SIMULATION STUDIES OF THE MOLIERE RADIUS FOR EM CALORIMETER MATERIALS

The Monte-Carlo calculations of the Moliere radius (RM) for some homogeneous and heterogeneous media used in electromagnetic calorimetry in the energy range from 50 MeV to 10 GeV are presented in detail. The obtained results, the uncertainties in determining RM, estimations of the absorbed energy, methods for approximating the absorbed energy, and the accuracy of the results are discussed as well. Some RM are shown for calorimeter proto-types of the Spin Physics Detector experiment (SPD). A one-parameter function of the Moliere radius dependence on the absorber-scintillator thickness ratio is obtained.

A Novel Feature of Valence Quark Distributions in Hadrons

Examining the evolution of the maximum of valence quark distribution, qV, weighted by Bjorken x, h(x,t)≡xqV(x,t), it is observed that h(x,t) at the peak becomes a one-parameter function; h(xp,t)=Φ(xp(t)), where xp is the position of the peak, t=logQ2, and Q2 is the resolution scale. This observation is used to derive a new model-independent relation which connects the partial derivative of the valence parton distribution functions (PDFs) in xp to the quantum chromodynamics (QCD) evolution equation through the xp derivative of the logarithm of the function Φ(xp(t)). A numerical analysis of this relation using empirical PDFs results in an observation of the exponential form of the Φ(xp(t))=h(xp,t)=CeDxp(t) for leading to next-to-next leading order approximations of PDFs for the range of Q2, covering four orders in magnitude. The exponent, D, of the observed “height-position” correlation function converges with the increase in the order of approximation. This result holds for all the PDF sets considered. A similar relation is observed also for the pion valence quark distribution, indicating that the obtained relation may be universal for any non-singlet partonic distribution. The observed “height-position” correlation is used also to indicate that no finite number of exchanges can describe the analytic behavior of the valence quark distribution at the position of the peak at fixed Q2.

The art design of industrialised manufacturing furniture products based on the simulation of mathematical curves

After a lot of literature reading and practical research, the paper uses the parametric modelling method of curve simulation characteristic line to establish the mathematical model of the furniture product leg shape. This article first uses the surface construction method to analyse the composition of the leg size of the industrialised production and manufacture of furniture products, and makes the solid modelling according to the construction method of non-uniform rational spline mathematical curve and surface simulation. At the same time, the parameter function of furniture leg type is set on SolidWorks, and the research results obtained in the paper are found by simulation, which opens up a new research path for the application of mathematical curve model in furniture design.

Study on Roughness Parameters Screening and Characterizing Surface Contact Performance based on Sensitivity Analysis

As microtopography can influence the contact behavior of materials, it is of great significance to study the correlation between morphology characterization parameters and contact performance. In the light of complex relevance of parameters, a method for screening roughness parameters (RP) to characterize contact performance is constructed to get the maximum influence parameters on the contact stress (CS) and avoid the error of experiential selection. Firstly, Pearson's coefficient and BP neural network are utilized to elaborate on correlation level between RP and CS and to build the regression model. Then global sensitivity analysis (Sobol) and local sensitivity analysis (MIV and Garson) are introduced to demonstrate RP quantitative influences on CS and select main RP for characterizing contact performance. The research shows: 1) In the correlation analysis, RP with high correlation and non-collinearity on σmax are Sa, Sdq, S5p, Spk and Svk; With regard to Mpmax and τmax, Sa, S5p, Sdq and Vmp are on display. 2) RP importance sequence based on the results of correlation analysis is: Sa, Spk, Sdq, Svk, S5p for σmax, and Sa, Vmp, Sdq, S5p for Mpmax and τmax. 3) For the comprehensive main parameters model, RP for characterizing contact performance under the three contact stresses are Sa, Spk and Vmp, belonging to height parameter, function parameter and volume parameter, respectively. According to definition, all of them can significantly affect the stress concentration and distribution on contact surface of materials, which validates the rationality of the method.

