Standard Limit Research Articles

Waste Water Management in Wet Coffee Processing Mills and their Impact on the Water quality status of Gidabo River and its Tributaries, Southern Ethiopia.

The Gidabo River and its tributaries are the main sources of water for more than 1,584,646 inhabitants. It is an important source of water for the surrounding rural communities for various uses such as domestic, irrigation, livestock watering, fishing, and recreation. The river is the main tributary of Lake Abaya. The present study was designed to investigate the water quality status of the Gidabo River and its tributaries for domestic and aquatic life. To assess the water quality status, water samples were collected in monthly intervals for a period of 3 months from September to November (coffee processing time), 2022. Arc GIS 9.3, 3 DEM, and spreadsheet were used to analyze the data collected from SRTM (Shuttle Radar Thematic Mapper, 90 m) and field observation. Of all the water quality parameters analyzed; turbidity, BOD5, DO, COD, pH, Ni, Fe, NO3 -, and PO4 3- were higher than the recommended limits of national and international standards for aquatic life. Based on the Weighted Arithmetic Mean (WAM), Water Quality Index (WQI) calculations of the River, WQI value of the river ranges between 34.83 and 54.31 in different reaches of the watershed which is classified under bad category. The wet coffee processing industry which is the main sources of contamination in the watershed uses 63 L of processing water to produce 1 kg of green coffee beans. Traditional lagoons, with an average hydraulic retention time (HRT) of 1.99 days, are the most common methods of treating wastewater. The river is at higher risk from harmful anthropogenic activities in the watershed and requires urgent monitoring and mitigation to prevent further degradation.

Enhancing force sensing in a squeezed optomechanical system with quantum non-demolition measurement

A theoretical scheme is proposed to enhance the sensitivity of force sensors with quantum non-demolition measurement (QND) in an optomechanical setup assisted by four-tone optical driving and an optical parametric amplifier (OPA). With the help of special drive, the system can be simplified as the typical type of QND for force sensing, so that the backaction noise can be evaded to surpass the standard quantum limit. Besides, the added noise can be suppressed owing to the modified optical susceptibility resulting from the OPA. By introducing two oscillators coupling with two charged bodies respectively, the signal can be enhanced with the nonlinearity caused by Coulomb interaction, while the noise presents an exponential decrease. Moreover, considering the homodyne detection effect, the range of system parameters and frequency bands will be broadened. The present investigation may provide a route toward simultaneously evading backaction noise, reducing the mechanical thermal noise, and enhancing the external signal, which can be an alternative design for sensitive devices.

Integrated Distributed Sensing and Quantum Communication Networks.

The integration of sensing and communication can achieve ubiquitous sensing while enabling ubiquitous communication. Within the gradually improving global communication, the integrated sensing and communication system based on optical fibers can accomplish various functionalities, such as urban structure imaging, seismic wave detection, and pipeline safety monitoring. With the development of quantum communication, quantum networks based on optical fiber are gradually being established. In this paper, we propose an integrated sensing and quantum network (ISAQN) scheme, which can achieve secure key distribution among multiple nodes and distributed sensing under the standard quantum limit. The continuous variables quantum key distribution protocol and the round-trip multiband structure are adopted to achieve the multinode secure key distribution. Meanwhile, the spectrum phase monitoring protocol is proposed to realize distributed sensing. It determines which node is vibrating by monitoring the frequency spectrum and restores the vibration waveform by monitoring the phase change. The scheme is experimentally demonstrated by simulating the vibration in a star structure network. Experimental results indicate that this multiuser quantum network can achieve a secret key rate of approximately 0.7 Mbits/s for each user under 10-km standard fiber transmission, and its network capacity is 8. In terms of distributed sensing, it can achieve a vibration response bandwidth ranging from 1 Hz to 2 kHz, a strain resolution of 0.50 , and a spatial resolution of 0.20 m under shot-noise-limited detection. The proposed ISAQN scheme enables simultaneous quantum communication and distributed sensing in a multipoint network, laying a foundation for future large-scale quantum networks and high-precision sensing networks.

