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Manufacturing of mycelium-based composites is an emerging biorefinery technology toward the development of environmentally positive materials within the circular economy: it benefits from waste and industrial by-products upcycling while excelling in biodegradability. This study investigates the compressive behavior of materials repurposed from local agricultural wastes (tree nuts and crop wastes in California’s Central Valley), using the fungal mycelium of Pleurotus ostreatus and Ganoderma lucidum, well-known edible and medicinal species. We also explore the hybridization of these mycelium-based composites with local textile waste fibers as reinforcements. Following guidelines from several ASTM standards, the compressive behavior of these composites is analyzed to determine the impact of biomass processing, composition, fungal species used, and post-processing strategy. We propose a post-processing strategy based on a short exposure to sodium chloride solutions in ambient conditions, to de-activate mycelium and prevent its fruiting, replacing the established energy-intensive heat-based post-processing. This work aims at contributing to the decarbonization of the built environment and the construction industry in particular, through materials designed with upcycled waste (agricultural and textile), fungal mycelium and low-carbon footprint processes.
Bio-Futures for Transplanetary Habitats (BFfTH) is a Special Interest Group within the Hub for Biotechnology in the Built Environment that aims to explore and enable interdisciplinary research on transplanetary habitats and habitats within extreme environments through an emphasis on the biosocial and biotechnological relations. BFfTH organized the online and onsite networking symposium BFfTH to examine how emerging biotechnologies, living materials, and more-than-human life can be implemented in habitat design and mission planning. The two-day symposium aimed to serve as a catalyst in establishing an international network and to support the development of novel methodologies to move beyond discipline-specific approaches. The symposium consisted of five sessions, including Mycelium for Mars and Novel Biotechnologies for Space Habitats. This opinion paper presents key outcomes and trends from these sessions, a moderated panel, and informal discussions. The identified research trends explored the use of biotechnology and biodesign to enhance safety, sustainability, habitability, reliability, crew efficiency, productivity, and comfort in extreme environments on Earth and off-world. Beyond design and engineering, the symposium also examined sociotechnical imaginaries, focusing on desired experiences and characteristics of life and technology in transplanetary futures. Some of the specific topics included innovative material-driven processes for transplanetary habitat design, socio-political and ethical implications, and technology transfer for sustainable living on Earth. The outcomes emphasize the necessity for advancing biosocial and biotechnological research from an interdisciplinary perspective in order to ethically and meaningfully enable transplanetary futures. Such a focus not only addresses future off-world challenges but also contributes to immediate ecological and architectural innovations, promoting a symbiotic relationship between space exploration and sustainability on Earth.
This study investigates an ancestral Biodesign technique associated with the fruits of the Amazonian tree Crescentia cujete. For centuries, Amazonian artisans have transformed these fruits into objects named cuias, which serve mainly as containers. Despite the continued practice of cuias production, a specific shaping technique discovered in historical accounts remains unknown and unused by contemporary artisans. The paper reports the recreation of this technique considering the ancestral ethos underpinning these traditions. A mixed-method approach has combined historical and museum research, direct interaction with trees in a bioeconomy context, and participatory observation of traditional artisans’ production. The findings reveal the ancient practice of “Growing Design” with that tree and other practices that resonate with Biodesign, establishing a connection between this field and indigenous knowledge. This study highlights the underappreciation of indigenous objects and techniques, emphasizing the potential that emerges from understanding the alignment of certain ancestral wisdom with Biodesign principles, such as amplifying indigenous heritage and opening new possibilities in design.
The previously unindexed laboratory X-ray powder diffraction data of mosapride dihydrogen citrate dihydrate, an API used to stimulate gastrointestinal motility, has been recorded at room temperature. Using these data, the crystal structure of this API has been refined in space group P21/c (No. 14) with a = 18.707(4) Å, b = 9.6187(1) Å, c = 18.2176(4) Å, β = 114.164(1)°, V = 2990.74(8) Å3, and Z = 4. The structure of this material corresponds to the phase associated with CSD Refcode LUWPOL determined at 93 K. The Rietveld refinement, carried out with TOPAS-Academic, proved the single nature of the sample and the quality of the data recorded.
