Length Lc Research Articles

Investigating the Effect of Incorporating Dimethylaminopropyl Side Chains into a Naphthalenediimide‐Based Conjugated Polymer

AbstractTwo approaches—fractional side‐chain truncation and complementary interactions—are employed in this study. In fractional side‐chain truncation, NDIDmap with the naphthalene diimide (NDI) group and the 3‐(dimethylamino)propyl (Dmap) chain is incorporated into P(NDI2OD‐T2), yielding various copolymers. Increasing the amount of NDIDmap in the polymer enhances π‐isotropy, which can improve charge transport. In complementary interactions, the NDIDmap group complexes with tris(pentafluorophenyl)borane (BCF) via complementary N–B interactions. Adding BCF to a naphthalenediimide‐based conjugated polymer with NDIDmap enhances the coherence length (Lc) of π‐stacking. However, the elongated Lc does not result in superior electron mobility, challenging the conventional perspective that long‐range π‐order is crucial for charge transport. For comparison, triphenylamine (TPA), which is electronically distinct from BCF, is used. TPA affects the thin‐film microstructure and charge‐transport parameters differently from BCF. Although the improvement in electron mobility is not very significant, this study demonstrates the effects of fractional side‐chain truncation and complementary interactions on the thin‐film microstructure and charge transport of naphthalenediimide‐based conjugated polymers, paving the way for further side‐chain engineering.

Scaling of N-Type Field-Effect Transistors Based on Aligned Carbon Nanotube Arrays.

Wafer-scale aligned carbon nanotubes (A-CNTs) are promising candidate semiconductors for building high-performance complementary metal-oxide-semiconductor (CMOS) transistors for future integrated circuits (ICs). A-CNT-based p-type field-effect transistors (P-FETs) have demonstrated excellent performance and scalability down to sub-10 nm nodes. However, the development of A-CNT n-type FETs (N-FETs) lags far behind, in regard to their electronic performance and device scaling. In this work, we fabricated top-gated N-FETs based on A-CNTs with a scandium (Sc)-contacted source and drain. High-performance A-CNT N-FETs were demonstrated with record on-state current (Ion) exceeding 1 mA/μm and peak transconductance (gm) of 0.4 mS/μm. Interestingly, the A-CNT N-FETs exhibited abnormal scaling behavior owing to the lateral oxidation of low-work function source/drain contacts, leading to formidable challenges to scale both the gate length (Lg) and the contact length (Lc) at the same time. Understanding of the abnormal scaling behavior contributes to seeking solutions for high-performance A-CNT N-FETs, and it paves the way for future CNT CMOS digital IC technology.

Road Geometric Redesign used AutoCAD 2D A Case Jalan Majalengka-Rajagaluh

Majalengka-Rajagaluh road is a road located in several sub-districts which is a link to the city and also one of the connecting roads to Cirebon City. This design planning starts in Cigasong sub-district and continues to Rajagaluh sub-district with the length of Majalengka-Rajagaluh road is 5.3 kilometers. The geometric design results are visualized in the form of drawings using AutoCAD 2D. The design speed (Vd) was set at 60 km/h with a horizontal curve radius of 358 m, a maximum slope of 4%, and an elevation (e max) of 8%. Based on these design criteria, a spiral curve with a circular curve length (Lc) of 74.996 m was obtained. Furthermore, the results of the vertical alignment calculation of the length (L) of one type of convex curve in PPV were also calculated.

Stock exploitation status of silver croaker (Pennahia argentata) from the East China Sea

