Catalytic upgrading of hydrothermal liquefaction biocrudes: Different challenges for different feedstocks

Hydrothermal liquefaction (HTL) followed by catalytic hydrotreating of the produced biocrude is increasingly gaining ground as an effective technology for the conversion of biomass into liquid biofuels. A strong advantage of HTL resides in its great flexibility towards the feedstock, since it is able to treat a large number of different organic substrates, ranging from dry to wet residual biomass. Nevertheless, the characteristics of biocrudes from different typologies of organic materials result in different challenges to be met during the hydrotreating step, leading to differences in heteroatoms removal and in the typology and composition of the targeted products. In this work, biocrudes were catalytically hydrotreated with a commercial NiMo/Al2O3 catalyst at different temperatures and pressures. Sewage sludge biocrude was found to be very promising for the production of straight-chain hydrocarbons in the diesel range, with considerable heteroatoms removal even at mild hydrotreating conditions. Similar results were shown by algal biocrude, although complete denitrogenation is challenging. Upgraded biocrudes from lignocellulosic feedstock (miscanthus) showed high yields in the gasoline range, with a remarkable content of aromatics. Operating at a higher H2 pressure was found to be crucial to prevent coking and decarboxylation reactions.Comment: Accepted manuscript for publication in Renewable Energ

Two-stage catalytic hydrotreatment of highly nitrogenous biocrude from continuous hydrothermal liquefaction: A rational design of the stabilization stage

Effective catalytic hydrotreatment of highly nitrogenous biocrudes derived from the hydrothermal liquefaction (HTL) of primary sewage sludge and microalga Spirulina biomass was explored. A critical issue is the lack of thermal stability of raw HTL biocrudes at the severe conditions (~400 {\deg}C) required for hydrodenitrogenation. This fact suggests the need for a two-stage approach, involving a first low-temperature stabilization stage followed by another one operated at higher temperature. In this study, DSC was successfully used to indicate the thermal stability of both biocrudes. During hydrotreating, it was observed that complete deoxygenation was already achieved in the first stage at 350 {\deg}C, with limited coke formation. Moreover, after second stage up to 92% denitrogenation associated with the higher hydrogen consumption (39.9 g kg -1 for Spirulina and 36.9 g kg -1 for sewage sludge) was obtained for both biocrudes. Consequently, comparable oil yields but significantly less coke yields were recorded during two stage upgrading (1.0% for Spirulina and 0.7% for sewage sludge), compared to direct processing at 400 {\deg}C (9.1% for Spirulina and 3.4% for sewage sludge). In addition, the properties of the upgraded oils were enhanced by increasing the temperature in the first stage (310 {\deg}C, 330 {\deg}C and 350 {\deg}C respectively). Finally, the results indicated that remarkable drop in fuel properties were obtained, with respect to heteroatom (O and N) removal, HHV, and H/C ratio during the two stage hydrotreatment. Two-stage hydrotreating is therefore proposed as a successful approach for the upgrading of HTL biocrudes with high nitrogen content.Comment: Accepted manuscript. Published in Biomass & Bioenergy (Elsevier

Resolvability in Hypergraphs

This article presents an extension of the study of metric and partition dimension to hypergraphs. We give sharp lower bounds for the metric and partition dimension of hypergraphs in general and give exact values under specified conditions

Zika virus infection: a public health emergency!

Zika virus belongs to the family of Flaviviridae. The Flaviviridae family also includes other human pathogens like West Nile virus (WNV), Yellow fever virus (YFV), mosquito transmitted Dengue virus (DENV), Tick borne encephalitic virus (TBEV) and Japanese encephalitis virus (JEV). Zika virus is a mosquito-borne disease and is transmitted by Aedes aegypti mosquito

Effects of holes radius on plasmonic photonic crystal fiber sensor with internal gold layer

In this study, a plasmonic photonic crystal fiber (PCF) sensor was designed with an internal gold layer between the liquid holes and the air holes. The study shown that the thickness of the gold layer, the radius of the air holes and the radius of the liquid holes all have a significant effect on the sensitivity of the sensor, where a wavelength sensitivity of (10,500 nm/RIU) was achieved at certain simulation conditions. Under these chosen conditions, the relationship of resonance wavelength with the refractive index of the liquid was linear and this gives flexibility to extend the range of the refractive index of the analyte without changing the sensor design. Approaching or moving away of the holes from center in the proposed design has a fundamental role in determining the sensor characteristics

Enteroenteric fistulae in ccute bowel ischemia

Gastrointestinal fistulae are classified as enteroenteric or enterocutaneous. Most gastrointestinal fistulae are formed after surgical procedures for inflammatory bowel disease or malignancy. For spontaneous enteroenteric fistulae, ischemia has been reported as a possible etiology. We report two cases of spontaneous enteroenteric fistulae arising after bowel ischemia; a 38-year male with a 10-day history of severe abdominal pain with fever and vomiting, and a 22-year female with a one-week history of abdominal pain and diarrhea. Arterial and venous thrombi in association with enteroenteric fistulae were identified on computed tomography. These cases point towards acute mesenteric ischemia as a rare cause of spontaneous enteroenteric fistulae. Surgical management of these fistulae can be effective in resolving this complication

