Allowable Limits Research Articles

Method Development and Validation for the Simultaneous Estimation of Lobeglitazone Sulphate and Glimepiride by HPLC Method.

A simple, precise, and accurate reverse-phase high-performance liquid chromatography (RP-HPLC) method was developed for the simultaneous estimation of lobeglitazone sulfate and glimepiride in bulk and tablet dosage forms. The method involved selecting various chromatographic parameters. Specifically, a new method was developed using a 250 mm × 4.6 mm (HSS) reverse-phase C18 column with 5 µm particle size (Shim-pack C18, 250 × 4.6 mm; 5 µm). The mobile phase consisted of 40 volumes of phosphate buffer (pH 3) and 60 volumes of acetonitrile, with methanol as the diluent, running as an isocratic elution. The flow rate was set at 1.0 mL/min, and UV detection was performed at 254 nm. The injection volume was 2 µL, and the total runtime was 10 minutes. The recoveries for lobeglitazone sulfate were found to be in the range of 101% to 100.6%, while those for glimepiride were in the range of 101.5% to 100%. The method’s accuracy is evident from these results. The inter-day and intra-day precision of the new method were both below the maximum allowable limit (RSD% ≤ 2.0), as per International Council on Harmonisation (Q2 R1) guidelines. The method exhibited a linear response, with correlation coefficient (r2) values of 0.9972% for pioglitazone and 0.998 for glimepiride. The validation parameters, such as accuracy, precision, linearity, specificity, stability in the analytical solution and robustness, met the acceptance criteria. Hence, this method can be effectively used for the simultaneous estimation of lobeglitazone sulfate and glimepiride in both bulk and pharmaceutical dosage forms.

Impact of xylene exposure during organogenesis on foeto-placental efficiency and foetal viability: Exploring its association with oxidative stress-induced inflammation and apoptosis in utero.

The potential maternal and foetal toxicity resulting from exposure to xylene at or below the allowable limit of 100 ppm during gestation is not thoroughly studied. The aim of this study was to investigate maternal and foetal outcomes following prenatal exposure to xylene during organogenesis. Pregnant Sprague Dawley (SD) rats were administered intraperitoneal (IP) corn oil (vehicle), 100, 500, and 1000 parts per million (ppm) of xylene from gestational day (GD) 6 until GD17. Clinical signs, maternal weight gain, and food consumption were recorded daily. A caesarean hysterectomy was performed on GD21 to assess the reproductive and foetal outcomes. Exposure to 1000 ppm of xylene caused a significant decrease in the maternal body weight and food consumption, and an increase in intrauterine foetal deaths. Foetal assessment revealed a significant decrease in foetal weight in both male and female foetuses of female rats treated with 500 and 1000 ppm. Male placental weight was significantly decreased in all xylene-treated groups, while 1000 ppm xylene significantly decreased female placental weight. Histologically, marked uterine inflammatory lesions, fibrosis of the liver and renal tissues, as well as increased placental glycogen content were observed. Immunohistochemistry revealed a significant increase in lipid peroxidation and apoptotic markers. Thus, the foeto-maternal toxicities of xylene have been shown to be mediated by a systemic inflammatory response that exacerbates intrauterine oxidative stress and impairs foeto-placental transfer, leading to an increase in foetal mortality.

Requirements for partial turbulence simulations using nondimensional turbulence energy contributions

Quantifying turbulence effects is crucial for understanding building aerodynamics and for ensuring accurate wind tunnel test methods. This is especially important in wind tunnel methods that require post-experiment adjustments because approximate wind fields are used, such as the Partial Turbulence Simulation (PTS) approach. Understanding and analyzing these effects enables load adjustments since the PTS method only requires matching the high frequency portions of the upstream spectra of the longitudinal velocity component in model and full-scale. However, the limits for which the PTS method is applicable are unclear in terms of the allowable range of wind field characteristics that can be used in the wind tunnel simulation. To address this, the paper utilizes two nondimensional parameters, one representing the small-scale turbulence energy, ES, and the other the large-scale turbulence energy, EL, to elaborate the aerodynamic effects of turbulence intensity and integral length scales in the upstream wind. The results show that the maximum allowable mismatch ratio of integral length scales and of Jensen numbers between model and full-scale simulations depend on the target small-scale turbulence energy and the maximum allowable deviation of small-scale energy. By quantifying the effects of ES and EL on area-averaged pressure coefficients, the allowable limits are identified for wind tunnel test parameters that lead to negligible differences in the resultant pressure coefficient statistics in regions of separated-reattaching flow on the roof of a low-rise building.