Silver croaker (Pennahia argentata) is an important economic species in the East China Sea (ECS); however, its population has been declining, and studies on its status are scarce. This study collected biological data, including length, weight, and gonadal maturity of silver croaker from the southern coastal waters of Zhejiang Province between 2015 and 2021, to evaluate its life history and assess stock status. Methods from the TropFishR package were employed to estimate population growth and natural mortality parameters. Two widely used length-based data-limited models, length-based bayesian biomass estimation method (LBB) and length-based spawning potential ratio method (LBSPR), were applied to assess the stock status of silver croaker in the ECS. The results indicated that with a maximum age (Amax) of 4 years, the asymptotic length (Linf) was 23.80 cm, growth rate (K) was 0.74/year, and natural mortality coefficient (M) ranged from 1.068 to 1.376. Under the assumption of Amax = 5 years, Linf was 26.77 cm, K was 0.63/year, and M ranged from 0.818 to 1.193. The LBB and LBSPR models showed that, except for scenarios with L∞ = 23.8 cm, M/K = 1.46, and L∞ = 26.77 cm, M/K = 1.30, 1.38, or 1.48, the selectivity at length parameters L50SandL95S for silver croaker exhibited an increasing trend over the years. In the LBB model, L50S for different years consistently fell below the optimum length (Lc_opt), indicating that most individuals did not reach the size at first sexual maturity or optimal catch length. Moreover, under high fishing pressure, the Spawning Potential Ratio (SPR) and the unfished biomass ratio (B/B0) for silver croaker showed a decreasing trend, despite some stability or recovery in recent years. However, in all scenarios, SPR values were below 0.2, and B/B0 values were below 0.5, suggesting a significant risk of population collapse for silver croaker in the ECS due to intense fishing pressure. Therefore, it is recommended to reduce the current fishing pressure and increase the minimum catch size of this species for effective conservation and management in this region.

Tip‐Enhanced Raman Spectroscopy Coherence Length of 2D Materials: An Application to Graphene

Herein, a protocol is presented for determining the tip‐enhanced Raman spectroscopy (TERS) coherence length (Lc) of the two main Raman bands of graphene. This method involves performing approach curve experiments and plotting the normalized areas of the G and 2D bands as a function of tip–sample distance. The resultant data are fitted using a specific TERS formula to extract Lc. The results indicate different coherence lengths for the G and 2D bands in graphene as and nm. While this protocol is specifically done for graphene, the underlying theoretical framework, based on mode symmetry, can be extended to other 2D materials, such as transition metal dichalcogenides. This demonstrates the versatility and potential of TERS in exploring the coherence properties of various 2D materials.

Optimizing the geometry of tube-in-tube Thermosyphon heat transport device from instability Perspective: A computational study

Since the Fukushima disaster, there has been a significant surge in the adoption of infinite time passive decay heat removal systems. In this context, the thermosyphon heat transport device (THTD) has distinct advantages over natural circulation loops (NCLs). Previous studies proved that the THTD experiences flow instability characterized by recirculating loops under specific geometric and operational conditions. However, identifying the critical value for these parameters remains unresolved. Therefore, the present study deals with the geometric optimization of THTD through computational (CFD) simulations.Initially, the CFD model is validated with earlier experimental data, which resulted in a minimal deviation of −2 % to 5 %. The parameters for geometric optimization of THTD are height of the system (H), the center-line elevation difference between the source and the sink (Δz), heater length (Lh), cooler length (Lc), hot leg length (Lhl), and area ratio (AR) between hot leg and cold leg, under the heater power range of 100 W to 1000 W. The impact of these geometric and operational variations on flow instability is evaluated by observing the presence of recirculation loops, which are identified by analyzing velocity vectors and contours. The key findings of the present study are: flow instability in the form of a single recirculating loop sweeping radially along the cross-section of the annulus, thereby leading to radial flow maldistribution; a center-line elevation greater than 0.8 m eliminates the flow instabilities; interchanging heating and cooling lengths for a given center-line elevation doesn’t alter the criteria for instability; Heater power of 100 W leads to instability irrespective of center-line elevation; the optimal cooling length can be considered as 5 % to 25 % of the total height of the THTD, whereas the optimal hot leg length can be considered as 25 % to 45 % of the total height; and the HTF flow rate increases with a rise in the area ratio until AR=2, after which a flow anomaly occurs, rendering the system unstable. In addition to these aspects, this study also suggests optimal geometric features of THTD to reduce instability and attain perfect unidirectional flow. By integrating findings from current research and past studies, the design methodology for conventional THTD is comprehensively presented to the scientific community.

