Pulverised Biomass Flame Propgation

A resource analysis for Pakistan has demonstrated that abundant crop residues offer a viable, and environmental-friendly alternative to currently inadequate, oil-based power generation. Similarly, in many countries there is legislative pressure and incentives to replace coal with biomass, in electricity production. Efficient and safe exploitation of such biofuels requires data on flame propagation rates and explosibility characteristics. Crop residues (bagasse, rice husk, wheat-straw, corn-cob and peanut-shell) and different raw and thermally treated woods were tested using the modified Hartmann tube and the modified 1 m3 explosion vessel. The modified Hartmann tube was operated for varying ignition delays using a digital timer. A hemispherical disperser with drilled pipe was calibrated for the testing of fibrous and coarse size biomass mixtures. Thermogravimetric analysis data from these materials enabled the application of two different models for the determination of volatile release kinetics. Biomass samples were found to have lower activation energies with higher volatile release rates at low temperatures, compared to coals. Despite their higher ash content, pulverised crop-residues showed leaner minimum explosible concentrations (0.2-0.5 equivalence-ratio) than woods (0.3-0.7) - depending on particle size. Biomass samples were more sensitive to explosion than coal, resulting in flame propagation in coarse-size-range fractions (300-500-μm) that was not experienced with coals. Maximum explosion pressures of near 9 barg were measured for the fine size fraction (less than 63-μm) samples, with no less than 7 barg for coarse size fraction (less than 1 mm). Milling of thermally treated biomass samples resulted in higher fines fraction than untreated biomass, for the same sieve size and this was considered as one of the reasons of the higher reactivity (higher flame speed and higher deflagration index of these samples). The detailed data from this work are usable in the design of safe and efficient combustion systems for power generation from crop residues and other biomass fuels

Is "Benign Childhood Epilepsy with Centrotemporal Spikes” Always Benign?