Clinical Decision-Making Suffers from Inequivalent Measurement Results and Inadequate Reference Intervals.

Appropriate clinical decision-making relies on the interpretation of equivalent measurement results in the context of valid clinical decision limits. Besides guideline-based decision limits, reference intervals (RIs) are commonly used to discriminate between abnormal results and results from "healthy" individuals. This study evaluated the suitability of RIs in light of the analytical bias for laboratories in the Netherlands using one standardized, one harmonized, and one unharmonized measurand (creatinine, hemoglobin, and ferritin, respectively). Three types of data were collected: (a) external quality assessment (EQA) performance data from the Dutch Foundation for Quality Assurance in Laboratory Medicine (SKML); (b) the RIs reported by laboratories for a 55-year-old female; and (c) harmonized RIs established by using unique routine patient results using RefineR. Routinely used RIs (b) were compared to the harmonized RIs (c) and evaluated in combination with the analytical bias at the lower and upper reference limits. Laboratories reported a variety of routinely used RIs that were inconsistent with the analytical bias, with differences between measurement procedures. The use of assays that perform within allowable bias limits does not automatically guarantee that the appropriate RI is used, allowing potential for structural misinterpretation of important diagnoses in patients. The use of RIs that are inconsistent with the analytical bias causes unnecessary between-laboratory differences in clinical decision-making. Adopting harmonized RIs facilitates similar interpretation of results across facilities. Harmonized RIs can be adopted immediately if the observed bias is acceptable or eliminated, or after standardization/harmonization of measurands without complete metrological traceability.

Heavy metal contamination in soil and food crops and associated human health risks in the vicinity of Iringa Municipal dumpsite, Tanzania

Heavy metal contamination and potential risks to human health related to consuming major food crops near Iringa Municipal dumpsite are presented. Soil samples, maize (Zea mays L.) and common beans (Phaseolus vulgaris L.) were collected downslope around the dumpsite during wet season. Soil samples were analyzed using Energy-Dispersive X-Ray Fluorescence (EDXRF) while crop (maize and beans) samples were analyzed using Flame Atomic Absorption Spectrophotometer (FAAS). The potential health risks associated with human exposure to heavy metals in maize and common beans was evaluated according to the method prescribed by the United States Environmental Protection Agency. The concentrations Cd (3.25–10.78 mg/kg), As (1.84–10.98 mg/kg) and Ni (71.74–55.10 mg/kg) in soil samples exceed the maximum allowable limits set by Tanzania Bureau of Standards (TBS). The average heavy metal concentration in food crops followed the trend Cd, As < Cr, Pb < Ni < Cu < Mn < Zn with Pb in maize (0.96 mg/kg) and common beans (0.81 mg/kg) above FAO/WHO regulatory standards of 0.3 mg/kg. This implied health concerns to consuming food crops grown in the vicinity of the dumpsite. Further, lifetime–incremental cancer risk (ILCR) assessment suggest that consuming maize and common beans from the study area could increase the risk of both cancer and non-cancerous diseases in both adults and children. However, the degree of ILCR in children was noticeably higher (1.0 × 10–2) than in adults (5.10. × 10–6) for Pb in common beans. Therefore sustainable waste management should be stressed and continuous monitoring of environments around dumpsites is crucial to mitigate the negative impacts on public and environments.

Revolutionizing Waste Management: Solidification of Landfill Leachates Using Alkali-Activated Slag

