Unaccounted Losses Research Articles

An Unprecedented Surprise Failure in a Refinery Hydrogen Generation Unit Jeoparadizing Process Safety and Operational Reliability

Oil and Gas business management started giving focused importance on process safety management in order to ensure sustained operation reliability without any surprise failure incident. Refinery Operation, especially lighter end hydrocarbon processing units are extremely safety critical which need high order reliability from material to maintenance to management perception on plant operation. Routine walk down and specific vigilance especially at hard to reach locations are essential to prevent any eventualities before it becomes too late to control. This paper will discuss about a surprise failure incident at Refinery Hydrogen Generation Unit (HGU) which made the entire refinery management in a state of “raised eyebrow” shock. The consequence of the failure is not only HGU shutdown but simultaneous outage of all critical units which needs hydrogen to operate leading to an unexpected and unaccounted business loss as well HSE impacts.

Same Me, Different View: Exploring Family Achievement Guilt in Post-Graduate First-Gen College Students

ABSTRACT This article will review family achievement guilt in post-graduate first-generation college students using an ambiguous loss theoretical framework. Those who have experienced this phenomenon may straddle two worlds because of their dual identities, and for all the accolades earned by achieving academic and economic success, there may be a sense of unaccounted loss. Three central themes were found: 1) A lack of support from family members; 2) Disconnect with family and development of new identity; and 3) Ambivalence between loyalty to family and sense of independence.

Effects of Chemicals in Reporter Gene Bioassays with Different Metabolic Activities Compared to Baseline Toxicity.

High-throughput cell-based bioassays are used for chemical screening and risk assessment. Chemical transformation processes caused by abiotic degradation or metabolization can reduce the chemical concentration or, in some cases, lead to the formation of more toxic transformation products. Unaccounted loss processes may falsify the bioassay results. Capturing the formation and effects of transformation products is important for relating the in vitro effects to in vivo. Reporter gene cell lines are believed to have low metabolic activity, but inducibility of cytochrome P450 (CYP) enzymes has been reported. Baseline toxicity is the minimal toxicity a chemical can have and is caused by the incorporation of the chemical into cell membranes. In the present study, we improved an existing baseline toxicity model based on a newly defined critical membrane burden derived from freely dissolved effect concentrations, which are directly related to the membrane concentration. Experimental effect concentrations of 94 chemicals in three bioassays (AREc32, ARE-bla and GR-bla) were compared with baseline toxicity by calculating the toxic ratio (TR). CYP activities of all cell lines were determined by using fluorescence-based assays. Only ARE-bla showed a low basal CYP activity and inducibility and AREc32 showed a low inducibility. Overall cytotoxicity was similar in all three assays despite the different metabolic activities indicating that chemical metabolism is not relevant for the cytotoxicity of the tested chemicals in these assays. Up to 28 chemicals showed specific cytotoxicity with TR > 10 in the bioassays, but baseline toxicity could explain the effects of the majority of the remaining chemicals. Seven chemicals showed TR < 0.1 indicating inaccurate physicochemical properties or experimental artifacts like chemical precipitation, volatilization, degradation, or other loss processes during the in vitro bioassay. The new baseline model can be used not only to identify specific cytotoxicity mechanisms but also to identify potential problems in the experimental performance or evaluation of the bioassay and thus improve the quality of the bioassay data.

