3,178 research outputs found
Pembuatan Ekosemen Dari Sampah Organik
The Huge volume of urban garbage despite limited space of garbage dump and inappropriate handling have become complicated and never ended problem. Helped to these issue, the research on Forming Ecocement from organic garbage was carried out. Ecocement was made from the mixture of the ash of organic garbage and limestone. The ashing was started by putting up the dry leaves and branches and some anorganic garbage (i.e paper) in pirolisis reactor, heated at temperatures 100, 150, 200, 250, 300 (oC). The resulted ash was mixed with limestone at (60:40) ; (55:45) ; (50:50) ; (45:55) ; (40:60) (%) ratio and blended with water. Next, the mixture was heated in a temperature of 900 oC for 1 hour. The ash analysis from the pirolisis process indicated that the best ash to produce cement was one that was heated in the temperature of 300 oC in the composition of CaO = 200.591,8 ppm SiO2 = 160.020, 8 ppm Al2O3 = 56.800,9 ppm dan Fe2O3 = 5.510,6 ppm, while the best ratio of ash : lime stone is 55 % : 45 % in the composition of CaO=60,8 % , SiO2 = 16,3 % , Al2O3 = 4,8 %, Fe2O3 = 0,3%. The resulted cement stand the tensile strengt 72,6 kg/cm2, min, in 7 days stored (standard grade of the tensile strengt 150 kg/cm2, min, in 7 days stored)
Evidence From HETE-2 For GRB Evolution With Redshift
After taking into account threshold effects, we find that the
isotropic-equivalent energies E_iso and luminosities L_iso of gamma-ray bursts
(GRBs) are correlated with redshift at the 5% and 0.9% signficance levels,
respectively. Our results are based on 10 BeppoSAX GRBs and 11 HETE-2 GRBs with
known redshifts. Our results suggest that the isotropic-equivalent energies and
luminosities of GRBs increase with redshift. They strengthen earlier clues to
this effect from analyses of the BATSE catalog of GRBs, using the variability
of burst time histories as an estimator of burst luminosities (and therefore
redshifts), and from an analysis of BeppoSAX bursts only. If the
isotropic-equivalent energies and luminosities of GRBs really do increase with
redshift, it suggests that GRB jets at high redshifts may be narrower and thus
the cores of GRB progenitor stars at high redshifts may be rotating more
rapidly. It also suggests that GRBs at very high redshifts may be more luminous
-- and therefore easier to detect -- than has been thought, which would make
GRBs a more powerful probe of cosmology and the early universe than has been
thought.Comment: 5 pages, 3 figures, to appear in proc. 2003 GRB Conference, Santa Fe,
N
Black pine (Pinus nigra) barks: A critical evaluation of some sampling and analysis parameters for mercury biomonitoring purposes
Abstract Tree barks are increasingly used as biomonitors of airborne pollutants. However, many authors stress the poor comparability of the results achieved in different studies. This drawback is mainly caused by a poor understanding of the critical sampling parameters to be considered. To minimize the biases that could be introduced during sampling, in this study the barks of Pinus nigra J.F. Arnold from thirteen sites were investigated in the abandoned Mt. Amiata mercury (Hg) mining district (Southern Tuscany, Italy) and surroundings. The influence of some sampling and analyzing parameters on Hg content was critically assessed. At each site, a total of eight bark samples were taken from a single tree at two heights (70 cm and 150 cm from soil) and at four different sides of the trunk, corresponding to the four cardinal directions; a composite soil sample was also collected. Mercury contents in barks range from 0.1 to 28.8 mg/kg, and are correlated with soil Hg contents (1–480 mg/kg), indicating that barks record both gaseous Hg concentrations in air, and wind-transported Hg-bearing particulate. For each tree, samples at 70 cm and 150 cm show Hg contents of the same order of magnitude, even if values for 150 cm are slightly less dispersed, possibly because barks at 70 cm are more influenced by random soil particles. There is no statistically significant dependence of Hg content on direction and tree age. Simulated rain events cause a negligible loss of Hg from barks. Results suggest that a convenient sampling practice for Pinus nigra is to collect a bark slice (typically 1–2 mm) within the outermost 1.5 cm layer
Penggunaan Suspensi Baculovirus Terhadap Oryctes Rhinoceros L. (Coleoptera : Scarabaeidae) Di Laboratorium
Use suspense of Baculovirus to Oryctes rhinoceros L. (Coleoptera; Scarabaeidae) in the Laboratory.The objective of this research was to know the suitable suspense of baculovirus to larvae in thelaboratory. This research was conducted in the laboratory of pest, Faculty of Agriculture, Universityof North Sumatra, Medan. Research using completely randomized design (CRD) non factorial with5 treatments and 5 replications. The results showed that the highest percentage of larval mortality(P4) (suspense of Baculovirus, 40/1 liter of water) by 48.00 % and the lowest on P0 (control) andP1 (suspense Baculovirus-infected larvae of O. rhinoceros larvae 5/1 liter of water) of 0.00 % and4.00 %
