Organochlorine pesticides removal from groundwater by citrus coal and uv/o3: A hybrid pilot-scale study

In this laboratory-scale study, organochlorine pesticides (OCPs) reduction using citrus coals and O3 assisted by solar UV as an integrated treatment of groundwater under visible UV to reach sustainable development were traced. The experimental parameters were set up throughout standard methods and analysis protocols. The best performance of citrus coal was observed at a reaction time of 90 min, pH: 6.5, adsorption bed height = 40 cm, initial OCPs concentration, respectively, as 100 µg/L for alachlor (ALC), α (±)-BHC, atrazine (ATZ), and α-chlordane, 150 µg/L for methoxychlor, 50 µg/L for heptachlor, and 90 µg/L for dieldrin. The best performance of citrus coal was observed at a reaction time of 90 min, pH: 6.5, adsorption bed height 40 cm, initial OCPs concentration of 100 µg/L for ALC, α (±)-BHC, ATZ, and α-chlordane, 150 µg/L for methoxychlor, 50 µg/L for heptachlor, and 90 µg/L for dieldrin. Under the above-mentioned operating conditions, the removal rates were estimated at more than 75 for all these compounds. The adsorption outputs were fitted to the Freundlich model with the average R2 > 0.97, while for the Langmuir model this value was >0.86. Thereby, it is concluded that OCPs adsorption occurs on a heterogeneous surface by multilayer sorption. With regard to Kf (1/n) parameter, for the Freundlich adsorption model, the order of OCPs adsorption was appeared to be methoxychlor > dieldrin > heptachlor > α-chlordane > ALC > α (±)-BHC > ATZ. The optimum variables for UV/O3 were obtained as 0.4 mg/L ozone, pH = 9, and 35 min reaction time, so that, more than 98 of these substances were degraded from the solution under this condition. The reaction kinetics were fitted with R2 value of more than 0.9 for most OCPs. The kinetic reaction constants (k) in pH values of 7 and 9.5 were higher than other ranges for all OCPs. The progress of pH at the alkaline area improved the pseudo-first-order constants. The kinetic model indicated that the reaction rates will be restricted by the initial pH value and the concentration of OH�. This evidence was well-established by monitoring dissolved O2 at the various pH ranges during the experiment runs. Eight intermediates were detected by gas chromatography-tandem mass spectrometry detection with chemical formula as C14 H20 ClNO3, C13 H16 ClNO3, C14 H18 ClNO4, �NHCH(CH3 )2, �NHCOCH3, �NH2, C13 H9 ClO, and C7 H5 ClO from the samples taken in the non-optimized UV/O3 effluent. However, all of them disappeared in the final effluent at the optimized condition. Altogether, this integrated strategy helped to remove OCPs more than 86 on average, with residues less than 1 µg/L and even 0.05 µg/L in some cases. Due to the generation of a large amount of citrus wastes (46,000 ton/y) in the north of Iran and the abundance of solar energy especially solar UV in the middle east, this hybrid approach to treat groundwater contaminated with agricultural OCPs as a type of EDCs can be an effective alternative for conventional and current removal strategies to provide safety and treat groundwater by this agricultural compound. © 2021 Desalination Publications. All rights reserved

The concentration and probabilistic health risk assessment of nitrate in Iranian drinking water: a case study of Ilam city

In this study, the concentration of nitrate in 11 drinking water points in Ilam city was investigated, and furthermore, the consumer's probabilistic health risk was assessed. The nitrate levels in cumulative probability plot (CPD) of 50 (C-EXP50) and 95 (C-EXP95) were calculated as 8.12 and 16.37 mg/L, respectively, while in all samples (n = 77) were measured as significantly (rho value) lower than 50 mg/L (the proposed reference value by the World Health Organization (WHO) as well as Iranian national standard. Considering the probabilistic health risk; Hazard Quotient 50 (HQ(50)) and Hazard Quotient 95 (HQ(95)) were measured as 0.21 and 0.4, (HQ men > women. The health risk assessment shows that all consumers are safe of health risk

www.ijllalw.org THE IMPACT OF CHAT ON THE VOCABULARY RETENTION OF IRANIAN EFL LEARNERS

Using the Internet to access “authentic language material ” is one of the ways that help students learn English, particularly English as a Foreign Language (EFL) students who may not have other ways to access this type of material. Since the evolution of networks, computers have been offering (EFL) learners more than drills: "they can be a medium of real communication in the target language, including composing and exchanging messages with other students in the classroom or around the world " (Oxford, 1990, p.79). No matter what target languages the learners study, most studies have found some positive attitudes towards text chat rooms for language learning, and confirmed that chat room can be a favorable environment for language practice especially for learners who do not live in target language –speaking areas (Blake, 2000). To evaluate the possible effects of chat on vocabulary retention of pre-university students studying in Ghasre- Shirin Pre-University centres, the researcher randomly selected 60 students-30 male and 30 female, from among 200 students. The design used for the research was Post test only control group. The students, who had been assigned to two groups (control and experimental), answered 28 multiple choice items test with varying levels of difficulty for posttest