AbstractLandfill leachate is a highly hazardous effluent characterized by a high concentration of recalcitrant pollutants, presenting a significant environmental challenge. This study investigated the solidification of landfill leachate contaminants using sodium hydroxide-activated Granulated Blast Furnace Slag (GBFS). The stability of the resulting geopolymer was evaluated through unconfined compressive strength and leaching tests. Optimal curing conditions were identified as 7 days at a sodium hydroxide concentration of 12 M, achieving an unconfined compressive strength of 45.738 MPa at a liquid-to-solid ratio of 15%. A linear relationship was observed between the liquid-to-solid ratio and flow workability, with maximum flow workability evidenced by an average diameter of 242 mm at a liquid-to-solid ratio of 0.25. However, a minimum liquid-to-solid ratio of 0.15 was necessary to obtain a workable mortar. The produced geopolymers were characterized using X-ray Fluorescence (XRF) for mineralogical analysis, Scanning Electron Microscopy (SEM) for morphological examination, and the Toxicity Characteristic Leaching Procedure (TCLP) for leaching tests. The findings demonstrated the successful solidification of landfill leachate using GBFS geopolymer. The leachability tests revealed that the geopolymer did not release metals in concentrations exceeding the allowable limits set by the United States Environmental Protection Agency (USEPA), indicating effective encapsulation of the pollutants within the geopolymer matrix. Furthermore, the resultant geopolymer brick is eco-sustainable and can be classified as a green construction material.

Assessing Heavy Metal Accumulation in Urban Plants: Implications for Environmental Health and Traffic-Related Pollution in Al-Diwaniyah City, Iraq

This study aimed to compare the ability of five plant species, including (Conocarpus erectus, Acacia sensu lato (s.l.), Melaleuca viminalis, Dodonaea viscosa and Lantana camara) to absorb and accumulate heavy elements in their tissues, which were grown in the central islands in the city of Diwaniyah. This included areas of street in front of the medical college, Umm Al Khail First Street, Umm Al-Khail Street, near Abbas Attiwi Bridge, Al-Adly Street in the Euphrates District, and Clock Field Street, respectively. Results showed that soil samples S1 and S3 were contaminated by Pb, and the rest of the sites were contaminated with nickel only. This indicates through the table findings a rise in these heavy metals’ concentrations with a rise in traffic momentum. Thus, the Pb concentrations in the growing plants’ shoot parts with respect to this research had surpassed the allowed critical limit of 5.00 mg.kg-1 dry matter, in which the highest value was recorded at the site with respect to S3 as well as S2. Meanwhile, the findings indicate that Cd concentrations in S3 and S1 had increased and exceeded the allowable limit of 0.20 mg.kg-1 dry matter. In the meantime, the nickel concentrations were within the permissible limits of 67.90 mg.kg-1 dry matter. The Zn concentration exceeded the permitted limits of 60.00 mg.kg-1 dry matter except for plants (Acacia s.l. and Lantana camara) in sites S5 and S2. The results confirmed that the values of Heavy Metals Bioaccumulation Coefficient (BAC) for most of the study elements had recorded the highest value in the Dodonaea plant for Zn, Cd, and Pb, except for Ni. It was more accumulated in the Melaleuca viminalis plant, which indicates the superiority of the Dodonaea plant in accumulating Pb, Cd, and Zn over the rest of the study plants, as they took the following order: Lantana camara &lt; Acacia s.l. &lt; Conocarpus erectus &lt; Melaleuca viminalis &lt; Dodonaea viscosa. The best plants accumulated nickel in the following order: Acacia s.l. &lt; Lantana camara &lt; Conocarpus erectus &lt; Dodonaea viscosa &lt; Melaleuca viminalis.

Dynamic Characteristics of LIT Girder Railway Bridges

This study analyzed the dynamic characteristics of railway bridges with low-weight, innovative truss (LIT) girders and evaluated their dynamic behavior under general and high-speed railway operating conditions. A dynamic analysis was performed considering various variables, including the span length (30, 35, 40, or 45 m), track (single or double), main girder type (three or five girders), track type (concrete or ballast), and train type (KTX, HEMU, freight train, Mugunghwa, or express EMU). The train load was modeled as a moving concentrated load, and the damping ratio was applied according to railway design standards. The results of the dynamic analysis showed that in most cases, railway bridges with LIT girders met the allowable criteria for vertical deflection, vertical acceleration, and warping. However, in the case of a 30 m span bridge, the vertical acceleration exceeded the allowable limit at a specific speed of the HEMU-430X high-speed train. The results of this study can be used to evaluate the applicability of LIT girders in railway bridges and provide useful information for future design and construction.

