Chemical and thermal profile of Plectranthus amboinicus essential oil for its application as a bioherbicide

The species Plectranthus amboinicus is an aromatic herb with great application in popular medicine due to the diversity of biological properties. Chemically, its essential oil (EO) is characterized by two chemotypes, thymol and carvacrol, which vary depending on factors such as seasonality. Despite being an extensively exploited species, studies of the bioherbicidal potential of this species are insufficient. In this context, the EO of P. amboinicus leaves, extracted in two different seasonal periods, were characterized regarding chemical profile (by gas chromatography mass spectrometry - GC-MS) and thermal profile (DTG) and was subjected to bioherbicide tests (germination test and seedling development) against Eragrostis plana, commonly known as capim annoni, an invader of pastures in the Pampas region. P. amboinicus EO was a potent inhibitor of E. plana germination, reducing accumulated germination by over 70% when exposed to 0.1% EO, and a complete inhibition of germination was observed when exposed to 0.5%. Following the effects observed in germination, the initial growth of E. plana was significantly affected by concentrations above 0.05%. The major constituent identified via GC-MS was carvacrol, representing 87.5% of the volatile composition of P. amboinicus leaves. In addition, P. amboinicus EO presented high thermal stability up to 100 °C, which is an interesting result regarding its use as a bioproduct.

Significance low oscillating magnetic field and Hall current in the nano-ferrofluid flow past a rotating stretchable disk

The present investigation involves the Hall current effects past a low oscillating stretchable rotating disk with Joule heating and the viscous dissipation impacts on a Ferro-nanofluid flow. The entropy generation analysis is carried out to study the impact of rotational viscosity by applying a low oscillating magnetic field. The model gives the continuity, momentum, temperature, magnetization, and rotational partial differential equations. These equations are transformed into the ODEs and solved by using bvp4c MATLAB. The graphical representation of arising parameters such as effective magnetization and nanoparticle concentration on thermal profile, velocity profile, and rate of disorder along with Bejan number is presented. Drag force and the heat transfer rate are given in the tabular form. It is comprehended that for increasing nanoparticle volume fraction and magnetization parameter, the radial, and tangential velocity reduce while thermal profile surges. The comparison of present results for radial and axial velocity profiles with the existing literature shows approximately the same results.

Role of Cattaneo–Christov heat flux in an MHD Micropolar dusty nanofluid flow with zero mass flux condition

This investigation aims to look at the thermal conductivity of dusty Micropolar nanoliquid with MHD and Cattaneo–Christov heat flux flow over an elongated sheet. The novelty of the envisioned mathematical model is augmented with the added impacts of the heat source/sink, chemical reaction with slip, convective heat, and zero mass flux boundary conditions. The salient feature of the existing problem is to discuss the whole scenario with liquid and dust phases. The graphical depiction is attained for arising pertinent parameters by using bvp4c a built-in MATLAB function. It is noticed that the thermal profile and velocity field increases for greater values of liquid particle interaction parameter in the case of the dust phase. An escalation in the thermal profile of both liquid and dust phases is noticed for the magnetic parameter. The rate of mass transfer amplifies for large estimates of the Schmidt number. The thickness of the boundary layer and the fluid velocity are decreased as the velocity slip parameter is augmented. In both dust and liquid phases, the thermal boundary layer thickness is lessened for growing estimates of thermal relaxation time. The attained results are verified when compared with a published result.

3D Measurement of ESP Motor Skin Thermal Profile in Horizontal SAGD Well

A high-density 3D Electric Submersible Pump (ESP) motor skin thermal measurement project was carried out in an operating Steam Assisted Gravity Drainage (SAGD) well under varying ESP operating conditions. Utilizing high density Bragg grating fiber and a novel fiber optic interrogator technology a fiber optic measurement string was developed to allow for temperature measurement in 4 cm spacing and on 5 sides of an ESP motor. Utilizing this technology, a special ESP motor housing was developed, and a novel means of fiber optic string deployment engineered which allowed an instrumented ESP motor to be installed in an operating SAGD wellbore and a 3D high density thermal profile to be obtained under operating conditions. The ESP was installed in a SAGD well in a relatively horizontal orientation and utilized a bottom-inflow style pump intake. The ESP was operated in several loading and flow rate scenarios to observe the effects of operating in different conditions. The objective of the testing program was to measure the thermal profile around the circumference and length of the ESP motor both to understand potential temperature differentials across the ESP motor and what thermal transfer may be occurring to the surrounding production fluid passing the ESP motor. The information collected from this testing program is intended to further the understanding of how the thermal profile of the ESP motor correlates with wellbore temperature, ESP motor loading and motor temperature modeling predictions.

Impact of autocatalytic chemical reaction in an Ostwald-de-Waele nanofluid flow past a rotating disk with heterogeneous catalysis

The nanofluids owing to their alluring attributes like enhanced thermal conductivity and better heat transfer characteristics have a vast variety of applications ranging from space technology to nuclear reactors etc. The present study highlights the Ostwald-de-Waele nanofluid flow past a rotating disk of variable thickness in a porous medium with a melting heat transfer phenomenon. The surface catalyzed reaction is added to the homogeneous-heterogeneous reaction that triggers the rate of the chemical reaction. The added feature of the variable thermal conductivity and the viscosity instead of their constant values also boosts the novelty of the undertaken problem. The modeled problem is erected in the form of a system of partial differential equations. Engaging similarity transformation, the set of ordinary differential equations are obtained. The coupled equations are numerically solved by using the bvp4c built-in MATLAB function. The drag coefficient and Nusselt number are plotted for arising parameters. The results revealed that increasing surface catalyzed parameter causes a decline in thermal profile more efficiently. Further, the power-law index is more influential than the variable thickness disk index. The numerical results show that variations in dimensionless thickness coefficient do not make any effect. However, increasing power-law index causing an upsurge in radial, axial, tangential, velocities, and thermal profile.