bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantifying the effects of dissolved nitrogen and carbon dioxide on drying pressure of hydrophobic nanopores
Authors: Binyaminov Hikmat , Elliott Janet A. W.
Published: May 2023

The effects of a dissolved gas on the behavior of liquid in cylindrical nanopores are investigated in the framework of Gibbsian composite system thermodynamics and classical nucleation theory. An equation is derived relating the phase equilibrium of a mixture of a subcritical solvent and a supercritical gas to the curvature of the liquid–vapor interface. Both the liquid and the vapor phases are treated nonideally, which is shown to be important for the accuracy of the predictions in the case of water with dissolved nitrogen or carbon dioxide. The behavior of water in nanoconfinement is found to be only affected when the gas amount is significantly more than the saturation concentration of these gases at atmospheric conditions. However, such concentrations can be easily reached at high pressures during intrusion if there is sufficient gas present in the system, especially considering gas oversolubility in confinement. By including an adjustable line tension term in the free energy equation (−44 pJ/m for all points), the theory can make predictions in line with the few data points available from recent experimental work. However, we note that such a fitted value empirically accounts for multiple effects and should not be interpreted as the energy of the three-phase contact line. Compared to molecular dynamics simulations, our method is easy to implement, requires minimal computational resources, and is not limited to small pore sizes and/or short simulation times. It provides an efficient path for first-order estimation of the metastability limit of water–gas solutions in nanopores.
When marbles challenge pearls
Authors: Jin Panlin , Zhao Kexin , Blin Zoé , Allais Malou , Mouterde Timothée , Quéré David
Published: May 2023

The spectacular nature of non-wetting drops mainly arises from their extreme mobility, and quick-silver, for instance, was named after this property. There are two ways to make water non-wetting, and they both rely on texture: either we can roughen a hydrophobic solid, which makes drops looking like pearls, or we can texture the liquid with a hydrophobic powder that “isolates” the resulting marble from its substrate. We observe, here, races between pearls and marbles, and report two effects: (1) the static adhesion of the two objects is different in nature, which we interpret as a consequence of the way they meet their substrates; (2) when they move, pearls are generally quicker than marbles, which might arise from the dissimilarity of the liquid/air interface between these two kinds of globules.
Thermal metamaterials with nonconformal geometry
Authors: Xing Xiaochang , Wu Lingling , Tian Xiaoyong , Li Dichen
Published: May 2023

Thermal metamaterials have garnered significant attention for their potential to manipulate heat flow, leading to the development of various thermal metadevices such as thermal cloaks, concentrators, and rotators. However, the theoretical study of thermal metadevices with nonconformal geometry remains limited due to design and fabrication challenges. This letter proposes a method for designing and manufacturing nonconformal thermal metamaterials using the conformal discrete theory to simplify the anisotropic thermal conductivity tensors. The method involves 3D printing three thermal metadevices (a thermal cloak, concentrator, and rotator) with complex nonconformal geometry. Simulation and experimental results demonstrate the successful implementation of cloaking, concentrating, and rotating functionalities. Moreover, the thermal metadevices still maintained thermal functionality well under the condition of omnidirectional heat flow. This work provides guidance for the design and manufacture of nonconformal thermal metamaterials, as well as their potential applications in other fields such as electrics/magnetics, electromagnetics/optics, and acoustics.
Unveiling controlling factors of the S0/S1 minimum-energy conical intersection (3): Frozen orbital analysis based on the spin-flip theory
Authors: Yoshikawa Takeshi , Ikabata Yasuhiro , Nakai Hiromi , Ogawa Kentaro , Sakata Ken
Published: May 2023

Conical intersections (CIs), which indicate the crossing of two or more adiabatic electronic states, are crucial in the mechanisms of photophysical, photochemical, and photobiological processes. Although various geometries and energy levels have been reported using quantum chemical calculations, the systematic interpretation of the minimum energy CI (MECI) geometries is unclear. A previous study [Nakai et al., J. Phys. Chem. A 122, 8905 (2018)] performed frozen orbital analysis (FZOA) based on time-dependent density functional theory (TDDFT) at the MECI formed between the ground and first electronic excited states (S0/S1 MECI), thereby inductively clarifying two controlling factors. However, one of the factors that the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energy gap became close to the HOMO–LUMO Coulomb integral was not valid in the case of spin-flip TDDFT (SF-TDDFT), which is frequently used as a means of the geometry optimization of MECI [Inamori et al., J. Chem. Phys. 152, 144108 (2020)]. This study revisited the controlling factors using FZOA for the SF-TDDFT method. Based on spin-adopted configurations within a minimum active space, the S0–S1 excitation energy is approximately represented by the HOMO and LUMO energy gap ΔεHL, a contribution from Coulomb integrals JHL″ and that from the HOMO–LUMO exchange integral KHL″. Furthermore, numerical applications of the revised formula at the SF-TDDFT method confirmed the control factors of S0/S1 MECI.
Effects of a large wildfire on the community composition of medium and large mammals in a neotropical savannah
Authors: Nunes Bruna A. , Cunha André , Vieira Emerson M.
Published: May 2023

