1,845 research outputs found
Prime rings having one-sided ideal with polynomial identity coincide with special Johnson rings
AbstractThroughout R is a prime ring and is regarded as an algebra over its centroid. Let RΔ(ΔR) denote the right (left) singular ideal of R. R is called Johnson ring if it satisfies any of the two equivalent conditions: (a) RΔ = 0 = ΔR and R possesses uniform right and left ideals, (b) the right (left) quotient ring of R (in the sense of Utumi) is HomD(V, V) where V is a vector space over a division ring D. In addition if D is finite dimensional over its center then R is called a special Johnson ring. Denote by C the center of Utumi's right quotient ring of R. The results shown are: (1) R is a special Johnson ring iff there exists a nonzero one-sided ideal with polynomial identity (PI), (2) R has generalized polynomial identity (GPI) nontrivial over C iff each nonzero right (left) ideal of R contains a nonzero right (left) ideal with PI, (3) If R has GPI nontrivial over C then R cannot have nonzero nil one-sided ideals, (4) If R is integral domain the R has GPI nontrivial over C iff R has PI, (5) There does not exist a simple radical ring R satisfying a generalized polynomial identity nontrivial over the center of HomR(R, R), (6) R is a special Johnson ring with nonzero socle iff each nonnil right (left) contains an idempotent (≠0) and there exists a nonzero one-sided ideal with PI
Fuzzy based approach for Temporary objective identification
This paper presents a new fuzzy-based approach which identifies the most effective temporary objective of an enterprise, which is usually set based on the pure judgment of top management members or enterprise's experts. The method is based on fuzzy-decision-making system and makes robust utilization of enterprise's experts' knowledge, intuition and expertise. A simple illustrative example is provided to demonstrate how the method can be efficiently and effectively used in practice. The proposed approach can be used to identify the short-term objective of any profit- making-enterprise, and is specially applicable to business industries that are full of qualitative, stochastic, uncertain, and vague variables such as the case in automobile business (e.g., cars, trucks, gears, bearings etc), and is generally applicable to any other business sector. Keywords: Temporary Objectives, fuzzy decision-making-system, fuzzy expert-syste
Quantitative approach for Theory of Constraints in Manufacturing
In this paper, a systematic and quantitative view is presented for the application of the theory of constraints in manufacturing. This is done employing the operational research technique of mathematical programming. The potential of the theory of constraints in manufacturing is demonstrated. By applying the TOC philosophy based on this information, managers will be able to take the right actions that will improve the profitability of their companies. The model is proposed to be used with the TOC philosophy in order to improve the financial performance of a company. Keywords: Theory of Constraints, bottlenecks, Capacity-constrained resources (CCR), Throughpu
Prevalence of Mental Distress and Addiction Habits among Medical Undergraduates
Introduction: Medical education across the globe is perceived as being inherently stressful leading to mental distress in medical undergraduates. Among all psychological problems, stress is one of the common problems faced by medical students. Stress is a situation that leads to tension, pressure or negative emotions such as anxiety, depression and anger. Exposure to chronic stress can lead to both physical and mental illnesses. The stressors among medical students are academic, social, personal and financial. Psychological distress among students reduces their self-esteem, quality of life and academic performance. They may engage in potentially harmful methods of coping with stress such as tobacco, alcohol and substance abuse. Objective: The present study was conducted to determine the prevalence of stressrelated problems among medical undergraduates using DASS 21 scale and also to find prevalence of addiction habits in relation to stress. Methods: It was a cross-sectional study done among medical undergraduate students. Prevalence of psychological mood disorders was assessed by using DASS-21. A pretested and predesigned questionnaire was also prepared assessing correlation of mental distress with sociodemographic characteristics and addiction habits among medical undergraduates. Results: Prevalence of depression, anxiety and stress was found to be very high among medical undergraduates with prevalence being more in females as compared to males. Hostellers were found to have more mental distress as compared to day scholars. As compared to females, males were more engaged in addiction habits mostly consumption of alcohol. Conclusion: Family support, counselling lessons and various other methods of stress management should be given to the medical students to decrease the stress level and make them aware of healthy ways of living
Nonnegative idempotent matrices and the minus partial order
AbstractWe describe the structure of nonnegative matrices dominated by a nonnegative idempotent matrix under the minus order
Effect of Penetration Enhancer DMSO on In-Vitro Skin Permeation of Acyclovir Transdermal Microemulsion Formulation
The aim of this research was to enhance the flux of transdermal drug delivery by using penetration enhancers DMSO. Skin penetration enhancers have been used to improve bioavailability and increase the range of drugs for which topical and transdermal delivery is a viable option which penetrate into skin to reversibly decrease the barrier resistance. Penetration enhancing activity of dimethylsulphoxide (DMSO) at 5% w/w and 10% w/w concentration were determined in aqueous solution of ACV and in microemulsion formulations though calculation of transdermal flux of ACV with Keshary Chein Frenz Diffusion cell by using wistar albino rat skin. The transdermal flux of formulations PD, PD5D, PD10D, ME1 and ME10D was found to be 2.47, 50.7529, 119.7691, 238.1432 and 266.6721μg/cm2/h. The flux of microemulsion formulation ME10D was found 266.6721± 8.49 μg/cm2/h. Which showed highest value and skin flux of the drug could be enhanced up to 107 fold compared to its aqueous solution by preparing microemulsion ME10D. DMSO in microemulsion formulation is safe to the skin at 10% DMSO w/w.Keywords: DMSO, Penetration enhancer, Ethanol, Transdermal Microemulsion, Acyclovir (ACV
Effect of Penetration Enhancer DMSO on In-Vitro Skin Permeation of Acyclovir Transdermal Microemulsion Formulation
The aim of this research was to enhance the flux of transdermal drug delivery by using penetration enhancers DMSO. Skin penetration enhancers have been used to improve bioavailability and increase the range of drugs for which topical and transdermal delivery is a viable option which penetrate into skin to reversibly decrease the barrier resistance. Penetration enhancing activity of dimethylsulphoxide (DMSO) at 5% w/w and 10% w/w concentration were determined in aqueous solution of ACV and in microemulsion formulations though calculation of transdermal flux of ACV with Keshary Chein Frenz Diffusion cell by using wistar albino rat skin. The transdermal flux of formulations PD, PD5D, PD10D, ME1 and ME10D was found to be 2.47, 50.7529, 119.7691, 238.1432 and 266.6721μg/cm2/h. The flux of microemulsion formulation ME10D was found 266.6721± 8.49 μg/cm2/h. Which showed highest value and skin flux of the drug could be enhanced up to 107 fold compared to its aqueous solution by preparing microemulsion ME10D. DMSO in microemulsion formulation is safe to the skin at 10% DMSO w/w.Keywords: DMSO, Penetration enhancer, Ethanol, Transdermal Microemulsion, Acyclovir (ACV
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