Temperature Dependent Current-voltage Characteristics of P-type Crystalline Silicon Solar Cells Fabricated Using Screen-printing Process

We have fabricated p-type crystalline silicon (Si) solar cells using screen-printing process and investigated their electrical properties. Ph screen printing process led to the uniform formation of n+ emitter. As a result of interaction between Ph-dopant paste and Si substrate, a phosphosilicate glass layer was formed on n+ emitter surface. The current-voltage characteristics were carried out in the temperature range of 175 – 450 K in steps of 25 K. The variation in current level at a particular voltage strongly depended on temperature, indicating that the current transport across the junction was a temperature activated process. The reverse leakage current gradually increased with increasing measurement temperature up to 350 K, above which it rapidly increased. Arrhenius plot of the leakage current revealed that reverse leakage current in low and high temperature regions were dominated by the tunneling mechanism, and generation and recombination mechanism, respectively. Keywords: P-type Si solar cell, screen-printing, I-V, tunneling, generation and recombination, reverse leakage curren

The Detection Data Processing Mechanism for Vehicular Cyber Physical System in IoT Environment

With the development of the Internet of Things and big data technology, it was easy to collect personal situation information. The information collected in this way requires the user to support customized services via big data technology. However, traditional situational awareness systems request action through user cognition or provide consistent services for the specific purposes of multiple users. Therefore, this paper proposes a mechanism of Vehicular CPS with situational cognitive function that minimizes direct user intervention for user customization services. In this paper, we designed the system configuration and detailed process based on the scenario of the situation where the user is driving a car. A vector is used to provide a method for determining a dangerous water level by analyzing an abnormal state of a reception threshold with a sensor. The proposed system was analyzed by simulation. By using the authorization step that operates based on the sensor data, we were able to know that the reliability of the user is improved and that the reliable processing of the IoT service is possible. In the future, research for personal authentication and encryption is needed for more secure information processing

All integral slopes can be Seifert fibered slopes for hyperbolic knots

Which slopes can or cannot appear as Seifert fibered slopes for hyperbolic knots in the 3-sphere S^3? It is conjectured that if r-surgery on a hyperbolic knot in S^3 yields a Seifert fiber space, then r is an integer. We show that for each integer n, there exists a tunnel number one, hyperbolic knot K_n in S^3 such that n-surgery on K_n produces a small Seifert fiber space.Comment: Published by Algebraic and Geometric Topology at http://www.maths.warwick.ac.uk/agt/AGTVol5/agt-5-16.abs.htm

Decreased abdominal fat and improved bone metabolism after taekwondo training in obese adolescents

Accumulation of abdominal fat during adolescence is associated with early metabolic dysfunctions and interrupting bone metabolism. This study aimed at investigating the effects of taekwondo training on abdominal fat and bone metabolism in obese adolescents. Twenty male obese adolescents, with a body mass index above 95th percentile (BMI: 29.4±1.90 kg/m2), aged 12-15 years, were assigned to the taekwondo training group (TKD, n=11) and control group (CON, n=9). Supervised taekwondo training was performed for 60 minutes/day, three times/week at 60-80% of participants’ heart rate reserve for 16 weeks. Body composition and bone mineral density (BMD) were estimated by dual X-ray absorptiometry. A computerized tomography scan was applied to estimate total abdominal fat (TAF), abdominal visceral fat (AVF), abdominal subcutaneous fat (ASF), and AVF to ASF ratio (VSR). Blood samples were analyzed for adipocytokines (leptin and adiponectin) and bone turnover markers (osteocalcin- OC and C-terminal telopeptide-CTx). There were significant interaction effects between abdominal fat variables and training where TAF (p<.01) and AVF (p<.05) decreased in TKD group. Bone metabolism including bone formation (OC, p<.05) and resorption markers (CTx, p<.05) were significantly increased only in the TKD group. The present study suggests that taekwondo training can be an effective afterschool activity program for providing health benefits including improving abdominal fat and bone metabolism in obese adolescents

