Admissible Limits Research Articles

Heavy Metal Pollutants Or Contaminant In Soil Samples Obtained From Wash Boreholes Within Pantisawa, Yorro L.G.A. Of Taraba State

The problem of environmental pollution and its compartments due to an increase in contamination as a result of the accumulation of heavy metals and microorganisms from soil has raised wide-spread of concerns in different parts of the nations and this has compromised the ability of the environments to foster life and render them an intrinsic value. Hence the study aimed to ascertain the level of environmental pollution in soil from wash borehole within Pantisawa Yorro Local Government Area of Taraba State, Nigeria. A total of 45 samples for soil were collected aseptically from the five different zones (Pantisawa Main Market YM, Kapazang YG, Dola YD, Kallau YK and Zabi YZ) of Pantisawa. The levels of trace metals in soil samples were determined using Atomic Absorption Spectroscopy (AAS) PG-990. The results were analyzed using SPSS Version 20. The soil samples result for these metals revealed that iron concentration was between 3000-4010mg/kg most especially for site SD which is higher than all other elements analyzed. Zinc ranges from 2.54-6800mg/kg which is above the standard as prescribed by WHO and FEPA in soil and also exceeded the dutch target values of (Zn: 50mg/kg and Cu: 30mg/kg) in some of the sampling sites. Nickel was between 8.47-19.09 mg/kg in soil samples, this is below the toxicity threshold limit of 35mg/kg for safe environment as stated by WHO. Arsenic ranges from 53.06mg/kg–141mg/kg, which is higher than the admissible limit of 50mg/kg in soil recommended by UNEP. The order of all the metal concentration in the areas was Fe>Zn>Mn>As>Pb>Cu>Mn>Co and Cd respectively. Based on this study, the high concentration of the metals such as Zn, As, Cd, Pb, and Co in some of these sites most especially SK, SM and SD within Pantisawa revealed that some of the soil samples collected from these areas were contaminated with heavy metal pollutants which may have serious health risk to the people using it for various activities. The higher concentrations of these toxic metals in soils need to be monitored regularly for heavy metal enrichment.

Impact of Lubumbashi's solar irradiation and ambient air on the quality and pharmacological value of root barks from four of the most used medicinal plants

BackgroundThe quality of medicinal plant products is highly dependent on drying conditions, which can lead to contaminated drugs, and/or with considerable phytochemical and pharmacological variations. In Lubumbashi (a very sunny city with polluted air), the used medicinal plants are exposed to the sun and ambient air for drying or on the sales premises, but the real impact of solar energy and ambient air on the quality and pharmacological value of exposed medicinal plant samples has never been studied. ObjectiveThis study seeks to determine the impact of solar irradiation and ambient air in Lubumbashi on the quality, and biological activities of samples from the most used medicinal plants in Lubumbashi/DR Congo. MethodsThe root barks of single-plant samples from Terminalia mollis M.A.Lawson, Securidaca longepedunculata Fresen, Oldfieldia dactylophylla (Welw. ex Oliv.) J.Léonard. and Phyllanthus muellerianus (Kuntze) Exell. were dried in the sun, oven, and shade respectively. Mineral and microbial contamination were assessed. In addition, phytochemical and pharmacological analyses were also done. ResultsSamples exposure to ambient air led to mineral contamination, with the appearance of highly toxic elements such as As, and a significant increase in others such as Al, Co, Cr, Cu, Ni, and Pb. Microbial contamination exceeded admissible limits in some samples and varied according to drying conditions and species, of which S. longepedunculata was the most contaminated. The levels of total phenols, flavonoids, and terpenoids varied significantly according to drying conditions and species. For example, in T. mollis, total phenols increased from 457.6 ± 2.33 to 536.4 ± 1.56 mg GAEq/g in fresh samples exposed to the sun for 10 days, total flavonoids increased from 455.2 ± 16.49 to 617.1 ± 14.29 mg QEq/g when dry samples were exposed to the sun for 10 days; total terpenoids decreased significantly compared to the shade-dried sample. Biological activity also varied according to species and experimental conditions. For example, an increase in activity against S. aureus (from 11.00 ± 1.00 to 17.33 ± 0.58 mm) was observed in the fresh sample of P. muellerianus exposed to sunlight for 10 days, while increases in hemozoin synthesis inhibitory (from 44.6 ± 3.9 to 52.7 ± 2.4 %) and antiradical activity (from 23.7 ± 0.7 to 29.5 ± 0.1 %) were observed in the fresh S. longepedunculata sample exposed to the sun for 5 days. ConclusionExposure of the studied medicinal plant samples to ambient air in the environmental conditions of Lubumbashi would result in worrying mineral contamination and drying of these samples in the sun in the above-mentioned region, in the oven, or the shade would result in variations, some of which are negative, in certain secondary metabolites and biological activities.

