Chip interleaved turbo codes for DS-CDMA mobile radio in fadingchannel

A new channel interleaving method, called chip interleaving, for direct sequence code division multiple access (DS-CDMA) is proposed. A chip interleaver scrambles the chips and transforms the transmission channel into a highly time-selective or highly memoryless channel. It was found that the turbo decoding performance which degrades in a fading channel is significantly improved with chip interleaving     

Assessment of impact of AICTE funding on R&;D and educational development

Summary An analysis of 330 questionnaires received from project investigators funded by AICTE indicates that project investigators preferred to present their research results at conferences rather than in national and international journals. Impact of funding has been better on human resource capability development as compared to research and technological output. Analysis of data using data envelopment analysis indicates that projects funded under electronics and communication engineering, mechanical engineering, electrical engineering and management displayed some consistency and uniformity with regard to impact on various output parameters.     

Study of Band Structure Properties of Pnictide LaO1−xF x FeAs (x = 0, 0.2) Superconducting Compound

This paper reports on the band structure properties and changes in band structure of fluorine-doped LaO_1?x F _x FeAs (x = 0, 0.2) compound, measured using X-ray photoemission spectroscopy (XPS). The band structure of the superconducting compound is compared with nonsuperconducting parent compound LaOFeAs. With fluorine doping, a shift of the shallow core level is observed in XPS spectra, which may be a response of the band structure due to fluorine doping in the system. The balance of the chemical potential shift with the screening effect of conduction electrons near the Fe and As ions is discussed using nearly unchanged Fe 2p and As 3d core-level spectra. The La 3d core-level spectra shift towards the high energy, ～0.36 eV, may be due to the chemical potential shift caused by fluorine doping. In our valence band spectra, a small peak at around 0.2 eV is observed, which disappeared with the fluorine doping in the system, indicating a change of Fe 3d state from low spin to high spin states and also confirming the nature of Fe 3d electrons as itinerant, which is responsible for superconductivity in these compounds.     

Studies on semi-cylindrical solar tunnel dryers: estimation of solar irradiance

This is the first part of a set of two papers, about the estimation of solar irradiance on the absorber plate and cover of a semi-cylindrical solar tunnel dryer (STD). The second part discusses the modelling and thermal performance results of the STD. A detailed analysis has been carried out in this paper for solar irradiance estimation for the general orientation of the STD with respect to reference positions (N-S, E-W). The obtained values of solar irradiance for the absorber plate and cover includes the internal reflection effect up to second-order. It is found that if the STD axis is in the E-W, the absorber plate receives more solar radiation as compared to the other reference position N-S. The amount of solar irradiation absorbed by the cover is also calculated and found very small compared to the absorber. All calculations have been made for Delhi climate (28.58°N latitude).     

Electromagnetic interference shielding behavior of poly(trimethylene terephthalate)/multi-walled carbon nanotube composites

Poly(trimethylene terephthalate) [PTT]/multiwalled carbon nanotube [MWCNT] composites having varying amounts of MWCNTs were fabricated with an aim to investigate the potential of such composites as an effective light weight electromagnetic interference (EMI) shielding material in the frequency range of 12.4-18 GHz (Ku-band). PTT/MWCNT composite with shielding effectiveness (SE) of 36-42 dB was obtained at 10% (w/w) MWCNT loading. Shielding mechanism was studied by resolving the total SE into absorption (SE_A) and reflection loss (SE_R). PTT/MWCNT composite showed absorption dominated shielding; thus it can be used as microwave, radar absorbing and stealth material. The effect of MWCNT loadings on electrical conductivity (σ) and dielectric properties of PTT and the correlation among conductivity, tan δ, absorption loss and reflection loss were also studied.     

Performance of an inexpensive underground shallow solar pond water heater

In this communication, an inexpensive underground shallow solar pond (SSP) water heater has been suggested, and its performance has also been studied in detail. An explicit analytical expression for temperature has been obtained. The effect of various parameters, viz duration of covering the system by insulation, duration of flow rate, flow rate, insulation thickness, water mass, etc. have also been discussed. Numerical calculations have been made for a typical cold day.     

A novel design approach of charge plasma tunnel FET for radio frequency applications

In this paper, the impact of extra electron source (EES) and dual metal gate engineering on conventional charge plasma TFET (CP-TFET) have been done for improving DC and analog/RF parameters. CP-TFET structure is upgraded to double source CP-TFET (DS-CP-TFET) by placing an EES below the source/channel junction for enhancing the device performance in terms of driving current and RF figures of merit (FOMs). But, in spite of these pros, the approach is having cons of higher leakage current similar to MOSFET and negative conductance (inherent nature of TFET). Both the issues have been resolved in the double source dual gate CP-TFET (DS-DG-CP-TFET) by gate workfunction engineering and drain underlapping respectively. Additionally, for getting the optimum performance of DS-DG-CP-TFET, the device sensitivity has been investigated in terms of position of EES, length of drain electrode and workfunction of gate electrode 1 (GE1).     

Pharmacological and Therapeutic Applications of Esculetin

Esculetin is a coumarin compound, which belongs to the class of benzopyrone enriched in various plants such as Sonchus grandifolius, Aesculus turbinata, etc. Free radicals lead to the development of oxidative stress causing inflammation, arthritis, cancer, diabetes, fatty liver disease, etc. These further reduce the efficacy of anticancer drugs, activate inflammatory signaling pathways, degrade joints and cartilage, and disrupt the glycemic index and normal function of liver enzymes. For instance, the current treatment modalities used in arthritis such as non-steroidal anti-inflammatory drugs, disease-modifying anti-rheumatoid drugs, and lipoxygenase inhibitors present limited efficacy and adverse effects. Thus, there is a constant need to find newer and safer alternatives. Esculetin has an immense antioxidative potential thereby alleviating arthritis, diabetes, malignancies, and hepatic disorders. Structurally, esculetin contains two hydroxyl groups, which enhance its ability to function as an antioxidant by inhibiting oxidative stress in pathological conditions. Leukotriene B4 synthesis, NF-κB and MPAK pathway activation, and inflammatory cytokine production are the main causes of bone and joint deterioration in arthritis, whereas esculetin treatment reverses these factors and relieves the disease condition. In contrast, lipid peroxidation caused by upregulation of TGF-β-mediated expression and dysfunction of antioxidant enzymes is inhibited by esculetin therapy, thus reducing liver fibrosis by acting on the PI3K/FoxO1 pathway. Therefore, targeting NF-κB, pro-inflammatory cytokines, TGF-β and oxidative stress may be a therapeutic strategy to alleviate arthritis and liver fibrosis.