Effectiveness of White Turmeric Curcuma Zedoaria Rhizome Essential Oil as Larvacide on Aedes Aegypti

White turmeric contains essential oil which has been considered as a potentiallarvacide. This study aimed to know the activity ofwhite turmeric volatile oil on Aedes aegypti larvae mortality IV instar. Volatile oil concentration used are 15,2 ppm, 30,3 ppm, 60,5 ppm, 121 ppm, 242 ppm as well as the positive control (abate) and negative control (CMC Na 1 %) using four replications in each treatment.White turmeric volatile oil was obtained by steam distillation method. Anova test on the result from 24 hour observation showed significant difference in the number of dead larvae between two groups (p = 0,000). Least Significant Difference (LSD) analysis showed that there were differences in total mortality between all treatments at various levels of concentration of essential oil on both control groups (p<0,05). Probit analysis test indicate that turmeric volatile oil on the concentration of 54,5 ppm was the effective concentration of essential oil (LC50) in killing the larvae of A. aegyptiRimpang kunyit putih mempunyai zat aktif berupa minyak atsiri yang selama ini diduga berpotensi sebagai larvasida. Penelitian ini merupakan penelitian eksperimental yang bertujuan untuk mengetahui aktivitas minyak atsiri rimpang kunyit putih terhadap kematian larva nyamuk Aedes aegypti instar IV awal. Tingkat konsentrasi yang dipilih adalah 15,2 ppm, 30,3 ppm, 60,5 ppm, 121 ppm, 242 ppm serta kontrol positif (abate) dan kontrol negatif (CMC Na 1 %) dengan 4 kali replikasi untuk tiap perlakuan. Minyak atsiri rimpang kunyit putih didapatkan melalui metode destilasi uap. Uji Anova dari hasil pengamatan selama 24 jam menunjukkan bahwa ada perbedaan jumlah kematian larva antara kedua kelompok perlakuan (p = 0,000). diperoleh nilai p = 0,000 yang artinya ada perbedaan jumlah kematian larva yang bermakna pada dua kelompok. Hasil analisis Beda Nyata Terkecil (BNT) menunjukkan bahwa terdapat perbedaan jumlah kematian larva antara perlakuan pada berbagai tingkat konsentrasi minyak atsiri rimpang kunyit putih baik pada kelompok kontrol (+) maupun (-) (p<0,05). Hasil uji analisis probit menunjukkan bahwa minyak atsiri rimpang kunyit putih pada konsentrasi 54,5 ppm merupakan konsentrasi yang efektif (LC50) dalam membunuh larva Ae. aegypti

EFFECT OF POST-WELD HEAT TREATMENT ON THE MICROSTRUCTURE AND MECHANICAL PROPERTIES OF ARC WELDED MEDIUM CARBON STEEL

Effect of post- weld heat treatment on the microstructure and mechanical properties of arc welded medium carbon steel was investigated. Medium carbon steel samples were butt- welded by using the shielded metal arc welding technique and, thereafter, heat treated by annealing, normalising and quench hardening in water. The microstructure of the as- welded and post- weld heated samples was characterised by means of optical microscopy while the hardness, toughness and tensile properties of the samples were determined by using Indentec universal hardness testing machine, Izod impact testing machine and Denison tensile testing machine respectively. The results of the optical microscopic test show that fine grains of pearlite in ferrite were obtained in normalized samples and martensite was also observed in quenched samples. On the other hand, mechanical property tests indicated that normalized welded specimens gave good combination of mechanical properties. http://dx.doi.org/10.4314/njt.v35i2.1

Investigating the cooling rate of cane molasses as quenching medium for 0.61% C high carbon steels