The Impact of Power Quality on VFD Application in Motor Fan Dust Collector

The technology to control the motor speed according to load requirements is variable frequency drive (VFD). The motor fan dust collector operates using a VFD to reduce the speed during idle smelting conditions. In addition to energy efficiency, the power quality of the electrical energy system is important to consider. Nonlinear loads from VFDs cause harmonics in the industry that affect electrical power. Power quality measurement and analysis to determine the harmonic and unbalance values of voltage and current are important for improving power quality. This paper discusses the effect of VFDs on power quality, as a real case study, data from existing VFDs in the steel industry are taken to analyze power quality. A large current harmonic of 45% occurs when the VFD decrease the motor speed during idle smelting operation and drops to 5% when the motor speed returns to full speed during smelting operation on. The average maximum current unbalance value is 10.8% and the voltage unbalance is 0.36%, which is still below the standard maximum limit whether the motor is at full or low speed.

Natural deep eutectic solvents for turbidity removal from synthetic pharmaceutical wastewater

Contamination of water resources by active pharmaceutical ingredient wastes is among major environmental concerns. To prevent major disruptions of aquatic life, an efficient and environmentally-friendly turbidity removal procedure of common contaminants such as paracetamol should be established. In this study, several natural deep eutectic solvents (NADESs) were screened to reduce the turbidity of simulated water contaminated with paracetamol below the standard turbidity limit recommended by the National Water Quality Standards for Malaysia (50 NTU). The optimal operating parameters (NADES dosage, stirring time and operating pH) were determined. Under optimized conditions, stearic acid-based NADES achieved the highest turbidity removal of 97.5 %. High coagulation performances were investigated based on molecular interaction using COSMO-RS (COnductor like Screening MOdel for Real Solvents) ?-profile and ?-potential (histogram of charge density distribution over molecular surface) and showed high affinity between the NADES compounds and paracetamol. Thus, NADESs are promising candidates for turbidity removal of paracetamol from water and are viable in further investigations for effluent treatment applications.

Theorising the Public Sphere

This paper examines the criticism of Jürgen Habermas's idea of the public sphere, which is essential for sociology to comprehend the possibility for consensus in the communication processes of modern society. The main objective of this paper is to examine the evolution of the notion of the public sphere. This will be achieved by investigating the traditional concept of the public sphere and scrutinising its mechanisms. The public sphere is crucial in providing a platform for thoughtful discussions that strive to involve society in the process of constructing society itself. Undoubtedly, the evolution of social interactions in contemporary times is influenced by the standard possibilities and limitations imposed by public discussions. Amidst the era of digital advancements, the discussion around the public sphere has gained significant significance and complexity. Given the abundance and variety of public areas. This paper aims to elucidate the evolution of the traditional notion of the public sphere and analyse its defining features.

Pushing coarse-grained models beyond the continuum limit using equation learning

Mathematical modelling of biological population dynamics often involves proposing high-fidelity discrete agent-based models that capture stochasticity and individual-level processes. These models are often considered in conjunction with an approximate coarse-grained differential equation that captures population-level features only. These coarse-grained models are only accurate in certain asymptotic parameter regimes, such as enforcing that the time scale of individual motility far exceeds the time scale of birth/death processes. When these coarse-grained models are accurate, the discrete model still abides by conservation laws at the microscopic level, which implies that there is some macroscopic conservation law that can describe the macroscopic dynamics. In this work, we introduce an equation learning framework to find accurate coarse-grained models when standard continuum limit approaches are inaccurate. We demonstrate our approach using a discrete mechanical model of epithelial tissues, considering a series of four case studies that consider problems with and without free boundaries, and with and without proliferation, illustrating how we can learn macroscopic equations describing mechanical relaxation, cell proliferation, and the equation governing the dynamics of the free boundary of the tissue. While our presentation focuses on this biological application, our approach is more broadly applicable across a range of scenarios where discrete models are approximated by approximate continuum-limit descriptions.

