Digitally tunable low noise amplifier

Low noise amplifiers are classified into two categories: Wideband low noise amplifiers and Narrowband low noise amplifiers. Wideband LNAs are known for achieving a poor noise performance. On the other hand, the noise performance of the narrowband amplifiers is good but only over a small frequency range. This constraint made their use restricted to certain applications, such as cellular phone applications (superheterodyne architecture), where a single operational frequency is needed. This thesis introduces a new low noise amplifier topology that provides a high selectivity and a low noise figure over a wide frequency range. The digitally tunable low noise amplifier can be implemented in narrowband applications as well as broadband applications. This thesis discusses in detail the design of the DTLNA. A detailed noise analysis is also discussed in this work. The noise analysis includes the effect of induced gate noise in CMOS, which is rarely cited but nonetheless of fundamental importance in establishing the limits of achievable noise performance. In addition, this thesis demonstrates the performance results of the digitally tunable low noise amplifier. These results prove that the overall performance of the DTLNA surpasses the performance of both wideband and narrowband amplifiers

Modelisation Du Risque D’érosion Hydrique Par L’équation Universelle Des Pertes En Terre Dans Le Rif Occidental: Cas Du Bassin Versant De Moulay Bouchta (Maroc)

Soil erosion causes many environmental and socio-economic problems: loss of biodiversity, decrease in the productivity of agricultural land, siltation of dams and increased risk of flooding. It is therefore essential to establish a detailed evaluation of this process before any spatial planning. To evaluate the effects of soil erosion spatially and quantitatively in order to face this phenomenon, and propose the best conservation and land development strategies, the Universal Soil Loss Equation (USLE) coupled with a geographic information system (GIS) is applied. This model is a multiplication of the five erosion factors: the erosivity of the rain, the erodibility of the soil, the inclination and the slope length, the vegetation cover and the anti-erosion practices. The study area is the Moulay Bouchta watershed (7 889 ha), which is located in the western part of the Rif Mountains, is characterized by a complex and contrasting landscape. The resulting soil loss map shows an average erosion rate of 39.5 (t/ha/yr), 87% of the basin has an erosion rate above the tolerance threshold for soil loss (7 (t/ha/yr)). Soil losses per subbasin range from 16.2 to 81.4 (t/ha/yr). The amount of eroded soil is estimated at 311,591 (t/yr), corresponding to a specific degradation of 12.1 (t/ha/yr). In the absence of any erosion control, 25% of the soil losses would reach the new dam located a little upstream of the basin outlet, reducing its water mobilization capacity to 59,625 (m3/yr). The application of Principal Component Analysis (PCA) to soil erosion factors shows a significant influence of topographic factor (LS) on soil erosion process, followed by the effect of support practices (P), then by soil erodibility (K)

Study of the Anti-Inflammatory and Healing Properties of the Rhizomes of Carthamus Caeruleus L. (Asteraceae) Harvested in the Region of Tipaza

Background: In some regions of Algeria, in Tipaza, natural medicine still occupies a place of choice in the treatment of many pathologies, among these natural remedies are quoted extracts of the rhizomes of Carthamus caeruleus L are used to treat burns with these astringent properties. Medicinal plant extracts contain a variety of phenolic compounds that are attributed to various biological activities (antioxidant and antimicrobial activity). Methods: Our present study was conducted on the roots of Carthamus caeruleus L. harvested in the Tipaza region during the spring season. In order to promote this plant, we evaluated the anti-inflammatory activity and healing activity of the aqueous extract of the powder of the roots of Carthamus caereulus L. Studying the anti-inflammatory effect by measuring the volume of the edema of the paw that has received carrageenan 1%. Circular incision of 2 cm in diameter was made in Wistar rats to evaluate the healing activity of the aqueous pasty extract of the rhizomes of Carthamus caeruleus L at 100 mg/kg. Results: They show that aqueous extracts of Carthamus caeruleus L rhizomes at the dose of 100 mg/kg are opposed to the increased edema induced by the carrageenan 1% in rats with a percentage of inhibition of edema volume of 87.34% at the 6th hour.  Concerning the healing activity, the results show that the application of the aqueous extracts of the roots of Carthamus caereulus L.at dose of 100 mg/kg on the wounds causes their healing at the end of 14 days. Conclusion: Aqueous extracts of the roots of Carthamus caereulus L. show healing properties and anti-inflammatory effects. These results could justify the use of this plant in traditional medicine against inflammatory diseases