Disentangling UV photodesorption and photoconversion rates of H2O ice at 20 K

Context. The nondissociative ultraviolet photodesorption of water ice is a nonthermal desorption mechanism required to account for detected abundances of gas-phase water toward cold regions within the interstellar medium. Previous experimental and theoretical studies provide a range of photodesorption rates for H2O ice and point to a convoluted competition with other molecular processes following the absorption of a UV photon in the ice. Ultraviolet irradiation also induces photodissociation, resulting in the formation of radicals that may directly desorb triggering gas-phase reactions or recombine in surface reactions. Aims. In this work, we aim to quantify the effects of photodesorption and investigate photoconversion upon UV photolysis of an H2O ice. Methods. We irradiated a porous amorphous H2O ice at 20 K with UV photons in the 7–10.2 eV range and compared the measurements to a nearly identical experiment that included a layer of argon coating on top of the water ice. The purpose of the argon coating is to quench any type of photon-triggered desorption. To trace ice composition and thickness, laser desorption post ionization time-of-flight mass spectrometry was utilized. This method is independent of the (non)dissociative character of a process and provides a diagnostic tool different from earlier studies that allows an independent check. Results. The total photodesorption rate for a porous amorphous H2O ice at 20 K we derive is (1.0 ± 0.2) × 10−3 per incident UV photon (7–10.2 eV), which is in agreement with the available literature. This rate is based on the elemental balance of oxygen-bearing species. As a result, we placed an upper limit on the intact (H2O) and dissociative (OH) desorption rates equal to 1.0 × 10−3 per incident UV photon, while for the reactive desorption (O2), this limit is equal to 0.5 × 10−3 per incident UV photon. Photoconversion depletes the H2O ice at a rate of (2.3 ± 0.2) × 10−3 per incident UV photon. At low UV fluence (9.0 × 1017 photons cm−2), the loss of H2O is balanced by photoproduct formation (O2 and H2O2). At high UV fluence (4.5 × 1018 photons cm−2), about 50% of the initial H2O molecules are depleted. This amount is not matched by the registered O-bearing products, which points to an additional, unaccounted loss channel of H2O.

Energy-Exergy Analysis of Diesel Engine Fueled with Microalgae Biodiesel-Diesel Blend

Renewable energy is getting more attention in recent times due to the rapid depletion of fossil fuel reserves. Production and consumption of biofuels derived from biomass has significantly increased. In the present work, Spirulina microalgae have been chosen as feedstock for biodiesel production. Diesel and biodiesel were mixed in different volumetric ratios to prepare fuel blends (SBF0, SBF20, SBF40, SBF60, SBF80, and SBF100). Energy and exergy analysis has been performed on a four-stroke, single-cylinder diesel engine. Experimentation was done under varying loads at 1500 RPM. The effect of multiple loads and blends was investigated for brake power (BP), cooling water losses (Qw), exhaust gas losses (Qexh), and unaccounted losses (Qun). Pure diesel SBF100 has the highest and lowest exergy efficiencies, respectively equaling roughly 31.65% and 29.75%. It has been observed that BP and Qw increase with the increase in load whereas Qexh and Qun show a decreasing trend. It was also observed that with an increase in blending, Qw increases while Qexh decreases. In the exergy analysis, it was observed that the exergy destruction rate has a maximum fraction of input exergy values of 46.01% and 46.29% for Diesel and SBF20 respectively. The system engine sustainability index was in the range of 1.27 to 1.46, which is directly related to exergy efficiencies.

THE EXCESSIVE TECHNICAL LOSSES OF ELECTRICITY IN ELECTRICAL SYSTEMS OF POWER CONSUMPTION

Reducing electricity losses in electrical networks is a complex complex problem that requires significant capital investments necessary for optimizing the development of electrical networks, improving the electricity accounting system, introducing new information technologies in marketing activities and managing network modes, training personnel and equipping them with means of testing measuring devices etc. In reality, in recent years, in connection with the inclusion of normative losses in the tariff for electric energy transmission services, a dangerous trend of adapting these norms to actual losses has emerged. The article analyzes the occurrence of power losses in electrical engineering systems and electrical networks of various voltage classes. Special attention is paid to the so-called excess losses, which are not taken into account during design and operation. These losses occur in insulators, linear fittings, current-limiting reactors, electricity meters, windings of current and voltage transformers, etc. Excessive losses of electricity in electric networks are direct financial losses of electric power companies. Savings from reducing losses could be directed to technical re-equipment of networks; staff salary increase; improvement of the organization of electricity transmission and distribution; increasing the reliability and quality of electricity supply to consumers. Unaccounted losses reach approximately 1% of the total amount. This fact must be taken into account. Because currently we are talking about millions of losses.

