Fire safe and sustainable lightweight materials based on Layer-by-Layer coated keratin fibers from tannery wastes

The increasing consciousness about the depletion of natural resources and the sustainability agenda are the major driving forces to try to reuse and recycle organic materials such as agri-food and industrial wastes. In this context, keratin fibers, as a waste from the tannery industry, represent a great opportunity for the development of green functional materials. In this paper, keratin fibers were surface functionalized using the Layer-by-Layer (LbL) deposition technique and then freeze-dried in order to obtain a lightweight, fire-resistant, and sustainable material. The LbL coating, made with chitosan and carboxymethylated cellulose nanofibers, is fundamental in enabling the formation of a self-sustained structure after freeze-drying. The prepared porous fiber networks (density 100 kg m–3) display a keratin fiber content greater than 95 wt% and can easily self-extinguish the flame during a flammability test in a vertical configuration. In addition, during forced combustion tests (50 kW m–2) the samples exhibited a reduction of 37 % in heat release rate and a reduction of 75 % in smoke production if compared with a commercial polyurethane foam. The results obtained represent an excellent opportunity for the development of fire-safe sustainable materials based on fiber wastes

A New Approach to Assess the Building Energy Performance Gap: Achieving Accuracy Through Field Measurements and Input Data Analysis

The performance gap is defined as the difference between a calculated and measured quantity, and in buildings, it may refer to the energy performance or the indoor thermal conditions. According to the literature analysis, most studies start from simulation results and define methods and approaches to minimise the discrepancy against the measured values. This paper presents an alternative and innovative approach to the problem, starting with measurements in a fully instrumented and monitored living lab consisting of seven office rooms used to build and validate an accurate calculation model. The model is applied to observe how different input modes of the most relevant parameters affect the performance gap. The model exhibits high accuracy: the coefficient of variation of the root mean square error scores is 2.3% for thermal free-floating and 10% and 14% for final cooling and heating energies, respectively. Depending on the single input variations, overestimation above 50% and underestimation below 40% are calculated for a given energy service. Results show that the weather data, occupancy profiles, related internal gains, and ventilation rates can significantly affect the performance gap. The outcomes of this field study call for new analyses aimed at generalising the achieved results and developing appropriate modes to input the relevant parameters to minimise the performance gap with limited calculation efforts

Experimental investigation of a novel modular multi-purpose floating structure concept

Modular multi-purpose floating structures (MMFS) provide a possible solution to the growing need for space resulting not only from the rapidly growing global population but also from the emerging blue economy and specifically offshore renewables sector. The desired space is generated in a more sustainable way than traditional land reclamation methods, by interconnecting together modular floating platforms, making this technology adaptable and suited to a broad range of possible offshore activities. This study experimentally investigates the hydrodynamic response of a novel concept of modular multi-purpose floating structure, composed by floating modules connected with semi-rigid connectors and moored at the seabed using a taut mooring system solution. The 1:50 model consists of three hexagonal floating platforms, linked together by a semi-rigid connector system that emulate the mechanical behaviour of the full-scale system. The model has been tested under representative sea state conditions at the wave basin of the Laboratory of Hydraulic Engineering (LIDR) of Università degli Studi di Bologna. This paper describes the experimental setup and preliminary results of the dynamic behaviour of the MMFS system, with particular focus on platforms kinematics, mooring and connectors loads

New insights in large-pores mesoporous silica microspheres for hemostatic application

