Exact Conditions Research Articles

Mycorrhizal and non-mycorrhizal mushroom cultivation- constraints and opportunities for Sub-Saharan Africa

Mushrooms have a long history of cultivation, dating back to 600 AD. However, most edible mushroom species worldwide are still gathered from the wild, a practice which is unsustainable in contributing to global food security. Cultivation of saprotrophic mushroom species has successfully used agricultural waste as growing substrate. Their mycorrhizal counterparts, however, remain dependent on their woody hosts and seasonality thereby being less accessible to urban communities. The main reason has been the lack of methods which effectively simulate mycorrhizal symbiotic environments. Apart from requiring particular species of bacteria for mycorrhization with their woody host species, mycorrhizal mushrooms also strictly require glucose or fructose as their only source of carbon. Hence, sustainable off-host cultivation of mycorrhizal mushrooms will require better understanding of exact conditions of mycorrhization and fructification. In this review, a brief history of use and general biology of mushrooms, and the cultivation methods employed for non-mycorrhizal and mycorrhizal mushrooms are discussed. Finally, a discussion is provided on the prospects for Sub-Saharan Africa in developing modern sustainable cultivation methods for wild mushrooms towards meeting the key UN Sustainable Development Goals.

Dynamic plastic response and impulse saturation of rectangular plates subjected to pressure pulse loading

A combination of the Membrane Factor Method (MFM) and Saturation Analysis (SA) has proven to be a simple yet effective theoretical tool to predict the dynamic inelastic response of various structures subjected to long-duration pressure pulse loading. In this study, this theoretical tool is extended to the analysis of rectangular plates. Boundary conditions are treated in a unified manner in the analysis, so that the influence of the boundary conditions on the saturation phenomenon is clarified based on MFM. By taking the transient response phase and the exact yield conditions into consideration, complete solutions of saturation deflection and impulse are obtained, and the effect of the aspect ratio of rectangular plates is examined. Results from the present methods are also compared with finite element simulation utilizing elastic-plastic material behavior and modal solutions. The effects of the yield condition adopted and the transient response phase on the saturation phenomenon of rectangular plates under pressure pulse loading are respectively discussed.

Developing the Maximum Incremental Reactivity for Volatile Organic Compounds in Major Cities of Central‐Eastern China

AbstractThe Chinese government has identified volatile organic compounds (VOCs) management as a key priority in the fourteenth Five‐Year Plan (2021–2025) to alleviate ground‐level ozone (O3) air pollution. To provide scientific support for VOCs management, we developed the localized maximum incremental reactivity (MIR) for 57 VOCs species (prescribed by the Photochemical Assessment Monitoring Stations (PAMS)) in eight representative cities and averaged urban conditions over Central‐Eastern China, with application of the Master Chemical Mechanism box model coupled with solid observational constraints. Though the exact environmental conditions differ among cities, all of them are in VOCs‐limited O3 formation regime, underlining the importance of VOCs to O3 formation. The MIRs constructed based on regional average scenarios are well representative of those constructed based on individual cities, with Guangzhou as an exception due to its vast variance in chemical environments. The localized MIRs displayed the same overall pattern as the U.S. MIRs, but differed largely with respect to a few species (especially alkenes), owing to a combined influence of many factors. We applied the localized MIRs to quantify the concentration‐weighted ozone formation potential (OFP), which elucidate the importance of aromatics to O3 formation in the Chinese metropolitan areas. The top 10 key VOC species together with their explicitly tracked emission sources were determined, which could offer references for the formulation of effective control policies. The localized MIRs developed in this study can be applied to quantify OFPs for VOCs in Chinese cities, which has a great significance to VOCs management and O3 pollution control.

The time‐domain scattering by the elastic shell in a two‐layered unbounded structure

The subject of this research is the time‐domain scattering problem for a three‐dimensional layered elastic shell submerged in a two‐layered fluid separated by an unbounded rough surface. The essence of the problem is to model the scattering interaction between the given elastic shell and some incident wave in a two‐layered medium. Using the exact transparent boundary condition (TBC), we reformulate the unbounded scattering problem into an equivalent initial‐boundary value problem. The well‐posedness is proved for the problem by the Laplace transform and variational method in the s‐domain. Moreover, we show that the reduced problem has a unique weak solution by the energy method. The priori estimates with explicit dependence on the time are derived for the acoustic pressure and the elastic displacement in the time domain.

