CERES :: Browsing by Author "Longhurst, Philip"

Browsing by Author "Longhurst, Philip"

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Open Access
Ammonia inhibition and toxicity in anaerobic digestion: a critical review
(Elsevier, 2019-07-20) Jiang, Ying; McAdam, Ewan; Zhang, Yue; Heaven, Sonia; Banks, Charles J.; Longhurst, Philip
As a waste management technology which offers environmental benefit and renewable energy production, anaerobic digestion (AD) has become the preferred technology for the treatment of organic waste. However, in such waste streams nitrogen contents are likely to be high. There is prevailing literature evidence suggests that high ammonia concentration especially its free molecular form (NH3), derived from nitrogen content in substrates is the cause of inhibition and sudden failure of the AD process. This paper comprehensively reviews previous knowledge from digestion studies using high nitrogen waste streams as feedstocks and critically analysed the considerable variations in the inhibition/toxicity levels reported for ammonia. Literature evidences suggest methanogens, particularly acetoclastic methanogens are most susceptible to ammonia toxicity, and therefore this review has a particular focus on the mechanism of the ‘selective’ inhibition to methanogens and the impact of ammonia toxicity to the overall methanogen population in an AD digester. This population change explains in many reported cases that sufficient acclimatisation can significantly alleviate the phenomenon of inhibition and specific requirement of certain trace nutrients. Currently available mitigation strategies for high nitrogen content feedstock digestion are reviewed and discussed in relation to the population change and trace nutrient requirements.
Open Access
Application of machine learning in assessment of combustion of liquified natural gas.
(Cranfield University, 2021-05) Alexandropoulos, Christos Dimosthenis; Hanak, Dawid P.; Longhurst, Philip
This work focuses on the implementation on carbon capture on ships which run on liquified natural gas (LNG). LNG ships present a real-world example of LNG as well as a study case for carbon capture on LNG combustion. There is also special interest for that as well, since the International Maritime Organization (IMO), imposed a limit of 0.5% wt. of sulphur content in ship fuel has been imposed from 2020 to reduce pollution emissions from global shipping activities. This initiative will lead to major changes since the previous limit was set at 3.5% wt., which broadened fuel options for ships. In addition, the IMO is developing a long-term plan to completely nullify shipping’s impact on CO₂ emissions by 2030. Consequently, stricter regulations will be imposed to marine activities worldwide. LNG fuel seems to be a promising solution. The sulphur emissions are lower, in compliance with the latest IMO regulations. Additionally, it has a greater energy density in comparison to traditional fuels, like heavy fuel oil (HFO). This paper aims to study the feasibility of a project, which equips an LNG fuelled ship with a carbon capture system. The study includes an examination of an on-board carbon capture system, by simulating the LNG engine as well as the carbon capture system in simulation software. The engine model chosen is the Wärtsilä 6L34DF. The results of these simulations are analysed to examine the correlation between the system’s variables and to evaluate the possibility of heat integration within the system. The economic feasibility of the project is then assessed, using economic data. The results show that heat integration is possible. For example, the heat provided from the flue gas is calculated at 1.323MW when the reboiler duty is 0.3353 MW. However, the project is not sustainable under current market conditions.
Open Access
Bioaerosol release from composting facilities
(Cranfield University, 2005-10) Mohamed Taha, M. P. B; Pollard, Simon; Longhurst, Philip
The use of composting is expected to increase dramatically due to its economic and environmental benefits. For public health protection, regulators and licensing authorities are requesting risk assessments to be conducted prior to the development and operation of composting. Significant amounts of microrganisms can be aerosolised and transported by winds to points of exposure. However, the source term factors that influence their release and their dispersal are not fully understood. In this thesis a method to measure viable bioaerosols emission rates from static compost pile surfaces and during the agitation of compost was developed. The factors that influence the emission of bioaerosols from compost piles of different ages and during different agitation activities were evaluated. A wind tunnel analysis was successfully used to measure the surface flux bioaerosols emission rate. Newly estimated emission rates from various source terms were then modelled to produce source depletion curves. The surface emission flux of a static pile was estimated to be 102 to 104cfu/m2/s for both A. fumigatus and actinomycetes. The turning of compost releases the highest bioaerosols concentration range from 104 to 108cfu/s compared with the shredding and screening. The turning of an early stage compost windrow emitted the highest amount of bioaerosols. This study introduces a new method for quantifying bioaerosols dispersal, thus improving the risk assessments required for environmental permitting.
