Adjacent Units Research Articles

Wideband Three-Dimensional Absorber Based on Notch-Slot Resonator with Lossy Coupled Microstrip Line

A wideband three-dimensional (3D) absorber based on a notch-slot resonator is proposed in this paper. A lossy coupled microstrip line was applied to eliminate the reflection band of the original lossy notch-slot resonator, resulting in a wide absorption band. A single-polarized design was first proposed, and the operating principle was demonstrated. Then, a dual-polarized design was presented, fabricated and measured. To eliminate the undesirable resonances caused by the securing slits cut between the two adjacent unit cells, some shorting pins were introduced. The measured results show that the dual-polarized absorber exhibits an absorption band from 2.74 GHz to 11.08 GHz (120.69% fractional bandwidth), and it is also stable under the incident angles up to 40° for both TE and TM polarizations.

G-quadruplex DNA: A Longer Story.

G-quadruplexes (G4s) are distinctive four-stranded DNA or RNA structures found within cells that are thought to play functional roles in gene regulation and transcription, translation, recombination, and DNA damage/repair. While G4 structures can be uni-, bi-, or tetramolecular with respect to strands, folded unimolecular conformations are most significant in vivo. Unimolecular G4 can potentially form in sequences with runs of guanines interspersed with what will become loops in the folded structure: 5'GxLyGxLyGxLyGx, where x is typically 2-4 and y is highly variable. Such sequences are highly conserved and specifically located in genomes. In the folded structure, guanines from each run combine to form planar tetrads with four hydrogen-bonded guanine bases; these tetrads stack on one another to produce four strand segments aligned in specific parallel or antiparallel orientations, connected by the loop sequences. Three types of loops (lateral, diagonal, or "propeller") have been identified. The stacked tetrads form a central cavity that features strong coordination sites for monovalent cations that stabilize the G4 structure, with potassium or sodium preferred. A single monomeric G4 typically forms from a sequence containing roughly 20-30 nucleotides. Such short sequences have been the primary focus of X-ray crystallographic or NMR studies that have produced high-resolution structures of a variety of monomeric G4 conformations. These structures are often used as the basis for drug design efforts to modulate G4 function.We believe that the focus on monomeric G4 structures formed by such short sequences is perhaps myopic. Such short sequences for structural studies are often arbitrarily selected and removed from their native genomic sequence context, and then are often changed from their native sequences by base substitutions or deletions intended to optimize the formation of a homogeneous G4 conformation. We believe instead that G-quadruplexes prefer company and that in a longer natural sequence context multiple adjacent G4 units can form to combine into more complex multimeric G4 structures with richer topographies than simple monomeric forms. Bioinformatic searches of the human genome show that longer sequences with the potential for forming multiple G4 units are common. Telomeric DNA, for example, has a single-stranded overhang of hundreds of nucleotides with the requisite repetitive sequence with the potential for formation of multiple G4s. Numerous extended promoter sequences have similar potentials for multimeric G4 formation. X-ray crystallography and NMR methods are challenged by these longer sequences (>30 nt), so other tools are needed to explore the possible multimeric G4 landscape. We have implemented an integrated structural biology approach to address this challenge. This approach integrates experimental biophysical results with atomic-level molecular modeling and molecular dynamics simulations that provide quantitatively testable model structures. In every long sequence we have studied so far, we found that multimeric G4 structures readily form, with a surprising diversity of structures dependent on the exact native sequence used. In some cases, stable hairpin duplexes form along with G4 units to provide an even richer landscape. This Account provides an overview of our approach and recent progress and provides a new perspective on the G-quadruplex folding landscape.

