Modeling of aerobic biodegradation of feces using sawdust as a matrix

Composting in the bio-toilet system is a continuous thermophilic-aerobic biodegradation process. Unlike to the traditional composting systems, biodegradation rates of organic matter are very important because feces are daily added into the composting reactor of the bio-toilet and an accelerated decomposition is aimed. The models developed for conventional composting processes include simple formulations of biodegradation kinetics and deal mainly with energy and water balances. Therefore, formulation of kinetics that can reasonably describe the biodegradation process in the bio-toilet system is required for better modeling predictions. In this work, a bio-kinetic model was introduced to describe the aerobic biodegradation of feces in the bio-toilet system. This model includes three processes for carbonaceous material degradation and is prepared by using the activated sludge modeling techniques and formulations. Stoichiometric parameters were adopted from literature on activated sludge processes. Kinetic parameters were estimated by conducting batch tests for several organic loadings and by using respirometry, curve-fitting techniques, and sensitivity analysis. Feasibility and applicability of these parameters were assessed by conducting feces intermittent-feeding tests and by simulating the experimental respiration rates. Model, stoichiometric and kinetic parameters proved to be affordable for describing the biodegradation of feces in the bio-toilet system.     

R&D and eco-innovation: opportunities for closer collaboration between universities and companies through technology centers

It is widely accepted that eco-innovation is the direction to make progress towards a sustainable innovation. Public and private actors seem to share a common point of view and agreement on the benefits of implementing eco-innovation. If this is the case, why eco-innovative activities are still exceptional and exemplary instead of being the usual reasoning and inspiring driver for all kind of actions? Going in depth into the reasons why eco-innovation techniques are not broadly spread, the main one is the lack of internalization of this attitude in all the everyday actions taken by companies and employees in the form of social responsibility. Definitively, society as a whole is responsible for the eco-innovation promotion. Large companies have long ago incorporated Social Responsibility into their strategic planning and invest on innovation as a competitive advantage. However, they are reluctant to contribute to the eco-innovation. Therefore, universities and technology centers (TCs) have to play this role and link the private sector, specially medium, and small size companies, with the society needs. However, Universities are not often leading the eco-innovation initiative. Currently, in the case of Spain, it is observed a huge gap between the scientific research efforts made by the Public University and the academic offering and the real needs of the private companies. In fact, mixed structures as TCs are needed in order to overcome this disconnection, increasing opportunities for subsequent cooperation in eco-innovation projects. This paper points out the causes of the Spanish R&D and innovation lag, and highlights the reasons of the disconnection between public and private research for innovation, while giving hints on what is working fine and what needs to be reviewed to catch up with the R&D reference countries in Europe.     

OBCAS: an agent-based system and ontology for mobile context aware interactions

Society is changing and technological advances provide mechanisms to facilitate the development of a large number of tasks in technical, humanities, health and social areas. Nowadays, application of the improvement of people’s quality of life is generating significant interest, giving birth to systems oriented to the supervision, care and help for people in the development of their daily affairs. Thus, we may assume that its application to the supervision of a specific group of people can improve the quality of life for many people. OBCAS implements a monitoring service through mobile devices capable of providing enough information for an intelligent system. The multi-agent component provides the intelligence for the system, allowing it to run the appropriate services by adjusting them to the user’s profile and preferences. AGATHA is an application based on OBCAS that provides an alarm service during a supervision process. AGATHA has been tested on the supervision of elderly and victims of gender violence, and the result shown in this paper has been satisfactory.     

Characterization of beef tallow biodiesel and their mixtures with soybean biodiesel and mineral diesel fuel

Tallow is a raw material for biodiesel production that, due to their highly centralized generation in slaughter/processing facilities and historically low prices, may have energy, environmental, and economic advantages that could be exploited. However beef tallow biodiesel have unfavorable properties due the presence of high concentration of saturated fatty esters. One way to overcome these inconveniences is using blending procedures. In this way, blends of beef tallow biodiesel with soybean biodiesel and with conventional mineral diesel fuel were prepared and the quality of the mixtures was monitored with the purpose to study ideal proportions of the fuels. By measurement of the viscosity, density, cold filter plugging point, and flash point, it was demonstrated that tallow biodiesel can be blended with both mineral diesel and soybean biodiesel to improve the characteristics of the blend fuels, over that of the tallow.     

