Analytical Model for the Fatigue Analysis of Steel Joints by Clamps According to the Lever Length.

Among the most commonly used materials in the construction of structures in the last two centuries are iron and steel. Clamp joints are a suitable type of joint when it is necessary to rehabilitate or modify a historical steel structure for new uses, reinforcing or modifying it with new beams, without the need to drill or weld on the original structure. The clamps allow beams to be joined with a flange (such as I-beams) without the need for any prior operation on the beams and allow the manufacture of completely removable and reconfigurable structures. Developing and analysing this type of fully removable and reconfigurable structure is necessary. To date, no studies have been carried out on the fatigue behaviour of steel joints by clamps, especially taking into account their main geometric characteristics, such as the size of the clamp levers. In this work, an analytical model is proposed that allows for the analysis of the number of cycles and the fatigue limit of clamp joints as a function of the size of the clamp levers. In addition, various fatigue tests are performed with different clamp sizes. The experimental results are compared with those obtained with the proposed methodology. Finally, the relationships between the lever length and the fatigue behaviour of the clamp joints have been determined. It is concluded that an increase in the size of the front lever is associated to a decrease in the fatigue limit. On the contrary, if the size of the rear lever is increased, the fatigue limit of the joint increases. In general, according to the obtained results, the resistance of the joint can be reduced to approximately one third when it is subjected to fatigue loads.

Analysis of Stiffness of Clamped Joints versus Bolted Joints in Steel Structures by Means of Accelerometers and Shaking Table Tests.

This work analyzes the difference in stiffness in a steel laboratory structure using clamped joints or bolted joints and analyzes if the stiffness varies in the same way when the frame is subjected to external dynamic loads that bring the joint materials to their yield strength. To make this comparison, the differences between clamp joint and bolted joint were evaluated using a novel methodology based on the analysis of the structure's natural frequencies from accelerometers. To perform this comparison, several laboratory tests were carried out on a frame made by clamped joints and the same frame made by bolted joints, using a set of tests on a medium-scale shake table for this purpose. The results achieved have verified the methodology used as adequate.

Sustainable Ecocements: Chemical and Morphological Analysis of Granite Sawdust Waste as Pozzolan Material.

The processes focused on stone cutting generate a large volume of waste. Small size waste, silt/clay, is not used and goes to landfill. However, the composition of these wastes makes them useful for adding to cements and for use in construction. In the present paper, 10% Ordinary Portland cement is replaced by 10% waste from granite sawmill, which is studied to obtain sustainable ecological cement. This replacement provides advantages from the morphological and chemical point of view at the cements. The waste has a particle size that does not exceed 15 µm and that when replacing in the cement, after the hydration reaction, generates structures where Calcium Silicate Hydrate (C-S-H) gels and double layered hydroxide compounds (LDH) are reaction products formed in high concentration. These products develop stable phases in the structures over long time periods such one year, which was the time frame used in this study.

An Experimental Test Proposal to Study Human Behaviour in Fires Using Virtual Environments.

Human behavior in an emergency situation is the starting point for all evacuation planning projects. A better understanding of the decisions made by the occupants during an emergency can help to develop calculation tools that can create more efficient forms of visual and audio communication and implement better procedures for evacuating people. The difficulty in studying human behavior lies in the very nature of emergencies, as they are unpredictable, somewhat exceptional and not reproducible. Fire drills play a role in training emergency teams and building occupants, but they cannot be used to collect real data on people's behavior unless the drill is so realistic that it could endanger the occupants' safety. In the procedure described here, through the use of a Virtual Reality device that encompasses all critical phases, including user characterization data before the virtual experience, building design parameters and fire scenario, key variables of human behavior can be recorded in order to evaluate each user's experience satisfactorily. This research shows that the average delay in starting an evacuation is greater than one minute, that anxiety levels and heart rates increase during a fire and that people do not pay attention to evacuation signals. Further analysis of the quantitative data may also provide the causes for decision-making. The use of devices that create realistic virtual environments is a solution for conducting "what if" tests to study and record the decisions taken by the users who undergo the experience in a way that is completely safe for them.

Reusing Discarded Ballast Waste in Ecological Cements.

Numerous waste streams can be employed in different cement production processes, and the inclusion of pozzolans will, moreover, permit the manufacture of concrete with improved hydraulic properties. Pozzolanic materials can be added to Ordinary Portland Cement (OPC) in the range of 10%-20% by mass of cement. One such example is the phyllosilicate kaolinite (K), and its calcined derivative metakaolin (MK), incorporated in international cement manufacturing standards, due to its high reactivity and utility as a pozzolan. In the present paper, discarded ballast classed as Construction and Demolition Waste (C&DW) is reused as a pozzolanic material. Various techniques are used to characterize its chemical, mineralogical, and morphological properties, alongside its mechanical properties, such as compressive and flexural strength. Discarded ballast in substitution of cement at levels of 10% and 20% produced type II or IV pozzolanic cements that yielded satisfactory test results.

Economic Analysis of the Reduction of Blood Transfusions during Surgical Procedures While Continuous Hemoglobin Monitoring Is Used.

