scholarly journals Comparative Assessment of Thermo-Syngas Fermentative and Liquefaction Technologies as Waste Plastics Repurposing Strategies

2020 ◽  
Vol 2 (3) ◽  
pp. 378-392 ◽  
Author(s):  
Oseweuba Valentine Okoro ◽  
Funmilayo D. Faloye

The present study comparatively investigates the potential of waste plastic utilization as a feedstock for the production of liquid fuels to satisfy the rising liquid fuel demands of the transportation industry while simultaneously resolving the global plastic waste pollution challenge. For the first time, therefore, conceptual models simulating the production of transportation fuels of ethanol and gasoline from waste plastics via the technologies of thermo-syngas fermentation and hydrothermal liquefaction were assessed using classic technoeconomic assessment methods. The conceptual models were developed based on existing experimental data as obtained from the literature and simulated using ASPEN Plus as the preferred process simulation tool. This study demonstrated the technical viability of both conversion pathways with the hydrothermal liquefaction (HTL) of waste plastics for gasoline production shown to constitute a more economically preferable pathway. This was because the HTL of waste plastics presented a higher internal rate of return (IRR) value and a lower unit processing cost of 51.3% and USD 0.38 per kg compared to the thermo-syngas fermentation pathway that presented an IRR value and a unit processing cost value of 22.2% and USD 0.42 per kg, respectively. Payback periods of 5 years and 2 years were also determined as vital to recoup initial capital invested in the thermo-syngas fermentation project and the HTL project, respectively. Therefore, this study provides a basis for further work regarding waste plastic management strategies while offering a useful guide for policy makers in determining the most cost-effective way to utilize waste plastic and thus promote favorable environmental outcomes.

2021 ◽  
Author(s):  
Dureem Munir ◽  
Muhammad Rashid Usman

Abstract Three micro-mesoporous HZSM-5 catalysts were synthesized using three different mesoporous templates and studied for the conversion of a model municipal waste plastic mixture to produce liquid fuels of high value. For the comparison, the conversion of an actual waste plastic mixture and HDPE was also studied. The experiments were performed in a batch stirred reactor at three reaction temperatures (350, 375, and 400 °C) and at fixed cold H2 pressure (20 bar), reaction time (60 min), and plastic to catalyst ratio (20:1 by wt.). The micro-mesoporous catalysts produced better activity and selectivity than their parent HZSM-5 catalyst. The catalyst, prepared by combining two different templates, was found to be the most favorable catalyst offering 67.1% liquid yield at 400 °C with actual waste plastic. The best performing catalyst has shown the prospects for commercial applications.


2021 ◽  
pp. 1-8
Author(s):  
Emily Kell ◽  
John A. Hammond ◽  
Sophie Andrews ◽  
Christina Germeni ◽  
Helen Hingston ◽  
...  

OBJECTIVES: Shoulder pain is a common musculoskeletal disorder, which carries a high cost to healthcare systems. Exercise is a common conservative management strategy for a range of shoulder conditions and can reduce shoulder pain and improve function. Exercise classes that integrate education and self-management strategies have been shown to be cost-effective, offer psycho-social benefits and promote self-efficacy. This study aimed to examine the effectiveness of an 8-week educational and exercise-based shoulder rehabilitation programme following the introduction of evidence-based modifications. METHODS: A retrospective evaluation of a shoulder rehabilitation programme at X Trust was conducted, comparing existing anonymised Shoulder Pain and Disability Index (SPADI) and Patient-Specific Functional Scale (PSFS) scores from two cohorts of class participants from 2017-18 and 2018-19 that were previously collected by the physiotherapy team. Data from the two cohorts were analysed separately, and in comparison, to assess class efficacy. Descriptive data were also analysed from a patient satisfaction survey from the 2018-19 cohort. RESULTS: A total of 47 patients completed the 8-week shoulder rehabilitation programme during the period of data collection (2018-2019). The 2018-19 cohort showed significant improvements in SPADI (p 0.001) and PSFS scores (p 0.001). No significant difference was found between the improvements seen in the 2017-18 cohort and the 2018-19 cohort. 96% of the 31 respondents who completed the patient satisfaction survey felt the class helped to achieve their goals. CONCLUSION: A group-based shoulder rehabilitation class, which included loaded exercises and patient education, led to improvements in pain, disability and function for patients with rotator cuff related shoulder pain (RCRSP) in this outpatient setting, but anticipated additional benefits based on evidence were not observed.