The crystal structure of perfluorononanoic acid (PFNA) was solved via parallel tempering using synchrotron powder diffraction data obtained from the Brockhouse X-ray Diffraction and Scattering (BXDS) Wiggler Lower Energy (WLE) beamline at the Canadian Light Source. PFNA crystallizes in monoclinic space group P21/c (#14) with lattice parameters a = 26.172(1) Å, b = 5.6345(2) Å, c = 10.9501(4) Å, and β = 98.752(2)°. The crystal structure is composed of dimers, with pairs of PFNA molecules connected by hydrogen bonds via the carboxylic acid functional groups. The Rietveld-refined structure was compared to a density functional theory-optimized structure, and the root-mean-square Cartesian difference was larger than normally observed for correct powder structures. The powder data likely exhibited evidence of disorder which was not successfully modeled.
In this work, the synthesis, characterization, and X-ray powder diffraction data for dichloridodioxido-[(4,7-dimethyl)-1,10-phenanthroline]molybdenum(VI) are reported. The crystal structure of this compound was solved from powder diffraction data using the simulated annealing method with a subsequent refinement using the Rietveld method. The dioxo-molybdenum (VI) complex C14H12Cl2MoN2O2 crystallizes in a monoclinic system with space group C2/c (N° 15) with refined unit-cell parameters a = 12.9495 (5) Å, b = 9.7752 (4) Å,c = 12.0069 (6) Å, β = 101.702 (3) °, unit-cell volume V = 1488.27 (11) Å3, and values of Z′ = 0.5 and Z = 4. The molecules are organized into chains diagonally along the a and c axis. Parallel polyhedra are observed along these axes formed by the interactions of Mo, Cl, O, and N atoms present in the coordination sphere. The crystalline packing of this dioxo-molybdenum (VI) complex is dominated by five intermolecular hydrogen bonds, two intramolecular hydrogen bonds, and the four interactions between the centroids (CgI⋯CgJ) of the aromatic rings. An analysis of the Hirshfeld surface revealed that the greatest contributions of the attractive forces are given by H⋯Cl/Cl⋯H, H⋯C/C⋯H, H⋯O/O⋯H, and H⋯H interactions.
Surface roughness is a critical factor affecting the performance of dental implants. One approach to influence this is through sandblasted, large grit, acid-etched (SLA) modification on pure titanium implant surfaces. In this study, SLA was performed on grade IV pure titanium. Sandblasting was conducted at distances of 2, 4, and 6 cm. Subsequently, the samples were etched with a mixed acid solution of HCl, H2SO4, and H2O for 0, 30, and 60 min. Surface roughness and X-ray diffraction (XRD) characterizations were conducted on the samples. The results revealed that surface roughness increased but was not too significant as the sandblasting distance decreased. Longer etching durations for sandblasted with acid-etched samples led to reduced surface roughness (Sa and Sz). It was found that a 60 min-etched sample resulted in optimal Sa, Sz, and Ssk values, i.e., 1.19 μm, 13.76 μm, and −0.60, respectively. The XRD texture was significantly influenced by sandblasting, with compressive residual stress increasing as the sandblasting distance decreased. Normal stress causes hill formations at shorter sandblasting distances. For etched samples, the residual stress decreased with longer etching durations. Normal stress-decreasing trend aligns with the initial reduction in hill and valley within the samples and subsequent hill enhancement at extended etching duration.
Shark vertebrae and their centra (vertebral bodies) are high-performance structures able to survive millions of cycles of high amplitude strain despite lacking a repair mechanism for accumulating damage. Shark centra consist of mineralized cartilage, a biocomposite of bioapatite (bAp), and collagen, and the nanocrystalline bAp's contribution to functionality remains largely uninvestigated. Using the multiple detector energy-dispersive diffraction (EDD) system at 6-BM-B, the Advanced Photon Source, and 3D tomographic sampling, the 3D functionality of entire centra were probed. Immersion in ethanol vs phosphate-buffered saline produces only small changes in bAp d-spacing within a great hammerhead centrum. EDD mapping under in situ loading was performed an entire blue shark centrum, and 3D maps of bAp strain showed the two structural zones of the centrum, the corpus calcareum and intermedialia, contained opposite-signed strains approaching 0.5%, and application of ~8% nominal strain did not alter these strain magnitudes and their spatial distribution.