Energy and Exergy Analyses of Multiple Biodiesel Blended Diesel Engine

Abstract This paper deals with the experimental investigation of direct injection compression ignition (DICI) engine runs with multiple biodiesels–diesel blended and neat diesel fuels along with the energy-exergy analysis to evaluate quantitative and qualitative data for determining energy and exergy efficiencies, losses, and exergy destruction. Second-generation biodiesels are utilized to conduct experiments on engine with constant speed and full throttle condition at a compression ratio of 17.5:1. Energy analysis is based on experimental data, and exergy analysis is performed with the help of derived formula using chemical and molecular structures. Variation in the performance, combustion, and emission parameters for B0, B10, and B20 blends reveals that BTE, AFR, η(mech.), η(vol.), CP, and CO decrease with the increase in BSEC, EGT, MGT, RPR, NHR, CO2, HC, and NOx. Energy-exergy analysis shows that the combustion and exergetic efficiencies are maximum for the B20 blend (+87.73%) and (+52.04%) at 2.5 kW and 3.3 kW BPs. Exergy destructed is observed to be three-fifth of total available exergy. Half of the heat supplied is carried away by cooling water while one-third of heat is converted into brake power, and the remaining heat is lost in exhaust gases and unaccounted losses.

Kinetics and Product Branching Ratio Study of the CH3O2 Self-Reaction in the Highly Instrumented Reactor for Atmospheric Chemistry.

The fluorescence assay by gas expansion (FAGE) method for the measurement of the methyl peroxy radical (CH3O2) using the conversion of CH3O2 into methoxy radicals (CH3O) by excess NO, followed by the detection of CH3O, has been used to study the kinetics of the self-reaction of CH3O2. Fourier transform infrared (FTIR) spectroscopy has been employed to determine the products methanol and formaldehyde of the self-reaction. The kinetics and product studies were performed in the Highly Instrumented Reactor for Atmospheric Chemistry (HIRAC) in the temperature range 268-344 K at 1000 mbar of air. The product measurements were used to determine the branching ratio of the reaction channel forming methoxy radicals, rCH3O. A value of 0.34 ± 0.05 (errors at 2σ level) was determined for rCH3O at 295 K. The temperature dependence of rCH3O can be parametrized as rCH3O = 1/{1 + [exp(600 ± 85)/T]/(3.9 ± 1.1)}. An overall rate coefficient of the self-reaction of (2.0 ± 0.9) × 10-13 cm3 molecule-1 s-1 at 295 K was obtained by the kinetic analysis of the observed second-order decays of CH3O2. The temperature dependence of the overall rate coefficient can be characterized by koverall = (9.1 ± 5.3) × 10-14 × exp((252 ± 174)/T) cm3 molecule-1 s-1. The found values of koverall in the range 268-344 K are ∼40% lower than the values calculated using the recommendations of the Jet Propulsion Laboratory and IUPAC, which are based on the previous studies, all of them utilizing time-resolved UV-absorption spectroscopy to monitor CH3O2. A modeling study using a complex chemical mechanism to describe the reaction system showed that unaccounted secondary chemistry involving Cl species increased the values of koverall in the previous studies using flash photolysis to initiate the chemistry. The overestimation of the koverall values by the kinetic studies using molecular modulation to generate CH3O2 can be rationalized by a combination of underestimated optical absorbance of CH3O2 and unaccounted CH3O2 losses to the walls of the reaction cells employed.

Combined effects of nozzle hole variation and piston bowl geometry modification on performance characteristics of a diesel engine with energy and exergy approach