Study of the Biological Activities of the Seeds of the Plant Ceratonia Siliqua L. Recovered in the Bejaia Region

Background: Ceratonia siliqua is a plant that belongs to the Fabaceae family. It is frequently used in our culinary and medical traditions to fight cholesterol, acute diarrhea and digestive disorders. Methods: The hydrogen atom or electron donation abilities of the corresponding extracts and some pure compounds were measured from the bleaching of the purple-colored methanol solution of 2, 20-diphenylpicrylhydrazyl (DPPH), studying the anti-inflammatory effect by measuring the volume of the edema of the paw that has received carrageenan 1%. Antimicrobial activity in vitro was screened by using disc diffusion and micro-dilution methods. Results: The determination of the polyphenols of the methanolic extracts of the seeds reveals the richness of our extracts in polyphenols is 30 mg of gallic acid / g of extract. The aqueous and methanolic extract flavonoid assay shows that they contain high levels of flavonoids with contents of 07 and 10 mg equivalent of quercetin / g of extract respectively. The aqueous and methanolic extracts of Ceratonia siliqua seeds from the Bejaia region could bring the stable free radical 2.2 diphenyl-1-picrylhydrazyl (DPPH) to yellow-colored diphenylpicrylhydrazine with respective IC 50 values of 0.7 mg/ml and 0.2 mg/ml. They exhibit lower antioxidant activity than ascorbic acid (0.038 μg / ml). Determination of anti-inflammatory activity revealed that our aqueous and methanolic extracts of Ceratonia siliqua L seeds are able to reduce edema up to 81.89%. The methanoid extracts of Ceratonia siliqua L. seeds have a medium antibacterial action against bacteria: E. coli (13 mm), Staphylococcus aureus (12 mm) and Pseudomonas aeruginosa (12 mm). On the other hand, the aqueous extracts of the seeds of Ceratonia siliqua L have a weak antibacterial action against the same bacteria with a diameter of inhibition of 9 mm. However, the aqueous extracts of Ceratonia siliqua L seeds are endowed with a very important inhibitory action against candida albicans and it is similar to that of the antibiotic, antifungal Econazole (1%). Conclusion: According to the results observed, the two extracts of the seeds and pods have a potential anti-free radical and antioxidant measured compared to the standard antioxidant used. The results of the antimicrobial activity carried out in vitro on the 3 bacterial strains indicate that the two methanolic extracts of this plant have low antibacterial activity

Biological activities (antioxidant and antimicrobial activity) of the aqueous extracts and essential oil of Ammoides verticillata (Nounkha)

The phytochemical review conducted on the aerial part Ammoides verticillata has revealed the presence of six chemical families: flavonoids, tannins; gallic tannins, anthocyanins and the coumarins, cateichic tannins. The aqueous extract of the Ammoides verticillata could bring back the stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) to the yellow-colored diphenylpicrylhydrazine with an IC50 of 0.020 mg.mL-1. It is gifted with antioxidant activity, however it was less effective than vitamin C (0.001 mL-1). The essential oil of the Ammoides verticillata has presented a strong antimicrobial activity against Gram negatif germs targets of original clinical action: E. coli (ESBL) (37 mm), E. coli (39.5 mm), Klebsiella pneumoniae (36.5 mm) and especially with the yeast: Candida albicans ATCC 10231 (47 mm) and Saccharomyces cerevisie ATCC (42 mm), which are highly sensitive to the oil inhibitory action. However, the oil has presented a low activity against the bacteria P. aeruginosa (12.5 mm)

A fast and accurate global maximum power point tracking controller for photovoltaic systems under complex partial shadings

The operating conditions of partially shaded photovoltaic (PV) generators created a need to develop highly efficient global maximum power point tracking (GMPPT) methods to increase the PV system performance. This paper proposes a simple, efficient, and fast GMPPT based on fuzzy logic control to reach the point of global maximum power. The approach measures the PV generator current in the areas where it is almost constant to estimate the local maximums powers and extracts the highest among them. The performance of this method is evaluated firstly by simulation versus four well-known recent methods, namely the hybrid particle swarm optimization, modified cuckoo search, scrutinization fast algorithm, and shade-tolerant maximum power point tracking (MPPT) based on current-mode control. Then, experimental verification is conducted to verify the simulation findings. The results confirm that the proposed method exhibits high performance for complex partial irradiances and can be implemented in low-cost calculators