Analysis and research on inherent angle ventilation control of residential kitchen range hoods

The emission of oil fume particles during kitchen cooking processes constitutes a significant factor that impacts indoor air quality and human health. Range hoods, as indispensable ventilation devices in kitchens, play a crucial role in reducing indoor particle concentrations. This study employs a combined approach of orthogonal experiments and computational fluid dynamics simulations to investigate the exhaust characteristics of inherent-angle-measurement-based range hoods. It analyzes the diffusion patterns of cooking-generated particulate matter under various cooking scenarios, considering factors such as the opening and closing of windows, cooking source velocities, and different airflow rates of the range hood. Based on different airflow organization patterns, a supplementary ventilation system is designed. The rationality and effectiveness of the supplementary ventilation system are analyzed to establish an effective control scheme for reducing particulate matter in various kitchen environments. The simulated research results indicate that particles disperse along the inclined surface of the side-draft range hood, resulting in higher pollutant concentrations in the breathing zone compared to the cooking zone. Increasing the exhaust airflow rate of the range hood enhances particle capture efficiency by 9.8 %. The induced airflow generated by opening windows improves particle capture efficiency by 12.9 %. However, when the velocity of the window-induced airflow exceeds 1.5 m/s, it hampers the promotion of particle capture efficiency. In the case of windows being unconditionally open, implementing a ceiling-mounted supplementary air supply system effectively improves the kitchen's particle concentration, achieving a maximum particle capture efficiency of 97.66 %. When windows can be opened, setting a baffle on the range hood, the simulation results revealed that with a baffle angle of 120° and a length of 0.3 m, the particle concentration capture efficiency in the breathing zone increased by 34.59 %. This achieved the standard limit requirement of 50 µg/m3, thus meeting the indoor air quality requirements.

Current status of stream water quality around selected Tea Gardens from Southern Western Ghats, Tamil Nadu, India – A case study

In this study, metal concentration in tea garden-associated stream water samples from the south Western Ghats of Tamil Nadu was evaluated using ICP-MS to know the current status of pollution level, sources of pollution, probable water quality, and impacts of heavy metals. Stream water pollution of hill regions communities using the heavy metal pollution index, principal compound analysis, and Pearson correlation analysis were measured. In addition, for this purpose, water phy-chem parameters were also measured, such as (pH, temperature, conductivity, salinity, and TDS) using a pH meter. PO4 and F- UV-spectrophotometer, Na, K, and calcium (flame photo meter), NO3- NO3-N (Electronic method-horiba), and turbidity meter to evaluate the stream-water quality were used, and heavy metals, particularly Al, As, Cd, Fe, Cr, Cu, Zn, Pb, Ni, and Mn are analyzed as heavy metal pollutions. The phy-chem average values of pH, Temp, EC, Tds, Salinity, alkalinity, cod, bod, do, chloride, calcium, C. hardness, M. hardness, T. hardness, N-Nitrogen, Phosphate, Potassium, Sodium, Turbidity, Fluoride, Sulphate, and Sulphur are found 8.13, 27.57 °C, 218, 111.67, 78.67, 70.39, 2029, 5.70, 3.83, 70.83, 737, 62.30, 166.11, 679, 1132, 149, 11, 28.33, 4.44, 07, 178, 180 respectively. Heavy metal concentrations, including aluminum, arsenic, cadmium, iron, chromium, copper, zinc, lead, nickel, and manganese, are detected at 32, 7.2, 6.24, 96.4, 0.00, 0.00, 40, 0.00, 0.00, 30 μg/L, respectively. Concentrations of studied heavy metals, particularly, Mn, Ni, Cd, and Fe, have measurements that are greater than the permissible standard limits of BIS, WHO.

"Could a subset of joint mobility tests define generalized joint hypermobility?": A descriptive observational inception study.

Generalized joint hypermobility is an inherited collagen phenotype based on clinical assessments of joint mobility. However, there is no international consensus to define generalized joint hypermobility, both considering which joint mobility tests should be included and limits for joint hypermobility. The primary aim of the study was to identify a subset of joint mobility tests to define generalized joint hypermobility. A further aim was to evaluate standardized limits for the classification of hypermobility in different joint types throughout the body. A total of 255 early pregnant women were included in the study. Joint mobility was measured according to a structured protocol. Correlation and principal component analysis were used to find a subset of joint mobility tests. To classify hypermobility in each joint mobility test, five different standard deviation levels plus 0.84, plus 1.04, plus 1.28, plus 1.64 and plus 2 were used, corresponding to 20%, 15%, 10%, 5% and 2.5% of the normal distribution. No subset of joint mobility test could define generalized joint hypermobility. The higher the standard deviation levels, the higher the limit to classify joint hypermobility and the lower the prevalence. As a result of no subset of joint mobility tests were found to define generalized joint hypermobility, different combinations of major and minor joints in upper and lower limbs and the axial skeleton, were systematically developed. These combinations were evaluated for each standard deviation level, resulting in a prevalence of generalized joint hypermobility between 0% and 12.9% and a clear variation in how the hypermobile joint mobility tests were distributed. It is probably not possible to choose a subset of joint mobility tests to define GJH. In order not to overlook generalized joint hypermobility, a broader assessment of different joint types and sizes of joints appears to be needed. The prevalence of generalized joint hypermobility is dependent on joint hypermobility limit and the chosen combination of joint mobility tests.

