Modelling of reduced GB transmission system in PSCAD/EMTDC

Energy and environmental issues are two of the greatest challenges facing the world today. In response to energy needs and environmental concerns, renewable energy technologies are now considered the future technologies of choice. Renewable energy is produced from natural sources that are clean and free; however, it is widely accepted that renewable energy is not a solution without challenges. An example of this can be seen in the UK, where there is much interest amongst generation developers in the construction of new large scale onshore and offshore wind farms, especially in Scotland. The stability of electric power systems is also an important issue. It is important to have full knowledge of the system and to be able to predict the behaviour under different situations is an important objective. As a result, several industrial grade power system simulator tools have been developed in order to estimate the behaviour of the electric power system under certain conditions. This paper presents a reduced Great Britain (GB) system model for stability analysis using PSCAD/EMTDC. The reduced model is based upon a future GB transmission system model and, hence, contains different types and mix of generation, HVDC transmission lines and additional interconnection. The model is based on the reduced DIgSILENT PowerFactory model developed by National Grid

PENGARUH MEDIA FILM ELEKTRONIK TERHADAP KEMAMPUAN KREATIF MATEMATIKA SISWA SEKOLAH DASAR

Pembelajaran anak pada usia sekolah dasar banyak yang kurang menggemari mata pelajaran matematika, mereka menganggap pelajaran matematika itu sulit, dikarenakan proses dan metode yang digunakan hanyalah hubungan satu arah yaitu antara guru ke siswa tanpa adanya timbal balik dari siswa ke guru itu sendiri. Hal tersebut menyebabkan anak menjadi pendengar yang pasif sehingga menghambat proses berfikir kreatif matematis seorang anak untuk menyelesaikan permasalahan yang ada dalam pembelajaran matematika. Salah satu hal yang dapat mendorong anak untuk berfikir kreatif matematis adalah dengan penggunaan media ajar yang tepat, salah satunya dengan menggunakan media film elektronik dalam pembelajaran matematika pokok bahasan bangun ruang. Pembelajaran menggunakan media film elektronik dapat mendorong anak untuk berfikir kreatif matematis dengan adanya gambar-gambar yang dapat memancing imajinasi siswa. Dengan demikian pengguanaan media film elektronik diharapkan dapat memberikan pegaruh positif terhadap kemampuan berfikir kreatif matematis siswa sekolah dasar. Penelitian ini menggunakan desain kuasi eksperimen yang menggunakan dua kelompok sebagai objek penelitian yaitu terbagi menjadi kelas eksperimen dan kelas kontrol. Masing-masing kelompok diberi perlakuan yang berbeda, kelas eksperimen menggunakan media film elektronik dalam proses pembelajaran sedangkan kelas kontrol hanya menggunakan pembelajaran konvensional seperti biasanya. Setelah diberi perlakuan rata-rata nilai yang diperoleh masing-masing kelas dibandingkan untuk mengetahui kemampuan berfikir kreatif matematis siswa. Kelas eksperimen mendapat rata-ratasebesar 74,83 sedangkan kelas kontrol mendapat nilai rata-rata sebesar 41,25. Jika dilihat perbandingannya maka kelas eksperimen memiliki nilai rata-rata lebih besar dari kelas kontrol. Dengan kata lain penggunaan media film elektronik memberikan pengaruh positif terhadap kemampuan berfikir kreatif matematis siswa Sekolah Dasar

The effects of antioxidant, butyl hydroxy anisole and polyphosphate on shelf-life of frozen (-180°C) crayfish (Astacus leptodactylus) of the Caspian Sea