This experimental work aims to address the challenges of waste management. Biomass waste is converted into useful fuel and considered as a replacement to conventional fuel in CI engines. In this context, the grape marc and grape pomace are crushed and further processed to produce grapeseed oil. The grapeseed oil is further trans esterified to produce grapeseed seed oil methyl ester. The present study aims in examining the effect of varying piston shapes and nozzle profile on energy and exergy rates of a CI engine run with grapeseed oil methyl ester (GSME) blended with cerium oxide nano particles. The CeO2 nano particles were suspended in the base fuel at a concentration of 100 ppm and stability tests were conducted. The experiments were performed on a single cylinder, water cooled diesel engine with rated power of 5.2 kW. The research work includes two additional piston shapes namely, toroidal and shallow deep and two additional nozzle profiles viz. 4 hole and 5-hole nozzle. The hemispherical shape and 3-hole nozzle were considered as the standard one. Energy and exergy analysis were done on the experimental data to understand the exergy associated with cooling water, exhaust gas and unaccounted losses. The energy and exergy rates show that increase in nozzle hole number, decreases the destructive availability of the system. The exergetic efficiency of 32.8% is higher proving that toroidal shape and 5-hole nozzle profile is comparatively better and suitable for effective engine operation. HC, CO and smoke emissions reduced considerably by 14.4%–30% by the engine modification. Brake thermal efficiency was improved from 28.2% to 31.02% for CI engine with biodiesel. The paper addresses the gap in fuel modification clubbed with engine modification using biomass waste derived fuel. Exergy and energy analysis further add value to this current experimental work.

Investigation of the limonene photooxidation by OH at different NO concentrations in the atmospheric simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber)

Abstract. The oxidation of limonene by the hydroxyl (OH) radical and ozone (O3) was investigated in the atmospheric simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) in experiments performed at different nitric oxide (NO) mixing ratios from nearly 0 up to 10 ppbv. For the experiments dominated by OH oxidation, the formaldehyde (HCHO) yield was experimentally determined and found to be (12 ± 3), (13 ± 3), and (32 ± 5) % for experiments with low (∼ 0.1 ppbv), medium (∼ 0.3 ppbv), and high NO (5 to 10 ppbv), respectively. The yield in an ozonolysis-only experiment was (10 ± 1) %, which agrees with previous laboratory studies. The experimental yield of the first-generation organic nitrates from limonene–OH oxidation is calculated as (34 ± 5) %, about 11 % higher than the value in the Master Chemical Mechanism (MCM), which is derived from structure–activity relationships (SARs). Time series of measured radicals, trace-gas concentrations, and OH reactivity are compared to results from zero-dimensional chemical box model calculations applying MCM v3.3.1. Modeled OH reactivity is 5 to 10 s−1 (25 % to 33 % of the OH reactivity at the start of the experiment) higher than measured values at the end of the experiments under all chemical conditions investigated, suggesting either that there are unaccounted loss processes of limonene oxidation products or that products are less reactive toward OH. In addition, model calculations underestimate measured hydroperoxyl radical (HO2) concentrations by 20 % to 90 % and overestimate organic peroxyl radical (RO2) concentrations by 50 % to 300 %. The largest deviations are found in low-NO experiments and in the ozonolysis experiment. An OH radical budget analysis, which uses only measured quantities, shows that the budget is closed in most of the experiments. A similar budget analysis for RO2 radicals suggests that an additional RO2 loss rate constant of about (1–6) × 10−2 s−1 for first-generation RO2 is required to match the measured RO2 concentrations in all experiments. Sensitivity model runs indicate that additional reactions converting RO2 to HO2 at a rate constant of about (1.7–3.0) × 10−2 s−1 would improve the model–measurement agreement of NOx, HO2, and RO2 concentrations and OH reactivity. Reaction pathways that could lead to the production of additional OH and HO2 are discussed, which include isomerization reactions of RO2 from the oxidation of limonene, different branching ratios for the reaction of RO2 with HO2, and a faster rate constant for RO2 recombination reactions. As the exact chemical mechanisms of the additional HO2 and OH sources could not be identified, further work needs to focus on quantifying organic product species and organic peroxy radicals from limonene oxidation.

Pitfalls and Protocols: Evaluating Catalysts for CO2 Reduction in Electrolyzers Based on Gas Diffusion Electrodes

The evaluation of catalysts on gas diffusion electrodes (GDEs) have propelled the progress of electrochemical CO2 reduction reaction (CO2RR) at industry-relevant activities. However, high experimental complexities exist in GDE-based flow electrolyzers, whereby various experimental factors can influence the evaluation of catalytic CO2RR performances. Not accounting for these experimental factors could result in inconsistent conclusions and thus hinder rational catalyst developments. This Perspective highlights a range of experimental factors that can affect the performance metrics for electrocatalysts. Specifically, the product faradaic efficiency can be influenced by the overestimation of the effluent gas flow rate, unaccounted losses of products, and unintended alteration of microenvironments. In addition, cathodic voltage can be inaccurately determined due to the unaccounted dynamic changes in uncompensated resistance. By raising awareness of these potential pitfalls and establishing appropriate protocols, we foresee a more meaningful benchmarking of catalytic performances across the literature.

