Application of the Nozzle Analogy to Easily Predict Steam Turbine Performance With Minimal Geometric Input

A simple method for modelling steam turbines using a nozzle analogy was recently published. The method describes both stator and rotor components of a turbine with an appropriate nozzle definition, and makes use of the traditional velocity triangles to determine work output. What makes the method convenient is that it only requires a reasonable estimate of the effective nozzle throat area per blade row, as well as properly chosen loss coefficients. A complete turbine train with multiple stages can easily be solved using a simple 1-D pressure correction method. The method was demonstrated to match detailed inter-stage turbine data quite accurately. This paper elaborates on the application of the method. It presents a more thorough procedure for establishing the nozzle throat areas using a turbine lay-out drawing, as well as consideration of possible reaction ratio variation between successive stages. Furthermore, the loss coefficients are determined using the methods described by Traupel and Zehner. The paper presents these in a compressed and digitized format for easy implementation in a software code. A case study is presented to show how the model can quantify improvements to blade profiles. Another case study models a complete boiler feed pump turbine connected to the feedwater pumps and includes the partial arc governing stage and cold re-heat supply. This specific model demonstrated the method’s ability to accurately model a turbine at low load and high back pressure conditions. Turbine system modelers can apply the method presented here to their own equipment and obtain trustworthy results without the need for detailed profile geometry or complex CFD analyses. The method is however limited to subsonic flow between blade rows, hence some modern transonic last stage blade designs might not be adequately represented.

Stoichiometry of equations through the Inverse de Donder relation

The stoichiometry of equations was revisited in light of the Law of Conservation of Matter at an atomic, elemental level. For a balanced chemical equation following the simplest general model aA → bB, the fact that ${a \over b} = {{{n_A}} \over {{n_B}}}$, where nA is the number of moles of A consumed and nB is the number of moles of B produced in the reaction during the experiment, was used to address the de Donder relation, introduced by Theophile de Donder (1873–1957). While crediting the Belgian scientist for pointing out that “the reaction-ratio method” may be utilized for stoichiometry, the inverse de Donder relation was applied to problems in reaction stoichiometry. Several examples were used to show that the latter relation can be used to form proportions in order to rapidly solve such stoichiometry problems and to do so with fundamental chemical understanding. Educators in general chemistry were encouraged to teach the discussed method in their courses.

Reversible 1,1-hydroaluminations and C–H activation in reactions of a cyclic (alkyl)(amino) carbene with alane

Varying the reaction ratio of cyclic (alkyl)(amino) carbene (cAACEt) with AlH3·NEtMe2 leads to the isolation of (cAACEtH)AlH2·NEtMe21 and (cAACEtH)2Al(μ-H)2AlH2·NEtMe22 and the first example of a monomeric dialkyl-aluminum hydride (cAACEtH)2AlH 3.

Generalised analysis of compensating balancing sleeves with experimental results from a scaled industrial turbine coupling shaft

The paper furthers the analysis of a recently proposed balancing methodology for high-speed, flexible shafts. This mechanism imparts corrective balancing moments, having the effect of simulating the fixing moments of equivalent double or single encastre mounted shafts. This is shown to theoretically eliminate/nullify the first lateral critical speed, and thereby facilitate safe operation with reduced lateral critical speed margins. The paper extends previously reported research to encompass a more generalised case of multiple, concentrated, residual imbalances, thereby facilitating analysis of any imbalance distribution along the shaft. Solutions provide greater insight of the behaviour of the balancing sleeve concept, and the beneficial implications for engineering design. Specifically, (1) a series of concentrated imbalances can be regarded as an equivalent level of uniform eccentricity, and balance sleeve compensation is equally applicable to a generalised unbalanced distribution, (2) compensation depends on the sum of the applied balancing sleeve moments and can therefore be achieved using a single balancing sleeve (thereby simulating a single encastre shaft), (3) compensation of the second critical speed, and to a lesser extent higher orders, is possible by use of two balancing sleeves, positioned at shaft ends, (4) the concept facilitates on-site commissioning of trim balance, which requires a means of adjustment at only one end of the shaft, (5) the Reaction Ratio, RR, (simply supported/encastre), is independent of residual eccentricity, so that the implied benefits resulting from the ratio (possible reductions in the equivalent level of eccentricity) are additional to any balancing procedures undertaken prior to encastre simulation. Analysis shows that equivalent reductions in the order of 1/25th, are possible. Experimental measurements from a scaled model of a typical drive coupling employed on an industrial gas turbine package, loaded asymmetrically with a concentrated point of imbalance, are used to support the analysis and conclusions.

Biodiesel Production from Sterculia foetida Oil by Using Solid Support Catalyst

In the present work, the properties of bioester from Samrong oil (Sterculia Foetida) and characteristics of cellulose solid catalyst are described. Heterogeneous catalyst was prepared via carbonization, sulfonation and purification giving solid catalyst as brown powder. Control parameters were time and temperature of carbonization and sulfonation reaction, ratio of sulfuric acid to solid material and weight of solid material. The optimized carbonization condition was 300 °C for 15 h. The sulfonation temperature was 150 oC for 18 h under N2 producing 7.99 mmol/g of acid concentration on solid catalyst. The acidity in water of solid catalyst after purification and drying was decreasing. The results of biodiesel production showed that the triglyceride could be converted to biodiesel directly by one-step sulfonic acid catalyzed process. The experimental condition of reaction process was 3.0 M of catalyst concentration with 9:1 M ratio of methanol to triglyceride at the temperature of 80 °C. This catalysts provided high reactivity of transesterification. The present procedure represents a simple method for biodiesel production with a short reaction time and with moderate conversion rate.