Open Access
The Capability of Design in Government
(2020-03) Geraghty, Rhonda Nadine; Longhurst, Philip; Encinas-Oropesa, Adriana
This research increases understanding of the scope and potential of design as resource in the context of government. Currently, there is limited knowledge and use of tangible and intangible dimensions of design in government and its potential remains unrealized. This despite designs established history of use, evidence to support its economic, social, environmental, and political value and encouragement from national and international bodies. What design is and its capacity to contribute in government is explored in this research. Accomplished through seven phases of investigations, the design-in- government context is first established and then explored followed by an examination of what design is and does within this context. A mixed methods approach was employed involving a critical assessment of both theoretical and empirical insights, including a scoping review, a focused review of literature, interviews with practitioners and primary and secondary observations of the design-in-government phenomena in practice. Interactions with stakeholders, academia and industry at international engagements informed the research process and evaluated study results incrementally over a 6-year period from 2013-2019. Results reveal a dimensional and holistic perspective of design as capability in operation within a dynamic design-in-government system. Here the potential exists for all facets of design to impact all areas of government simultaneously. The establishment of the design-in-government conceptual framework and definition of design for this context are also significant outcomes from this study. Together they constitute constructs that contribute to the furtherance of the novel field of research and practice with implications for design education and the evolving design profession. Finally, the distinctive scoping review process from this research contributes to the theoretical advancement of the methodology.
Open Access
A critical review on risk evaluation and hazardous management in carcass burial
(Elsevier, 2019-01-23) Chowdhury, Saikat; Kim, Geon-Ha; Bolan, Nanthi; Longhurst, Philip
Carcass disposal from livestock disease outbreaks or on-farm, routine mortalities present a number of challenges. Proper management of carcasses can no longer be addressed as an incidental occurrence, as they represent a persistent pathway of infectious agricultural wastes with potential to harm the environment. The long-term management of carcass disposal sites is essential irrespective of the cause of mortality. Critically this ensures eradication of disease and environmental protection from a range of biological and chemical hazards. Strategies for large-scale carcass disposal require preparation and coordinated, proactive planning in advance of emergencies to meet environmental protection guidelines and maximize the efficiency of response. Carcass disposal methods include burial, incineration, composting, alkaline hydrolysis, lactic acid fermentation and anaerobic digestion. Burial techniques include trench burial, landfill, and notably mass burial as one of the most common methods of disposal. However, there are concerns about possible impacts to the environment and subsequent risk to human health regardless of the initial logistical and economic advantages. This review provides an overview of our current understanding of the potential threats of carcass burial and possible management options. The environmental implications of terminating burials is discussed as is the role of biochar and phytoremediation which can contribute to the management of burials. These examples are considered in the case study context of Korea where long-term considerations remain a priority. The outcome of the review is structured to provide information to decision-makers that is of value when equipping themselves with comprehensive guidelines for the sustained management of carcass burials. Finally, recommendations that address future research needs are outlined.
Open Access
Development of a method to classify and analyse the composition of mixed waste materials in real-time.