Ni(II)–Mg(II)–Al(III) catalysts for hydrogen production from ethanol steam reforming: Influence of the activation treatments

The effect of the Ni(II)–Mg(II)–Al(III) layered double hydroxide (LDH) activation conditions over the surface and bulk composition and the catalytic performance in ethanol steam reforming (ESR) is studied. Ternary oxides were prepared by thermal decomposition of LDHs synthesized using the homogeneous precipitation method with urea. Catalyst precursor is submitted to two different activation treatments: calcinations at 400, 500, 600 and 700 °C with subsequent reduction at 720 °C, or direct reduction at 720 °C. The samples were characterized by sorptometry, H₂ chemisorption, ICP chemical analysis, thermogravimetric analysis, X-ray diffraction, X-ray photoelectronic spectroscopy and temperature programming reduction. The catalysts obtained by calcination at 600 °C and then reduction at 720 °C and those directly reduced at 720 °C showed the better performance in ESR. The precursor submitted to a proper thermal treatment develops, through a decoration-demixing process, a Ni(II)-poor spinel-type shell onto NiO domains.     

Implementation of a Scale-Lab Lower-Limb Exoskeleton with Motion in Three Anatomical Planes

Abstract

This work deals with modeling, simulating and construction of a lower-limb exoskeleton with motion in the three anatomical planes, as well as to evaluate its performance to resolve trajectory tracking by means of feedback control schemes. The purpose is to create a scale-lab platform of a full-actuated exoskeleton to test tracking control of the main lower-limb joints to reproduce anatomical movements of a human being with no neuromuscular diseases. This functional scale-lab platform is the first step towards the design of neuromuscular rehabilitation tests based in full-automated assistive devices such as a lower-limb exoskeleton.     

Agroecology and the conversion of lárge‐scale conventional systems to sustainable management

This paper describes the agroecological principles necessary to guide the conversion of high‐input conventional systems to a low‐input management based on crop diversification and livestook integration schemes which break the monoculture nature of conventional systems. The new crop‐crop and crop‐animal combinations result in a series of synergisms and complementarities among farming system components which lead to optimal recycling of organic matter and nutrients, and to balanced pest‐natural enemy populations. Thus, agroecological design goes beyond “input‐substitution” by establishing systems capable of sponsoring their own soil fertility, crop protection and yield constancy. These new agroecosystems provide a sustainable level of productivity with minimal need for external (conventional or organic) resources. Biological structuring sponsors the functioning of the system.     

Evaluating the deterioration of electrodes when increasing the number of pulses in the welding time using galvanised IF and HSLA steels and assigning mechanical properties in the spot welds

ABSTRACT

Resistance spot welding is the most important method in the industry of self-supporting or monocoque body joinery because of its automation, its speed, the flexibility of welding parts with a complicated shape, and it is economical because it does not require a filler metal, and it is also possible to apply pre-heating and post-heating pulses to improve the weldability of the spot weld, which is defined as the ability of the structure to adequately protect passengers against injuries in the event of a collision, and this mainly depends on the integrity and mechanical performance of the weld button. In order to extend the lifetime of vehicles, galvanized steels are produced. However, zinc coatings have increased the difficulty of weldability, with higher currents being required in the process, since there is less resistance at the weld interface due to improved electrical conductivity. This work investigates the effect of galvanizing on the reduction of the lifetime of the electrodes, for this reason, it follows that there is a loss in the mechanical properties in the weld buttons as the number of spot welds increases. The main aim of this study is to correlate the electrode wear with the mechanical properties of the weld buttons. The experiment procedure consists of making 1,000 spot welds; and every twenty-fifth spot weld after the first was examined by means of stereoscopy, hardness tests, unbuttoning tests and shear stress tests. In terms of electrode wear, the face was evaluated using impressions on carbon paper, optical microscopy and X-ray spectroscopy.