Background The Cerrado is a neotropical savannah with high mammalian diversity where wildfires are rather common and highly relevant to its ecological patterns and processes. The effects of fire on Cerrado mammals, however, are poorly understood. Aims We investigated the effects of an unplanned large wildfire (burned area ~66 000 ha) on medium and large mammals in a Cerrado area in Brazil, focusing on fire-driven changes in community composition up to 3 years after fire. Methods We evaluated burned and unburned sites before and after the wildfire, using 54 camera traps between 2017 and 2020. Total trap effort was 6334 days (unburned areas) and 7670 days (burned areas). Key results We recorded 25 species in burned and 19 in unburned areas. Fire markedly affected the community up to 3 years after burning. A canonical correspondence analysis indicated that herbivores (tapirs and pampas deer) were common in the burned areas, with an increase in the relative abundance of carnivores the second year after fire. Conclusions Community-level responses were complex, with guild-dependent changes and effects still detected 3 years after fire. Implications Management strategies that include patch mosaic burns (with areas unburned and burned 1 and 2 years earlier) could contribute to maintenance of local mammal diversity.
Solvo/hydrothermal upcycling of polyethylene plastic-waste into carbon-based nanocomposite for supercapacitor application
Authors: Kigozi Moses , Tebandeke Emmanuel , Baptist Kirabira John , Kasozi Gabriel N.
Published: May 2023

One of the most worrying environmental issues affecting all forms of life, the economy, and natural ecosystems globally is the accumulation of polyethylene (PE) plastic garbage. Creating peaceful and environmentally friendly alternatives to conventional disposal techniques, like transforming plastic waste into cherished carbonaceous nanomaterials, is of utmost importance considering this threat. The current study carefully employed a cleaner upcycling technique to create carbon-based nanomaterials (CNMs) for supercapacitors. Using solvothermal/hydrothermal synthetic techniques, the PE waste was transformed into CNMs used in energy storage supercapacitors application. With an energy density of 21.6 W h kg−1 and a current density of 0.25 A g−1, the electrochemical test showed a specific capacitance of 155.5 F g−1. Additionally, the materials demonstrated 98.5% capacitance retention after 9000 cycles at a constant current density of 1.0 A g−1.

Abbreviations: AC: activated carbon; CNM: carbon nanomaterials; CV: cyclic voltammetry; EC: electrochemical system; EDLC: electrical double layer capacitor; EIS: electrochemical impedance spectroscopy; FESEM: field emission scanning electron microscopy; FTIR: Fourier transform infrared; GCD: galvanostatic charge–discharge; HDPE: high-density polyethene; KOH: potassium hydroxide; LLDPE: linear low-density polyethene; Mn: manganese; PE: polyethene; Rct: charge transfer resistance; SSA: specific surface area; TEM: transmission electron microscopy; TGA: thermogravimetric analysis; UV–VIS: ultraviolet–visible spectroscopy; XRD: X-ray diffraction

Highlights

The article explored a low-temperature and non-emission upcycling method of polyethylene plastic waste into carbon-based nanomaterials (CNMs). CNMs were characterised for physical–chemical properties using different characterisation techniques. The carbon material was used with other materials like activated carbon and manganese to produce nanocomposites tested for electrical double layer capacitor energy storage and exhibited higher energy density.
Reticular adhesions are assembled at flat clathrin lattices and opposed by active integrin α5β1
Authors: Hakanpää Laura , Abouelezz Amr , Lenaerts An-Sofie , Culfa Seyda , Algie Michael , Bärlund Jenny , Katajisto Pekka , McMahon Harvey , Almeida-Souza Leonardo
Published: May 2023

Reticular adhesions (RAs) consist of integrin αvβ5 and harbor flat clathrin lattices (FCLs), long-lasting structures with similar molecular composition as clathrin-mediated endocytosis (CME) carriers. Why FCLs and RAs colocalize is not known. Here, we show that RAs are assembled at FCLs in a process controlled by fibronectin (FN) and its receptor, integrin α5β1. We observed that cells on FN-rich matrices displayed fewer FCLs and RAs. CME machinery inhibition abolished RAs and live-cell imaging showed that RA establishment requires FCL coassembly. The inhibitory activity of FN was mediated by the activation of integrin α5β1 at Tensin1-positive fibrillar adhesions. Conventionally, endocytosis disassembles cellular adhesions by internalizing their components. Our results present a novel paradigm in the relationship between these two processes by showing that endocytic proteins can actively function in the assembly of cell adhesions. Furthermore, we show this novel adhesion assembly mechanism is coupled to cell migration via unique crosstalk between cell-matrix adhesions.
On the visibility of singularities in general relativity and modified gravity theories
Authors: Mosani Karim , Dey Dipanjan , Joshi Pankaj S , Samanta Gauranga C , Menon Harikrishnan , Patel Vaishnavi D
Published: May 2023

We investigate the global causal structure of the end state of a spherically symmetric marginally bound Lemaitre–Tolman–Bondi (LTB) (Lemaitre 1933 Ann. Soc. Sci. Brux. A 53 51, Tolman 1934 Proc. Natl Acad. Sci. USA
20 169–76, Bondi 1947 Mon. Not. Astron. Soc.
107 410) collapsing cloud (which is well studied in general relativity) in the framework of modified gravity having the generalized Lagrangian

