77 research outputs found
Effect of taper and twisted blade in Steam Turbines
Turbo machinery is critical to various processes and their application range from steam turbines to aircraft turbines. Turbo machinery bladed disks are subjected to severe centrifugal loads.The centrifugal force is one of the problems that face the designers of blades especially the long ones. The severe loading leads to large peak stresses. One way to tackle this is by using twisted blades or using variable cross-section area blades. Rotating structures having the shape of pre-twisted blades commonly affect the modal characteristics. In order to design the rotating
structures properly, their modal characteristics must be estimated accurately. The modal characteristics of rotating structures often vary significantly
due to the effect of the centrifugal inertia force induced by the rotation motion. For this reason, the modal characteristics of rotating structures have to be investigated. In this paper effect of taper
and twist in steam turbine blade is analyzed using A
NSYS. Blades are idealized as tapered cantilever beams that are fixed to a rotating disc.The results obtained are then utilized in the design of the constant stress blad
Formulation and evaluation of fermented Ayurvedic formulation: Asava
Asava, an Ayurvedic formulation is used since more than 3000 years for the treatment of various diseases. Due to accelerated commercialization, the assurances on safety and efficacy of Ayurvedic products have become an important issue. Growing awareness about harmful side effects of modern medicine has led to interest in Ayurveda at the international level as well as within India. It is prepared by using decoction of herbal drug and contains self generated alcohol. Although these formulations are mentioned in traditional literature and used regularly their scientific investigation and reporting is essential to strengthen Ayurveda in global market. Determination of qualitative as well as quantitative evaluation parameters of various asava is warranted to ensure the quality and safety of these preparations. Therefore, to achieve this, the world health organization advocates to undertake various standardization parameters. In present study attempt has been made for formulation and evaluation of prepared asava.
Life Estimation of a Steam Turbine Blade using Low Cycle Fatigue Analysis
This work is primarily focused in utilising a technique to assess low cycle fatigue life of steam turbine blade. Two approaches are employed here, first is based on the linear elastic finite element analysis. Fictive elastic results are recalculated using Neuber's rule. Second approach is based on elastic-plastic Finite Element analysis (FEA). Strain amplitude approach is followed through Universal slope method and Coffin-Manson equation to determine the number of start-up and shut down cycles
Proper blade design with conservative stress levels is important for reliability in rotor blade design. Finite Element Analysis based fatigue tools enable reliable fatigue life calculations to be done at the design stage of a development process and a proper design methodology is important to predict the catastrophic failure of turbine blade due to fatigue
Liderazgo innovador en la gestión y desarrollo de la innovación en el siglo XXI
La innovación es cada vez más necesaria en un mundo globalizado, dinámico y complejo, estando en juego la supervivencia de las organizaciones. Entonces, para adentrarse en la innovación, se propone un modelo basado en el liderazgo innovador que se encargue impulsar y desarrollar una estrategia de innovación, bajo las condiciones exigibles en el siglo XXI. Por una parte, los líderes innovadores, respecto de su persona y organización, deberán desarrollar la inteligencia emocional, gestionar la innovación, dirigir a su equipo innovador y desarrollar una cultura innovadora, así como potenciar las habilidades que le son propias. Por otro lado, los líderes innovadores serán los artífices en establecer una estrategia de innovación, clarificando su propósito, mentalidad, cultura del cambio, aprovechar oportunidades y pasar a la acción. Se concluirá con que la innovación no requiere de ideas grandes, sino servirse de una pequeña y transformarlo en grande, sabiendo que toda innovación es el resultado de aprovechar una oportunidad
Structural Studies of Cysteine and Serine Protease Inhibitors Towards Therapeutic Applications
Ph.DDOCTOR OF PHILOSOPH
Smart contracts from a legal perspective
Smart contracts are a new technology emerging with force due to the opportunities and benefits it can offer. The main innovation is that the terms parties agree to regulate their relations are executed automatically by a computer program. The intention of this Paper is to examine if the Spanish Contract Law is prepared for smart contracts or its modification is needed. First, it is necessary to understand the blockchain technology it can deploy on and the features of smart contracts. Then, under a legal perspective, it analyses if they comply with the essential contract elements -consent, object and cause- and main concerns during its existence regarding formation, performance and breach. Finally, it concludes by recognizing that smart contracts go along with existing Contract Law principles, offers some remedies and encourage legislators and jurists not to ignore these contracts for legal security
Analysis of corrugated shells
Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Civil and Sanitary Engineering, 1959.Vita.Includes bibliographical references (leaves 147-148).by Surendra Tulsidas Shah.Sc.D
Validation of Simultaneous Quantitative Method of HIV Protease Inhibitors Atazanavir, Darunavir and Ritonavir in Human Plasma by UPLC-MS/MS
