A review of environmental friendly green composites: production methods, current progresses, and challenges.

The growing concern about environmental damage and the inability to meet the demand for more versatile, environmentally friendly materials has sparked increasing interest in polymer composites derived from renewable and biodegradable plant-based materials, mainly from forests. These composites are mostly referred to as "green" and they can be widely employed in many industrial applications. Green composites are less harmful to the environment and could be potential substitutes for petroleum-based polymeric materials. It is helpful to limit usage of fossil oil assets by developing biopolymer matrices such as cellulose-reinforced biocomposites using renewable assets such as plant oils, carbohydrates, and proteins. This paper focuses on green composites processing utilizing a variety of naturally available resources, sustainable materials which are not detrimental to the environment, new scientific signs of progress in achieving green sustainable development, as well as nanotechnology and its environmental consequences. Additionally, the environmental impacts of different composite materials are examined in this paper, along with their production from eco-friendly materials. Moreover, the manufacturing aspects of green composites and some concerns related to their production are also discussed. The merits of green composite materials and valid reasons why they are a valuable substitute for the traditionally used composite materials are also covered.

Body mass index and waist/height ratio for prediction of severity of coronary artery disease.

BACKGROUND: To determine whether waist-to-height ratio correlates with coronary artery disease (CAD) severity better, than the body mass index (BMI) as assessed by coronary angiography in Bangladeshi population. METHODS: This cross sectional study was done on patients in Department of Cardiology in DMCH and those referred in the cath-lab of the Department of Cardiology for CAG during November 2009 to October 2010 involving 120 patients. They were divided into group-A (with coronary score ≥7) and group-B (coronary score <7) depending on Gensisni score. RESULT: There were no statistically significant difference regarding the distribution of age, sex and clinical diagnosis and parameters between the two groups. The mean age of patients was 51.7 ± 8.2 years and 48.8 ± 9.1 years in Group A and Group B respectively with a male predominance in both the groups. Patients in group A had higher BMI ≥25 and waist to height ratio (≥0.55) than Group B which showed a statistically significant association (p < 0.001). Though a significant positive correlation (r = 0.296, p = 0.006) was observed between BMI and Coronary artery disease score in group A patients, scenario was reverse fro group B (r = 0.076, p = 0.659). The statement was also true for Waist-to-height ratio and Waist-to-height ratio with BMI. Multivariate analysis also yeilded that a patient with BMI ≥25 kg/m2 and waist-to height ratio of ≥0.55 are 3.06 times and 6.77 times, more likely to develop significant coronary artery disease respectively. CONCLUSION: The waist-to-height ratio showed better correlation with the severity of coronary artery disease than the BMI.

Ergonomic design and evaluation of pliers.

OBJECTIVE: In the present study, bent-handled needle-nose pliers, designed from an ergonomic perspective as an improvement over the conventional plier were investigated. PARTICIPANTS: A convenience sample of fourteen volunteer male university students aged between (20 and 24 years old) participated in the study. METHODS: Three angles to the jaws of plier (0°, 10° and 20°) were provided in the redesigned pliers to reduce ulnar deviation of wrist. Other two angles (0° and 5°) of jaws with respect to the vertical plane. From this, (3 × 2) six redesigned pliers were investigated. Dependent variables were discomfort--scored on 10~cm Visual Analogue Scale (VAS) and difference in systolic and dysystolic blood pressure (BP). RESULTS: The results of ANOVA showed that the main and interaction effects of the angle to prevent ulnar deviation of wrist and angle to prevent extension of wrist were highly significant (i.e., p< 0.001) on discomfort score. Effect of angle to prevent ulnar deviation of wrist was only found significant on difference in systolic blood pressure. Of the redesigned pliers, the pliers with 10° angle of handle from jaw to prevent ulnar deviation, and 5° angle of handle to prevent extension of wrist was found to give the minimum level of discomfort score. CONCLUSIONS: Hence it is concluded that bent handle pliers up to certain angles may reduce discomfort, and after that discomfort will increases drastically. These finding will be very significant for the designers to use one more angle as per the requirement of the comfortable use of pliers. Many ergonomically redesigned pliers are available. However none was found be considering angle to give extension of the wrist based on scientific findings.

Effects of ulnar deviation of the wrist combined with flexion/extension on the maximum voluntary contraction of grip.

Work-related musculoskeletal disorders (WMSDs) is related with the frequency of exertion for repetitive tasks requiring heavy load. Different researchers have reported that a poor posture is very much responsible for WMSD if combined with increased load and/or frequency. In the assembly tasks in different industries involve the gripping very commonly. Therefore in the present study it was tried to find the effect of a wrist posture on grip strength. For design of experiment, subjects, flexion/extension and ulnar deviation of the wrist were taken as independent variables and the dependent variable was maximum voluntary contraction (MVC) of grip. The results showed that the effect of flexion/extension angle, ulnar angle and the subject on MVC grip were highly significant (i.e., p<0.001, 0.001 and 0.002 respectively). The two-way interaction effect of flexion/extension angle of the wrist and the subject on MVC grip was also found significant at p<0.001. The other interaction effects were not found significant. MVC grip was found maximum at the neutral wrist posture.

Synthesis of [1,2,4]triazolo[1,5-a]pyrazines as adenosine A2A receptor antagonists.

Potent and selective antagonists of the adenosine A2A receptor often contain a nitrogen-rich fused-ring heterocyclic core. Replacement of the core with an isomeric ring system has previously been shown to improve target affinity, selectivity, and in vivo activity. This paper describes the preparation, by a novel route, of A2A receptor antagonists containing the [1,2,4]triazolo[1,5-a]pyrazine nucleus, which is isomeric with the [1,2,4]triazolo[1,5-c]pyrimidine core of a series of known A2A antagonists with in vivo activity in animal models of Parkinson's disease.

Synthesis of alkyne derivatives of a novel triazolopyrazine as A(2A) adenosine receptor antagonists.

A novel [1,2,4]triazolo[1,5-a]pyrazine core was synthesized and coupled with terminal acetylenes. The structure-activity relationship of the alkynes from this novel template was studied for their in vitro and in vivo adenosine A(2A) receptor antagonism. Selected compounds from this series were shown to have potent in vitro and in vivo activities against adenosine A(2A) receptor. Compound 12, in particular, was found to be orally active at 3mg/kg in both a mouse catalepsy model and a 6-hydroxydopamine-lesioned rat model.