Molecular dynamics simulation in concrete research: A systematic review of techniques, models and future directions

This paper presents a comprehensive review of the application of molecular dynamics simulation in concrete research. The study addresses the background and significance of the topic, providing an overview of the principles, applications, and types of molecular dynamics simulation, with a particular focus on its role in enhancing the understanding of concrete properties. Moreover, it critically examines existing research studies that employ molecular dynamics simulation in concrete research, highlighting the associated benefits and limitations. The paper further investigates various simulation techniques and models employed in concrete research, offering a comparative analysis of their effectiveness. Additionally, the study explores future directions and identifies research needs in the field of molecular dynamics simulation in concrete, while also discussing the potential impact of this approach on the sustainability of the construction industry. By providing a comprehensive overview and critical analysis, this review serves as a valuable resource for researchers and practitioners interested in leveraging molecular dynamics simulation for advancing concrete science and engineering

A COMPARATIVE PLACEBO, CONTROL CLINICAL EVALUATION OF PHALATRIKADI KWATH IN MADHUMEHA WITH SPECIAL REFERENCE TO DIABETES MELLITUS TYPE2

The study was aimed to have a conceptual review of the disease Madhumeha and its treatment in particular to the use of an herbal drug†Phalatrikadi Kwath†and to compare its efficacy with the control drug (metformin) and placebo through scientific parameters in a double blind clinical control trial. Madhumeha, also known as Diabetes Mellitus is one of the types of Vataja prameha, that has been considered as an incurable disease (Mahagada). Due to indulgence in etiological factors it results in the incomplete formation of Kapha and Meda which further proceeds downward through the channels of Mutravaha srotas and get localized at Basti mukha leading to the symptoms like Prabhoota mutrata (polyurea), Avila mutrata (tubidity of urine) etc. As the disease is Chirakari, it requires an effective treatment which can be continued for a long time without any ill effects. Among the many treatment measures mentioned, Phalatrikadi kwath has been selected in this study and the effect was evaluated. The clinical study includes 50 patients of either sex between 30-60 years of age with Madhumeha (Type2 Diabetes Mellitus) were recruited having range of blood sugar (fasting 126-180 mg/dl, postprandial sugar, 200-250 mg/dl) attending the OPD of G.A.M Puri, Odisha and were divided into three groups. Group I (30 patients) were treated with trial drug (Phalatrikadi kwatha), Group II (10 patients) were treated with control drug (Metformin) and Group III (10 patients) were treated with placebo. All the three groups were recommended with uniform classically described diet (Ahara) & regimen (Vihara). Patients were evaluated in an interval of 15 days for one month. FBS, PPBS with clinical sign & symptoms were assayed. After evaluating the total effects of the treatment, it was observed that Phalatrikadi kwath along with diet and regimen gave satisfactory relief in comparison to control drug (metformin)which is an established drug

An Outbreak of Cholera Associated with an Unprotected Well in Parbatia, Orissa, Eastern India

In November 2003, an outbreak (41 cases; attack rate–4.3%; no deaths) of severe diarrhoea was reported from a village in Orissa, eastern India. Thirteen of these cases were hospitalized. A matched case-control study was conducted to identify the possible exposure variables. Since all wells were heavily chlorinated immediately after the outbreak, water samples were not tested. The cases were managed symptomatically. Descriptive epidemiology suggested clustering of cases around one public well. Vibrio cholerae El Tor O1, serotype Ogawa was isolated from four of six rectal swabs. The water from the public well was associated with the outbreak (matched odds ratio: 12; 95% confidence interval 1.2–44.1). On the basis of these conclusions, access to the well was barred immediately, and it was protected. This investigation highlighted the broader use of field epidemiology methods to implement public-health actions guided by epidemiologic data to control a cholera epidemic

Solutions of the Renormalisation Group Equation in Minimal Supersymmetric Standard Model

Renormalisation Group Equation(RGE) for color and top couplings sector of MSSM has been solved. The mass of the top comes out to be 180.363$\pm$ 10.876 GeV and $\beta_{top}$=$\frac{\pi}{2}$. It is conjectured that the masses of the other 11 fermions and the CKM phase angle $\phi$ can be theoretically estimated. The results confirm the fact that the quarks and leptons have been created having equal mass $\sim$ 115 GeV at the MSSM GUT scale $\sim ~2.2\times 10^{16}$ GeV