Consumption of foods contaminated with heavy metals and their association with cardiovascular disease (CVD) using GAM software (cohort study)

IntroductionHeavy metals can enter the environment and food through industrial activities, acid rain, chemical fertilizers, pesticides, and sewage. A large amount of these metals is dangerous because they tend to bio accumulate. A concern with these metals is the long-term, low-dose exposure seen in the general population. HMs can cause disorders in the cardiovascular system through various mechanisms such as the production of free radicals, DNA damage, lipid peroxidation, and oxidative stress. Material and methodFood items measured in the present study included rice, bread, and vegetables. 210 participants (105 controls and 105 patients) were randomly selected for this study. The demographic information of the subjects was obtained from the Hoveyzeh Cohort Center. The relationship between heavy metals in food and cardiovascular diseases is investigated by The Generalized Additive Model (GAM). ResultThe results of the present study showed that when urine Cd was smoothed based on rice Cd, there was a significant correlation between urine Cd and Cd consumed in vegetables and rice. The GAM coefficient for urinary Cd excreted in case-control groups and Cd consumed in vegetables were 479.79(SE: 6.49–73.87) and 818.56(SE: 11.96–68.43), respectively, and for rice consumed, it was 0.03(SE: 0.015–2.103) and 0.04(SE: 0.017–2.338), respectively. The GAM coefficient for As consumption in vegetables and As in urine of case and control groups was 1.61 (SE: 9.48–0.16) and 22.36 (SE: 13.60–1.64), respectively. The same coefficient for rice consumption in case and control groups was 4.5 (SE: 0.62–7.22) and 10.48 (SE: 1.46–7.16), respectively. There was a very strong and significant correlation between the Sr in the urine of both groups and the Sr in the food consumed, so that the urinary Sr in the control group is excreted more than in the cardiovascular group. ConclusionGAM analysis indicates that As in vegetable and rice is more than the standard limitation value. Also, Sr and Cd in vegetables, rice, and bread were more than the standard limitation value. According to the GAM model As had a significant value in rice and vegetables indicating that As is more than the standard limitation value, therefore, it is associated with CVD.

Analysis and Monitoring of Indoor Radon Concentrations of 37 Kindergartens - Beijing Municipality, China, 2023.

Radon (222Rn or 222radon) is a radioactive gas emitted from building materials, foundations, and soil. Children are especially susceptible to radon exposure, underscoring the need to assess indoor radon levels in kindergartens. This study monitored radon concentrations in 37 Beijing kindergartens from June to October 2023. A random sample of 37 kindergartens was selected from 18 administrative districts in Beijing. The indoor radon concentration was measured using the solid track accumulation method, with radon detectors continuously monitored over a 3-month period. The mean indoor radon level in 37 kindergartens, observed at 252 monitoring points, was 84.3 Bq/m3, with values varying from 12.9 to 263.5 Bq/m3. About 20.2% of points showed radon levels between 100.0 and 200.0 Bq/m3, while 2.4% exceeded 200.0 Bq/m3. Notably, radon levels were significantly elevated on the ground floor compared to the upper floors. Indoor radon levels in 37 kindergartens remained below the national standard limit of 300.0 Bq/m3 for buildings (GB/T 16146-2015). Nonetheless, 18.9% of the kindergartens exceeded the 100.0 Bq/m3 limit set for new constructions. It is advised to improve radon monitoring in kindergartens and consider developing a national standard for maximum permissible radon levels in such facilities.

