Energy and exergy analysis of using turbulator in a parabolic trough solar collector filled with mesoporous silica modified with copper nanoparticles hybrid nanofluid

Designing the most efficient parabolic trough solar collector (PTSC) is still a demanding and challenging research area in solar energy systems. Two effective recommended methods for this purpose that increase the thermal characteristics of PTSCs are adding turbulators and nanofluids. To study the effects of the two approaches on the energy efficiency of PTSCs, a stainless steel turbulator was used and solid nanoparticles of Cu/SBA-15 were added to the water with the volume concentrations of 0.019% to 0.075%. The generated turbulence in the fluid flow was modeled by the SST k–ω turbulent model. The results in daylight demonstrated that energy efficiency increases steadily by 11:30 a.m., and then, starts to drop gradually due to more irradiations at noon. It was observed that applying the turbulator to the studied PTSC has a significant influence on the enhancement of energy efficiency. Adding the nanoparticles augmented the average Nusselt number inside the solar collector in various studied Reynolds numbers. It was also found that the increase in volume concentrations of nanoparticles enhances heat transfer regularly

Uniform and virus-free citrus rootstocks production via nucellus culture

Prevalence of various virus and virus-like diseases is among the main reasons for the decrease in quality and quantity of citrus crops. These diseases are mainly spread through the propagation method in citrus which is budding. Using nucellus culture of bitter orange and Mexican lime seeds, uniform and virus-free rootstocks could be produced so that the diseases prevalence could be prevented. In order to generate adventitious shoots from nucellus culture in each of the two rootstocks, direct organogenesis method is used. In all conducted experiments, Murashige and Skoog (MS) medium were used. Two plant growth regulators of benzyl adenine (BA) in 0, 1, 1.5 and 2 mg l-1 concentration and gibberellins (GA) in 0, 1 and 2 mg l-1 concentration were used in the medium and the main effects of each plant growth regulator were studied separately and their interaction on shoot generation were also surveyed. Considering the retrieved data, it was determined that the interaction of BA and GA have a higher impact on shooting, comparing to the cases where each of the regulators is used alone. In Mexican lime rootstock, the best culture medium for generating shoots from nucellus culture is the culture medium containing 2 mg l-1 BA and 2 mg l-1 GA and in bitter orange rootstock, the highest shooting rate was attributed to the culture medium containing 2 mg l-1 GA and 1 mg l-1 BA. For the Mexican lime and bitter orange shoots rooting, indole butyric acid (IBA) was used. The concentrations of this plant growth regulator used in Mexican lime were 0, 0.5, 1 and 1.5 mg l-1 and for bitter orange were 0, 1 and 1.5 mg l-1. The highest rooting rate for Mexican lime was in culture medium containing 0.5 mg l-1 IBA and for bitter orange, it was the culture medium containing 1 mg l-1 IBA. The obtained plantlets were gradually adapted with the external environment

Analysis of the effects of Glomus etunicatum fungi and Pseudomonas fluorescence bacteria symbiosis on some morphological and physiological characteristics of Mexican lime (Citrus aurantifolia L.) under drought stress conditions

To analyze the effects of Glomus etunicatum fungi and Pseudomonas fluorescence bacteria on some morphological and physiological characteristics of Mexican lime plant under drought stress conditions, a factorial experiment was conducted. This experiment was based on a completely randomized design with three replicates; each replicate was composed of two pots. The factors used consisted of G. etunicatum fungi and control, Pseudomonas fluorescence bacteria and control, and drought stress at three levels (-0.35, -0.47, and -0.6 bars). The analyzed characteristics were leaf chlorophyll content, leaf temperature, rate of net photosynthesis, transpiration, leaf relative water content (RWC), and percentage of root colonization. Data analysis revealed that both fungi and bacteria increased leaf chlorophyll content, net photosynthesis rate, transpiration, and leaf RWC. Moreover, the presence of fungi reduced leaf temperature while inoculation of bacteria had no effects on that the parameter. In addition, with the increase of irrigation periods, leaf temperature and transpiration were also increased. Results showed that root colonization percentage dropped with increased irrigation and the highest root colonization percentage was observed in simultaneous inoculations of fungi and bacteria with a two-day irrigation period

KIR2DS3 is associated with protection against acute myeloid leukemia

Background: Interaction between killer cell immunoglobulin-like receptors (KIR) and human leukocyte antigen (HLA) class I molecules is important for regulation of natural killer (NK) cell function. Objective: The aim of this study was to investigate the impact of compound KIR-HLA genotype on susceptibility to acute leukemia. Methods: Cohorts of Iranian patients with acute myeloid leukemia (AML; n=40) and acute lymphoid leukemia (ALL; n=38) were genotyped for seventeen KIR genes and their three major HLA class I ligand groups (C1, C2, Bw4) by a combined polymerase chain reaction-sequence-specific primers (PCR-SSP) assay. The results were compared with those of 200 healthy control individuals. Results: We found a significantly decreased frequency of KIR2DS3 in AML patients compared to control group (12.5 vs. 38, odds ratio=0.23, p=0.0018). Also, the KIR3DS1 was less common in AML group than controls (27.5 vs. 44.5, p=0.0465, not significant after correction). Other analyses including KIR genotypes, distribution and balance of inhibitory and activating KIR+HLA combinations, and coinheritance of activating KIR genes with inhibitory KIR+HLA pairs were not significantly different between leukemia patients and the control group. However, in AML patients a trend toward less activating and more inhibitory KIR-HLA state was observed. Interestingly, this situation was not found in ALL patients and inhibition enhancement through increase of HLA ligands and inhibitory combinations was the main feature in this group. Conclusion: Our findings may suggest a mechanism for escape of leukemic cells from NK cell immunity