A simplified analytical solution of pipeline response under normal faulting

Buried pipelines are one of the critical lifeline structures, and the evaluation of pipeline performance under seismic faulting is essential for protection of pipeline networks. This paper explores an analytical solution incorporating implementation of Winkler models around a beam-type structure using the finite difference method to evaluate the pipeline response under normal faulting. The effectiveness of the analytical solution is assessed by comparing the calculated pipe strains with centrifuge and full-scale laboratory testing measurements. Subsequently, the effect of pipe size, faulting condition, and burial condition on pipe response are investigated. It can be found that a pipeline with a smaller pipe wall thickness or larger pipe diameter is generally more prone to failure. Larger pipe wall thickness or lower D/t ratio should be used for pipe design crossing an active fault. In geotechnically problematic areas, shallow burial depth and less stiff soil with lower modulus are recommended to reduce the probability of exceedance of allowable limit states due to normal faulting. In the end, empirical functions relating to critical D/t ratio are proposed to evaluate the critical states of fault displacement, burial depth, and spread of fault rupture with different diameter-to-thickness ratio considering the controlled limit of failure modes.

Efficiency of acid mixtures for mitigating the radioactive contaminants in phosphogypsum

This present work aims to mitigate the radioactive contaminants in Phosphogypsum (PG), a by-product generated from phosphate rock processing, by applying a new chemical additive before precipitation to repurpose it for construction materials. PG contains different concentrations of rare earth elements, trace elements, and radioactive nuclides, such as 226Ra derived from phosphate rock (PR), which could cause environmental and health risks if not properly managed. In this context, a new approach is suggested, requiring the addition of a specific combination of concentrated sulfuric acid and nitric acid or hydrochloric acid. Gamma spectroscopy has been used to determine the activity of 226Ra, which is successfully reduced by about 49 %, decreasing from 831 to 424 Bq/kg. Several radiological parameters have been calculated, including radium equivalent activity, Raeq = 437 Bq/kg, which is found to be quite close to the allowable limits for construction (370 Bq/kg). The results of the proposed approach seem to be an effective means of reducing the activity of PG, leading to enhanced environmental responsibility and adherence to regulations in the phosphate sector.

Design, construction, and calibration of a weighable lysimeter for measuring water requirements of field crops for data-scarce areas of Ethiopia

A simple weighable lysimeter was designed, constructed, and calibrated for measuring the water requirements and crop coefficients of shallow-rooted crops. It has a portable weighing mechanism to quantify changes in soil moisture content. The weighing mechanism consists of a horizontal steel bar, a hydraulic car jack, both ends hooked vertical steel bars, a stand, and a digital weighing balance. As the lysimeter's inner tank, a plastic drum with a 55 cm diameter that yields 0.24 m2 of internal area was used. A performance test was conducted, and a rating curve was developed at the beginning of the growing seasons in 2023 and 2024 to evaluate the sensitivity of the weighing mechanism in determining crop water use. Linearity, repeatability, and measurement uncertainty tests were conducted. The linearity error was ±0.04 kg and ±0.03 kg for the years 2023 and 2024, respectively, which is within the allowable limit. The weighing system repeats the measurement perfectly with no error (repeatability error was zero). The combined uncertainty of the measurements was 0.023 kg, representing the cumulative effect of individual errors. The lysimeter weighing system is capable of detecting variations in mass as small as 0.2 mm of moisture content. Therefore, the developed lysimeter can be used to determine water requirements and crop coefficients of shallow-rooted crops for the design and management of irrigation in data-scarce areas of Ethiopia.

Exploring the Structural Response of High-Rise Buildings using Fuzzy Logic and Genetic Algorithms

Exploring the dynamic behaviour of high-rise buildings presented a critical challenge. In this study, Fuzzy Logic and Genetic Algorithm (FLGA) were employed to comprehensively investigate the structural response of high-rise buildings (HRBs) for adaptive vibration control systems employing semiactive damper devices. The study integrated a fuzzy logic inference system with a Genetic Algorithm (GA) to create FLGA, which was then employed in a 3-story shear building under real earthquake conditions and multi-dimensional wind loads. The analytical model for a semi-active tuned mass damper (STMD) was examined and evaluated before integrating it into the proposed FLGA system. The results indicated that FLGA reduced story acceleration by an average of 20% and story drift by approximately 50% while efficiently controlling the structure within allowable movement limits and resident comfort criteria under multi-directional wind loads. The suggested optimal controller mitigated both displacement and acceleration responses by 15 to 20% without amplification. The study demonstrated FLGA's effectiveness as a model-free control strategy for managing structural response uncertainties.

