scholarly journals Identification of best fit crude oil of upper Assam basin for pipeline transportation

Author(s):  
Bondita Robidas ◽  
Subrata Borgohain Gogoi

AbstractThis paper attempts to identify a crude oil (CO) from eight different CO samples with a wide range of oAPI gravity from 13 to 43 belonging to Upper Assam Basin, India, to formulate the identified CO for pipeline transportation. Studies were conducted to understand the physical, rheological, and viscoelastic properties of the CO samples where physical properties included pour point (PP) and oAPI gravity, the rheological properties included viscosity (η), kinematic viscosity (K.V.), viscosity gravity constant (VGC), shear stress (τ) and shear strain (γʹ) and the viscoelastic properties were elastic modulus (G)' and viscous modulus (G''). This research aims at achieving PP < 9 °C for CO for the ease of flow through pipeline even during the extreme winter season in Assam when the ambient temperature drops below 10o C. SKO in 0%, 5%, 10%, and 15% was added with all CO samples to determine the physical, rheological and viscoelastic properties at 30 °C, since PP of most of the CO samples was near 30 °C. However, the important properties of SKO, i.e. smoke point, flash point and boiling point, were not addressed here as SKO was used for improving flowability through pipeline. Correlation coefficients (CC) were determined using CORREL function in Microsoft Excel to investigate the relationship between oAPI gravity and the other properties for all the CO samples to identify the best fit CO. CO3 and CO8 were identified from the relationships as the most desired CO samples and CO3 was obtained as the best fit CO for the pipeline transportation.

2020 ◽  
Vol 43 (1) ◽  
pp. 75-80
Author(s):  
Md Zulfekar Ali ◽  
Mohammad Moktader Moula ◽  
Zafar Ahmed Bhuiyan ◽  
Muhammad Tariq Javed

AbstractChicken astroviruses (CAstV) are enteric viruses of poultry causing gastroenteritis, malabsorption, gout and white chick disease commonly known as runting-stunting syndrome (RSS). It can affect the wide range of poultry birds, especially chicken, turkey and duck worldwide. To our best knowledge there is no published report on presence of antibodies against CAstV in Bangladesh. Therefore, the study aimed to detect the presence of CAstV antibodies in broilers and sonali chickens (a cross-bread) in Bangladesh through a cross-sectional survey. A total of 454 blood samples from 66 flocks of broiler (n=343) and sonali chickens (n=111) of different ages were obtained during 2017 from four districts. The birds were healthy but were not vaccinated against CAstV. The samples were tested for specific antibodies against CAstV Group B by using commercially available ELISA kit. Overall, 16.74% (76/454) samples and 34.84% (23/66) flocks were positive for CAstV antibodies. The seroprevalence of CAstV was significantly (p=0.001) higher in sonali chickens (36.96%) than broiler (10.20%), while it was significantly higher (p=0.001) in birds of Bogura district (36.94%) than the other three districts. Regarding the age groups, seroprevalence was insignificantly (p=0.192) higher in sonali chicken before laying age (45%) than during laying age (27.45%). Regarding the seasons, CAstV infection was prevalent significantly (p=0.001) higher in winter season. Thus, the present study indicated the presence of CAstV in poultry in Bangladesh, so further studies are required to find out the magnitude of the problem in the country.