The concentration and probabilistic health risk assessment of nitrate in Iranian drinking water: a case study of Ilam city

In this study, the concentration of nitrate in 11 drinking water points in Ilam city was investigated, and furthermore, the consumer’s probabilistic health risk was assessed. The nitrate levels in cumulative probability plot (CPD) of 50 (CEXP50) and 95 (CEXP95) were calculated as 8.12 and 16.37 mg/L, respectively, while in all samples (n = 77) were measured as significantly (ρ value) lower than 50 mg/L (the proposed reference value by the World Health Organization (WHO) as well as Iranian national standard. Considering the probabilistic health risk; Hazard Quotient 50 (HQ50) and Hazard Quotient 95 (HQ95) were measured as 0.21 and 0.4, (HQ <1), respectively. Based on acceptable daily intake dose, HQ50s for men, women, and children were 0.09, 0.07, and 0.11 while HQ95s were 0.16, 0.12, and 0.22, respectively. Therefore, the order of the Hazard Quotients (HQ50 and HQ95) based on the age group of consumers was summarized as children > men > women. The health risk assessment shows that all consumers are safe of health risk. © 2019 Informa UK Limited, trading as Taylor & Francis Group

3-Dimensional Model to Study Apoptosis Induction of Activated Natural Killer Cells Conditioned Medium Using Patient-Derived Colorectal Cancer Organoids

Natural killer (NK) cells are innate lymphocytes that can kill tumor cells via different pathways, including the secretion of cytotoxic granules in immunological synapses and the binding of apoptosis-inducing ligands with cognate death receptors on tumor cells. These ligands are also soluble in NK cells conditioned medium (NK-CM). However, novel preclinical in vitro models are required for solid tumors such as colorectal cancer (CRC) to investigate apoptosis induction of activated NK-CM in a tissue-like structure. In the present study, we established a patient-derived CRC organoid culture system as a new tool for CRC research in the last decade. Tumor organoids were stained with hematoxylin and eosin (H&E) and compared with the original tumor taken from the patient. Goblet cell differentiation and mucus secretion were evaluated using periodic acid�Schiff and alcian blue histochemical staining. Moreover, tumor organoids were stained for CDX2 and Ki67 markers with immunohistochemistry (IHC) to investigate gastrointestinal origin and proliferation. Histopathological evaluations indicated tumor organoids represent patient tumor characteristics. Primary NK cells were isolated and characterized using CD56 marker expression and the lack of the CD3 marker. Flow cytometry results showed the purity of isolated CD3�and CD56 + NK cells about 93. After further ex vivo expansion, IL-2-activated NK-CM was collected. Secretions of IFN-γ and TNF-α were measured to characterize activated NK-CM. Cytokines levels were significantly elevated in comparison to the control group. Soluble forms of apoptosis-inducing ligands, including TNF-related apoptosis-inducing ligand (TRAIL) and FasL, were detected by western blot assay. Colon cancer organoids were treated by IL-2-activated NK-CM. Apoptosis was assessed by Annexin V-FITC/PI staining and quantified by flow cytometry. In conclusion, despite the activated NK-CM containing apoptosis-inducing ligands, these ligands� soluble forms failed to induce apoptosis in patient-derived colon cancer organoids. Nevertheless, we report a reliable in vitro assessment platform in a personalized setting. Copyright © 2022 Parseh, Khosravi, Fazel, Ai, Ebrahimi-Barough, Verdi and Shahbazi

Comparative analysis of NES and TMD performance via high-dimensional invariant manifolds

A comparative study between a tuned mass damper (TMD) and a nonlinear energy sink (NES), attached to a linear two-degree-of-freedom (DoF) mechanical system under impulsive excitation, is performed. The analysis involves different scenarios; namely, we consider the cases in which only one or both modes of the primary system are initially excited. First, exploiting a harmonic balance approach, the invariant manifolds describing the slow dynamics of the system are identified. Then, introducing the so-called relative dissipation power, the performance of the two absorbers is carefully compared, based on analytical computations. Results illustrate that the two absorbers have similar performance, albeit resorting to different mechanical properties: The NES achieve a broad frequency band of operation exploiting nonlinearity, while the TMD by increasing damping. An interesting feature, highlighted by the invariant manifold, is that the NES is generally unable to resonate with more than one mode of the primary system at the same time, rather, it experiences a sort of modal cascade

Vibration reduction by using two tuned mass dampers with dry friction damping

Vibration reduction of a single-degree-of-freedom system connected to two tuned mass dampers (TMDs) equipped with dry friction dampers is considered in this work. The system is subjected to sinusoidal base excitation. Parameters of TMDs are optimized to minimize the peak values of the response of the primary system. Harmonic balance method (HBM) is used to obtain the steady state solution of the three-degrees-of-freedom nonlinear system in frequency domain. Newton’s method with arc length continuation is utilized to solve the resulting nonlinear algebraic equation set. In addition to that, optimum linear system and other nonlinear elements are investigated. Genetic algorithm is used to optimize parameters of TMDs