5,082 research outputs found
A New Weighting Scheme in Weighted Markov Model for Predicting the Probability of Drought Episodes
Drought is a complex stochastic natural hazard caused by prolonged shortage
of rainfall. Several environmental factors are involved in determining drought
classes at the specific monitoring station. Therefore, efficient sequence
processing techniques are required to explore and predict the periodic
information about the various episodes of drought classes. In this study, we
proposed a new weighting scheme to predict the probability of various drought
classes under Weighted Markov Chain (WMC) model. We provide a standardized
scheme of weights for ordinal sequences of drought classifications by
normalizing squared weighted Cohen Kappa. Illustrations of the proposed scheme
are given by including temporal ordinal data on drought classes determined by
the standardized precipitation temperature index (SPTI). Experimental results
show that the proposed weighting scheme for WMC model is sufficiently flexible
to address actual changes in drought classifications by restructuring the
transient behavior of a Markov chain. In summary, this paper proposes a new
weighting scheme to improve the accuracy of the WMC, specifically in the field
of hydrology
Mechanical properties and thermal behaviour of two-stage concrete containing palm oil fuel ash
Two-stage concrete (TSC) is a special type of concrete which is made by placing coarse aggregate in a formwork and injecting a grout either by pump or under the gravity force to fill the voids. Over the decades, the application of supplementary cementing materials in conventional concrete has become widespread, and this trend is expected to continue in TSC as well. Palm oil fuel ash (POFA) is one of the ashes which has been recognized as a good pozzolanic material. This paper presents the experimental results on the performance behaviour of POFA in developing physical and mechanical properties of two-stage concrete. Four concrete mixes namely, TSC with 100% OPC as a control, and TSC with 10, 20 and 30% POFA were cast, and the temperature growth due to heat of hydration and heat transfer in the mixes was recorded. It has been found that POFA significantly reduced the temperature rise in two-stage aggregate concrete and delayed the transfer of heat to the mass of concrete. The compressive and tensile strengths, however, increased with the replacement of up to 20% POFA. The results obtained and the observation made in this study suggest that the substitution of OPC by POFA is beneficial, particularly for prepacked mass concrete where thermal cracking due to extreme heat rise is of great importance
Parametric investigation of fixed-tray, semi-continuous distillation column for ethanol separation from water
This work was aimed to evaluate the parameters affecting the separation of model fermentation broth (7 mole% ethanol) using 10-tray, semi-continuous distillation column. Ethanol compositions in distillate and bottoms were determined at different reflux ratios and feed locations. Results show that the distillation of lower ethanol concentration is better carried out at higher reflux ratio with feed charged at the middle or bottom tray for good overall tray efficiency. The distillation unit is able to purify the feed to 78 mole% ethanol in distillate. Through trial-and-error stepping off, about 81 mole% was predicted as optimum ethanol purity at reflux ratio of 2.33, while a lower reflux ratio of 1.44 was estimated for 78 mole%. Fixed-tray, semi-continuous distillation is a suitable option to concentrate fermentation broth with sufficient ethanol purity
End User Adoption of ERP Systems: Investigation of Four Beliefs
This paper studies the effects of four beliefs of a group of end users on the adoption of ERP systems. The beliefs examined were perceived usefulness, ease of use, expected capability, and expected value. A sample of 58 SAP users was collected, via online survey, from a large company in Saudi Arabia. The validity and the reliability of the data collection instrument were tested using the exploratory factor analysis and Cronbach\u27s Alpha coefficients, respectively. Using multiple regression analysis, the perceived ease of use and the expected value of ERP system was found to have a significant direct effect on the acceptance of ERP system. However, the perceived usefulness and expected capability did not have a direct significant effect on acceptance of ERP systems. The study provides insights for organizations implementing ERP systems in developing countries
Examining a moderating role of migration on news usage in an intra-national ethnic setting
The effect of cross border migration on news consumption has been well explored in uses and gratifications studies. Most of these studies focus on international migrants with little empirical attention on intra-national migrants. Besides, most of these studies have not examined migration within the context of ethnic variables like ethnic identity. This study is examining a possible moderating effect of migration on ethnic identity as a predictor of news usage among the three major ethnic groups in Nigeria. Survey questionnaires were administered on 400 undergraduates in three universities in Nigeria between January and April, 2014. We use Partial Least Square Structural Equation Modeling (PLS-SEM) approach to measure the relationships among the variables Findings show ethnic migration having a significant moderating effect on the predictive power of ethnic identity on news gratifications
Standardization of DNA extraction from invasive alien weed Parthenium hysterophorus