Transmission Characteristics Analysis of a Twin-Waveguide Cavity

The transmission spectrum of a twin-waveguide cavity is systematically analyzed based on coupled mode theory, using the transfer matrix method (TMM). The results show that the traveling-wave transmission spectra of the twin-waveguide cavity is entirely determined by the coherent coupling effect involving the parameters of the effective refractive indices of the upper and lower waveguides, the coupling length Lc, and the ratio of the cavity length L to the coupling length (L/Lc). Filters with single, double, or triple-notch filtering could be obtained by choosing an appropriate L/Lc value. When the facet reflection is taken into consideration, the traveling-wave transmission spectrum is modified by the Fabry––Perot (FP) resonance, making it a standing-wave transmission spectrum. As a result, resonance splitting has been observed in the transmission spectrum of twin-waveguide resonators with high facet reflectivity. Further analysis shows that such an abnormal resonance phenomenon can be attributed to the destructive interference between the two FP resonance modes of the upper and lower waveguide through coherent coupling. In addition, narrow bandwidth amplification has also been observed through asymmetric facet reflections. Undoubtedly, all these unique spectral characteristics should be beneficial to the twin-waveguide cavity, achieving many more functions and being widely used in photonic integration circuits (PICs).

Scaling behavior of the localization length for TE waves at critical incidence on short-range correlated stratified random media

We theoretically investigate the scaling behavior of the localization length for s-polarized electromagnetic waves incident at a critical angle on stratified random media with short-range correlated disorder. By employing the invariant embedding method, extended to waves in correlated random media, and utilizing the Shapiro–Loginov formula of differentiation, we accurately compute the localization length ξ of s waves incident obliquely on stratified random media that exhibit short-range correlated dichotomous randomness in the dielectric permittivity. The random component of the permittivity is characterized by the disorder strength parameter σ2 and the disorder correlation length lc. Away from the critical angle, ξ depends on these parameters independently. However, precisely at the critical angle, we discover that for waves with wavenumber k, kξ depends on the single parameter klcσ2, satisfying a universal equation kξ≈1.3717klcσ2−1/3 across the entire range of parameter values. Additionally, we find that ξ scales as λ4/3 for the entire range of the wavelength λ, regardless of the values of σ2 and lc. We demonstrate that under sufficiently strong disorder, the scaling behavior of the localization length for all other incident angles converges to that for the critical incidence.

Multi-objective optimization and performance improvement of CD nozzle design parameters for cold spray coating process using RSM, ANN and GA

This study presents the multi-objective optimization of the convergent-divergent (CD) nozzle for the cold spray (CS) process and investigates the impact of five key nozzle design parameters. A 2D axisymmetric baseline nozzle was optimized through face central composite design (FCCD), computational fluid dynamics (CFD) simulations, response surface methodology (RSM), artificial neural networks (ANN), and genetic algorithms (GA). The nozzle performance in the CS process advances the manufacturing technologies by significantly optimizing the four response variables. Comparative analysis shows that RSM models (R² = 0.9893) were more accurate on average than ANN models (R² = 0.9848), although ANN provided a deeper understanding of complex interactions with an overall correlation coefficient of 0.99191. Sensitivity analysis suggested that increasing convergent length (Lc) increases particle velocity (PV) before it stabilizes while particle temperature (PT) decreases due to cooling effects. Divergent length (Ld) increases PV to an optimal range, but reduces PT, indicating energy loss. Smaller injector inner diameter (Did) enhances PV but reduces PT. Injector length (Li) increases PV to a certain limit, beyond which benefits stabilizes, and also increases surface pressure (SP). Expanding the exit diameter (De) increases PV, drops PT and heat flux (HF), and reduces SP, indicating decreased flow resistance. Optimization with RSM coupled with numerical simulation (RSM-DF) improved PV, PT, HF, and SP by 9.1 %, 4.4 %, 17.9 %, and 27.6 % respectively. Further optimization with a 5–6–4 ANN and GA (NSGA-II) improved PV by 5 %, PT by 5.4 %, HF by 15.7 %, and reduced SP by 20.9 %. Integrating CFD, RSM, ANN, and GA provides an effective approach for optimizing CD nozzle parameters.

