Investigation of optimal thermal parameters for essential oils extraction using laboratory and solar distillation systems

Essential oils are used in medicines, foods, fragrances, perfumery and cosmetics etc.  Different methods are used for essential oils extraction.  Out of all these methods, distillation methods have advantage of extracting refine essence of the plant materials and herbs by evaporating volatile components.  The main object of the research is to investigate optimal thermal parameters and to develop simple and best methodologies for easy adaptation of these techniques for decentralized applications.  The research for essential oils extraction was conducted under laboratory conditions and by using solar energy.  For each laboratory experiment, equal weights of the herbs were used.  The energy consumption for different herbs was recorded with the help of energy meters and process curves were drawn for comparison.  The heat energy consumption to extract one milliliter of essential oil from Cloves buds, Fennel, Cumin, Patchouli, Cassia and Orange barks was found to be 0.133, 0.503, 0.574, 2.716, 2.807 kWh respectively.  The methodology and thermal parameters provide useful information regarding temperature and energy requirements to process different herbs.  On the basis of laboratory results, a de-centralized solar distillation system was developed using Scheffler reflector (8 m2 aperture area) and evaluated.  The power and system efficiency of solar based system was found to be 1.58 kW and 43.25% respectively.  Successful results were obtained for essential oils extraction from herbs by using solar energy.  These results were found similar to that of laboratory showing that the solar energy can be effectively used for the distillation of essential oils.Keywords: Essential oils, herbs, scheffler reflector, solar distillation Citation: Munir A., and O. Hensel.  Investigation of optimal thermal parameters for essential oils extraction using laboratory and solar distillation systems.  Agric Eng Int: CIGR Journal, 2010, 12(1): 107-114

Experimental evaluation of sorption isotherms of chili pepper: an Ethiopian variety, Mareko Fana (Capsicum annum L.)

Moisture sorption isotherms of chili peppers of  Ethiopian variety, “Mareko Fana” ,were determined at three different temperatures (30℃, 50℃ and 70℃) and relative humidity between (10%-90%), using the standard static, gravimetric method.  The modified Halsey, GAB, Oswin, and Henderson sorption models were tested to fit the experimental data.  A nonlinear regression analysis method using SPSS 16.0, and Sigma Plot 11.0 software were used to evaluate the constants of sorption models, to select the best equation and to plot graphs.  The net isosteric heats of sorption isotherms were determined from the equilibrium data.  The models were evaluated statistically by calculating mean bias errors (MBE), mean relative deviations (MRD), root mean square errors (RMSE) and coefficient of determination (R2).  The ranking of statistical errors for each model were done by calculating the average grade. High coefficient of determination and the lowest average grade of statistical errors (1.3 for desorption and 1.0 for adsorption) were obtained from the GAB model indicating that it  fits the best to the experimental data followed by modified Halsey’s equation.  The worst results were obtained from Henderson’s equation.  The values of constant a, b and c of “Mareko Fana” were within the ranges recommended by other researchers (Bell and Labuza, 2000).  The results also showed hysteresis indicating that “Mareko Fana” cannot adsorb the same quantity of water vapour as it released during desorption process.  The net isosteric heat of sorption were determined from the experimental data where the energy requirements for drying processes as well as design of drying equipment be obtained.Keywords: chili pepper, equilibrium moisture content, water activity, mathematical models, net isosteric heat of sorption&nbsp

Investigation of dynamic quality changes and optimization of drying parameters of carrots (Daucus carota var. laguna)