Generation of multiple photonic hooks in reflection mode

Generation of multiple photonic hooks (PHs) at THz region in reflection mode by a multi-dielectric structure that consists of periodical or aperiodical scatterer units on top surface of a reflection screen has been systematically studied. The study focuses on effects of geometric and optical parameters of the multi-dielectric structure on characteristics of the PHs generated, especially the bending angle. These geometric and optical parameters include spacing between adjacent scatterer units, length of reflection screen, as well as the size, refractive index and number of scatterer units. The results show that these geometric and optical parameters are key factors in tailoring the performance of the multiple PHs generated. The spacing determines bending direction of PHs and there exists a critical spacing value. Smaller than this critical value, the PHs generated bend outwards. Larger than this critical value, the PHs bend inwards. In addition, the spacing can be also used to effectively adjust the intensity and bending angle of the PHs. Screen length affects mainly PH's bending. The size and refractive index differences between scatterer units introduce additional optical inhomogeneity that leads to the generation of asymmetrical multiple PHs. Finally, the possibility of generation of an arrayed PHs in the reflection mode is demonstrated.

Observed and simulated urban-scale seismic damage of masonry buildings in aggregate on soft soil: The case of Visso hit by the 2016/2017 Central Italy earthquake

The paper focuses on the seismic response of masonry buildings in the historical centre of Visso, severely hit by the 2016–2017 Central Italy earthquake. This represents an emblematic case of site effects and, also, of soil-foundation-structure (SFS) interaction. Maps of the observed damage at urban scale are compared with those estimated from fragility curves derived for the building stock that characterizes the Visso municipality. Similarly to what is quite recurring in typical small historical centres in Italy and Europe, the key feature of Visso is to be mostly composed by unreinforced masonry (URM) buildings (85%), the majority of which is in aggregate (93%). Fragility curves were developed through a numerical procedure based on nonlinear dynamic analyses on 3D equivalent frame models, both fixed and compliant base, accounting for site effects and SFS interaction. The procedure aims at balancing the computational effort with the potential of defining fragility curves customized for the building under investigation and, thus, hopefully capable to improve the reliability of risk assessment. The fragility curves for URM buildings in aggregate explicitly account for the recurring failure mechanisms that post-earthquake evidence has testified, i.e. in-plane (IP) and out-of-plane (OOP) responses, as well as the interaction effects among adjacent units and pounding effects. The numerical procedure has been applied and validated in previous works of Authors on various archetypes representative either of an isolated school and one aggregate. In this work, additional archetypes have been analyzed and, then, the whole set of achieved fragility curves has been generalized to be applicable for a risk assessment at urban scale and develop damage scenarios of the Visso's urban settlement. To this aim, simplified modification factors have been proposed to be applied to fragility curves of rock soil condition to account for the possible effect of soft soil as well as the activation of OOP mechanisms. Results have shown that the match between the observed and simulated response improves when the interaction between the structure and the soil is considered.

X-ray structure and magnetic properties of a mononuclear complex and a 1D coordination polymer assembled by cobalt(II) ions and a flexible oxamate ligand

This work describes the synthesis, crystal structures and direct current (dc) magnetic properties of two air-stable oxamato-containing cobalt(II) complexes, [Co(H2edpba)(dmso)2]·dmso·H2O (1) and [Co(H2edpba)(H2O)2] n ·n(dmso) (2) [H4edpba = N,N′-2,2′-ethylenediphenylenebis(oxamic acid); dmso = dimethylsulfoxide]. 1 is a mononuclear compound, whereas 2 is a neutral chain. Cobalt(II) ions in both compounds are six-coordinate by six oxygen atoms, four of them from two monodeprotonated oxamate groups and the other two from dmso (1)/water (2) molecules in cis (1) and trans (2) positions. Hydrogen bonds between monodeprotonated oxamate fragments of adjacent mononuclear units in 1 lead to a supramolecular chain growing along the crystallographic c axis. Hydrogen bonds involving coordinated water molecules and monodeprotonated oxamate fragments from adjacent chains in 2 result in a supramolecular 2D network. Cryomagnetic measurements reveal the occurrence of magnetically isolated high-spin cobalt(II) ions in agreement with the large values of the shortest intramolecular (1)/intrachain (2) metal···metal separation [ca. 10.3 (1) and 10.4 Å (2)]. Simultaneous simulation of the χ M T versus T and M against H data through the Griffith–Figgis Hamiltonian led to the best-fit parameters: λ = −141.1 (1)/–174.8 cm−1 (2), σ = −1.45 (1)/–1.25 (2) and ν = −121.42 (1)/−247.29 cm−1 (2).

