Uncontrolled Structures Research Articles

Seismic performance of soft soil foundation with a new type of assembled wall tuned mass damper.

The design of tuned mass damper (TMD) parameters is influenced by the soil-structure-TMD coupling system; thus, it is important to consider the soil-structure interaction (SSI) for the vibration control effect of the TMD. Recently, the acquisition of TMD parameters considering soil-structure interactions has only remained at the theoretical stage, lacking relevant experimental verification. Traditional TMD face the problems of occupying a large building space, increasing construction costs, and non-replaceable components. In this study, an assembled wall-type damping TMD was designed. By comparing the dynamic response of the uncontrolled and controlled structures equipped with the newly assembled wall-type damping TMD in the shaking table test on a soft soil foundation, we analyzed whether the SSI effect was considered in the TMD design parameters on the damping effect of the newly assembled wall-type tuned mass damper. The TMD parameters optimized using the artificial intelligence algorithm were verified experimentally. The results indicated that the traditional TMD design parameters were discordant because the SSI effect was not considered. The SSI effect in the soil effectively reduces the dynamic response of the superstructure. By considering the SSI effect and improving the multi-population genetic algorithm, a wall-type damping TMD with optimized parameters can achieve a good damping effect.

Inerter-based tuned mass dampers for response control of multi-degree-of-freedom structures subjected to wind and earthquake excitations

The present work explores the utilization of the tuned mass damper-inerter (TMDI) in controlling the structural response subjected to wind and earthquake excitations. An example of a 25-storey reinforced concrete building is taken up. The equations of motion of the structure-TMDI combined system are established by assuming the building behaves as a shear-building with multiple degrees of freedom. These equations are solved using Newmark’s time integration method. The objective functions are the wind- and earthquake-induced structural response quantities, such as the maximum inter-storey drift ratio (MIDR) and peak floor acceleration (PFA). The prime contribution of this study is the inclusion of statistical measures such as the mean, 85th, and 95th percentiles for these quantities. A genetic algorithm-based multi-objective optimization is performed to estimate the optimum TMDI parameters. Based on the outcomes of this study, it can be recommended that the TMDI be optimized to perform well under the 95th percentile for MIDR and PFA in effectively reducing the peak structural responses. Frequency domain analysis results demonstrate TMDI’s multiple-mode controlling capability. The energy comparison plots of the uncontrolled and controlled structures prove the effectiveness of the optimum TMDI in providing enough damping and ensuring structural stability.

Bidirectional performance assessment of UFREI-isolated structures with single and multiple tuned mass dampers under earthquakes and winds

An innovative hybrid vibration controller (HVC) composed of unbonded fiber-reinforced elastomeric isolators (UFREIs) and tuned mass dampers (TMDs) is utilized for the vibration control of an existing hospital building under the multi-hazard scenario of earthquakes and (nonconcurrent) winds. A 3-dimensional nonlinear model of the considered hospital building is analyzed. Four configurations of the HVC are investigated, wherein single or multiple TMDs are utilized, having various tuning properties and locations along the height of the building. All the various controlled and uncontrolled structures are subjected to site-specific bidirectional earthquake and wind excitations. Results reveal that the HVC with two TMDs, having favorable tuning conditions for both earthquakes and winds, are the most efficient under the multi-hazard scenario. Interestingly, the increase in the TMD mass ratio always improves the performance of the HVC under wind excitations, however under earthquakes, it may also result in enhanced deterioration of HVC performance in detuned conditions.

Study on seismic performance of nanometakaolin-reinforced fluororubber sector damper (NFSD)

In order to improve the mechanical performance of the core energy-dissipating material of the viscoelastic damper, a novel Nanometakaolin-reinforced Fluororubber Sector Damper (NFSD) is proposed for providing a strong guarantee for the seismic safety of the structure joints subjected to seismic earthquake. Firstly, in order to systematically study the shock absorption performance of NFSD, the core energy dissipation material(nano metakaolin reinforced fluororubber composite) of NFSD is prepared by melt blending method, and the vulcanization performance and microscopic mechanism of the nano composite are analyzed by vulcanization test and X-ray diffraction test. Secondly, the nanocomposite material is used as the core energy dissipation material, and NFSD based on nano reinforced fluororubber is proposed. Finally, the dynamic characteristics of NFSD and the structural seismic performance of NFSD controlled reinforced concrete (RC) frames are studied using refined finite element simulation methods. The research results indicate that 20 phr NMK increase the maximum torque MH of FKM by 20 %, while also shortening the scorching time t10 by 0.28 min. It means greatly improving the vulcanization performance of FKM. Compared to uncontrolled structures, NFSD reduces the peak displacement, interstory displacement angle, and maximum vertex acceleration of the 4-story RC structure by 16.2 %−67.4 %, 12.4 %−64.6 %, and 16.8 %−43 %, respectively. NFSD possesses excellent seismic absorption performance.