Evidence of a Rod-like Structure for Hydroxypropyl Cellulose Samples in Aqueous Solution.

Because hydroxypropyl cellulose (HpC) is a popular polymeric material that forms a liquid crystalline phase in solutions with various kinds of solvents, including water, it is commonly thought that HpC has a typical rod-like structure in solution. In this study, the structures of commercial HpC samples in aqueous solution with average molar substitution numbers (MS) ranging from 3.6 to 3.9 and weight-average molar masses (Mw) ranging from 36 to 740 kg mol-1 were investigated in detail. We first used multiple techniques, including standard static and dynamic light scattering (SLS and DLS), neutron and X-ray scattering experiments, and viscometric measurements, to obtain clear evidence of rod-like structures quantitatively. The dependence of excess scattering intensities for HpC samples under dilute conditions on the magnitude of the scattering vector over a wide range from 8.9 × 10-3 to 3.0 × 10 nm-1 was reasonably described by the form factor of rod particles with length (L) and diameter (d). Although the determined L value was close to the contour length (lc) calculated from the Mw values in the lower Mw range, L became obviously less than lc with increasing Mw. The radius of gyration (Rg) determined via SLS measurements was proportional to L by a factor of approximately 3.5 ∼ √12 over the Mw range examined. These observations revealed that the conformation of HpC molecules changes from an elongated single chain to a certain folded structure, maintaining the shape of the rod-shaped particles. Moreover, the Mw dependencies of the intrinsic viscosities and translational diffusion coefficients of the HpC samples resulting from DLS measurements were reasonably described with a theoretical rod-like particle model, assuming that L and d are identical to those resulting from the scattering behaviors.

Localization patterns emerging in CPTu tests in a saturated natural clay soil

In this work, the mechanics of cone penetration during CPTu tests in Osaka clay, a natural structured silty clay, was investigated with the Particle Finite Element Method (PFEM). To describe the behavior of the soil, the FD_MILAN model, recently proposed by the Authors, was adopted. The model, based on the multiplicative decomposition of the deformation gradient, incorporates a scalar internal variable, the bond strength Pt, to quantify the effects of structure. The macroscopic description of mechanical destructuration effects is provided by the hardening law of Pt, according to which the bond strength decreases monotonically with accumulated plastic deformations. The brittle behavior resulting from the softening process associated to destructuration make the soil quite susceptible to the spontaneous development of strain localization in the form of shear bands. In order to deal with strain localization phenomena, the model is equipped with a non-local version of the hardening laws, incorporating a material constant – the characteristic length ℓc – which provides the material with an internal length scale. The objective of this work was to get some insight on the effects of the characteristic length and of the initial degree of structure on: the kinematics of the soil deformation around the advancing cone tip; the evolution of soil structure with accumulated plastic deformations; the excess pore pressure field generated in the soil as a result of the hydro-mechanical coupling between the solid skeleton and the pore water, and the net cone resistance measured at the base of the cone. The results of the PFEM simulations show that the deformations around the piezocone are strongly affected by the characteristic length. For heavily structured soils, when ℓc is relatively small with respect to cone radius, the accumulated plastic deviatoric deformation field is characterized by clearly visible shear bands while, as ℓc increases, the detection of localized deformation regions becomes more difficult, if not impossible. This depends on the fact that, for large values of ℓc, the shear band width may be of comparable size to the cone radius. In all cases, the soil around the advancing piezocone is subjected to a very strong destructuration process, which leads to the complete loss of bond strength in a large region around the cone tip and shaft. As a consequence, the use of conventional Nc values from the literature in the interpretation of the CPTu test performed in heavily structured soils could provide undrained strength values closer to the ultimate undrained shear strength. At the same time, the use of empirical correlation to estimate the yield stress in oedometric conditions would lead to a significant underestimation of the overconsolidation ratio.

