Calculation procedure of the shading factor under complex boundary conditions

Together with the evolution of buildings and systems, energy assessment models have become more and more detailed, requiring a precise evaluation of the building loads and gains.For an accurate analysis of solar heat gains, technical standards introduce an external shading reduction coefficient of the incident solar radiation, called shading factor. Its value is provided for simple geometries, which are usually not suitable to properly describe a real environment. In addition, the relations adopted to evaluate the shading factor are based on simplified hypotheses, which cause non-negligible errors when compared to more complex algorithms.The objective of this study is the development of a calculation procedure of the shading factor under complex boundary conditions. The algorithms have been implemented in a software tool written in Matlab language. It can provide for the value of the shading factor on a generically oriented and tilted surface. After setting the site and the time for the simulation, generic-shaped windows can be modelled. The external environment, which can be imported from DXF files, can include a horizon profile, generic-shaped obstructions and vegetation. The calculation can be performed for every sky condition: clear, average or generic. In addition, the simulation can be run to obtain instantaneous, daily average or monthly average shading factor values.     

Comment

The paper by Haewon McJeon and coauthors seeks to estimate the benefits (measured as avoided climate policy costs) of different carbon-free and low-carbon technologies in the context of climate stabilization. The paper does not include a full cost-benefit analysis of these technologies nor does it evaluate what would be needed to bring these technologies about (e.g., in an optimal R&D investment portfolio). Nonetheless, in its main conclusions, the paper provides a sensible analysis and adds to the expanding literature on this extremely relevant topic by exploring a new dimension, that of the interactions among technologies and their combined impact.     

Modelling Sewer Systems Costs with Multiple Linear Regression

The aim of this paper is the establishment and validation of cost functions for the various assets of sewer systems, namely gravity and raising pipes, manholes and pumping-stations. Costs are defined as a function of the main physical characteristics of the assets, such as, the pipe material and diameter, excavation depth and percentage of pavement (for sewer pipes), the manhole depth (for manholes) and flow rate, pump head and pump power (for pumping stations,). A four-step methodology was followed: 1) data collection, processing and analysis, 2) present value calculation, 3) key parameters identification and cost functions estimation, and 4) cost functions validation. Cost and infrastructure data for construction contracts of sewer systems managed by Águas de Portugal (AdP) were analyzed. Cost functions were estimated based on multiple linear regression analysis and compared with the ones obtained in previous studies.     

The effect of different enzymes on the quality of high-fibre enriched brewer’s spent grain breads

The brewing industry produces large quantities of waste co-products. There is increasing pressure to ensure total utilisation of such products to address economic and environmental concerns. Brewer’s spent grain (BSG) the main by-product of the brewing industry is rich in dietary fibre and has a strong potential to be recycled. The overall objective of this study was to incorporate BSG into wheat flour breads together with a range of different enzymes (Maxlife 85, Lipopan Extra, Pentopan Mono BG and Celluclast) and evaluate the bread quality. A number of nutritional and textural properties of the finished product were studied. The incorporation of BSG significantly (P < 0.0001) improved the dietary fibre but the major difficulty encounted was to achieve a good structure and high loaf volume. Increasing the level of dietary fibre significantly (P < 0.001) increased dough development time, dough stability and crumb firmness but decreased the degree of softening and loaf volume. It was found that addition of Lipopan Extra (LE), Pentopan Mono (PE) and a mixture of Pentopan Mono and Celluclast (PCE) enzymes improved the texture, loaf volume and shelf life while Maxlife 85 enzyme (ME) was not significantly different from control samples (wheat flour breads containing 0%, 10%, 20% and 30% BSG). Image analysis of the bread structure obtained from the C-cell analyzer showed that the most significantly (P < 0.001) open network was obtained using LE, followed by PE and PCE.     

Search for New Three-, Four-Component Petasis,Passerini, Hantzsch,Kabachnic-Fields,Ugi Reactions with Organic Compounds of Phosphorus,Arsenic, Antimony and Bismuth

It is discovered a new three-, four-component Petasis, Passerini, Hantzsch, Kabachnic-Fields, Ugi reactions with of arsine, stibine and bismuthine in organometallic chemistry. Modifications were replaced to a nitrogen atom of classical reactions of atoms of phosphorus, arsenic, antimony and bismuth. It has been proposed a new mechanism for possible reactions.     

Long-term stability of sodium borohydrides for hydrogen generation

As a source of the high purity hydrogen, sodium and potassium borohydrides are investigated in terms of long-term stability in the form of the concentrated solutions, heterogeneous mixtures and in the solid state corresponding to NaBH₄ or KBH₄ crystal hydrates. In order to improve their stability during the long-term storage sodium and potassium hydroxides were added to the initial borohydride compositions. The effect of temperature, concentration of the borohydride and the alkaline solution, and the nature of the cation in the alkaline solution on the rate of borohydride hydrolysis was investigated. The differential technique developed for evaluation of the rate of borohydride hydrolysis was successfully applied for the determination of the long-term stability of the water-alkaline solutions containing NaBH₄(KBH₄)·5H₂O with 1–10 wt.% of NaOH or KOH at 30 °C and 50 °C.     

An efficient LMI approach for the quadratic stabilisation of a class of linear,uncertain, time-varying systems

The purpose of this article is to provide a numerically efficient method for the quadratic stabilisation of a class of linear, discrete-time, uncertain, time-varying systems. The considered class of systems is characterised by an interval time-varying (ITV) matrix and constant sensor and actuator matrices. It is required to find a linear time-invariant (LTI) static output feedback controller yielding a quadratically stable closed-loop system independently of the parameter variation rate. The solvability conditions are stated in terms of linear matrix inequalities (LMIs). The set of LMIs includes the stability conditions for the feedback connection of a unique suitably defined extreme plant with an LTI output controller and the positivity of a closed-loop extremal matrix. A consequent noticeable feature of the article is that the total number of LMIs is independent of the number of uncertain parameters. This greatly enhances the numerical efficiency of the design procedure.     

Fast and accurate fuzzy C‐means algorithm for MR brain image segmentation

Fuzzy theory based intelligent techniques are widely preferred for medical applications because of high accuracy. Among the fuzzy based techniques, Fuzzy C‐Means (FCM) algorithm is popular than the other approaches due to the availability of expert knowledge. But, one of the hidden facts is that the computational complexity of the FCM algorithm is significantly high. Since medical applications need to be time effective, suitable modifications must be made in this algorithm for practical feasibility. In this study, necessary changes are included in the FCM approach to make the approach time effective without compromising the segmentation efficiency. An additional data reduction approach is performed in the conventional FCM to minimize the computational complexity and the convergence rate. A comparative analysis with the conventional FCM algorithm and the proposed Fast and Accurate FCM (FAFCM) is also given to show the superior nature of the proposed approach. These techniques are analyzed in terms of segmentation efficiency and convergence rate. Experimental results show promising results for the proposed approach. © 2016 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 26, 188–195, 2016