How to Cite This Article: Saeed M, Azam M, Shabbir N, Qamar ShA. Is "Benign Childhood Epilepsy with Centrotemporal Spikes" Always Benign? Iran J Child Neurol. 2014 Summer;8(3): 39-45.AbstractObjectiveTo determine the prevalence of associated behavioral problems and prognosis with Benign Childhood Epilepsy with CentroTemporal Spikes (BCECTS).Descriptive, Cross Sectional study that was conducted from October 2009 to April 2013 in the Department of Pediatric Neurology, the Children’s Hospital Taif, KSA.Material & MethodsThis study was conducted after approval from the Ethics Committee of the Children’s Hospital Taif, Saudi Arabia. Thirty-two patients from the age of 3 to 10 years old were recruited from the pediatric neurology clinic over a period of 4 years. All the patients were selected based on history, EEGs, and neuropsychological and neurological examinations.EEGs were performed for all the patients while in awake and sleep states. Those who had centrotemporal discharges were included in the study. All the patients also underwent a brain MRI. Only two patients had mild cortical atrophy but developmentally they were normal.ResultsIn our study, prevalence of BRE is 32/430 (7.44%). Among the 32 cases, 24 were male and eight were female. Six cases out of 32 indicated a family history of BRE. Twenty-eight cases had unilateral right sided centrotemporal discharges and four had bilateral discharges.ConclusionIt is possible that for BECTS, a high number of seizures might play an important role in the development of mild cognitive impairment and/or behavior disturbances.ReferencesBradley WG, Daroff RB, Fenichel JM, Jahrovic J. Neurology of clinical practice. 5th Ed. 2009: pp. 1953-1990.Berg AT, Berkovic SF, Brodie MJ, Buchhalter J, Cross H, Van Emde Boas M, et al: Revised terminology and concepts for organization of seizures and epilepsies: Report of the ILAE Commission on Classification and Terminology, 2005–2009. Epilepsia. 2010; 51(4):676-685.Weglage J, Demsky A, Pietsch M. Neuropsychological, intellectual, and behavioral findings in patients with centrotemporal spikes with and without seizures. Dev Med Child Neurol. 1997; 39:646.Kramer U. Atypical presentations of benign childhood epilepsy with centrotemporal spikes: a review. 2008. J. Child Neurol 23 (7): 785–90.Chahine LM, Mikati MA. Benign pediatric localizationrelated epilepsies. Epileptic Disord. 2006. 8(4): 243–58.Danielsson J, Petermann F. Cognitive deficits in children with benign rolandic epilepsy of childhood or rolandic discharges: a study of children between 4 and 7 years of age with and without seizures compared with healthy controls. Epilepsy Behav. 2009; 16:646–651.Ay Y, Gokben S, Serdaroglu G, Polat M, Tosun A, Tekgul H, et al. Neuropsychologic impairment in children with rolandic epilepsy. Pediatr Neurol. 2009; 41:359–363.Wirrell E, Sherman EM, Vanmastrigt R, Hamiwka L. Deterioration in cognitive function in children with benign epilepsy of childhood with central temporal spikes treated with sulthiame. J Child Neurol. 2008; 23:14–21.Lundberg S, Eeg-Olofsson O. Rolandic epilepsy: a challenge in terminology and classification, European Journal of Paediatric Neurology. 2003; 7: 239–241.Bouma PA, Bovenkerk AC, Westendorp RG, Brouwer OF. The course of benign partial epilepsy of childhood with centrotemporal spikes: a meta-analysis. Neurology. 1997;48:430-437.Deltour L, Quaglino V, Barathon M, De Broca A, Berquin P. Clinical evaluation of attentional processes in children with benign childhood epilepsy with centrotemporal spikes (BCECTS) Epileptic Disord. 2007; 9:424–431.Nicolai J, Aldenkamp AP, Arends J, Weber JW, Vles JS. Cognitive and behavioral effects of nocturnal epileptiform discharges in children with benign childhood epilepsy with centrotemporal spikes. Epilepsy Behav. 2006; 8:56–70.Goldberg-Stern H, Gonen OM, Sadeh M, Kivity S, Shuper A, Inbar D. Neuropsychological aspects of benign childhood epilepsy with centrotemporal spikes. Seizure. 2010; 19:12–16.Genizi J, Shamay-Tsoory SG, Shahar E, Yaniv S, Aharon- Perez J. Impaired social behavior in children with benign childhood epilepsy with centrotemporal spikes. J Child Neurol. 2012; 27:156–161.Zenkov LR, Konstantinov PA, Shiriaeva IIu, Miasnikov VN, Sirazitdinova EB, Shevel’chisnkiĭ SI. Mental and behavioral disorders in idiopathic focal epileptiform spikes. Zh Nevrol Psikhiatr Im S Korsakova. 2007; 107:39–49.Winckler MIB, Rotta NT. Prognostic factors for recurrence of a first seizure during childhood. Arq Neuropsiquiatr.1997; 55:749-756.Holmes GL. Rolandic epilepsy: clinical and electroencephalographic features. In: Degen R, Dreifuss FE, editors. Benign localized and generalized epilepsies of early childhood. Amsterdam: Elsevier ;1992: p.29-43.Gregory DL, Wong PKH. Clinical relevance of a dipole field in rolandic spikes. Epilepsia. 1992; 33:36-44.Bouma PAD, Bovenkerk AC, Westendorp RGJ, Brouwer OF. The course of benign partial epilepsy of childhood with centrotemporal spikes: a meta- analysis. Neurology. 1997; 48: 430-437.Fejerman N, Caraballo R, Tenembaum S. Atypical evolutions of benign -localization-related epilepsies in children: are they predictable? Epilepsia. 2000; 4: 380-390.Peters JM, Camfield CS, Camfield PR. Population study of benign rolandic epilepsy: is treatment needed? Neurology. 2001; 57: 537-539.Holmes GL. Rolandic epilepsy: clinical and electroencephalographic features. In Degen R, Dreifuss FE. editors. Benign localized and generalized epilepsies of early childhood. Amsterdam: Elsevier 1992:p. 29-43.Laub MC, Funke R, Kirsch CM, Oberst U. BECT: comparison of cerebral blood flow imaging, neuropsychological testing and long-term EEG findings. Epilepsy Res Suppl. 1992;6:95-98.Coppola G. Cognitive and linguistic abnormalities in benign childhood epilepsy with centrotemporal spikes. Acta Paediatr. 2011;100(5):768-772.Sarco DP, Boyer K, Lundy-Krigbaum SM, Takeoka M, Jensen F, Gregas M, Waber DP. Benign rolandic epileptiform discharges are associated with mood and behavior problems. Epilepsy Behav. 2011;22 (2):298-303.Jones JE, Watson R, Sheth R, Caplan R, Koehn M, Seidenberg M, et al. Psychiatric comorbidity in children with new onset epilepsy. Dev Med Child Neurol. 2007;49:493-7.Austin JK, Harezlak J, Dunn DW, Huster GA, Rose DF, Ambrosius WT. Behavior problems in children before first recognized seizures. Pediatrics. 2001; 107:115-22.Bhise VV, Burack GD, Mandelbaum DE. Baseline cognition, behavior, and motor skills in children with new-onset, idiopathic epilepsy. Dev Med Child Neurol. 2010;52:22-6.Kavros PM, Clarke T, Strug LJ, Halperin JM, Dorta NJ, Pal DK. Attention impairment in rolandic epilepsy: systematic review. Epilepsia. 2008; 49:1570-80.Beaussart M. Benign epilepsy of children with Rolandic (centro-temporal) paroxysmal foci: A clinical entity: Study of 221 cases. 1972. Epilepsia 13 (6): 795–811.