(Cranfield University, 2022-07) Vrancken, Carlos; Wagland, Stuart; Longhurst, Philip
There is a need for innovative technologies to classify and monitor the composition of solid waste in real-time. This research project has highlighted which information is required to improve current process designs. It also identified visible spectrum cameras as the solution that can better inform waste composition and quality without requiring complementing technologies. The experiments applied deep learning methods to classify the materials based on their images, and a method to analyse the composition of mixed waste was developed. There is a high variability in the appearance of waste materials in the context of a material recovery facility. An image capture setup using multiple cameras and light sources was implemented and tested to acquire a representative set of images. The hardware captures images from different angles, with enhanced shadow details, and different exposure levels. Image processing software further augmented the data by rotating and changing the images resolutions. The images were converted to greyscale to increase the method robustness without affecting classification performance. Deep convolutional neural networks were trained on the augmented datasets. The trained networks obtained state-of-the-art performance when tested and validated for the task of waste material classification. Based on this, a composition analysis methodology was developed and tested with mixed material samples. The methodology provides results as accurate as current manual solutions, but it can analyse a waste stream on a conveyor belt in real-time. The findings and observations from the experimental results contribute to knowledge in three main areas: data capture, data processing, and deep learning. This thesis presents the progressive development of the methodology and discusses different applications for waste management. The composition analysis can provide real-time waste data to improve the overall efficiency of the waste treatment industry. This information can be also used by stakeholders for better decision-making in the future.
Open Access
Feasibility study of a novel bio-based material through a design thinking approach.
(2018-06) Huerta Cardoso, Omar Ivan; Encinas-Oropesa, Adriana; Longhurst, Philip
Landfilling of non-biodegradable materials is one of the most significant long-term pollution legacies. This practice represents a loss of energy-intensive produced materials alongside with an opportunity for recycling. Environmental and economic concerns arising from the large-scale production and consumption of oil-based materials, have led to an increased interest in developing more sustainable alternatives. Natural fibres (e.g. sisal, jute, flax, etc.) offer a potentially low environmental impact raw material for the packaging industry. Current research in the use of natural fibres in composite materials is reviewed initially in this work. This covers natural fibre properties, surface treatments, composite properties, and manufacturing processes. The rationale for the use of poly(lactic) acid (PLA) as a matrix system is defined. There are studies on the use of Agave tequilana fibres (ATF), but, there is no work reported to date attempting their use as a reinforcement/filler for poly(lactic acid) to replace polystyrene in consumer good applications. In this research, the importance of using a design thinking method in the development of more sustainable materials to be integrated into a circular economy, is established and principles for doing so are drafted. An initial life-cycle approach was used to design a biodegradable ATF and poly(lactic acid) bio-based composite. Experimental work included the development of different grades of fully degradable ATF/PLA bio-based composites using two diverse manufacturing processes; extrusion-press moulding, and film stacking. Bio-based composite properties were modified by exploring several surface treatments. Their resulting bio-based composite properties were investigated to provide enough information about the material behaviour in order to evaluate its potential uses. Mechanical and physical properties (tension, flexural, impact, and moisture) were assessed using standardised tests and methods. The possible routes for recycling or energy recovery of the material to close the material life cycle loop were explored. Despite the by-product character of ATF, it offers a potential low-cost alternative as a reinforcement source for bio-based composites. ATF were observed to have a density of 1.2±0.1 g/cm³ with a tensile strength of 79±38 MPa, and Young’s modulus of 3.3±1.4 GPa. Surface treatments improved ATF tensile properties and interfacial shear strength (IFSS) with PLA. Alkali-treated ATF resulted in a maximum improvement of ~50% in tensile strength and IFSS. According to the results obtained, ATF/PLA bio-based composites with a high fibre content of 60wt% have some properties capable of outperforming those of general purpose polystyrene in several conditions (i.e. ~15% in flexural modulus and ~17% in flexural strength), while in other cases properties did not presented significant improvements (i.e. Young modulus ~3 GPa). The impact of the new ATF/PLA bio-based composite on the current waste management system in Mexico was studied in terms of the “best” economic-environmental-social balanced route at the end-of-life of the material. It is considered that a continuous looping with the least possible loss of carbon and energy is best achieved through biological recycling. Anaerobic digestion of the material was ~14% after 20 days of incubation, with production of ~20 mL CH₄/gVS. Due to the performance presented regarding their economic viability and environmental acceptability within a circular economy, ATF/PLA bio-based composites have the potential to be used in non-structural applications within the consumer goods industry, e.g., packaging, casings for electronic appliances, crates, etc.