The effect of cooling rate of cane molasses as quenching medium for 0.61% C high carbon steels was investigated. Samples of high carbon steel were spheroidized annealed and then machined prior to the hardening process. Molasses solution of viscosity equals to that of engine oil was prepared by adding water. The samples were normalized and then austenitised at 800oC and soaked for 40 minutes and then quenched in water, engine oil, raw molasses and the prepared molasses solution. Cooling rate curves of all the quenching media used were developed. The highest cooling rate of 60oC/s was attained by the prepared molasses solution. Hardness of the test samples was evaluated. The test results obtained show that the highest hardness value (525 HVN) was obtained from the sample quenched in the prepared molasses solution. Microstructures of the various samples were analyzed using OM and SEM. In all the tests samples martensite structure was observed. It was observed that the prepared molasses solution has higher severity of quenching than that of engine oil but lower than that of water. The research showed that cane molasses can harden high carbon steel without cracking the component in the same way as engine oil, hence, molasses could be a very good alternative to engine oil for use as quenching medium

Water Condition of Tajwid Lake in the Langgam District, Pelalawan Regency, Riau Province

Tajwid Lake is an oxbow lakes that located in the Langgam District, Pelalawan Regency,Riau Province. The potency of the Tajwid Lake is currently under reviewed by the governmentof Pelalawan as it will be developed into a tourist destination. Water quality in the lake Tajwidmight be changed as a result of human activities conducted around the lake. A study aims toprovide basic information on water quality and determine the trophic status of the lake wasconducted in February 2016. There are three stations (Station 1, Station 2 and Station 3) and thewater was sampled from three depths, surface, middle and the bottom of the lake. The samplingswere conducted 3 times, once / week. The water quality parameters measured were depth,transparency, temperature, pH, free CO2-, DO, Nitrate and Phosphate concentration. Resultsshown that the depth of the lake was ranged from 6.3 to 12.3 m, transparency 51.3- 69 cm,temperature 27.7-30.3 °C, pH 5, dissolved oxygen 2.3-8.3 mg / L. Free carbon dioxide ranged4.9-13.9 mg / L, nitrate 0.02- 0.11 mg / L, phosphate from 0.02 to 0.1 mg /L. The Nitrate andphosphate concentrations indicate that the condition of the Tajwid Lake is between oligotrophicto mesotrophic

Aktivitas Larvisida Minyak Atsiri Rimpang Kunyit Putih (Curcuma zedoaria) terhadap Larva Aedes aegypti

Abstrak Rimpang kunyit putih (Curcuma zedoaria) mempunyai zat aktif berupa minyak atsiri yang selama ini diduga berpotensi sebagai larvisida. Penelitian ini merupakan penelitian eksperimental yang bertujuan untuk mengetahui daya bunuh minyak atsiri rimpang kunyit putih terhadap larva Ae. aegypti instar IV. Variasi konsentrasi yang digunakan adalah 15,2 ppm, 30,3 ppm, 60,5 ppm, 121 ppm, 242 ppm serta kontrol positif (temefos 1%) dan kontrol negatif (CMC Na 1%) dengan empat kali replikasi untuk tiap perlakuan. Minyak atsiri didapatkan melalui metode destilasi uap. Hasil pengamatan selama 24 jam untuk menguji aktivitas minyak atsiri sebagai larvisida diuji dengan Anava, diperoleh nilai p = 0,000, artinya terdapat perbedaan jumlah kematian larva yang bermakna pada dua kelompok. Analisis Post-Hoc (LSD) menunjukkan ada perbedaan jumlah kematian larva antara perlakuan pada kelompok kontrol positif dengan semua perlakuan pada berbagai tingkat konsentrasi minyak atsiri rimpang kunyit putih (p<0,05). Demikian juga perlakuan pada kelompok kontrol negatif, terdapat perbedaan bermakna dengan semua perlakuan pada berbagai tingkat konsentrasi minyak atsiri rimpang kunyit putih (p<0,05). Hasil uji analisis probit menunjukkan bahwa pada konsentrasi 54,5 ppm mengakibatkan kematian 50% populasi larva uji. Kesimpulannya bahwa minyak atsiri rimpang kunyit putih berpotensi sebagi larvisida nyamuk Ae. aegypti. Kata kunci: minyak atsiri rimpang kunyit putih, larva Ae. aegypti Abstract White turmeric (Curcuma zedoaria) has an active substance in the form of volatile oils that have been alleged potential as larvacide. This was an experimental study aimed to determine the white turmeric rhizome volatile oils’ activity against the in star 4 larvae Aedes aegypti. The concentrations used were 15.2 ppm, 30.3 ppm, 60.5 ppm, 121 ppm, 242 ppm. Furthermore, a positive control (temefos 1%) and negative control (CMC Na 1%) with 4 times replication for each treatment were applied. White turmeric volatile oil was obtained by steam distillation method. The observation for 24 hours to test the volatile oils’ activity as larvicide were tested with Anava. The p value = 0.000 was obtained, which means at least there was difference of larvae mortality in the two groups. The results post-hoc analysis (LSD) showed that there were differences in the number of dead larvae between the treatments in the positive control group to all various levels treatment of white turmeric rhizome volatile oil concentration (p<0.05). Then, the treatment of negative control group showed significant differences in all various levels treatment of white turmeric rhizome essential oil concentration (p<0.05). Probit analysis of the test results showed that white turmeric rhizome volatile oil at the concentration of 54.5 ppm could result in the death of 50% population of test larvae. It could be concluded that the white turmeric volatile oil could be used as potential larvicide to eradicate Ae. aegypti mosquito. Hence, to destroy the dengue hemorrhagic fever disease vector. Keywords: white turmeric rhizome essential oil, Ae. aegypti larva