Physical vapor deposited (PVD) molybdenum disulfide (nominal composition MoS2) is employed as a thin film solid lubricant for extreme environments where liquid lubricants are not viable. The tribological properties of MoS2 are highly dependent on morphological attributes such as film thickness, orientation, crystallinity, film density, and stoichiometry. These structural characteristics are controlled by tuning the PVD process parameters, yet undesirable alterations in the structure often occur due to process variations between deposition runs. Nondestructive film diagnostics can enable improved yield and serve as a means of tuning a deposition process, thus enabling quality control and materials exploration. Grazing incidence X-ray diffraction (GIXRD) for MoS2 film characterization provides valuable information about film density and grain orientation (texture). However, the determination of film stoichiometry can only be indirectly inferred via GIXRD. The combination of density and microstructure via GIXRD with chemical composition via grazing incidence X-ray fluorescence (GIXRF) enables the isolation and decoupling of film density, composition, and microstructure and their ultimate impact on film layer thickness, thereby improving coating thickness predictions via X-ray fluorescence. We have augmented an existing GIXRD instrument with an additional X-ray detector for the simultaneous measurement of energy-dispersive X-ray fluorescence spectra during the GIXRD analysis. This combined GIXRD/GIXRF analysis has proven synergetic for correlating chemical composition to the structural aspects of MoS2 films provided by GIXRD. We present the usefulness of the combined diagnostic technique via exemplar MoS2 film samples and provide a discussion regarding data extraction techniques of grazing angle series measurements.
Light stimulation can realise the remote control of the deformation of the specific position of 4D printing structure. Shape-memory polymer–carbon nanotube (CNT) composite materials, with outstanding near-infrared photothermal conversion rate and shape-memory ability, is one type of the most popular light responsive smart materials. However, current studies focused on the photothermal effect and shape-memory applications of light-responsive shape-memory polymer composite (SMPC) sheet structures, and there is no research on the photothermal effect in the depth direction of light-responsive SMPC three-dimensional structures. Here, we prepared a UV curable, mechanically robust, and highly deformable shape-memory polymer (IBBA) as the matrix of light responsive SMPC. CNTs were added as photothermal conversion materials. We explore the photothermal effect of near-infrared laser on the surface and depth of IBBA–CNT composites cube. Shape-memory experiments show that different folded shapes can be obtained by selective near-infrared laser programming. Selective near-infrared laser programming three-dimensional movable type plate shows a programming application in depth direction of three-dimensional light-responsive intelligent structure. This research extends the application of near-infrared laser in 4D printing to the depth direction of intelligent structures, which will bring more complex and interesting 4D printing structures in the future.
Chemical nucleation involves cluster growth by chemical reactions. In the case where clusters grow via a simple sequence of reversible chemical reactions, a summation expression for the steady-state nucleation rate can be derived. However, in many cases the chemical pathway to cluster growth is more complicated, and requires solving a set of species population balance equations that depend on the specific chemical system. Two examples are considered: soot nucleation in hydrocarbon combustion and nucleation of silicon particles in thermal decomposition of silane. In both cases, chemical kinetic mechanisms have been developed that allow for numerical simulations of particle formation. Soot nucleation is believed to proceed through the formation of polycyclic aromatic hydrocarbons. Models have been developed for the formation of the first aromatic ring and for subsequent growth, either through reaction with small molecules or by coagulation. Silicon nucleation from silane involves a large set of silicon hydride species, which can be grouped into classes according to their structure and reactivity, facilitating estimates of their free energies and reaction rate constants.