Semantic Factorization and Descent

Let {mathbb {A}} be a 2-category with suitable opcomma objects and pushouts. We give a direct proof that, provided that the codensity monad of a morphism p exists and is preserved by a suitable morphism, the factorization given by the lax descent object of the two-dimensional cokernel diagram of p is up to isomorphism the same as the semantic factorization of p, either one existing if the other does. The result can be seen as a counterpart account to the celebrated Bénabou–Roubaud theorem. This leads in particular to a monadicity theorem, since it characterizes monadicity via descent. It should be noted that all the conditions on the codensity monad of p trivially hold whenever p has a left adjoint and, hence, in this case, we find monadicity to be a two-dimensional exact condition on p, namely, to be an effective faithful morphism of the 2-category {mathbb {A}}.

Spallation of Carbon Ablators in Arcjet Facility Experiments

Spallation is the mostly undesirable phenomenon where solid particles are ejected from ablative materials leaving less mass to be decomposed at the ablator surface. The exact mechanisms and conditions that promote spallation as well as the extent of it are unclear to this date. This paper presents the results of an extensive test campaign targeted at measuring spallation of carbonaceous ablator materials in an arc heated air flow of . The employed diagnostic methods are photogrammetric surface measurements, high-speed imaging, thermography, and two-color-ratio pyrometry using the raw digital single-lens reflex camera images from the photogrammetry setup. Data from the high-speed camera show a much higher spallation rate for the carbon preform Calcarb than for carbon-phenolic ablators. Temperature measurements show a difference of up to 300 K between carbon fibers and surrounding matrix. The pyrolysis gas from the phenolic resin is found to decrease the spallation rate of the carbon-phenolic ablator ZURAM compared to Calcarb, and the pyrolysis gas pressure slightly increases the distance that particles travel upstream after ejection from the front surface.

Exact artificial boundary condition and 1D time-domain method for seismic response analysis of layered saturated poroelastic half-space

This study proposed a one-dimensional (1D) time-domain finite element method (FEM) for seismic response analysis of a layered saturated soil half-space under obliquely incident plane waves, based on Biot's u-w wave equations. The spatially two-dimensional problem was transformed into an equivalent 1D time-domain problem along the depth according to Snell's law. An exact artificial boundary condition for saturated poroelastic media was developed to simulate the wave absorption and input effects of the truncated half-space. Using the displacement and stress continuity conditions between the adjacent saturated poroelastic-medium layers and combining all finite elements and the exact artificial boundary condition, the total dynamic equation for the spatially 1D problem was obtained. The 1D dynamic equation was solved using the FEM with explicit time integration. The proposed method was verified by analyzing two engineering sites in the time domain and a comparison with the frequency-domain transfer matrix method with fast Fourier transform.

Stable Spinning Deployment Control of a Triangle Tethered Formation System.

The tethered formation system has been widely studied due to its extensive use in aerospace engineering, such as Earth observation, orbital location, and deep space exploration. The deployment of such a multitethered system is a problem because of the oscillations and complex formation maintenance caused by the space tether's elasticity and flexibility. In this article, a triangle tethered formation system is modeled, and an exact stable condition for the system's maintaining is carefully analyzed, which is given as the desired trajectories; then, a new control scheme is designed for its spinning deployment and stable maintenance. In the proposed scheme, a novel second-order sliding mode controller is given with a designed nonsingular sliding-variable. Based on the theoretical proof, the addressed sliding variable from the arbitrary initial condition can converge to the manifold in finite time, and then sliding to the equilibrium in finite time as well. The simulation results show that compared with classic second sliding-mode control, the proposed scheme can speed up the convergence of the states and sliding variables.