Toxins ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 503 ◽  
Author(s):  
David M. Hartnell ◽  
Ian J. Chapman ◽  
Nick G. H. Taylor ◽  
Genoveva F. Esteban ◽  
Andrew D. Turner ◽  
...  

Freshwater cyanobacteria blooms represent a risk to ecological and human health through induction of anoxia and release of potent toxins; both conditions require water management to mitigate risks. Many cyanobacteria taxa may produce microcystins, a group of toxic cyclic heptapeptides. Understanding the relationships between the abiotic drivers of microcystins and their occurrence would assist in the implementation of targeted, cost-effective solutions to maintain safe drinking and recreational waters. Cyanobacteria and microcystins were measured by flow cytometry and liquid chromatography coupled to tandem mass spectrometry in two interconnected reservoirs varying in age and management regimes, in southern Britain over a 12-month period. Microcystins were detected in both reservoirs, with significantly higher concentrations in the southern lake (maximum concentration >7 µg L−1). Elevated microcystin concentrations were not positively correlated with numbers of cyanobacterial cells, but multiple linear regression analysis suggested temperature and dissolved oxygen explained a significant amount of the variability in microcystin across both reservoirs. The presence of a managed fishery in one lake was associated with decreased microcystin levels, suggestive of top down control on cyanobacterial populations. This study supports the need to develop inclusive, multifactor holistic water management strategies to control cyanobacterial risks in freshwater bodies.


Sociobiology ◽  
2021 ◽  
Vol 68 (2) ◽  
pp. 5813
Author(s):  
Matan Shelomi ◽  
Bo-Jun Qiu ◽  
Lin-Ting Huang

An accumulation of questionable scientific reports on the use of natural plant extracts to control household pest insects, using biologically irrelevant experimental designs and extremely high concentrations, has resulted in a publication bias: “promising” studies claiming readily available plants can repel various insects, including social insects, despite no usable data to judge cost-effectiveness or sustainability in a realistic situation. The Internet provides a further torrent of untested claims, generating a background noise of misinformation. An example is the belief that cucumbers are “natural” ant repellent, widely reported in such informal literature, despite no direct evidence for or against this claim. We tested this popular assertion using peel extracts of cucumber and the related bitter melon as olfactory and gustatory repellents against ants. Extracts of both fruit peels in water, methanol, or hexane were statistically significant but effectively weak gustatory repellents. Aqueous cucumber peel extract has a significant but mild olfactory repellent effect: about half of the ants were repelled relative to none in a control. While the myth may have a grain of truth to it, as cucumber does have a mild but detectable effect on ants in an artificial setup, its potential impact on keeping ants out of a treated perimeter would be extremely short-lived and not cost-effective. Superior ant management strategies are currently available. The promotion of “natural” products must be rooted in scientific evidence of a successful and cost-effective implementation prospect.


2021 ◽  
Vol 8 (15) ◽  
pp. 977-981
Author(s):  
Prakash Chandra Ghosh ◽  
Mitali Bera ◽  
Punyabrata Barma ◽  
Arijit Roy ◽  
Sananda Majumder ◽  
...  

BACKGROUND Though epilepsy remains a significant problem for children and adolescents in our country, studies delineating the clinical profile and response to treatment in childhood epilepsy are lacking. The current study was carried out for obtaining a baseline profile and to predict the response to treatment in childhood epilepsy in India that may be helpful in planning management strategies from a public health point of view. METHODS Patients with clinical suggestion of active epilepsy (N = 141) from one month to 12 years, were enrolled into the study over a period of 1 year (February 2010 to January 2011) from the out-patient department and epilepsy clinic of Bangur Institute of Neurology. Detailed history was taken along with neurological examination. Electroencephalography (EEG) and neuroimaging (MRI / CT scan) were done on all patients. Each patient included in the study was kept in followup for a period of 6 months and their response to the treatment was recorded. RESULTS About 48.9 % (N = 69) patients had localisation related epilepsy while the rest had generalised epilepsy. Of those with generalised epilepsy, generalised tonicclonic seizures (GTCS) was by far the most common type. Of those with focal EEG activity, the highest proportion (50 %), were localised to the temporal lobe. Symptomatic aetiology accounted for 59.6 % (N = 84) of the patients. 20.6 % (N = 29) had poor response to treatment at 6 months follow-up. Abnormal neuroimaging (OR = 6.708) and abnormal EEG (OR = 6.357) were effective factors in predicting poor response to treatment. CONCLUSIONS Our study highlights the need to link specialised epilepsy services with primary health centres for early detection and treatment. EEG is an essential cost-effective modality in determining seizure localisation and response to treatment. KEYWORDS Paediatric, Epilepsy, Clinical Profile, Response to Treatment


