940 research outputs found

    Effect of van-Hove singularities in single-walled carbon nanotube leads on transport through double quantum dot system

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    The double quantum dot system with single-walled metallic armchair carbon nanotube leads has been studied using Non-equilibrium Green function in the Keldysh formalism. The effect of relative spacing between the energy levels of the dots, interdot tunneling matrix-element, interdot Coulomb interaction and van-Hove singularities in density of states characteristics of quasi-one-dimensional carbon nanotube leads on the conductance of the double quantum dot system has been studied. The conductance and dot occupancies are calculated at finite temperature. It is observed that the density of states of the carbon nanotube leads play a significant role in determining the conductance profile. In particular, whenever the chemical potential of the isolated double quantum dot system is aligned with the position of a van-Hove singularity in the density of states of armchair carbon nanotube leads, the height of the corresponding conductance peak falls considerably. It is further observed that the suppression in the heights of the alternate peaks depends on the relative positions of the energy levels of the dots and their magnitude of separation.Comment: 16 pages and 16 figure

    The Population of Aphis Gossypii Glove on the Black Grape by the Method of Direct Account

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    A field study was conducted in Yathrib province Salahuddin government to study determination of population of  Aphis gossypii on black grapes by using the method of direct account for upper , medium and lower parts of the plant were chosen  (40 plants ) at randomize  from one of the fields , counting had done for one plant only .Results of the study showed that the highest population density was in May ( 22.8 ) adult / tree insect , and lowest  population was in June ( 9.7 ) adult / tree insect , statistical analysis showed significantly differences , while the results showed that the upper layer from plant was more effectiveof infection by ( 23.7 ) adult forupper layer ,( 17.4 ) adult in medium layer and ( 12.5 ) adult in lower layer plant , the statistical analysis showed significant differences between the three layers of the plant. Keywords: adult insect ,Aphids gossypii , population , black grape

    Morbidity Pattern Among Out-Patients Attending Urban Health Training Centre in Srinagar

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    The current study was designed to identify the morbidity pattern of out-patients attending Urban Health Training Centre in an urban area of a medical college in Srinagar, Pauri Garhwal district, Uttarakhand, North India. The present study record-based retrospective study was conducted among the out-patients attending the regular clinic at the Urban Health Training Centre, of a medical college in Srinagar city of Uttarakhand State of North India during the study period of one year in 2014. Data was retrieved from the OPD registers maintained at the clinic. Data was collected pertaining to socio-demographic profile, morbidity details and treatment pattern. Diseases were identified using the International Classification of Diseases (ICD-10) code. Descriptive analysis was done. During the study period, a total of 9343 subjects attended the OPD. Among them, majority of them (60%) were females. More than half (56 %) belonged to the age group of 35-65 year age-group. The association of disease classification was found to be statistically significant with respect to gender. The leading morbidity of communicable disease was found to be certain infectious and parasitic diseases especially Typhoid whereas musculoskeletal system and connective tissue disorders were the most common cause among morbidity due to NCDs. Out of all, typhoid was found to cause maximum of morbidity among the subjects. The present study highlights the morbidity pattern of communicable and NCDs among the population of hilly areas of Garhwal, Uttarakhand India. Priority should be preferred for the regular tracking of diseases in terms of preventive and promotive aspects. Morbidity in the out- door clinics reflects the emerging trend of mixed disease spectrum burden comprising communicable and non-communicable diseases

    Lymphangioma circumscriptum in the scrotum: A case report

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    Introduction: Lymphangioma circumscriptum is a rare benign skin disorder involving hamartomatous lymphatic malformation of deep dermal and subcutaneous lymphatic channels. It is a therapeutic challenge for the dermatologist when it occurs at common sites such as axilla, shoulder, groin and buttocks and a diagnostic challenge for the surgeon when it occurs at rare sites such as the scrotum. Surgical treatment is the most commonly used method to treat scrotal lymphangioma circumscriptum but there are high rates of recurrence.Case Presentation: We report the case of a 30-year-old Pakistani man who presented with scrotal swelling which was clinically misinterpreted as an infectious disorder. Later on re-resection of deeper tissue was performed to prevent recurrence. He is still being followed-up on a regular basis.Conclusion: Awareness of the occurrence of lymphangioma circumscriptum in the scrotum in adult men without prior disease is mandatory to avoid missing the diagnosis and to ensure proper treatment

    New brominated sesquiterpenes from the red alga Laurencia hetroclada Harvey, and their immunosuppressive activity studies

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    Red algae of the genus Laurencia Harvey (Ceramiales, Rhodomelaceae) is a complex genus, encompassing a large variety of morphologicallycomplex algal species. In continuation of our work on chemistry and biological activity studies of some Sri Lankan seaweeds, we examined the chemistry of MeOH extract of Laurencia hetroclada collected from Tangalle coast. Above extract was subjected to column chromatography followed by PTLC gave a new brominated sesquiterpene 1 along with two known compounds, algoane 2, and caulerpin 3. The 13C NMR spectrum along with the DEPT experiments of 1 revealed only 15 carbon signals corresponding to four methyls, five methylene, one methine and five quaternary carbons. The 1H NMR (CD3OD, 500 MHz) spectrum of 1 showed signals due to three methyls, four methylenes, and two methine protons. The singlets resonated at 1.25 (3H, s), 1.27 (3H, s), and 1.85 (3H, s) were assigned to Me-8’, Me-6’, and Me-9’, respectively. The characteristic downfield proton at 4.83 (dd, J = 4.2,15 Hz) was assigned to H-4, geminal to the Br atom, whereas the proton that resonated at 3.96 (d, J = 1.7 Hz) was assigned to the oxymethine H- 1. Furthermore, the olefinic singlet resonated at 5.26 was assigned to Ha-7’ and Hb-7. The down field carbon atoms resonated at 110.2 and 165.2 were assigned to olefinic carbon atoms. The positive CI MS of 1 showed the molecular ion peak [M+H]+ at m/z 349 along with isotopic peak at m/z 351 (1:1), indicating the presence of a Br atom in the molecule. The above MS data were found to be consistent with the molecular formula C15H25O4Br with 3 degrees of unsaturation. A comparison of the NMR spectroscopic data of 1 with those of 2 suggested a similar skeleton with differences in substitution pattern and unsaturation sites. From the above spectral data, the structure of 1 was confirmed as a new natural product 4-bromo-5-methyl-2-(3’-hydroxy-1’,3’- dimethyl-2’ methylenecyclopentyl) cyclohexane-1,2,5- triol. Caulerpin (3) showed a significant dose suppressive effect with an IC50 5.8 ± 1.0 μg/mL on Tcell proliferation assay

    A review on various Smart Grid Technologies used in Power System

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    Electrical infrastructure is expanding day by day due to which smart grid gives better vision for electrical reliability. Various parameters like quality and quantity of power transmitted should be available with the electricity board which can be achieved using smart sensing, metering and communication technologies. If all the above requirements are met in power system then it is called smart grid (SG). SG also helps consumers to manage the load patters and also to manage their expenses. The main component of SG is the communication technology to share data between consumers and grid since grid operators requires real time data to schedule their supply. The Wireless Sensor Network (WSN) uses Aggregation Protocol with Error Detection (APED) to improve the security of data. The SG with SCADA is facilitated by data acquisitions which includes the meter reading, system conditions, etc. that are monitored and transmitted at regular intervals in real time. This paper reviews the modern technologies used in smart grid communication based on IEEE 802.15.4 standard to the SG and how it is modified to ensure effective, efficient and economical and secured communication of the huge real time data from the smart meters
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