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Abstract:

Development of thermal efficiency of the concentrated solar energy especially parabolic trough collector using various nanofluids types has a taken high interest in recent years. In this article enhancement thermal performance inside the heating collecting element of trough collector type LS-2 was simulated and improved using nanofluid consist of Tungsten Oxide WO3 inserting in Syltherm 800. Nanofluid effect was examined by solving the energy balance equation using MATLAB Software to cover wide range concentration volume 1-5% and inlet temperatures ranging from 350-650 K for the turbulent flow. The heat transfer performance and thermal efficiency were improved based on the results, and a notable increase was obtained when volume concentration had been increased compared with base fluid.

Open access

Abstract

The phenomenon of capillary rise happens in soils, and it has a crucial effect on many engineering applications. Many researchers have concluded several experimental equations to estimate this height. This paper presents a comparative and practical study of the three most important equations used in most researches, which are Lane and Washburn, Fetter, and P-K equations. The estimated heights by these three equations were compared with the experimental tests on sand samples taken from Al-Adalah, Al-Furat, and Al-Jameah districts located in Al-Najaf city in the southwest of Iraq. The percentage change for each equation compared with the experimental work. The results illustrated that the Fetter equation is the closest equation to experimental height and gives moderate values, unlike the Lane and Washburn and P-K equations, to save estimation of the pollutants penetration in unsaturated soils.

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Abstract:

This paper describes the adaptation of the formex configuration processing to the computer program Grasshopper 3D and focuses on the applied mathematical solutions. Formex algebra is a mathematical system, primarily used for planning structural systems like truss-grid domes and vaults, together with the programming language Formian. The goal of the research is to allow architects to plan truss-grid structures easily with parametric design tools based on the versatile formex algebra mathematical system. To produce regular structures, coordinate system transformations are used. Owing to the abilities of the parametric design software, it is possible to apply further modifications on the structures and gain special forms. The paper covers the basic dome types, and it introduces additional dome-based structures using special coordinate-system solutions based on a spherical coordinate system, vault structures and their modifications based on a cylindrical coordinate system and circular structures and their modifications based on polar coordinates. Moreover two rotational grid tools are introduced, which uses coordinate system transformations on a unique way to create surfaces of revolutions based on the given generating curve and create grid structures on these surfaces. It also describes the solution technique to implement the triangular grid version of every one of these tools based on diamatic domes. The adaptation of formex algebra and the parametric workflow of Grasshopper together give the possibility of quick and easy design and optimization of special truss-grid domes.

Open access
Pollack Periodica
Authors: Dávid Nagy, Tamás Mihálydeák and László Aszalós

Abstract:

Correlation clustering is a widely used technique in data mining. The clusters contain objects, which are typically similar to one another and different from objects from other groups. In the authors previous works the possible usage of correlation in rough set theory were investigated. In rough set theory, two objects are treated as indiscernible if all of their attribute values are the same. A base set contains those objects that are indiscernible from one another. The partition, gained from the correlation clustering, can be understood as the system of base sets, as the clusters contain the typically similar objects (not just to a distinguished member) and it considers the real similarity among the objects. In this work the extension of this study is presented, using the method to approximate graphs representing similarity relations.

Open access
Pollack Periodica
Authors: László Pusztai, Balázs Kocsi, István Budai and Lajos Nagy

Abstract:

A key role of production managers at manufacturing companies is to make economy-based decisions related to production scheduling. If the production is subject to uncertain factors, like human resource or lack of standardization, production planning becomes difficult and calls for advanced models that are tailored to the manufacturing process. This research investigates a real furniture manufacturing system from both managerial and materialflow points of view. Statistical simulation was run on the manufacturing process, where the possible production structures were given. ANOVA analysis was calculated in order to identify those activities that have the most significant influence on the profit.

Open access

Abstract:

This paper deals with the dynamical analysis of a crane model. Truss finite elements are used to discretize the suspending chains with the so called updated Lagrangian description. This nonlinear model is regarded to be the best approximation to which linear models are compared. The inertia and independent degrees of freedom are also taken into consideration by linear models. The goal is to find a linear model, which can be used as an observer in antisway control of a crane.

Open access

Abstract:

Modeling and robotic handling of a plastic box buckle is discussed in this paper. The closing mechanism of the box buckle is simulated to determine the characteristic of the nonlinear load-deflection curve. An intelligent end-effector was designed and manufactured to handle the assembly with a robot. The closing force is measured by a built-in load cell and its values are processed by a micro-controller. The intelligent end-effector can be used in a robotic system, which deals with different snap-fit applications.

Open access

Abstract:

In 2013 Typhoon Haiyan, devastated several portions of the Philippines, which resulted in more than 7,000 deaths and thousands made homeless. The aim of this study is to propose a design of a permanent shelter as a continuation of the I-Siguro Daan Transitional Shelter, which was successfully deployed in 2014 and produce a transitional shelter prototype, for the victims of typhoon Haiyan. In order to develop the methodological design of the Permanent Shelter, the author presented several factors into consideration: the understanding how the rural communities use the present I-Siguro Daan Transitional Shelter; to further develop and improve the interior space of the shelter; to propose a better roof design; and to design a sustainable toilet and kitchen area for the users. Methodologies used in the study were the use of surveys and interactions with the community, which focuses on gaining the understanding how the communities use the present I-Siguro Daan Transitional Shelter. By exploring related case studies and literatures, site surveys and consultations with different groups, the resulting Permanent Shelter will a promising solution for improving the lives of the communities while also providing groundwork for future shelter related studies.

Free access

Abstract:

This paper proposes the application of energy efficient, low tech (passive) building design strategies and concepts in an industrial facility case study, in order to create a building with high efficiency and comfort within the boundaries of a tight investment cost. The planning process is supported by dynamic thermal and daylight simulations. Two versions were considered, a conventional industry building and a low tech one with climate zone based space organization. According to the evaluation of thermal and visual comfort as well as energy demand the selected version with the innovative passive concept delivered considerably better performance. According to the constructor’s concept, the reference building had to be placed by minimal adaptation on the new site. After considering and calling this concept into question, a new ‘energy design’ concept was elaborated at the sketch planning level. The new concept was compared with the reference building and a quantified, simulation assisted evaluation was provided about the cases. Since there was an essential improvement in comfort and energy level and, in addition, at architectural standard, the constructor could have been convinced to accept the new concept.

Open access

Abstract:

Day-lighting studies in buildings play a major role in indoor environmental investigation and can be conducted at the early stages of building design. Window position significantly affects day-lighting performance. This paper assessed the impacts of the window position on the visual comfort through two main factors; daylight factor and light uniformity in the hot and dry climate zone. In this study different window positions have been examined to achieve optimal visual comfort, using a dynamic simulation through Vi-suit plugin for Blender 3D software that controls the external application Radiance software. The results revealed that the window position at sill start from 1.4 m of a room characterized by (4.30 m × 3.00 m × 3.00 m) is the best compromising solution that complies with the daylight factor and light uniformity standards in the indoor environment. The findings of this study provide a more detailed and comprehensive analysis of the window design for architects/designers in the early building design stages in the hot and dry climate region.

Open access