Dynamic characteristics of edge plasma profiles during the opening of edge islands on the J-TEXT tokamak

On the J-TEXT tokamak, the dynamics of edge magnetic topology during the opening of the edge magnetic islands induced by the external Resonant Magnetic Perturbation (RMP) are investigated. The edge island chain is pushed outward by increasing plasma toroidal current to intersect the poloidally and toroidally localized divertor plate, forming an open magnetic island in the Scrape-Off Layer (SOL). The location of the strike points on the divertor plate predicted by the HINT code is in agreement with the experimental observations. The influence of the magnetic topology on edge plasma profiles has also been investigated using Langmuir probes. The properties of edge Te , ne , Pe and Er profiles are studied as function of three magnetic structures in qa -dependence experiments and two magnetic structures in RMP configuration-dependence experiments. Some common features are observed. Inside the edge closed and SOL remnant islands, flat Pe but non-flat Te and ne profiles are detected. When transitioning from the edge closed island to the partially open island with remnant island, the local flat Pe profile is shifted outward accompanied by a narrower flattened Pe region. The steep slopes of Te , ne and Pe are measured in the SOL regions characterized by a long connection length Lc , and the longer Lc , the steeper slopes. Er exhibits a negative well inside the remnant island with infinite Lc and in the SOL regions where Lc significantly exceeds than the electron mean free path λe , but develops a positive value in the SOL regions where Lc is relatively short.

Stock Assessment of the Commercial Small Pelagic Fishes in the Beibu Gulf, the South China Sea, 2006-2020.

Long-term variations in population structure, growth, mortality, exploitation rate, and recruitment pattern of two major commercial small pelagic fishes (CSPFs) (Decapterus maruadsi and Trachurus japonicus) are reported based on bottom trawl survey data collected during 2006-2020 in the Beibu Gulf, South China Sea. All individuals collected during each sampling quarter over a period of 15 years were subjected to laboratory-based analysis. In this study, the stock of D. maruadsi and T. japonicus inhabiting the Beibu Gulf was assessed using length-based methods (bootstrapped electronic length frequency analysis (ELEFAN)) to complete stock assessment in different fishery management periods (the division of fisheries management periods was based on China's input and output in the South China Sea offshore fisheries over 15 years, specifically divided into period I (2006-2010), period II (2011-2015), and period III (2016-2020)). The results showed that the mean body length, dominant body size, and estimated asymptotic length of two CSPFs decreased, whereas their growth coefficient decreased, indicating miniaturization and slower growth, respectively. Estimated exploitation rates and catching body length for two CSPFs indicated that both stocks in the Beibu Gulf were overexploited in period I and moderately exploited after 2011. These stocks were taking a good turn in status in period III, with the exploitation rate much lower than the initial period and reversing the downward trend in catching body length. Furthermore, the variations in the spawning season of the two CSPF stocks and their barely satisfactory expected yield indicated the complexity of the current fishery management in the Beibu Gulf. These results suggest that management measures to reduce fishing pressure may have a positive influence on the biological characteristics of those CSPFs in the Beibu Gulf; however, the stock structure already affected by overfishing will be a huge challenge for the conservation and restoration of fisheries resources in the future. Given that the current stocks of D. maruadsi and T. japonicus in the Beibu Gulf still have low first-capture body length (Lc) and high fishing mortality (F) (compared to F0.1), we identify a need to refine population structure by controlling fishing efforts and increasing catchable size, and more consideration should be given to the local fishery resource status in fisheries management.

Constraining the onset of orogenic contraction in fold-and-thrust belts using sedimentary stylolite populations (Umbria-Marche Apennines, Italy)

Stylolites are pressure solution structures, the roughness of which yields quantitative information about the magnitude of the normal stress applied to the stylolite plane. The stress magnitude is calculated from the cross over length (Lc) determined using the signal analysis of a 2D track. For a sedimentary, bedding-parallel stylolite (BPS), Lc scales to the magnitude of the vertical maximum principal stress σ1, hence to the burial depth at the time the roughness of the stylolite froze. We present a dataset of nearly 200 BPS from Meso-Cenozoic folded carbonates across the Umbria Marche Apennine Ridge. The BPS population is used to address the discrepancies between Lc values obtained by using different signal analysis methods. Assuming that in compressional settings burial-related pressure-solution more probably halts because of the switch of σ1 from a burial-related vertical attitude to a tectonic-related horizontal attitude, the vertical stress magnitudes derived from the inversion of the BPS roughness were combined to burial models at each investigated fold to reconstruct the absolute timing at which the orogenic stress started to prevail. The results indicate that the onset of horizontal compression started at ∼10 Ma and ∼8 Ma in the innermost and outermost folds, respectively, and predated fold development as indicated by the age of growth strata. These results establish Stylolite Roughness Inversion Technique as a reliable depth gauge that enables refining the timing of the onset of contraction in fold-and-thrust belts.

