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In this research, cooling of the target surface consisting of a flat plate with constant heat flux using a pulsating impinging jet is investigated experimentally. In the investigations, the jet Reynolds number (Rej), Prandtl number (Pr) and geometric parameters were kept constant and the effects of these parameters on the heat transfer were analyzed while changing the distance between the jet and the target surface (H/D), amplitude (Ao) and jet frequency (Wo). Experiments were performed for three different blowing distances, four different amplitudes and six different frequencies. The pulsating jet is used as an active heat transfer enhancement method, temperature measurements were made in detail on the experimental setup and Nusselt numbers were calculated with the based on measured temperatures. The results are expressed as a function of dimensionless numbers, and the results are compared with the heat transfer results of continuous jet impingement. Experimental results showed that the pulsating jet has a significant effect on heat transfer enhancement. It was observed that the pulsating jet significantly increased the heat transfer compared to the continuous jets.

Pesticides are commonly used in modern agriculture and are important for global food security. However, postapplication losses due to degradation, photolysis, evaporation, leaching, surface runoff, and other processes may substantially reduce their efficacy. Controlled-release formulations can achieve the permeation-regulated transfer of an active ingredient from a reservoir to a target surface. Thus, they can maintain an active ingredient at a predetermined concentration for a specified period. This can reduce degradation and dissipation and other losses and has the potential to improve efficacy. Recent developments in controlled-release technology have adapted the concepts of intelligence and precision from the pharmaceutical industry. In this review, we present recent advances in the development of controlled-release formulations and discuss details of the preparation methods, material improvements, and application technologies.

The purpose of this research was to study forward-spatter misting patterns by shooting a firearm through a chamber of blood encased in ballistic gel to determine if there is a relationship between bloodstain pattern size as a function of distance and orientation. There is a lack of research on forward spatter, blood travelling in the direction of a bullet, as most studies focus on back spatter, blood travelling in the opposite direction of a bullet. A bullet was fired through ballistic gel containing a blood chamber, depositing bloodstains onto a large sheet of butcher paper as the target surface. In total, there were 34 trials. The distances observed were 10, 20, 40, and 80 cm, the angles tested were 30°, 60°, and 90°. The orientation between the ballistic gel and paper target varied. A criterion was established to observe the overall area and symmetry of the bloodstain patterns. Statistical analyses indicated a negative linear relation relationship between the bloodstain pattern size and the paper’s angle and distance (R2 = 0.78) and the vertical symmetry of the bloodstain (R2 = 0.87). The orientation between the ballistic gel and paper target can impact the bloodstain pattern’s symmetry and size.

A shape memory polymer (SMP) adhesive forms a conformal and hermetic contact with a target surface at the soft, rubbery state and provides a high-strength dry adhesion at the rigid, glassy state. In particular, recent SMP adhesive studies show SMP's ability to adhere to various rough and even underwater yet rigid surfaces. However, achieving and retaining the strong adhesion on flexible target surfaces such as common fabrics has not been reported since a flexible target surface would easily be peeled off from an SMP adhesive, which is too rigid to accommodate the target surface flexing. Here, we introduce the dual adaptation of an SMP adhesive composed of a thin SMP layer and a backing fabric, which involves the shape adaptation to make a strong adhesive contact and the flexure adaptation to tolerate a target surface flexing. To discover the criteria for optimizing both shape and flexure adaptations, we present the theoretical rationale as well as the computational and experimental studies in this work. Based on the findings here, we design a thin SMP adhesive and demonstrate its dry and underwater adhesive performances on common clothes to highlight its potential applications.