Open Access
Influence of coalification on methane diffusion dynamics in middle-high rank coals
(Taylor and Francis, 2021-01-11) Jiang, Jingyu; Zhang, Shuo; Longhurst, Philip; Zhao, Ke; Wang, Deyang
Understanding the effect of coalification on the diffusion of methane in middle-high rank coals (MHRC) is fundamental for optimizing the coalbed methane (CBM) drainage strategies. Safe coal mining relies critically on this approach. Hence, CH4 adsorption/desorption experiments and a new methane diffusion model were used to study methane diffusion behavior in five different metamorphic degree coals from China. The results indicate that, as the vitrinite reflectance (Ro) increase, the Langmuir volume (VL) shows a downward trend at first, then increases. Coalification especially for the third coalification jump (Ro = 1.26%) shows a turning effect on diffusion dynamics of MHRC. The desorption volume and initial diffusion coefficient (D0) both show a slight decreasing, then rapid increasing trend. The D0 of five coals jumps at Ro = 1.26%. VL increases alongside that of the micropores volume. With the decrease of the Raman parameter ID1/IG, the VL, methane desorption volume within 7200 s and D0 all increase. Results show that coalification changes the microporous structure and the macromolecular structure of the coal, which finally affects the diffusion capacity of coal. Coalification has a positive effect for the gas extraction and the development of CBM for the semianthracites.
Embargo
Influencing factors and mechanisms of local government green development behaviour: evidence from China
(Cranfield University, 2024-01) Zhu, Xiaowen; Unal, Enes; Longhurst, Philip
Green development has become an important strategy for local governments to achieve greater sustainability, and adopting green development behaviours has significant implications for local governments in addressing the relationship between the environment and the economy. Previous research demonstrated that the unique characteristics of green development practices have received considerable attention from scholars. Most studies have highlighted green development practices in the private sector, although the adoption of green development practices in the public sector remains understudied. Current research on green development behaviour in the public sector primarily reflects, at the individual level, the green behaviour of employees and, at the organisational level, the green purchasing behaviour of a particular government department. The discussion of local government green development behaviour is not predominant. Therefore, this thesis proposes that a detailed understanding of the processes and specific practices of local government green development behaviours may be essential for local governments to improve the effectiveness of implementing sustainable practices. Although existing studies have addressed the influencing factors that lead to the adoption of sustainable development by local governments, there needs to be a more systematic theoretical analysis of the underlying mechanisms adopted by local governments to achieve green development behaviours. Accordingly, this thesis aims to explore the factors that influence the implementation of green development behaviours by local governments and the mechanisms of influence between the factors. This study draws on mixed methods to develop two studies. The first is a qualitative study that explores local government green development behaviour and its influencing factors. It applies various data collection methods, including semi-structured interviews and document analysis. Fifty-three officials from local government departments related to green development in China’s Jiangsu province were interviewed, and the data were analysed using a grounded theory method. The second is a quantitative study. Seven hundred twenty-two valid questionnaires were collected, and the model proposed in the first study with Structural Equation Modelling (SEM). The findings illustrate how the interactions between various factors shape the green development behaviour of local governments. The main findings show that: (1) local government green development behaviour is a kind of behavioural change, which can be divided into local government green development policy formulation and implementation. (2) The three main influences on local governments’ green development behaviours include internal driving factors, external environmental pressures, and the basis of regional green development. (3) Internal driving factors and external environmental pressure can influence local governments’ green development behaviours. (4) Internal driving factors mediate the relationship between external environmental pressure and green development behaviour. The basis of regional green development has a moderating effect on the relationship between internal driving factors and green development behaviours, as well as the relationship between external environmental pressures and green development behaviours. This thesis provides a framework that supports local government behaviour's decision-making process on the managerial implications. Paper I analyses the specific processes and practices of local government green development behaviour, Paper II constructs a theoretical model of local government green development behaviour, and Paper III examines the mechanisms by which various factors influence local green development behaviour. At a broader level, this thesis enriches and expands the research content of sustainable practices in the public sector. It also provides novel insights for local governments to formulate effective green development policies, which will help them develop green development directions and implement green development behaviours to promote more remarkable sustainable development in the region.
