Electromigration effect on Sn-58 % Bi solder joints with various substrate metallizations under current stress

The electromigration behavior of low-melting temperature Sn-58Bi (in wt%) solder joints was investigated with a high current density between 3 and 4.5 × 10³ A/cm² between 80 and 110 °C. In order to analyze the impact of various substrate metallizations on the electromigration performance of the Sn-58Bi joint, we used representative substrate metallizations including electroless nickel immersion gold (ENIG), electroless nickel electroless palladium immersion gold (ENEPIG), and organic solderability preservatives (OSP). As the applied current density increased, the time to failure (TTF) for electromigration decreased regardless of the temperature or substrate metallizations. In addition, the TTF slightly decreased with increasing temperature. The substrate metallization significantly affected the TTF for the electromigration behavior of the Sn-58Bi solder joints. The substrate metallizations for electromigration performance of the Sn-58Bi solder are ranked in the following order: OSP-Cu, ENEPIG, and ENIG. Due to the polarity effect, current stressing enhanced the fast growth of intermetallic compounds (IMCs) at the anode interface. Cracks occurred at the Ni₃Sn₄ + Ni₃P IMC/Cu interfaces on the cathode sides in the Sn-58Bi/ENIG joint and the Sn-58Bi/ENEPIG joint; this was caused by the complete consumption of the Ni(P) layer. Alternatively, failure occurred via deformation of the bulk solder in the Sn-58Bi/OSP-Cu joint. The experimental results confirmed that the electromigration reliability of the Sn-58Bi/OSP-Cu joint was superior to those of the Sn-58Bi/ENIG or Sn-58Bi/ENEPIG joints.     

Biomedical applications of mRNA nanomedicine

As an attractive alternative to plasmid DNA, messenger RNA (mRNA) has recently emerged as a promising class of nucleic acid therapeutics for biomedical applications. Advances in addressing the inherent shortcomings of mRNA and in the development of nanoparticle-based delivery systems have prompted the development and clinical translation of mRNA-based medicines. In this review, we discuss the chemical modification strategies of mRNA to improve its stability, minimize immune responses, and enhance translational efficacy. We also highlight recent progress in nanoparticle-based mRNA delivery. Considerable attention is given to the increasingly widespread applications of mRNA nanomedicine in the biomedical fields of vaccination, protein-replacement therapy, gene editing, and cellular reprogramming and engineering.     

Higher earnings, bursting trains and exhausted bodies: the creation of travelling psychosis in post-reform China

This paper examines the biomedical construction of "travelling psychosis" (TP), a contested psychiatric diagnosis pertaining to a severe mental disturbance that occurs among migrant workers who travel long distance in China's overcrowded trains. Although TP can produce substantial psychiatric morbidity, it is also a socially constructed entity that serves social uses. By subscribing to a ritualistic model of validation and by invoking the rhetoric of scientific authority, Chinese psychiatrists who created TP have been able to accomplish such goals as legitimating its forensic function, securing research funds, enhancing their academic status and raising railway authorities' consciousness about passengers' safety issues. But the "biopsychosocial" paradigm they espouse supplies only a parochial form of social analysis and a spurious sense of comprehensiveness. By privileging proximate risk factors, it fails to address the wider environment of the post-reform political economy that ultimately governs population movement and put migrant workers at risk of health problems. This paper submits that a critical examination of this sanitised biopsychosocial paradigm will enliven biomedical research as well as augment its impact on policy development in China.     

Optical monitoring of silver-based transparent heat mirrors

Both three-layer (TiO(2)-Ag-TiO(2)) and five-layer (TiO(2)-Ag-TiO(2)-Ag-TiO(2)) heat mirrors with optimum transmission in the visible and good reflectance in the IR have been designed by admittance diagram techniques. The mirrors were fabricated successfully by optical monitoring. An interesting anomalous layer was found and explained, and its equivalent refractive index and thickness are 2.015 - i0.016 and 2.56 nm, respectively.     

Will the experience of playing a violent role in a video game influence people’s judgments of violent crimes?

The present study investigates the impact of the experience of role playing a violent character in a video game on attitudes towards violent crimes and criminals. People who played the violent game were found to be more acceptable of crimes and criminals compared to people who did not play the violent game. More importantly, interaction effects were found such that people were more acceptable of crimes and criminals outside the game if the criminals were matched with the role they played in the game and the criminal actions were similar to the activities they perpetrated during the game. The results indicate that people’s virtual experience through role-playing games can influence their attitudes and judgments of similar real-life crimes, especially if the crimes are similar to what they conducted while playing games. Theoretical and practical implications are discussed.     

