This paper presents the design and hardware implementation of an efficient and optimal induction heating circuit for induction sealing. The circuit has a low implementation cost, so the proposed system with a simple and efficient structure can cover the needs of this technology field. Here, the focus is on the implementation process and practical tips in this field. The proposed induction sealing circuit uses zero-voltage switching technology with parallel MOSFETs. In this structure, by using inductors and capacitors with appropriate tolerable current and voltage, it can provide the power and frequency of the output signal applied to the induction coil for various applications. The use of transistors with suitable current capability makes the circuit appropriate for applications that require stronger magnetic fields. In addition, the induction coil has an elliptical structure, which makes it efficient for sealing a wide range of bottles. It is constructed using Litz wire to reduce power loss in the coil. In the presented structure, the frequency of the output signal is equal to 31 kHz, which is suitable for creating an eddy current in the aluminum foil in the bottle caps. The circuit has been tested and investigated and has acceptable sealing for various industries.

Background: Enteral nutrition through a Naso-Gastric (NG) tube is a technique often used for hospitalized patients who have problems with oral nutrition. It can reduce patients mortality and morbidity if be performed correctly. Several methods are used to reduce risk of misplacement of the tube. In present study, we suggest a type of guide wire for correct placement of NG tubes.Methods: It was a clinical trial study carried out in operation room of Al-Zahra hospital, Isfahan, on 60 patients. After abdominal incision, NG tube was placed using guide wire in first group (n=30) and without it in second group (n=30). Patients’ profiles, times of trial for tube placement, as well as complications were completely registered and analyzed by SPSS (ver.13).Findings: Mean age of patients was 44.9 years (rang: 18-60). The results show that the mean of trials in first group was 1.26, compared with 2.13  in second group (P-value: 0.011). Seven patients in first group and 11 patients in second group confronted with early complications during performing the procedure. These complications were tube entrapment in nasopharynx (16% in first group and 20% in second group), epistaxis (3% in both groups), and revolving of the tube (3% in first group and 13% in second group) (P-value>0.05).Conclusion: It seems that use of guide wire for placing the NG tube lead to lower misplacement of the device and may reduce the risk of further complications.

Cutting with high accuracy is possible using wire electrical discharge machining or WEDM. Nonetheless, while machining parts, amplitude of vibration causes inaccuracy of cutting. The main topic of this research is investigating the factors affecting amplitude of vibration of the wire-tool in WEDM using mathematical governing equation of motion of wire electrode. Hence, machining and finding ways to reduce the amplitude of vibration is the main purpose of this research. The consequence of reducing amplitude of wire vibration is cutting with higher accuracy and having smoother finished surface. In this research, the governing equations of motion of the wire-tool vibration are obtained using the Euler-Bernoulli beam model, fixed at both ends and moving in axial direction. The wire undergoes different forces including the body force produced by electrical discharge, damping force caused by the dielectric fluid, thermal force produced in the machining area and the axial force. Thereafter, the partial differential equation of motion of the wire-tool is converted to an ODE equation using Galerkin's method and then it will be solved using fourth order Runge-Kutta method. The results of this research show that the amplitude of vibration can be decreased by increasing the axial force and the decreasing of electrical discharge frequency, wire length, temperature differences and reduction of the workpiece width. Also, the results show that increasing the temperature by 70 degrees in the axial force of 17.5N can lead to a 60% increase in the vibration amplitude of the wire. Also, the results show that increasing the temperature by 70 degrees in the axial force of 17.5N can lead to a 60% increase in the vibration amplitude of the wire.

The wires used in the wire EDM process are of great importance in this new machining process as the cutting agent of the workpiece. Factors such as the diameter of these wires, their material, and their manufacturing method make their production simply not possible. In the upcoming research, a widely used type of Chinese wire in the domestic industry has been selected, examined, and analyzed. In the early stages of the research, the Chinese wire sample was elementally analyzed and its compounds were extracted, then it was subjected to a tensile test and its mechanical properties were also extracted. In the next steps, the wire was made with the aim of making a Chinese model by two methods of casting and extrusion and was again subjected to chemical analysis and tensile test. Also, in the final stage, all the wires made on the wire EDM machine were put under the same parameters and conditions and tested on a piece of work. The important innovation of the current research is in making wire EDM wire by extrusion method for mass production inside the country. The manufactured wire sample has up to 80% more strength than Chinese wire and is also 10 times softer than that, which increases the strength and softness of the wire leading to greater resistance of the wire and reducing the possibility of its tearing during machining operations.

In this paper, a new feeding structure is applied in the patch antenna design to overcome undesirable features of the earlier multilayer feeding structures while maintaining their interesting features.To more readily understand the operation mechanism of proposed feeding structure, an efficient circuit model has been also presented.It is known that proximity and aperture coupled feeding structures are sensitive to the transverse feed point location. In contrast, the proposed feeding architecture is very easy to fabricate and it overcomes the alignment difficulties arising from the proximity and aperture coupled feeding structures. The CST simulation results, analytic results and measurement ones show good agreement with each other. Moreover, a new miniaturization technique which is based on using High Impedance Wire (HIW) structures has been introduced. Due to their artificial high permeability properties, using proposed method, someone may miniaturize conventional patch antenna without bandwidth and efficiency corruption. Applying suggested method to the proposed antenna structure, two different feeding structures have been designed and compared. Finally, by using AMC structures to load HIW, more miniaturization factor has been achieved.

Single staggered is a design development of normal wire and tube heat exchanger that wires are welded with staggered configuration on two sides. Capacity of wire and tube heat exchanger is the ability of the heat exchanger to release heat. The objective of this study is to analyse the effect of wire pitch (pw) on capacity of single staggered wire and tube heat exchanger. The research method uses Computational Fluid Dynamic (CFD) simulation by ANSYS Fluent to analyse heat transfer of wire and tube; also to analyse airflow at surface the wire and tube. The simulation is experimentally validated by measuring temperatures at some points of wire and tube. Based on results, temperature contours increasing capacity of heat exchanger depend on smaller wire pitch that the highest value is 72.02 W at pw 7 mm. The reason is smaller wire pitch increases area of convection heat transfer surface. Whereas, airflow patterns show air move slowly at the wire and tube surface and flow with free convection. This study contributes new design of wire and tube heat exchanger with CFD and it can be applied to improve the performance of this heat exchanger in refrigeration system and other applications.

Central vein catheterization is a routine and relatively safe procedure in critically ill patients. Complications with this procedure depend to the site of catheterization and the skill of the operator. In addition to the common complications with femoral vein catheterization there are some rare usually preventable side effects related to guide wire and catheter. In our patient who underwent femoral catheterization for acute hemodialysis, we report migration of guide wire through the systemic circulation from the femoral vein to the jugular vein. This is a very rare complication that is a human error and is totally preventable by doing the procedure by a skilled doctor and considering the standards described for central vein catheter insertion.