Open Access
Influencing factors for sustainable design implementation in the front-end of new product development process within the Fast-Moving-Consumer-Goods sector
(Cranfield University, 2015) Park, Curie; Charnley, Fiona; Longhurst, Philip
This study examines and verifies the influencing factors for sustainable design implementation in the front-end stages of New Product Development (NPD) process within the Fast-Moving-Consumer-Goods (FMCG) sector. Despite many arguments that the early consideration of sustainable design is key to successful sustainable product development, there is a paucity of research that approaches sustainable design implementation from an NPD front-end perspective. Moreover, sustainable design research in the FMCG sector is rare in spite of the sector’s substantial impact to the environment and society. In order to gain holistic insights of the subject, this study explores different epistemic communities ranging from industrial sustainable design, engineering sustainable design, NPD front-end studies, to corporate social responsibility (CSR) studies. Subsequently, multiple FMCG case studies are conducted to confirm and elaborate the literature findings. Among a total of 11 factors and 32 elements of case studies findings, nine factors and 19 elements confirm the previous findings, and two factors and 13 elements are newly identified. Six confirming factors including senior management support, internal communication, cross-‐functional team, and supportive corporate culture are common sustainable design and NPD front-end factors. Three other confirming factors including sustainability tools, and sustainability champions are distinct sustainable design factors, and two new factors including balanced focus on growth and maturity of external contexts and seven elements are specific to the FMCG context. Also a disparity between the perception and practice of the factors is highlighted. More positive, frequent evidence of the factors is observed in higher sustainability maturity level companies. A conceptual framework is suggested to explain the interrelationships of factors. The research findings contribute to a holistic understanding of the nature of sustainable design implementation in the front-end of NPD for FMCG. The research is hoped to serve as guide for FMCG practitioners in diagnosing their sustainable design implementation within the NPD process, and developing more holistic sustainability strategy in a long-term view.
Open Access
Investigation of the impact of trace elements on anaerobic volatile fatty acid degradation using a fractional factorial experimental design
(Elsevier, 2017-09-05) Jiang, Ying; Zhang, Yue; Banks, Charles; Heaven, Sonia; Longhurst, Philip
The requirement of trace elements (TE) in anaerobic digestion process is widely documented. However, little is understood regarding the specific requirement of elements and their critical concentrations under different operating conditions such as substrate characterisation and temperature. In this study, a flask batch trial using fractional factorial design is conducted to investigate volatile fatty acids (VFA) anaerobic degradation rate under the influence of the individual and combined effect of six TEs (Co, Ni, Mo, Se, Fe and W). The experiment inoculated with food waste digestate, spiked with sodium acetate and sodium propionate both to 10 g/l. This is followed by the addition of a selection of the six elements in accordance with a 26−2 fractional factorial principle. The experiment is conducted in duplicate and the degradation of VFA is regularly monitored. Factorial effect analysis on the experimental results reveals that within these experimental conditions, Se has a key role in promoting the degradation rates of both acetic and propionic acids; Mo and Co are found to have a modest effect on increasing propionic acid degradation rate. It is also revealed that Ni shows some inhibitory effects on VFA degradation, possibly due to its toxicity. Additionally, regression coefficients for the main and second order effects are calculated to establish regression models for VFA degradation.
Open Access
Meeting energy demand for critical health care in developing economies: a case study modelling renewable energy systems.