Boron Neutron Capture Therapy (BNCT) using Compact Neutron generator

<span>Boron Neutron Capture Therapy (BNCT) must be appropriate with five criteria from IAEA. These criteria in order to prevent neutron beam output harm the patient. It can be by using Collimator of neutron source Compact Neutron Generator (CNG) and Monte Carlo simulation method with N particles 5 .CNG is developed by deuteriumtritium reaction (DT) and deuterium-deuterium (DD) reaction. The manufacture result of the collimator is obtained </span><span>epithermal neutron flux value of 1.69e-9 n/cm^2s for D-T reaction and 8e6 n/cm^2s for D-D reaction, ratio of epithermal and thermal is 1.95e-13 Gy cm^2/n for D-T reaction and for D-D reaction, ratio of fast neutron component is 1.69e-13 Gy cm^2/n for D-T reaction and for D-D reaction, ratio of gamma component is 1.18e-13 Gy cm^2/nfor D-T reaction and for D-D reaction. The Latest </span><span>reaction is current ratio 0.649 for D-T reaction and 0.46 for D-D reaction.</span>

CAD-Based Adjoint Shape Optimisation of a One-Stage Turbine With Geometric Constraints

An extension of the CAD-based parametrisation termed ‘NURBS-based parametrisation with complex constraints’, or NsPCC, is developed and applied to the aerodynamic shape optimisition of a one-stage high pressure turbine. NsPCC uses a test-point approach to impose various geometric constraints such as continuity, thickness and trailing edge radius constraint. To perform the shape optimisation using NsPCC, The surface sensitivity is first computed efficiently using a discrete adjoint solver. The displacements of the control points of the NURBS patches are used as the design variables and linked to the surface sensitivity through consistent application of Automatic Differentiation. A robust mesh deformation based on linear elasticity and further enhanced with sliding mesh capability is used to deform the mesh at each design step. Finally, the optimised rotor shape is exported as a STEP file. The method is demonstrated on a turbine stage where isentropic efficiency is improved by over 0.4% with both the inlet capacity and rotor reaction ratio deviation below the prescribed thresholds. Satisfaction of the G1 continuity, thickness and trailing radius constraints is verified.

GAMBARAN EFEK PEMBERIAN ANESTESI LOKAL DENGAN TEKNIK BLOK MANDIBULA FISHER PADA PEMINUM ALKOHOL

The habit of consuming alcoholic beverages have special characteristics when dealing with drugs, especially related to the anesthesia, when compared with those who did not consume alcoholic beverages because alcohol may alter the response to drugs given simultaneously. Anesthetic drugs and alcohol has the same content, namely the content of ether. Ether is a substance that is widely used as an anesthetic in medicine today. This study aims to describe the provision of local anesthetic effects with mandibular block technique fisher drinkers of alcoholic beverages and also to know the reaction to anesthesia and anesthesia reaction ratio. The research was conducted in a non-descriptive statistics, the data processing and analysis is based on data which is then treated observations described qualitatively. The data is processed and presented in tables and described textually. The results of research on the treatment of anesthesia and extraction indicate that there are differences in the duration of time to react calculated from first injection until such time as the disappearance of pain at the time of extraction. Similarly, there are differences in the duration of time when anesthesia is performed on the area of ​​the lips, tongue, buccal mucosa, and lingual mucosa based on the amount of alcohol you drink and the alcohol content. Keywords: Anesthesia, Mandibular block fisher, Alcoholic beverages. Abstrak: Kebiasaan mengonsumsi minuman beralkohol memiliki karakteristik khusus bila berhubungan dengan obat-obatan, terlebih berkaitan dengan anestesi, jika dibanding dengan orang yang tidak mengonsumsi minuman beralkohol karena alkohol dapat merubah respon terhadap obat yang diberikan secara bersamaan. Obat anestesi dan alkohol mempunyai kandungan yang sama yaitu kandungan eter. Eter ialah suatu zat yang banyak digunakan sebagai anestesi dalam dunia kedokteran hingga saat ini. Penelitian ini bertujuan untuk mengetahui gambaran pemberian efek anestesi lokal dengan teknik blok mandibula fisher pada peminum minuman beralkohol dan juga untuk mengetahui masa reaksi anestesi serta perbandingan reaksi anestesi. Penelitian ini dilakukan secara deskriptif non-statistik, yaitu pengolahan data dan analisis yang didasarkan pada data hasil observasi perlakuan yang kemudian dijelaskan secara kualitatif. Data diolah dan disajikan dalam bentuk tabel serta diuraikan secara tekstual. Hasil penelitian pada perlakuan anestesi dan ekstraksi menunjukkan bahwa terdapat perbedaan durasi masa bereaksi dihitung dari injeksi pertama sampai dengan waktu hilangnya rasa sakit pada saat dilakukan ekstraksi. Begitu pula terdapat perbedaan durasi waktu ketika anestesi dilakukan pada area bibir, lidah, mukosa bukal dan mukosa lingual berdasarkan jumlah alkohol yang diminum serta kandungan kadar alkohol. Kata kunci: Anestesi, Blok mandibula fisher, Minuman beralkohol.