The effect of air temperature and sample thickness on the color changes and total carotenoids content of carrot slices was investigated. Temperature, exposure time, and moisture levels significantly affected the dynamic changes of total carotenoids and color. A slow and linear decrease in total carotenoids was observed at higher moisture content until reaching an inflection point at around 0.45 gw/gdm for all temperatures studied. Thereafter, the retention in total carotenoids decreased rapidly. The highest retention for a final product was 66.2% when drying at 60°C while retention was between 42.2 and 51.1% when drying at 50 and 70°C. These changes occurred alongside a noticeable change in color at moisture contents below the inflection point of 0.45 gw/gdm for all drying temperatures. Design of experiment based optimization of the drying process resulted in an ideal temperature of 59.8°C and 3.5 mm slice thickness with the predicted values for La*b*; ΔE of 62.18 ± 5.12, 22.46 ± 1.98, 40.35 ± 6.64, 6.31 ± 4.74; rehydration ratio of 0.48 ± 0.07; and total carotenoids of 163.83 ± 17.38 μg/g or 67.38%, respectively, all at a 95% prediction interval

Time to shape up – assessment and reporting standards for data quality in clinical research using echocardiographic imaging techniques require improvement

Abstract: Advanced echocardiography techniques such as speckle tracking imaging are sensitive diagnostic tools frequently used in various clinical and scientific scenarios. Importantly, imperfect reproducibility and dependence of post-processing algorithms on echocardiographic image quality are potential methodological limitations. Therefore, meticulous assessment of data quality and detailed reporting of study methodology, sample specifics, technical peculiarities and measurement conditions are crucial. Unfortunately, despite the recognized importance of this, there is still no broadly accepted standard for assessing the quality of echocardiographic images in clinical research reports. This article quintessentially highlights important shortcomings of data quality assessment and methodological study design, commonly occurring in clinical research reports using advanced echocardiography techniques. Finally, suggestions are made as to how researchers, scientific communities and biomedical journals can contribute to the ever-lasting process of improving the quality of clinical research in cardiovascular imaging

Novel functional advanced echocardiography for the assessment of myocardial mechanics in children with neurocardiogenic syncope - a blinded prospective speckle tracking head-up tilt-table challenge study.

BACKGROUND: Data on left ventricular (LV) function in patients with neurocardiogenic syncope (NS) is conflicting in adults and lacking in children. The aim of this study was to analyze LV myocardial performance in children with NS at rest and during head-up tilt-table (HUTT) testing. METHODS: This is the first study to combine HUTT and speckle-tracking echocardiography (STE) in children with NS. 43 consecutive normotensive pediatric patients with NS (mean age 13.9 ± 2.6 years, 51% female) and 41 sex- and age-matched healthy controls were included in the study. The study groups consisted of 21 patients with a positive HUTT reaction (HUTT+) and 22 with a negative HUTT reaction (HUTT-). STE was used to analyze peak systolic LV myocardial strain and strain rate. RESULTS: Conventional echocardiographic parameters were similar in all analyzed groups. When compared to healthy controls, children with NS had depressed levels of circumferential strain rate (p = 0.032) and significantly depressed longitudinal strain rate (p <  0.001) at rest. Interestingly, during HUTT testing LV global strain and strain rate were similar in both groups. LV strain rate was lowest in HUTT+ followed by HUTT- and control subjects both at rest and during HUTT. CONCLUSIONS: Resting LV longitudinal strain rate is attenuated in children with NS, especially in those with a positive HUTT response. This is further evidence that NS patients feature altered cardiac mechanics rendering them prone to vasovagal perturbations that can ultimately result in collapse. TRIAL REGISTRATION: Witten/Herdecke University ethics committee clinical study number: UWH-73-2014

First steps towards smart drying of beef slices seasoned with different pre-treatments

In this study, beef slices seasoned with salt (S) and salt and vinegar (S+V) were dried at 60 °C in a convective drier and the development of moisture ratio (MR) and colour change (ΔE) was compared to blind samples (B). Hyperspectral imaging (HSI) was applied to create prediction models for moisture content and L, a* and b* values. Regression coefficients of >0.9 could be achieved related to each pre-treatment, but also for combined data of all the pre-treatments

Episomal HBV persistence within transcribed host nuclear chromatin compartments involves HBx.