Impact of Process Parameters on the Diameter of Nanobubbles Generated by Electrolysis on Platinum-Coated Titanium Electrodes Using Box–Behnken Experimental Design

(1) The generation of nanobubbles by electrolysis is an interesting method of using electrical energy to form bubble nuclei, effectively creating a multiphase system. For every process, the effectiveness of nanobubble generation by electrolysis depends on various process parameters that impact should be determined. (2) In this work, the electrolytic generation of hydrogen and oxygen bubbles was performed in a self-built setup, in which a Nafion membrane separated two chambers. The generation of bubbles of both gases was investigated using Box–Behnken experimental design. Three independent variables were salt concentration, current density, and electrolysis time, while the dependent variables were Sauter diameters of generated bubbles. An ANOVA analysis and multivariate regression were carried out to propose a statistical and power model of nanobubble size as a process parameter function. (3) The generation of bubbles of hydrogen and oxygen by electrolysis showed that different factors or their combinations determine their size. The results presented in this work proved to be complementary to previous works reported in the literature. (4) The Sauter diameter of bubbles increases with salt concentration and stays constant with increasing current density in investigated range. The proposed correlations allow the Sauter diameters of nanobubbles generated during electrolysis to be predicted.

Sidney Holt on principles for the conservation of wild living resources, whaling in the Antarctic, and the Beverton–Holt stock–recruitment relationship

I review my interactions with Sidney Holt concerning principles for the conservation of wild living resources, the whaling case between Australia and Japan in the International Court of Justice, and the Beverton–Holt stock–recruitment relationship (BH-SRR). Holt and Lee Talbot published a monograph on principles for conservation in 1977; I lead the publication of an update ∼20 years later. I compare the two versions and discuss Holt’s contributions. Holt was active in the world-wide campaign to cease whaling and in efforts to have the Japanese special permit whaling programme in the Antarctic recognized as violating the moratorium on commercial whaling. I describe my involvement in the case and my interactions with him during oral arguments in the case and when the International Court of Justice rendered its decision that the Japanese programme of special permit whaling contravened the international treaty for the regulation of whaling because it was not for purposes of scientific research. In response to a paper of mine concerning steepness, Holt wrote to me that the BH-SSR is a one-, not two-, parameter function. I explain my current understanding of his reasoning, which involves how we use the SRR in fishery management.

Influence of propulsion installation performance on travel efficiency

This paper presents an analysis of exploitation parameters for naval propulsion plant at different operating regimes. For naval propulsion plant with internal combustion engines, is considered as independent variables which give its operating regimes. Functional parameters of analysis of navigational regimes considered representative of the operation of the ship. Propulsion of the ship is provided by a fixed pitch propeller that allows modification propulsion performance by adjusting a single parameter function: speed propeller.

Penentuan Daerah Prioritas di Wilayah Pelayanan Bandung Utara Berdasarkan Parameter Fungsi dan Nilai Daerah