Real-time experimental demonstration of a computationally efficient hybrid OFDM DFMA PON

This paper presents the first real-time experimental demonstration of a hybrid OFDM DFMA PON. The presented PON is validated for two channels (I or Q) occupying two subwavelength bands. The hybrid OFDM DFMA PON eliminates the need for a dedicated matching filter at the receiver for each individual channel, by employing a single FFT operation to recover all channels, thereby achieving lower computational complexity. The hybrid OFDM DFMA PON used in conjunction with a joint sideband processing technique, when compared to a DFMA PON under the exact same operating conditions, is shown to offer increased performance, including a lower received optical power of up to 1.2 dB for the adopted FEC limit at a given bit rate. The experimentally demonstrated PON is also proven to be significantly more tolerant to the symbol timing offset effect at the OLT receiver. Furthermore, compared to the DFMA PON’s OLT receiver, the implemented FFT-based receiver is shown to operate at a drastically reduced logic clock rate and with significantly lower DSP complexity. The hybrid OFDM DFMA PON is thus shown to have numerous advantages over the DFMA PON.

Influence of Additive N2 on O2 Plasma Ashing Process in Inductively Coupled Plasma.

One of the cleaning processes in semiconductor fabrication is the ashing process using oxygen plasma, which has been normally used N2 gas as additive gas to increase the ashing rate, and it is known that the ashing rate is strongly related to the concentration of oxygen radicals measured OES. However, by performing a comprehensive experiment of the O2 plasma ashing process in various N2/O2 mixing ratios and RF powers, our investigation revealed that the tendency of the density measured using only OES did not exactly match the ashing rate. This problematic issue can be solved by considering the plasma parameter, such as electron density. This study can suggest a method inferring the exact maximum condition of the ashing rate based on the plasma diagnostics such as OES, Langmuir probe, and cutoff probe, which might be useful for the next-generation plasma process.

Point scintillator dosimetry in ultra-high dose rate electron “FLASH” radiation therapy: A first characterization

FLASH radiation therapy is a novel technique combining ultra-high dose rates (UHDR) with very short treatment times to strongly decrease normal tissue toxicity while preserving the anti-tumoral effect. However, the radiobiological mechanisms and exact conditions for obtaining the FLASH-effect are still under investigation. There are strong indications that parameters defining the beam structure, such as dose per pulse, instantaneous dose rate and pulse repetition frequency (PRF) are of importance. UHDR irradiations therefore come with dosimetric challenges, including both dose assessment and temporal ones. In this work, a first characterization of 6 real-time point scintillating dosimeters with 5 phosphors (Al2O3:C,Mg; Y2O3:Eu; Al2O3:C; (C38H34P2)MnBr4 and (C38H34P2)MnCl4, was performed in an UHDR pulsed electron beam. The dose rate independence of the calibration was tested by calibrating the detector at conventional and UHDR. Dose rate dependence was observed, however, further investigation, including intermediate dose rates, is needed. Linearity of the response with dose was tested by varying the number of pulses and a linearity with R2> 0.9989 was observed up to at least 200 Gy. Dose per pulse linearity was investigated by variation of the pulse length and SSD. All point scintillators showed saturation effects up to some extent and the instantaneous dose rate dependence was confirmed. A PRF dependence was observed for the Al2O3:C,Mg and Al2O3:C- based point scintillators. This was expected as the luminescence decay time of these materials exceeds the inter-pulse time.

Numerical and experimental investigations of uniform fluid distribution for droplet formation in parallelized microfluidics

Droplet microfluidics, which is the manipulation and handling of fluid in microscale channels, has excellent applications in material science, chemical synthesis, genetic analysis, drug discovery and delivery, organ on chips, and tissue engineering. Consequently, this field has attracted significant attention from both academic institutions and industries. However, one of the major constraints is increasing the droplet production rate from a single generator to thousands of generators in order to move from a laboratory scale to industrial standards. Although the scale-up method (in this case, parallelization) of droplet production using theoretical calculations has been extensively investigated, it has been discovered to be occasionally unreliable during experiments. The use of computational fluid dynamics (CFD) simulation, which has recently been applied to droplet microfluidics, has helped to determine the exact factors and conditions required for uniform droplet formation in flow-focusing devices. Thus far, there has been limited study on the simulation of distribution structures that effectively supply fluids to microfluidic devices in parallel orientation. In this study, CFD is used to provide detailed insights into the conditions required to achieve uniform fluid distribution in the delivery and/or distribution channel of microfluidic devices, and experimental analysis is used to further validate the findings.