Mandibular biomechanics rehabilitated with different prosthetic restorations under normal and impact loading scenarios

BackgroundRestorative treatment options for edentulous patients range from traditional dentures to fixed restorations. The proper selection of materials greatly influences the longevity and stability of fixed restorations. Most prosthetic parts are frequently fabricated from titanium. Ceramics (e.g. zirconia) and polymers (e.g. PEEK and BIOHPP) have recently been included in these fabrications. The mandibular movement produces complex patterns of stress and strain. Mandibular fractures may result from these stresses and strains exceeding the critical limits because of the impact force from falls or accidents. Therefore, it is necessary to evaluate the biomechanical behavior of the edentulous mandible with different restorations under different loading situations.ObjectiveThis study analyzes the biomechanical behavior of mandibles after four prosthetic restorations for rehabilitation under normal and impact loading scenarios.Material and MethodsThe mandibular model was constructed with a fixed restoration, which was simulated using various materials (e.g. Titanium, Zirconia & BIOHPP), under frontal bite force, maximum intercuspation, and chin impact force. From the extraction of tensile and compressive stresses and strains, as well as the total deformation of mandible segments, the biomechanical behavior and clinical situations were studied.ResultsUnder frontal bite, the anterior body exhibited the highest tensile (60.34 MPa) and compressive (108.81 MPa) stresses using restoration 4, while the condyles and angles had the lowest tensile (7.12 MPa) and compressive (12.67 MPa) stresses using restoration 3. Under maximum intercuspation, the highest tensile (40.02 MPa) and compressive (98.87 MPa) stresses were generated on the anterior body of the cortical bone using restoration 4. Additionally, the lowest tensile (7.7 MPa) and compressive (10.08 MPa) stresses were generated on the condyles and angles, respectively, using restoration 3. Under chin impact, the highest tensile (374.57 MPa) and compressive (387.3 MPa) stresses were generated on the anterior body using restoration 4. Additionally, the lowest tensile (0.65 MPa) and compressive (0.57 MPa) stresses were generated on the coronoid processes using restoration 3. For all loading scenarios, the anterior body of the mandible had the highest stress and strain values compared with the other segments. Compared to the traditional titanium restoration.2, restoration.1(zirconia) increases the tensile and compressive stresses and strains on the mandibular segments, in contrast to restoration.3 (BIOHPP). In addition, zirconia implants exhibited higher displacements than the other implants.ConclusionIn the normal loading scenario, the tensile and compressive stresses and strains on the mandible were within the allowable limits when all restorations were used. Under the chin impact loading scenario, the anterior body of the mandible was damaged by restorations 1 and 4.

Uptake and translocation of cadmium and trace metals in common rice varieties at different growth stages.

Rice (Oryza sativa) is an important nutritional grain for the majority of Asian countries, but it is also a major source of cadmium (Cd) accumulation. A pot experiment was carried out to investigate the Cd uptake and translocation of high Cd (IR-50) and low Cd (White Ponni) rice cultivars in Cd-contaminated soils. The findings revealed that Cd impacts on rice development and growth differed depending on rice cultivars. Soil Cd levels in the seedling stage exceeded the critical levels (3-6mgkg-1) only 5.0mgkg-1 Cd treatment for the IR-50 (7.47mgkg-1). At higher Cd treatments (1.0 and 5.0mgkg-1), morphometric characteristics and yield of grains showed a declining and increasing trend in both rice varieties, respectively. The accumulation of Cd was higher in soil and roots during seedling and tillering stages, whereas in booting and maturity stages increased in stems and leaves in IR-50 and WP rice varieties. Cd levels in rice grains above the maximum allowable limit (0.4mgkg-1) only in IR-50 (0.51mgkg-1) rice cultivar at maturity stage. The EF of Cd were classified as minor enrichment to 'moderate enrichment' in both rice cultivars. TF values exhibited > 1 in booting and maturity stages in both rice cultivars at higher Cd treatments. The study concluded that the IR-50 rice variety exhibited increased Cd intake and transported to various parts of rice plants, particularly grains. The findings indicate that WP rice cultivar is more resistant to Cd toxicity, reducing health hazards for persons who preferred the staple food rice.