Оценка предельно допустимых концентраций тяжелых металлов в почвах с учетом взаимосвязей свойств почв

It has been proved in the work that admissible concentration limits of mobile fraction of heavy metals in the soils have to be additionally rated for the water- soluble fractions taking into consideration the rate of the ion transition into solution and soil deposit capacity, with respect to environment pH, as pH = 4,8 in the CH3COONH4 exudate basically does not appear in the soils. The admissible concentration limits have to be assessed due to the soil characteristics combination which determines heavily the concentration of heavy metal water-soluble fractions (efficient solubility of their deposits, effective constants of the ion exchange and effective constants of the complex instability). The correlation of water-soluble fractions of heavy metals depending on pH in the common black soils was: for Pb = -0,40; for Cd = -0,32; for Co = -0,39; for Ni = -0,47. The proportion of positively charged species not linked into complexes increases under the pollution augment in the soil. This way, PbL7PbL+ ratio was 0,33±0,01 in the check, under the pollution it was Pb - 0,08±0,01. The feedback systems on photosynthesis activity, sprout development, microbial flora change, genetic tests on drosophila are offered for the assessment of the heavy metal influence over the biotests. Keywords: HEAVY METALS, ADMISSIBLE CONCENTRATION LIMITS, BIOTESTS

Urban food waste for soil amendment? Analysis and characterisation of waste-based compost for soil fertility management in agroecological horticultural production systems in the city of Rosario, Argentina

Urban and peri-urban lands can be an important source of food production for localised and sustainable food systems, however, their soils can be of poor quality, degraded or damaged by anthropic activities, and little is known about their suitability or safety. This paper aims to contribute to this knowledge gap by assessing the soil remediation capacity and qualities of different types of compost made from urban and peri-urban organic wastes for agroecological food production. Prepared over the course of 2021, and used in 2022 for food growing, five different composts were observed and analysed, in two different farms in the city of Rosario, Argentina. Four raw materials generated largely by local industries were used to make the composts: chicken manure, rumen (cow’s stomachs), brewer’s bagasse (byproducts of the beer industry) and urban leaves collected from the municipality waste collection. These were mixed in different proportions (all reaching the 20–30 C/N ratio, typical of quality compost) to produce viable growing substrates where radishes and lettuces were grown. The aim of the study was to assess the possibility, quality and limitations to use locally available organic inputs for soil fertility management in agroecological farming, in the context of urbanisation and to assess pathways to develop closed-cycle agroecological agriculture at metropolitan level. Natural manure substrates (raw and composted) were analysed, as well as crops grown and fertilised with each of the substrates. The attributes and limiting factors of each substrate and their response to local soil conditions were compared and physicochemical, biochemical, and microbiological analyses were performed, including among others, the study of microbial biomass, biological activity, biophytotoxicity, pH, aerobic heterotrophs, nitrogen fixation, and the presence of antibiotics, agrochemicals and heavy metals. The results of the analyses show that all the composted materials improved the physical, chemical and biological properties. However, in some cases, pollutants were present even after composting. Analysis carried out on the vegetables generally indicate undetectable levels or levels below the admissible limits, demonstrating the filtering capacity of the different composts and the soil.