Investigating the cooling rate of cane molasses as quenching medium for 0.61% C high carbon steels

The effect of cooling rate of cane molasses as quenching medium for 0.61% C high carbon steels was investigated. Samples of high carbon steel were spheroidized annealed and then machined prior to the hardening process. Molasses solution of viscosity equals to that of engine oil was prepared by adding water. The samples were normalized and then austenitised at 800oC and soaked for 40 minutes and then quenched in water, engine oil, raw molasses and the prepared molasses solution. Cooling rate curves of all the quenching media used were developed. The highest cooling rate of 60oC/s was attained by the prepared molasses solution. Hardness of the test samples was evaluated. The test results obtained show that the highest hardness value (525 HVN) was obtained from the sample quenched in the prepared molasses solution. Microstructures of the various samples were analyzed using OM and SEM. In all the tests samples martensite structure was observed. It was observed that the prepared molasses solution has higher severity of quenching than that of engine oil but lower than that of water. The research showed that cane molasses can harden high carbon steel without cracking the component in the same way as engine oil, hence, molasses could be a very good alternative to engine oil for use as quenching medium

Characterization of West and Central African accessions from a pearl millet reference collection for agro-morphological traits and Striga resistance

To promote the utilization of West and Central African (WCA) genetic resources of pearl millet [Pennisetum glaucum (L.) R. Br.], this study aimed at agro-morphological characterization of selected accessions from the pearl millet reference collection, established by the Generation Challenge Program and the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT). A total of 81 accessions were included, comprising 78 landraces originating from 13, predominantly WCA countries and three improved cultivars. All 81 accessions were evaluated together with 18 checks for resistance to the parasitic weed Striga hermonthica (Del.) Benth. in an artificially infested field at one location in Niger. Determined by available seed quantity, 74 accessions were characterized together with seven checks in the rainy season 2009 in field trials under low-input and fertilized conditions in Nigeria, Niger and Mali, respectively. Wide ranges were observed for various traits. Several accessions were identified as sources for specific traits of interest, i.e. long panicles, high-grain density, earliness, Striga resistance and stable yielding across environments. The observed yield inferiority of all Genebank accessions compared with checks may indicate lost adaptation or inbreeding depression due to an insufficient effective population size during multiplication. A principal component analysis revealed an immense diversity but also strong admixture among the tested accessions, i.e. there were no clearly distinct groups. The seed of all genotypes is available from ICRISAT. The online availability of the characterization data is expected to facilitate efficient use of these pearl millet accessions by breeding programmes in WCA and worldwide

The acrylic vessel for JSNS2^{2}-II neutrino target

The JSNS$^{2}$ (J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron Source) is an experiment designed for the search for sterile neutrinos. The experiment is currently at the stage of the second phase named JSNS$^{2}$-II with two detectors at near and far locations from the neutrino source. One of the key components of the experiment is an acrylic vessel, that is used for the target volume for the detection of the anti-neutrinos. The specifications, design, and measured properties of the acrylic vessel are described