In vitro selection of salt-tolerant Ailanthus altissimaSwingle

Salt-tolerant cell lines of Ailanthus altissima were selected from callus derived protoplasts. Murashige–Skoog (MS) liquid medium incorporated with various concentrations of NaCl was employed to enrich salt-tolerant A. altissima cell lines. Salt-resistant A. altissima cells were transferred on MS solid medium supplemented with 2.5 μM 2,4-dichlorophenoxy acetic acid (2,4-D), 0.5 μM benzyl adenine (BA) and various NaCl concentrations. The callus was cultured on MS medium containing NaCl for 5 months, to determine the survival rate as an index of salt tolerance. The measurement of growth parameters for salt-tolerant cells showed that the selected plant cell lines grew better than the unselected ones at all levels of NaCl tested. The salt-tolerant callus accumulated proline in correlation to the concentration of salts. Media supplemented with BA induced shoot differentiation of salt-resistant A. altissima cells

Vitamin D3 Supplementation Reduces the Symptoms of Upper Respiratory Tract Infection during Winter Training in Vitamin D-Insufficient Taekwondo Athletes: A Randomized Controlled Trial

Vitamin D insufficiency may be associated with increased risk of upper respiratory tract infection (URTI) in athletes. This study examined the effects of vitamin D3 supplementation on salivary immune functions and symptoms of URTI in vitamin D-insufficient taekwondo athletes. Twenty-five male taekwondo athletes, aged 19–22 years with vitamin D insufficiency [serum 25-hydroxyvitamin-D concentrations (25(OH)D, 31.3 ± 1.39 nmol/L)], participated in this study. They were randomized to receive 5000 IU/day of vitamin D3 (n = 13) or placebo capsule (n = 12) during 4 weeks of winter training. Blood samples were collected two times (pre- and post-tests) for analyzing serum 25(OH)D concentration while salivary samples were obtained three times (pre-, mid-, and post-tests) for secretory immunoglobulin A (SIgA) and lactoferrin analyses. The symptoms of URTI were reported daily during the intervention. Serum 25(OH)D concentration significantly increased by 255.6% in the vitamin D group, whereas in the placebo group it did not change (p \u3c 0.001). While the significant increase in SIgA was observed in both groups (p \u3c 0.001), elevated salivary lactoferrin level in response to winter training was found only in the placebo group (p = 0.011). The change in serum 25(OH)D concentration was negatively associated with total URTI symptoms (r = −0.435, p = 0.015). Vitamin D3 supplementation may be effective in reducing the symptoms of URTI during winter training in vitamin D-insufficient taekwondo athletes

Identification of the optimal hiit protocol for fatigue resistance in adolescent athletes: a randomized controlled trial

The combat sports athletes developed great gains in both muscular function and fatigue resistance by utilizing high-intensity interval training (HIIT). However, it has not been investigated fully whether different work-to-rest ratios of HIIT show the effectiveness on muscle function in adolescent athletes. The purpose of the study was to compare different work-to-rest ratios by applying different rest times in response to the identical work time during HIIT on muscle function in adolescent taekwondo athletes. Forty-seven adolescent male taekwondo athletes (mean age: 16.7±0.8 years) were randomly assigned to the control group (n=11) vs. three HIIT groups by work-to-rest ratios; (1) 1:2 [30s:60s] (n=12), (2) 1:4 [30s:120s] (n=12), and (3) 1:8 [30s:240s] (n=12). All groups completed 10 experimental sessions over four weeks, while the control group maintained their regular taekwondo training. Muscular functions were measured by assessing isokinetic muscle strength and endurance of the knee extensor and flexor. The participants performed three sets of twenty maximal extension and flexion contractions at 120°s-1 with a 1-min interval between the sets for fatigue resistance. Blood samples were collected to measure free-testosterone, cortisol, creatine kinase, and urea as stress-to-recovery indicators. A positive effect on improving muscle fatigue resistance was observed at the first set of assessments in the HIIT with 1:4 (Δ10.2%, p<.05) and 1:8 groups (Δ8.6%, p<.05). Additionally, the 1:4 group exhibited fatigue resistance improvement in the second set (Δ7.7%, p<.01) without any changes of stress-to-recovery indicators, while the other groups did not show any improvement. The 30s all-out work with 120s rest time, lasting over a brief 4-week period, improved participants’ fatigue resistance. A certain amount of rest time between high-intense movements is required to optimize muscle development in adolescent athletes compared with insufficient rest time