Design of cylindrical steel liquid tanks with stepped walls using One-foot method

Cylindrical steel tanks are used in most countries to store bulk volumes of both solid and liquid products such as water, oil, gasoline and grain. Such steel tanks are prone to buckling when subjected to external pressure either due to vacuum or due to wind. These types of shell structures are generally controlled by elastic buckling failure because of the thin wall thickness. Cylindrical shells are commonly constructed with stepwise variable wall thickness due to economic reasons. The thickness of the tank shell wall is designed to increase from top to bottom because the stress resultants on the tank wall gradually increase towards the base of the tank. For open-top tanks, a primary stiffening ring is required at or near the top to maintain roundness under all loads. Stress resultants in a primary stiffening ring were previously identified by the Author for uniform wall thick tanks. In this new study, the applicability of this hand calculation method in stepped wall tanks has been investigated. Pursuant to this goal, a specified tank shell was designed considering One-foot method. Then, the stepped wall tank was transformed into an equivalent 1-course tank for hand calculation. Using the previously developed hand calculation method by Author, a test for the in-plane bending moment in the ring was conducted to achieve an acceptable value for stepped wall tanks. The analysis results show that the previously proposed method for uniform wall thick tanks may also be used for stepped wall tanks considering an equivalent thickness. On the other hand, using Linear Buckling Analysis (LBA), the buckling mode was obtained for two different stepped wall tanks in the study.

Cost Aanalysis and Comparison of Rectangular and Trapezoidal Box Girder Section

The present study aims at design, analysis and parametric comparison of two different cross section of box girder deck system. Objectives of this study are to compare the stresses at important location like top slab and bottom slab using analysis tool MIDAS-2016. And design and estimates different sizes of rectangular and trapezoidal box girder section using hand calculation. Keywords: Box Girder, Rectangular box girder, Trapezoidal box girder and MIDAS-2016

Introduction to Genetic Algorithms in Search and Optimization

This chapter is all about introducing genetic algorithms in the search process, which are based on the theory of natural selection, genetics, and survival of fittest. By detailed understanding of the algorithm, one would be able to apply it in your respective field for optimization. At the end of this chapter, the reader will have acquired basic theory and working of these algorithms. Since genetic algorithms are used in diverse fields, the tone and language of this chapter is kept simple and casual for better understanding. Genetic algorithms in this chapter are applied through a hand calculation example. Genetic algorithms are basically mathematical calculations based on Darwin's theory of survival of fittest. This chapter gives a detailed understanding of the theory and working of genetic algorithms based on hand calculation examples. Comparison of genetic algorithms with other search procedures is also done.

Researcher Degrees of Freedom and a Lack of Transparency Contribute to Unreliable Results of Nonparametric Statistical Analyses Across SPSS, SAS, Stata, and R

The replication crisis within the social and behavioral sciences has called into question the consistency of research methodology. A lack of attention to minor details in replication studies may limit researchers’ abilities to reproduce the results. One such overlooked detail is the statistical programs used to analyze the data. In the current investigation, we compared the results of several nonparametric analyses and measures of normality conducted on a large sample of data in SPSS, SAS, Stata, and R with results obtained through hand-calculation using the raw computational formulas. Multiple inconsistencies were found in the results produced between statistical packages due to algorithmic variation, computational error, and lack of clarity and/or specificity in the statistical output generated. We also highlight similar inconsistencies in supplementary analyses conducted on subsets of the data, which reflect realistic sample sizes. These inconsistencies were largely due to algorithmic variations used within packages when the analyses are performed on data from small- or medium-sized samples. We discuss how such inconsistencies may influence the conclusions drawn from the results of statistical analyses depending on the statistical software used, and we urge researchers to analyze their data across multiple packages, report details regarding the statistical procedure used for data analysis and consider these details when conducting direct replications studies.

IDENTIFIKASI SERANGGA PERUSAK DAN TINGKAT KERUSAKAN PADA BIBIT MAHONI (Swietenia macrophyla King) DI AREAL PERSEMAIAN PERMANEN BPDASHL KAPUAS PONTIANAK

Mahogany (Swietenia macrophyla King) is a wood plant that has the potential to be developed in plantations. One of the factors that interfered in the development of mahogany was destructive insects. This study aimed to identify the species of destructive insects and calculate the level of damage to mahogany seedlings in the permanent nursery BPDASHL Kapuas Pontianak conducted by the survey method. Collecting insects on mahogany seedlings is identified by using insect nets and catching them directly by hand. Calculation of damage level is to use the criteria table and crop assessment category. The results showed that there were 4 species of insects which damaged the seedlings of mahogany in the nursery, namely Valanga nigricornis, Tagasta marginella, Anoplolepis longipes and Xyloxandrus sp. The number of seeds attacked as many 585 seeds from 2.176 seeds, with the level of damage to the entire pathway which is 12,39% and included in the category of minor damage. Keywords: Destructive insects, Identification, level of damage, mahogany seedlings, permanent nursery

Groups, Algorithms and Programming (GAP) and the Nonabelian Tensor Square of Groups of Order 8q

In this paper, the software package Groups, Algorithms and Programming (GAP) is used to verify the hand calculation of the nonabelian tensor square for groups of order 8q, where q is an odd prime.

Comparative Study of Daylighting Calculation Methods

The aim of this study is to assess five daylighting calculation method commonly used in architectural study. The methods used include hand calculation methods (SNI/DPMB method and BRE Daylighting Protractors), scale models studied in an artificial sky simulator and computer programs using Dialux and Velux lighting software. The test room is conditioned by the uniform sky conditions, simple room geometry with variations of the room reflectance (black, grey, and white color). The analyses compared the result (including daylight factor, illumination, and coefficient of uniformity value) and examines the similarity and contrast the result different. The color variations trial is used to analyses the internally reflection factor contribution to the result.