Simultaneous implementation of rotary pressure exchanger and ejectors for CO2 refrigeration system

Natural refrigerant CO2 has become a viable choice for refrigeration units. The CO2 systems are working efficiently on land-based facilities, and their demand is increasing for offshore applications, e.g., cruise ships and fishing vessels, due to their environment-friendly nature and compactness. The investigated application of the CO2 system in this work is a single-stage system for air conditioning and a two-stage system for provision refrigeration at high heat rejection temperatures. The CO2 transcritical cycle allows operating in higher ambient temperatures and in a colder climate with significant heat recovery. However, the system efficiency decreases in higher ambient conditions due to the high-pressure ratio and expansion losses. Therefore, ejectors are implemented to boost the cycle efficiency at high heat rejection temperature conditions. The pressure exchanger (PX) device recently came up and claimed to be an option to recover expansion work in CO2 systems. PX is already in use for reverse osmosis (RO) desalination units to recover pressure work from the high pressure reject concentrate to low-pressure seawater. This work theoretically investigates the implementation of a CO2-PX for transcritical CO2 systems combined with ejectors and compressors. The energy efficiency of alternative system configurations is evaluated for various operating conditions.Simultaneous implementation of rotary pressure exchanger and ejectors for CO2 refrigeration systemacceptedVersio

Experimental investigation of a transcritical CO2 refrigeration system incorporating rotary gas pressure exchanger and low lift ejectors

Natural refrigerants like CO2 are playing a significant role in making refrigeration and heat pump systems climate-friendly by slowly phasing out the high global warming refrigerants like hydrofluorocarbons (HFCs). However, the efficiency of a transcritical CO2 refrigeration system declines significantly when the ambient temperature increases, primarily attributed to the high-pressure lift and the losses incurred during expansion. To remedy this issue, this paper presents a novel rotary gas pressure exchanger (PXG) device, which simultaneously achieves high differential pressure expansion work recovery and the “free compression” of the portion of the flash gas in a compact, rotary machine. For this, a PXG device is designed, fabricated, and tested to achieve free compression of CO2 over the entire differential pressure of approximately 70 bar between a receiver and a gas cooler. This is one of the highest free-pressure lift provided by any device to date in CO2 refrigeration. However, there is a small pressure loss of approximately 1–2 bar in the system due to viscous and inertia losses in the piping and in the PXG itself, which needs to be overcome by an external booster device. Results on a baseline PXG integrated system with two low lift booster compressors are presented, which show up to 60 bar free pressure lift and up to 18.2 % COP improvement provided by PXG. Additionally, key performance characteristics of the PXG, like the expansion work recovery, the mass boost ratio, direct fluid-to-fluid contact, and no pass-through operation are experimentally quantified. This work also presents a novel method to integrate two low lift ejectors with PXG to eliminate the need for separate low lift compressors. The low lift ejectors are designed, fabricated, and tested in-house, followed by their integration with the PXG device. A new type of transcritical CO2 refrigeration system is designed to integrate these low lift ejectors with PXG, and experiments are conducted at various evaporator thermal duties and gas cooler exit temperatures, simulating varying ambient temperature conditions. A novel control system to control the gas cooler pressure to optimal thermodynamic levels using PXG rotational speed is demonstrated experimentally. Further, automated control of high-pressure low lift ejector mass flow using an in-built needle design has been successfully demonstrated to optimise PXG mass boost performance. The LP low lift ejector achieved a successful pressure lift of 3.8 bar, and the HP low lift ejector showed a lift of 5.7 bar on the top of 42 bar free pressure lift provided by PXG for up to 5.8 kg/min mass flow delivered by free PXG compression. The results from this study demonstrate that the PXG device provides a significant energy efficiency improvement to the transcritical CO2 refrigeration system, and the novel low lift ejectors, when integrated with PXG, provide a successful method to maximise PXG's thermodynamic potential. © 2024 The Author(s)publishedVersio

