Iranian Journal of Science and Technology, Transactions A: Science最新文献

In this article, the geometric process (GP) is employed to conduct statistical inference for accelerated life testing under constant stress, using type-I censoring within the Power function distribution (PFD). The lifespans of test items forms a GP as stress levels increases. The maximum likelihood estimation approach is applied to obtain both point and interval estimates of the model parameters. In addition, Bayesian estimation is carried out via the Markov Chain Monte Carlo (MCMC) procedure, incorporating the squared error loss function (SELF), the general entropy loss function (GELF), and the linear exponential loss function (LINEX). The performance of these estimation methods is evaluated through simulation studies, and their practical applicability is demonstrated using two real datasets.

This paper presents a novel sequence of operators based on parameterized Laguerre polynomials for the approximation of functions on ([0,infty )). It incorporates an additional shape parameter (rho _{o}) in the formulation of parameterized Laguerre polynomials, enabling greater flexibility and improved behavior of the proposed operators. It also examines their convergence properties using mathematical tools. The results of the approximation performance of these new operators are shown through numerical examples and graphs. The proposed modification improves the approximation properties of the operators.

Weed management in wheat production systems increasingly demands sustainable alternatives to synthetic herbicides. This study evaluated the bioherbicidal potential of crude hydroalcoholic extracts of root and aerial parts of Ferula persica (FRE and FSE, respectively) for managing canary grass (Phalaris minor Retz.) in wheat (Triticum aestivum L.) systems. Extracts (0.25% and 0.5% w/v) were tested for their effects on germination, physiological traits, and competitive performance of both species under monoculture and co-culture conditions. Ferula extracts significantly reduced seed germination of both wheat and canary grass seeds. In monoculture conditions, the extracts increased shoot wheat and canary grass biomass. Under co-culture conditions, however, the combined stress of wheat competition and extract application significantly reduced biomass, soluble sugars, and secondary metabolites, including phenolics, flavonoids, and anthocyanins in canary grass, while in wheat caused greater physiological tolerance and, in some cases, enhanced secondary metabolism. Competitive indices confirmed strong asymmetric competition in favor of wheat: relative yield values for wheat were consistently above 1.0 (RYw = 1.09–1.71), whereas canary grass exhibited extremely low relative yields (RYp = 0.031–0.049). The competitive balance index (Cb = 3.10–4.01) consistently indicated wheat dominance across all treatments, and weed suppression exceeded 95% even at the lowest extract concentration (0.25%), without any reduction in crop relative yield. These findings demonstrate that F. persica extracts can suppress canary grass growth through a combination of allelopathic and competition-mediated mechanisms in wheat, supporting their potential development as natural bioherbicides for sustainable weed management in wheat production systems.

The effect of electron-beam plasma (EBP) on the charging of a typical virus model is investigated analytically. This study aims to determine how EBP disrupts the viral envelope and the conditions under which virus destruction occurs most rapidly. These conditions are analyzed by considering the relevant cross-section for EBP–microparticle interactions within the orbit-limited motion (OLM) model and by applying Maxwellian and Tsallis distributions. The results indicate that both the physical characteristics of the EBP and the structural properties of the viruses directly affect the charging rate. Major parameters, including the initial conditions, non-extensive parameter, Young’s modulus, EBP flux, energy, and density, are identified as essential factors governing the charging process. This process, in turn, leads to the inactivation and destruction of viruses and other similar microorganisms. Therefore, the theoretical framework developed here supports the broad applicability of plasma technology in practical healthcare-related applications, particularly for environmental pollution control, decontamination and the treatment of viral diseases.

In this paper, we study n-secondary submodules and introduce the concept of weakly n-secondary submodules. Then we investigate some basic properties of this class of submodules.

Let (mathfrak {A}) be a prime (*)-algebra containing a nontrivial projection, and let (Psi = {psi _{m}}_{min mathbb {N}}) be a family of nonlinear mappings satisfying

for all (A_1, A_2, cdots , A_{n+1}in mathfrak {A}) and (n ge 2). In this article, we prove that (Psi ={psi _{m}}_{min mathbb {N}}) is an additive higher (*)-derivation, except in the case where n is even and (diamond _{2u-1} = cdot), (diamond _{2u} = circ) for (1 le u le [n/2]). For this exceptional case, a conjecture is proposed in the paper. As applications, we characterize the structure of such nonlinear mixed bi-skew Jordan-type higher derivations on factor von Neumann algebras.

This paper investigates a coordinated search problem in three-dimensional space when the target location is random and described by a spatial probability distribution. The search region is modeled as a spherical domain centered at the origin and partitioned into N symmetric spherical sectors, each assigned to a search agent. Within its sector, each agent performs an expanding radial search combined with systematic scanning of spherical surfaces. Using spherical coordinates and a probabilistic decomposition of the domain into successive spherical shells, an analytical expression for the expected detection time is derived. The optimal search strategy is obtained by minimizing the expected detection time with respect to the sequence of expansion radii. For the case of a spherical normal distribution, explicit probabilistic expressions are obtained and recursive relations are established that characterize the optimal radii ensuring monotone spatial coverage. The analytical formulation further allows asymptotic analysis with respect to the number of searchers, showing that the expected detection time decreases as the number of coordinated agents increases. Numerical experiments illustrate the theoretical results and highlight the influence of key parameters on search efficiency. The proposed framework extends coordinated sector-based search models from planar environments to three-dimensional domains and provides a scalable mathematical basis for multi-agent search operations under spatial uncertainty.

This paper presents the Hausdorff measure of noncompactness (MNC) within the framework of the generalized Hahn sequence space. By applying the MNC, we explore the existence of solutions for nonlinear Caputo fractional differential equations subject to three-point integral boundary conditions in the generalized Hahn sequence space. We apply certain sufficient conditions to ensure the uniqueness of solutions to the aforementioned problem, utilizing the Banach fixed-point theorem, and discuss the Hyers-Ulam stability of the problem. In conclusion, the analytical framework is complemented by illustrative examples that demonstrate the validity and applicability of the main results.

This study investigated genetic variation associated with ethyl methanesulfonate (EMS) treatment in in vitro–grown shoots of potato (Solanum tuberosum L.) cultivars Agria, Marfona, and Lady Olympia using Inter Simple Sequence Repeat (ISSR) molecular markers. Shoot-tip explants were exposed to different EMS concentrations and exposure durations, and regenerated plantlets were analyzed to evaluate molecular polymorphism. Out of 24 ISSR primers screened, 11 produced clear and reproducible polymorphic banding patterns. ISSR analysis revealed differences in band profiles among cultivars and treatment combinations, indicating treatment- and genotype-associated genetic variation. The highest polymorphism level was observed in the Agria cultivar, while lower levels were recorded in Marfona and Lady Olympia. Cluster analysis (UPGMA) and principal component analysis (PCA) showed partial grouping of samples according to genetic similarity, with some EMS-treated individuals displaying divergence from control samples. Analysis of Molecular Variance (AMOVA) indicated that most genetic variation was distributed within cultivars, while a smaller proportion was attributed to differences among cultivars. Overall polymorphism was slightly higher in EMS-treated samples compared with controls, suggesting that EMS treatment may contribute to detectable molecular variation under in vitro conditions. However, ISSR markers detect dominant banding patterns and do not directly confirm specific mutation events. Therefore, the observed variation should be interpreted as EMS-associated genetic diversity rather than confirmed EMS-induced mutations. These findings demonstrate that ISSR markers can be effectively used as a preliminary tool to assess genetic variation induced under mutagenic conditions in potato breeding materials.