Experimental studies on in-cylinder combustion, exergy performance, and exhaust emission in a Compression Ignition engine fuelled with neat biodiesels

In the last decade, the search for cleaner fuels like biodiesels is gaining wide popularity, and exergy analysis are widely used in design and performance evaluation to identify the various losses. In this study, three neat biodiesels are tested for energy and exergetic performance in a single-cylinder, four-stroke IDI diesel engine. The experiments are conducted for waste poultry fat biodiesel (WPFBD), palm oil biodiesel (POBD), and waste cooking oil biodiesel (WCOBD) at various loads by maintaining a fixed rpm of 1500. Parameters like exergetic efficiency, exergy destruction, and various heat loss factors are computed from the thermodynamic models. The in-cylinder combustion pressures, heat release rate, and fuel consumption are also measured. Results show that WCOBD dominates the other two biodiesels by achieving high exergetic efficiency (52.74%) and low exergetic destruction (3.74 kJ). The in-cylinder combustion pressures and net heat release for WCOBD show smoother combustion with better torque conversion. In contrast, POBD shows high fuel consumption and more unaccounted heat losses. Better utilization of heat input by converting it into useful work was achieved for WCOBD at 75 and 100% loads. Similarly, the exhaust emissions from WCOBD compared with diesel fuel at all the loads reveal that except for NOx, there is a drastic reduction of CO, UHC, and exhaust smoke.

An experimental study on biodiesel production and impact of EGR in a CRDI diesel engine propelled with leather industry waste fat biodiesel

The purpose of the predominant endeavor is the way of through an experiment aspect for the reticular effect of exhaust gas recirculation (EGR) on combustion, performance, emissions besides energy characteristic of common rail direct injection (CRDI) engine fuelled with leather industry waste fat biodiesel and diesel blends. Biodiesel was converted by the transesterification process from the raw fat oil extracted with leather waste fat feedstock. This work takes advantage of blends of both like B10, B20, B30 along with engines that were run with various EGR rates (5%, 10%, and 15%) to evaluate engine outcome parameters. The maximum in-cylinder pressure was examined with the blend B20 with EGR 5% rate about 6.65% higher than pure diesel fuel. The high heat release rate (HRR) was ascertained with the blend B30 with EGR 10% rate about 23.81% higher than neat diesel fuel. The brake thermal efficiency (BTE) for the blend B10 with EGR 5% rate is higher than other test conditions but 4.2% let down associated with simple diesel fuel. The nitrogen oxides (NOx) were lesser than the clean diesel fuel at all test fuels, the highest NOx emission reduction was achieved in blend B30 with EGR 15% rate of about 87.59% than neat diesel fuel operation. The smoke opacity increased by raising the EGR level, the combination B30 with EGR 5% rate displayed low smoke opacity about 64.5% lower than neat diesel fuel. The hydrocarbon (HC) emission was lower than neat diesel at a low EGR rate, the blend B10 with EGR 5% rate displayed the lowest HC emission about 85.71% decreased then neat diesel operation. The carbon monoxide (CO) emission displayed lower than neat diesel at low EGR rate, the blend B10 with EGR 5% rate displayed the lowest CO emission about 50% than neat diesel. As of energy analysis, it was noted that the heat equivalent to brake power and heat lost to engine cooling water is higher in diesel fuel than biodiesel blends and the heat lost to exhaust gases and heat unaccounted loss were lower in diesel than biodiesel blend. Finally, the TOPSIS optimization study was carried out for finding the optimum input conditions which could result in improved combustion, performance, and reduced emissions. The B30% blend with EGR 15% at full load achieved 1st rank with 0.849 relative closeness value. So, this operating condition was projected as the best prospect for the application of a CRDI diesel engine.