Partial Substitution of Chemical Fertilizers with Organic Supplements Increased Wheat Productivity and Profitability under Limited and Assured Irrigation Regimes

Crop wastes could be applied in conjunction with synthetic fertilizers to satisfy crop nutritional needs and enhance soil fertility. A field experiment was carried out during winter 2019–2020 at the AMK Research Farm (Palatoo) Mardan, KPK (Pakistan) to investigate the combined effect of phosphorous (PS) and organic sources (OSs) on wheat productivity under different irrigation regimes. The experimental factors were: two irrigation regimes (limited and full irrigation), three inorganic sources of phosphorus (triple super phosphate (TSP), single super phosphate (SSP) and di-ammonium phosphate (DAP)) applied at 90 kg ha−1, and three organic amendments (farmyard manure (FYM), mung bean residue (MBR), and canola residue (CR)) applied at a rate of 10 t ha−1. A control plot (no phosphorus or organic supply) was included. A randomized complete block design (RCBD) with three replications was adopted. Among the fertilization strategies, SSP + FYM outperformed all other P fertilizers combined with legume or nonlegume residues in terms of grains per spike−1 (52), thousand-grain weight (41.6 g), biological yield (9.7 t ha−1), and grain yield (4 t ha−1). Under full irrigation, improved yield, yield components, and profits were obtained compared to the limited irrigation regime. Three clusters were obtained after applying an Agglomerative Hierarchical Clustering (AHC), and Principal Component Analysis (PCA) conferred the positive effects of inorganic P with FYM on the wheat yield and its related parameters. This study indicated that the productivity of wheat under the SSP + FYM fertilization strategy was found to be more economical with respect to the benefit–cost ratio (BCR). The combined application of SSP + FYM was more profitable in terms of a higher BCR (3.25) than other treatments under the full irrigation regime

Advancing sustainable decomposition of biomass tar model compound: Machine learning, kinetic modeling, and experimental investigation in a non-thermal plasma dielectric barrier discharge reactor

This study examines the sustainable decomposition reactions of benzene using non-thermal plasma (NTP) in a dielectric barrier discharge (DBD) reactor. The aim is to investigate the factors influencing benzene decomposition process, including input power, concentration, and residence time, through kinetic modeling, reactor performance assessment, and machine learning techniques. To further enhance the understanding and modeling of the decomposition process, the researchers determine the apparent decomposition rate constant, which is incorporated into a kinetic model using a novel theoretical plug flow reactor analogy model. The resulting reactor model is simulated using the ODE45 solver in MATLAB, with advanced machine learning algorithms and performance metrics such as RMSE, MSE, and MAE employed to improve accuracy. The analysis reveals that higher input discharge power and longer residence time result in increased tar analogue compound (TAC) decomposition. The results indicate that higher input discharge power leads to a significant improvement in the TAC decomposition rate, reaching 82.9%. The machine learning model achieved very good agreement with the experiments, showing a decomposition rate of 83.01%. The model flagged potential hotspots at 15% and 25% of the reactor’s length, which is important in terms of engineering design of scaled-up reactors.Web of Science1615art. no. 583

Combustion and explosion characteristics of pulverised wood, valorized with mild pyrolysis in pilot scale installation, using the modified ISO 1 m(3) dust explosion vessel

Featured Application Design of explosion safety measures for torrefaction installations and design of pulverized-fired burners for biocoal. Biomass is a renewable energy source with great potential worldwide and in the European Union. However, valorization is necessary to turn many types of waste biomass into a tradable commodity that has the potential to replace coal in power plants without significant modifications to firing systems. Mild pyrolysis, also known as torrefaction, is a thermal valorization process of low-quality biomass that could be suitable for such a purpose. In this work, typical Spruce-Pine-Fir residues from a sawmill were tested in terms of the explosion and flame propagation properties. The ISO 1 m(3) dust explosion vessel was used, with a modified and calibrated dust dispersion system that could cope with very coarse particles. The deflagration index, K-st, was higher for the torrefied sample, with a peak at 36 bar m/s compared with 27 for the raw biomass. The peak flame speeds were similar for both samples, reaching 1 m/s. The peak P-max/P-i was between 7.3 and 7.4 bar for both untreated and torrefied biomass. The mechanism for coarse particle combustion is considered to be influenced by the explosion-induced wind blowing the finer fractions ahead of the flame, which burns first, subsequently devolatilizing the coarser fractions.Web of Science1224art. no. 1292