Aspects of the combustion variability analysis at an automotive engine fuelled with hydrogen

Over the last decades, the use of the alternative fuels was one of the main research activities for specialists in the field of internal combustion engines. The development of the modern automotive engines is constantly challenged by the more severe emission legislation. The engine emissions levels and the fuel efficiency are directly influenced by the engine operation, reproduction of the combustion phases from one cycle to other, cyclic dispersion during combustion process being important. In general, the use of alternative fuels in internal combustion engines provides an improvement of the energetic and pollution performance, or just a slight improvement of them, but the study of the combustion process must be completed with aspects regarding the cyclic variability. In particular, using this alternative fuel, a study of cyclic variation of the combustion process would be necessary in order to establish if the normal operation of the engine can be ensured. The paper presents some aspects of the analysis of the cyclic variability at a spark ignition engine fuelled with gasoline and hydrogen. During the engine operation at the regime of 2500 rev/min speed and 55% engine load, a number of 250 consecutive combustion cycles was recorded for classic fuel use and for hydrogen use. The coefficient of cyclic variation (CCV) or the coefficient of variation (COV) is determined for different combustion parameters such as maximum pressure, maximum pressure rise rate and mass fraction burned, defined by angles at which the conventional fractions of 10%, 50% and 90% of the heat of reaction is released. Thus, the values of the COV for maximum pressure (COV)pmax, maximum pressure rise rate (COV)dp/dα, angles of 10, 50 and 90% heat release as (COV)10%, (COV)50% and (COV)90% were calculated and compared with the admissible limit of 10%. The combustion variability analysis establishes the limits of the normal operation of the spark ignition engine fuelled with gasoline and hydrogen compared with the classic fuelling method.

Assessing Benzene and TVOC Pollution and the Carcinogenic and Noncarcinogenic Risks to Workers in an Industrial Plant in Southeastern Romania.

The article aims to analyze the pollution with Volatile Organic Compounds (VOC) emitted from the biggest refinery in Romania, using the daily and monthly series registered for two years in two sites on the industrial platform, and the carcinogenic and noncarcinogenic risks for workers at the industrial plant. Since the values of the basic statistics (minimum, maximum, and average) and outliers indicate that most recorded values exceed the maximum admissible limits established by law, the Peaks Over Threshold (POT) method was utilized to model the maximum values of the series and determine the return levels for benzene and total VOC (TVOC). Given the high values obtained for relatively short return periods, indicating potential danger for the workers, we assessed the noncarcinogenic and carcinogenic risks to benzene and TVOC exposure by computing the hazard index (HI) and lifetime cancer risk (LCR). The results indicate that 43.75% of the HI values are above 1, indicating a relatively high noncarcinogenic risk for different categories of workers. LRC indicates a high LRC for 93.75% of the workers in all considered categories exposed to TVOC.

Polyharmonic potential theory on the Poincaré disk

We consider the open unit disk D equipped with the hyperbolic metric and the associated hyperbolic Laplacian L. For λ∈C and n∈N, a λ-polyharmonic function of order n is a function f:D→C such that (L−λI)nf=0. If n=1, one gets λ-harmonic functions. Based on a Theorem of Helgason on the latter functions, we prove a boundary integral representation theorem for λ-polyharmonic functions. For this purpose, we first determine nth-order λ-Poisson kernels. Subsequently, we introduce the λ-polyspherical functions and determine their asymptotics at the boundary ∂D, i.e., the unit circle. In particular, this proves that, for eigenvalues not in the interior of the L2-spectrum, the zeroes of these functions do not accumulate at the boundary circle. Hence the polyspherical functions can be used to normalise the nth-order Poisson kernels. By this tool, we extend to this setting several classical results of potential theory: namely, we study the boundary behaviour of λ-polyharmonic functions, starting with Dirichlet and Riquier type problems and then proceeding to Fatou type admissible boundary limits.