NeoReviews ◽  
2021 ◽  
Vol 22 (12) ◽  
pp. e819-e836
Author(s):  
Amy G. Feldman ◽  
Ronald J. Sokol

Cholestatic jaundice is a common presenting feature of hepatobiliary and/or metabolic dysfunction in the newborn and young infant. Timely detection of cholestasis, followed by rapid step-wise evaluation to determine the etiology, is crucial to identify those causes that are amenable to medical or surgical intervention and to optimize outcomes for all infants. In the past 2 decades, genetic etiologies have been elucidated for many cholestatic diseases, and next-generation sequencing, whole-exome sequencing, and whole-genome sequencing now allow for relatively rapid and cost-effective diagnosis of conditions not previously identifiable via standard blood tests and/or liver biopsy. Advances have also been made in our understanding of risk factors for parenteral nutrition–associated cholestasis/liver disease. New lipid emulsion formulations, coupled with preventive measures to decrease central line–associated bloodstream infections, have resulted in lower rates of cholestasis and liver disease in infants and children receiving long-term parental nutrition. Unfortunately, little progress has been made in determining the exact cause of biliary atresia. The median age at the time of the hepatoportoenterostomy procedure is still greater than 60 days; consequently, biliary atresia remains the primary indication for pediatric liver transplantation. Several emerging therapies may reduce the bile acid load to the liver and improve outcomes in some neonatal cholestatic disorders. The goal of this article is to review the etiologies, diagnostic algorithms, and current and future management strategies for infants with cholestasis.


2017 ◽  
Vol 27 (3) ◽  
pp. 344-353 ◽  
Author(s):  
Skyler Simnitt ◽  
Tatiana Borisova ◽  
Dario Chavez ◽  
Mercy Olmstead

The study focuses on frost protection for early-season (early-ripening) peach (Prunus persica) varieties, which are an important crop for producers in the southeastern United States. Using in-depth interviews with four major Georgia peach producers, we explore their frost protection management strategies. This information is the first step in developing a comprehensive research agenda to advise cost-effective frost protection methods for peach cultivation. We found that peach producers are concerned about frost impacts on their crops. Although early-season peach varieties are particularly susceptible to frost impacts, producers still dedicate significant acreage to these varieties, aiming to extend the market window, satisfy sales contracts, and meet obligations for hired labor. However, early-season varieties do not result in high profits, so producers prefer to concentrate on frost protection for mid- and late-season varieties. Producers employ a variety of frost protection methods, including passive methods (such as planting sensitive varieties in areas less susceptible to frost and adjusting pruning/thinning schedules) and active methods (such as frost protection irrigation and wind machines). The choice among active frost protection methods is based on factors such as the planning horizon, initial investment needs, frequency of frost events, and the effectiveness of the frost protection method. Problem areas that producers identified included improving the effectiveness of frost protection methods; reducing initial investments required to install frost protection systems; and employing better spatial targeting and configuration of frost protection strategies (to reduce investment costs while maintaining or improving the effectiveness of frost protection). Although the initial investment costs of enhanced protection systems may limit producers from actually adopting such methods, the operating costs of such systems are relatively low and have a limited effect on the decision to employ frost protection during a particular frost event. However, producers use information about critical temperatures for different bud stages, and hence, improving the quality of information regarding frost susceptibility can help producers make better frost protection decisions (and potentially reduce electricity costs and water use for frost protection).