Characteristics and radiological hazard assessment of 210Po in tilapia (Oreochromis niloticus) in Vietnam.

210Po is one of the most toxic natural radionuclides. This isotope's characteristics and radiological hazard assessment have been concerned in different objects. In this study, the 210Po activities were determined in different tilapia organs/parts of 20 sample groups by alpha spectrometry. The 210Po activities in muscle, bone, intestine organs, and stomach contents unevenly distributed with a wide range from 0.5 ± 0.2 to 2.8 ± 0.4 and 1.4 ± 0.2Bq·kg-1 wet.wt on average, from 0.6 ± 0.3 to 6.3 ± 0.7 and 3.5 ± 0.4Bq·kg-1 wet.wt on average, from 46.3 ± 2.9 to 263 ± 9.7 and 115 ± 6Bq·kg-1 wet.wt on average, and 20.9 ± 1.2 to 800 ± 29 and 197 ± 9Bq·kg-1 wet.wt on average, respectively. The average 210Po activities in different parts of tilapia trend in order of CMuscle < CBone < CIntestine < CStomach contents. Insignificant correlations were observed between 210Po activities in tilapia organs with their total fish mass. The result could depend on feeding types, diet, different nutrient levels, metabolism, and excretion of 210Po in different ages. The concentration ratios (CRs) of tilapia muscle and bone organs were recorded with low values, while it was far greater than the CRs for the intestine organ. Annual committed effective doses contributing from 210Po concentration due to tilapia fish consumption were within the allowable limits for muscle and bone organs, while those values for intestine organs were far higher than the allowable limit value (assuming similar amount consumption of 30kg·year-1 for each organ). The Erica tool was used to estimate the dose and risk to tilapia from 210Po exposure. Based on the calculated results, it can be seen that there was insignificant concern for tilapia due to ionizing radiation in the study area.

Age-dependent dose assessment of uranium exposure in groundwater of Ganderbal and Budgam districts in Jammu and Kashmir

ABSTRACT Using an LED fluorimeter Quantalase LF-2a, the uranium concentration of the groundwater in the Ganderbal and Budgam districts of Jammu and Kashmir was assessed at 30 distinct places. It has been determined that the uranium concentrations in the districts of Ganderbal and Budgam vary from 0.17 to 1.36 μgl−1 and 0.04 to 1.71 μgl−1, respectively, with average values of 0.32 and 1.71 μg−1. It is observed that newborns are more radiation-sensitive than adults. The epidermis, thyroid gland, red bone marrow, and bones receive the maximum radiation doses. As a result, these organs are more vulnerable to uranium's radioactive effects. In the current investigation, every sample has been found to fall within the 30 μgl−1 allowable limits established by the United States Environmental Protection Agency (USEPA) and the World Health Organization (WHO).

Assessment of the Traditional Processing Methods in the Reduction of Aflatoxin Levels in Maize and Maize Products in Kenya

Aflatoxins are fungal secondary toxic metabolites produced predominantly by certain strains of the Aspergillus molds. The objective of this study was to investigate the effectiveness of Kenyan traditional processing methods in reduction of aflatoxin in maize. The traditional methods used included; alkaline cooking using Magadi soda and maize cob ash, decortication by pounding wet maize with mortar and pestle, dehulling in mechanical mill and exposure to solar radiation. Standardization of alkali cooking was done before actual treatment of the contaminated samples. Naturally contaminated samples of maize were sampled and used in the experiment. Aflatoxin analysis before and after each of the treatments was done using ELISA method and total aflatoxins expressed in parts per billion (ppb) (dry weight basis). The results were subjected to statistical analysis at 5% significance levels (p≤0.05). The reduction of aflatoxin was found to be highest when maize was boiled in maize cob ash solution which resulted in loss of aflatoxin from 83.1±0.3 ppb to 7.0±3.9 ppb. Dry decortication reduced aflatoxin from 51.3±15.3 to 9.6±0.8 ppb, boiling in Magadi soda led to a drop from 59.5±3.818 ppb to 13.4±0.424 ppb, solar irradiation caused a drop from 60.8±1.8 ppb to 13.7±0.1 ppb and pounding in Magadi soda resulted in least loss of aflatoxin from 81.5±0.3 to 72.7±0.2ppb. Aflatoxin loss in all the treatments was significant except for dry decortication. Only dry decortication and boiling in maize cob ash solution brought down the aflatoxin levels to below the maximum allowable limit as set by the Kenya Bureau of Standards (10ppb)

