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The purpose of this paper is to present a new method for the fabrication of a large-scaled muscle scaffold containing an artificial hollow tube network, which may solve the problems of nutrient supply, oxygen exchange and metabolic waste removal.

In this paper, a ferric chloride structural strength-enhanced sodium alginate hollow tube was used to build the hollow tube network. Gelatin infill was then added to make a large alginate/gelation gel soft tissue scaffold. A pilot experiment was performed and an osmotic test platform was built to study the perfusion and osmotic ability of the 3D printed hollow tube. The essential fabrication parameters (printing velocity and gap) for building the vascular (i.e., hollow tube) network-contained scaffold were investigated. Moreover, cells in culture were spread within the gelation scaffold, and the circulation characteristics of the hollow tube network were studied.

The printed large-scaled scaffold that contained a ferric chloride structural strength-enhanced sodium alginate hollow tube had good perfusion ability. The osmotic distance of the hollow tube reached 3.7 mm in 8 h in this experiment.

The osmotic distance was confirmed by perfusing a phenol solution; although it is more reliable to test for cell viability, this will be investigated in our later research.

This research may provide new insights in the area of tissue engineering for large-scaled vascularized scaffold fabrication.

This paper presents a new method for fabricating large-scaled scaffolds, and the perfusion ability and osmotic distance of a ferric chloride structural strength-enhanced sodium alginate hollow tube are shown.

This paper aims to discuss the inverse problems that arise in various practical heat transfer processes. The purpose of this paper is to provide an identification method for predicting the internal boundary conditions for thermal analysis of mechanical structure. A few examples of heat transfer systems are given to illustrate the applicability of the method and the challenges that must be addressed in solving the inverse problem.

In this paper, the thermal network method and the finite difference method are used to model the two-dimensional heat conduction inverse problem of the tube structure, and the heat balance equation is arranged into an explicit form for heat load prediction. To solve the matrix ill-conditioned problem in the process of solving the inverse problem, a Tikhonov regularization parameter selection method based on the inverse computation-contrast-adjustment-approach was proposed.

The applicability of the proposed method is illustrated by numerical examples for different dynamically varying heat source functions. It is proved that the method can predict dynamic heat source with different complexity.

The modeling calculation method described in this paper can be used to predict the boundary conditions for the inner wall of the heat transfer tube, where the temperature sensor cannot be placed.

This paper presents a general method for the direct prediction of heat sources or boundary conditions in mechanical structure. It can directly obtain the time-varying heat flux load and thtemperature field of the machine structure.

During the past several years, research and studies in the field of solar energy have been continuously increased. One of the substantial applications of solar energy is related to industrial utilization for the drying process by efficient heat transfer methods. This study aims to upgrade the overall performance of an indirect solar dryer using a solar absorber extension tube (SET) equipped with ball-type turbulators.

In this work, three various SETs including hollow (SET Type 1), 6-balls (SET Type 2) and 10-balls (SET Type 3), have been simulated using Fluent software to evaluate heat transfer characteristics and flow structure along the air passage. Then, the modified solar drying system has been manufactured and tested at different configurations.

The findings indicated that adding a SET improved the performance notably. According to the results, using turbulators in the tube has a positive effect on heat transfer. The highest overall thermal efficiency was found in the range of 51.47%–64.71% for the system with SET Type 3. The maximum efficiency increment of the system was found as 19% with the use of SET. Also, the average specific moisture extraction rate, which is a significant factor to survey the effectiveness of the dehumidification system was found between 0.20 and 0.38 kg kWh⁻¹.

In the present study, a novel SET has been developed to upgrade the performance of the solar dehumidifier. This new approach makes it possible to improve both thermal and drying performances.

Concrete-filled double skin tube (CFDST) columns are considered one of the most effective steel-concrete composite sections owing to the higher load carrying capacity as compared to its counterpart concrete-filled tube (CFT) columns. This paper aims to numerically investigate the performance of axially loaded, circular CFDST short columns, with the innovative strengthening technique of providing stiffeners in outer tubes. Circular steel hollow sections have been adopted for inner as well as outer tubes, while varying the length of rectangular steel stiffeners, fixed inside the outer tubes only, to check the effect of stiffeners in partially and full-length stiffened CFDST columns.

The behaviour of these CFDST columns is investigated numerically by using a verified finite element analysis (FEA) model from the ABAQUS. The behaviour of 20-unstiffened, 80-partially stiffened and 20-full-length stiffened CFDST columns is studied, while varying the strength of steel (f_yo = 250–750 MPa) and concrete (30–90 MPa).

The FEA results are verified by comparing them with the previous test results. FEA study has exhibited that, there is a 7%–25% and 39%–49% increase in peak-loads in partially stiffened and full-length stiffened CFDST columns, respectively, compared to unstiffened CFDST columns.

Enhanced strength has been observed in partially stiffened and full-length stiffened CFDST columns as compared to unstiffened CFDST columns. Also, a significant effect of strength of concrete has not been observed as compared to the strength of steel.

Industrial robots are extensively deployed to perform repetitive and simple tasks at high speed to reduce production time and improve productivity. In most cases, a compliant gripper is used for assembly tasks such as peg-in-hole assembly. A compliant mechanism in the gripper introduces flexibility that may cause oscillation in the grasped object. Such a flexible gripper–object system can be considered as an under-actuated object held by the gripper and the oscillations can be attributed to transient disturbance of the robot itself. The commercially available robots do not have a control mechanism to reduce such induced vibration. Thus, this paper aims to propose a contactless vision-based approach for vibration suppression which uses a predictive vibrational amplitude error-based second-stage controller.