R
+
α

R
2

in the action. Here R is the Ricci scalar, and

α
⩾
0

is a constant. By fixing the functional form of the metric components of the LTB spacetime, using up the available degree of freedom, we realize that the matching surface of the interior and the exterior metric are different for different values of α. This change in the matching surface can alter the causal property of the first central singularity. We depict this by showing a numerical example. Additionally, for a globally naked singularity to have physical relevance, a congruence of null geodesics should escape from such singularity to be visible to an asymptotic observer for infinite time. For this to happen, the first central singularity should be a nodal point. We here give a heuristic method to show that this singularity is a nodal point by considering the above class of theory of gravity, of which general relativity is a particular case.
Density and pseudo-spin rotons in a bilayer of soft-core bosons
Authors: Pouresmaeeli F , Abedinpour S H , Tanatar B
Published: May 2023

We study the dynamics of a bilayer system of bosons with repulsive soft-core Rydberg-dressed interactions within the mean-field Bogoliubov-de Gennes approximation. We find roton minima in both symmetric and asymmetric collective density modes of the symmetric bilayer. Depending on the density of bosons in each layer and the spacing between two layers, the homogeneous superfluid phase becomes unstable in either (or both) of these two channels, leading to density and pseudo-spin-density wave instabilities in the system. Breaking the symmetry between two layers, either with a finite counterflow or a density imbalance renormalizes the dispersion of collective modes and makes the system more susceptible to density-wave instability.
Energy harvesting by uniaxially-stretched poly(lactide) films at low tensile strain frequencies for powering wearable sensors: experimental results and theoretical extrapolation
Authors: Ben Achour Mohamed Aymen , Rguiti Mohamed , Samuel Cédric , Barrau Sophie , Lacrampe Marie-France , Courtois Christian
Published: May 2023

Poly(lactide) (PLA) is an eco-friendly and low-cost polymer with a shear piezoelectricity easily induced by uniaxial stretching and without poling process. These interesting features make PLA as a good candidate to replace the widely-used poly(vinylidene difluoride) (PVDF) piezoelectric polymer, in particular for flexible energy harvesting applications aiming to power wearable sensors. In this work, PLA films were fabricated by a simple extrusion–orientation process. The energy harvesting efficiency of the PLA films were characterized using a custom-built test bench designed for flexible piezoelectric materials and working in tensile mode at low strain frequencies. The measurements on PLA films show a maximal output power about 3.7 μW harvested by applying a strain of 1% at 20 Hz. A theoretical model was developed based on electromechanical parameters to ascertain the energy harvesting performances of PLA. The validated model was also helpful to estimate the output power from PLA films by increasing their active surface areas and/or improving their shear piezoelectric coefficients (d
14). The optimized PLA film could produce an output power comparable to that produced by PVDF film in the same mechanical excitation conditions. This study consequently highlights the potential of PLA for energy harvesting applications and the utility of the developed model to estimate the electrical power generated by piezoelectric polymers.
Towards Stirling engine using an optically confined particle subjected to asymmetric temperature profile
Authors: Nalupurackal Gokul , Lokesh Muruga , Suresh Sarangi , Roy Srestha , Chakraborty Snigdhadev , Goswami Jayesh , M Gunaseelan , Pal Arnab , Roy Basudev
Published: May 2023

The realization of microscopic heat engines has gained a surge of research interest in statistical physics, soft matter, and biological physics. A typical microscopic heat engine employs a colloidal particle trapped in a confining potential, which is modulated in time to mimic the cycle operations. Here, we use a lanthanide-doped upconverting particle (UCP) suspended in a passive aqueous bath, which is highly absorptive at 975 nm and converts near infra red (NIR) photons to visible, as the working substance of the engine. When a single UCP is optically trapped with a 975 nm laser, it behaves like an active particle by executing motion subjected to an asymmetric temperature profile along the direction of propagation of the laser. The strong absorption of 975 nm light by the particle introduces a temperature gradient and results in significant thermophoretic diffusion along the temperature gradient. However, the activity of the particle vanishes when the trapping wavelength is switched to 1064 nm. We carefully regulate the wavelength-dependent activity of the particle to engineer all four cycles of a Stirling engine by using a combination of 1064 nm and 975 nm wavelengths. Since the motion of the particle is stochastic, the work done on the particle due to the stiffness modulation per cycle is random. We provide statistical estimation for this work averaged over five cycles which can be extended towards several cycles to make a Stirling engine. Our experiment proposes a robust set-up to systematically harness temperature which is a crucial factor behind building microscopic engines.
Experimental study on the pressure characteristics of laser-induced shock waves under different energy distribution
Authors: Nie Xiangfan , Tang Yuyuan , Zhao Feifan , Li Yang , He Weifeng , Wei Chen , Wang Xuede , Wu Haonian , Yan Li
Published: May 2023