Stable sodium-metal batteries with a hierarchical structured electrode toward reversible confinement of Na dendrites

Sodium metal is a promising candidate for the future of rechargeable batteries. However, a significant problem, that is, the growth of sodium dendrites, which are uncontrolled microscopic structures that reduce battery performance and stability, remains unaddressed. To resolve this issue, the development of three-dimensional (3D) nanostructured hosts to prevent dendrite growth and cease the buildup of inactive sodium has been proposed. However, research on developing an uncomplicated process to design these 3D hosts is currently lacking. In this study, we used the ice-templating method to form a self-supporting 3D hierarchical porous structure using a graphene oxide dispersion. This approach offers significant benefits in terms of scalability and cost-effectiveness. The resulting porous design offers numerous nucleation sites, which in turn reduce the intensity of local electric fields around dendrites and lower the current density. Consequently, sodium ions are deposited more evenly, which helps inhibit dendrite growth. Our test results indicated stable cycling performance, with 250, 200, and 150 cycles achieved for deposition volumes of 0.25, 0.5, and 1.0 mAh cm−2, respectively, at a constant current density of 0.25 mA cm−2. By utilizing in situ optical cell analysis, we observed the effective suppression of dendrite growth. Furthermore, ex situ examination confirmed the absence of dendrite formation, even at a high deposition capacity of 5.0 mAh cm−2. These results underline the potential of using a 3D hierarchical porous structure to effectively improve the performance and longevity of sodium-metal batteries.

Performance of tuned particle impact damper and tuned mass damper seismic control systems considering mainshock-aftershock

Generally, seismic structural design codes have been defined in accordance with a single shock or mainshock. Also, seismic control systems are usually designed and studied based on single events. considering that ground motions in seismic zones are not a single event and usually several remarkable aftershocks accompany a mainshock, the seismic behavior of controlled structures and performance of the seismic control systems are not clear under real seismic sequences. The current study investigates the seismic behavior of a 3D seismic controlled steel structure and the performance of the seismic control systems under seven real mainshock-aftershocks using non-linear implicit analysis. A tuned particle impact damper (TPID) was used that combines a passive TMD and a particle impact damper (PID) to increase efficiency and performance by working out-of-phase with the main structure and increasing energy absorption. The efficiency of the TPID and TMD seismic control systems was studied by comparing the seismic behavior of the TPID-controlled, TMD-controlled and uncontrolled structures under seismic sequences. The parameters of the frequency response, top-story maximum relative displacement, structural damage (residual displacement) and inter-story drift ratio were studied. Additionally, by considering the structural system as a closed adiabatic isolated system with ground motion energy as the only system input energy, the absorbed kinetic and potential (inelastic dissipated energy) energies in seismic control systems were calculated and compared. Results showed that both TPID and TMD seismic control systems are efficient under seismic sequences. But the TPID system is a more efficient seismic control system compared to the TMD system. Also, this case showed that because of the high performance of the TPID and TMD seismic controlled systems, unlike the moment-resisting uncontrolled structures, there is no need to consider seismic sequences in the design of TPID- and TMD-controlled structures.

