Dynamic model of A DC-DC quasi-Z-source converter (q-ZSC)

Two quasi-Z-source DC-DC converters (q-ZSCs) with buck-boost converter gain were recently proposed. The converters have advantages of continuous gain curve, higher gain magnitude and buck-boost operation at efficient duty ratio range when compared with existing q-ZSCs. Accurate dynamic models of these converters are needed for global and detailed overview by understanding their operation limits and effects of components sizes. A dynamic model of one of these converters is proposed here by first deriving the gain equation, state equations and state space model. A generalized small signal model was also derived before localizing it to this topology. The transfer functions (TF) were all derived, the poles and zeros analyzed with the boundaries for stable operations presented and discussed. Some of the findings include existence of right-hand plane (RHP) zero in the duty ratio to output capacitor voltage TF. This is common to the Z-source and quasi-Z-source topologies and implies control limitations. Parasitic resistances of the capacitors and inductors affect the nature and positions of the poles and zeros. It was also found and verified that rather than symmetric components, use of carefully selected smaller asymmetric components L1 and C1 produces less parasitic voltage drop, higher output voltage and current under the same conditions, thus better efficiency and performance at reduced cost, size and weight

Aktivitas antioxidan ekstrak metanol bunga Gmelina elliptica dari Kalimantan Timur

Gmelina elliptica digunakan penduduk di desa Talisayan, Kalimantan Timur, untuk mengobati otorrhea. Penelitian tentang aktifitas biologi dan antioksidan dari G. elliptica telah banyak dilakukan. Walaupun demikian penelitian aktivitas antioksidan bunga G. elliptica dari Kalimantan Timur belum dilakukan. Penelitian ini dilakukan untuk menganalisa aktivitas antioksidan ekstrak kasar metanol bunga G. elliptica dari desa Talisayan. Aktivitas antioksidan menggunakan uji penangkapan radikal 2,2-diphenyl-1-picrylhydrazyl (DPPH). Aktivitas penangkapan radikal DPPH dari ekstrak mencapai 89,77% pada konsentrasi 0,0050 mg/ml. Jadi bunga G. elliptica dari Kalimantan Timur berpotensi sebagai sumber antioksidan

Aktivitas antioxidan ekstrak metanol bunga Gmelina elliptica dari Kalimantan Timur

Gmelina elliptica digunakan penduduk di desa Talisayan, Kalimantan Timur, untuk mengobati otorrhea. Penelitian tentang aktifitas biologi dan antioksidan dari G. elliptica telah banyak dilakukan. Walaupun demikian penelitian aktivitas antioksidan bunga G. elliptica dari Kalimantan Timur belum dilakukan. Penelitian ini dilakukan untuk menganalisa aktivitas antioksidan ekstrak kasar metanol bunga G. elliptica dari desa Talisayan. Aktivitas antioksidan menggunakan uji penangkapan radikal 2,2-diphenyl-1-picrylhydrazyl (DPPH). Aktivitas penangkapan radikal DPPH dari ekstrak mencapai 89,77% pada konsentrasi 0,0050 mg/ml. Jadi bunga G. elliptica dari Kalimantan Timur berpotensi sebagai sumber antioksidan

Pencegahan dadah golongan berisiko menurut pendekatan psikospiritual al-Ghazālī (W. 505 H.): Drug prevention for risk group based on psychospiritual approaches of al-Ghazālī (D. 505 H.)

The issue of drug abuse nowadays is very worrying despite various research and approaches taken to address this issue. New and recurring drug addiction numbers every year indicate a crucial need for improvements in existing prevention efforts. Prevention is the best approach in combating drug abuse because of the effectiveness and cost-friendly. In addition, risk groups should be a priority in prevention approach so that drug addiction can be avoided before it occurs. Islamic psychospiritual therapy is a spiritual treatment method based on Islamic practices and divine reference. This treatment focuses on the purification of the soul, the formation of self-actualization, and spiritual enhancement which ultimate objective is seeking the pleasure of Allah Almighty. Spiritual therapy implemented in Islamic psychospiritual can form a stronghold to prevent drug use and addiction among risk groups. Al-Ghazālī was one of the most prominent and influential Islamic scholars and has produced numerous works that have been made references in the world of Islamic studies throughout the world. Thus, using qualitative methods, this article outlines Al-Ghazālī's Islamic psychospiritual module. Risk group prevention is managing the risk factors by equipping the group with protective factors. The findings of this article indicate that Islamic psychospiritual approaches discussed by al-Ghazālī contain protective factors of religious belief, endurance, self-esteem, appreciation, hope, gratitude, self-reliance, the purpose of life, and love. Therefore, addressing the issue of drug addiction based on the Islamic psychospiritual approach is a viable alternative

Pencegahan dadah dalam kalangan belia berisiko melalui elemen penghayatan akidah: Drug prevention among at-risk youth through element of aqidah comprehension