Landscape patterns and their spatial associations with ecosystem service balance: Insights from a rapidly urbanizing coastal region of southeastern China

Abstract: Assessing ecosystem service (ES) balance and exploring critical drivers are crucial for landscape management. However, a lack of understanding of the determinants of the ecosystem service supply–demand budget, their spillover effects, and spatial variabilities offsets the efficacy of landscape planning and ecosystem conservation. This novel study attempted to close this gap by quantifying ecosystem service budget using an expert knowledge-based supply–demand matrix and explored its dependencies through spatial econometrics and geographically weighted regression approaches instead of using ordinary model simulation and conventional statistical analysis. The overall patterns of ecosystem service balance in the southeastern coast were found to have remained stable in 1980, 2000, and 2017, although remarkable ecosystem service deficits were identified in hotspots of rapid urbanization. The ecosystem service balance was negatively associated with the proportions of built-up land and cropland (p < 0.0001) and exhibited positive associations with the proportions of woodland and grassland (p < 0.0001). Landscape structure and population density were identified as the primary determinants of ecosystem service balance and exhibited spatial variability and spillover effects (i.e., determining ecosystem service balance in both individual and adjacent units). These findings demonstrate the significance of spatial disparities and external effects of determinants of the supply–demand budget in integrative landscape governance. Consequently, localized and targeted strategies for landscape planning are increasingly needed to optimize landscape configuration and alleviate ecosystem service imbalance according to individual socioeconomic conditions and landscape structures. In addition, the spillover effects demonstrate that the maintenance of regional ecosystem service balance and ecosystem sustainability depends not only on individual areas but also on cross-regional collaborations with neighboring regions. These findings have critical implications on strategy formulation for coastal landscape management and ecosystem sustainability.

Metasurface Terahertz Perfect Absorber with Strong Multi-Frequency Selectivity.

In this paper, we design a metasurface terahertz perfect absorber with multi-frequency selectivity and good incident angle compatibility using a double-squared open ring structure. Simulations reveal five selective absorption peaks located at 0–1.2 THz with absorption 94.50% at 0.366 THz, 99.99% at 0.507 THz, 95.65% at 0.836 THz, 98.80% at 0.996 THz, and 86.70% at 1.101 THz, caused by two resonant absorptions within the fundamental unit (fundamental mode of resonance absorption, FRA) and its adjacent unit (supermodel of resonance absorption, SRA) in the structure, respectively, when the electric field of the electromagnetic wave is incident perpendicular to the opening. The strong frequency selectivity at 0.836 THz with a Q-factor of 167.20 and 0.996 THz with a Q-factor of 166.00 is due to the common effect of the FRA and SRA. Then, the effect of polarized electromagnetic wave modes (TE and TM modes) at different angles of incidence (θ) and the size of the open rings on the device performance is analyzed. We find that for the TM mode, the absorption of the resonance peak changes only slightly at θ = 0–80°, which explains this phenomenon. The frequency shift of the absorption peaks caused by the size change of the open rings is described reasonably by an equivalent RLC resonant circuit. Next, by adjusting two-dimensional materials and photosensitive semiconductor materials embedded in the unit structure, the designed metasurface absorber has excellent tunable modulation. The absorption modulation depth (MD) reaches ≈100% using the conductivity of photosensitive semiconductor silicon (σSI-ps), indicating excellent control of the absorption spectrum. Our results can greatly promote the absorption of terahertz waves, absorption spectrum tunability, and frequency selectivity of devices, which are useful in the applications such as resonators, bio-detection, beam-controlled antennas, hyperspectral thermal imaging systems, and sensors.

