Jammed architectural structures: towards large-scale reversible construction

This paper takes a first step in characterizing a novel field of research—jammed architectural structures—where load-bearing architectural structures are automatically aggregated from bulk material. Initiated by the group of Gramazio Kohler Research at ETH Zürich and the Self-Assembly Lab at Massachusetts Institute of Technology, this digital fabrication approach fosters a combination of cutting-edge robotic fabrication technology and low-grade building material, shifting the focus from precise assembly of known parts towards controlled aggregation of granular material such as gravel or rocks. Since the structures in this process are produced without additional formwork, are fully reversible, and are produced from local or recycled materials, this pursuit offers a radical new approach to sustainable, economical and structurally sound building construction. The resulting morphologies allow for a convergence of novel aesthetic and structural capabilities, enabling a locally differentiated aggregation of material under digital guidance, and featuring high geometrical flexibility and minimal material waste. This paper considers (1) fundamental research parameters such as design computation and fabrication methods, (2) first results of physical experimentation, and (3) the architectural implications of this research for a unified, material-driven digital design and fabrication process. Full-scale experimentation demonstrates that it is possible to erect building-sized structures that are larger than the work-envelope of the digital fabrication setup.     

Fumonisin-Producing Fusarium from Maize Grains in Tretep,Indonesia

Fusarium species commonly occur in maize are fungal pathogen which produce mycotoxins, such as fumonisin, trichothecene and zearalenone. In this study, Fusarium species were isolated from maize kernel from Tretep, maize producer region and were identified based on microscopic- and macroscopic characters as well as molecular characters using PCR assays and the partial sequence of TEF 1-α gene （Translation Elongation Factor 1-α. The fumonisin-producing ability of these Fusarium was determined by growing them in corn medium and analyzed their fumonisin by ELISA （enzyme-linked immuno assay）. Among 9 isolates, three of them were identified as Fusarium verticillioides, two as Fusarium temperatum, two as Fusarium globosum, one as Fusarium proliJeratum and one as Fusarium subglutinans. Fusarium temperatum is similar morphologically to F. subglutinans, however, both of their differences can be found by molecular analysis. Fumonisin-producing abilities of Fusarium were determined in concentrations 20.51 pg/g-1,109.74 pg/g medium with the highest producer was identified as F. globosum.     

Structural Assignment of Commercial Polyisobutylene Succinic Anhydride-based Surfactants

Concentration of the surface active agents in industrial products is a common source of error. In order to compare the efficiency of a number of polyisobutylene succinic anhydride (PIBSA) based surfactants, their concentration needs to be determined with a fair degree of accuracy. Industrial samples of the monoethanolamine adduct of PIBSA (PIBSA-MEA) concentrate were used for chromatographic separation of the functionalized surfactant from the sample matrix. Complete spectroscopic assignments were based on detailed analysis of all the precursors and of the purified mixture of structural isomers. The structures of the double bond isomers were consistent with the expected addition products of the classic Alder-ene reaction-derived PIBSA. The carbon–carbon connectivity of the succinamide head group to the bulky polymer tail of PIBSA-MEA was more complicated than previously thought, pointing towards regioselectivity in the nucleophilic substitution of PIBSA. By analogy, further structural assignments of two other surfactants, branded as PIBSA-IMIDE and PIBSA-UREA were made from the spectroscopic data recorded on crude industrial samples. Detailed nuclear magnetic resonance (NMR) assignments for all three surfactants reported here were utilized to develop a semi-quantitative ¹³C-NMR based method for the estimation of the amount of the functionalized surfactant relative to the total PIB content in the industrial concentrates. The results highlight common sources of structure- and concentration-dependent errors in high internal phase emulsion formulations.     

Real-Time,Model-Based Spray-Cooling Control System for Steel Continuous Casting

This article presents a new system to control secondary cooling water sprays in continuous casting of thin steel slabs (CONONLINE). It uses real-time numerical simulation of heat transfer and solidification within the strand as a software sensor in place of unreliable temperature measurements. The one-dimensional finite-difference model, CON1D, is adapted to create the real-time predictor of the slab temperature and solidification state. During operation, the model is updated with data collected by the caster automation systems. A decentralized controller configuration based on a bank of proportional-integral controllers with antiwindup is developed to maintain the shell surface-temperature profile at a desired set point. A new method of set-point generation is proposed to account for measured mold heat flux variations. A user-friendly monitor visualizes the results and accepts set-point changes from the caster operator. Example simulations demonstrate how a significantly better shell surface-temperature control is achieved.     