AbstrakWilayah Pelayanan (WP) Bandung Utara merupakan salah satu wilayah pelayanan sampah di Kota Bandung yang terdiri dari 7 kecamatan dan 31 kelurahan dengan karakteristik yang beragam. Tujuan studi ini menentukan daerah prioritas di WP Bandung Utara berdasarkan parameter fungsi dan nilai daerah pada SNI 19-2454-2002. Studi dilakukan dengan menentukan kriteria penilaian, identifikasi sumber dan jenis data yang tersedia, dan penentuan data yang digunakan, menyusun penilaian penentuan daerah prioritas dengan pembuatan standar kelas penilaian dan skoring, pembobotan nilai akhir dan pembuatan peta daerah prioritas. Daerah prioritas 1 yaitu Kelurahan Pasteur, Sukagalih, Citarum dan Tamansari. Daerah prioritas 2 yaitu Kelurahan Lebak Gede, Sadang Serang, Sekeloa, Gegerkalong, Sarijadi, Sukabungah, Cihaurgeulis, Sukaluyu, Cikutra dan Cihapit, daerah prioritas 3 yaitu Kelurahan Ciumbuleuit, Hegarmanah, Ledeng, Cipaganti, Dago, Lebak Siliwangi, Isola, Sukarasa, Cipedes, Sukawarna, Cigadung, Neglasari, Cicadas Padasuka, Pasirlayung, Sukamaju, dan Sukapada.Kata kunci: Wilayah pelayanan , Fungsi dan nilai daerahAbstractService Area North Bandung is one of the areas of waste management services in Bandung, which consists of 7 districts and includes 31 villages with various characteristics. The purpose of this study was to determine priority areas in North Bandung WP by parameter function and values based on SNI 19-2454-2002. The study was done by determination of the assessment criteria, identification of sources and types of data available, and the determination of the data used, then make assessment determining the priority areas to manufacture class standards of assessment and scoring, weighting the value of the final and mapping areas of priority. The priority area 1 of waste management services were the Village Pasteur, Sukagalih, Citarum and Tamansari. The priority area 2 comprised the Village Lebak Gede, Sadang Serang, Sekeloa, Gegerkalong, Sarijadi, Sukabungah, Cihaurgeulis, Sukaluyu, Cikutra and Cihapit. The priority area 3 consisted of the Village Ciumbuleuit, Hegarmanah, Ledeng, Cipaganti, Dago, Lebak Siliwangi, Isola, Sukarasa, Cipedes, Sukawarna, Cigadung, Neglasari, Cicadas Padasuka, Pasirlayung, Sukamaju, and Sukapada.Keywords: The area of services, functions and value of the area

A mechanical cusp catastrophe imposes a universal developmental constraint on the shapes of tip-growing cells

Understanding the mechanistic basis for cell morphology is a central problem in biology. Evolution has converged on tip growth many times, yielding filamentous cells, yet tip-growing cells display a range of apical morphologies. To understand this variability, we measured the spatial profiles of cell-wall expansion for three species that spanned the phylogeny and morphology of tip-growth. Profiles were consistent with a mechanical model whereby the wall was stratified and stretched by turgor pressure during cell growth. We calculated the spatial profiles of wall mechanical properties, which could be accurately fit with an empirical two-parameter function. Combined with the mechanical model, this function yielded a “morphospace” that accounted for the shapes of diverse tip-growing species. However, natural shapes were bounded by a cusp bifurcation in the morphospace that separated thin, fast-growing cells from (nonexistent) wide, slow-growing cells. This constraint has important implications for our understanding of the evolution of tip-growing cells.

Metamodeling Time-Temperature Creep Parameters

There exist many time-temperature parameter (TTP) models for creep rupture prediction of components including the Larson–Miller (LM), Manson–Haferd (MH), Manson–Brown (MB), Orr–Sherby–Dorn (OSD), Manson–Succop (MS), Graham–Walles (GW), Chitty–Duval (CD), Goldhoff–Sherby (GS) models. It remains a challenge to determine which model is “best”, capable of accurate interpolation and physically realistic extrapolation of creep rupture data for a given material. In this study, metamodeling is applied to create a unified TTP metamodel that combines and regresses into twelve TTP models (eight existing and four newly derived). An analysis of the mathematical problems that exist in TTP models is provided. A matlab code is written that can: (1) calibrate the material constants of any of the twelve TTP models (using the metamodel); (2) determine the most suitable stress-parameter function; (3) and report the normalized mean square error (NMSE) of rupture predictions for a given material database. Using the metamodel, and code, a design engineer can make an intelligent selection of the “best” TTP model for creep resistant design. This process is demonstrated using four isotherms of alloy P91 creep rupture data. To assess the influence of material, further validation is performed on alloys Hastelloy X, 304SS, and 316SS. It is determined that the “best” model is dependent on material type and the quality and quantity of available data.