Load-Independent Power-Repeater Capacitive Power Transfer System With Multiple Constant Voltage Outputs

In this article, a novel load-independent capacitive power transfer (CPT) system with multiple constant voltage (CV) outputs is proposed. The capacitive repeater unit is designed to enhance the power transfer capability, which contains four plates where two plates are used to receive power from its previous unit and the other two plates transfer power to the next unit. Electric coupling between the receiving and transmitting plates in the repeater unit can be eliminated by placing them perpendicularly and employing the split-inductor matching network. The load is connected with each capacitive repeater unit so that multiple loads can be powered simultaneously. Aluminum oxide ceramic is placed between the two adjacent units to enhance their electric coupling. The <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$L$ </tex-math></inline-formula> -LCL network is adopted to compensate each capacitive repeater unit. Thus, CV outputs can be achieved for all loads, which ensure the independent operation of each load. The output voltages and efficiency are analyzed when considering the parasitic resistances. Finally, a three-load experimental setup is built to verify the effectiveness of the proposed system with an efficiency of 93.21%.

Geochemical characteristics and sources of crude oil in the Wenchang B depression and the western Qionghai uplift of the Zhu-3 sub-basin, Pearl River Mouth Basin, south China sea

The Wenchang B depression and the western Qionghai uplift, in the south of the Zhu-3 sub-basin, are two adjacent sub-tectonic units with multiple oil-bearing structures. The former contains well-developed source rocks, whereas the latter does not. Previous studies have preliminarily explored the source of crude oil in the Wenchang B depression and the western Qionghai uplift. However, systematic investigations have been absent in characterizing the two main source rocks (i.e. Enping and Wenchang formations) and elucidating the migration of crude oil, which has significantly hindered oil and gas exploration. In this study, multiple methods are integrated to re-evaluate the source rocks of the depression, clarify crude oil sources, and analyse vertical oil migration and accumulation characteristics. The methods used included Rock-Eval pyrolysis, carbon isotope analysis, gas chromatography-mass spectrometry (GC-MS), hierarchical cluster analysis (HCA), and basin modelling. The source rocks of the Wenchang formation are demonstrated to have good to excellent hydrocarbon generation potential, whereas those of the Enping Formation have fair to good potential. Both source rocks are further divided into two members (i.e. EP1 and EP2 members for the Enping Formation and WC1 and WC2 members for the Wenchang Formation) based on differences in the biomarkers including ratios of bicadinanes (W + T)/C30hopane (C30H), ∑C30 4-methylsterane (MSt)/∑C29 regular sterane (RSt), pristane (Pr)/phytane (Ph), and ∑C27RSt/∑C29RSt, the source rocks are divided into four sets, named E1, E2 of the Enping Formation, and W1, W2 of the Wenchang Formation, respectively. Both W1 and W2 source rocks were weakly oxidizing-weakly reducing sedimentary environments. The input of organic matter to W2 source rock was dominated by aquatic organisms such as algae. The parent source of W1 source rock has both the contribution of aquatic organisms and the input of terrestrial organic matter. The E1 source rock was formed in an oxidative depositional environment, and its parent source is similar to that of W1. E2 source rock was a weakly oxidizing-weakly reducing depositional environment, and the parent source was resins from higher plants. There are great differences in crude oil characteristics. Through HCA and oil-source correlation analysis, the crude oil in the Wenchang B depression was found to be mainly from the W2 source rock. However, in the northern part of the depression, some crude oil was suggested to originate from both W1 and E1 source rock, presenting mixed characteristics. The crude oil in the western Qionghai uplift was mainly derived from W1 and E1 source rocks, with a small part was from the W2 source rock.

G-quadruplexes formation within the promoter of TEAD4 oncogene and their interaction with Vimentin.

G-quadruplexes (G4s) are nucleic acid secondary structures detected within human chromosomes, that cluster at gene promoters and enhancers. This suggests that G4s may play specific roles in the regulation of gene expression. Within a distinct subgroup of G-rich domains, the formation of two or more adjacent G4 units (G4-repeats) is feasible. Recently it was shown that Vimentin, a protein highly expressed within mesenchymal cells, selectively recognizes these arrangements. Putative G4-repeats have been searched within the human gene proximal promoters by the bioinformatics tool QPARSE and they resulted to be enriched at genes related to epithelial-to-mesenchymal transition (EMT). This suggested that Vimentin binding at these sites might be relevant for the maintenance of the mesenchymal phenotype. Among all the identified sequences, in the present study we selected the one located within the promoter of the TEAD4 oncogene. TEAD4 codifies for a transcriptional enhancer factor, TEAD4, that actively promotes EMT, supporting, cell proliferation and migration. Moreover, in colorectal cancer cells TEAD4 directly enhances the expression of Vimentin. Thus, the possible interaction of Vimentin with TEAD4 promoter could highlight a positive feedback loop between these two factors, associated to important tumor metastasis related events. Here, we exploited spectroscopic and electrophoretic measurements under different conditions to address the folding behavior of the selected sequence. This allowed us to validate the folding of TEAD4 promoter into a G4-repeat able to interact with Vimentin.