Possible effects of antioxidant Butyl Hydroxy Anisole (BHA) and sodium polyphosphate on the shelf-life of frozen Astacus leptodactylus of the Caspian Sea was studied. Samples of the crayfish were dipped in 0.02 and 0.2% BHA and 0.04 and 0.4% sodium polyphosphate for 30 and 60 minutes. The control samples were packed without immersion in the mixture of BHA and sodium polyphosphate. The Peroxide Value (PV), Total Volatile Nitrogen (TVN), total bacteria count and organoleptic tests were carried out on the samples using a time schedule. The results showed that the minimum increase in PV for the samples which were soaked in a mixture of 0.2% BHA and 0.4% sodium polyphosphate for 1 hour were from 0.59 to 0.88 meq/1000g, as compared to the control samples with an increase in the range 0.59 to 3.53meq/1000 g after four months. The PV Value after four month started to be decrease and reached 1.4 meq/1000 grams after sixth months. The results showed that the minimum increase of TVN for the samples which were soaked in a mixture of 0.2% BHA and 0.4% sodium polyphosphate for I hour were from 12.88 to 17.8 mg/100 grams and for the control samples, the increase was from 12.88 to 19.8 mg/100 grams after sixth month. The results also demonstrated that the minimum increase in Total Bacteria Count of for the samples soaked in a mixture of 0.2% BHA and 0.4% sodium polyphosphate for 1 hour were from 9 x 103 to 2 x 101 per gram and for the control samples, the count was from 9 x 103 to 7 x 102 per gram after sixth months. Kruskal—Wallis, chi-square and Duncan tests were conducted on five samples for each specific shelf-life time. Using the results, we conclude that immersing the samples into a mixture of 0.2% BHA and 0.4% sodium polyphosphate for one hour gives the best results in terms of shelf-life and organoleptic tests

Mechanisms Of Telomere Maintenance In Trypanosoma Brucei

Telomeres are a nucleoprotein structure at the end of the chromosome and are essential for genome integrity and chromosome stability. Telomere lengths are primarily maintained by a telomerase-mediated pathway but can be maintained by a homologous recombination-mediated pathway. However, detailed mechanisms of telomere maintenance are still unclear in many eukaryotes, including an important human pathogen, Trypanosoma brucei. Telomeres can be elongated by telomerase in T. brucei, a causative agent of fatal sleeping sickness in humans and nagana in cattle. T. brucei evades host immune response by regularly switching its major surface antigen, variant surface glycoprotein (VSG), a process known as antigenic variation. The telomere structure and telomere proteins play critical roles in T. brucei pathogenesis. In mammalian, yeast, and plant cells, ssDNA binding proteins with OB-fold domains play important roles in coordinating telomere G- and C-strand syntheses. However, no such protein has been described in T. brucei to be specifically associated with the telomere. We identified POLIE, an A-type DNA polymerase, as a crucial telomere complex component in T. brucei and essential in maintaining telomere integrity in T. brucei. Depletion of POLIE in T. brucei leads to an increased amount of DNA damage at telomere/subtelomere, increased frequency of gene conversion-mediated VSG switching, and an increased amount of the telomeric circles (T-circles), suggesting a potential role of POLIE in suppressing DNA recombination at the telomere and the subtelomere. However, I find that telomeric and subtelomeric DNA recombination is unlikely to be mediated by the increased telomeric R-loop level as the telomeric repeat-containing RNA (TERRA) level is significantly lower in POLIE-depleted cells. The telomere G-rich 3’overhangs are dramatically elongated in POLIE-depleted cells, indicating a potential role of POLIE to coordinate telomere G- and C-strand syntheses and suggesting that the long telomere 3’ overhang can induce more telomeric and subtelomeric recombination. In addition, I find that POLIE inhibits telomerase-dependent telomere G-strand extension, identifying POLIE as the first telomere protein that potentially suppresses telomerase in T. brucei. Moreover, depletion of POLIE greatly increases the amount of telomeric C-circles which can be derived from replication stress in the telomere C-strand. Importantly, the elongated telomere 3’ overhang and elevated telomeric C-circle level phenotypes are independent of the telomerase, which suggests that POLIE may promote the telomere C-strand synthesis. Therefore, we identified that POLIE plays a major role in suppressing telomere recombination, coordinating telomerase-mediated telomere G-strand extension, and telomere C-strand synthesis, and maintaining telomere integrity in T. brucei

