Normal-strength and high-strength concrete columns under cyclic axial load and biaxial moment

The technique of using Carbon Fiber Reinforced Polymer (CFRP) materials to repair and strengthen various concrete members has become popular in the structural retrofitting field as an effective way to enhance the strength and ductility of concrete members due to its superior mechanical properties. In this study a method was introduced to study the behavior of concrete columns with and without CFRP jackets under constant axial load and variable lateral load. The lateral load was applied monotonically and cyclically. To predict the behavior of concrete columns under monotonic and cyclic compressive loadings, a computer code was developed to produce the moment-curvature diagram for concrete sections. The moment-curvature diagram was then input in SAP2000 to study the behavior of reinforced concrete columns. The result of this analysis was found to correlate with experimental data well. The behavior of high-strength concrete (HSC) columns having various properties and subjected to a variety of loading conditions has been the topic of considerable investigation. Of particular significance in this area is the behavior of HSC columns under cyclic compressive load with bidirectional eccentricity. For the experimental investigation, tests of six square slender HSC columns were conducted under stroke control to achieve both ascending and descending branches of the load-deformation curves. Analysis of HSC columns subjected to cyclic axial compression with bidirectional eccentricity was approached from the standpoint of a three-dimensional problem. A computer program based on the extended finite segment method and accounting for geometrical nonlinearity has been proposed here to predict the load-deflection curves of HSC columns under cyclical loading. The HSC stress-strain relationship obtained by parametric study and experimental investigation into the behavior of concrete under cyclical load history has been incorporated into the numerical procedure. The presented computer analysis results have been compared with the experimental data, and a satisfactory agreement was attained for both the ascending and descending branches of the load-deformation curves

The effect of cognitive rehabilitation therapy (CRT) on the executive functions of children with autism spectrum disorder (ASD)

BACKGROUND: Executive functions (EF) impairments are considered as central deficits in autism spectrum disorder (ASD). The purpose of this study was to determine the effectiveness of cognitive rehabilitation therapy (CRT) on EFs of children with high-functioning ASD (HFA).METHODS: This was a quasi-experimental study with a pretest-posttest design and control group. The study population included all children with HFA referred to the comprehensive Arman Shayan Rehabilitation Center in Tehran, Iran. Using the high-functioning Autism Spectrum Screening Questionnaire (ASSQ) and clinical diagnostic interviews by two clinical psychologists, 24 children with HFA were selected purposefully and were randomly assigned to experimental or control groups. Subjects in both groups completed the Behavior Rating Inventory of Executive Function (BRIEF) in pretest and posttest. The experimental group received 1-2 sessions (1 hour) per week of CRT for 6 months. Data analysis was performed using analysis of covariance (ANCOVA) in SPSS.RESULTS: Data analysis showed that the use of CRT resulted in a significant difference between groups in terms of the total EFs score, which was 88.5%, as well as the components of inhibition (57%), orientation (46%), emotional control (42%), initiate (43%), working memory (55%), planning (56%), organizing (36%),and monitoring (36%).CONCLUSION: CRT, as an evidence-based intervention, seems to be effective in improving neuropsychological functions in children with HFA

Covid-19, Challenges and Recommendations in Agriculture

On 11 March 2020, the World Health Organization declared Covid-19 is a pandemic disease that is spreading at different speeds in different countries of the world. Given these issues, the global economy is experiencing a different and new experience that is currently taking place in different countries. We are seeing a decrease in production, logistical problems, as well as a change in production patterns, demand and consumption. The agricultural sector has not been immune to the economic damage of the outbreak and has suffered serious damage. If the necessary measures are not taken for sustainable production in agriculture and maintaining the supply and demand cycle, health and food security will face a crisis. Given that there is always a zero point again about the prevalence and infection, social quarantine and health care are still essential. To manage the problems caused by the Corona crisis, accurate and appropriate programs, mechanisms, and evaluations with different strategies are needed, and appropriate sustainable models should be considered for spatial and temporal requirement

A New Approach to Root Formation

In endodontics, treatment of an open apex tooth with necrotic pulp is a problem. It seems that with promotion of remnants of Hertwig’s epithelial sheath or rest of malassez accompany with a good irrigation of root canal we can expect root formation

Comparação da concentração de metais pesados em alguns vegetais (aipo, brócolis e alface)