Laser shock peening has been widely used in anti-fatigue strengthening of metals. The different types of lasers (Flattop laser and Gaussian laser) used have influence on the pressure characteristics of shock wave and the strengthening effect. In this work, using PDV (photonic doppler velocimetry) system, the difference of peak pressure of Flattop laser-induced shock wave and Gaussian laser-induced shock wave is studied experimentally and theoretically. Research shows that the peak pressure of shock wave induced by Gaussian laser is higher than that of Flattop laser, because of the infinitesimal power density in the center of Gaussian laser spot is higher than that of Flattop laser. Furthermore, at the same power density, Gaussian laser can implant a larger and deeper residual stress field in the material.
The effect of depositions parameters on the nanostructural and optical properties of CuPc organic thin films growth by oblique angle deposition CSP technique
Authors: Tatar B , Demiroğlu D
Published: May 2023

Organic semiconductor CuPc thin films were deposited on different substrates with OAD CSP technique. The effects of substrate type, glancing angle and deposition temperature on surface and structural properties of CuPc thin films was reported in this study. The structural and morphological properties of CuPc thin films were investigated by XRD, RAMAN and FEG-SEM analysis. Dendritic nanostructures and nanoporous-straticulate sponge like structures were determined at surface area of CuPc thin films. XRD patterns showed that these CuPc thin films have orthorhombic α-phase structure with 2θ peak at 6.89˚, which is %100. The optical properties of all CuPc films which were determined from transmittance and reflectance measurements. The increasing of spray glancing angle and substrate temperature were decreased the UV-VIS absorption intensities at S-band and Q-band. However at 200 °C and 250 °C deposition temperatures at 45° spray glancing angle affected the Q-band absorption acerbically and red shift observed in here.
Dynamics of a non-smooth pest-natural enemy model with the threshold control strategy
Authors: Zhu Yuxun , Liu Lu , Zhang Zhengdi
Published: May 2023

Pest issues have always been the focus of attention in agriculture. The Integrated Pest Management(IPM) method is currently the most popular way to be applied for pest control. In this study, according to the IPM strategy, we regard pest quantity as a threshold index and extend the Leslie-Gower model into a non-smooth Filippov system through combining chemical and biological control. To maintain the pest population at or below the given economic threshold(ET), we investigate the global dynamics of the proposed model, including the existence of sliding mode and various equilibria, sliding dynamics and bifurcations, and global stability of equilibria. The result shows that desired equilibria can be globally stable under some conditions, meaning that our control tactics work. In particular, the case where our strategy fails to be effective arouses interest. In the end, the biological implications of the results are discussed and given in detail.
Design of sign-reversible Berry phase effect in 2D magneto-valley material
Authors: Han 韩 Yue-Tong 曰通 , Yang 杨 Yu-Xian 宇贤 , Li 李 Ping 萍 , Zhang 张 Chang-Wen 昌文
Published: May 2023

Manipulating sign-reversible Berry phase effects is both fundamentally intriguing and practically appealing for searching for exotic topological quantum states. However, the realization of multiple Berry phases in the magneto-valley lattice is rather challenging due to the complex interactions from spin–orbit coupling (SOC), band topology, and magnetic ordering. Here, taking single-layer spin-valley RuCl2 as an example, we find that sign-reversible Berry phase transitions from ferrovalley (FV) to half-valley semimetal (HVS) to quantum anomalous valley Hall effect (QAVHE) can be achieved via tuning electronic correlation effect or biaxial strains. Remarkably, QAVHE phase, which combines both the features of quantum anomalous Hall and anomalous Hall valley effect, is introduced by sign-reversible Berry curvature or band inversion of

d

x
y

/

d

x
2

−

y
2

and

d

z
2

orbitals at only one of the K/Kʹ valleys of single-layer RuCl2. And the boundary of QAVHE phase is the HVS state, which can achieve 100% intrinsically valley polarization. Further, a k ⋅ p model unveiled the valley-controllable sign-reversible Berry phase effects. These discoveries establish RuCl2 as a promising candidate to explore exotic quantum states at the confluence of nontrivial topology, electronic correlation, and valley degree of freedom.
Prediction of a monolayer spin-spiral semiconductor: CoO with a honeycomb lattice
Authors: Zhang Jie , Song Shunuo , Zhang Yan-Fang , Zhang Yu-Yang , Pantelides Sokrates T. , Du Shixuan
Published: May 2023

The recent successful fabrication of two-dimensional (2D) CoO with nanometer-thickness motivates us to investigate monolayer CoO due to possible magnetic properties induced by Co atoms. Here, we employ first-principles calculations to show that monolayer CoO is a 2D spin-spiral semiconductor with a honeycomb lattice. The calculated phonon dispersion reveals the monolayer's dynamical stability. Monolayer CoO exhibits a type-I spin-spiral magnetic ground state. The spin-spiral state and the direct bandgap character are both robust under biaxial compressive strain (−5%) to tensile strain (5%). The bandgap varies only slightly under either compressive or tensile strain up to 5%. These results suggest a potential for applications in spintronic devices and offer a new platform to explore magnetism in the 2D limit.
Design of PCM-based heat sinks through topology optimization
Authors: Bianco Nicola , Fragnito Andrea , Iasiello Marcello , Mauro Gerardo Maria
Published: May 2023