Multi-objective optimization of performance and emission characteristics of a CRDI diesel engine fueled with sapota methyl ester/diesel blends

This study examines the combined effect of compression ratio (CR) and exhaust gas recirculation (EGR) on combustion, performance, and emissions characteristic of a common rail direct injection (CRDI) engine fueled by sapota methyl ester (SME) and diesel blend. Biodiesel extracted from sapota fruits waste seeds through the transesterification process. This work utilised diesel-biodiesel blend B50% blend (D50SME50 by vol.), and the engine was run with different compression ratios (16, 17.5, and 19) and EGR rates (0%, 10%, and 20%) to evaluate engine outcome parameters. The result found that the ignition delay was reduced with an increased compression ratio. The high heat release rate (HRR) was ascertained with the CR 16 and EGR 10% rate, about 6.01% higher than diesel fuel. The highest in-cylinder pressure was observed with the CR 19 and EGR 0% rate, about 2.02% higher than diesel. The thermal brake efficiency (BTE) for CR 16 and EGR, 0% rate, is higher than other test conditions but 11.21% lower than neat diesel. The nitrogen (NOx) emission oxides for all the test conditions were lower than neat diesel. The highest NOx emission reduction was achieved in CR 16, and EGR 20% rate about 61.91% lower than diesel operation. The smoke opacity increased by increasing the EGR rate. The CR 17.5 and EGR 0% rate displayed lower smoke opacity, about 2.5% lower than diesel operation. The hydrocarbon (HC) emission was lower than neat diesel at all operating parameters. The CR 17.5 and EGR, 0% rate, displayed the lowest HC emission, about 44.82% decreased than neat diesel operation. The carbon monoxide (CO) emission displayed lower for the EGR 0% rate at all the compression ratios. The CR 16 and EGR 0% rate displayed the lowest HC emission, about 10.77%, than diesel operation. The energy analysis noted that the fuel energy input and energy for brake power and energy flown through the exhaust gases are higher in diesel fuel than biodiesel blend. The unaccounted losses were low in diesel than biodiesel blend. Finally, the TOPSIS optimization study was carried out to find the optimum input conditions to improve combustion, performance, energy, and reduced emissions. The B50% blend with CR 16 and EGR 20% at full load achieved 1st rank with 0.809 relative closeness value. So, this operating condition was projected as the best prospect for applying in a CRDI diesel engine.

Atmospheric photooxidation and ozonolysis of Δ&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;-carene and 3-caronaldehyde: rate constants and product yields

Abstract. The oxidation of Δ3-carene and one of its main oxidation products, caronaldehyde, by the OH radical and O3 was investigated in the atmospheric simulation chamber SAPHIR under atmospheric conditions for NOx mixing ratios below 2 ppbv. Within this study, the rate constants of the reaction of Δ3-carene with OH and O3 and of the reaction of caronaldehyde with OH were determined to be (8.0±0.5)×10-11 cm3 s−1 at 304 K, (4.4±0.2)×10-17 cm3 s−1 at 300 K and (4.6±1.6)×10-11 cm3 s−1 at 300 K, in agreement with previously published values. The yields of caronaldehyde from the reaction of OH and ozone with Δ3-carene were determined to be 0.30±0.05 and 0.06±0.02, respectively. Both values are in reasonably good agreement with reported literature values. An organic nitrate (RONO2) yield from the reaction of NO with RO2 derived from Δ3-carene of 0.25±0.04 was determined from the analysis of the reactive nitrogen species (NOy) in the SAPHIR chamber. The RONO2 yield of the reaction of NO with RO2 derived from the reaction of caronaldehyde with OH was found to be 0.10±0.02. The organic nitrate yields of Δ3-carene and caronaldehyde oxidation with OH are reported here for the first time in the gas phase. An OH yield of 0.65±0.10 was determined from the ozonolysis of Δ3-carene. Calculations of production and destruction rates of the sum of hydroxyl and peroxy radicals (ROx=OH+HO2+RO2) demonstrated that there were no unaccounted production or loss processes of radicals in the oxidation of Δ3-carene for conditions of the chamber experiments. In an OH-free experiment with added OH scavenger, the photolysis frequency of caronaldehyde was obtained from its photolytical decay. The experimental photolysis frequency was a factor of 7 higher than the value calculated from the measured solar actinic flux density, an absorption cross section from the literature and an assumed effective quantum yield of unity for photodissociation.