Observation and implications of the Epeak - Eiso correlation in Gamma-Ray Bursts
The availability of a few dozen GRB redshifts now allows studies of the
intrinsic properties of these high energy transients. Amati et al. recently
discovered a correlation between Epeak, the intrinsic peak energy of the spectrum, and Eiso, the isotropic equivalent energy radiated by the
source. Lamb et al. have shown that HETE-2 data confirm and extend this
correlation. We discuss here one of the consequences of this correlation: the
existence of a 'spectral standard candle', which can be used to construct a
simple redshift indicator for GRBs.Comment: Proceedings of the GRB 2003 Conference in SantaFe, 5 pages, 4 figure
Status of the Fermilab Muon (g-2) Experiment
The New Muon Collaboration at Fermilab has proposed to measure the
anomalous magnetic moment of the muon, , a factor of four better than
was done in E821 at the Brookhaven AGS, which obtained ppm. The last digit of is changed
from the published value owing to a new value of the ratio of the
muon-to-proton magnetic moment that has become available. At present there
appears to be a difference between the Standard-Model value and the measured
value, at the standard deviation level when electron-positron
annihilation data are used to determine the lowest-order hadronic piece of the
Standard Model contribution. The improved experiment, along with further
advances in the determination of the hadronic contribution, should clarify this
difference. Because of its ability to constrain the interpretation of
discoveries made at the LHC, the improved measurement will be of significant
value, whatever discoveries may come from the LHC.Comment: Proceedings of the PhiPsi09, Oct. 13-16, 2009, Beijing, China, 4
pages 2 figures. Version 2 includes Fermilab report number, minor corrections
and one additional referenc
Utilization of print media for agriculture development: A case study of peasants
Shetkari is the print media that is focused to provide improved methods and techniques of cultivation to provide improved methods and techniques of cultivation to peasants in Western Maharashtra especially the literate, youth and commercial cultivator. Peasants are utilizing latest agricultural ideas for agricultural development. Agricultural development means economic growth along with maintaining their fertility of soil. To illustrate the role of print media, a study of Yalgund village of Kolhapur District is conducted. Case studies of big, medium marginal and large peasants are conducted to illustrate the importance of agricultural communication. It is found that big and small peasants have been applying the ideas to boots their agricultural economic into commercial profitable industry. The marginal farmer has implemented the technique of mixed cropping profitably. However, there is no utilization by the landless
The Effect of Biomass Physical Properties on Top-Lit Updraft Gasification of Woodchips
The performance of a top-lit updraft gasifier affected by biomass (pine wood) particle size, moisture content and compactness was studied in terms of the biochar yield, biomass burning rate, syngas composition and tar content. The highest biochar yield increase (from 12.2% to 21.8%) was achieved by varying the particle size from 7 to 30 mm, however, larger particles triggered tar generation that reached its maximum of 93.5 g/m3 syngas at 30-mm biomass particles; in contrast, the hydrogen content in syngas was at its minimum of 2.89% at this condition. The increase in moisture content from 10% to 22% reduced biochar yield from 12% to 9.9%. It also reduced the tar content from 12.9 to 6.2 g/m3 which was found to be the lowest range of tar content in this work. Similarly, the carbon monoxide composition in syngas decreased to its minimum of 11.16% at moisture content of 22%. Finally, the biomass compactness increased biochar yield up to 17% when the packing mass was 3 kg. However, the addition of compactness also increased the tar content in syngas, but little effect was noticed in syngas composition.The performance of a top-lit updraft gasifier affected by biomass (pine wood) particle size, moisture content and compactness was studied in terms of the biochar yield, biomass burning rate, syngas composition and tar content. The highest biochar yield increase (from 12.2% to 21.8%) was achieved by varying the particle size from 7 to 30 mm, however, larger particles triggered tar generation that reached its maximum of 93.5 g/m3 syngas at 30-mm biomass particles; in contrast, the hydrogen content in syngas was at its minimum of 2.89% at this condition. The increase in moisture content from 10% to 22% reduced biochar yield from 12% to 9.9%. It also reduced the tar content from 12.9 to 6.2 g/m3 which was found to be the lowest range of tar content in this work. Similarly, the carbon monoxide composition in syngas decreased to its minimum of 11.16% at moisture content of 22%. Finally, the biomass compactness increased biochar yield up to 17% when the packing mass was 3 kg. However, the addition of compactness also increased the tar content in syngas, but little effect was noticed in syngas composition
- …