Ever-increasing heat fluxes of electronic components ask for higher performance of devices responsible for their cooling. Against that background, PCM-based heat sinks – because of their compactness, and effectiveness – are well-established solutions for thermal management issues. Even though solutions for the thermal enhancement of PCM devices have been widely presented, new ways to optimize such systems are emerging. Among them, this work investigates the application of density-based topology optimization to define innovative heat sinks design able to minimize thermal resistance under constant wall temperature. A 2D numerical model is developed by means of a finite element tool. The heat equation is solved for the topology optimization problem with the objective of minimizing the average temperature, considering further manufacturing restrictions. Solid-isotropic-material-with-penalization (SIMP) method is applied to link the design variable to material properties. Parameterization of Helmholtz filter’s minimum feature size and projection based on the hyperbolic tangent function is performed, showing improved performance as well as feature size decrease. The optimized prototype – with PCM – is then simulated with the enthalpy-porosity model to assess the benefits, i.e., reduction in the melting time, with respect to the baseline. Results show the potential of optimizing heat sinks via a topology-based approach and confirm it as a promising tool for finding new heat sink geometry, whatever the application.
Energy demand in secondary steel making process: numerical analysis to assess the influence of the ladle working lining properties
Authors: Neri M , Lezzi A M
Published: May 2023

In secondary steel making process, steel scrap is melted in an electric arc furnace, then poured into a ladle where ferroalloy are added to obtain the desired steel composition. Energy is also supplied in LF (Ladle Furnace) to guarantee steel temperature required in the teeming phase. In this paper a simplified, but sound numerical model of the process the ladle undergoes is presented: it is meant to provide a way to compare energy demand for different choices of materials used in the ladle or for changes in the ladle work cycle. As an example of application of the model, energy demand in LF are evaluated and compared for two different choices of the refractory material used as working lining: magnesia and alumina. To take into account the reduction of the working lining due to wear processes, energy demand has been calculated for three different thicknesses. In addition, the beneficial effect of a lid during the waiting phase after cleaning is investigated.
Lattice Boltzmann model of a square natural circulation loop with small inner diameter: working fluid effects
Authors: Bocanegra Johan Augusto , Misale Mario
Published: May 2023

Natural circulation loops are systems used to transport heat by the free convection of a working fluid in a closed thermo-hydraulic circuit. Many examples of the Lattice Boltzmann method applied to free convection can be found in the literature, but most of them are limited to model simple enclosures. This work is one of the first approaches to an engineering system as the Natural Circulation Loops using this numerical method. This study describes the implementation and validation of a numerical model of a rectangular loop characterized by a small inner diameter. This research is focused on the thermohydraulic response of the NCL varying the working fluid. We have obtained satisfactory results demonstrating that accepted analytical correlations for the steady-state behavior are reproduced by the thermal Lattice Boltzmann Method (double distribution function). Overall, these results suggest that the temperature and velocity oscillations during the transient increase directly with the fluid Prandtl number; instead, the temperature difference between the vertical legs is inversely correlated and decreases.
Preliminary design and modeling of mini channels to enhance heat transfer in a millimetric catalytic combustor
Authors: La Terra Caterina , Corti Maria , Nespoli Adelaide , Fanciulli Carlo , Niro Alfonso
Published: May 2023

Mini channel solution is used in devices that require a high density of transmitted thermal power as a very large-scale integration design in computer systems and compact exchangers. Furthermore, the mini channels are extensively investigated in the literature for turbulent and laminar regimes. In this project, different configurations of mini channels have been studied to enhance heat transfer, using simulations with a commercial multi-physics code. Thanks to the results of the models, more promising configurations with 3D printing technique may be built. The project challenge is improving convective thermal power extracted by the exhaust gases of a mini-catalytic combustor. The combustor feeds six modules for thermoelectric power production (TEMs). As the first step, three different mini channel geometries have been chosen; the first one with 19 channels with rectangular cross-section, the second one with 6 channels with a convergent profile, and the latter with 2 channels with a fractal branching geometry. Simulations started from studying fluid dynamic to investigate the velocity field at the exit of the mini channels. The analysis has been extended by adding the conjugate heat exchange between fluid and combustor wall. The results show an increase in heat exchange compared to the base case for all configurations, with a maximum value for the 19 mini channels configuration.
Fouling effect in a shell-and-tube heat exchanger with twisted tape inserts applied to a small-scale biomass gasification power plant
Authors: Allesina Giulio , Pedrazzi Simone , Ottani Filippo , Tartarini Paolo
Published: May 2023

In this work the over-time behaviour of a shell-and-tube type heat exchanger applied to a commercial and small-scale wood biomass gasification system was investigated. The heat exchanger, equipped with twisted tape turbulators, was used to cool down the syngas produced by the power plant. An experimental campaign was conducted to evaluate the performance trend in the first 15 hours of operation. The results showed an increase in heat transfer which led to a progressive reduction of the gas outlet temperature from 105.4 °C to 90.0 °C. The data collected confirm the literature studies on the positive effect that the deposits of particulate matter and tars have in reducing the clearance between the heat exchanger pipes and the turbulators, providing information for the temporal optimization of the cleaning strategy of the heat exchanger itself.
Hidden Grid Background Oriented Schlieren in studying convective flows
Authors: Ambrosini Dario , Rubeis Tullio de , Paoletti Domenica , Ramaiah Jagadesh , Gannavarpu Rajshekhar
Published: May 2023

