In the recent years, there has been an increasing interest in the enhancement of the efficiency and functionality of engines, particularly the petrol ones. In this work, the four stroke spark ignition internal combustion engine cycle is simulated based on the first law of thermodynamics. The second law analysis is also been conducted to analyse the effects of the ignition timings and combustion duration as well as the engine speed upon the engine efficiency and performance. The availability (exergy) balance equations of the engine cylinder are considered in details. Moreover, the total availability fractions and process irreversibilities are evaluated. By considering the results obtained for brake and indicated mean effective pressure, it is shown that they behave in an opposite way in terms of increasing the engine speed. After perusing the figures, a conclusion is made, revealing that the exergetic efficiency rises by increasing the engine speed, whereas the opposite is true for the brake thermal efficiency. Furthermore, the optimum point at which the total efficiency (both thermal and exergetic) occurs shows that the highest possible level happens at a speed of 2500 rpm.

In this article, the electrode erosion and the gap growth of spark plugs were measured on of a CNG fueled engine after durability tests. Then, the required ignition voltage and the spark quality were investigated by a spark plug test rig. Considering results of measurements, the gap growth increased as the running time increased. Thus, the gap growth of spark plugs with 200 and 280 hours running time were 2 and 4.4 times more than the gap growth of spark plugs with 80 hours running time. Results of the voltage test show that the required voltage is increased with the pressure. The required voltage at 9 bar was 2 times higher than 1 bar. The increase of the required voltage and the adverse effect on the spark quality due to the gap growth are due to more running time. Accordingly, the required voltage was increased 11% at 5 bar while the gap growth was 20%. Comparing results of new and used spark plugs showed that in addition to the gap growth, deposits on the electrodes surface could lead to increase the required voltage.

Originality is an essential requirement for the copyrightability of any artistic and literary work. Creative works are afforded copyright protection only if they are original. Originality has yet to be defined by international or national laws including Iranian Laws. The judicial interpretation of national laws also differ from one another and there is no consensus on the concept of Originality. Under traditional approach, Originality is often referred as to "labor and effort" or "self expression " of the author, whereas the more approach is that of "creativity " and exercise of "skill and judgment ". However, all legal systems recognize that the work must be independent and not copied from another work.The main question of this Article is which approach can strike a balance between author’s rights and public interest to cheap and easy access to artistic works. This article will examine originality under different jurisdictions and concludes the Canadian definition is the more appropriate approach to the said question. Finally, it suggests that the Iranian legislature shall replace the term “creativity” with “skill and judgment” in 14 of article 1 of the copyright bill.

In this study, Y3Al5O12-MgAl2O4 (YAG-Spinel) composites, with different molar ratios (1: 1 and 1: 3), were in-situ fabricated using Reactive Spark Plasma Sintering (RSPS) technique. To this end, Al2O3, MgO, and Y2O3 powders were used as the starting materials. In-situ formation of YAG-Spinel composites was investigated based on the reaction 3. 5 Al2O3 + MgO + 1. 5 Y2O3 → Y3Al5O12 + MgAl2O4. Both synthesis and densification processes were accomplished using a single-cycle RSPS with one-step heating. The RSPS process was performed at a sintering temperature of 1300 ° C for 30 min hold time with a maximum uniaxial pressure of 90 MPa under vacuum conditions. The synthesized phases and microstructures were investigated by X-ray diffraction and field emission scanning electron microscopy. The unwanted phases such as YAP (YAlO3) in a composite microstructure were removed using LiF additive. LiF was used as a sintering aid in the process of sintering. The in-situ synthesized YAG-Spinel composites exhibited no internal infrared transmittance over the infrared wavelength ranges of 2. 5-25 μ m.

Lack of movement or immobility is considered one of the main causes of depression and decrease in quality of life and anxiety in children, by designing targeted movement programs, children's movement and mental health can be helped. In this regard, the aim of this study was to investigate the effect of Spark movement program on reducing children's anxiety. The current research strategy was semi-experimental with a pre-test-post-test design with a control group. The statistical population consisted of female students in one district of Tehran, with an age range of 8 to 12 years, 24 of whom were selected using the available sampling method and after completing the pre-test (completion of the Spence anxiety questionnaire by parents) randomly in Two experimental and control groups were replaced. The experimental group participated in the Spark movement program for 16 sessions, the control group did not do any activity. Finally, the post-test was performed and the results were recorded, and multivariate analysis of variance was used to analyze the data using SPSS version 24 software. The results showed that the level of anxiety of children in the experimental group, compared to the control group, significantly decreased in all 6 scales (obsessive-compulsive disorder, panic / agora phobia, social anxiety, generalized anxiety, separation anxiety and fear of physical injuries). According to the findings of the present study, it seems that Spark movement program as a method of controlling and improving performance can have a significant effect in reducing children's anxiety symptoms.

This article presents the development of a multielectrode spark discharge generator designed to produce multicomponent nanoparticles with precise control over the elemental ratios. This capability is achieved through the creation of two independent spark discharges positioned extremely close to one another, facilitating improved mixing of materials. Both theoretical and experimental studies demonstrate that this new generator exhibits similarities with its predecessor, which simplifies the integration process. The EDX analysis clearly demonstrated the capability to systematically control the atomic fraction of aluminum in combinations of tungsten, copper, and aluminum. This proportion varied from 22% to 2% in nanoparticles, which had an average mobility diameter of 27 nm. These nanoparticles were composed of atomic clusters of the respective materials with an average size of 2 nm. Also, using two independent discharges the elemental composition of two-component nanoparticles can be precisely adjusted over the entire range by using two electrodes made of the same material. Additionally, HR-TEM coupled with SAED analysis revealed a high degree of amorphousness in the nanoparticles, indicating effective mixing of the components. These findings pave the way for the development of multicomponent nanoparticles with tailored properties, holding significant potential for a wide array of scientific and technological applications.