Some Growth Characteristics of Pellonula leonensis from Luubara Creek, Niger Delta, Nigeria

The Growth, mortality, population and yield parameters of the Clupeid Pellonula leonensis were studied based on the data collected from artisanal fishers during throughout 2020 along Luubara Creek, Niger Delta. The fish were caught using the Kara cane trap. Total specimen lengths ranged from 4.50-14.50cm and weighing from 0.50-50.00g. The growth pattern of Pellonula leonensis was estimated K (2.300) L∞ (14. 22cm), to (2.140) and Ø (2.72). The value of K and Ø showed that Pellonula leonensis from the creek grows fast and regularly. The evaluation of mortality characteristics of Pellonula leonensis for twelve months showed that total mortality (Z) 7.08yr-1, natural mortality (M) 3.97yr-1 and fishing mortality (F) 3.11yr-1 from the value of M and F, it is crystal clear that M is higher than F. Exploitation (E) of 0.439 obtained in the study showed that the species is under exploited as E was lower than 0.5. The ratio of length at first capture to asymptotic length (Lc/ L∞) estimated showed that Pellonula leonensis with Lc (0.34cm) was caught at a small size. This scenario will lead to growth overfishing if adequate management and regulations are not put in place.

Does the Larkin length exist?

The yield stress of random solid solutions is a classic theme in physical metallurgy that currently attracts a renewed interest in connection to high entropy alloys. Here, we revisit this subject using a minimal dislocation dynamics model, where a dislocation is represented as an elastic line with a constant line tension embedded in the stochastic stress field of the solutes. Our exploration of size effects reveals that the so-called Larkin length (Lc ) is not a length scale over which a dislocation can be geometrically decomposed. Instead, Lc is a crossover length scale marking a transition in dislocation behavior identifiable in at least three properties: (1) below Lc , the dislocation is close to straight, aligned in a single energy valley, while above Lc , it roughens and traverses several valleys; (2) the yield stress exhibits pronounced size-dependence below Lc but becomes size-independent above Lc ; (3) the power-spectral density of the dislocation shape changes scaling at a critical wavelength directly proportional to Lc . We show that for white and correlated stress noises, Lc and the thermodynamic limit of the yield stress can be predicted using Larkin’s model, where the noise dependence in the glide direction is neglected. Moreover, we show that our analysis is relevant beyond the minimal line tension model by comparison with atomic-scale simulations. Finally, our work suggests a practical approach for predicting yield stresses in atomistic models of random solid solutions, which only involves small-scale atomistic simulations below Lc .

Wavelength dependent transmission in multimode graded-index microstructured polymer optical fibers

Up to now, there have been no commercial simulation tools accessible for researching the transmission properties of multimode microstructured optical fibers (MOFs). In order to avoid this problem, this study uses the time-independent power flow equation (TI PFE) numerical solution to examine the wavelength dependency of the equilibrium mode distribution (EMD) and steady state distribution (SSD) in multimode graded-index microstructured polymer optical fibers (GI mPOF) with a solid core. We showed that the lengths zs at which an SSD is obtained in GI mPOF and the coupling length Lc necessary to create an EMD are shorter at λ = 568 nm than they are found to be at λ = 633 nm. The lengths Lc and zs stay constant when the wavelength decreases further from λ = 568 to 522 and then to 476 nm. As a result, it is anticipated that a faster bandwidth enhancement in the tested GI mPOF will take place at wavelengths around λ = 568 nm as opposed to λ = 633 nm. Such a bandwidth improvement is not brought about by additional wavelength reduction. The study’s findings can be used in communication and sensory systems that use multimode GI mPOFs at different wavelengths.