On the definition of the intuitionistic fuzzy subgroups

In this paper, a new kind of intuitionistic fuzzy subgroup theory, which is different from that of Ma, Zhan and Davvaz (2008) [22], [23], is presented. First, based on the concept of cut sets on intuitionistic fuzzy sets, we establish the neighborhood relations between a fuzzy point $x_a$ and an intuitionistic fuzzy set $A$. Then we give the definitions of the grades of $x_a$ belonging to $A$, $x_a$ quasi-coincident with $A$, $x_a$ belonging to and quasi-coincident with $A$ and $x_a$ belonging to or quasi-coincident with $A$, respectively. Second, by applying the 3-valued Lukasiewicz implication, we give the definition of $(\alpha ,\beta )$-intuitionistic fuzzy subgroups of a group $G$ for $\alpha ,\beta \in \{\in ,q,\in \wedge q,\in \vee q\}$, and we show that, in 16 kinds of $(\alpha ,\beta )$-intuitionistic fuzzy subgroups, the significant ones are the $(\in ,\in )$-intuitionistic fuzzy subgroup, the $(\in ,\in \vee q)$-intuitionistic fuzzy subgroup and the $(\in \wedge q,\in )$-intuitionistic fuzzy subgroup. We also show that $A$ is a $(\in ,\in )$-intuitionistic fuzzy subgroup of $G$ if and only if, for any $a\in (0,1]$, the cut set $A_a$ of $A$ is a 3-valued fuzzy subgroup of $G$, and $A$ is a $(\in ,\in \vee q)$-intuitionistic fuzzy subgroup (or $(\in ,\in \vee q)$-intuitionistic fuzzy subgroup) of $G$ if and only if, for any $a\in (0,0.5]$(or for any $a\in (0.5,1]$), the cut set $A_a$ of $A$ is a 3-valued fuzzy subgroup of $G$. At last, we generalize the $(\in ,\in )$-intuitionistic fuzzy subgroup, $(\in ,\in \vee q)$-intuitionistic fuzzy subgroup and $(\in \wedge q,\in )$-intuitionistic fuzzy subgroup to intuitionistic fuzzy subgroups with thresholds, i.e., $(s,t]$-intuitionistic fuzzy subgroups. We show that $A$ is a $(s,t]$-intuitionistic fuzzy subgroup of $G$ if and only if, for any $a\in (s,t]$, the cut set $A_a$ of $A$ is a 3-valued fuzzy subgroup of $G$. We also characterize the $(s,t]$-intuitionistic fuzzy subgroup by the neighborhood relations between a fuzzy point $x_a$ and an intuitionistic fuzzy set $A$.     

Robust finite-time boundedness of multi-agent systems subject to parametric uncertainties and disturbances

In this paper, we consider finite-time control problems for linear multi-agent systems subject to exogenous constant disturbances and impulses. Some sufficient conditions are obtained to ensure the finite-time boundedness of the multi-agent systems, which could be then reduced to a feasibility problem involving linear matrix inequalities. Numerical examples are given to illustrate the results.     

Humanoid Posture Selection for Reaching Motion and a Cooperative Balancing Controller

Our goal in this research was to develop a motion planning algorithm for a humanoid to enable it to remove an object that is blocking its path. To remove an object in its path, a humanoid must be able to reach it. Simply stretching its arms, which in a humanoid are shorter than its body and legs, is not sufficient to reach an object located at some distance away or on the ground. Therefore, reachability has to be ensured by a combination of motions that include kneeling and orienting the pelvis. However, many posture selection options exist because of the redundancy of a humanoid. In this research, we focused on the optimization of the posture of a humanoid that is reaching toward a point. The posture selected depends on the initial posture, the location of the point, and the desired manipulability of the humanoid’s arms. A cooperative balancing controller ensures the stability of the reaching motion. In this paper, we propose an algorithm for reaching posture selection and a balancing controller for humanoids, and we present the results of several experiments that confirm the effectiveness of the proposed algorithm and controller.     

An efficient reversible data hiding with reduplicated exploiting modification direction using image interpolation and edge detection

Multimedia Tools and Applications - Data hiding is a technique that embeds a cluster of secret messages into the original image. The image with secret messages can be distributed on the Internet...