Heavy metal contamination is one of the main environmental and food safety concerns. This study was conducted with the objective of determining the concentration of heavy metals such as cadmium, lead, copper, zinc and iron in stems and leaves in various vegetables (celery, broccoli and lettuce) in Shiraz. The metal concentrations in the vegetable samples were determined by atomic absorption spectroscopy (AAS). The results for the vegetable samples showed that the leaves contained much higher concentrations of heavy metals. The concentrations of Cd detected in the vegetable samples varied from a very low infection to 0.0025 mg / kg; very low infection at 0.51 mg / kg Pb; 0.93 to 2.91 mg / kg Cu. 1.44 to 9.69 mg / kg Zn and 2.54 to 11.05mg / kg Fe. The findings of this study indicated that although most of the sampling plants were contaminated, except for lettuce, other crops have an EDI below the Tolerable Daily Intake (PTDI) recommended by the Institute of Standards and Industrial Research of Iran and the FAO / WHO.La contaminación por metales pesados es uno de las principales preocupaciones ambientales y de seguridad alimentaria. Este studio se realizó con el objetivo de determinar la concentración de metales pesados como cadmio, plomo, cobre, zinc y hierro en tallos y hojas en varios vegetales (apio, brócoli y lechuga) en Shiraz. Las concentraciones de metal en las muestras de vegetales se determinaron mediante espectroscopia de absorción atómica (AAS). Los resultados para muestras de vegetales mostraron que las hojas contenían concentraciones mucho más altas de metales pesados. Las concentraciones de Cd detectadas en las muestras de vegetales variaron desde una infección muy baja hasta 0,0025 mg / kg; infección muy baja a 0,51 mg / kg Pb; 0,93 a 2,91 mg / kg Cu. 1.44 a 9.69 mg / kg Zn y 2.54 a 11.05mg / kg Fe. Los hallazgos de este estudio indicaron que aunque la mayoría de las plantas del muestreo estaban contaminadas, la ingesta diaria estimada de cada metal (EDI) mostró que, excepto la lechuga, otros cultivos tienen un EDI por debajo de la ingesta diaria tolerable (PTDI) recomendada por el Instituto de Normas e Investigación Industrial de Irán y FAO / OMS.A contaminação por metais pesados é uma das principais preocupações ambientais e de segurança alimentar. Este estúdio foi realizado a fim de determinar a concentração de metais pesados tais como cádmio, chumbo, cobre, zinco e ferro em caules e folhas em vários produtos hortícolas (aipo, brócolos e alface) em Shiraz. As concentrações de metais nas amostras vegetais foram determinadas por espectroscopia de absorção atômica (AAS). Os resultados par a as amostras vegetais mostraram que as folhas continham concentrações muito mais altas de metais pesados. As concentrações de Cd detectadas nas amostras vegetais variaram de uma infecção muito baixa a 0,0025 mg / kg; infecção muito baixa a 0,51 mg / kg Pb; 0,93 a 2,91 mg / kg Cu. 1,44 a 9,69 mg / kg Zn e 2,54 a 11,05 mg / kg Fe. Os resultados deste estudo indicaram que, embora a maioria das plantas amostradas foram contaminados, exceto alface, outras culturas têm EDI abaixo da ingestão diária tolerável (PTDI) recomendado pelo Instituto de Padrões e Pesquisa Industrial de Irã e FAO / OMS

Finite Element Modeling of New Composite Floors Having Cold-Formed Steel and Concrete Slab

In this research, the structural behavior of a new type of U.S. patented composite floor system is explored through finite element modeling. The new composite floor incorporates cold-formed (light-gauge) steel profiles as the joist on bottom, a corrugated steel deck as the formwork for concrete, a hat channel (furring channel) as the continuous shear connector and finally a concrete slab on top. All steel parts in the system are cold-formed and connected together by self-drilling fasteners. In this study, a comprehensive three-dimensional finite element modeling is performed for the composite floor system. A local bond-slip model is applied to simulate the slip of the shear connector inside the concrete slab. A nonlinear analysis is performed on the composite floor considering all different types of structural nonlinearities and the behavior of the system is monitored from beginning of loading all the way to failure. Results of finite element analysis are compared with experimental results. Further, during the course of this study, several parametric studies are conducted to determine the effect of bond-slip behavior on reducing ultimate strength and initial stiffness of such a floor system

External root resorption: Arrested or progressing?

External root resorption may be an uncontrolled phenomenon, and the most known interventions have no effect. Even progressive external root resorption may not be controlled by long term Ca(OH)2 therapy. Currently, there are no treatment options for vital tooth that suffer from root resorption. This invasive resorption can lead to extraction of the tooth. The use of new technologies such as low power laser may control this type of resorption

Protective effect of citrus lemon on inflammation and adipokine levels in acrylamide-induced oxidative stress in rats

The high exposure to acrylamide (AA) due to smoking and increased consumption of processed and fast foods in recent years, has become one of the health threatening problems. This study examined the effect of lemon juice on inflammation and adipokines in acrylamide-induced oxidative stress in rats. Forty animals were divided into five groups. Toxicity was induced by AA (35mg/kg) for two weeks in all groups except normal control group. After that, lemon juice in three doses was administrated to treatment groups for 4 weeks. Serum levels of adipokines and inflammatory parameters and both serum and liver levels of oxidative stress parameters were measured. The results showed groups were received AA had significant higher levels of malondialdehyde, tumor necrosis factor alpha, leptin and C-reactive protein and lower levels of total antioxidant capacity compared to the negative control group. Lemon juice in all three doses significantly improved serum levels of TAC, MDA, TNFα and hs-CRP in treated groups. Also, 7.5 ml/kg lemon juice significantly decreased leptin levels. However, lemon juice had no significant effect on adiponectin levels. This study suggests lemon juice as a potential dietary alternative could attenuate leptin levels and manage oxidative and inflammatory damages in acrylamide- induced toxicity in rats