Вплив мікробіологічної біоплівки на технологічний процес цукрового виробництва

During the processing of frozen and thawed sugar beets, invert sugar, in particular glucose and fructose, accumulates in them. This is due to the process of hydrolysis of carbohydrates. As a result of temperature fluctuations, beets lose elasticity, and tissue walls become soft. The activity of microorganisms intensifies on damaged beets. In the sugar industry, harmful microorganisms enter the production with raw materials, water, unwashed soil and air. Under improper storage conditions of raw materials the rapid development of microorganisms begins leading to sugar loss. The microflora of raw materials in sugar production is due to spore-forming and non-spore-forming bacteria, as well as micromycetes. Processing in the production of such raw materials is complicated. This leads to non-rhythmic operation of the sugar factory, technological processes and metal corrosion of technological equipment. Sugar yield and quality are significantly reduced. An important factor is the protection from the formation of microbial biofilms. The article considers the problem of formation of microbial biofilm in the process of obtaining diffusion juice in the sugar industry. The structure of the biofilm and its stability over time are considered. Under the conditions of active biofilm formation, uncontrolled unaccounted losses of sucrose are observed. Under conditions of low-quality beet processing, biocides and enzymes must be used in the production. They reduce the contamination of intermediate products by microorganisms, greatly facilitate the technological process. They also allow you to predict unaccounted sugar losses and improve its quality and yield. The article considers the effect of different types of biocides on dextran, which is an example of the formation of microbial biofilms. The comparative characteristic of influence of biocides on dextran is given and their resistance is noted.

Nitrogen fertilizer management for mitigating ammonia emission and increasing nitrogen use efficiencies by 15N stable isotopes in winter wheat

Chemical nitrogen (N) fertilizer is essential for achieving high yield in winter wheat. However, the over-use of N fertilizer not only significantly reduces N use efficiencies (NUEs) but also leads to serious environmental concerns. An efficient N fertilizer management is thus urgently required for mitigating NH3 volatilization and increasing grain yield and NUEs of wheat. A 3-year field study using 15N stable isotopes was conducted to evaluate the fate of 15N-labelled fertilizer and to investigate the NH3 flux, grain yield, yield-scaled NH3 emissions and NUEs of various N application rates under two different application techniques comprising split-N method (basal N plus top-dressed N application) and pre-plant-only (without top-dressed N). Daily NH3 fluxes peaked within one week after basal N fertilizer application. Total NH3 volatilization, NH3 emission factor (EF) and yield-scaled NH3 emission were enhanced significantly with an increase in N application rates. Pre-plant-only N method greatly increased total NH3 volatilization, NH3 EF and yield-scaled NH3 emission by 43%, 58% and 63%, respectively, compared with split-N method when averaged across N application rates and years. The residual 15N in soil and the unaccounted 15N losses were greater under pre-plant-only N method and under high N application rate compared with split-N method and under low N application rate, respectively. Higher values of unaccounted 15N loss (nearly 50% of the total N applied) and residual 15N (27% of the total N applied) were the major contributors to lower NUEs, that could be predominantly attributed to the higher NH3 emission under elevated N application rate and pre-plant-only N method. Considering the overall environmental impact and yield performance, 120 kg N ha−1 in combination with split-N method could be recommended for improving the overall economic return and mitigating environmental pollution to ensure cleaner production of winter wheat.

