Although there are many lead-free soldering alloys on the market, none of them have ideal qualities. The researchers are combining binary alloys with a variety of additional materials to create the soldering alloys’ ...Although there are many lead-free soldering alloys on the market, none of them have ideal qualities. The researchers are combining binary alloys with a variety of additional materials to create the soldering alloys’ features. The eutectic Sn-9Zn alloy is among them. This paper investigated the mechanical and electrical properties of Sn-9Zn-x (Ag, Cu, Sb);{x = 0.2, 0.4, and 0.6} lead-free solder alloys. The mechanical properties such as elastic modulus, ultimate tensile strength (UTS), yield strength (YS), and ductility were examined at the strain rates in a range from 4.17 10−3 s−1 to 208.5 10−3 s−1 at room temperature. It is found that increasing the content of the alloying elements and strain rate increases the elastic modulus, ultimate tensile strength, and yield strength while the ductility decreases. The electrical conductivity of the alloys is found to be a little smaller than that of the Sn-9Zn eutectic alloy.展开更多
This article exhibits the sizing, modelling, and characterization of a power supply (output 3.3 V, 200 mA max, 11 days full autonomy) dedicated to powering a wireless sensor node without a battery but usable as simply...This article exhibits the sizing, modelling, and characterization of a power supply (output 3.3 V, 200 mA max, 11 days full autonomy) dedicated to powering a wireless sensor node without a battery but usable as simply as with a battery. This system is modular for various light levels (indoor and outdoor). It is easily integrable into a sensor node, using only commercial circuits. The choices of the photovoltaic surface (amorphous silicon, η 5%, 35 cm<sup>2</sup>) and of the supercapacitors value (2x 25F, 2.7 V) are explained for permanent operation, considering the solar potential and the consumption. An original part of the paper is devoted to the issue of the startup, in which we demonstrate that after a particular preload, once installed, the device can start on request at the desired time (within 15 days) using as a trigger any light source, such as the LED of a mobile phone.展开更多
Introduction: Cleft lip, palate and alveolar (CLPA) are congenital malformations of the face due to a defect in the fusion of embryonic buds during the first weeks of embryogenesis. These malformations affect the uppe...Introduction: Cleft lip, palate and alveolar (CLPA) are congenital malformations of the face due to a defect in the fusion of embryonic buds during the first weeks of embryogenesis. These malformations affect the upper lip, the alveolar bone and the palate. The incidence in Africa ranges from 1/2000 to 1/500 births. Their multidisciplinary management is long and costly. Thus, the help provided by humanitarian organisations during free care campaigns is welcome. Materials and Methods: This is a retrospective descriptive study conducted from August 2014 to July 2016 in the Maxillofacial Surgery and Stomatology Department of the Treichville University Hospital in Abidjan, Côte d’Ivoire. The objective was to describe the epidemiological, clinical and therapeutic aspects of CLPA during a humanitarian campaign for free care. Results: 51 cases of CLPA were operated on. Males were involved in 54.9% of the cases, i.e. a sex ratio of 1.2. The average age of the patients at the time of the operation was 3.44 years with extremes of 3 months and 52 years. Patients with low socioeconomic status represented 84.3% of the cases. Cleft lips (31.4%) and cleft palates (33.33%) predominated. For cleft lips, unilateral forms were the most frequent (73.5%) and the left side was most often affected (59.2%). The most common surgical techniques used were MILLARD cheiloplasty for cleft lips (79.36%) and Dorrance pushback for cleft palates (78.05%). The postoperative course was simple in the majority of cases (80.47%). Patients and/or parents were satisfied with the postoperative results in over 90% of cases. Discussion: Cleft lip and palate are common. Their management by humanitarian missions through mass campaigns allows us to receive a large number of patients affected by this pathology who are treated with a high satisfaction rate. Conclusion: The characteristics of cleft lip and palate in this study are in many respects identical to those described in the literature, but with some differences specific to Africa, notably the absence of antenatal diagnosis and the advanced age at the time of treatment.展开更多
文摘Although there are many lead-free soldering alloys on the market, none of them have ideal qualities. The researchers are combining binary alloys with a variety of additional materials to create the soldering alloys’ features. The eutectic Sn-9Zn alloy is among them. This paper investigated the mechanical and electrical properties of Sn-9Zn-x (Ag, Cu, Sb);{x = 0.2, 0.4, and 0.6} lead-free solder alloys. The mechanical properties such as elastic modulus, ultimate tensile strength (UTS), yield strength (YS), and ductility were examined at the strain rates in a range from 4.17 10−3 s−1 to 208.5 10−3 s−1 at room temperature. It is found that increasing the content of the alloying elements and strain rate increases the elastic modulus, ultimate tensile strength, and yield strength while the ductility decreases. The electrical conductivity of the alloys is found to be a little smaller than that of the Sn-9Zn eutectic alloy.
文摘This article exhibits the sizing, modelling, and characterization of a power supply (output 3.3 V, 200 mA max, 11 days full autonomy) dedicated to powering a wireless sensor node without a battery but usable as simply as with a battery. This system is modular for various light levels (indoor and outdoor). It is easily integrable into a sensor node, using only commercial circuits. The choices of the photovoltaic surface (amorphous silicon, η 5%, 35 cm<sup>2</sup>) and of the supercapacitors value (2x 25F, 2.7 V) are explained for permanent operation, considering the solar potential and the consumption. An original part of the paper is devoted to the issue of the startup, in which we demonstrate that after a particular preload, once installed, the device can start on request at the desired time (within 15 days) using as a trigger any light source, such as the LED of a mobile phone.
文摘Introduction: Cleft lip, palate and alveolar (CLPA) are congenital malformations of the face due to a defect in the fusion of embryonic buds during the first weeks of embryogenesis. These malformations affect the upper lip, the alveolar bone and the palate. The incidence in Africa ranges from 1/2000 to 1/500 births. Their multidisciplinary management is long and costly. Thus, the help provided by humanitarian organisations during free care campaigns is welcome. Materials and Methods: This is a retrospective descriptive study conducted from August 2014 to July 2016 in the Maxillofacial Surgery and Stomatology Department of the Treichville University Hospital in Abidjan, Côte d’Ivoire. The objective was to describe the epidemiological, clinical and therapeutic aspects of CLPA during a humanitarian campaign for free care. Results: 51 cases of CLPA were operated on. Males were involved in 54.9% of the cases, i.e. a sex ratio of 1.2. The average age of the patients at the time of the operation was 3.44 years with extremes of 3 months and 52 years. Patients with low socioeconomic status represented 84.3% of the cases. Cleft lips (31.4%) and cleft palates (33.33%) predominated. For cleft lips, unilateral forms were the most frequent (73.5%) and the left side was most often affected (59.2%). The most common surgical techniques used were MILLARD cheiloplasty for cleft lips (79.36%) and Dorrance pushback for cleft palates (78.05%). The postoperative course was simple in the majority of cases (80.47%). Patients and/or parents were satisfied with the postoperative results in over 90% of cases. Discussion: Cleft lip and palate are common. Their management by humanitarian missions through mass campaigns allows us to receive a large number of patients affected by this pathology who are treated with a high satisfaction rate. Conclusion: The characteristics of cleft lip and palate in this study are in many respects identical to those described in the literature, but with some differences specific to Africa, notably the absence of antenatal diagnosis and the advanced age at the time of treatment.