Cannabis sativa L. oil extract affects neuroinflammation, clinical score, and cannabinoid receptor-1 gene expression in C57bl/6 experimental autoimmune encephalomyelitis

Introduction: Multiple sclerosis (MS) is a degenerative central nervous system disease derived by immune mechanisms, which ultimately results in clinical debilities. Numerous nutraceuticals have been cited to be effective in treatment of central nervous system complications. Objectives: This study investigated the effect of Cannabis sativa L. seed oil on experimental autoimmune encephalomyelitis (EAE). Materials and Methods: Female C57bl/6 mice were assigned randomly into three groups (8 in each). Group-A received no myelin oligodendrocyte glycoprotein (MOG), group B was immunized by MOG and treated with oil, while in group C animals were immunized and treated with normal saline. Clinical scores were recorded every other day throughout the study and after four weeks, all mice were sacrificed and spinal cords were incised for molecular and histopathological evaluations. Results: Significant differences were observed in mean clinical scores between control and experiment groups (P&lt;0.001). Cannabinoid receptor-1 gene expression increased significantly in treatment group (P&lt;0.001). Histopathologic evaluations also showed a significant decrease in overall infiltrated and vacuolated area and immune cells infiltration into the central nervous system in the treatment group (P&lt;0.01). Conclusion: Cannabis sativa L. oil extract administration alleviated inflammation and paralysis in animal model. Therefore, its oil extract might be useful in soothing inflammatory and auto-immune diseases. However, additional research might be required.</jats:p

Forced convection around horizontal tubes bundles of a heat exchanger using a two-phase mixture model: Effects of nanofluid and tubes Configuration

In this paper, numerical simulation of laminar flow and heat transfer of nanofluid on a group of heat exchanger tubes is described. For better prediction of the behavior of the nanofluid flow on the tube arrays, two-phase mixture model was used. To achieve this aim, heat transfer and laminar flow of two-phase nanofluid as cooling fluid at volume fraction of 0, 2, 4, and 6% solid nanoparticles of silver and Reynolds numbers of 100 to1800 were investigated for different Configurations of tube arrays. The results indicated when the nanofluid collides with the tube arrays, the growth of heat boundary layer and gradients increase. The increase in the growth of boundary layer in the area behind the tubes was very remarkable, such that at the Reynolds number of 100, due to diffusion of the effect of wall temperature in the cooling fluid close to the wall, it had a considerable growth. Further, from the second row onwards, the slope of pressure drop coefficient diagrams was descending. Among the different Configuration s of tubes and across all the investigated Reynolds numbers, square Configuration had the maximum pressure drop coefficient as well as the highest extent of fluid momentum depreciatio

Exploring cancer register data to find risk factors for recurrence of breast cancer – application of Canonical Correlation Analysis

BACKGROUND: A common approach in exploring register data is to find relationships between outcomes and predictors by using multiple regression analysis (MRA). If there is more than one outcome variable, the analysis must then be repeated, and the results combined in some arbitrary fashion. In contrast, Canonical Correlation Analysis (CCA) has the ability to analyze multiple outcomes at the same time. One essential outcome after breast cancer treatment is recurrence of the disease. It is important to understand the relationship between different predictors and recurrence, including the time interval until recurrence. This study describes the application of CCA to find important predictors for two different outcomes for breast cancer patients, loco-regional recurrence and occurrence of distant metastasis and to decrease the number of variables in the sets of predictors and outcomes without decreasing the predictive strength of the model. METHODS: Data for 637 malignant breast cancer patients admitted in the south-east region of Sweden were analyzed. By using CCA and looking at the structure coefficients (loadings), relationships between tumor specifications and the two outcomes during different time intervals were analyzed and a correlation model was built. RESULTS: The analysis successfully detected known predictors for breast cancer recurrence during the first two years and distant metastasis 2–4 years after diagnosis. Nottingham Histologic Grading (NHG) was the most important predictor, while age of the patient at the time of diagnosis was not an important predictor. CONCLUSION: In cancer registers with high dimensionality, CCA can be used for identifying the importance of risk factors for breast cancer recurrence. This technique can result in a model ready for further processing by data mining methods through reducing the number of variables to important ones

Vibration analysis of viscoelastic single-walled carbon nanotubes resting on a viscoelastic foundation

Vibration responses were investigated for a viscoelastic Single-walled carbon nanotube (visco-SWCNT) resting on a viscoelastic foundation. Based on the nonlocal Euler-Bernoulli beam model, velocity-dependent external damping and Kelvin viscoelastic foundation model, the governing equations were derived. The Transfer function method (TFM) was then used to compute the natural frequencies for general boundary conditions and foundations. In particular, the exact analytical expressions of both complex natural frequencies and critical viscoelastic parameters were obtained for the Kelvin-Voigt visco-SWCNTs with full foundations and certain boundary conditions, and several physically intuitive special cases were discussed. Substantial nonlocal effects, the influence of geometric and physical parameters of the SWCNT and the viscoelastic foundation were observed for the natural frequencies of the supported SWCNTs. The study demonstrates the efficiency and robustness of the developed model for the vibration of the visco-SWCNT-viscoelastic foundation coupling system