs showed high ROS sensitivity. Taking advantage of a high loading capacity, redox sensitivity, and biocompatibility, the NGs can be used as strong theranostic systems in inflammation-associated diseases

    Antimicrobial Efficacy and Cytocompatibility of Calcium Hypochlorite Solution as a Root Canal Irrigant: An in Vitro Investigation

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    Introduction: The purpose of this study was to compare the antimicrobial efficacy of sodium hypochlorite (SH) and calcium hypochlorite (CH) against Enterococcus faecalis (E. faecalis) using quantitative real-time polymerase chain reaction (qPCR) analysis and also to compare their cytocompatibility on L929 murine fibroblasts using Mossman’s tetrazolium toxicity (MTT) assay. Methods and Materials: A broth micro-dilution susceptibility test was used to determine the minimum inhibitory concentration (MIC) of each irrigant against E. faecalis. Then, the root canals of 50 mature extracted human mandibular premolars were contaminated with E. faecalis and were randomly divided into three groups according to the irrigant used (n=20). Canals were irrigated with SH in group I (n=20) and CH in group II (n=20) at their obtained MIC. In group III (n=10), sterile saline was used. Microbial sampling was performed before and after biomechanical preparation. Quantitative PCR was used to quantify E. faecalis in the root canal samples. For cytocompatibility assessment, L929 murine fibroblasts were exposed to various concentrations of the irrigants. Results: Irrigation with test materials resulted in significant reduction in colony forming units (CFU) in post-instrumentation samples (with the MIC values of SH and CH against E. faecalis being 0.5% and 5%, respectively). However, the reduction in the normal saline group was not significant (P=0.203). In addition, 5% CH was more effective than 0.5% SH (P=0.006) in eliminating E. faecalis. Among the different concentrations of tested irrigants, 0.5% CH and 5% SH showed the least and the most cytotoxicity, respectively (P&lt;0.001). The cytotoxicity of 5% CH and 0.5% SH was similar (P=0.99), and lower than 2.5% SH (P&lt;0.001). Conclusion: CH at an MIC of 5% was effective in eliminating E. faecalis in planktonic state and also its biofilm and exhibited comparable cytocompatibility to that of 0.5% SH.Keywords: Calcium Hypochlorite; Enterococcus faecalis; Polymerase Chain Reaction; Root Canal Irrigant; Sodium Hypochlorit
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