1975 ◽  
Vol 10 (1) ◽  
pp. 73-83
Author(s):  
J.E.S. Graham ◽  
T.C. Hutchinson

Abstract Crude oil spills are increasingly likely to occur from drilling, pumping and transportation activities as oil development proceeds at a rapid pace. These spills may occur over the wide range of climatic conditions which obtain in Canada. Little is known of oil toxicity at different temperatures; consequently, laboratory studies were made of the variability of the toxicity of aqueous extracts of a Norman Wells crude oil to freshwater algae over the temperature range 5°C to 35°C. Two unicellular green algae were studied: Chlamydomonas eugametos and Chlorella vulgaris. Their response (measured by cell numbers) varied with temperature and species. Whereas Chlamydomonas eugametos showed a general pattern of growth inhibition by oil at all temperatures with maximum inhibition at 25°C, Chlorella vulgaris showed general growth stimulation by oil with maximum stimulation at 25°C, this temperature was chosen for all further experimentation. All experiments were done using unialgal cultures and sterile technique. Cells were grown in 50 ml of nutrient medium (BBM) in 125 ml Erlenmeyer flasks. Such flasks allow gas exchange and permit loss of volatile hydrocarbons. Aqueous extracts were made by slowly stirring 5% crude oil with the nutrient medium for six hours using a magnetic mixer. The extract was then allowed to sit for two to four hours before the lower fraction was drawn off for use. Experiments were carried out in controlled environment chambers (±2°C) with a twelve hour light-dark cycle. All further experiments used a similar methodology. (Note: Chlamydomonas eugametos experiments were carried out on a rotary shaker at 125 rpm.) An attempt was made to determine the reason for the remarkable stimulation in growth of Chlorella vulgaris #29 at 25°C. This organism has been described in the literature as heterotrophic. Thus three reasons for stimulation seemed possible: 1. heterotrophic uptake of hydrocarbons directly from solution; 2. heterotrophic uptake of organic compounds formed or released by microbial breakdown of hydrocarbons (the aqueous extract of crude was not sterile); or 3. the use of CO2 released to solution by microbial respiration. The original experiment was repeated in the dark at 20°C to determine if stimulation still occurred. It did not, since cells exposed to the aqueous extract decreased in numbers. However, after two weeks the cells were illuminated and even though experimental flasks started off with depleted populations, they outgrew the control cells within two weeks. This suggested that if stimulation was related to heterotrophism, it must, at least in this case, have been the unusual case of photoheterotrophism. The reasons for this stimulation of growth are currently under investigation. Several methods are being employed to investigate the suspected heterotrophism. Experiments will be done to determine whether light energy is essential to the stimulation. Two varieties of Chlorella vulgaris, i.e. #29 and #260 are heterotrophic and autotrophic respectively, are to be used in experiments. Sterile aqueous extracts made by pressure ultrafiltration will be used. These experiments should determine whether algal growth stimulation is related to heterotrophism or whether microbial degradation of hydrocarbons is the real source of stimulation. Although the toxicity of crude oil may be rapidly ameliorated by physical and/or biological phenomena, one must still be aware of the possibility of a large input of organic carbon causing extensive eutrophication. Thus both toxicity and eutrophication will cause a selection, in terms of survival, in a natural environment. It is evident that although an oil spill may not totally destroy an ecosystem, it will certainly alter its natural composition considerably.


Fuel ◽  
2010 ◽  
Vol 89 (5) ◽  
pp. 1095-1100 ◽  
Author(s):  
Shadi W. Hasan ◽  
Mamdouh T. Ghannam ◽  
Nabil Esmail

2009 ◽  
Vol 9 (20) ◽  
pp. 7737-7751 ◽  
Author(s):  
M. M. Kvalev&amp;aring;g ◽  
G. Myhre ◽  
C. E. Lund Myhre

Abstract. Human activity influences a wide range of components that affect the surface UV radiation levels, among them ozone at high latitudes. We calculate the effect of human-induced changes in the surface erythemally weighted ultra-violet radiation (UV-E) since 1750. We compare results from a radiative transfer model to surface UV-E radiation for year 2000 derived by satellite observations (from Total Ozone Mapping Spectroradiometer) and to ground based measurements at 14 sites. The model correlates well with the observations; the correlation coefficients are 0.97 and 0.98 for satellite and ground based measurements, respectively. In addition to the effect of changes in ozone, we also investigate the effect of changes in SO2, NO2, the direct and indirect effects of aerosols, albedo changes and aviation-induced contrails and cirrus. The results show an increase of surface UV-E in polar regions, most strongly in the Southern Hemisphere. Furthermore, our study also shows an extensive surface UV-E reduction over most land areas; a reduction up to 20% since 1750 is found in some industrialized regions. This reduction in UV-E over the industrial period is particularly large in highly populated regions.


2008 ◽  
Vol 57 (4) ◽  
pp. 2014-2026 ◽  
Author(s):  
David W. Matolak ◽  
Indranil Sen ◽  
Wenhui Xiong

We describe results from a channel measurement and modeling campaign for the airport surface environment in the 5-GHz band. Using a 50-MHz bandwidth test signal, thousands of power delay profiles (PDPs) were obtained and processed to develop empirical tapped-delay line statistical channel models for large airports. A log-distance path loss model was also developed. The large airport surface channel is classified into three propagation regions, and models are presented for each of the regions for two values of bandwidth. Values of the median root-mean-square (RMS) delay spread range from 500 to 1000 ns for these airports, with the 90 th percentile RMS delay spreads being approximately 1.7 ms. Corresponding correlation bandwidths (i.e., correlation value 1/2) range from approximately 1.5 MHz in non-line-of-sight (NLOS) settings to 17.5 MHz in line-of-sight (LOS) settings. Two types of statistical nonstationarity were also observed: 1) multipath component persistence and 2) propagation region transitions. We provide the multipath component probability of occurrence models and describe Markov chains that are used for modeling both phenomena. Channel tap amplitude statistics are also provided, using the flexible Weibull probability density function (pdf). This pdf was found to best fit fading tap amplitude data, particularly for frequently observed severe fading, which is characterized by fade probabilities that are worse than the commonly used Rayleigh model. Fading parameters equivalent to Nakagami-m-model values ofmnear 0.7 were often observed (withm= 1 being Rayleigh and m &lt; 1 being worse than Rayleigh). We also provide channel tap amplitude correlation coefficients, which typically range from 0.1 to 0.4 but occasionally take values greater than 0.7.