In this paper, we present a new BOS (Background Oriented Schlieren), based on a hidden grid, for studying heat flows. In the setup, we record a grid-based intensity pattern whose phase map carries information about the temperature gradient. The background (undistorted) pattern is hidden in the light source. Quantitative analysis is obtained by a windowed Fourier transform approach. Some experimental results are given to demonstrate the feasibility of the technique.
Convective condensation of R134a and R1234ze(E) inside microfin tube
Authors: Lucchini A , Carraretto I M , Phan T N , Pittoni P G , Molinaroli L , Colombo L P M
Published: May 2023

Environmental concerns are forcing the replacement of the commonly used refrigerants and finding new fluids is a top priority. The hydro-fluoro-olefin (HFO) R1234ze(E), because of its smaller global warming potential (GWP) and shorter atmospheric lifetime, replaced R134a. Accordingly, for HVAC systems design, a detailed knowledge of the thermo-fluid-dynamic characteristics of the fluids and reliable predictive models are required. To improve the understanding, R134a and R1234ze(E) were employed in convective condensation experiments (saturation temperature Tsat
= 35°C, mean quality xm
= 0.1~0.9, quality changes Δx = 0.05~0.6, mass flux G = 43~444 kg·m−2s−1) inside a microfin tube (outer diameter D = 9.52 mm, fin number n = 60, fin height H = 0.2 mm). The results were used for two goals: the former is the comparison of the heat transfer features of the two fluids, while the latter aims at testing the performance of prediction models available in the open literature. At the saturation temperature T = 35°C, the two fluids show small differences in the thermal properties so that, as expected, the experiments highlighted a very similar behavior in the typical operating conditions of HVAC systems. In fact, for all the operating conditions marginal differences were observed in the pressure drop, the heat transfer coefficient and the flow pattern maps. The issue of prediction reliability, however, is still open. Actually, not all the models achieving good results for R134a show the same performance for R1234ze(E), especially for the pressure drop.
The role of collective action in the cacao sector in enhancing sustainability, market upgrading and agro-biodiversity conservation
Authors: Rueda Ximena , Middendorp Romaike , Puerto Sergio
Published: May 2023

Many farmers around the world are confronted with the decision of adopting high-yielding varieties or maintaining the diverse portfolio of ancient varieties and cultivars that constitute the basis of local and global agrobiodiversity. This dilemma often resolves towards ensuring short-term individual profits at the expense of long-term biodiversity conservation. In this paper we argue that specialty markets can act as a driving force to resolve this balance towards the conservation of agrobiodiversity, supported by collective action. We use the case of the Ecuadorian cacao producers to illustrate this possibility. The upper Amazon is the center of origin of cacao, one of the top traded global commodities. Since the 1990s Ecuadorian farmers have been substituting regional varieties with a clone developed in the country, the CCN-51 that has shown to be a high-yielding variety that is also resistant to monilia, a common cacao disease. In some areas of the country, however, farmers belonging to cooperatives have been able to keep local varieties, obtain ecological certifications for adhering to the recommended practices, and reach specialty markets that pay higher prices for their cacao. We call this set of benefits upgrading. We conducted a study of 205 household surveys and several interviews in four provinces along the West coast of Ecuador. We assessed the role of collective action (in the form of cooperative participation) in enhancing farmers’ access to high-value chains. Our results show that collective action enables economic upgrading by providing participants with higher incomes and more formal contracts. As farmers join direct trade and certification, other benefits are accrued, such as cacao and non-cacao tree biodiversity conservation. This analysis shows that, once niche markets are open for farmers, collective action boosts the benefits of such opportunities.
Impact of S,B and S,P co-doping on the photovoltaic performance of graphene quantum dots
Authors: Cui Peng , Zhang Jian
Published: May 2023

Co-doping is an effective strategy to optimise the photovoltaic performance of GQDs. However, due to the heterogeneity of GQDs, it is difficult to achieve controllable photovoltaic performance without determining the structure-property relationship. In this work, we perform first-principles calculations to investigate the optoelectronic properties of GQDs doped with S, B, and P atoms. Our results show that S doping is crucial for tuning the photoelectric performance of S,B and S,P co-doped GQDs. Increasing the polarity of the solvent improves the charge transfer performance of single P-doped GQDs. Moreover, single P-doped GQDs show better photovoltaic performance than other doping configurations. Furthermore, the addition of B co-dopants to GQDs with Sh doping configuration improves the energy conversion of GQDs compared to B doping alone. Our study provides guidance for the rational design of GQDs for various photovoltaic applications.
Preparation and antibacterial property of silver nanoparticles loaded into bacterial cellulose
Authors: Homwan Wittaya , Chaisen Konkanok , Audtarat Sasiporn , Suwonnachot Wittaya , Dasri Thananchai
Published: May 2023