Inducing multistability in discrete chaotic systems using numerical integration with variable symmetry

Multistability is an inherent property of many nonlinear dynamical systems. However, finding exact conditions where a certain nonlinear system is multistable, is a complex problem. In this study, we propose a novel approach for inducing multistability in a discrete system by applying the numerical integration method with variable symmetry to a continuous monostable system and finding a range of the symmetry coefficients for which multiple attractors coexist in its discrete model. We consider the well-known Chen system as an example, showing that multistability can be induced by discretization with variable symmetry. A special two-stage algorithm is proposed for a fast search for hidden attractors. Using the proposed algorithm, we found several multistable versions of the discrete Chen system and investigated their attractors and basins of attraction. By applying numerical backward error analysis, we discovered a generalized continuous Chen system with additional terms which were not present in the original system and have shown its approximate equivalence to the obtained discrete system. The results of this study can be used for inducing artificial multistability in a wide range of chaotic systems with possible applications in chaotic cryptography, communication, and chaos-based sensing.

RT-qPCR Made Simple: A Comprehensive Guide on the Methods, Advantages, Disadvantages, and Everything in Between

Introduction: In the world of science, many technologies and methodologies exist to contribute to the process of research. Polymerase Chain Reaction (PCR) is a technology that aids in amplifying specific DNA sequences. PCR can be used to determine the presence of a certain DNA gene. In contrast, reverse transcriptase quantitative PCR (RT-qPCR) converts ribonucleic acids (RNA) into complementary DNA (cDNA) which can then be amplified to give a Ct (threshold cycle) value, a representation of how much of the original RNA transcript was present in the sample. Utility: RT-qPCR is a technique that can be used in many areas of research, including forensic pathology to identify individuals through polymorphic repetitive regions of the DNA called short tandem repeats. This method can also be used in diagnosing various viral diseases such as the recent COVID-19 virus. RT-qPCR is also used in numerous laboratory procedures, such as determining cell growth, cell survival, genetic persistence, and more. Challenges: This method does come with many challenges, such as determining the normalization technique to be used in order to effectively compare the Ct value of the sample with the Ct value of the control gene, as there are numerous ways to perform this comparison. This challenge can be mitigated by establishing a common technique within each lab. Determining which housekeeping gene should be used in the normalization process is also a persistent challenge. This can be addressed by researching the different genes and determining which housekeeping gene will best be established as an accurate control. Ensuring the purification of RNA and gathering knowledge of a few base pairs to design primers are other challenges that must be considered as well but can be resolved fairly easily. Limitations: Limitations such as the difficulty in replication can hinder the reliability of the method. The ‘Monte Carlo’ effect and the lack of an established method for normalization further contribute to the difficulty in comparing studies with differing RT-qPCR protocols used. These limitations can be addressed by publishing data with the exact conditions and methods used in the RT-qPCR reaction.

An exact DtN artificial boundary condition for motion analysis of water wave with undulated seabed

This paper is concerned with three-dimensional water wave motion over undulated seabed. For the wave motion problem in seawater of finite depth, the fluid domain is usually unbounded horizontally but bounded vertically by free water surface and seabed which have their own boundary conditions. To study local wave motion over undulated region only, a novel Dirichlet-to-Neumann (DtN) boundary condition is suggested on an artificial circular cylindrical surface by which the fluid domain is divided into an interior region with finite volume and an exterior region. A unique solution of wave motion in the interior region is guaranteed by the novel boundary condition on the artificial cylindrical surface and the other boundary conditions on mean free water surface and undulated seabed. The solution is obtained by using Boundary Integral Equation (BIE) with all boundary conditions including the novel artificial boundary condition. Upon verification for a submerged square cylinder, the present model is extended to the case of an array of rounded-rectangular cylinders or circular paraboloidal shoals.