Seismic failure probability of adjacent frame structures retrofitted by flexible control measure

Due to the randomness of earthquake and the difference of dynamic characteristics of adjacent structures, the mechanical behavior of the adjacent structures under earthquake is very complex. A flexible control method using steel strands is proposed, which has little impact on the dynamic characteristics of the adjacent structures. A three-dimensional numerical calculation model of the adjacent frame structures is established by using LS-DYNA. The interstory drift ratios of the single structure, the adjacent uncontrolled structure and the adjacent controlled structure are analyzed by using incremental dynamic analysis (IDA) method. The failure probabilities of different limit states (LS) are studied based on the vulnerability, and the annual average and the design life failure probabilities are further discussed by the probabilistic seismic failure risk analysis. The results show that the maximum interstory drift ratio of the structure is reduced by the flexible control, and the failure probability of the adjacent controlled structure is less than that of the single structure and the adjacent uncontrolled structures. It should be noted that the influence of the flexible control on the failure probability is reduced when the PGA is close to 1.0 g. The four limit states LS1, LS2, LS3 and LS4 represent the slight damage, the moderate damage, the severe damage and the complete damage, respectively. The annual average failure probability from LS1 to LS4 decreases in turn, and the difference is about 10 times. Compared with the adjacent uncontrolled structures, the flexible control reduces the design life failure probabilities of the 10-storey structure and the 8-storey structure by 13.82% and 11.79%, respectively. The proposed control measure is helpful to reduce the failure probability of the adjacent frame structures under earthquake action.

Planar Spin Glass with TopologicallyProtected Mazes in the Liquid Crystal Targeting for Reconfigurable Micro Security Media.

The planar spin glass pattern is widely known for its inherent randomness, resulting from the geometrical frustration. As such, developing physical unclonable functions (PUFs)-which operate with device randomness-with planar spin glass patterns is a promising candidate for an advanced security systems in the upcoming digitalized society. Despite their inherent randomness, traditional magnetic spin glass patterns pose considerable obstacles in detection, making it challenging to achieve authentication in security systems. This necessitates the development of facilely observable mimetic patterns with similar randomness to overcome these challenges. Here, a straightforward approach is introduced using a topologicallyprotected maze pattern in the chiral liquid crystals (LCs). This maze exhibits a comparable level of randomness to magnetic spin glass and can be reliably identified through the combination of optical microscopy with machine learning-based object detection techniques. The "information" embedded in the maze can be reconstructed through thermal phase transitions of the LCs in tens of seconds. Furthermore, incorporating various elements can enhance the optical PUF, resulting in a multi-factor security medium. It is expected that this security medium, based on microscopically controlled and macroscopically uncontrolled topologicallyprotected structures, may be utilized as a next-generation security system.

Theoretical and experimental research on damping performance of suspended multiple mass pendulums damper

Conventional suspended mass pendulum damper (SMPD) include suspended single mass pendulum damper (SSMPD), tandem suspended multiple mass pendulums damper without springs (TSMP), and parallel suspended multiple mass pendulums damper without springs (PSMP), these types of SMPD have the advantages such as clear mechanism, simple construction, and good damping effect, but they have a narrow tuning frequency band and the pendulum length needs to be set too long for low-frequency super tall structures and too short for high-frequency tall structures, limiting their application in practical engineering. Because of this, the paper proposes connecting the spring to the mass pendulum, forming a tandem suspended multiple mass pendulums damper with spring (TSMP-S) and a parallel suspended multiple mass pendulums damper with spring (PSMP-S), and establishing structural system dynamics equations and performing the dynamic characterization of the TSMP-S and PSMP-S, obtain their frequency resolved solutions to explain the damping mechanism. In order to study the vibration-damping performance of these two types of SMPD, through numerical simulations to compare the damping effect of the conventional SMPD, TSMP-S, and PSMP-S on the controlled structures, and a series of shaking table tests on controlled and uncontrolled structures to verify the effectiveness of SSMPD, TSMP, PSMP, TSMP-S and PSMP-S for damping control of controlled structures under conventional earthquake and earthquake at four types of sites. Numerical simulations and shaking table test results in both show that the TSMP-S has the best damping effect, with the advantages of increasing the tuning frequency band, achieving multi-order vibration control, and flexible adjustment of the pendulum length, which is suitable for actual engineering.

Revisiting the Early Discourse of the Information Age and Its Interplay with Humanity

This paper examines scholars’ discourses on the coming of the Information Age. It starts by discussing scholars who measured the emergence of the Information Age in the early 1960s. Machlup and Galbraith used economic indicators, followed by the exploration of network and knowledge sharing, which is a crucial process in the formation of the Information Age. Ellul (1964) paralleled humanity with technology as a “system,” and Mumford (1966) coined the term “megamachine.” These early arguments were pessimistic that humans were considered as inevitably confined by uncontrolled structures due to information and its byproducts—technology. However, in the 1980s, Nora and Minc considered the Information Age optimistically by introducing the concept of “Decentralization” to indicate the freedom of “choices” for modern people.