2019 ◽  
Vol 10 (01) ◽  
pp. 20-27
Author(s):  
Dian Kurnia Sari ◽  
Rian Ternando

Minyak bumi dievaluasi guna menentukan potensi minyak bumi sebagai bahan baku kilang minyak untuk menghasilkan fraksi yang dikehendaki. Evaluasi yang dilakukan meliputi pengujian sifat umum minyak bumi, klasifikasi minyak bumi dengan distilasi True Boiling Point (TBP) wide cut (pemotongan jarak lebar) serta analisis fraksi kerosin. Fraksi kerosin yang dihasilkan dari primary process dapat diolah menjadi bahan bakar rumah tangga (minyak  tanah) dan bahan bakar lampu penerangan. Selain itu fraksi kerosin juga dapat dioalah menjadi bahan bakar untuk pesawat terbang jenis jet (avtur). Avtur adalah kerosin yang dengan  spesifikasi yang diperketat, terutama mengenai titik uap dan titik beku. Untuk melakukan pengolahan pada minyak bumi perlu diketahui karakteristik dan spesifikasi minyak  bumi (bahan baku) yang akan diolah untuk mengetahui mutu dan manfaat minyak bumi tersebut. Salah satu parameter uji analisis minyak bumi yaitu parameter sifat fisika. Dari data distilasi TBP diperoleh persentase fraksi kerosin Crude Oil 99 PT HS sebesar 29 % vol sedangkan Crude Oil 165 PT RT sebesar 23 % vol. Berdasarkan analisis sifat fisika yang meliputi Specific Gravity, Refractive Index nD20, Freezing Point, Smoke Point, Flash Point “Abel”, Aniline Point, Copper Strip Corrosion, Kinematic Viscosity dan Characterization KUOP. Crude Oil 99 dan Crude Oil 165 memiliki mutu yang baik serta memenuhi spesifikasi produk kerosin maupun produk avtur.


Author(s):  
Martina Ladrova ◽  
Radek Martinek ◽  
Jan Nedoma ◽  
Marcel Fajkus

Electromyogram (EMG) recordings are often corrupted by the wide range of artifacts, which one of them is power line interference (PLI). The study focuses on some of the well-known signal processing approaches used to eliminate or attenuate PLI from EMG signal. The results are compared using signal-to-noise ratio (SNR), correlation coefficients and Bland-Altman analysis for each tested method: notch filter, adaptive noise canceller (ANC) and wavelet transform (WT). Thus, the power of the remaining noise and shape of the output signal are analysed. The results show that the ANC method gives the best output SNR and lowest shape distortion compared to the other methods.


Author(s):  
J. S. Chin ◽  
A. H. Lefebvre

The influence of fuel composition on soot emissions from continuous flow combustors is examined. A study of the combustion characteristics of a wide range of present and potential aviation fuels suggests that smoke point provides a better indication of sooting tendency than does hydrogen content. It is concluded from this study that the best empirical relationship between fuel chemical composition and soot emissions is one which combines two fuel composition parameters — smoke point and naphthalene content — into a single parameter which is shown to correlate successfully soot emissions data acquired from several different fuels burning in a variety of gas turbine and model combustors.


2019 ◽  
Vol 2 (04) ◽  
pp. 15-26
Author(s):  
Beniah Obinna Isiuku ◽  
Francis Chizoruo Ibe

The biosorption of metanil yellow on hen egg membrane from aqueous solution in a batch process was investigated at 29oC with a view to determine the potential of the membrane in removing metanil yellow from aqueous solution.  The effects of contact time, initial biosorbate concentration, biosorbent dosage and initial biosorbate pH were determined. Various isotherm models were used to analyze experimental data. The highest experimental equilibrium biosorption capacity obtained was 129.88 mg/g. The optimum pH was 3. Adsorption capacity increased with increase in initial solution concentration but decreased with increase in time. The isotherm models applied were good fits based on correlation coefficients. Flory-Huggins isotherm was the best fit (R2 0.986). The biosorption was endothermic, good, physisorptive and spontaneous. This work shows that hen egg membrane is a potential biosorbent for the removal of metanil yellow from aqueous solution.


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