Model-based fit procedure for power-law-like spectra

$1/f^\alpha$ noises are ubiquitous and affect many measurements. These noises are both a nuisance and a peculiarity of several physical systems; in dielectrics, glasses and networked liquids it is very common to study this noise to gather useful information. Sometimes it happens that the noise has a power-law shape only in a certain frequency range, and contains other important features, that are however difficult to study because simple fits often fail. Here I propose a model-based fit procedure that performs well on spectra obtained in a molecular dynamics simulation.Comment: 12 postscript figures, submitted to J. Comp. Phy

Antibacterial activity and brine shrimp lethality of Vitex doniana sweet, stem bark extracts

The stem bark of Vitex doniana was extracted with n-hexane, chloroform, ethylacetate, acetone, ethanol and water sequentially using cold extraction method. The fractions were tested for antibacterial activity using disc agar diffusion technique and brine shrimp lethality followed by screening for secondary metabolites. All the fractions showed a remarkable activity against some respiratory tract pathogenic bacteria particularly the n-hexane and ethanol soluble fractions at 100 μg/disc, 300 μg/disc and 500 μg/disc concentrations. The Brine shrimp test showed highest toxicity in n-hexane and ethanol soluble fractions with LC50 values of 6.7674μg/ml and 5.3421μg/ml respectively. Phytochemical analysis of the fractions revealed the presence of alkaloids, steroids, cardiac glycosides, tannins, reducing sugars and flavonoids

WISATA KERAJINAN LOGAM BEJIJONG

Wisata Kerajinan Logam Bejijong merupakan suatu proyek yang dilator belakangi dengan adanya warisan budaya Kerajaan Majapahit berupa kerajinan, ini ditandai dengan adanya prasasti-prasasti di jamannya. Dimana nantinya di dalam proyek ini, lebih menekankan fasilitas-fasilitas bagi para seniman atau perajin serta pengunjung atau tamu sebagai pengguna utama bangunan ini. Selain itu akan ditekankan pula untuk lansekap sebagai alternatif ruang pameran terbuka. Wisata Kerajinan Logam Bejijong diharapkan dapat tetap melestarikan warisan budaya Kerajaan Majapahit dengan mewadahi seniman atau perajin, serta bagi para pengunjung atau tamu, agar seni kerajinan ini terus berkembang. Seni kerajinan ini telah menjadi mata pencaharian baik utama maupun sampingan bagi hampir seluruh warga Desa Bejijong

Effect of the Berendsen thermostat on dynamical properties of water

The effect of the Berendsen thermostat on the dynamical properties of bulk SPC/E water is tested by generating power spectra associated with fluctuations in various observables. The Berendsen thermostat is found to be very effective in preserving temporal correlations in fluctuations of tagged particle quantities over a very wide range of frequencies. Even correlations in fluctuations of global properties, such as the total potential energy, are well-preserved for time periods shorter than the thermostat time constant. Deviations in dynamical behaviour from the microcanonical limit do not, however, always decrease smoothly with increasing values of the thermostat time constant but may be somewhat larger for some intermediate values of $\tau_B$, specially in the supercooled regime, which are similar to time scales for slow relaxation processes in bulk water.Comment: 21 pages, 5 figures, To be published in Mol. Phy

Screening and Bioassay-guided Isolation of Antimicrobial Components from Laggera mollis

There are about 20 identified species in the genus Laggera and only few have been extensively investigated. The study was aimed at evaluation the antimicrobial activity of Laggera mollis and isolation of the bioactive component(s) for new potent antimicrobial agent. Four fractions each from the leaves and stem-root of the plant were sequentially extracted with petroleum ether, chloroform, ethyl acetate and ethanol using soxhlet extraction scheme, while the marcs were decocted for the aqueous extracts. Phytochemical screening of four extract fractions each from the leaves and stem-root of the plant revealed the presence of alkaloids, tannins, flavanoids, saponins, steroids, terpenoids and reducing sugar distributed across the fractions. Disc diffusion method of Antimicrobial Sensitivity Test (ATS) was adopted in testing the bioactivity of the plant extracts against seven bacteria and one fungus. Bioassay-guided isolation from the petroleum ether fraction (LM1-01) of the leaves of the Laggera mollis using column chromatography, led to the isolation of two pure compounds. The results of the antimicrobial activity of the isolated compounds indicted that LM1-1-10 was more potent against Salmonella typhi (11 mm) at 40 μg/disc followed by Streptococcus pyogens (10 mm) at 40 μg/disc and Staphylococcus aureus (10 mm) at 40 μg/disc. The spectra of the activity exhibited by the isolates signified their potency for the development of therapeutic agents against these pathogenic microorganisms.Keywords: Bioassay-guided isolation, antimicrobial activity, Laggera mollis, clinical isolates, extracts

Nigerian maritime administration : its role in marine environmental protection : a case study on the Escravos Oil Terminal, Niger delta

The dissertation is an attempt to examine the Nigerian oil industry and its impact on the environment. The world pre occupation in recent years, with green house gas emission and climatic changes has tended to over shadow an equally important problem, oil pollution either land based or marine. Oil spills have an equally devastating impact on the environment, especially in developing countries which have little or no capacity to deal with this problem. Thus the focal point of this paper is to analyse the Nigerian oil sector and the environmental impact of its activities. This involves identifying sectors within the oil industry that have the most impact on the enviromnent. Oil terminals as an important component of the oil industry is analysed in greater detail, its operational structure and impact on the environment is analysed. Additionally a comparative analysis is made on oil terminal operation in the in the United States of America and Malaysia, and type of regulatory and safety mechanism in place to prevent oil spills. The dissertation also looks at the function and frame work of the various organisations involved in pollution prevention and control, their strength and weakness. Finally the paper makes recommendation on ways through which the oil industry could reduce their operational impact on the environment and operate in a more enviromnental friendly manner. The recommendation entails a combination of legal, political and technical instruments to tackle the above problem.

SPAMMER DETECTION BASED ON ACCOUNT, TWEET, AND COMMUNITY ACTIVITY ON TWITTER

Spammers are the activities of users who abuse Twitter to spread spam. Spammers imitate legitimate user behavior patterns to avoid being detected by spam detectors. Spammers create lots of fake accounts and collaborate with each other to form communities. The collaboration makes it difficult to detect spammers' accounts. This research proposed the development of feature extraction based on hashtags and community activities for the detection of spammer accounts on Twitter. Hashtags are used by spammers to increase popularity. Community activities are used as features for the detection of spammers so as to give weight to the activities of spammers contained in a community. The experimental result shows that the proposed method got the best performance in accuracy, recall, precision and g-means with are 90.55%, 88.04%, 3.18%, and 16.74%, respectively.  The accuracy and g-mean of the proposed method can surpassed previous method with 4.23% and 14.43%. This shows that the proposed method can overcome the problem of detecting spammer on Twitter with better performance compared to state of the art