Smart Plant Monitoring System for Plant Fitness Using IoT

Technology has made amazing strides in all regions of lifestyles which includes enterprise and agriculture. Agricultural improvement is vital to our survival. Researchers are looking to comprise current era into agriculture to broaden new techniques to enhance agricultural lifestyles. People in large towns have a difficult time retaining their veggies in exact condition. This article indicates smart IoT based plant fitness tracking system using microcontroller, sensors like soil moisture, Light detecting register. With the assist of Bolt-IoT cloud user may be capable of get statistics approximately plant fitness on their phone App. Users might be capable of higher control their gardens plant fitness and increase with the assist of this system. The basic application is terrace garden where working people can take care of their plants at office time plus get updated information on their Mobile App. The cause of this system is to introduce and enhance the improvement of IoT for cultivating terrace garden in smart towns in our society.

Integrating pressure sensor control into semi-solid extrusion 3D printing to optimize medicine manufacturing

Semi-solid extrusion (SSE) is a three-dimensional printing (3DP) process that involves the extrusion of a gel or paste-like material via a syringe-based printhead to create the desired object. In pharmaceuticals, SSE 3DP has already been used to manufacture formulations for human clinical studies. To further support its clinical adoption, the use of a pressure sensor may provide information on the printability of the feedstock material in situ and under the exact printing conditions for quality control purposes. This study aimed to integrate a pressure sensor in an SSE pharmaceutical 3D printer for both material characterization and as a process analytical technology (PAT) to monitor the printing process. In this study, three materials of different consistency were tested (soft vaseline, gel-like mass and paste-like mass) under 12 different conditions, by changing flow rate, temperature, or nozzle diameter. The use of a pressure sensor allowed, for the first time, the characterization of rheological properties of the inks, which exhibited temperature-dependent, plastic and viscoelastic behaviours. Controlling critical material attributes and 3D printing process parameters may allow a quality by design (QbD) approach to facilitate a high-fidelity 3D printing process critical for the future of personalized medicine.

K-median: exact recovery in the extended stochastic ball model

We study exact recovery conditions for the linear programming relaxation of the k-median problem in the stochastic ball model (SBM). In Awasthi et al. (Relax, no need to round: integrality of clustering formulations. arXiv:1408.4045, 2015; in: Proceedings of the 2015 conference on innovations in theoretical computer science, pp 191–200, 2015), the authors give a tight result for the k-median LP in the SBM, saying that exact recovery can be achieved as long as the balls are pairwise disjoint. We give a counterexample to their result, thereby showing that the k-median LP is not tight in low dimension. Instead, we give a near optimal result showing that the k-median LP in the SBM is tight in high dimension. We also show that, if the probability measure satisfies some concentration assumptions, then the k-median LP in the SBM is tight in every dimension. Furthermore, we propose a new model of data called extended stochastic ball model (ESBM), which significantly generalizes the well-known SBM. We then show that exact recovery can still be achieved in the ESBM.

Leading Correction to the Local Density Approximation for Exchange in Large-Z Atoms.

The large-Z asymptotic expansion of atomic energies has been useful in determining exact conditions for corrections to the local density approximation in density functional theory. The correction for exchange is fit well with a leading ZlnZ term, and we find its coefficient numerically. The gradient expansion approximation also has such a term, but with a smaller coefficient. Analytic results in the limit of vanishing interaction with hydrogenic orbitals (a Bohr atom) lead to the conjecture that the coefficients are precisely 2.7 times larger than their gradient expansion counterparts, yielding an analytic expression for the exchange-energy correction which is accurate to ∼5% for all Z.

Study and application of Sternberg’s triangular theory in homoeopathic therapeutics

In Homoeopathy, emotion is placed at the highest position to evaluate a healthy person or any diseased condition, but no positive step was taken for evaluation of emotion. From “Sternberg’s triangular theory” intimacy, passion and commitment component were used as instrument or diagnostic tool to find out the exact emotional condition which help us to find out exact similimum. We can also use this triangle as prognostic tool to assess the emotional condition of the patients during the course of the treatment. The objective of our study is to establish a cause-effect relationship of emotional behavior of the patient and the correction of the negative emotion in an easier way.