Energy management strategy for a hybrid micro-grid system using renewable energy

This paper introduces an energy management strategy for a hybrid renewable micro-grid system. The efficient operation of a hybrid renewable micro-grid system requires an advanced energy management strategy able to coordinate the complex interactions between different energy sources and loads. This strategy must consider some factors such as weather fluctuations and demand variations. Its significance lies in achieving the overarching objectives of these systems, including optimizing renewable energy utilization, reducing greenhouse gas emissions, promoting energy independence, and ensuring grid resilience. The intermittent nature of renewable sources necessitates a predictive approach that anticipates the energy availability and adjusts the system operation. The aim of this study was to develop an energy management system for a hybrid renewable micro-grid system to optimize the deployment of renewable energy resources and increase their integration in the power system. Therefore, the main objective of this work was to develop an energy management strategy that controls the flow of energy between the hybrid micro-grid system and the load connected directly as well as the load connected to the utility grid using MATLAB/Simulink software. The second objective was to control the charging and discharging of the battery. The results show that the developed algorithm was able to control the energy flow between the hybrid micro-grid system and the utility grid and also to ensure a proper relation between the charging /discharging rate of the battery based on their operating conditions. In this application, the battery was charged at higher power. It was seen that a higher charging power enables to fully recharge the battery in a shorter amount of time than usual. The results have shown that it is possible to maximize the charging time by using a greater power and this algorithm ensures the state of charge (SOC) of battery to remain in the admissible limits (between 20 and 100%).

Power Quality Analysis of Photovoltaic Systems

This research analyses the quality of the electricity produced on photovoltaic systems connected to the power grid in the city of Cuenca (Ecuador). For this, an overview of the literature and the Ecuadorian, American, and European regulations concerning power quality was carried out to determine the regulatory parameters and admissible limits. From the quality records, it is concluded that, in general, there are no power quality problems, except for momentary current imbalances. In one of the cases, violations of voltage parameters, voltage unbalance, current unbalance and flicker were found. The recommended parameters to be included in the Ecuadorian quality standards are individual harmonic distortion and frequency have been registered.

Analysis of fluoride concentration in ground waters of Charkhi Dadri District, Haryana, India

The purpose of the present research was to assess the fluoride concentration of the groundwater in the Charkhi Dadri Tehsil and Baund Kalan Sub Tehsil of Haryana, which serves as the area’s main supply of drinking water. One hundred eight groundwater samples were collected either from handpumps, tubewells or wells and were tested for fluoride content. Fluoride concentrations ranged from 0.01 mg/l to 8 mg/l in Charkhi Dadri Tehsil, and the fluoride concentration of 9 out of 21 villages was found to be under 0.7 mg/ l. In Baund Sub-tehsil of Charkhi Dadri District in Haryana. All 21 villages in Baund Sub-Tehsil of Charkhi Dadri district had fluoride levels that were below the WHO’s highest admissible limit of 1.5 mg/l; however, Fluoride levels in 11 out of 87 villages/towns exceeded the permissible level in Charkhi Dadri Tehsil of Charkhi Dadri District, making them inadequate for drinking. Furthermore, skeletal and dental fluorosis is at an alarming level among nearby residents in these areas. The principal origins of fluoride in groundwater are assumed to be the abundance of fluoride-bearing minerals in the host rock, along with chemical characteristics like dissociation, dissolution and decomposition, in addition to their interaction with water. The suggested disciplinary measures to minimize fluoride contamination include dilution by blending, effective irrigation practices, artificial recharge and construction of well.

Nigerian Open and Distance Learning Students and the Mandatory National Youth Service Corps (NYSC) Scheme