Extragonadal mixed germ cell tumor of the right arm: description of the first case in the literature

<p>Abstract</p> <p>Background</p> <p>Extragonadal localization of germ cell tumors (GCTs) is rare; to the best of our knowledge, a location in the soft tissue of the arm has never been previously reported in the literature.</p> <p>Case presentation</p> <p>We report the case of a 37-year-old man who presented with a primary malignant mixed non-seminomatous GCT (teratocarcinoma variety) in the right arm, treated by a combination of cisplatin-based chemotherapy and surgery. After 18 months of close follow-up, no locoregional recurrence or distant metastases have been detected.</p> <p>Conclusions</p> <p>A combination of chemotherapy and surgery is the most appropriate treatment strategy for extragonadal GCTs, to ensure both local and systemic control.</p

Schwannome cervical du nerf vague: Stratégies diagnostique et thérapeutique

Les schwannomes cervicaux sont des tumeurs bénignes des nerfs périphériques développées exclusivement à partir des cellules de Schwann. L'atteinte du nerf vague cervical est relativement rare, et les auteurs en rappellent, à partir d'un cas, les signes radiologiques évocateurs ainsi que les caractéristiques histologiques. Le traitement de ces tumeurs est chirurgical. Un patient de 32 ans consultait pour une masse latéro-cervicale supérieure droite isolée, évoluant depuis trois ans. Une imagerie médicale (TDM et IRM) cervicale mettait en évidence une masse vascularisée au temps retardé, refoulant la veine jugulaire interne en dehors et l'axe carotidien en dedans. Un examen cytologique non contributif conduisait à réaliser une exérèse chirurgicale extracapsulaire de la masse par voie de cervicotomie. Il s'agissait d'une tumeur rétro-jugulo-carotidienne développée aux dépens du nerf vague cervical droit. L'analyse histologique concluait à un schwannome. Les suites opératoires étaient simples. Le schwannome du nerf vague est une tumeur bénigne rare, qui doit être évoquée devant toute masse latérocervicale isolée. L'imagerie médicale (TDM et IRM) cervicale préopératoire représente les examens de choix indispensable pour évoquer le diagnostic. Le traitement est chirurgical, afin de confirmer le diagnostic histologique. L'exérèse chirurgical complète extracapsulaire est possible et est le seul garant de la non récidive.Pan African Medical Journal 2013; 14: 7

Chapitre 48. Gestion du ruissellement et restauration de la productivité des terres de montagne au Nord-Ouest algérien (Beni Snouss)

Les auteurs ont évalué la capacité de certaines techniques traditionnelles de conservation de l’eau et des sols dans les montagnes du Nord-Ouest algérien où les risques de dégradation sont élevés. Les analyses et les observations effectuées sur le terrain montrent que les aménagements traditionnels utilisés aujourd’hui qui donnent le plus de satisfaction sont surtout les terrasses et terrassettes avec des murets en pierres agencées qui permettent une accumulation progressive de sédiments et une bonne protection des dispositifs d’irrigation. Les agriculteurs ont développé plusieurs techniques pour gérer l’eau (bassin d’accumulation, canaux traditionnels, ouvrages de dérivation), le sol et la biomasse y compris, les cultures favorisant une meilleure diversité écologique. La dynamique de l’érosion a été ralentie et la production agricole nettement améliorée. Cette étude a permis de mieux comprendre l’environnement agroécologique de la région et de développer un bon dialogue avec les agriculteurs en vue de la préservation de leur environnement.Authors have estimated the efficiency of some traditional techniques of soil restoration developed in very degraded areas of north-western Algeria. Field observations showed that traditional terraces with stony embankments allow a progressive accumulation of ground and a good protection of irrigation systems. Farmers have developed numerous irrigation systems (earth channels, basins, divisor systems) and numerous cropping systems maintaining a good biodiversity. This inquiry showed that erosion has been reduced, the production improved and the rural environment better understood during the discussions with farmers