Materials and Mix Optimization Procedures for PCC Pavements, March 2006

Severe environmental conditions, coupled with the routine use of deicing chemicals and increasing traffic volume, tend to place extreme demands on portland cement concrete (PCC) pavements. In most instances, engineers have been able to specify and build PCC pavements that met these challenges. However, there have also been reports of premature deterioration that could not be specifically attributed to a single cause. Modern concrete mixtures have evolved to become very complex chemical systems. The complexity can be attributed to both the number of ingredients used in any given mixture and the various types and sources of the ingredients supplied to any given project. Local environmental conditions can also influence the outcome of paving projects. This research project investigated important variables that impact the homogeneity and rheology of concrete mixtures. The project consisted of a field study and a laboratory study. The field study collected information from six different projects in Iowa. The information that was collected during the field study documented cementitious material properties, plastic concrete properties, and hardened concrete properties. The laboratory study was used to develop baseline mixture variability information for the field study. It also investigated plastic concrete properties using various new devices to evaluate rheology and mixing efficiency. In addition, the lab study evaluated a strategy for the optimization of mortar and concrete mixtures containing supplementary cementitious materials. The results of the field studies indicated that the quality management concrete (QMC) mixtures being placed in the state generally exhibited good uniformity and good to excellent workability. Hardened concrete properties (compressive strength and hardened air content) were also satisfactory. The uniformity of the raw cementitious materials that were used on the projects could not be monitored as closely as was desired by the investigators; however, the information that was gathered indicated that the bulk chemical composition of most materials streams was reasonably uniform. Specific minerals phases in the cementitious materials were less uniform than the bulk chemical composition. The results of the laboratory study indicated that ternary mixtures show significant promise for improving the performance of concrete mixtures. The lab study also verified the results from prior projects that have indicated that bassanite is typically the major sulfate phase that is present in Iowa cements. This causes the cements to exhibit premature stiffening problems (false set) in laboratory testing. Fly ash helps to reduce the impact of premature stiffening because it behaves like a low-range water reducer in most instances. The premature stiffening problem can also be alleviated by increasing the water–cement ratio of the mixture and providing a remix cycle for the mixture.

Regulated Materials Facility Revenue Bond Funds, Iowa State University of Science and Technology, Independent Auditor's Report, Basic Financial Statement and Supplementary Information, June 30, 2006

State University Audit Report

Surface deterioration of dental materials after simulated toothbrushing in relation to brushing time and load.

OBJECTIVES: (1) To evaluate the changes in surface roughness and gloss after simulated toothbrushing of 9 composite materials and 2 ceramic materials in relation to brushing time and load in vitro; (2) to assess the relationship between surface gloss and surface roughness. METHODS: Eight flat specimens of composite materials (microfilled: Adoro, Filtek Supreme, Heliomolar; microhybrid: Four Seasons, Tetric EvoCeram; hybrid: Compoglass F, Targis, Tetric Ceram; macrohybrid: Grandio), two ceramic materials (IPS d.SIGN and IPS Empress polished) were fabricated according to the manufacturer's instructions and optimally polished with up to 4000 grit SiC. The specimens were subjected to a toothbrushing (TB) simulation device (Willytec) with rotating movements, toothpaste slurry and at three different loads (100g/250g/350g). At hourly intervals from 1h to 10h TB, mean surface roughness Ra was measured with an optical sensor and the surface gloss (Gl) with a glossmeter. Statistical analysis was performed for log-transformed Ra data applying two-way ANOVA to evaluate the interaction between load and material and load and brushing time. RESULTS: There was a significant interaction between material and load as well as between load and brushing time (p<0.0001). The microhybrid and hybrid materials demonstrated more surface deterioration with higher loads, whereas with the microfilled resins Heliomolar and Adoro it was vice versa. For ceramic materials, no or little deterioration was observed over time and independent of the load. The ceramic materials and 3 of the composite materials (roughness) showed no further deterioration after 5h of toothbrushing. Mean surface gloss was the parameter which discriminated best between the materials, followed by mean surface roughness Ra. There was a strong correlation between surface gloss and surface roughness for all the materials except the ceramics. The evaluation of the deterioration curves of individual specimens revealed a more or less synchronous course suspecting hinting specific external conditions and not showing the true variability in relation to the tested material. SIGNIFICANCE: The surface roughness and gloss of dental materials changes with brushing time and load and thus results in different material rankings. Apart from Grandio, the hybrid composite resins were more prone to surface changes than microfilled composites. The deterioration potential of a composite material can be quickly assessed by measuring surface gloss. For this purpose, a brushing time of 10h (=72,000 strokes) is needed. In further comparative studies, specimens of different materials should be tested in one series to estimate the true variability.