Control measures of collapse-pounding dynamic responses of adjacent structures under earthquake action

The adjacent structures are easy to impact under earthquake, and the huge impact force will destroy the structural members, such as beams and columns, and even cause partial or total structural collapse. In order to control the pounding and the collapse of the adjacent structures, the flexible control measures with steel strands is proposed, which has little influence on the dynamic characteristics of the structure itself. The 3-D calculation model of the adjacent 10-storey and 8-storey frame structures are established by explicit dynamic program. The influence of steel strand arrangements on pounding and collapse is studied, and the parameter analysis is conducted. The results show that the uncontrolled adjacent structures are prone to collapse under strong earthquake, and the reasonable control measures can avoid structure collapse when the PGA is 0.62g. The maximum reduction rate of the impact force is 38.28%, the maximum reduction rates of the inter storey displacement angles of the taller and the lower structures are 16.36% and 24.74%, respectively. The lower structure is more affected by the pounding compared with the taller structure. The impact force does not always decrease with the increase of the gap size, and the earthquake intensity is one of the factors affecting the change law. The height difference of adjacent structures has great influence on the impact force and vertical displacement. The structure damage is aggravated with the increase of seismic dimension. The reasonably designed flexible measures are very effective for controlling the pounding and collapse of the adjacent structures under earthquake.

EFFECT OF ISO 17025 STANDARD ON QUALITY MANAGEMENT SYSTEM IN ACCREDITED CIVIL ENGINEERING LABORATORIES

Due to the earthquakes that have occurred in recent years, many lives and property have been lost in the world. After these earthquakes, national and international regulations used in the world have updated with various changes. Especially the regions where the population and industry in Turkey are dense are under the risk of heavy earthquakes. When the damages in the buildings after the earthquakes were examined, it has seen that they are in poor quality and uncontrolled structures. The inspection of the buildings has built in Turkey is carried out by the relevant municipalities and ministries. The most important part of these inspections is carried out by laboratories that inspect the suitability of the materials used. The importance of public and private control laboratories in the field of construction organized under the ISO/IEC 17025 standard in Turkey is important for the safety of buildings. In this context, the effectiveness of the construction materials laboratories in Turkey according to the ISO 17025 standard has investigated. In this context, the establishment processes of the civil engineering laboratory, which is in the process of establishment and for which an accreditation application will be made, have examined in accordance with the ISO 17025 standard. In addition, the compliance of the laboratory's quality management system documents with the ISO 17025 standard has investigated. Thanks to this study, it is aimed to assist the accreditation processes of organizations that want to be accredited. Keywords: ISO 17025, Quality management, Accreditation

Optimal Design of Inertial Amplifier Base Isolators for Dynamic Response Control of Multi-Storey Buildings

The optimal design of inertial amplifier base isolators (IABI) for dynamic response mitigation of multi-storey buildings subjected to base excitations has been studied in this paper. In order to achieve the closed-form expressions for optimal design parameters of IABI, [Formula: see text] optimization method has been employed. The effectiveness of the closed-form expressions for optimal design parameters was evaluated by determining the isolated structures’ frequency and time domain responses and comparing them to the corresponding responses obtained from equivalent uncontrolled structures. A numerical study employing the Newmark-beta method is conducted to obtain time-domain responses using near-field earthquake base excitation. The response reduction capacity (%) of the optimum inertial amplifier base isolator is compared to the response reduction capacity (%) of the optimum traditional base isolators, demonstrating that inertial amplifiers have increased the vibration reduction performance of traditional base isolators by 50% to 60%. All the outcomes from the study are mathematically accurate and also feasible for practical design purposes.