(Cranfield University, 2018-10) Adewole, Adekunle; Longhurst, Philip; Shafiee, Mahmood
Most of the world’s fastest population growth is occurring in cities of developing countries. With this growth comes higher demand for energy and modern energy services. However, the utility grids in many developing countries are unreliable with dire consequences for economic and social wellbeing with the health sector in these nations experiencing some of the most severe impacts. Review of WHO-sponsored and other related research documents reveals that there is a gap in current frameworks for healthcare energy provision. Existing frameworks for measuring and improving access and quality of electricity for healthcare facilities lack essential demand-side elements to identify potential levels of energy requirements. Research to further define demand-side requirements and optimal power supply technologies in different settings is required. Consequently, this research initiated a multi-dimensional energy framework to address this gap using Nigeria as a case study. First, a focus group of experts was recruited to assess essential electricity demand for an energy intensive treatment based on WHO's SARA compendium of health services. Second, a post-energy assessment criticality analysis was conducted to create a lower level energy demand based on the most essential (or critical) applications in the treatment. Third, renewable energy technologies (RETs) were modelled in microgrid systems to determine the most viable systems in terms of cost effectiveness, reliability and environmental sustainability. Results show that two levels of energy demand for health services - essential and critical - can be created using a criticality assessment method. An Event Resilience Index of 0.34 was derived i.e. an energy system should power 34% of essential equipment in a secondary or lower level health facility for it to be resilient to unexpected power outages. On the supply- side, DER systems in settings with high solar but low hydro potentials in Nigeria require backup generators to ensure reliability and lower costs based on pre-set benchmarks (CoE of ≤$0.14/kWh and emission of ≤1000 gCO₂-eq/kWh) without producing unhealthy levels of pollutant emissions. Systematically determined reduced loads can be powered economically using fully renewable power resources. Furthermore, the modelling of energy resources in Nigeria's six geopolitical zones revealed that Nigeria has significantly more microhydro potential than wind.
Open Access
Perceptual Methods for Environmental Assessment: Odour and Landfill
(Cranfield University, 1998-09) Hitchin, Suzanne; Seaton, R. A. F.; Longhurst, Philip
This thesis investigates the phenomenon of environmental annoyance from waste management, specifically landfill odours. The research study identifies the scope and significance of parameters that influence the extent of impact and includes these in a framework that can be used to influence the design and development of a population response model for odours. The research design considers the physiological, lifestyle and location factors that influence exposure and response to landfill odour and addresses three research objectives: • To produce a framework within which a community based population response model could be developed. • Determine and demonstrate the variability of response within a popUlation exposed to landfill odour. • To determine and demonstrate how spatial and temporal factors also contribute to the differential exposure and response of individuals to odour pollution. The research activity involved the design and implementation of an odour monitoring panel. Volunteers were recruited in the vicinity of two landfill sites where they monitored daily for odours for three months. This programme provided information on their routine activities and exposure to odour at the time. The thesis concludes by noting the following: • Location and climatic factors may generate more variability (at this scale of sample) than interpersonal differences. • The results from laboratory experiments examining hedonic properties were not repeated in the external environment. • The response levels between males and females were inconsistent with current knowledge and research assessing gender differences in the ability to detect odours. Additionally, the research demonstrates how data on the detection of odour in communities could be included in research activity that links olfactometry and the experience of odour in the environment.
Open Access
Performance assessment of biofuel production via biomass fast pyrolysis and refinery technologies
(Cranfield University, 2016-01) Shemfe, Mobolaji B.; Fidalgo, Beatriz; Longhurst, Philip
Biofuels have been identified as one of several GHG emission strategies to reduce the use of fossil fuels in the transport sector. Fast pyrolysis of biomass is one approach to producing second generation biofuels. The bio-oil product of fast pyrolysis can be upgraded into essential gasoline and diesel range products with conventional refinery technologies. Thus, it is important to assess their techno- economic and environmental performance at an early stage prior to commercialisation. This research was conducted with the goal of evaluating and comparing the techno-economic and environmental viability of the production of biofuels from fast pyrolysis of biomass and upgrading of bio-oil via two refinery technologies, viz. hydroprocessing and zeolite cracking. In order to achieve this aim, process models of fast pyrolysis of biomass and bio-oil upgrading via hydroprocessing and zeolite cracking were developed. The fast pyrolysis model was based on multi-step kinetic models. In addition, lumped kinetic models of the hydrodeoxygenation reactions of bio-oil were implemented. The models were verified against experimental measurements with good prediction and formed the foundation for the development of a 72 t/day fast pyrolysis plant model in Aspen Plus®. Several strategies were proposed for the two pathways to enhance energy efficiency and profitability. All in all, the results revealed that the hydroprocessing route is 16% more efficient than the zeolite cracking pathway. Moreover, the hydroprocessing route resulted in a minimum fuel selling price of 15% lower than that from the zeolite cracking pathway. Sensitivity analysis revealed that the techno-economic and environmental performance of the both pathways depends on several process, economic and environmental parameters. In particular, biofuel yield, operating cost and income tax were identified as the most sensitive techno-economic parameters, while changes in nitrogen feed gas to the pyrolysis reactor and fuel yield had the most environmental impact. It was concluded that hydroprocessing is a more suitable upgrading pathway than zeolite cracking in terms of economic viability, energy efficiency, and GHG emissions per energy content of fuel produced.