The evolution of membrane-type electronics has facilitated the development of stick-and-play systems, which confer diverse electrical functions to various planar or arbitrary curvilinear surfaces. The stick-and-play concept is based on the development of thin electronic devices in a printable format and their subsequent transfer to target surfaces. The development of this technology requires control of the interfacial adhesion of the electronic prints for retrieval from a carrier and transfer to the target surface. First, we discuss the transfer printing for membrane-type electronics, starting from an overview of materials available for flexible substrates, transfer printing of electronic prints for retrieval, and assembly for further integration. Second, we explain the stick-and-play concept based on fabricated membrane-type electronics; “stick” and “play” refer to the transfer of electronic devices and the performance of their electronic functions, respectively. In particular, we broadly survey various methods based on micro/nanostructures, including gecko-inspired, interlocking, cephalopod-sucker-inspired, and cilia structures, which can be employed to stick-and-play systems for enhancing interfacial adhesion with complex target surfaces under dynamic and wet conditions. Finally, we highlight the stick-and-play system application of micro/nanostructures for skin-attachable biomedical electronics, e-textiles, and environmental monitoring electronics.

Experimental investigations have been carried out for impingement heat transfer characteristics of an enclosed dual swirling flame for various enclosure configurations. Effects of the size of the enclosure (DE = 70 mm, 90 mm, 90 mm, 110 mm and 150 mm) and the level of gap between the top of the enclosure and the target surface (G = 12, 16, 20, 24 and 28 mm) have been examined at fixed other operating conditions (Re(o), H/Dh and S). In addition to this, the effects of variation in outer swirling flame Reynolds numbers (Re(o) = 7000–13,000), dimensionless separation distances (H/Dh = 2–5) and the swirl number (S = 0.86, 1.54 and 2.4) have also been examined. Impingement heat transfer characteristics strongly depend on the size of the enclosure (DE) and the level of gap (G). Larger sized enclosures (DE of 110 and 150 mm) with smaller gap levels (G of 12 and 16 mm) perform much better than small sized enclosures (DE of 70 and 80 mm) with larger gap levels (G of 24 and 28 mm). Heat transfer performance continuously increases with an increase in Re(o) in presence of an enclosure in contrast to unenclosed flames where performance deteriorates at high Re(o). The heat transfer enhancement effect in presence of enclosure is more pronounced at larger separation distances (H/Dh of 4 and 5) because of the formation of the outer recirculation zone (ORZ). The effect of the presence of enclosure on impingement heat transfer enhancement becomes more significant at higher levels of swirl.

A novel fast algorithm is proposed to analyze the EM scattering from electrically large conducting targets with varying geometrical shapes. Firstly, the target surface can be constructed with several control points by using the non-uniform rational B-spline surface modeling method. More specifically, the surface integral equation can be rewritten in terms of these control points, which contains the geometrical coordinate information. Moreover, it should be noted that the derivatives of both the L and K operates are needed to describe the perturbation of electric currents. Therefore, a perturbed multilevel fast multipole algorithm (P-MLFMA) is proposed to accelerate the matrix vector multiplication. At last, numerical results are given to verify the accuracy and efficiency of the proposed P-MLFMA. It can be seen that higher computational efficiency can be obtained when compared with both the traditional Monte Carlo method and the Perturbation Approach for MoM.

In magnetron sputtering, only a fraction of the sputtered target material leaving the ionization region is directed toward the substrate. This fraction may be different for ions and neutrals of the target material as the neutrals and ions can exhibit a different spread as they travel from the target surface toward the substrate. This difference can be significant in high power impulse magnetron sputtering (HiPIMS) where a substantial fraction of the sputtered material is known to be ionized. Geometrical factors or transport parameters that account for the loss of produced film-forming species to the chamber walls are needed for experimental characterization and modeling of the magnetron sputtering discharge. Here, we experimentally determine transport parameters for ions and neutral atoms in a HiPIMS discharge with a titanium target for various magnet configurations. Transport parameters are determined to a typical substrate, with the same diameter (100 mm) as the cathode target, and located at a distance 70 mm from the target surface. As the magnet configuration and/or the discharge current are changed, the transport parameter for neutral atoms xi(tn) remains roughly the same, while transport parameters for ions xi(ti) vary greatly. Furthermore, the relative ion-to-neutral transport factors, xi(ti)/xi(tn), that describe the relative deposited fractions of target material ions and neutrals onto the substrate, are determined to be in the range from 0.4 to 1.1. Funding Agencies|Icelandic Research Fund [196141]; Free State of Saxony; European Regional Development Fund [100336119]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009-00971]