A model for interacting instabilities and texture dynamics of patterns

A simple model to study interacting instabilities and textures of resulting patterns for thermal convection is presented. The model consisting of twelve-mode dynamical system derived for periodic square lattice describes convective patterns in the form of stripes and patchwork quilt. The interaction between stationary zig-zag stripes and standing patchwork quilt pattern leads to spatiotemporal patterns of twisted patchwork quilt. Textures of these patterns, which depend strongly on Prandtl number, are investigated numerically using the model. The model also shows an interesting possibility of a multicritical point, where stability boundaries of four different structures meet.Comment: 4 pages including 4 figures, page width revise

Tuning gaps and phases of a two-subband system in a quantizing magnetic field

In this work we study the properties of a two-subband quasi-two-dimensional electron system in a strong magnetic field when the electron filling factor is equal to four. When the cyclotron energy is close to the intersubband splitting the system can be mapped onto a four-level electron system with an effective filling factor of two. The ground state is either a ferromagnetic state or a spin-singlet state, depending on the values of the inter-level splitting and Zeeman energy. The boundaries between these phases are strongly influenced by the inter-electron interaction. A significant exchange-mediated enhancement of the excitation gap results in the suppression of the electron-phonon interaction. The rate of absorption of non-equilibrium phonons is calculated as a function of Zeeman energy and inter-subband splitting. The phonon absorption rate has two peaks as a function of intersubband splitting and has a step-like structure as a function of Zeeman energy

Diffusion of particles moving with constant speed

The propagation of light in a scattering medium is described as the motion of a special kind of a Brownian particle on which the fluctuating forces act only perpendicular to its velocity. This enforces strictly and dynamically the constraint of constant speed of the photon in the medium. A Fokker-Planck equation is derived for the probability distribution in the phase space assuming the transverse fluctuating force to be a white noise. Analytic expressions for the moments of the displacement $$ along with an approximate expression for the marginal probability distribution function $P(x,t)$ are obtained. Exact numerical solutions for the phase space probability distribution for various geometries are presented. The results show that the velocity distribution randomizes in a time of about eight times the mean free time ($8t^*$) only after which the diffusion approximation becomes valid. This factor of eight is a well known experimental fact. A persistence exponent of $0.435 \pm 0.005$ is calculated for this process in two dimensions by studying the survival probability of the particle in a semi-infinite medium. The case of a stochastic amplifying medium is also discussed.Comment: 9 pages, 9 figures(Submitted to Phys. Rev. E

Stable two-dimensional solitary pulses in linearly coupled dissipative Kadomtsev-Petviashvili equations

A two-dimensional (2D) generalization of the stabilized Kuramoto - Sivashinsky (KS) system is presented. It is based on the Kadomtsev-Petviashvili (KP) equation including dissipation of the generic (Newell -- Whitehead -- Segel, NWS) type and gain. The system directly applies to the description of gravity-capillary waves on the surface of a liquid layer flowing down an inclined plane, with a surfactant diffusing along the layer's surface. Actually, the model is quite general, offering a simple way to stabilize nonlinear waves in media combining the weakly-2D dispersion of the KP type with gain and NWS dissipation. Parallel to this, another model is introduced, whose dissipative terms are isotropic, rather than of the NWS type. Both models include an additional linear equation of the advection-diffusion type, linearly coupled to the main KP-NWS equation. The extra equation provides for stability of the zero background in the system, opening a way to the existence of stable localized pulses. The consideration is focused on the case when the dispersive part of the system of the KP-I type, admitting the existence of 2D localized pulses. Treating the dissipation and gain as small perturbations and making use of the balance equation for the field momentum, we find that the equilibrium between the gain and losses may select two 2D solitons, from their continuous family existing in the conservative counterpart of the model (the latter family is found in an exact analytical form). The selected soliton with the larger amplitude is expected to be stable. Direct simulations completely corroborate the analytical predictions.Comment: a latex text file and 16 eps files with figures; Physical Review E, in pres