4 research outputs found
Low-frequency noise in AlTiO/AlGaN/GaN metal-insulator-semiconductor heterojunction field-effect transistors
No full textUsing aluminum titanium oxide (AlTiO, an alloy of Al2O3 and TiO2) as a high-k gate insulator, we fabricated and investigated AlTiO/AlGaN/GaN metal-insulator-semiconductor heterojunction field-effect transistors. From current low-frequency noise (LFN) characterization, we find Lorentzian spectra near the threshold voltage, in addition to 1/f spectra for the well-above-threshold regime. The Lorentzian spectra are attributed to electron trapping/detrapping with two specific time constants, ~25 ms and ~3ms, which are independent of the gate length and the gate voltage, corresponding to two trap level depths of 0.5-0.7 eV with a 0.06 eV difference in the AlTiO insulator. In addition, gate leakage currents are analyzed and attributed to the Poole-Frenkel mechanism due to traps in the AlTiO insulator, where the extracted trap level depth is consistent with the Lorentzian LFN. [ABSTRACT FROM AUTHOR]</p
GAMBARAN DAYA HAMBAT EKSTRAK ETANOL BIJI PETAI (Parkia speciosa Hassk.) TERHADAP BAKTERI Salmonella typhi
No full textDemam tifoid merupakan penyakit endemik di Indonesia yang disebabkan oleh bakteri Salmonella typhi. Banyaknya kasus resisten antibiotik menyebabkan masyarakat mulai beralih ke obat-obatan alternatif salah satunya tanaman petai (P.speciosa Hassk). Biji petai (P.speciosa Hassk) berpotensi untuk menjadi obat alternatif terhadap penyakit demam tifoid. Penelitian ini bertujuan untuk mengetahui aktivitas antibakteri ekstrak etanol biji petai (P.speciosa Hassk) terhadap bakteri Salmonella typhi.
Penelitian ini berupa penelitian eksperimental menggunakan metode difusi cakram. Biji petai diekstraksi menggunakan teknik maserasi dengan pelarut etanol. Ekstrak kental dilarutkan menjadi konsentrasi 25%, 50%, 75%, dan 100%. Kertas saring yang telah direndam di dalam konsentrasi uji diletakkan di atas media agar yang telah ditanami bakteri S.typhi. Cawan perti selanjutnya diinkubasi selama 24 jam. Diameter zona hambat diukur menggunakan jangka sorong. Data hasil penelitian dianalisis secara statistik.
Hasil penelitian menunjukkan rerata diameter zona hambat tiap konsentrasi secara berurutan adalah 0,75mm (25%), 0,87mm (50%), 1,62mm (75%), dan 2mm (100%). Rerata zona hambat ekstrak biji petai berbeda jauh dibandingkan rerata zona hambat kontrol positif (kloramfenikol) yaitu 22,45 mm.
Kesimpulan penelitian ini adalah ekstrak etanol biji petai (P.speciosa Hassk) memiliki efek antibakteri yang lemah atau tidak sensitif terhadap bakteri S.typhi. Tidak terdapat perbedaan yang signifikan hasil rerata zona hambat antar tiap konsentrasi ekstrak etanol biji petai (P.speciosa Hassk). Saran untuk penelitian selanjutnya adalah menguji aktivitas antibakteri dengan menggunakan senyawa aktif yang terkandung dalam petai (Parkia speciosa Hassk)
Unveiling the Antibacterial Activity of Petai Seed Ethanol Extract (Parkia speciosa Hassk) with the Kirby-Bauer Method
No full textThe increasing number of antibiotic resistance cases have to seek alternative treatments, including the petai plant (Parkia speciosa Hassk). Petai seeds primarily contain chemical compounds such as tannins, saponins, alkaloids, and flavonoids, which are known for their antibacterial properties. Objective: To determined the antibacterial activity of petai seed ethanol extract (P. speciosa Hassk) against Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella typhi. Methods: This experiment used the Kirby-Bauer Method. Petai seeds were extracted with ethanol using maceration techniques, and the viscous extract was dissolved into concentrations of 25%, 50%, 75%, and 100%. Screening paper soaked in the extract was placed on agar plates inoculated with the test bacteria, and the plates were incubated for 24 hours. The inhibition zones were measured with a caliper, and the data were analyzed statistically. Results: The study found that the ethanol extract of petai seeds exhibited moderate antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa and weak antibacterial activity against Salmonella typhi. Conclusion: Increasing the concentration of the extract significantly enhanced its antibacterial effect against Staphylococcus aureus and Pseudomonas aeruginosa, indicating that petai seed ethanol extract could be a potential alternative treatment for bacterial infections.Keywords: antibacterial, extract ethanol, Kirby-Bauer method, petai see
Agricultural productivity and climate smart solutions in southwestern Bangladesh
No full textThis study evaluated the impacts of fertilizer deep placement (FDP) technology introduced by the International Fertilizer Development Center (IFDC) in the designated Feed the Future (FTF) districts in Southwestern Bangladesh. The traditional method of applying fertilizer to rice in this area is broadcasting urea on the flooded rice fields just before planting the crop and then broadcasting more urea after the rice is established. The rice plants absorb only about 30% of the nitrogen that is broadcasted and the rest ends up polluting water sources with excess nitrates and emitting nitrous oxide (N20) through volatilization. The IFDC introduced fertilizer deep placement (FDP) technology to farmers in Bangladesh to improve domestic food security and farmer resiliency among the most vulnerable populations to climate change. According to the IFDC, FDP increases the efficiency of nitrogen applied by placing urea briquettes 7-10 cm into the soil by the roots. The urea briquettes slowly release nitrogen in the soil increasing the plant’s absorption of nutrients and decreases nitrates released into the air, irrigated water and runoff. The objective of this research was to examine the effects of adopting FDP technology on farmer yields, fertilizer productivity and revenues and the differences in fertilizer input (kg/ha) between broadcasting and FDP application. This study uses data from a survey of 2,000 farmers from 10 districts in Southwest Bangladesh collected in 2015 and 2016. All farmers surveyed used either deep-placement and/or broadcast prilled urea, thus all farmers used fertilizer during production. The surveyed population is divided into two treatment groups: (1) Fully adopted FDP; and (2) Mixed users using both fertilizer practices. Their yields, revenues, fertilizer productivity and average fertilizer inputs are analyzed through OLS fixed effects regressions. The results show a positive significant relationship between fertilizer deep placement use and yields, total revenues, net-revenues and fertilizer productivity. There is a negative significant relationship between FDP technology and average fertilizer input. The farmers that fully adopted fertilizer deep placement had higher yields, revenues and fertilizer productivity, and less fertilizer input than the mixed and broadcasted users. Additionally, the adoption behavior in the 2015 treatment groups is compared to the behavior in 2016 from the surveyed households. Our study shows that deep-placement technology can be a climate-smart practice in helping farmers mitigate greenhouse gas emissions and slow climate change; however, it continues to face adoption barriers for farmers in Bangladesh.M.S.Includes bibliographical referencesby Selen Altio