DNA isolation from the weed, Parthenium hysterophorus is complicated due to the presence of high amount of allelochemicals in the form of secondary metabolites that causes hindrance in extraction and enzymatic reactions. A modified and efficient DNA extraction from P. hysterophorus leaf has been developed. The present protocol is a modified version of cetyltrimethylammonium bromide (CTAB) method constituting high salt concentration to remove polysaccharides. The increased concentration of β-mercaptoethanol, polyvinylpolypyrrolidone (PVPP), and phenol/chloroform/isoamyl alcohol extractions eliminated protein and phenolic compounds well. Good amount and quality DNA was obtained by this method. The resulted genomic DNA showed fine random amplified polymorphic DNA (RAPD), inter-simple sequence repeat (ISSR) banding pattern, polymerase chain reaction (PCR) amplification of actin gene and restriction digestion confirm the efficiency of modified procedure.Keywords: Allelochemicals, DNA extraction, Parthenium hysterophorus, stress toleranc
Examining a moderating role of migration on news usage in an intra-national ethnic setting
The effect of cross border migration on news consumption has been well explored in uses and grtifications studies. Most of these studies focus on inter-national migrants with little empirical attention on intra-national migrants. Besides, most of these studies have not examined migration within the context of ethnic variables like
ethnic identity. This study is examining a possible moderating effect of migration on ethnic identity as a predictor of news usage among the three major ethnic groups in Nigeria. Survey questionnaires were administered on 400 undergraduates in three universities in Nigeria between January and April, 2014.We use Partial Least Square Structural Equation Modeling (PLS-SEM) approach to measure the relationships among the variables Findings show ethnic migration having a significant moderating effect on ithe predictive power of ethnic identity on news gratifications
Hubungan Kerapatan Rumput Laut Sargassum SP. dengan Kelimpahan Epifauna di Pantai Barakuda Pulau Kemojan, Kepulauan Karimunjawa, Jepara
Perairan Pantai Barakuda merupakan perairan yang terletak di Pulau Kemojan, Kepulauan Karimunjawa yang memiliki berbagai kekayaan alam hayati dan non hayati. Salah satu sumberdaya diantaranya adalah rumput laut Sargassum sp. yang tumbuh subur pada perairan tersebut. Tegakan rumput laut berfungsi sebagai penahan arus dan gelombang sehingga dapat memberikan perlindungan di bawah akar rumput yang mendukung bagi berbagai kehidupan organisme akuatik dan secara ekologi berfungsi sebagai perangkap sedimen dan pencegah abrasi. Penelitian ini bertujuan untuk mengetahui kelimpahan epifauna pada ekosistem Sargassum sp. dan untuk mengetahui hubungan antara kerapatan dari Sargassum sp. dengan kelimpahan epifauna di Pantai Barakuda, Karimunjawa. Penelitian ini dilaksanakan pada bulan Maret 2013. Metode penelitian yang digunakan adalah metode survey lapangan dan metode pengambilan sampel adalah sistematik sampling. Lokasi sampling terdiri dari line yang tegak lurus garis pantai dengan panjang 100 meter. Hasil penelitian menunjukan kelimpahan epifauna terdapat 623 individu yang terdiri dari Gastropoda dan Bivalvia . Epifauna yang ditemukan lima spesies epifauna dari kelas Gastropoda yaitu Cerithium sp., Nassarius sp., Conus sp., Colubraria sp., Latirus sp. Terdapat Tiga spesies dari kelas bivalvia yaitu Donax sp. , Acanthocardia sp., Lioconcha sp. Kelimpahan epifauna secara nyata dipengaruhi oleh kerapatan rumput laut Sargassum sp. (Uji Regresi Linier sederhana P= 0,05). Dengan persamaan y = 20,731x + 1,8734 dimana y adalah kelimpahan epifauna dan x adalah kerapatan rumput laut Sargassum sp. Sedangkan, kelimpahan epifauna secara nyata tidak dipengaruhi oleh luasan penutupan daripada Sargassum sp. yang ditunjukan dengan grafik linier yang negatif dan menjauhi garis. Dari hasil penelitian ini dapat disimpulkan bahwa kelimpahan epifauna ada hubungan dengan kerapatan rumput laut Sargassum sp. Barakuda Beach is located at Kemujan Island was part of Karimunjawa Islands which has various biotic and abiotic resources. One of those was Sargassum sp. seaweed that grow well and fertile in that coastal. The trunks of seaweed is function as a current and wave protection which be able to give protection among seweed roots for living kinds of aquatic organisms, and ecologically it function as a sediment trap and abration prohibition. This research was aimed to know epifauna abundances on Sargassum sp. ecosystem and to knows the relationship between of Density from Sargassum sp. by abundances of ephifauna in Barakuda Beach, Karimunjawa. This research was held on March and April 2013. The research method was field survey method and sample collection by systematic sampling method. Sampling location divide into 2 lines were one of line has long 50 meters. The research result showed that ephifauna abundances has 623 individu of eppifauna. There were found five species of ephifauna each as class Gastrophoda consist of Cerithium sp., Nassarius sp., Conus sp., Colubraria sp., Latirus sp. There were three species of ephifauna each as class Bivalvia consist of Donax sp. , Acanthocardia sp., Lioconcha sp . Ephifauna abundances significantly determained by Sargassum sp. density (Simple Linier Test, P= 0,05). The formula was y= 20,731x - 1,8734 which y is ephifauna abundances and x is Sargassum sp. seaweed density. Beside that, there weren't a determained for ephifauna abundances by canopy of Sargassum sp. which showed by negatif linier graphic who long from main line of graphic. From the research result could be concluded that ephifauna abundances was significant relationship between of Density from Sargassum sp. seaweed density and ephifauna abundances
- …