High Efficiency Analog and Digital Circuits for Wireless Applications Based on III-V HEMTs

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The (Z_2)^3 symmetry of the non-tri-bimaximal pattern for the neutrino mass matrix

In view of the recent neutrino oscillation data pointing to a non-vanishing value for the smallest mixing angle ($\theta_z$), we derive and find explicit realizations of the $(Z_2)^3$ flavor symmetry which characterizes, for the neutrino mass matrix, uniquely a variant of the tripartite form, originally conceived to lead to the tri-bimaximal mixing with $\theta_z=0$, so that to allow now for a non-tri-bimaximal pattern with non-zero $\theta_z$. We impose this flavor symmetry in a setting including the charged leptons and we see that it can make room, through higher order terms involving new SM-singlet scalars, for the mass hierarchy of charged leptons. Moreover, within type-I seesaw mechanism augmented with the flavor symmetry, certain patterns occurring in both the Dirac and the Majorana neutrino mass matrices can accommodate all types of mass hierarchies in the effective neutrino mass matrix, but no lepton/baryon asymmetry can be generated. Finally, we discuss how type-II seesaw mechanism, when supplemented with the flavor symmetry, could be used to interpret the observed baryon asymmetry through leptogenesis.Comment: 14 pages, 1 table, added references, version to appear in PRD. arXiv admin note: text overlap with arXiv:1008.406

Adsorbents from the by-product of palm oil refinery for methylene blue removal

The present work was aimed at evaluating the removal of methylene blue by palm fatty acid distillate-based adsorbents. The adsorbents at different weight ratios of palm fatty acid distillate (PFAD) to palm kernel shell (PKS) were prepared at 600 °C for 2 hours. Results show that the yield of adsorbent upon heat treatment decreased with increasing weight ratio, with yield as low as 0.53% was recorded by adsorbent derived by using only PFAD. The methylene blue adsorption data show a promising performance of PFAD-based adsorbents as compared to that of PKS-adsorbent (char) with qe = 7.6 mg/g at Co = 20.8 mg/L. To conclude, PFAD is a potential candidate of dye adsorbent

Physicochemical properties of char derived from palm fatty acid distillate

The present work was aimed to evaluate the physiochemical properties of chars derived from palm fatty acid distillate. The palm fatty acid distillate was heat-treated at 500 °C and 600 °C in a muffle furnace for 0.5 h, and the resultant products were characterized for elemental composition, surface functional groups, thermogravimetric profile and methylene blue adsorption. Results show that the char samples are rich in carbon content with unique surface functional groups that could be useful in the liquid-phase adsorption. The solid chars depict a thermally stable profile with the increase of temperature during the heat treatment. The char demonstrated the maximum removal of methylene blue of 7.6 mg/g and obeyed the monolayer-trend adsorption of Langmuir isotherm. The findings concluded that the palm fatty acid distillate-based char could be an adsorbent candidate for the removal of methylene blue

Safety Profile of Carthamus Tinctorius L. in Lactation: Brain, Renal and Hepatotoxicity

Background and Objective: Safflower (Carthamus tinctorius L.) is used as dye and flavor in food industry. However, its effects on the infant during lactation has not been yet determined. The present study was conducted with the aim of investigating the possible effects of taking this herb during lactation on brain, liver, kidney and hematologic parameters of newborn mice. Methodology: In this experimental study, 32 pregnant Balb/C mice were randomly divided into four groups of 8. Following the delivery, group 1 (control group) received normal saline injection, and group 2 to 4 received daily intraperitoneal injection of 10, 20 and 40mg/kg methanolic safflower extract for 25 days (until the end of lactation period), respectively. The newborns' hematological parameters were assessed at the end of the study period. Liver, kidney and brain tissue samples of male newborns were histopathologically studied after staining with Hematoxylin & Eosin. Data were analyzed using ANOVA and Scheffe's tests. Results: Use of safflower did not cause any significant difference in the number of White Blood Cells, Red Blood Cells, Hemoglobin and Hematocrit in treatment group in comparison with the control group. In histopathological study, mild to severe injuries were observed in kidney, liver and brain tissues of newborn mice treated with the extract. Conclusions: The results of the present study revealed that taking Safflower extract during lactation period may be toxic for infants and cause some damage in the liver, kidney and brain tissue. Therefore, it is better for lactating mothers to refrain from its use