Bending Ferrocenes with Low Coordinated Bridging Units: The Investigation of Carbenes and Their Analogues with a Ferrocenophane Backbone

[3]ferrocenophanes with X–E–X ansa moieties containing a low coordinated center E stabilized by adjacent donor units X were studied by density functional theory methods. The cyclopentadienyl (Cp) rings favor an eclipsed position in most cases and exhibit a shortened C(1)–C(1′) distance compared to parent ferrocene. In case of bridges with the second row elements, the tilt of the Cp rings is more significant than that in case of third row elements; however, the estimated strain does not exceed 6 kcal/mol. The ansa unit has similar structural characteristics to the X–E–X-fragment in a six-membered saturated ring, with bond angles larger than that in the well-known heterocycles featuring five-membered cyclic systems. For compounds with X = PMe and E = C, Si, Ge, the non-planar coordination of the phosphorus atoms yields two symmetric minimum structures that are distinguished by trans and cis alignment of the PMe groups and are connected by a low-energy asymmetric transition structure with one planarized and one highly pyramidal phosphorus. In case of the analogous species with E = P+, this asymmetric structure was located as the sole minimum. A detailed analysis of the Kohn–Sham orbitals and the analysis of the electron density show that the electronic system of the ferrocene fragment is not mixing considerably with that of the low coordinated center of the ansa unit.

A Deep Learning-Based Assisted Teaching System for Oral English

The progress of global economic integration has forced English learners to have an urgent need to improve their oral English. College students’ oral English ability is currently the worst of the four abilities of listening, speaking, reading, and writing. The main reasons are internal and external. The internal reason is that the pronunciation characteristics of Chinese students are different from those of English. The external cause is that the practice environment and tools of oral English are not ideal, which affects the improvement of learners’ oral English. This study proposes using a deep learning algorithm (DLA) English in the evaluation of oral English quality to improve learners’ oral English level. The quality of oral English can be comprehensively evaluated in terms of pitch, speed of sound, and rhythm. The standard of pronunciation is the foundation of oral English and is the most critical factor. In many DLAs, the input unit of DNN at a certain moment and its upper and lower moment input units have no relationship and are independent of each other, and the timing dependencies of adjacent units are not fully considered. The results are generally not very good on speech recognition tasks. This study proposes a time-delay neural network (TDNN) and a long short-term memory (LSTM) network to calculate the posterior probability of the model state to model context-dependent features in order to solve this problem. The fusion model TDNN-LSTM is applied in the English spoken pronunciation recognition task. To compare the accuracy of oral English pronunciation, several classic DLAs are introduced. The experimental results show that the method described in this study has a number of advantages. Although the performance improvement of this method in terms of recognition accuracy is not large, a certain degree of improvement is also very important for the oral English teaching assistant system.

Dual-Polarized Wide-Angle Scanning Phased Array Antenna for 5G Communication Systems

A dual-polarized phased array antenna is presented with wide-angle scanning capability in this article. To improve the mutual coupling in the array, a current cancellation method (CCM) is proposed by changing the current distribution on the excited unit to induce a pair of the canceled currents on the adjacent unit. Meanwhile, this current distribution broadens the beamwidth of the unit in the array. Besides, the proposed method can also optimize the array unit size and achieve a small inter-unit distance for wide-angle scanning capability. A low-profile dual-polarization antenna operating in the bandwidth from 4.4 to 5.0 GHz is designed as a linear array and a planar array to verify the proposed method. Regardless of the linear array or planar array, the mutual coupling in the array is below −19 dB, which is better than that in conventional arrays. Meanwhile, the antenna unit in the array can radiate a wide-beam pattern. Two arrays can scan over ±60° for both polarizations. Within the scanning range, the realized gain reduction is less than 3 dB and the sidelobe level is lower than −7.5 dB. To verify the performance, two array antenna prototypes are fabricated and tested. The experimental results agree well with the simulation.