Groovy Electrodes Enable Facile O2 and H+ Transport in PEMFCs

Polymer electrolyte membrane fuel cells (PEMFCs) are promising alternative to internal combustion engines, owing to their capability to produce on-demand power with zero local carbon emissions. However, PEMFCs suffer from limitations related to performance, particularly for heavy-duty vehicle applications [1]. A major contributor to the performance loss is the cathode electrode; uncontrolled conventional electrode structures lead to non-ideal transport pathways of O2 and H+ [2], subsequently leading to performance loss. Here, we report an alternative electrode structure termed groovy electrodes, fabricated via patterned Si templates. Si templates with desired patterns are fabricated through photolithography and deep-reactive ion etching techniques (Fig. 1a), and an electrode layer is coated onto the template and subsequently transferred to the membrane or the gas diffusion layer. The resulting electrode features ordered grooves with consistent depth and width (Fig. 1b-c). We will present how this alternative structure enables improved H+ transport (enabled by higher ionomer content) with grooves facilitating effective O2 transport to reaction sites. We will also demonstrate the benefits of a groovy electrode for the durability of PEMFCs. Reference Cullen et al., Nat. Energy, 6, 462 (2021).Ramaswamy et al., J. Electrochem. Soc., 167, 064515 (2020). Figure 1

Semi-active control of nonlinear smart base-isolated structures using MR damper: sensitivity and reliability analyses

Semi-active control of base-isolated structures using magneto-rheological (MR) dampers is well studied in recent years. However, there is a study gap for sensitivity and reliability analyses assessment of the structure in the literature. Besides, the reliability analysis of the structures based on the importance of the building from a user perspective categorized into three groups including very high, high, and medium is an interesting topic that is considered in this study. Extension of the study for the case of uncontrolled base-isolated structures and controlled ones in both passive-off and passive-on modes of the MR dampers and tuning the command voltage of the MR dampers by a multi-objective modified clipped optimal (MOMCO) controller are also addressed in this paper in different seismic hazard regions with different peak ground accelerations. The Monte Carlo simulation-based Sobol’s indices and importance sampling (IS) method are applied for the sensitivity and reliability analyses. Studies are conducted on an eight-story nonlinear base-isolated structure. The sensitivity analyses show the main seismic responses are more influenced by the changing uncertainties of the stochastic ground acceleration; the mass, and stiffness of the structural model; and the yield force of the isolation system. MR dampers can significantly reduce the failure probabilities of the structures in different seismic hazard regions. By increasing seismic hazard, an increment is observed in failure probability. Enhancing the importance of the building from medium to very-high status leads to an increase in the failure probabilities of the structure in all cases. However, the performance of three control cases in reducing the failure probabilities of the structure is often increased. The MOMCO controller and passive-on mode represent fewer failure probabilities than the uncontrolled and passive-off mode in different seismic hazard regions and groups. However, the MOMCO gives the best performance in the reduction of failure probabilities.

Structural Vibration Control Using Novel Adaptive Tuned Mass Inertance Damper (ATMID) with Adjustable Inertance

In this paper, an inerter-based device for structural vibration control is proposed with which inertance can be altered relying on the frequency changes of the excitation. In this manner, a tuned mass damper is developed in such a way that it is assembled with a ball-screw inerter along with a new continuously variable transmission system. The device is termed an adaptive tuned mass inertance damper (ATMID). The ATMID is able to produce an alterable inertance, which gives rise to seamless variability in device frequency; consequently, the device frequency can be tuned to that of the excitation. To assess the efficiency of the device, the response amplitude of a single-degree-of-freedom harmonically induced structure controlled by the ATMID is compared with those of the passive-controlled and uncontrolled structures. Results show that in the frequency band where the effectiveness of the passive device with a mass ratio of 0.2 is degraded and even destructed, the adaptive device with a mass ratio of 0.1 and diverse inertance behaves impressively. As a result, notable oscillation suppression is obtained using the proposed adaptive device compared with passive-controlled (56%) and uncontrolled cases (21%). The presented extensive variability in the frequency of the device utilizing its transmission ratio of 0.45–2.2 leads the device to a superior level of oscillatory motion reduction in structural responses along an enlarged frequency band.

Performance of Structure Equipped AP‐TMD Compared with MTMD, ATMD, and PTMD against Earthquake Using Genetic Fuzzy Algorithm