Sustained remission in a case of lupus nephritis with cyclosporin therapy

Systemic lupus erythematosus (SLE) in severe form still presents a major therapeutic challenge. Aggressive treatment of severe renal lesions has improved the prognosis of renal disease over the last decade. However, this benefit is quite frequently offset by the side effects and toxicity of the treatment. Moreover, the disease may appear to be poorly responsive to treatment with steroids and cytotoxic drugs. We report a case of lupus nephritis that relapsed despite having adequate steroid and cytotoxic therapy, but later was successfully treated with cyclosporin. Fifteen months after discontinuing the treatment with cyclosporin, the patient continued to remain in remission

Heavy metal flocculation at Pirbazar River, Banadar Anzali, south west Caspian Sea

Heavy metal flocculation process was studied in the year 2002 in order to determine the interaction of water in Pirbazar River with Caspian Sea water. The effects of various salinity concentrations of Caspian Sea water were studied on determined heavy metals including Fe, Zn, Pb, Cu, Cd and Cr level of Pirbazar River using APHA method of extraction and measurement. The results illustrated that the level of heavy metal concentration in Pirbazar River were above standard limits and the extent of flocculation depended on both the salinity level and the heavy metal itself. The maximum flocculation for Cd and Cr were recorded at 7.65ppt, for Zn and Fe at 9.35ppt while for Pb and Cd were at 2.55ppt salinity. The order of flocculation with respect to percentage of original concentrations was found to be Zn > Fe > Cr> Cu > Cd> Pb

EVALUATION OF APPARENT DIGESTIBILITY COEFFICIENTS OF DIFFERENT DIETARY PROTEIN LEVELS WITH AND WITHOUT FISH MEAL FOR LABEO ROHITA

The apparent digestibility coefficients of three protein levels of reference diets (without fish meal) and test diets (with fish meal) were estimated for Labeo rohita. Three test diets (test diet-I, test diet-II and test diet-III) and three reference diets (reference diet-I, reference diet-II and reference diet-III) having 28, 30 and 32% protein levels were prepared. Chromic oxide was used as an internal marker in the experimental diets for the evaluation of digestibility of protein levels. The differences in apparent digestibility for dry matter, crude protein, crude fat and gross energy of reference and test diets were highly significant (P<0.01). The apparent digestibility coefficients (ADCs) of dry matter were 32.10 ± 0.30 and 35.30 ± 0.30% for reference and test diets -III. The ADCs of crude protein and crude fat were 77.92 ± 0.10, 69.23 ± 0.06 and 75.77 ± 0.05, 70.40 ± 0.22% for reference and test diets-III, respectively. The values of ADCs of gross energy were maximum for reference diet-III (52.28 ± 0.25%) and test diet-III (48.65 ± 0.78%). The ADCs of dry matter were 19.80 ± 1.40 and 18.15 ± 0.05% for reference and test diet-I. The ADCs of crude protein and crude fat were 73.93 ± 0.05, 68.43 ± 1.58 and 59.49 ± 1.13, 57.02 ± 2.42% for reference and test diet-I respectively. The ADCs values of gross energy were for reference diet-I (42.43 ± 0.36%) and test diet-I (39.09 ± 1.35%). The better ADCs for dry matter, crude protein, crude fat and gross energy were at 32% protein level

Study of total seed storage protein in indigenous Brassica species based on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE)

Genetic diversity was studied in 234 accessions of locally collected Brassica species for total seed protein content through sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). These accessions were collected from different locations of Pakistan. After the study of these accessions on SDS-PAGE, 28 reproducible bands were used for cluster analysis and with the help of these bands, genetic diversity were estimated. Out of 28, four major bands were observed. Dendogram was constructed and the accessions were divided into two main groups comprising 11 clusters. The results obtained from these clusters showed minimum genetic diversity in these accessions on SDS-PAGE level. Due to low genetic diversity on SDS-PAGE level, it is suggested that two dimensional (2D)- electrophoresis can be used for protein study.Key words: Genetic variation, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), protein electrophoresis, cluster analysis, brassica