Earticle

In recent years, along with the increase in the use of electrical energy, the number of electrical disasters tends to increase. An electrical connection exists to use the electrical energy where it is needed, and the contact resistance increases at the electrical connection, causing electrical heat generation. Electric fires are caused by such electrical heat generation. In this paper, we evaluated the fire risk of electrical connection finish treatment methods. It has been confirmed that the twist connection by the finish treatment method of the electrical connection causes a relatively high temperature rise, resulting in a high risk of fire. When a dedicated connection terminal was used for the electrical connection, the temperature rise occurred in a limited manner, and the temperature change to the extent that it led to a fire did not occur. Therefore, in order to prevent fires from occurring at the electrical connections that inevitably occur, it is judged that fires can be minimized by using dedicated connection terminals.

본 논문에서는 절연전선의 접속형태에 따라 진동 인가 전․후 접촉저항을 측정하고 분석하였다. 절연전선 중, ‘단선과 연선’, ‘연선과 연선’ 등 다양한 조합으로 접속형태 를 분류하여 실험을 실시하였다. 초저항 측정기(나노볼트미터)를 이용하여 일정한 전류 를 전선에 인가하고 접속부 양단 전압을 측정하여 접촉저항을 계산하였다. 실험결과 구부림이 없는 종단접속의 경우 눈에 띄게 접촉저항이 감소하였으나, 슬리브의 유무에 따라서 접촉저항의 변화는 없었다. 진동시간에 따른 접촉저항의 증·감 유무 또는 풀림 현상은 단시간 진동 실험으로 인해 유의미한 결과를 얻을 수 없었다. 향후, 지속적인 연구가 필요함을 알 수 있었다.

A cylindrical tube connection that has a voltage difference and is separated electrically by an insulator was modelled. The penetration efficiencies of charged particles passing through the connector tube were investigated. Typically, as the particle size decreases and the applied voltage difference increases, the penetration efficiency decreases. To assess the effect of the electrode geometry, various lengths of electric insulator and aerosol flow rate with a fixed tube length and tube diameter were used when calculating penetration efficiencies. The comparison of penetration efficiencies for various electrode geometry setups suggests that the penetration efficiency can be described as a function of the product of applied voltage and electrical mobility of charged particles. The diffusion loss from this and previous studies are compared. Further, an explicit form for penetration efficiency is provided as a function of a new non-dimensional parameter, $Es(=Z_pV/U_{avg}W);\;P_{es}=0.2{\cdot}{\exp}(-Es/0.6342)+0.8{\cdot}{\exp}(-Es/4.7914)$.

Particle connection in a two-component powder compact was quantitatively evaluated by electrical conductivity measurements. As a model system, an alumina powder (median size 0.33 µm, insulator) was mixed with an indium tin oxide powder (ITO, In2O3-SnO2, median size 0.20 µm, electronic conductor) in aqueous solutions at pH 3.0-10.3 to make different types of microstructures of the consolidated powder compacts. The rheological properties of the suspensions and the packing density and electrical conductivity of the powder compacts consolidated by filtration were greatly dominated by the dispersibility of the matrix phase particles (Al2O3) rather than by the dispersibility of the second phase particles (ITO). The Al2O3-ITO compacts prepared from a well-dispersed suspension at pH 3, showed a high electrical conductivity which was independent of the relative density (60-95%). Particle connection between ITO particles was formed in the consolidated green compacts. The electrical conductivity of the powder compacts processed with a high viscosity suspension at pH 10, was low and enhanced when the bulk density exceeded 60% relative density by sintering. The network of ITO particles was formed by a decrease in the distance between ITO particles during the densification.

The power relay can easily control high voltage and high current through metallic contacts. In addition, it has the advantage in reasonable price. So it has been used in many applications. But the power relay has a weak point by mechanical movements. These mechanical movements cause the bouncing phenomenon. Arc and bouncing phenomenon are the main causes of electric abrasion and material erosion. In this study, mechanical repetitive experiments and repetitive experiments in electrically connected state are conducted. Then these two experimental results in terms of bouncing phenomenon and changes in the contact surface are compared. In all number of repetitions, contacts in an electrically connected state cause smaller number of bounce. Also, It has lower contents of silver on eroded surface than the other. The experimental results would be helpful to the further study of contacts life span.

This study examines the religious imagination engendered by the invention of the telegraph in mid-nineteenth-century America and traces its transmission into modern Korean religious literature. In Seongsan Myeonggyeong (聖山明鏡, 1909), the earliest work of comparative religion in Korea, authored by Choe Byeongheon, the telegraph serves as a rhetorical instrument for demonstrating the superiority of Christianity. On the one hand, it is presented as physical evidence that communication with an invisible, transcendent realm is possible. On the other, it functions as a structural model for explaining the relationship between the human nervou s system and the b rain. The o rigins o f this religious imagination surrounding the telegraph can be located in nineteenth-century American religious sources. Samuel Morse, a devout Christian and inventor of the telegraph, understood his invention not merely as a technological innovation but as a religious event, encapsulated in the biblical phrase “What hath God wrought.” The national celebrations surrounding the completion of the transatlantic telegraph cable likewise revealed a confluence of technological progressivism and religious aspiration. Mainstream Protestantism hailed the telegraph as a divinely ordained instrument for connecting the entire world through the Gospel. The Oneida Community, a utopian religious movement, interpreted the telegraph as tangible proof that divine perfection was being realized on earth. Spiritualism, which emerged contemporaneously with the telegraph, adopted electricity as the scientific principle underlying spiritual communication, developed the concept of the “spiritual telegraph,” and constructed a cosmological framework of connectivity extending from the human body to the universe through an analogy between the telegraphic network and the nervous system. In conclusion, as the first technology to enable instantaneous communication across vast distances, the telegraph interacted profoundly with the religious theme of connection to invisible beings. This study demonstrates that religion and technology in the modern world were not separate domains but stood in a relationship of mutual constitution, and proposes that the religious imagination catalyzed by the nineteenth-century telegraph remains a historically valuable resource for reflecting on the relationship between technology and religion in the contemporary Internet age.