in this paper, the effects of scintillation phenomena on bit error rate (ber) and signal to noise ratio (snr), which are essential characteristics in free space optical (fso) communication system, are studied. until now various methods have been introduced to decrease ber and increase the link's reliability. optimizing snr is one of the fundamental methods to decrease ber value. intensity fluct...

The throughput enhancement of Space-Time Spreading (STS)-based Multicarrier Direct Sequence Code Division Multiple Access (MC DS-CDMA) system is investigated in this paper. Variable Spreading Factor (VSF) is utilized to improve the data throughput of the system. In this contribution, an analytical approach is proposed to compute a new expression for the Bit Error Rate (BER) performance of t...

background: a few studies have investigated the effect of the activation mode of adhesive systems on bond strength of fi ber posts to root canal dentin. this study investigated the push-out bond strengths of a glass fi ber post to different root canal regions with the use of two adhesives with light- and dual-cure polymerization modes. materials and methods: in this in vitro study, 40 maxillary...

background and objective: basal cell carcinoma (bcc) and squamous cell carcinoma (scc) are two common tumors of the skin. in some cases, distinction between bcc and scc can be difficult. this study aimed to clarify this uncertainty through immunohistochemical analysis. in this respect, epithelial membrane antigen (ema) and ber-ep4 are the two immunohistochemical markers on which we focus in dif...

Objective(s): Iron is an essential element for living organisms. Iron overload can have detrimental effects on health. This study pertains to the protective role of berberine against ferrous sulfate-induced hepatic and renal functional disorders and histological damages in rats.Materials and Methods: The rats were divided into four groups (n=7): Sham, Ber (10 mg/kg/day for 14 days, by gavage), ...

In this paper, we investigate the effects of auto-tracking subsystem together with different beam divergences on SNR, BER and stability of FSO communication links. For this purpose we compute the values of power, SNR and BER on receiver, based on analytic formula of Gaussian beam on receiver plane. In this computation the atmospheric effects including absorption, scattering and turbulence are c...

The effect of different pre-sowing seed treatments and sowing dates on germination and rootstock quality of ber was assessed to standardize a combination which could yield optimum germination and quality rootstock. Of the fourteen pre-sowing treatments, highest seed germination and best seedling growth was obtained in T10 x D2 (seed soaking in water for 48 hours followed by 6 days storage in mo...