Akidah merupakan kunci hubungan dan keyakinan umat Islam kepada Allah SWT. Perkara pertama yang dilakukan Rasulullah SAW ketika diutuskan sebagai Rasul adalah membetulkan akidah masyarakat yang telah terpesong. Di Malaysia, umat Islam berpegang dengan akidah berdasarkan aliran Ahli Sunnah Waljamaah. Meskipun pembelajaran akidah ini telah diterapkan sejak bangku sekolah lagi, namun cabaran penghayatan akidah belia kini berada di tahap yang membimbangkan. Hal ini mengakibatkan pelbagai krisis dan masalah. Dalam menangani isu belia, permasalahan dadah merupakan isu serius yang sering diberi perhatian. Statisitik pertambahan penagih dadah belia baru dan berulang pada saban tahun amat meresahkan meskipun pelbagai pendekatan telah diambil untuk menyelesaikan isu ini. Terdapat keperluan untuk mengenalpasti elemen penghayatan akidah dalam membina daya tahan belia untuk menangani isu dadah. Hal ini kerana daya tahan yang kuat dilihat sebagai faktor pelindung daripada terjebak dengan najis dadah. Justeru, berdasarkan metode kualitatif kepustakaan, artikel ini membincangkan elemen penghayatan akidah yang dapat membina daya tahan belia lalu membentuk pencegahan dadah yang berkesan. Dapatan artikel ini menunjukkan elemen penghayatan akidah, iaitu kefahaman, perasaan dan amalan mempunyai faktor pelindung kepercayaan, pengharapan, pengawasan, konsep balasan, ketaatan, pengawasan, keredaan, kesyukuran, penghargaan, kecintaan, kecekalan, kepatuhan, pengurusan diri dan ketekunan. Nilai-nilai ini menyumbang kepada daya tahan indvidu. Oleh yang demikian, elemen penghayatan akidah hendaklah diperkasakan dalam strategi pencegahan dan diberi perhatian oleh pihak sewajarnya supaya usaha pencegahan dadah di negara ini dapat diperkasakan

Membentuk spiritual individu menurut hadis untuk pencegahan dadah: Moulding individual spirituality in accordance to hadiths for drug prevention

Buku Maklumat Dadah 2017 mencatatkan seramai 18,440 orang penagih baru dikesan dan 7,482 penagih berulang. Angka ini membuktikan terdapat keperluan untuk satu kajian dan sumbangan bagi pemerkasaan langkah pencegahan dadah di negara ini. Pencegahan merupakan kaedah terbaik dan efektif dalam mengurangkan kos menangani penyalahgunaan dadah. Program pencegahan yang lemah akan menyebabkan peningkatan kadar penagihan dan seterusnya wujud pelbagai permasalahan sosial dan peningkatan kos dalam rawatan pemulihan. Kajian menunjukkan kerohanian diri yang lemah merupakan punca utama penagihan dan yang memberi kesan paling kuat. Untuk itu, kajian ini bertujuan untuk mengumpulkan hadis-hadis berkaitan pembentukan spiritual individu sebagai kaedah untuk mencegah diri dari terjebak ke kancah dadah. Kajian menggunakan kaedah analisis secara tematik iaitu dengan mengenal pasti hadis-hadis yang berkaitan. Kajian mendapati elemen spiritual berkaitan mempunyai tujuan hidup, bersyukur, berdikari dan pegangan agama yang utuh memberi peranan dalam mencegah seseorang dari terlibat di dalam dadah

Effect of GA4+7 treatment on the capsaicinoid content of chilli (Capsicum annuum L. var. Kulai)

The effect of GA4+7 treatment on the capsaicinoid content of chilli was studied in chilli fruit grown under glasshouse and field conditions. The major capsaicinoids – capsaicin (CAP), nordihyrocapsaicin (NDHC) and dihydrocapsaicin (DHC) were separated and quantified by HPLC and their identity further confirmed by GCMS. Higher total capsaicinoid content was obtained with GA4+7 treatment compared with the untreated control. More pronounced effect of GA4+7 was observed on NDHC and DHC. The capsaicin content was significantly increased by GA4+7 treatment at peak flowering (PF) and with double application at early flowering and peak flowering (EF + PF) only. The difference between glasshouse and field treated fruit was not significant

Buck–boost converter with no dead or overlap-times

A DC–DC synchronous buck–boost converter that is capable of operation with or without dead or overlap-time is proposed. The topology of the converter is derived from the topology of quasi-impedance source converter where two capacitors and two inductors are used for second-order filtering and energy storage. However, its gain is identical to that of the conventional buck–boost converter (BBC), thereby qualifying it as a BBC. The elimination of dead or overlap-time reduces control complexities and permits higher frequency operation which implies the use of smaller capacitors and inductors. Operation of the converter was successfully verified using control signals without dead or overlap-time using a 50 kHz prototype and its output voltage is compared with the ideal theoretical values