Open Access
Reaction mechanism of arsenic capture by a calcium-based sorbent during the combustion of arsenic-contaminated biomass: A pilot-scale experience
(Springer, 2019-03-28) Lei, Mei; Dong, Ziping; Jiang, Ying; Longhurst, Philip; Wan, Xiaoming; Zhou, Guangdong
Large quantities of contaminated biomass due to phytoremediation were disposed through combustion in low-income rural regions of China. This process provided a solution to reduce waste volume and disposal cost. Pilot-scale combustion trials were conducted for in site disposal at phytoremediation sites. The reaction mechanism of arsenic capture during pilot-scale combustion should be determined to control the arsenic emission in flue gas. This study investigated three Pteris vittata L. biomass with a disposal capacity of 600 kg/d and different arsenic concentrations from three sites in China. The arsenic concentration in flue gas was greater than that of the national standard in the trial with no emission control, and the arsenic concentration in biomass was 486 mg/kg. CaO addition notably reduced arsenic emission in flue gas, and absorption was efficient when CaO was mixed with biomass at 10% of the total weight. For the trial with 10% CaO addition, arsenic recovery from ash reached 76%, which is an ∼8-fold increase compared with the control. Synchrotron radiation analysis confirmed that calcium arsenate is the dominant reaction product.
Open Access
Recycling of food waste into chemical building blocks
(Elsevier, 2018-05-30) Kumar, Vinod; Longhurst, Philip
Enormous quantities of food waste (FW) arise from global production. Roughly, one third of all food for human consumption is wasted resulting in huge costs to the world economy alongside significant environmental problems. FW is a potential reservoir of functionalized molecules, i.e. carbohydrates, proteins and lipids that can be recovered, concentrated and transformed into high value products. Conversion of renewable carbon from FW to building block chemicals can also more profitable than conventional processing methods. Recent studies have used microbial routes to recover value from FW into a number of chemical building blocks. Recycling FW into valuable chemicals directly contributes to the transition from current fossil fuel-based economies to a bioeconomy and reduced waste society. This paper reviews the potential for using FW and focuses on recent updates in second-generation valorisation methods where the bioproduction of chemical building blocks uses FW as a feedstock.