The proposed predictive vibrational amplitude error-based second-stage controller is a real-time vibration control strategy that uses predicted error to estimate the second-stage controller output. Based on controller output, input trajectories were estimated for the internal controller of the robot. The control strategy efficiently handles the system delay to execute the control input trajectories when the oscillating object is at an extreme position.

The present controller works along with the internal controller of the robot without any interruption to suppress the residual vibration of the object. To demonstrate the robustness of the proposed controller, experimental implementation on Asea Brown Boveri make industrial robot (IRB) 1410 robot with a low frame rate camera has been carried out. In this experiment, two objects have been considered that have a low (<2.38 Hz) and high (>2.38 Hz) natural frequency. The proposed controller can suppress 95% of vibration amplitude in less than 3 s and reduce the stability time by 90% for a peg-in-hole assembly task.

The present vibration control strategy uses a camera with a low frame rate (25 fps) and the delays are handled intelligently to favour suppression of high-frequency vibration. The mathematical model and the second-stage controller implemented suppress vibration without modifying the robot dynamical model and the internal controller.

That are the responsibilities of facilities managers and within what boundaries and contexts do they undertake them? A common talking point in the facilities management press and on the conference circuit, the question still begs an answer.

The purpose of this paper is to synthesize SnO₂–ZnO hollow nanofibers, study their sensing properties and introduce an attractive candidate for formaldehyde detection in practice.

Pure and SnO₂–ZnO hollow nanofibers were synthesized by electrospinning method and characterized via X-ray diffraction, field-emission scanning electron microscopy and Fourier transform infrared spectroscopy. The formaldehyde-sensing properties were investigated.

The optimum performance was obtained at 260°C by the 14 at.% SnO₂–ZnO hollow nanofiber sensor. The sensor could detect formaldehyde down to 0.1 ppm with rapid response–recovery time (4-6 s and 7-9 s, respectively), high sensitivity, good selectivity and stability. The relationship between the sensor’s sensitivity and formaldehyde concentration suggests that the adsorbed oxygen species on the sensor’s surface is O2−. The prominent sensing properties are attributed to the one dimensional hollow nanofiber structures and the promoting effects of SnO₂.

The sensor fabricated from 14 at.% SnO₂–ZnO fibers exhibits excellent formaldehyde-sensing characteristics. It can be used for formaldehyde detection in practice.

The electrospinning method is a very simple and convenient method for fabricating hollow nanofibers and the sensing material is of low cost.

To the best of the authors’ knowledge, studies on formaldehyde sensing of SnO₂–ZnO hollow nanofibers have not been reported before.

MCP Equipment has introduced a metal‐spraying system capable of coating out‐of‐sight areas — like the interiors of pipes, tubing, cylinders, and hollow castings — previously difficult if not impossible to reach by spray.

The purpose of this study is to examine the energy savings in the indoor environment, using strategies that adopt the characteristics of nature, called biomimetic solutions. This research designed a biomimetic window system to bring daylight into interior spaces in educational buildings where daylight cannot be reached. Specifically, this study assessed how the daylight that was achieved via a biomimetic window system would affect energy savings using an energy simulation method.

This study explored how biomimetic methods would affect the building environment and which biomimetic method would involve the building's energy saving with daylight. The research intended to develop a novel biomimetic window system that can bring daylight to the basement floor of an existing building on a university campus to find out how much the biomimetic window system would affect the energy savings of the building. Referring to the existing building's layout and structure, energy simulation models were developed, and the energy consumptions were estimated.

Simulation models proved that the biomimetic window system has sufficient performance to bring more daylight to the basement floor of the building. Furthermore, it was confirmed that the use of the biomimetic window system for the building could reduce energy usage compared to the actual energy usage of the current building without biomimetic windows.

First, this study was adopted as a computer-designed simulation method instead of using a real-world system. Although this study designed the biomimetic window system based on previous studies, it should be considered the possibility of other problems when the system is actually built in. Second, it is necessary to predict how much an initial budget is required when the system is built. It means that this study did not calculate the lifecycle cost of the biomimetic window system. It will also be necessary to compare energy consumption to the required initial budget. Lastly, this study was simulated based on weather data in cold regions, and it did not compare/analyze different climate regions. Different results may be predicted if the biomimetic window system is built in different climatic regions.

This research showed new practical ways to capture and transmit solar heat and light using a biomimetic solution. Furthermore, using the proposed novel biomimetic window system, the amount of energy reduction can be calculated, and this method could be applied in the interior non-window spaces of academic and related types of buildings.

The purpose of this paper is to study elastic properties of III-V nitride nanotubes (NNTs) using second generation (REBO) potential.

In the present research paper elastic properties of BN, AlN and GaN nanotubes have been investigated, using the second generation REBO potential by Brenner and co-workers, which is a bond order potential earlier used for carbon nanostructures successfully. In the present calculation, the same form of potential is used with adjusted parameters for h-BN, h-AlN and h-GaN. In all these cases the authors have considered graphite like network and strongly polar nature of these atoms so electrostatic forces are expected to play an important role in determining elastic properties of these nanotubes. The authors generate the coordinates of nanotubes of different chirality’s and size. Each and every structure thus generated is allowed to relax till the authors obtain minima of energy. The authors then apply the requisite compressions, elongations and twists to the structures and compute the elastic moduli. Young’s Modulus, Shear Modulus and Poisson’s ratio for single-walled armchair and zigzag tubes of different chirality’s and size have been calculated. The computational results show the variation of Young’s Modulus, Poisson’s ratio and Shear Modulus for these NNTs with nanotube diameter. The results have been compared with available data, experimental as well as theoretical.

The authors have calculated bond length, cohesive energy/bond, Strain energy, Young’s Modulus, Shear Modulus and Poisson’s ratio.

To the best of the knowledge this work is the first attempt to study elastic properties of III-V NNTs using second generation REBO potential