Experimental validation of a dynamic modelling of a Reversible Solid Oxide Cells (rSOCs)

The integration of Hydrogen technologies in different end-uses such as transport, electric microgrids, residential and industrial applications, will increase exponentially soon. Hydrogen as energy carrier allows more favourable energy conversion than other conventional systems and is crucial in worldwide decarbonize end uses. The production of green hydrogen, using RES, is a key area for the evolution of this technology. In this context, SWITCH is a Horizon 2020 European Project that aims to design, build and test an in-situ fully integrated and continuous multisource hydrogen production system, based on solid oxide cell technology. Reversible Solid Oxide Cell (rSOCs) technologies allow to convert renewable energy as hydrogen in the power-to-gas application (P2G) and in reversible mode is able to produce electricity from hydrogen stored, power-to-power application (P2P). rSOCs are really interesting to stabilize the random nature of RES because a combined electrolysis and fuel cell system should be able to switch between the two modes as quickly as possible in order to optimize the integration and the use of RES. However, rSOCs need a complex BoP from the thermal point of view, able to guarantee high efficiency even at partial load mode as well as easy start-up and shutdown procedures. In this work, a Stack Box Module dynamic model was developed in Modelica environment as a dynamic tool for the definition and optimization of BoP requirements. Stack model was validated in SOFC (Solid Oxide Fuel Cell) and SOE (Solid Oxide Electrolyser). The results of the simulation provide verification of the technical/thermodynamic behaviour and flexibility of a stack box of 70 cells. Dynamic modelling allows to evaluate the effect of the reagent inlet temperatures on the operation and hydrogen production/consumption in terms of yield as well as the transients between the different operative modes. Model has been validated by experimental measurements performed in the laboratory. In particular, the kinetics of the reactions governing steam methane reforming (SMR) was considered from data found in the literature, while the ASR (Area Specific Resistance) value was calibrated according to experimental data. The results of the dynamic model show as model can be a useful design and optimization tool for the SOCs technology.

Near Infrared Spectroscopic Evaluation of Starch Properties of Diverse Sorghum Populations

Starch, mainly composed of amylose and amylopectin, is the major nutrient in grain sorghum. Amylose and amylopectin composition affects the starch properties of sorghum flour which in turn determine the suitability of sorghum grains for various end uses. Partial least squares regression models on near infrared (NIR) spectra were developed to estimate starch and amylose contents in intact grain sorghum samples. Sorghum starch calibration model with a coefficient of determination (R2) = 0.87, root mean square error of cross validation (RMSECV) = 1.57% and slope = 0.89 predicted the starch content of validation set with R2 = 0.76, root mean square error of prediction (RMSEP) = 2.13%, slope = 0.93 and bias = 0.20%. Amylose calibration model with R2 = 0.84, RMSECV = 2.96% and slope = 0.86 predicted the amylose content in validation samples with R2 = 0.76, RMSEP = 2.60%, slope = 0.98 and bias = −0.44%. Final starch and amylose cross validated calibration models were constructed combining respective calibration and validation sets and used to predict starch and amylose contents in 1337 grain samples from two diverse sorghum populations. Protein and moisture contents of the samples were determined using previously tested NIR spectroscopy models. The distribution of starch and protein contents in the samples of low amylose (<5%) and normal amylose (>15%) and the overall relationship between starch and protein contents of the sorghum populations were investigated. Percent starch and protein were negatively correlated, low amylose lines tended to have lower starch and higher protein contents than lines with high amylose. The results showed that NIR spectroscopy of whole grain can be used as a high throughput pre-screening method to identify sorghum germplasm with specific starch quality traits to develop hybrids for various end uses.

Analysis of Human-Building Interactions in Office Environments: to What Extent Energy Saving Boundaries can be Displaced?

Building energy consumption can be enhanced to a certain level, but human-oriented dimensions can open the doors to new opportunities. This article presents an assessment on the interactions between human-driven factors and energy consumption patterns in office buildings based on empirical evidence and a co-simulation. The objective of this work is to evaluate a range for saving capacities as a result of readjusting occupants’ prior habits and engaging them in building operation by determining internal and external factors associated with human-building drivers, needs, actions, and systems. The study is based on a real office building, and according to real behavioral data and subjective measurement to analyze human attitudes and interactions with the building end-uses such as cooling, lighting, and equipment along with factors that directly impact energy use such as fenestrations and window blinds. The survey results are extensively investigated and the correlations between demographic/socioeconomic traits and behavioral factors are examined. The survey results are incorporated into a co-simulation testbed to represent occupant attitudes and behaviors and model human-building interactions accordingly. Different scenarios are designed to perform an assessment on the role of human factors such as attitude, awareness of consequences, habits, ascription of responsibility and personal/social norms on building energy end-uses. The outcomes of this study demonstrate that by adjusting behavioral factors in an office building, an energy saving between 9 and 18% can be achieved without sophisticated technology interface or building retrofit/upgrade. The results are elaborated, and recommendations are explained in detail.

New Challenges in Wood and Wood-Based Materials

Wood and wood-based composites are key engineering materials that can be successfully designed and manufactured with predetermined exploitation properties, making them suitable for a wide range of applications and end uses [...]

Recent Advances in Nondestructive Evaluation of Wood: In-Forest Wood Quality Assessments

Efficient wood production and utilization requires knowing the wood quality attributes of forest resources relevant to various end uses, prescribing appropriate silvicultural treatments that positively influence wood quality, and then, at the time of harvesting, sorting and allocating standing timbers to the most appropriate markets [...]

Effect of washing on performance attributes of fabrics for Basic School Uniforms

The determination of the suitability of fabrics for specific end-uses require the subjection of selected fabrics to conditions they would be exposed to during use and care such as washing. Three different brands of fabrics commonly used for Ghanaian Basic School Uniforms and labelled A, B and C were evaluated after washing to suggest suitable fabric(s) to be used to achieve quality in uniforms. Specimens were subjected to three washing cycles and strength, elongation, dimensional stability and colourfastness tested. Data were analyzed using the Predictive Analytical Software for windows version 22. Means of the performance characteristics of the fabrics were determined and hypotheses were tested using analysis of variance at 0.05 alpha level. Washing had effect on the parameters investigated. In all, fabric brand B performed best as throughout the wash cycles, its strength values were above the standard requirements set by the Ghana Standards Authority for uniform fabrics. Since the fabric brand B performed best with the parameters investigated, it is suggested for use as school uniform fabric. However, further studies can be conducted on these same fabrics where other parameters such as absorbency and abrasion resistance can be evaluated.