Concentration of soybean isoflavones by nanofiltration and the effects of thermal treatments on the concentrate

An investigation was performed on the profile and the content of isoflavones in the concentrate of aqueous Defatted Soy Flour (DSF) extract obtained by nanofiltration. The effect of thermal treatments on these isoflavones was also evaluated according to a Central Composite Design (CCD 2^k) with varying temperatures (70 to 90 °C) and times (15 to 45 min). Through nanofiltration it was possible to concentrate β-glucosides and malonyl glucosides (p < 0.05) in aqueous DSF extract but it was not possible to concentrate aglycones (p > 0.05). The thermal treatments applied on the concentrate showed that the malonyl glucosides were influenced by temperature (p < 0.05), while the β-glucosides were influenced not only by temperature but also by the time of interaction of the factors investigated (p < 0.05). Moreover, there was no alteration in the contents (p > 0.05) of aglycone or total isoflavones.     

Effect of Silicon on the Desulfurization of Al-Killed Steels: Part I. Mathematical Model

Recent observations suggest that increased silicon levels improve ladle desulfurization of aluminum-killed steel. While the overall desulfurization reaction of Al-killed steels does not show a direct role of silicon in desulfurization, model calculations are presented which test the idea that silicon suppresses the reduction of silica which can consume aluminum at the slag/metal interface. Consumption of aluminum would increase the oxygen potential at the slag/metal interface and decrease the sulfur partition coefficient between slag and metal. The model considers the coupled reactions of the reduction of silica, iron oxide, and manganese oxide in the slag and desulfurization of the steel by aluminum. The results show that silicon can indeed suppress consumption of aluminum at the slag/metal interface by side reactions other than desulfurization, with silicon affecting both the kinetics and the equilibrium of desulfurization.     

Annual planning of harvesting resources in the forest industry

A cost‐efficient use of harvesting resources is important in the forest industry. The main planning is carried out in an annual resource plan that is continuously revised. The harvesting operations are divided into harvesting and forwarding. The harvesting operation fells trees and puts them in piles in the harvest areas. The forwarding operation collects piles and moves them to storage locations adjacent to forest roads. These operations are conducted by machines (harvesters, forwarders and harwarders), and these are operated by crews living in cities/villages that are within some maximum distance from the harvest areas. Machines, harvest teams and harvest areas have different characteristics and properties and it is difficult to find the best possible match throughout the year. The aim of the planning is to find an annual plan with the lowest possible cost. The total cost is based on three parts: production cost, traveling cost and moving cost. The production cost is the cost for the harvesting and forwarding. The traveling cost is the cost for driving back and forwards (daily) from the home base to the harvest area and the moving cost is associated with moving the machines and equipment between harvest areas. The Forest Research Institute of Sweden (Skogforsk), together with a number of Swedish forest companies, has developed a decision support platform for the planning. One important element of this platform is that it should find high‐quality plans within short computational times. One central element is an optimization model that integrates the assignment of machines to harvest areas and schedules the harvest areas during the year for each machine. The problem is complex and we propose a two‐phase solution method where, first, we solve the assignment problem and, second, the scheduling. In order to be able to control the scheduling in phase 1 as well, we have introduced an extra cost component that controls the geographical distribution of harvest areas for each machine in phase 1. We have tested the solution approach on a case study from one of the larger Swedish forest companies. This case study involves 46 machines and 968 harvest areas representing a log volume of 1.33 million cubic meters. We describe some numerical results and experience from the development and tests.     

Storage stability of prebiotic fermented milk obtained from permeate resulting of the microfiltration process

The permeate, obtained from the best microfiltration process, was employed in the preparation of fermented milks, without inulin (control) and with 5 g 100 g^?1 inulin (prebiotic), stored at 5 ± 1 °C for 28 days. It could be verified that the storage period and addition of inulin increased the total solids and carbohydrate contents, the caloric value and the acidity, and decreased the pH. The addition of inulin resulted in a fermented product with a lower syneresis index, and greater firmness and cohesiveness. The inulin employed resulted in a product with a greater tendency toward a greenish coloration.