Hemorrhages are still considered a common cause of death and despite the availability of different hemostatic agents it is still necessary to develop more effective hemostats for bleeding managements in emergency situations. Herein, large-pores mesoporous silica microspheres (MSM) were synthesized, and their surface was modified to enrich the hydroxyls population with the aim of achieving a material with enhanced water adsorption capacity and high hemostatic ability. The success of surface modification was investigated by Fourier Transform Infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA), which confirmed the increase in the amount of surface hydroxyl groups. A hemolysis assay as well as a clotting test were carried out to evaluate the hemocompatibility and hemostatic ability, respectively. It was found that the modified material presented the lowest hemolytic ratio and the lowest clotting time. The novelty of the paper is mainly due to the coupling of the hemostatic ability test with the adsorption microcalorimetry of water. In fact, being the water adsorption on the material surface a crucial factor in the hemostatic activity, microcalorimetry was used for the first time to study the adsorption of water and estimate its heat of adsorption. The data obtained showed that the modified MSM presents a surface able to adsorb a higher amount of water, compared to the pristine MSM, with a low molar heat of adsorption (about 35 kJ/mol), which renders the modified MSM presented in the present study an excellent candidate for producing novel hemostats

Tensile Response and Durability of Flax-TRMs

Textile Reinforced Mortar (TRM) systems are currently among the most effective retrofitting solutions for masonry structures, thanks to their high compatibility with the substrate, and reversibility. Recently, the adoption of natural textiles as reinforcement in TRM systems has attracted the interest of researchers and industry, due to their great potential of providing a cost effective and sustainable solution while ensuring adequate structural performance. Despite the increasing number of studies focusing on the characterisation of short-term tensile properties, the long-term durability performance of natural TRMs, which is fundamental to ensure their viability in construction applications, has not been examined in detail. This paper aims to investigate the tensile behaviour of flax textiles and flax-TRM composites and assess their residual performance after exposure to accelerated ageing. Composites consisting of two and three layers of a bi-directional flax fabric embedded in a lime-based mortar were conditioned in water for 1000 h and 2000 h at controlled temperatures of 23°C and 40°C. Bare textiles were also aged in an alkaline solution for equivalent exposure times and temperatures, to replicate the conditions within the lime-based matrix environment. Both unconditioned and aged textiles and composites were tested under uniaxial tension to determine their tensile behaviour. The complete load-deformation response was assessed employing both contact and non-contact methods (i.e. 2D Digital Image Correlation). It is shown that ageing strongly affects the textile reinforcement, resulting in a significant strength loss of the composite system

Unfolding Potential and Challenges in Molecular Field-Coupled Nanocomputing

Molecular Field-Coupled Nanocomputing (MolFCN) represents a revolutionary approach to computational technology, exploiting single molecules for encoding and processing logical information. MolFCN permits zero-current logical operations to achieve ultra-low power and hyper-miniaturized computing units. This perspective article explores the current state and future potential of MolFCN, highlighting recent technological advancements, potential applications, and the significant challenges that lie ahead. Despite the challenges, the pathway to practical implementation holds significant promise, with obstacles such as scalability, stability, integration, and practical considerations offering opportunities for innovation and advancement. MolFCN can shape the future of nanocomputing and contribute to current major challenges in nanoelectronics by opening key research directions

Easy Direct Functionalization of 2D MoS2 Applied in Covalent Hybrids with PANI as Dual Blend Supercapacitive Materials

The pressing demand for more sustainable energy provision and the ongoing transition toward renewable resources underline the critical need for effective energy storage solutions. To address this challenge, scientists persistently explore new compounds and hybrids and, in such a dynamic research field, 2D materials, particularly transition metal di-chalcogenides (TMDCs), show great potential for electrochemical energy storage uses. Simultaneously, also conductive polymers (CPs) are interesting and versatile supercapacitor materials, especially polyaniline (PANI), which is extensively studied for this purpose. In this work, a powerful method to combine TMDCs and PANI into covalently grafted hybrids starting from aniline functionalized few-layers 1T-MoS2, attained by a facile direct arylation with iodoaniline, is presented. The hybrids provide circa 70 F g(-1) specific capacitance in a pseudo device setup, coupled with a robust capacitance retention of well over 80% for up to 5000 cycles. These findings demonstrate the potential of similar covalent composites to work as active components for novel, innovative energy storage technologies. At the same time, the successful synthesis marks the efficacy of direct covalent grafting of conductive polymer on the surface of 2D TMDCs for stable functional materials