Optimizing Optical Dielectrophoretic (ODEP) Performance: Position- and Size-Dependent Droplet Manipulation in an Open-Chamber Oil Medium.

An optimization study is presented to enhance optical dielectrophoretic (ODEP) performance for effective manipulation of an oil-immersed droplet in the floating electrode optoelectronic tweezers (FEOET) device. This study focuses on understanding how the droplet's position and size, relative to light illumination, affect the maximum ODEP force. Numerical simulations identified the characteristic length (Lc) of the electric field as a pivotal factor, representing the location of peak field strength. Utilizing 3D finite element simulations, the ODEP force is calculated through the Maxwell stress tensor by integrating the electric field strength over the droplet's surface and then analyzed as a function of the droplet's position and size normalized to Lc. Our findings reveal that the optimal position is xopt= Lc+ r, (with r being the droplet radius), while the optimal droplet size is ropt = 5Lc, maximizing light-induced field perturbation around the droplet. Experimental validations involving the tracking of droplet dynamics corroborated these findings. Especially, a droplet sized at r = 5Lc demonstrated the greatest optical actuation by performing the longest travel distance of 13.5 mm with its highest moving speed of 6.15 mm/s, when it was initially positioned at x0= Lc+ r = 6Lc from the light's center. These results align well with our simulations, confirming the criticality of both the position (xopt) and size (ropt) for maximizing ODEP force. This study not only provides a deeper understanding of the position- and size-dependent parameters for effective droplet manipulation in FEOET systems, but also advances the development of low-cost, disposable, lab-on-a-chip (LOC) devices for multiplexed biological and biochemical analyses.

The dichotomy property in stabilizability of 2 × 2 linear hyperbolic systems

This paper is devoted to discuss the stabilizability of a class of 2 × 2 non-homogeneous hyperbolic systems. Motivated by the example in the Section 5.6 of Bastin and Coron’s book in 2016, we analyze the influence of the interval length L on stabilizability of the system. By spectral analysis, we prove that either the system is stabilizable for all L > 0 or it possesses the dichotomy property: there exists a critical length Lc > 0 such that the system is stabilizable for L ∈ (0, Lc) but unstabilizable for L ∈ [Lc,+∞). In addition, for L ∈ [Lc, +∞), we obtain that the system can reach equilibrium state in finite time by backstepping control combined with observer. Finally, we also provide some numerical simulations to confirm our developed analytical criteria.

Reduced‐Order Models Unravel the Joint Impact of Aperture Heterogeneity and Shear‐Thinning Rheology on Fracture‐Scale Flow Metrics

AbstractSubsurface industrial operations often make use of complex engineered fluids. In fractured media, the hydraulic behavior of a geological fracture is affected by the shear‐thinning (ST) rheology of such fluids, depending on the imposed pressure gradient. Besides, owing to the stochastic nature of heterogeneities in the fracture's local apertures, obtaining the generic behavior of a fracture under ST flow requires large statistics of fractures whose aperture fields have the same statistical properties, namely their mean value, standard deviation, correlation length Lc, and Hurst exponent (which controls the scale invariances at scales smaller than Lc). The first such Monte Carlo study was recently proposed by Lenci, Putti, et al. (2022) using a new lubrication‐based model relying on a non‐linear Reynolds equation. This model describes the flow of an Ellis fluid, with both a low shear rate quasi‐Newtonian viscosity plateau and a large shear rate power law ST behavior, as measured for engineered fluids such as biopolymer solutions (e.g., xanthan gum). Here we aim to obtain the dependence of the fracture transmissivity and its dispersion over the statistics, as well as of the flow correlation length, on fracture closure, geometry correlation length, and applied pressure gradient, over a vast volume of the parameter space, and in a simple mathematical form. Employing reduced‐order models based on the polynomial chaos expansion theory to this aim, we discuss the properties of the obtained topographies of interest in the parameter space.