Author(s):  
Edward Rollason ◽  
Pammi Sinha ◽  
Louise J Bracken

Water scarcity is a global issue, affecting in excess of four billion people. Interbasin Water Transfer (IBWT) is an established method for increasing water supply by transferring excess water from one catchment to another, water-scarce catchment. The implementation of IBWT peaked in the 1980s and was accompanied by a robust academic debate of its impacts. A recent resurgence in the popularity of IBWT, and particularly the promotion of mega-scale schemes, warrants revisiting this technology. This paper provides an updated review, building on previously published work, but also incorporates learning from schemes developed since the 1980s. We examine the spatial and temporal distribution of schemes and their drivers, review the arguments for and against the implementation of IBWT schemes and examine conceptual models for assessing IBWT schemes. Our analysis suggests that IBWT is growing in popularity as a supply-side solution for water scarcity and is likely to represent a key tool for water managers into the future. However, we argue that IBWT cannot continue to be delivered through current approaches, which prioritise water-centric policies and practices at the expense of social and environmental concerns. We critically examine the Socio-Ecological Systems and Water-Energy-Food (WEF) Nexus models as new conceptual models for conceptualising and assessing IBWT. We conclude that neither model offers a comprehensive solution. Instead, we propose an enhanced WEF model (eWEF) to facilitate a more holistic assessment of how these mega-scale engineering interventions are integrated into water management strategies. The proposed model will help water managers, decision-makers, IBWT funders and communities create more sustainable IBWT schemes.


Author(s):  
Gary C. Longo ◽  
John Harms ◽  
John R. Hyde ◽  
Matthew T. Craig ◽  
Ana Ramón-Laca ◽  
...  

AbstractThe vermilion rockfish complex, which consists of the cryptic sister species vermilion and sunset rockfish, is one of the most valuable recreational fisheries on the U.S. West Coast. These species are currently managed as a single complex, and because of uncertainty surrounding the relative contribution of each species within existing data sources, the stock status of each species is not fully known. A reliable and cost-effective method is needed to disentangle these species that will allow for the development of abundance indices, life history profiles, and catch histories that may potentially support species-specific stock assessments. Using restriction-site associated DNA sequence (RADseq) markers we generated 10,003 polymorphic loci to characterize the vermilion rockfish complex. PCA and Bayesian clustering approaches based on these loci clearly distinguished between sunset and vermilion rockfishes and identified hybrid individuals. These loci included 203 highly differentiated (FST ≥ 0.99) single nucleotide polymorphisms, which we consider candidates in the planned development of a diagnostic assay capable of distinguishing between these cryptic species. In addition to clearly delineating to species, subsets of the interspecific markers allowed for insight into intraspecific differentiation in both species. Population genetic analyses for sunset rockfish identified two weakly divergent genetic groups with similar levels of genetic diversity. Vermilion rockfish, however, were characterized by three distinct genetic groups with much stronger signals of differentiation and significantly different genetic diversities. Collectively, these data will contribute to well-informed, species-specific management strategies to protect this valuable species complex.


Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7609
Author(s):  
Muhammad Asif Ali Rehmani ◽  
Saad Aslam ◽  
Shafiqur Rahman Tito ◽  
Snjezana Soltic ◽  
Pieter Nieuwoudt ◽  
...  

Next-generation power systems aim at optimizing the energy consumption of household appliances by utilising computationally intelligent techniques, referred to as load monitoring. Non-intrusive load monitoring (NILM) is considered to be one of the most cost-effective methods for load classification. The objective is to segregate the energy consumption of individual appliances from their aggregated energy consumption. The extracted energy consumption of individual devices can then be used to achieve demand-side management and energy saving through optimal load management strategies. Machine learning (ML) has been popularly used to solve many complex problems including NILM. With the availability of the energy consumption datasets, various ML algorithms have been effectively trained and tested. However, most of the current methodologies for NILM employ neural networks only for a limited operational output level of appliances and their combinations (i.e., only for a small number of classes). On the contrary, this work depicts a more practical scenario where over a hundred different combinations were considered and labelled for the training and testing of various machine learning algorithms. Moreover, two novel concepts—i.e., thresholding/occurrence per million (OPM) along with power windowing—were utilised, which significantly improved the performance of the trained algorithms. All the trained algorithms were thoroughly evaluated using various performance parameters. The results shown demonstrate the effectiveness of thresholding and OPM concepts in classifying concurrently operating appliances using ML.


Sign in / Sign up

Export Citation Format

Share Document