Performance evaluation of turbulence-accentuated interchannel crosstalk for hybrid fibre and free-space optical wavelength-division-multiplexing systems using digital pulse-position modulation

A hybrid fibre and free-space optical communication link using digital pulse-position modulation (DPPM) in a wavelength-division-multiplexing system is proposed. Such a system, which could provide a power efficient, robust and flexible solution to high-speed access networks, is a contender for a passive optical network solution and could readily be deployed in areas with restrictions in optical fibre installation, or alternatively as a disaster recovery network. Interchannel crosstalk and atmospheric turbulence are major impairments in such a system and could combine in some cases to degrade the system. Both impairments are investigated here and the results are presented in the form of bit error probability, required optical transmission power and power penalties. Depending on the position of the interferer relative to the desired user, power penalties of about 0.2–3.0 dB for weak turbulence and above 20 dB for strong turbulence regimes are reported for bit error rate of 10−6. DPPM scheme with a coding level of 2 show about 2 dB improvements over on–off-keying scheme

Evaluating the efficacy of probiotic on treatment in patients with small intestinal bacterial overgrowth (SIBO) - A pilot study

Background & objectives: Small intestinal bacterial overgrowth (SIBO) leads to several gastrointestinal (GI) problems and complications leading to malabsorption. The effectiveness of probiotics in the treatment of SIBO syndrome has not been well studied. This pilot study was aimed to assess the efficacy of a probiotic consisting of lactobacilli in the treatment of SIBO. Methods: In this study, 30 cases suffering from chronic abdominal pain or diarrhoea and with a positive hydrogen breath test were randomized in a double-blind manner into two groups: probiotic drug user and control group. After an initial 3-week aggressive therapy with broad-spectrum antibiotics, a 15-day maintenance antibiotic therapy with lactol was administered for the study group and the same regimen without lactol for the control group. After six months the HBT result and the GI symptoms were analyzed and compared between the two groups. Results: The result of hydrogen breath test and the clinical symptoms in patients receiving the maintenance regimen with lactol probiotic showed a better response. The hydrogen breath test turned negative in 93.3 per cent of those receiving lactol compared to 66.7 per cent of the controls. In all the cases receiving lactol, the abdominal pain disappeared completely ( p =0.002). In addition, other GI problems including flatulence, belching and diarrhoea significantly improved in the study group ( p <0.05). Interpretation & conclusions: Based on the preliminary data it seems that adding lactol probiotic to the maintenance therapy of small intestinal bacterial overgrowth patients on routine antibiotic therapy will be beneficial in preventing the complications of this syndrome

Processing and stabilization of Aloe Vera leaf gel by adding chemical and natural preservatives

Background and objectives: Aloe vera has been used as a medicinal herb for thousands of years. Aloe vera leaves can be separated into latex and gel which have biological effects. Aloe gel is a potent source of polysaccharides. When the gel is exposed to air, it quickly decomposes and decays and loses most of its biological activity. There are various processing techniques for sterilizing and stabilizing the gel. The aim of this study was to improve stabilization of the gel by adding some chemical and natural preservatives. Methods: The gel was obtained from Aloe vera leaves and after some processing chemical and natural preservatives were added. Chemicals included citric acid, ascorbic acid, vitamin E and potassium sorbate while natural preservatives were two essential oils derived from Cinnamomum zeylanicum and Eugenia caryophyllata. All these operations were performed under sterile conditions and they were evaluated at different temperatures and times. Appearance and taste changes of gel were studied organoleptic. Microbiological tests and some physical assays such as pH, refractometry and viscosity properties as well as determination of total sugars were measured. NMR and FT-IR analyses were performed for determining the quality of samples. Results: After data analyzing, the results showed that the samples formulated with chemical additives together with essential oils were more suitable and stable compared to the control samples after 90 days and the effective ingredient acemannan, remained stable. Conclusion: The stable gel can be considered for therapeutic properties and be used for edible and medicinal purposes

Turbulence Mitigation by Aperture Averaging in Wireless Optical Systems

International audienc

Extraction and phytoanalysis of chemical compounds of Eucalyptus globulus leaf native to Dehloran, Ilam province, Iran by HS-SPME and GC-MS

Eucalyptus globulus Labill. belongs to the Myrtaceae family, which extracted essential oils uses for medicinal, nutritional, and ornamental purposes. The present study conducted to extract the essential oil of Dehloran native eucalyptus leaf and recognize its biochemical components by the HS-SPME method. The eucalyptus leaf collected from Dehloran city, Ilam province, in October 2019. The leaves were dried for 72 hours at standard temperature and powdered. The essential oils and their volatiles extracted by solid-phase microextraction in the head space (HS-SPME) and their biochemical components analyzed by GC-MS. The final results revealed that the essential oil includes 43 composites that 1,8-cineol with 51.25 was the most important chemical composition of Eucalyptus leaves essential oil. Camphor (9.58), borneol (7.63), and camphene (3.77) were the other most important compounds identified. The major identified compounds were bicyclic monoterpenes, aromatic terpenoids, cyclic ether, and terpenes. It concluded that Eucalyptus culture in Dehloran, with a high amount of 1, 8-cineol has high pharmaceutical and healthful value. © 2020 Abbasi et al

Fading Reduction by Aperture Averaging and Spatial Diversity in Optical Wireless Systems

International audienc