PRELIMINARY REPORT ON THE CAMPAIGNS 2022-2023 OF THE ITALIAN ARCHAEOLOGICAL EXPEDITION AT SELEUCIA ON THE TIGRIS (IAES)

This report makes available the preliminary results of field research conducted at Tell ‘Umar/Seleucia on the Tigris by the Italian Archaeological Expedition (IAES), in the months of October-November 2022 and April 2023. The IAES started activity anew after a long gap, resuming research being conducted for decades at the site since 1963. Geomatic and magneto-geophysical surveys have been conducted with the purpose of better defining the topography of the archaeological area and acquiring new data on some features of the north part of the city. A test-trench was opened to check stratigraphy at a point very close to one of the former excavations

Polymer nanocomposites based on gold nanoparticles: Synthesis, properties and applications

Polymer nanocomposites have great potential in materials science research for different applications in the fields of industrial engineering, catalysis, sensing, biology, and medicine. Nanocomposites based on polymers and gold nanoparticles (AuNPs) combine the mechanical properties and processability of polymers with the electrical, plasmonic, and catalytic properties of the AuNPs. Various synthetic approaches can be used to produce these nanocomposites, such as the colloidal synthesis of AuNPs with reducing agents (sodium borohydride, sodium citrate) and the direct mixing of the presynthetized polymers; and electrochemical route by oxidative electropolymerization of monomers and reduction of gold salts. Usually, the final composite can be characterized by electron microscopy and spectroscopic techniques. A wide range of nanocomposites can be prepared through physical (adsorption) or chemical (covalent bond) interactions between polymers and nanoparticles, resulting in unique properties. To illustrate, the incorporation of metallic nanoparticles in conducting polymers can promote a synergistic effect, increasing the individual performance of the composite for applications in electrocatalysis, sensors and biosensors, energy storage devices, and solar cells. Natural polymers such as polysaccharides can interact with AuNPs, acting as a nontoxic reducing agent and/or stabilizer, increasing their biocompatibility and expanding their use in nanomedicine applications. Biopolymers bring their biodegradability, biocompatibility, low toxicity, and cost-effectiveness advantages into the nanocomposites, further improving applications in nanomedicine such as controlled release and tissue engineering. In this chapter, different syntheses of polymer and gold nanoparticle composites were explored. The chapter also focuses on composite properties, mainly optical, electrochemical, and biocompatibility, and the possible characterization methods, evidencing the versatility in the application of these materials

From hinterland granary fort to frontier mountain fortress: Initiation, construction, and expansion of the Diaoyucheng Fortress, Hechuan, China, in the wars during 1125–1279

The Southern Song planned and constructed the Diaoyucheng Fortress at Hezhou of the Sichuan Theatre, during the 13th century. This fortress became famous for its 36-year resistance against the Mongols and the death of Mo ̈ngke Khan in 1259. Based on historical documents and data from re-analysis of archaeological report and field survey, this study explores its initiation, construction and transition, to build a coherent narrative for its transformation from a hinterland transport hub during the Song-Jin War (1125e1234) to a frontier stronghold during the Song-Mongol War (1235e1279), which experiences the establishment of Zhuanban Granary in the 1130s, the construction of Xinyuguan Fort in the 1160se1170s, the transformation into a refuge in 1240, and the expansion into the Diaoyucheng Fortress in 1243e1279. By combining spatial analysis with military history, this study discusses how the peninsular site, the “dustpan” form, and the fort cluster were formed under the influence of military strategies in different war periods and the topography in Sichuan. With the comparisons with the fortifications across Eurasia around the same period, this study illustrates this fortress epitomizes the development of knowledge system for fortification design in ancient China, especially the river defense fortress taking advantage of topography and nav