Open Access
Resilience and adaptivity in the management of workplace disruption for the service sector
(Cranfield University, 2007-02) Kufuor, A.; Longhurst, Philip
In the last two decades the service sector has dominated the UK economy. Recently, performance and service quality delivery has become a critical issue to the sustainability of businesses in this sector. Disruption to day-to-day operations is increasingly becoming an emergent pattern for organizations across this sector. This has implications for how service organisations structure and organize to deliver efficient and uninterrupted services to clients and stakeholders. Managers and staff within the service sector have been portrayed as struggling to deal with the impact of occurrences of unexpected change and uncertainty on their business operations. Literatures from organizational learning, change management and organizational crisis are drawn upon to develop this study. Concepts of resilience and adaptive capacity form a framework for exploring disruption occurrences on daily operations in the service sector. Investigations are carried out into the experiences of managers and staff to disruption occurrences. Organizational barriers to individual response are examined. Target groups for the study are drawn mainly from the finance, telecommunications, aerospace and defence related sectors. Research methodology and data analysis is based on the grounded theory approach. Fieldwork activity is undertaken in three phases over a twenty-four month period. Twenty six in-depth interviews with senior managers are carried out and two hundred postal questionnaires are administered. There are three main outcomes of the study. These are; i) core categories of disruption & core categories of response behaviour, ii) the Codar Dial; mapping core disruption categories and typical behaviour in response, iii) the five (5) 'C' drivers for enhancing resiliency in dealing with occurrences of disruption. Findings contribute to current knowledge on the concept of disruption and organizational behaviour in management studies. The research contributes also to the fields of change management and organizational learning. The findings have implications for service sector managers in relation to work structures and human resource practices at the management and individual level.
Open Access
Results from deep learning tests using balanced databases for the classification of paper and cardboard materials.
(Cranfield University, 2019-10-14 14:28) Vrancken, Carlos; Wagland, Stuart; Longhurst, Philip
For methodology used to obtain these results please refer to the publication: "Deep learning in material recovery: Development of method to create training database".These results were obtained using grayscale version of the images.The "Balanced dataset - classification results" spreadsheet includes:Sheet 1 - classification results when classifying 3 classes of fibre materials using increasing number of samples per class in a balanced training datasetSheet 2 - classification results when using a balanced dataset with 5,000 training samples per class to classify 10 classes of fibre waste material
Open Access
Risk assessments, quality protocols and other publically-available research reports supporting the risk estimates presented in "Environmental International Risk assessments for quality-assured, source-segregated composts and anaerobic digestates for a circular bioeconomy in the UK".
(Cranfield University, 2019-03-20 09:27) Pollard, Simon; Longhurst, Philip; Villa, Raffaella; Sakrabani, Ruben; Leinster, Paul; Tyrrel, Sean
Longhurst et al. (2019) Environment International. Risk assessments for quality-assured, source-segregated composts and anaerobic digestates for a circular bioeconomy in the UK. The publically-available risk assessments, quality protocols and other publically-available research reports supporting the risk estimates presented in this paper (accepted to ENVINT) are collated here. The Environment International paper reports residual risk estimates and hazard quotients for microbiological and chemical risks in quality-assured composts and digestates prepared under quality protocols from source-segregated biodegradable wastes. This CORD record here collates WRAP and associated research reports supporting the risk estimates and hazard quotients discussed in this summary paper, including risk assessments and quality protocols.
Open Access
The role of communication in enterprise system implementation
(Cranfield University, 2006-04) Sedmak, Melissa; Longhurst, Philip
The research efforts up to date have not been directed towards the study of the role of communication during an implementation of an enterprise system. However, some efforts are noted which stress communication as a critical factor and a problem in general during the implementation. During the scoping phase of this research, communication was proved to be of significance as a process in the realisation of embedding of an enterprise system into the business. Considering the complexity of an implementation of a system and consequently the complexity of its study, the research method based on processual approach was developed to enable a better understanding of the dynamics of this process. Three case studies have been conducted with the focus on the understanding of the role and significance of communication. They included interviews with the employees involved in the project or affected by the new system: project managers, top managers, system specialists, and users. The findings focus on the elements important to realise the communication process: communication strategy, management activities such as announcements, motivation to communicate, resources such as time, how informed the people who are involved are, communication across the project, communication structure and process, facilitators as people who enable the communication process, and communication about the technical issues. Special focus was on the effect of communication on the transfer of psychological ownership of the system, concerns about change and employee commitment. Additionally, several themes are found to affect communication. These are: organisational structure, team cohesion and trust. The role of communication confirms that all the parties need to use the same language to enable common understanding. The communication process is found to have direct and indirect influence on development of common organisational goals, positive attitude towards the new system, and embedding of the new system in current organisational functioning.

Browsing by Author "Longhurst, Philip"

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