This work focuses on the erodent capability of yttria-stabilized zirconia beads impacting on a limestone target surface. The target surface was used as the cap of a hardened steel vial clamped on a SPEX Mixer/Mill 8000. The vial three-dimensional swing results in repeated bead impacts that cause the material removal from the target surface. The mass loss varies linearly with the number of beads, which allowed estimating the mass lost per bead per impact. It amounts approximately to 70 ng, a value that compares fairly well with the one of about 80 ng estimated from the volume of the indents left on the target surface by individual impacts. Experimental findings indicate that the methodology developed can be reliably utilized to investigate solid particle erosion under highly reproducible and controllable experimental conditions.

A computational analysis was carried out on the film cooling technique over the surfaces of eroded plates. The air–water mist coolant was injected through the slotted hole. A flat plate was patterned with various erosions. The loading fraction, f = 4–16%, and blowing ratio, M = 1–1.6, were simulated to understand their influence on the mist film cooling effectiveness. The coolant injection angle or the inclined angle of the secondary slot was kept at α = 35°. It can be observed that the increasing loading fraction raises the film cooling performance. Likewise, a higher blowing ratio can provide a better film cooling over the target surface. Again, it is found that the presence of erosion increases the cooling effectiveness at the particular surface of erosion. Simultaneously, a decrease in the effectiveness can also be noticed at the adjacent flat surfaces. Additionally, the erosions at the further downstream are more effective over the eroded surface compared to the upstream erosions. Considering the size of erosion as a crucial parameter, it was investigated for three different depth sizes. An increment in the mist film cooling performance is observed for the higher depth erosion.

Purpose To characterize treatment plan (TP) quality, a quantitative quality control (QC) tool is proposed. The tool is validated using volumetric modulated arc therapy (VMAT) plans for treatment of prostate cancer by estimating the achievable organ at risk (OAR) sparing, based on the knowledge learned from prior plans. Methods Prostate TP quality was investigated by evaluating the achieved OAR sparing in the rectum and bladder, based on their proximity to target surface. The knowledge base used in this work comprises 450 plans, consisting of 181 homogenous prostate plans and 269 simultaneous integrated boost (SIB) prostate plans. A knowledge‐based algorithm was used to relate the absorbed doses of the OARs (rectum and bladder) and their proximity to the planning target volume (PTV). A metric (Mq,r value) was calculated to characterize the OAR sparing based on the weighted differences of the mean doses at binned distances to the PTV surface. The 90% probability ellipse of the normally distributed OARs Mq,r values was considered to define a threshold above which the treatment plan was re‐optimized. Results Following re‐optimization, 8/11 of the homogenous plans and 6/13 of the SIB plans outside the 90% probability ellipse could be re‐optimized to gain better OAR sparing while achieving the same or better target coverage. However, 3/4 of the homogenous TPs and 1/9 of the SIB TPs between 80% and 90% were improved. Mq,r values of bladder and rectum after re‐optimizing the plans in both groups of homogenous and SIB showed lower values compared to the corresponding values before re‐optimization, which implies that better OARs sparing was achieved. Conclusions This work demonstrates an effective anatomy‐specific QC tool for identifying suboptimal plans and determining the achievable OAR sparing for each individual patient anatomy., publishedVersion

The array model of double-T shock pressure sensor is established. Shock wave is produced by a supersonic object in the air. Pressure is produced in the process of shock wave transmission. Different shock pressure sensors have different time to receive the pressure signal. In this paper, the shooting point calculation model and the finite element model of the double T-shaped array method are established. The simulation experiment is carried out. The law of shock wave propagation is verified. The model can be used to calculate the coordinates of shooting point quickly. This method is suitable for small angle oblique fire location problem, and improves the detection accuracy of shooting point.

Provided are numerically predicted flow structural data for a flow passage with an impingement jet array, as well as numerically predicted surface Nusselt number data for the target surface of the ...