Composite nanomaterials based on silver nanoparticles (AgNPs) are considered promising antimicrobial agents due to their excellent antimicrobial activity. The aim of this work is to develop bacterial cellulose (BC) composites that act synergistically with AgNPs. BC@AgNPs composites were developed using an ex-situ composite development strategy and evaluated for their structural characteristics and antimicrobial activities. Field emission scanning electron microscopy (FESEM) showed impregnation of AgNPs into the porous BC network. The composite formulation was also confirmed by x-ray diffraction (XRD) analysis, which showed the presence of additional crystalline peaks along with those of the pure BC. Bactericidal tests of BC@AgNPs nanocomposites against common pathogens, including Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, showed a significant reduction in their growth compared to pure BC. These results suggest that the synthesized BC@AgNPs composites could be promising antibacterial materials for potential applications in a wide range of medical and environmental applications.
Influence of different pretreatments on the adhesion of nanodiamond composite films on Ti substrates via coaxial arc plasma deposition
Authors: Osman Lama , Ali Ali M , Zkria Abdelrahman , Naragino Hiroshi , Yoshitake Tsuyoshi
Published: May 2023

In this study, we report on the novel growth of nanodiamond composite (NDC) films on titanium (Ti) substrates using the coaxial arc plasma deposition (CAPD) at room temperature, which offers several advantages over conventional growth techniques. CAPD employs a unique coaxial arc plasma gun structure that provides a supersaturated condition of highly energetic carbon ions (C+) for ultrafast quenching on the substrate, promoting the growth of nanodiamond grains. This allows for NDC films’ growth on diverse substrates without the need for initial seeding or substrate heating. However, the growth of NDC films on Ti substrates at room temperature is challenging due to the native oxide layer (TiO2). Here, we grew NDC films on Ti substrates using three different pretreatments: (i) hydrofluoric acid (HF) etching, (ii) insertion of a titanium carbide (TiC) intermediate layer, and (iii) in situ Ar+ plasma etching. The morphology and structure of the grown NDC films were examined by 3D laser, high-resolution scanning electron microscopies (HR-SEM), Raman, and x-ray photoelectron (XPS) spectroscopies. Our results demonstrate that in situ Ar+ plasma etching is the most effective pretreatment method for completely removing the native TiO2 layer compared to the other two ex situ pretreatments, in which re-oxidation is more likely to occur after these pretreatments. Furthermore, NDC films grown using the hybrid Ar+ ion etching gun (IG) and CAPD exhibit the highest sp
3 content (63%) and adhesion strength (16 N).
A Qualitative Examination of Tobacco Use and Smoking Cessation Among Gender Minority Adults
Authors: Sun Christina J , Doran Kye M , Sevelius Jae M , Bailey Steffani R
Published: May 2023

Background

Despite the elevated prevalence of smoking among gender minority adults, little is known about the factors that influence their tobacco use and cessation.

Purpose

We identified and examined factors that influence tobacco use and cessation for gender minority adults, using a conceptual framework based on the Model of Gender Affirmation and Gender Minority Stress Model.

Methods

Nineteen qualitative, semi-structured in-depth interviews were conducted with gender minority adults who smoke or no longer smoke and were recruited from the Portland, OR metropolitan area. Interviews were audio-recorded, professionally transcribed, and analyzed utilizing thematic analysis.

Results

Four main themes were generated. Gender minority adults smoke to cope with general and gender minority-specific stressors. Smoking was described as a social behavior that was influenced and sustained by community and interpersonal relationships. Smoking cessation was motivated by health concerns (both general and gender minority-specific) and moderated by conducive life circumstances. Recommendations for tobacco cessation interventions highlighted the importance and role of social support. Participants expressed a strong desire for gender minority-specific tobacco cessation programs. There are unique and complex factors that contribute to the higher prevalence of smoking observed among gender minority adults.

Conclusions

Tobacco cessation interventions are urgently needed for this population and should be tailored to address the unique factors that impact tobacco use and cessation among gender minority people to increase the likelihood of success.
Addressing barriers to increased adoption of DPYD genotyping at a large multisite cancer center
Authors: Morris Sarah A , Moore Donald C , Musselwhite Laura W , Lopes Karine Eboli , Hamilton Alicia , Steuerwald Nury , Hanson Sarah L , Larck Chris , Swift Kristen , Smith Mathew , Kadakia Kunal C , Chai Seungjean , Hwang Jimmy J , Patel Jai N
Published: May 2023

Purpose

To describe the implementation of an in-house genotyping program to detect genetic variants linked to impaired dihydropyrimidine dehydrogenase (DPD) metabolism at a large multisite cancer center, including barriers to implementation and mechanisms to overcome barriers to facilitate test adoption.