During the past years, different control devices have been introduced and used to reduce the response of structures. This article presents the performance of active‐passive tuned mass dampers (AP‐TMDs) in the reduction of structural responses and a comparison between the uses of different controllers, including tuned mass damper (TMD), active tuned mass damper (ATMD), and multituned mass damper (MTMD). Analyzing and modeling the structure under four near‐ and far‐field earthquakes are performed in MATLAB and SIMULINK. Finally, the responses of controlled and uncontrolled structures equipped with these controllers are investigated. Fuzzy and genetic‐based fuzzy logic controllers are used to determine the control force of ATMD and AP‐TMD, respectively. In order to compare the performance of the dampers, the mass ratio of TMDs is fixed in all cases and is taken to be 5%. Damping of the structure is considered equal to 5%. The frequency and damping ratio of TMDs with maximum and RMS displacement optimization criteria are obtained. The mass ratio of TMDs in controlled structures with MTMD and AP‐TMD is calculated by numerical analysis. It can be inferred that using control force affects response reduction in both ATMD and AP‐TMD controllers significantly. In addition, using AP‐TMD can bring the merits of both passive and active systems by providing active control and reducing power requirements for control forces. All controllers are recommended for structural control although AP‐TMD reduced maximum and RMS displacement by about 50% in the best case, which has better performance than others. On the other hand, ATMD decreased RMS acceleration by 37.5% on average in four earthquakes compared to the uncontrolled structure.

Structural Vibration Control with the Implementation of a Tuned Mass Rocking Wall System

A tuned mass rocking wall (TMRW)-frame structure system is proposed to improve the energy dissipation ability of the traditional rocking wall-frame system. Based on the energy dissipation principle of the traditional tuned mass damper (TMD), a TMRW is designed with proper mass and stiffness according to the dynamic characteristic of the host structure. Firstly, considering the presence of inherent structural damping, the dynamic amplification factor of the main mass was derived from the dynamic equations of the TMRW mechanism. A practical design table was then obtained after parameter study. Secondly, by taking a six-story frame structure as an example, the dynamic time-history analysis was conducted to study TMRW’s seismic performance. The inter-story drift ratios of the TMRW-frame, the traditional rocking wall-frame, and the frame structures were compared, and the seismic responses of the controlled and uncontrolled structures were also compared. The results demonstrate that the TMRW can effectively reduce the inter-story displacement of the host structure, and the lateral deformation mode of the host structure tends to be more uniform. However, compared with the traditional rocking wall-frame system, the proposed TMRW has less ability on coordinating deformation.

High Interfacial-Energy and Lithiophilic Janus Interphase Enables Stable Lithium Metal Anodes.

The stability of solid electrolyte interphase (SEI) layers is critical for developing lithium (Li) metal batteries. However, the fabrication of stable SEI layers is plagued by un-controlled structures, properties, and functions. Here a controllable design of an ordered LiF-rich and lithiophilic hybrid Janus interphase (LiF-HJI) is reported using organic fluorination reagent as a functional SEI precursor. The LiF-HJI with a lower crystalline LiF layer and an upper Li organosulfide layer provides high interfacial energy with the Li metal and strong Li-ion affinity, allows homogenous Li-ion distribution, fast and uniform Li-ion transport, and excellent mechanical and passivation properties, enabling stable Li metal anodes under harsh conditions, such as high deposition capacities (6mAhcm-2 ), current densities (10mAcm-2 ), and rates (5 C). Stable LiF-HJI@Li greatly improves cycling stability and capacity retention (80.1% after 300 cycles) of Li||LiNi0.8 Co0.1 Mn0.1 O2 cells at a commercial-level areal capacity (≈4.2mAhcm-2 ). Even under a lean-electrolyte condition of 3gAh-1 , 80% capacity retention can be maintained after 100 cycles, demonstrating excellent cycling performance under such harsh conditions.

PrOx nanoparticles: Active and stable catalysts for soot combustion

PrOx nanoparticles (10 nm; 81 m2/g) were synthesized and analysed as soot combustion catalyst in comparation with other reference materials including CeO2 nanoparticles and PrOx and CeO2 catalysts with three dimensionally ordered (3DOM) and without controlled structure. PrOx nanoparticles reached the highest activity; T50 decreases from 603 °C (uncatalysed combustion) to 494 °C. This high activity can be attributed to the high surface area/low crystal size, which enhances the soot catalyst contact, and to the improved reducibility. PrOx nanoparticles kept high activity (T50 = 520 °C) after aging at 800 °C, being significantly more active than aged PrOx catalysts with 3DOM and uncontrolled structure and also significantly more active than all aged CeO2 catalysis which suffer almost total deactivation upon aging. In all cases, PrOx catalysts are more active than CeO2 counterpart materials with the same structure and thermal history, and this applies to nanoparticles, 3DOM and uncontrolled structures.