Quality Control Analysis of Piston Gasoline Products using the DMAICApproach

The manufacturing company in this study is a company engaged in the automotive sector that produces pistons and non-pistons. The problem that occurs in the company is that the average percentage of defects exceeds the company's standard limit of 5% while the maximum defect limit is set by the company at 1%. Identify the dominant type of defect, identify the biggest factors causing the dominant type of defect and make suggestions for improvement. In this study using the DMAIC method (Define, Measure, Analyze, Improve and Control) in the production process of the type x gasoline piston, there are several types of defects, namely monoiri, misrun,coating loss. The types of defects that occur are based on the Pareto diagram, namely the type of defect monoiri with a percentage of 56%, misrun 28% and coating loss 16%, and the causal factors are known using a fishbone diagram, there are 5 factors, namely material, people, methods, machines and environment. Based on the results of the identification of FMEA and the calculation of the highest RPN, it is known that the monoirritic defects that occur in the causative factor of the material with an RPN value of 175. For proposed improvements, namely monitoring and creating monitoring forms to facilitate cleaning of materials on a scale, and to facilitate cleaning of larger materials. scheduled.

Coupled fixed point theorem for pairs with joint standard limits

Coupled fixed point theorem for pairs with joint standard limits

The influence of occupational heat stress on serum inflammatory cytokines among traditional bakery workers in Iran.

Heat exposure exceeding the ISO7243:1989 standard limit can contribute to health problems among employees in a variety of workplaces. Ignoring heat standard requirements in hot working conditions such as bakeries results in physiologic and health problems, as well as an elevated risk of later illnesses. In this analytical case-control study, the serum levels of four inflammatory factors (interleukin-1 beta, interleukin-6, tumor necrosis factor-α, and C-reactive protein) were assessed using an enzyme-linked immunosorbent assay. 105 male artisan bakers (in four job classifications in bakeries and staff) were compared based on demographic characteristics and inflammatory factors. The findings of the study showed correlations between serum interleukin-1β, interleukin-6, and C-reactive protein levels and thermal exposure in the occupational environment and employment type. Moreover, some differences in serum level of interleukin-1β and job type were observed. Heat overexposure affected the increase of interleukin-1β and C-reactive protein secretion. As a result of years of working in high-temperature conditions, inflammation can lead to subsequent diseases in workers. To protect their health from this occupational hazard, additional safeguards are needed. Our recommendations could also be applied to overly hot work environments that may cause heat stress in workers.

Isotachophoretic quantification of total viable bacteria on meat and surfaces

BackgroundThe quantification of microbes, particularly live bacteria, is of utmost importance in assessing the quality of meat products. In the context of meat processing facilities, prompt identification and removal of contaminated carcasses or surfaces is crucial to ensuring the continuous production of safe meat for human consumption. The plate count method and other traditional detection methods are not only labour-intensive but also time-consuming taking 24–48 h. ResultsIn this report, we present a novel isotachophoretic quantification method utilizing two nucleic acid stains, SYTO9 and propionic iodide, for the detection of total viable bacteria. The study employed E. coli M23 bacteria as a model organism, with an analysis time of only 30 min. The method demonstrated a limit of detection (LOD) of 184 CFU mL−1 and 14 cells mL−1 for total viable count and total cell count, respectively. Furthermore, this new approach is capable of detecting the microbial quality standard limits for food contacting surfaces (10 CFU cm−2) and meat (1.99 × 104 CFU cm−2) by swabbing an area of 10 × 10 cm2. SignificanceIn contrast to the culture-based methods usually employed in food processing facilities, this isotachophoretic technique enables easy and rapid detection (<30 min) of microorganisms, facilitating crucial decision-making essential for maintaining product quality and safety.

Towards a green climate: Production of slag–red brick waste-based geopolymer mingled with WO3 nanoparticles with bio-mechanical achievements

