RF Receiver front end for 28.5 GHz applications on a 70 GHz F-T SiGe BiCMOS process

This article presents the design and test of a receiver front end aimed at LMDS applications at 28.5 GHz. It presents a system-level design after which the receiver was designed. The receiver comprises an LNA, quadrature mixer and quadrature local oscillator. Experimental results at 24 GHz center frequency show a conversion voltage gain of 15 dB and conversion noise figure of 14 5 dB. The receiver operates from a 2 5 V power supply with a total current consumption of 31 mA

A 107GHz LNA in 65nm CMOS with inductive neutralization and slow-wave transmission lines

This paper presents a 107GHz LNA prototype using TSMC 65nm CMOS technology. It explores the limit of the CMOS technology by effectively optimizing the active and passive devices. An improvement of 1.6dB higher maximum stable/available gain (MSG/MAG) on the transistor is achieved around 110GHz by layout optimization and inductor neutralization technique. A high quality factor co-planar waveguide (CPW) transmission line is designed utilizing the slow-wave effect. A quality factor of 23.6 is demonstrated by EM-simulations while taken the consideration of satisfying the stringent layout design rules. Based on the optimization on the active and passive devices, a dual-stage LNA is designed, with a simulated power gain of 10.2dB and noise figure of 8dB at 107GHz, verified by chip-level EM-simulations. The power consumption is 28.2mW

Embryonic development and growth performances of an endangered fish species Nandus nandus: effects of dietary polyunsaturated fatty acids supplementation

The present study explored the embryonic and larval development of an endangered fish species Nandus nandus and resolved larval growth performances with the dietary supplementation of different types of lipids. Fertilized eggs were collected from fiber glass tanks immediately after spontaneous spawning of N. nandus, which were fed with a 1% phospholipid (squid meal) supplemented diet for 3 months. Fertilized eggs were transparent, spherical, yellowish and sticky in nature. The first cleavages of eggs were observed 0.3±0.01 h post fertilization at 26°C water temperature. Hatching started around 18 h post-fertilization and newly hatched larvae were found to be 1.2±0.1 mm in length. First feeding started 64.0±0.30 h post hatching. After rearing for 10 days, they were divided into 4 groups and separately fed with only dry tubificid worms, 1% docosahexaenoic (DHA) supplemented with dry tubificid worm, 1% phospholipid supplemented with dry tubificid worm and live tubificid worms as treatment I, treatment II, treatment III and treatment IV, respectively. After 50 days of the trial, larvae of treatment II showed significantly (p<0.01) higher growth performances in length: 3.18±0.13 cm, weight: 339.8 ± 36.94 mg and survival rate: 78±2 % which were comparable to that of treatment IV, which showed the highest (p<0.01) length of 3.4±0.1 cm, weight of 406.6±27.99 mg and survival rate of 97±1 %. Larvae in treatment I showed the lowest growth performances in length: 2.73 ± 0.16 cm, weight: 259.8±29.97 mg and survival rate of 63±3 %. As this is the first record for the determination of embryonic and larval development of N. nandus with different lipid supplemented diets, it might be possible to save this endangered fish species by adopting this technology at field level

A 107GHz LNA in 65nm CMOS with inductive neutralization and slow-wave transmission lines

This paper presents a 107GHz LNA prototype using TSMC 65nm CMOS technology. It explores the limit of the CMOS technology by effectively optimizing the active and passive devices. An improvement of 1.6dB higher maximum stable/available gain (MSG/MAG) on the transistor is achieved around 110GHz by layout optimization and inductor neutralization technique. A high quality factor co-planar waveguide (CPW) transmission line is designed utilizing the slow-wave effect. A quality factor of 23.6 is demonstrated by EM-simulations while taken the consideration of satisfying the stringent layout design rules. Based on the optimization on the active and passive devices, a dual-stage LNA is designed, with a simulated power gain of 10.2dB and noise figure of 8dB at 107GHz, verified by chip-level EM-simulations. The power consumption is 28.2mW

Blood glucose and cholesterol levels in adult population of Bangladesh: Results from STEPS 2006 survey

Background: A nationally representative survey was carried out to determine the distribution of blood glucose and cholesterol in adult population of Bangladesh in the absence of existing data. Methods: The study adopted a multistage and geographically clustered sampling technique of households. A total of 2610 individuals (1444 men and 1166 women) aged 25–64 years were selected from rural and urban areas. Capillary blood glucose and total cholesterol levels were measured using an overnight fasting state. Results: The mean age of the participants was 41 years [standard deviation (SD), 11 years]. Half of them (49%) were from urban areas. Half of them (51%) had primary or higher education. Mean glucose was 74 mg/dL (SD 23 mg/dL). Men had higher mean glucose levels (79 mg/dL) than women (67 mg/dL). Age-standardized prevalence of diabetes (blood glucose level ≥126 mg/dL and/or use of anti-diabetic medication) was 5.5%. In men, it was almost two-and-half times (7.6%) compared with women (2.8%). It was also double in urban areas (7.8%) compared with rural areas (3.4%). Mean cholesterol level among all participants was 167 mg/dL (SD 26 mg/dL). Men and women had almost similar levels (169 mg/dL versus 166 mg/dL, respectively). Prevalence of high cholesterol level (≥240 mg/dL) was very low (1.3%) in both men (2.2%) and women (0.5%). However, the prevalence of borderline high cholesterol was substantial (5.8%) in this sample. Conclusion: The prevalence of high hypercholesterolemia is low, whereas there is a high prevalence of borderline high cholesterol and diabetes in the adult population of Bangladesh. This warrants population-based interventions to tackle this problem