Singlet Fission in Colloidal Nanoparticles of Amphipathic Diketopyrrolopyrrole Derivatives: Probing the Role of the Charge Transfer State.

To evaluate the role of the charge transfer (CT) state in the singlet fission (SF) process, we prepared three 3,6-bis(thiophen-2-yl)diketopyrrolopyrrole (TDPP) derivatives with zero (Ph2TDPP), one (Ph2TDPP-COOH), and two (Ph2TDPP-(COOH)2) carboxylic groups, respectively. Their colloidal nanoparticles were also prepared by a simple precipitation method. The SF dynamics and mechanism in these colloid nanoparticles were investigated by using steady-state/transient absorption and fluorescence spectroscopy. Steady-state absorption spectra reveal that the strength of the CT resonance interactions between the adjacent DPP units is increased gradually from Ph2TDPP to Ph2TDPP-COOH and then to Ph2TDPP-(COOH)2. Fluorescence and transient absorption spectra demonstrate that SF is proceeded via a CT-assisted superexchange mechanism in these three nanoparticles. Furthermore, SF rate and yield are enhanced gradually with the increase of the number of the carboxylic group, which may be attributed to the enhancement of the CT coupling strength. The result of this work not only provides a better understanding of the SF mechanism especially for the role of the CT state but also gives some new insights for the design of efficient SF materials based on DPP derivatives.

Evaluation of inter-unit dependency effect on site core damage frequency: Internal and seismic event

Since the Fukushima Daiichi accident occurred, the probabilistic safety assessment on multi-unit sites has been studied so far. Several studies addressed to reflect the factor that can affect an adjacent unit, called inter-unit dependency, in the assessment and various research has been made to investigate or evaluate the dependencies. In this study, researches on inter-unit dependency are implemented to internal and seismic level 1 site risk assessment in the purpose of the evaluation on their effect on the probabilistic safety assessment. The assessments are conducted on the hypothetical site in Korea with 4 units of APR-1400. To reflect the redundancy changes in safety system by operation state, the approach is suggested based on the study of dependent accidents. The result showed that the earthquake and loss of offsite power would induce most of the multi-unit core damage. The inter-unit dependency models related to the electric system were sensitive to the result and the synergies between the models were found. The seismic correlation made site core damage frequency decrease. The expectation is proposed as alternative metric for the risk of site and the necessity of site risk assessment is pointed out in this study.

Natural Fibers for Out-of-Plane Strengthening Interventions of Unreinforced Masonry Buildings in Aggregate Configuration

Most of the Italian historical centers are composed of unreinforced masonry (URM) buildings arranged in aggregate configurations. Past and recent seismic events have underlined the high vulnerability of these buildings especially towards out-of-plane mechanisms. In order to reduce their vulnerability, the use of strengthening interventions based on fiber reinforced composite materials has become widespread in the last years. More recently, strengthening systems using natural fibers have been the object of experimental tests since they represent an innovative environmentally sustainable solution. The aim of this paper is to numerically analyze the feasibility of strengthening systems made of natural fibers embedded into cementitious matrices to prevent the out-of-plane mechanisms of perimeter façades belonging to masonry buildings in aggregate configurations. For this purpose, numerical analyses based on a macro-modeling approach for out-of-plane mechanisms are performed by considering the influence of adjacent structural units and the presence of strengthening systems made of natural fibers. Both aspects have been analyzed in detail and taken into account by introducing in the equation governing the problem both the friction acting between adjacent walls of building units, when in aggregate, and the contribution of the strengthening system. A building case study forming part of an aggregate of an Italian historical center has been considered for the development of the numerical analyses.