The principal means of accessing admission into higher educational institutions in Nigeria is the Unified Tertiary Matriculation Examination (UTME) carried out by the Joint Admission and Matriculation Board (JAMB). The total number of candidates looking for admission into the different Nigerian institutions of higher learning has been on the increase over the years. The main motivation behind setting up any Open Distance Learning (ODL) institutions in Nigeria is to give a scope of chance to admittance to advanced education to students who, for one explanation or the other, really like to have their schooling in a more adaptable way. Moreover, the low admission limit of Nigerian universities for full time studies places a limit on the number of prospective learners who can be admitted into universities thereby making a monstrous hole between the people who want higher education and the framework accessible to cater for their necessities. The National Youth Service Corps (NYSC) scheme is an obligatory programme set up by the Nigerian government to include graduates of Nigerian educational tertiary institutions who are 30 years and below with the aim of promoting national unity and integration as well as to contribute to the accelerated growth of the national economy. However, graduates of open and distance learning institutions in the country do not take part in the NYSC programme. An attempt is made in this paper to investigate the level of preparedness and interests of ODL students and their disappointment in their exclusion from the programme. To achieve this, a descriptive survey research design was adopted for the study with a random sample of 201 respondents comprising 114 male and 87 female distant learners within the stipulated age for the NYSC scheme. A researcher-developed questionnaire was used to gather data from respondents. Four research questions were raised and three hypotheses were tested at 0.05 level of significance. Data gathered were analyzed and presented using figures, simple percentages, frequency tables and the Independent T-test. The findings revealed that 98% of respondents believe that they are prepared for the NYSC scheme, while 2% of respondents are not prepared. 99% are interested and 97% are disappointed at their exclusion from the scheme. No significant gender difference was observed in the level of preparedness, extent of interest and degree of disappointment in exclusion from the scheme among respondents. The study recommends a collaborative effort of ODL institutions and their counselling units in addressing anxieties and disappointments among students. The study also advocates a review of government’s policy on the NYSC scheme for possible inclusion of young graduates of ODL institutions in the scheme.

The Impact of Flexural/Torsional Coupling on the Stability of Symmetrical Laminated Plates

In this study, we will evaluate the effect of bending/torsion coupling on the buckling instability and free vibration behavior of symmetrical laminated plates. We will load these plates in-plane with bi-axial or uni-axial, uniform or non-uniform mechanical loads. To quantify this behavior, we’ll compare the results obtained with those of specially orthotropic symmetrical plates (where bending/torsion coupling is absent). A parametric study will be carried out by varying the plate’s aspect ratio, anisotropy ratio and/or lamination angle. The aim of these studies is to construct a planar loading margin for the plate while remaining elastically stable, and to determine a physically admissible limit where we can approximate the behavior of symmetrical laminates to that of specially orthotropic plates (easy to study). We will base ourselves on a Rayleigh-Ritz energy formulation of the problem because of the difficulty of finding closed-form solutions. Following validation of this formulation, a numerical survey of the results will be carried out to quantify the effect of bending/torsion coupling on the instability of this type of plate. Various conditions on the plate boundaries will be used.

Rail Wear Evolution on Small-Radius Curves under Mixed Traffic Conditions, In-Field Investigations

This paper’s aim is to assess the rail wear evolution of railway tracks under mixed traffic conditions for sharp curves. Field investigations were conducted over a period of five years, at 800 points on a rail track, for two curves that underwent maintenance interventions: sleeper and rail replacements during measurements. Lateral and vertical wear measurements were monitored with mechanical instruments, and Prokon and Sap simulations were performed in order to determine the bearing capacity of the rail at different stages of wear. The results obtained after five years of investigation show wear speed propagation on the outer rail of small-radius curves as well as the bending moments and admissible stress variation. At more than 18% of the studied points, lateral wear exceeded the maximum admissible limit, showing a faster propagation speed on the outer rail compared to the vertical wear rate.

The ambient noise level in the city of Galati and surroundings

The intense and sustained noise to which we are subjected can cause disorders of the auditory system. It affects especially those who suffer from heart problems, but it also has dramatic consequences on the nervous system. It can cause stress, depression, sleep disturbances, cognitive problems and reduced ability to concentrate. The city of Galati is located in the southeastern part of Romania, in the southeastern part of the county with the same name. Galati ranked fifth in terms of noise pollution and unfortunately the local authorities do not run any noise reduction or control program. Through this paper we want to join those who sound the alarm to the authorities to take concrete measures in order to manage and control noise pollution. Data were collected in different areas of the city of Galati and its surroundings. Equivalent noise level was determined with a professional digital acoustic sound level meter with two frequency filters: “A” and “C”. The device can record sound values between 30 dB-130 dB in the 31.3 Hz and 8 kHz range. In general, the sound level exceeded the maximum admissible limit or came close to this value.