Health Risk Assessment of Metal Contamination in Four Green Leafy Vegetables from Various Open Markets in Benghazi

This study analysed aluminium, essential metals (chromium, manganese, iron, nickel, copper and zinc), and toxic metals (lead and cadmium) in green leafy vegetables (arugula, mint, parsley, and spinach) obtained from various markets in Benghazi city. A flame Atomic Absorption Spectrometer was used to determine the metal contents. Hazard quotient (HQ) and hazard index (HI) calculations were employed to assess non-carcinogenic and carcinogenic risks associated with the metals in the vegetables. Results showed that aluminium was detected in only 50% of the samples. All vegetable samples contained manganese, iron, copper and zinc within the ranges of 1.072-6.87mg, 26.71-298.4mg, 1.00-3.45mg and 3.61-9.33mg per 1kg of vegetable dry weight, respectively. Nickel and chromium were found in 33% and 50% of the samples, respectively. Cadmium and lead were present in all samples except for two spinach and two parsley samples. The levels of essential metals in the samples were below the maximum allowable limits set by FAO-WHO regulations. However, the contents of nickel, cadmium and lead in some vegetable samples exceeded the maximum limits. The metal contents in the collected vegetables were mostly lower than reported results from previous international studies. The HQ and HI values for the analysed metals were all below unity, suggesting that the consumption of these selected vegetables as part of a daily diet poses no threat to human health.

Structural Performance and Stress Contour Analysis of Multi Utility Tunnels Using LISA V.8 Finite Element Analysis

The growing complexity of urban infrastructure necessitates efficient management of utilities like electricity, water, and telecommunications. Multi Utility Tunnels (MUTs) provide a consolidated approach to housing these utilities, reducing surface disruption and enhancing maintenance efficiency. This study assesses the structural performance and stress distribution within MUTs using Finite Element Analysis (FEA) through LISA FEA V.8 software. The analysis involved detailed geometric modeling of the MUT, considering initial conditions and potential subsidence. Material properties for steel, concrete, wood, backfill soil, and the top surface layer were defined, focusing on their Young's modulus, density, and Poisson's ratio. The MUT was subjected to a uniform line pressure of 86.49 kN/m, representing vehicular traffic and pedestrian loads. Results showed that the applied stresses and observed deflections were within safe limits, with a tensile strength of 3.4 MPa and current stress at 3046 kN/m², indicating no risk of cracking. The observed deflection of 3.9 mm was significantly below the allowable limit of 10 mm, affirming structural stability. The reinforcing steel also exhibited stress levels well within its allowable limit, demonstrating the design's adequacy and ensuring the structure's safety and efficiency under the specified load conditions

Life cycle assesment on water treatment: Case study in Cau Do water treatment plant – Da Nang city - VietNam

Abstract Production, transportation, use, and disposal consumes resources, energy, and chemicals and causes emissions and waste, contributing to various impacts on the environment, such as heat, global warming, and acidification. Applying the Life Cycle Assessment (LCA) method can identify environmental impacts, to have solutions to control energy use and reduce waste. Research applied at Cau Do water supply plant - Da Nang city with an exploitation flow of 290,000 m3/day shows the results that the plant’s water treatment system has impacts within the allowable limits for with the geological environment in the area, but exploitation requires strict assessment to prevent possible unusual impacts. Assess the environmental impact of using electricity and chemicals in the system by estimating CO2 emissions from the electricity and chemical production process, which indirectly contribute to global warming. Direct sources of greenhouse gases come from the treatment of sludge and wastewater. The impacts discussed in this study are Global Warming, Acidification, depletion of fossil resources and Water Consumption. The amount of electricity consumed at Cau Do plant in 2018 was 16,742,752 kWh/year. The results of the analysis using the Life Cycle Assessment (LCA) method, show that the largest impact on the environment is Water Consumption 1.101 m3/m3 clean water, followed by Global Warming 0.158 kg CO2 eq/m3 Acidification 1.06 × 10−3 kg SO2 eq/m3.