Objectives. HIV protease inhibitors are used in the treatment of patients suffering from AIDS and they act at the final stage of viral replication by interfering with the HIV protease enzyme. The paper describes a selective, sensitive, and robust method for simultaneous determination of three protease inhibitors atazanavir, darunavir and ritonavir in human plasma by ultra performance liquid chromatography-tandem mass spectrometry. Materials and Methods. The sample pretreatment consisted of solid phase extraction of analytes and their deuterated analogs as internal standards from 50 μL human plasma. Chromatographic separation of analytes was performed on Waters Acquity UPLC C18 (50 × 2.1 mm, 1.7 μm) column under gradient conditions using 10 mM ammonium formate, pH 4.0, and acetonitrile as the mobile phase. Results. The method was established over a concentration range of 5.0–6000 ng/mL for atazanavir, 5.0–5000 ng/mL for darunavir and 1.0–500 ng/mL for ritonavir. Accuracy, precision, matrix effect, recovery, and stability of the analytes were evaluated as per US FDA guidelines. Conclusions. The efficiency of sample preparation, short analysis time, and high selectivity permit simultaneous estimation of these inhibitors. The validated method can be useful in determining plasma concentration of these protease inhibitors for therapeutic drug monitoring and in high throughput clinical studies
Identifying barriers and finding solutions to implement best practices for cancer surgery at Maputo Central Hospital, Mozambique
Purpose: The aim of this study was to assess the surgical resources and surgical oncology team skills at the Surgical Department of Maputo Central Hospital (MCH) in Mozambique in order to define an educational program to support surgical oncology practice. Methods: From January 2017 to December 2017, a general evaluation of the resources of MCH was carried out, as well as its offerings in oncological care in different services. Data were obtained by reviewing documents, visiting surgical services and interviewing key informants and others informally. In addition, a group of seven surgeons of the Surgical Department of MCH answered a questionnaire about the quality of the cancer units (The Cancer Units Assessment Checklist for low- or middle-income African countries). Subsequently, surgical, anaesthesiology and intensive care facilities were evaluated according to the Portuguese-speaking African Countries Assessment of Surgical Oncology Capacity Survey (PSAC-Surgery). All the data were triangulated in order to identify gaps, develop an action plan and define an educational program. Results: Breast, oesophagus and colorectal cancers were the most commonly treated neoplasms in MCH. A range of technical and resource needs as well as the gaps in knowledge and skills were identified. All surgeons recognised the need to create a training program in oncology at the undergraduate level, specific training for residents and continuing oncological education for general surgeons to improve the practice of surgical oncology. It was evident that all these interventions needed to be formalised, appropriately certified and count for professional career progression. Based on the local epidemiological data and on these study findings, oncology education programs were developed for surgeons. Conclusions: The findings of this study contributed to the development of an educational program in surgical oncology, considered essential to the training of surgeons at MCH. The cancer educational programs and the mobilisation of adequate resources will ensure the provision of adequate surgical oncology treatments for MCH. The training requirements should be tailored to suit the local needs based on the most prevalent malignancies diagnosed in the region. In our view, this methodology may apply to other countries with similar realities in the formation of surgical oncologists.publishersversionpublishe
Development and optimization of an in-house heterologous ELISA for detection of prednisolone drug in enzyme conjugates using spacers
The introduction of spacers in coating steroid protein complexes and/or enzyme conjugates or immunogens is known to exert an influence on the sensitivity of steroid enzyme immunoassays. We investigated the impact of different homobifunctional spacers, ranging in atomic length from 3 to 10, on the sensitivity and specificity of prednisolone (PSL) enzyme immunoassays. In this study, four homo-bifunctional spacers, namely, carbohydrazide (CH), adipic acid dihydrazide (ADH), ethylene diamine (EDA), and urea (U), were incorporated between PSL and horseradish peroxidase (HRP) for preparing the enzyme conjugate with an aim to improve the sensitivity of the assay without compromising assay specificity. The assays were developed using these enzymes conjugated with antibodies raised against the PSL-21-HS-BSA immunogen. The sensitivity of the PSL assays after insertion of a bridge in the enzyme conjugate was 1.22 ng/mL, 0.59 ng/mL, 0.48 ng/mL, and 0.018 ng/mL with ADH, CH, EDA, and urea as a spacer, respectively. Among the four combinations, the PSL-21-HS-BSA-antibody with PSL-21-HS-U-HRP-enzyme conjugate gave better sensitivity and less cross-reaction. The percent recovery of PSL from the exogenously spiked human serum pools was in the range of 88.32%-102.50%. The intra and inter-assay CV% was< 8.46%. The PSL concentration was estimated in the serum samples of patients on PSL treatment. The serum PSL values obtained by this method correlated well with the commercially available kit (r2 = 0.98). The present study suggests that the nature of the spacer is related to assay sensitivity and not the spacer length
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