Identification of the damage mechanism in orthopaedic implant. Case study including the biomechanical analysis

Implant breaking destabilizing the fracture may be caused by its structural defect, inappropriate use, or massive overloads. We present the patient, who broke the plate stabilizing comminuted clavicular fracture at the sixth postoperative week due to the, primarily reported, simple loading of the limb that should not exceeded admissible limits. Macroscopic examination excluded its manufacturing defect of an explant, but revealed areas of fatigue fractures, as well as anterior and inferior bending of its edges. Mechanical analysis proved sufficient material durability. Those findings clearly showed that the plate broke in consequence of repetitive overloads exceeding its durability. Patient, when acquitted with those results, confessed that the plate broke, while fishing. Moreover, he reported an episode of alcohol overuse that could contribute to implant failure bringing the risk of additional injury. Biomechanical analysis confirmed that mechanical loads throwing the spinner exceed values adequate for plate breaking. Thus, the real circumstances of the complication seem to be unveiled pointing out to facts that some patients disobey postoperative recommendations to avoid overloading of stabilized extremity, thus participating actively in this type of complications, that they dissemble the real circumstances of the complications, and that they may exhibit risky and irrational behavior. Basing on the presented case we concluded that in some cases plaster cast immobilization supporting stabilized fracture may be beneficial precluding banned activities and preventing from secondary injuries reducing the risk of postoperative complications.

Do the pollution related to ozone pose a real health threat to the population in Upper Silesia?

Abstract Background Air pollution is a leading environmental factor, that influences human health. Although Ozone plays crucial role in the screening Earth's surface and lower atmosphere layers from the ultraviolet radiation, the troposphere ozone is proved to have negative effect on human body. Long-term exposure to a higher ozone concentration is related to a decrease in life expectancy. Objectives The objective of this study was the measurement-based assessment for determining whether the concentrations of ozone is within admissible limits or exceeded in Silesia province (5 million agglomeration) and therefore pose a threat to the local population together with the levels of PM2.5 and PM10 significantly exceeded at the same time. Material and methods The data provided by the Voivodship Inspectorate for Environmental Protection in Katowice for period 2015-2022 was used in the statistical analysis. The received data constitutes the result of 8-hour concentrations of ozone in selected air monitoring stations of Silesian province. The locations of 3 monitoring stations were found useful for the aim of this research; one site is situated in rural background area, another one is located in medium - sized city and the Katowice station is representative for urban background situation. Results The alarm level hasn't been exceeded in indicated measurements stations in Silesian Voivodship in period 2015-2022 (averaging time 1 hour: 240 µg/m3 four 3 hours). The target level has been exceeded in 2015-2017, in all three measurements stations and in the following years in one station (in Zloty Potok - 2018 and in Katowice -2019). Each year the largest number of exceedances occurred in August. Conclusions The results clearly indicate lack of hazards for general population health in terms of increased concentrations of ozone in the city centres and outside in Upper Silesia agglomeration and the situation even improved in last years. We identified the main sources of ozone. Key messages • The troposphere ozone is proved to have negative effect on human body, long-term exposure to a higher ozone concentration is related to a decrease in life expectancy. • The results clearly indicate lack of hazards for general population health in terms of increased concentrations of ozone in the city centres and outside in Upper Silesia agglomeration.

Petrography, Geochemistry and Mineralogy of Serpentinite Rocks Exploited in the Ophiolite Units at the Calabria-Basilicata Boundary, Southern Apennine (Italy)

A multi-analytical study on serpentinites in the ophiolite units (Calabria-Basilicata boundary, southern Apennines) was carried out on samples collected from a serpentinite quarry, locally called “Pietrapica”, which sitsin the Pollino UNESCO Global Geopark. Optical microscopy observations revealed the petrographic characteristics, ICP-MS was used to assess the chemical composition while EMPA mineral chemistry, Raman spectroscopy and X-Ray Powder Diffraction and were used altogether to trace the mineral composition of the rocks. Petrography revealed that serpentinites from Pietrapica quarry are essentially composed of serpentine group minerals, amphibole and carbonate minerals with lower abundances of talc and Cr-spinel. Raman spectroscopy and X-ray powder diffraction analysis clearly allowed to establish that carbonate minerals, serpentine and amphibole-like minerals, are the dominant phases, followed by 2:1 phyllosilicate. Electron probe microanalyses were carried out on different minerals in serpentinites samples including serpentine, amphibole, chlorite, clinopyroxene, magnetite, talc, quartz and titanite which are often associated with carbonate veins. Bulk geochemistry is dominated by major oxides SiO2, MgO and Fe2O3 while the most abundant trace elements are Ni and Cr. Chemical analysis showed that some heavy metals in the studied serpentinites such as Ni and Cr, are beyond the maximum admissible limits for Italian normative for public, private and residential green as well as for commercial and industrial use representing a potential environmental concern. Anyway, some of these heavy metals have been recently listed by Europe as critical raw materials and therefore, the Pietrapica abandoned quarry could represent a new resource considering their economic potentiality.