According to the sustainability concept, this work developed a green geopolymeric composite (Geo) prepared by mingling 50 wt%slag+ 50 wt%brick-waste (BW) as an alternative eco-friendly and low-cost cementitious material. The main target of this study is to fnd a solution to the problem of poor characteristics of binding materials containing high proportions of BW; most previous studies recommended using only 10–20 wt%BW. The compressive-strength results showed that replacing slag with 50 wt% BW reduced the strength from 47 to 24.6 MPa at normal curing conditions for 28-days, referring to the detrimental impact of BW on mechanical performance. In an endeavour to enhance the mechanical performance of this composite, different doses from laboratory-prepared tungsten oxide nanoparticles (0.25, 0.5, 1 wt%WO3-NPs) and hydrothermal curing at various steam-pressure/periods were used. From an economic point of view, hydrothermally treated Geo-paste modified with 0.25 wt%WO3-NPs at 3 bar/4hrs was selected as an ideal composition/curing-conditions; the compressive-strength reached 54.5 MPa exceeding the standard limit of Portland cement (42.5 MPa). This clearly shows the synergistic role of using WO3-NPs and hydrothermal curing to enhance the compressive-strength, which was confirmed using different analysis techniques. XRD, TGA/DTG and SEM/mapping proved that the catalytic performance of WO3-NPs/hydrothermal-curing participates in augmenting binding hydrates, creating a cubic-stable-phase of tricalcium-aluminate-hydrate (C3AH6) and different types of zeolitic-like structure (spherical Zeolite-NaP, rods analcime and stacked-plates cancrinite). To maximize the benefits of employing WO3-NPs in the developed composites, their anti-microbial activity was studied. The measured inhibition zone around specimens containing WO3-NPs proved that these composites have a superior self-cleaning efficiency against Candida albicans, Mucor circinelloides, Salmonella typhi and Staphylococcus aureus due to the WO3-NPs’ photocatalytic activity.

Elemental composition, corrosion resistance and mechanical properties of computer-aided design and computer-aided manufacturing fixed retainers versus conventional fixed retainers.

To investigate the elemental composition, corrosion resistance, and mechanical properties of computer-aided design and computer-aided manufacturing (CAD-CAM) retainers versus conventional fixed retainers (FRs). Eight different retainer wires were investigated. Energy dispersive X-ray spectroscopy was used to determine the elemental composition. Leakage was analysed according to ISO 10271:2020 guidelines. Hardness was tested using the Vickers method with a load of 0.3 kg. The tensile force and tensile strength were evaluated. Multiple comparisons among wires of hardness, tensile force, and strength were conducted using the Welch t-test, with Bonferroni correction. Nickel was present in all wires. The CAD-CAM-FR wire, which contained more nickel than the other wires, had no measurable leakage. The gold-plated wires had the highest total leakage, but did not exceed the ISO standard limit. The hardness of the stainless-steel twisted wires was the highest and that of the CAD-CAM-FR wire was the lowest. The tensile strength of the CAD-CAM-FR wire was significantly lower than that of the other wires and similar to the other twisted-wire retainers. The CAD-CAM-FR wire is likely to have high corrosion resistance and flexibility due to its low hardness.

Transition Energétique - Remplacement d’une Microcentrale Diesel par un Système Renouvelable Hybride : Etude de cas.

This paper aims to study the replacement of a Diesel Generator based plant by a hybrid renewable system. To overcome both source and load fluctuations, a battery-based storage system is used. The renewable energy resources available in southern Algeria is considerable. Actually, this region has one of the largest wind capacity in the country with wind speeds up to 4 to 6 m/sec, the wind energy density is 280-Watt/m2/ day. Meanwhile, the solar potential is characterized by an average duration of sunshine above 11 hours/day and the energy they can provide for a large-scale industry can change the development of the region and of the whole country.Genetic algorithms under optimtool is used to size hybrid systems. The resulting levelized cost of electricity (LPSP) of $0.262/kWh, is competitive and economical if a large-scale electricity production is undertaken. The loss of power supply probability or customer dissatisfaction rate (LPSP) of 1.2545 %, which is within standard limits.

Pengukuran Kualitas Air Limbah Sawit Berdasarkan Baku Mutu Air Limbah Menggunakan AAS

Palm oil industry waste is waste generated from the palm oil processing process. Palm oil liquid waste generally contains heavy metals, one of which is Cu and Zn. The presence of excessive Cu and Zn heavy metals can have a negative impact on living things and the surrounding environment. In this journal, the determination of the heavy metal content of Cu and Zn in palm oil wastewater was carried out using the AAS method with acetylene gas at a wavelength of 324.8 nm to determine the content of Cu metal content and at a wavelength of 213.9 nm to determine the Zn metal content. The results of determining the content of heavy metals Cu and Zn in sempel 1, 2 and 3 contained in palm oil wastewater which are still below the maximum limit of the quality standards obtained, namely less than 2 ppm for Cu metal and less than 5 ppm for Zn metal. utilized by living things and the surrounding environment.