BACKGROUND: In hepatocyte nuclei, hepatitis B virus (HBV) genomes occur episomally as covalently closed circular DNA (cccDNA). The HBV X protein (HBx) is required to initiate and maintain HBV replication. The functional nuclear localization of cccDNA and HBx remains unexplored. RESULTS: To identify virus-host genome interactions and the underlying nuclear landscape for the first time, we combined circular chromosome conformation capture (4C) with RNA-seq and ChIP-seq. Moreover, we studied HBx-binding to HBV episomes. In HBV-positive HepaRG hepatocytes, we observed preferential association of HBV episomes and HBx with actively transcribed nuclear domains on the host genome correlating in size with constrained topological units of chromatin. Interestingly, HBx alone occupied transcribed chromatin domains. Silencing of native HBx caused reduced episomal HBV stability. CONCLUSIONS: As part of the HBV episome, HBx might stabilize HBV episomal nuclear localization. Our observations may contribute to the understanding of long-term episomal stability and the facilitation of viral persistence. The exact mechanism by which HBx contributes to HBV nuclear persistence warrants further investigations

Solar energy policy implementation in Ghana: A LEAP model analysis

Current global climate change mitigation programs have been unable to meet the Paris Agreement's targets, and Ghana's situation is no exception. There is, therefore, an increased need for intensification of renewable energy deployment programs with an emphasis on solar energy as it constitutes about 90% of Ghana's installed renewable energy generation capacity. The study demonstrates how appropriate renewable energy policy can drive solar energy development in Ghana. Electricity demand scenarios were developed using historical data from 2000 to 2018, after which projections were made up to 2030 based on the average year-on-year electricity growth rate. Of the three electricity demand categories, residential demand experienced a steeper growth rate in comparison with the special load tariff, non-residential, and street lighting sectors. On the supply side, low, moderate, and visionary supply scenarios had increased solar penetration of 5 %, 10 %, and 15 % of the installed generation capacity respectively. While appreciable gains were made in the low and moderate supply scenarios, the visionary supply scenario could meet the renewable energy target with solar energy by 2030; leading to universal access to electricity while offsetting over 13 million metric tonnes of carbon dioxide in the process

Std fimbriae-fucose interaction increases Salmonella-induced intestinal inflammation and prolongs colonization

Author summary The intestinal epithelium is a crucial biological interface, interacting with both commensal and pathogenic microorganisms. It’s lined with heavily glycosylated proteins and glycolipids which can act as both attachment sites and energy sources for intestinal bacteria. Fut2, the enzyme governing epithelial α1,2-fucosylation, has been implicated in the interaction between microbes and intestinal epithelial cells. Salmonella is one of the most important bacterial gastrointestinal pathogens affecting millions of people worldwide. Salmonella possesses fimbrial and non-fimbrial adhesins which can be used to adhere to host cells. Here we show that Salmonella expresses Std fimbriae in the gastrointestinal tract in vivo and exploit Std fimbriae to bind fucosylated structures in the mucus and on the intestinal epithelium. Furthermore, we demonstrate that the Std fimbriae-fucose interaction is necessary for bacterial colonization of the intestine and for triggering intestinal inflammation. These data lend new insights into bacterial adhesion-epithelial interactions which are essential for bacterial pathogenesis and key factors in determining tissue tropism and host susceptibility to infectious disease

Guidance on the interpretation of faecal calprotectin levels in children.

BACKGROUND: Faecal calprotectin (FCP) is a powerful tool to predict inflammatory bowel disease (IBD) in patients with gastrointestinal symptoms. In the paediatric patient population, the reference value of 50 μg/g, 15% were ≥ 250 μg/g. Children 50 μg/g) was the sole reason for being referred for suspected IBD did not have IBD. CONCLUSION: Children with an FCP < 600 μg/g and without matching symptoms suggestive of IBD are unlikely to have IBD. A higher FCP reference value may provide cost-effective improvement that could avoid redundant investigations and specialist referrals. A guideline for specialist referrals is proposed