Thermal balancing and exergetic performance evaluation of a compression ignition engine fuelled with waste plastic pyrolytic oil and different fuel additives

This study aims at evaluating the heat energy and exergy values of waste plastic oil (WPO) blended diesel mixed with different fractions of fuel additives (ethanol as oxygenated fuel additive and nano graphene as nano additive) with a view to establish the thermal balancing of a diesel engine analytically taking experimental data and comparing with neat diesel oil. The research engine used was a four stroke, constant speed, stationary, direct injected, single cylinder, water-cooled compression ignition engine tested at different loading conditions. The thermal balance was prepared in respect of work output, heat loss in cooling, heat loss in exhaust gas, heat loss in lubrication and additional unaccounted heat losses in order to measure the efficiency of the engine in agreement with thermodynamics energy principles. Three test fuels with same plastic oil and different fuel additives concentration (comprising of 80% Diesel+20%WPO, 60% Diesel + 20%WPO+20% Ethanol and 80%Diesel +20% WPO+100 ppm nano graphene) are prepared for the engine test. The addition of ethanol in WPO blended diesel fuel mixture contributes marginal increase in brake thermal efficiency, decrease in brake specific fuel consumption, higher exhaust gas temperature and lower exergetic efficiency as compared to that of diesel. Nano graphene added to WPO blended diesel enhanced its energy along with exergy efficiency values as compared to other fuel mixtures under higher operating load condition. Fuel exergy for this fuel was increased by 18.57% in comparison to diesel at highest load. However, Exergy destruction and exhaust exergy were decreased by 34.97% and 14.03% respectively in comparison to diesel at highest load. Moreover, exergetic efficiency was enhanced by 18.9% than diesel at maximum load condition.

Early Results of Liver Resection and Role of Extended Histology (LIREcH) Study

Introduction: Positive margin of the resected colorectal liver metastases (CRLM) is an independent negative prognostic factor. However, liver resection involves an unaccounted 5-6mm tissue loss due to the use of energy devices or CUSA. The aim of this study is to assess the correlation between the margin status on the specimen side(R1s) and that from the patient side (base of resection)(R1p) and its influence on the outcomes. Methods: In this prospective study, patients over 18 years undergoing resection of CRLM (< 5cm), with suspected close resection margins were included. Sample from resection base was collected using CUSA for the evaluation of R1p. Primary outcome was the correlation of R1s and R1p. Secondary endpoints were the rates of local recurrence, liver specific recurrence, overall morbidity, and post-operative hospital stay. Results: 45 specimens and the corresponding CUSA samples from the base from 26 patients were analysed. 82% patients received neo-adjuvant chemotherapy. RAS mutation was positive in 14% of patients. Among the 45 specimens, 28(62%) had margin clearance of < 1mm, 1-4mm in 15%, 5-6mm in 13%, >9mm in 20%. However, only 5/28(17%) had tumour cells on the patient side (R1p). Overall, one patient had liver specific recurrence at 8 months. None of the others had local recurrence. Median post-operative hospital stay was 6.4 days. Conclusion: Early results of this on-going study suggest poor correlation between R1s and R1p. Confirmation of the results from larger cohort might help in patient counselling, surveillance, and in pre-operative planning of the resection of bilobar metastases.

Exploring the Knowledge and Practice of Water Conservation Measures: A Case of Low-Cost Housing Setting in South Africa

The water crisis has reached a fever pitch in South Africa, with threats of ground zero and disruption of water supplies. The paper focuses on household knowledge and awareness of the water crisis and conservation efforts to reduce water consumption in a low-cost housing setting within the eThekwini municipality, KwaZulu-Natal, South Africa. A mixed method that consists of qualitative and quantitative phases was adopted to explore water practices. Focus group discussions were conducted with a representative sample of 22 people residing in the Waterloo area, situated north of Durban. Subsequently, the results from the discussions were used to design a questionnaire which was administered to 304 residents in the same location. Data was collected through an anonymised research questionnaire. The qualitative data was analysed using content analysis by generating codes to theme the data while descriptive analysis was performed on the quantitative data. In synthesising the results, three recurring key issues are identified, namely (1) access to knowledge; (2) community engagement as part of the solution; and (3) allocation of incentives. While participants had knowledge of water conservation practices, there was, however, a high amount of water consumption and high unaccounted water losses in the area. Although some of the participants held the view that providing incentives like free airtime and electricity could help influence water conservation, many were, however, in favour of installing water-harvesting facilities such as JoJo tanks. The study conclusively proposes economic nudging in the LCH areas as a cost-effective measure towards water conservation.