Effect of liner thermal properties and liner pre-cooling on the thermal management of fast-filling of hydrogen tanks

In transportation applications, filling high pressurised hydrogen tanks within a few minutes implies a fast and large temperature increase that can compromise the structural integrity of the storage system and the safety of the process. Common approaches to control this temperature increase mainly involve hydrogen pre-cooling using complex and energy-demanding refrigeration systems. This study proposes and assesses alternative and energy efficient thermal management strategies for fast filling of hydrogen tanks including the modification of the liner's thermal properties and the use of existing on-board refrigeration systems. The analysis is performed by means of a Computational Fluid Dynamics model validated against experimental observations. Results show that proposed solutions provide a robust and efficient alternative to hydrogen pre-cooling, potentially simplifying the hydrogen supply system, reducing its associated energy demand, maintaining the hydrogen temperature below admissible limits and increasing the state of charge of the tank.

A high-throughput UHPLC-MS/MS method for the determination of eight anti-tumor drugs in plasma

Rapidly developing UHPLC-MS/MS bioassays with high throughput and quality are challenging yet desired in routine clinics. Methods & resultsA high-throughput UHPLC-MS/MS bioassay has been built for simultaneously quantifying gefitinib, ruxolitinib, dasatinib, imatinib, ibrutinib, methotrexate, cyclophosphamide and paclitaxel. After the protein precipitation with methanol, samples were separated on an Acquity BEH C18 column following a gradient elution system with methanol and 2 mM ammonium acetate in water at 40 °C with a run time of 3 min (flow rate 0.4 mL/min). Mass quantification in the positive ion SRM mode was then performed with electrospray ionization. The method of specificity, linearity, accuracy, precision, matrix effects, recovery, stability, dilution integrity and carryover were all validated as per the guideline of the China Food and Drug Administration whose values met the admissible limits. Application of the bioassay to therapeutic drug monitoring revealed important variability in the studied anti-tumour drugs. ConclusionThis validated approach was shown to be reliable and effective in clinical management, being a valuable support in therapeutic drug monitoring and subsequent individualized dosing optimization.

Relevance of Soil Heavy Metal XRF Screening for Quality and Landscaping of Public Playgrounds.

Heavy metals have become widespread urban pollutants, exposing vulnerable age groups such as children to potential risk. Specialists need feasible approaches that can routinely assist them in customizing options for sustainable and safer urban playgrounds. The aim of this research was to explore the practical relevance of the X-ray Fluorescence (XRF) method from the perspective of landscaping specialists, and the practical significance of screening for those heavy metals that currently present elevated levels across urban environments Europe-wide. Soil samples from six public children's playgrounds of different typologies from Cluj-Napoca, Romania, were analyzed. The results indicated that this method was sensitive to identifying thresholds stipulated in legislation for the screened elements (V, Cr, Mn, Ni, Cu, Zn, As, and Pb). Coupled with the calculation of pollution indexes, this method can serve as a quick orientation in landscaping options for urban playgrounds. The pollution load index (PLI) for the screened metals showed that three sites displayed baseline pollution with incipient deterioration in soil quality (PLI = 1.01-1.51). The highest contribution to the PLI among the screened elements, depending on the site, was due to Zn, Pb, As, and Mn. The average levels of the detected heavy metals were within admissible limits according to national legislation. Implementable protocols addressed to different categories of specialists could help to transition towards safer playgrounds and more research on accurate cost-effective procedures to overcome the limitations of existing approaches is currently needed.