BACKGROUND: Two million transfusions are performed in Spain every year. These come at a high economic price for the health system, increasing the morbidity and mortality rates. The way of obtaining the hemoglobin concentration value is via invasive and intermittent methods, the results of which take time to obtain. The drawbacks of this method mean that some transfusions are unnecessary. New continuous noninvasive hemoglobin measurement technology can save unnecessary transfusions. METHODS: A prospective study was carried out with a historical control of two homogeneous groups. The control group used the traditional hemoglobin measurement methodology. The experimental group used the new continuous hemoglobin measurement technology. The difference was analyzed by comparing the transfused units of the groups. The economic savings was calculated by multiplying the cost of a transfusion by the difference in units, taking into account measurement costs. RESULTS: The percentage of patients needing a transfusion decreased by 7.4%, and the number of transfused units per patient by 12.56%. Economic savings per patient were €20.59. At the national level, savings were estimated to be 13,500 transfusions (€1.736 million). CONCLUSIONS: Constant monitoring of the hemoglobin level significantly reduces the need for blood transfusions. By using this new measurement technology, health care facilities can significantly reduce costs and improve care quality.

Analysis of economic and social costs of adverse events associated with blood transfusions in Spain.

OBJECTIVE: To calculate, for the first time, the direct and social costs of transfusion-related adverse events in order to include them in the National Healthcare System's budget, calculation and studies. In Spain more than 1,500 patients yearly are diagnosed with such adverse events. METHOD: Blood transfusion-related adverse events recorded yearly in Spanish haemovigilance reports were studied retrospectively (2010-2015). The adverse events were coded according to the classification of Diagnosis-Related Groups. The direct healthcare costs were obtained from public information sources. The productivity loss (social cost) associated with adverse events was calculated using the human capital and hedonic salary methodologies. RESULTS: In 2015, 1,588 patients had adverse events that resulted in direct health care costs (4,568,914€) and social costs due to hospitalization (200,724€). Three adverse reactions resulted in patient death (at a social cost of 1,364,805€). In total, the cost of blood transfusion-related adverse events was 6,134,443€ in Spain. For the period 2010-2015: the trends show a reduction in the total amount of transfusions (2 vs. 1.91M€; -4.4%). The number of adverse events increased (822 vs. 1,588; +93%), as well as their related direct healthcare cost (3.22 vs. 4.57M€; +42%) and the social cost of hospitalization (110 vs 200M€; +83%). Mortality costs decreased (2.65 vs. 1.36M€; -48%). DISCUSSION: This is the first time that the costs of post-transfusion adverse events have been calculated in Spain. These new figures and trends should be taken into consideration in any cost-effectiveness study or trial of new surgical techniques or sanitary policies that influence blood transfusion activities.

Risk Analysis of a Fuel Storage Terminal Using HAZOP and FTA.

The size and complexity of industrial chemical plants, together with the nature of the products handled, means that an analysis and control of the risks involved is required. This paper presents a methodology for risk analysis in chemical and allied industries that is based on a combination of HAZard and OPerability analysis (HAZOP) and a quantitative analysis of the most relevant risks through the development of fault trees, fault tree analysis (FTA). Results from FTA allow prioritizing the preventive and corrective measures to minimize the probability of failure. An analysis of a case study is performed; it consists in the terminal for unloading chemical and petroleum products, and the fuel storage facilities of two companies, in the port of Valencia (Spain). HAZOP analysis shows that loading and unloading areas are the most sensitive areas of the plant and where the most significant danger is a fuel spill. FTA analysis indicates that the most likely event is a fuel spill in tank truck loading area. A sensitivity analysis from the FTA results show the importance of the human factor in all sequences of the possible accidents, so it should be mandatory to improve the training of the staff of the plants.

Environmental Criteria in the Spanish Public Works Procurement Process.

Green Public Procurement (GPP) is defined as a process of contracting products, services, and works with the least possible damage to the environment during their life cycle. In order to improve the knowledge about GPP, a study of the use of environmental tendering criteria in the Spanish public construction sector has been performed. The results of this study show that the use of environmental criteria in Spanish public sector construction procurement is low in comparison to a certain group of countries, known as "Green 7", in the European Union. Environmental criteria is the fourth criterion in importance, but its weight in the global of the process is much lower than other criteria such as price, memory of the construction process and the delivery time. National administrations use environmental criteria more frequently because they have more resources and staff training about environmental issues. Environmental criteria are more used in the tendering of civil projects and works whose budget exceeds ten million euro due to the environmental impact of these kind and/or size of projects.

A comparative study of classroom and online distance modes of official vocational education and training.

The study discussed in this paper had two principal objectives. The first was to evaluate the distance model of official vocational education and training offered by means of a virtual learning platform. The second was to establish that both on-site classroom and online distance modes of vocational education and training can be seen as complementary in terms of responding to the majority of modern educational needs. We performed a comparative study using data and results gathered over the course of eleven academic years for 1,133 of our students enrolled in an official vocational education and training program, leading to the awarding of a certificate as an Administrative Management Expert. The classes were offered by the Alfonso de Avellaneda Vocational Education and Training School, located in the city of Alcalá de Henares near Madrid, Spain. We offered classes both in traditional classroom mode and through online distance learning. This paper begins with a descriptive analysis of the variables we studied; inferential statistical techniques are subsequently applied in order to study the relationships that help form the basis for the conclusions reached. This study's results provide evidence that a broad offering of vocational education and training opportunities will facilitate access to such learning for students who require it, regardless of their age, employment status, or personal circumstances, with the online distance mode playing a fundamental role while also yielding results equivalent to those observed for classroom instruction.