Effect of stem cell and vitamin E for the reduction of liver fibrosis

Liver disease is seventh leading cause of death worldwide. In the past, liver transplantation was thought to be the only treatment for the last stage liver disease but currently stem cells therapy is an alternative method for the treatment of liver disease. So mesenchymal stem cells (MSCs) transplantation is one of the best tool for treatment of liver disease. The aim of the current study was to investigate the combined effect of vitamin E (Vit E) and MSCs on liver fibrosis. Liver damage was induced in male albino mice intraperitoneally with carbon tetrachloride (CCl4) twice a week for six weeks. Mice bone marrow derived MSC was cultured in vitro and then transplanted to CCl4 injured mice through their tail vain injection. Two weeks after MSCs transplantation, all group of mice were examined. The morphological result showed that the combined therapy of Vit E (orally) and MSCs transplantation have significant therapeutic effect on CCl4 injured mice as compared to Vit E and MSCs individually. Biochemical data also showed that serum ALT and bilirubin level were found to be significantly decreased by the combined treatment of Vit E and MSCs as compared to those mice which received MSCs and Vit E separately. MSCs and Vit E treated mice combined showed a significant decrease in liver weight, closely to normal. Reverse transcriptase PCR result also confirmed a significant anti fibrotic effect of Vit E combined with MSCs transplanted mice on liver fibrosis as showed by down-regulating apoptotic marker (Bax) expression and increasing the expression of antiapoptotic marker (Bcl-xl). Therefore Vit E along with MSCs have strong therapeutic potential on liver fibrosis in CCl4 injured mice

Syntheses and crystal structures of mixed-ligand copper(II)–imidazole–carboxylate complexes

Crystallographic data for the structures in this paper have been deposited with the Cambridge Crystallographic Data Center, CCDC, 12 Union Road, Cambridge CB2 1EZ, UK. Copies of the data can be obtained free of charge on quoting depository numbers CCDC-1543434 (1), CCDC-1543435 (2) and CCDC-1543436 (3) (Fax:+44-1223-336–033; E-mail: [email protected]; http://www.ccdc.cam.ac.uk). Supplemental data for this article can be accessed at https://doi.org/10.1080/00958972.2018.1460471.Peer reviewedPostprin

A crisis within a crisis: Role of COVID-19 pandemic in poor compliance of Community-based Management of Severe Acute Malnutrition among children younger than five years in Pakistan

IntroductionIn order to attain Sustainable Development Goal 2 (SDG-II) of eradicating malnutrition among children by 2030, Pakistan has initiated a Community-based Management of Severely Acute Malnutrition (CMAM) program. This program has been established at the public level to detect and treat uncomplicated Severely Acute Malnourished (SAM) children at an early stage. However, during the outbreak of COVID-19, very poor compliance with the CMAM program was observed. Consequently, the nutritional quality of children’s diets has deteriorated, with malnutrition rates expected to rise. Therefore, this study has been set up to evaluate the effect of the COVID-19 lockdown on the health of SAM children and compliance with the CMAM program.MethodologyThis study used a multicenter cross-sectional design in District Dera Ghazi Khan’s rural areas located in the Southern Province of Punjab. Data were collected from the parents/guardians of SAM children through the researcher-administrated questionnaire. The sample size was 196, and data were analyzed through SPSS version 25.ResultsThe majority of the children enrolled were males (52.5%), had fathers aged between 41 and 50 years (52.0%), mothers aged between 21 and 30 years (52.5%), had illiterate fathers (40.1%), illiterate mothers (73.8%) and had a monthly household income of PKR <15,000 (91.1%). All of the respondents mentioned that COVID-19 affected them in one way or the other (100.0%), with a majority of them did not visit the hospital during COVID-19 for their SAM child (52.5%) as they were afraid of COVID-19 (63.2%) and/or they lacked access to transport for visiting a hospital (93.4%). Bivariate analysis revealed that the father’s age (P = 0.02) and income (P = 0.00) is associated with the perceived effect of COVID-19 on income. In contrast, only the gender of the child (P = 0.00) is related to the visit to the hospital, and the gender of the child (P = 0.01) and mother’s literacy (P = 0.00) is associated with the choice of treatment from any other setup, including Hakeem and Peer.ConclusionThis study concludes that health emergencies like the COVID-19 pandemic pose a significant barrier to access to healthcare services and subject a more vulnerable state to already vulnerable groups like SAM children. To lessen their vulnerability, initiatives like mobile health care services should be introduced, especially for socially disadvantaged communities, localities, and groups on regular basis and for future emergencies