Integrated Materials and Construction Practice for Concrete Pavement: A State-of-the-Practice Manual, 2006

At the heart of all concrete pavement projects is the concrete itself. This manual is intended as both a training tool and a reference to help concrete paving engineers, quality control personnel, specifiers, contractors, suppliers, technicians, and tradespeople bridge the gap between recent research and practice regarding optimizing the performance of concrete for pavements. Specifically, it will help readers do the following:

The nurse in the management of materials in teaching hospitals

OBJECTIVETo present the nurse's integration within materials management of six teaching hospitals of Paraná - Brazil, and to describe the activities performed by nurses within this process.METHODA study of a qualitative approach and descriptive nature, conducted in teaching hospitals in Paraná, between June and August of 2013. The data collection was conducted through semi-structured interviews with eight nurses who worked in materials management; data were analyzed using content analysis.RESULTSThese showed that nurses perform ten categories of activities, distributed into four of the five steps of the materials management process.CONCLUSIONThe nurse, in performing of these activities, in addition to favoring the development of participative management, contributes to the organization, planning, and the standardization of the hospital supply process, giving greater credibility to the work with professionals who use the materials, and to the suppliers.

Audit of the Regulated Materials Facility Revenue Bond Funds of Iowa State University of Science and Technology (Iowa State University) as of and for the year ended June 30, 2007

Audit of the Regulated Materials Facility Revenue Bond Funds of Iowa State University of Science and Technology (Iowa State University) as of and for the year ended June 30, 2007

Report of the Regulated Materials Facility Revenue Bond Funds of Iowa State University of Science and Technology as of and for the year ended June 30, 2008

Report of the Regulated Materials Facility Revenue Bond Funds of Iowa State University of Science and Technology as of and for the year ended June 30, 2008

DIGITAL LIBRARY FOR DIGITAL DIVIDE AND ENVIRONMENT OF SCARCE ACCESS TO PRINTED MATERIALS: THE CASE OF UNIVERSITY JEAN PIAGET OF CAPE VERDE

With the failure of the traditional mechanisms of distributing bibliographic materials into developing countries, digital libraries show up as a strong alternative in accomplishing such job, despite the challenges of the digital divide. This paper discusses the challenges of building a digital library (DL) in a developing country. The case of Cape Verde as a digital divide country is analyzed, in terms of current digital library usage and its potentiality for fighting the difficulties in accessing bibliographic resources in the country. The paper also introduces an undergoing project of building a digital library at the University Jean Piaget of Cape Verde.

Possibles materials amb destinació a obres portuàries a la Costa Brava (Girona)

The metodology used in the research of materials destinated to port constructions in the Costa Brava is described. This metodology follows a set of work steps. The first three allow to do a selection of the stone quarries that exist in the zone. The other steps consists in studing the materials and the characteristics of the chosen quarries and the zones closed to them, as to order them according to their utility in port constmctions. Finally, the main results obtained are explained

Síntesi de nous catecols amb aplicació en materials funcionals bioinspirats

Els catecols (compostos aromàtics amb dos hidroxils veïnals) són una unitat estructural present en la naturalesa de formes molt diverses. En el present treball es sintetitza el catecol amb una cadena alquílica saturada de 32 carbonis. L’objectiu és mimetitzar el comportament de les proteïnes segregades pels musclos que formen els filaments pels quals aquest mol·lusc pot adherir-se sobre diverses superfícies de manera hidrofòbica permanent i que li permet mantenir-se adherit tot i estar submergit en l’aigua del mar. Aquesta síntesi es realitza gràcies a l’obtenció d’un valuós intermedi tipus sal de fosfoni que permet introduïr la cadena hidrocarbonada a l’esquelet catecol.

Artificial Urinary Sphincter based on smart materials

Objective: There are only a few established artificial urinary sphincters for treatment of incontinence. We have developed a new device composed by three parts: the actuator, three contractile rings and a control unit. The actuator is made of Nitinol fibers, driven by microprocessor. The fibers are linked to the rings placed around the urethra. They function with alternance in their open and closed position. This concept is called piano concept. With this set-up, the constant compression on the urethra is strongly reduced. Methods: Six male sheep have been used for this study. The sphincter was open each hour for a period of 10 min., to guaranty urination. The bladder was filled with water while one cuff was closed and bladder pressure was monitored. The animals were sacrificed. Two biopsies around two cuffs of each explant and all three cuffs from each explant including urethra were analyzed. Urethra not surrounded by a cuff was taken as control. Results: The pressure exerted by the sphincter around the urethra provided continence. Simulated incontinence occurred at a pressure of 1bar measured on the bladder wall using a pressure probe. The closing force of the cuff was approx. 0·7N. No difference in tissue structure and organization of the urethra with and without artificial sphincter was observed. Conclusions: This device has several advantages compared to other urinary sphincters. It is easy to implant, has no hydraulic nature and reduces ischemic injury of the urethra by the alternance of urethral part compressed. Proof of concept in vivo has been demonstrated. Other studies are planned to determine long-term outcome.

Treball de selecció de materials

L’objectiu principal de l’activitat és desenvolupar l’aprenentatge autònom mitjançant eldesenvolupament d’un treball en grup relacionat amb l’àmbit dels materials.

Bateries de qüestions bàsiques de materials

Fomentar l’estudi i l’aprenentatge autònom de continguts bàsics de les assignatures troncals de materials (Fonaments de Ciència dels Materials, Tecnologia dels Materials i Materials Aeroespacials), de les titulacions d’Enginyeria Industrial i Enginyeria Aeronàutica.