In single-component homogeneous nucleation, the summation expression for the steady-state nucleation rate requires values of the forward rate constants and Gibbs free energies of cluster formation. If atomistic data are available for these quantities, then these could be used instead of CNT. In an atomistic approach, clusters are treated as distinct molecular species, rather than as a small piece of the bulk condensed phase. Examples are presented of atomistic data generated by means of computational chemistry for water clusters up to size 10, and for aluminum clusters up to size 60. In both cases, the free energy of cluster formation is found to be a multimodal function of cluster size, both quantitatively and qualitatively different than in CNT. Condensation rate constants can be affected by the need for a third body as a collision partner, and by attractive intermolecular forces in collisions between clusters and monomers. An approach is suggested for constructing a “master table” of free energies of cluster formation, based on a hybrid of atomistic data, experimental values inferred by means of the nucleation theorem, and extrapolations to larger cluster sizes based on CNT.
Particle nucleation in plasmas occurs under a wide range of conditions. In some cases, such as thermal plasma synthesis of metal nanoparticles, nucleation may follow the conventional scenarios of single-component homogeneous or ion-induced nucleation. In other cases, such as dust formation in nonthermal plasmas of the type used in semiconductor processing, the paths to nucleation are specific to the chemistry of the gases introduced into the processing chamber. In such cases, nucleation typically involves a mix of phenomena that combine chemical nucleation with plasma physics, with the chemistry being driven by electron impact, and the charging of small clusters by free electrons and ions playing an important role in cluster growth. The charging and transport of clusters and particles affect the electric field profile, causing the plasma and the aerosol phase to be strongly coupled. An example is considered of silicon particle nucleation in silane-containing plasmas, the most studied system because of its importance in semiconductor processing. Cluster growth in this system is dominated by reactions between anion clusters and neutral molecules.
In most experimental nucleation studies, it is assumed that steady-state nucleation exists, meaning that the time required to reach steady state is much shorter than the timescales for changes in temperature and saturation ratio. To examine this assumption, we solve the time-dependent equations for cluster number densities and nucleation currents, for clusters of each size. Assuming CNT values for condensation and evaporation rate constants, one finds that the time lag for achieving steady-state nucleation is typically on the order of microseconds. This is usually short enough to justify the steady-state assumption, a possible exception being systems such as rapid nozzle expansions. If instead atomistic values are used for rate constants, one finds that it may take much longer to achieve steady state. This is at least partially due to the multimodal nature of atomistic free energy profiles, with local minima corresponding to “magic numbers,” clusters that are more stable than clusters of adjacent sizes. The existence of magic numbers can significantly slow the approach to steady-state nucleation and may therefore invalidate the steady-state assumption in many cases.
The late nineteenth-century Wilson cloud chamber experiments found that the presence of ions caused water vapor to nucleate at lower saturation ratios than in air free of ions. The classical theory of ion-induced nucleation is based on the Thomson model of an ionic droplet, in which an ionic core is surrounded by liquid of the condensing substance. A potential difference exists between the ionic core and the droplet surface, which introduces an electric work term into the Gibbs free energy of cluster formation. This term leads to the existence of stable prenuclei that are smaller than the critical size clusters and more abundant, at steady state, than the bare ions. With assumptions otherwise the same as in CNT for neutral self-nucleation, an expression can be derived for the steady-state rate of ion-induced nucleation. Deficiencies of this theory, in addition to those of CNT for neutral self-nucleation, include that it neglects the effect of the ion on condensation rate constants. Moreover, the theory predicts that the sign of the ion makes no difference in the nucleation rate, in contradiction to the results of most experimental studies for various substances.
The classical theory of multicomponent nucleation, including binary nucleation, ternary nucleation, etc., makes similar key assumptions as in CNT for single-component nucleation. Clusters are modeled as spherical liquid droplets consisting of an ideal multicomponent solution. The surface tension is assumed to equal that of a flat surface of liquid having the same composition, in equilibrium with its multicomponent vapor. The Gibbs free energy of cluster formation is a function of the cluster’s size and composition and of the gas-phase partial pressures of each component. The critical size and composition are found at a saddle point on the multidimensional free energy surface, where the free energy of cluster formation is a maximum in one direction and a minimum in all orthogonal directions. Several improvements have been proposed within the framework of classical theory. These include models of the cluster growth trajectory near the critical point; studies that account for composition-dependent surface tension; and models that consider the existence of surface-active layers that cause the chemical composition near the cluster surface to be different than in the core.