Hydrolysis, Microstructural Profiling and Utilization of Cyamopsis tetragonoloba in Yoghurt

The present study investigates the hydrolysis, microstructural profiling and utilization of guar gum (Cyamopsis tetragonoloba) as a prebiotic in a yoghurt. Guar galactomannans (GG) was purified and partially depolymerized using an acid, alkali and enzyme to improve its characteristics and increase its utilization. The prebiotic potential of hydrolyzed guar gum was determined using Basel and supplemented media. Crude guar galactomannans (CGG), purified guar galactomannans (PGG), base hydrolyzed guar galactomannans (BHGG), acid hydrolyzed guar galactomannans (AHGG) and enzymatic hydrolyzed guar galactomannans (EHGG) were analyzed using scanning electron microscope (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Yoghurt was prepared with a starter culture and incorporating guar gum, its hydrolyzed forms (0.1, 0.5 and 1%) and Bifidobacterium bifidum. The results showed that PHGG significantly improved the viability of B. bifidum. SEM revealed a significant change in the surface morphology of guar gum after acidic and enzymatic hydrolysis. Enzymatic hydrolysis developed a well-defined framework within guar gum molecules. The XRD pattern of CGG, PGG and AHGG presented an amorphous structure and showed low overall crystallinity while EHGG and BHGG resulted in slightly increased crystallinity regions. FTIR spectral analysis suggested that, after hydrolysis, there was no major transformation of functional groups. The addition of the probiotic and prebiotic significantly improved the physiochemical properties of the developed yoghurt. The firmness, cohesiveness, adhesiveness and syneresis were increased while consistency and viscosity were decreased during storage. In sum, a partial hydrolysis of guar gum could be achieved using inexpensive methods with commercial significance

Steam exploded pine wood burning properties with particle size dependence

Power generation using waste material from the processing of agricultural crops can be a viable biomass energy source. However, there is scant data on their burning properties and this work presents measurements of the minimum explosion concentration (MEC), flame speed, deflagration index (Kst), and peak pressure for pulverised pine wood and steam exploded pine wood (SEPW). The ISO 1 m3 dust explosion vessel was used, modified to operate on relatively coarse particles, using a hemispherical dust disperser on the floor of the vessel and an external blast of 20 bar compressed air. The pulverized material was sieved into the size fractions <500 μm, <63 μm, 63–150 μm, 150–300 μm, 300–500 μm to study the coarse particles used in biomass power generation. The MEC (Ø) was measured to be leaner for finer size fraction with greater sensitivity of explosion. The measured peak Kst was 43–122 bar m/s and the maximum turbulent flame speeds ∼1.4–5.4 m/s depending on the size distribution of the fraction. These results show that the steam exploded pine biomass was more reactive than the raw pine, due to the finer particle size for the steam exploded biomass

Advances and Challenges in Conventional and Modern Techniques for Halal Food Authentication: A Review

Food is one of the most necessary needs since human civilization. For Muslims, it is mandatory to consume halal food. From a halal authentication perspective, adulteration of food products is an emerging challenge worldwide. The demand for halal food consumption has resulted in an ever-increasing need for halal product validity. In the market, there are several food products in which actual ingredients and their source are not mentioned on the label and cannot be observed by the naked eye. Commonly nonhalal items include pig derivatives like lard, pork, and gelatin derivatives, dead meats, alcohol, blood, and prohibited animals. Purposely, various conventional and modern methods offer precise approaches to ensure the halalness and wholesomeness of food products. Conventional methods are physiochemical (dielectric) and electrophoresis. At the same time, modern techniques include high-pressure liquid chromatography (HPLC), gas chromatography (GC), electronic nose (E-Nose), polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR), near-infrared (NIR) spectroscopy, and Fourier transform infrared (FTIR) spectroscopy. This review intends to give an extensive and updated overview of conventional and modern analytical methods for ensuring food halal authenticity