Market strategies and core capabilities in the building industry

The objective of this study is to show that the core competence approach has validity when applied to construction. The focus is on the analysis of the fit between market strategies of firms in the building industry and their core capabilities. Certain strategies require specific core capabilities and key external and internal conditions supporting these capabilities. The resource-based approach focuses on the conditions in a firm, the internal capabilities, and supports a core capability that is demanded. The network literature will be related to external conditions that support a core capability of a firm active in a certain market. In a multiple case study, firms are analysed that are involved in different stages of the building process. The case studies demonstrate firms with consistent patterns of market strategies, core capabilities, and supporting internal and external conditions. The specific core capability of the firm under investigation determines the types of external and internal conditions that are critical.     

Planning Belgian Congo’s network of medical infrastructure: type-plans as tools to construct a medical model-colony, 1949–1959

ABSTRACT

Throughout the 1950s, the Belgian colonial government constructed a vast network of hospital infrastructure as part of its Ten-Year Plan, a colony-wide socio-economic scheme emblematic for the era of ‘welfare colonialism.’ This network played a key role in Belgian colonialism, by providing healthcare, but also by boosting labour productivity, facilitating state presence and control, and by advertising Congo as a medical model-colony. In this article, we unpack the extensive administrative apparatus that was necessary to buttress this ambitious building programme, and we highlight type-plans as crucial government tools to construct such a vast network of healthcare infrastructure. At first glance, the use of type-plans confirms classic characterizations of the Belgian colonial government as an omnipotent and technocratic state apparatus that implemented large, top-down government plans through authoritative methods, often discarding local realities. However, tracing hospital construction on the ground reveals that type-plans did not function as immutable models, but rather as modular blueprints that allowed local administrations to adapt hospitals to local needs and contingencies. As such, our article illustrates how, facilitated by surprisingly flexible type-plans, everyday colonial policymaking in Belgian Congo was, contrary to the still dominant discourse, deeply reliant on the agency and aptitude of local officials.     

水泥混凝土路面固化翘曲试验研究

在水泥混凝土路面硬化过程中,由于各种因素引起的固化翘曲将长期存在,会对其平整度、耐久性产生重要影响.通过野外铺筑水泥混凝土足尺试验路面,观测、分析了5种养生方式下其早期、终凝时的温度场.结果表明：普通养护剂养生和塑料薄膜养生分别使水泥混凝土路面产生了7.1,6.5℃/26cm的内嵌温度梯度;虽然不同养生方式下水泥混凝土路面早期温度场变化规律基本相同,但差异也较为明显,而且这种差异主要由养生材料的太阳辐射吸收率、热交换系数等参数不同所致.     

铁路无砟轨道水泥乳化沥青砂浆吸振与隔振特性

采用加速度计测定了冲击荷载作用下普通混凝土与水泥乳化沥青砂浆（CA砂浆）试件以及试件下部钢板的振动加速度随时间的变化,并用落锤法对比了普通混凝土与CA砂浆的抗冲击破坏特性.研究表明：普通混凝土受到冲击后,其振动加速度随时间衰减不明显,且振动时间较长,其下部钢板也有类似规律;CA砂浆受到冲击后,其振动加速度表现为3个明显的衰减阶段,振动时间也要短于普通混凝土,同样CA砂浆下部钢板也有类似规律;与普通混凝土相比,CA砂浆表现出较好的吸振与隔振功能.抗冲击破坏的结果表明,CA砂浆的抗冲击性能优于普通混凝土.     

On education

The following observations are intended only to outline some concerns about, and to offer observations on, the teaching of design disciplines in the University of Buenos Aires and to rehearse the current educational challenges relating to achieving the standards expected of a professional graduate competent to improve our environmental demands.     

Au/TS‐1 catalyst for propene epoxidation with H2/O2: A novel strategy to enhance stability by tuning charging sequence

For propene epoxidation with H₂ and O₂, the catalytic performance of Au/TS‐1 catalyst is extremely sensitive to preparation parameters of deposition‐precipitation (DP) method. In this work, effect of charging sequence in DP process on catalyst structure and catalytic performance of Au/TS‐1 catalyst is first investigated. For different charging sequences, the compositions of Au complexes (e.g., [AuCl(OH)₃]^?) and pore property of TS‐1 (i.e., with or without H₂O prefilling micropores) could affect the transfer of Au complexes into the micropores, resulting in different Au locations and thus significantly different catalytic performance. Notably, when TS‐1 is first filled with H₂O and then mixed with Au complexes, the reduced Au/TS‐1 catalyst could expose Au nanoparticles on the external surface of TS‐1 and show high stability. The results provide direct evidence showing that micropore blocking is the deactivation mechanism. Based on the results, a simple strategy to design highly stable Au/Ti‐based catalysts is developed. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3963–3972, 2016     

Fabrication and Property of Mullite Whiskers Frameworks with an Ultrahigh Porosity by Expandable Mesocarbon Microbeads

Mullite whiskers frameworks with an ultrahigh porosity were fabricated by the vapor‐phase reaction of AlF₃, Al₂O₃, and SiO₂ and adding expandable mesocarbon microbeads (MCMB) as a pore‐forming agent. A large volume expansion of 122% for MCMB due to its layered structure occurred during the formation of mullite whiskers, resulting in the expansion of samples and high porosities of 87.7%–98.2% at 50–90 wt% MCMB contents. Perfect whiskers and a lap‐joint structure formed due to the formation of mullites through the vapor‐phase reaction. A bimodal pore structure was achieved from the spaces of the whiskers framework and burning of the expanded MCMB. High compressive strengths of 1.7 to 5.4 MPa were obtained for the porous mullite at porosities of 94.2%–87.7%, which suggested a rigid structure; these strengths at the ultrahigh porosities are attributed to the merit of the framework with high strength whiskers and their strong bonding.     

ForceSpinning of polyacrylonitrile for mass production of lithium‐ion battery separators

We present results on the Forcespinning^® (FS) of Polyacrylonitrile (PAN) for mass production of polymer nanofiber membranes as separators for Lithium‐ion batteries (LIBs). Our results presented here show that uniform, highly fibrous mats from PAN produced using Forcespinning^®, exhibit improved electrochemical properties such as electrolyte uptake, low interfacial resistance, high oxidation limit, high ionic conductivity, and good cycling performance when used in lithium ion batteries compared to commercial PP separator materials. This article introduces ForceSpinning^®, a cost effective technique capable of mass producing high quality fibrous mats, which is completely different technology than the commonly used in‐house centrifugal method. This Forcespinning^® technology is thus the beginning of the nano/micro fiber revolution in large scale production for battery separator application. This is the first time to report results on the cycle performance of LIB‐based polymer nanofiber separators made by Forcespinning^® technology. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 132, 42847.     

Dry Sliding Wear Properties of AZ31-Mg<Subscript>2</Subscript>Si Magnesium Matrix Composites

AZ31-Mg₂Si in situ composites were prepared from AZ31 Mg alloy and Si particles by a gravity casting method. Several parameters, such as Si content, normal load, and environmental temperature, were varied in order to study their effects on the composite dry sliding wear properties. Tensile properties and hardness of the composites were also investigated. The obtained results showed that the wear resistance, yield strength, and hardness of the AZ31-Mg₂Si composites increased with size and quantity of the Mg₂Si phase. However, when the environmental temperature increased from 25 to 190 °C, the composite wear resistance and ultimate tensile strength gradually decreased due to softening of the AZ31 matrix.