Design strategy of a 2.8–3.6 GHz 20W GaN Doherty power amplifier

This paper presents the design of a 20W GaN Doherty Power Amplifier working in the range 2.8 GHz–3.6 GHz. The design strategy adopted for the design of the Doherty output combiner is discussed, which consists in embedding the device parasitics into the latter, implemented as a multi-stage quarter-wavelength transformer, in order to achieve wideband behaviour. The saturated output power ranges from 42dBm to 44 dBm, with a corresponding drain efficiency in excess of 47%. The efficiency at 6 dB of output back-off is higher than 42% over the whole frequency band, and the small-signal gain is higher than 10 dB. Due to the discrepancies of the measured scattering parameters compared to the simulated ones, which could not be corrected with post-tuning, a redesign of the prototype is ongoing

3.1-3.6 GHz 22 W GaN Doherty Power Amplifier

This paper presents a Doherty power amplifier working from 3.1 GHz to 3.6 GHz. It adopts 10 W packaged GaN HEMTs from Cree/Wolfspeed and achieves a saturated output power in excess of 43.4 dBm. Saturated efficiency ranges from 57.7 % to 75.2 %, while efficiency at 6 dB back-off is between 44.2 % and 59.8 %. System-level simulations at 3.5 GHz adopting a 16QAM signal with 5 MHz bandwidth and 4 dB peak to average power ratio showed an adjacent channel power ratio of -28 dBc/Hz without pre-distortion, at an average output power of 43 dBm and with an average efficiency of 71 %

Broadband Class-J GaN Doherty Power Amplifier

This paper presents a broadband 3 GHz–3.7GHz class-J Doherty power amplifier exploiting second harmonic tuning in the output network. Furthermore, the output impedance inverter is eliminated and its effect is embedded in the main device’s output matching network, thus trading off among bandwidth, efficiency, and gain. The proposed amplifier adopts two 10W packaged GaN transistors, and it achieves in measurement 60–74%, and 46–50% drain efficiency at saturation and 6 dB output back-off, respectively, with a saturated output power of 43 dBm–44.2dBm and a small-signal gain of 10 dB–13 dB. The proposed DPA exhibits a simulated adjacent channel power ratio less than 30 dBc at 36dBm average output power when a 16-QAM modulation with 5 MHz bandwidth is applied to the 3.5 GHz carrier

A 3-3.8 GHz Class-J GaN HEMT Power Amplifier

This paper presents a wideband class J power amplifier (PA) based on a packaged 10 W GaN HEMT device covering the 3 GHz to 3.8 GHz frequency range. A good trade-off between efficiency and gain has been pursued in synthesizing the second harmonic output termination. The achieved output power is in excess of 41 dBm with drain efficiency ranging from 59 % to 65.5 % and a small signal gain above 14 dB. Preliminary large signal measurements at 3.3 GHz confirm the proper behavior of the PA

The synthesis of methotrexate-loaded F127 microemulsions and their in vivo toxicity in a rat model

Methotrexate (MTX) has been often formulated as nano and micro-emulsions, nominally to address its poor solubility and off-target effects. Nanoformulated MTX is universally reported to be a more efficacious anti-cancer agent than direct-dissolved drug; however, these investigations generally fail to screen for in vivo toxicity. This study aims to remedy this oversight. MTX was formulated as a standard Pluronic oil-in-water microemulsion with good drug encapsulation efficiency (73.0% ± 8.4). Preliminary in vitro free radical scavenging studies found that formulation reduces drug oxidation four-fold. The toxic effects of formulated and unformulated MTX were investigated in a Wistar rat model. Rats received 0.05 mg/kg MTX as either the microemulsion or directly dissolved in phosphate-buffered saline. A drug-free microemulsion, PBS solution, and saline solution were used as controls. After 28 days, serum levels of enzymes indicative of kidney and liver damage were quantified. Significantly higher serum liver, and serum kidney enzymes were observed in the rats that received the directly dissolved MTX drug (P \u3c 0.05) compared to those who received the encapsulated form. Following sacrifice, the levels of catalase and superoxide dismutase (SOD) were significantly lower and the level of malondialdehyde higher, in rats who received either form of MTX relative to untreated controls. However, the SOD levels were lower in those who received the microemulsion than those who received free MTX. Histology supported the observation that the microemulsion formulation caused no gross structural toxicity to the liver, unlike the free drug. Although toxicity was reduced compared to the free drug, the microemulsion still caused damage to the kidneys. This organ-specific toxicity is consistent with the mode of clearance of the drug. This data demonstrates that the toxicity of formulated drugs must be considered when discussing the relative merits of formulations: encapsulation almost always improves efficacy but may not improve safety