Chemically Converted Graphene as a Hole Transport Layer (HTL) Inorganic Photovoltaics (OPVS)

oai:ojs.pkp.sfu.ca:article/170Concerns about Global Warming and diminishing fossil fuel reserves have accelerated the search for low cost sources of renewable energy. Organic photovoltaics (OPVs) could be one such source; however, they have a list of shortcomings, including low efficiencies, short lifetimes, and reliance on poly (3, 4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS), an expensive and highly acidic (pH = 1) hole transport layer. Replacing PEDOT: PSS with chemically derived graphene may eliminate one of the drawbacks associated with OPVs. This paper took the first step towards that goal by developing a process to synthesize and characterize inverted and normal poly (3-hexylthiophene) (P3HT), [6, 6]-phenyl-C61 butyric acid methyl ester (PCBM) solar cells. Although detrimental to the stability of the cells, ambient synthesis replicated the conditions required for large-scale, industrial production. The utilization of graphene oxide (GO) thin films as the hole transport and electron blocking layer in organic photovoltaics (OPVs) is demonstrated. The incorporation of GO deposited from neutral solutions between the photoactive poly(3-hexylthiophene) (P3HT):phenyl-C61 butyric acid methyl ester (PCBM) layer and the transparent and conducting indium tin oxide (ITO) leads to a decrease in recombination of electrons and holes and leakage currents. This results in a dramatic increase in the OPV efficiencies to values that are comparable to devices fabricated with PEDOT: PSS as the hole transport layer. Our results indicate that GO could be a simple solution process able Alternative to PEDOT: PSS as the effective hole transport and electron blocking layer in OPV and light-emitting diode devices

Implications of organic matter on arsenic mobilization into groundwater: evidence from northwestern (Chapai-Nawabganj), central (Manikganj) and southeastern (Chandpur) Bangladesh

Boreholes (50 m depth) and piezometers (50 m depth) were drilled and installed for collecting As-rich sediments and groundwater in the Ganges, Brahmaputra, and Meghna flood plains for geochemical analyses. Forty-one groundwater samples were collected from the three areas for the analyses of cations (Ca2+, Mg2+, K+, Na+), anions (Cl−, NO3−, SO42−), total organic carbon (TOC), and trace elements (As, Mn, Fe, Sr, Se, Ni, Co, Cu, Mo, Sb, Pb). X-ray powder diffraction (XRD) and X-ray fluorescence (XRF) were performed to characterize the major mineral and chemical contents of aquifer sediments. In all three study areas, results of XRF analysis clearly show that fine-grained sediments contain higher amounts of trace element because of their high surface area for adsorption. Relative fluorescent intensity of humic substances in groundwater samples ranges from 30 to 102 (mean 58 ± 20, n = 20), 54–195 (mean 105 ± 48, n = 10), and 27–243 (mean 79 ± 71, n = 11) in the Ganges, Brahmaputra and Meghna flood plains, respectively. Arsenic concentration in groundwater (20–50 m of depth) ranges from 3 to 315 μg/L (mean 62.4 ± 93.1 μg/L, n = 20), 16.4–73.7 μg/L (mean 28.5 ± 22.4 μg/L, n = 10) and 4.6–215.4 μg/L (mean 30.7 ± 62.1 μg/L, n = 11) in the Ganges, Brahmaputra and Meghna flood plains, respectively. Specific ultra violet adsorption (SUVA) values (less than 3 m−1 mg−1 L) indicate that the groundwater in the Ganges flood plain has relatively low percentage of aromatic organic carbon compared to those in the Brahmaputra and Meghna flood plains. Arsenic content in sediments ranges from 1 to 11 mg/kg (mean 3.5 ± 2.7 mg/kg, n = 17) in the three flood plains. Total organic carbon content is 0.5–3.7 g/kg (mean 1.9 ± 1.1 g/kg) in the Ganges flood plain, 0.5–2.1 g/kg (mean: 1.1 ± 0.7 g/kg) in the Brahmaputra flood plain and 0.3–4.4 g/kg (mean 1.9 ± 1.9 g/kg) in the Meghna flood plain. Arsenic is positively correlated with TOC (R2 = 0.50, 0.87, and 0.85) in sediments from the three areas. Fourier transform infrared (FT-IR) analysis of the sediments revealed that the functional groups of humic substances in three areas include amines, phenol, alkanes, and aromatic carbon. Arsenic and Fe speciation in sediments were determined using XANES and the results imply that As(V) and Fe(III) are the dominant species in most sediments. The results also imply that As (V) and Fe (III) in most of the sediment samples of the three areas are the dominant species. X-ray absorption fine structure (EXAFS) analysis shows that FeOOH is the main carrier of As in the sediments of three areas. In sediments, As is well correlated with Fe and Mn. However, there is no such correlation observed between As and Fe as well as As and Mn in groundwater, implying that mobilizations of Fe, Mn, and As are decoupled or their concentrations in groundwater have been affected by other geochemical processes following reductive dissolution of Fe or Mn-hydroxides. For example, dissolved Fe and Mn levels may be affected by precipitation of Fe- and Mn-carbonate minerals such as siderite, while liberated As remains in groundwater. The groundwaters of the Brahmaputra and Meghna flood plains contain higher humic substances in relative fluorescence intensity (or fluorescence index) and lower redox potential compared to the groundwater of Ganges flood plain. This leads to the release of arsenic and iron to groundwater of these three plains in considerable amounts, but their concentrations are distributed in spatial variations