Fluoropyrimidines, including fluorouracil and capecitabine, are commonly used chemotherapy agents in the treatment of solid tumors, such as gastrointestinal cancers. DPD is encoded by the DPYD gene, and individuals classified as DPYD intermediate and poor metabolizers due to certain genetic variations in DPYD can experience reduced fluoropyrimidine clearance and an increased risk of fluoropyrimidine-related adverse events. Although pharmacogenomic guidelines provide evidence-based recommendations for DPYD genotype–guided dosing, testing has not been widely adopted in the United States for numerous reasons, including limited education/awareness of clinical utility, lack of testing recommendations by oncology professional organizations, testing cost, lack of accessibility to a comprehensive in-house test and service, and prolonged test turnaround time. Based on stakeholder feedback regarding barriers to testing, we developed an in-house DPYD test and workflow to facilitate testing in multiple clinic locations at Levine Cancer Institute. Across 2 gastrointestinal oncology clinics from March 2020 through June 2022, 137 patients were genotyped, and 13 (9.5%) of those patients were heterozygous for a variant and identified as DPYD intermediate metabolizers.

Conclusion

Implementation of DPYD genotyping at a multisite cancer center was feasible due to operationalization of workflows to overcome traditional barriers to testing and engagement from all stakeholders, including physicians, pharmacists, nurses, and laboratory personnel. Future directions to scale and sustain testing in all patients receiving a fluoropyrimidine across all Levine Cancer Institute locations include electronic medical record integration (eg, interruptive alerts), establishment of a billing infrastructure, and further refinement of workflows to improve the rate of pretreatment testing.
ProgCAE: a deep learning-based method that integrates multi-omics data to predict cancer subtypes
Authors: Liu Qingchun , Song Kai
Published: May 2023

Determining cancer subtypes and estimating patient prognosis are crucial for cancer research. The massive amount of multi-omics data generated by high-throughput sequencing technology is an important resource for cancer prognosis. Deep learning methods can integrate such data to accurately identify more cancer subtypes. We propose a prognostic model based on a convolutional autoencoder (ProgCAE) that can predict cancer subtypes associated with survival using multi-omics data. We demonstrated that ProgCAE predicted subtypes of 12 cancer types with significant survival differences and outperformed traditional statistical methods for predicting the survival of most patients with cancer. Supervised classifiers can be constructed based on subtypes predicted by robust ProgCAE.
An inhibitory mechanism for suppressing high salt intake inDrosophila
Authors: Dey Manali , Ganguly Anindya , Dahanukar Anupama
Published: May 2023

High concentrations of dietary salt are harmful to health. Like most animals, Drosophila melanogaster are attracted to foods that have low concentrations of salt, but show strong taste avoidance of high salt foods. Salt in known on multiple classes of taste neurons, activating Gr64f sweet-sensing neurons that drive food acceptance and 2 others (Gr66a bitter and Ppk23 high salt) that drive food rejection. Here we find that NaCl elicits a bimodal dose-dependent response in Gr64f taste neurons, which show high activity with low salt and depressed activity with high salt. High salt also inhibits the sugar response of Gr64f neurons, and this action is independent of the neuron’s taste response to salt. Consistent with the electrophysiological analysis, feeding suppression in the presence of salt correlates with inhibition of Gr64f neuron activity, and remains if high salt taste neurons are genetically silenced. Other salts such as Na2SO4, KCl, MgSO4, CaCl2, and FeCl3 act on sugar response and feeding behavior in the same way. A comparison of the effects of various salts suggests that inhibition is dictated by the cationic moiety rather than the anionic component of the salt. Notably, high salt-dependent inhibition is not observed in Gr66a neurons—response to a canonical bitter tastant, denatonium, is not altered by high salt. Overall, this study characterizes a mechanism in appetitive Gr64f neurons that can deter ingestion of potentially harmful salts.
Life history and bionomics ofGlycobius speciosus(Coleoptera: Cerambycidae: Cerambycinae: Clytini)
Authors: Adams Kim B , Allen Douglas C , Stehman Stephen V
Published: May 2023

Glycobius speciosus (Say) was studied in New York State to elucidate poorly known aspects of its biology. Head capsule size from excavated larvae coupled with gallery lengths measured at the time of excavation was used to characterize larval development. Partial life tables indicated nearly 20% of G. speciosus survive to adulthood. Larvae experienced 30% of their mortality during early development, 27% during mid-larval development, and 43% during late larval development. Predation by hairy woodpeckers, Dryobates villosus (Linnaeus) (Piciformes: Picidae), the only unambiguous source of mortality, accounted for 43% mortality in naturally infested trees located and followed 2004–2009, and 74% late instar mortality. One parasitoid, Dolichomitus irritator (Fabricius) (Hymenoptera: Ichneumonidae), was recovered from a single larva. Beetles emerged between 316 accumulated DD (base 10 °C) and 648 DD. Males emerged prior to, or simultaneously with, females and lived longer. Female fecundity averaged 41.3 ± 6 eggs. Larval eclosion occurred 7–10 days after oviposition. Non-functional ovipositors observed in 16% of females represented an appreciable reproductive loss. In 77% of infested trees 1 oviposition site was located and in 70% of oviposition sites examined only 1 or 2 larvae successfully eclosed, penetrated the bark to the phloem-xylem interface, and began feeding. Beetles preferred southern and eastern aspects for oviposition which occurred preferentially on the lower bole (<20 cm). Male beetles had longer and wider antennae than females, pronotal pits containing gland pores, and a straight to concave posterior margin of the terminal sternite compared to the more rounded margin of females.