Optimal inspection and advance payment policy for deteriorating items using differential evolution metaheuristic

The deterioration of items such as fruits, eatables, etc. may influence the adjacent units and intercept the supply. In many circumstances, the existence of a spoiled unit accelerates the deterioration process. The degradation effect can be mitigated by removing the affected unit. This research investigation explores an impact of frequent inspection on the spoiling items in an inventory system and can be used as a step forward to reduce food wastage due to mutual spoilage. In many business transactions, the retailer has the ability to make judgments regarding advance payment. The present work attempts to develop a lot-sizing model for price-sensitive demand under the premise of partial advance payment and deterioration rate as a function of inspection frequency. We suggest an optimal prepayment strategy from the retailer’s point of view. A mixed-integer programming problem is formulated and solved by using a genetic algorithm (GA) and differential evolution (DE) algorithm based on different mutation strategies. It is established that DE performs better in comparison to GA. Based on some statistical measures, we have selected the mutation scheme which is most suitable for the proposed problem. The inventory-related measures are established for the proposed problem and used to present a numerical simulation and optimal inventory policy. The numerical findings show that the ideal inspection and prepayment strategy boost profitability by reducing spoilage. The managerial insights are discussed that may be beneficial in decision-making for inspection and advance payment.

Apposition compound-eye image scanner by glass plate optics.

We propose a design approach for a thin image scanner using the concept of an apposition compound eye comprising many imaging units that take only one pixel image. Although light shielding between adjacent imaging units is always one of the main issues for an artificial compound eye, a simple plane structure using three aperture array layers on two glued glass plates prevents such stray light. Our prototyped scanner, with only 6.8-mm thickness as a packaged module, has 632 microlenses with 200-dpi resolution, resulting in a field of view of 80 mm. The evaluated images show no ghost images.

Coexistence of circular dichroism and asymmetric transmission in Babinet-complementary metamaterials.

Chiral metamaterials with circular dichroism (CD) or asymmetric transmission (AT) draw enormous attention for their attractive applications in polarization transformers, circular polarizers, and biosensing. In this study, a feasible trilayer chiral metamaterials (TCM) is designed and investigated in theory and simulation. The proposed TCM is composed of a nanoslit layer and a Babinet-complementary nanorod layer separated by a nanoslit spacer. Owing to symmetry breaking by the tilted nanoslit in metal film, the TCM shows simultaneous CD and AT effects in the near-infrared region. The simulated electric charge distributions prove that the chirality arises from the excitation of asymmetric electric dipole resonant modes due to the coupling of adjacent unit cells. Moreover, CD and AT can be tuned by the tilted angle of the nanoslit and the thickness of the spacer, the fitting functions of which are consistent with the theoretical formulas based on transmittance matrix analysis. The proposed nanostructure offers a potential strategy for manipulating metamaterials with simultaneous CD and AT effects, allowing a multitude of exciting applications such as ultra-sensitive polarization transformer and biosensor.

Model predictive control for steady-state performance in integrated continuous bioprocesses

Perfusion bioreactors are commonly used for the continuous production of monoclonal antibodies (mAb). One potential benefit of continuous bioprocessing is the ability to operate under steady-state conditions for an extended process time. However, the process performance is often limited by the feedback control of feed, harvest, and bleed flow rates. If the future behavior of a bioprocess can be adequately described, predictive control can reduce set point deviations and thereby maximize process stability. In this study, we investigated the predictive control of biomass in a perfusion bioreactor integrated to a non-chromatographic capture step, in a series of Monte-Carlo simulations. A simple algorithm was developed to estimate the current and predict the future viable cell concentrations (VCC) of the bioprocess. This feature enabled the single prediction controller (SPC) to compensate for process variations that would normally be transported to adjacent units in integrated continuous bioprocesses (ICB). Use of this SPC strategy significantly reduced biomass, product concentration, and harvest flow variability and stabilized the operation over long periods of time compared to simulations using feedback control strategies. Additionally, we demonstrated the possibility of maximizing product yields simply by adjusting perfusion control strategies. This method could be used to prevent savings in total product losses of 4.5–10% over 30 days of protein production.